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. Results Here we showed that glucose has the ability to induce lactose synthesis in dairy cow mammary epithelial cells, as well as increase cell viability and proliferation. A concentration of 12 m M glucose was the optimum concentration to induce cell growth and lactose synthesis in cultured dairy cow mammary epithelial cells. In vitro, 12 m M glucose enhanced lactose content, along with the expression of genes involved in glucose transportation and the lactose biosynthesis pathway, including GLUT1, SLC35A2, SLC35B1, HK2, β4GalT-I, and AKT1. In addition, we found that AKT1 knockdown inhibited cell growth and lactose synthesis as well as expression of GLUT1, SLC35A2, SLC35B1, HK2, and β4GalT-I. Conclusions Glucose induces cell growth and lactose synthesis in dairy cow mammary epithelial cells. Protein kinase B alpha acts as a regulator of metabolism in dairy cow mammary gland to mediate the effects of glucose on lactose synthesis.

Vaccaria segetalis has very strong effect on lactogenesis, but the mechanism is still unknown: This study aims to reveal the influence of Vaccaria segetalis on cellular lactogenesis signaling pathway of dairy cow mammary epithelial cells (DCMECs). In this study the purified DCMECs was used to screen the-most effective-concentration of Vaccaria segetalis water decoction. for lactogenesis. DCMECs were treated with prolactin (PRL), E (estrogen) or water extraction of Vaccaria segetalis, and many lactogenesis signal molecules in DCMECs including prolactin receptor (PRLR), estrogen receptor alpha (ER alpha), p-STAT5, p-mTOR p100, GARS, PPAR gamma and cyclinD1 were detected by using western blot assay. It was found that Vaccaria segetalis, E and PRL could promote lactogenesis of DCMECs and up-regulate these lactogenesis signal molecules except PPAR gamma. These data reveals that Vaccaria segetalis has a similar. role as E or PRL and activates cellular lactogenesis signaling pathway of DCMECs on both the translational and transcriptional levels.

Made an overview of the glucose regulates the lactose bio-synthesis of the lactation progress in the mammary gland.My expermental study is about the procedure of bio-synthesis between glucose and lactose in the mammary gland,the mechanism of transmembrance transport of glucose,and the regulation of glucose for the lactose synthesizing a key enzyme.

To study the effect of Vaccaria segetalis on cellular signal transduction pathway associated with milk protein synthesis in dairy cow,water extraction of Vaccaria segetalis was prepared.Western blotting was used to study the changes of the signal molecules associated with milk protein synthesis of dairy cow mammary gland epithelial cells(DCMECs),treated with estrogen(ER),prolactin(PRL) and Vaccaria segetalis.The results showed that the Vaccaria segetalis extraction liquid,ER and PRL could promote milk protein synthesis and up-regulate the expression of p-STAT5,p100,GAS,S6K1 and p-mTOR,furthmore,methionine could enhance this action.These datas suggested that Vaccaria segetalis had a similar role with ER/PRL and up-regulated expression of the genes of DCMECs for lactation on the translational and transcriptional level.