miR-503 通过靶向 MafK 抑制皮下前体脂肪细胞的脂肪生成，导致关中黑猪背膘厚度降低。

miR-503 targets MafK to inhibit subcutaneous preadipocyte adipogenesis causing a decrease of backfat thickness in Guanzhong Black pigs.

机构信息

Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China.

出版信息

Meat Sci. 2023 Apr;198:109116. doi: 10.1016/j.meatsci.2023.109116. Epub 2023 Jan 13.

DOI:10.1016/j.meatsci.2023.109116

PMID:36657261

Abstract

Reducing backfat thickness (BFT), determined by subcutaneous fat deposition, is vital in Chinese developed pig breeds. The level of miR-503 in the backfat of Guanzhong Black pigs was found to be lower than that in Large White pigs, implying that miR-503 may be related to BFT. However, the effect and mechanism of miR-503 on adipogenic differentiation in subcutaneous preadipocytes remain unknown. Compared with Large White pigs, the BFT and body fat content of Guanzhong Black pigs were greater, but the level of miR-503 was lower in subcutaneous adipose tissue (SAT) at 180 days of age. Furthermore, miR-503 promoted preadipocyte proliferation by increasing the proportion of S-phase and EdU-positive cells. However, miR-503 inhibited preadipocyte differentiation by downregulating adipogenic gene expression. Mechanistically, miR-503 directly targeted musculoaponeurotic fibrosarcoma oncogene homolog K (MafK) in both proliferating and differentiating preadipocytes to repress adipogenesis. Our findings provide a novel miRNA biomarker for reducing pig BFT levels to improve carcass quality.

摘要

降低背部脂肪厚度（BFT），由皮下脂肪沉积决定，这对中国培育的猪品种至关重要。研究发现，关中黑猪背部脂肪中的 miR-503 水平低于大白猪，表明 miR-503 可能与 BFT 有关。然而，miR-503 对皮下前体脂肪细胞成脂分化的影响及其机制尚不清楚。与大白猪相比，180 日龄时关中黑猪的 BFT 和体脂含量较高，但 SAT 中的 miR-503 水平较低。此外，miR-503 通过增加 S 期和 EdU 阳性细胞的比例促进前体脂肪细胞增殖。然而，miR-503 通过下调脂肪生成基因的表达抑制前体脂肪细胞分化。从机制上讲，miR-503 可直接靶向增殖和分化前体脂肪细胞中的肌动蛋白结合蛋白丝氨酸苏氨酸激酶同源物 K（MafK），抑制脂肪生成。本研究为降低猪 BFT 水平以改善胴体品质提供了一种新的 miRNA 生物标志物。