SOX9 is required for kidney fibrosis and activates NAV3 to drive renal myofibroblast function

2021 ◽  
Vol 14 (672) ◽  
pp. eabb4282 ◽  
Author(s):  
Sayyid Raza ◽  
Elliot Jokl ◽  
James Pritchett ◽  
Katherine Martin ◽  
Kim Su ◽  
...  

Renal fibrosis is a common end point for kidney injury and many chronic kidney diseases. Fibrogenesis depends on the sustained activation of myofibroblasts, which deposit the extracellular matrix that causes progressive scarring and organ failure. Here, we showed that the transcription factor SOX9 was associated with kidney fibrosis in humans and required for experimentally induced kidney fibrosis in mice. From genome-wide analysis, we identified Neuron navigator 3 (NAV3) as acting downstream of SOX9 in kidney fibrosis. NAV3 increased in abundance and colocalized with SOX9 after renal injury in mice, and both SOX9 and NAV3 were present in diseased human kidneys. In an in vitro model of renal pericyte transdifferentiation into myofibroblasts, we demonstrated that NAV3 was required for multiple aspects of fibrogenesis, including actin polymerization linked to cell migration and sustained activation of the mechanosensitive transcription factor YAP1. In summary, our work identifies a SOX9-NAV3-YAP1 axis involved in the progression of kidney fibrosis and points to NAV3 as a potential target for pharmacological intervention.

2019 ◽  
Author(s):  
Sayyid Raza ◽  
Elliot Jokl ◽  
James Pritchett ◽  
Katherine Martin ◽  
Kim Su ◽  
...  

AbstractRenal fibrosis is a common endpoint for many chronic kidney diseases. Extracellular matrix (ECM) from myofibroblasts causes progressive scarring and organ failure. The mechanisms underlying fibrogenesis and how it is sustained are incompletely understood. Here, we show that the transcription factor, Sex determining region Y-box 9 (SOX9), is required for kidney fibrosis. From genome-wide analysis we identify Neuron navigator 3 (NAV3) downstream of SOX9. NAV3 was upregulated in kidney disease in patients and following renal injury in mice colocalised with SOX9. By establishing an in vitro model of renal pericyte transition to myofibroblast we demonstrated that NAV3 is required for multiple aspects of fibrogenesis including actin polymerization linked to cell migration and sustaining SOX9 and active YAP1 levels. In summary, our work discovers novel SOX9-NAV3-YAP1/SOX9 circuitry as a new mechanism to explain the progression of kidney fibrosis and points to NAV3 as a novel target for pharmacological intervention.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Ruizhao Li ◽  
Xingchen Zhao ◽  
Shu Zhang ◽  
Wei Dong ◽  
Li Zhang ◽  
...  

AbstractAutophagy is an important renal-protective mechanism in septic acute kidney injury (AKI). Receptor interacting protein kinase 3 (RIP3) has been implicated in the renal tubular injury and renal dysfunction during septic AKI. Here we investigated the role and mechanism of RIP3 on autophagy in septic AKI. We showed an activation of RIP3, accompanied by an accumulation of the autophagosome marker LC3II and the autophagic substrate p62, in the kidneys of lipopolysaccharide (LPS)-induced septic AKI mice and LPS-treated cultured renal proximal tubular epithelial cells (PTECs). The lysosome inhibitor did not further increase the levels of LCII or p62 in LPS-treated PTECs. Moreover, inhibition of RIP3 attenuated the aberrant accumulation of LC3II and p62 under LPS treatment in vivo and in vitro. By utilizing mCherry-GFP-LC3 autophagy reporter mice in vivo and PTECs overexpression mRFP-GFP-LC3 in vitro, we observed that inhibition of RIP3 restored the formation of autolysosomes and eliminated the accumulated autophagosomes under LPS treatment. These results indicated that RIP3 impaired autophagic degradation, contributing to the accumulation of autophagosomes. Mechanistically, the nuclear translocation of transcription factor EB (TFEB), a master regulator of the lysosome and autophagy pathway, was inhibited in LPS-induced mice and LPS-treated PTECs. Inhibition of RIP3 restored the nuclear translocation of TFEB in vivo and in vitro. Co-immunoprecipitation further showed an interaction of RIP3 and TFEB in LPS-treated PTECs. Also, the expression of LAMP1 and cathepsin B, two potential target genes of TFEB involved in lysosome function, were decreased under LPS treatment in vivo and in vitro, and this decrease was rescued by inhibiting RIP3. Finally, overexpression of TFEB restored the autophagic degradation in LPS-treated PTECs. Together, the present study has identified a pivotal role of RIP3 in suppressing autophagic degradation through impeding the TFEB-lysosome pathway in septic AKI, providing potential therapeutic targets for the prevention and treatment of septic AKI.


2017 ◽  
Vol 381 ◽  
pp. 643-644 ◽  
Author(s):  
J.S. Jun ◽  
J. Moon ◽  
T.J. Kim ◽  
S.T. Lee ◽  
K.H. Jung ◽  
...  

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Sandeep B Shelar ◽  
Madhusudhanan Narasimhan ◽  
Gobinath Shanmugam ◽  
Neelu E Vargees ◽  
Ramasamy Sakthivel ◽  
...  

Background: Progressive accumulation of misfolded or unfolded proteins is a symbol of impaired proteostasis and proteotoxicity. Such a chronic proteotoxicity is amenable to cell types that are post mitotically matured with lack of further differentiation or proliferation. Our recent discovery using a mouse model of familial human cardiac disease displayed protuberant shift in the redox state towards reductive stress (RS) in association with accumulation of toxic protein aggregates. Further, sustained trans-activation of Nrf2/antioxidant signaling caused RS in the myopathy hearts. Accordingly, we hypothesized that whether profound activation of Nrf2/antioxidant signaling and subsequent RS may cause pathological remodeling in cardiomyocyte. The aim of this study was to investigate the effect of sustained pharmacological activation of Nrf2 on cardiac remodeling. Methods: HL1 cardiomyocytes were used as an in vitro model to study the RS-mediated cardiac remodeling. They were treated with 2-10 μM of potential Nrf2-inducers; sulforaphane (SF), di-methyl fumarate (DMF) and novel small molecules (C-38, C-50, C-63 and C-66) to establish RS by sustained activation of Nrf2/antioxidant signaling. Next, we investigated the implications of RS in cardiomyocyte remodeling by analyzing transcriptional and translational mechanisms using immunoblotting, qPCR, immunofluorescence, GSH and NADPH redox measurements in HL1 cells. Results: Dose dependent effects for individual small molecules including known Nrf2 inducers (SF and DMF) revealed distinct pro-reductive and reductive intracellular (i.e. reductive stress) environments. In fact, the obligatory activation of Nrf2 signaling was associated with significant upregulation of antioxidant enzymes and small molecular thiols including glutathione (GSH). Surprisingly, while pro-reductive condition in HL1 cells was subdued, the RS induced cardiomyocyte hypertrophy was evident from microscopic examination and molecular signature (increased expression of ANF and BNF) after 24-48 hrs of Nrf2 activation. Conclusion: In summary, the chemical induced sustained activation of Nrf2 leading to formation of reductive stress showed hypertrophic remodeling in HL1 cardiomyocytes.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yong Chul Kim ◽  
Junghun Lee ◽  
Jung Nam An ◽  
Jin Hyuk Kim ◽  
Young-Wook Choi ◽  
...  

Abstract Hepatocyte growth factor (HGF) and its receptor, cMet, activate biological pathways necessary for repair and regeneration following kidney injury. Because HGF is a highly unstable molecule in its biologically active form, we asked whether a monoclonal antibody (Ab) that displays full agonist activity at the receptor could protect the kidney from fibrosis. We attempted to determine whether the cMet agonistic Ab might reduce fibrosis, the final common pathway for chronic kidney diseases (CKD). A mouse model of kidney fibrosis disease induced by unilateral ureteral obstruction was introduced and subsequently validated with primary cultured human proximal tubular epithelial cells (PTECs). In kidney biopsy specimens from patients with CKD, cMet immunohistochemistry staining showed a remarkable increase compared with patients with normal renal functions. cMet Ab treatment significantly increased the levels of phospho-cMet and abrogated the protein expression of fibrosis markers such as fibronectin, collagen 1, and αSMA as well as Bax2, which is a marker of apoptosis triggered by recombinant TGF-β1 in PTECs. Remarkably, injections of cMet Ab significantly prevented kidney fibrosis in obstructed kidneys as quantified by Masson trichrome staining. Consistent with these data, cMet Ab treatment decreased the expression of fibrosis markers, such as collagen1 and αSMA, whereas the expression of E-cadherin, which is a cell-cell adhesion molecule, was restored. In conclusion, cMet-mediated signaling may play a considerable role in kidney fibrosis. Additionally, the cMet agonistic Ab may be a valuable substitute for HGF because it is more easily available in a biologically active, stable, and purified form.


2019 ◽  
Vol 44 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Christoph Mann ◽  
Brajesh Pratap Kaistha ◽  
Michael Kacik ◽  
Thorsten Stiewe ◽  
Joachim Hoyer

Background/Aims: Activated fibroblasts are key controllers of extracellular matrix turnover in kidney fibrosis, the pathophysiological end stage of chronic kidney disease. The proliferation of activated fibroblasts depends on the expression of the calcium-dependent potassium channel KCNN4. Expression of this ion channel is upregulated in fibrotic kidneys. Genetic and pharmacological blockade of KCNN4 inhibits fibrosis in vitro and in vivo. Methods: We studied the regulation of KCNN4 and possible involvement of miRNAs in an in-vitro fibrosis model using murine kidney fibroblasts. We tested fibroblast proliferation, channel function, channel expression and expression regulation after FGF-2 stimulation. Results: Proliferation was significantly increased by FGF-2, channel current and expression were almost doubled (+ 91% and +125%, respectively). MiRNA microarray identified upregulation of miRNA-503, which targets RAF1 and thereby controls KCNN4-expression via disinhibition of the Ras/Raf/MEK/ ERK-cascade. Conclusion: This data show a) a profound upregulation of KCNN4 in stimulated fibroblast and b) identifies miR-503 as a regulator of KCNN4 expression.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julie Belliere ◽  
Audrey Casemayou ◽  
Eloïse Colliou ◽  
Hélène El Hachem ◽  
Clément Kounde ◽  
...  

AbstractRecent studies suggested that ibrutinib, a Bruton tyrosine kinase (BTK) inhibitor, developed for the treatment of chronic lymphocytic leukemia, may prevent NLRP3 inflammasome activation in macrophages, IL-1β secretion and subsequent development of inflammation and organ fibrosis. The role of NLRP3 has been underlined in the various causes of acute kidney injury (AKI), a pathology characterized by high morbimortality and risk of transition toward chronic kidney disease (CKD). We therefore hypothesized that the BTK-inhibitor ibrutinib could be a candidate drug for AKI treatment. Here, we observed in both an AKI model (glycerol-induced rhabdomyolysis) and a model of rapidly progressive kidney fibrosis (unilateral ureteral obstruction), that ibrutinib did not prevent inflammatory cell recruitment in the kidney and fibrosis. Moreover, ibrutinib pre-exposure led to high mortality rate owing to severer rhabdomyolysis and AKI. In vitro, ibrutinib potentiated or had no effect on the secretion of IL-1β by monocytes exposed to uromodulin or myoglobin, two danger-associated molecule patterns proteins involved in the AKI to CKD transition. According to these results, ibrutinib should not be considered a candidate drug for patients developing AKI.


2006 ◽  
Vol 26 (12) ◽  
pp. 4758-4768 ◽  
Author(s):  
Jaya Rajaiya ◽  
Jamee C. Nixon ◽  
Neil Ayers ◽  
Zana P. Desgranges ◽  
Ananda L. Roy ◽  
...  

ABSTRACT Bright/ARID3a/Dril1, a member of the ARID family of transcription factors, is expressed in a highly regulated fashion in B lymphocytes, where it enhances immunoglobulin transcription three- to sixfold. Recent publications from our lab indicated that functional, but not kinase-inactive, Bruton's tyrosine kinase (Btk) is critical for Bright activity in an in vitro model system, yet Bright itself is not appreciably tyrosine phosphorylated. These data suggested that a third protein, and Btk substrate, must contribute to Bright-enhanced immunoglobulin transcription. The ubiquitously expressed transcription factor TFII-I was identified as a substrate for Btk several years ago. In this work, we show that TFII-I directly interacts with human Bright through amino acids in Bright's protein interaction domain and that specific tyrosine residues of TFII-I are essential for Bright-induced activity of an immunoglobulin reporter gene. Moreover, inhibition of TFII-I function in a B-cell line resulted in decreased heavy-chain transcript levels. These data suggest that Bright functions as a three-component protein complex in the immunoglobulin locus and tie together previous data indicating important roles for Btk and TFII-I in B lymphocytes.


2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Lisa FP Ng ◽  
Martin L Hibberd ◽  
Eng-Eong Ooi ◽  
Kin-Fai Tang ◽  
Soek-Ying Neo ◽  
...  

2019 ◽  
Vol 20 (10) ◽  
pp. 2462 ◽  
Author(s):  
Benjamin Bochon ◽  
Magdalena Kozubska ◽  
Grzegorz Surygała ◽  
Agnieszka Witkowska ◽  
Roman Kuźniewicz ◽  
...  

Mesenchymal stem cells constitute a pool of cells present throughout the lifetime in numerous niches, characteristic of unlimited replication potential and the ability to differentiate into mature cells of mesodermal tissues in vitro. The therapeutic potential of these cells is, however, primarily associated with their capabilities of inhibiting inflammation and initiating tissue regeneration. Owing to these properties, mesenchymal stem cells (derived from the bone marrow, subcutaneous adipose tissue, and increasingly urine) are the subject of research in the settings of kidney diseases in which inflammation plays the key role. The most advanced studies, with the first clinical trials, apply to ischemic acute kidney injury, renal transplantation, lupus and diabetic nephropathies, in which beneficial clinical effects of cells themselves, as well as their culture medium, were observed. The study findings imply that mesenchymal stem cells act predominantly through secreted factors, including, above all, microRNAs contained within extracellular vesicles. Research over the coming years will focus on this secretome as a possible therapeutic agent void of the potential carcinogenicity of the cells.


Sign in / Sign up

Export Citation Format

Share Document