• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.493-501
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• 1998

The most significant direct role of estrogen in vivo is its ability to elicit receptor-mediated cellular proliferation in mammalian target tissues. However, the mechanism by which exogenously added estrogen causes the neoplastic transformation of renal cortical cells is yet to be uncovered. The present study was designed to evaluate interaction of $17{\beta}-estradiol\;(E_2)$ with epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) on proliferation and $P_i$ uptake in primary cultured rabbit renal proximal tubular cells in phenol red-free, hormonally defined-medium. $[^3H]-thymidine$ incorporation increased markedly by about 133% and 141% more in the presence of $10^{-9}\;and\;10^{-6}\;M\;E_2$, respectively, than that of control. Cell count was 162% and 143% greater in the presence of $10^{-9}\;and\;10^{-6}\;M\;E_2$ , respectively, compared with control. Among all time points examined, there was an increase in $[^3H]-thymidine$ incorporation in the presence of $10^{-9}\;M\;E_2$ at day 9 or 13, respectively. However, $E_2$ ($10^{-9}\;M$) significantly drove up cell count to 160% of that of control at day 13, while it had a slight but statistically insignificant effect at day 9. $E_2-induced$ stimulation of $[^3H]-thymidine$ incorporation was completely reversed by $E_2$ antagonists (progesterone or tamoxifen). $E_2$ ($10^{-9}\;M$) or EGF ($10^{-8}\;M$) significantly stimulated $[^3H]-thymidine$ incorporation by 144% and 154% of control. $E_2$ plus EGF was synergistic on $[^3H]-thymidine$ incorporation (204% of control), while $E_2$ plus IGF-I showed a slight but no significant synergistic effect. Cell number also displayed similar pattern. $E_2$ ($10^{-9}\;M$) significantly stimulated $P_i$ uptake to 134% of control. $E_2$-induced stimulation of $P_i$ uptake was partially reversed by $E_2$ antagonists. EGF or IGF-I ($10^{-8}\;M$) significantly also increased $P_i$ uptake to 132% or 129% of control. $E_2$ plus EGF had synergistic effect on $P_i$ uptake, while $E_2$ plus IGF-I did not. In conclusion, $E_2$ may act not only directly interaction with its receptors but also indirectly as a modulator of EGF in proliferation and $P_i$ uptake of primary cultured rabbit renal proximal tubular cells.

• YAKHAK HOEJI
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• v.38 no.5
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• pp.602-607
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• 1994

Based upon the previous experiments showing that kidney and lung tissues of rat had relatively abundant bradykinin binding sites, we tried to characterize and determine the densities of the bradykinin binding sites in the rabbit kidney tissue and proximal tubular cells under different growing conditions. Among the kidney tissue renal medulla segments showed the highest bradykinin binding sites. To determine which growth factors are to add in the serum free culture medium to express selectively the bradykinin binding sites in the rabbit kidney proximal tubular cells, we tried so called hormone-deletion approach and in here insulin, hydrocortisone, transferrin, triiodothyronine and prostaglandin $E_1$ are examined. By performing receptor binding assay and determination of protein concentrations, we may conclude that the most required hormones in the expression for bradykinin binding sites are insulin and transferrin, and fetal bovine serum is shown to be less effective in this regard.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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• pp.297-304
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• 2016

Klotho functions as a tumor suppressor predominantly expressed in renal tubular cells, the origin of clear cell renal cell carcinoma (ccRCC). Altered expression and/or activity of growth factor receptor have been implicated in ccRCC development. Although Klotho suppresses a tumor progression through growth factor receptor signaling including insulin-like growth factor-1 receptor (IGF-1R), the role of Klotho acting on IGF-1R in ccRCC and its clinical relevance remains obscure. Here, we show that Klotho is favorable prognostic factor for ccRCC and exerts tumor suppressive role for ccRCC through inhibiting IGF-1R signaling. Our data shows the following key findings. First, in tumor tissues, the level of Klotho and IGF-1R expression are low or high, respectively, compared to that of adjacent non-neoplastic parenchyma. Second, the Klotho expression is clearly low in higher grade of ccRCC and is closely associated with clinical outcomes in tumor progression. Third, Klotho suppresses IGF-1-stimulated cell proliferation and migration by inhibiting PI3K/Akt pathway. These results provide compelling evidence supporting that Klotho acting on IGF-1R signaling functions as tumor suppressor in ccRCC and suggest that Klotho is a potential carcinostatis substance for ccRCC.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.2
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• pp.71-77
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• 2007

Cisplatin treatment increases the excretion of inorganic phosphate in vivo. However, the mechanism by which cisplatin reduces phosphate uptake through renal proximal tubular cells has not yet been elucidated. We examined the effect of cisplatin on $Na^+$-dependent phosphate uptake in opossum kidney (OK) cells, an established proximal tubular cell line. Cells were exposed to cisplatin for an appropriate time period and phosphate uptake was measured using $[^{32}P]$-phosphate. Changes in the number of phosphate transporter in membranes were evaluated by kinetic analysis, $[^{14}C]$phosphonoformic acid binding, and Western blot analysis. Cisplatin inhibited phosphate uptake in a time- and dose-dependent manner, and also the $Na^+$-dependent uptake without altering $Na^+$-independent uptake. The cisplatin inhibition was not affected by the hydrogen peroxide scavenger catalase, but completely prevented by the hydroxyl radical scavenger dimethylthiourea. Antioxidants were ineffective in preventing the cisplatin-induced inhibition of phosphate uptake. Kinetic analysis indicated that cisplatin decreased Vmax of $Na^+$-dependent phosphate uptake without any change in the Km value. $Na^+$-dependent phosphonoformic acid binding was decreased by cisplatin treatment. Western blot analysis showed that cisplatin caused degradation of $Na^+$-dependent phosphate transporter protein. Taken together, these data suggest that cisplatin inhibits phosphate transport in renal proximal tubular cells through the reduction in the number of functional phosphate transport units. Such effects of cisplatin are mediated by production of hydroxyl radicals.

• Journal of the Korean Society of Food Culture
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• v.37 no.6
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• pp.503-509
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• 2022

Methylglyoxal is a highly reactive precursor which forms advanced glycation end products (AGEs). AGEs and methylglyoxal are known to induce various diseases such as diabetes, vascular disorders, Diabetes Mellitus (DM), and neuronal disorders. Juglans regia L is an important food commonly used worldwide, having nutritious components, including phenolic compounds. Since ancient times, Juglans regia L have been differently applied by various countries for health and in diverse diseases, including arthritis, asthma, skin disorders, cancer, and diabetes mellitus. However, the effect of diabetes-induced renal damage against AGEs remains unclear. This study evaluates the anti-glycation and renal protective effects of ethanol extract of Juglans regia L against methylglyoxal-induced renal tubular epithelial cell death. Exposure to methylglyoxal resulted in reduced cell viability in NRK-52E cells, but co-treatment with Juglans regia L extracts significantly increased the cell viability. In addition, we examined the anti-glycation effect of Juglans regia L extracts. Compared to the positive control aminoguanidine and Alagebrium, treatment with Juglans regia L extracts significantly inhibited the formation of AGEs, collagen cross-linking, and breaking collagen cross-linking. Taken together, our results indicate that Juglans regia L is a potential therapeutic agent for regulating diabetic complications by exerting anti-glycation and renal protective activities.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.427-438
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• 2022

Pyroptosis, a form of cell death associated with inflammation, is known to be involved in diabetic nephropathy (DN), and discoid domain receptor 1 (DDR1), an inflammatory regulatory protein, is reported to be associated with diabetes. However, the mechanism underlying DDR1 regulation and pyroptosis in DN remains unknown. We aimed to investigate the effect of DDR1 on renal tubular epithelial cell pyroptosis and the mechanism underlying DN. In this study, we used high glucose (HG)-treated HK-2 cells and rats with a single intraperitoneal injection of streptozotocin as DN models. Subsequently, the expression of pyroptosis-related proteins (cleaved caspase-1, GSDMD-N, Interleukin-1β [IL-1β], and interleukin-18 [IL-18]), DDR1, phosphorylated NF-κB (p-NF-κB), and NLR family pyrin domain-containing 3 (NLRP3) inflammasomes were determined through Western blotting. IL-1β and IL-18 levels were determined using ELISA. The rate of pyroptosis was assessed by propidium iodide (PI) staining. The results revealed upregulated expression of pyroptosisrelated proteins and increased concentration of IL-1β and IL-18, accompanied by DDR1, p-NF-κB, and NLRP3 upregulation in DN rat kidney tissues and HG-treated HK-2 cells. Moreover, DDR1 knockdown in the background of HG treatment resulted in inhibited expression of pyroptosis-related proteins and attenuation of IL-1β and IL-18 production and PI-positive cell frequency via the NF-κB/NLRP3 pathway in HK-2 cells. However, NLRP3 overexpression reversed the effect of DDR1 knockdown on pyroptosis. In conclusion, we demonstrated that DDR1 may be associated with pyroptosis, and DDR1 knockdown inhibited HG-induced renal tubular epithelial cell pyroptosis. The NF-κB/NLRP3 pathway is probably involved in the underlying mechanism of these findings.

• Korean Journal of Acupuncture
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• v.24 no.1
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• pp.171-187
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• 2007

Objectives : This study was performed to determine if Orostachys japonicus A. Berger herbal acupuncture (OjB) provides the protective effect against the loss of cell viability and DNA damage induced by oxidant in renal proximal tubular cells. Methods : The cell viability was evaluated by a MTT reduction assay and DNA damage was estimated by measuring double stranded DNA breaks in opossum kidney (OK) cells, an established proximal tubular cell line. Lipid peroxidation was determined by measuring malondialdehyde (MDA), a product of lipid peroxidation. Results : H2O2 increased the loss of cell viability in a time-dependent manner, which were prevented by 0.1% OjB. The protective effect of OjB was dose-dependent over concentration range of 0.05-0.5%. H2O2 caused ATP depletion and DNA damage, which were prevented by OjB and the hydrogen peroxide scavenger catalase. The loss of cell viability by H2O2 was not affected by the antioxidant DPPD, but lipid peroxidation by the oxidant was completely inhibited by DPPD. Generation of superoxide and H2O2 in neutrophils activated by phorbol-12,13-dibutyrate was inhibited by OjB in a dose-dependent manner. OjB inhibited generation of H2O2 in OK cells treated with antimycin A and exerted a direct H2O2 scavenging effect. Exposure of OK cells to 1 mM tBHP caused a significant depletion of glutathione which was prevented by OjB. OjB accelerated the recovery in cells cultured for 20 hr in normal medium without oxidant following oxidative stress. Conclusions : These results suggest that OjB exerts the protective effect against oxidant-induced cell injury and its protective effect was resulted from radical scavenging and antioxidant activities.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.1
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• pp.11-19
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• 2024

Acute kidney injury (AKI) is one of the major complications of sepsis. Aurantio-obtusin (AO) is an anthraquinone compound with antioxidant and anti-inflammatory activities. This study was developed to concentrate on the role and mechanism of AO in sepsis-induced AKI. Lipopolysaccharide (LPS)-stimulated human renal proximal tubular epithelial cells (HK-2) and BALB/c mice receiving cecal ligation and puncture (CLP) surgery were used to establish in vitro cell model and in vivo mouse model. HK-2 cell viability was measured using MTT assays. Histological alterations of mouse renal tissues were analyzed via hematoxylin and eosin staining. Renal function of mice was assessed by measuring the levels of serum creatinine (SCr) and blood urea nitrogen (BUN). The concentrations of pro-inflammatory cytokines in HK-2 cells and serum samples of mice were detected using corresponding ELISA kits. Protein levels of factors associated with nuclear factor kappa-B (NF-κB) pathway were measured in HK-2 cells and renal tissues by Western blotting. AO exerted no cytotoxic effect on HK-2 cells and AO dose-dependently rescued LPS-induced decrease in HK-2 cell viability. The concentrations of pro-inflammatory cytokines were increased in response to LPS or CLP treatment, and the alterations were reversed by AO treatment. For in vivo experiments, AO markedly ameliorated renal injury and reduced high levels of SCr and BUN in mice underwent CLP operation. In addition, AO administration inhibited the activation of NF-κB signaling pathway in vitro and in vivo. In conclusion, AO alleviates septic AKI by suppressing inflammatory responses through inhibiting the NF-κB pathway.

• Journal of Veterinary Clinics
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• v.6 no.2
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• pp.319-327
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• 1989

In order to study the effects of neomycin sulfate on the kidney of Korean black goats after dosing at 36mg/kg(A group) or 18mg/kg of body weight (B group) twice a day, serum chemical values(BUN, SCr), urinary enzyme(GGT) excretion and urinary analysis were checked and renal lesions were observed by light microscope. The proteinuria and granular casts were observed on the 5-6th day and 7th day of treatment with neomycin respectively in the A group. While these changes were observed on the 4th day and the 6th day respectively in one goat of the B group. Urinary GGT excretion began to increase from the 9th day and reached to maximum concentration on the 15th day of treatment with neomycin in the A group. Thereafter, GGT excretion began to decrease and reach to normal level on the 21th day. But GGT excretion increased on the 9th day in only one goat of the B group. Concentrations of BUN and SCr increased on the 12th day in the A group and in one goat of B group. The kidneys were swollen gross pathologically and the renal tubular epithelial cell changes were noticed histologically in the A group and in one goat of the B group. These changes were included degeneration with hyaline droplet formation, flattened epithelial cells and necrotic epithelium. Granular casts were showed in many tubular lumens. Prfesent results indicated that nephrotoxicosis would not occured in Korean black goats dosing with neomycin sulfate less that 36mg/kg of body weight a day.

• Korean Journal of Veterinary Pathology
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• v.3 no.1
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• pp.7-14
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• 1999

We investigated the effect of a single intravenous dose of Fumonisin $B_1(FB_1$) of rat kidney on the time sequence. Male Sprague-Dawley rats were intravenouslyin jected with FB$_1$at 1.25 mg/kg and were euthanized at 12 hrs, 1, 2, 4, and 6 days after the injection. In $FB_1$ treated rats, serum BUN and creatinine were elevated from 12 hrs. Microscopically, the initial target site was tubules of inner stripe, with mild degenerative and necrotic changes at 12 hrs, but the tubules recovered on day 4. In outer stripe, there were only a few scattered necrotic cells on day 1. These changes became more obvious over the time passed and most severe on day 4. On day 6, regeneration occurred, manifest as hypertrophic, basophilic tubular cells. The dying cells were proved to necrotic cells instead of apoptotic cells by TUNEL. Ultrastructural changes were cytoplasmic vacuole, dilated endoplasmic reticulum, swollen mitochondria, ballooned microvilli of the tubular cell in the outer stripe. These results showed that the renal tubules of outer medulla were the target to $FB_1$-induced nephrotoxicity in the rat. However, initial target was mner stnpe of medulla.