3βHSD/17βHSD介导雄激素调控公猪脂肪沉积的分子机理解析

The male pig will increase fat deposition after castration, which will reduce pig production benefit. Currently, the molecular mechanism of fat deposition caused by low androgen is still unclear. Our preliminary study focus on the regulation pattern of 3βHSD and 17βHSD gene, the key enzymes in androgen metabolism, between castrated and intact male pigs, and the metabolic patterns of androgen in porcine liver primary cells was also investigated. Based on our previous results, the aim of this study is going to further investigate the androgen mediating the fat deposition by 3βHSD/17βHSD-dependent pathway in male pigs. RNA-Seq and iTRAQ genomic data were used to double identify the differentially expressed genes of porcine preadipocytes in castrated and intact full-sib pair male pigs. Subsequently, the results from in vivo and in vitro were combined for elucidating the molecular mechanism involved in androgen mediating the adipocyte differentiation by 3βHSD/17βHSD-dependent pathway; Finally, above results were integrated into the metabonomic data (from TOF LC-MS/MS) to investigate the metabolic pattern of testosterone in porcine preadipocytes. Furthermore, with the Loss of function strategy, the relationship and signal pathway between key candidate genes and 3βHSD/17βHSD were identified in porcine preadipocytes with testosterone treatment. In general, above results will provide the evidence for dissecting the increasing of fat deposition caused by androgen absence and improving lean pork production; This study will also provide some model data for treating obesity in man with low testosterone.

去势会导致公猪体内脂肪沉积增加，从而降低养猪生产效益。目前有关去势公猪低雄激素水平导致脂肪沉积增加的分子机制仍不清楚。申请人前期分析了去势和非去势公猪中雄激素代谢关键酶3βHSD与17βHSD基因的表达调控，并初步分析了猪肝脏原代细胞中雄激素的代谢模式。本项目拟在前期基础上进一步开展3βHSD/17βHSD介导的猪脂肪沉积研究。选取全同胞去势和非去势组公猪，通过多重表达组学鉴定雄激素缺乏条件下猪前脂肪细胞分化差异表达基因，进而基于功能组学联合分析3βHSD/17βHSD介导的性激素抑制脂肪分化信号通路，并整合性激素在猪前脂肪细胞中的TOF质谱代谢组学数据，综合分析并验证3βHSD/17βHSD介导的雄激素调控脂肪沉积的关键基因和信号通路。上述研究将为解析雄激素调控脂肪沉积以及猪瘦肉产量的提高提供理论依据；也可为解析低睾酮男性肥胖研究提供模型数据。

去势会导致公猪体内脂肪沉积增加，降低产肉量，从而降低养猪生产效益。目前有关去势公猪脂肪沉积的分子机理仍不清楚。项目组在前期初步分析了猪体内肝脏原代细胞中雄激素的代谢模式，在此基础上本项目进一步分析了去势和非去势全同胞配对大白猪背膘和板油组织全转录组表达谱，鉴定了去势和非去势群体间脂肪组织差异表达基因，并以差异表达基因为核心元构建了LncRNA、mRNA与miRNA互作网络调控图。项目组进而采用多组学分析筛选验证与雄激素调控脂肪沉积相关的功能候选基因，并在细胞水平上探究候选基因HSD11B1、SGK1、SPP1和miRNA（ssc-miR-4331、 ssc-miR-124a 、novel-miR-659）在雄激素调控脂肪沉积中的作用模式。利用外源添加雄激素细胞模型模拟去势和非去势猪体内激素情况，构建了激素到基因到表型的分子调控网络，最终解析了miR-4331、novel-miR-659、ssc-miR-124a分别通过靶向抑制HSD11B1、SPP1、SGK1基因影响雄激素调控脂肪沉积的分子机制。上述猪脂肪沉积性状关键功能基因的筛选鉴定以及基因表达调控模式的清晰阐述，为养猪生产中猪脂肪性状的选育提供了分子基础，同时也可为人类因雄激素减少导致的肥胖研究提供医学模型。