ABSTRACT
Alterations in lipids metabolism are one of the important mechanisms for the treatment of insulin resistance and, hence for type 2 diabetes. On the other hand, PGC-1alpha, as a key regulator of mitochondrial biogenesis and function, by increasing beta-oxidation of lipids plays an important role in improving insulin sensitivity. In the present study, the effects of Epigallocatechin-3-Gallate [EGCG], an anti-obesity and enhancer of lipid catabolism agent, on PGC-1alpha protein expression was examined and compared with the anti-diabetic drug Rosiglitazone [RGZ]. After differentiation of C2C12 myoblasts to myotubes, insulin resistance was induced by palmitate treatment. Afterward, PGC-1alpha protein expression was examined using the western blot method before and after treatment with insulin and after EGCG and RGZ treatment. Palmitate treatment significantly decreased PGC-1 alpha protein expression in the C2C12 cells [P=0.001]. Treatment of these cells with EGCG had no significant effect on the PGC-1 alpha protein expression [P=0.67], whereas treatment with RGZ significantly increased expression of this gene at protein level [P=0.003]. In addition, this significant increase in PGC-1 alpha protein expression was maintained by simultaneous treatment with EGCG and RGZ [P=0.001]. Our results showed that the effect of EGCG on PGC-1 a protein expression was not significant, whereas RGZ significantly improved the palmitate-induced reduction of PGC-1 alpha protein expression. Overall, it seems that anti-diabetic effect of EGCG is not exerted through its effect on the expression of PGC-1alpha gene, in contrast to that of RGZ
ABSTRACT
Hydatidosis or cystic hydatid disease is one of the most important diseases in human and animals. Identification of strains is important for improvement of control and prevention of disease. The aim of this study was to determine the strains isolated from human and domestic animals in Ilam Province, Iran, using PCR-RFLP method. Respectively, 30 and 4 animal and human hydatid cysts were collected from different slaughterhouses and hospitals of the province. Protoscolices were separated and their DNA genome was extracted by extraction kit. rDNA-ITS1 of each isolated samples was duplicated by BD1 [Forward] and 4s [Reverse] Primers. PCR products were studied by electrophoresis and then were digested using TaqI, HpaII, Rsal and Alul restriction enzymes. RFLP products were studied using electrophoresis on 1% agar gel. A fragment of l000bp was produced from amplification of rDNA-ITS1 of protoscolices using PCR method. After digestion of PCR product by Alul enzyme, 200bp and 800bp, by Rsal, 655bp and 345bp and by HpaII 700bp and 300bp sizes were obtained. TaqI enzyme had no change in fragment size and it remained l000bp. Considering the method. Ham strains was specified as E. granulosus sensu stricto [G1-G3]. Although sheep strain [G1] is dominated in human and different animal in Iran and the world, but more efforts should be done to clarify the true genotype of Ilam strains specified as E. granulosus sensu stricto [G1-G3]
ABSTRACT
Insulin resistance plays a major role in type 2 diabetes and obesity. In this disorder, lipid accumulation is accompanied by increased TNF-alpha expression in the muscle. The aims of this study were to evaluate the effects of tumor necrosis factor-a [TNF-alpha] gene knockdown on key elements of insulin signaling pathway [IRS-1 and. Akt] and insulin resistance in C2C12 muscle cells in the presence and absence of palmitate. To knockdown protein expression of TNF-alpha, the C2C12 cells were transfected with the shRNA containing antisense sequence of murine TNF-alpha gene. The analysis of TNF-alpha protein expression and phosphorylation and protein levels of IRS-1 and Akt were subsequently detected by western blot. In TNF-alpha knockdown cells, the protein expression level of TNF-alpha was reduced by 58%. Under treatment with palmitate, insulin stimulated phosphorylation of IRS-1 [Tyr632] and Akt [Ser473] in knockdown cells was increased 1.7 and 2.6 fold, respectively, compared to the controls. Our findings showed that decreasing the TNF-alpha protein level can enhance the activity of the important elements of insulin signaling pathway [IRS-1 and Akt], leading to the improvement of insulin resistance in myotubes, data suggesting that TNF-alpha may potentially be a therapeutic target for fatty acid induced insulin resistance observed in type 2 diabetes and metabolic syndrome