scholarly journals In Vivo Investigation of the Ameliorating Effect of Tempol against MIA-Induced Knee Osteoarthritis in Rats: Involvement of TGF-β1/SMAD3/NOX4 Cue

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6993
Author(s):  
Hagar B. Abo-zalam ◽  
Rehab F. Abdel-Rahman ◽  
Mohamed F. Abd-Ellah ◽  
Rania M. Abdelsalam ◽  
Mahmoud M. Khattab
Keyword(s):  
Structural Changes ◽  
Complex Disease ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Bone Alkaline Phosphatase ◽  
Mitogen Activated Protein Kinase ◽  
Knee Oa ◽  
Nadph Oxidase 4 ◽  
Tgf Β1

Osteoarthritis (OA) is a complex disease characterized by structural, functional, and metabolic deteriorations of the whole joint and periarticular tissues. In the current study, we aimed to investigate the possible effects of tempol on knee OA induced by the chemical chondrotoxic monosodium iodoacetate (MIA) which closely mimics both the pain and structural changes associated with human OA. Rats were administrated oral tempol (100 mg/kg) one week post-MIA injection (3 mg/50 μL saline) at the right knee joints for 21 consecutive days. Tempol improved motor performance and debilitated the MIA-related radiological and histological alterations. Moreover, it subsided the knee joint swelling. Tempol decreased the cartilage degradation-related biomarkers as matrix metalloproteinase-13, bone alkaline phosphatase (bone ALP), and fibulin-3. The superoxide dismutase mimetic effect of tempol was accompanied by decreased NADPH oxidase 4 (NOX4), inflammatory mediators, nuclear factor-kappa B (NF-κB), over-released transforming growth factor-β1 (TGF-β1). Tempol decreased the expression of chemokine (C-C motif) ligand 2 (CCL2). On the molecular level, tempol reduced the phosphorylated protein levels of p38 mitogen-activated protein kinase (MAPK), and small mother against decapentaplegic 3 homologs (SMAD3). These findings suggest the promising role of tempol in ameliorating MIA-induced knee OA in rats via collateral suppression of the catabolic signaling cascades including TGF-β1/SMAD3/NOX4, and NOX4/p38MAPK/NF-κB and therefore modulation of oxidative stress, catabolic inflammatory cascades, chondrocyte metabolic homeostasis.

scholarly journals The Antioxidant tempol delays the MIA-induced osteoarthritis progression in rats via modulation of signaling pathways involving TGF-β1/SMAD3/NOX4 axis

2021 ◽  
Author(s):  
Hagar B. Abo-zalam ◽  
Rehab F. Abdel-Rahman ◽  
Mohamed F. Abd-Ellah ◽  
Rania M. Abdalsalam ◽  
Mahmoud M. Khattab
Keyword(s):  
Growth Factor ◽  
Protein Kinase ◽  
Matrix Protein ◽  
Structural Changes ◽  
Complex Disease ◽  
Transforming Growth Factor ◽  
Mitogen Activated Protein Kinase ◽  
Knee Oa ◽  
Nadph Oxidase 4 ◽  
Tgf Β1

Abstract Osteoarthritis (OA) is a complex disease characterized by structural, functional, and metabolic deteriorations of the whole joint and periarticular tissues. In the current study, we aimed to investigate the possible effects of tempol on knee OA induced by the chemical chondrotoxic monosodium iodoacetate (MIA) which closely mimics both the pain and structural changes associated with human OA. Rats were administrated oral tempol (100 mg/kg) one week post-MIA injection (3 mg/ 50 μL saline) at the right knee joints for 21 consecutive days. Tempol improved motor performance and debilitated the MIA-related radiological and histological alterations. Besides, it subsided the knee joint swelling. Tempol decreased the cartilage degradation-related biomarkers as matrix metalloproteinase-13, cartilage oligomeric matrix protein, and fibulin-3. The superoxide dismutase mimetic effect of tempol was accompanied by decreased NADPH oxidase 4 (NOX4), inflammatory mediators, nuclear factor kappa-B (NF-κB), over-released insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1). Tempol decreased the expression of chemotactic cytokine ligand 2 (CCL2), dickkopf‑related protein-1 (DKK-1), and protein kinase C (PKC). On the molecular level, tempol reduced the phosphorylated protein levels of p38 mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and small mother against decapentaplegic 3 homologs (SMAD3). These findings suggest the promising role of tempol in ameliorating MIA-induced knee OA in rats via collateral suppression of the catabolic signaling cascades including TGF-β1/SMAD3/NOX4, NOX4/p38MAPK/NF-κB, and PI3K/Akt/NF-κB and therefore modulation of oxidative stress, catabolic inflammatory cascades, chondrocyte metabolic homeostasis, autophagy, and cell survival.

scholarly journals JNK and p38 Inhibitors Prevent Transforming Growth Factor-β1-Induced Myofibroblast Transdifferentiation in Human Graves’ Orbital Fibroblasts

2021 ◽  
Vol 22 (6) ◽  
pp. 2952
Author(s):  
Tzu-Yu Hou ◽  
Shi-Bei Wu ◽  
Hui-Chuan Kau ◽  
Chieh-Chih Tsai
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Mapk Pathway ◽  
Transforming Growth Factor Β1 ◽  
Tissue Growth ◽  
Mitogen Activated Protein Kinase ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Western Blots ◽  
Orbital Fibroblasts ◽  
Tgf Β1

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.

MKP2 inhibits TGF-β1-induced epithelial-to-mesenchymal transition in renal tubular epithelial cells through a JNK-dependent pathway

2018 ◽  
Vol 132 (21) ◽  
pp. 2339-2355 ◽  
Author(s):  
Zhenzhen Li ◽  
Xianghua Liu ◽  
Fengyan Tian ◽  
Ji Li ◽  
Qingwei Wang ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Mitogen Activated Protein Kinase ◽  
Jnk Signaling ◽  
Mesenchymal Transition ◽  
Amino Terminal ◽  
Ureter Obstruction ◽  
Tgf Β1

Epithelial-to-mesenchymal transition (EMT) is a phenotypic conversion that plays a crucial role in renal fibrosis leading to chronic renal failure. Mitogen-activated protein kinase phosphatase 2 (MKP2) is a member of the dual-specificity MKPs that regulate the MAP kinase pathway involved in transforming growth factor-β1 (TGF-β1)-induced EMT. However, the function of MKP2 in the regulation of EMT and the underlying mechanisms are still largely unknown. In the present study, we detected the expression of MKP2 in an animal model of renal fibrosis and evaluated the potential role of MKP2 in tubular EMT induced by TGF-β1. We found that the expression of MKP2 was up-regulated in the tubular epithelial of unilateral ureter obstruction rats. Meanwhile, we also demonstrated that TGF-β1 up-regulated MKP2 expression in NRK-52E cells during their EMT phenotype acquisition. Importantly, overexpression of MKP2 inhibited c-Jun amino terminal kinase (JNK) signaling and partially reversed EMT induced by TGF-β1. Moreover, reducing MKP2 expression enhanced JNK phosphorylation, promoted the E-cadherin suppression and induced α-SMA expression and fibronectin secretion in response to TGF-β1, which could be rescued by a JNK inhibitor. These results provide the first evidence that MKP2 is a negative feedback molecule induced by TGF-β1, and MKP2 overexpression inhibits TGF-β1-induced EMT through the JNK signaling pathway. MKP2 could be a promising target to be used in gene therapy for renal fibrosis.

scholarly journals Rapid Up-Regulation of α4 Integrin-mediated Leukocyte Adhesion by Transforming Growth Factor-β1

2003 ◽  
Vol 14 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Rubén A. Bartolomé ◽  
Francisco Sanz-Rodrı́guez ◽  
Mar M. Robledo ◽  
Andrés Hidalgo ◽  
Joaquin Teixidó
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Human Peripheral Blood ◽  
Transforming Growth Factor Β1 ◽  
Small Gtpase ◽  
Mitogen Activated Protein Kinase ◽  
Intracellular Camp ◽  
Tgf Β1

The α4 integrins (α4β1 and α4β7) are cell surface heterodimers expressed mostly on leukocytes that mediate cell-cell and cell-extracellular matrix adhesion. A characteristic feature of α4 integrins is that their adhesive activity can be subjected to rapid modulation during the process of cell migration. Herein, we show that transforming growth factor-β1 (TGF-β1) rapidly (0.5–5 min) and transiently up-regulated α4 integrin-dependent adhesion of different human leukocyte cell lines and human peripheral blood lymphocytes (PBLs) to their ligands vascular cell adhesion molecule-1 (VCAM-1) and connecting segment-1/fibronectin. In addition, TGF-β1 enhanced the α4 integrin-mediated adhesion of PBLs to tumor necrosis factor-α–treated human umbilical vein endothelial cells, indicating the stimulation of α4β1/VCAM-1 interaction. Although TGF-β1 rapidly activated the small GTPase RhoA and the p38 mitogen-activated protein kinase, enhanced adhesion did not require activation of both signaling molecules. Instead, polymerization of actin cytoskeleton triggered by TGF-β1 was necessary for α4 integrin-dependent up-regulated adhesion, and elevation of intracellular cAMP opposed this up-regulation. Moreover, TGF-β1 further increased cell adhesion mediated by α4 integrins in response to the chemokine stromal cell-derived factor-1α. These data suggest that TGF-β1 can potentially contribute to cell migration by dynamically regulating cell adhesion mediated by α4 integrins.

Identification of Platelet Releasate Proteins that Bind to Mastoparan, a Peptide that Inhibits Shear-Induced TGF-β1 Activation,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3271-3271
Author(s):  
Teresa M Brophy ◽  
Jasimuddin Ahamed ◽  
Barry S. Coller
Keyword(s):  
Transforming Growth Factor ◽  
Coagulation Factor ◽  
Transforming Growth Factor Β1 ◽  
Affinity Column ◽  
Factor V ◽  
Disulfide Exchange ◽  
Control Peptide ◽  
Tgf Β1

Abstract Abstract 3271 Transforming growth factor β1 (TGF-β1) is a disulfide-bonded, 25 kD homodimeric protein produced by most cell types, including platelets, that functions as a cytokine in many physiologic and pathologic processes. Platelets contain 40–100 times more TGF-β1 than other cells and release it as an inactive large latent complex (LLC) comprised of TGF-β1 non-covalently associated with its latency-associated peptide (LAP), which is, in turn, disulfide-bonded to latent TGF-β binding protein 1 (LTBP-1). Thrombospondin-1 (TSP1), proteases, and reactive oxygen species have all been shown to activate TGF-β1 in vitro and a role for integrins in vivo has been inferred from studies of transgenic mice. Recently, we discovered that shear force can activate latent TGF-β1 released from platelets in vitro and that thiol-disulfide exchange contributes to shear-dependent TGF-β1 activation. A number of thiol isomerase enzymes that can catalyze thiol-disulfide exchange have been identified in platelets, including protein disulfide isomerase (PDI), ERp5, ERp57, ERp72, ERp44, ERp29, and TMX3. As shear-induced activation of TGF-β1 is partially thiol-dependent, we investigated if thiol isomerases can affect this process. Mastoparan is a non-thiol-containing wasp venom peptide known to inhibit the chaperone activity of PDI, ERp5, and perhaps other thiol isomerases. We recently showed that mastoparan, (INLKALAALAKKIL), inhibits stirring-induced TGF-β1 activation by more than 90% (100 μM; n=3, p=0.03), whereas no inhibition was observed with an inactive mastoparan-like control peptide (INLKAKAALAKKLL) at 100 μM (n=3, p=0.66). To identify the proteins that bind to mastoparan, either directly or indirectly, platelet releasates were chromatographed on a mastoparan affinity column prepared from N-hydroxysuccinimide Sepharose. Two control columns were employed: 1. unconjugated Sepharose, and 2. Sepharose conjugated with the mastoparan-like control peptide. Elution of bound proteins was achieved by increasing the NaCl concentration. Proteins identified by mass spectrometry as specifically binding to the mastoparan peptide column included LTBP-1, TGF-β1 precursor, clusterin, coagulation Factor V, multimerin-1, 14-3-3 protein zeta/delta, and α-actinin 4. These results were confirmed by immunoblotting. Furthermore, the thiol isomerases PDI, ERp5, ERp57, and ERp72 were all found to bind specifically to mastoparan as confirmed by immunoblotting. We conclude that mastoparan affinity chromatography identified a number of proteins in platelet releasates that may contribute to shear-induced TGF-β1 activation. Disclosures: Coller: Centocor/Accumetrics/Rockefeller University:.

CD28 disruption exacerbates inflammation in Tgf-β1-/- mice: in vivo suppression by CD4+CD25+ regulatory T cells independent of autocrine TGF-β1

Blood ◽  
2004 ◽  
Vol 103 (12) ◽  
pp. 4594-4601 ◽  
Author(s):  
Mizuko Mamura ◽  
WoonKyu Lee ◽  
Timothy J. Sullivan ◽  
Angelina Felici ◽  
Anastasia L. Sowers ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Transforming Growth Factor ◽  
Cytotoxic T Lymphocyte ◽  
Tumor Necrosis Factor Receptor ◽  
Transforming Growth Factor Β1 ◽  
Autoimmune Inflammatory Disease ◽  
Lymph Node Cells ◽  
Tgf Β1

Abstract Tgf-β1-/- mice develop a progressive, lethal, inflammatory syndrome, but mechanisms leading to the spontaneous activation of Tgf-β1-/- T cells remain unclear. Here we show the disruption of CD28 gene expression accelerates disease in Tgf-β1-/- mice, and we link this increase in severity to a reduction in the number of CD4+CD25+ regulatory T cells. CD4+CD25+ T cells develop normally in Tgf-β1-/- mice and display characteristic expression of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), glucocorticoid-induced tumor necrosis factor receptor (GITR), αEβ7 integrin, and Foxp3. Adoptive transfer of Tgf-β1-/- splenocytes to Tgf-β1+/+/Rag2-/- mice induced an autoimmune inflammatory disease with features similar to those of the Tgf-β1-/- phenotype, and disease transfer was accelerated by the depletion of Tgf-β1-/- CD4+CD25+ T cells from donor splenocytes. Cotransfer of Tgf- β1-/- CD4+CD25+ T cells clearly attenuated disease in Rag2-/- recipients of CD25+-depleted Tgf-β1-/- spleen and lymph node cells, but suppression was incomplete when compared with Tgf-β1+/+ CD4+CD25+ T cells. These data demonstrate that CD4+CD25+ regulatory T cells develop in complete absence of endogenous transforming growth factor-β1 (TGF-β1) expression and that autocrine TGF-β1 expression is not essential for these cells to suppress inflammation in vivo. (Blood. 2004;103:4594-4601)

Comparison of Release Profiles of Various Growth Factors from Biodegradable Carriers

1998 ◽  
Vol 530 ◽  
Author(s):  
Y. Tabata ◽  
M. Yamamoto ◽  
Y. Ikada
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
The Body ◽  
Bone Morphogenetic Protein 2 ◽  
Biodegradable Hydrogel ◽  
Tgf Β1

AbstractA biodegradable hydrogel was prepared by glutaraldehyde crosslinking of acidic gelatin with an isoelectric point (IEP) of 5.0 as a carrier to release basic growth factors on the basis of polyion complexation. Basic fibroblast growth factor (bFGF), transforming growth factor β1 (TGF-β1), and bone morphogenetic protein-2 (BMP-2) were sorbed from their aqueous solution into the dried gelatin hydrogels to prepare respective growth factor-incorporating hydrogels. Under an in vitro non-degradation condition, approximately 20 % of incorporated bFGF and TGF-β1 was released from the hydrogels within initial 40 min, followed by no further release, whereas a large initial release of BMP-2 was observed. After subcutaneous implantation of the gelatin hydrogels incorporating 125I-labeled growth factor in the mouse back, the remaining radioactivity was measured to estimate the in vivo release profile of growth factors. Incorporation into gelatin hydrogels enabled bFGF and TGF-β1 to retain in the body for about 15 days and the retention period well correlated with that of the gelatin hydrogel. Taken together, it is likely that the growth factors ionically complexed with acidic gelatin were released in vivo as a result of hydrogel biodegradation. On the contrary, basic BMP-2 did not ionically interact with acidic gelatin, resulting in no sustained released by the present biodegradable carrier system.

scholarly journals Targeting Follistatin like 1 ameliorates liver fibrosis induced by carbon tetrachloride through TGF-β1-miR29a in mice

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Xin-Yi Xu ◽  
Yan Du ◽  
Xue Liu ◽  
Yilin Ren ◽  
Yingying Dong ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Neutralizing Antibody ◽  
Transforming Growth Factor Β1 ◽  
Chemokine Ligand ◽  
Tgf Β1

Abstract Background Hepatic fibrosis is a pathological response of the liver to a variety of chronic stimuli. Hepatic stellate cells (HSCs) are the major source of myofibroblasts in the liver. Follistatin like 1 (Fstl1) is a secreted glycoprotein induced by transforming growth factor-β1 (TGF-β1). However, the precise functions and regulation mechanisms of Fstl1 in liver fibrogenesis remains unclear. Methods Hepatic stellate cell (HSC) line LX-2 stimulated by TGF-β1, primary culture of mouse HSCs and a model of liver fibrosis induced by CCl4 in mice was used to assess the effect of Fstl1 in vitro and in vivo. Results Here, we found that Fstl1 was significantly up regulated in human and mouse fibrotic livers, as well as activated HSCs. Haplodeficiency of Fstl1 or blockage of Fstl1 with a neutralizing antibody 22B6 attenuated CCl4-induced liver fibrosis in vivo. Fstl1 modulates TGF-β1 classic Samd2 and non-classic JNK signaling pathways. Knockdown of Fstl1 in HSCs significantly ameliorated cell activation, cell migration, chemokines C-C Motif Chemokine Ligand 2 (CCL2) and C-X-C Motif Chemokine Ligand 8 (CXCL8) secretion and extracellular matrix (ECM) production, and also modulated microRNA-29a (miR29a) expression. Furthermore, we identified that Fstl1 was a target gene of miR29a. And TGF-β1 induction of Fstl1 expression was partially through down regulation of miR29a in HSCs. Conclusions Our data suggests TGF-β1-miR29a-Fstl1 regulatory circuit plays a key role in regulation the HSC activation and ECM production, and targeting Fstl1 may be a strategy for the treatment of liver fibrosis. Graphical abstract

scholarly journals Characterization of Mice with a Platelet-Specific Deletion of the Adapter Molecule ADAP

2019 ◽  
Vol 39 (9) ◽  
Author(s):  
Jochen Michael Rudolph ◽  
Karina Guttek ◽  
Gabriele Weitz ◽  
Clara Antonia Meinke ◽  
Stefanie Kliche ◽  
...  
Keyword(s):  
T Cells ◽  
Knockout Mice ◽  
Transforming Growth Factor ◽  
Severe Disease ◽  
Transforming Growth Factor Β1 ◽  
Regulatory Function ◽  
Platelet Factor ◽  
Tgf Β1

ABSTRACT The adhesion and degranulation-promoting adapter protein (ADAP) is expressed in T cells, NK cells, myeloid cells, and platelets. The involvement of ADAP in the regulation of receptor-mediated inside-out signaling leading to integrin activation is well characterized, especially in T cells and in platelets. Due to the fact that animal studies using conventional knockout mice are limited by the overlapping effects of the different ADAP-expressing cells, we generated conditional ADAP knockout mice (ADAPfl/fl PF4-Cretg) (PF4, platelet factor 4). We observed that loss of ADAP restricted to the megakaryocytic lineage has no impact on other hematopoietic cells even under stimulation conditions. ADAPfl/fl PF4-Cretg mice showed thrombocytopenia in combination with reduced plasma levels of PF4 and transforming growth factor β1 (TGF-β1). In vitro, platelets from these mice revealed reduced P-selectin expression, lower levels of TGF-β1 release, diminished integrin αIIbβ3 activation, and decreased fibrinogen binding after stimulation with podoplanin, the ligand of C-type lectin-like receptor 2 (CLEC-2). Furthermore, loss of ADAP was associated with impaired CLEC-2-mediated activation of phospholipase Cγ2 (PLCγ2) and extracellular signal-regulated kinase 1/2 (ERK1/2). Induction of experimental autoimmune encephalomyelitis (EAE) in mice lacking ADAP expression in platelets caused a more severe disease. In vivo administration of TGF-β1 early after T cell transfer reduced EAE severity in mice with loss of ADAP restricted to platelets. Our results reveal a regulatory function of ADAP in platelets in vitro and during autoimmune disease EAE in vivo.

scholarly journals Pharmacological inhibition of autophagy by 3-MA attenuates hyperuricemic nephropathy

2018 ◽  
Vol 132 (21) ◽  
pp. 2299-2322 ◽  
Author(s):  
Jinfang Bao ◽  
Yingfeng Shi ◽  
Min Tao ◽  
Na Liu ◽  
Shougang Zhuang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Signaling Pathways ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Growth Factor Receptor ◽  
Nuclear Factor Κb ◽  
Transforming Growth Factor Β1 ◽  
Renal Tissue ◽  
Tgf Β1

Autophagy has been identified as a cellular process of bulk degradation of cytoplasmic components and its persistent activation is critically involved in the renal damage induced by ureteral obstruction. However, the role and underlying mechanisms of autophagy in hyperuricemic nephropathy (HN) remain unknown. In the present study, we observed that inhibition of autophagy by 3-methyladenine (3-MA) abolished uric acid-induced differentiation of renal fibroblasts to myofibroblasts and activation of transforming growth factor-β1 (TGF-β1), epidermal growth factor receptor (EGFR), and Wnt signaling pathways in cultured renal interstitial fibroblasts. Treatment with 3-MA also abrogated the development of HN in vivo as evidenced by improving renal function, preserving renal tissue architecture, reducing the number of autophagic vacuoles, and decreasing microalbuminuria. Moreover, 3-MA was effective in attenuating renal deposition of extracellular matrix (ECM) proteins and expression of α-smooth muscle actin (α-SMA) and reducing renal epithelial cells arrested at the G2/M phase of cell cycle. Injury to the kidney resulted in increased expression of TGF-β1 and TGFβ receptor I, phosphorylation of Smad3 and TGF-β-activated kinase 1 (TAK1), and activation of multiple cell signaling pathways associated with renal fibrogenesis, including Wnt, Notch, EGFR, and nuclear factor-κB (NF-κB). 3-MA treatment remarkably inhibited all these responses. In addition, 3-MA effectively suppressed infiltration of macrophages and lymphocytes as well as release of multiple profibrogenic cytokines/chemokines in the injured kidney. Collectively, these findings indicate that hyperuricemia-induced autophagy is critically involved in the activation of renal fibroblasts and development of renal fibrosis and suggest that inhibition of autophagy may represent a potential therapeutic strategy for HN.

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