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Cell Death and Differentiation Aug 2021Renal tubular cell (RTC) death and inflammation contribute to the progression of obstructive nephropathy, but its underlying mechanisms have not been fully elucidated....
Renal tubular cell (RTC) death and inflammation contribute to the progression of obstructive nephropathy, but its underlying mechanisms have not been fully elucidated. Here, we showed that Gasdermin E (GSDME) expression level and GSDME-N domain generation determined the RTC fate response to TNFα under the condition of oxygen-glucose-serum deprivation. Deletion of Caspase-3 (Casp3) or Gsdme alleviated renal tubule damage and inflammation and finally prevented the development of hydronephrosis and kidney fibrosis after ureteral obstruction. Using bone marrow transplantation and cell type-specific Casp3 knockout mice, we demonstrated that Casp3/GSDME-mediated pyroptosis in renal parenchymal cells, but not in hematopoietic cells, played predominant roles in this process. We further showed that HMGB1 released from pyroptotic RTCs amplified inflammatory responses, which critically contributed to renal fibrogenesis. Specific deletion of Hmgb1 in RTCs alleviated caspase11 and IL-1β activation in macrophages. Collectively, our results uncovered that TNFα/Casp3/GSDME-mediated pyroptosis is responsible for the initiation of ureteral obstruction-induced renal tubule injury, which subsequentially contributes to the late-stage progression of hydronephrosis, inflammation, and fibrosis. This novel mechanism will provide valuable therapeutic insights for the treatment of obstructive nephropathy.
Topics: Animals; Disease Models, Animal; Fibrosis; Humans; Inflammation; Kidney Diseases; Mice; Pore Forming Cytotoxic Proteins; Pyroptosis
PubMed: 33664482
DOI: 10.1038/s41418-021-00755-6 -
Cell Death & Disease Aug 2022Renal fibrosis is a common consequence of various progressive nephropathies, including obstructive nephropathy, and ultimately leads to kidney failure. Infiltration of...
Renal fibrosis is a common consequence of various progressive nephropathies, including obstructive nephropathy, and ultimately leads to kidney failure. Infiltration of inflammatory cells is a prominent feature of renal injury after draining blockages from the kidney, and correlates closely with the development of renal fibrosis. However, the underlying molecular mechanism behind the promotion of renal fibrosis by inflammatory cells remains unclear. Herein, we showed that unilateral ureteral obstruction (UUO) induced Gasdermin D (GSDMD) activation in neutrophils, abundant neutrophil extracellular traps (NETs) formation and macrophage-to-myofibroblast transition (MMT) characterized by α-smooth muscle actin (α-SMA) expression in macrophages. Gsdmd deletion significantly reduced infiltration of inflammatory cells in the kidneys and inhibited NETs formation, MMT and thereby renal fibrosis. Chimera studies confirmed that Gsdmd deletion in bone marrow-derived cells, instead of renal parenchymal cells, provided protection against renal fibrosis. Further, specific deletion of Gsdmd in neutrophils instead of macrophages protected the kidney from undergoing fibrosis after UUO. Single-cell RNA sequencing identified robust crosstalk between neutrophils and macrophages. In vitro, GSDMD-dependent NETs triggered p65 translocation to the nucleus, which boosted the production of inflammatory cytokines and α-SMA expression in macrophages by activating TGF-β1/Smad pathway. In addition, we demonstrated that caspase-11, that could cleave GSDMD, was required for NETs formation and renal fibrosis after UUO. Collectively, our findings demonstrate that caspase-11/GSDMD-dependent NETs promote renal fibrosis by facilitating inflammation and MMT, therefore highlighting the role and mechanisms of NETs in renal fibrosis.
Topics: Caspases; Extracellular Traps; Fibrosis; Humans; Intracellular Signaling Peptides and Proteins; Kidney; Kidney Diseases; Macrophages; Myofibroblasts; Phosphate-Binding Proteins; Pore Forming Cytotoxic Proteins; Signal Transduction; Ureteral Obstruction
PubMed: 35941120
DOI: 10.1038/s41419-022-05138-4 -
Cellular and Molecular Life Sciences :... Feb 2022Renal interstitial fibrosis is the pathological basis of end-stage renal disease, in which the heterogeneity of macrophages in renal microenvironment plays an important...
Renal interstitial fibrosis is the pathological basis of end-stage renal disease, in which the heterogeneity of macrophages in renal microenvironment plays an important role. However, the molecular mechanisms of macrophage plasticity during renal fibrosis progression remain unclear. In this study, we found for the first time that increased expression of Twist1 in macrophages was significantly associated with the severity of renal fibrosis in IgA nephropathy patients and mice with unilateral ureteral obstruction (UUO). Ablation of Twist1 in macrophages markedly alleviated renal tubular injury and renal fibrosis in UUO mice, accompanied by a lower extent of macrophage infiltration and M2 polarization in the kidney. The knockdown of Twist1 inhibited the chemotaxis and migration of macrophages, at least partially, through the CCL2/CCR2 axis. Twist1 downregulation inhibited M2 macrophage polarization and reduced the secretion of the profibrotic factors Arg-1, MR (CD206), IL-10, and TGF-β. Galectin-3 was decreased in the macrophages of the conditional Twist1-deficient mice, and Twist1 was shown to directly activate galectin-3 transcription. Up-regulation of galectin-3 recovered Twist1-mediated M2 macrophage polarization. In conclusion, Twist1/galectin-3 signaling regulates macrophage plasticity (M2 phenotype) and promotes renal fibrosis. This study could suggest new strategies for delaying kidney fibrosis in patients with chronic kidney disease.
Topics: Animals; Fibrosis; Galectin 3; Humans; Kidney Diseases; Macrophage Activation; Male; Mice; Mice, Inbred C57BL; Signal Transduction; Twist-Related Protein 1; Ureteral Obstruction
PubMed: 35182235
DOI: 10.1007/s00018-022-04137-0 -
Nature Communications Sep 2020Recent studies have reported that upregulation of disulfide-bond A oxidoreductase-like protein (DsbA-L) prevented lipid-induced renal injury in diabetic nephropathy...
Recent studies have reported that upregulation of disulfide-bond A oxidoreductase-like protein (DsbA-L) prevented lipid-induced renal injury in diabetic nephropathy (DN). However, the role and regulation of proximal tubular DsbA-L for renal tubulointerstitial fibrosis (TIF) remains unclear. In current study, we found that a proximal tubules-specific DsbA-L knockout mouse (PT-DsbA-L-KO) attenuated UUO-induced TIF, renal cell apoptosis and inflammation. Mechanistically, the DsbA-L interacted with Hsp90 in mitochondria of BUMPT cells which activated the signaling of Smad3 and p53 to produce connective tissue growth factor (CTGF) and then resulted in accumulation of ECM of BUMPT cells and mouse kidney fibroblasts. In addition, the progression of TIF caused by UUO, ischemic/reperfusion (I/R), aristolochic acid, and repeated acute low-dose cisplatin was also alleviated in PT-DsbA-L-KO mice via the activation of Hsp90 /Smad3 and p53/CTGF axis. Finally, the above molecular changes were verified in the kidney biopsies from patients with obstructive nephropathy (Ob). Together, these results suggest that DsbA-L in proximal tubular cells promotes TIF via activation of the Hsp90 /Smad3 and p53/CTGF axis.
Topics: Aged; Animals; Apoptosis; Connective Tissue Growth Factor; Diabetic Nephropathies; Disease Models, Animal; Female; Fibrosis; Genetic Predisposition to Disease; Glutathione Transferase; HSP90 Heat-Shock Proteins; Humans; Inflammation; Kidney; Kidney Diseases; Kidney Tubules, Proximal; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Signal Transduction; Smad3 Protein; Tumor Suppressor Protein p53
PubMed: 32948751
DOI: 10.1038/s41467-020-18304-z -
International Journal of Molecular... Jun 2021Acute kidney injury (AKI) is a global health challenge of vast proportions, as approx. 13.3% of people worldwide are affected annually. The pathophysiology of AKI is... (Review)
Review
Acute kidney injury (AKI) is a global health challenge of vast proportions, as approx. 13.3% of people worldwide are affected annually. The pathophysiology of AKI is very complex, but its main causes are sepsis, ischemia, and nephrotoxicity. Nephrotoxicity is mainly associated with the use of drugs. Drug-induced AKI accounts for 19-26% of all hospitalized cases. Drug-induced nephrotoxicity develops according to one of the three mechanisms: (1) proximal tubular injury and acute tubular necrosis (ATN) (a dose-dependent mechanism), where the cause is related to apical contact with drugs or their metabolites, the transport of drugs and their metabolites from the apical surface, and the secretion of drugs from the basolateral surface into the tubular lumen; (2) tubular obstruction by crystals or casts containing drugs and their metabolites (a dose-dependent mechanism); (3) interstitial nephritis induced by drugs and their metabolites (a dose-independent mechanism). In this article, the mechanisms of the individual types of injury will be described. Specific groups of drugs will be linked to specific injuries. Additionally, the risk factors for the development of AKI and the methods for preventing and/or treating the condition will be discussed.
Topics: Animals; Drug-Related Side Effects and Adverse Reactions; Humans; Immune Checkpoint Inhibitors; Kidney; Kidney Diseases; Kidney Tubules; Metabolome
PubMed: 34204029
DOI: 10.3390/ijms22116109 -
Kidney International Jun 2009Renal fibrosis is the hallmark of progressive renal disease of virtually any etiology. The model of unilateral ureteral obstruction (UUO) in the rodent generates... (Review)
Review
Renal fibrosis is the hallmark of progressive renal disease of virtually any etiology. The model of unilateral ureteral obstruction (UUO) in the rodent generates progressive renal fibrosis. Surgically created UUO can be experimentally manipulated with respect to timing, severity, and duration, while reversal of the obstruction permits the study of recovery. The use of genetically engineered mice has greatly expanded the utility of the model in studying molecular mechanisms underlying the renal response to UUO. Ureteral obstruction results in marked renal hemodynamic and metabolic changes, followed by tubular injury and cell death by apoptosis or necrosis, with interstitial macrophage infiltration. Proliferation of interstitial fibroblasts with myofibroblast transformation leads to excess deposition of the extracellular matrix and renal fibrosis. Phenotypic transition of resident renal tubular cells, endothelial cells, and pericytes has also been implicated in this process. Technical aspects of the UUO model are discussed in this review, including the importance of rodent species or strain, the age of the animal, surgical procedures, and histological methods. The UUO model is likely to reveal useful biomarkers of progression of renal disease, as well as new therapies, which are desperately needed to allow intervention before the establishment of irreversible renal injury.
Topics: Animals; Disease Models, Animal; Fibrosis; Kidney Diseases; Mice; Ureteral Obstruction
PubMed: 19340094
DOI: 10.1038/ki.2009.86 -
Molecular Therapy : the Journal of the... May 2019Renal fibrosis is the main pathological characteristic of chronic kidney disease (CKD), whereas the underlying mechanisms of renal fibrosis are not clear yet. Herein, we...
Renal fibrosis is the main pathological characteristic of chronic kidney disease (CKD), whereas the underlying mechanisms of renal fibrosis are not clear yet. Herein, we found an increased expression of microRNA-34a (miR-34a) in renal tubular epithelial cells of patients with renal fibrosis and mice undergoing unilateral ureteral obstruction (UUO). In miR-34a mice, miR-34a deficiency attenuated the progression of renal fibrosis following UUO surgery. The miR-34a overexpression promoted epithelial-to-mesenchymal transition (EMT) in cultured human renal tubular epithelial HK-2 cells, which was accompanied by sharp downregulation of Klotho, an endogenous inhibitor of renal fibrosis. Luciferase reporter assay revealed that miR-34a downregulated Klotho expression though direct binding with the 3' UTR of Klotho. Conversely, overexpression of Klotho prevented miR-34a-induced EMT in HK-2 cells. Furthermore, results showed that miR-34a was induced by transforming growth factor β1 (TGF-β1) through p53 activation, whereas dihydromyricetin could inhibit TGF-β1-induced miR-34a overexpression. Accordingly, dihydromyricetin administration dramatically restored the aberrant upregulation of miR-34a and Klotho reduction in obstructed kidney, and markedly ameliorated renal fibrosis in the Adriamycin nephropathy and UUO model mice. These findings suggested that miR-34a plays an important role in the progression of renal fibrosis, which provides new insights into the pathogenesis and treatment of CKD.
Topics: Animals; Cell Line; Disease Models, Animal; Doxorubicin; Epithelial Cells; Epithelial-Mesenchymal Transition; Fibrosis; Flavonols; Glucuronidase; Humans; Kidney; Kidney Diseases; Kidney Tubules; Klotho Proteins; Mice; MicroRNAs; Signal Transduction; Transforming Growth Factor beta1; Ureteral Obstruction
PubMed: 30853453
DOI: 10.1016/j.ymthe.2019.02.009 -
Internal Medicine (Tokyo, Japan) May 2000Obstructive nephropathy is a relatively common entity that is treatable and often reversible. It occurs at all ages from infancy to elderly subjects. Obstructive... (Review)
Review
Obstructive nephropathy is a relatively common entity that is treatable and often reversible. It occurs at all ages from infancy to elderly subjects. Obstructive uropathy is classified according to the degree, duration and site of the obstruction. It is the result of functional or anatomic lesions located in the urinary tract. The causes of obstructive uropathy are many. Obstruction of the urinary tract may decrease renal blood flow and the glomerular filtration rate. Several abnormalities in tubular function may occur in obstructive nephropathy. These include decreased reabsorption of solutes and water, inability to concentrate the urine and impaired excretion of hydrogen and potassium. Renal interstitial fibrosis is a common finding in patients with long-term obstructive uropathy. Several factors: macrophages, growth factors, hypoxia, cytokines are involved in the pathogenesis of interstitial fibrosis. It has been shown that ACE inhibitors ameliorate the interstitial fibrosis in animals with obstructive uropathy.
Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Humans; Hydronephrosis; Kidney Diseases; Kidney Glomerulus; Kidney Tubules; NF-kappa B; Nephritis, Interstitial; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renal Circulation; Tumor Necrosis Factor-alpha
PubMed: 10830173
DOI: 10.2169/internalmedicine.39.355 -
Theranostics 2022A deficiency of fatty acid oxidation (FAO) is the metabolic hallmark in proximal tubular cells (PTCs) in renal fibrosis owing to utilization of fatty acids by PTCs as...
A deficiency of fatty acid oxidation (FAO) is the metabolic hallmark in proximal tubular cells (PTCs) in renal fibrosis owing to utilization of fatty acids by PTCs as the main energy source. Lipid accumulation may promote lipotoxicity-induced pathological injury in renal tissue. However, the molecular mechanism underlying lipotoxicity and renal tubulointerstitial fibrosis (TIF) remains unclear. Twist1 has been identified to play an essential role in fatty acid metabolism. We hypothesized that Twist1 may regulate FAO in PTCs and consequently facilitate lipotoxicity-induced TIF. We used hypoxia-induced Twist1 overexpression to incite defective mitochondrial FAO in PTCs, and used renal ischemia-reperfusion or unilateral ureteral obstruction to induce renal injury in mice. We used knockout cells, mice of Twist1, and Harmine to determine the role of Twist1 in FAO and TIF. : Overexpression of Twist1 downregulates the transcription of PGC-1α and further inhibits the expression of FAO-associated genes, such as PPARα, CPT1 and ACOX1. Consequently, reduced FAO and increased intracellular lipid droplet accumulation in a human PTC line (HK-2), leads to mitochondrial dysfunction, and production of increased profibrogenic factors. Twist1 knockout mice with renal injury had increased expression of PGC-1α, which restored FAO and obstructed progression of TIF. Strikingly, pharmacological inhibition of Twist1 by using Harmine reduced lipid accumulation and restored FAO and . Our findings suggest that Twist1-mediated inhibition of FAO in PTCs results in TIF and suggest that Twist1-targeted inhibition could provide a potential strategy for the treatment of renal fibrosis.
Topics: Animals; Down-Regulation; Epithelial Cells; Fatty Acids; Fibrosis; Harmine; Kidney; Kidney Diseases; Mice
PubMed: 35664054
DOI: 10.7150/thno.71722 -
Journal of the American Society of... Dec 2020Little is known about the roles of myeloid cell subsets in kidney injury and in the limited ability of the organ to repair itself. Characterizing these cells based only...
BACKGROUND
Little is known about the roles of myeloid cell subsets in kidney injury and in the limited ability of the organ to repair itself. Characterizing these cells based only on surface markers using flow cytometry might not provide a full phenotypic picture. Defining these cells at the single-cell, transcriptomic level could reveal myeloid heterogeneity in the progression and regression of kidney disease.
METHODS
Integrated droplet- and plate-based single-cell RNA sequencing were used in the murine, reversible, unilateral ureteric obstruction model to dissect the transcriptomic landscape at the single-cell level during renal injury and the resolution of fibrosis. Paired blood exchange tracked the fate of monocytes recruited to the injured kidney.
RESULTS
A single-cell atlas of the kidney generated using transcriptomics revealed marked changes in the proportion and gene expression of renal cell types during injury and repair. Conventional flow cytometry markers would not have identified the 12 myeloid cell subsets. Monocytes recruited to the kidney early after injury rapidly adopt a proinflammatory, profibrotic phenotype that expresses , before transitioning to become macrophages that accumulate in late injury. Conversely, a novel macrophage subset acts during repair.
CONCLUSIONS
Complementary technologies identified novel myeloid subtypes, based on transcriptomics in single cells, that represent therapeutic targets to inhibit progression or promote regression of kidney disease.
Topics: Animals; Disease Models, Animal; Disease Progression; Kidney Diseases; Macrophages; Male; Mice; Mice, Inbred C57BL; Myeloid Cells; Sequence Analysis, RNA; Single-Cell Analysis; Ureteral Obstruction
PubMed: 32978267
DOI: 10.1681/ASN.2020060806