scholarly journals MO331LINEAGE TRACING OF REGENERATING PROXIMAL TUBULE CELLS (STC) BY SINGLE CELL PROFILING IN ACUTE KIDNEY INJURY

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Eleni Stamellou ◽  
Mingbo Cheng ◽  
Viktor Sterzer ◽  
Katja Leuchtle ◽  
Thiago Strieder ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Proximal Tubule ◽  
Single Cell ◽  
Transgenic Mouse ◽  
Ischemia Reperfusion ◽  
Expression Patterns ◽  
Kidney Injury ◽  
Multiple Time ◽  
Proximal Tubule Cells ◽  
Tubule Cells

Abstract Background and Aims Acute tubular injury accounts for the most common intrinsic cause for acute kidney injury (AKI). The scattered tubular cell (STC) phenotype was discovered as a uniform reaction of tubule cells triggered by injury. Our group was the first to identify an inducible transgenic mouse (PEC-rtTA-mouse) specifically labeling STCs with eGFP. Analysis of the transcriptional factors and associated signaling pathways might reveal the function and role of STCs in AKI. Method Here, we performed single-cell RNA sequencing of unilateral ischemia-reperfusion murine model of AKI 8, 24, 48 hours and 6 and 12 days after AKI induction. Results Genes expressing proximal tubular proteins and transporters were markedly downregulated during transition into the STC phenotype upon injury; but expression recovered over time and upon resolution and tubular cells re-differentiated into proximal tubule cells. This provides evidence for the first time that the STC phenotype is a transient and reversible phenotype triggered by injury. Among cells in the STC phenotype, we could identify 2 sub-clusters; a highly proliferating sub-cluster that in the cell cycle analysis showed the highest proportion of cycling cells. The second eGFP-positive cluster appeared very early after AKI and expressed a distinct set of genes (defined by 7 anchor genes). Some of the highly up-regulated genes are known markers of STCs hence confirming the specificity of our transgenic mouse line. Conclusion Our study provides gene expression patterns specifically in STCs upon injury and repair at multiple time points and suggests that the STC phenotype is a transient and reversible phenotype triggered by injury.

scholarly journals Acute Kidney Injury in SARS-CoV-2 Infection: Direct Effect of Virus on Kidney Proximal Tubule Cells

2020 ◽  
Vol 21 (9) ◽  
pp. 3275 ◽  
Author(s):  
Manoocher Soleimani
Keyword(s):  
Acute Kidney Injury ◽  
Severe Acute Respiratory Syndrome ◽  
Proximal Tubule ◽  
Rna Viruses ◽  
Kidney Injury ◽  
The Novel ◽  
Proximal Tubule Cells ◽  
Severe Respiratory Infection ◽  
Tubule Cells ◽  
Novel Coronavirus

Coronaviruses (CoVs), including Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and the novel coronavirus disease-2 (SARS-CoV-2) are a group of enveloped RNA viruses that cause a severe respiratory infection which is associated with a high mortality [...]

Renal organic anion transporter 1 is maldistributed and diminishes in proximal tubule cells but increases in vasculature after ischemia and reperfusion

2008 ◽  
Vol 295 (6) ◽  
pp. F1807-F1816 ◽  
Author(s):  
Osun Kwon ◽  
Wei-Wei Wang ◽  
Shane Miller
Keyword(s):  
Proximal Tubule ◽  
Ischemia Reperfusion ◽  
Organic Anion ◽  
Basolateral Membrane ◽  
Kidney Injury ◽  
Organic Anion Transporter ◽  
Membrane Domain ◽  
Proximal Tubule Cells ◽  
Anion Transporter ◽  
Tubule Cells

Renal solute clearances are reduced in ischemic acute kidney injury. However, the mechanisms explaining how solute clearance is impaired have not been clarified. Recently, we reported that cadaveric renal allografts exhibit maldistribution of organic anion transporter 1 (OAT1) in proximal tubule cells after ischemia and reperfusion, resulting in impairment of PAH clearance. In the present study, we characterized renal OAT1 in detail after ischemia-reperfusion using a rat model. We analyzed renal OAT1 using confocal microscopy with a three-dimensional reconstruction of serial optical images, Western blot, and quantitative real-time RT-PCR. OAT1 was distributed to basolateral membranes of proximal tubule cells in controls. With ischemia, OAT1 decreased in basolateral membrane, especially in the lateral membrane domain, and appeared diffusely in cytoplasm. After reperfusion following 60-min ischemia, OAT1 often formed cytoplasmic aggregates. The staining for OAT1 started reappearing in lateral membrane domain 1 h after reperfusion. The basolateral membrane staining was relatively well discernable at 240 h of reperfusion. Of note, a distinct increase in OAT1 expression was noted in vasculature early after ischemia and after reperfusion. The total amount of OAT1 protein expression in the kidney diminished after ischemia-reperfusion in a duration-dependent manner until 72 h, when they began to recover. However, even at 240 h, the amount of OAT1 did not reach control levels. The kidney tissues tended to show a remarkable but transient increase in mRNA expression for OAT1 at 5 min of ischemia. Our findings may provide insights of renal OAT1 in its cellular localization and response during ischemic acute kidney injury and recovery from it.

scholarly journals 6-Shogaol protects against ischemic acute kidney injury by modulating NF-κB and heme oxygenase-1 pathways

2019 ◽  
Vol 317 (3) ◽  
pp. F743-F756 ◽  
Author(s):  
Sang Jun Han ◽  
Mihwa Kim ◽  
Vivette D. D’Agati ◽  
H. Thomas Lee
Keyword(s):  
Acute Kidney Injury ◽  
Proximal Tubule ◽  
Heme Oxygenase ◽  
Kidney Injury ◽  
Heme Oxygenase 1 ◽  
Zinc Protoporphyrin ◽  
Mrna Synthesis ◽  
Proximal Tubule Cells ◽  
Tnf Α ◽  
Tubule Cells

Acute kidney injury (AKI) due to renal ischemia-reperfusion (I/R) is a major clinical problem without effective therapy. Ginger is one of the most widely consumed spices in the world, and 6-shogaol, a major ginger metabolite, has anti-inflammatory effects in neuronal and epithelial cells. Here, we demonstrate our novel findings that 6-shogaol treatment protected against renal I/R injury with decreased plasma creatinine, blood urea nitrogen, and kidney neutrophil gelatinase-associated lipocalin mRNA synthesis compared with vehicle-treated mice subjected to renal I/R. Additionally, 6-shogaol treatment reduced kidney inflammation (decreased proinflammatory cytokine and chemokine synthesis as well as neutrophil infiltration) and apoptosis (decreased TUNEL-positive renal tubular cells) compared with vehicle-treated mice subjected to renal I/R. In cultured human and mouse kidney proximal tubule cells, 6-shogaol significantly attenuated TNF-α-induced inflammatory cytokine and chemokine mRNA synthesis. Mechanistically, 6-shogaol significantly attenuated TNF-α-induced NF-κB activation in human renal proximal tubule cells by reducing IKKαβ/IκBα phosphorylation. Furthermore, 6-shogaol induced a cytoprotective chaperone heme oxygenase (HO)-1 via p38 MAPK activation in vitro and in vivo. Consistent with these findings, pretreatment with the HO-1 inhibitor zinc protoporphyrin IX completely prevented 6-shogaol-mediated protection against ischemic AKI in mice. Taken together, our study showed that 6-shogaol protects against ischemic AKI by attenuating NF-κB activation and inducing HO-1 expression. 6-Shogaol may provide a potential therapy for ischemic AKI during the perioperative period.

scholarly journals Single-cell Analysis of ACE2 Expression in Human Kidneys and Bladders Reveals a Potential Route of 2019-nCoV Infection

2020 ◽  
Author(s):  
Wei Lin ◽  
Longfei Hu ◽  
Yan Zhang ◽  
Joshua D. Ooi ◽  
Ting Meng ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Single Cell ◽  
Single Cell Analysis ◽  
Kidney Injury ◽  
Cell Types ◽  
Gene Expressions ◽  
Proximal Tubule Cells ◽  
Bladder Cell ◽  
Short Period ◽  
Tubule Cells

AbstractSince December 2019, a novel coronavirus named 2019 coronavirus (2019-nCoV) has emerged in Wuhan of China and spread to several countries worldwide within just one month. Apart from fever and respiratory complications, acute kidney injury has been observed in some patients with 2019-nCoV. In a short period of time, angiotensin converting enzyme II (ACE2), have been proposed to serve as the receptor for the entry of 2019-nCoV, which is the same for severe acute respiratory syndrome coronavirus (SARS). To investigate the possible cause of kidney damage in 2019-nCoV patients, we used both published kidney and bladder cell atlas data and an independent unpublished kidney single cell RNA-Seq data generated in-house to evaluate ACE2 gene expressions in all cell types in healthy kidneys and bladders.Our results showed the enriched expression of all subtypes of proximal tubule cells of kidney and low but detectable levels of expression in bladder epithelial cells. These results indicated the urinary system is a potential route for 2019-nCoV infection, along with the respiratory system and digestion system. Our findings suggested the kidney abnormalities of SARS and 2019-nCoV patients may be due to proximal tubule cells damage and subsequent systematic inflammatory response induced kidney injury. Beyond that, laboratory tests of viruses and related indicators in urine may be needed in some special patients of 2019-nCoV.

scholarly journals Integration of spatial transcriptomic and single cell sequencing identifies expression patterns underlying immune and epithelial cell cross-talk in acute kidney injury

2021 ◽  
Author(s):  
Ricardo Melo Ferreira ◽  
Angela R. Sabo ◽  
Seth Winfree ◽  
Kimberly S. Collins ◽  
Danielle Janosevic ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Single Cell ◽  
Ischemia Reperfusion ◽  
Expression Patterns ◽  
Regional Distribution ◽  
Kidney Injury ◽  
Cell Types ◽  
Chemotactic Factor ◽  
Single Cell Sequencing ◽  
Transcriptomic Signature

AbstractDespite important advances in studying experimental and clinical acute kidney injury (AKI), the pathogenesis of this disease remains incompletely understood. Single cell sequencing studies have closed this knowledge gap by characterizing the transcriptomic signature of different cell types within the kidney. However, the spatial distribution of injury can be regional and affect cells heterogeneously. We first optimized coordination of spatial transcriptomics and single nuclear sequencing datasets, mapping 30 dominant cell types to a human nephrectomy sample. The predicted cell type spots corresponded with the underlying hematoxylin and eosin histopathology. To study the implications of acute kidney injury on the distribution of transcript expression, we then characterized the spatial transcriptomic signature of two murine AKI models: ischemia reperfusion injury (IRI) and cecal ligation puncture (CLP). Localized regions of reduced overall expression were found associated with tissue injury pathways. Using single cell sequencing, we deconvoluted the signature of each spatial transcriptomic spot, identifying patterns of colocalization between immune and epithelial cells. As expected, neutrophils infiltrated the renal medullary outer stripe in the ischemia model. Atf3 was identified as a chemotactic factor in S3 proximal tubule cells. In the CLP model, infiltrating macrophages dominated the outer cortical signature and Mdk was identified as a corresponding chemotactic factor. The regional distribution of these immune cells was validated with multiplexed CO-Detection by inDEXing (CODEX) immunofluorescence. Spatial transcriptomic sequencing can aid in uncovering the mechanisms driving immune cell infiltration and allow detection of relevant subpopulations in single cell sequencing. The complementarity of these technologies facilitates the development of a transcriptomic kidney atlas in health and disease.

scholarly journals Proximal Tubule–Derived Amphiregulin Amplifies and Integrates Profibrotic EGF Receptor Signals in Kidney Fibrosis

2019 ◽  
Vol 30 (12) ◽  
pp. 2370-2383 ◽  
Author(s):  
Eirini Kefaloyianni ◽  
Manikanda Raja Keerthi Raja ◽  
Julian Schumacher ◽  
Muthu Lakshmi Muthu ◽  
Vaishali Krishnadoss ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Reperfusion Injury ◽  
Knockout Mice ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Proximal Tubule Cell ◽  
Tubule Cell ◽  
Proximal Tubule Cells ◽  
Kidney Fibrosis ◽  
Tubule Cells

BackgroundSustained activation of EGF receptor (EGFR) in proximal tubule cells is a hallmark of progressive kidney fibrosis after AKI and in CKD. However, the molecular mechanisms and particular EGFR ligands involved are unknown.MethodsWe studied EGFR activation in proximal tubule cells and primary tubular cells isolated from injured kidneys in vitro. To determine in vivo the role of amphiregulin, a low-affinity EGFR ligand that is highly upregulated with injury, we used ischemia-reperfusion injury or unilateral ureteral obstruction in mice with proximal tubule cell–specific knockout of amphiregulin. We also injected soluble amphiregulin into knockout mice with proximal tubule cell–specific deletion of amphiregulin’s releasing enzyme, the transmembrane cell-surface metalloprotease, a disintegrin and metalloprotease-17 (ADAM17), and into ADAM17 hypomorphic mice.ResultsYes-associated protein 1 (YAP1)–dependent upregulation of amphiregulin transcript and protein amplifies amphiregulin signaling in a positive feedback loop. YAP1 also integrates signals of other moderately injury-upregulated, low-affinity EGFR ligands (epiregulin, epigen, TGFα), which also require soluble amphiregulin and YAP1 to induce sustained EGFR activation in proximal tubule cells in vitro. In vivo, soluble amphiregulin injection sufficed to reverse protection from fibrosis after ischemia-reperfusion injury in ADAM17 hypomorphic mice; injected soluble amphiregulin also reversed the corresponding protective proximal tubule cell phenotype in injured proximal tubule cell–specific ADAM17 knockout mice. Moreover, the finding that proximal tubule cell–specific amphiregulin knockout mice were protected from fibrosis after ischemia-reperfusion injury or unilateral ureteral obstruction demonstrates that amphiregulin was necessary for the development of fibrosis.ConclusionsOur results identify amphiregulin as a key player in injury-induced kidney fibrosis and suggest therapeutic or diagnostic applications of soluble amphiregulin in kidney disease.

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