MicroRNA-483-5p accentuates cisplatin-induced acute kidney injury by targeting GPX3.

The ability of cisplatin (cis-diamminedichloroplatinum II) toxicity to induce acute kidney injury (AKI) has attracted attention and concern for a long time, but the molecular mechanism of action for cisplatin is not clear. MicroRNA-483 is involved in several diseases, such as tumorigenesis and osteoarthritis, but its renal target and potential role in AKI are unknown. In this study, we explored the pathogenic role and underlying mechanism of miR-483-5p in cisplatin-induced AKI, using transgenic mice, clinical specimen, and in vitro cell line. We found that miR-483-5p was significantly upregulated by cisplatin in a cisplatin-induced mouse model, in serum samples of patients who received cisplatin therapy, and in NRK-52E cells. Overexpression of miR-483-5p in mouse kidneys by stereotactic renal injection of lentiviruses mediated miR-483-5p or generation of conditional miR-483-overexpressing transgenic mice accentuated cisplatin-induced AKI by increasing oxidative stress, promoting apoptosis, and inhibiting autophagy of tubular cells. Furthermore, our results revealed miR-483-5p directly targeted to GPX3, overexpression of which rescued cisplatin-induced AKI by inhibiting oxidative stress and apoptosis of tubular cells, but not by regulating autophagy. Collectively, miR-483-5p is upregulated by cisplatin and exacerbates cisplatin-induced AKI via negative regulation of GPX3 and contributing oxidative stress and tubular cell apoptosis. These findings reveal a pathogenic role for miR-483-5p in cisplatin-induced AKI and suggest a novel target for the diagnosis and treatment of AKI.

The inhibition of UDP-glucuronosyltransferases (UGTs) by tetraiodothyronine (T4) and triiodothyronine (T3).

1. UDP-glucuronosyltransferases (UGTs) are important drug-metabolizing enzymes (DMEs) catalyzing the glucuronidation elimination of various xenobiotics and endogenous substances. Endogenous substances are important regulators for the activity of various UGT isoforms. Triiodothyronine (T3) and thyroxine (T4) are important thyroid hormones essential for normal cellular differentiation and growth. The present study aims to elucidate the inhibition behavior of T3 and T4 on the activity of UGT isoforms. 2. In vitro recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was used to screen the inhibition potential of T3 and T4 on the activity of various UGT isoforms. Initial screening results showed that T4 exerted stronger inhibition potential than T3 on the activity of various UGT isoforms at 100 µM. Inhibition kinetics was determined for the inhibition of T4 on the representative UGT isoforms, including UGT1A1, -1A3, -1A7, -1A8, -1A10 and -2B7. The results showed that T4 competitively inhibited the activity of UGT1A1, -1A3, -1A7, 1A10 and -2B7, and noncompetitively inhibited the activity of UGT1A8. The inhibition kinetic parameters were calculated to be 1.5, 2.4, 11, 9.6, 4.8 and 3.0 µM for UGT1A1, -1A3, -1A7, -1A8, -1A10 and -2B7, respectively. In silico docking method was employed to demonstrate why T4 exerted stronger inhibition than T3 towards UGT1A1. Stronger hydrogen bonds and hydrophobic interaction between T4 and activity cavity of UGT1A1 than T3 contributed to stronger inhibition of T4 towards UGT1A1. 3. In conclusion, more clinical monitoring should be given for the patients with the elevation of T4 level due to stronger inhibition of UGT isoforms-catalyzed metabolism of drugs or endogenous substances by T4.

Effects of magnesium sulfate combined with labetalol on inflammatory stress and pregnancy outcome of patients with gestational hypertension.

Gestational hypertension (GH) is a common disorder during pregnancy that can cause adverse pregnancy outcomes. In the present study, magnesium sulfate (MgSO4) combined with labetalol was used for clinical treatment. Randomized controlled trial was conducted in 100 patients with GH, documented in the Department of Obstetrics and Gynecology (Taicang TCM Hospital) grouped into the experimental (Expt) and control (Ctrl) groups (n=50 cases/group). The Ctrl group was treated with MgSO4, whereas the Expt group was treated with MgSO4 + labetalol. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the Expt group were not significantly different from those in the Ctrl group (P>0.05). By contrast, the SBP and DBP were significantly lower after treatment than those before treatment in both groups (P<0.05). Whole blood viscosity, plasma viscosity and hematocrit were significantly lower in the Expt group compared with those in the Ctrl group after treatment (P<0.05). High mobility group box-1 protein, homocysteine and serum cystatin C levels in the Expt group were also markedly lower than those in the Ctrl group after treatment (P<0.05). In the Expt group, the rate of spontaneous vaginal delivery was much higher, whereas the rates of cesarean section and postpartum hemorrhage were markedly lower than those in the Ctrl group (P<0.05). The occurrence of fetal intrauterine distress, placental abruption, neonatal asphyxia, premature birth and neonatal death were also significantly lower in the Expt group than those in the Ctrl group (P<0.05). In conclusion, MgSO4 + labetalol could improve inflammatory stress and the hemodynamics of patients with GH, and may have a marked antihypertensive effect. Thus, it may improve pregnancy outcome and reduce perinatal complications.

A Versatile Approach to Electrochemical In Situ Ambient-Pressure X-ray Photoelectron Spectroscopy: Application to a Complex Model Catalyst.

We present a new technique for investigating complex model electrocatalysts by means of electrochemical in situ ambient-pressure X-ray photoelectron spectroscopy (AP-XPS). Using a specially designed miniature capillary device, we prepared a three-electrode electrochemical cell in a thin-layer configuration and analyzed the active electrode/electrolyte interface by using "tender" X-ray synchrotron radiation. We demonstrate the potential of this versatile method by investigating a complex model electrocatalyst. Specifically, we monitored the oxidation state of Pd nanoparticles supported on an ordered Co3O4(111) film on Ir(100) in an alkaline electrolyte under potential control. We found that the Pd oxide formed in the in situ experiment differs drastically from the one observed in an ex situ emersion experiment at similar potential. We attribute these differences to the decomposition of a labile palladium oxide/hydroxide species after emersion. Our experiment demonstrates the potential of our approach and the importance of electrochemical in situ AP-XPS for studying complex electrocatalytic interfaces.

[Expression of kinesin KIF3A in the kidney of mice with unilateral ureteral obstruction].

OBJECTIVE: To investigate the expression of KIF3A in mice with unilateral ureteral obstruction (UUO) and TGF-ß1-induced NRK-52E cells and the role of KIF3A in renal tubular epithelial cell transdifferentiation. METHODS: Thirty-six C57BL/6J mice were randomly divided into the sham group (n=18) and UUO group (n=18). Six mice in each group were sacrificed at 7, 14 and 21days after the operation. The degree of renal tubulointerstitial fibrosis of the mice was observed by HE staining, Masson trichrome staining and Sirius red staining. The expression and distribution of KIF3A in the kidney of the mice was detected using RT-PCR, Western blotting and immunohistochemistry. Western blotting was used to detect the expression of KIF3A, E-cadherin and α-SMA proteins in the renal tissue of the mice. The expressions of KIF3A, E-cadherin, α-SMA, Wnt4 and ß-catenin proteins in NRK-52E cells with TGF-ß1-induced transdifferentiation were detected by Western blotting. RESULTS: Compared with the sham-operated mice, the mice with UUO showed worsened renal interstitial fibrosis with the increase of obstruction time, indicating successful modeling. The expressions of KIF3A mRNA and protein increased progressively and reached the peaked level at 21 days after UUO. The expression of α-SMA protein was significantly increased while E-cadherin protein expression was significantly reduced after UUO. The transdifferentiated NRK-52E cells showed significantly increased expressions of KIF3A (P < 0.001), Wnt4 (P < 0.05) and ß-catenin proteins (P < 0.0001). CONCLUSIONS: KIF3A may participate in the development of renal fibrosis through epithelial-mesenchymal transition mediated by wnt/ß-catenin signaling pathway.

Cisplatin Toxicology: The Role of Pro-inflammatory Cytokines and GABA Transporters in Cochlear Spiral Ganglion.

BACKGROUND: The current study was conducted to examine the specific activation of pro-inflammatory cytokines (PICs), namely IL-1ß, IL-6 and TNF-α in the cochlear spiral ganglion of rats after ototoxicity induced by cisplatin. Since γ-aminobutyric acid (GABA) and its receptors are involved in pathophysiological processes of ototoxicity, we further examined the role played by PICs in regulating expression of GABA transporter type 1 and 3 (GAT-1 and GAT-3), as two essential subtypes of GATs responsible for the regulation of extracellular GABA levels in the neuronal tissues. METHODS: ELISA and western blot analysis were employed to examine the levels of PICs and GATs; and auditory brainstem response was used to assess ototoxicity induced by cisplatin. RESULTS: IL-1ß, IL-6 and TNF-α as well as their receptors were significantly increased in the spiral ganglion of ototoxic rats as compared with sham control animals (P<0.05, ototoxic rats vs. control rats). Cisplatin-ototoxicity also induced upregulation of the protein levels of GAT-1 and GAT-3 in the spiral ganglion (P<0.05 vs. controls). In addition, administration of inhibitors to IL-1ß, IL-6 and TNF-α attenuated amplification of GAT-1 and GAT-3 and improved hearing impairment induced by cisplatin. CONCLUSION: Our data indicate that PIC signals are activated in the spiral ganglion during cisplatin-ototoxicity which thereby leads to upregulation of GABA transporters. As a result, it is likely that de-inhibition of GABA system is enhanced in the cochlear spiral ganglion. This supports a role for PICs in engagement of the signal mechanisms associated with cisplatin-ototoxicity, and has pharmacological implications to target specific PICs for GABAergic dysfunction and vulnerability related to cisplatin-ototoxicity.

Plasma tyrosine and its interaction with low high-density lipoprotein cholesterol and the risk of type 2 diabetes mellitus in Chinese.

AIMS/INTRODUCTION: Metabolomic markers have the potential to improve the predicting accuracy of existing risk scores for type 2 diabetes mellitus. The present study aimed to test the associations between plasma tyrosine and type 2 diabetes mellitus with special attention to identifying possible cut-off points for type 2 diabetes mellitus, and its interactive effects with low high-density lipoprotein cholesterol (HDL-C) and/or high triglyceride for type 2 diabetes mellitus. METHODS: From 27 May 2015 to 3 August 2016, we retrieved the medical notes of 1,898 inpatients with type 2 diabetes mellitus as the cases, and 1,522 individuals without diabetes as the controls who attended annual medical checkups from the same tertiary care center in Jinzhou, China. Logistic regression analyses were carried out to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Restricted cubic spline analysis nested in the logistic regression analysis was used to identify possible cut-off points of tyrosine for type 2 diabetes mellitus. The additive interaction was used to estimate interactions between high tyrosine and low HDL-C in type 2 diabetes mellitus patients. RESULTS: The OR of tyrosine for type 2 diabetes mellitus did not increase until 46 µmol/L and after that point, the OR rapidly rose with increasing tyrosine in a nearly linear manner. If 46 µmol/L was used to define high tyrosine, high tyrosine was associated with an increased OR of type 2 diabetes mellitus (adjusted OR 1.88, 95% CI 1.44-2.45). The presence of low HDL-C greatly enhanced the ORs of tyrosine for type 2 diabetes mellitus from 1.11 (95% CI 0.82-1.51) to 54.11 (95% CI 33.96-86.22) with significant additive interaction. CONCLUSIONS: In Chinese adults, tyrosine >46 µmol/L was associated with increased odds of type 2 diabetes mellitus, which was contingent on low HDL-C.

[A method for efficient transduction of miR-483-5p in the kidney of mice].

OBJECTIVE: To establish a method for gene delivery in murine renal tissue using lentivirus vector encoding miR-483-5p. METHODS: Thirty-five C57BL/6J mice were randomly divided into control group, low-dose treatment group (5 µL each kidney) , and high?dose treatment group (20 µL each kidney), and in the latter two groups, the lentivirus vector encoding miR-483-5p were injected in the renal cortex. The tissue samples were collected at 7 and 21 days after the injection. A transgenic mouse model with inducible systemic overexpression of miR-483-5p was established in TG483 mice. The Cre-loxp system was used to create a mouse model with renal tubule-specific expression of miR-483-5p. The levels of BUN in the mice were detected and HE staining and fluorometric TUNEL assay were used to observe the morphological changes of the kidneys; real-time qPCR was used to detect miR-483-5p expression in the renal cortex. RESULTS: The mice with overexpression of miR-483-5p had normal renal function without obvious pathological changes or apoptosis in the renal tissue. Renal cortex injection of 20 µL lentivirus resulted in obviously increased level of miR-483-5p at 21 days (1.2∓0.43 vs 8.6∓1.09, P<0.001). miR-483-5p showed a low expression (0.9∓0.09 vs 1.7∓0.19, P<0.05) in TG483 mice and a high expression in the kidney of the transgenic mice established using the Cre-loxp system (1.6∓1.13 vs 12.36∓3.89, P<0.05). CONCLUSION: The transgenic mice with renal tubule-specific expression of miR-483-5p show normal renal function, and this model facilitates further study of the role of miR-483-5p in the kidney.

[Estradiol significantly increases the expression of antioxidant enzymes in osteoporotic rats and osteoblasts in vitro].

OBJECTIVE: To investigate the effect of estradiol on the expression of antioxidant enzymes in osteoblasts and its role in postmenopausal osteoporosis. METHODS: Rat models of osteoporosis established by ovariectomy were treated with estradiol for 3 months, and the changes in serum levels of reactive oxygen species (H2O2) and antioxidant enzymes (γ -GCS, GSH-ST and GSH-px) were detected. The effects of estradiol on the expression of γ -GCS mRNA and protein in osteoblast-like cells MC3T3-E1, MG63 and OB were examined with PCR and Western blotting. Using a mRNA microarray, we analyzed the changes in the expressions of 84 antioxidant enzymes in the osteoblast cell line MC3T3-E1 following estradiol treatment, and the enzymes with significant changes were verified by PCR. CCK-8 kit was used to evaluate the effect of estradiol and antioxidant NAC on the proliferation of MC3T3-E1 cells. RESULTS: Rat models of osteoporosis were successfully established with ovariectomy. The osteoporotic rats showed significantly increased serum level of reactive oxygen species (H2O2) and decreased levels of antioxidant enzymes. Estrogen treatment of the osteoporotic rats obviously reversed the phenotype of osteoporosis, lowered serum level of reactive oxygen species, and increased the level of γ -GCS. In MC3T3-E1, MG63 and OB cells, estradiol treatment significantly upregulated the expression levels of γ -GCS mRNA and protein. In MC3T3-E1 cells treated with estrogen, the mRNA chip identified 6 upregulated antioxidant enzymes (Gpx6, Gstk1, Nos2, Prdx2, Ngb and Ccs), and the results of PCR verified that estradiol upregulated Ccs and Ngb mRNAs in MC3T3-E1, MG63 and OB cells. Estradiol and antioxidant NAC obviously promoted the proliferation of MC3T3-E1 cells. CONCLUSION: Estradiol significantly increases the expression of antioxidase γ -Gcs, Ccs and Ngb in osteoblasts in vitro. Postmenopausal osteoporosis is closely related with the increase of reactive oxygen species and the decrease of antioxidant levels. In osteoblasts, estrogen deficiency may increase the level of reactive oxygen species, decrease the level of antioxidant enzymes, activate the oxidative stress cascade, and consequently inhibit the proliferation of osteoblasts to aggravate the condition of osteoporosis.