Mechanism of miRNA-141-3p in Calcium Oxalate-Induced Renal Tubular Epithelial Cell Injury via NLRP3-Mediated Pyroptosis.

BACKGROUND/AIMS: Renal calculi represent a prevalent disorder associated with mineral deposition in renal calyces and the pelvis. Aberrant microRNA (miRNA) expression is implicated in renal injury. This study investigated the mechanism of miR-141-3p in calcium oxalate (CaOx) crystal-induced renal tubular epithelial cell (RTEC) injury. METHODS: Human RTECs HK-2 cells were treated with CaOx crystals to induce RTEC injury. Cell viability was evaluated using Cell Counting Kit-8 assay, and apoptosis was measured using flow cytometry. The contents of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), interleukin (IL)-1ß, and IL-18 were measured using enzyme-linked immunosorbent assay kits. The expressions of NLRP3, cleaved caspase-1, and GSDMD-N were detected using Western blot. miR-141-3p and NLRP3 expressions were determined using reverse transcription quantitative polymerase chain reaction. The binding of miR-141-3p and NLRP3 was validated using a dual-luciferase assay. The role of NLRP3 in the protection of miR-141-3p on RTEC injury was verified using functional rescue experiments. RESULTS: CaOx crystals induced RTEC injury, manifested as attenuated cell viability, enhanced apoptosis, elevated intracellular LDH and MDA levels, and decreased SOD level. Pyroptosis of RTECs was enhanced by CaOx crystal induction, evidenced by elevated expressions of cleaved caspase-1, GSDMD-N, IL-1ß, and IL-18. miR-141-3p expression was reduced in CaOx crystal-induced RTECs. miR-141-3p overexpression alleviated CaOx crystal-induced RTEC injury and suppressed pyroptosis of RTECs. miR-141-3p bound to NLRP3 and thereby repressed NLRP3 expression. NLRP3 overexpression reversed the protective effect of miR-141-3p overexpression on RTECs. CONCLUSION: miR-141-3p repressed NLRP3-mediated pyroptosis by suppressing NLRP3 expression, thus protecting CaOx crystal-induced RTEC injury.

Phosphatidylserine eversion regulated by phospholipid scramblase activated by TGF-ß1/Smad signaling in the early stage of kidney stone formation.

The mechanism underlying phosphatidylserine eversion in renal tubule cells following calcium oxalate-mediated damage remains unclear; therefore, we investigated the effects of TGF-ß1/Smad signaling on phosphatidylserine eversion in the renal tubule cell membrane during the early stage of kidney stone development. In a rat model of early stage of calcium oxalate stone formation, phosphatidylserine eversion on the renal tubular cell membrane was detected by flow cytometry, and the expression of TGF-ß1 (transforming growth factor-ß1), Smad7, and phospholipid scramblase in the renal tubular cell membrane was measured by western blotting. We observed that the TGF-ß1/Smad signaling pathway increased phosphatidylserine eversion at the organism level. The results of in vitro studies demonstrated that oxalate exposure to renal tubule cells induced TGF-ß1 expression, increasing phospholipid scramblase activity and phosphatidylserine eversion in the renal tubule cell membrane. These results indicate that TGF-ß1 stimulates phosphatidylserine eversion by increasing the phospholipid scramblase activity in the renal tubule cell membrane during the early stage of kidney stone development. The results of this study form a basis for further detailed research on the development of therapeutic agents that specifically treat urolithiasis and exert fewer adverse effects.

Externalization of phosphatidylserine via multidrug resistance 1 (MDR1)/P-glycoprotein in oxalate-treated renal epithelial cells: implications for calcium oxalate urolithiasis.

OBJECTIVES: We investigated the possible involvement of multidrug resistance protein 1 P-glycoprotein (MDR1 P-gp) in the oxalate-induced redistribution of phosphatidylserine in renal epithelial cell membranes. METHODS: Real-time PCR and western blotting were used to examine MDR1 expression in Madin-Darby canine kidney cells at the mRNA and protein levels, respectively, whereas surface-expressed phosphatidylserine was detected by the annexin V-binding assay. RESULTS: Oxalate treatment resulted in increased synthesis of MDR1, which resulted in phosphatidylserine (PS) externalization in the renal epithelial cell membrane. Treatment with the MDR1 inhibitor PSC833 significantly attenuated phosphatidylserine externalization. Transfection of the human MDR1 gene into renal epithelial cells significantly increased PS externalization. CONCLUSIONS: To our knowledge, this study is the first to show that oxalate increases the synthesis of MDR1 P-gp, which plays a key role in hyperoxaluria-promoted calcium oxalate urolithiasis by facilitating phosphatidylserine redistribution in renal epithelial cells.

The utility of fluorescence in situ hybridization for diagnosis and surveillance of bladder urothelial carcinoma.

PURPOSE: To evaluate the clinical value of fluorescence in situ hybridization (FISH) for diagnosis and surveillance of bladder urothelial carcinoma (BUC). MATERIALS AND METHODS: Between November 2010 and December 2013, patients suspected of having BUC were examined using urine cytology and FISH assay. Based on histopathological examination results, FISH results were com­pared with urine cytology. In addition, patients with a history of non-muscle invasive BUC were also examined using urine cytology and FISH assay at the first time of visit and then monitored with cystoscopy during follow-up period. RESULTS: A total of 162 patients included in this study and 12 patients were excluded due to uninformative FISH assays. The remaining 150 patients consisted of 108 patients suspected for BUC and 42 patients with a history of non-muscle invasive BUC. The sensitivities of FISH analysis and urine cytology were 72.8% and 27.2%, respectively, and the difference was statistically significant (P <.05). Difference between specificity of urine cytology (100%) and FISH assay (85%) was not statistically significant (P >.05). At the first visit, of 42 patients, one patient had positive cystoscopy, and FISH assay was positive in 26 of 41 patients with negative cystoscopy. During the follow-up period (mean, 29.5 months), 18 of 26 patients developed recurrence, and recurrence occurred in only one of 15 patients with negative FISH analysis. CONCLUSION: Our results suggest that FISH analysis can be used as a non-invasive diagnostic tool for patients suspect­ed of having new BUC. In addition, FISH analysis may provide important prognostic information to better define the individual risk for BUC recurrence.& nbsp;

Oxalate impairs aminophospholipid translocase activity in renal epithelial cells via oxidative stress: implications for calcium oxalate urolithiasis.

PURPOSE: We evaluated the possible involvement of phospholipid transporters and reactive oxygen species in the oxalate induced redistribution of renal epithelial cell phosphatidylserine. MATERIALS AND METHODS: Madin-Darby canine kidney cells were labeled with the fluorescent phospholipid NBD-PS in the inner or outer leaflet of the plasma membrane and then exposed to oxalate in the presence or absence of antioxidant. This probe was tracked using a fluorescent quenching assay to assess the bidirectional transmembrane movement of phosphatidylserine. Surface expressed phosphatidylserine was detected by annexin V binding assay. The cell permeable fluorogenic probe DCFH-DA was used to measure the intracellular reactive oxygen species level. RESULTS: Oxalate produced a time and concentration dependent increase in phosphatidylserine, which may have resulted from impaired aminophospholipid translocase mediated, inward directed phosphatidylserine transport and from enhanced phosphatidylserine outward transport. Adding the antioxidant N-acetyl-L-cysteine significantly attenuated phosphatidylserine externalization by effectively rescuing aminophospholipid translocase activity. CONCLUSIONS: To our knowledge our findings are the first to show that oxalate induced increased reactive oxygen species generation impairs aminophospholipid translocase activity and decreased aminophospholipid translocase activity has a role in hyperoxaluria promoted calcium oxalate urolithiasis by facilitating phosphatidylserine redistribution in renal epithelial cells.

Expressions of voltage-gated K+ channel 2.1 and 2.2 in rat bladder with detrusor hyperreflexia.

BACKGROUND: Voltage-gated K+ channel (Kv) plays a critical role in the modulation of detrusor contraction. This study was conducted to investigate the expressions of Kv2.1 and Kv2.2 in rat bladder with detrusor hyperreflexia (DH). METHODS: Thirty adult female Sprague-Dawley rats (200-220 g) were randomly divided into the control group and the experimental group. The experimental group was subjected to spinal cord injury (SCI). In the controls, the surgical procedure was identical with the exception that dura and spinal cord were transected. Four weeks after SCI, in vivo cystometry and mechanical pulling tests of isolated detrusor strips were performed. mRNA was extracted from the detrusors of normal and DH rats for the detection of expression of Kv2.1 and Kv2.2 by RT-PCR. Differences in expression between normal and overactive detrusors were identified by gel imaging. RESULTS: Fourteen rats in the experimental group exhibited uninhibited bladder contraction (>8 cmH2O) before voiding after SCI. One rat died from infection. The frequency of DH in the experimental group was significantly different from that in the control group with or without treatment with 4-aminopyridine (4-AP) (P < 0.05), while the amplitude of DH did not change markedly. The rates of variation of the automatic contractile frequency and amplitude were (66.8 +/- 12.4)% and (42.6 +/- 12.6)% respectively in the control group, and (38.4 +/- 9.8)% and (28.0 +/- 4.6)% respectively in the DH group. 4-AP increased the automatic contractile frequency apart from the automatic contractile amplitude in both the control and DH groups (P < 0.05). 4-AP increased the rate of variation of the automatic contractile frequency more markedly in the control group than in the DH group (P < 0.05). Significant expression of Kv2.2 was not detected in bladders in the control group. Compared to the mRNA levels of beta-actin, the mRNA level of Kv2.1 was 1.26 +/- 0.12 in the control group and 0.66 +/- 0.08 in the DH group. SCI significantly reduced the mRNA level of Kv2.1 in rat bladders with DH (P < 0.05). CONCLUSIONS: Our study showed that the mRNA level of Kv2.1 decreased significantly in rat bladder with DH, which was one of the important pathogenetic mechanisms for DH, and suggested that Kv2.1 might be one of the therapeutic targets for bladder overactivity.

Effects of alcohol intake on penile structure and function in rats.

OBJECTIVE: To investigate the effects of alcohol intake on penile structure and function in rats. METHODS: Thirty adult male Wistar rats were randomly divided into two groups: control group and alcohol intake group. They were administered with 2 mL of normal saline and 40% alcohol solution respectively through gastric tubes every day. Three months later, the animal model of alcohol intake was evaluated by modified Nayagida's method, and the effects of alcohol on the rats were studied by sexual behavior, the number of apomorphine-induced penile erection, level of testosterone in the sera, and the content of penile smooth muscle. RESULTS: The scores of animal model of alcohol intake evaluated by Nayagida's method were 0.66 +/- 2.05 in the control group and 9.26 +/- 5.50 in the alcohol intake group (P < 0.05), which indicated that an animal model of alcohol intake was successfully established. Sexual behavior, the number of apomorphine-induced penile erection, testosterone level in the sera, and the content of penile smooth muscle of the alcohol intake group were all statistically different as compared with the control group (P < 0.05). CONCLUSION: Alcohol intake induces sexual dysfunction in rats, which may be due to the decline of testosterone level in the sera and decline of penile smooth muscle.

[The effect of ethanol on sexual function of males and its mechanism].

Though an adequate volume of ethanol relieves nervousness and enhances sexual desire,long term and excessive intake of ethanol can induce sexual dysfunction. The reasons that ethanol results in sexual dysfunction are as follows: ethanol inhibits the hypothalamo-pituitary-testes axis and decreases serum testosterone level. The decline of smooth muscle, choline acetyltransferase and nitric oxide synthase in the penis may be responsible for it.

[Relationship between ethanol intake and sexual function in rats].

OBJECTIVE: To investigate the relationship between the intake of ethanol and sexual function of rats. METHODS: Sixty adult male Wistar rats were randomly divided into five groups: the control, 10% , 20% , 30% and 40 ethanol groups, which received. . 9% sodium chloride, 10% , 20% , 30% and 40% ethanol solutions respectively at a dose of 2 ml through gastric tubes once a day. Three months later, we observed the effects of ethanol on the sexual function of the rats by their sexual behaviors, the number of apomorphine-induced penile erections, and the content of testosterone in the serum and nitric oxide synthase ( NOS) in the penis. RESULTS: Compared with the control group, the number of apomorphine-induced penile erections in the 10% and 20% ethanol groups was not inhibited significantly (P > 0.05), but the latent period of mounting and intromission in the 10% ethanol group was prolonged and the sexual behaviors in the 20% ethanol group were inhibited except the latent period of ejaculation. The sexual behaviors and the number of apomorphine-induced penile erections of the 30% and 40% ethanol groups were inhibited significantly (P < 0.05). Testosterone in the serum and NOS activity in the penis of the experimental groups were reduced (Pat < 0.05). CONCLUSION: An adequate volume of ethanol does not induce sexual dysfunction in rats, but long term and excessive intake of ethanol may cause penile erectile dysfunction.

[The dynamic effects of allogenic transplantations with the bladder acellular matrix grafts of rabbits].

OBJECTIVE: To study the dynamic effects of allogenic transplantations with the bladder acellular matrix grafts (BAMG) of rabbits. METHODS: Hemi-cystectomies were performed in 25 rabbits, and the defects were repaired with BAMG about half bladder size. The rabbits underwent postoperative assessment of bladder function at 8 weeks, including cystometry, vesical volume, vesical compliance and cystography. The allografts were observed by light microscope and electron microscope at 1, 2, 4, 8, 12, 16 weeks after surgery. RESULTS: Macroscopic observation revealed that BAMG regenerated gradually. All urodynamic results of 8 weeks after surgery were not different statistically as compared with these of preoperation (P > 0.05). Cystography revealed that the morphous of bladder was recovered. Epithelialization and neovascularity occurred accompanied by infiltration of inflammatory cell at 1 week. Smooth muscle cell and stratified epithelium regenerated 2 weeks after grafting. Neural elements formed around smooth muscle bundles as early as 4 weeks. Each component regenerated on the frame of BAMG sequentially. After 16 weeks, it was difficult to delineate the junction between the host bladder and BAMG by histology. CONCLUSION: After allogenic transplantation with rabbits' BAMG, the constitution and function of the allografts regenerate completely and gradually on the frame of BAMG.