High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.

BACKGROUND: Inflammation plays a key role in the development and progression of diabetic nephropathy (DN). KCa3.1, a calcium activated potassium channel protein, is associated with vascular inflammation, atherogenesis, and proliferation of endothelial cells, macrophages, and fibroblasts. We have pre...

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Main Authors: Chunling Huang, Carol A Pollock, Xin-Ming Chen
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3986377?pdf=render
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author Chunling Huang
Carol A Pollock
Xin-Ming Chen
author_facet Chunling Huang
Carol A Pollock
Xin-Ming Chen
author_sort Chunling Huang
collection DOAJ
description BACKGROUND: Inflammation plays a key role in the development and progression of diabetic nephropathy (DN). KCa3.1, a calcium activated potassium channel protein, is associated with vascular inflammation, atherogenesis, and proliferation of endothelial cells, macrophages, and fibroblasts. We have previously demonstrated that the KCa3.1 channel is activated by TGF-β1 and blockade of KCa3.1 ameliorates renal fibrotic responses in DN through inhibition of the TGF-β1 pathway. The present study aimed to identify the role of KCa3.1 in the inflammatory responses inherent in DN. METHODS: Human proximal tubular cells (HK2 cells) were exposed to high glucose (HG) in the presence or absence of the KCa3.1 inhibitor TRAM34 for 6 days. The proinflammatory cytokine chemokine (C-C motif) ligand 20 (CCL20) expression was examined by real-time PCR and enzyme-linked immunosorbent assay (ELISA). The activity of nuclear factor-κB (NF-κB) was measured by nuclear extraction and electrophoretic mobility shift assay (EMSA). In vivo, the expression of CCL20, the activity of NF-κB and macrophage infiltration (CD68 positive cells) were examined by real-time PCR and/or immunohistochemistry staining in kidneys from diabetic or KCa3.1-/- mice, and in eNOS-/- diabetic mice treated with the KCa3.1 channel inhibitor TRAM34. RESULTS: In vitro data showed that TRAM34 inhibited CCL20 expression and NF-κB activation induced by HG in HK2 cells. Both mRNA and protein levels of CCL20 significantly decreased in kidneys of diabetic KCa3.1-/- mice compared to diabetic wild type mice. Similarly, TRAM34 reduced CCL20 expression and NF-κB activation in diabetic eNOS-/- mice compared to diabetic controls. Blocking the KCa3.1 channel in both animal models led to a reduction in phosphorylated NF-κB. CONCLUSIONS: Overexpression of CCL20 in human proximal tubular cells is inhibited by blockade of KCa3.1 under diabetic conditions through inhibition of the NF-κB pathway.
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spelling doaj.art-961f386853d5472da521f8532d01bc2b2022-12-21T19:37:23ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0194e9517310.1371/journal.pone.0095173High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.Chunling HuangCarol A PollockXin-Ming ChenBACKGROUND: Inflammation plays a key role in the development and progression of diabetic nephropathy (DN). KCa3.1, a calcium activated potassium channel protein, is associated with vascular inflammation, atherogenesis, and proliferation of endothelial cells, macrophages, and fibroblasts. We have previously demonstrated that the KCa3.1 channel is activated by TGF-β1 and blockade of KCa3.1 ameliorates renal fibrotic responses in DN through inhibition of the TGF-β1 pathway. The present study aimed to identify the role of KCa3.1 in the inflammatory responses inherent in DN. METHODS: Human proximal tubular cells (HK2 cells) were exposed to high glucose (HG) in the presence or absence of the KCa3.1 inhibitor TRAM34 for 6 days. The proinflammatory cytokine chemokine (C-C motif) ligand 20 (CCL20) expression was examined by real-time PCR and enzyme-linked immunosorbent assay (ELISA). The activity of nuclear factor-κB (NF-κB) was measured by nuclear extraction and electrophoretic mobility shift assay (EMSA). In vivo, the expression of CCL20, the activity of NF-κB and macrophage infiltration (CD68 positive cells) were examined by real-time PCR and/or immunohistochemistry staining in kidneys from diabetic or KCa3.1-/- mice, and in eNOS-/- diabetic mice treated with the KCa3.1 channel inhibitor TRAM34. RESULTS: In vitro data showed that TRAM34 inhibited CCL20 expression and NF-κB activation induced by HG in HK2 cells. Both mRNA and protein levels of CCL20 significantly decreased in kidneys of diabetic KCa3.1-/- mice compared to diabetic wild type mice. Similarly, TRAM34 reduced CCL20 expression and NF-κB activation in diabetic eNOS-/- mice compared to diabetic controls. Blocking the KCa3.1 channel in both animal models led to a reduction in phosphorylated NF-κB. CONCLUSIONS: Overexpression of CCL20 in human proximal tubular cells is inhibited by blockade of KCa3.1 under diabetic conditions through inhibition of the NF-κB pathway.http://europepmc.org/articles/PMC3986377?pdf=render
spellingShingle Chunling Huang
Carol A Pollock
Xin-Ming Chen
High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.
PLoS ONE
title High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.
title_full High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.
title_fullStr High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.
title_full_unstemmed High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.
title_short High glucose induces CCL20 in proximal tubular cells via activation of the KCa3.1 channel.
title_sort high glucose induces ccl20 in proximal tubular cells via activation of the kca3 1 channel
url http://europepmc.org/articles/PMC3986377?pdf=render
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AT xinmingchen highglucoseinducesccl20inproximaltubularcellsviaactivationofthekca31channel