1
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Torrico S, Hotter G, Muñoz Á, Calle P, García M, Poch E, Játiva S. PBMC therapy reduces cell death and tissue fibrosis after acute kidney injury by modulating the pattern of monocyte/macrophage survival in tissue. Biomed Pharmacother 2024; 178:117186. [PMID: 39067165 DOI: 10.1016/j.biopha.2024.117186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 07/16/2024] [Accepted: 07/22/2024] [Indexed: 07/30/2024] Open
Abstract
In this study, we investigated if the therapeutic potential of peripheral blood mononuclear cell (PBMC) therapy in a murine model of ischemic AKI is related with the survival pattern of monocyte/macrophages in tissue. CD-1 mice were subjected to bilateral renal ischemia followed by reperfusion to induce AKI. M2-polarized PBMCs isolated from CD-1 mice were administered intravenously at different time points post-injury. Our results demonstrate that early administration of PBMC therapy attenuates renal tissue damage, reduces tissue cell death and prevents fibrosis development. Reduction of tissue pyroptosis was observed by reduction on NLRP3 inflammasome activation and decreasing IL-1beta and Caspase-1 expression in the kidney. Furthermore, the therapy was shown to mitigate ferroptosis by inducing GPX4 overexpression. Early administration of PBMCs increased the survival pattern of renal tissue-macrophages, promoting a "pro-survival phenotype" resulting in decreased pyroptotic marker NLRP3, IL-1beta and Caspase 1 and increased anti-ferroptotic gene GPX4. Conversely, delayed administration of PBMC therapy exhibits diminished efficacy in preventing cell death and fibrosis in tissue and provoked a decrease in the pro-survival phenotype of both monocyte /macrophages in tissue. Our findings highlight the therapeutic potential of PBMC therapy in mitigating AKI and preventing CKD progression by modulating tissue-resident macrophage survival and reducing their cell death pathways. The fact that the effectiveness of the therapy depends on the time of administration after the injury underscores the importance of early intervention in AKI management.
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Affiliation(s)
- Selene Torrico
- Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona-Consejo Superior de Investigaciones Científicas (IIBB-CSIC), Institut d' Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; M2rlab-XCELL, Madrid 28010, Spain; Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Georgina Hotter
- Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona-Consejo Superior de Investigaciones Científicas (IIBB-CSIC), Institut d' Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; CIBER-BBN, Networking Center on Bioengineering, Biomaterials and Nanomedicine, Zaragoza 50018, Spain
| | - Ángeles Muñoz
- Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona-Consejo Superior de Investigaciones Científicas (IIBB-CSIC), Institut d' Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain
| | - Priscila Calle
- Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona-Consejo Superior de Investigaciones Científicas (IIBB-CSIC), Institut d' Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; M2rlab-XCELL, Madrid 28010, Spain
| | - Miriam García
- Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona-Consejo Superior de Investigaciones Científicas (IIBB-CSIC), Institut d' Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; M2rlab-XCELL, Madrid 28010, Spain
| | - Esteban Poch
- Nefrologia i Trasplantament Renal, Hospital Clínic, IDIBAPS, Universidad de Barcelona, Barcelona 08036, Spain
| | - Soraya Játiva
- Department of Experimental Pathology, Instituto de Investigaciones Biomédicas de Barcelona-Consejo Superior de Investigaciones Científicas (IIBB-CSIC), Institut d' Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain; M2rlab-XCELL, Madrid 28010, Spain.
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2
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Hinze C, Lovric S, Halloran PF, Barasch J, Schmidt-Ott KM. Epithelial cell states associated with kidney and allograft injury. Nat Rev Nephrol 2024; 20:447-459. [PMID: 38632381 DOI: 10.1038/s41581-024-00834-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2024] [Indexed: 04/19/2024]
Abstract
The kidney epithelium, with its intricate arrangement of highly specialized cell types, constitutes the functional core of the organ. Loss of kidney epithelium is linked to the loss of functional nephrons and a subsequent decline in kidney function. In kidney transplantation, epithelial injury signatures observed during post-transplantation surveillance are strong predictors of adverse kidney allograft outcomes. However, epithelial injury is currently neither monitored clinically nor addressed therapeutically after kidney transplantation. Several factors can contribute to allograft epithelial injury, including allograft rejection, drug toxicity, recurrent infections and postrenal obstruction. The injury mechanisms that underlie allograft injury overlap partially with those associated with acute kidney injury (AKI) and chronic kidney disease (CKD) in the native kidney. Studies using advanced transcriptomic analyses of single cells from kidney or urine have identified a role for kidney injury-induced epithelial cell states in exacerbating and sustaining damage in AKI and CKD. These epithelial cell states and their associated expression signatures are also observed in transplanted kidney allografts, suggesting that the identification and characterization of transcriptomic epithelial cell states in kidney allografts may have potential clinical implications for diagnosis and therapy.
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Affiliation(s)
- Christian Hinze
- Department of Nephrology and Hypertension, Hannover Medical School, Hannover, Germany
| | - Svjetlana Lovric
- Department of Nephrology and Hypertension, Hannover Medical School, Hannover, Germany
| | - Philip F Halloran
- Alberta Transplant Applied Genomics Centre, Edmonton, Alberta, Canada
- Department of Medicine, Division of Nephrology and Transplant Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Jonathan Barasch
- Division of Nephrology, Columbia University, New York City, NY, USA
| | - Kai M Schmidt-Ott
- Department of Nephrology and Hypertension, Hannover Medical School, Hannover, Germany.
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3
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Beamish JA, Watts JA, Dressler GR. Gene regulation in regeneration after acute kidney injury. J Biol Chem 2024; 300:107520. [PMID: 38950862 PMCID: PMC11325799 DOI: 10.1016/j.jbc.2024.107520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 07/03/2024] Open
Abstract
Acute kidney injury (AKI) is a common condition associated with significant morbidity, mortality, and cost. Injured kidney tissue can regenerate after many forms of AKI. However, there are no treatments in routine clinical practice to encourage recovery. In part, this shortcoming is due to an incomplete understanding of the genetic mechanisms that orchestrate kidney recovery. The advent of high-throughput sequencing technologies and genetic mouse models has opened an unprecedented window into the transcriptional dynamics that accompany both successful and maladaptive repair. AKI recovery shares similar cell-state transformations with kidney development, which can suggest common mechanisms of gene regulation. Several powerful bioinformatic strategies have been developed to infer the activity of gene regulatory networks by combining multiple forms of sequencing data at single-cell resolution. These studies highlight not only shared stress responses but also key changes in gene regulatory networks controlling metabolism. Furthermore, chromatin immunoprecipitation studies in injured kidneys have revealed dynamic epigenetic modifications at enhancer elements near target genes. This review will highlight how these studies have enhanced our understanding of gene regulation in injury response and regeneration.
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Affiliation(s)
- Jeffrey A Beamish
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Jason A Watts
- Epigenetics and Stem Cell Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Gregory R Dressler
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA.
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4
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Loeb GB, Kathail P, Shuai R, Chung R, Grona RJ, Peddada S, Sevim V, Federman S, Mader K, Chu A, Davitte J, Du J, Gupta AR, Ye CJ, Shafer S, Przybyla L, Rapiteanu R, Ioannidis N, Reiter JF. Variants in tubule epithelial regulatory elements mediate most heritable differences in human kidney function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599625. [PMID: 38948875 PMCID: PMC11212968 DOI: 10.1101/2024.06.18.599625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Kidney disease is highly heritable; however, the causal genetic variants, the cell types in which these variants function, and the molecular mechanisms underlying kidney disease remain largely unknown. To identify genetic loci affecting kidney function, we performed a GWAS using multiple kidney function biomarkers and identified 462 loci. To begin to investigate how these loci affect kidney function, we generated single-cell chromatin accessibility (scATAC-seq) maps of the human kidney and identified candidate cis-regulatory elements (cCREs) for kidney podocytes, tubule epithelial cells, and kidney endothelial, stromal, and immune cells. Kidney tubule epithelial cCREs explained 58% of kidney function SNP-heritability and kidney podocyte cCREs explained an additional 6.5% of SNP-heritability. In contrast, little kidney function heritability was explained by kidney endothelial, stromal, or immune cell-specific cCREs. Through functionally informed fine-mapping, we identified putative causal kidney function variants and their corresponding cCREs. Using kidney scATAC-seq data, we created a deep learning model (which we named ChromKid) to predict kidney cell type-specific chromatin accessibility from sequence. ChromKid and allele specific kidney scATAC-seq revealed that many fine-mapped kidney function variants locally change chromatin accessibility in tubule epithelial cells. Enhancer assays confirmed that fine-mapped kidney function variants alter tubule epithelial regulatory element function. To map the genes which these regulatory elements control, we used CRISPR interference (CRISPRi) to target these regulatory elements in tubule epithelial cells and assessed changes in gene expression. CRISPRi of enhancers harboring kidney function variants regulated NDRG1 and RBPMS expression. Thus, inherited differences in tubule epithelial NDRG1 and RBPMS expression may predispose to kidney disease in humans. We conclude that genetic variants affecting tubule epithelial regulatory element function account for most SNP-heritability of human kidney function. This work provides an experimental approach to identify the variants, regulatory elements, and genes involved in polygenic disease.
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Affiliation(s)
- Gabriel B. Loeb
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, US
| | - Pooja Kathail
- Department of Electrical Engineering and Computer Science, Center for Computational Biology, University of California Berkeley, Berkeley, CA, USA
| | - Richard Shuai
- Department of Electrical Engineering and Computer Science, Center for Computational Biology, University of California Berkeley, Berkeley, CA, USA
| | - Ryan Chung
- Department of Electrical Engineering and Computer Science, Center for Computational Biology, University of California Berkeley, Berkeley, CA, USA
| | - Reinier J. Grona
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Sailaja Peddada
- Laboratory for Genomics Research, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Volkan Sevim
- Laboratory for Genomics Research, University of California, San Francisco, San Francisco, CA, USA
- Genomic Sciences, GlaxoSmithKline, San Francisco, CA, USA
| | - Scot Federman
- Laboratory for Genomics Research, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Karl Mader
- Laboratory for Genomics Research, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Audrey Chu
- Genomic Sciences, GlaxoSmithKline, San Francisco, CA, USA
| | | | - Juan Du
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Alexander R. Gupta
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Chun Jimmie Ye
- Division of Rheumatology, Department of Medicine; Bakar Computational Health Sciences Institute; Parker Institute for Cancer Immunotherapy; Institute for Human Genetics; Department of Epidemiology & Biostatistics; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA and Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
| | - Shawn Shafer
- Laboratory for Genomics Research, University of California, San Francisco, San Francisco, CA, USA
- Genomic Sciences, GlaxoSmithKline, San Francisco, CA, USA
| | - Laralynne Przybyla
- Laboratory for Genomics Research, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Radu Rapiteanu
- Genomic Sciences, GlaxoSmithKline, San Francisco, CA, USA
| | - Nilah Ioannidis
- Department of Electrical Engineering and Computer Science, Center for Computational Biology, University of California Berkeley, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Jeremy F. Reiter
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, US
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
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5
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Ressel S, Kumar S, Bermúdez-Barrientos JR, Gordon K, Lane J, Wu J, Abreu-Goodger C, Schwarze J, Buck A. RNA-RNA interactions between respiratory syncytial virus and miR-26 and miR-27 are associated with regulation of cell cycle and antiviral immunity. Nucleic Acids Res 2024; 52:4872-4888. [PMID: 38412296 PMCID: PMC11109944 DOI: 10.1093/nar/gkae116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 02/01/2024] [Accepted: 02/12/2024] [Indexed: 02/29/2024] Open
Abstract
microRNAs (miRNAs) regulate nearly all physiological processes but our understanding of exactly how they function remains incomplete, particularly in the context of viral infections. Here, we adapt a biochemical method (CLEAR-CLIP) and analysis pipeline to identify targets of miRNAs in lung cells infected with Respiratory syncytial virus (RSV). We show that RSV binds directly to miR-26 and miR-27 through seed pairing and demonstrate that these miRNAs target distinct gene networks associated with cell cycle and metabolism (miR-27) and antiviral immunity (miR-26). Many of the targets are de-repressed upon infection and we show that the miR-27 targets most sensitive to miRNA inhibition are those associated with cell cycle. Finally, we demonstrate that high confidence chimeras map to long noncoding RNAs (lncRNAs) and pseudogenes in transcriptional regulatory regions. We validate that a proportion of miR-27 and Argonaute 2 (AGO2) is nuclear and identify a long non-coding RNA (lncRNA) as a miR-27 target that is linked to transcriptional regulation of nearby genes. This work expands the target networks of miR-26 and miR-27 to include direct interactions with RSV and lncRNAs and implicate these miRNAs in regulation of key genes that impact the viral life cycle associated with cell cycle, metabolism, and antiviral immunity.
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Affiliation(s)
- Sarah Ressel
- Institute of Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Sujai Kumar
- Institute of Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | | | - Katrina Gordon
- Institute of Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Julia Lane
- Institute of Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Jin Wu
- Janssen Research & Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Cei Abreu-Goodger
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Jürgen Schwarze
- Child Life and Health, Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Amy H Buck
- Institute of Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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6
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Livingston MJ, Zhang M, Kwon SH, Chen JK, Li H, Manicassamy S, Dong Z. Autophagy activates EGR1 via MAPK/ERK to induce FGF2 in renal tubular cells for fibroblast activation and fibrosis during maladaptive kidney repair. Autophagy 2024; 20:1032-1053. [PMID: 37978868 PMCID: PMC11135847 DOI: 10.1080/15548627.2023.2281156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
Macroautophagy/autophagy contributes to maladaptive kidney repair by inducing pro-fibrotic factors such as FGF2 (fibroblast growth factor 2), but the underlying mechanism remains elusive. Here, we show that EGR1 (early growth response 1) was induced in injured proximal tubules after ischemic acute kidney injury (AKI) and this induction was suppressed by autophagy deficiency in inducible, renal tubule-specific atg7 (autophagy related 7) knockout (iRT-atg7 KO) mice. In cultured proximal tubular cells, TGFB1 (transforming growth factor beta 1) induced EGR1 and this induction was also autophagy dependent. Egr1 knockdown in tubular cells reduced FGF2 expression during TGFB1 treatment, leading to less FGF2 secretion and decreased paracrine effects on fibroblasts. ChIP assay detected an increased binding of EGR1 to the Fgf2 gene promoter in TGFB1-treated tubular cells. Both Fgf2 and Egr1 transcription was inhibited by FGF2 neutralizing antibody, suggesting a positive feedback for EGR1-mediated FGF2 autoregulation. This feedback was confirmed using fgf2-deficient tubular cells and fgf2-deficient mice. Upstream of EGR1, autophagy deficiency in mice suppressed MAPK/ERK (mitogen-activated protein kinase) activation in post-ischemic renal tubules. This inhibition correlated with SQSTM1/p62 (sequestosome 1) aggregation and its sequestration of MAPK/ERK. SQSTM1/p62 interacted with MAPK/ERK and blocked its activation during TGFB1 treatment in autophagy-deficient tubular cells. Inhibition of MAPK/ERK suppressed EGR1 and FGF2 expression in maladaptive tubules, leading to the amelioration of renal fibrosis and improvement of renal function. These results suggest that autophagy activates MAPK/ERK in renal tubular cells, which induces EGR1 to transactivate FGF2. FGF2 is then secreted into the interstitium to stimulate fibroblasts for fibrogenesis.Abbreviation: 3-MA: 3-methyladenine; ACTA2/α-SMA: actin alpha 2, smooth muscle, aorta; ACTB/β-actin: actin, beta; AKI: acute kidney injury; aa: amino acid; ATG/Atg: autophagy related; BUN: blood urea nitrogen; ChIP: chromatin immunoprecipitation; CKD: chronic kidney disease; CM: conditioned medium; COL1A1: collagen, type I, alpha 1; COL4A1: collagen, type IV, alpha 1; CQ: chloroquine; DBA: dolichos biflorus agglutinin; EGR1: early growth response 1; ELK1: ELK1, member of ETS oncogene family; FGF2: fibroblast growth factor 2; FN1: fibronectin 1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HAVCR1/KIM-1: hepatitis A virus cellular receptor 1; IP: immunoprecipitation; LIR: LC3-interacting region; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAP2K/MEK: mitogen-activated protein kinase kinase; MAPK: mitogen-activated protein kinase; NFKB: nuclear factor kappa B; PB1: Phox and Bem1; PFT: pifithrin α; PPIB/cyclophilin B: peptidylprolyl isomerase B; RT-qPCR: real time-quantitative PCR; SQSTM1/p62: sequestosome 1; TGFB1/TGF-β1: transforming growth factor beta 1; VIM: vimentin.
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Affiliation(s)
- Man J. Livingston
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Research Department, Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Sang-Ho Kwon
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Jian-Kang Chen
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Honglin Li
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Santhakumar Manicassamy
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Research Department, Charlie Norwood VA Medical Center, Augusta, GA, USA
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7
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Yang J, Zhuang H, Li J, Nunez-Nescolarde AB, Luo N, Chen H, Li A, Qu X, Wang Q, Fan J, Bai X, Ye Z, Gu B, Meng Y, Zhang X, Wu D, Sia Y, Jiang X, Chen W, Combes AN, Nikolic-Paterson DJ, Yu X. The secreted micropeptide C4orf48 enhances renal fibrosis via an RNA-binding mechanism. J Clin Invest 2024; 134:e178392. [PMID: 38625739 PMCID: PMC11093611 DOI: 10.1172/jci178392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 03/27/2024] [Indexed: 04/17/2024] Open
Abstract
Renal interstitial fibrosis is an important mechanism in the progression of chronic kidney disease (CKD) to end-stage kidney disease. However, we lack specific treatments to slow or halt renal fibrosis. Ribosome profiling identified upregulation of a secreted micropeptide, C4orf48 (Cf48), in mouse diabetic nephropathy. Cf48 RNA and protein levels were upregulated in tubular epithelial cells in human and experimental CKD. Serum Cf48 levels were increased in human CKD and correlated with loss of kidney function, increasing CKD stage, and the degree of active interstitial fibrosis. Cf48 overexpression in mice accelerated renal fibrosis, while Cf48 gene deletion or knockdown by antisense oligonucleotides significantly reduced renal fibrosis in CKD models. In vitro, recombinant Cf48 (rCf48) enhanced TGF-β1-induced fibrotic responses in renal fibroblasts and epithelial cells independently of Smad3 phosphorylation. Cellular uptake of Cf48 and its profibrotic response in fibroblasts operated via the transferrin receptor. RNA immunoprecipitation-sequencing identified Cf48 binding to mRNA of genes involved in the fibrotic response, including Serpine1, Acta2, Ccn2, and Col4a1. rCf48 binds to the 3'UTR of Serpine1 and increases mRNA half-life. We identify the secreted Cf48 micropeptide as a potential enhancer of renal fibrosis that operates as an RNA-binding peptide to promote the production of extracellular matrix.
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Affiliation(s)
- Jiayi Yang
- Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Nephrology, National Health Commission and Guangdong Province, Guangzhou, China
| | - Hongjie Zhuang
- Department of Paediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jinhua Li
- Department of Nephrology and
- Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
- The Second Clinical College, Guangdong Medical University, Dongguan, Guangdong, China
- Department of Nephrology, Monash Health and Department of Medicine and
| | - Ana B. Nunez-Nescolarde
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Ning Luo
- Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Nephrology, National Health Commission and Guangdong Province, Guangzhou, China
| | - Huiting Chen
- The Second Clinical College, Guangdong Medical University, Dongguan, Guangdong, China
| | - Andy Li
- Department of Nephrology, Monash Health and Department of Medicine and
| | - Xinli Qu
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Qing Wang
- Department of Nephrology and
- Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jinjin Fan
- Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Nephrology, National Health Commission and Guangdong Province, Guangzhou, China
| | - Xiaoyan Bai
- Department of Nephrology and
- Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zhiming Ye
- Department of Nephrology and
- Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Bing Gu
- Department of Clinical Laboratory, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yue Meng
- Department of Clinical Laboratory, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xingyuan Zhang
- Department of Biostatistics, UNC Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Di Wu
- Department of Biostatistics, UNC Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Youyang Sia
- School of Life Science, Tsinghua University, Beijing, China
| | - Xiaoyun Jiang
- Department of Paediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Wei Chen
- Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Nephrology, National Health Commission and Guangdong Province, Guangzhou, China
| | - Alexander N. Combes
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | | | - Xueqing Yu
- Department of Nephrology and
- Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
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8
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Sugahara S, Brooks CR. Adenine Nucleotide Translocators Control Kidney Metabolism and Lipid Handling. J Am Soc Nephrol 2024; 35:257-258. [PMID: 38356156 PMCID: PMC10962857 DOI: 10.1681/asn.0000000000000314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Affiliation(s)
- Sho Sugahara
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Craig R. Brooks
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
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9
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Yamao Y, Oami T, Yamabe J, Takahashi N, Nakada TA. Machine-learning model for predicting oliguria in critically ill patients. Sci Rep 2024; 14:1054. [PMID: 38212363 PMCID: PMC10784288 DOI: 10.1038/s41598-024-51476-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 01/05/2024] [Indexed: 01/13/2024] Open
Abstract
This retrospective cohort study aimed to develop and evaluate a machine-learning algorithm for predicting oliguria, a sign of acute kidney injury (AKI). To this end, electronic health record data from consecutive patients admitted to the intensive care unit (ICU) between 2010 and 2019 were used and oliguria was defined as a urine output of less than 0.5 mL/kg/h. Furthermore, a light-gradient boosting machine was used for model development. Among the 9,241 patients who participated in the study, the proportions of patients with urine output < 0.5 mL/kg/h for 6 h and with AKI during the ICU stay were 27.4% and 30.2%, respectively. The area under the curve (AUC) values provided by the prediction algorithm for the onset of oliguria at 6 h and 72 h using 28 clinically relevant variables were 0.964 (a 95% confidence interval (CI) of 0.963-0.965) and 0.916 (a 95% CI of 0.914-0.918), respectively. The Shapley additive explanation analysis for predicting oliguria at 6 h identified urine values, severity scores, serum creatinine, oxygen partial pressure, fibrinogen/fibrin degradation products, interleukin-6, and peripheral temperature as important variables. Thus, this study demonstrates that a machine-learning algorithm can accurately predict oliguria onset in ICU patients, suggesting the importance of oliguria in the early diagnosis and optimal management of AKI.
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Affiliation(s)
- Yasuo Yamao
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
| | - Takehiko Oami
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
| | | | - Nozomi Takahashi
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
| | - Taka-Aki Nakada
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan.
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10
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De Chiara L, Semeraro R, Mazzinghi B, Landini S, Molli A, Antonelli G, Angelotti ML, Melica ME, Maggi L, Conte C, Peired AJ, Cirillo L, Raglianti V, Magi A, Annunziato F, Romagnani P, Lazzeri E. Polyploid tubular cells initiate a TGF-β1 controlled loop that sustains polyploidization and fibrosis after acute kidney injury. Am J Physiol Cell Physiol 2023; 325:C849-C861. [PMID: 37642236 PMCID: PMC10635654 DOI: 10.1152/ajpcell.00081.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/08/2023] [Accepted: 08/08/2023] [Indexed: 08/31/2023]
Abstract
Polyploidization of tubular cells (TC) is triggered by acute kidney injury (AKI) to allow survival in the early phase after AKI, but in the long run promotes fibrosis and AKI-chronic kidney disease (CKD) transition. The molecular mechanism governing the link between polyploid TC and kidney fibrosis remains to be clarified. In this study, we demonstrate that immediately after AKI, expression of cell cycle markers mostly identifies a population of DNA-damaged polyploid TC. Using transgenic mouse models and single-cell RNA sequencing we show that, unlike diploid TC, polyploid TC accumulate DNA damage and survive, eventually resting in the G1 phase of the cell cycle. In vivo and in vitro single-cell RNA sequencing along with sorting of polyploid TC shows that these cells acquire a profibrotic phenotype culminating in transforming growth factor (TGF)-β1 expression and that TGF-β1 directly promotes polyploidization. This demonstrates that TC polyploidization is a self-sustained mechanism. Interactome analysis by single-cell RNA sequencing revealed that TGF-β1 signaling fosters a reciprocal activation loop among polyploid TC, macrophages, and fibroblasts to sustain kidney fibrosis and promote CKD progression. Collectively, this study contributes to the ongoing revision of the paradigm of kidney tubule response to AKI, supporting the existence of a tubulointerstitial cross talk mediated by TGF-β1 signaling produced by polyploid TC following DNA damage.NEW & NOTEWORTHY Polyploidization in tubular epithelial cells has been neglected until recently. Here, we showed that polyploidization is a self-sustained mechanism that plays an important role during chronic kidney disease development, proving the existence of a cross talk between infiltrating cells and polyploid tubular cells. This study contributes to the ongoing revision of kidney adaptation to injury, posing polyploid tubular cells at the center of the process.
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Affiliation(s)
- Letizia De Chiara
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Roberto Semeraro
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Benedetta Mazzinghi
- Nephrology and Dialysis Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Samuela Landini
- Medical Genetics Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Alice Molli
- Nephrology and Dialysis Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Giulia Antonelli
- Nephrology and Dialysis Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Maria Lucia Angelotti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Maria Elena Melica
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Laura Maggi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Carolina Conte
- Nephrology and Dialysis Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Anna Julie Peired
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Luigi Cirillo
- Nephrology and Dialysis Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Valentina Raglianti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
- Nephrology and Dialysis Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Alberto Magi
- Department of Information Engineering, University of Florence, Florence, Italy
| | - Francesco Annunziato
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
- Flow Cytometry Diagnostic Center and Immunotherapy (CDCI), Careggi University Hospital, Florence, Italy
| | - Paola Romagnani
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
- Nephrology and Dialysis Unit, Meyer Children's University Hospital, IRCCS, Florence, Italy
| | - Elena Lazzeri
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
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11
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Dai Y, Chen Y, Mo D, Jin R, Huang Y, Zhang L, Zhang C, Gao H, Yan Q. Inhibition of ACSL4 ameliorates tubular ferroptotic cell death and protects against fibrotic kidney disease. Commun Biol 2023; 6:907. [PMID: 37670055 PMCID: PMC10480178 DOI: 10.1038/s42003-023-05272-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 08/22/2023] [Indexed: 09/07/2023] Open
Abstract
Ferroptosis is a recently recognized form of regulated cell death, characterized by iron-dependent accumulation of lipid peroxidation. Ample evidence has depicted that ferroptosis plays an essential role in the cause or consequence of human diseases, including cancer, neurodegenerative disease and acute kidney injury. However, the exact role and underlying mechanism of ferroptosis in fibrotic kidney remain unknown. Acyl-CoA synthetase long-chain family member 4 (ACSL4) has been demonstrated as an essential component in ferroptosis execution by shaping lipid composition. In this study, we aim to discuss the potential role and underlying mechanism of ACSL4-mediated ferroptosis of tubular epithelial cells (TECs) during renal fibrosis. The unbiased gene expression studies showed that ACSL4 expression was tightly associated with decreased renal function and the progression of renal fibrosis. To explore the role of ACSL4 in fibrotic kidney, ACSL4 specific inhibitor rosiglitazone (ROSI) was used to disturb the high expression of ACSL4 in TECs induced by TGF-β, unilateral ureteral obstruction (UUO) and fatty acid (FA)-modeled mice in vivo, and ACSL4 siRNA was used to knockdown ACSL4 in TGF-β-induced HK2 cells in vitro. The results demonstrated that inhibition and knockdown of ACSL4 effectively attenuated the occurrence of ferroptosis in TECs and alleviated the interstitial fibrotic response. In addition, the expression of various profibrotic cytokines all decreased after ROSI-treated in vivo and in vitro. Further investigation showed that inhibition of ACSL4 obviously attenuates the progression of renal fibrosis by reducing the proferroptotic precursors arachidonic acid- and adrenic acid- containing phosphatidylethanolamine (AA-PE and AdA-PE). In conclusion, these results suggest ACSL4 is essential for tubular ferroptotic death during kidney fibrosis development and ACSL4 inhibition is a viable therapeutic approach to preventing fibrotic kidney diseases.
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Affiliation(s)
- Yue Dai
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuting Chen
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dexiameng Mo
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rui Jin
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yi Huang
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Le Zhang
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cuntai Zhang
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hongyu Gao
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Qi Yan
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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12
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Packer M. Fetal Reprogramming of Nutrient Surplus Signaling, O-GlcNAcylation, and the Evolution of CKD. J Am Soc Nephrol 2023; 34:1480-1491. [PMID: 37340541 PMCID: PMC10482065 DOI: 10.1681/asn.0000000000000177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/07/2023] [Indexed: 06/22/2023] Open
Abstract
ABSTRACT Fetal kidney development is characterized by increased uptake of glucose, ATP production by glycolysis, and upregulation of mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1 alpha (HIF-1 α ), which (acting in concert) promote nephrogenesis in a hypoxic low-tubular-workload environment. By contrast, the healthy adult kidney is characterized by upregulation of sirtuin-1 and adenosine monophosphate-activated protein kinase, which enhances ATP production through fatty acid oxidation to fulfill the needs of a normoxic high-tubular-workload environment. During stress or injury, the kidney reverts to a fetal signaling program, which is adaptive in the short term, but is deleterious if sustained for prolonged periods when both oxygen tension and tubular workload are heightened. Prolonged increases in glucose uptake in glomerular and proximal tubular cells lead to enhanced flux through the hexosamine biosynthesis pathway; its end product-uridine diphosphate N -acetylglucosamine-drives the rapid and reversible O-GlcNAcylation of thousands of intracellular proteins, typically those that are not membrane-bound or secreted. Both O-GlcNAcylation and phosphorylation act at serine/threonine residues, but whereas phosphorylation is regulated by hundreds of specific kinases and phosphatases, O-GlcNAcylation is regulated only by O-GlcNAc transferase and O-GlcNAcase, which adds or removes N-acetylglucosamine, respectively, from target proteins. Diabetic and nondiabetic CKD is characterized by fetal reprogramming (with upregulation of mTOR and HIF-1 α ) and increased O-GlcNAcylation, both experimentally and clinically. Augmentation of O-GlcNAcylation in the adult kidney enhances oxidative stress, cell cycle entry, apoptosis, and activation of proinflammatory and profibrotic pathways, and it inhibits megalin-mediated albumin endocytosis in glomerular mesangial and proximal tubular cells-effects that can be aggravated and attenuated by augmentation and muting of O-GlcNAcylation, respectively. In addition, drugs with known nephroprotective effects-angiotensin receptor blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors-are accompanied by diminished O-GlcNAcylation in the kidney, although the role of such suppression in mediating their benefits has not been explored. The available evidence supports further work on the role of uridine diphosphate N -acetylglucosamine as a critical nutrient surplus sensor (acting in concert with upregulated mTOR and HIF-1 α signaling) in the development of diabetic and nondiabetic CKD.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute , Dallas , Texas and Imperial College , London , United Kingdom
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13
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Jung G, Park S, Kim H, Lee J, Jeong CW. Comparative analysis of mortality and progression to end-stage renal disease between surgically induced and medical chronic kidney disease: A study using the National Health Insurance customized database. Investig Clin Urol 2023; 64:338-345. [PMID: 37417558 DOI: 10.4111/icu.20230095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 07/08/2023] Open
Abstract
PURPOSE We aimed to compare the mortality rate and the risk for progression to end-stage renal disease (ESRD) and cardiovascular disease (CVD) between patients who underwent surgery for localized renal cell carcinoma (RCC) and those with chronic kidney disease (CKD) without surgery by investigating the National Health Insurance Service. MATERIALS AND METHODS The surgical group (CKD-S) included patients who underwent radical or partial nephrectomy for RCC from 2007 to 2009. Grades of surgical CKD were classified according to the estimated glomerular filtration rate (eGFR) measured at a health screening within 2 years after surgery. The nonsurgical group (CKD-M) was graded according to the eGFR in the 2009-2010 health screenings. We performed 1:5 propensity score matching for age, gender, diabetes, hypertension, Charlson comorbidity index, smoking, alcohol consumption, baseline eGFR, and body mass index. RESULTS A total of 8,698 patients (CKD-S, n=1,521; CKD-M, n=7,177) were analyzed. The CKD-M group was at higher risk for progression to ESRD (hazard ratio [HR] 1.90, 95% confidence interval [CI] 1.04-3.44, p=0.036) and CVD (HR 1.17, 95% CI 1.06-1.29, p=0.002) than the CKD-S group. In the group of patients with grade 3 disease or higher, the CKD-M group was at significantly higher risk for progression to ESRD (HR 2.21, 95% CI 1.47-3.31, p<0.001), CVD (HR 1.32, 95% CI 1.20-1.45, p<0.001), and overall mortality (HR 1.50, 95% CI 1.21-1.86, p<0.001). CONCLUSIONS The risk for progression to ESRD, CVD, or mortality in patients with CKD-S may be lower than in patients with CKD-M.
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Affiliation(s)
- Gyoohwan Jung
- Department of Urology, Hanyang University Seoul Hospital, Seoul, Korea
| | - Seokwoo Park
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hasung Kim
- Data Science Team, Hanmi Pharm. Co., Ltd, Seoul, Korea
| | - Jungkuk Lee
- Data Science Team, Hanmi Pharm. Co., Ltd, Seoul, Korea
| | - Chang Wook Jeong
- Department of Urology, Seoul National University Hospital, Seoul, Korea
- Department of Urology, Seoul National University College of Medicine, Seoul, Korea.
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14
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Cippà PE, McMahon AP. Proximal tubule responses to injury: interrogation by single-cell transcriptomics. Curr Opin Nephrol Hypertens 2023; 32:352-358. [PMID: 37074682 PMCID: PMC10330172 DOI: 10.1097/mnh.0000000000000893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
PURPOSE OF REVIEW Acute kidney injury (AKI) occurs in approximately 10-15% of patients admitted to hospital and is associated with adverse clinical outcomes. Despite recent advances, management of patients with AKI is still mainly supportive, including the avoidance of nephrotoxins, volume and haemodynamic management and renal replacement therapy. A better understanding of the renal response to injury is the prerequisite to overcome current limitations in AKI diagnostics and therapy. RECENT FINDINGS Single-cell technologies provided new opportunities to study the complexity of the kidney and have been instrumental for rapid advancements in the understanding of the cellular and molecular mechanisms of AKI. SUMMARY We provide an update on single-cell technologies and we summarize the recent discoveries on the cellular response to injury in proximal tubule cells from the early response in AKI, to the mechanisms of tubule repair and the relevance of maladaptive tubule repair in the transition to chronic kidney disease.
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Affiliation(s)
- Pietro E Cippà
- Division of Nephrology, Ente Ospedaliero Cantonale, Lugano, Switzerland
- Faculity of Biomedical Sciences, Università della Svizzera Italiana, Lugano Switzerland
| | - Andrew P McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
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15
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Humphreys BD. Decoupling dedifferentiation and G2/M arrest in kidney fibrosis. J Clin Invest 2022; 132:163846. [PMID: 36453550 PMCID: PMC9711866 DOI: 10.1172/jci163846] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Understanding the cellular mechanisms underlying chronic kidney disease (CKD) progression is required to develop effective therapeutic approaches. In this issue of the JCI, Taguchi, Elias, et al. explore the relationship between cyclin G1 (CG1), an atypical cyclin that induces G2/M proximal tubule cell cycle arrest, and epithelial dedifferentiation during fibrogenesis. While CG1-knockout mice were protected from fibrosis and had reduced G2/M arrest, protection was unexpectedly independent of induction of G2/M arrest. Rather, CG1 drove fibrosis by regulating maladaptive dedifferentiation in a CDK5-dependent mechanism. These findings highlight the importance of maladaptive epithelial dedifferentiation in kidney fibrogenesis and identify CG1/CDK5 signaling as a therapeutic target in CKD progression.
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Affiliation(s)
- Benjamin D. Humphreys
- Division of Nephrology, Department of Medicine and,Department of Developmental Biology, Washington University in St. Louis, St. Louis, Missouri, USA
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