Objective:To investigate the antifibrotic effects of curcumin in a transverse aortic constriction(TAC)mouse model and elucidate its molecular mechanisms.Methods:Male C57BL/6 mice underwent TAC and received vehicle,low...Objective:To investigate the antifibrotic effects of curcumin in a transverse aortic constriction(TAC)mouse model and elucidate its molecular mechanisms.Methods:Male C57BL/6 mice underwent TAC and received vehicle,low-dose curcumin(50 mg/kg),high-dose curcumin(200 mg/kg),high-dose curcumin plus a scrambled control antagomir,or high-dose curcumin plus anti-miR-29b treatments.Cardiac function was assessed by echocardiography.Fibrosis was evaluated by histology,collagen volume fraction,and hydroxyproline content.Expression of miR-29b,HDAC4,and fibrosis-related markers(Col1a1,Col3a1,TGF-β1)was measured by quantitative RT-PCR and Western blotting assays.Myocardial procollagen type I carboxy-terminal propeptide was determined by ELISA,and HDAC4-specific enzymatic activity was assayed using a fluorogenic kit.Results:Curcumin improved cardiac function,reduced fibrosis,restored miR-29b expression,and suppressed HDAC4 expression and activity in a dose-dependent manner.Furthermore,curcumin decreased myocardial procollagen type I carboxy-terminal propeptide levels,confirming reduced collagen synthesis.Anti-miR-29b administration partially abrogated the antifibrotic and cardioprotective effects of curcumin.Conclusions:Curcumin attenuates pressure overload-induced cardiac fibrosis and dysfunction in a TAC mouse model via modulation of the miR-29b/HDAC4 axis and suppression of collagen synthesis.展开更多
Spinal cord injury is a critical event characterized by intricate pathogenic mechanisms.Although recent studies have highlighted tissue exosomes as key mediators of inflammatory responses in diverse organs and tissues...Spinal cord injury is a critical event characterized by intricate pathogenic mechanisms.Although recent studies have highlighted tissue exosomes as key mediators of inflammatory responses in diverse organs and tissues,their role in spinal cord injury has yet to be determined.In this study,we investigated the role and mechanisms of spinal cord tissue exosomes in the inflammatory response following spinal cord injury.We found morphological,concentration,and functional differences between exosomes extracted from injured and normal spinal cord tissues,and identified proinflammatory effects associated with spinal cord injury-generated tissue exosomes but not with exosomes derived from normal spinal cord tissue.Our in vivo and in vitro analyses showed that spinal cord injury-generated tissue exosomes promoted microglial M1 polarization and inflammatory cytokine expression,thereby exacerbating tissue and neuronal injury in the spinal cord.In addition,the combination of exosomal miRNA sequencing and experimental verification showed that the miR-155-5p level was higher in spinal cord injury-generated tissue exosomes than in spinal cord tissue.We further found that spinal cord injury-generated tissue exosomes-derived miR-155-5p induced a significant inhibition of forkhead box O3a phosphorylation and activated the nuclear factor-kappa B pathway,thereby promoting microglial M1 polarization and inflammatory cytokine expression.These findings suggest that injury-induced miR-155-5p-containing exosomes exacerbate spinal cord injury via the promotion of microglial M1 polarization and inflammatory responses.Thus,targeting miR-155-5p expression or exosome secretion could be a novel strategy for attenuating inflammation and reducing secondary injury post-spinal cord injury.展开更多
基金supported by China International Medical Foundation(Z-2019-42-1908-4)Natural Science Basic Research Program of Shaanxi Province(2019JM-440).
文摘Objective:To investigate the antifibrotic effects of curcumin in a transverse aortic constriction(TAC)mouse model and elucidate its molecular mechanisms.Methods:Male C57BL/6 mice underwent TAC and received vehicle,low-dose curcumin(50 mg/kg),high-dose curcumin(200 mg/kg),high-dose curcumin plus a scrambled control antagomir,or high-dose curcumin plus anti-miR-29b treatments.Cardiac function was assessed by echocardiography.Fibrosis was evaluated by histology,collagen volume fraction,and hydroxyproline content.Expression of miR-29b,HDAC4,and fibrosis-related markers(Col1a1,Col3a1,TGF-β1)was measured by quantitative RT-PCR and Western blotting assays.Myocardial procollagen type I carboxy-terminal propeptide was determined by ELISA,and HDAC4-specific enzymatic activity was assayed using a fluorogenic kit.Results:Curcumin improved cardiac function,reduced fibrosis,restored miR-29b expression,and suppressed HDAC4 expression and activity in a dose-dependent manner.Furthermore,curcumin decreased myocardial procollagen type I carboxy-terminal propeptide levels,confirming reduced collagen synthesis.Anti-miR-29b administration partially abrogated the antifibrotic and cardioprotective effects of curcumin.Conclusions:Curcumin attenuates pressure overload-induced cardiac fibrosis and dysfunction in a TAC mouse model via modulation of the miR-29b/HDAC4 axis and suppression of collagen synthesis.
基金supported by the Joint Funds for the Innovation of Science and Technology,Fujian Province,No.2023Y9233(to HH)the QuanzhouScience and Technology Project,No.2022C036R(to HH)+1 种基金the Science and Technology Bureau of Quanzhou,No.2020CT003(to SL)the Quanzhou MunicipalMedical and Health Guiding Science and Technology Project,No.2023N066S(to YZhou).
文摘Spinal cord injury is a critical event characterized by intricate pathogenic mechanisms.Although recent studies have highlighted tissue exosomes as key mediators of inflammatory responses in diverse organs and tissues,their role in spinal cord injury has yet to be determined.In this study,we investigated the role and mechanisms of spinal cord tissue exosomes in the inflammatory response following spinal cord injury.We found morphological,concentration,and functional differences between exosomes extracted from injured and normal spinal cord tissues,and identified proinflammatory effects associated with spinal cord injury-generated tissue exosomes but not with exosomes derived from normal spinal cord tissue.Our in vivo and in vitro analyses showed that spinal cord injury-generated tissue exosomes promoted microglial M1 polarization and inflammatory cytokine expression,thereby exacerbating tissue and neuronal injury in the spinal cord.In addition,the combination of exosomal miRNA sequencing and experimental verification showed that the miR-155-5p level was higher in spinal cord injury-generated tissue exosomes than in spinal cord tissue.We further found that spinal cord injury-generated tissue exosomes-derived miR-155-5p induced a significant inhibition of forkhead box O3a phosphorylation and activated the nuclear factor-kappa B pathway,thereby promoting microglial M1 polarization and inflammatory cytokine expression.These findings suggest that injury-induced miR-155-5p-containing exosomes exacerbate spinal cord injury via the promotion of microglial M1 polarization and inflammatory responses.Thus,targeting miR-155-5p expression or exosome secretion could be a novel strategy for attenuating inflammation and reducing secondary injury post-spinal cord injury.
