miR-30a-3p Regulates Autophagy in the Involution of Mice Mammary Glands.

The mammary gland undergoes intensive remodeling during the lactation cycle, and the involution process of mammary gland contains extensive epithelial cells involved in the process of autophagy. Our studies of mice mammary glands suggest that miR-30a-3p expression was low during involution compared with its high expression in the mammary glands of lactating mice. Then, we revealed that miR-30a-3p negatively regulated autophagy by autophagy related 12 () in mouse mammary gland epithelial cells (MMECs).

Controlled synchronization of prolactin/STAT5 and AKT1/mTOR in bovine mammary epithelial cells.

The prolactin/STAT5 and AKT1/mTOR pathways play a key role in milk protein transcription and translation, respectively. However, the correlation between them in bovine mammary epithelial cells remains unclear. Here, mRNA and protein expression levels of AKT1, STAT5, and mTOR and the phosphorylation of these proteins were determined.

Let-7g-5p regulates mouse mammary cells differentiation and function by targeting PRKCA.

MicroRNAs (miRNAs) are closely related with the posttranscriptional regulation of gene expression. Our past study showed that let-7g-5p decreased during pregnancy and lactation in mouse mammary gland, what suggested the prospective regulating role of let-7g-5p in mammary epithelial cells. In this study, to unravel the role of let-7g-5p, we found PRKCA (PKC-alpha, PKC-α) might serve as potential targets of let-7g-5p by bioinformatics.

Comparative transcriptome analysis to investigate the potential role of miRNAs in milk protein/fat quality.

miRNAs play an important role in the processes of cell differentiation, biological development, and physiology. Here we investigated the molecular mechanisms regulating milk secretion and quality in dairy cows via transcriptome analyses of mammary gland tissues from dairy cows during the high-protein/high-fat, low-protein/low-fat or dry periods. To characterize the important roles of miRNAs and mRNAs in milk quality and to elucidate their regulatory networks in relation to milk secretion and quality, an integrated analysis was performed.

MiR-139 suppresses β-casein synthesis and proliferation in bovine mammary epithelial cells by targeting the GHR and IGF1R signaling pathways.

Background: MicroRNAs have important roles in many biological processes. However, the role of miR-139 in healthy mammary gland remains unclear. The objective of this study was to investigate the effects of miR-139 on lactation in dairy cows.

The effects of cell death-inducing DNA fragmentation factor-α-like effector C (CIDEC) on milk lipid synthesis in mammary glands of dairy cows.

Adequate lipid synthesis by the mammary gland during lactation is essential for the survival of mammalian offspring. Cell death-inducing DNA fragmentation factor-α-like effector C (CIDEC) is a lipid droplet-associated protein and functions to promote lipid accumulation and inhibit lipolysis in mice and human adipocytes. However, the function of CIDEC in regulation of milk lipid synthesis in dairy cow mammary gland remains largely unknown.

Regulation of peroxisome proliferator-activated receptor gamma on milk fat synthesis in dairy cow mammary epithelial cells.

Peroxisome proliferator-activated receptor gamma (PPARγ) participates in lipogenesis in rats, goats, and humans. However, the exact mechanism of PPARγ regulation on milk fat synthesis in dairy cow mammary epithelial cells (DCMECs) remains largely unexplored. The aim of this study was to investigate the role of PPARγ regarding milk fat synthesis in DCMECs and to ascertain whether milk fat precursor acetic acid and palmitic acid could interact with PPARγ signaling to regulate milk fat synthesis.

Effects of glucose on lactose synthesis in mammary epithelial cells from dairy cow.

Background: Lactose, as the primary osmotic component in milk, is the major determinant of milk volume. Glucose is the primary precursor of lactose. However, the effect of glucose on lactose synthesis in dairy cow mammary glands and the mechanism governing this process are poorly understood.

The effect of G protein-coupled receptor kinase 2 (GRK2) on lactation and on proliferation of mammary epithelial cells from dairy cows.

Milk protein is an important component of milk and a nutritional source for human consumption. To better understand the molecular events underlying synthesis of milk proteins, the global gene expression patterns in mammary glands of dairy cow with high-quality milk (>3% milk protein; >3.5% milk fat) and low-quality milk (<3% milk protein; <3.

14-3-3γ regulates cell viability and milk fat synthesis in lipopolysaccharide-induced dairy cow mammary epithelial cells.

Our previous study demonstrated that 14-3-3γ overexpression was able to inhibit the production of lipopolysaccharide (LPS)-induced cytokines in dairy cow mammary epithelial cells (DCMECs) by inhibiting the activation of nuclear factor-κB (NF-κB) signaling pathways. However, the association between 14-3-3γ overexpression and milk fat synthesis in LPS-induced DCMECs remains unclear. Therefore, the present study investigated the effect of 14-3-3γ on cell viability and milk fat synthesis in LPS-induced DCMECs.

Spleen tyrosine kinase regulates mammary epithelial cell proliferation in mammary glands of dairy cows.

Spleen tyrosine kinase (SYK) is a nonreceptor tyrosine kinase that has been considered a hematopoietic cell-specific signal transducer involved in cell proliferation and differentiation. However, the role of SYK in normal mammary gland is still poorly understood. Here we show that SYK is expressed in mammary glands of dairy cows.

14-3-3γ Regulates Lipopolysaccharide-Induced Inflammatory Responses and Lactation in Dairy Cow Mammary Epithelial Cells by Inhibiting NF-κB and MAPKs and Up-Regulating mTOR Signaling.

As a protective factor for lipopolysaccharide (LPS)-induced injury, 14-3-3γ has been the subject of recent research. Nevertheless, whether 14-3-3γ can regulate lactation in dairy cow mammary epithelial cells (DCMECs) induced by LPS remains unknown. Here, the anti-inflammatory effect and lactation regulating ability of 14-3-3γ in LPS-induced DCMECs are investigated for the first time, and the molecular mechanisms responsible for their effects are explored.

14-3-3γ affects mTOR pathway and regulates lactogenesis in dairy cow mammary epithelial cells.

14-3-3 proteins are an acidic protein family that is highly conserved and widely distributed in eukaryotic cells. Recent studies have found that 14-3-3 proteins play critical roles in cell signal transductions, cell growth and differentiation, and protein synthesis. 14-3-3γ is an important member of 14-3-3 protein family.

MiR-486 regulates lactation and targets the PTEN gene in cow mammary glands.

Mammary gland development is controlled by several genes. Although miRNAs have been implicated in mammary gland function, the mechanism by which miR-486 regulates mammary gland development and lactation remains unclear. We investigated miR-486 expression in cow mammary gland using qRT-PCR and ISH and show that miR-486 expression was higher during the high-quality lactation period.

Epigenetic Regulation of miR-29s Affects the Lactation Activity of Dairy Cow Mammary Epithelial Cells.

Milk is important for human nutrition, and enhanced milk quality has become a major selection criterion for the genetic improvement of livestock. Epigenetic modifications have been shown to be involved in mammary gland development; but the mechanisms underlying their effects remain unknown. MicroRNAs are involved in the regulation of milk synthesis and in mammary gland development.

Thyroid hormone responsive protein spot 14 enhances lipogenesis in bovine mammary epithelial cells.

Thyroid hormone responsive spot 14 (THRSP, Spot14, S14) is a nuclear protein that regulates milk fat synthesis. To investigate the role of THRSP in lipogenesis in the dairy cow mammary gland, first, we examined the association between milk fat concentration and THRSP expression in the mammary gland. We found that the dairy cow mammary glands that produced milk with high fat had high THRSP mRNA and protein levels.

Up-regulation of integrin α6β4 expression by mitogens involved in dairy cow mammary development.

In dairy cows, the extracellular microenvironment varies significantly from the virgin state to lactation. The function of integrin α6β4 is dependent on cell type and extracellular microenvironment, and the precise expression profile of α6β4 and its effects on mammary development remain to be determined. In the present study, real-time PCR and immunohistochemistry were used to analyze the expression and localization of integrin α6β4 in Holstein dairy cow mammary glands.

Molecular network including eIF1AX, RPS7, and 14-3-3γ regulates protein translation and cell proliferation in bovine mammary epithelial cells.

14-3-3γ, an isoform of the 14-3-3 protein family, was proved to be a positive regulator of mTOR pathway. Here, we analyzed the function of 14-3-3γ in protein synthesis using bovine mammary epithelial cells (BMECs). We found that 14-3-3γ interacted with eIF1AX and RPS7 by 14-3-3γ coimmunoprecipitation (CoIP) and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight (MALDI-TOF/TOF) peptide mass fingerprinting analysis.

Function of SREBP1 in the milk fat synthesis of dairy cow mammary epithelial cells.

Sterol regulatory element-binding proteins (SREBPs) belong to a family of nuclear transcription factors. The question of which is the most important positive regulator in milk fat synthesis in dairy cow mammary epithelial cells (DCMECs) between SREBPs or other nuclear transcription factors, such as peroxisome proliferator-activated receptor γ (PPARγ), remains a controversial one. Recent studies have found that mTORC1 (the mammalian target of rapamycin C1) regulates SREBP1 to promote fat synthesis.

Pten regulates development and lactation in the mammary glands of dairy cows.

Pten is a tumor suppressor gene regulating many cellular processes, including growth, adhesion, and apoptosis. In the aim of investigating the role of Pten during mammary gland development and lactation of dairy cows, we analyzed Pten expression levels in the mammary glands of dairy cows by using western blotting, immunohistochemistry, and quantitative polymerase chain reaction (qPCR) assays. Dairy cow mammary epithelial cells (DCMECs) were used to study the function of Pten in vitro.

GSK3β regulates milk synthesis in and proliferation of dairy cow mammary epithelial cells via the mTOR/S6K1 signaling pathway.

Glycogen synthase kinase 3 (GSK3) is a serine/threonine kinase, whose activity is inhibited by AKT phosphorylation. This inhibitory phosphorylation of GSK3β can in turn play a regulatory role through phosphorylation of several proteins (such as mTOR, elF2B) to promote protein synthesis. mTOR is a key regulator in protein synthesis and cell proliferation, and recent studies have shown that both GSK3β and mTORC1 can regulate SREBP1 to promote fat synthesis.

MicroRNA-152 regulates DNA methyltransferase 1 and is involved in the development and lactation of mammary glands in dairy cows.

MicroRNAs (miRNAs) are a class of small non-coding, endogenous regulatory RNAs that function by controlling gene expression at the post-transcriptional level. Using small RNA sequencing and qRT-PCR techniques, we found that the expression of miR-152 was significantly increased during lactation in the mammary glands of dairy cows producing high quality milk compared with that in cows producing low quality milk. Furthermore, DNA methyltransferase 1 (DNMT1), which is a target of miR-152, was inversely correlated with the expression levels of miR-152 in the mammary glands of dairy cows.

Functional analysis of FABP3 in the milk fat synthesis signaling pathway of dairy cow mammary epithelial cells.

Milk fat is the major energy component of milk, and regulation of its production relies on transcription factors sterol regulatory element-binding protein 1 (SREBP1) and peroxisome proliferator-activated receptor gamma (PPARγ). As one of the target genes of SREBP1 and PPARγ, fatty acid-binding protein 3(FABP3) is the main protein allowing for rapid diffusion and selective targeting of long-chain fatty acids toward specific organelles for metabolism. Whether FABP3 plays an important role in milk fat synthesis signaling pathway is largely unknown.

Leucyl-tRNA synthetase regulates lactation and cell proliferation via mTOR signaling in dairy cow mammary epithelial cells.

The role of LeuRS, an aminoacyl-tRNA synthetase, as an intracellular l-leucine sensor for the mTORC1 pathway has been the subject of much research recently. Despite this, the association between LeuRS and lactation in dairy cow mammary epithelial cells (DCMECs) remains unknown. In this study, we found that LeuRS expression in mammary gland tissue was significantly higher during lactation than pregnancy.

SOCS3-mediated blockade reveals major contribution of JAK2/STAT5 signaling pathway to lactation and proliferation of dairy cow mammary epithelial cells in vitro.

Suppressor of cytokine signaling 3 (SOCS3) is a cytokine-induced negative feedback-loop regulator of cytokine signaling. More and more evidence has proved it to be an inhibitor of signal transducers and activators of transcription 5 (STAT5). Here, we used dairy cow mammary epithelial cells (DCMECs) to analyze the function of SOCS3 and the interaction between SOCS3 and STAT5a.