| Pork is the main source of animal protein food for our residents,and its production and consumption account for about 50% of the world.Skeletal muscle and adipose tissue are the main components of pig carcass.Therefore,the growth and development mechanism and genetic improvement of skeletal muscle and fat in pigs have always been as one of the most concerned scientific issues in livestock breeding.In addition,the evolutionary distance between pigs and humans is closer than that of rodents,pigs are still ideal experimental animals and disease models.Uncoupling protein family(UCPs)is a kind of transporters family located in the mitochondrial inner membrane.The main function of them are included to control the uncoupling of oxidative phosphorylation through proton leakage,and inhibit ATP production.As a reactive oxygen species(ROS)regulator,UCP2 has the functions of reducing oxidative stress in organisms and preventing peroxide damage in tissues and organs.UCP3 mainly plays a role in skeletal muscle and fat,and is involved in the process of heat production,energy metabolism and lipid metabolism by various hormones.There have been many studies on the transcriptional mechanisms and hormone regulation of UCP2 and UCP3 in humans and mice,and there are few studies on the regulation of these two genes in pigs.The main results are as follows:1?Bioinformatics analysis showed that the porcine UCP2 protein is 94% similar to human and mouse UCP2 proteins.The porcine UCP3 is 90% similar to human UCP3,and that is86% similar to mice.It is speculated that UCP2 and UCP3 have similar effects in pigs compared with that in humans and mice.2?Analysis of expression profiles of UCP2 and UCP3 in new born Landrace piglets' heart,liver,spleen,lung,kidney,longissimus dorsi and neck adipose tissue.Tissue expression profile indicated that the expression level of UCP2 was the highest in the lungs of newborn piglets,and the expression profile of UCP3 was the highest in cervical adipose tissue3?The promoter deletion vectors were constructed by cloning the promoter regions of UCP2 and UCP3 from Landrace pig,and double luciferase activity assay was performed.It was detected that the activity of UCP2-F5 promoter region of UCP2 was significantly higher than Basic,and the activity of UCP3-F1 promoter region of UCP3 was significantly higher than Basic;then the conserved Motif and Cp G islands in the promoter region of different species,the transcription factor binding site in the more active fragment were predicted by bioinformatics analysis.At last,a STAT5 b binding site was verified to exist in the UCP3 promoter region by EMSA.4?A model of pig adipocyte was established by culturing pig bone marrow mesenchymal stem cells and inducing adipogenic differentiation.The formation of lipid droplet was observed through oil red O staining on the 12 th day of differentiation,which indicated that the adipogenic differentiation was successful.The expression levels of UCP2 and UCP3 were analysis with q PCR during the differentiation,the expression levels of UCP2 and UCP3 reached the peak on the 6th day of differentiation.5?The expression levels UCP2 and UCP3 were quantitatively analyzed in adipocytes from differented pig bone marrow mesenchymal stem cells after treated with growth hormone,oleic acid and benzefibrate,respectively.UCP2 expression was down-regulated and UCP3 expression was up-regulated compared with control after GH treatment for 12 h,24 h and 36 h.UCP2 expression was down-regulated as the concentration increasing,and UCP3 expression was significantly higher than that of the control group at 0.9 mol/L.The expression levels of UCP2 and UCP3 were significantly up-regulated after bendazabate treatment. |
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