• Applied Microscopy
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• v.21 no.2
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• pp.76-95
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• 1991

A single injection of cadmium chloride (3.75 mg/kg) was made into the peritoneal cavities of albino rats. The cortices of kidney were obtained from the experimental animals at 3 hr., 6 hr., 12 hr., 24 hr. and 36 hr. after administration of cadmium chloride, respectively. The specimens of each experimental animal were prefixed in 2% glutaraldehyde-4% paraformaldehyde solution for $2{\sim}4$ hours, and these specimens were post-fixed in 1% osmic acid. After fixation, the specimens were dehydrated with alcohol and acetate and embedded in Epon 812. Ultrathin sections, $600{\sim}800{\AA}$ thickness were made and stained with uranyl acetate and lead citrate. And all the preparations were observed with Hitachi-600 transmission electron microscope. The results obtained were as follows: 1. The main changes in ultrastructures of the glomeruli observed at 3 hr. after cadmium chloride administration include loss of filtration slit and fenestrae of capillary endothelium that was resulted from thickings of the basal lamina and fusion of pedicels of the podocytes. At 12 hr. after cadmium chloride administration the Bowman's capsules were mostly filled with abnormally thickened and fused pedicels. After 24 hr. however, the only recognized change was loss of fenestrae of the capillary endothelium. And the ultrastructure of the glomeruli were almost normal in 36 hr. after cadmium chloride treatment. 2. At 3 hr. after treatment with cadmium chloride, in the renal tubular cells the vesicles and vacuoles increased in number at the apical portion, of the tubular epithelial cells, the basal infoldings were reduced and the basal lamina was thickened. After 12 hr., a number of phagosomes appeared at the apical portion and the cisternae of rough endoplasmic reticulum were swollen. At 24 hr. after cadmium chloride administration irregularly shaped mitochondria were observed in the apical area, and mitochondria with swollen cristae were found at the basal portion. And after 36 hr. The ultrastructures of the epithelial cells appeared almost normal except for a moderate increase in the number of vesicles and vacuoles. Consequently it is suggested that in albino rats, cadmium chloride induces acute reversible degenerative changes in the glomeruli as well as in the epithelial cells of the proximal convoluted tubules.

• Natural Product Sciences
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• v.28 no.4
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• pp.194-200
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• 2022

Albizia julibrissin Durazz. (AJ; family Minosaceae) is widely distributed worldwide, and its stem bark has been used as a traditional herbal medicine. Acute kidney injury (AKI) is a clinical syndrome that results in sudden loss of renal function. This study aimed to investigate the effects of AJ against cisplatin-induced AKI using a human kidney proximal tubule epithelial cell line (HK-2) and cisplatin-treated mice. In vitro, cisplatin treatment increased apoptosis in HK-2 cells. However, AJ treatment decreased apoptosis of cisplatin-treated HK-2 cells. In vivo, cisplatin treatment accelerated renal injury by increasing the levels of renal injury markers, such as blood urea nitrogen, creatinine, kidney injury molecule 1, and neutrophil gelatinase-associated lipocalin, which were reversed by AJ treatment. Histopathologically, AJ treatment resulted in decreased renal damage with less tubular necrosis and brush border desquamation compared with the AKI group. Additionally, cisplatin treatment upregulated mitochondrial fission, a pathological characteristic of AKI, which was downregulated by AJ treatment. Along with increased mitochondrial fission, AJ treatment also reduced cisplatin-induced apoptosis. These results suggest that AJ may be a potential therapeutic agent for cisplatin-induced AKI.

• Kidney Research and Clinical Practice
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• v.36 no.2
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• pp.145-157
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• 2017

Background: Vitamin D is considered to exert a protective effect on various renal diseases but its underlying molecular mechanism remains poorly understood. This study aimed to determine whether paricalcitol attenuates inflammation and apoptosis during lipopolysaccharide (LPS)-induced renal proximal tubular cell injury through the prostaglandin $E_2$ ($PGE_2$) receptor EP4. Methods: Human renal tubular epithelial (HK-2) cells were pretreated with paricalcitol (2 ng/mL) for 1 hour and exposed to LPS ($1{\mu}g/mL$). The effects of paricalcitol pretreatment in relation to an EP4 blockade using AH-23848 or EP4 small interfering RNA (siRNA) were investigated. Results: The expression of cyclooxygenase-2, $PGE_2$, and EP4 were significantly increased in LPS-exposed HK-2 cells treated with paricalcitol compared with cells exposed to LPS only. Paricalcitol prevented cell death induced by LPS exposure, and the cotreatment of AH-23848 or EP4 siRNA offset these cell-protective effects. The phosphorylation and nuclear translocation of p65 nuclear factor-kappaB ($NF-{\kappa}B$) were decreased and the phosphorylation of Akt was increased in LPS-exposed cells with paricalcitol treatment. AH-23848 or EP4 siRNA inhibited the suppressive effects of paricalcitol on p65 $NF-{\kappa}B$ nuclear translocation and the activation of Akt. The production of proinflammatory cytokines and the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells were attenuated by paricalcitol in LPS exposed HK-2 cells. The cotreatment with an EP4 antagonist abolished these anti-inflammatory and antiapoptotic effects. Conclusion: EP4 plays a pivotal role in anti-inflammatory and antiapoptotic effects through Akt and $NF-{\kappa}B$ signaling after paricalcitol pretreatment in LPS-induced renal proximal tubule cell injury.

• Molecules and Cells
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• v.42 no.12
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• pp.893-905
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• 2019

Mitochondria are highly dynamic organelles that constantly undergo fission and fusion processes that closely related to their function. Disruption of mitochondrial dynamics has been demonstrated in acute kidney injury (AKI), which could eventually result in cell injury and death. Previously, we reported that augmenter of liver regeneration (ALR) alleviates renal tubular epithelial cell injury. Here, we gained further insights into whether the renoprotective roles of ALR are associated with mitochondrial dynamics. Changes in mitochondrial dynamics were examined in experimental models of renal ischemia-reperfusion (IR). In a model of hypoxia-reoxygenation (HR) injury in vitro, dynamin-related protein 1 (Drp1) and mitochondrial fission process protein 1 (MTFP1), two key proteins of mitochondrial fission, were downregulated in the Lv-ALR + HR group. ALR overexpression additionally had an impact on phosphorylation of Drp1 Ser637 during AKI. The inner membrane fusion protein, Optic Atrophy 1 (OPA1), was significantly increased whereas levels of outer membrane fusion proteins Mitofusin-1 and -2 (Mfn1, Mfn2) were not affected in the Lv-ALR + HR group, compared with the control group. Furthermore, the mTOR/4E-BP1 signaling pathway was highly activated in the Lv-ALR + HR group. ALR overexpression led to suppression of HR-induced apoptosis. Our collective findings indicate that ALR gene transfection alleviates mitochondrial injury, possibly through inhibiting fission and promoting fusion of the mitochondrial inner membrane, both of which contribute to reduction of HK-2 cell apoptosis. Additionally, fission processes are potentially mediated by promoting tubular cell survival through activating the mTOR/4E-BP1 signaling pathway.

• Journal of Acupuncture Research
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• v.20 no.6
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• pp.128-139
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• 2003

Juglans sinensis Dode has been reported to have antioxidant activity. However, the effect of Juglans sinensis Dode aquacupuncture(JS) on reactive oxygen species(ROS)-induced alterations in membrane transport function in renal tubular cells. This study was performed to evaluate the effect of JS on the organic hydroperoxide t-butylhydroperoxide(tBHP)-induced inhibition of $Na^+$-dependent phosphate($Na^+$-Pi) uptake in opossum kidney (OK) cells, an established renal proximal epithelial cell line. tBHP inhibited $Na^+$-Pi uptake in a time-dependent manner. The inhibitory effect of tBHP was prevented by JS over concentration range of 0.05-1mg/100ml in a dose-dependent manner. Kinetic studies showed that tBHP caused an decrease in Vmax for $Na^+$-Pi uptake without any a significant change in Km. $Na^+$-dependent phosphonoformic acid binding, a irreversible inhibitor of renal $Na^+$-Pi uptake, was decreased by tBHP treatment. The reduction in Vmax and phosphonoformic acid binding by tBHP was prevented by JS. tBHP induced lipid peroxidation and its effect was completely inhibited by JS and antioxidant N,N'-diphenyl-p-phenylenediamine. These data suggest that the oxidant inhibits phosphate uptake by a reduction in the number of active carrier across the membrane. JS may prevent oxidant-induced inhibition of membrane transport function by a mechanism similar to antioxidants in renal epithelial cells. Although the precise constituents remain to be explored, JS may be employed as a useful candidate herb for drug development to prevent and treat oxidant-mediated renal failure.

• Clinical and Experimental Pediatrics
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• v.52 no.8
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• pp.944-952
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• 2009

Purpose : To investigate the effects of angiotensin II inhibition on the epithelial to mesenchymal transition (EMT) in the developing kidney, we tested the expression of EMT markers and nestin in angiotensin converting enzyme (ACE) inhibitor-treated kidneys. Methods : Newborn rat pups were treated with enalapril (30 mg/kg/d) or a vehicle for 7 days. Immunohistochemistry for the expression of ${\alpha}$-smooth muscle actin (SMA), E-cadherin, vimentin, and nestin were performed. The number of positively-stained cells was determined under 100 magnification in 10 random fields. Results : In the enalapril-treated group, ${\alpha}SMA-positive$ cells were strongly expressed in the dilated tubular epithelial cells. The number of ${\alpha}SMA-positive$ cells in the enalapril-treated group increased in both the renal cortex and medulla, compared to the control group (P<0.05). The expression of E-cadherin-positive cells was dramatically reduced in the cortical and medullary tubular epithelial cells in the enalapril-treated group (P<0.05). The number of vimentin- and nestin-positive cells in the cortex was not different in comparisons between the two groups; however, their expression increased in the medullary tubulointerstitial cells in the enalapril-treated group (P<0.05). Conclusion : Our results show that ACE inhibition in the developing kidney increases the renal EMT by up-regulating ${\alpha}SMA$ and down-regulating E-cadherin. Enalapril treatment was associated with increased expression of vimentin and nestin in the renal medulla, suggesting that renal medullary changes during the EMT might be more prominent, and ACE inhibition might differentially modulate the expression of EMT markers in the developing rat kidney.

• 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.18 no.1
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• pp.70-73
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• 2001

Five-month-old a female mongrel puppy weighing 3.5 kg showed no systemic disorder and particular discomfort except abdominal distension at the first visit. On physical examination an irregular abdominal mass was palpated. One month later she was clumsy and uncoordinated. In addition, lethargy and anorexia were appeared. Then she became comatose and died in spite of initial therapy. In radiographic examination enlargement of both sides of kidney was observed. The hematological examination the dog had WBC of 16,250/$\mu$l, RBC of $7.2{\times}10^6$ $\mu$l, PCV of 32%, total protein of 8.0 g/dl, and fibrinogen of 900 mg/dl. In serum chemistry BUN was 87.4 mg/dl and creatinine was 5.1 mg/dl. Urinalysis revealed pH of 5.6, SG of 1.009 and protein of 500 mg/dl. In urine sediment test many RBCs, leukocytes, inflammatory cells and a few epithelial cells were observed. On histopathologic examination the size of right and left kidney were 15 cm, 16 cm in length, 6 cm, 6 cm in widths, respectively. Both sides of kidney were filled with brown-orange fluid and had irregular capsular surface. The cysts of various sizes were located throughout the cortex and medulla. No abnormality was found in any other organs. Histologically, cyst was lined by cuboidal to slightly flattened tubular epithelium and surrounded by mature fibrous connective tissue. Glomeruli, tubule and renal pelvis remained normal between cysts and exfoliated epithelial cells.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.233-239
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• 2017

Background: Nephrotoxicity is the major side effect in cisplatin chemotherapy. Previously, we reported that the ginsenosides Rk3 and Rh4 reduced cisplatin toxicity on porcine renal proximal epithelial tubular cells (LLC-PK1). Here, we aimed to evaluate the protective effect of ginsenosides Rk3 and Rh4 on kidney function and elucidate their antioxidant effect using in vitro and in vivo models of cisplatin-induced acute renal failure. Methods: An enriched mixture of ginsenosides Rk3 and Rh4 (KG-KH; 49.3% and 43.1%, respectively) was purified from sun ginseng (heat processed Panax ginseng). Cytotoxicity was induced by treatment of $20{\mu}M$ cisplatin to LLC-PK1 cells and rat model of acute renal failure was generated by single intraperitoneal injection of 5 mg/kg cisplatin. Protective effects were assessed by determining cell viability, reactive oxygen species generation, blood urea nitrogen, serum creatinine, antioxidant enzyme activity, and histopathological examination. Results: The in vitro assay demonstrated that KG-KH ($50{\mu}g/mL$) significantly increased cell viability (4.6-fold), superoxide dismutase activity (2.8-fold), and glutathione reductase activity (1.5-fold), but reduced reactive oxygen species generation (56%) compared to cisplatin control cells. KG-KH (6 mg/kg, per os) also significantly inhibited renal edema (87% kidney index) and dysfunction (71.4% blood urea nitrogen, 67.4% creatinine) compared to cisplatin control rats. Of note, KG-KH significantly recovered the kidney levels of catalase (1.2-fold) and superoxide dismutase (1.5-fold). Conclusion: Considering the oxidative injury as an early trigger of cisplatin nephrotoxicity, our findings suggest that ginsenosides Rk3 and Rh4 protect the kidney from cisplatin-induced oxidative injury and help to recover renal function by restoring intrinsic antioxidant defenses.