2012年1月4日,據(jù)《每日科學(xué)》報道,,精神疾病,,可以從許多層面進(jìn)行描述,其中最傳統(tǒng)的層面是沮喪經(jīng)歷的主觀描述和使用評定量表量化抑郁癥狀,。在過去二十年中,研究開發(fā)了其他一些策略,,用于描述抑郁癥的生物學(xué)基礎(chǔ),,包括使用磁共振成像(MRI)測量大腦體積以及白細(xì)胞中的基因表達(dá)模式等。
在此期間,,大量的研究試圖找到特征性的基因,,即能導(dǎo)致抑郁癥反映在評定量表上人的情緒狀態(tài),能反映MRI測量到的大腦結(jié)構(gòu)和功能的改變,,以及能解釋抑郁癥患者驗尸報告中腦組織的基因表達(dá)模式,。
因此,如果能試圖找到一個或數(shù)個基因,,能解釋所有這些搜集的不同類型信息所組合出的"全貌",,這將會是怎么情況?這正是David Glahn博士(耶魯大學(xué)和哈特福德醫(yī)院生活研究所)和他的同事們想要試圖去做的,。
"他們提供了一個非常激動人心的策略,,將我們在試圖鑒定出風(fēng)險基因的過程中搜集的各種類型的臨床研究數(shù)據(jù)結(jié)合起來,"John Krystal說,,《生物精神病學(xué)》(Biological Psychiatry)的編輯,。
他們的工作定位了一個基因,稱為RNF123,,它可能在嚴(yán)重抑郁癥中發(fā)揮著作用,。
他們有兩個明確的目標(biāo):描述一種新方法從基因?qū)膊〉?quot;重要性"方面將腦結(jié)構(gòu)和功能的測量進(jìn)行排名,定位抑郁癥的候選基因,。
"我們試圖找出一種方法能將生物學(xué)測量與(精神科)疾病風(fēng)險聯(lián)系起來,,"John Blangero博士說,德克薩斯州生物醫(yī)學(xué)研究所基因組學(xué)計算中心主任,。"在我們首次將這個方法應(yīng)用于嚴(yán)重抑郁癥時,,我們實際上確實發(fā)現(xiàn)了一些令人興奮的東西。"
盡管先前RNF123并沒有與抑郁癥聯(lián)系起來,,但它已被證明能夠影響大腦中的海馬,,在嚴(yán)重抑郁癥患者中被改變了。
"我們認(rèn)為,生物學(xué)測量更接近于大腦疾病進(jìn)展?jié)摬氐臋C(jī)制,。然而,,最終我們感興趣的是主觀經(jīng)驗和精神疾病相關(guān)的功能障礙,"Krystal補充道,。 "在這項研究中采用的方法可能有助于將所有這些信息利用起來,,有希望提高我們確定導(dǎo)致抑郁癥或可能靶向治療基因的能力。"
Glahn說,,"我們還需要進(jìn)行更多的研究來確定這確實是一個本壘基因,,但我們已經(jīng)有了一個很好的候選基因。盡管這在抑郁癥研究中很難,。"(生物谷bioon.com)
doi:10.1016/j.biopsych.2011.08.022
PMC:
PMID:
High Dimensional Endophenotype Ranking in the Search for Major Depression Risk Genes
David C. Glahn, Joanne E. Curran, Anderson M. Winkler, Melanie A. Carless, Jack W. Kent, Jac C. Charlesworth, Matthew P. Johnson, Harald H.H. Göring, Shelley A. Cole, Thomas D. Dyer, Eric K. Moses, Rene L. Olvera, Peter Kochunov, Ravi Duggirala, Peter T. Fox, Laura Almasy, John Blangero.
Abstract: Background: Despite overwhelming evidence that major depression is highly heritable, recent studies have localized only a single depression-related locus reaching genome-wide significance and have yet to identify a causal gene. Focusing on family-based studies of quantitative intermediate phenotypes or endophenotypes, in tandem with studies of unrelated individuals using categorical diagnoses, should improve the likelihood of identifying major depression genes. However, there is currently no empirically derived statistically rigorous method for selecting optimal endophentypes for mental illnesses. Here, we describe the endophenotype ranking value, a new objective index of the genetic utility of endophenotypes for any heritable illness. Methods: Applying endophenotype ranking value analysis to a high-dimensional set of over 11,000 traits drawn from behavioral/neurocognitive, neuroanatomic, and transcriptomic phenotypic domains, we identified a set of objective endophenotypes for recurrent major depression in a sample of Mexican American individuals (n = 1122) from large randomly selected extended pedigrees. Results: Top-ranked endophenotypes included the Beck Depression Inventory, bilateral ventral diencephalon volume, and expression levels of the RNF123 transcript. To illustrate the utility of endophentypes in this context, each of these traits were utlized along with disease status in bivariate linkage analysis. A genome-wide significant quantitative trait locus was localized on chromsome 4p15 (logarithm of odds = 3.5) exhibiting pleiotropic effects on both the endophenotype (lymphocyte-derived expression levels of the RNF123 gene) and disease risk. Conclusions: The wider use of quantitative endophenotypes, combined with unbiased methods for selecting among these measures, should spur new insights into the biological mechanisms that influence mental illnesses like major depression.