Tissue Culture Models of Acute Kidney Injury: From Tubule Cells to Human Kidney Organoids

Acute kidney injury (AKI) affects approximately 13.3 million people around the world each year, causing chronic kidney disease and/or mortality. The mammalian kidney cannot generate new nephrons after postnatal renal damage and regenerative therapies for AKI are not available. Human kidney tissue culture systems can complement animal models of AKI and/or address some of their limitations. Donor-derived somatic cells, such as renal tubule epithelial cells or cell lines (RPTEC/hTERT, ciPTEC, HK-2, Nki-2, and CIHP-1), have been used for decades to permit drug toxicity screening and studies into potential AKI mechanisms. However, tubule cell lines do not fully recapitulate tubular epithelial cell properties in situ when grown under classic tissue culture conditions. Improving tissue culture models of AKI would increase our understanding of the mechanisms, leading to new therapeutics. Human pluripotent stem cells (hPSCs) can be differentiated into kidney organoids and various renal cell types. Injury to human kidney organoids results in renal cell type crosstalk and upregulation of kidney injury biomarkers that are difficult to induce in primary tubule cell cultures. However, current protocols produce kidney organoids that aren't mature and contain off-target cell types. Promising bioengineering techniques, such as bioprinting and "kidney-on-a17 chip" methods, as applied to kidney nephrotoxicity modeling advantages and limitations are discussed. This review explores the mechanisms and detection of AKI in tissue culture, with an emphasis on bioengineered approaches such as human kidney organoid models.

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Insulin-like growth factor binding protein 7 and tissue inhibitor of metalloproteinases-2: differential expression and secretion in human kidney tubule cells

AJP Renal Physiology ◽

10.1152/ajprenal.00271.2016 ◽

2017 ◽

Vol 312 (2) ◽

pp. F284-F296 ◽

Cited By ~ 38

Author(s):

David R. Emlet ◽

Nuria Pastor-Soler ◽

Allison Marciszyn ◽

Xiaoyan Wen ◽

Hernando Gomez ◽

...

Keyword(s):

Cell Culture ◽

Acute Kidney Injury ◽

Kidney Injury ◽

Human Kidney ◽

Distal Tubule ◽

Cell Types ◽

Tissue Inhibitor Of Metalloproteinases ◽

Tubule Cell ◽

Tubule Cells

We have characterized the expression and secretion of the acute kidney injury (AKI) biomarkers insulin-like growth factor binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in human kidney epithelial cells in primary cell culture and tissue. We established cell culture model systems of primary kidney cells of proximal and distal tubule origin and observed that both proteins are indeed expressed and secreted in both tubule cell types in vitro. However, TIMP-2 is both expressed and secreted preferentially by cells of distal tubule origin, while IGFBP7 is equally expressed across tubule cell types yet preferentially secreted by cells of proximal tubule origin. In human kidney tissue, strong staining of IGFBP7 was seen in the luminal brush-border region of a subset of proximal tubule cells, and TIMP-2 stained intracellularly in distal tubules. Additionally, while some tubular colocalization of both biomarkers was identified with the injury markers kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin, both biomarkers could also be seen alone, suggesting the possibility for differential mechanistic and/or temporal profiles of regulation of these early AKI biomarkers from known markers of injury. Last, an in vitro model of ischemia-reperfusion demonstrated enhancement of secretion of both markers early after reperfusion. This work provides a rationale for further investigation of these markers for their potential role in the pathogenesis of acute kidney injury.

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A Porthole over AKI: Cell Dynamics in Damage and Repair

Nephron ◽

10.1159/000508504 ◽

2020 ◽

Vol 144 (12) ◽

pp. 650-654

Author(s):

Luca Bordoni ◽

Donato Sardella ◽

Ina Maria Schiessl

Keyword(s):

Acute Kidney Injury ◽

Renal Cell ◽

Kidney Injury ◽

Cell Types ◽

Cell Interactions ◽

Intravital Imaging ◽

Cell Dynamics ◽

Powerful Technique ◽

Increased Risk ◽

Cell Crosstalk

Acute kidney injury (AKI) is associated with an increased risk of CKD. Injury-induced multifaceted renal cell-to-cell crosstalk can either lead to successful self-repair or chronic fibrosis and inflammation. In this mini-review, we will discuss critical renal cell types acting as victims or executioners in AKI pathology and introduce intravital imaging as a powerful technique to further dissect these cell-to-cell interactions.

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Modeling acute kidney injury in kidney organoids with cisplatin

10.1101/2019.12.22.886572 ◽

2019 ◽

Author(s):

Jenny L. M. Digby ◽

Aneta Przepiorski ◽

Alan J. Davidson ◽

Veronika Sander

Keyword(s):

Dna Damage ◽

Acute Kidney Injury ◽

Proximal Tubule ◽

Kidney Injury ◽

Induced Pluripotent Stem Cell ◽

Human Kidney ◽

Distal Tubule ◽

Dependent Manner ◽

Kidney Organoids

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.

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Cell profiling of mouse acute kidney injury reveals conserved cellular responses to injury

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2005477117 ◽

2020 ◽

Vol 117 (27) ◽

pp. 15874-15883 ◽

Cited By ~ 4

Author(s):

Yuhei Kirita ◽

Haojia Wu ◽

Kohei Uchimura ◽

Parker C. Wilson ◽

Benjamin D. Humphreys

Keyword(s):

Acute Kidney Injury ◽

Proximal Tubule ◽

Communication Networks ◽

Rat Kidney ◽

Kidney Injury ◽

Human Kidney ◽

Cellular Responses ◽

Acute Injury ◽

Proximal Tubule Cell ◽

Tubule Cell

After acute kidney injury (AKI), patients either recover or alternatively develop fibrosis and chronic kidney disease. Interactions between injured epithelia, stroma, and inflammatory cells determine whether kidneys repair or undergo fibrosis, but the molecular events that drive these processes are poorly understood. Here, we use single nucleus RNA sequencing of a mouse model of AKI to characterize cell states during repair from acute injury. We identify a distinct proinflammatory and profibrotic proximal tubule cell state that fails to repair. Deconvolution of bulk RNA-seq datasets indicates that this failed-repair proximal tubule cell (FR-PTC) state can be detected in other models of kidney injury, increasing during aging in rat kidney and over time in human kidney allografts. We also describe dynamic intercellular communication networks and discern transcriptional pathways driving successful vs. failed repair. Our study provides a detailed description of cellular responses after injury and suggests that the FR-PTC state may represent a therapeutic target to improve repair.

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Kidney Organoids as a Novel Platform to Evaluate Lipopolysaccharide-Induced Oxidative Stress and Apoptosis in Acute Kidney Injury

Frontiers in Medicine ◽

10.3389/fmed.2021.766073 ◽

2021 ◽

Vol 8 ◽

Author(s):

Weitao Zhang ◽

Ruochen Qi ◽

Tingting Li ◽

Xuepeng Zhang ◽

Yi Shi ◽

...

Keyword(s):

Oxidative Stress ◽

Acute Kidney Injury ◽

Immune Cell ◽

Kidney Injury ◽

Human Kidney ◽

Kidney Cells ◽

Pathological Changes ◽

Kidney Organoids

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.

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SARS-CoV-2 Causes Acute Kidney Injury by Directly Infecting Renal Tubules

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.664868 ◽

2021 ◽

Vol 9 ◽

Author(s):

Zhaohui Chen ◽

Junyi Hu ◽

Lilong Liu ◽

Rong Chen ◽

Miao Wang ◽

...

Keyword(s):

Acute Kidney Injury ◽

Cohort Analysis ◽

Kidney Injury ◽

Human Kidney ◽

Cell Types ◽

Progressive Increase ◽

Renal Tubules ◽

Spike Gene ◽

Tubular Cells ◽

Renal Tubular Cells

Acute kidney injury (AKI) is one of the most prevalent complications among hospitalized coronavirus disease 2019 (COVID-19) patients. Here, we aim to investigate the causes, risk factors, and outcomes of AKI in COVID-19 patients. We found that angiotensin-converting enzyme II (ACE2) and transmembrane protease serine 2 (TMPRSS2) were mainly expressed by different cell types in the human kidney. However, in autopsy kidney samples, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein was detected in ACE2+ or TMPRSS2+ renal tubular cells, whereas the RNAscope® Assay targeting the SARS-CoV-2 Spike gene was positive mainly in the distal tubular cells and seldom in the proximal tubular cells. In addition, the TMPRSS2 and kidney injury marker protein levels were significantly higher in the SARS-CoV-2-infected renal distal tubular cells, indicating that SARS-CoV-2-mediated AKI mainly occurred in the renal distal tubular cells. Subsequently, a cohort analysis of 722 patients with COVID-19 demonstrated that AKI was significantly related to more serious disease stages and poor prognosis of COVID-19 patients. The progressive increase of blood urea nitrogen (BUN) level during the course of COVID-19 suggests that the patient’s condition is aggravated. These results will greatly increase the current understanding of SARS-CoV-2 infection.

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