Aim To study the effect of melatonin on expression and activity of myosin light chain kinase in the artery wall of atherosclerotic rabbits.Methods The rabbit model of atherosclerosis was induced by a high-cholesterol diet.The blood lipid levels were assayed in the serum of each group.MLCK expression was detected by Western blot and immunohistochemical method.MLCK activity was measured by ?-32P-ATP incorporation into myosin light chain.Results The atherosclerosis model was established successfully.The levels of lipids decreased after MLT treatment.After fed with cholesterol for twelve weeks,the expression and activity of MLCK in the artery of atherosclerotic rabbits increased markedly,whereas there was no obvious difference in expression of MLCK in the artery of atherosclerotic rabbits fed with cholesterol and melatonin for twelve weeks compared with that of control.Conclusions It was suggest that high expression and activity of MLCK in the artery might be closely correlated with the development of atherosclerosis.Melatonin played an important role in inhibiting the development of atherosclerosis by decreasing the expression and activity of MLCK.

BACKGROUND/AIMS: Kruppel-like factor 4 (KLF4) is an epithelial-specific transcription factor primarily expressed in the gastrointestinal tract that mediates growth arrest in the colonic epithelium. We tried to find whether KLF4 expression is associated with the progression and differentiation of colorectal cancer. METHODS: We detected KLF4 expression in 109 colorectal specimens (40 normal appearing mucosa, 7 adenomas, and 62 carcinomas) by immunohistochemistry using a tissue microarray. Western blot and RT-PCR analyses were also performed. RESULTS: The upregulation of KLF4 expression in carcinoma tissue was statistically significant (p<0.05) when compared to normal appearing mucosa. The negative and weak positive staining rates in normal appearing mucosa, adenoma, and carcinoma were 42.5%, 71.4%, and 82.3%, respectively, indicating a decreased degree of KLF4 expression over the course of progressive transformation of normal cells into malignant derivatives. KLF4 protein levels showed no correlation with sex, age, or metastatic state (p>0.05), while KLF4 protein expression correlated with the diagnostic stage (p<0.05). Furthermore, strong KLF4 staining was detected in 22.9% (11/48) and 0% (0/14) of well/moderately and poorly differentiated colorectal cancers, respectively. Our results clearly indicate that KLF4 protein expression significantly correlates with the degree of differentiation in colorectal cancers (p<0.05). KLF4 expression in RKO cells is also upregulated by butyrate, an inducer of differentiation. CONCLUSIONS: Downregulation of KLF4 expression may lead to more poorly differentiated tumors.
Adenoma ; Blotting, Western ; Butyrates ; Colon ; Colorectal Neoplasms ; Down-Regulation ; Epithelium ; Gastrointestinal Tract ; Immunohistochemistry ; Kruppel-Like Transcription Factors ; Mucous Membrane ; Transcription Factors ; Up-Regulation

Objective:To analyze the characteristics of viral isolation and unique recombinant from untreated HIV-1 patients infected through sexual transmission and injection drug use, so as to provide evidence for understanding the biological characteristics and precise prevention and control of HIV-1 infection in different transmission routes.Methods:In view of the different HIV-1 transmission risks, newly diagnosed untreated HIV-1 patients from Beijing, Guangxi and Sichuan were carefully selected. Venous blood was collected to detect the viral load and CD4 + T cell count, and peripheral blood lymphocytes were isolated for virus isolation. Viral RNAs were extracted from the virus supernatant, and the near full-length genome sequences were obtained using in-house method, then the recombination patterns were determined. Results:Among the 65 HIV-1 infection, 32(49.2%), 20(30.8%) and 13(20.0%) were infected via men who have sex with men (MSM), heterosexual and injection drug use (IDU), respectively; genotypes mainly included 26(40.0%) CRF07_ BC, 23(35.4%) CRF01_ AE, and 9(13.8%) unique recombinant types (URFs). A total of 46 HIV-1 clinical strains were isolated. The positive rate of HIV-1 isolation was significantly negatively correlated with CD4 + T cells ( X2=4.22, P=0.04), but positively correlated with viral load ( X2=22.4, P<0.001); the multi-variate generalized estimating equations(GEE) model analysis of HIV-1 P24 antigen content showed similar result. In addition, GEE model showed a positive correlation between viral P24 antigen content and virus-producing culture time (52.14, 95% CI: 9.42~94.87, P=0.017). Viral growth curve analysis showed that the level of viral P24 antigen in MSM Group was significantly higher than that in heterosexual group and IDU group (adjusted P values were p<0.01 and P<0.05, respectively), on the 14th day after culture. The proportion of URFs in MSM Group was higher than that in heterosexual group, and the recombinant breakpoints in MSM Group were more than that in heterosexual group. Conclusions:MSM population was more sensitive to HIV-1 virus isolation; there was unique diversity of recombinant forms of HIV-1 among those with sexually transmitted infections, especially in the MSM population.