Abstract
Mercury produces acute renal failure in experimental animal models, but the mechanism of tubular injury has not completely been clarified. There is an increased interest in the role of apoptosis in the pathogenesis of renal diseases that result primarily from injury to renal tubular epithelial cells. However, detailed studies of morpho-functional alterations induced by mercuric chloride in kidney cell lines are scarce. This work characterizes these alterations in OK cell cultures. Morphological alterations were profiled using light microscopy, transmission electron microscopy, and confocal microscopy, as well as mitochondrial functional assays in the cells exposed to low concentrations of HgCl2. At concentrations of 1 and 10 μM of HgCl2 there were no morphological or ultrastructural alterations, but the mitochondrial function (MTT assay) and intracellular ATP content was increased, especially at longer incubation times (6 and 9 h). At 15 μM HgCl2, both the mitochondrial activity and the endogenous ATP decreased significantly. At this concentration the OK cells rounded up, had increased number of cytoplasmic vacuoles, and detached from the cell monolayer. At 15 μM HgCl2 ultrastructural changes were characterized by dispersion of the ribosomes, dilatation of the cisterns of the rough endoplasmic reticulum, increase of number of cytoplasmic vacuoles, chromatin condensation, invaginations of the nuclear envelope, presence of cytoplasmic inclusion bodies, and alterations in the size and morphology of mitochondria. At 15 μM HgCl2 apoptotic signs included membrane blebbing, chromatin condensation, mitochondrial alterations, apoptotic bodies, and nuclear envelope rupture. Using confocal microscopy and the mitochondrial specific dye MitoTracker Red, it was possible to establish qualitative changes induced by mercury on the mitochondrial membrane potential after incubation of the cells for 6 and 9 h with 15 μM HgCl2. This effect was not observed at short times (1 and 3 h) with this same concentration, neither with 1 and 10 μM HgCl2 in all the studied times. Taken together, these findings indicate that low concentrations of HgCl2 induce apoptosis by inhibiting mitochondrial function, and the OK cell line may be considered a useful tool for the study of programmed cell death involving mercurial species and other heavy metals.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 111-121 |
| Number of pages | 11 |
| Journal | Toxicology |
| Volume | 210 |
| Issue number | 2-3 |
| DOIs | |
| State | Published - Jun 1 2005 |
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Keywords
- Apoptosis
- Mercuric chloride
- Nephrotoxicity
- OK cells
- Ultrastructure
ASJC Scopus subject areas
- Toxicology
Cite this
Morphologic and functional alterations induced by low doses of mercuric chloride in the kidney OK cell line : Ultrastructural evidence for an apoptotic mechanism of damage. / Carranza-Rosales, Pilar; Said-Fernández, Salvador; Sepúlveda-Saavedra, Julio; Cruz-Vega, Delia E.; Gandolfi, A Jay.
In: Toxicology, Vol. 210, No. 2-3, 01.06.2005, p. 111-121.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Morphologic and functional alterations induced by low doses of mercuric chloride in the kidney OK cell line
T2 - Ultrastructural evidence for an apoptotic mechanism of damage
AU - Carranza-Rosales, Pilar
AU - Said-Fernández, Salvador
AU - Sepúlveda-Saavedra, Julio
AU - Cruz-Vega, Delia E.
AU - Gandolfi, A Jay
PY - 2005/6/1
Y1 - 2005/6/1
N2 - Mercury produces acute renal failure in experimental animal models, but the mechanism of tubular injury has not completely been clarified. There is an increased interest in the role of apoptosis in the pathogenesis of renal diseases that result primarily from injury to renal tubular epithelial cells. However, detailed studies of morpho-functional alterations induced by mercuric chloride in kidney cell lines are scarce. This work characterizes these alterations in OK cell cultures. Morphological alterations were profiled using light microscopy, transmission electron microscopy, and confocal microscopy, as well as mitochondrial functional assays in the cells exposed to low concentrations of HgCl2. At concentrations of 1 and 10 μM of HgCl2 there were no morphological or ultrastructural alterations, but the mitochondrial function (MTT assay) and intracellular ATP content was increased, especially at longer incubation times (6 and 9 h). At 15 μM HgCl2, both the mitochondrial activity and the endogenous ATP decreased significantly. At this concentration the OK cells rounded up, had increased number of cytoplasmic vacuoles, and detached from the cell monolayer. At 15 μM HgCl2 ultrastructural changes were characterized by dispersion of the ribosomes, dilatation of the cisterns of the rough endoplasmic reticulum, increase of number of cytoplasmic vacuoles, chromatin condensation, invaginations of the nuclear envelope, presence of cytoplasmic inclusion bodies, and alterations in the size and morphology of mitochondria. At 15 μM HgCl2 apoptotic signs included membrane blebbing, chromatin condensation, mitochondrial alterations, apoptotic bodies, and nuclear envelope rupture. Using confocal microscopy and the mitochondrial specific dye MitoTracker Red, it was possible to establish qualitative changes induced by mercury on the mitochondrial membrane potential after incubation of the cells for 6 and 9 h with 15 μM HgCl2. This effect was not observed at short times (1 and 3 h) with this same concentration, neither with 1 and 10 μM HgCl2 in all the studied times. Taken together, these findings indicate that low concentrations of HgCl2 induce apoptosis by inhibiting mitochondrial function, and the OK cell line may be considered a useful tool for the study of programmed cell death involving mercurial species and other heavy metals.
AB - Mercury produces acute renal failure in experimental animal models, but the mechanism of tubular injury has not completely been clarified. There is an increased interest in the role of apoptosis in the pathogenesis of renal diseases that result primarily from injury to renal tubular epithelial cells. However, detailed studies of morpho-functional alterations induced by mercuric chloride in kidney cell lines are scarce. This work characterizes these alterations in OK cell cultures. Morphological alterations were profiled using light microscopy, transmission electron microscopy, and confocal microscopy, as well as mitochondrial functional assays in the cells exposed to low concentrations of HgCl2. At concentrations of 1 and 10 μM of HgCl2 there were no morphological or ultrastructural alterations, but the mitochondrial function (MTT assay) and intracellular ATP content was increased, especially at longer incubation times (6 and 9 h). At 15 μM HgCl2, both the mitochondrial activity and the endogenous ATP decreased significantly. At this concentration the OK cells rounded up, had increased number of cytoplasmic vacuoles, and detached from the cell monolayer. At 15 μM HgCl2 ultrastructural changes were characterized by dispersion of the ribosomes, dilatation of the cisterns of the rough endoplasmic reticulum, increase of number of cytoplasmic vacuoles, chromatin condensation, invaginations of the nuclear envelope, presence of cytoplasmic inclusion bodies, and alterations in the size and morphology of mitochondria. At 15 μM HgCl2 apoptotic signs included membrane blebbing, chromatin condensation, mitochondrial alterations, apoptotic bodies, and nuclear envelope rupture. Using confocal microscopy and the mitochondrial specific dye MitoTracker Red, it was possible to establish qualitative changes induced by mercury on the mitochondrial membrane potential after incubation of the cells for 6 and 9 h with 15 μM HgCl2. This effect was not observed at short times (1 and 3 h) with this same concentration, neither with 1 and 10 μM HgCl2 in all the studied times. Taken together, these findings indicate that low concentrations of HgCl2 induce apoptosis by inhibiting mitochondrial function, and the OK cell line may be considered a useful tool for the study of programmed cell death involving mercurial species and other heavy metals.
KW - Apoptosis
KW - Mercuric chloride
KW - Nephrotoxicity
KW - OK cells
KW - Ultrastructure
UR - http://www.scopus.com/inward/record.url?scp=17144399886&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=17144399886&partnerID=8YFLogxK
U2 - 10.1016/j.tox.2005.01.006
DO - 10.1016/j.tox.2005.01.006
M3 - Article
VL - 210
SP - 111
EP - 121
JO - Toxicology
JF - Toxicology
SN - 0300-483X
IS - 2-3
ER -