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

Nephrotoxicity is a major limiting factor in the use of aminoglycoside antibiotics, the mechanisms for which are still speculative. To clarify the mechanisms of renal tubular cell death induced by aminoglycosides, we examined the renal proximal tubule-like cell line, LLC-PK1, after inducing apoptosis through a chronic treatment with gentamicin (GM). Changes in the expression of the Fas were also investigated. On flow cytometric analysis, 5.7 +/- 3.3% of the control cells appeared in a region of decreased forward light scatter and increased side light scatter, where both indices represent the characteristics of apoptotic cell death. Compared to the control, treatment with 10 mM of GM for 15 days significantly increased the proportion of cells in the apoptotic region to 23.9 +/- 8.5%. This finding was supported by electrophoretic analysis of the DNA extracted from the GM-treated cells, where a series of bands corresponding to integer multiples of 180 to 200 base pairs was visualized. However, the 15-day GM treatment did not cause a significant elevation in the expression of the 45 kD Fas protein, the cell surface molecule that stimulates apoptosis, by Western blot analysis. In conclusion, long-term exposure to GM induces apoptosis of the renal tubular epithelial cells, and this process may contribute to some of the aminoglycoside nephrotoxicities. Further studies are needed on the mechanism(s) of apoptosis induced by GM.
Animal ; Antibiotics, Aminoglycoside/toxicity* ; Antigens, CD95/analysis ; Apoptosis/drug effects* ; Cell Line ; Gentamicins/toxicity* ; Kidney Tubules, Proximal/pathology ; Kidney Tubules, Proximal/drug effects* ; Swine

In this study,in-depth systematic evaluation of rat of acute kidney injury(AKI) caused by renal arteriovenous ligation was conducted to better master and apply this model for drug research. Male SD rats of 2-3 months old were employed in this study.The left kidney was removed,and the right kidney received ligation for 40 min and reperfusion for 24 h. Serum creatinine(Crea),urea nitrogen(BUN) and the renal tissue sections were assayed as the basic indicators to evaluate their renal function. The mRNA expression of inflammatory necrosis factors and apoptotic factors was used to evaluate the mechanism of molecular pathophysiological changes. The results showed that the serum Crea and BUN caused by ligation of both renal arteries and veins were significantly higher than those of rats with renal artery ligation. After renal arteriovenous ligation for 40 min and reperfusion for 24 h in rats,the serum Crea of the rats varied from less than 100 μmol·L-1 to more than 430 μmol·L-1. Among them,5 rats showed less than 100 μmol·L-1 serum Crea,20 rats with 100-200 μmol·L-1 serum Crea and 12 rats with more than 430 μmol·L-1. Rats with serum Crea between 300-430 μmol·L-1 accounted for 66.3%(122/184) of the total number of the experiment rats. After 72 h reperfusion,serum Crea in the group of Crea 370-430 μmol·L-1 continued to increase,while the serum Crea in the group of Crea 200-300 μmol·L-1 and the group of Crea 300-370 μmol·L-1 recovered quickly. No matter serum Crea was elevated or decreased,the renal tubules showed pathological changes such as vacuolar degeneration or even necrosis. The mRNA expression levels of Toll-like receptor(TLR4),tumor necrosis factor(TNF-α) and interleukin(IL-6) in renal tissueswere significantly up-regulated,and the effect was most obvious in the group of serum Crea 370-430 μmol·L-1. The study indicated that the model for AKI caused by renal arteriovenous ligation and reperfusion is easy to operate,and the serum Crea and BUN have the characteristics of continuous increase,beneficial to the observation of drug effects. This acute kidney injury is mainly related to the pathophysiological response of inflammatory necrosis.
Acute Kidney Injury ; pathology ; Animals ; Blood Urea Nitrogen ; Creatinine ; blood ; Disease Models, Animal ; Kidney ; pathology ; Kidney Tubules ; pathology ; Ligation ; Male ; Rats ; Rats, Sprague-Dawley ; Renal Artery ; Reperfusion Injury

AIMTo study the relativity of the renocortical lipid peroxidation with renal tubules structure damage in renal injury induced by cisplatin in rats.

METHODSFemale Wistar rats were randomly divided into NS group, CDDP(I) group, CDDP(II) group and CDDP(III) group. All rats were injected via the tail vein with NS or cisplatin and NS qd in five days. The changes in content of Scr, BUN and MDA, the activity of SOD and GSH-Px of the renal cortex were measured. Alkaline phosphatase of renal tubular epithelia was stained by histochemistry and the slices of renal cortex were observed.

RESULTSThe contents of Scr and BUN of CDDP groups were significantly higher than those of NS group (P < 0.01). The content of renocortical MDA was significantly higher than that of NS group (P < 0.05). The activities of renoconical SOD and GSH-Px were lower than those of NS group (P < 0.05). The content of MDA, activities of renocortical SOD and GSH-Px with the content of Scr and BUN were significantly correlative. Alkaline phosphatase of renal tubular epithelia cells was losed largely and renal tubular epithelia cells were denaturative and necrotic partly in sections.

CONCLUSIONThe damage of renal cortex was correlative with its lipid peroxidation. The injury of renal cortex became heavier with cisplatin dose increased.

Animals ; Cisplatin ; adverse effects ; Female ; Kidney Cortex ; drug effects ; physiopathology ; Kidney Tubules ; pathology ; Lipid Peroxidation ; Rats ; Rats, Wistar

OBJECTIVETo observe the expression of caspase-3 in the kidney of a rat model of renal tubular damage induced by endotoxin and hypoxia and explore the mechanism of renal tubular damage.

METHODSTen rats were anesthetized with artificial ventilation and received 2 mg/kg lipopolysaccharide (LPS) injection through the penile vein. The FiO2 was reduced 90 min later from 21% to 5%, and the ventilation was withdrawn after another 90 min. Immediately after ventilation withdrawal, the kidney of the rats were obtained for immunocytochemistry and HE staining.

RESULTSHE staining showed obvious hyperemia in most of the glomeruli, mild swelling of the endothelial and mesangial cells, severe swelling and turbidity in the proximal tubular epithelial cells without obvious changes in most of the distal proximal tubules. A small portion of the interstitial epithelial cells showed swelling and turbidity, and the entire renal interstitium appeared hyperemic but without inflammatory cell infiltration. Immunocytochemistry detected the presence of caspase-3 in the cytoplasm, and most of the distal renal tubule cells were positive for caspase-3, while only occasional cells showed caspase-3 positivity in the proximal tubular epithelial cells. Most of the proximal tubular epithelial and glomerulus cells were negative for caspase-3.

CONCLUSIONSEndotoxin and hypoxia can induce renal damage, particularly in the proximal renal tubule cells, and the distal tubular epithelial cells sustain relatively light damage. Caspase-3 is strongly expressed in the distal renal tubular cells, suggesting that in renal tubular damage induced by endotoxin and hypoxia, cell degeneration, necrosis and apoptosis coexist in the tubular epithelial cells; degeneration and necrosis occur primarily in the proximal tubular epithelial cells, while apoptosis is obvious in the distal renal cells.

Animals ; Caspase 3 ; genetics ; metabolism ; Hypoxia ; chemically induced ; Kidney ; metabolism ; Kidney Tubules ; metabolism ; pathology ; Lipopolysaccharides ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVEGlucocorticoid (GC) is the first therapeutic choice of primary nephrotic syndrome (PNS). The response to GC treatment is an important indicator for the outcome of PNS children. Children with GC-resistant PNS present with incomplete or no response to GC, and may herald the progression to end-stage renal failure. However, the detailed mechanism of GC-resistance or GC-sensitive effect in these PNS children has not been clearly elucidated. The previous study by the authors indicated that there was increased expression of GR beta in PBMCs in GC-resistant children with PNS, and the over expression of GR beta resulted in GC resistance via influencing the ability of GR alpha nuclear translocation. To elucidate the relationship between GR beta expression in renal and in PBMCs and the effect of glucocorticoid on glucocorticoid-resistance children with PNS, the expression of GR alpha and GR beta in renal tissue and in PBMCs were detected by immunohistochemistry.

METHODSForty children with PNS were divided into two groups, GC-resistant group(20) and GC-sensitive group(20), the expression of GR alpha and GR beta in renal intrinsic cells and in PBMCs were measured with the immunohistochemistry technique. A semiquantitative score was used to evaluate the injury degree of the glomeruli and tubulointerstitium.

RESULTSCompared with GC-sensitive group, the glomerular pathologic scores (6.91 +/- 1.98) and renal tubular pathologic scores (7.12 +/- 1.62) in GC- resistant group were significantly different (P < 0.01, respectively). GR alpha expressions of renal tissue and PBMCs were higher in the control group (58.3 +/- 2.6, 59.1 +/- 7.2) than those in the GC-sensitive group (40.2 +/- 7.2 and 36.6 +/- 5.1, P < 0.01, respectively) and GC-resistant group (35.0 +/- 8.2 and 36.4 +/- 6.6, P < 0.01, respectively). GR beta expressions of renal tissue and PBMCs were higher in the GC-resistant group (13.8 +/- 3.0 and 12.1 +/- 4.1) and in the GC-sensitive group (6.5 +/- 1.9 and 5.9 +/- 1.0) than that in control group (2.3 +/- 0.4 and 3.2 +/- 1.1, P < 0.01, respectively). GR beta expressions in renal tissue and PBMCs were higher in the GC-resistant group than that in the GC-sensitive group (P < 0.01). Compared with control group, GR beta expressions in PBMCs and in renal tissue were lower than those in mild renal lesion group (5.4 +/- 2.8, 6.46 +/- 2.50), midmedium renal lesion group (8.7 +/- 2.4 and 11.4 +/- 3.7) and (17.1 +/- 0.4 and 18.7 +/- 0.7) in severe renal lesion group (F = 5.8, 15.6, P < 0.01, respectively). GR beta expression of PBMCs had a positive correlation with GR beta expression of renal intrinsic cells (r = 0.651, P < 0.01). GR beta expressions by PBMCs and renal intrinsic cells were positively correlated with renal pathologic scores (r = 0.579 and 0.623, P < 0.01, respectively).

CONCLUSIONGC-resistant children with PNS were related to the increased GR beta expression in PBMCs and renal intrinsic cells. There was no correlation between the GR alpha expressions in PBMCs and in renal intrinsic cells. Increased GR beta expression might decrease the effect of GC via inhibiting the activity of GR alpha.

Adolescent ; Child ; Child, Preschool ; Drug Resistance ; Female ; Glucocorticoids ; therapeutic use ; Humans ; Kidney Glomerulus ; pathology ; Kidney Tubules ; pathology ; Male ; Nephrotic Syndrome ; drug therapy ; pathology ; Receptors, Glucocorticoid ; analysis

This study was purposed to investigate the relationship between the catalysis of Bence Jones protein (BJP) in urine of patients with multiple myeloma(MM) and toxicity on the renal proximal tubular cells in vitro, and to explore the potential mechanism for the toxicity of BJP to renal impairment in patients with MM. The Michaelis-Menten constant (K(m)) and catalytic constant (k(cat)) of the amidase activity of BJP was calculated by Hanes equation. The LLC-PK1 cells were cultured with different concentration of BJP for 24 h, then proliferation of the cells were determined by MTT method and apoptosis were determined by flow cytometry. The results showed that the BJP from the MM patients with renal impairment significantly inhibited cell proliferation, as compared with that from MM patients without renal impairment. The BJP with higher k(cat) had higher toxicity to LLC-PK1 cells. BJP could induce apoptosis and necrosis of LLC-PK1 cells when reached a certain concentration and this effect enhanced with increase of BJP concentration. It is concluded that the catalysis of BJP and its toxicity to renal tubular epithelial cells has a positive correlation, and toxic effect of BJP on renal tubular epithelial cells results from inhibiting proliferation and inducing apoptosis and necrosis of the cells, which may be one of renal impairment mechanisms in MM patients.
Animals ; Bence Jones Protein ; metabolism ; toxicity ; Catalysis ; Coculture Techniques ; Epithelial Cells ; metabolism ; pathology ; Humans ; Kidney ; metabolism ; pathology ; Kidney Tubules ; cytology ; LLC-PK1 Cells ; Multiple Myeloma ; metabolism ; pathology ; Swine

OBJECTIVETo study the expression of transforming growth factor-beta (TGF-beta) and hepatocyte growth factor (HGF) in kidney tissues of children with primary focal segmental glomerular sclerosis (FSGS) and the possible role of the two growth factors in the development of FSGS.

METHODSKidney specimens were obtained from 33 children with primary FSGS and 7 children with isolated haematuria but without FSGS (control group). Of the 33 children with primary FSGS, 6 children had no renal tubule interstitial pathological damage (Experimental I group) and 27 children had renal tubule interstitial pathological damage (Experimental II group). Expression of TGF-beta and HGF in kidney tissues was ascertained by the immunohistochemical method.

RESULTSTGF-beta and HGF were expressed in the three groups, but there were significant differences among the three groups. The expression of TGF-beta and HGF in the two experiment groups increased significantly compared with that in the control group. The Experimental II group had increased TGF-beta expression but a significantly decreased HGF expression compared with the Experimental I group. The index of tubule interstitial pathological changes was positively correlated with the TGF-beta expression (r=0.763, P<0.01), but negatively correlated with the HGF expression (r=-0.461, P<0.05) in the Experimental II group. There was a negative correlation between TGF-beta and HGF expression in children with primary FSGS (r=-0.425, P<0.05).

CONCLUSIONSThe expression of TGF-beta and HGF in kidney tissues is increased in children with primary FSGS. TGF-beta might be a fibrogenic factor and HGF might be an anti-fibrotic factor in the kidney in primary FSGS.

Child ; Glomerulosclerosis, Focal Segmental ; metabolism ; pathology ; Hepatocyte Growth Factor ; analysis ; Humans ; Immunohistochemistry ; Kidney ; chemistry ; Kidney Tubules ; pathology ; Transforming Growth Factor beta ; analysis

PURPOSE: Recent studies have showed that epithelial-mesenchymal transition (EMT) is a key process of glomerular and tubulointerstitial pathology in many chronic kidney diseases. However, there are no data of EMT in humane autosomal dominant polycystic kidney disease (ADPKD). PATIENTS AND METHODS: ADPKD kidneys (N = 5) with end stage renal disease (ESRD) and control kidneys (N = 4) were analyzed immnunohistochemically. We evaluated alpha-SMA, E-cadherin, vimentin, TGF-beta1 and Smad 2/3 expression in ADPKD and compared them with those in control kidney. These immunohistochemical findings were quantitatively analyzed by computer-assisted image analyzer and positive tubules (%). RESULTS: There were severe interstitial fibrosis and proliferation of alpha-SMA+ myofibroblasts in ADPKD. Cystic tubular epithelial cells in ADPKD lost epithelial marker (E-cadherin) and expressed mesenchymal markers (alpha-SMA, vimentin). There were significant increases of alpha-SMA (34.3 +/- 11.7% vs 0.9 +/- 1.5%), vimentin (19.9 +/- 3.9% vs 3.3 +/- 1.4%), TGF-beta1 (5.42 +/- 2.83% vs 0%) and Smad 2/3 (3.4 +/- 1.7% vs 0.7 +/- 0.6%) in ADPKD kidneys compared with control kidneys evidenced by computer-assisted image analyzer. When we analyze the positive tubules (%), the results were the same as computer-assisted image analyzer. CONCLUSION: Our results showed that the end stage of ADPKD is associated with TGF-beta, Smad 2/3 and markers of EMT. It suggests that TGF-beta mediated EMT has a role in progression of ADPKD.
Aged ; Biological Markers/metabolism ; Cell Division ; Disease Progression ; Epithelial Cells/*pathology ; Female ; Fibrosis ; Humans ; Kidney Glomerulus/pathology ; Kidney Tubules/pathology ; Male ; Mesoderm/*pathology ; Middle Aged ; Polycystic Kidney, Autosomal Dominant/*metabolism/*pathology ; Transforming Growth Factor beta/*metabolism