lncRNA MPFAST Promotes Proliferation and Fatty Acid Synthesis of Bovine Mammary Epithelial Cell by Sponging miR-103 Regulating PI3K-AKT Pathway

Abstract

Long noncoding RNAs (lncRNAs) have an essential role in mammary gland development and lactation. Our earlier study showed that the lncRNA mammary proliferation and fatty acid synthesis-associated transcript (MPFAST) is highly expressed in the Holstein cow mammary gland during the middle lactation period compared to the dry period, which indicates its potential role in lactation. Therefore, gain- and loss-of-function experiments were performed on bovine mammary epithelial cells (BMECs) by cell counting kit 8 (CCK8), 5-ethynyl-2′-deoxyuridine (EdU), real-time quantitative polymerase chain reaction (RT-qPCR), and western blot. The results indicated that MPFAST promoted the viability and proliferation of BMECs. The oil red O staining and cellular triglyceride assay further showed that MPFAST promoted the number of lipid droplets and cellular triglyceride synthesis in BMECs. Bioinformatics analysis showed that MPFAST could act as a molecular sponge for miR-103, and PIK3R1 was a potential target of miR-103, which was further confirmed by the dual-luciferase reporter assay, RT-qPCR, and western blot. The overexpression of MPFAST promoted the expression of PIK3R1 at mRNA and protein levels. It also significantly increased the mRNA relative expression levels of AKT, mTOR, and SREBP1, and the protein relative expression levels of AKT and p-AKT in the PI3K-AKT signaling pathway. In contrast, the inhibition of MPFAST resulted in the downregulation of the PI3K-AKT signaling pathway genes. These results indicated that MPFAST regulates the expression of the genes in the PI3K-AKT signaling pathway through sponging miR-103 and promotes the proliferation and synthesis of fatty acids of BMECs. Our results would provide a new direction for further exploring the regulatory mechanism of lncRNA in the mammary gland.

Browning of Mammary Fat Suppresses Pubertal Mammary Gland Development of Mice via Elevation of Serum Phosphatidylcholine and Inhibition of PI3K/Akt Pathway

“…It has been well-documented that the PI3K/Akt pathway plays a vital part in cell survival, proliferation, and metabolism [40,41]. In the present study, we found that DOPC inhibited the activation of the PI3K/Akt pathway, while the activator of Akt reversed the inhibitory effects of DOPC on HC11 proliferation.…”

Transcriptome analysis of the Bactrian camel (Camelus bactrianus) reveals candidate genes affecting milk production traits

“…The PI3K–Akt signaling pathway is a canonical pathway involved in mammary development and lipid metabolism [ 75 ]. Liu et al [ 76 ] found that the lncRNA mammary proliferation and fatty acid synthesis-associated transcript promotes proliferation and fatty acid synthesis in bovine mammary epithelial cells by sponging miR-103, which regulates the PI3K–Akt pathway. Among the downregulated gene enrichment pathways, MAPK signaling pathways are related to higher milk yields in cattle [ 77 ].…”

MicroRNA‐2285f regulates milk fat metabolism by targeting MAP2K2 in bovine mammary epithelial cells

“…They can bind to the 3′ untranslated region or coding region of the target gene sequence through complementary base pairing and bind to the 5′ untranslated region of the target mRNA to regulate gene expression and further affect the protein expression level inside cells (Jabed et al, 2012). miRNA expression is characterized by developmental stage specificity and tissue specificity and plays a specific role in regulating biological functions such as mammary gland development (Liu et al, 2022), lactation process (Dysin et al, 2021), fat metabolism (Chen, Chu, Wang, Fan, et al, 2019;Chen, Chu, Wang, Sun, et al, 2019), and innate immunity (Yuan et al, 2018).…”

“…With the development of candidate gene screening and sequencing and comparative genomics research methods, more genes and regulatory factors related to fat milk metabolism have been discovered. Their functions are verified, and miRNA is one of the critical regulatory factors (Liu et al., 2022). Milk is a highly complex liquid made up of water (86–88%), fat (3–5%), protein (3.3–3.6%), carbohydrates (4.5–5.0%), minerals (0.7%) and enzymes, as well as many other minor components (Foroutan et al., 2019).…”

“…miRNA expression is characterized by developmental stage specificity and tissue specificity and plays a specific role in regulating biological functions such as mammary gland development (Liu et al., 2022), lactation process (Dysin et al., 2021), fat metabolism (Chen, Chu, Wang, Fan, et al., 2019; Chen, Chu, Wang, Sun, et al., 2019), and innate immunity (Yuan et al., 2018).…”