Yang Yunqiu, Chen Yongfang, Wang Lijun, Du Min, Zhang Rui, Lu Yao, Pan Shifeng
College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China.
Department of Animal Sciences, Washington State University, Pullman, WA 99163, USA.
Vet Sci. 2025 Apr 17;12(4):375. doi: 10.3390/vetsci12040375.
In the efforts towards germplasm innovation of livestock and poultry, strategies to improve meat quality have faced some increasingly challenging and dynamic concerns. Intramuscular fat (IMF) content and backfat thickness are two important traits contributing to meat quality. MicroRNAs (miRNAs)-a class of endogenous noncoding RNAs maintaining cell homeostasis by inhibiting target gene expression-have been proven as critical regulators of body fat deposition, thus affecting farm animal production. Our previous in vitro and in vivo models of pigs have clarified that miR-130b overexpression can obviously suppress adipogenesis of subcutaneous preadipocytes and lower backfat thickness. However, the way miR-130b regulates proliferation and adipogenesis of primary cultured porcine intramuscular preadipocytes (PIMPA) and the underlying mechanism are still unknown. PIMPA derived from longissimus dorsi muscle were employed to examine the role of miR-130b in proliferation and adipogenesis and to further elucidate its underlying mechanism. Lipid deposition in cytoplasm was evaluated by TG quantification and ORO-staining, and EDU-staining was employed to measure cell proliferation. Adipogenic and proliferation-related gene expression were conducted by qPCR and Western blot. MiR-130b overexpression markedly stimulated proliferation of PIMPA by increasing cell cycle-related gene expression. Furthermore, overexpression of miR-130b significantly inhibited adipogenic differentiation of PIMPA, mainly by inhibiting expression of adipogenic differentiation marker genes PPAR-γ and SREBP1. In addition, we proved that miR-130b significantly inhibited expression of PPAR-γ downstream target genes and ultimately repressed adipogenesis. Ssc-miR-130b accelerated proliferation but inhibited adipogenic differentiation of PIMPA, contributing to an enhanced knowledge of the function of ssc-miR-130b in lipid deposition, and providing potential implications for enhancing pork quality.
在畜禽种质创新的努力中，改善肉质的策略面临着一些日益具有挑战性和动态变化的问题。肌内脂肪（IMF）含量和背膘厚度是影响肉质的两个重要性状。微小RNA（miRNA）——一类通过抑制靶基因表达维持细胞内稳态的内源性非编码RNA——已被证明是体脂沉积的关键调节因子，从而影响家畜生产。我们之前建立的猪的体外和体内模型已经阐明，miR-130b过表达可以明显抑制皮下前体脂肪细胞的脂肪生成并降低背膘厚度。然而，miR-130b调节原代培养的猪肌内前体脂肪细胞（PIMPA）增殖和脂肪生成的方式及其潜在机制仍不清楚。本研究采用取自背最长肌的PIMPA来研究miR-130b在增殖和脂肪生成中的作用，并进一步阐明其潜在机制。通过甘油三酯（TG）定量和油红O染色评估细胞质中的脂质沉积，采用5-乙炔基-2'-脱氧尿苷（EDU）染色测量细胞增殖。通过实时定量聚合酶链反应（qPCR）和蛋白质免疫印迹法检测脂肪生成和增殖相关基因的表达。miR-130b过表达通过增加细胞周期相关基因的表达显著促进PIMPA的增殖。此外，miR-130b过表达显著抑制PIMPA的脂肪生成分化，主要是通过抑制脂肪生成分化标记基因过氧化物酶体增殖物激活受体γ（PPAR-γ）和固醇调节元件结合蛋白1（SREBP1）的表达。此外，我们证明miR-130b显著抑制PPAR-γ下游靶基因的表达并最终抑制脂肪生成。猪miR-130b（ssc-miR-130b）促进PIMPA的增殖但抑制其脂肪生成分化，有助于加深对ssc-miR-130b在脂质沉积中功能的认识，并为提高猪肉品质提供潜在指导。
