AIM:This study aims to investigate the role of histone methyltransferase SET and MYND domain containing 2(SMYD2)in facilitating renal fibrosis through the macrophage-myofibroblast transition in diabetic kidney dis-ease(DKD).METHODS:(1)C57BL/6J mice were intraperitoneally administered 55 mg/kg of streptozotocin to induce diabetes mellitus(DM).The experimental groups were categorized as follows:normal control,DM(20 weeks),DM(28 weeks),and DM(36 weeks).Blood glucose(BG),serum creatinine(SCr)and blood urea nitrogen(BUN)levels were determined using a biochemical analyzer.Hematoxylin-eosin(HE)staining and Masson staining were performed to assess morphological and fibrotic changes in renal tissues.Western blot analysis was used to measure the protein levels of SMYD2,histone H3 lysine 4 trimethylation(H3K4me3),arginase-1,matrix metalloproteinase 9(MMP9),collagen type Ⅰ(Col Ⅰ)and α-smooth muscle actin(α-SMA).Immunofluorescence staining was conducted to examine the localization and expression of F4/80,α-SMA,SMYD2,CD86,CD206 and CD163.(2)Mouse monocyte/macrophage RAW264.7 cells were cultured in vitro and assigned to groups as follows:normal glucose(NG)+negative control siRNA(siNC),high glucose(HG)+siNC,NG+SMYD2 siRNA(siSMYD2),and HG+siSMYD2.Western blot analysis was used to assess the expression of relevant proteins.RESULTS:(1)Compared with normal control group,the levels of BG,SCr and BUN were significantly elevated in DM(28 weeks)and DM(36 weeks)groups(P＜0.05).Renal tissue exhibited tubular atro-phy,dilation,and collagen fiber deposition.The levels of H3K4me3,arginase-1,MMP9,Col Ⅰ and α-SMA proteins were up-regulated(P＜0.05).The CD86,CD206,CD163 and F4/80 were primarily localized in the interstitial macrophages of the renal tubules,α-SMA was predominantly detected in the renal interstitium,and SMYD2 was mainly expressed in renal tubular epithelial cells and the renal interstitium.(2)Compared with NG+siNC group,the protein levels of SMYD2,H3K4me3,arginase-1,CD163,Col Ⅰ,α-SMA,transforming growth factor-β1(TGF-β1)and p-Smad3 in the cells of HG+siNC group were significantly increased(P＜0.05).Knockdown of SMYD2 resulted in a reduction of these indicators(P＜0.05).CONCLUSION:The SMYD2 protein appears to facilitate renal fibrosis in DKD by promoting the macrophage-myofibroblast transition,potentially through the modulation of TGF-β1/Smad3 signaling pathway.

AIM:This study aims to investigate the role of histone methyltransferase SET and MYND domain containing 2(SMYD2)in facilitating renal fibrosis through the macrophage-myofibroblast transition in diabetic kidney dis-ease(DKD).METHODS:(1)C57BL/6J mice were intraperitoneally administered 55 mg/kg of streptozotocin to induce diabetes mellitus(DM).The experimental groups were categorized as follows:normal control,DM(20 weeks),DM(28 weeks),and DM(36 weeks).Blood glucose(BG),serum creatinine(SCr)and blood urea nitrogen(BUN)levels were determined using a biochemical analyzer.Hematoxylin-eosin(HE)staining and Masson staining were performed to assess morphological and fibrotic changes in renal tissues.Western blot analysis was used to measure the protein levels of SMYD2,histone H3 lysine 4 trimethylation(H3K4me3),arginase-1,matrix metalloproteinase 9(MMP9),collagen type Ⅰ(Col Ⅰ)and α-smooth muscle actin(α-SMA).Immunofluorescence staining was conducted to examine the localization and expression of F4/80,α-SMA,SMYD2,CD86,CD206 and CD163.(2)Mouse monocyte/macrophage RAW264.7 cells were cultured in vitro and assigned to groups as follows:normal glucose(NG)+negative control siRNA(siNC),high glucose(HG)+siNC,NG+SMYD2 siRNA(siSMYD2),and HG+siSMYD2.Western blot analysis was used to assess the expression of relevant proteins.RESULTS:(1)Compared with normal control group,the levels of BG,SCr and BUN were significantly elevated in DM(28 weeks)and DM(36 weeks)groups(P＜0.05).Renal tissue exhibited tubular atro-phy,dilation,and collagen fiber deposition.The levels of H3K4me3,arginase-1,MMP9,Col Ⅰ and α-SMA proteins were up-regulated(P＜0.05).The CD86,CD206,CD163 and F4/80 were primarily localized in the interstitial macrophages of the renal tubules,α-SMA was predominantly detected in the renal interstitium,and SMYD2 was mainly expressed in renal tubular epithelial cells and the renal interstitium.(2)Compared with NG+siNC group,the protein levels of SMYD2,H3K4me3,arginase-1,CD163,Col Ⅰ,α-SMA,transforming growth factor-β1(TGF-β1)and p-Smad3 in the cells of HG+siNC group were significantly increased(P＜0.05).Knockdown of SMYD2 resulted in a reduction of these indicators(P＜0.05).CONCLUSION:The SMYD2 protein appears to facilitate renal fibrosis in DKD by promoting the macrophage-myofibroblast transition,potentially through the modulation of TGF-β1/Smad3 signaling pathway.

A corresponding calibration method was proposed for the key performance parameters of the endoscopic liquid expansion pump,such as the pressure indication error,the flow rate indication error and the flow rate repeatability.4 different brands of endoscopic liquid expansion pumps in clinical use in the hospital were selected for calibration,and the feasibility of the calibration method was evaluated.In the pressure and flow range of the endoscope liquid expansion pump,3 calibration points of high,medium and low were selected,and each flow point was calibrated 3 times.The calibration results showed that the maximum error of pressure indication was 4.3%,the maximum error of flow indication was 9.3%,and the maximum repeatability of flow indication value was 0.8%,all of which met the technical requirements for the maximum allowable error of"Medical Endoscopes.Endoscope Functional Supply Units.Irrigation Pump"(YY/T 0864-2011)and"Calibration Specification for Syringe Pumps and Infusion Pumps"(JJF 1259-2018).The calibration method for endoscopic liquid expansion pump can improve the metrological traceability system of this type of equipment,ensure the accuracy and reliability of equipment values,improve product quality,and ensure medical safety.