HSP47 regulates ECM accumulation in renal proximal tubular cells induced by TGF-β1 through ERK1/2 and JNK MAPK pathways

Heat shock protein (HSP)47 is a collagen-specific molecular chaperone that is essential for the biosynthesis of collagen molecules. It is likely that increased levels of HSP47 contribute to the assembly of procollagen and thereby cause an excessive accumulation of collagens in disease processes associated with fibrosis. Although HSP47 promotes renal fibrosis, the underlying mechanism and associated signaling events have not been clearly delineated. We examined the role of HSP47 in renal fibrosis using a rat unilateral ureteral obstruction model and transforming growth factor (TGF)-β1-treated human proximal tubular epithelial (HK-2) cells. An upregulation of HSP47 in both in vivo and in vitro models was observed, which correlated with the increased synthesis of extracellular matrix (ECM) proteins and expression of tissue-type plasminogen activator inhibitor (PAI)-1. Blockade of HSP47 by short interfering RNA suppressed the expression of ECM proteins and PAI-1. In addition, TGF-β1-induced HSP47 expression in HK-2 cells was attenuated by ERK1/2 and JNK MAPK inhibitors. These data suggest that ERK1/2 and JNK signaling events are involved in modulating the expression of HSP47, the chaperoning effect of which on TGF-β1 would ultimately contribute to renal fibrosis by enhancing the synthesis and deposition of ECM proteins.

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Inhibition of clot lysis and decreased binding of tissue-type plasminogen activator as a consequence of clot retraction

Blood ◽

10.1182/blood.v79.6.1420.bloodjournal7961420 ◽

1992 ◽

Vol 79 (6) ◽

pp. 1420-1427 ◽

Cited By ~ 1

Author(s):

S Kunitada ◽

GA FitzGerald ◽

DJ Fitzgerald

Keyword(s):

Plasminogen Activator ◽

Tissue Type ◽

Clot Lysis ◽

Plasminogen Activator Inhibitor 1 ◽

Clot Retraction ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator ◽

Pai 1

Tissue-type plasminogen activator (t-PA) is less active in vivo and in vitro against clots that are enriched in platelets, even at therapeutic concentrations. The release of radioactivity from 125I-fibrin-labeled clots was decreased by 47% 6 hours after the addition of t-PA 400 U/mL when formed in platelet-rich versus platelet-poor plasma. This difference was not due to the release of plasminogen activator inhibitor-1 (PAI-1) by platelets. Thus, the fibrinolytic activity of t- PA in the supernatant was similar in the two preparations and fibrin autography demonstrated only a minor degree of t-PA-PAI-1 complex formation. Furthermore, a similar platelet-dependent reduction in clot lysis was seen with a t-PA mutant resistant to inhibition by PAI-1. The reduction in t-PA activity correlated with a decrease in t-PA binding to platelet-enriched clot (60% +/- 3% v platelet-poor clot, n = 5). This reduction in binding was also shown using t-PA treated with the chloromethylketone, D-Phe-Pro-Arg-CH2Cl (PPACK) (36% +/- 13%, n = 3), and with S478A, a mutant t-PA in which the active site serine at position 478 has been substituted by alanine (43% +/- 6%, n = 3). In contrast, fixed platelets and platelet supernatants had no effect on the binding or lytic activity of t-PA. Pretreatment with cytochalasin D 1 mumol/L, which inhibits clot retraction, also abolished the platelet- induced inhibition of lysis and t-PA binding by platelets. These data suggest that platelets inhibit clot lysis at therapeutic concentrations of t-PA as a consequence of clot retraction and decreased access of fibrinolytic proteins.

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Smad3 mediates ANG II-induced hypertensive kidney disease in mice

AJP Renal Physiology ◽

10.1152/ajprenal.00595.2011 ◽

2012 ◽

Vol 302 (8) ◽

pp. F986-F997 ◽

Cited By ~ 59

Author(s):

Zhen Liu ◽

Xiao R. Huang ◽

Hui Y. Lan

Keyword(s):

Angiotensin Ii ◽

Renal Fibrosis ◽

Transforming Growth Factor ◽

Mesangial Cells ◽

Type I ◽

Hypertensive Nephropathy ◽

Renal Inflammation ◽

Monocyte Chemoattractant Protein 1

Although Smad3 is a key mediator for fibrosis, its functional role and mechanisms in hypertensive nephropathy remain largely unclear. This was examined in the present study in a mouse model of hypertension induced in Smad3 knockout (KO) and wild-type (WT) mice by subcutaneous angiotensin II infusion and in vitro in mesangial cells lacking Smad3. After angiotensin II infusion, both Smad3 KO and WT mice developed equally high levels of blood pressure. However, disruption of Smad3 prevented angiotensin II-induced kidney injury by lowering albuminuria and serum creatinine ( P < 0.01), inhibiting renal fibrosis such as collagen type I and IV, fibronectin, and α-SMA expression (all P < 0.01), and blocking renal inflammation including macrophage and T cell infiltration and upregulation of IL-1β, TNF-α, and monocyte chemoattractant protein-1 in vivo and in vitro (all P < 0.001). Further studies revealed that blockade of angiotensin II-induced renal transforming growth factor (TGF)-β1 expression and inhibition of Smurf2-mediated degradation of renal Smad7 are mechanisms by which Smad3 KO mice were protected from angiotensin II-induced renal fibrosis and NF-κB-driven renal inflammation in vivo and in vitro. In conclusion, Smad3 is a key mediator of hypertensive nephropathy. Smad3 promotes Smurf2-dependent ubiquitin degradation of renal Smad7, thereby enhancing angiotensin II-induced TGF-β/Smad3-mediated renal fibrosis and NF-κB-driven renal inflammation. Results from this study suggest that inhibition of Smad3 or overexpression of Smad7 may be a novel therapeutic strategy for hypertensive nephropathy.

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Effect of Shenkang on renal fibrosis and activation of renal interstitial fibroblasts through the JAK2/STAT3 pathway

BMC Complementary Medicine and Therapies ◽

10.1186/s12906-020-03180-3 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Tianyu Qin ◽

You Wu ◽

Tonghua Liu ◽

Lili Wu

Keyword(s):

Renal Fibrosis ◽

Sham Group ◽

Smooth Muscle Actin ◽

Protective Action ◽

Underlying Mechanism ◽

Cytokine Signaling ◽

Stat3 Pathway ◽

Fibroblast Activation

Abstract Background Activation of renal fibroblasts is a critical mechanism in the process of renal fibrosis. As a commonly used herbal formula, Shenkang (SK) has been found to attenuate renal fibrosis and renal parenchyma destruction. However, the effect of SK on renal fibroblast activation in unilateral ureteral obstruction (UUO) mice and its molecular mechanism remain undetermined. The present study was performed to elucidate the effect of SK on renal fibroblast activation and renal fibrosis, as well as the potential underlying mechanism, in both NRK-49F cells and UUO mice. Methods NRK-49F cells were stimulated with 10 ng/ml TGF-β1 for 48 h. After SK treatment, the CCK-8 method was used to evaluate cell viability. Thirty-six C57BL/6 mice were randomly divided into the sham group, UUO group, angiotensin receptor blocker (ARB) group, and SK high-, moderate- and low-dose groups. UUO was induced in mice except those in the sham group. Drugs were administered 1 day later. On the 13th day, the fractional anisotropy (FA) value was determined by MRI to evaluate the degree of renal fibrosis. After 14 days, serum indexes were assessed. Hematoxylin and eosin (HE) and Sirius red staining were used to observe pathological morphology and the degree of fibrosis of the affected kidney. Western blotting and PCR were used to assess the expression of related molecules in both cells and animals at the protein and gene levels. Results Our results showed that SK reduced extracellular matrix (ECM) and α-smooth muscle actin (α-SMA) expression both in vitro and in vivo and attenuated renal fibrosis and the pathological lesion degree after UUO, suppressing JAK2/STAT3 activation. Furthermore, we found that SK regulated the JAK2/STAT3 pathway regulators peroxiredoxin 5 (Prdx5) in vitro and suppressor of cytokine signaling protein 1 (SOCS1) and SOCS3 in vivo. Conclusions These results indicated that SK inhibited fibroblast activation by regulating the JAK2/STAT3 pathway, which may be a mechanism underlying its protective action in renal fibrosis.

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Inhibitor-Resistant Tissue-Type Plasminogen Activator: An Improved Thrombolytic Agent In Vitro

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642395 ◽

1994 ◽

Vol 71 (01) ◽

pp. 124-128 ◽

Cited By ~ 7

Author(s):

R V Shohet ◽

S Spitzer ◽

E L Madison ◽

R Bassel-Duby ◽

M-J Gething ◽

...

Keyword(s):

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Tissue Type ◽

Wild Type ◽

Plasminogen Activator Inhibitor 1 ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator ◽

Pai 1

SummaryPlatelet-rich clots are inefficiently lysed by current fibrinolytic agents. Platelets contain a great deal of plasminogen activator inhibitor 1 (PAI-1), the principal endogenous inhibitor of tissue-type plasminogen activator (t-PA). We have tested whether PAI-1 resistant t-PAs would be more effective thrombolytic agents in an in vitro model of platelet rich clots. Clots were formed with recalcified human plasma without or with the addition of platelets. The lysis of these clots was followed by the release of incorporated 125I-fibrinogen. Mutant and wild-type t-PA were almost equally effective against clots lacking platelets but the mutant was twice as effective at lysing platelet-rich clots. A mechanism for this effect is suggested by the demonstration that a complex between wild-type t-PA and extruded platelet contents resembles that between purified t-PA and PAI-1 and that the PAI-1 resistant t-PA does not interfere with formation of this adduct. Because of its enhanced ability to lyse platelet-rich clots in vitro, further in vivo work may find that PAI-1 resistant t-PA is a more efficacious therapeutic agent than wild-type t-PA in situations where platelets contribute to the failure of thrombolysis.

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Mechanical strains induced by tubular flow affect the phenotype of proximal tubular cells

AJP Renal Physiology ◽

10.1152/ajprenal.2001.281.4.f751 ◽

2001 ◽

Vol 281 (4) ◽

pp. F751-F762 ◽

Cited By ~ 60

Author(s):

Marie Essig ◽

Fabiola Terzi ◽

Martine Burtin ◽

Gérard Friedlander

Keyword(s):

Actin Cytoskeleton ◽

Tissue Type ◽

Proximal Tubular Cells ◽

Tubular Cells ◽

Tubulointerstitial Lesions ◽

Proximal Tubular ◽

Tubular Flow ◽

Upa Mrna

The effects of flow-induced mechanical strains on the phenotype of proximal tubular cells were addressed in vivo and in vitro by subjecting LLC-PK1and mouse proximal tubular cells to different levels of flow. Laminar flow (1 ml/min) induced a reorganization of the actin cytoskeleton and significantly inhibited the expression of plasminogen activators [tissue-type (tPA) activity: 25% of control cells; tPA mRNA: 70% of control cells; urokinase (uPA) mRNA: 56% of control LLC-PK1cells]. In vivo, subtotal nephrectomy (Nx) decreased renal fibrinolytic activity and uPA mRNA content detectable in proximal tubules. Nx also induced a reinforcement of the apical domain of the actin cytoskeleton analyzed by immunofluorescence. These effects of flow on tPA and uPA mRNA were prevented in vitro when reorganization of the actin cytoskeleton was blocked by cytochalasin D and were associated, in vitro and in vivo, with an increase in shear stress-responsive element binding activity detected by an electrophoretic mobility shift assay in proximal cell nuclear extracts. These results demonstrate that tubular flow affects the phenotype of renal epithelial cells and suggest that flow-induced mechanical strains could be one determinant of tubulointerstitial lesions during the progression of renal diseases.

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Inhibition of clot lysis and decreased binding of tissue-type plasminogen activator as a consequence of clot retraction

Blood ◽

10.1182/blood.v79.6.1420.1420 ◽

1992 ◽

Vol 79 (6) ◽

pp. 1420-1427 ◽

Cited By ~ 70

Author(s):

S Kunitada ◽

GA FitzGerald ◽

DJ Fitzgerald

Keyword(s):

Plasminogen Activator ◽

Tissue Type ◽

Clot Lysis ◽

Plasminogen Activator Inhibitor 1 ◽

Clot Retraction ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator ◽

Pai 1

Abstract Tissue-type plasminogen activator (t-PA) is less active in vivo and in vitro against clots that are enriched in platelets, even at therapeutic concentrations. The release of radioactivity from 125I-fibrin-labeled clots was decreased by 47% 6 hours after the addition of t-PA 400 U/mL when formed in platelet-rich versus platelet-poor plasma. This difference was not due to the release of plasminogen activator inhibitor-1 (PAI-1) by platelets. Thus, the fibrinolytic activity of t- PA in the supernatant was similar in the two preparations and fibrin autography demonstrated only a minor degree of t-PA-PAI-1 complex formation. Furthermore, a similar platelet-dependent reduction in clot lysis was seen with a t-PA mutant resistant to inhibition by PAI-1. The reduction in t-PA activity correlated with a decrease in t-PA binding to platelet-enriched clot (60% +/- 3% v platelet-poor clot, n = 5). This reduction in binding was also shown using t-PA treated with the chloromethylketone, D-Phe-Pro-Arg-CH2Cl (PPACK) (36% +/- 13%, n = 3), and with S478A, a mutant t-PA in which the active site serine at position 478 has been substituted by alanine (43% +/- 6%, n = 3). In contrast, fixed platelets and platelet supernatants had no effect on the binding or lytic activity of t-PA. Pretreatment with cytochalasin D 1 mumol/L, which inhibits clot retraction, also abolished the platelet- induced inhibition of lysis and t-PA binding by platelets. These data suggest that platelets inhibit clot lysis at therapeutic concentrations of t-PA as a consequence of clot retraction and decreased access of fibrinolytic proteins.

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Oligo-Fucoidan Improves Diabetes-Induced Renal Fibrosis via Activation of Sirt-1, GLP-1R, and Nrf2/HO-1: An In Vitro and In Vivo Study

Nutrients ◽

10.3390/nu12103068 ◽

2020 ◽

Vol 12 (10) ◽

pp. 3068 ◽

Cited By ~ 1

Author(s):

Wen-Chun Yu ◽

Ren-Yeong Huang ◽

Tz-Chong Chou

Keyword(s):

Renal Fibrosis ◽

Molecular Mechanisms ◽

Transforming Growth Factor ◽

High Mobility ◽

Renal Diseases ◽

Heme Oxygenase 1 ◽

Diabetic Mice ◽

Tgf Β1

Fucoidan extracted from brown algae has multiple beneficial functions. In this study, we investigated the effects of low-molecular-weight fucoidan (oligo-FO) on renal fibrosis under in vitro and in vivo diabetic conditions, and its molecular mechanisms. Advanced glycation product (AGE)-stimulated rat renal proximal tubular epithelial cells (NRK-52E) and diabetic mice induced by high-fat diet and intraperitoneal injection of streptozotocin and nicotinamide were used. Oligo-FO treatment significantly inhibited anti-high mobility group box 1 (HMGB1)/RAGE/ anti-nuclear factor-kappa B (NF-κB)/transforming growth factor-β1 (TGF-β1)/TGF-β1R/Smad 2/3/fibronectin signaling pathway and HIF-1α activation in AGE-stimulated NRK-52E cells. Conversely, the expression and activity of Sirt-1; the levels of ubiquitin-specific peptidase 22 (USP22), p-AMPK, glucagon-like peptide-1 receptor (GLP-1R), and heme oxygenase-1 (HO-1); and Nrf2 activation were remarkably increased by oligo-FO in AGE-stimulated cells. However, the above effects of oligo-FO were greatly diminished by inhibiting Sirt-1, HO-1, or GLP-1R activity. Similar changes of these pro-fibrotic genes in the kidney and a marked attenuation of renal injury and dysfunction were observed in oligo-FO-treated diabetic mice. These findings indicated that the inhibitory effects of the oligo-FO on diabetes-evoked renal fibrosis are mediated by suppressing TGF-β1-activated pro-fibrogenic processes via Sirt-1, HO-1, and GLP-1R dependence. Collectively, fucoidan-containing foods or supplements may be potential agents for ameliorating renal diseases due to excessive fibrosis.

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TGF-β1 modulates temozolomide resistance in glioblastoma via altered microRNA processing and elevated MGMT

Neuro-Oncology ◽

10.1093/neuonc/noaa198 ◽

2020 ◽

Author(s):

Er Nie ◽

Xin Jin ◽

Faan Miao ◽

Tianfu Yu ◽

Tongle Zhi ◽

...

Keyword(s):

Transforming Growth Factor Beta ◽

Dna Methyltransferase ◽

Transforming Growth Factor ◽

Regulatory Protein ◽

Underlying Mechanism ◽

Epidermal Keratinocytes ◽

Methylguanine Dna Methyltransferase ◽

Tgf Β1

Abstract Background Our previous studies have indicated that miR-198 reduces cellular methylguanine DNA methyltransferase (MGMT) levels to enhance temozolomide sensitivity. Transforming growth factor beta 1 (TGF-β1) switches off miR-198 expression by repressing K-homology splicing regulatory protein (KSRP) expression in epidermal keratinocytes. However, the underlying role of TGF-β1 in temozolomide resistance has remained unknown. Methods The distribution of KSRP was detected by western blotting and immunofluorescence. Microarray analysis was used to compare the levels of long noncoding RNAs (lncRNAs) between TGF-β1–treated and untreated cells. RNA immunoprecipitation was performed to verify the relationship between RNAs and KSRP. Flow cytometry and orthotopic and subcutaneous xenograft tumor models were used to determine the function of TGF-β1 in temozolomide resistance. Results Overexpression of TGF-β1 contributed to temozolomide resistance in MGMT promoter hypomethylated glioblastoma cells in vitro and in vivo. TGF-β1 treatment reduced cellular MGMT levels through suppressing the expression of miR-198. However, TGF-β1 upregulation did not affect KSRP expression in glioma cells. We identified and characterized 2 lncRNAs (H19 and HOXD-AS2) that were upregulated by TGF-β1 through Smad signaling. H19 and HOXD-AS2 exhibited competitive binding to KSRP and prevented KSRP from binding to primary miR-198, thus decreasing miR-198 expression. HOXD-AS2 or H19 upregulation strongly promoted temozolomide resistance and MGMT expression. Moreover, KSRP depletion abrogated the effects of TGF-β1 and lncRNAs on miR-198 and MGMT. Finally, we found that patients with low levels of TGF-β1 or lncRNA expression benefited from temozolomide therapy. Conclusions Our results reveal an underlying mechanism by which TGF-β1 confers temozolomide resistance. Furthermore, our findings suggest that a novel combination of temozolomide with a TGF-β inhibitor may serve as an effective therapy for glioblastomas.

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EZH2 is involved in psoriasis progression by impairing miR-125a-5p inhibition of SFMBT1 and leading to inhibition of the TGFβ/SMAD pathway

Therapeutic Advances in Chronic Disease ◽

10.1177/2040622320987348 ◽

2021 ◽

Vol 12 ◽

pp. 204062232098734

Author(s):

Shengming Qu ◽

Zhe Liu ◽

Bing Wang

Keyword(s):

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Underlying Mechanism ◽

Luciferase Reporter ◽

Hacat Cells ◽

Loss Of Function ◽

Smad Pathway ◽

The Impact

Aims: In this study, we aimed to decipher the impact of enhancer of zeste homolog 2 (EZH2) in psoriasis as well as the underlying mechanism. Methods: A mouse model of psoriasis was developed by means of imiquimod induction, with the expression of EZH2, microRNA-125a-5p (miR-125a-5p), and SFMBT1 determined. The role of EZH2, miR-125a-5p, and SFMBT1 in malignant phenotypes of HaCaT cells and the development of psoriasis in vivo was subsequently investigated through gain- and loss-of-function experiments. Chromatin immunoprecipitation assay and dual-luciferase reporter assay were conducted to explore the relationship between EZH2 or SFMBT1 and miR-125a-5p. Finally, the effects of EZH2 and miR-125a-5p on the transforming growth factor β (TGFβ)/SMAD pathway were analyzed. Results: Overexpressed SFMBT1 and EZH2 was detected while miR-125a-5p were downregulated in psoriasis tissues and human keratinocyte (HaCaT) cells. EZH2 increased the levels of IL-17A-induced cytokines and promoted the malignant phenotypes of HaCaT cells. Functionally, EZH2 reduced miR-125a-5p expression while miR-125a-5p targeted SFMBT1 to activate the TGFβ/SMAD pathway in vitro. Knockdown of EZH2 or up-regulation of miR-125a-5p inhibited cell proliferation and the levels of IL-17A-induced cytokines, but increased the expression of TGFβ1 and the extent of smad2 and smad3 phosphorylation in HaCaT cells. Notably, EZH2 contributed to the development of psoriasis in vivo by inhibiting the TGFβ/SMAD pathway via impairment of miR-125a-5p-mediated SFMBT1 inhibition. Conclusion: Taken together, the results of the current study highlight the ability of EZH2 to potentially inactivate the TGFβ/SMAD pathway via upregulation of miR-125a-5p-dependent SFMBT1during the progression of psoriatic lesions.

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In vitro and in vivo effects of tPA and PAI-1 on blood vessel tone

Blood ◽

10.1182/blood-2003-05-1685 ◽

2004 ◽

Vol 103 (3) ◽

pp. 897-902 ◽

Cited By ~ 81

Author(s):

Taher Nassar ◽

Sa'ed Akkawi ◽

Ahuva Shina ◽

Abdullah Haj-Yehia ◽

Khalil Bdeir ◽

...

Keyword(s):

Blood Vessel ◽

Plasminogen Activator ◽

Density Lipoprotein ◽

Plasminogen Activator Inhibitor ◽

Tissue Type ◽

Plasminogen Activator Inhibitor 1 ◽

Isolated Aorta ◽

Pai 1

Abstract Tissue type plasminogen activator (tPA) is a key enzyme in the fibrinolytic cascade. In this paper we report that tPA contains 2 independent epitopes that exert opposite effects on blood vessel tone. Low concentrations of tPA (1 nM) inhibit the phenylephrine (PE)–induced contraction of isolated aorta rings. In contrast, higher concentrations (20 nM) stimulate the contractile effect of PE. The 2 putative vasoactive epitopes of tPA are regulated by the plasminogen activator inhibitor-1 (PAI-1) and by a PAI-1–derived hexapeptide that binds tPA. TNK-tPA, a tPA variant in which the PAI-1 docking site has been mutated, stimulates PE-induced vasoconstriction at all concentrations used. The stimulatory, but not the inhibitory, effect of tPA on the contraction of isolated aorta rings was abolished by anti–low-density lipoprotein receptor–related protein/α2-macroglobulin receptor (LRP) antibodies. Administering tPA or TNK-tPA to rats regulates blood pressure and cerebral vascular resistance in a dose-dependent mode. In other in vivo experiments we found that the vasopressor effect of PE is more pronounced in tPA knockout than in wild-type mice. Our findings draw attention to a novel role of tPA and PAI-1 in the regulation of blood vessel tone that may affect the course of ischemic diseases.

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