scholarly journals Modeling oxidative injury response in human kidney organoids

Author(s):  
Aneta Przepiorski ◽  
Thitinee Vanichapol ◽  
Eugenel B. Espiritu ◽  
Amanda E. Crunk ◽  
Emily Parasky ◽  
...  

Abstract BackgroundPersistent acute kidney injury (AKI) leads to tubular atrophy, kidney fibrosis, and, if severe enough, chronic kidney disease (CKD). A common feature of AKI is the generation of excessive reactive oxygen species (ROS) which damage cells and induce inflammation. MethodsHuman kidney organoids were treated with hemin, an iron-containing porphyrin derived from lysed red blood cells, that generates ROS in disease settings such as rhabdomyolysis, sepsis and ischemia reperfusion leading to AKI. In addition, we developed an induced pluripotent stem cell line expressing the biosensor, CytochromeC-GFP (CytoC-GFP), which provides a real-time readout of mitochondrial morphology, health, and early apoptotic events. ResultsWe found that hemin-treated kidney organoids show oxidative damage, increased expression of injury markers, impaired functionality of organic anion and cation transport and undergo fibrosis. Tubule injury could be detected in live CytoC-GFP organoids by cytoplasmic localization of fluorescence. Finally, we show that 4-(phenylthio)butanoic acid, an HDAC inhibitor with anti-fibrotic effects in vivo , reduces hemin-induced human kidney organoid fibrosis. ConclusionTogether this work establishes a hemin-induced model of kidney organoid injury and fibrosis as a new model to study renal repair and a human platform for developing AKI therapeutics.

2018 ◽  
Vol 29 (6) ◽  
pp. 1690-1705 ◽  
Author(s):  
Dario R. Lemos ◽  
Michael McMurdo ◽  
Gamze Karaca ◽  
Julia Wilflingseder ◽  
Irina A. Leaf ◽  
...  

Background Kidney injury is characterized by persisting inflammation and fibrosis, yet mechanisms by which inflammatory signals drive fibrogenesis remain poorly defined.Methods RNA sequencing of fibrotic kidneys from patients with CKD identified a metabolic gene signature comprising loss of mitochondrial and oxidative phosphorylation gene expression with a concomitant increase in regulators and enzymes of glycolysis under the control of PGC1α and MYC transcription factors, respectively. We modeled this metabolic switch in vivo, in experimental murine models of kidney injury, and in vitro in human kidney stromal cells (SCs) and human kidney organoids.Results In mice, MYC and the target genes thereof became activated in resident SCs early after kidney injury, suggesting that acute innate immune signals regulate this transcriptional switch. In vitro, stimulation of purified human kidney SCs and human kidney organoids with IL-1β recapitulated the molecular events observed in vivo, inducing functional metabolic derangement characterized by increased MYC-dependent glycolysis, the latter proving necessary to drive proliferation and matrix production. MYC interacted directly with sequestosome 1/p62, which is involved in proteasomal degradation, and modulation of p62 expression caused inverse effects on MYC expression. IL-1β stimulated autophagy flux, causing degradation of p62 and accumulation of MYC. Inhibition of the IL-1R signal transducer kinase IRAK4 in vivo or inhibition of MYC in vivo as well as in human kidney organoids in vitro abrogated fibrosis and reduced tubular injury.Conclusions Our findings define a connection between IL-1β and metabolic switch in fibrosis initiation and progression and highlight IL-1β and MYC as potential therapeutic targets in tubulointerstitial diseases.


2019 ◽  
Author(s):  
Jenny L. M. Digby ◽  
Aneta Przepiorski ◽  
Alan J. Davidson ◽  
Veronika Sander

ABSTRACTAcute kidney injury (AKI) remains a major global healthcare problem and there is a need to develop human-based models to study AKI in vitro. Towards this goal, we have characterized induced pluripotent stem cell-derived human kidney organoids and their response to cisplatin, a chemotherapeutic drug that induces AKI and preferentially damages the proximal tubule. We found that a single treatment with 50 µM cisplatin induces HAVCR1 and CXCL8 expression, DNA damage (γH2AX) and cell death in the organoids in a dose-dependent manner but greatly impairs organoid viability. DNA damage was not specific to the proximal tubule but also affected the distal tubule and interstitial populations. This lack of specificity correlated with low expression of the proximal tubule-specific SLC22A2/OCT2 transporter for cisplatin. To improve viability, we developed a repeated low-dose regimen of 4x 5 µM cisplatin over 7 days and found this causing less toxicity while still inducing a robust AKI response that included secretion of known AKI biomarkers and inflammatory cytokines. This work validates the use of human kidney organoids to model aspects of AKI in vitro, with the potential to identify new AKI biomarkers and develop better therapies.


2021 ◽  
Author(s):  
Mai M Abdelmageed ◽  
Eirini Kefaloyianni ◽  
Akshayakeerthi Arthanarisami ◽  
Fatima Khamissi ◽  
Jeff Atkinson ◽  
...  

AbstractInflammation is a key driver of fibrosis and progression of human chronic kidney disease (CKD), often caused or worsened by acute kidney injury (AKI-to-CKD transition). Sustained epidermal-growth-factor-receptor (EGFR) activation in injured proximal-tubule-cells (PTC) is strongly pro-inflammatory and has emerged as a key paradigm in AKI-to-CKD transition and CKD progression. Whether the key Type 1 inflammatory cytokine tumor-necrosis-factor (TNF) has a role in CKD progression and how TNF relates to the PTC-EGFR pathway is unknown, but retrospective analysis of patients using TNF biologic inhibitors suggests that TNF inhibition reduces incident CKD and CKD progression in humans. Here, we compared mice treated with control, TNF inhibition (murine etanercept, soluble TNF-scavenger), EGFR inhibition (erlotinib, EGFR-kinase-inhibitor) or their combination in an AKI-to-CKD bilateral renal-ischemia-reperfusion model. TNF- or EGFR-inhibition did not affect initial kidney injury, but significantly overlapped in reducing kidney injury-upregulated cytokines and equally strongly reduced kidney fibrosis, while combination treatment had no additive effect, suggesting EGFR and TNF act in the same fibrosis pathway. TNF exerted its profibrotic effects downstream of PTC-EGFR, as TNF-inhibition did not affect tubular EGFR activation in vivo. Consistent with this, TNF PTC-KO did not reduce inflammation or fibrosis, suggesting that PTC-derived TNF does not contribute to profibrotic PTC-EGFR activation. Kidney single-cell RNAseq analysis identified macrophages, dendritic cells and T cells, but not PTC, as dominant TNF sources after AKI. Only EGFR inhibition, but not TNF inhibition significantly blocked injury-induced kidney ingress of chemokine-receptor-2 (CCR2) positive cells and accumulation of macrophages, however, macrophage numbers where equal one month after AKI independent of treatment. Thus EGFR inhibition reduces ingress and accumulation of TNF-producing proinflammatory and profibrotic immune cells whereas TNF inhibition mechanistically largely acts by neutralizing their proinflammatory and profibrotic activities. Our work provides mechanistic background to motivate examination of TNF pathway inhibition in human AKI or CKD.


2021 ◽  
Vol 8 ◽  
Author(s):  
Weitao Zhang ◽  
Ruochen Qi ◽  
Tingting Li ◽  
Xuepeng Zhang ◽  
Yi Shi ◽  
...  

Sepsis-associated acute kidney injury (SA-AKI) is a life-threatening syndrome. Lipopolysaccharide (LPS) is a widely used inducer for modeling SA-AKI both in vivo and in vitro. However, due to the innate complexity of the kidney architecture, the mechanisms underlying the pathogenesis of SA-AKI, as well as those involved in LPS-induced kidney injury remain to be clarified. Kidney organoids derived from human pluripotent stem cells (hPSCs) act as a model of multiple types of kidney cells in vitro and eliminate potential confounders in vivo. In the current study, we established LPS-induced kidney injury models both in vivo and in human kidney organoids. Kidney function, pathological changes, and markers of oxidative stress were evaluated with/without the presence of methylprednisolone (MP) treatment both in vivo and in vitro. The extent of LPS-induced oxidative stress and apoptosis in kidney organoids was further investigated in vitro. LPS-induced acute kidney injury in mice, together with pathological changes and increased oxidative stress, as well as enhanced apoptosis in kidney cells were evaluated. These phenomena were ameliorated by MP treatment. Experiments in kidney organoids showed that the LPS-induced apoptotic effects occurred mainly in podocytes and proximal tubular cells. Our experiments demonstrated the efficacy of using kidney organoids as a solid platform to study LPS-induced kidney injury. LPS induced oxidative stress as well as apoptosis in kidney cells independently of changes in perfusion or immune cell infiltration. MP treatment partially alleviated LPS-induced injury by reducing kidney cell oxidative stress and apoptosis.


2018 ◽  
Vol 29 (9) ◽  
pp. 2287-2297 ◽  
Author(s):  
Yoichiro Ikeda ◽  
Zhao Sun ◽  
Xiao Ru ◽  
Luk H. Vandenberghe ◽  
Benjamin D. Humphreys

BackgroundAfter injury, mesenchymal progenitors in the kidney interstitium differentiate into myofibroblasts, cells that have a critical role in kidney fibrogenesis. The ability to deliver genetic material to myofibroblast progenitors could allow new therapeutic approaches to treat kidney fibrosis. Preclinical and clinical studies show that adeno-associated viruses (AAVs) efficiently and safely transduce various tissue targets in vivo; however, protocols for transduction of kidney mesenchymal cells have not been established.MethodsWe evaluated the transduction profiles of various pseudotyped AAV vectors expressing either GFP or Cre recombinase reporters in mouse kidney and human kidney organoids.ResultsOf the six AAVs tested, a synthetic AAV called Anc80 showed specific and high-efficiency transduction of kidney stroma and mesangial cells. We characterized the cell specificity, dose dependence, and expression kinetics and showed the efficacy of this approach by knocking out Gli2 from kidney mesenchymal cells by injection of Anc80-Cre virus into either homozygous or heterozygous Gli2-floxed mice. After unilateral ureteral obstruction, the homozygous Gli2-floxed mice had less fibrosis than the Gli2 heterozygotes had. We observed the same antifibrotic effect in β-catenin–floxed mice injected with Anc80-Cre virus before obstructive injury, strongly supporting a central role for canonical Wnt signaling in kidney myofibroblast activation. Finally, we showed that the Anc80 synthetic virus can transduce the mesenchymal lineage in human kidney organoids.ConclusionsThese studies establish a novel method for inducible knockout of floxed genes in mouse mesangium, pericytes, and perivascular fibroblasts and are the foundation for future gene therapy approaches to treat kidney fibrosis.


2020 ◽  
Vol 318 (4) ◽  
pp. F971-F978 ◽  
Author(s):  
Jenny L. M. Digby ◽  
Thitinee Vanichapol ◽  
Aneta Przepiorski ◽  
Alan J. Davidson ◽  
Veronika Sander

Acute kidney injury (AKI) remains a major global healthcare problem, and there is a need to develop human-based models to study AKI in vitro. Toward this goal, we have characterized induced pluripotent stem cell-derived human kidney organoids and their response to cisplatin, a chemotherapeutic drug that induces AKI and preferentially damages the proximal tubule. We found that a single treatment with 50 µM cisplatin induces hepatitis A virus cellular receptor 1 ( HAVCR1) and C-X-C motif chemokine ligand 8 ( CXCL8) expression, DNA damage (γH2AX), and cell death in the organoids but greatly impairs organoid viability. DNA damage was not specific to the proximal tubule but also affected the distal tubule and interstitial cell populations. This lack of specificity correlated with low expression of proximal tubule-specific SLC22A2/organic cation transporter 2 ( OCT2) for cisplatin. To improve viability, we developed a repeated low-dose regimen of 4 × 5 µM cisplatin over 7 days and found this caused less toxicity while still inducing a robust injury response that included secretion of known AKI biomarkers and inflammatory cytokines. This work validates the use of human kidney organoids to model aspects of cisplatin-induced injury, with the potential to identify new AKI biomarkers and develop better therapies.


2021 ◽  
pp. 1-15
Author(s):  
Lu Zhou ◽  
Xian Xue ◽  
Qing Hou ◽  
Chunsun Dai

<b><i>Background:</i></b> Ferroptosis, an iron-dependent form of regulated necrosis mediated by lipid peroxidation, predominantly polyunsaturated fatty acids, is involved in postischemic and toxic kidney injury. However, the role and mechanisms for tubular epithelial cell (TEC) ferroptosis in kidney fibrosis remain largely unknown. <b><i>Objectives:</i></b> The aim of the study was to decipher the role and mechanisms for TEC ferroptosis in kidney fibrosis. <b><i>Methods:</i></b> Mouse models with unilateral ureter obstruction (UUO) or ischemia/reperfusion injury (IRI) were generated. <b><i>Results:</i></b> We found that TEC ferroptosis exhibited as reduced glutathione peroxidase 4 (GPX4) expression and increased 4-hydroxynonenal abundance was appeared in kidneys from chronic kidney disease (CKD) patients and mouse models with UUO or IRI. Inhibition of ferroptosis could largely mitigate kidney injury, interstitial fibrosis, and inflammatory cell accumulation in mice after UUO or IRI. Additionally, treatment of TECs with (1S,3R)-RSL-3, an inhibitor of GPX4, could enhance cell ferroptosis and recruit macrophages. Furthermore, inhibiting TEC ferroptosis reduced monocyte chemotactic protein 1 (MCP-1) secretion and macrophage chemotaxis. <b><i>Conclusions:</i></b> This study uncovers that TEC ferroptosis may promote interstitial fibrosis and inflammation, and targeting ferroptosis may shine a light on protecting against kidney fibrosis in patients with CKDs.


2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Chenguang Ding ◽  
Xiaoming Ding ◽  
Jin Zheng ◽  
Bo Wang ◽  
Yang Li ◽  
...  

Abstract Renal tubular cell death is the key factor of the pathogenesis of ischemia/reperfusion (I/R) kidney injury. Ferroptosis is a type of regulated cell death (RCD) found in various diseases. However, the underlying molecular mechanisms related to ferroptosis in renal I/R injury remain unclear. In the present study, we investigated the regulatory role of microRNAs on ferroptosis in I/R-induced renal injury. We established the I/R-induced renal injury model in rats, and H/R induced HK-2 cells injury in vitro. CCK-8 was used to measure cell viability. Fe2+ and ROS levels were assayed to evaluate the activation of ferroptosis. We performed RNA sequencing to profile the miRNAs expression in H/R-induced injury and ferroptosis. Western blot analysis was used to detect the protein expression. qRT-PCR was used to detect the mRNA and miRNA levels in cells and tissues. We further used luciferase reporter assay to verify the direct targeting effect of miRNA. We found that ischemia/reperfusion-induced ferroptosis in rat’s kidney. We identified that miR-182-5p and miR-378a-3p were upregulated in the ferroptosis and H/R-induced injury, and correlates reversely with glutathione peroxidases 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) expression in renal I/R injury tissues, respectively. In vitro studies showed that miR-182-5p and miR-378a-3p induced ferroptosis in cells. We further found that miR-182-5p and miR-378a-3p regulated the expression of GPX4 and SLC7A11 negatively by directly binding to the 3′UTR of GPX4 and SLC7A11 mRNA. In vivo study showed that silencing miR-182-5p and miR-378a-3p alleviated the I/R-induced renal injury in rats. In conclusion, we demonstrated that I/R induced upregulation of miR-182-5p and miR-378a-3p, leading to activation of ferroptosis in renal injury through downregulation of GPX4 and SLC7A11.


2013 ◽  
Vol 304 (7) ◽  
pp. C591-C603 ◽  
Author(s):  
Gabriela Campanholle ◽  
Giovanni Ligresti ◽  
Sina A. Gharib ◽  
Jeremy S. Duffield

Chronic kidney disease, defined as loss of kidney function for more than three months, is characterized pathologically by glomerulosclerosis, interstitial fibrosis, tubular atrophy, peritubular capillary rarefaction, and inflammation. Recent studies have identified a previously poorly appreciated, yet extensive population of mesenchymal cells, called either pericytes when attached to peritubular capillaries or resident fibroblasts when embedded in matrix, as the progenitors of scar-forming cells known as myofibroblasts. In response to sustained kidney injury, pericytes detach from the vasculature and differentiate into myofibroblasts, a process not only causing fibrosis, but also directly contributing to capillary rarefaction and inflammation. The interrelationship of these three detrimental processes makes myofibroblasts and their pericyte progenitors an attractive target in chronic kidney disease. In this review, we describe current understanding of the mechanisms of pericyte-to-myofibroblast differentiation during chronic kidney disease, draw parallels with disease processes in the glomerulus, and highlight promising new therapeutic strategies that target pericytes or myofibroblasts. In addition, we describe the critical paracrine roles of epithelial, endothelial, and innate immune cells in the fibrogenic process.


2021 ◽  
Author(s):  
Jitske Jansen ◽  
Bartholomeus T van den Berge ◽  
Martijn van den Broek ◽  
Rutger J Maas ◽  
Brigith Willemsen ◽  
...  

Nephrotic syndrome (NS) is characterized by severe proteinuria as a consequence of kidney glomerular injury due to podocyte damage. In vitro models mimicking in vivo podocyte characteristics are a prerequisite to resolve NS pathogenesis. Here, we report human induced pluripotent stem cell derived kidney organoids containing a podocyte population that heads towards adult podocytes and were superior compared to 2D counterparts, based on scRNA sequencing, super-resolution imaging and electron microscopy. In this study, these next-generation podocytes in kidney organoids enabled personalized idiopathic nephrotic syndrome modeling as shown by activated slit diaphragm signaling and podocyte injury following protamine sulfate treatment and exposure to NS plasma containing pathogenic permeability factors. Organoids cultured from cells of a patient with heterozygous NPHS2 mutations showed poor NPHS2 expression and aberrant NPHS1 localization, which was reversible after genetic correction. Repaired organoids displayed increased VEGFA pathway activity and transcription factor activity known to be essential for podocyte physiology, as shown by RNA sequencing. This study shows that organoids are the preferred model of choice to study idiopathic and congenital podocytopathies.


Sign in / Sign up

Export Citation Format

Share Document