靶向MAPK信號(hào)通路調(diào)控脂肪細(xì)胞分化的microRNAs

張秀秀，郭云濤，黃萬(wàn)龍，李 嬡，苗向陽(yáng)

(中國(guó)農(nóng)業(yè)科學(xué)院北京畜牧獸醫(yī)研究所，北京 100193)

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靶向MAPK信號(hào)通路調(diào)控脂肪細(xì)胞分化的microRNAs

張秀秀，郭云濤，黃萬(wàn)龍，李 嬡，苗向陽(yáng)*

(中國(guó)農(nóng)業(yè)科學(xué)院北京畜牧獸醫(yī)研究所，北京 100193)

脂肪細(xì)胞分化是一個(gè)多能間充質(zhì)干細(xì)胞(MSCs)逐漸向成熟脂肪細(xì)胞分化的復(fù)雜過(guò)程，該過(guò)程受很多轉(zhuǎn)錄因子、激素以及信號(hào)通路相關(guān)分子的嚴(yán)格調(diào)控。體內(nèi)外的試驗(yàn)表明，microRNAs(miRNAs)也參與了脂肪細(xì)胞分化的調(diào)節(jié)，且可以靶向轉(zhuǎn)錄因子和信號(hào)通路中的關(guān)鍵分子發(fā)揮作用。絲裂原活化蛋白激酶(MAPK)信號(hào)通路是真核細(xì)胞將胞外信號(hào)轉(zhuǎn)導(dǎo)至胞內(nèi)引起細(xì)胞反應(yīng)的一類重要信號(hào)系統(tǒng)，研究證明，miRNAs可以靶向MAPK信號(hào)通路中的某些基因，影響該通路的信號(hào)轉(zhuǎn)導(dǎo)，參與脂肪細(xì)胞分化的調(diào)控。因此本文總結(jié)了近幾年有關(guān)miRNA改變MAPK信號(hào)轉(zhuǎn)導(dǎo)，實(shí)現(xiàn)調(diào)控脂肪細(xì)胞分化功能的研究，以期為深入了解脂肪細(xì)胞分化的機(jī)制，為治療脂肪型疾病提供新的思路。

microRNA; MAPK信號(hào)通路; 靶基因; 脂肪細(xì)胞分化

脂肪組織不僅是一個(gè)儲(chǔ)存能量的組織，還是一個(gè)內(nèi)分泌組織，調(diào)控著體內(nèi)的代謝平衡，在肥胖的狀態(tài)下，脂肪組織會(huì)增生，表現(xiàn)為脂肪細(xì)胞數(shù)目的增多和體積增大，這會(huì)導(dǎo)致葡萄糖和脂肪代謝的失調(diào)，最終可能導(dǎo)致機(jī)體能量代謝失調(diào)，增加胰島素拮抗，高血壓以及血脂異常的風(fēng)險(xiǎn)[1-2]。因此對(duì)脂肪細(xì)胞分化機(jī)制的研究有助于治療肥胖疾病。

脂肪細(xì)胞分化分為很多個(gè)階段，第一步，MSCs被誘導(dǎo)分化為前體脂肪細(xì)胞，MSCs是一種多能干細(xì)胞，一旦被決定分化為脂肪細(xì)胞，就失去了分化為其他細(xì)胞類型的能力；其次前體脂肪細(xì)胞進(jìn)行有絲分裂進(jìn)入克隆增殖期；最后進(jìn)入生長(zhǎng)停滯期或終末分化期，分化為成熟的脂肪細(xì)胞。這個(gè)過(guò)程受一系列轉(zhuǎn)錄因子如CCAAT增強(qiáng)子結(jié)合蛋白(C/EBPs)、過(guò)氧化物酶體增殖劑激活受體γ(PPARγ)、信號(hào)通路及miRNA的嚴(yán)格調(diào)控(圖1)，其中重要的信號(hào)通路有MAPK信號(hào)通路、Wnt信號(hào)通路、Insulin信號(hào)通路等。近年來(lái)研究發(fā)現(xiàn)MAPK信號(hào)通路在脂肪細(xì)胞分化中也發(fā)揮重要作用,成為研究脂肪細(xì)胞分化調(diào)控機(jī)制的熱點(diǎn)，且有研究證明miRNA調(diào)控脂肪細(xì)胞分化的很多靶基因都富集于MAPK通路中，所以本文著重探討靶向MAPK調(diào)控脂肪細(xì)胞分化的miRNAs，以期為今后的試驗(yàn)作指導(dǎo)，為脂肪相關(guān)疾病的預(yù)防和治療以及動(dòng)物體脂肪沉積的調(diào)控提供新的思路。

1 MAPK信號(hào)轉(zhuǎn)導(dǎo)通路概述

絲裂原活化蛋白激酶(Mitogen-activated protein kinases，MAPKs)是細(xì)胞內(nèi)重要的信號(hào)通路之一，是哺乳動(dòng)物體內(nèi)廣泛存在的一類絲/蘇氨酸(Ser/Thr)蛋白激酶，可使多種核轉(zhuǎn)錄因子和蛋白激酶磷酸化，且能被一系列的細(xì)胞外信號(hào)或刺激所激活，如物理應(yīng)激，炎性細(xì)胞因子，生長(zhǎng)因子，細(xì)菌復(fù)合物等。目前在哺乳動(dòng)物中已鑒定了4條MAPK信號(hào)轉(zhuǎn)導(dǎo)通路，即ERK1/2信號(hào)通路、JNK通路、p38 MAPK通路和ERK5/BMK1通路，它們由不同的刺激因素激活，形成不同的轉(zhuǎn)導(dǎo)途徑，激活各不相同的轉(zhuǎn)錄因子，介導(dǎo)不同的生物學(xué)效應(yīng)，參與細(xì)胞的增殖、分化、凋亡及細(xì)胞間的功能同步等一系列生理過(guò)程，在動(dòng)物的生長(zhǎng)發(fā)育、炎性反應(yīng)等多種生命活動(dòng)中發(fā)揮重要作用[3-6]。MAPK信號(hào)轉(zhuǎn)導(dǎo)是以三級(jí)激酶級(jí)聯(lián)的方式進(jìn)行的，首先MAPKKK受有絲分裂原刺激磷酸化而激活，在此基礎(chǔ)上MAPKKK磷酸化激活 MAPKK，最后由MAPKK磷酸化 MAPK，然后激活的MAPK作用于相應(yīng)的轉(zhuǎn)錄因子，調(diào)控特定的基因表達(dá)。研究發(fā)現(xiàn)MAPK信號(hào)通路在脂肪細(xì)胞分化的各個(gè)階段均有參與，且發(fā)揮了重要作用。

2 MAPK信號(hào)通路對(duì)脂肪細(xì)胞分化的調(diào)控

四條MAPK信號(hào)通路都與脂肪細(xì)胞分化或脂肪代謝相關(guān)，ERK1/2是最早發(fā)現(xiàn)的MAPK家族成員，其對(duì)細(xì)胞成脂分化的調(diào)控比較復(fù)雜，很多研究都得到了完全相反的結(jié)果，E. Turpin 與V. A. Constant等[7-8]發(fā)現(xiàn)ERK1/2可能抑制了脂肪細(xì)胞分化，而也有研究證明ERK1/2在脂肪細(xì)胞分化早期發(fā)揮積極的促進(jìn)作用[9-12]，具體調(diào)控機(jī)制可能是脂肪細(xì)胞分化早期激活的ERK1/2促進(jìn)了C/EBPα和PPARγ的表達(dá)[13]，從而促進(jìn)脂肪細(xì)胞分化，而在后期激活的ERK1/2會(huì)磷酸化PPARγ使其失活[14-15]，導(dǎo)致了脂肪細(xì)胞分化的抑制，所以ERK1/2對(duì)脂肪細(xì)胞分化的調(diào)控作用可能取決于該通路被激活的時(shí)間。p38MAPK是1993年J. L.Brewster等[16]發(fā)現(xiàn)的相對(duì)分子質(zhì)量為38 ku的酪氨酸磷酸化的蛋白激酶，包括 p38α、p38β、p38γ、p38δ 4種亞型。M. Aouadi和J.Ji等[17-18]發(fā)現(xiàn)p38MAPK可以促進(jìn)人類前體脂肪細(xì)胞和3T3-L1前體脂肪細(xì)胞的成脂分化，而M. Aouadi等[19]也發(fā)現(xiàn)p38MAPK抑制了小鼠胚胎成纖維細(xì)胞及成年鼠脂肪前體細(xì)胞成脂分化，可見(jiàn)p38MAPK通路對(duì)脂肪細(xì)胞分化的調(diào)控與物種和細(xì)胞類型有關(guān)。JNK(c-Jun氨基末端激酶)是相對(duì)分子質(zhì)量54 ku的絲/蘇氨酸蛋白激酶，S. Tominaga等[20]證實(shí)JNK抑制劑SP600125促進(jìn)了人類間充質(zhì)干細(xì)胞(hMSCs)成脂分化，M. Feng等[21]發(fā)現(xiàn)微管親和調(diào)節(jié)蛋白激酶4(Mark4)可以通過(guò)激活JNK1信號(hào)通路來(lái)促進(jìn)脂肪細(xì)胞分化，說(shuō)明JNK信號(hào)通路在調(diào)節(jié)脂肪細(xì)胞分化方面發(fā)揮了重要作用。此外，ERK5/BMK1通路，一類非典型的MAPK通路，也參與了脂肪細(xì)胞分化及脂肪代謝的調(diào)控[22-23]。綜上可得，這些MAPK信號(hào)通路通過(guò)不同途徑，不同分子的參與，調(diào)控了脂肪細(xì)胞分化，為預(yù)防和治療肥胖相關(guān)疾病提供了重要的靶點(diǎn)。

3 miRNAs的特點(diǎn)及調(diào)控機(jī)制

miRNA 是一種長(zhǎng)為18～22 nt的內(nèi)源性非編碼RNA，它可通過(guò)與靶基因mRNA的3′非翻譯區(qū)(3′UTR)互補(bǔ)配對(duì)，抑制靶基因的翻譯，對(duì)基因表達(dá)進(jìn)行轉(zhuǎn)錄后調(diào)控[24-26]，在動(dòng)物細(xì)胞的增殖、分化、凋亡和代謝等許多生物學(xué)過(guò)程中發(fā)揮重要作用[27-29]。大量研究顯示miRNA 也參與調(diào)控動(dòng)物脂肪細(xì)胞的分化[30]，這些miRNAs在脂肪細(xì)胞分化的早期或者后期通過(guò)靶向作用信號(hào)通路中的分子或轉(zhuǎn)錄因子發(fā)揮調(diào)節(jié)功能。Y. F. Tang等[31]發(fā)現(xiàn)在脂肪干細(xì)胞(ADSCs)成脂分化期間miR-31和miR-326分別通過(guò)靶向轉(zhuǎn)錄因子C/EBPα和信號(hào)分子RASSF1來(lái)調(diào)節(jié)ADSCs分化，S. Y. Kim與E. K. Lee等[32-33]證明miR-27a和miR-130a也可以靶向轉(zhuǎn)錄因子PPARγ抑制脂肪細(xì)胞分化。此外有研究表明，部分miRNAs可以靶向MAPK信號(hào)通路中的信號(hào)分子ERK5、ERK1/2等在脂肪細(xì)胞分化中發(fā)揮重要調(diào)控作用。因此本文著重闡述了靶向MAPK調(diào)控脂肪細(xì)胞分化的miRNAs，有助于我們對(duì)脂肪細(xì)胞分化機(jī)制的進(jìn)一步探索和研究。

4 靶向MAPK信號(hào)通路調(diào)節(jié)脂肪細(xì)胞分化的miRNAs

4.1 miRNA-143靶向MAP2K2-ERK5

C. Esau等[34]利用反義RNA寡核苷酸(ASOs)轉(zhuǎn)染技術(shù)以及芯片技術(shù)分析了參與人類脂肪細(xì)胞分化的miRNAs。結(jié)果顯示miR-143在人成熟脂肪細(xì)胞和前體脂肪細(xì)胞中存在顯著差異表達(dá)，且在成熟脂肪細(xì)胞中上調(diào)，說(shuō)明miR-143可能促進(jìn)脂肪細(xì)胞分化。此外Esau等還發(fā)現(xiàn)ERK5的蛋白表達(dá)水平在轉(zhuǎn)染有miR-143 ASO的細(xì)胞中明顯高于對(duì)照組，推測(cè)ERK5可能是miR-143的一個(gè)作用靶基因。在Esau研究的基礎(chǔ)上，L. Chen等[35]首次證明了miR-143對(duì)脂肪干細(xì)胞(ADSC)成脂分化的作用不是持續(xù)不變的，而是取決于發(fā)揮作用的階段，即miR-143在ADSC分化的克隆增殖期產(chǎn)生抑制作用，在生長(zhǎng)停滯期或終末分化期發(fā)揮促進(jìn)作用。為了探索其機(jī)制，L. Chen等利用生物信息學(xué)方法和試驗(yàn)方法證實(shí)MAP2K2是miR-143調(diào)節(jié)脂肪細(xì)胞分化的一個(gè)直接靶基因，而其下游的ERK5是miR-143的間接靶基因[35]，所以推測(cè)在ADSC克隆增殖期miR-143抑制了MAP2K2的表達(dá)，導(dǎo)致其下游ERK5活性降低，脂肪細(xì)胞分化受到抑制，而在終末分化期，miR-143抑制了MAP2K2-ERK5的活性后，ERK5介導(dǎo)的PPARγ磷酸化減少，從而促進(jìn)了脂肪細(xì)胞分化。綜上可得miR-143通過(guò)調(diào)節(jié)MAP2K2-ERK5通路在脂肪細(xì)胞分化過(guò)程中扮演重要角色。

4.2 miRNA-21靶向SPRY2-ERK-MAPK

miR-21是脂肪細(xì)胞分化的正調(diào)控因子[36]，其調(diào)控機(jī)制不斷地被探索，近年來(lái)也有研究證明miR-21靶向TGF-β信號(hào)通路中的TGFRB2來(lái)調(diào)節(jié)脂肪細(xì)胞分化[37]。在此基礎(chǔ)上Y. Mei等[38]發(fā)現(xiàn)ERK-MAPK信號(hào)通路也是miR-21的靶標(biāo)，在MSC成脂分化的早期過(guò)表達(dá)miR-21，發(fā)現(xiàn)脂肪細(xì)胞分化標(biāo)志基因PPARγ和ap2的表達(dá)水平顯著增加，且ERK-MAPK信號(hào)通路的活性顯著增強(qiáng)[38]，由于ERK-MAPK通路在脂肪細(xì)胞分化早期發(fā)揮促進(jìn)作用[13]，故miR-21可能與ERK-MAPK共同參與促進(jìn)了MSC成脂分化。生物信息學(xué)方法預(yù)測(cè)可知miR-21的靶基因大多與ERK-MAPK通路有關(guān)，利用轉(zhuǎn)染技術(shù)和熒光素酶報(bào)告分析法證明SPRY2是miR-21的直接靶基因[38]，SPRY2蛋白是SPRY家族的成員，是ERK-MAPK通路的負(fù)調(diào)控者[39]，故miR-21是通過(guò)直接抑制SPRY2活性來(lái)調(diào)節(jié)和維持ERK-MAPK通路活性，且三者構(gòu)成一個(gè)反饋回路網(wǎng)絡(luò)，共同促進(jìn)脂肪細(xì)胞分化。

4.3 miR-375靶向ERK1/2

研究表明，miR-375參與了胰島素分泌的調(diào)節(jié)[40]，且對(duì)于維持內(nèi)環(huán)境穩(wěn)態(tài)以及抑制神經(jīng)突細(xì)胞分化有著非常重要的作用[41-43]。近來(lái)H. Y. Ling等[44]探索了miR-375在脂肪細(xì)胞分化中的作用，芯片技術(shù)檢測(cè)結(jié)果顯示miR-375在3T3-L1成熟脂肪細(xì)胞中上調(diào)，且在3T3-L1前體脂肪細(xì)胞中過(guò)表達(dá)miR-375后發(fā)現(xiàn)脂肪細(xì)胞分化標(biāo)志基因PPARγ、C/EBPα、aP2表達(dá)量顯著增加，說(shuō)明miR-375可以促進(jìn)3T3-L1脂肪細(xì)胞的分化。此外H. Y. Ling等[44]還發(fā)現(xiàn)miR-375的過(guò)表達(dá)抑制ERK1/2的磷酸化，然而敲除 miR-375可以顯著促進(jìn)ERK1/2磷酸化，且降低了PPARγ、C/EBPα、aP2的表達(dá)量，故推測(cè)ERK1/2介導(dǎo)了miR-375對(duì)脂肪細(xì)胞分化的調(diào)控。然而由于ERK1/2的表達(dá)量不受miR-375影響，故miR-375調(diào)控脂肪細(xì)胞分化是直接靶向ERK1/2還是其他未知的靶基因仍有待探索。

4.4 其他通過(guò)MAPK調(diào)控脂肪細(xì)胞分化的miRNAs

miR-14可以調(diào)控胰島細(xì)胞的內(nèi)分泌，調(diào)節(jié)果蠅體內(nèi)的脂肪代謝及能量代謝[45]，P. Xu等[46]發(fā)現(xiàn)在果蠅中抑制miR-14的表達(dá)會(huì)導(dǎo)致脂肪細(xì)胞中脂滴數(shù)和甘油三酯積累的增加，即miR-14對(duì)脂肪代謝有抑制作用，且是通過(guò)靶基因p38和MAPK實(shí)現(xiàn)的[46]。此外， miR-27a和miR-27b也可以通過(guò)間接影響MAPK信號(hào)通路的信號(hào)轉(zhuǎn)導(dǎo)參與調(diào)控脂肪細(xì)胞的分化. MiR-27a/b是脂肪細(xì)胞分化的負(fù)調(diào)控因子[47], T. Kang等[48]利用生物信息學(xué)方法和熒光素酶檢測(cè)試驗(yàn)證明抑制素(PHB)是miR-27a和miR-27b的靶基因，PHB在脂肪細(xì)胞中高度表達(dá)，與脂肪細(xì)胞分化有密切的關(guān)系[49]。在3T3-L1細(xì)胞中過(guò)表達(dá)PHB抑制了胰島素誘導(dǎo)的成脂分化，但是在胰島素缺乏的情況下，PHB會(huì)通過(guò)上調(diào)MAPK/ERK信號(hào)通路促進(jìn)脂肪細(xì)胞分化。在脂肪來(lái)源干細(xì)胞(ASC)中轉(zhuǎn)染miR-27使得PHB沉默，脂肪細(xì)胞的分化就會(huì)被抑制[50]，推測(cè)在胰島素缺乏的情況下，PHB可以作用于下游的MAPK信號(hào)通路來(lái)促進(jìn)脂肪的分化，而miR-27a和miR-27b通過(guò)抑制PHB間接靶向MAPK通路抑制脂肪細(xì)胞分化。此外，miR-448[51]和miR-378[52]也可以通過(guò)直接或間接調(diào)節(jié)MAPK信號(hào)分子來(lái)調(diào)控脂肪細(xì)胞分化。綜上所述，miR-143、miR-21、miR-375、miR-27a/b等miRNAs通過(guò)直接或間接靶向MAPK信號(hào)通路中的相關(guān)分子，參與了脂肪細(xì)胞分化的調(diào)控(表1)。

圖1 MSCs成脂分化過(guò)程中的調(diào)控因素Fig.1 The regulatory factors during adipogenic differentiation of MSCs

表1 通過(guò)靶向MAPK信號(hào)通路中的靶基因調(diào)節(jié)脂肪細(xì)胞分化的miRNAs

Table 1 miRNAs in the regulation of adipocyte differentiation via targeting genes in MAPK signaling pathway

miRNAmiRNA靶基因Targetgene功能Function細(xì)胞模型Cellmodel物種Species參考文獻(xiàn)ReferencesmiR-143ERK5、MAP2K2-+3T3L1、ADSCsH、M[35]miR-21SPRY2、MAPK+MSC、3T3L1M[38]miR-375ERK、MAPK+3T3L1M[44]miR-14p38、MAPK-Drosophila[46]miR-27(a、b)PHB、MAPK-ADSCs、3T3L1H、M[48-50]miR-448KLF5、MAPK-3T3L1M[51]miR-378MAPK1、MAPK+3T3L1M[52]

+.miRNA促進(jìn)脂肪細(xì)胞分化; -.miRNA抑制脂肪細(xì)胞分化；- +.miRNA在脂肪細(xì)胞分化的早期發(fā)揮抑制作用，而在分化后期發(fā)揮促進(jìn)作用。H.人；M.小鼠

+. Promoting adipocyte differentiation by miRNA; -. Inhibiting adipocyte differentiation by miRNA ; - +. Inhibiting effect and promoting effect, respectively during the early stage and late stage of adipocyte differentiation by miRNA. H. Human; M. Mouse

5 展望

肥胖、Ⅱ型糖尿病等代謝性疾病已經(jīng)成為危害人類健康的殺手，其病理過(guò)程與脂肪細(xì)胞分化失調(diào)及脂代謝紊亂密切相關(guān)，目前脂肪細(xì)胞分化的機(jī)制已經(jīng)成為了研究的熱點(diǎn)。而miRNA對(duì)脂肪細(xì)胞分化的調(diào)控機(jī)制更是吸引了越來(lái)越多的科研工作者。試驗(yàn)證明miRNA可以通過(guò)靶向轉(zhuǎn)錄因子和信號(hào)通路中的關(guān)鍵分子影響脂肪細(xì)胞分化，故針對(duì)特定的miRNA尋找下游靶基因，研究其如何調(diào)控脂肪細(xì)胞分化成為了研究重點(diǎn)。隨著分子生物學(xué)領(lǐng)域的不斷發(fā)展，利用新一代測(cè)序技術(shù)研究miRNA已經(jīng)越來(lái)越受歡迎，該技術(shù)快速、準(zhǔn)確，在發(fā)現(xiàn)新的 miRNA 方面具有突出優(yōu)勢(shì)，且測(cè)序成本逐年降低。本實(shí)驗(yàn)室前期已經(jīng)完成了日本黑毛和牛與荷斯坦牛皮下脂肪組織miRNA的Illumina測(cè)序，日本黑毛和牛與荷斯坦牛同為世界知名牛種，但在脂肪沉積方面二者卻形成了顯著差異，為研究脂肪細(xì)胞分化機(jī)制提供良好的素材。測(cè)序結(jié)果共鑒定出17個(gè)差異表達(dá)的已知miRNAs，以及15個(gè)新的miRNAs，對(duì)差異表達(dá)miRNAs的靶基因進(jìn)行KEGG Pathway富集分析，發(fā)現(xiàn)某些差異表達(dá)miRNAs可能通過(guò)靶向甘油磷脂代謝，脂肪酸代謝及PPAR[53]等脂肪細(xì)胞分化相關(guān)信號(hào)通路中的重要基因調(diào)節(jié)了牛脂肪細(xì)胞分化或脂肪代謝，影響了牛的脂肪沉積，為研究脂肪代謝疾病提供有用的信息。

影響脂肪細(xì)胞分化的信號(hào)通路非常多，MAPK是其中較關(guān)鍵的一個(gè)通路，此外pRB-E2F[54]、Wnt[55]以及本試驗(yàn)中鑒定出來(lái)的PPAR信號(hào)通路也在脂肪細(xì)胞分化中發(fā)揮了重要的作用，這些通路之間存在廣泛的“cross talk”，且與miRNA形成一個(gè)龐大的網(wǎng)絡(luò)共同調(diào)控脂肪細(xì)胞分化，本文著重闡述了靶向MAPK信號(hào)通路調(diào)節(jié)脂肪細(xì)胞分化的miRNAs，希望有助于調(diào)控網(wǎng)絡(luò)的研究，有助于miRNA調(diào)控脂肪細(xì)胞分化機(jī)制的闡明，為防治人類肥胖及其相關(guān)疾病提供新的靶點(diǎn)。目前，miRNA已經(jīng)被用于研發(fā)新一代治療疾病的藥物。Santaris醫(yī)藥公司進(jìn)行了靶向miRNA藥物的首次人類臨床試驗(yàn)，他們將SPC3649，一種miR-122的反義鎖核苷酸(locked nucleic acid,LNA)用于丙型肝炎的治療，反義鎖核苷酸能夠沉默相關(guān)的miRNAs[56]，miR-122可以影響丙型肝炎病毒的復(fù)制，也可以調(diào)控膽固醇的合成[57]，基于這些特點(diǎn)miR-122已經(jīng)成為了第一代基于miRNA治療代謝性疾病的發(fā)展對(duì)象，盡管安全、有效。但是靶向miRNA的藥物治療仍然處于研究的初期，每次藥物試驗(yàn)非常昂貴且失敗風(fēng)險(xiǎn)很大，故將靶向miRNA藥物應(yīng)用于臨床仍需很大的努力。

未來(lái)miRNA調(diào)控脂肪細(xì)胞分化機(jī)制的研究已經(jīng)不僅僅局限于對(duì)下游靶基因的尋找和驗(yàn)證，其上游的轉(zhuǎn)錄因子、細(xì)胞因子以及環(huán)境因素等也逐漸受到學(xué)者們的關(guān)注，miRNA與其下游的靶基因、上游的轉(zhuǎn)錄因子和細(xì)胞因子等構(gòu)成了復(fù)雜的網(wǎng)絡(luò)共同發(fā)揮調(diào)控作用。隨著研究的深入，miRNA調(diào)控脂肪細(xì)胞分化的機(jī)制會(huì)越來(lái)越清楚，再加上靶向miRNA藥物的治療技術(shù)日趨成熟，相信不久以后利用miRNA抵御和治療肥胖將成為現(xiàn)實(shí)。

[1] GUILHERME A, VIRBASIUS J V, PURI V, et al. Adipocyte dysfunctions linking obesity to insulin resistance and type 2 diabetes[J].NatRevMolCellBiol, 2008, 9(5): 367-377.

[2] ABOOUF M A, HAMDY N M, AMIN A I, et al. Genotype screening of APLN rs3115757 variant in Egyptian women population reveals an association with obesity and insulin resistance[J].DiabetesResClinPract, 2015, 109(1): 40-47.

[3] CHEN H, XU X, TENG J, et al. CXCR4 inhibitor attenuates allergen-induced lung inflammation by down-regulating MMP-9 and ERK1/2[J].IntJClinExpPathol, 2015, 8(6): 6700-6707.

[4] BAO M H, ZHANG Y W, ZHOU H H. Paeonol suppresses oxidized low-density lipoprotein induced endothelial cell apoptosis via activation of LOX-1/p38MAPK/NF-kappaB pathway[J].JEthnopharmacol, 2013, 146(2): 543-551.

[5] LIU J, CHANG F, LI F, et al. Palmitate promotes autophagy and apoptosis through ROS-dependent JNK and p38 MAPK[J].BiochemBiophysResCommun, 2015, 463(3): 262-267.

[6] HU K H, LI W X, SUN M Y, et al. Cadmium induced apoptosis in MG63 cells by increasing ROS, activation of p38 MAPK and inhibition of ERK 1/2 pathways[J].CellPhysiolBiochem, 2015, 36(2): 642-654.

[7] TURPIN E, MUSCAT A, VATIER C, et al. Carbamazepine directly inhibits adipocyte differentiation through activation of the ERK 1/2 pathway[J].BrJPharmacol, 2013, 168(1): 139-150.

[8] CONSTANT V A, GAGNON A, YARMO M, et al. The antiadipogenic effect of macrophage-conditioned medium depends on ERK1/2 activation[J].Metabolism, 2008, 57(4): 465-472.

[9] GWON S Y, AHN J Y, JUNG C H, et al. Shikonin suppresses ERK 1/2 phosphorylation during the early stages of adipocyte differentiation in 3T3-L1 cells[J].BMCComplementAlternMed, 2013, 13:207.

[10] KWAK D H, LEE J H, KIM D G, et al. Inhibitory effects of hwangryunhaedok-tang in 3T3-L1 adipogenesis by regulation of Raf/MEK1/ERK1/2 pathway and PDK1/Akt phosphorylation[J].EvidBasedComplementAlternatMed, 2013, 2013: 413906.

[11] LIAO Q C, LI Y L, QIN Y F, et al. Inhibition of adipocyte differentiation by phytoestrogen genistein through a potential downregulation of extracellular signal- regulated kinases 1/2 activity[J].JCellBiochem, 2008, 104(5): 1853-1864.

[12] CHOI J S, KIM J H, ALI M Y, et al. Anti-adipogenic effect of epiberberine is mediated by regulation of the Raf/MEK1/2/ERK1/2 and AMPKalpha/Akt pathways[J].ArchPharmRes, 2015, 38(12):2153-2162.

[13] PRUSTY D, PARK B H, DAVIS K E, et al. Activation of MEK/ERK signaling promotes adipogenesis by enhancing peroxisome proliferator-activated receptor gamma(PPAR gamma) and C/EBPalpha gene expression during the differentiation of 3T3-L1 preadipocytes[J].JBiolChem, 2002, 277(48): 46226-46232.

[14] TANABE Y, KOGA M, SAITO M,et al. Inhibition of adipocyte differentiation by mechanical stretching through ERK-mediated downregulation of PPARγ2[J].JCellSci, 2004, 117(Pt 16): 3605-3614.

[15] REGINATO M J, KRAKOW S L, BAILEY S T, et al. Prostaglandins promote and block adipogenesis through opposing effects on peroxisome proliferator-activated receptor gamma[J].JBiolChem, 1998, 273(4): 1855-1858.

[16] BREWSTER J L, DE VALOIR T, DWYER N D, et al. An osmosensing signal transduction pathway in yeast[J].Science, 1993, 259(5102): 1760-1763.

[17] AOUADI M, JAGER J, LAURENT K, et al. p38MAP Kinase activity is required for human primary adipocyte differentiation[J].FEBSLett, 2007, 581(29): 5591-5596.

[18] JI J, ZHU J, HU X, et al. (2S)-7,4'-dihydroxy-8-prenylflavan stimulates adipogenesis and glucose uptake through p38MAPK pathway in 3T3-L1 cells[J].BiochemBiophysResCommun, 2015, 460(3): 578-582.

[19] AOUADI M, LAURENT K, PROT M, et al. Inhibition of p38MAPK increases adipogenesis from embryonic to adult stages[J].Diabetes, 2006, 55(2): 281-289.

[20] TOMINAGA S, YAMAGUCHI T, TAKAHASHI S, et al. Negative regulation of adipogenesis from human mesenchymal stem cells by Jun N-terminal kinase[J].BiochemBiophysResCommun, 2005, 326(2): 499-504.

[21] FENG M, TIAN L, GAN L, et al. Mark4 promotes adipogenesis and triggers apoptosis in 3T3-L1 adipocytes by activating JNK1 and inhibiting p38MAPK pathways[J].BiolCell, 2014, 106(9): 294-307.

[22] ZHU H, GUARIGLIA S, LI W, et al. Role of extracellular signal-regulated kinase 5 in adipocyte signaling[J].JBiolChem, 2014, 289(9): 6311-6322.

[23] SHARMA G, GOALSTONE M L. Dominant negative FTase (DNFTalpha) inhibits ERK5, MEF2C and CREB activation in adipogenesis[J].MolCellEndocrinol, 2005, 245(1-2): 93-104.

[24] VALENCIA-SANCHEZ M A, LIU J, HANNON G J, et al. Control of translation and mRNA degradation by miRNAs and siRNAs[J].GenesDev, 2006, 20(5): 515-524.

[25] BARCKMANN B, SIMONELIG M. Control of maternal mRNA stability in germ cells and early embryos[J].BiochimBiophysActa, 2013, 1829(6-7): 714-724.

[26] LOH B, JONAS S, IZAURRALDE E. The SMG5-SMG7 heterodimer directly recruits the CCR4-NOT deadenylase complex to mRNAs containing nonsense codons via interaction with POP2[J].GenesDev, 2013, 27(19): 2125-2138.

[27] XUE Z, ZHAO J, NIU L, et al. Up-regulation of miR-300 promotes proliferation and invasion of osteosarcoma by targeting BRD7[J].PLoSOne, 2015, 10(5): e0127682.

[28] VIMALRAJ S, SELVAMURUGAN N. Regulation of proliferation and apoptosis in human osteoblastic cells by microRNA-15b[J].IntJBiolMacromol, 2015, 79:490-497.

[29] ZHAO M, SUN L, CHEN S, et al. Borna disease virus infection impacts microRNAs associated with nervous system development, cell differentiation, proliferation and apoptosis in the hippocampi of neonatal rats[J].MolMedRep, 2015, 12(3):3697-3703.

[30] 賈夏麗,潘洋洋,喬利英, 等. 脂肪分化相關(guān)信號(hào)通路及microRNA調(diào)節(jié)研究進(jìn)展[J]. 畜牧獸醫(yī)學(xué)報(bào), 2015,46(4): 518-525.

JIA X L, PAN Y Y, QIAO L Y, et al. Research progress in signaling pathways and microRNA regulation of adipocyte differentiation[J].ActaVeterinariaetZootechnicaSinica, 2015, 46(4): 518-525.(in Chinese)

[31] TANG Y F, ZHANG Y, LI X Y, et al. Expression of miR-31, miR-125b-5p, and miR-326 in the adipogenic differentiation process of adipose-derived stem cells[J].OMICS, 2009, 13(4): 331-336.

[32] KIM S Y, KIM A Y, LEE H W, et al. miR-27a is a negative regulator of adipocyte differentiation via suppressing PPARgamma expression[J].BiochemBiophysResCommun, 2010, 392(3): 323-328.

[33] LEE E K, LEE M J, ABDELMOHSEN K, et al. miR-130 suppresses adipogenesis by inhibiting peroxisome proliferator-activated receptor gamma expression[J].MolCellBiol, 2011, 31(4): 626-638.

[34] ESAU C, KANG X, PERALTA E, et al. MicroRNA-143 regulates adipocyte differentiation[J].JBiolChem, 2004, 279(50): 52361-52365.

[35] CHEN L, HOU J, YE L, et al. MicroRNA-143 regulates adipogenesis by modulating the MAP2K5-ERK5 signaling[J].SciRep, 2014, 4:3819.

[36] SEEGER T, FISCHER A, MUHLY- REINHOLZ M, et al. Long-term inhibition of miR-21 leads to reduction of obesity in db/db mice[J].Obesity(SilverSpring), 2014, 22(11): 2352-2360.

[37] KIM Y J, HWANG S J, BAE Y C, et al. MiR-21 regulates adipogenic differentiation through the modulation of TGF-beta signaling in mesenchymal stem cells derived from human adipose tissue[J].StemCells, 2009, 27(12): 3093-3102.

[38] MEI Y, BIAN C, LI J, et al. miR-21 modulates the ERK-MAPK signaling pathway by regulating SPRY2 expression during human mesenchymal stem cell differentiation[J].JCellBiochem, 2013, 114(6): 1374-1384.

[39] CASCI T, VINS J, FREEMAN M. Sprouty, an intracellular inhibitor of Ras signaling[J].Cell, 1999, 96(5): 655-665.

[40] POY M N, ELIASSON L, KRUTZFELDT J, et al. A pancreatic islet-specific microRNA regulates insulin secretion[J].Nature, 2004, 432(7014): 226-230.

[41] LYNN F C. Meta-regulation: microRNA regulation of glucose and lipid metabolism[J].TrendsEndocrinolMetab, 2009, 20(9): 452-459.

[42] EL OUAAMARI A, BAROUKH N, MARTENS G A, et al. miR-375 targets 3′-phosphoinositide-dependent protein kinase-1 and regulates glucose-induced biological responses in pancreatic beta-cells[J].Diabetes, 2008, 57(10): 2708-2717.

[43] ABDELMOHSEN K, HUTCHISON E R, LEE E K, et al. miR-375 inhibits differentiation of neurites by lowering HuD levels[J].MolCellBiol, 2010, 30(17): 4197-4210.

[44] LING H Y, WEN G B, FENG S D, et al. MicroRNA-375 promotes 3T3-L1 adipocyte differentiation through modulation of extracellular signal-regulated kinase signalling[J].ClinExpPharmacolPhysiol, 2011, 38(4): 239-246.

[45] VARGHESE J, LIM S F, COHEN S M. Drosophila miR-14 regulates insulin production and metabolism through its target, sugarbabe[J].GenesDev, 2010, 24(24): 2748-2753.

[46] XU P, VERNOOY S Y, GUO M, et al. The Drosophila microRNA Mir-14 suppresses cell death and is required for normal fat metabolism[J].CurrBiol, 2003, 13(9): 790-795.

[47] 陳 晨,胡雄貴,朱 吉, 等. 豬脂肪發(fā)育相關(guān)miRNAs的功能研究進(jìn)展[J]. 畜牧獸醫(yī)學(xué)報(bào), 2015,46(12): 2117-2126.

CHEN C, HU X G, ZHU J, et al. Progress on the research of miRNAs associated with fat development in pigs[J].ActaVeterinariaetZootechnicaSinica, 2015,46(12): 2117-2126.(in Chinese)

[48] KANG T, LU W, XU W, et al. MicroRNA-27 (miR-27) targets prohibitin and impairs adipocyte differentiation and mitochondrial function in human adipose-derived stem cells[J].JBiolChem, 2013, 288(48): 34394-34402.

[49] ANDE S R, XU Z, GU Y, et al. Prohibitin has an important role in adipocyte differentiation[J].IntJObes(Lond), 2012, 36(9): 1236-1244.

[50] LIN Q, GAO Z, ALARCON R M, et al. A role of miR-27 in the regulation of adipogenesis[J].FEBSJ, 2009, 276(8): 2348-2358.

[51] KINOSHITA M, ONO K, HORIE T, et al. Regulation of adipocyte differentiation by activation of serotonin (5-HT) receptors 5-HT2AR and 5-HT2CR and involvement of microRNA-448 mediated repression of KLF5[J].MolEndocrinol, 2010, 24(10): 1978-1987.

[52] HUANG N, WANG J, XIE W, et al. MiR-378a-3p enhances adipogenesis by targeting mitogen-activated protein kinase 1[J].BiochemBiophysResCommun, 2015, 457(1): 37-42.

[53] PARK H J, YUN J, JANG S H, et al. Coprinus comatus cap inhibits adipocyte differentiation via regulation of PPARγ and Akt signaling pathway[J].PLoSOne, 2014, 9(9): e105809.

[54] WANG Q, LI Y C, WANG J, et al. miR-17-92 cluster accelerates adipocyte differentiation by negatively regulating tumor-suppressor Rb2/p130[J].ProcNatlAcadSciUSA, 2008, 105(8): 2889-2894.

[55] CHEN C, PENG Y, PENG Y, et al. miR-135a-5p inhibits 3T3-L1 adipogenesis through activation of canonical Wnt/beta-catenin signaling[J].JMolEndocrinol, 2014, 52(3): 311-320.

[57] WAHID F, SHEHZAD A, KHAN T, et al. MicroRNAs: synthesis, mechanism, function, and recent clinical trials[J].BiochimBiophysActa, 2010, 1803(11): 1231-1243.

(編輯 郭云雁)

Regulation of Adipocyte Differentiation via microRNAs Targeting MAPK Signaling Pathway

ZHANG Xiu-xiu, GUO Yun-tao, HUANG Wan-long, LI Yuan, MIAO Xiang-yang*

(InstituteofAnimalScience,ChineseAcademyofAgriculturalSciences,Beijing100193,China)

Adipocyte differentiation is a complicated process in which pluripotent mesenchymal stem cells (MSCs) differentiate into mature adipocytes. The process of adipocyte differentiation is strictly regulated by a number of transcription factors, hormones and signaling pathway molecules.Invivoandinvitroresearch has revealed that microRNAs (miRNAs) are also involved in adipocyte differentiation and play a role by targeting transcription factors and key signaling molecules. MAPK signaling pathway is one of important signaling systems which transduce the extracellular signal to intracellular space and cause cell response. The studies showed that, miRNAs can target certain genes in MAPK and affect its signal transduction, thus regulating adipocyte differentiation. Therefore, a summary of researches how miRNAs change the signal transduction of MAPK pathway and regulate adipocyte differentiation was performed in order to further understand the adipocyte differentiation mechanism and offer new ideas for curing the fat-associated diseases.

microRNA; MAPK signaling pathway; target gene; adipocyte differentiation

10.11843/j.issn.0366-6964.2016.11.002

2016-03-01

轉(zhuǎn)基因生物新品種培育科技重大專項(xiàng)(2009ZX08008-004B；2008ZX08008-003)；國(guó)家“863”計(jì)劃項(xiàng)目(2008AA10Z140)；國(guó)家自然科學(xué)基金項(xiàng)目(30571339)；中國(guó)農(nóng)業(yè)科學(xué)院農(nóng)業(yè)科技創(chuàng)新項(xiàng)目(ASTIP-IAS05)；國(guó)家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(“973”計(jì)劃)(2015CB943100)；中國(guó)農(nóng)業(yè)科學(xué)院創(chuàng)新基金項(xiàng)目(2004-院-1)；中央級(jí)公益性科研院所基本科研業(yè)務(wù)費(fèi)專項(xiàng)資金項(xiàng)目(2013ywf-yb-5；2013ywf-zd-2)

張秀秀(1989-)，女，山西大同人，碩士，主要從事轉(zhuǎn)基因與細(xì)胞工程研究，E-mail:13261953358@163.com

*通信作者：苗向陽(yáng)，研究員，博士，博士生導(dǎo)師，主要從事基因工程與功能基因組學(xué)及轉(zhuǎn)基因動(dòng)物研究，E-mail：mxy32@sohu.com

S813.2

A

0366-6964(2016)11-2159-08