Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
School of Natural Resources and Environmental Studies, University of Juba, P. O. Box 82, Juba, South Sudan.
BMC Genomics. 2023 Aug 17;24(1):464. doi: 10.1186/s12864-023-09466-3.
Folic acid is a water-soluble B vitamin (B9), which is closely related to the body's immune and other metabolic pathways. The folic acid synthesized by rumen microbes has been unable to meet the needs of high-yielding dairy cows. The incidence rate of subclinical mastitis in dairy herds worldwide ranged between 25%~65% with no obvious symptoms, but it significantly causes a decrease in lactation and milk quality. Therefore, this study aims at exploring the effects of folic acid supplementation on the expression profile of lncRNAs, exploring the molecular mechanism by which lncRNAs regulate immunity in subclinical mastitic dairy cows.
The analysis identified a total of 4384 lncRNA transcripts. Subsequently, differentially expressed lncRNAs in the comparison of two groups (SF vs. SC, HF vs. HC) were identified to be 84 and 55 respectively. Furthermore, the weighted gene co-expression network analysis (WGCNA) and the KEGG enrichment analysis result showed that folic acid supplementation affects inflammation and immune response-related pathways. The two groups have few pathways in common. One important lncRNA MSTRG.11108.1 and its target genes (ICAM1, CCL3, CCL4, etc.) were involved in immune-related pathways. Finally, through integrated analysis of lncRNAs with GWAS data and animal QTL database, we found that differential lncRNA and its target genes could be significantly enriched in SNPs and QTLs related to somatic cell count (SCC) and mastitis, such as MSTRG.11108.1 and its target gene ICAM1, CXCL3, GRO1.
For subclinical mastitic cows, folic acid supplementation can significantly affect the expression of immune-related pathway genes such as ICAM1 by regulating lncRNAs MSTRG.11108.1, thereby affecting related immune phenotypes. Our findings laid a ground foundation for theoretical and practical application for feeding folic acid supplementation in subclinical mastitic cows.
叶酸是一种水溶性 B 族维生素（B9），与机体的免疫等代谢途径密切相关。反刍动物瘤胃微生物合成的叶酸已不能满足高产奶牛的需要。全世界奶牛隐性乳房炎的发病率在 25%~65%之间，没有明显的症状，但它会显著导致泌乳量和牛奶质量下降。因此，本研究旨在探讨叶酸补充对长链非编码 RNA（lncRNA）表达谱的影响，探索 lncRNA 调节隐性乳房炎奶牛免疫的分子机制。
共鉴定出 4384 个 lncRNA 转录本。随后，在两组（SF 与 SC、HF 与 HC）的比较中鉴定出差异表达的 lncRNA 分别为 84 个和 55 个。此外，加权基因共表达网络分析（WGCNA）和 KEGG 富集分析结果表明，叶酸补充影响炎症和免疫反应相关途径。两组之间很少有共同的途径。一个重要的 lncRNA MSTRG.11108.1 及其靶基因（ICAM1、CCL3、CCL4 等）参与了免疫相关途径。最后，通过将 lncRNA 与 GWAS 数据和动物 QTL 数据库进行综合分析，发现差异 lncRNA 及其靶基因可显著富集在与体细胞计数（SCC）和乳房炎相关的 SNP 和 QTL 中，如 MSTRG.11108.1 及其靶基因 ICAM1、CXCL3、GRO1。
对于隐性乳房炎奶牛，叶酸补充通过调节 lncRNA MSTRG.11108.1 可显著影响 ICAM1 等免疫相关途径基因的表达，从而影响相关免疫表型。本研究结果为在隐性乳房炎奶牛中添加叶酸补充提供了理论和实践应用的基础。
