Necroptosis mediates high glucose-induced injury in human umbilical vein endothelial cells / 中国病理生理杂志

AIM: To explore whether necroptosis contributes to the high glucose (HG)-induced damage in hu-man umbilical vein endothelial cells (HUVECs).METHODS: The protein levels of receptor-interacting protein 3 (RIP3) and cleaved caspase-3 were detected by Western blot.The intracellular levels of reactive oxygen species (ROS) were deter-mined by DCFH-DA staining followed by photofluorography.Mitochondrial membrane potential (MMP) was measured by rhodamine 123 staining followed by photofluorography.RESULTS: Treatment of HUVECs with HG at different concentra-tions (10, 20 and 40 mmol/L glucose) for 24 h gradually enhanced the expression levels of RIP3.Treatment of HUVECs with HG (40 mmol/L glucose) for different time (3 h, 6 h, 9 h, 12 h and 24 h) also up-regulated the expression levels of RIP3, peaking at 9 h.Pretreatment of HUVECs with 20 μmol/L Z-VAD-FMK (an inhibitor of caspase) for 30 min before exposure to HG enhanced the expression level of RIP3.Pretreatment of HUVECs with 100 μmol/L necrostatin-1 (an inhi-bitor of necroptosis) for 1 h before exposure to HG alleviated the HG-induced injuries, such as a decrease in cell viability, an increase in ROS generation and dissipation of MMP, but up-regulated the protein level of cleaved caspase-3.CON- CLUSION: Necroptosis mediates HG-induced injury in HUVECs.There is a negative interacting between necroptosis and apoptosis.

Opening of ATP-sensitive K+channels protects H9c2 cardiac cells against high glucose-induced injury and inflammation by inhibiting TLR4/NF-κB pathway / 中国病理生理杂志

AIM:To investigate whether the opening of ATP-sensitive K+(KATP) channels protects H9c2 car-diac cells against high glucose ( HG)-induced injury and inflammation by inhibiting the Toll-like receptor 4 ( TLR4 )/nu-clear factor-κB ( NF-κB) pathway.METHODS:The protein levels of TLR4 and NF-κB p65 were determined by Western blot.The levels of interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) were detected by ELISA.The cell viabil-ity was measured by CCK-8 assay.Mitochondrial membrane potential (MMP) was examined by rhodamine 123 (Rh 123) staining followed by photofluorography.The intracellular levels of reactive oxygen species ( ROS) were detected by 2′, 7′- dichlorfluorescein-diacetate (DCFH-DA) staining followed by photofluorography.The number of apoptotic cells was ob-served by Hoechst 33258 nuclear staining followed by photofluorography.RESULTS: After the H9c2 cardiac cells were treated with HG (35 mmol/L glucose) for 24 h, the protein levels of TLR4 and phosphorylated NF-κB p65 ( p-NF-κB p65) were significantly increased.Pretreatment of the cells with 100 μmol/L diazoxide ( DZ, a KATP channel opener) for 30 min before exposure to HG considerably blocked the up-regulation of the TLR4 and p-NF-κB protein levels induced by HG.Moreover, co-treatment of the cells with 30 μmol/L TAK-242 (an inhibitor of TLR4) obviously inhibited the HG-in-duced up-regulation of the p-NF-κB p65 protein level.On the other hand, pretreatment of the cells with 100 μmol/L DZ had a clear myocardial protection effect, which attenuated the HG-induced cytotoxicity, inflammatory response, mitochon-drial damage, oxidative stress and apoptosis, evidenced by an increase in the cell viability, and decreases in the levels of IL-1βand TNF-α, MMP loss, ROS generation and the number of apoptotic cells.Similarly, co-treatment of H9c2 cardiac cells with 30μmol/L TAK-242 or 100μmol/L PDTC ( an inhibitor of NF-κB) and HG for 24 h also obviously reduced the above injuries and inflammation induced by HG.CONCLUSION: The opening of KATP channels protects H9c2 cardiac cells against HG-induced injury and inflammation by inhibiting the TLR4/NF-κB pathway.

Role of ATP-sensitive potassium channels in inhibitory effect of hydrogen sulfide on high glucose-induced inflammation mediated by necroptosis in H9c2 cardiac cells / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the role of ATP-sensitive potassium ( KATP ) channels in the inhibitory effect of hydrogen sulfide ( H2 S) on high glucose ( HG)-induced inflammation mediated by necroptosis in H 9c2 cardiac cells. METHODS:The expression levels of receptor-interacting protein 3 ( RIP3; an indicator of necroptosis ) and cyclooxyge-nase-2 (COX-2) were determined by Western blot.The levels of interleukin-1β(IL-1β) and tumor necrosis factor-α( TNF-α) were detected by ELISA .RESULTS:After H9c2 cardiac cells were treated with 35 mmol/L glucose ( HG) for 24 h, the expression of RIP3 was significantly increased .Pre-treatment of the cells with 100 μmol/L diazoxide ( DZ; a KATP channel opener) or 400 μmol/L NaHS (a donor of H2S) for 30 min considerably blocked the up-regulation of RIP3 induced by HG.Moreover, pre-treatment of the cells with 100 μmol/L 5-hydroxydecanoic acid (5-HD; a KATP channel blocker) attenuated the inhibitory effect of NaHS on HG-induced up-regulation of RIP3.On the other hand, co-treatment of the cells with 100μmol/L necrostatin-1 ( a specific inhibitor of necroptosis ) or pre-treatment of the cells with 100 μmol/L DZ or 400 μmol/L NaHS attenuated HG-induced inflammatory responses , evidenced by decreases in the expression of COX-2 and secretion levels of IL-1βand TNF-α.However , pre-treatment of the cells with 100 μmol/L 5-HD significantly attenuated the above anti-inflammatory effects of NaHS.CONCLUSION:KATP channels play an important role in the inhib-itory effect of H2 S on HG-induced inflammation mediated by necroptosis in H 9c2 cardiac cells.

Nicorandil protects H9 c2 cardiac cells against high glucose-induced injury and inflammation / 中国药理学通报

Aim To investigate whether nicorandil (Nic)protects H9c2 cardiac cells against high glucose (HG)-induced injury and inflammation by inhibiting nuclear factor-κB (NF-κB )/cyclooxygenase-2 (COX-2 )pathway.Methods Cell viability was measured by cell counter kit-8 (CCK-8)assay.The expression lev-els of NF-κB,COX-2 and cleaved caspase-3 were de-termined by Western blot.The activity of lactate dehy-drogenase (LDH)in the culture medium was measured with commercial kits.The intracellular level of reactive oxygen species (ROS)was detected by 2′,7′-dichlor-fluorescein-diacetate (DCFH-DA)staining followed by photofluorography.The number of apoptotic cells was observed by Hoechst 33258 nuclear staining followed by photofluorography.Mitochondrial membrane poten-tial (MMP)was examined by rhodamine 123 staining followed by photofluorography.The secretion levels of interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) were detected by ELISA.Results After H9 c2 cardiac cells were treated with 35 mmol · L-1 glucose (high glucose,HG)for 24 h,the cell viability was significantly decreased .Pre-treatment of the cells with 20~100 μmol·L-1 Nic for 60 min or 50 μmol· L-1 Nic for 30~120 min before exposure to HG signif-icantly attenuated the decrease in viability induced by HG.On the other hand,HG increased the expression levels of phosphorated (p)-NF-κB p65 and cyclooxy-genase-2 (COX-2 )in H9c2 cardiac cells.Pre-treat-ment of the cells with 50 μmol·L-1 Nic for 60 min at-tenuated the up-regulation of p-NF-κB p65 and COX-2 expression levels induced by HG.Furthermore,HG induced considerable injuries and inflammatory re-sponse,leading to increases in LDH activity,ROS generation,MMP loss,the number of apoptotic cells, the expression of cleaved caspase-3 as well as the se-cretion levels of IL-1βand TNF-α.Pre-treatment of the cells with 50 μmol·L-1 Nic for 60 min before HG exposure,or co-treatment of the cells with 100 μmol· L-1 PDTC (an inhibitor of NF-κB)or 10 μmol·L-1 NS-398 (an inhibitor of COX-2)and HG for 24 h ob-viously reduced the above injuries and inflammatory re-sponse induced by HG. Conclusion Nic protects H9 c2 cardiac cells against HG-induced injury and in-flammation by inhibiting NF-κB/COX-2 pathway.

Angiotensin-(1-7) protects H9c2 cardiac cells against high glucose-in- duced injury and inflammation by inhibiting the interaction between TLR4 activation and necroptosis / 中国病理生理杂志

AIM:To investigate whether angiotensin-(1-7) [Ang-(1-7)] protects H9c2 cardiac cells against high glucose (HG)-induced injury and inflammation by inhibiting the interaction between Toll-like receptor 4 (TLR4) acti-vation and necroptosis .METHODS:The expression levels of receptor-interacting protein 3 ( RIP3;an indicator of necrop-tosis) and TLR4 were determined by Western blot .Cell viability was measured by CCK-8 assay.The activity of lactate de-hydrogenase ( LDH) in the culture medium was measured with a commercial kit .The releases of interleukin-1β( IL-1β) and tumor necrosis factor-α( TNF-α) were measured by ELISA .The intracellular level of reactive oxygen species ( ROS) was analyzed by 2 ’ , 7 ’-dichlorfluorescein-diacetate ( DCFH-DA ) stating followed by photofluorography .Mitochondrial membrane potential ( MMP) was examined by rhodamine 123 staining followed by photofluorography .RESULTS:After the H9c2 cardiac cells were treated with HG (35 mmol/L glucose) for 24 h, the expression of RIP3 was obviously increased . Co-treatment of the cells with 30μmol/L TAK-242 (an inhibitor of TLR4) attenuated the up-regulation of RIP3 induced by HG.Furthermore, the expression of TLR4 was significantly increased after the cells were exposed to HG for 24 h, and co-treatment of the cells with 100μmol/L necrostatin-1 ( Nec-1;a specific inhibitor of necroptosis ) and HG for 24 h attenua-ted the up-regulation of TLR4 expression induced by HG .Moreover, 1μmol/L Ang-(1-7) simultaneously blocked the up-regulation of the RIP3 and TLR4 induced by HG.On the other hand, co-treatment of the cells with 1μmol/L Ang-(1-7), 30 μmol/L TAK-242 or 100 μmol/L Nec-1 and HG for 24 h attenuated HG-induced injuries and inflammatory response , leading to the increase in the cell viability , and the decreases in the activity of LDH , ROS generation , MMP loss as well as the releases of IL-1βand TNF-α.CONCLUSION:Ang-(1-7) protects H9c2 cardiac cells against HG-induced injury and inflammation by inhibiting the interaction between TLR 4 activation and necroptosis .