scholarly journals All-Trans Retinoic Acid Attenuates Fibrotic Processes by Downregulating TGF-β1/Smad3 in Early Diabetic Nephropathy

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 525 ◽  
Author(s):  
Edith Sierra-Mondragon ◽  
Rafael Rodríguez-Muñoz ◽  
Carmen Namorado-Tonix ◽  
Eduardo Molina-Jijon ◽  
Daniel Romero-Trejo ◽  
...  

Diabetic nephropathy (DN) involves damage associated to hyperglycemia and oxidative stress. Renal fibrosis is a major pathologic feature of DN. The aim of this study was to evaluate anti-fibrogenic and renoprotective effects of all-trans retinoic acid (ATRA) in isolated glomeruli and proximal tubules of diabetic rats. Diabetes was induced by single injection of streptozotocin (STZ, 60 mg/Kg). ATRA (1 mg/Kg) was administered daily by gavage, from days 3–21 after STZ injection. ATRA attenuated kidney injury through the reduction of proteinuria, renal hypertrophy, increase in natriuresis, as well as early markers of damage such as β2-microglobulin, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL). The following parameters increased: macrophage infiltration, localization of alpha-smooth muscle actin (αSMA)-positive cells in renal tissue, and pro-fibrotic proteins such as transforming growth factor-β (TGF-β1), laminin beta 1 (LAM-β1), and collagens IV and I. Remarkably, ATRA treatment ameliorated these alterations and attenuated expression and nuclear translocation of Smad3, with increment of glomerular and tubular Smad7. The diabetic condition decreased expression of retinoic acid receptor alpha (RAR-α) through phosphorylation in serine residues mediated by the activation of c-Jun N-terminal kinase (JNK). ATRA administration restored the expression of RAR-α and inhibited direct interactions of JNK/RAR-α. ATRA prevented fibrogenesis through down-regulation of TGF-β1/Smad3 signaling.

Blood ◽  
2003 ◽  
Vol 101 (2) ◽  
pp. 498-507 ◽  
Author(s):  
Zhouhong Cao ◽  
Kathleen C. Flanders ◽  
Daniel Bertolette ◽  
Lyudmila A. Lyakh ◽  
Jens U. Wurthner ◽  
...  

We have investigated the role of Smad family proteins, known to be important cytoplasmic mediators of signals from the transforming growth factor–β (TGF-β) receptor serine/threonine kinases, in TGF-β–dependent differentiation of hematopoietic cells, using as a model the human promyelocytic leukemia cell line, HL-60. TGF-β–dependent differentiation of these cells to monocytes, but not retinoic acid–dependent differentiation to granulocytes, was accompanied by rapid phosphorylation and nuclear translocation of Smad2 and Smad3. Vitamin D3 also induced phosphorylation of Smad2/3 and monocytic differentiation; however the effects were indirect, dependent on its ability to induce expression of TGF-β1. Simultaneous treatment of these cells with TGF-β1 and all-trans-retinoic acid (ATRA), which leads to almost equal numbers of granulocytes and monocytes, significantly reduced the level of phospho–Smad2/3 and its nuclear accumulation, compared with that in cells treated with TGF-β1 alone. TGF-β1 and ATRA activate P42/44 mitogen-activated protein (MAP) kinase with nearly identical kinetics, ruling out its involvement in these effects on Smad phosphorylation. Addition of the inhibitor-of-protein serine/threonine phosphatases, okadaic acid, blocks the ATRA-mediated reduction in TGF-β–induced phospho-Smad2 and shifts the differentiation toward monocytic end points. In HL-60R mutant cells, which harbor a defective retinoic acid receptor–α (RAR-α), ATRA is unable to reduce levels of TGF-β–induced phospho-Smad2/3, coincident with its inability to differentiate these cells along granulocytic pathways. Together, these data suggest a new level of cross-talk between ATRA and TGF-β, whereby a putative RAR-α–dependent phosphatase activity limits the levels of phospho-Smad2/3 induced by TGF-β, ultimately reducing the levels of nuclear Smad complexes mediating the TGF-β–dependent differentiation of the cells to monocytic end points.


2001 ◽  
Vol 12 (11) ◽  
pp. 2300-2309 ◽  
Author(s):  
CHRISTIAN MORATH ◽  
CLAUDIUS DECHOW ◽  
INGO LEHRKE ◽  
VOLKER HAXSEN ◽  
RÜDIGER WALDHERR ◽  
...  

Abstract. Transforming growth factor—β1 (TGF-β1) overexpression plays a key role in the glomerular accumulation of extracellular matrix proteins in renal disease. Retinoids have previously been shown to significantly limit glomerular damage in rat experimental glomerulonephritis. Therefore, the effects of all-trans retinoic acid and isotretinoin on the components of the TGF-β system and extracellular matrix proteins in anti-Thy1.1-nephritis (Thy-GN) were investigated. Vehicle-injected control rats were compared with rats treated with daily subcutaneous injections of 10 mg/kg body wt all-trans retinoic acid or 40 mg/kg body wt isotretinoin (n= 9 per group) either with a pretreatment (day -2 through 8) or posttreatment protocol (day +3 through 8),i.e., starting before or after induction of Thy-GN, respectively. Urinary TGF-β1 excretion was 60% lower in all-trans retinoic acid-treated animals with Thy-GN (P< 0.025). The increase of cortical TGF-β1 gene expression in Thy-GN rats was significantly attenuated with all-trans retinoic acid and even more with isotretinoin treatment as compared with untreated animals (P< 0.025). Cortical expression of TGF receptor II, but not receptor I gene expression, was significantly lower in animals treated with all-trans retinoic acid or isotretinoin (P< 0.05). In all-trans retinoic acid—treated animals with Thy-GN, the increase of glomerular TGF-β1 protein (P< 0.008) and TGF-β1 (P< 0.025) and TGF receptor II mRNA (P< 0.015) was significantly less. Immunohistochemistry revealed less glomerular staining for TGF-β1 and TGF receptor II in the presence of all-trans retinoic acid. TGF-β1 immunostaining was not restricted to monocytes and macrophages, as indicated by double-staining. Glomerular staining for collagen IV and collagen III was less in animals treated with isotretinoin (P< 0.02 for both) in contrast to all-trans retinoic acid, whereas fibronectin remained unchanged. It was concluded that the beneficial effects of retinoids on glomerular damage are presumably due to a marked reduction in renal TGF-β1 and TGF receptor II expression.


2018 ◽  
Vol 60 ◽  
pp. 47-60 ◽  
Author(s):  
Edith Sierra-Mondragon ◽  
Eduardo Molina-Jijon ◽  
Carmen Namorado-Tonix ◽  
Rafael Rodríguez-Muñoz ◽  
Jose Pedraza-Chaverri ◽  
...  

2021 ◽  
Vol 14 ◽  
Author(s):  
Hanaa Wanas ◽  
Zeinab El Shereef ◽  
Laila Rashed ◽  
Basma Emad Aboulhoda

Background: Idiopathic pulmonary fibrosis (IPF) is a serious disease with high mortality rate. Activation of transforming growth factor (TGF)-β1 production and signalling is considered the corner stone in the epithelial-mesenchymal transition (EMT) process. EMT plays a central role in development of fibrosis in many organs including the lungs. Activated platelets is an important source of TGF-β1 and play a pivotal role in EMT and fibrosis process. The antiplatelet, ticagrelor was previously found to inhibit the EMT in different types of cancer cells, but its ability to serve as an anti-pulmonary fibrosis (PF) agent was not previously investigated. Objective: In this study, we aim to investigate the potential ability of ticagrelor to ameliorate bleomycin-induced fibrosis in rats. Methods: PF was induced in rats by intratracheal BLM at a dose of 3 mg/kg. The effect of daily daily 20 mg/kg oral ticagrelor on different histological and biochemical parameters of fibrosis was investigated. Results: Our results revealed that ticagrelor can alleviate lung fibrosis. We found that ticagrelor inhibited TGF-β1 production and suppressed Smad3 activation and signaling pathway with subsequent inhibition of Slug and Snail. In addition, ticagrelor antagonized PI3K/AKT/mTOR pathway signaling. Moreover, ticagrelor inhibited the EMT that revealed by its ability to up-regulate the epithelial markers as E-cadherin (E-cad) and to decrease the expression of the mesenchymal markers as vimentin (VIM) and alpha-smooth muscle actin (α-SMA). Conclusion: Our results suggest that the P2Y12 inhibitor, ticagrelor may have a therapeutic potential in reducing the progression of PF.


2016 ◽  
Vol 38 (1) ◽  
pp. 229-236 ◽  
Author(s):  
Yong Xu ◽  
Ai-Mei Gao ◽  
Li-Juan Ji ◽  
Xing Li ◽  
Li-Li Zhong ◽  
...  

Background/Aims: Hypoxia has recently been proposed as one of the most important factors in progressive renal injury. Hypoxia-induced vascular endothelial growth factor (VEGF) expression may play a critical role in maintaining peritubular capillary endothelium in renal disease. This study was designed to investigate the effect and underlying mechanism of all-trans retinoic acid (ATRA) on hypoxia-induced injury in NRK52E cells. Methods: For mimicking hypoxia, cells were treated with 100 µM of cobalt chloride (CoCl2). The cell viability, expression of VEGF, p65, transforming growth factor-β2 (TGF-β2) and serine carboxypeptidase 1 (Scpep1), and nuclear factor of kappaB (NF-κB) activities after ATRA treatment were determined by MTT, western blot and electrophoretic mobility shift assay. Co-immunoprecipitation analysis was performed to demonstrate whether Scpep1 interacted with TGF-β2. Results: It was found that CoCl2 triggered hypoxia injury and significantly reduced cell viability. ATRA pretreatment increased the cell survival rate. Under hypoxic conditions, the expression of VEGF, p65 and TGF-β2 increased. Addition of ATRA significantly attenuated the expression of VEGF, p65 and TGF-β2. There was a corresponding variation of NF-κB/DNA binding activities. In addition, ATRA stimulated Scpep1 expression under normoxic and hypoxia condition. Furthermore, TGF-β2 interacted with Scpep1. Conclusions: This study indicated that ATRA may attenuate hypoxia-induced injury in NRK52E cells via inhibiting NF-κB/VEGF and TGF-β2/VEGF pathway.


Sign in / Sign up

Export Citation Format

Share Document