ObjectiveTo investigate the regulatory effect and potential mechanisms of isocitrate dehydrogenase 3A （IDH3A） on cardiomyocyte hypertrophy. MethodsThe expression of IDH3A in the myocardium of healthy volunteers （n=10） and patients with heart failure （HF） （n=10）， and in the myocardium of mice subjected to transverse aortic constriction （TAC） surgery and sham operation， as well as in phenylephrine （PE）-induced neonatal rat ventricular cardiomyocytes （NRVCs）， was assessed by real-time quantitative polymerase chain reaction （RT-qPCR） and Western blot assay. The effect of adenovirus-mediated overexpression of IDH3A on the expression of hypertrophy-related genes in PE-induced NRVCs was also evaluated. The effect of IDH3A on NRVCs area was examined by phalloidin staining assay. A mutant of IDH3A with abolished enzymatic activity， IDH3A_D208A， was generated through site-directed mutagenesis. The impact of this IDH3A mutant on the hypertrophic phenotype， ATP and ROS levels in NRVCs was evaluated to investigate whether the regulatory role of IDH3A in cardiomyocyte hypertrophy was dependent on its enzymatic activity. The effect of exogenous α-ketoglutaric acid （AKG） on cardiomyocyte hypertrophy was also detected by Western blot and phalloidin staining assay， respectively. ResultsIDH3A was significantly decreased in the myocardium of HF patients， in the myocardium of TAC-operated mice， and in PE-induced NRVCs （P = 0.005 2，P = 0.026 6，P = 0.041 3 and P = 0.006 6， respectively）. Overexpression of IDH3A markedly suppressed the expression of hypertrophy-related genes and the increase of cell size of PE-induced NRVCs （P < 0.000 1， P = 0.000 1 and P = 0.000 2， respectively）. The ATP and ROS analysis indicated that IDH3A inhibited the increases of ATP and ROS levels in PE-induced NRVCs （P = 0.001 2 and P<0.000 1， respectively）， whereas the enzymatically inactive IDH3A mutant lacked this effect. Exogenous AKG provision could， but overexpression of IDH3A mutant failed to suppress PE-induced NRVCs hypertrophy. ConclusionIDH3A inhibits cardiomyocyte hypertrophy via elevating AKG level， providing scientific evidence for study on IDH3A-based treatment of cardiac hypertrophy.

Objective:To assess the clinical features and effectiveness of antiviral therapy in newborns with sensorineural hearing loss (SNHL) caused by congenital congenital cytomegalovirus (cCMV) infection, and to speculate the risk factors for poor hearing outcomes.Methods:A multicenter prospective cohort study wasconducted, enrolling 176 newborns diagnosed with cCMV at four research centers in Zhejiang Province from March 1, 2021, to April 30, 2024. Clinical characteristics at birth were recorded and hearing was followed up. The children were divided into groups based on their condition at birth, specifically into asymptomatic, mild symptom, and moderate to severe symptom groups. Additionally, they were divided into SNHL and normal hearing groups based on the results of air conduction brainstem audiometry at birth. And they were also divided into treatment and untreated groups according to antiviral treatment. Mann Whitney U test, and chi square test were used for inter group comparison to analyze the differences in clinical features between different disease groups, and to analyze the effects of clinical features, antiviral therapy, and other factors on hearing improvement. Logistic regression analysis was employed to identify the risk factors influencing hearing outcomes. Results:Among the cohort of 176 children diagnosed infection with cCMV, 90 cases were male and 86 cases were female. Of these, 79 cases were asymptomatic, 12 cases classified as mild cCMV and 85 cases as moderate to severe cCMV. Fifty cases belonged to SNHL group, with different degrees of severity, including 30 cases of mild, 9 cases of moderate, 5 cases of severe, and 6 cases of extremely severe SNHL. Among the 121 cases in the normal hearing group, 2 cases (1.7%) exhibited late-onset hearing loss despite having normal hearing at birth. Among 81 cases (46.0%) who completed the hearing follow-up, 71 cases (87.7%) had good hearing outcomes and 10 cases (12.3%) had poor hearing outcomes. Among the 81 children, 29 cases (35.8%) had SNHL at birth. During follow-up, the hearing threshold improved in 19 cases (65.5%), remained stable in 7 cases (24.1%) and progressed in 3 cases (10.3%). A total of 26 cases in the treatment group and 55 cases in the untreated group completed the hearing follow-up assessment. The rate of hearing improvement in the treatment group was found to be higher compared to the untreated group (13 cases (50.0%) vs. 6 cases (10.9%), χ2=15.00, P<0.01), with individuals in the treatment group having a 4.58 times greater likelihood of experiencing hearing improvement ( RR=4.58,95% CI 1.96-10.70, P<0.05). However, no statistically significant difference was observed in hearing outcomes between the antiviral treatment group and the untreated group ( RR=0.90, 95% CI 0.57-1.41, P=0.517). Multivariate analysis further confirmed SNHL ( OR=11.58, 95% CI 2.10-63.93, P=0.005) and preterm birth ( OR=4.98, 95% CI 1.06-23.41, P=0.042) as independent risk factors for poor hearing outcomes. Conclusions:SNHL resulting from cCMV infection presents symptoms at birth and can be improved by antiviral therapy. Poor hearing outcomes are associated with SNHL and prematurity.

OBJECTIVETo investigate the role of miR-199a-3p in cardiac fibrosis and the potential target of miR-199a-3p.

METHODSCardiac fibroblasts were isolated from C57BL/6 mice and cultured. The miR-199a-3p mimic and Smad1 siRNA were transiently transfected into the cardiac fibroblasts via liposome. Dual luciferase reporter assay was performed to confirm the interaction between miR-199a-3p and the 3'-UTR of Smad1. The expressions of Smad1 and fibrosis-related genes at the mRNA and protein levels in the cells after miR-199a-3p mimic transfection were determined using RT-qPCR and Western blotting, respectively. The expressions of Smad1, Smad3 and fibrosis-related genes at the protein level in cells transfected with miR-199a-3p mimic and Smad1 siRNA were detected using Western blotting.

RESULTSOver-expression of miR-199a-3p significantly increased the expression of cardiac fibrosis-related genes in cultured mouse cardiac fibroblasts. Dual luciferase reporter assay revealed the interaction of miR-199a-3p with the 3'-UTR of Smad1. The results of RT-qPCR and Western blotting confirmed that miR-199a-3p inhibited Smad1 expression at the post- transcriptional level. Transfection with miR-199a-3p mimic and siRNA-mediated Smad1 silencing consistently activated the Smad3 signaling pathway and enhanced the expressions of cardiac fibrosis-related genes in the cardiac fibroblasts.

CONCLUSIONSAs the target gene of miR-199a-3p, Smad1 mediates the pro-fibrotic effect of miR-199a-3p by activating the Smad3 signaling in cultured mouse cardiac fibroblasts.

AIM:Increasing evidence indicates that inflammation contributes to the initiation and perpetuation of atrial fibrillation ( AF) .Al-though tumor necrosis factor ( TNF)-αlevels are increased in patients with AF , the role of TNF-αin the pathogenesis of AF remains unclear.Recent research has revealed that T-type Ca2+currents ( ICa,T ) play an important role in the pathogenesis of AF .METH-ODS:In this study , we used the whole-cell voltage-clamp technique and biochemical assays to explore the role of TNF-αin the regula-tion of ICa,T in atrial myocytes.RESULTS:We found that compared with sinus rhythm (SR) controls, T-type calcium channel (TCC) subunit mRNA levels were decreased , while TNF-αexpression levels were increased , in human atrial tissue from patients with AF .In murine atrial myocyte HL-1 cells, after cultured for 24 h, 12.5, 25 and 50 μg/L TNF-αsignificantly reduced the protein expression levels of the TCC α1G subunit in a concentration-dependent manner .The peak current was reduced by the application of 12.5 or 25μg/L TNF-αin a concentration-dependent manner [from ( -15.08 ±1.11) pA/pF in controls to ( -11.89 ±0.83) pA/pF and (-8.54 ±1.55) pA/pF in 12.5 and 25 μg/L TNF-αgroups, respectively].TNF-αapplication also inhibited voltage-dependent inactivation of ICa,T shifted the inactivation curve to the left .CONCLUSION:These results suggest that TNF-αis involved in the path-ogenesis of AF, probably via decreasing ICa,T function in atrium-derived myocytes through impaired channel function and down -regula-tion of channel protein expression .This pathway thus represents a potential pathogenic mechanism in AF .

AIM:MicroRNAs ( miRNAs) were recognized to play significant roles in cardiac hypertrophy .But, it remains unknown whether cyclin/Rb pathway is modulated by miRNAs during cardiac hypertrophy .This study investigates the potential roles of microRNA-1 (miR-1) and microRNA-16 (miR-16) in modulating cyclin/Rb pathway during cardiomyocyte hypertrophy .METHODS:An animal model of hypertrophy was established in a rat with abdominal aortic constriction (AAC).In addition, a cell model of hypertrophy was also achieved based on PE-promoted neonatal rat ventricular cardiomyocyte .RESULTS:miR-1 and-16 expression were markedly de-creased in hypertrophic myocardium and hypertrophic cardiomyocytes in rats .Overexpression of miR-1 and -16 suppressed rat cardiac hypertrophy and hypertrophic phenotype of cultured cardiomyocytes .Expression of cyclins D1, D2 and E1, CDK6 and phosphorylated pRb was increased in hypertrophic myocardium and hypertrophic cardiomyocytes , but could be reversed by enforced expression of miR-1 and -16.CDK6 was validated to be modulated post-transcriptionally by miR-1, and cyclins D1, D2 and E1 were further validated to be modulated post-transcriptionally by miR-16.CONCLUSION: Attenuations of miR-1 and -16 provoke cardiomyocyte hypertrophy via derepressing the cyclins D1, D2, E1 and CDK6, and activating cyclin/Rb pathway.

AIM:To investigate the effect of miR-214 on cardiomyocyte hypertrophy and the expression of the potential target genes . METHODS:A cell model of hypertrophy was established based on angiotensin-Ⅱ( Ang-Ⅱ)-induced neonatal mouse ventricular car-diomyocytes (NMVCs).Dual luciferase reporter assay was performed to verify the interaction between miR-214 and the 3’ UTR of MEF2C.The expression of MEF2C and hypertrophy-related genes at mRNA and protein levels was determined by RT-qPCR and Wes-tern blotting, respectively.RESULTS:The expression of ANP, ACTA1,β-MHC and miR-214 was markedly increased in Ang-Ⅱ-in-duced hypertrophic cardiomyocytes .Dual luciferase reporter assay revealed that miR-214 interacted with the 3’ UTR of MEF2C, and miR-214 was verified to inhibit MEF2C expression at the transcriptional level .The protein expression of MEF2C was markedly in-creased in the hypertrophic cardiomyocytes .Moreover, miR-214 mimic, in parallel to MEF2C siRNA, inhibited the expression of hy-pertrophy-related genes in Ang-Ⅱ-induced NMVCs.CONCLUSION:MEF2C is a target gene of miR-214, which mediates the effect of miR-214 on attenuating cardiomyocyte hypertrophy .

AIM:To determine circular RNA (circRNA) profiles in the diabetic mouse myocardium , and to investigate the effect of circRNA_000203 on fibrotic phenotypes in cardiac fibroblasts .METHODS:Masson trichrome stai-ning was performed on the myocardium of the diabetic db /db mice and the non diabetic db/m control mice .circRNA ex-pression profile in the diabetic myocardium was detected by circRNAs microarray .The expression of circRNA_000203 was determined by real time fluorescence quantitative PCR ( RT-qPCR ) .Recombinant circRNA_000203 adenovirus was pre-pared for enforced the expression of circRNA_000203 in mouse cardiac fibroblasts.The expression of Col1a2, Col3a1andα-SMA was determined in circRNA_000203-modified cardiac fibroblasts , respectively .RESULTS:Masson trichrome stai-ning showed that fibrosis was increased in the diabetic mouse myocardium .The results of circRNA array detection revealed that circRNAs were dysregulated in the diabetic myocardium .circRNA_000203 was up-regulated in the diabetic myocardi-um.Significant over-expression of circRNA_000203 was achieved in the cardiac fibroblasts after infection with the recombi-nant circRNA_000203 adenovirus.The mRNA and protein expression of Col1a2, Col3a1 and α-SMA was significantly in-creased in the cardiac fibroblasts with over-expression of circRNA_000203.CONCLUSION:circRNA_000203 is up-regu-lated in the diabetic mouse myocardium .It has pro-fibrotic effect on the cardiac fibroblasts .

AIM:To investigate the effect of microRNA-214 ( miR-214) on cardiomyocyte hypertrophy and the expression of the potential target genes .METHODS:A cell model of hypertrophy was established based on angiotensin-Ⅱ( Ang-Ⅱ)-induced neonatal mouse ventricular cardiomyocytes ( NMVCs) .Dual luciferase reporter assay was performed to verify the interaction between miR-214 and the 3’ UTR of MEF2C.The expression of MEF2C and hypertrophy-related genes at mRNA and protein levels was determined by RT-qPCR and Western blot , respectively .RESULTS:The expression of ANP, ACTA1,β-MHC and miR-214 was markedly increased in Ang-Ⅱ-induced hypertrophic cardiomyocytes .Dual lu-ciferase reporter assay revealed that miR-214 interacted with the 3’ UTR of MEF2C, and miR-214 was verified to inhibit MEF2C expression at the transcriptional level .The protein expression of MEF2C was markedly increased in the hypertro-phic cardiomyocytes .Moreover, miR-214 mimic, in parallel to MEF2C siRNA, inhibited the expression of hypertrophy-re-lated genes in Ang-Ⅱ-induced NMVCs.CONCLUSION:MEF2C is a target gene of miR-214, which mediates the effect of miR-214 on attenuating cardiomyocyte hypertrophy .

AIM:To investigate whether the association of connexin 43 ( Cx43 ) and L-type calcium channel involved in the pathogenesis of atrial fibrillation ( AF) .METHODS:The biochemical assays and whole-cell patch-clamp technique were used to study the expression of Cx43 in human atrial tissue.The co-localization of Cx43 and L-type calcium channel, and the regulation of L-type calcium current in atrial myocytes were investigated.RESULTS:The expression of Cx43 at mRNA and protein levels was decreased in human atrial tissues of AF patients.In cultured atrium-derived myocytes ( HL-1 cells) , knockdown of Cx43 significantly inhibited the mRNA expression of L-type calcium channelα1c subunit, as well as L-type calcium current.Co-localization of Cx43 with L-type calcium channel α1c subunit in mouse atrial myocytes was observed.CONCLUSION:The decrease in Cx43 is involved in the pathogenesis of AF, probably through reducing the L-type calcium current in atrial myoctyes by co-localization with L-type calcium channel, thus representing the potential pathogenesis in atrial fibrillation.

AIM:To investigate the effect of caspase-8 small hairpin RNA ( shRNA) on attenuating apoptosis of human mesenchymal stem cells ( hMSCs ) .METHODS: Two recombinant plasmids for over-expression of caspase-8 shRNA, pAd-Cap8 shRNA1 and pAd-Cap8 shRNA2, were constructed.Caspase-8 mRNA was determined in pAd-Cap8 shRNA-transfected human HEK293 cells by Q-PCR.The screened pAd-Cap8 shRNA was used to construct the recombinant adenovirus plasmid , which was linearized and transfected into HEK 293 cells for packaging and amplification of the recombi-nant adenovirus rAd-Cap8 shRNA.The expression of caspase-8 at mRNA and protein levels was determined by Q-PCR and Western blotting .Annexin V/PI staining and determination of caspase-8 activity were performed to assess apoptosis of hM-SCs under the conditions of serum deprivation and hypoxia .The mRNA expression of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), insulin-like growth factor 1 (IGF-1), Bcl-2 and Bcl-xL was analyzed by Q-PCR.RESULTS:The pAd-Cap8 shRNA, which efficiently inhibited caspase-8 expression, was screened by Q-PCR.The recombinant adenovirus plasmid for caspase-8 shRNA was constructed and used to package and amplify the recombinant ad-enovirus ( rAd)-Cap8 shRNA successfully .rAd-Cap8 shRNA-mediated caspase-8 shRNA markedly inhibited caspase-8 ex-pression in hMSCs .Over-expression of caspase-8 shRNA by infection of rAd-Cap8 shRNA also efficiently decreased the ap-optotic rate and caspase-8 activity in hMSCs under the conditions of serum deprivation and hypoxia , with up-regulation of the mRNA expression of HGF, IGF-1 and Bcl-2.CONCLUSION:Caspase-8 shRNA attenuates hMSC apoptosis under the conditions of serum deprivation and hypoxia .