Effect of siglidine on glucose lipid metabolism and the expression of iNOS and GLP-1 receptors in diabetic rats.

OBJECTIVE: Diabetic nephropathy (DN) has become the major complication of diabetes. The progression of the disease impedes the efficacy of DN treatment. Therefore, the strategies to inhibit or reverse kidney damage in DN patients are of critical importance. We aim to investigate the effect of sitagliptin on DN within rat model and analyze the associated metabolism and expression of iNOS/GLP-1 receptor. MATERIALS AND METHODS: Diabetic model was generated by using Sprague-Dawley (SD) rats, which received an intra-peritoneal injection of 30 mg/kg streptozotocin. Rats were then treated with saline or 15 mg/(kg.d) sitagliptin by gavage. After 12 weeks, fasting blood glucose and insulin resistance were measured. Rat glucose and lipid metabolism were evaluated by high triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Western blot was used to measure expression of glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) related with glucose-lipid metabolism, and expression of iNOS and GLP-1 expression in kidney tissues. RESULTS: After 12 weeks of feeding, the levels of blood glucose and lipid in sitagliptin group were significantly decreased compared to those in control group (p<0.05), whilst insulin sensitivity was enhanced (p<0.05). Western blot showed that sitagliptin downregulated the expressions of glucose-lipid metabolism proteins such as G6Pase, PEPCK, ACC and FAS in rat livers, inhibited iNOS expression in kidneys and elevated GLP-1 receptor activity (p<0.05). CONCLUSIONS: Sitagliptin effectively stabilizes blood glucose and lipid levels in DN rats, significantly improves glucose-lipid metabolism and protects kidney and vascular endothelial cells during DN pathogenesis through inhibiting iNOS expression and elevating GLP-1 receptor activity.

Effect of everolimus on the expression of Ki-67 and caspase-3 in patients with neuroendocrine tumors.

Tumors, especially neuroendocrine tumors (NETs), can cause adverse effects on human health. The expression and significance of Ki-67 and caspase-3 in NET remain to be further explored. Everolimus is an important drug used for the treatment of NETs. In this study, we aimed to investigate whether everolimus exerts anti-tumor effects by suppressing the expression of Ki-67 and caspase-3 in NET. Tumor (different developmental stages) and adjacent tissues were collected from patients with NET. The expression of Ki-67 and caspase-3 were detected in 244 paraffin sections of NET using immunohistochemistry. RT-PCR and western blot were used to detect the expression of Ki-67 and caspase-3 at mRNA and protein levels, respectively. The patients (N = 244) were randomly divided into everolimus-intervention and control groups. RT-PCR and western blot were used to measure the expression changes of Ki-67 and caspase-3 before and after everolimus treatment. The rates of Ki-67 expression in NET grades 1-6 were 14.2, 22.1, 37.5, 59.9, 69.9, and 77.8%, respectively. The difference between the groups was significant. The rates of caspase-3 expression in NET grades 1-6 were 28.6, 33.3, 31.3, 60.0, 80.0, and 88.9%, respectively, and the difference between groups was significant. Moreover, the expression of Ki-67 and caspase-3 showed a significant negative correlation. The expression of Ki-67 decreased while that of caspase-3 increased after everolimus treatment. In conclusion, the decrease in Ki-67 expression and increase in caspase-3 expression after everolimus treatment indicated that everolimus exerted its anti-cancer effect by regulating the expression of Ki-67 and caspase-3.

Association between ERCC1 and ERCC2 gene polymorphisms and chemotherapy response and overall survival in osteosarcoma.

We aimed to evaluate the influence of four SNPs in ERCC1 and ERCC2 on the response to cisplatin-based treatment and on clinical outcome in patients with osteosarcoma. We identified 186 patients with osteosarcoma diagnosed between April 2009 and April 2011 who were eligible for inclusion in our study. Genotyping of ERCC1 rs11615, rs3212986, and rs2298881; and ERCC2 rs1799793 and rs13181 was conducted by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. By conditional logistic regression analysis, patients carrying the CC genotypes of ERCC1 rs11615 and rs2298881 were shown to be more likely to have good response to chemotherapy when compared with patients carrying wild-type genotypes; the ORs (95%CIs) were 2.56 (1.02-7.35) and 3.01 (1.07-9.71), respectively. By Cox regression analysis, individuals carrying the CC genotype of ERCC1 rs11615 were associated with longer overall survival time and decreased risk of death from osteosarcoma; the hazards ratio (95%CI) was 0.32 (0.07-0.98). In summary, our results suggested that the ERCC1 rs11615 and rs2298881 polymorphisms play important roles in the response to chemotherapy mediated by the DNA repair pathway and in the clinical outcome of osteosarcoma.

Construction of a tissue engineered intervertebral disc with high biological activity using an allogeneic intervertebral disc supplemented with transfected nucleus pulposus cells expressing exogenous dopamine beta-hydroxylase.

This study addressed the in vitro construction and biological activity of tissue engineered intervertebral discs with exogenous human dopamine beta-hydroxylase (DBH) nucleus pulposus cells. pSNAV2.0-DBH expression plasmids were utilized to enhance the survival rates of intervertebral disc tissue cells. Various concentrations of transfected nucleus pulposus cells were injected into the discs, and DBH mRNA expression was determined using polymerase chain reaction amplification. Polysaccharide content and total collagen protein content in the engineered disc nucleus pulposus tissue were determined. The visible fluorescence intensities of the 1 x 10(5) and 1 x 10(6) groups vs the 1 x 10(4) group were significantly increased (P < 0.05); no significant difference was observed between the 1 x 10(5) and 1 x 10(6) groups (P > 0.05) at 7 days after injection. DBH mRNA expression could be detected in the all but the EGFP control group at 14 days culture. No significant difference was observed in the protein content between the 1 x 10(4) and the control groups at various times, while the protein content was significantly higher in the 1 x 10(5) vs the control and the 1 x 10(4) groups at 7-, 14-, and 21-day cultures. These results demonstrate that a tissue engineered intervertebral disc with high biological activity can be constructed by utilizing allogeneic intervertebral discs stored in liquid nitrogen and a 1 x 10(5) transfected nucleus pulposus cell complex with in vitro culture for 14 days. This model can be used in animal experiments to study the biological activity of the engineered discs.

A mutation in the Kit gene leads to novel gonadal phenotypes in both heterozygous and homozygous mice.

The direct sequencing of the Kit cDNA obtained from mutant mice was used to reveal the molecular nature of the W(-3Bao) ENU-induced mutation. There was a T to A transversion at the 441st nucleotide in the W(-3Bao) open reading frame (ORF), which introduced a pre-mature termination codon at residue 147. The gross embryonic development, hematopoiesis and spermatogenesis were examined in the mutant mice. There was no visible difference among the W(-3Bao/+), W(-3Bao/3Bao) and wild type embryos before embryonic day 12.5. W(-3Bao/3Bao) embryos appeared pale after E14.5 and dwarf after E16.5. An extremely low level of hematochrome and large red blood cells were found in W(-3Bao/3Bao) 18.5 days old embryos, leading to the stillbirth of the homozygotes. In 18.5 days old embryos the spermatogonia of W(-3Bao/3Bao) embryos did not migrate to the contorted seminiferous tubules properly, but instead were found in the interstitial tissue. The spermatogonia of W(-3Bao/+) or W(+/+) mice were present in both the interstitial tissue and contorted seminiferous tubules. In the adult male hetereozygotes, there are contorted seminiferous tubules with no spermatogonia, suggesting that the migration defect was dominant. In female W(-3Bao/3Bao) ovaries, primordial follicles were absent while primordial follicles appeared clearly in the ovaries of W(-3Bao/+) or W(+/+) mice. With a nonsense mutation in the Kit gene, W(-3Bao/+) mice show white spotting and an abnormal development of the contorted seminiferous tubules and W(-3Bao/3Bao) mice are stillborn due to severe macrocytic anemia, and have abnormal genital glands in both the male and female.