RESUMO
To study the effects of berberine on the gene mRNA expressions of BMP4 transcriptional pathways and brown/white adipose tissue conversion transcriptional pathways in visceral white adipose tissues(VWAT) in type 2 diabetic hamsters and explore the relevant mechanisms. The obese insulin-resistant hamster model were induced by using high-fat diet, and then the type 2 diabetic hamster model was created through injection with low-dose streptozotocin in the obese insulin-resistant hamster model. After the modeling, the hamsters were randomly divided into normal control, obese insulin-resistant, type 2 diabetic and berberine-treated diabetic groups. After the nine-week treatment, real-time quantitative PCR was used to measure the changes in gene mRNA expressions of VWAT BMP4 transcriptional pathways, brown/white adipose tissue conversion transcriptional pathways and their target genes in different groups. The results showed that the gene mRNA expressions of BMP4, BMPRⅡ, BMPRlA, Smad1, Smad5, Smad8, p38/MAPK, ATF2, PRDM16, C/EBPβ, PGC1α, PPARγ and brown adipose tissue-specific genes was decreased and that of Smad6, Smurf1 and white adipose tissue-specific genes was increased in VWAT of model hamsters. Treatment with berberine regulated BMP4 transcriptional pathways and brown adipose tissue transcriptional pathways and induced the gene mRNA expression of brown adipose tissue-specific genes in VWAT to develop browning gene phenotype of white adipose tissues, and then improved fat-induced insulin resistance. These findings indicated that BMP4 transcriptional pathways involved in the formation of fat-induced visceral white adipose tissues insulin resistance (FIVWATIR) and the browning molecular mechanism of white adipose tissues induced by berberine.