賈振偉

(內(nèi)蒙古民族大學(xué)動(dòng)物科技學(xué)院,黃牛遺傳繁育研究所,內(nèi)蒙古通遼 028043)

賈振偉

(內(nèi)蒙古民族大學(xué)動(dòng)物科技學(xué)院,黃牛遺傳繁育研究所,內(nèi)蒙古通遼 028043)

動(dòng)物卵母細(xì)胞含有大量的脂肪酸,脂肪酸通過-氧化能夠?yàn)槁涯讣?xì)胞成熟發(fā)育提供能量。許多研究表明,脂肪酸-氧化促進(jìn)了卵母細(xì)胞成熟和受精后早期胚胎發(fā)育。基于此,本文綜述了卵母細(xì)胞內(nèi)脂肪酸的種類、來源,脂肪酸-氧化和調(diào)控及其對(duì)卵母細(xì)胞成熟發(fā)育的影響。

卵母細(xì)胞;脂肪酸;-氧化;體外成熟

動(dòng)物卵母細(xì)胞體內(nèi)生長發(fā)育期間逐漸獲得發(fā)育能力,而且,卵母細(xì)胞發(fā)育潛能與自身及周圍的顆粒細(xì)胞能量代謝密切相關(guān)[1-2]。目前,關(guān)于動(dòng)物卵母細(xì)胞葡萄糖、乳酸及丙酮酸等碳水化合物的能量代謝研究較多[3-4],卵母細(xì)胞內(nèi)含有較多數(shù)量的脂肪酸,脂肪酸通過-氧化能夠提供大量ATP,但對(duì)其在卵母細(xì)胞內(nèi)氧化代謝的研究關(guān)注較少。通過對(duì)卵母細(xì)胞脂肪酸-氧化及其對(duì)卵母細(xì)胞成熟發(fā)育影響的深入研究,有利于科學(xué)合理的調(diào)控卵母細(xì)胞脂肪酸利用、促進(jìn)卵母細(xì)胞成熟發(fā)育,進(jìn)而提高動(dòng)物的繁殖力。

1 卵母細(xì)胞脂肪酸的種類及來源

卵母細(xì)胞脂肪酸主要以甘油三酯的形式儲(chǔ)存在胞質(zhì)內(nèi)的中性脂滴中,另外也以部分磷脂、膽固醇及游離脂肪酸的形式存在。動(dòng)物卵母細(xì)胞及卵泡液內(nèi)脂肪酸主要為棕櫚酸、硬脂酸、油酸、亞麻酸及亞油酸[5-6]。動(dòng)物脂肪組織細(xì)胞分解釋放或日糧提供的脂肪酸經(jīng)血液循環(huán)后進(jìn)入卵泡液被顆粒細(xì)胞吸收,顆粒細(xì)胞將其酯化為中性脂滴后運(yùn)轉(zhuǎn)至卵母細(xì)胞,是卵母細(xì)胞脂滴的主要來源[7]。值得注意的是,有研究表明,卵母細(xì)胞也能將外源的脂肪酸吸收酯化為脂滴的組分,進(jìn)而影響脂質(zhì)貯備[8]。

2 卵母細(xì)胞脂肪酸β-氧化

Dunning等[9]研究發(fā)現(xiàn),脂肪酸通過-氧化為卵母細(xì)胞成熟發(fā)育提供能量。卵母細(xì)胞成熟期間脂肪酸-氧化發(fā)生在線粒體內(nèi),脂肪酸進(jìn)入線粒體前在脂酰輔酶A合成酶的作用下被催化成為脂酰輔酶A?；罨闹舅?脂酰輔酶A)在位于線粒體內(nèi)膜上的肉堿脂酰轉(zhuǎn)移酶1(CPT1)作用下與肉堿結(jié)合后被轉(zhuǎn)運(yùn)至線粒體,然后在位于線粒體內(nèi)膜上的CPT2的作用下除去肉堿,脂肪酸進(jìn)入線粒體基質(zhì)后通過-氧化經(jīng)三羧酸循環(huán)和電子傳遞鏈為卵母細(xì)胞成熟發(fā)育提供ATP。

3 卵母細(xì)胞脂肪酸β-氧化的調(diào)控

此外,Hardie等[15]發(fā)現(xiàn),乙酰輔酶A羧化酶(acetyl coA carboxylase,ACAC)能夠抑制CPT1的活性阻滯活化的脂肪酸進(jìn)入線粒體,同時(shí)促進(jìn)長鏈脂肪酸合成。但當(dāng)卵母細(xì)胞內(nèi)AMP/ADP增加時(shí),高濃度的AMP將激活其依賴的蛋白激酶 (AMP-activated protein kinase,AMPK),激活的AMPK通過磷酸化ACAC化使其滅活,促進(jìn)脂肪酸進(jìn)入線粒體、增強(qiáng)-氧化。

4 脂肪酸β-氧化對(duì)卵母細(xì)胞成熟發(fā)育的影響

由于不同物種卵母細(xì)胞的脂滴含量存在差異, Paczkowski等[21]比較研究了抑制脂肪酸-氧化對(duì)豬、牛及小鼠卵母細(xì)胞體外成熟的影響,結(jié)果表明,脂肪酸-氧化對(duì)卵母細(xì)胞核成熟的影響與脂肪酸含量有關(guān)。豬和牛卵母細(xì)胞脂肪含量較高,較低濃度的CPT1抑制劑阻滯了減數(shù)分裂,說明脂肪酸-氧化是其成熟過程必需的代謝通路。小鼠卵母細(xì)胞脂肪含量較少,高濃度的CPT1抑制劑能夠阻滯減數(shù)分裂,揭示小鼠卵母細(xì)胞成熟期間對(duì)脂肪酸-氧化代謝通路依賴的程度不如豬和牛等大家畜。而且,Paczkowski等[21]研究也發(fā)現(xiàn),卵母細(xì)胞脂肪酸-氧化異常后影響了脂肪酸-氧化、糖酵解及氧化應(yīng)激相關(guān)信號(hào)通路基因表達(dá),其中豬和小鼠卵母細(xì)胞在脂肪酸-氧化異常的情況下,脂肪酸-氧化、糖酵解及氧化應(yīng)激相關(guān)信號(hào)通路基因表達(dá)下調(diào),相反牛卵母細(xì)胞以上基因表達(dá)上調(diào),可能牛卵母細(xì)胞存在適應(yīng)機(jī)制。

Paczkowski等[22]研究發(fā)現(xiàn),小鼠卵母細(xì)胞脂肪酸-氧化異常后導(dǎo)致脂肪酸-氧化代謝通路相關(guān)基因表達(dá)下降,同時(shí)促進(jìn)了葡萄糖轉(zhuǎn)運(yùn)基因(Glutl)表達(dá),揭示脂肪酸-氧化抑制后可能刺激了葡萄糖的轉(zhuǎn)運(yùn),卵母細(xì)胞啟動(dòng)糖酵解代謝通路滿足成熟期間的能量需要。

5 小結(jié)

卵母細(xì)胞內(nèi)含有不同種類的脂肪酸(包括飽和和不飽和脂肪酸),而且這些脂肪酸對(duì)卵母細(xì)胞成熟發(fā)育的影響存在差異,為優(yōu)化卵母細(xì)胞體外成熟體系,卵母細(xì)胞體外成熟期間同時(shí)補(bǔ)充脂肪酸和L-肉堿對(duì)其成熟發(fā)育的影響尚不明確,需要深入研究。

[1] Preis K A,Seidel Ge J R,Gardner D K.Reduced oxygen concentration improves the developmental competence of mouse oocytes following in vitro maturation[J].Mol Reprod Dev,2007, 74(7):893-903.

[2] Thompson J G,Lane M,Gilchrist R B.Metabolism of the bovine cumulus oocyte complex and influence on subsequent developmental competence[J].Soc Reprod Fertil,2007,64:179-190.

[3] Sutton M L,Gilchrist R B,Thompson J G.Effects of in vivo and in vitro environments on the metabolism of the cumulus-oocyte complex and its influence on oocyte developmental capacity[J]. Hum Reprod Update,2003,9(1):35-48.

[4] Krisher R L,Brad A M,Herrick J R,et al.A comparative analysis of metabolism and viability in porcine oocytes during in vitro maturation[J].Anim Reprod Sci,2007,98(1-2):72-96.

[5] Mcevoy T G,Coull G D,Broadbent P J,et al.Fatty acid composition of lipids in immature cattle,pig and sheep oocytes with intact zona pellucida[J].J Reprod Fertil,2000,118(1): 163-170.

[6] Aardema H,Lolicato F,Van De Lest C H,et al.Bovine cumulus cells protect maturing qocytes from Increased fatty acid levels by massive intracellular lipid storage[J].Biol Reprod,2013, 88(6):1-5.

[7] Ferguson E M,Leese H J.Triglyceride content of bovine oocytes and early embryos[J].J Reprod Fertil,1999,116(2):373-378.

[8] Aardema H,Vos P L,Lolicato F,et al.Oleic acid prevents detrimental effects of saturated fatty acids on bovine oocyte developmental competence[J].Biol Reprod,2011,85(1):62-69.

[9] Dunning K R,Cashman K,Russell D L,et al.-oxidation is essential for mouse oocyte developmental competence and early embryo development[J].Biol Reprod,2010,83(6):909-918.

[10]Valsangkar D,Downs S M.A Requirement for Fatty Acid Oxidation in the Hormone-Induced Meiotic Maturation of Mouse Oocytes[J].Biol Reprod,2013,89(2):1-9.

[11]Ferguson E M,Leese H J.A potential role for triglyceride as an energy source during bovine oocyte maturation and early embryo development[J].Mol Reprod Dev,2006,73(9):1195-201.

[12]Assimacopoulos-Jeannet F,Thumelin S,Roche E,et al.Fatty acids rapidly induce the carnitine palmitoyltransferase Igene in the pancreatic beta-cell line INS-1[J].J Biol Chem,1997, 272:1659-1664.

[13] Desvergne B,WahliW.Peroxisome proliferator-activated receptors:nuclear control of metabolism[J].Endocrine Reviews, 1999,20(5):649-688.

[14]Lehmann J M,Lenhard J M,Oliver B B,et al.Peroxisome proliferator-activated receptors alpha and gamma are activatedby indomethacin and other non-steroidal anti-inflammatory drugs[J].J Biol Chem,1997,272(6):3406-3410.

[15]Hardie D G,Pan D A.Regulation of fatty acid synthesis and oxidation by the AMP-activated protein kinase[J].Biochem Soc Trans,2002,30:1064-1070.

[16]Fan Cy,Pan J,Chu R,et al.Hepatocellular and hepatic peroxisomal alterations in mice with a disrupted peroxisomal fatty acyl-coenzyme A oxidase gene[J].J Biol Chem,1996,271 (40):24698-24710.

[17]Yuan Y,Ida J M,Paczkowski M,et al.Identification of developmental competence-related genes in mature porcine oocytes[J].Mol Reprod Dev,2011,78(8):565-575.

[18]Dunning K R,Anastasi M R,Zhang V J,et al.Regulation of fatty acid oxidation in mouse cumulus-oocyte complexes during maturation and modulation by PPAR agonists[J].PLoS One, 2014,9(2):e87327.

[19]Ferguson E M,Leese H J.A potential role for triglyceride as an energy source during bovine oocyte maturation and early embryo development[J].Mol Reprod Dev,2006,73(9):1195-1201.

[20]Downs S M,Mosey J L,Klinger J.Fatty acid oxidation and meiotic resumption in mouse oocytes[J].Mol Reprod Dev,2009, 76(9):844-853.

[21]Paczkowski M,Silva E,Schoolcraft W B,et al.Comparative importance of fatty acid beta-oxidation to nuclear maturation, gene expression,and glucose metabolism in mouse,bovine,and porcine cumulus oocyte complexes[J].Biol Reprod,2013,88(5): 1-11.

[22]Paczkowski M,Schoolcraft W B,Krisher R L.Fatty acid metabolism during maturation affects glucose uptake and is essential to oocyte competence[J].Reproduction,2014,148(4): 429-439.

[23]Chankitisaku V,Somfai T,Inaba Y,et al.Supplementation of maturation medium with L-carnitine improves cryo-tolerance of bovine in vitro matured oocytes[J].Theriogenology,2013,79(4): 590-598.

[24]Somfai T,Kaneda M,Akagi S,et al.Enhancement of lipid metabolism with L-carnitine during in vitro maturation improves nuclear maturation and cleavage ability of follicular porcine oocytes[J].Reprod Fert Develop,2011,23(7):912-920.

[25]Wu L L,Russell D L,Norman R J,et al.Endoplasmic reticulum (ER)stress in cumulus-oocyte complexes impairs pentraxin-3 secretion,mitochondrial membrane potential(DeltaPsi m),and embryo development[J].Mol Endocrinol,2012,26(4):562-573.

[26]Wu G Q,Jia B Y,Li J J,et al.L-carnitine enhances oocyte maturation and development of parthenogenetic embryos in pigs [J].Theriogenology,2011,76(5):785-793.

[27]You J,Lee J,Hyun S H,et al.L-carnitine treatment during oocyte maturation improves in vitro development of cloned pig embryos by influencing intracellular glutathione synthesis and embryonic gene expression[J].Theriogenology,2012,78(2):235-243.

[28]Dunning K R,Akison L K,Russell D L,et al.Increased betaoxidation and improved oocyte developmental competence in response to l-carnitine during ovarian in vitro follicle development in mice[J].Biol Reprod,2011,85(3):548-555.

[29]Sutton-Mcdowall M L,Feil D,Robker R L,et al.Utilization of endogenous fatty acid stores for energy production in bovine preimplantation embryos[J].Theriogenology,2012,77(8):1632-1641.

[30]Mansour G,Abdelrazik H,Sharma R K,et al.L-carnitine supplementation reduces oocyte cytoskeleton damage and embryo apoptosis induced by incubation in peritoneal fluid from patients with endometriosis[J].Fertil Steril,2009,91(5 Suppl):2079-2086

[31]Miyamoto K,Sato E F,Kasahara E,et al.Effect of oxidative stress during repeated ovulation on the structure and functions of the ovary,oocytes,and their mitochondria[J].Free Radical Bio Med,2010,49(4):674-681.

Research Progress on Beta-Oxidation of Fatty Acids and Its Effect on Oocyte Maturation and Development

JIA Zhen-wei
(Institute of Yellow Cattle Genetics-Breeding and Reproduction,College of Animal Science and Technology,Inner Mongolia University for the Nationalities,Inner Mongolia Tongliao 028000,China)

Animal oocytes contain large amounts of endogenous fatty acid that is capable of generating ATP molecules to support oocyte maturation and development through the process of fatty acid-oxidation.Many researches indicated that fatty acid-oxidation is essential for oocyte maturation and early embryo development.Therefore,this paper reviewed the source and categories of fatty acid,its-oxidation physiological process,some factors regulating its-oxidation,and the effect of promoting its-oxidation on oocyte maturation and development.

oocyte;fatty acids;-oxidation;in viro maturation

S814.2

:A

:0258-7033(2015)13-0090-04

2014-10-16;

2014-11-29

內(nèi)蒙古民族大學(xué)科學(xué)研究基金項(xiàng)目(NMDGP1401);內(nèi)蒙古自治區(qū)自然科學(xué)基金項(xiàng)目(2015MS0304)

賈振偉(1974-),男,遼寧營口人,博士,講師,主要從事配子與胚胎生物技術(shù)研究,E-mail:zhenwei1999@sina.com