Expression of ciliary neurotrophic factor and its receptor in experimental obstructive nephropathy / 대한해부학회지

Ciliary neurotrophic factor (CNTF) is well known as a growth/survival factor of neuronal tissue. We investigated the expression of CNTF and its specific receptor alpha (CNTFRalpha) in a unilateral ureteral obstruction (UUO) model. Complete UUO was produced by left ureteral ligation in Sprague-Dawley rats. The animals were sacrificed on days 1, 3, 5, 7, 14, 21, and 28 after UUO. The kidneys were fixed, and processed for both immunohistochemistry and in situ hybridization. CNTF immunoreactivity in sham-operated kidneys was observed only in the descending thin limb (DTL) of the loop of Henle. In UUO kidneys, CNTF expression was induced in the S3 segment (S3s) of the proximal tubule from day 1, and progressively expanded into the entire S3s and a part of the convoluted proximal tubules, distal tubules (DT), and glomerular parietal epithelium up to day 7. Upregulated CNTF expression was maintained to day 28. From day 14, the inner medullary collecting duct showed weak CNTF immunoreactivity. The CNTFRalpha mRNA hybridization signal in sham-operated kidneys was weakly detected in the DTL, DT, medullary thick ascending limb, and in a few S3s cells. After UUO, CNTFRalpha mRNA expression increased progressively in both the renal cortex and the medulla up to day 7 and increased expression was maintained until day 28. The results suggest that the S3s may be the principal induction site for CNTF in response to renal injury, and that CNTF may play a role in chronic renal injury.

Expression of calponin in periglomerular myofibroblasts of rat kidney with experimental chronic injuries / 대한해부학회지

Our previous research demonstrated that calponin-immunoreactivity was localized in myofibroblasts of the periglomerular region of human kidney specimens obtained at the time of transplantation from organ recipients. In the present study we examined calponin expression in two chronic nephropathy models, puromycin aminonucleoside (PAN) nephropathy and subtotal nephrectomy (SNx), to investigate the role of calponin in chronic renal injury. Male Sprague-Dawley rats were used, and both nephropathy models were established at 1, 2, 4, and 8 weeks after surgery. There were no periglomerular calponin-positive cells in sham, PAN 1 and 2 week, and SNx 1, 2, and 4 week groups. In SNx 8 week and PAN 4 and 8 week groups, only a few glomeruli with periglomerular calponin-reactivity, which covered half or a very small part of the periglomerular space, were observed. All glomeruli with periglomerular calponin-reactivity showed sclerotic changes, especially thickening of parietal epithelial cells (PECs). In conjunction with our previous report, this data represents the first documentation of the expression of calponin in renal myofibroblasts. We suggest that interactions between PECs and calponin-positive myofibroblasts may play a key role in the late stage of glomerulosclerosis.

Expression of iNOS and NADPH-diaphroase Reactivity in the Lipopolysaccharide Treated Rat Kidney / 대한해부학회지

Inducible nitric oxide synthase (iNOS) has been known to be involved in the various physiological metabolim and has been attracting topic. However, there are extensive differences in the reports about the localization of iNOS expression. To resolve this discrepancy, we compared immunohistochemical data from four iNOS antibody produced by different company (Chemicon, CH; Sigma, SI; Transduction Laboratories, TL; Upstate, UP), and NADPHdiaphorase (NADPH-d) enzyme-histochemical results using light- and transmission electorn-microscope in the lipopolysaccharide (LPS)-treated rat kidney. Electron microscopical examination revealed two different distribution of the NADPH-d reaction product. In the majority of NADPH-d reaction-positive cells, reaction depositions were restricted to the mitochondia, and in the cells of macula densa, descending thin limb (DTL), capsular epithelium (CE) and interstitial wandering cells (WC), NADPH-d positivities were found in the cytoplasm. In immunohistochemical results from LPStreated animal, DTL, CE and WC were positively stained with TL and UP antibodies but with CH and SI antibodies. We conclude that NADPH-d histochemistry may be usefull for identifing the iNOS-positive cells morphologically.

Expression of Nestin in the Rat Kidney with Ischemia-Reperfusion Injury / 대한해부학회지

Nestin, a type VI intermediate filament,is a marker for stem cells.Although it is expressed abundantly in various organs during development,its expression in adults is restricted to certain types of cells.However,nestin is reinduced in activated cells involved in the regeneration and survival of injured tissues.We investigated the expression of nestin in the ischemia-reperfusion injured rat kidney by immunohistochemistry using anti-nestin antiserum. Kidneys were preserved from normal adults and at 1,3,5,7 and 14 d after ischemia-reperfusion injury,and processed using pre-embedding.In the normal adult kidney,nestin was expressed strongly in the glomerular podocyte.Capillary endothelial cells,except for those of the glomeruli,showed nestin positivity.Fibroblast-like interstitial cells were also nestin positive except for lipid-laden interstitial cells of the inner medulla.After ischemia-reperfusion injury,the renal expression of nestin increased progressively to 7 d and then returned almost to a normal level by 14 d.These changes of nestin expression were attributed mainly to changes in the number and staining intensity of immunostained interstitial cells.The podocytes and endothelial cells showed no change in immunoreactivity throughout any stage in the experimental animals.Interestingly,nestin-positive tubular cells,which were nestin negative in normal kidney,were observed from 3 to 14 d.Nestin immunostained cells were increased in the interstitium around these nestin-positive tubules.These results suggest that nestin is induced in both interstitial cells and regenerating tubular cells and that it can be used as a histological marker related to epithelial-mesenchymal transformation in the injured kidney.

The Expression of Interleukin-6 and Its Receptor in the Developing Rat Kidney / 체질인류학회지

Interleukin-6 (IL-6) and its receptor are presumed to play important roles in the developing nervous system. However, little is known about their potential role(s) in the developing kidney. To investigate this, we have studied the expression of IL-6 and its receptor (IL-6R) in the developing rat kidney. Kidneys from 16- (F16), 18- and 20-day-old (F20) fetuses, 1- (P1), 3- (P3), 7- (P7) and 14-day-old (P14) pups, and adult rats were extracted. Renal expressions of IL-6 and its receptors were examined by immunohistochemistry and in situ hybridization respectively. Il-6 protein already appeared in F16. The early stage of renal development before birth, IL-6 showed strong immunoreactivity in the ureteric bud, metanephric mesenchymal cells (MMC) and developing glomerulus. The expression pattern of IL-6 in nephrogenic zone are very similar even after birth. In matured nephron after birth, IL-6 immunoreactivities were detected in distal tubules strongly, and collecting ducts moderately and thick ascending limb weekly. IL-6R hybridization signals have also already appeared in 16-day old fetal kidney. Before birth, IL-6R mRNAs were expressed in ureteric bud, MMC and developing glomerulus. In the matured nephron after birth, IL-6R mRNA was expressed in the thick ascending limb, distal tubules, collecting ducts and S3 segment of proximal tubule. These results suggest that IL-6 and its receptor may be involved in regulation of nephron formation in nephrogenic zone of rat, and play a role in distal nephron including collecting duct after birth.