Animals ; Calpain ; metabolism ; Epithelial Cells ; metabolism ; Kidney ; cytology ; Kidney Tubules ; cytology ; metabolism ; Rats ; Reperfusion Injury ; metabolism

OBJECTIVETo investigate the expression and function of PKD1 and PKD2 in different kidney tissues and cell lines.

METHODSImmunoprecipitation, Western blotting, In situ hybridization and immunohistochemical staining methods were used to observe the expression of PKD1 mRNA and PKD2 mRNA and their protein abundance in different kidney tissues and cell lines.

RESULTSCoordinate expressions of PKD1 and PKD2 were found in all kidney tissues and cell lines. Distribution of PKD1 mRNA and PKD2 mRNA and their protein polycystin-1 and polycystin-2 in normal human adult kidney tissue were mainly expressed in the medullary collecting ducts and distal tubules. Positive staining was also found in the majority of cyst-lining epithelial cells of PKD1 cystic kidney tissue, PKD1 cyst-lining epithelia cell line and LLC-PK1. The expression level of them in cystic epithelia of ADPKD kidney tissue was much higher than that in adult renal tubules (P < 0.01).

CONCLUSIONSSimilar expression pattern of PKD1 and PKD2 and their different tissue distribution in different kidney tissues show that the molecular mutuality of PC-1 and PC-2 might be the base of their functional correlation. Polycystins might play an important role in the maintenance of tubular architecture.

Adult ; Animals ; Cell Line ; Gene Expression ; Humans ; Kidney ; metabolism ; Kidney Tubules, Collecting ; metabolism ; Kidney Tubules, Distal ; metabolism ; Kidney Tubules, Proximal ; cytology ; Polycystic Kidney, Autosomal Dominant ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Swine ; TRPP Cation Channels ; metabolism

Animals ; Epithelial Cells ; cytology ; drug effects ; Humans ; Kidney Tubules ; cytology ; drug effects ; Oleanolic Acid ; analogs & derivatives ; pharmacology ; Podocytes ; drug effects

Animals ; Epithelial-Mesenchymal Transition ; Fibrosis ; Kidney ; pathology ; Kidney Tubules ; cytology ; Male ; Rats ; Rats, Sprague-Dawley ; Ureteral Obstruction ; pathology

Phospholipase D (PLD) is an enzyme involved in signal transduction and widely distributed in mammalian cells. The signal transduction pathways and role for phospholipid metabolism during hormonal response in cortical collecting duct remain partly undefined. It has been reported that dexamethasone increases transepithelial transport in M-1 cells that are derived from the mouse cortical collecting duct. We investigated the expression and activity of PLD in M-1 cells. Basal PLD activity of M-1 cells cultured in the presence of dexamethasone (5 microM) was higher than in the absence of dexamethasone. Dexamethasone and ATP activated PLD in M-1 cells but phorbol ester did not stimulate PLD activity. Vasopressin, bradykinin, dibutyryl cyclic AMP, and ionomycin were ineffective in activating PLD of the cells. The PLD2 isotype was detected by immunoprecipitation but PLD1 was not detected in M-1 cells. Addition of GTPgammaS and ADP-ribosylation factor or phosphatidylinositiol 4,5-bisphosphate to digitonin-permeabilized cells did not augment PLD activity. In intact cells PLD activity was increased by sodium oleate but there was no significant change between dexamethasone treated- and untreated cells by oleate. These results suggest that at least two types of PLD are present in M-1 cells and PLD plays a role in the corticosteroid-mediated response of cortical collecting duct cells.
Animal ; Biological Transport/drug effects ; Dexamethasone/pharmacology* ; Dose-Response Relationship, Drug ; Drug Interactions ; Glycerophospholipids/analysis ; Isoenzymes/drug effects ; Kidney Cortex/cytology ; Kidney Tubules, Collecting/drug effects* ; Kidney Tubules, Collecting/cytology ; Mice ; Mice, Transgenic ; Oleic Acid/pharmacology ; Phospholipase D/drug effects*

The purpose of this study was to determine the expression and distribution of band 3 in the collecting duct and connecting tubules of the kidney of the marmoset monkey (Callithrix jacchus), and to establish whether band 3 is expressed in type A intercalated cells. The intracellular localization of band 3 in the different populations of intercalated cells was determined by double-labeling immunohistochemistry. Immunohistochemical microscopy demonstrated that band 3 is located in the basolateral plasma membranes of all type A intercalated cells in the connecting tubule (CNT), cortical collecting duct (CCD), and outer medullary collecting duct (OMCD) of the marmoset. However, type B intercalated cells and non-A/ non-B intercalated cells did not show band 3 labeling. Electron microscopy of the CNT, CCD and OMCD confirmed the light microscopic observation of the basolateral plasma membrane staining for band 3 in a subpopulation of interacted cells. Basolateral staining was seen on the plasma membrane and small coated vesicles in the perinuclear structure, some of which were located in the Golgi region. In addition, there was no labeling of band 3 in the mitochondria of the CNT, CCD and in OMCD cells. The intensity of the immunostaining of the basolateral membrane was less in the CNT than in the CCD and OMCD. In contrast, band 3 immunoreactivity was greater in the intracellular vesicles of the CNT. From these results, we suggest that the basolateral Cl-/HCO3- exchanger in the monkey kidney is in a more active state in the collecting duct than in the CNT.
Animals ; Anion Exchange Protein 1, Erythrocyte/*metabolism ; Callithrix/*metabolism ; Gene Expression Profiling/veterinary ; *Gene Expression Regulation ; Immunohistochemistry/veterinary ; Kidney Tubules/cytology/physiology/ultrastructure ; Kidney Tubules, Collecting/cytology/*metabolism/ultrastructure ; Male ; Microscopy, Electron, Transmission/veterinary

Phosphorylation of beta-catenin tyrosine residue 654 plays an important role in the epithelial to myofibroblast transition (EMT). Introducing mimic peptide of tyrosine residue 654 domain of beta-catenin into cells may influence phosphorylation of beta-catenin tyrosine residue 654. To deliver this mimic peptide into renal epithelial cells, we used penetratin as a vector, which is a novel cell permeable peptide, to deliver hydrophilic molecules into cells. A tyrosine 654 residue domain mimic peptide of beta-catenin (PM) with fused penetratin was constructed, purified and then detected for the penetration of the mimic peptide into human renal tubular epithelial cells (HK-2). The results showed that purified fusion mimic peptide could efficiently and rapidly translocate into human renal tubular epithelial cells. It is concluded that a cell-permeable peptides mimic of tyrosine residue 654 domain of beta-catenin was successfully obtained, which may provide a useful reagent for interfering the human renal tubular epithelial-mesenchymal transition.
Carrier Proteins/*metabolism ; Epithelial Cells/cytology ; Epithelial Cells/*metabolism ; Fibroblasts/cytology ; Fibroblasts/metabolism ; Kidney Tubules/*cytology ; Peptides/metabolism ; Permeability ; Phosphorylation ; Tyrosine/*metabolism ; beta Catenin/*metabolism

OBJECTIVETo explore the toxic effects of lead acetate on the apoptosis and ultrastructure of human renal tubular epithelial cells (HK-2).

METHODSAfter HK-2 cells were exposed to 5, 10 and 20 µmol/L lead acetate for 24 h, the morphological changes of HK-2 cells were observed by Hochest 33342-PI staining, and the ultrastructure changes of HK-2 cells were examined under a electron microscope, LDH activity and MDA content in supernatant of HK-2 cellular culture were detected by spectrophotometer, DNA damage of HK-2 was determined by DNA ladder and the apoptotic rates of HK-2 cells were measured by flow cytometry.

RESULTSThe morphological changes of apoptotic HK-2 cells in exposure group were observed by Hochest 33342-PI staining. The cytoplasm vacuoles, karyopycnosis, nuclear membrane vague and apoptotic bodies in HK-2 cells of exposure group were found under electron microscopy. LDH activity and MDA contents in exposure group increased significantly, as compared to control group (P < 0.01). The results of DNA Ladder showed that DNA damage of HK-2 cells in exposure group appeared. The apoptotic rates of HK-2 cells exposed to 5, 10, 20 µmol/L lead acetate were 14.16% ± 2.94%, 19.45% ± 2.73%, 25.01% ± 3.97%, respectively, which were significantly higher than that (5.81% ± 2.18%) in control group (P < 0.05).

CONCLUSIONLead acetate could remarkably induce the apoptosis of HK-2 cells and affect the kidney.

Apoptosis ; drug effects ; Cell Line ; Epithelial Cells ; cytology ; drug effects ; ultrastructure ; Humans ; Kidney Tubules, Proximal ; cytology ; drug effects ; ultrastructure ; Organometallic Compounds ; toxicity

OBJECTIVETo study effects of Yishen Kangxian Compound (YKC) and benazepril containing serums on HK-2 cells (human renal proximal tubule epithelial cells) in the process of renal tubular epithelial cells to mesenchymal myofibroblasts transdifferentiation (TEMT) by gene chip.

METHODSYKC and benazepril containing serums were prepared. Their inhibitory effects on HK-2 cells in the transforming growth factor-beta1 (TGF-beta1)-induced TEMT process were observed. HK-2 cells were randomly divided into four groups, i.e., the blank control group, the model group, the benazepril group, and the YKC group. The gross RNAs were extracted and purified by taking advantage of the HumanHT-12 v4 of IlluminaBeadChip. Differentially expressed genes were obtained after they were reversely transcribed to cDNA, incorporating biotin labeling probe, hybridized with GeneChip, picture signals of fluorescence in gene array scanned and compared with differential genes by computer analysis.

RESULTSDifferentially expressed genes were successfully identified by gene chip. Compared with the model group, there were 227 differentially expressed genes in the benazepril group, including 118 up-regulated genes and 109 downregulated genes. Compared with the model group, there were 97 differentially expressed genes in the YKC group, including 69 up-regulated genes and 28 down-regulated genes. The Gene Ontology (GO) analysis indicated that YKC was more actively involved in the regulatory process than benazepril in terms of cell damage, apoptosis, growth, NF-KB, protein kinase, neuron, and blood vessel growth.

CONCLUSIONSYKC and benazepril could inhibit the TEMT process of HK-2 cells. But YKC also had taken part in cell damage, apoptosis, growth,and more pathways of early stage TEMT.

Cell Line ; Cell Transdifferentiation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Epithelial Cells ; cytology ; drug effects ; Genomics ; Humans ; Kidney Tubules, Proximal ; cytology ; pathology

OBJECTIVETo observe the effect of bone morphogenetic protein-7 (BMP-7) on aristolchic acid induced renal tubular epithelial cell trans-differentiation to look for new therapeutic approach for aristolchic acid nephropathy (AAN).

METHODSIn vitro cultured human proximal renal tubular epithelial cell line HK-2 cells were treated with different concentrations of BMP-7 (75 ng/mL, 150 ng/mL and 300 ng/mL) after trans-differentiation of the cells was induced by AA (10 microg/mL). Levels of alpha-SMA mRNA and protein expressions were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively.

RESULTSBMP-7 reversed the AA inducing alpha-SMA expressions in HK-2 cells in a dose-dependent manner.

CONCLUSIONBMP-7 can inhibit the trans-differentiation of human renal tubular epithelial cell induced by AA, thereby might be a new potential drug for AAN prevention and treatment.

Actins ; metabolism ; Aristolochic Acids ; adverse effects ; Bone Morphogenetic Protein 7 ; pharmacology ; Cell Line ; Cell Transdifferentiation ; drug effects ; Epithelial Cells ; cytology ; Humans ; Kidney Tubules, Proximal ; cytology