AIM:To investigate the effect of circular RNA MYO9A-006(circMYO9A_006)on hypertrophic phenotype of cardiomyocytes and the underlying mechanism.METHODS:The effect of adenovirus-mediated overexpres-sion of circMYO9A_006 on the expression of hypertrophy-related proteins,including β-myosin heavy chain(β-MHC),skeletal muscle actin alpha 1(ACTA1)and atrial natriuretic peptide(ANP),was evaluated in neonatal mouse ventricular cardiomyocytes(NMVCs).Moreover,a neonatal rat ventricular cardiomyocyte(NRVC)model of phenylephrine(PE)-in-duced hypertrophy was established.The effect of circMYO9A_006 overexpression on NRVC size was ascertained using Phalloidin-iFluor 647 staining method.Dual-luciferase reporter assay was employed to measure the activity of potential in-ternal ribosome entry sites(IRES)in circMYO9A_006.The translation and intracellular location of the circMYO9A_006-translated protein,MYO9A-208aa,were verified using Western blot.To investigate the role of MYO9A-208aa in the ef-fect of circMYO9A_006 on the cardiomyocyte hypertrophic phenotype,we prepared and used the following adenoviruses:the recombinant circMYO9A_006-ORF adenovirus to express MYO9A-208aa,the recombinant circMYO9A_006-ATG-mut adenovirus that does not express MYO9A-208aa,the recombinant circMYO9A_006 adenovirus,and the adenovirus vector control.These were then employed to infect NRVCs.RESULTS:Successful adenovirus-mediated overexpression of circMYO9A_006 was observed in NMVCs.The increased expression of circMYO9A_006 notably reduced the expres-sion of hypertrophy-related proteins in NMVCs(P<0.01).Concurrently,overexpression of circMYO9A_006 substantially reduced the expression of hypertrophy-associated proteins and diminished the size of PE-induced NRVCs(P<0.05).Dual-luciferase reporter assay identified the activity of 2 IRES in circMYO9A_006.Western blot results indicated that circ-MYO9A_006 could produce the MYO9A-208aa protein with an anticipated molecular weight of 28 kD in NRVCs,primari-ly found in the cytoplasm.Elevated expression of both circMYO9A_006 and MYO9A-208aa consistently reduced the ex-pression of hypertrophy-associated proteins(P<0.01),and counteracted the enlarged size of PE-induced NRVCs(P<0.05).However,increased expression of circMYO9A_006-ATG-mut did not counteract the PE-induced hypertrophic phe-notype of NRVCs.CONCLUSION:circMYO9A_006 attenuates the hypertrophic phenotype of cardiomyocytes by synthe-sizing the MYO9A-208aa protein.

AIM:To investigate the mechanism of Piezo1 channel activation promoting the increase in intra-cellular Ca2+ concentration([Ca2+]i)of rat coronary artery smooth muscle cells(CASMCs).METHODS:The primary CASMCs of SD rats were cultured,and the expression and subcellular localization of Piezo1 in the cells were observed by immunofluorescence staining.The Piezo1 and stromal interaction molecule 1(STIM1)in CASMCs were knocked down by siRNA transfection,and the expression levels of the proteins were detected by Western blot.Utilizing laser confocal mi-croscopy,the change of[Ca2+]i in CASMCs was detected by Fluo-4 AM fluorescent probes.RESULTS:It was confirmed by immunofluorescence staining that the expression of Piezo1 existed in primary rat CASMCs.Immunofluorescence staining also showed that Piezo1 was co-located with sarco-/endoplasmic reticulum Ca2+-ATPase 2(SERCA2),mitochondrial outer membrane protein TOM20 and nuclear membrane protein lamin B1.Western blot results showed that the protein expres-sion levels of STIM1 and Piezo1 were significantly down-regulated by siRNA transfection(P<0.05).Compared with con-trol group,Yoda1,the agonist of Piezo1,could increase the extracellular Ca2+ influx of CASMCs(P<0.01).However,the Ca2+ influx mediated by Yoda1 was not affected by the inhibition of L-type calcium channels.Treatment with Yoda1 in-creased the intracellular Ca2+ release of CASMCs(P<0.01).However,inhibition of calcium channels on endoplasmic re-ticulum,ryanodine receptor and inositol 1,4,5-triphosphate receptor,did not affect intracellular Ca2+ release mediated by Yoda1.After the Ca2+ in endoplasmic reticulum was emptied using thapsigargin(TG),Yoda1 also mediated the Ca2+ re-lease of other organelles in CASMCs(P<0.01).After inhibition of L-type calcium channels,treatment with store-operated calcium channel(SOCC)inhibitor BTP2 or knockdown of STIM1 led to the decrease in extracellular Ca2+ influx of CASMCs mediated by Yoda1(P<0.01).Treatment with TG increased the release of Ca2+ from the endoplasmic reticulum of CASMCs after knockdown of Piezo1(P<0.05),but the extracellular Ca2+ influx mediated by TG was not affected.After inhibition of L-type calcium channels and SOCC,knockdown of Piezo1 led to the decreases in intracellular Ca2+ release and extracellular Ca2+ influx induced by Yoda1(P<0.01).CONCLUSION:The Piezo1 agonist orchestrates the influx of extracellular Ca2+ by activating Piezo1 channels on the cell membrane and inducing the indirect activation of SOCC.More-over,it facilitates the release of Ca2+ from organelles.Consequently,these pathways synergistically elevate the[Ca2+]i of rat CASMCs.

AIM:To investigate the effects of adipose-derived stem cells(ADSCs)with overexpression or si-lencing of long noncoding RNA(lncRNA)SNHG8 on the viability,migration,angiogenesis,and the expression of vasoac-tive factors in human umbilical vein endothelial cells(HUVECs).METHODS:Identification of ADSCs derived from morbidly obese patients(O-ADSCs)was conducted using flow cytometry and induction of lipogenesis and osteogenesis.The expression of lncRNA SNHG8 in healthy human ADSCs(H-ADSCs)and O-ADSCs was detected by RT-qPCR.Tran-swell method was used to establish the indirect co-culture system of ADSCs and HUVECs for 48 h,and the cells were di-vided into O-ADSCs+HUVECs group,H-ADSCs+HUVECs group,and HUVECs alone group.The mRNA and protein ex-pression levels of angiotensin Ⅱ(Ang Ⅱ),endothelin-1(ET-1)and endothelial nitric oxide synthase(eNOS)in HUVECs were detected by RT-qPCR and Western blot.The lncRNA SNHG8 overexpression and silencing lentiviruses were con-structed and used to infect O-ADSCs.The indirect co-cultured ADSCs and HUVECs were divided into O-ADSCs-OE-SNHG8+ HUVECs group,O-ADSCs-OE-NC+HUVECs group,O-ADSCs-sh-SNHG8+HUVECs group,and O-ADSCs-sh-NC+HUVECs group.After co-culture for 48 h,the viability,migration and tubule formation of HUVECs were detected by CCK-8,scratch and angiogenesis assays,respectively.The mRNA and protein expression levels of Ang Ⅱ,ET-1 and eNOS in HU-VECs were detected by RT-qPCR and Western blot,respectively.The nitrate reductase method was used to detect the con-tent of NO in HUVECs.RESULTS:(1)The cultured cells were identified as ADSCs.(2)Compared with H-ADSCs,ln-cRNA SNHG8 expression was significantly up-regulated in O-ADSCs(P<0.01).(3)Compared with H-ADSCs+HUVECs group and HUVECs group,the mRNA and protein expression levels of Ang Ⅱ and ET-1 in HUVECs in O-ADSCs+HU-VECs group were up-regulated(P<0.01).(4)Overexpression of lncRNA SNHG8 in O-ADSCs enhanced the viability,mi-gration and tube formation ability of HUVECs,up-regulated the mRNA and protein expression levels of Ang Ⅱ and ET-1,down-regulated the mRNA and protein expression levels of eNOS,and decreased the content of NO in HUVECs(P<0.05).However,silencing of lncRNA SNHG8 in O-ADSCs exerted opposite results(P<0.05).CONCLUSION:(1)The O-ADSCs can promote endothelial cell viability,migration and tubule formation through paracrine effects.(2)The O-ADSCs with overexpression of lncRNA SNHG8 promote the imbalance of diastolic and contractile factors secreted by endo-thelial cells,and induce the dysfunction of vascular endothelial cells.

AIM:To explore the effects of CD38 on lysosome reformation and cholesterol efflux in macro-phages.METHODS:Bone marrow-derived macrophages from low-density lipoprotein(LDL)receptor knockout(LDLr-/-)mice were cultured as cell model.Live cell imaging system was applied to evaluate the effect of nicotinic acid adenine di-nucleotide phosphate(NAADP)on lysosome number.ELISA was conducted to measure NAADP level in macrophages.After the cells were treated with nicotinic acid(NA),RT-qPCR was conducted to detect CD38 mRNA expression,and Western blot was conducted to observe CD38 protein expression and phosphorylated transcription factor EB(TFEB)level.Laser scanning confocal microscopy was applied to evaluate the influence of CD38/NAADP signaling on lysosome number and cholesterol egression.RESULTS:NAADP remarkably increased lysosome number(P<0.05),and this effect was significantly inhibited by NAADP antagonist NED-19,Ca2+ chelator BAPTA,and calcineurin inhibitor CsA(P<0.05).CD38 markedly enhanced NAADP synthesis in macrophages(P<0.05).NAADP synthetic substrate NA prominently ele-vated the expression of CD38 mRNA and protein(P<0.05).NA significantly decreased the phosphorylated TFEB level;this effect was also attenuated by NED-19,BAPTA and CsA(P<0.05).Disrupting CD38/NAADP signaling pathway markedly inhibited NA-induced enhancement of lysosome number,lysosomal free cholesterol and cytosol cholesterol ester efflux in macrophages(P<0.05).NA-induced enhancement of lysosome number,lysosomal free cholesterol and cytosol cholesterol ester efflux abolished in LDLr/CD38 DKO macrophages(P<0.05),whereas these effects induced by NA were recovered after CD38 gene rescue.CONCLUSION:CD38 triggers lysosome reformation via TFEB and consequently pro-motes the efflux of lysosomal free cholesterol and cytosol cholesterol ester.

AIM:This study aim to investigate the effects of lipopolysaccharide(LPS)-induced inflammation on the aging phenotype of hematopoietic stem/progenitor cells(HSPCs)in the bone marrow(BM)and spleen of mice.METHODS:(1)Young(2-month old)wild-type(WT)mice were treated with LPS to establish an actue inflammation model.The percentage of HSPCs in the BM and spleen of mice after LPS stimulation,as well as the ratio of mature cells in peripheral blood(PB)and spleen,were analyzed using flow cytometry.The proliferation of HSPCs in the BM and spleen was evaluated by examining the expression of the proliferation marker Ki67.In addition,changes in CD45 expression on HSPCs in the spleen of mice following LPS exposure were investigated by flow cytometry.(2)The percentage of HSPCs in BM and mature cells in PB and spleen of both young(2-month old)and old(24-month old)WT mice were analyzed by flow cytometry.(3)The transcriptome changes of hematopoietic stem cells(HSCs)after LPS stimulation was performed by an in silico analysis.RESULTS:(1)Mice exposed to LPS exhibited a significant increase in the percentage of HSPCs in BM and a marked elevation in the percentages of myeloid cells in PB and spleen compared to the mice in control group(P<0.05).(2)LPS exposure resulted in increased spleen weight and cell counts(P<0.05),along with a higher per-centage of HSPCs in the spleen compared to controls(P<0.05).(3)LPS stimulation promoted the proliferation of HSPCs in the BM and spleen(P<0.05).(4)The expression of CD45 was reduced on HSPCs from spleen of mice after LPS stimu-lation(P<0.01).(5)In comparison to young mice,aged mice showed an increase in spleen weight and a higher percent-age of HSPCs in the spleen(P<0.05).(6)Aged mice,in comparison to young mice,demonstrated a significantly higher percentage of HSPCs in the BM and myeloid skewing in the PB and spleen(P<0.01).(7)The silico analysis revealed up-regualtion of reactive oxygen species(ROS)and apoptosis signaling in HSPCs following LPS stimulation.CONCLU-SION:Young HSPCs stimulated by LPS exhibited an increase in cell number,a bias towards myeloid differentiation,en-hanced extramedullary hematopoiesis,and elevated levels of ROS and apoptosis,all of which collectively manifested the aging phenotype of HSPCs.

AIM:To explore the expression of RhoC in oral squamous cell carcinoma(OSCC)and its effects on the malignant biological behavior of OSCC cells.METHODS:The UALCAN and K-M plotter databases,alongside tis-sue sample analyses,facilitated understanding RhoC expression in cancer and its links to clinicopathological traits.Two small interfering RNAs(RhoC-siRNA)were constructed according to the RhoC gene sequence.The mRNA and protein ex-pression levels of RhoC in OSCC cells were determined.The protein levels of FAK,p-FAK,MAPK,p-MAPK,matrix me-talloproteinase-2(MMP-2)and MMP-9 were also examined by Western blot.Furthermore,the invasion and migration of OSCC cells were analyzed by Transwell assay and scratch test.Finally,the pulmonary metastasis model of nude mice was established.RESULTS:The results of the databases showed that RhoC was highly expressed in OSCC tissues,which was closely related to pathological stage,pathological grade and lymph node metastasis,but not significantly related to the sur-vival rate of patients.Furthermore,compared with paracancer tissues,the mRNA and protein expression levels of RhoC were increased in OSCC tissues(P<0.01).Silencing of RhoC prominently reduced the migration and invasion of OSCC cells as well as the protein levels of p-FAK,p-MAPK,MMP2 and MMP9(P<0.05).The protein levels of MAPK and FAK were unchanged(P>0.05).The fluorescence intensity of the experimental group was significantly lower than that of the control group,and the results of HE staining showed that the number of lung nodules in the experimental group was sig-nificantly reduced(P<0.05).CONCLUSION:RhoC can effectively influence the migration and invasion of OSCC cells,and its potential mechanism may be related to FAK/MAPK/MMPs signaling pathway.

AIM:To observe the effect of Pingwei capsule on the precancerous lesions of gastric cancer(PLGC)cell model induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG),and to preliminarily explore its mecha-nism.METHODS:Blank serum and Pingwei capsule-containing serum were prepared for later use.A PLGC cell model was established by MNNG-induced human gastric mucosal epithelial cell line GES-1.To evaluate the model,cell morpho-logical changes were observed under inverted microscope,and the expression of proliferating cell-related antigen Ki67 was detected by immunofluorescence staining.CCK-8 assay was used to screen the optimal intervention concentration and time of serum containing drugs.Reactive oxygen species(ROS)content in cells was detected using a fluorescent probe DCFH-DA.Malondialdehyde(MDA)content was detected by ELISA,and the activity of superoxide dismutase(SOD)and gluta-thione peroxidase(GSH-Px)was detected using biochemical reagents.A novel fluorescent probe JC-10 was used to detect mitochondrial membrane potential.The mRNA expression levels of Ki67 and melanoma differentiation-associated gene-7(MDA-7)were detected by real-time fluorescence quantitative PCR.The protein expression levels of Ki67,interleukin-6(IL-6)and MDA-7 were detected by Western blot.RESULTS:Compared with normal group,the ROS and MDA levels in model group and blank serum group were significantly increased(P<0.01),while the activity of SOD and GSH-Px was significantly decreased(P<0.01).The mitochondrial membrane potential was significantly decreased(P<0.01).The protein expression levels of Ki67 and IL-6 were significantly increased(P<0.01),while the protein expression level of MDA-7 was significantly decreased(P<0.01).There were no significant differences of the above indicators between model group and blank serum group(P>0.05).Compared with blank serum group,the Pingwei capsule-containing serum group showed significantly decreased ROS and MDA levels(P<0.01),significantly increased activity of SOD and GSH-Px(P<0.05),significantly increased mitochondrial membrane potential(P<0.01),significantly decreased protein expres-sion levels of Ki67 and IL-6(P<0.01),and significantly increased protein and mRNA expression levels of MDA-7(P<0.01).CONCLUSION:Pingwei capsule can significantly alleviate MNNG-induced oxidative damage and inflammatory response,and regulate the expression of oncogenes and tumor suppressor genes,thereby playing a role in prevention and treatment of PLGC.

AIM:To investigate the regulatory effect of oxidative stress-AMP-activated protein kinase(AMPK)-connexin 43(Cx43)-nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)pathway on extracellular matrix(ECM)remodeling of gastric smooth muscle cells under high glucose(HG)condition.METHODS:Primary rat smooth muscle cells cultured in vitro were divided into normal glucose group,HG group,HG+NLRP3 inhibitor MCC950(15 nmol/L)group,HG+Cx43 hemichannel blocker GAP19(100 μmol/L)group,HG+AMPK inhibitor Compound C(CC;10 μmol/L)group,and high glucose+antioxidant α-lipoic acid(α-LA;100 μmol/L)group,which were all cultured for 48 h for detection.The protein levels of caspase-1,matrix metalloproteinase-2(MMP-2),NLRP3,Cx43,transforming growth factor-β1(TGF-β1),TGF-β3,tissue inhibitor of metalloproteinase-1(TIMP-1),purinergic P2X7 receptor(P2X7R)and phosphorylated AMPK(p-AMPK)in the cells were detected by Western blot.The levels of adenosine tri-phosphate,interleukin-1β,collagen type Ⅰ(Col I)and collagen type Ⅲ(Col Ⅲ)in the cell culture medium were deter-mined by ELISA.RESULTS:Compared with HG group,the levels of MMP-2 and TGF-β3 in HG+MCC950 group were decreased(P<0.01),while the levels of TGF-β1 and TIMP-1 were increased(P<0.01).The levels of NLRP3 and cas-pase-1 in HG+GAP19 group were decreased(P<0.01),while the expression of P2X7R was not changed.The levels of NLRP3,caspase-1,P2X7R,total Cx43 and membrane Cx43,and the ratio of membrane Cx43 to cytoplasmic Cx43 were decreased in HG+CC group(P<0.01).The levels of p-AMPK,caspase-1,NLRP3,P2X7R,total Cx43 and membrane Cx43,and the ratio of membrane Cx43 to cytoplasmic Cx43 were decreased in HG+α-LA group(P<0.05).CONCLU-SION:High glucose regulates the content of Col I and Col Ⅲ through the oxidative stress-AMPK-Cx43-NLRP3 pathway,thereby participating in the extracellular matrix remodeling of gastric smooth muscle cells.

AIM:To investigate the mechanism of action of Wenweiyang decoction(WWYD)in treating func-tional dyspepsia in rats based on mast cell activation and stem cell factor(SCF)/receptor tyrosine kinase c-Kit signaling pathway.METHODS:Sixty SD rats were randomly divided into control group,model group,ranitidine hydrochloride capsule group,and low-,medium-and high-dose WWYD groups,with 10 rats in each group.The rat model of functional dyspepsia was established by tail clamping and irregular feeding compound senna method.After modeling,the rats in con-trol group and model group were given normal saline,while those in low-,medium-and high-dose(0.743 g/mL,1.485 g/mL and 2.970 g/mL)WWYD groups and ranitidine hydrochloride capsule(3 g/L)group were treated with corresponding drugs by intragastric administration.After treatment,the propulsion rate of the small intestine was measured by the carbon ink propulsion method.Rat duodenal mast cells were observed and counted by toluidine blue staining.ELISA was used for determination of mast cell tryptase(MCT)and histamine(HA)content in rat duodenum.The mRNA levels of SCF and c-Kit in duodenum were detected by RT-qPCR.Western blot and immunohistochemistry were employed to determine the ex-pression levels of SCF and c-Kit in the duodenum.RESULTS:Compared with model group,WWYD treatment signifi-cantly increased the propulsion rate of the small intestine in rats(P<0.05).ELISA results showed that WWYD reduced the number of mast cells and the content of MCT and HA in the duodenal mucosa tissue of rats(P<0.05).Western blot and immunohistochemistry results suggested that WWYD up-regulated the protein expression levels of c-Kit and SCF in the duodenal tissue of rats(P<0.05),and increased the numbers of SCF and c-Kit positive cells.RT-qPCR results indicated that WWYD up-regulated the mRNA expression of c-Kit and SCF in the duodenum of rats(P<0.05).Moreover,the small intestinal propulsion rate was negatively correlated with MCT and HA content,and positively correlated with the expres-sion of SCF and c-Kit.CONCLUSION:Wenweiyang decoction promotes rat duodenal motility,and its mechanism may be related to the inhibition of rat duodenal MCT and HA production and activation of SCF/c-Kit signaling pathway.

AIM:To elucidate the possible biological mechanism of silica-induced acute lung injury in rats.METHODS:Sixteen Male Sprague-Dawley rats were divided into control and acute silicosis model groups,and instilled intratracheally with 1 mL of normal saline and 50 g/L silica suspension,respectively.After 7 d,the rats were sacrificed for collection of lung tissue and serum.The serum levels of interleukin-1β(IL-1β),IL-18 and tumor necrosis factor-α(TNF-α)were measured by using ELISA.The protein expression levels of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)and gasdermin D(GSDMD)were measured by immunohistochemistry.Bacterial DNA was ex-tracted from the lung tissue for 16S ribosomal RNA gene sequencing to characterize changes in the composition of lung flo-ra.The differences in the structure of bacterial flora between control and model groups were analyzed by bioinformatic analy-ses.RESULTS:Immunohistochemical analysis showed that the protein expression levels of NLRP3 and GSDMD were higher in the lungs of the rats in model group.In addition,serum cytokine profiling showed that IL-1β,IL-18 and TNF-α levels were significantly higher in model group.The most abundant bacterial genera in the lung flora of the rats in model group were Bifidobacterium,Clostridium sensu stricto 1,and Parasutterella.The NLRP3 and GSDMD levels in the lung tissue and IL-1β and TNF-α levels in serum were positively correlated with the abundance of Parasutterella.CONCLU-SION:The alterations in lung flora structure and increased inflammation levels may be the actual biological mechanisms underlying silica-induced acute lung injury.The modulation of lung flora may provide a basis for the prevention and treat-ment of silica-induced acute lung injury.