cAMP-dependent protein kinase activated Fyn in spinal dorsal horn to regulate NMDA receptor function during inflammatory pain.

Selective inhibition of GluN2B-containing NMDA receptor (GluN2BR) in spinal dorsal horn effectively alleviates inflammatory pain, suggesting the up-regulation of GluN2BR function involved in central sensitization. Previous studies have demonstrated that the increase in GluN2BR synaptic expression serves as a key step to enhance GluN2BR function after intradermal injection of Complete Freund's Adjuvant (CFA). Here, we showed that cAMP-dependent protein kinase (PKA) played an important role in redistributing GluN2BR at synapses, because inhibition of PKA activity impaired GluN2BR accumulation at post-synaptic density (PSD)-enriched fraction in CFA-injected mice, and direct stimulation of PKA in naïve mice mimicked the effect of CFA by recruiting GluN2BR at PSD fraction to evoke pain sensitization. Analysis of PKA-initiated signalings unraveled that PKA was able to activate Src-family protein tyrosine kinases member Fyn, possibly by disrupting Fyn association with its inhibitory partner striatal-enriched protein tyrosine phosphatase 61. The active Fyn then promoted GluN2B phosphorylation at Tyr1472, a molecular event known to prevent GluN2BR endocytosis. As a result, pharmacological or genetic manipulation of Fyn activity greatly depressed GluN2BR accumulation at PSD-enriched fraction and ameliorated mechanical allodynia induced by PKA. Our data thus elucidated a critical role of PKA/Fyn/GluN2B signaling in triggering GluN2BR hyperfunction and pain hypersensitivity.

Isoflavone regulates lipid metabolism via expression of related genes in OVX rats fed on a high-fat diet.

OBJECTIVE: To investigate the effects of isoflavone on body weight, fat mass, and gene expression in relation to lipid metabolism. METHODS: Thirty-six female SD rats were ovariectomized or sham-operated and fed on a high-fat diet. Two months later, abdominal incision was made, blood was collected to separate serum, and the liver and adipose tissue were immediately collected and weighed. Some portions of these tissues were frozen in liquid nitrogen and stored at -80 degrees C. RESULTS: Ovariectomy (OVX) with a high-fat diet could induce obesity in rats, while treatment with isoflavone significantly inhibited the increase in body weight and fat mass in abdomen. Serum total cholesterol and leptin were significantly decreased in isoflavone group, compared with the OVX group. The mRNA expression of liver fatty acid synthase (FAS) in the OVX group was significantly higher than that in sham-operated group, while this difference was not observed in the isoflavone group. The mRNA expression of liver hormone-sensitive lipase (HSL) in the OVX rats tended to be lower than that in the sham-operated rats. Furthermore, a large amount of isoflavone maintained the mRNA expression at a sham level. CONCLUSION: Isoflavone may prevent obesity induced by ovariectomy with a high-fat diet, in part by modulating gene expression related to lipid metabolism.

[Effect of apoptosis in human breast cancer cells and its probable mechanisms by genistein].

OBJECTIVE: To investigate the effects of genistein on human breast cancer cell MCF-7 apoptosis and its probable mechanisms. METHODS: In this study, the methods of MTT, cell apoptosis detecting in fluorescent and electronic microscope and flow cytometry, and expression of Bax and erbB-2 protein were employed. RESULTS: The results showed that genistein could significantly inhibit the growth and induce the apoptosis of MCF-7 cells. Apoptotic cells of morphology from MCF-7 cells treated by different concentrations of genistein were observed by fluorescent and electronic microscope and the frequency of apoptosis in MCF-7 cells by flow cytometry showed increasingly with concentrations of genistein increased. The expression of Bax protein in MCF-7 cells was increased and the expression of erbB-2 protein was decreased with the doses of genistein. CONCLUSION: Genistein can induce MCF-7 cells apoptosis and it may be one of the mechanisms for the inhibitory effect of genistein in human cancer cells.

Blocking effects of genistein on cell proliferation and possible mechanism in human gastric carcinoma.

AIM: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism. METHODS: MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution. Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D1, cyclin B1 and p21(waf1/cip1). RESULTS: Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901). Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 microg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7% respectively and cell cycles were arrested at the G(2)/ M phase. Genistein decreased cyclin D1 protein expression and enhanced cyclin B1 and p21(waf/cip1) protein expression in a concentration-dependent manner. CONCLUSION: The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle, with reduced expression of cyclin D1 and enhanced expression of cyclin B1 and p21(waf/cip1) protein in the concentration range of 0-20 microg/mL.