Exogenous H2S promotes cancer progression by activating JAK2/STAT3 signaling pathway in esophageal EC109 cells.

Hydrogen sulfide (H2S) plays an important role in diverse physiological and pathophysiological processes in cancer cells both in vitro and in vivo. We have previously shown that exogenous H2S exerts its biological effects on hepatoma, glioma, and esophageal cancer cells through the activation of NF-κB, p38-MAPK/ERK1/2-COX-2, and HSP90 pathways. However, the role of H2S and the underlying mechanism in esophageal squamous cell carcinoma remain unclear. Here we investigated whether exogenous H2S contributes to the biological behavior of esophageal squamous cancer cell line EC109, through the activation of JAK2/STAT3 signaling pathway. EC109 cells were treated with NaHS (a donor of H2S) and AG490 (a specific inhibitor of JAK2/STAT3 signaling pathway). The expression levels of p-JAK2, p-STAT3, caspase-3/9/12, Bax, Bcl-2, MMP-2/9, and VEGFR were measured by western blot analysis. Cell viability was detected by CCK-8 and quantified by direct counting of cells under a microscope. Cell migration was analyzed by the scratch-wound assay, while the level of VEGF was measured by ELISA. Cells treated with NaHS for 24 h showed significant upregulation of p-JAK2, and p-STAT3 expression, as well as increased cell viability when compared to the control cells. The expression levels of caspase-3/9/12 and Bax decreased, while those of Bcl-2, MMP-2/9, VEGFR, and VEGF increased. NaHS induced the migration of EC109 cells. However, co-treatment with NaHS and AG490 significantly inhibited these effects. Thus, JAK2/STAT3 signaling pathway may contribute to H2S-induced cell proliferation, anti-apoptosis, migration, and angiogenesis in EC109 cells.

[Angiotensin-(1-7) protects cardiac myocytes against high glucose-induced injury by inhibiting ClC-3 chloride channels].

OBJECTIVE: To explore whether angiotensin-(1-7) [Ang-(1-7)] protects cardiac myocytes against high glucose (HG)-induced injury by inhibiting ClC-3 chloride channels. METHOD: H9c2 cardiac cells were exposed to 35 mmol/L glucose for 24 h to establish a cell injury model. The cells were treated with Ang-(1-7) or the inhibitor of chloride channel (NPPB) in the presence of HG for 24 h to observe the changes in HG-induced cell injury. Cell counter kit 8 (CCK-8) assay was used to test the cell viability, and the morphological changes of the apoptotic cells were detected using Hoechst 33258 staining and fluorescent microscopy. The intracellular level of reactive oxygen species (ROS) was examined by DCFH-DA staining, SOD activity in the culture medium was measured using commercial kits, and the mitochondrial membrane potential (MMP) of the cells was tested with rodamine 123 staining. The expression level of cardiac ClC-3 chloride channels was detected with Western blotting. RESULTS: Exposure of H9c2 cardiac cells to 35 mmol/L glucose for 24 h markedly enhanced the expressions of cardiac ClC-3 channel protein (P<0.01). Co-treatment of the cells with 1 µmol/L Ang-(1-7) and HG for 24 h significantly attenuated HG- induced upregulation of ClC-3 channel protein expression (P<0.01). Co-treatment of the cells exposed to HG with 1 µmol/L Ang-(1-7) or 100 µmol/L NPPB for 24 h obviously ameliorated HG-induced injuries as shown by increased cell viability, enhanced SOD activity, decreased number of apoptotic cells, and reduced intracellular ROS generation and loss of MMP (P<0.01). CONCLUSION: ClC-3 channels are involved in HG-induced injury in cardiac cells. Ang-(1-7) protects cardiac cells against HG-induced injury by inhibiting ClC-3 channels.

[Exogenous hydrogen sulfide inhibits high-glucose-induced injuries via regulating leptin/leptin receptor signaling pathway in human umbilical vein endothelial cells].

OBJECTIVE: To investigate whether exogenous hydrogen sulfide (H2S) inhibits the high-glucose (HG)-induced injury by modulating leptin/leptin receptor (LEPR) signal pathway in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were treated with 40 mmol/L glucose for 3-24 h, and the cell viability was examined by CCK-8 assay. The changes of cell morphology and the number of apoptotic cells were assessed by Hoechst 33258 nuclear staining followed by photofluorography. The intracellular levels of reactive oxygen species (ROS) was detected by DCFH-DA staining followed by photofluorography. Mitochondrial membrane potential (MMP) was determined by Rhodamine 123 (Rh123) staining and photofluorography. The expression levels of leptin and LEPR protein were measured by Western blotting. RESULTS: s The expression of leptin and LERP in HUVECs began to significantly increase at 3 h after HG exposure and reached the peak levels at 9 h (P<0.01). Pretreatment of HUVECs with 400 µmol/L sodium hydrosulfide (H2S donor) for 30 min inhibited HG-induced increase in leptin and leptin receptor expressions in HUVECs (P<0.01). Pretreatment of HUVECs with 400 µmol/L NaHS for 30 min or 50 ng/mL leptin antagonists (LA) for 1 h obviously alleviated HG-induced injury by increasing cell viability, decreasing cell apoptosis and lowering accumulation of intracellular ROS and MMP loss (P<0.01). CONCLUSION: Exogenous H2S protects against HG-induced injury by inhibiting leptin/LEPR pathway in HUVECs.

The effects of types of degradable polymers on porcine chondrocyte adhesion, proliferation and gene expression.

Understanding how a specific biomaterial may influence chondrocyte adhesion, proliferation and gene expression is important in cartilage tissue engineering. In this study several biodegradable polymers that are commonly used in tissue engineering were evaluated with respect to their influence on chondrocyte attachment, proliferation and gene expression. Primary cultures of porcine chondrocytes were performed in films made of poly-L-lactic acid (PLLA), poly-D,L-lactic acid (PDLLA), poly-(lactide-co-glycolide) (PLGA), or polycaprolactone (PCL). Chondrocytes adhered to PDLLA or PLGA after 1-day incubation better than to PLLA or PCL. After 7 or 14 day culture, the cell numbers on PDLLA or PLGA was still higher than PLLA or PCL. The results suggested that cell attachment and growth might depend on degradation rate of biodegradable polymers. Along with the fact that PDLLA or PLGA supported expression of chondrocyte specific genes more than PLLA or PCL, the former two materials seemed to be more suitable for cartilage tissue engineering than the latter ones. Besides, we found that chondrocyte phenotype prior to seeding was important in the expression of ECM proteins.