Background: Downregulation of claudin-5 in the heart is associated with the end-stage heart failure. However, the underlying mechanism ofclaudin-5 is unclear. Here we investigated the molecular actions of claudin-5 in perspective of mitochondria in cardiomyocytes to better understand the role of claudin-5 in cardioprotection during ischemia.
Methods: Myocardial ischemia/reperfusion (I/R; 30 min/24 h) and hypoxia/reoxygenation (H/R; 24 h/4 h) were used in this study. Confocal microscopy and transmission electron microscope (TEM) were used to observe mitochondrial morphology.
Results: Claudin-5 was detected in murine heart tissue and neonatal rat cardiomyocytes (NRCM). Its protein level was severely decreased after myocardial I/R or H/R. Confocal microscopy showedclaudin-5 presented in the mitochondria of NRCM. H/R-induced claudin-5 downregulation was accompanied by mitochondrial fragmentation. The mitofusin 2 (Mfn2) expressionwas dramatically decreased while the dynamin-related protein (Drp) 1 expression was significantly increased after H/R. The TEM indicatedH/R-induced mitochondrial swelling and fission. Adenoviral claudin-5 overexpression reversed these structural disintegration of mitochondria. The mitochondria-centered intrinsic pathway of apoptosis triggered by H/R and indicated by the cytochrome c and cleaved caspase 3 in the cytoplasm of NRCMs was also reduced by overexpressing claudin-5. Claudin-5 overexpression in mouse heart also significantly decreased cleaved caspase 3 and the infarct size in ischemic heart with improved systolic function.
Conclusion: We demonstrated for the first time the presence of claudin-5 in the mitochondria in cardiomyocytes and provided the firm evidence for the cardioprotective role of claudin-5 in the preservation of mitochondrial dynamics and cell fate against hypoxia- or ischemia-induced stress.
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http://dx.doi.org/10.1016/j.cjca.2021.03.021 | DOI Listing |
Eur J Pharmacol
December 2024
School of Pharmaceutical Science, Sun Yat-sen University, Guangzhou 510006, China. Electronic address:
Stroke is a serious condition with sudden onset, high severity, and significant rates of mortality and disability, ranking as the second leading cause of death globally at 11.6%. Hemorrhagic stroke, characterized by non-traumatic rupture of cerebral vessels, can cause secondary brain injury such as neurotoxicity, inflammation, reactive oxygen species, and blood-brain barrier (BBB) damage.
View Article and Find Full Text PDFPLoS One
December 2024
Department of Environmental and Radiological Health Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America.
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) infection, is a chronic inflammatory disease. Although typically associated with inflammation of the lungs and other peripheral tissues, increasing evidence has uncovered neurological consequences attributable to Mtb infection. These include deficits in memory and cognition, increased risk for neurodegenerative disease, and progressive neuropathology.
View Article and Find Full Text PDFExp Eye Res
December 2024
Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
Intraocular pressure (IOP) is regulated through the balance of production and drainage of aqueous humor. The main route of aqueous-humor outflow comprises the trabecular meshwork (TM) and Schlemm's canal (SC). We reported that IL-6 trans-signaling can inhibit TGF-β signaling in TM cells and may affect regulation of IOP.
View Article and Find Full Text PDFArthritis Res Ther
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Department of Emergency Medicine, Rhode Island Hospital, Providence, RI, USA.
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View Article and Find Full Text PDFNeuropathology
December 2024
Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan.
Multiple system atrophy (MSA) is a rare neurodegenerative disease characterized by an accumulation of phosphorylated α-synuclein (p-αsyn) in oligodendrocytes in the form of glial cytoplasmic inclusions (GCIs). In MSA, not only mature oligodendrocytes but also oligodendrocyte precursor cells (OPCs) are affected. The latter play an important role in remyelination by differentiating into mature oligodendrocytes, as well as maintaining the blood-brain barrier (BBB) by promoting the expression of tight junction proteins.
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