Post on 13-Dec-2015
Radiation Effects on Regulation of Gene Expression
Mitsuru Nenoi, Bing Wang, Tetsuo Nakajima
Radiation Effect Mechanisms Research Group, Natl. Inst. Radiol. Sci., Chiba, Japan
Risk of Radiation-Induced Cancers
?
From Hall,E.J., Radiobiology for the Radiologist. J.B. Lippincott Company
Experiment of continuous low-dose-rate irradiation at IES
42-49days 400 days until spontaneous death
0 Gy/min
40 nGy/min
800 nGy/min
16,000 nGy/minsignificantly different
significantly differentin female
not significantlydifferent
Life Span
gene expression profile ?
SPF condition
Dose-rate range used in the study at IES
dose-rate(nGy/min)
Natural radiation in Guarapari, Brazil
Natural radiation level in J apan
Space station (ship outside)
Space station (ship inside)
Cosmic radiation at 12,000m elevation
1
10
100
1000
1000016 mGy/min
800 nGy/min
40 nGy/min
Large-scale study on the effect of continuous low-
dose-rate irradiation
atInstitute for
Environmental Sciences (IES),
J apan
Number of genes whose expression levels were changed more than 1.6-fold by irradiation
dose-rate(nGy/min)
32 1 5 6650 18 3 21
13,000 16 11 2732 & 650 1 0 1
650 & 13,000 3 1 413,000 & 32 0 0 0
up-regulated down-regulated total
Functional analysis of deregulated genes Four genes whose expression was enhanced after irradiat
ion at 650 nGy/min and 13,000 nGy/min were involved in mitochondrial oxidative phosphorylation pathway.
(mGy/ min) (mGy/ min)
Uqcrb
0
0.65
0.03
2
1.6
0.5
1
(mGy/ min)
13
Ndufb9
0 13
0.65
0.03
2
Atp5k
0
0.65
0.03
2
Ndufv2
0 13
0.65
0.03
213(mGy/ min)
Genes whose expression levels were significantly varied by irradiation
Welch’s ANOVAp<0.05MTC: None
621 genes
Clustering analysis of selected genes
①
③④⑤⑥⑦⑧
⑮
⑬⑭
⑫⑪⑩
⑯
⑨
②
0Gy/
min
13 m
Gy/
min
650
nGy/
min
32 n
Gy/
min
① ② ③
④
⑤ ⑥ ⑦ ⑧
⑨ ⑩ ⑪ ⑫
⑬ ⑭ ⑮ ⑯
0.5
1.6
1
0.5
1.6
1
0.5
1.6
1
0.5
1.6
1
0Gy/
min
13 m
Gy/
min
650
nGy/
min
32 n
Gy/
min
0Gy/
min
13 m
Gy/
min
650
nGy/
min
32 n
Gy/
min
0Gy/
min
13 m
Gy/
min
650
nGy/
min
32 n
Gy/
min
0Gy/
min
13 m
Gy/
min
650
nGy/
min
32 n
Gy/
min
GO category containing similar gene list to the clusters
①
78 2.8E-07cytoplasm
78 4.0E-10mitochondrion organization and biogenesis 78 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-10
nucleosome
78 4.0E-10
mitochondrion
78 4.0E-1078 4.0E-10
organelle organization and biogenesis
78 4.0E-10
cytoplasm organization and biogenesis
78 4.0E-10
cell organization and biogenesis
78 4.0E-10
transferase
78 4.0E-10
cytoplasm organization and biogenesis
78 4.0E-10
cell organization and biogenesis
78 4.0E-10
organelle organization and biogenesis
24 0.0013energy pathways
22 5.7E-04mitochondrion
24 0.0055
78 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1037 0.007137 0.0071
37 0.0071
78 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1017 1.4E-0548 0.031
17 1.4E-05
⑩
17 1.4E-05
94
Overlapped gene
numberp valueGO category
GO SLIMS Cellular Componentmitochondrion organization and biogenesis 78 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-1078 4.0E-109 0.032
39 0.040
mitochondrioncytoplasm 22 0.0016
9 0.00614 0.012
Conclusion1 Mitochondrial oxidative phosphorylation was suggested t
o be elevated after irradiation at 650 nGy/min and 13,000 nGy/min.
Mice irradiated with low dose-rate radiation in this range may suffer oxidative stresses caused by elevated mitochondrial respiratory activity. This oxidative stress may be one of the factors that cause life spans-shortening of irradiated mice.
Multiple genes were found whose expression was changed more than 1.6-fold after 32 nGy/min, but their biological significances are unclear.
Radioadaptive response
Chromatid deletions
1.5 Gy X-rays3H-thymidine
(0.01-0.1 µCi.mL-1)
Olivieri et al., 1984
When cells are exposed to a priming low-dose or low dose-rate of radiation, they show a reduced biological response to a challenging high dose of radiation.
Adaptive response
Humanlymphocytes
Radioadaptive response in mice during late embryogenesis
Digital defects
Prenatal death
E11 E12 E18 E20
Prim
ing
IRC
halle
ngin
g IR
Fertilization 1
2
3
4
5
6
7
0 10 20 30 40 50
Nu
mb
ers
per
Dam
of
Fet
use
s
Priming Dose (cGy)
*
*
Living FetusesLiving Malformed Fetuses
(A) (B)
Experimental model
E11 E12
Priming irradiation
cDNA Microarray analysis
Whole-fetus removed
RNA extraction
10.34F
Non-effective
dose
0.50.34E
Non-effective
DR0.32.5D
0.34.2C
Effective dose-rate
(DR)
0.30.34B
Control00A
Description
DOSE
(Gy)
Dose Rate
(Gy/min)
Priming irradiation parameters:
AR genes
Identification of global differences
AR-inducible conditions (B and C)
AR-uninducible conditions (D, E and F)
861 AR genes
Selection of genes with:
• similar expression ratios inside each group
• significantly different modulation ratios between both groups
Functional annotation
Gene enrichment
Functional annotation and gene enrichment analysis
Cyt
oki
nes
an
d In
flam
ma
tory
Re
spon
se
0.0%
Se
nso
ry p
erc
eptio
n o
f ch
emic
al s
timu
lus
Pe
nto
se P
hosp
ha
te P
ath
wa
yA
cety
lch
olin
e S
ynth
esi
sC
ell p
rolif
era
tion
3M
ono
amin
e G
PC
Rs
Se
nso
ry p
erc
eptio
nG
lyco
gen
Met
ab
olis
mS
ma
ll lig
and
GP
CR
sN
ucle
otid
e G
PC
Rs
Fa
tty A
cid
Be
ta O
xida
tion
3 B
iGC
aT
GP
CR
DB
Cla
ss A
Rh
odo
psin
-like
Me
tallo
pep
tida
se a
ctiv
ityM
itoch
ond
rial
mem
bra
neT
ran
slat
ion
HS
P7
0 a
nd
Ap
opto
sis
TG
F B
eta
Sig
nalin
g P
ath
wa
yG
row
th f
acto
r a
ctiv
ityP
ota
ssiu
m c
han
nel a
ctiv
ity2-
Tis
sue
s-B
loo
d a
nd L
ymp
hp
38 M
AP
K s
igna
ling
pat
hway
1-T
issu
e-E
ndoc
rine
and
CN
SC
yto
sol
Hor
mo
ne a
ctiv
ityM
atr
ix M
eta
llopr
otei
nas
esE
lect
ron
Tra
nsp
ort
Ch
ain
Cel
l pro
life
ratio
nT
ota
l
10.0%
20.0%
30.0%
40.0%
% of AR genes in each molecular pathway
Significantly enriched
Non significantly enriched
Conclusion2
Intracellular and intercellular signaling activities are suggested to be important bases for radioadaptive response in mouse fetuses during late organogenesis.
The present cDNA microarray analysis failed to show evidences for involvement of DNA damage repair genes in the radioadaptive response.
Acknowledgements
Tetsuya Ono,T (Tohoku Univ.)
Guillaum Vares (NIRS) Keiko Taki,K (NIRS) Jianyu Wu (ADSTEC)
Tsuneya Matsumoto (IES)
Yoichi Oghiso,Y (IES) Kimio Tanaka (IES) Kazuaki Ichinohe (IES) Shingo Nakamura,S (IES) Satoshi Tanaka (IES)
This work was supported by the Budget for New Nuclear Crossover Research from the Ministry of Education, Culture, Sports, Sciences and Technology, Japan