Expression and function of leptin and its receptor in dairy goat mammary gland.
Leptin is an autocrine and paracrine factor which affects the development and function of mammary gland. The purpose of this study was to investigate the presence and regulatory effect of leptin in Chinese Guan Zhong dairy goat mammary gland from the virgin state to involution. The protein expression and localization of leptin and its long form receptor (OB-Rb) were detected by western blot and a confocal laser scanning microscope. Explants were cultured to detect the impacts of leptin on mammary gland, western blot was used to research leptin signal transduction pathway in pregnancy, lactation and involution. Leptin and amounts of OB-Rb protein were high throughout the virgin stage and at the beginning of pregnancy, lower at mid-pregnancy and throughout lactation, then higher at involution. Immunofluorescence performed with the anti-leptin and anti-leptin receptor antibody showed labelling located in adipose, epithelial cells, or extracellular matrix at different stages. The localization of leptin and OB-Rb revealed that leptin induced the expression of OB-Rb specifically and controlled the development and physiological function of the mammary gland by binding to OB-Rb. Leptin stimulated the proliferation and differentiation of ductal epithelial cells in pregnancy by JAK-MAPK signal pathway, enhanced the amount of beta-casein in cultured lactating mammary gland by JAK-STAT5 signal pathway, made the mammary duct disappear and induced apoptosis of mammary epithelial cells and mammary gland restitution by JAK-STAT3 signal pathway in involution. Overall, this study demonstrated the importance and complexity of leptin and OB-Rb during mammary gland development and provides a valuable resource for future research in this area.
Li
Meng
M
The Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University, Harbin, China.
Li
Qingzhang
Q
Gao
Xuejun
X
D017667:Adipocytes / Q000378:metabolism; D000818:Animals; D000829:Animals, Domestic; D017209:Apoptosis; D002364:Caseins / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D003612:Dairying; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D006041:Goats; D053612:Janus Kinases / Q000378:metabolism; D007774:Lactation / Q000378:metabolism*; D020738:Leptin / Q000378:metabolism* / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D011247:Pregnancy; D054411:Receptors, Leptin / Q000378:metabolism; D050791:STAT Transcription Factors / Q000378:metabolism; D015398:Signal Transduction
D002364:Caseins; D020738:Leptin; D054411:Receptors, Leptin; D050791:STAT Transcription Factors; D053612:Janus Kinases; D020928:Mitogen-Activated Protein Kinases