Abstract
Par-3 is a component of Par complex, which is critical for the integrity of tight junction. We previously reported that TGF-β down-regulated Par-3 expression in rat proximal tubular epithelial cells, but the underlying mechanism remains unknown. In the present study, we demonstrated by a luciferase reporter assay that miR-491-5p down-regulated the luciferase activity through a binding site in the 3' UTR of Par-3. Overexpression of miR-491-5p dramatically decreased the expression of endogenous Par-3, disrupted tight junction, and resulted in decreased transepithelial resistance. Moreover, miR-491-5p expression was induced by TGF-β1 through the MEK/p38 MAPK pathway. Importantly, miR-491-5p levels were increased significantly in a rat model of obstructive nephropathy, in parallel with decreased Par-3 levels. Taken together, we conclude that up-regulation of miR-491-5p contributes to TGF-β-regulated Par-3 expression. Our study uncovered a novel mechanism by which TGF-β disrupts cell junction.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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3' Untranslated Regions / genetics
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Animals
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Carrier Proteins / biosynthesis*
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Carrier Proteins / genetics
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Disease Models, Animal
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Down-Regulation*
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Intercellular Junctions / genetics
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Intercellular Junctions / metabolism
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Intercellular Junctions / pathology
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Kidney Diseases / genetics
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Kidney Diseases / metabolism*
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Kidney Diseases / pathology
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Kidney Tubules, Proximal / metabolism*
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Kidney Tubules, Proximal / pathology
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MAP Kinase Kinase Kinases / genetics
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MAP Kinase Kinase Kinases / metabolism
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Male
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MicroRNAs / biosynthesis*
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MicroRNAs / genetics
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Nerve Tissue Proteins
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Rats
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Rats, Sprague-Dawley
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Transforming Growth Factor beta1 / genetics
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Transforming Growth Factor beta1 / metabolism*
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Up-Regulation*
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p38 Mitogen-Activated Protein Kinases
Substances
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3' Untranslated Regions
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Carrier Proteins
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MicroRNAs
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Nerve Tissue Proteins
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Pard3 protein, rat
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Transforming Growth Factor beta1
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p38 Mitogen-Activated Protein Kinases
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MAP Kinase Kinase Kinases