Limits...
Calcium oxalate crystals and oxalate induce an epithelial-to-mesenchymal transition in the proximal tubular epithelial cells: Contribution to oxalate kidney injury

View Article: PubMed Central - PubMed

ABSTRACT

TGF-β1 is the main mediator of epithelial-to-mesenchymal transition (EMT). Hyperoxaluria induces crystalluria, interstitial fibrosis, and progressive renal failure. This study analyzed whether hyperoxaluria is associated with TGF-β1 production and kidney fibrosis in mice and if oxalate or calcium oxalate (CaOx) could induce EMT in proximal tubule cells (HK2) and therefore contribute to the fibrotic process. Hyperoxaluria was induced by adding hydroxyproline and ethylene glycol to the mice’s drinking water for up to 60 days. Renal function and oxalate and urinary crystals were evaluated. Kidney collagen production and TGF-β1 expression were assessed. EMT was analyzed in vitro according to TGF-β1 production, phenotypic characterization, invasion, cell migration, gene and protein expression of epithelial and mesenchymal markers. Hyperoxaluric mice showed a decrease in renal function and an increase in CaOx crystals and Ox urinary excretion. The deposition of collagen in the renal interstitium was observed. HK2 cells stimulated with Ox and CaOx exhibited a decreased expression of epithelial as well as increased expression mesenchymal markers; these cells presented mesenchymal phenotypic changes, migration, invasiveness capability and TGF-β1 production, characterizing EMT. Treatment with BMP-7 or its overexpression in HK2 cells was effective at preventing it. This mechanism may contribute to the fibrosis observed in hyperoxaluria.

No MeSH data available.


Related in: MedlinePlus

As a result of loss of cell adhesion and morphological changes from cuboid to fusiform form, these cells acquire the ability to invade (transwell chamber assays) and move in the extracellular matrix.The HK2-WT (A) and HK2T + siRNA (D) acquired invasive capacity, while HK2 cells receiving BMP-7 (HK2 + BMP-7) (B), and HK2 cells overexpressing BMP-7 (HK2T) (C) behaved similarly the control (CTL) situation even in cell culture exposed to potassium oxalate (Ox), calcium oxalate (CaOx) and TGF-β1. Results were expressed as optical density (OD) and (*) groups were significantly different from the control situation (p < 0.05). N = 15 for each group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5384284&req=5

f5: As a result of loss of cell adhesion and morphological changes from cuboid to fusiform form, these cells acquire the ability to invade (transwell chamber assays) and move in the extracellular matrix.The HK2-WT (A) and HK2T + siRNA (D) acquired invasive capacity, while HK2 cells receiving BMP-7 (HK2 + BMP-7) (B), and HK2 cells overexpressing BMP-7 (HK2T) (C) behaved similarly the control (CTL) situation even in cell culture exposed to potassium oxalate (Ox), calcium oxalate (CaOx) and TGF-β1. Results were expressed as optical density (OD) and (*) groups were significantly different from the control situation (p < 0.05). N = 15 for each group.

Mentions: To determine whether HK2-WT cells exposed to Ox, CaOx, or TGF-β1 became more active in the invasion than in the control cells, we evaluated the invasive ability of cells using a transwell chamber assay. As shown in Fig. 5, Ox, CaOx, and TGF-β1 stimulated the HK2-WT (Fig. 5A) to migrate (cells were fixed and stained with Toluidine Blue) faster than the control cells, as shown by spectrophotometric quantification. Nevertheless, this ability was lost in cells treated with BMP-7 (HK2 + BMP-7, Fig. 5B) or overexpressing BMP-7 (HK2T, Fig. 5C). When BMP-7 overexpression was blunted (Fig. 5D, HK2T + siRNA), the invasive ability in response to Ox, CaOx and TGF-β1 was recovered.


Calcium oxalate crystals and oxalate induce an epithelial-to-mesenchymal transition in the proximal tubular epithelial cells: Contribution to oxalate kidney injury
As a result of loss of cell adhesion and morphological changes from cuboid to fusiform form, these cells acquire the ability to invade (transwell chamber assays) and move in the extracellular matrix.The HK2-WT (A) and HK2T + siRNA (D) acquired invasive capacity, while HK2 cells receiving BMP-7 (HK2 + BMP-7) (B), and HK2 cells overexpressing BMP-7 (HK2T) (C) behaved similarly the control (CTL) situation even in cell culture exposed to potassium oxalate (Ox), calcium oxalate (CaOx) and TGF-β1. Results were expressed as optical density (OD) and (*) groups were significantly different from the control situation (p < 0.05). N = 15 for each group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384284&req=5

f5: As a result of loss of cell adhesion and morphological changes from cuboid to fusiform form, these cells acquire the ability to invade (transwell chamber assays) and move in the extracellular matrix.The HK2-WT (A) and HK2T + siRNA (D) acquired invasive capacity, while HK2 cells receiving BMP-7 (HK2 + BMP-7) (B), and HK2 cells overexpressing BMP-7 (HK2T) (C) behaved similarly the control (CTL) situation even in cell culture exposed to potassium oxalate (Ox), calcium oxalate (CaOx) and TGF-β1. Results were expressed as optical density (OD) and (*) groups were significantly different from the control situation (p < 0.05). N = 15 for each group.
Mentions: To determine whether HK2-WT cells exposed to Ox, CaOx, or TGF-β1 became more active in the invasion than in the control cells, we evaluated the invasive ability of cells using a transwell chamber assay. As shown in Fig. 5, Ox, CaOx, and TGF-β1 stimulated the HK2-WT (Fig. 5A) to migrate (cells were fixed and stained with Toluidine Blue) faster than the control cells, as shown by spectrophotometric quantification. Nevertheless, this ability was lost in cells treated with BMP-7 (HK2 + BMP-7, Fig. 5B) or overexpressing BMP-7 (HK2T, Fig. 5C). When BMP-7 overexpression was blunted (Fig. 5D, HK2T + siRNA), the invasive ability in response to Ox, CaOx and TGF-β1 was recovered.

View Article: PubMed Central - PubMed

ABSTRACT

TGF-&beta;1 is the main mediator of epithelial-to-mesenchymal transition (EMT). Hyperoxaluria induces crystalluria, interstitial fibrosis, and progressive renal failure. This study analyzed whether hyperoxaluria is associated with TGF-&beta;1 production and kidney fibrosis in mice and if oxalate or calcium oxalate (CaOx) could induce EMT in proximal tubule cells (HK2) and therefore contribute to the fibrotic process. Hyperoxaluria was induced by adding hydroxyproline and ethylene glycol to the mice&rsquo;s drinking water for up to 60 days. Renal function and oxalate and urinary crystals were evaluated. Kidney collagen production and TGF-&beta;1 expression were assessed. EMT was analyzed in vitro according to TGF-&beta;1 production, phenotypic characterization, invasion, cell migration, gene and protein expression of epithelial and mesenchymal markers. Hyperoxaluric mice showed a decrease in renal function and an increase in CaOx crystals and Ox urinary excretion. The deposition of collagen in the renal interstitium was observed. HK2 cells stimulated with Ox and CaOx exhibited a decreased expression of epithelial as well as increased expression mesenchymal markers; these cells presented mesenchymal phenotypic changes, migration, invasiveness capability and TGF-&beta;1 production, characterizing EMT. Treatment with BMP-7 or its overexpression in HK2 cells was effective at preventing it. This mechanism may contribute to the fibrosis observed in hyperoxaluria.

No MeSH data available.


Related in: MedlinePlus