Adipocyte long noncoding RNA transcriptome …...2018/03/08 · Adipocyte long noncoding RNA...
Transcript of Adipocyte long noncoding RNA transcriptome …...2018/03/08 · Adipocyte long noncoding RNA...
1
Adipocyte long noncoding RNA transcriptome analysis of obese mice identified Lnc-leptin which
regulates Leptin
Kinyui Alice Lo1,2
, Shiqi Huang3, Arcinas Camille Esther Walet
2, Zhi-chun Zhang
2, Melvin Khee-Shing
Leow2,4,5,6
, Meihui Liu3, Lei Sun
1,2*
1Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673
2Cardiovascular & Metabolic Disorders, Duke-NUS, 8 College Road, Singapore 169857
3Food Science and Technology Program c/o Department of Chemistry, National University of Singapore,
Singapore, 117543 4Clinical Nutrition Research Centre (CNRC), Singapore Institute for Clinical Sciences (SICS), Agency for
Science, Technology and Research (A*STAR) and National University Health System (NUHS), 117599, Singapore 5National University Health System (NUHS), 119074, Singapore
6Department of Endocrinology, Tan Tock Seng Hospital, 308433, Singapore
*Corresponding: Lei Sun Cardiovascular & Metabolic Disorders, Duke-NUS, 8 College Road, Singapore 169857 Phone: 65-66013021 [email protected]
CONFLICT OF INTEREST STATEMENT
The authors have declared that no conflict of interest exists.
Page 1 of 46 Diabetes
Diabetes Publish Ahead of Print, published online March 8, 2018
2
Abstract
Obesity induces profound transcriptome changes in adipocytes; recent evidence suggests that lncRNAs
play key roles in this process. Here, we performed a comprehensive transcriptome study by RNA-Seq in
adipocytes isolated from interscapular brown, inguinal and epididymal white adipose tissues in diet-
induced obese mice. Our analysis reveals a set of obesity-dysregulated lncRNAs, many of which exhibit
dynamic changes in fed vs. fasted state, potentially serving as novel molecular markers reflecting adipose
energy status. Among the most prominent ones is Lnc-leptin, an lncRNA transcribed from an enhancer
region upstream of Leptin. Expression of Lnc-leptin is sensitive to insulin and closely correlates to Leptin
expression across diverse pathophysiological conditions. Functionally, induction of Lnc-leptin is essential
for adipogenesis, and its presence is required for the maintenance of Leptin expression in vitro and in
vivo. Direct interaction was detected between DNA loci of Lnc-leptin and Leptin in mature adipocytes,
which diminished upon Lnc-leptin knockdown. Our study establishes Lnc-leptin as a new regulator of
Leptin.
Page 2 of 46Diabetes
3
Introduction
Obesity has reached an epidemic level worldwide (1). Central to the obesity problem is adipocytes, which
play a dual role of storing excess energy as triglycerides and secreting adipokines that exert systemic
effects on metabolic homeostasis (2). Governing adipose tissue function is a set of expressed transcripts
and proteins, many of which are dysregulated upon obesity. In order to discover novel obesity genes,
transcriptome analysis has been extensively carried out in both mouse and human adipose tissues (3–7),
but most studies have primarily focused on protein-coding genes. Long non-coding RNAs (lncRNAs) are
relatively new players in the field of gene regulation (8, 9). We and others have shown that lncRNAs are
essential regulators of adipogenesis, insulin sensitivity and thermogenesis (10–12). Using RNA-
Sequencing on three types of mouse adipose tissues, namely inguinal white adipose tissue (iWAT),
epididymal white adipose tissue (eWAT) and interscapular brown adipose tissue (BAT), and followed by
de novo transcriptome assembly, we have built a catalogue of over 1500 mouse adipose lncRNAs (13).
Recently, another catalogue of lncRNAs regulating energy metabolism in liver, adipose tissue and muscle
has been built based on microarray data (14).
Mutation in Lep, a circulating adipokine released from adipocytes, leads to an extreme form of
obesity, exemplified by the ob/ob mice (15). A few cases of obese human patients harboring Lep mutation
have been reported, and such patients are responsive to recombinant LEP treatment (16)(17). There is a
great interest in understanding the regulation of the leptin gene. Using leptin-BAC EGFP transgenic mice,
a region 4.5kb upstream of Lep has been found to act as an adipocyte-specific enhancer, and this region
was bound by the transcription factor FOSL2 (18). A similar strategy reveals a totally different element
required for Lep expression in vivo: it is a nuclear-factor Y-bound element -16.5kb upstream of the Lep
transcription start site (19).
To systemically evaluate the changes of lncRNA transcriptome upon obesity, we performed RNA-
Seq on adipocytes isolated BAT, iWAT and eWAT from control and diet-induced obese mice. We
identified 68 lncRNAs that are differentially expressed upon obesity, termed as lnc-ORIAs (obesity-
regulated lncRNAs in adipocytes). Specifically, we focused on one particular lnc-ORIA, Lnc-leptin, which
is located in an enhancer region upstream of Lep and highly correlates to the expression of Lep. Using
Page 3 of 46 Diabetes
4
multiple independent loss-of-function approaches, we show that Lnc-leptin regulates the expression of
Lep in vitro and in vivo.
Research Design and Methods
Diet-induced obesity models
Male mice on the C57BL/6 background were kept at the Duke-NUS animal facilities. Mice were fed
regular chow diet or high fat diet (Research Diets, #D12492) for 16 weeks commenced upon weaning at 3
weeks of age.
Primary adipocyte culture and differentiation
Inguinal fat pads from 3-week-old C57BL/6 pups were excised, minced and digested in collagenase
solution at 37ºC for 20min. The suspension was filtered through 100µm strainers and spun at 2000rpm for
5min. The pelleted stromal vascular fraction was resuspended in 10ml of Dulbecco’s modified Eagle’s
medium (DMEM) supplemented with 10% new calf bovine serum (Invitrogen), 100 units/ml penicillin,
100µg/ml streptomycin and 10 µg/ml of gentamicin (Invitrogen). Cells were grown to confluence, and
differentiation was initiated at Day0 with DMEM containing 10% fetal bovine serum (FBS), 0.5µM
dexamethasone, 850nM insulin, 0.25mM 3-isobutyl-1-methyxanthine and 1µM rosiglitazone for 2 days.
Cells were then incubated in DMEM containing 10% FBS and 170 nM insulin for 2 more days. After Day 4,
cells were maintained for two more days in DMEM containing 10% FBS. Experiments were performed on
mature adipocytes at Day 6.
Adipocytes and stromal vascular fraction (SVF) isolation from adipose tissue
Adipose tissues were excised from mice and immediately minced in a collagenase solution comprising
0.2% collagenase (C6885, Sigma) and 2% BSA dissolved in Hanks’ balanced salt solution (HBSS, Gibco).
Minced tissues were transferred to a 50ml tube and incubated at 37ºC for 20min (for EPI and ING) or
40min (for BAT) at 500rpm. 10ml complete DMEM was subsequently added. Cell resuspensions were
filtered through 100µm strainers, spun at 2000rpm for 5min, and washed once with PBS. The floating
adipocyte layer and the pelleted SVF fraction were collected separately. The SVF fraction was treated
with ammonium chloride solution (STEMCELL, # 07800) to lyse red blood cells.
Lnc-leptin knockdown using shRNAs
Page 4 of 46Diabetes
5
Sequences targets Lnc-leptin were cloned into a retroviral vector pSUPER (oligoengine). shRNA
sequences are listed in Supplemental Table 4. Retroviral vectors were transfected into packaging cell line
293T cells using XtremeGENE 9 (Roche). Viruses-containing media were harvested 48h later post-
transfection and were used to infect primary preadipocytes at ~60% confluence supplemented with
8µg/ml polybrene. Media were changed the next day and cells were induced to differentiate 48h post
infection.
Lnc-leptin knockdown using DisRNAs or antisense oligos (ASOs) in vitro
For knocking down Lnc-leptin in preadipocytes to assess its role in adipogenesis, DsiRNA or ASO and
their respective controls were transfected into Day -2 preadipocytes (> 90% confluence) using
lipofectamine (6ul/ml, Life Technology). Media were changed the next day and cells were induced to
differentiate 48h post transfection. For knocking down Lnc-leptin in primary mature adipocytes, a reverse
transfection protocol was used (35). 200nM of DsiRNA (IDT) or 150nM of antisense oligos (Gapmers,
Exiqon) mixed with lipofectamine in Opti-MEM medium (6ul/ml) were added to each well of a 24-well plate
pre-coated with 0.1% gelatin. Mature primary adipocytes at Day6 were trypsinsed and reseeded onto the
oligo-lipofectamine mix. Medium was changed the next day and knockdown efficiency was measured 48h
post-transfection. Sequences of DsiRNAs and antisense oligos used in this study are listed in
Supplemental Tables 5 and 6 respectively.
Lnc-leptin knockdown using antisense oligos (ASOs) in vivo
8-12 week-old C57BL/6 male mice were anesthetized. Hair located at the inguinal area was removed with
a trimmer, the underlying skin was incised, and the inguinal adipose tissue exposed. Control ASO or ASO
Lnc-leptin (20mg/kg) were injected into the left and right inguinal adipose tissue (~50ul/injection),
respectively. The surgical wounds were closed with sutures and disinfected with 70% ethanol. Adipose
tissues from both sides of the inguinal depot were excised 48h post-injection and RNA was extracted and
subjected to reverse transcription qPCR.
Chromatin Immunoprecipitation (ChIP)
Preadipocytes or mature adipocytes were trypsinized and resuspended in PBS. A two-step crosslinking
protocol was used (44): Cells were incubated with 1.5mM of ethylene glycol-bis (EGS, Sigma) at room
temp for 30min, it was followed by 1% formaldehyde for 10min. Crosslinking was stopped by quenching
Page 5 of 46 Diabetes
6
with 0.125M of glycine. ChIP experiment was performed as described (45). 5ug of Med1 antibody (Bethyl
Laboratories, A300-793A) was used for immunoprecipitation, normal rabbit IgG (Santa Cruz
Biotechnology, sc-2027) was used as control. ChIP primers used in this study are listed in Supplemental
Table 7.
Chromatin conformation capture (3C)
3C was performed as described previously (46) with modifications. Briefly, mouse adipose cells and
tissues were cross-linked with 1% formaldehyde for 10 mins and the reaction was quenched by 125mM
glycine for 5mins. Lysed nuclei were resuspended in 500 µl of 1.2 x restriction enzyme buffer before
incubation at 65°C for 20 min with 22.5 µl of 20% SDS, followed by additional 1 hr incubation at 37°C.
Then, 150 µl of 20% Triton X-100 was added and samples were incubated at 37°C for other 1 hr.
Samples were then digested with 800 units of XbaI (NEB) by incubating at 37°C overnight. After
restriction enzyme digestion, 40 µl of 20% SDS was added to the digested nuclei and incubated at 65°C
for 15 min. 6.125 ml of 1.15x ligation buffer and 375 µl 20% Triton X-100 was added to dilute the total
DNA to favour intramolecular ligation. The diluted sample was incubated at 37°C for 1 hr before the
addition of 100 units of T4 DNA ligase (NEB) at 16°C for 4 hr followed by 30min at room temperature.
Samples were finally de-crosslinked at 65°C overnight with addition of 300 µg of proteinase K (Thermo
Scientifics) before phenol-chloroform extraction and ethanol precipitation. Samples were further purified
by QIAquick spin columns (Qiagen) and total DNA concentration quantified using Nanodrop. BAC that
spans the whole locus of interest is: RP24-369M21. All primers were designed to be within a region of
25-150 bp from the restriction enzyme digestion site and are unidirectional from the 5’ side of the
restriction fragment. Primers were designed using Primer3 software listed in Supplemental Table 8.
Quantitative real time PCR was carried out with SYBR green master mix on the ABI Vii7. Semi-
quantitative PCR of these primers pairs using the control template re-confirmed that there was only a
single PCR product of the correct size when visualized on a 2% agarose gel. The identities of the PCR
products were also confirmed through direct sequencing. To obtain data points for “normalized relative
interaction” in the final results, Ct values of 3C template were first normalized with values from an
internal primer of “control interaction frequencies”, which was commonly used Ercc3 locus in mouse (46,
Page 6 of 46Diabetes
7
47). Each qPCR was carried out in duplicates and 3C validations were repeated between four to six
times independently for each condition.
Hierarchical clustering
Clustering was done in Cluster and visualized in Treeview. For each model and for each gene, the gene
expression value in fpkm was log transformed and mean-centered before clustering.
Western Blot and Realtime PCR
Antibodies used for Western: Leptin (Abcam: Ab16227), Pparg (Santa Cruz, sc-7273) and β-actin
antibody (Sigma A1978, 43kD) as loading control. Total RNA was extracted using Qiagen kit. Sequences
of qPCR primers are listed on Supplemental Table 3.
RNA-Seq library preparation, sequencing, and analysis
1ug of total RNA was used for each RNA-Seq library preparation according to the manufacturer's
instructions (New England Biolab), and sequencing was done on HiSeq 2000 (Illumina). Pair-end reads
from each sample were aligned to the mouse genome (mm10 build) using TopHat (version 2.0.9).
Differential expression between high-fat diet and normal chow samples was quantified using Cuffdiff
(version 2.1.1). Differentially expressed genes are those that have a log2 fold change of > 1 or < -1 and a
q-value < 0.05 when compared to the control condition. We also required that the differentially expressed
genes used for downstream analysis have a FPKM greater than 1 in any of the condition.
Gene Ontologies and pathway analysis
For obesity-induced protein-coding genes, gene ontology and network analysis was performed using
GeneGo (Thomson Reuters). For obesity-induced lncRNAs, gene ontology and motif analysis was done
using GREAT (Genomic Regions Enrichment of Annotations Tools) (25).
Study Approval
All studies involving animals have been approved by the institutional review board in Duke-NUS.
Results
Transcriptome analysis of adipocytes from three different adipose depots identified a set of
obesity-regulated lncRNAs (lnc-ORIAs)
Page 7 of 46 Diabetes
8
To systemically evaluate the changes of adipocyte lncRNA transcriptome during obesity, we isolated
adipocytes from BAT, inguinal WAT and epididymal WAT of mice on a high-fat diet (HFD) or a normal
chow diet (ND) using a collagenous digestion and fractionation method (Figure 1A). As adipose tissue is
infiltrated with macrophages and other immune cells upon obesity (20), this step enriches for adipocytes
and minimizes the contribution from the other cell types. Leptin (Lep), an adipocyte-specific gene, was
enriched over hundred folds in the floating adipocyte layer compared to the pelleted stromal vascular
fraction (SVF) (Figure 1B). In contrast, expression of the macrophage marker F4/80 (Emr1) was highly
enriched in SVF compared to adipocytes (Figure 1B). Lineage marker expression such as Hoxc9, Hoxc10
and Ucp1 both before and after collagenous digestion indicated that our brown adipose tissue and
isolated adipocytes were not contaminated by each other (Figure 1S).
We performed RNA-Seq on adipocytes isolated from three different adipose depots (BAT, ING
and EPI) under two different diets (HFD vs ND). Over 200 million paired-end reads in total were aligned
(Supplemental Table 1) to Ensembl protein-coding genes (mm10) and a published adipose lncRNA
catalogue (13). To assess if obesity affects global mRNA and lncRNA transcriptomes in a similar manner,
we performed unsupervised hierarchical clustering on the sets of expressed mRNAs and lncRNAs
(FPKM > 1), respectively. The main branch of the dendrogram, with the exception of BAT that only has
one data set per condition, primarily separates all samples based on diet rather than sites of origin in both
mRNA and lncRNA clustering (Figure 1C). There are 353 protein-coding genes differentially expressed in
adipocytes from the three different depots upon obesity (Figure 1D). They include Lep (15), Sfrp5 (21)
and Egr1 (22); many of which have previously been identified and studied in the context of obesity.
Network analysis of the obesity-upregulated genes using GeneGo which incorporates curated data from
published literature identified the NF-κB subunit RelA, Esr1 and Creb1 to be the top three transcription
factor hubs (Figure S2A) mediating the expression changes. Gene ontology (GO) analysis identified
developmental processes (p<1E-17), response to stress (p<9E-14) and cell differentiation (p<3E-11) as
the top categories associated with the obesity-upregulated protein-coding genes (Figure S2B). These
processes, together with the transcription factors NF-κB, Esr1 and Creb1, have been implicated in
previous studies (23, 24), indicating that our data do reflect biological changes of adipocytes during
obesity.
Page 8 of 46Diabetes
9
Compared to protein-coding genes, less is known about adipocyte lncRNA changes upon obesity.
Our data indicates that 68 lncRNAs are significantly differentially expressed between normal chow and
high-fat diet in at least two of the three types of adipocytes that we profiled (Figure 1D). We termed them
obesity-regulated lncRNAs in adipocytes (lnc-ORIAs, Supplemental Table 2). Many of them display
adipocyte-specific expression (Figure 1E & Figure S3). Using the software GREAT (Genomic Regions
Enrichment of Annotations Tool) that infers function of genomic regions based on the ontology
annotations of their neighboring protein-coding genes (25), we found that activation of JNK kinase activity
is the only significant (pval < 1E-6) GO category associated with the obesity-induced lncRNAs (Figure 1F).
Furthermore, the C/EBPβ motif was found to be enriched from this group of induced lncRNA genes
(Figure S1C). JNK has been shown to have a central role in obesity (26), while C/EBPβ has recently been
implicated in adipose insulin resistance (27). Together, our data suggests that meaningful biological
insight could be gleaned from transcriptome analysis of lncRNAs, and lncRNAs could be important
regulators of obesity.
Many lnc-ORIAs are regulated in various metabolic conditions and bound by PPARG
To confirm the expression changes of the lnc-ORIAs that we identified from our high-throughput RNA-Seq,
we isolated RNA from independent cohorts of control and high fat diet-fed mice, and we confirmed the
expression changes of 10 selected lnc-ORIAs based on their expression values, fold changes and gene
structures (Figure 2A). Out of the 10 lnc-ORIAs chosen based on their higher expression level and
unambiguous gene structure, 9 were induced upon obesity and 1 was repressed (Lnc-ORIA1). The
expression changes generally occurred in all the three tissues profiled, though tissue-specific differences
exist (e.g.Lnc-ORIA6). To test whether the changes of these lncRNAs are a general feature in other
obesity models, we examined their expression in adipose tissue from ob/ob and control mice and found
that the expression of all 10 lnc-ORIAs change in the same direction as that in diet-induced obesity, with
8 reach significant level (Figure S4).
To investigate if these selected lnc-ORIAs are responsive to alteration of nutritional status, we
measured their expression in adipose tissue of ad libitum mice (fed) and mice underwent an overnight
fast (fasted). 9 of 10 of these targets (except Lnc-ORIA7) have significant decreased expression in the
Page 9 of 46 Diabetes
10
different adipose tissues upon fasting (Figure 2B). Fasting and diet-induced obesity represents two
extremes of nutritional spectrum, one being an acute nutrient-deprived state and the other a chronic
nutrient-excess state. The majority of the lncRNAs examined display an inverse correlation pattern of
expression in these two conditions (Figure 2C), suggesting that these lnc-ORIAs could be molecular
sensors reflecting the energy status in adipose tissue.
Previous studies have shown that tissue- or condition-specific lncRNAs, similar to protein-coding
genes, are often bound and regulated by key transcription factors. Using published PPARG ChIP-Seq
data from mouse white and brown adipose tissue (28), we found that half of the 10 lnc-ORIAs that we
studied are bound by PPARG at their promoters (3 are shown in Figure 2D), suggesting that many of
these lnc-ORIAs are transcriptionally regulated by PPARG in vivo.
Lnc-leptin is an enhancer lncRNA
We are particularly intrigued by Lnc-ORIA9, hereafter we named Lnc-leptin, which lies 28kb upstream of
Lep, a satiety hormone secreted by adipocytes that acts centrally to regulate systemic metabolism and
immunity (17). Lnc-leptin has 2 exons, and it overlaps largely with an uncharacterized known transcript
Gm30838, which shares the same splice sites as Lnc-leptin (Figure 3A). The promoter of Lnc-leptin has
an open chromatin conformation as shown by published DNase-Seq data. There is positive H3K4
trimethylation (H3K4Me3) signal and RNA Polymerase II binding at the transcription start site of Lnc-leptin
as shown by published ChIP-Seq data (Figure 3B and Figure S5A), indicating that this gene is actively
transcribed in adipose tissue. Lnc-leptin also harbors positive H3K4 methylation 1 (H3K4Me1) and H3K27
acetylation (H3K27Ac) marks in white adipose tissue (Figure 3B); these histone modifications typically
associate with enhancers (H3K4Me1) and active enhancers (H3K27Ac) (29). Similar histone modification
architecture in this region was also observed in BAT (Figure S5B). Furthermore, to test whether the Lnc-
leptin region is associated with MED1, a component of the Mediator complex known to bridge enhancer
regions with the general transcription machinery and RNA Pol II at gene promoters (30), we performed
chromatin immunoprecipitation (ChIP) experiment in differentiated white primary adipocyte culture (Figure
3C). Because Lnc-leptin is undetectable in brown adipocytes culture, the ChIP experiment was only
performed in differentiated white primary adipocytes. Our ChIP result indicates that MED1 is recruited to
Page 10 of 46Diabetes
11
the promoter regions of Lnc-leptin and Lep (Figure 3C). Taken together, Lnc-leptin is transcribed from an
enhancer near Lep and is an enhancer lncRNA.
Expression of Lnc-leptin is highly correlated to that of Lep
Next, we investigated the spatial and temporal expression of Lnc-leptin. Using mouse SVF-derived
primary adipocyte culture, we found that expression of Lnc-leptin increases gradually as differentiation
progresses, in a similar manner as Lep and Pparg (Figure 4A). To assess if the expression of Lnc-leptin is
specific to adipose tissue, we measured its expression in 20 different mouse tissues, and we found that it
is highest in epididymal white fat, followed by inguinal white fat and interscapular brown fat. It is also
expressed, albeit at a much lower level, in testicle and eye (Figure 4B). Interestingly, the tissue specific
expression of Lnc-leptin highly mirrors that of Lep (Figure 4B). To examine if the expression of these two
genes are correlated, we plotted the expression of Lnc-leptin and Lep across a variety of conditions
including HFD vs ND (n=45), ob/ob vs wildtype (n=9), fasted vs fed (n=42) in mouse adipose tissues. A
very tight correlation (r>0.76) was found between the expression of Lnc-leptin and Lep in all examined
conditions (Figure 4C). To further assess whether Lnc-leptin and Lep respond to hormonal signaling in a
similar manner, we treated differentiated primary adipocytes with different agents that are known to alter
the expression of Lep. Acute insulin stimulation induced Lep expression (31, 32); we found that such
increase was accompanied by an induction of Lnc-leptin (Figure 4D). Conversely, upon TNFα and
norepinephrine treatment where Lep was repressed (33, 34), Lnc-leptin expression was concomitantly
reduced (Figures 4E and 4F). Taken together, we have demonstrated a close correlation between the
expression of Lnc-leptin and Lep, pointing to a potential causative relationship between them.
Lnc-leptin is required for adipogenesis
To investigate the role of Lnc-leptin during adipogenesis, we employed two independent strategies to
knock it down in primary adipocyte cultures: short hairpin RNAs (shRNA) and Dicer-substrate short
interfering RNA (DsiRNA). First, we infected primary white preadipocytes with retrovirus harboring control
shRNA or shRNA constructs targeting Lnc-leptin. Cells were then differentiated as per normal, and RNA
was harvested at Day6 post differentiation. Lnc-leptin knockdown using 2 different shRNA constructs led
Page 11 of 46 Diabetes
12
to more than 80% reduction of the gene (Figure 5A). Furthermore, it almost completely blocked adipocyte
differentiation: oil red O staining shows there was very little lipid accumulation in the knockdown cells
compared to the control (Figure 5B). This defect was accompanied by a reduction in Lep and the
adipocyte-markers Pparg and Adipoq (Figure 5C). Similar results were obtained when Lnc-leptin was
knocked down in preadipocytes by DsiRNA (Figure 5D). These results suggest that Lnc-leptin is required
for adipogenesis.
Lnc-leptin regulates the expression of Lep in mature adipocytes
Depletion of Lnc-leptin during adipogenesis results in severe inhibition of cell differentiation that can
indirectly block Lep expression, so it is unclear whether Lnc-leptin can directly affect Lep expression. To
test this, we knocked down Lnc-leptin in mature adipocytes. Primary white preadipocytes were
differentiated into mature adipocytes and DsiRNAs or Antisense oligos (ASOs) were transfected into the
cells using a reverse transfection protocol (35). Both methods resulted in more than 80% reduction in
Lnc-leptin expression (Figures 5E and 5F), and both were accompanied by a concomitant reduction of
Lep expression. Interestingly, the expression of two mature adipocyte markers, Pparg and Adipoq were
also significantly reduced upon Lnc-leptin knockdown, but the extent of reduction is less. To test if
knocking down Lnc-leptin would affect Lep expression in vivo, we injected ASO against Lnc-leptin directly
into one side of mouse inguinal tissue, with the contralateral side injected with a scrambled control.
Tissues were harvested 2 days later for expression analysis. Both Lnc-leptin and Lep expression were
significantly reduced upon ASO injection (Figure 5G), and such decrease was accompanied by a less
significant reduction in Lep and Pparg mRNA (Figure 5G). Importantly, Lnc-leptin knockdown led to a
decrease in LEP but not PPARG protein expression (Figure 5H), arguing that the reduction of LEP protein
is not due to a decreased PPARG protein level. Taken together, we show that knocking down Lnc-leptin
affects Lep expression in mature adipocytes both in vitro and in vivo.
To test whether Lnc-leptin is sufficient to promote Lep expression, we used retroviral vector to
overexpress Lnc-leptin in primary white adipocyte culture. Overexpression of Lnc-leptin did not promote
the expression of Lep or other adipocyte markers (Figure S6). Thus, Lnc-leptin is necessary, but not
sufficient to promote Lep expression or adipogenesis.
Page 12 of 46Diabetes
13
Lnc-leptin mediates a loop formation between genomic loci of Lep and Lnc-leptin
Studies above demonstrate that Lnc-leptin is transcribed from an enhancer region and positively
regulates the expression of Lep. A common mechanism used by many enhancers is to form a long-
distance interaction with the promoter of their target genes to facilitate transcription by recruiting positive
regulators. We hypothesize that Lnc-leptin may be involved in such interaction near the Lep promoter. To
test if there is any long-range chromatin interaction between the genomic loci of Lnc-leptin and Lep,
chromatin conformation capture (3C) experiments were performed to interrogate the chromatin structure
around these two genes (Figure 6A). Using the promoter of Lep as an anchoring point, the genomic locus
encompasses exon2 of Lnc-leptin was found to interact with Lep promoter (Figure 6B). The 3C ligated
fragment was sequenced to confirm that it is indeed a hybrid product ligated from the two separate
genomic regions. This interaction was attenuated upon knocking down of Lnc-leptin (Figure 6C),
indicating that Lnc-leptin is required for the looping event. We propose that Lnc-leptin is a novel enhancer
lncRNA that regulates Lep expression by bringing Lep with its upstream enhancer and the transcriptional
machinery to close proximity (Figure 6D).
Discussion
Whole-genome sequencing efforts in the past two decades have revolutionized our understanding of the
mammalian genome: it is now recognized that the mammalian genome is pervasively transcribed to
generate thousands of non-coding RNA species including lncRNAs (36). Several lncRNAs have been
shown to play key roles in regulating energy metabolism (37). Here, we systemically profiled lncRNAs in
three different types of adipocytes in diet-induced obese mice and identified 68 regulated lncRNAs,
termed as lnc-ORIAs (obesity-regulated lncRNAs in adipocytes). Among the lnc-ORIAs, we focused on
Lnc-leptin because of its proximity to Lep. The local genomic structure and histone modification patterns
of Lnc-leptin are reminiscent of those of a typical enhancer. However, in contrast to the neuronal
enhancer RNAs (eRNAs) which are generally unspliced and lack polyadenylated tails (38), Lnc-leptin was
identified through polyA tail-enriched RNA-Seq and consists of 2 exons. It also differs from the
bidirectional enhancer-derived transcripts (39) as our directional RNA-Seq did not detect any transcript
coming out from the opposite direction (Figure 2D).
Page 13 of 46 Diabetes
14
Knockdown experiments using DsiRNA and ASO indicate that knocking down Lnc-leptin leads to a
concomitant reduction in Lep expression both in vitro and in vivo (Figure 5), suggesting that it is the RNA
transcript itself, rather than the act of transcription, which confers the lncRNA’s function. Lnc-Leptin
positively regulates the expression of Lep, similar to those lncRNAs that activate the expression of their
neighboring protein-coding genes (40–42). We showed by 3C experiment that Lnc-leptin is likely to be
required for chromatin interaction between exon2 of Lnc-leptin and the promoter of Lep (Figure 6). This
putative interaction brings the two genes in close proximity in a 3 dimensional space that potentially
enhance the expression of Lep (Figure 6). In our proposed model (Figure 6D), the Lnc-leptin transcript
acts as a bridge to enhance the interaction between the Lep promoter and enhancer: it could directly
interact with Lep promoter or merely serve as a scaffold to bring transcription factors and histone
modifying proteins together. We acknowledge that many details about the mechanism remain
unanswered. For example, we do not know what proteins Lnc-leptin directly interact with, whether Lnc-
leptin forms a RNA-DNA duplex directly with the enhancer or the promoter (or both), whether Lnc-leptin
can interact with other DNA segments. Those questions warrant further investigation in future studies.
It is noteworthy that the regulatory mechanism of Lnc-leptin on Lep may not account for its effects
on adipogenesis. Knockdown of Lnc-leptin during adipogenesis resulted in a severe reduction of lipid
accumulation and expression of mature adipocytes markers (Figure 5A-D). Because the formation of
mature adipocytes in ob/ob mice is not impaired, we believe that Lnc-leptin may employ a LEP-
independent mechanism in regulating adipogenesis, which warrant further investigation. In mature
adipocytes, knocking down Lnc-leptin seem to reduce the expression of adipocyte markers Pparg and
Adipoq, in addition to Lep. How such reduction occurs remains to be answered.
In two previous studies, the genomic region of Lnc-leptin was not identified as a cis-regulatory
element that regulates the adipose-specific expression of Lep. Both studies used BAC transgenic reporter
mice to identify the cis- and trans-regulatory elements of Lep in vivo. Wrann et al. identified a region
containing the three Lep exons, both introns, and 5.2kb of 5’ flanking sequence was sufficient to drive
adipocyte-specific EGFP expression(18), while Lu et al. identified a region -22kb to +8.8kb of Lep as the
region required for adipose-specific Lep expression (19). Both studies excluded the genomic location of
Page 14 of 46Diabetes
15
Lnc-leptin, which lies ~28kb upstream of Lep. It is plausible that Lnc-leptin is not primarily involved in the
basal expression of Lep but instead serves as a metabolic sensor to regulate the expression of Lep upon
different energy statues in adipocytes. For a very dynamically regulated gene such like Lep, its regulation
is likely to be controlled by the coordination of multiple regulatory mechanisms. Our study reveals a new
layer of regulatory complexity, while earlier studies(18)(19) identified several cis and trans regulatory
factors. These layers of regulation are not mutually exclusive but are all orchestrated by the cellular
energy status. They together weave a sophisticated network to rapidly adjust Lep expression to respond
to the nutritional level alternation.
Page 15 of 46 Diabetes
16
Article information
Funding. This work was supported by Singapore NRF fellowship (NRF-2011NRF-NRFF 001-025) and
Tanoto Initiative in Diabetes Research to L.S. This research was supported by the Singapore National
Research Foundation under its CBRG grant (NMRC/CBRG/0070/2014 and NMRC/CBRG/0101/2016),
Open Fund - Individual Research (OF-IRG) Grant (NMRC/OFIRG/0062/2017) and Ministry of
Education (MOE) Tier2 grant (MOE2017-T2-2-009). This work was supported by the RNA Biology
Center at CSI Singapore, NUS, from funding by the Singapore Ministry of Education’s Tier 3 grants,
grant number MOE2014-T3-1-006. M.H.L and S.H are supported by an NMRC–Cooperative Basic
Research Grant (NMRC-CBRG) New Investigator Grant (NMRC/BNIG/2027/2015).
Duality of interest. No potential conflicts of interest relevant to this article were reported.
Author contributions. K.A.L, S.Q.H, A.C.E.W, M.H.L, Z.Z, M.K.L performed the experiments and
analyzed the data. K.A.L and L.S designed the project, interpreted the data and wrote the manuscript. L.S
is the guarantor of this manuscript.
Page 16 of 46Diabetes
17
References
1. Haslam DW, James WPT. Obesity. [Internet]. Lancet 2005;366(9492):1197–209.
2. Rosen ED, Spiegelman BM. What we talk about when we talk about fat.. Cell 2014;156(1-2):20–44.
3. Morton NM et al. A stratified transcriptomics analysis of polygenic fat and lean mouse adipose tissues identifies novel candidate obesity genes. [Internet]. PLoS One 2011;6(9):e23944.
4. Tam CS et al. An early inflammatory gene profile in visceral adipose tissue in children. [Internet]. Int. J. Pediatr. Obes. 2011;6(2-2):e360–3.
5. Rodríguez-Acebes S et al. Gene expression profiling of subcutaneous adipose tissue in morbid obesity using a focused microarray: distinct expression of cell-cycle- and differentiation-related genes. [Internet]. BMC Med. Genomics 2010;3(1):61.
6. Grove KL, Fried SK, Greenberg AS, Xiao XQ, Clegg DJ. A microarray analysis of sexual dimorphism of adipose tissues in high-fat-diet-induced obese mice. [Internet]. Int. J. Obes. (Lond). 2010;34(6):989–1000.
7. Kogelman LJA et al. Identification of co-expression gene networks, regulatory genes and pathways for obesity based on adipose tissue RNA Sequencing in a porcine model. [Internet]. BMC Med. Genomics 2014;7(1):57.
8. Rinn JL, Chang HY. Genome regulation by long noncoding RNAs. [Internet]. Annu. Rev. Biochem. 2012;81:145–66.
9. Fatica A, Bozzoni I. Long non-coding RNAs: new players in cell differentiation and development. [Internet]. Nat. Rev. Genet. 2014;15(1):7–21.
10. Sun L et al. Long noncoding RNAs regulate adipogenesis. [Internet]. Proc. Natl. Acad. Sci. U. S. A. 2013;110(9):3387–92.
11. Zhao X-Y, Li S, Wang G-X, Yu Q, Lin JD. A long noncoding RNA transcriptional regulatory circuit drives thermogenic adipocyte differentiation. [Internet]. Mol. Cell 2014;55(3):372–82.
12. Xu B et al. Multiple roles for the non-coding RNA SRA in regulation of adipogenesis and insulin sensitivity. [Internet]. PLoS One 2010;5(12):e14199.
13. Alvarez-Dominguez J et al. De novo Reconstruction of Adipose Tissue Transcriptomes Reveals Novel Long Non-coding RNAs that Regulate Brown Adipocyte Development. Cell Metab. 2015;Resubmitte.
14. Yang L et al. Integrative Transcriptome Analyses of Metabolic Responses in Mice Define Pivotal LncRNA Metabolic Regulators [Internet]. Cell Metab. 2016;24(4):627–639.
15. Zhang Y et al. Positional cloning of the mouse obese gene and its human homologue.1. Zhang Y, Proenca R, Maffei M, Barone M, Leopold L, Friedman JM. Positional cloning of the mouse obese gene and its human homologue. Nature [Internet] 1994 [cited 2015 Jan 7]; 372:425–32 [Internet]. Nature 1994;372(6505):425–32.
16. Wabitsch M et al. Biologically Inactive Leptin and Early-Onset Extreme Obesity. [Internet]. N. Engl. J. Med. 2015;372(1):48–54.
17. Friedman J. Leptin at 20: An overview. J. Endocrinol. 2014;223(1):T1–T8.
18. Wrann CD et al. FOSL2 promotes leptin gene expression in human and mouse adipocytes. [Internet]. J. Clin. Invest. 2012;122(3):1010–21.
19. Lu YH, Dallner OS, Birsoy K, Fayzikhodjaeva G, Friedman JM. Nuclear Factor-Y is an adipogenic
Page 17 of 46 Diabetes
18
factor that regulates leptin gene expression [Internet]. Mol. Metab. 2015;4(5):392–405.
20. Weisberg SP et al. Obesity is associated with macrophage accumulation in adipose tissue. J. Clin. Invest. 2003;112(12):1796–1808.
21. Mori H et al. Secreted frizzled-related protein 5 suppresses adipocyte mitochondrial metabolism through WNT inhibition2012;122(7). doi:10.1172/JCI63604DS1
22. Yu X et al. Egr-1 decreases adipocyte insulin sensitivity by tilting PI3K/Akt and MAPK signal balance in mice. [Internet]. EMBO J. 2011;30(18):3754–3765.
23. Manrique C et al. Loss of Estrogen Receptor α Signaling Leads to Insulin Resistance and Obesity in Young and Adult Female Mice. [Internet]. Cardiorenal Med. 2012;2(3):200–210.
24. Qi L et al. Adipocyte CREB Promote insulin resistance in Obesity. Cell Metab. 2010;9(3):277–286.
25. McLean CY et al. GREAT improves functional interpretation of cis-regulatory regions. [Internet]. Nat. Biotechnol. 2010;28(5):495–501.
26. Hirosumi J et al. A central role for JNK in obesity and insulin resistance.. Nature 2002;420(6913):333–336.
27. Lo KA et al. Analysis of in vitro insulin-resistance models and their physiological relevance to in vivo diet-induced adipose insulin resistance. [Internet]. Cell Rep. 2013;5(1):259–70.
28. Rajakumari S et al. EBF2 Determines and Maintains Brown Adipocyte Identity [Internet]. Cell Metab. 2013;17(4):562–574.
29. Creyghton MP et al. Histone H3K27ac separates active from poised enhancers and predicts developmental state. [Internet]. Proc. Natl. Acad. Sci. U. S. A. 2010;107(50):21931–21936.
30. Allen BL, Taatjes DJ. The Mediator complex: a central integrator of transcription. [Internet]. Nat. Rev. Mol. Cell Biol. 2015;16(3):155–166.
31. Buyse M, Viengchareun S, Bado a, Lombès M. Insulin and glucocorticoids differentially regulate leptin transcription and secretion in brown adipocytes.. FASEB J. 2001;15:1357–1366.
32. Lee KN, Jeong IC, Lee SJ, Oh SH, Cho MY. Regulation of leptin gene expression by insulin and growth hormone in mouse adipocytes.. Exp. Mol. Med. 2001;33(4):234–9.
33. Gettys TW, Harkness PJ, Watson PM. The beta 3-adrenergic receptor inhibits insulin-stimulated leptin secretion from isolated rat adipocytes. [Internet]. Endocrinology 1996;137(9):4054–7.
34. Ruan H, Hacohen N, Golub TR, Van Parijs L, Lodish HF. Tumor necrosis factor-alpha suppresses adipocyte-specific genes and activates expression of preadipocyte genes in 3T3-L1 adipocytes: nuclear factor-kappaB activation by TNF-alpha is obligatory. [Internet]. Diabetes 2002;51(5):1319–36.
35. Isidor MS et al. An siRNA-based method for efficient silencing of gene expression in mature brown adipocytes [Internet]. Adipocyte 2015;3945(NOVEMBER):00–00.
36. Birney E et al. Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project. [Internet]. Nature 2007;447(7146):799–816.
37. Kornfeld J-W, Brüning JC. Regulation of metabolism by long, non-coding RNAs. [Internet]. Front. Genet. 2014;5(March):57.
38. Kim T-K et al. Widespread transcription at neuronal activity-regulated enhancers [Internet]. Nature 2010;465(7295):182–187.
Page 18 of 46Diabetes
19
39. Andersson R et al. An atlas of active enhancers across human cell types and tissues [Internet]. Nature 2014;507(7493):455–461.
40. Ørom UA et al. Long noncoding RNAs with enhancer-like function in human cells. [Internet]. Cell 2010;143(1):46–58.
41. Trimarchi T et al. Genome-wide mapping and characterization of notch-regulated long noncoding RNAs in acute leukemia [Internet]. Cell 2014;158(3):593–606.
42. Hsieh C-L et al. Enhancer RNAs participate in androgen receptor-driven looping that selectively enhances gene activation. [Internet]. Proc. Natl. Acad. Sci. U. S. A. 2014;111(20):7319–24.
43. Lo KA, Ng PY, Kabiri Z, Virshup D, Sun L. Wnt inhibition enhances browning of mouse primary white adipocytes2016;3945(May). doi:10.1080/21623945.2016.1148834
44. Zeng PY, Vakoc CR, Chen ZC, Blobel G a., Berger SL. In vivo dual cross-linking for identification of indirect DNA-associated proteins by chromatin immunoprecipitation. Biotechniques 2006;41(6):694–698.
45. Lo KA et al. Genome-Wide Profiling of H3K56 Acetylation and Transcription Factor Binding Sites in Human Adipocytes [Internet]. PLoS One 2011;6(6):12.
46. Hagège H et al. Quantitative analysis of chromosome conformation capture assays (3C-qPCR).. Nat. Protoc. 2007;2:1722–1733.
47. Medvedovic J et al. Flexible Long-Range Loops in the VH Gene Region of the Igh Locus Facilitate the Generation of a Diverse Antibody Repertoire. Immunity 2013;39(2):229–244.
Page 19 of 46 Diabetes
20
Figure legends
Figure 1. Adipocyte lncRNA transcriptomes reveal meaningful insights of diet-induced obesity
(A) Study schematics: C57BL/6J male mice were put under normal control chow (ND) or high-fat diet
(HFD) for 16 weeks after weaning at 3 weeks. Adipocytes were isolated from interscapular brown adipose
tissue (BAT), inguinal (ING) and epididymal (EPI) adipose tissues by collagenase digestion and
centrifugation. RNA was extracted from the floating adipocyte layer and subjected to high-throughput
RNA-Seq.
(B) qPCR analysis of an adipocyte-specific gene (Lep) and a macrophage marker (Emr1) on isolated
adipocytes and pelleted stromal vascular fraction (SVF). For both genes, the expression in the different
adipose tissues or different fraction was normalized to that in BAT adipocyte, which has a value of 1.
Comparison was made between adipocyte and SVF in the HFD condition (n=4-6). Expression differences
of adipocyte and SVF under ND were also significant but not shown. All data are presented as mean ±
SEM. * p < 0.05, ** p< 0.01 and *** p< 0.001 comparing with the control condition using 2-tailed Student’s
t tests.
(C) Unsupervised hierarchical clustering of fpkm from expressed (fpkm > 1 in all conditions) mRNAs
(n=9640) and lncRNAs (n=355) from adipocytes of mice underwent normal diet (ND) vs high-fat diet
(HFD). Height of each arm of the dendrogram above the heatmaps represents the distance between the
different data sets. Normalized gene expression data (fpkm values after log transformed and mean-
centered) are shown.
(D) Venn diagram showing overlap of obesity-regulated mRNAs (left) and lncRNAs (right) among
adipocytes from BAT, ING and EPI.
(E) Relative abundance of the identified obesity-induced lncRNAs across 30 different mouse tissues
using RNA-Seq data from ENCODE. Adipose tissues (BAT, ING and EPI) were shown in the first three
columns.
(F) Gene Ontology analysis of the obesity-induced lncRNAs using the software GREAT (Genomic
Regions Enrichment of Annotations Tool). The lncRNA-mRNA pairs that are associated with the GO term
“Activation of JNK activities” are shown.
Page 20 of 46Diabetes
21
Figure 2. Selected obesity-regulated lncRNAs in adipocyte (lnc-ORIAs) are dynamically regulated
in diverse pathophysiological conditions
(A) qPCR analysis of selected lnc-ORIAs from BAT, ING and EPI of mice on normal chow (n=8) vs high-
fat diet (n=7).
(B) qPCR analysis of selected lnc-ORIAs from BAT, ING and EPI of mice underwent an overnight fast
(fasted, n=6) vs control (fed, n=7). For A-B, all data are presented as mean ± SEM. * p < 0.05, ** p< 0.01
and *** p< 0.001 comparing with the control condition using 2-tailed Student’s t tests.
(C) Heatmap illustrating the expression fold changes of the 10 selected lnc-ORIAs under high-fat diet vs
normal diet and fasting vs ad libitum. Red represents an increase in expression in HFD (or fasted)
compared to ND (or fed), whereas blue represents a decrease in expression in HFD (or fasted) compared
to ND (or fed).
(D) UCSC genome browser tracks showing promoters of Fabp4 and selected lnc-ORIAs are bound by
PPARG in mouse brown and epididymal adipose tissue. The RNA-Seq tracks were generated in the
current study and corresponds to the expression changes upon HFD in EPI, while the PPARG ChIP-Seq
data were from published data (GSE43763) (28). Red arrows indicate the direction of transcription. Scale
bars indicate a distance of 5kb.
Figure 3. The identification of Lnc-leptin, an enhancer lncRNA upstream of Lep
(A) Genomic location of Lnc-leptin in mm10. Both Lnc-leptin and Lep are on the positive strand and are
28kb apart.
(B) Mouse DNaseI hypersensitivity, histone modification, RNA Polymerase II binding profile and Pparg-
bound sites in a 15kb region around Lnc-leptin. DNaseI hypersensitivity profile of genital fat pad, fat pad
and liver from 8-week old mice (pink) is from ENCODE/University of Washington. Histone modification
data (H3K4Me3, H3K4ME1 and H3K27ac) of pooled white adipose tissue from eWAT and iWAT (green)
is from GSE92590. Epididymal white adipose tissue (WAT) and BAT RNA Polymerase II and histone3
control ChIP-Seq data (blue) is from GSE63964. PPARG ChIP-Seq data from eWAT and BAT (red) is
from GSE43763.
(C) Chromatin immunoprecipitation (ChIP) experiment using Mediator1 (MED1) antibody showing MED1
binding in the promoters of Lnc-leptin and Lep in white mature primary adipocytes differentiated in vitro
Page 21 of 46 Diabetes
22
(Day 7) at Lnc-leptin promoter, Lnc-leptin transcription start site (TSS) and Lep promoter. Insulin genomic
region (Ins) is used as negative control. All data (n=3) are presented as mean ± SEM. * p < 0.05, ** p<
0.01 and *** p< 0.001 comparing with the control condition using 2-tailed Student’s t tests.
Figure 4. Expression of Lnc-leptin is highly correlated to that of Lep.
(A) qPCR analysis of expression of Lnc-leptin, Lep and Pparg upon differentiation of primary white
adipocytes (n=4). Gene expression was expressed relative to Day 0.
(B) Lnc-leptin and Lep RNA expression measured by qPCR in 20 different mouse tissues.
(C) Correlation between the expression of Lnc-leptin and Lep under different conditions in mouse adipose
tissue: ND vs HFD (n=45), fasted vs fed (n=38), ob/ob vs control (n=9). δCt of Lnc-leptin (Ct of Lnc-leptin
– Ct of housekeeping gene Rpl23) were plot against δCT of Lep.
(D) Mature primary white adipocytes (Day6) were treated with 100nM of insulin for 3h (n=4). Gene
expression was expressed relative to control treatment.
(E) Mature primary brown and white adipocytes were treated with 2.5nM of TNFα for 24h (n=4). Gene
expression was expressed relative to control treatment.
(F) Mature primary white adipocytes were treated with 1µM of norepinephrine for 24h (n=4). For D-F,
qPCR analysis results were calculated using Rpl23 as housekeeping gene. Data is presented as mean ±
SEM. * p < 0.05, ** p< 0.01 and *** p< 0.001 comparing with the control model using 2-tailed Student’s t
tests.
Figure 5. Knocking down Lnc-leptin represses Lep
(A) Retrovirus-mediated transduction of primary preadipocytes (Day -2) using control and two separate
shRNAs targeting Lnc-leptin. Cells were induced to differentiate and RNA was harvested at Day6.
Expression of Lnc-leptin at Day6 was measured by qPCR (n=4).
(B) Oil red O staining showing adipocyte differentiation defect upon Lnc-leptin knockdown by shRNAs.
Scale bar =100µm.
(C) Expression of three adipocyte maker genes at Day6 upon shRNA transduction as described in A
(n=4).
Page 22 of 46Diabetes
23
(D) Transfection of DsiRNA control or DsiRNAs targeting Lnc-leptin (Dsi1,Dsi2 and Dsi3) was performed
at the preadipocyte stage at Day-2 and RNA was extracted at Day 4. Expression of Lnc-leptin and other
adipocyte marker genes were measured at Day4 using qPCR (n=4).
(E) Expression of Lnc-leptin and other adipocyte markers in mature primary adipocytes reverse-
transfected with DsiRNA control or a specific DsiRNA targeting Lnc-leptin (Dsi2). Transfection was
performed at Day6 and RNA was extracted 48h later (n=4).
(F) Expression of Lnc-leptin and other adipocyte markers in mature primary adipocytes reverse-
transfected with antisense oligo targeting Lnc-leptin (ASO Lnc-leptin) or scrambled control (ASO
scrambled). Transfection was performed at Day6 and RNA was extracted 48h later (n=4).
(G) Lnc-leptin was knock-downed in vivo in mouse inguinal adipose tissue using ASO Lnc-leptin and
compared with control (ASO scrambled) (n=7). For each mouse, ASO Lnc-leptin was injected on one side
and scrambled control was injected on the contralateral side. Tissue was harvested and RNA was
extracted 48h post injection.
(H) Western blots showing the reduced protein expression of LEP in mouse inguinal adipose tissue after
knockdown of Lnc-leptin using ASO.
Figure 6. Chromatin looping between Lnc-leptin and Lep is diminished upon Lnc-leptin
knockdown in mature adipocytes
(A) Chromatin Conformation Capture (3C) experiment was performed to explore the 3D chromosome
configuration in the proximity of Lnc-leptin and Lep. Blue lines indicate sites at which restriction enzyme
Xba1 cut in a 47000bp genomic region spanning Lnc-leptin and Lep. Arrows next to the Xba1 cut sites
indicate direction of primers used in the 3C experiment. #15 is the anchor primer that encompasses the
transcription start site of Lep. Black rectangles indicate the exons of Lnc-leptin and Lep genes while
linking lines represent introns.
(B) Interaction frequency between the anchoring point and upstream distal fragments was determined by
qPCR (n=4) and normalized to BAC and control regions in primary adipocytes. Chromatin looping was
detected between fragment 6 (which contains exon2 of Lnc-leptin) and anchoring fragment 15.
Page 23 of 46 Diabetes
24
(C) 3C-qPCR result of mouse primary adipocytes with Lnc-leptin knockdown against its scramble control
using ASO. There is a noticeable decrease in interaction frequency between anchoring fragment 15 and
fragment 6 upon Lnc-leptin knockdown (p=0.1).
(D) Model of how Lnc-leptin potentially regulates Lep expression: Lnc-leptin is required for chromatin
interaction between the genomic loci of Lnc-leptin and Lep. Expression of Lnc-leptin enhances the
expression of Lep by bringing together the two genes and their transcription machinery.
Page 24 of 46Diabetes
EPI ING
B*T
vb-h vvOw v-bf
w-wh+h hvb
hOv
C
E
+W wh W-
vOvv W
fh
ND
cEpi
ND
cIng
ND
cBat
HF
DcB
atH
FD
cEpi
HF
DcIn
g
mRN* lncRN*
exp
ress
ion
D
mRN* lncRN*
EPI ING
B*T
eugu(cLepScSfrp4SEgr1
F
B*
TIN
GE
PI
Mam
mar
ycgl
ad
ME
FS
kele
talcm
uscl
eLu
ngH
eart
*dr
ena
lB
ladd
erC
olon
Kid
ney
Live
rS
tom
ach
Bon
ecm
arro
wM
acro
phag
eE
ryth
robl
ast
Meg
aka
ryoc
yte
Bcc
ellcC
Db
wkB
ccel
lcCD
vfd
Tcc
ellcn
aive
Spl
een
Thy
mus
Who
lecb
rain
Cer
ebel
lum
Cer
ebru
mE
SC
Pla
cen
taO
vary
Tes
tis
InguinalcW*T
v+cweekscofchighkfatcdiet
,HFDM
EpididymalcW*T
Collagenasecdigestion
Fractionationcby
centrifugation
PelletedcSVF
Controlcdietc,NDM
Floating*dipocytes
RN*kSeqc
InterscapularcB*T
C-WBL+N
* B
Figurecv NDc*dipocyteHFDc*dipocyteNDcSVFHFDcSVF
Rel
ativ
ecE
xpre
ssio
nex
pres
sion
K h b + O
GOcfromcupregulatedclncRN*s
*ctivationcofcJNKcactivities
klog,pvalueM
*ssociatedcmRN*cinvolvedcincJNKcactivitiesc
lncRN*cgenomicclocic
CcrW
Mapwkv
Spagf
Syk
Wnt-a
chrvv(ffv+Ov-+kffvW-WbKc
chrvw(vvvO+WfhWkvvvOW--K-
chrvv(fbvwwb--(fbv--Ovw
chrvw(-h--bwfvk-h-+wOb-
chrvb(hOwKwvvWkhOwKOWOwchrvb(hO-Kb+vwkhO-K+hf+
Obe
sity
kre
gula
tedc
lncR
N*
scin
cadi
pocy
tesc
,lnck
OR
I*sM
0
20
40
60
80
100
K
-
vK
v-
hK
B*T EPI ING B*T EPI ING
yyy
yyy
yyy
Leptin
yyy
yyy
yyEmrv
ND
cEpi
ND
cIng
ND
cBat
HF
DcB
atH
FD
cEpi
HF
DcIn
g
Page 25 of 46 Diabetes
BAT
EPI
ND
HFD
Fabp4
Ppa
rg1
ChI
PsS
eqR
NA
sSeq
lncsORIA5 lncsORIA9
4dd
+3dd
2dddd
53
446
+dd
+8
+7+
8dd
4d
4dd
6d
B
Figure12
A
D
8
6
4
2
d
8642d
+d
+5
+d
5
d
8d
6d
4d
2d
d
3d
2d
+d
d
3d
2d
+d
d
4d
5432+d
BATNDHFD
EPINDHFD
INGNDHFD
ttt
ttttt
ttt ttttt
ttt
tt
ttt
t
ttt
ttt
ttt
t
ttt
ttt
tttttttt
tt
tt
tttt
ttt
ttt
ttt
ttt
ttt
ttttt
tt
tt
ttt
tt
t
ttt
t
tttttt
tt
tt
t
tttt
ttttt
Rel
ativ
e1E
xpre
ssio
nR
elat
ive1
Exp
ress
ion
BAT
EPI
ING
fedfasted
fedfasted
fedfasted
HFD1vs1ND
fasted1vs1fed
BATEPI
ING
lncsORIA+
BATEPI
ING
lncsORIA3lncsORIA2lncsORIA8lncsORIA5lncsORIA7lncsORIA6lncsORIA4lncsORIA+dlncsORIA9
C
v
s
252d+5+d5d
2dd
+5d
+dd
5d
d
5d4d3d2d+dd
lncsORIA+
4
3
2
+
d
3
2
+
d
2d
+5
+d
5
d
+5
+d
5
d
4
3
2
+
d
4
3
2
+
d
+d
+5
5
d
d
+
23
2
+
d
+d8642d
lncsORIA2 lncsORIA3 lncsORIA4 lncsORIA5
lncsORIA+ lncsORIA2 lncsORIA3 lncsORIA4 lncsORIA5
lncsORIA6 lncsORIA7 lncsORIA8 lncsORIA9 lncsORIA+d
lncsORIA6 lncsORIA7 lncsORIA8 lncsORIA9 lncsORIA+d
fold
1cha
nge
lncsORIA4
Page 26 of 46Diabetes
Lnc%leptin
*8G99CGIII*8G979GIII
5kb
WATrHCK*7acWATrHCK4medWATrHCK4meC
WATrinputliverrHCK*7ac
eWATrPol*eWATrHCBATrPol*
BATrHCgWATrDNase
WATrDNase
BATrPpargeWATrPparg
LiverrDNase
FigurerC
A
mmdI*9GI*5GIII *9GIC5GIII *9GI45GIII *9GI55GIII *9GI65GIII *9GI75GIIIchr6
dIkb
Mir%d*9 Lep
GmCI8C8Lnc%leptin
Drin
put
I
I.5
d
d.5
*.5
*
dI
8
6
4
*
I I
I.5
d
d.5
I
I.5
d
d.5
*
lnc%leptinpromoter
lnc%leptinrTSS
Leprpromoter
Ins
Medd
IgGhh
hhhhh ns
B
C
Page 27 of 46 Diabetes
Page 28 of 46Diabetes
Figure 5B
sh control sh1 sh2
1.5
1.0
0.5
0
sh c
ontr
ol
sh1
sh2
C
Lnc-leptin
*** ******* ** **
**
*** *** ******
*
A
Lep Pparg Adipoq
0
0.5
1.0
1.5
0
0.5
1.0
1.5
0
0.5
1.0
1.5
sh c
ontr
ol
sh1
sh2
sh c
ontr
ol
sh1
sh2
sh c
ontr
ol
sh1
sh2
D
Dsi contr
ol
Dsi1
Dsi2
Dsi3
Dsi contr
ol
Dsi1
Dsi2
Dsi3
Dsi contr
ol
Dsi1
Dsi2
Dsi3
Dsi contr
ol
Dsi1
Dsi2
Dsi3
Lep Pparg AdipoqLnc-leptin
0
0.5
1.0
1.5
2
0
0.5
1.0
1.5
0
0.5
1.0
1.5
Dsi control
Dsi2ASO scrambledASO Lnc-leptin
E F
G
Lnc-leptin Lep
ASO
scra
mbled
ASO
Lnc-
lept
in
0
0.5
1
1.5
2
2.5 10
8
6
4
2
0
ASO
scra
mbled
***n=7
H
Leptin
�-actin
ASO
scrambled
ASO
Lnc-leptin
0
0.5
1.0
1.5
2
ASO
Lnc-
lept
in
Rela
tive e
xp
ressio
n
Rela
tive e
xp
ressio
n
Rela
tive e
xp
ressio
n
Rela
tive e
xp
ressio
n
Rela
tive e
xp
ressio
n
Rela
tive e
xp
ressio
n
1.5
1
0.5
0
Lnc-
lept
inLe
p
Ppa
rg
Adipo
q
Lnc-
lept
inLe
p
Ppa
rg
Adipo
q
1.5
1
0.5
0
*** *** * ***** ***
*** ***
Pparg Adipoq1.5
1
0.5
0
1.5
1
0.5
0
ASO
scra
mbled
ASO
Lnc-
lept
inASO
scra
mbled
ASO
Lnc-
lept
in
*
Pparg
Page 29 of 46 Diabetes
1
2
3
4
5
Nor
mal
ised
.rel
ativ
ein
tera
ctio
n.fr
eque
ncy
3 4 5 6 9 11 13 14
Lnc-leptin Leptin
Fragment.No.
| | |5 6 9 11Fragments.
| | | | | |
XbaI
43 13 14 15.Anchor
Figure.6
A
Lnc-leptin Leptin
B C
D
Lnc-leptin
Leptin
Lnc-leptin Leptin
Fragment.No.3 4 5 6 9 11 13 14
Nor
mal
ised
.rel
ativ
ein
tera
ctio
n.fr
eque
ncy
1
2
3
4Lnc-leptin.knockdownControlp=0.1
**
Page 30 of 46Diabetes
1
SUPPLEMENTARY FIGURES
Figure S1. Depot-specific markers were examined by real-time PCR (Related to Figure 1)
(A) Adipose tissue from each depot (BAT, EPI and ING) was minced into small pieces. A small fraction of
the minced tissue was kept before collagenase digestion for RNA-exaction and realtime PCR to examine
the expression of WAT markers (HoxC10, HoxC9 and Lep) and BAT marker (Ucp1).
(B) FPKM expression values from the RNA-Seq data of the above WAT and BAT markers in adipocytes
isolated after collagenous digestion.
**
HoxC10
020406080
100
800
1000
1200
1400
Rela
tive e
xpre
ssio
n
Leptin
0
10
20
30
40
50
Rela
tive e
xpre
ssio
n
**
Ucp1
0.0
0.5
1.0
1.5
Rela
tive e
xpre
ssio
n
**
BAT
EPI
ING
HoxC9
0
100
200
300
400
500
Rela
tive e
xpre
ssio
n
**
HoxC10
0.00.20.40.60.81.0
8
10
12
14
16
FP
KM
Hoxc9
0.0
0.5
1.0
1.5
2.0
2.5
FP
KM
Ucp1_seq
0
50
100
150
FP
KM
A
B
Page 31 of 46 Diabetes
2
Figure S2. Biological insights about obesity can be gleaned from both obesity-regulated mRNAs
and lncRNAs (Related to Figure 1)
(A) Network analysis of obesity-induced mRNAs using GeneGo identified RelA as the top-scoring
transcription factor that connects with the most number of induced genes.
(B) Gene ontologies and pathways analysis of obesity-induced mRNAs using GeneGo.
(C) Promoter motif analysis of obesity-induced lncRNAs.
Page 32 of 46Diabetes
3
Figure S3. Expression of lnc-ORIAs in fatty liver (Related to Figure 1)
Real-time PCR was performed to detect the 10 lnc-ORIAs expression in livers from chow and HFD fed
mice. 3 of 10 are detectable. Error bar represent SEM. * P<0.05, Student T test. N=6
lnc-ORIA6
lnc-ORIA3
lnc-ORIA10
0.0
0.5
1.0
1.5
2.0Chow
HFD
Relative expression
* *
Page 33 of 46 Diabetes
4
Figure S4. Many lnc-ORIAs are regulated in ob/ob mice (Related to Figure 2)
qPCR analysis of selected lncRNAs from inguinal tissue of ob/ob (n=3) vs control mice (n=4)
Page 34 of 46Diabetes
5
Figure S5 Genomic profile around Lnc-leptin (Related to Figure 3)
(A) Mouse DNaseI hypersensitivity, histone modification, RNA Polymerase II binding profile and Pparg-bound sites in a 400kb region around Lnc-leptin. DNaseI hypersensitivity profile of genital fat pad, fat pad and liver from 8-week old mice (pink) is from ENCODE/University of Washington. Histone modification data (H3K4Me3, H3K4ME1 and H3K27ac) of pooled white adipose tissue from eWAT and iWAT (green) is from GSE92590. Epididymal white adipose tissue (WAT) and BAT RNA Polymerase II and histone3 control ChIP-Seq data (blue) is from GSE63964. PPARG ChIP-Seq data from eWAT and BAT (red) is from GSE43763. (B) Mouse DNaseI hypersensitivity profile and histone modification (H3K4Me3, H3K4ME1 and H3K27ac) as measured by ChIP-Seq at the vicinity of Lnc-leptin and Lep. DNaseI hypersensitivity data of mouse fat pad was made available from ENCODE/University of Washington. Brown adipose tissue (BAT) histone modification data was ChIP-Seq datasets made available by ENCODE/LICR. Both sets of data were downloaded via UCSC genome browser.
Page 35 of 46 Diabetes
6
Figure S6. Overexpression of lnc-Leptin doesn’t affect Leptin expression (Related to Figure 5)
iWAT preadipocytes were infected by retroviral for Lnc-leptin overexpression, followed by induction of
differentiation for 5 days. Realtime PCR was performed to examine the expression of Lnc-leptin, Lep and
other markers.
Lnc-
Lept
in
Lept
in
Pparγ
Adipo
Q
Ceb
pα
Fabp4
0
50
100
150
VectorlncLeptin overexpression
*
Rela
tive e
xpre
ssio
n
Page 36 of 46Diabetes
7
List of Supplemental Tables
Supplemental Table 1: Summary of RNA-Seq data
Supplemental Table 2: The genomic coordinates of the 68 lnc-ORIAs
Supplemental Table 3: Sequences of qPCR primers for lnc-ORIAs and protein-coding genes
Supplemental Table 4: Sequences of shRNAs used to knockdown Lnc-leptin
Supplemental Table 5: Sequences of DisRNAs and antisense oligos used to knockdown Lnc-leptin
Supplemental Table 6: Sequences of anti-sense oligo used to knockdown Lnc-leptin
Supplemental Table 7: Sequences of ChIP primers
Supplemental Table 8: Sequences of 3C primers
Page 37 of 46 Diabetes
8
Supplemental Table 1: Summary of RNA-Seq data
Samples input Aliigned pairs Concordant pair alignment rate
Concordant aligned pairs
ND_subq1 11,638,518 11,088,443 93.7% 10,905,291
ND_subq2 14,329,770 13,367,078 89.4% 12,810,814
ND_subq3 9,504,510 8,580,019 84.4% 8,021,806
HFD_subq1 18,924,192 18,087,008 92.2% 17,448,105
HFD_subq2 15,741,275 14,902,029 90.5% 14,245,854
HFD_subq3 22,513,698 21,043,689 88.7% 19,969,650
ND_bat1 13,457,147 12,727,660 88.6% 11,923,032
HFD_bat1 16,712,661 15,963,833 92.3% 15,425,786
ND_epi1 22,372,276 21,195,223 92.1% 20,604,866
ND_epi2 18,467,744 17,537,206 92.7% 17,119,599
ND_epi3 25,495,193 23,839,442 91.6% 23,353,597
HFD_epi1 18,037,866 17,158,404 92.3% 16,648,950
HFD_epi2 16,597,865 15,823,064 93.1% 15,452,612
HFD_epi3 18,099,336 17,211,156 92.8% 16,796,184
Page 38 of 46Diabetes
9
Supplemental Table 2: The genomic coordinates of the 68 lnc-ORIAs in mm10
Name Chromosome Start End
lnc-ORIA1 chr9 85331071 85348086
lnc-ORIA2 chr9 102740573 102741913
lnc-ORIA3 chr9 83117508 83127348
lnc-ORIA4 chr2 61533518 61541880
lnc-ORIA5 chr1 58885697 58890986
lnc-ORIA6 chr1 133977469 133984516
lnc-ORIA7 chr10 114112126 114119642
lnc-ORIA8 chr15 11966755 11971861
lnc-ORIA9 chr6 29032107 29039688
lnc-ORIA10 chr11 83224152 83226572
lnc-ORIA11 chr14 50870363 50880633
lnc-ORIA12 chr14 63652994 63666133
lnc-ORIA13 chr14 103403341 103449863
lnc-ORIA14 chr14 103463810 103512978
lnc-ORIA15 chr15 74930296 74938747
lnc-ORIA16 chr16 42882899 42912104
lnc-ORIA17 chr16 49980486 50049732
lnc-ORIA18 chr16 84713334 84715783
lnc-ORIA19 chr17 36159164 36181074
lnc-ORIA20 chr17 81370555 81377640
lnc-ORIA21 chr18 67321336 67327949
lnc-ORIA22 chr2 11521730 11543659
lnc-ORIA23 chr2 104084898 104120296
lnc-ORIA24 chr2 118553202 118562303
lnc-ORIA25 chr2 131946591 131955930
lnc-ORIA26 chr2 167571295 167580687
lnc-ORIA27 chr2 173110767 173138211
lnc-ORIA28 chr3 59870359 59876968
lnc-ORIA29 chr4 45531357 45533398
lnc-ORIA30 chr4 47198847 47206364
lnc-ORIA31 chr4 60544271 60547243
lnc-ORIA32 chr4 82507878 82547284
lnc-ORIA33 chr4 107433861 107434413
lnc-ORIA34 chr4 125228322 125229981
lnc-ORIA35 chr4 141207569 141211161
lnc-ORIA36 chr4 154637549 154644919
lnc-ORIA37 chr5 123133727 123140725
lnc-ORIA38 chr6 3328537 3346117
lnc-ORIA39 chr6 93193584 93244268
lnc-ORIA40 chr10 25298450 25306389
lnc-ORIA41 chr7 67712915 67716588
lnc-ORIA42 chr7 73544131 73557982
lnc-ORIA43 chr7 92705266 92710324
Page 39 of 46 Diabetes
10
lnc-ORIA44 chr8 13210273 13214034
lnc-ORIA45 chr8 34052373 34056819
lnc-ORIA46 chr8 84200888 84209606
lnc-ORIA47 chr1 31045092 31096637
lnc-ORIA48 chr9 35498199 35501504
lnc-ORIA49 chr9 61260956 61268588
lnc-ORIA50 chr9 120351498 120359838
lnc-ORIA51 chrX 8860453 8892939
lnc-ORIA52 chrX 19145397 19146279
lnc-ORIA53 chrX 95960481 95968036
lnc-ORIA54 chr11 59505435 59511216
lnc-ORIA55 chr11 79712040 79732287
lnc-ORIA56 chr11 99168157 99175740
lnc-ORIA57 chr11 113043902 113130598
lnc-ORIA58 chr11 117557675 117560472
lnc-ORIA59 chr12 80120456 80132892
lnc-ORIA60 chr1 70893858 70918402
lnc-ORIA61 chr13 43489823 43494462
lnc-ORIA62 chr13 49260845 49262424
lnc-ORIA63 chr13 52554392 52561721
lnc-ORIA64 chr1 72857935 72862280
lnc-ORIA65 chr13 81754189 81762256
lnc-ORIA66 chr14 28303118 28308783
lnc-ORIA67 chr14 28504614 28506296
lnc-ORIA68 chr14 34661520 34662690
Page 40 of 46Diabetes
11
Supplemental Table 3: Sequences of qPCR primers for lnc-ORIAs and protein-coding genes
lnc-ORIA1_F TAATTGGGCCTGGCTTACAG
lnc-ORIA1_R ACTATGGGTGTGGGCTTCAG
lnc-ORIA2_F ATTCAGAGTCCCTTGTGAGC
lnc-ORIA2_R CTTGTGCAGTGATGTTGACC
lnc-ORIA3_F GAAATTCAGCAAGAGCGTCC
lnc-ORIA3_R TGGCTTAGGCATGTTCCATT
lnc-ORIA4_F ACACAGAGAAATTTTGGTAGTCA
lnc-ORIA4_R GTGTATTTTGAGCTTTGGGGA
lnc-ORIA5_F TTGTTCCTCCGGAATGTCTC
lnc-ORIA5_R AGAGCAGCAAAGCATCTTCT
lnc-ORIA6_F CCAAGTTTGGCAGTAGAGGA
lnc-ORIA6_R CAGCAGGATTGATGGATGGA
lnc-ORIA7_F ACAACTTTAGAGGCTGAAAACTC
lnc-ORIA7_R CTGATGCCGCTTTCTTGATT
lnc-ORIA8_F CGGCTTTCTGTCCATTCCTA
lnc-ORIA8_R GTGAAAATTGTGCCGCTGAT
lnc-ORIA9_F1 GCTCCCTCTGATCCTTGTTG
lnc-ORIA9_R1 CTTGGTGGTCTTGGTCCTGT
lnc-ORIA10_F GGTTCTGGGCAAAATCCTTC
lnc-ORIA10_R TTCTGCCTCTTGATGTGGTT
Lep_F GAGACCCCTGTGTCGGTTC
Lep_R CTGCGTGTGTGAAATGTCATTG
Rpl23_F TGTGAAGGGAATCAAGGGAC
Rpl23_R TGTTTACTATGACCCCTGCG
Ccl9_F CCCTCTCCTTCCTCATTCTTACA
Ccl9_R AGTCTTGAAAGCCCATGTGAAA
Page 41 of 46 Diabetes
12
Supplemental Table 4: Sequences of shRNAs used to knockdown Lnc-leptin
sh_anti-lncLeptin1_F
GATCCCCGGGCACCGTGATTCTGAAATACGAATATTTCAGAATCACGGTGCCCTTTTTA
sh_anti-lncLeptin1_R
AGCTTAAAAAGGGCACCGTGATTCTGAAATATTCGTATTTCAGAATCACGGTGCCCGGG
sh_anti-lncLeptin2_F
GATCCCCGGCACCGTGATTCTGAAATAGCGAACTATTTCAGAATCACGGTGCCTTTTTA
sh_anti-lncLeptin2_R
AGCTTAAAAAGGCACCGTGATTCTGAAATAGTTCGCTATTTCAGAATCACGGTGCCGGG
Page 42 of 46Diabetes
13
Supplemental Table 5: Sequences of DisRNAs and antisense oligos used to knockdown Lnc-leptin
Dsi_1_antisense rArGrGrUrArGrArGrUrCrCrArUrCrGrArCrUrCrUrGrArArUrCrUrU
Dsi_1_sense rGrArUrUrCrArGrArGrUrCrGrArUrGrGrArCrUrCrUrArCCT
Dsi2_antisense rGrGrArGrArCrUrUrUrGrCrCrUrUrCrUrUrGrGrUrUrCrUrUrGrGrA
Dsi2_sense rCrArArGrArArCrCrArArGrArArGrGrCrArArArGrUrCrUCC
Dsi3_antisense rUrUrCrArArCrUrUrCrCrUrGrArGrGrUrGrUrGrUrGrUrCrArUrUrU
Dsi3_sense rArUrGrArCrArCrArCrArCrCrUrCrArGrGrArArGrUrUrGAA
Dsi_control_antisense rArUrArCrGrCrGrUrArUrUrArUrArCrGrCrGrArUrUrArArCrGAC
Dsi_control_sense rCrGrUrUrArArUrCrGrCrGrUrArUrArArUrArCrGrCrGrUAT
Page 43 of 46 Diabetes
14
Supplemental Table 6: Sequences of anti-sense oligo used to knockdown Lnc-leptin
ASO Lnc-leptin ATGCAGCCGGAGTAT
ASO4 scrambled control TTACAGCCGGAGAGT
Page 44 of 46Diabetes
15
Supplemental Table 7: Sequences of ChIP primers
LncLeptin_ChIP_TSS_F GACTTGGAGGGGGTAGTAAC
LncLeptin_ChIP_TSS_R AGAAAGAGGTCAATGAGGGC
LncLeptin_ChIP_promoter_F CCCGAATAGTCTACACCCTG
LncLeptin_ChIP_promoter_R GTTACTACCCCCTCCAAGTC
Lep_ChIP_promoter_F TTCGGGTACCAAAGGAAGAC
Lep_ChIP_promoter_R CTACTGAGCAGCGGTAGTTT
Ins_ChIP_F GGACCCACAAGTGGAACAAC
Ins_ChIP_R GTGCAGCACTGATCCACAAT
Page 45 of 46 Diabetes
16
Supplemental Table 8: Sequences of 3C primers
Name Sequence Note
X-369-15 GCACCCCATACCCTGTATCC Anchor primer, fragment 15 with XbaI
XbaI-369-3 CGCATGGATATCTGTCATCG Lnc-leptin promoter, fragment 3 with XbaI
XbaI-369-4 CGCTCTGACTCTGACTGTGG Lnc-leptin promoter, fragment 4 with XbaI
XbaI-369-5 CAATCACCACACCCACAAAG Lnc-leptin intron, fragment 5 with XbaI
XbaI-369-6 CCAGCTCCTGTTGCCTTGTA Lnc-leptin exon2, fragment 6 with XbaI
XbaI-369-9 GCTAGCTCCTTCATCCTTGCT Negative control, fragment 9 with XbaI
XbaI-369-11 CAGCTCCTTTCTGGGTGACT Negative control, fragment 11 with XbaI
XbaI-369-13 CAAAGTGGCATGGTGTTCAT Negative control, fragment 13 with XbaI
XbaI-369-14 CTCCTTTCCAGTGCCTCAAA Neighbor fragment (14) & positive control with XbaI
Page 46 of 46Diabetes