20130606omega3&HypogonadismGene

Report
Journal Club
Risk and Prevention Study Collaborative Group, Roncaglioni MC, Tombesi M, Avanzini F,
Barlera S, Caimi V, Longoni P, Marzona I, Milani V, Silletta MG, Tognoni G, Marchioli R.
n-3 fatty acids in patients with multiple cardiovascular risk factors.
N Engl J Med. 2013 May 9;368(19):1800-8. doi: 10.1056/NEJMoa1205409.
Margolin DH, Kousi M, Chan YM, Lim ET, Schmahmann JD, Hadjivassiliou M, Hall JE,
Adam I, Dwyer A, Plummer L, Aldrin SV, O'Rourke J, Kirby A, Lage K, Milunsky A,
Milunsky JM, Chan J, Hedley-Whyte ET, Daly MJ, Katsanis N, Seminara SB.
Ataxia, dementia, and hypogonadotropism caused by disordered ubiquitination.
N Engl J Med. 2013 May 23;368(21):1992-2003. doi: 10.1056/NEJMoa1215993. Epub
2013 May 8.
2013年6月6日 8:30-8:55
8階 医局
埼玉医科大学 総合医療センター 内分泌・糖尿病内科
Department of Endocrinology and Diabetes,
Saitama Medical Center, Saitama Medical University
牧野 佑子
Makino, Yuko
髙嶋 正利
Takashima, Masatoshi
魚介類供給量と平均寿命の関係
(歳)
イタリア
84
豪州
スイス
82
日本
ニュージーランド
スウェーデン
フランス
ドイツ
カナダ
80
ギリシア
英国
78
平
均 76
寿
命
スペイン
アイルランド
オーストリア
オランダ
チェコ
アイスランド
ノルウェー
フィンランド
ポルトガル
韓国
デンマーク
米国
メキシコ
ポーランド
74
スロバキア
トルコ
72
70
0
10
20
30
40
50
60
70
80
90 (kg/人/年)
FAO「Food balance sheets」(日本以外の国)、農林水産省「食料需給表」、WHO「Statistical Information System
(WHOSIS)」に基づき水産庁で作成。
平成22年水産白書
In our study, the average daily
consumption of ω-3
PUFAs(polyunsaturated fatty acid)
from seal oil was ~8 g. We based
this estimate on a 30% ω-3 PUFA
content of seal oil.
Compared with less-than-daily consumption, both daily seal oil (odds ratio [OR] 0.2, 95%
confidence interval [CI] 0.1-0.8) and daily salmon consumption (OR 0.5, CI 0.2-1.1) were
associated with a lower prevalence of glucose intolerance, controlling for age, ethnicity, body
mass index, and sex. The effects were similar when limited to newly discovered cases: OR 0.3, CI
0.1-1.3 for seal oil and OR 0.4, CI 0.1-1.3 for salmon. Consumption of seal oil at least five times
per week was required to reduce risk.
Adler AI, Boyko EJ, Schraer CD, Murphy NJ.: Lower prevalence of impaired glucose tolerance and diabetes associated with
daily seal oil or salmon consumption among Alaska Natives. Diabetes Care. 1994 Dec;17(12):1498-501.
GISSI-Prevenzioneの試験概要
EPA・DHA製剤投与群(n=2,836)
心筋梗塞急性期*患者
(n=11,324)
*心筋梗塞発現後3ヵ月以内
EPA・DHA製剤+ビタミンE投与群(n=2,830)
ビタミンE投与群(n=2,830)
プラセボ群(n=2,828)
観察期間:3.5年間
【主要評価項目】
• 全死亡
• 非致死性心筋梗塞、非致死性脳卒中
• 心血管死、非致死性心筋梗塞、非致死性脳卒中
【副次評価項目】
• 主要評価項目の各因子
GISSI-Prevenzione Investigators., Lancet 1999;354:447より作図
オメガ3系脂肪酸の心血管系イベントへの影響
(%)
(%)
総死亡
5.0
4.0
-28%*
発 3.0
現
率 2.0
突然死
5.0
4.0
発 3.0
現
率 2.0
-34%*
-47%*
1.0
0
-57%*
1.0
0
3
(%)
6
9
12 (月)
0
0
3
6
9
12 (月)
心血管死
5.0
EPA・DHA製剤投与群(n-5,665)
EPA・DHA製剤非投与群(n=5,658)
4.0
*:p<0.05 vs. EPA・DHA製剤非投与群、log-rank検定
-30%*
発 3.0
現
率 2.0
心筋梗塞発現後3ヵ月以内の11,323例を対象に、
EPA・DHA製剤1g群、ビタミンE300mg群、両薬剤併
用群、コントロール群(両薬剤非投与群)の4群に無作
為に分け、3.5年間追跡したGISSI-Prevenzioneから、
心血管系イベントへの影響について検討した。
-34%
1.0
0
0
3
6
9
12 (月)
Marchioli R et al., Circulation 2002; 105, 1897より作図
EPA・DHA製剤投与後のTGの推移
TG
(mg/dL)
170
160
150
EPA・DHA製剤投与群(n=5,665)
EPA・DHA製剤非投与群(n=5,658)
140
0
0
6
12
18
30
42 (月)
心筋梗塞発現後3ヵ月以内の11,323例を対象に、EPA・DHA製剤1g群、ビタミンE300mg群、両薬剤併用群、
コントロール群(両薬剤非投与群)の4群に無作為に分け、3.5年間追跡したGISSI-Prevenzioneから、心血管系
イベントへの影響について検討した。
Marchioli R et al., Circulation 2002;105:1897より改変
42ヵ月後のリスク低下率
(%)
死亡
非致死
心筋梗塞・
脳卒中
心血管死
非致死
心筋梗塞・
脳卒中
総死亡
心血管死
心臓死
冠動脈死
突然死
0
-5
-10
-15
リ
ス -20
ク
変 -25
化 -30
率
-15*
-20**
-21**
-30***
-35
-32**
-35***
-40
-45
*:p<0.05、 **:p<0.01、 ***:p<0.001
-45***
-50
心筋梗塞発現後3ヵ月以内の11,323例を対象に、EPA・DHA製剤1g群、ビタミンE300mg群、両薬剤併用群、
コントロール群(両薬剤非投与群)の4群に無作為に分け、3.5年間追跡したGISSI-Prevenzioneから、心血管系
イベントへの影響について検討した。
Marchioli R et al., Circulation 2002;105:1897より作図
EPA・DHA製剤によるイベント低下は、
投与早期から42ヵ月後まで認められた
(%)
0
死亡
非致死
心筋梗塞・
脳卒中
心血管死
非致死
心筋梗塞・
脳卒中
総死亡
心血管死
心臓死
冠動脈死
突然死
-10
†
-20
リ
ス -30
ク
変
化 -40
率
*
†
†
†
†
‡
‡
†
†
†
*
‡
‡
-50
-60
*
†§
†§
†
‡
†§
‡
§
*:p<0.1、†:p<0.05、 ‡:p<0.01、 §:p<0.001
3ヵ月後
6ヵ月後
9ヵ月後
12ヵ月後
* †
42ヵ月後
‡
-70
心筋梗塞発現後3ヵ月以内の11,323例を対象に、EPA・DHA製剤1g群、ビタミンE300mg群、両薬剤併用群、
コントロール群(両薬剤非投与群)の4群に無作為に分け、3.5年間追跡したGISSI-Prevenzioneから、心血管系
イベントへの影響について検討した。
Marchioli R et al., Circulation 2002;105:1897より作図
GISSI-HFの試験概要
慢性心不全患者
(n=7,046)
• 18歳以上
• NYHA分類Ⅱ~Ⅳ度
• 1年以内に慢性心不全により入院
(LVEF≧40%の場合)
EPA・DHA製剤(1g/日)投与群
(n=3,529)
プラセボ群
(n=3,517)
観察期間:3.9年間(中央値)
主要評価項目
• 全死亡
• 全死亡および心血管系イベントによる
入院
副次評価項目
• 心血管死
• 心血管死および入院
• 心臓突然死
• 入院
• 心血管による入院
• 心不全、心筋梗塞、脳卒中による入院
GISSI-HF Investigators., Lancet 2008;372:1223より作図
EPA・DHA製剤による慢性心不全患者への影響
総死亡
(%)
70
(%)
70
プラセボ
EPA・DHA製剤
60
プラセボ
EPA・DHA製剤
60
+
総
死
亡
総死亡+心血管系イベントによる入院
心
血
管
系
イ
ベ
ン
ト
に
よ
る
入
院
50
総
死
亡
40
Adjusted HR* 0.91(95.5% CI 0.833-0.998); p=0.041
Unadjusted HR* 0.93(95.5% CI 0.852-1.021); p=0.124
30
20
10
50
40
30
20
Adjusted HR* 0.92(99% CI 0.849-0.999); p=0.009
Unadjusted HR 0.94(99% CI 0.869-1.022); p=0.059
10
p=0.124(log-rank検定)
p=0.059(log-rank検定)
0
0
0
6
12
18
24
30
36
42
48
54 (月)
0
6
12
18
24
30
36
42
48
54 (月)
NYHAⅡ~Ⅳ度の慢性心不全患者を対象に、EPA・DHA製剤1g投与群またはプラセボ群に無作為に分け、心血管
系イベントに及ぼす影響について検討した(平均観察期間:3.9年)。
※補正因子:心不全治療歴、ペースメーカーの使用、大動脈弁狭窄症
GISSI-HF investigators et al., Lancet 2008; 372: 1223.
オメガ3系脂肪酸による心機能への影響
ANOVA p=0.03
LVEF
(%)
30
6
投与前
3ヵ月後
29
5
28
LVEF変化率
27
26
LVEF
5.5±5.9
25
24
23
22
4
3
2.5±3.7
2
1
1.0±3.8
21
20
プラセボ
0
1g/日
4g/日
プラセボ
1g/日
4g/日
非虚血性心不全患者43例を対象に、EPA・DHA製剤1g/日投与群、EPA・DHA製剤4g/日投与群、または、プラセボ
群に無作為化し、3ヵ月間観察した。
Moertl D et al., Am Heart J 2011;161:915.e1より作図
慢性心不全患者における
オメガ3系脂肪酸の炎症(IL-6)への影響
(pg/mL)
プラセボ
IL-6
4.5
(pg/mL)
投与前
3ヵ月後
4.0
3.5
30
1.5
p=0.64
30
(pg/mL)
p=0.12
30
20
20
10
10
10
8
8
8
6
6
6
4
4
4
2
2
2
IL-6
IL-6
2.0
(pg/mL)
EPA・DHA製剤4g/日
20
3.0
2.5
EPA・DHA製剤1g/日
p=0.03
1.0
0.5
0
プラセボ
1g/日
4g/日
0
0ヵ月
3ヵ月
0
0ヵ月
3ヵ月
0
0ヵ月
3ヵ月
3.39 -> 3.67
4.09 -> 1.64
2.98 -> 0.68
(0.22, 3.85)(0.53, 3.83)
(0.44, 5.87)(0.02, 3.97)
(0.49, 5.26)(0.02, 1.23)
非虚血性心不全患者43例を対象に、EPA・DHA製剤1g/日投与群、EPA・DHA製剤4g/日投与群、または、プラセボ
群に無作為化し、3ヵ月間観察した。
Moertl D et al., Am Heart J 2011;161:915.e1より作図
GISSI-HF/3ヵ月後の変化
左室駆出率(EF)
FMD
12
30
投与前
3ヵ月後
29
IL-6
5
4.5
11.5
4
28
11
3.5
27
10.5
26
25
10
24
9.5
3
2.5
2
1.5
23
9
1
22
8.5
21
20
プラセボ
8
1g/日
4g/日
0.5
プラセボ
0
1g/日
4g/日
プラセボ
1g/日
4g/日
非虚血性心不全患者43例を対象に、EPA・DHA製剤1g/日投与群、EPA・DHA製剤4g/日投与群、または、プラセボ
群に無作為化し、3ヵ月間観察した。
Moertl D et al., Am Heart J 2011;161:915.e1より作図
EPA・DHA製剤による左室駆出率への影響
(%)
34.5
EPA・DHA製剤投与群(n=312)
33.5
左
室
駆
出
率
32.5
31.5
プラセボ投与群(n=296)
30.5
平均値、95%CI
29.5
p = 0.005
28.5
0
ベースライン
1
2
3
(年)
GISSI-HF試験に登録された慢性心不全患者のうち、心エコーにより心機能を評価した608例を対象に、
EPA・DHA製剤による心機能への影響について検討した。
Ghio S et al., Eur J Heart Fail 2010;12:1345.
eicosapentaenoic acid (EPA).
1800mg/day
Kromhout D, Giltay EJ, Geleijnse JM; Alpha Omega Trial Group.: n-3 fatty acids and cardiovascular events after
myocardial infarction. N Engl J Med. 2010 Nov 18;363(21):2015-26.
Low-dose supplementation with EPA–DHA
or ALA did not significantly reduce the rate
of major cardiovascular events
Figure 2. Kaplan–Meier Curves for Primary and Secondary End Points. Kaplan–Meier curves are shown for the cumulative
incidence of major cardiovascular events (the primary end point) and fatal coronary heart disease (a secondary end point) among
4837 patients who had had a myocardial infarction and were assigned to receive a study margarine containing supplemental
eicosapentaenoic acid (EPA) combined with docosahexaenoic acid (DHA), a margarine containing alpha-linolenic acid (ALA), a
margarine containing both EPA–DHA and ALA, or a placebo margarine.
ORIGIN Trial Investigators, Bosch J, Gerstein HC, Dagenais GR, Díaz R, Dyal L, Jung H, Maggiono AP, Probstfield J, Ramachandran A, Riddle MC, Rydén LE, Yusuf S.: n-3 fatty acids and cardiovascular outcomes in patients with dysglycemia. N Engl J Med. 2012 Jul 26;367(4):309-18.
The members of the writing group are as follows: Maria Carla Roncaglioni, M.Sc., Istituto di
Ricovero e Cura a Carattere Scientifico (IRCCS)–Istituto di Ricerche Farmacologiche Mario Negri,
Milan; Massimo Tombesi, M.D., Centro Studi e Ricerche in Medicina Generale, Monza; Fausto
Avanzini, M.D., IRCCS–Istituto di Ricerche Farmacologiche Mario Negri, Milan; Simona Barlera,
M.Sc., IRCCS– Istituto di Ricerche Farmacologiche Mario Negri, Milan; Vittorio Caimi, M.D., Centro
Studi e Ricerche in Medicina Generale, Monza; Paolo Longoni, M.D., Centro Studi e Ricerche in
Medicina Generale, Monza; Irene Marzona, M.Sc., IRCCS–Istituto di Ricerche Farmacologiche
Mario Negri, Milan; Valentina Milani, M.Sc., IRCCS–Istituto di Ricerche Farmacologiche Mario
Negri, Milan; Maria Giuseppina Silletta, M.Sc., Consorzio Mario Negri Sud, Santa Maria Imbaro,
Chieti; Gianni Tognoni, M.D., Consorzio Mario Negri Sud, Santa Maria Imbaro, Chieti; and Roberto
Marchioli, M.D., Consorzio Mario Negri Sud, Santa Maria Imbaro, Chieti — all in Italy.
N Engl J Med 2013;368:1800-8.
BACKGROUND
Trials have shown a beneficial effect of n−3
polyunsaturated fatty acids in patients with
a previous myocardial infarction or heart
failure. We evaluated the potential benefit of
such therapy in patients with multiple
cardiovascular risk factors or atherosclerotic
vascular disease who had not had a
myocardial infarction.
METHODS
In this double-blind, placebo-controlled clinical trial, we
enrolled a cohort of patients who were followed by a
network of 860 general practitioners in Italy. Eligible
patients were men and women with multiple
cardiovascular risk factors or atherosclerotic vascular
disease but not myocardial infarction. Patients were
randomly assigned to n−3 fatty acids (1 g daily) or
placebo (olive oil). The initially specified primary end
point was the cumulative rate of death, nonfatal
myocardial infarction, and nonfatal stroke. At 1 year,
after the event rate was found to be lower than
anticipated, the primary end point was revised as time to
death from cardiovascular causes or admission to the
hospital for cardiovascular causes.
ADVERSE EVENTS
Gastrointestinal side effects (abdominal pain, nausea,
diarrhea, and other symptoms) were the most frequently
reported adverse drug reactions, but the incidence did not
differ significantly between the two groups (Table 3).
The investigators attributed two cases of severe epistaxis,
both in patients who were also receiving anticoagulant or
antiplatelet therapy, to the experimental treatment. Among
the serious adverse events, there were 490 diagnoses of
cancer among patients who received n−3 fatty acids (7.9%
of patients) and 453 among those who received placebo
(7.2%, P = 0.19); bleeding occurred in 16 patients who
received n−3 fatty acids (0.3%) and in 12 who received
placebo (0.2%, P = 0.44).
The beneficial effect of n−3 fatty acids in those two
trials was due to a reduction in sudden deaths from
cardiac causes. It is conceivable that the effects of
n−3 fatty acids become manifest primarily in
patients who are particularly prone to ventricular
arrhythmic events (e.g., those with a myocardial
scar or left ventricular dysfunction). Our trial had
extremely limited power to detect a reduction in
sudden deaths from cardiac causes or arrhythmic
events. The safety profile of n−3 fatty acids in this
population of older persons who are already
receiving many treatments for chronic disease could
be of interest for their use in patient populations that
are more prone to fatal and nonfatal arrhythmic
events.
RESULTS
Of the 12,513 patients enrolled, 6244 were
randomly assigned to n−3 fatty acids and 6269 to
placebo. With a median of 5 years of follow-up,
the primary end point occurred in 1478 of 12,505
patients included in the analysis (11.8%), of
whom 733 of 6239 (11.7%) had received n−3 fatty
acids and 745 of 6266 (11.9%) had received
placebo (adjusted hazard ratio with n−3 fatty
acids, 0.97; 95% confidence interval, 0.88 to
1.08; P=0.58). The same null results were
observed for all the secondary end points.
CONCLUSIONS
In a large general-practice cohort of
patients with multiple cardiovascular
risk factors, daily treatment with n−3
fatty acids did not reduce
cardiovascular mortality and morbidity.
(Funded by Società Prodotti Antibiotici
and others; ClinicalTrials.gov number,
NCT00317707.)
Message
心血管リスクまたは動脈硬化を有するが心筋梗
塞の既往はない患者コホート(約1万人)を対象
に、n-3脂肪酸の効果を無作為化プラセボ対照
試験で検討。追跡期間中央値5年で、心血管疾患
による死亡または入院の発生率はn-3脂肪酸群
11.7%、プラセボ(オリーブオイル)群11.9%
だった(調整後ハザード比0.97、P=0.58)。
オリーブオイルが対象となってフィシュオイル
と比較している。同じくらい有効ということで
あろう。
Ubiquitin is a small regulatory protein that has been found in almost all tissues
(ubiquitously) of eukaryotic organisms. It directs proteins to compartments in the
cell, including the proteasome which destroys and recycles proteins. Ubiquitin
can be attached to proteins and label them for destruction. This discovery won
the Nobel Prize for chemistry in 2004. Ubiquitin tags can also direct proteins to
other locations in the cell, where they control other protein and cell mechanisms.
In the ubiquitination cascade, E1 can bind
with dozens of E2s, which can bind with
hundreds of E3s in a hierarchical way. Other
ubiquitin-like proteins (ULPs) are also
modified via the E1–E2–E3 cascade.
E3 enzymes possess one of two domains:
• The HECT (Homologous to the E6-AP
Carboxyl Terminus) domain
• The RING (Really Interesting New Gene)
domain (or the closely related U-box
domain)
2009
https://en.wikipedia.org/wiki/Ubiquitin
From the Department of Neurology (D.H.M., J.D.S.), Harvard Reproductive Sciences Center and Reproductive Endocrine Unit (Y.M.C., J.E.H., A.D., L.P., S.V.A., J.O., S.B.S.), Analytic and Translational Genetics Unit (E.T.L., A.K., K.L., M.J.D.), Department of
Medicine, Pediatric Surgical Research Laboratories (K.L.), and Department of Neuropathology (E.T.H.-W.), Massachusetts General
Hospital, Division of Endocrinology, Department of Medicine, Boston Children’s Hospital (Y.-M.C.), and Department of Pathology,
Brigham and Women’s Hospital ( J.C.) — all in Boston; Center for Human Genetics, Cambridge, MA (A.M., J.M.M.); Center for
Human Disease Modeling, Department of Cell Biology (M.K., N.K.), and Department of Pediatrics (N.K.), Duke University Medical
Center, Durham, NC; Department of Neurology, Royal Hallamshire Hospital, Sheffield, United Kingdom (M.H.); Specialty Hospital,
Amman, Jordan (I.A.); and Center for Biological Sequence Analysis, Technical University of Denmark, Lyngby, and Center for Protein
Research, University of Copenhagen, Copenhagen (K.L.). Address reprint requests to Dr. Seminara at the Reproductive Endocrine
Unit, Massachusetts General Hospital, Boston, MA 02115, or at seminara.stephanie@ mgh.harvard.edu; or to Dr. Katsanis at the
Center for Human Disease Modeling, Duke University, Durham NC 27710, or at [email protected]
N Engl J Med 2013;368:1992-2003.
Background
The combination of ataxia and
hypogonadism was first described
more than a century ago, but its
genetic basis has remained elusive.
Methods
We performed whole-exome sequencing in
a patient with ataxia and hypogonadotropic
hypogonadism, followed by targeted
sequencing of candidate genes in similarly
affected patients. Neurologic and
reproductive endocrine phenotypes were
characterized in detail. The effects of
sequence variants and the presence of an
epistatic interaction were tested in a
zebrafish model.
Figure 1. Segregation of RNF216 and OTUD4 Mutations in the Index Pedigree and Identification of
Additional RNF216 Mutations in Unrelated Probands. The seven-generation pedigree shown in
Panel A includes Patients 1, 2, and 3, all of whom presented with ataxia, dementia, and
hypogonadotropic hypogonadism and were homozygous for both RNF216 p.R751C and OTUD4
p.G333V. Double lines indicate consanguineous unions. Genotyped, unaffected family members
are shown to be either homozygous for the nonmutated alleles (denoted with a + symbol) or
heterozygous for one or both changes. The pedigrees shown in Panel B are for the families of
additional RNF216 mutation-positive patients (Patients 4 through 8), all of whom presented with
ataxia and hypogonadotropic hypogonadism. Squares denote male family members, circles female
family members, solid symbols affected family members, slashes deceased family members,
diamonds siblings of either sex, the triangle miscarriages, and Arabic numbers the number of
siblings or miscarriages.
Figure 2. Functional Studies of rnf216 in Zebrafish.
Panels A through D show dorsal views of control zebrafish embryos (Panel A) and embryos injected
with rnf216 morpholino oligonucleotides (MO) (Panel B), rnf216 MO plus nonmutant human
RNF216 (Panel C), and rnf216 MO plus mutant human RNF216 (with RNF216 carrying the
p.R751C mutation identified in the index pedigree) (Panel D) at 3 days after fertilization (staining
with an antibody against α acetylated tubulin). The circles outline the area of the optic tectum, the
structure on which all measurements were based. The bar graph in Panel E shows the relative size
of the optic tectum in control embryos and the embryos injected with rnf216 MO, rnf216 MO plus
nonmutant human RNF216, and rnf216 MO plus mutant human RNF216. P values are based on
two-tailed t-tests. I bars indicate standard errors. AU denotes arbitrary units.
Figure 3. Epistatic Effects of the
OTUD4 p.G333V Allele. Panels A
through F show dorsal views of
control zebrafish embryos (Panel A)
and embryos injected with rnf216 MO
(morpholino oligonucleotides) (Panel
B), otud4 MO (Panel C), double MO
(DMO, rnf216 MO plus otud4 MO)
(Panel D), double MO plus
nonmutant human OTUD4 (Panel E),
and double (DMO) plus mutant
human OTUD4 (OTUD4 carrying the
p.G333V mutation identified in the
index pedigree) (Panel F) at 3 days
after fertilization (anti-α acetylated
tubulin stain). The asterisks indicate
the optic tecta that were measured to
assess the differences between the
conditions being evaluated. The bar
graph in Panel G shows the mean
relative size of the optic tecta in
control embryos and the five groups
of injected embryos. I bars indicate
standard errors. P values are based
on two-tailed t-tests.
Panels H, I, and J show dorsal
views of control embryos
(Panel H) and embryos
injected with DMO (Panel I)
and DMO plus nonmutant
human OTUD4 (Panel J) at 3
days after fertilization (anti-α
acetylated tubulin stain). The
rectangles outline the
cerebellar area; maximum
disorganization is observed in
embryos injected only with
DMO (Panel I). The bar graph
in Panel K shows the
percentage of embryos with
cerebellar defects under the
conditions being evaluated (as
shown in Panels A through F
and Panels H, I, and J).
RNF216 encodes an E3 ubiquitin ligase that
attaches ubiquitin to protein substrates,
marking them for proteasome-mediated
degradation.
Figure 4. Neuroradiologic and
Neuropathological Findings.
Panel A shows a sagittal T2-weighted
magnetic resonance imaging scan of
the brain in Patient 3. Diffuse
cerebellar atrophy (arrow) and cortical
atrophy can be seen. Panel B shows
a transverse image obtained with
fluid-attenuated inversion recovery
imaging, revealing multiple distinct
and confluent foci of hyperintensity in
the white matter. In Panel C,
immunohistochemical analysis of a
hippocampal brain section from
Patient 2 shows a neuronal
intranuclear inclusion with
immunoreactivity (brown) to an
antibody against ubiquitin,
counterstained with hematoxylin and
eosin. An electron micrograph of the
hippocampal neurons, in Panel D,
also shows an intranuclear inclusion,
which consists of aggregates of
granular material and fine filaments,
10 to 15 nm in diameter (arrow), that
are for the most part randomly
oriented. The scale bar corresponds
to 1 μm.
OTUD4 encodes a deubiquitinating enzyme.
Deubiquitinases allow target proteins and
ubiquitin itself to be recycled and often
function in partnership with specific E3
Figure 5. Endocrine Phenotypes.
In Panels A through D, the graphs at the left
show the endogenous secretion of luteinizing
hormone over a period of up to 12 hours.
Patient 6 was studied on two occasions, 15
months apart (Panels A and B). Arrowheads
indicate pulses of luteinizing hormone
secretion, and boxes duration of sleep; the
shading indicates the reference range for
healthy men and women. Concentrations of
estradiol (E2) and testosterone (T),
measured from pooled samples obtained
during the study, are indicated. In Panels A,
B, and D, the graphs at the right show the
response to exogenous pulsatile
gonadotropin-releasing hormone (GnRH)
over the course of up to 7 days. The dose of
GnRH was 75 ng per kilogram of body
weight, with the exception of the first dose of
GnRH on day 1 for Patient 6 (Panel A), which
was 165 ng per kilogram. (Note the
difference in the y axis scales in Panels A
and B.) In Panel C, the graph at the right
shows the secretion of luteinizing hormone in
response to varying doses of GnRH (black
circles and regression line). The data for the
patient fall to the right of the 95% confidence
interval (dashed red lines) for the mean
amplitude of the response to a range of
GnRH doses in 6 other men with idiopathic
hypogonadotropic hypogonadism (solid red
line).
Results
Digenic homozygous mutations in RNF216 and OTUD4, which
encode a ubiquitin E3 ligase and a deubiquitinase, respectively,
were found in three affected siblings in a consanguineous family.
Additional screening identified compound heterozygous truncating
mutations in RNF216 in an unrelated patient and single
heterozygous deleterious mutations in four other patients.
Knockdown of rnf216 or otud4 in zebrafish embryos induced
defects in the eye, optic tectum, and cerebellum; combinatorial
suppression of both genes exacerbated these phenotypes, which
were rescued by nonmutant, but not mutant, human RNF216 or
OTUD4 messenger RNA. All patients had progressive ataxia and
dementia. Neuronal loss was observed in cerebellar pathways
and the hippocampus; surviving hippocampal neurons contained
ubiquitin- immunoreactive intranuclear inclusions. Defects were
detected at the hypothalamic and pituitary levels of the
reproductive endocrine axis.
Conclusion
The syndrome of hypogonadotropic
hypogonadism, ataxia, and dementia can be
caused by inactivating mutations in RNF216 or
by the combination of mutations in RNF216
and OTUD4. These findings link disordered
ubiquitination to neurodegeneration and
reproductive dysfunction and highlight the
power of whole-exome sequencing in
combination with functional studies to unveil
genetic interactions that cause disease.
(Funded by the National Institutes of Health and others.)
Message
低ゴナドトロピン性性腺機能低下を合併し
た運動失調症患者の遺伝子変異を全エクソ
ン配列解析などで調査。血族同胞3人にユビ
キチン化に関与する遺伝子RNF216とOTUD4の
ホモ接合変異が、また他の5人にRNF216のヘ
テロ接合変異が見られた。ゼブラフィッ
シュにおけるこれらの遺伝子ノックアウト
は眼、視蓋と小脳の異常をもたらした。
全エクソン配列解析!をしてコンピュータ
で異常遺伝子を見つけている!

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