[Differential expression and correlation to cytokine expressions of FFAR4 in peritoneal and alveolar macrophages].

Objective To investigate the expression level of free fatty acid receptor 4 (FFAR4) and its correlation with cytokine expressions in peritoneal macrophages and alveolar macrophages. Methods Peritoneal macrophages and alveolar macrophages were purified and collected using flow cytometry from adult BALB/c mice. Real-time quantitative PCR was used to measure mRNA expression levels. The correlation between FFAR4 expression level and cytokine expression levels was analyzed using linear regression. Results The expression levels of FFAR4, interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-α) were significantly higher in the alveolar macrophages than in the peritoneal macrophages. In contrast, the expression levels of IL-10 and IL-6 were significantly lower in the alveolar macrophages than in the peritoneal macrophages. In the peritoneal macrophages, FFAR4 expression was positively correlated to the mRNA expressions of IL-10, IL-6 and TNF-α, but negatively correlated to IL-1 mRNA expression. In the alveolar macrophages, FFAR4 expression was positively correlated to the mRNA expressions of IL-1, IL-6 and TNF-α, but negatively correlated to IL-10 mRNA expression. Conclusion FFAR4 is differentially expressed and correlated to cytokine expressions in peritoneal macrophages and alveolar macrophages from BALB/c mice.

Urotensin II inhibits the proliferation but not the differentiation of cardiac side population cells.

Urotensin II (UII) induces the development of cardiac remodeling and atherosclerosis by promoting hypertrophy of cardiomyocytes and mitogenesis of fibroblasts and vascular smooth muscle cells. But its effect on cardiac side population cells (CSPs), one of somatic stem cells, is unclear. The present study examined the influences of UII on the differentiation and proliferation of CSPs. CSPs were isolated from neonatal rat hearts by fluorescence-activated cell sorting (FACS) and cultured with or without the presence of UII (10(-8), 10(-7), 10(-6)mol/l). The expressions of α-cardiac myosin heavy chain (α-MHC), α-smooth muscle actin (SMA) and Von Willebrand factor (vWF) mRNAs and proteins were analyzed by reverse transcriptional PCR (RT-PCR) and immunofluorescence to evaluate the differentiation of CSPs into cardiomyocytes, smooth muscle cells and endothelial cells, respectively. The proliferation of CSPs was assessed by Luminescent Cell Viability Assay. The influence of UII on the proliferation of CSPs in vivo was also evaluated by FACS. Our results revealed that UII did inhibit the proliferation of CSPs through up-regulation of phosphorylated c-Jun N-terminal protein kinase (JNK), although it didn't affect the differentiation of cultured CSPs. Experiments in vivo also showed that UII reduced the number of CSPs in mice compared with control group. These data indicate that UII reduces the number of CSPs by inhibiting the proliferation of CSPs possibly through increase of JNK phosphorylation.

[Effects of hepatectomized rat serum on the transdifferentiation of adult rat bone marrow cells into hepatocyte-like cells].

OBJECTIVES: To study the effects of hepatectomized rat serum and hepatocyte growth factor (HGF) on the transdifferentiation of adult rat bone marrow stem cells (ABMSCs) into hepatic parenchymal cells. METHODS: The serum was collected from the rats 24 hours after being subjected to subtotal hepatectomy. ABMSCs were collected and cultured in DMEM/F12 (1:1) containing the hepaetectomized rat serum or HGF. The differentiated hepatocyte-like cells were labeled with CM-DiI and administrated by tail vein injection into the isogeneic rats. The cultured and injected cells were both identified by immunocytochemistry and cultured cells were assayed using RT-PCR and Western blot. RESULTS: Hepatectomized rat serum and HGF were demonstrated to have the effect of inducing transdifferentiation of ABMSCs into hepatocyte-like cells in vitro. The differentiated cells expressed albumin mRNA and albumin after 7 days++'s co-incubation. Albumin-expressing and CM-DiI positive hepatocyte-like cells were characterized in livers and spleens of the rats injected with the cultivated cells. CONCLUSION: ABMSCs could transdifferentiate into hepatic parenchymal cells by hepatectomized rat serum or HGF.