• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.2
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• pp.92-98
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• 2000

Mesangial cell has several key roles in thee control of glomerular function: it partocipates in the regulation of glomerular filtration rate, macromolecular clearance, and as both a source and target of numerous hormones and autocrines. Many of these insights into mesangial cell function have been obtained by studying mesangial cells in culture. However, no suitble cell lines have established yet. We here reported the immortalization of rat kidney glomeruar mesangial cell by transfection of E6 and E7 genes of human papillomavirus type 16 (HPV-16) via electroporation and lipofection. The reslts showed that only electroporation could transfect the genes to mesangial cells and the transfected cells maintained the viability for longer than 6 months. Fluorescence microscopic observation showed that cellular contractility and phagocytosis, which are the two main phenotypes of mesangial cells with rat glomerular epithelial cells showed that the growth of mesangial dells was suppressed by epithelial cell, but the growth of epithelisl cells was enhanced by mesangial cells. Moreover, Such results may imply that the glomerular cell-cell interaction plays an important role in the regulation of cell proliferation and differentiation.

• Applied Microscopy
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• v.44 no.4
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• pp.117-122
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• 2014

We previously have reported that periglomerular calponin expression of the glomerulosclerotic glomeruli in the chronic nephropathy. To investigate the role of calponin during glomerulosclerosis, we examined the detailed localization pattern of calponin in chronic nephropathy rat model using serial morphometric analysis. Male Sprague-Dawley rats were used, and chronic nephropathy models were established at 8 and 12 weeks after single intraperitoneal injection of adriamycin (10 mg/kg body weight; n=5). In nephropathy models, 16.3% (8 weeks) and 23.4% (12 weeks) glomeruli showed calponin-positivity at glomerular area. In all these glomeruli, showing various sclerotic changes, calponin-immunoreactivities were present only both the glomerular parietal epithelial cells (PECs) and periglomerular myofibroblasts (PMFs). However, in the glomeruli with weak calponin-positive, immunoreactivity was mostly detected in PECs, suggesting that calponin may be expressed in PECs earlier than in PMFs in the glomerulosclerotic change. Some calponin-positive PECs invaded glomerular tuft with loop-shaped projection, and around this projection, nestin expression of glomerular tuft were much reduced. These results suggested that calponin-positive PECs may play a key role in the development of glomerulosclerosis, and direct contact with PECs and glomerular tuft may be more important to degenerative changes of glomeruli.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.303-310
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• 2002

Cell therapy applied to wound healing or tissue regeneration presents a revolutionary realm to which principles of gene engineering and delivery may be applied. One promising application is the transplantation of cells into the wounded tissue to help the tissue repair. However, when cells are transplanted from in vitro to in vivo, immune rejection occurs due to the immune response triggered by the activation of T-cell, and the transplanted cells are destroyed by the attack of activated T-cell and lose their function. Immune suppressant such as FK506 is commonly used to suppress immune rejection during transplantation. However, such kind of immune suppressants not only suppresses immune rejection in the periphery of transplanted cells but also suppresses whole immune response system against pathogenic infection. In order to solve this problem, we developed a method to protect the desired cells from immune rejection without impairing whole immune system during cell transplantation. Previously, we reported the success of constructing glomerular epithelial cells for removal of immune complex, in which complement receptor of type 1 (CR1) was over-expressed on the membrane of renal glomerular epithelial cells and could bind immune complex of DNA/anti-DNA-antibody to remove immune complex through phagocy-tosis [1]. Attempting to apply the CR1-expressing cells to cell therapy and evade immune rejection during cell transplantation, we constructed three plasmids containing genes encoding a soluble fusion protein of cytolytic T lymphocyte associated antigen-4 (CTLA4Ig) and an enhanced green fluorescent protein (EGFP). The plasmids were transfected to the above-mentioned glomerular epithelial cells to express both genes simultaneously. Using the clone cells for cell transplantation showed that mice with autoimmune disease prolonged their life significantly as compared with the control mice, and two injections of the cells at the beginning of two weeks resulted in remarkable survivability, whereas it requires half a year and 50 administrations of proteins purified from the same amount of cells to achieve the same effect.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.8-17
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• 2006

Purpose : We describe the changes of rat glomerular epithelial cells when exposed to high levels of glucose and advanced glycosylation endproducts(AGE) in the in vitro diabetic condition. We expect morphological alteration of glomerular epithelial cells and permeability changes experimentally and we may correlate the results with a mechanism of proteinuria in DM. Methods : We made 0.2 M glucose-6-phsphate solution mixed with PBS(pH 7.4) containing 50 mg/mL BSA and pretense inhibitor for preparation of AGE. As control, we used BSA. We manufactured and symbolized five culture dishes as follows; B5 - normal glucose(5 mM) + BSA, B30 - high glucose(30 mM) + BSA, A5 - normal glucose(5 mM) + AGE, A30 - high glucose(30 mM) + AGE, A/B 25 - normal glucose(5 mM) + 25 mM of mannitol(osmotic control). After the incubation period of both two days and seven days, we measured the amount of heparan sulfate proteoglycan(HSPG) in each dish by ELISA and compared them with the B5 dish at 2nd and 7th incubation days. We observed the morphological changes of epithelial cells in each culture dish using scanning electron microscopy(SEM). We tried the permeability assay of glomerular epithelial cells using cellulose semi-permeable membrane measuring the amount of filtered BSA through the apical chamber for 2 hours by sandwich ELISA. Results : On the 2nd incubation day, there was no significant difference in the amount of HSPG between the 5 culture dishes. But on the 7th incubation day, the amount of HSPG increased by 10% compared with the B5 dish on the 2nd day except the A30 dish(P<0.05). Compared with the B5 dish on the 7th day the amount of HSPG in A30 and B30 dish decreased to 77.8% and 95.3% of baseline, respectively(P>0.05). In the osmotic control group (A/B 25) no significant correlation was observed. On the SEM, we could see the separated intercellular junction and fused microvilli of glomerular epithelial cells in the culture dishes where AGE was added. The permeability of BSA increased by 19% only in the A30 dish on the 7th day compared with B5 dish on the 7th day in the permeability assay(P<0.05). Conclusion: We observed not only the role of a high level of glucose and AGE in decreasing the production of HSPG of glomerular epithelial cells in vitro, but also their additive effect. However, the role of AGE is greater than that of glucose. These results seems to correlate with the defects in charge selective barrier. Morphological changes of the disruption of intercellular junction and fused microvilli of glomerular epithelial cells seem to correlate with the defects in size-selective barrier. Therefore, we can explain the increased permeability of glomerular epithelial units in the in vitro diabetic condition.

• Childhood Kidney Diseases
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• v.8 no.1
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• pp.1-9
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• 2004

Purpose : Minimal Change Disease (MCD) is the most common primary nephrotic syndrome in children. Some suggested that tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) are involved in the pathogenesis of MCD. Methods : This study was done to see the changes of plasma and urinary $TNF-{\alpha}$, and its effect on the determination of permeability of the glomerular basement membrane (BM) contributed by heparan sulfate proteoglycan (HSPG). Study patients consisted of 19 biopsy-proven MCD children aged 2-15 years old. Both plasma and urinary $TNF-{\alpha}$ were measured. Employing the Millicell system, $TNF-{\alpha}$ was screened for the permeability factors. We examined whether $TNF-{\alpha}$ regulated BM HSPG gene expression and HS synthesis in the glomerular epithelial cells (GECs). Results : Urinary $TNF-{\alpha}$ during relapse was significantly increased when compared with that of during remission or controls ($364.4{\pm}51.2$ vs $155.3{\pm}20.8,\;36.0{\pm}4.5$ ng/mg cr) (P<0.05). However, negative results were obtained in the permeability assay using the Millicell system. No difference was seen in the BM HSPG gene expression and HS synthesis in the GECs. Conclusion : It seems that $TNF-{\alpha}$ may not play a disease-specific role in the pathogenesis of MCD.

• Radiation Oncology Journal
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• v.24 no.1
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• pp.58-66
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• 2006

Purpose: Renal irradiation can lead to the development of radiation nephropathy, and this is characterized by the accumulation of extracellular matrix and final fibrosis. To determine the possible role of the glomerular epithelial cell, the radiation-induced changes in the expression of its genes associated with the extracellular matrix were analyzed. Materials and Methods: Rat glomerular epithelial cells (GEpC) were irradiated with a single dose of 0, 2, 5, 10 and 20 Gy with using 6 MV LINAC (Siemens, USA), and the samples were collected 6, 24, 48 and 72 hours post-irradiation, respectively. Northern blotting, western blotting and zymography were used to measure the expression level of fibronectin (Fn), plasminogen activator inhibitor-1 (Pai-1), matrix metalloproteinases-2, 9 (MMP-2, 9), tissue inhibitor of metalloproteinase-2 (TIMP-2), tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA). Results: Irradiation with a single dose of 10 Gy resulted in a significant increase in Fn mRNA since 24 hours post-irradiation, and a single dose of 5 and 10 Gy significantly increased the Fn immunoreactive protein measured 48 hours post-irradiation. An increase in Pai-1 mRNA and protein was also observed and especially, a single dose of 10 Gy significantly increased the mRNA measured 24 and 48 hours post-irradiation. The active MMP-2 measured 24 hours post-irradiation slightly increased in a dose dependent manner, but this increase did not reach statistical significance. The levels of MMP-9, TIMP-2, t-PA and u-PA appeared unaltered after irradiation. Conclusion: Irradiation of the glomerular epithelial cells altered the expression of genes associated with the extracellular matrix, implying that the glomerular epithelial cell may be involved in the development of radiation nephropathy.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.119-127
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• 2005

Purpose : Podocytes are critical in maintaining the filtration barrier of the glomerulus and are dependent on the integrity of slit diaphragm(SD) proteins including nephrin, p-cadherin, and others. Diabetic proteinuric condition demonstrates defects in SD molecules as well as ultrastructural changes in podocytes. We examined the molecular basis for this alteration of SD molecules especially on P-cadherin as a candidate regulating the modulation of pathogenic changes in the barrier to protein filtration. Methods : To investigate whether high glucose and AGE induce changes in SD, we cultured rat GEpC under normal(5 mM) or high glucose(30 mM) and AGE- or BSA-added conditions and measured the change of P-cadherin expression by Western blotting and RT-PCR. Results : We found that administration of high glucose decreased the P-cadherin production significantly in the presence or absence of AGE by Western blotting. In RT-PCR high glucose with or without AGE also significantly decreased the expression of P-cadherin mRNA compared to those of controls. Such changes were not seen in the osmotic control. Conclusion : We suggest that high glucose with or without AGE suppresses the Production of P-cadherin at the transcriptional level and that these changes nay explain the functional changes of SD in diabetic conditions. (J Korean Soc Pediatr Nephrol 2005;9:119-127)

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.2
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• pp.61-66
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• 2020

Epithelial-mesenchymal transition (EMT) is the process by which epithelial cells lose their characters and acquire the properties of mesenchymal cells. EMT has been reported to exert an essential role in embryonic development. Recently, EMT has emerged as a pivotal mechanism in the metastasis of cancer and the fibrosis of chronic diseases. In particular, EMT is drawing attention as a mechanism of renal fibrosis in chronic kidney diseases such as diabetic nephropathy. In this study, we developed an EMT model by treating TGF-β1 on the podocytes, which play a key role in the renal glomerular filtration. This study explored the effects of Hwanggeum-tang (HGT) recorded in Dongeuibogam as being able to be used for the treatment of Sogal whose concept had been applied to Diabetes Mellitus (DM), on the TGF-β1-induced podocyte EMT. HGT suppressed the expression of vimentin and α-SMA, the EMT marker, in the human podocytes stimulated by TGF-β1. However, HGT increased the expression of ZO-1 and nephrin. Interestingly, HGT selectively inhibited the mTOR pathway rather than the classical Smad pathway. HGT also activated the AMPK signaling. HGT's inhibitory effect on the podocyte EMT through regulation of the mTOR pathway was achieved through the activation of AMPK, which was confirmed by comparison with cells treated with compound C (CC), an inhibitor of AMPK signaling. In conclusion, HGT can be applied to the renal fibrosis by preventing TGF-β1-induced EMT of podocytes through AMPK activation and mTOR inhibition.

• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.54-61
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• 2008

Purpose : This study was designed to clarify the mechanism of proteinuria in nephrotic syndrome patients by using puromycin aminonucleoside (PAN) nephrosis model. Methods : Following administration of various concentrations of PAN and antioxidants we observed the changes of podocyte cytoskeletons in cultured rat glomerular epithelial cells (GEpC) by method of scanning electron microscope, reactive oxyten species (ROS) analysis, permeability assay, confocal microscope, and Western blot assay. Results : PAN not only induced the ultrastructural changes of GEpC, such as shortening and fusion of microvilli, but also separated the intercellular gaps and linear ZO-1. PAN induced oxidative stresses in time and dose dependent manners and increases of intercellular permeability in anti-oxidants inhibitable manners. High concentration of PAN induced not only actin polymerization and disorganization, but also the conglomerulation and internal dislocation of ${\alpha}-actinin$ protein. The intensities of fluorescences of ZO-1 protein were diminished and internalized by PAN in a dose-dependent manner, which were inhibited by anti anti-oxidants. Conclusion : PAN induced the changes of podocytes cytoskeleton and junctional barriers by way of increasing ROS in GEpC that resulted in increasing their permeability in a antioxidatn-inhibitable manner. Glomerular hyperpermeability induced by PAN mediateing through oxidative stresses is thought to take part in the mechanism of proteinuria in nephrotic syndrome.

• Clinical and Experimental Pediatrics
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• v.55 no.10
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• pp.371-376
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• 2012

Purpose: Puromycin aminonucleoside (PAN) specifically injures podocytes, leading to foot process effacement, actin cytoskeleton disorganization, and abnormal distribution of slit diaphragm proteins. p130Cas is a docking protein connecting F-actin fibers to the glomerular basement membrane (GBM) and adapter proteins in glomerular epithelial cells (GEpCs; podocytes). We investigated the changes in the p130Cas expression level in the PAN-induced pathological changes of podocytes in vitro. Methods: We observed changes in the p130Cas expression in cultured rat GEpCs and mouse podocytes treated with various concentrations of PAN and antioxidants, including probucol, epigallocatechin gallate (EGCG), and vitamin C. The changes in the p130Cas expression level were analyzed using confocal immunofluorescence imaging, Western blotting, and polymerase chain reaction. Results: In the immunofluorescence study, p130Cas showed a diffuse cytoplasmic distribution with accumulation at distinct sites visible as short stripes and colocalized with P-cadherin. The fluorescences of the p130Cas protein were internalized and became granular by PAN administration in a dose-dependent manner, which had been restored by antioxidants, EGCG and vitamin C. PAN also decreased the protein and mRNA expression levels of p130Cas at high doses and in a longer exposed duration, which had been also reversed by antioxidants. Conclusion: These findings suggest that PAN modulates the quantitative and distributional changes of podocyte p130Cas through oxidative stress resulting in podocyte dysfunction.