Potential autocrine and paracrine mechanisms of recovery from mechanical injury of renal tubular epithelial cells

1998 ◽  
Vol 274 (3) ◽  
pp. F463-F472 ◽  
Author(s):  
Robert J. Anderson ◽  
Carla J. Ray
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Mechanical Injury ◽  
Renal Tubular Cell ◽  
Thymidine Uptake ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
The Media ◽  
Renal Tubular

The present studies were done to clarify potential pathways of the nephrogenic repair process. Media removed from mechanically injured vascular smooth muscle cells and LLC-PK1 renal tubular epithelial cells significantly stimulated[Formula: see text]thymidine uptake and cell number in quiescent LLC-PK1 cells, demonstrating the existence of potential autocrine and paracrine pathways of nephrogenic repair. The effect of mechanical injury resulting in release of one or more growth factors into culture media was also found in the opossum kidney OK renal tubular cell line. The nonspecific peptide growth factor antagonist suramin inhibited the effect of media from injured LLC-PK1 cells to stimulate[Formula: see text]thymidine uptake in quiescent LLC-PK1 cells. Exposure of quiescent LLC-PK1 cells to six growth factors, including acidic and basic fibroblastic growth factors (aFGF and bFGF), platelet-derived growth factors AA and BB (PDGF-AA and PDGF-BB), endothelin-2, and hepatocyte growth factor, reproduced the biological responses seen when quiescent LLC-PK1 cells were exposed to media from injured cells. Immunoblotting and enzyme-linked immunosorbent assay experiments demonstrated the presence of aFGF, bFGF, and PDGF-BB but not other candidate growth factors in the media from injured LLC-PK1 cells. A neutralizing antibody directed against bFGF attenuated the effect of media from injured cells to stimulate[Formula: see text]thymidine uptake in serum-starved LLC-PK1 cells. These results demonstrate that mechanical injury to renal tubular epithelial cells results in release of aFGF, bFGF, and PDGF-BB into the media and suggests that bFGF may be involved in an autocrine fashion to promote recovery from injury.

Cross talk between primary human renal tubular cells and endothelial cells in cocultures

2012 ◽  
Vol 302 (8) ◽  
pp. F1055-F1062 ◽  
Author(s):  
Farah Tasnim ◽  
Daniele Zink
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Renal Disease ◽  
Cross Talk ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Tubular Cells ◽  
Renal Tubular

Interactions between renal tubular epithelial cells and adjacent endothelial cells are essential for normal renal functions but also play important roles in renal disease and repair. Here, we investigated cocultures of human primary renal proximal tubular cells (HPTC) and human primary endothelial cells to address the cross talk between these cell types. HPTC showed improved proliferation, marker gene expression, and enzyme activity in cocultures. Also, the long-term maintenance of epithelia formed by HPTC was improved, which was due to the secretion of transforming growth factor-β1 and its antagonist α2-macroglobulin. HPTC induced endothelial cells to secrete increased amounts of these factors, which balanced each other functionally and only displayed in combination the observed positive effects. In addition, in the presence of HPTC endothelial cells expressed increased amounts of hepatocyte growth factor and vascular endothelial growth factor, which have well-characterized effects on renal tubular epithelial cells as well as on endothelial cells. Together, the results showed that HPTC stimulated endothelial cells to express a functionally balanced combination of various factors, which in turn improved the performance of HPTC. The results give new insights into the cross talk between renal epithelial and endothelial cells and suggest that cocultures could be also useful models for the analysis of cellular communication in renal disease and repair. Furthermore, the characterization of defined microenvironments, which positively affect HPTC, will be helpful for improving the performance of this cell type in in vitro applications including in vitro toxicology and kidney tissue engineering.

scholarly journals SOX9 promotes stress-responsive transcription of VGF nerve growth factor inducible gene in renal tubular epithelial cells

2020 ◽  
Vol 295 (48) ◽  
pp. 16328-16341
Author(s):  
Ji Young Kim ◽  
Yuntao Bai ◽  
Laura A. Jayne ◽  
Ferdos Abdulkader ◽  
Megha Gandhi ◽  
...  
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Gene Ablation ◽  
Renal Tubular ◽  
Inducible Gene

Acute kidney injury (AKI) is a common clinical condition associated with diverse etiologies and abrupt loss of renal function. In patients with sepsis, rhabdomyolysis, cancer, and cardiovascular disorders, the underlying disease or associated therapeutic interventions can cause hypoxia, cytotoxicity, and inflammatory insults to renal tubular epithelial cells (RTECs), resulting in the onset of AKI. To uncover stress-responsive disease-modifying genes, here we have carried out renal transcriptome profiling in three distinct murine models of AKI. We find that Vgf nerve growth factor inducible gene up-regulation is a common transcriptional stress response in RTECs to ischemia-, cisplatin-, and rhabdomyolysis-associated renal injury. The Vgf gene encodes a secretory peptide precursor protein that has critical neuroendocrine functions; however, its role in the kidneys remains unknown. Our functional studies show that RTEC-specific Vgf gene ablation exacerbates ischemia-, cisplatin-, and rhabdomyolysis-associated AKI in vivo and cisplatin-induced RTEC cell death in vitro. Importantly, aggravation of cisplatin-induced renal injury caused by Vgf gene ablation is partly reversed by TLQP-21, a Vgf-derived peptide. Finally, in vitro and in vivo mechanistic studies showed that injury-induced Vgf up-regulation in RTECs is driven by the transcriptional regulator Sox9. These findings reveal a crucial downstream target of the Sox9-directed transcriptional program and identify Vgf as a stress-responsive protective gene in kidney tubular epithelial cells.

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