Specificity protein 1 and Smad-dependent regulation of human heme oxygenase-1 gene by transforming growth factor-β1 in renal epithelial cells

2007 ◽  
Vol 293 (3) ◽  
pp. F885-F894 ◽  
Author(s):  
Amie Traylor ◽  
Thomas Hock ◽  
Nathalie Hill-Kapturczak

Excess transforming growth factor-β1 (TGF-β1) in the kidney leads to increased cell proliferation and deposition of extracellular matrix, resulting in progressive kidney fibrosis. TGF-β1, however, stabilizes and attenuates tissue injury through the activation of cytoprotective proteins, including heme oxygenase-1 (HO-1). HO-1 catabolizes pro-oxidant heme into substances with anti-oxidant, anti-apoptotic, anti-fibrogenic, vasodilatory and immune modulatory properties. Little is known regarding the molecular regulation of human HO-1 induction by TGF-β1 except that it is dependent on de novo RNA synthesis and requires a group of structurally related proteins called Smads. It is not known whether other DNA binding proteins are required to initiate transcription of HO-1 and, furthermore, the promoter region(s) involved in TGF-β1-mediated induction of HO-1 has not been identified. The purpose of this study was to further delineate the molecular regulation of HO-1 by TGF-β1 in human renal proximal tubular cells. Actinomycin D and nuclear run-on studies demonstrate that TGF-β1 augments HO-1 expression by increased gene transcription and does not involve increased mRNA stability. Using transient transfection, mithramycin A, small interfering RNA, electrophoretic mobility shift assays, and decoy oligonucleotide experiments, a TGF-β1-responsive region is identified between 9.1 and 9.4 kb of the human HO-1 promoter. This ∼280-bp TGF-β1-responsive region contains a putative Smad binding element and specificity protein 1 binding sites, both of which are required for human HO-1 induction by TGF-β1.

PLoS ONE ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. e0176052 ◽  
Author(s):  
Shu-Jui Kuo ◽  
Wei-Hung Yang ◽  
Shan-Chi Liu ◽  
Chun-Hao Tsai ◽  
Horng-Chaung Hsu ◽  
...  

1998 ◽  
Vol 83 (4) ◽  
pp. 396-403 ◽  
Author(s):  
Andrea Pellacani ◽  
Philippe Wiesel ◽  
Arunabh Sharma ◽  
Lauren C. Foster ◽  
Gordon S. Huggins ◽  
...  

2021 ◽  
Vol 22 (6) ◽  
pp. 2952
Author(s):  
Tzu-Yu Hou ◽  
Shi-Bei Wu ◽  
Hui-Chuan Kau ◽  
Chieh-Chih Tsai

Transforming growth factor-β1 (TGF-β1)-induced myofibroblast transdifferentiation from orbital fibroblasts is known to dominate tissue remodeling and fibrosis in Graves’ ophthalmopathy (GO). However, the signaling pathways through which TGF-β1 activates Graves’ orbital fibroblasts remain unclear. This study investigated the role of the mitogen-activated protein kinase (MAPK) pathway in TGF-β1-induced myofibroblast transdifferentiation in human Graves’ orbital fibroblasts. The MAPK pathway was assessed by measuring the phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular-signal-regulated kinase (ERK) by Western blots. The expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and fibronectin representing fibrogenesis was estimated. The activities of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) responsible for extracellular matrix (ECM) metabolism were analyzed. Specific pharmacologic kinase inhibitors were used to confirm the involvement of the MAPK pathway. After treatment with TGF-β1, the phosphorylation levels of p38 and JNK, but not ERK, were increased. CTGF, α-SMA, and fibronectin, as well as TIMP-1 and TIMP-3, were upregulated, whereas the activities of MMP-2/-9 were inhibited. The effects of TGF-β1 on the expression of these factors were eliminated by p38 and JNK inhibitors. The results suggested that TGF-β1 could induce myofibroblast transdifferentiation in human Graves’ orbital fibroblasts through the p38 and JNK pathways.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yueyi Yang ◽  
Wenjing Liu ◽  
JieYa Wei ◽  
Yujia Cui ◽  
Demao Zhang ◽  
...  

AbstractGap junction (GJ) has been indicated to have an intimate correlation with adhesion junction. However, the direct interaction between them partially remains elusive. In the current study, we aimed to elucidate the role of N-cadherin, one of the core components in adhesion junction, in mediating connexin 43, one of the functional constituents in gap junction, via transforming growth factor-β1(TGF-β1) induction in osteoblasts. We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43, and the enhancement of functional gap junctional intercellular communication (GJIC) triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line. Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell–cell contact. Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43. Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced. TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation, whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43. Overall, these data indicate the direct interactions between N-cadherin and Cx43, and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.


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