Alleviation of TGF-ß1 induced tubular epithelial-mesenchymal transition via the δ-opioid receptor.

Renal fibrosis is a common pathological feature of progressive chronic kidney disease (CKD). It is indicated that transforming growth factor-ß1 (TGF-ß1) plays as a central mediator in renal fibrosis. The present study aimed to investigate the role of δ-opioid receptor (DOR) on renal fibrosis of the rat renal proximal tubular epithelial cell line (NRK-52E) induced by TGF-ß1 and to elucidate its underlying mechanism, as well as its involvement in signaling pathways. Cells were treated with TGF-ß1 (10 ng·mL-1 ), along with a specific DOR agonist (UFP-512) or naltrindole (a DOR antagonist). Cell viability and morphology, as well as cell migration, were measured after drug administration. Western blotting was employed to examine the extracellular matrix (ECM) protein Fibronectin, and the tubular epithelial-mesenchymal transition (EMT) markers (E-cadherin and α-smooth muscle actin (α-SMA)), signal transducer (p-Smad3), and EMT-regulatory gene (Snail). The expression level of phosphorylated Akt and p38 was also examined. Our results showed that TGF-ß1 induced fibroblastic appearance and increased the expression of Fibronectin, α-SMA, P-Smad3, and Snail, while it decreased the expression of E-cadherin in NRK-52E cells. Moreover, TGF-ß1 induced the activation of Akt and p38 MAPK signaling pathways. DOR activation was found to efficiently block morphological changes and cell migration, as long as the expression changes of Fibronectin, E-cadherin, α-SMA, P-Smad3, Snail, P-Akt, and P-p38 were induced by TGF-ß1. These findings suggest that DOR may serve as an antifibrotic factor for renal proximal tubule cells by inhibiting the fibrosis process via TGF-ß/Smad, Akt, and p38 MAPK signaling pathways.

Prognostic Effect of Preoperative Apolipoprotein B Level in Surgical Patients with Clear Cell Renal Cell Carcinoma.

BACKGROUND: The aim of this study was to assess the prognostic value of the preoperative apolipoprotein B (ApoB) level in surgical patients with clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS: The study included 307 ccRCC patients receiving radical or partial nephrectomy between 2003 and 2012 in our center. The correlations among the preoperative ApoB, clinicopathological parameters, and overall survival (OS) were evaluated. RESULTS: A total of 193 males (62.9%) and 114 females (37.1%) with ccRCC who underwent radical or partial nephrectomy were enrolled in the present study. The OS at 5 years after the operation was 90.6% for all patients, 87.4% for the lower ApoB group, and 97.0% for the higher-ApoB group. The cause-specific survival (CSS) at 5 years after surgery was 90.2% for all patients, 86.7% for the lower-ApoB group, and 97.0% for the higher-ApoB group. A higher-ApoB level was related to a better OS and CSS in ccRCC patients (p = 0.001 and p < 0.001, respectively). In multivariate analysis, age >60 years (p = 0.008 and p = 0.023) and a lower Apo B level (p = 0.019 and p = 0.018) were independent prognostic factors for OS and CSS, respectively. CONCLUSIONS: In the Apo apolipoprotein family, the preoperative ApoB level had an important clinical significance for predicting the prognosis and survival rate of ccRCC patients.

GATA3 suppresses human fibroblasts-induced metastasis of clear cell renal cell carcinoma via an anti-IL6/STAT3 mechanism.

Tumorigenesis and metastasis depend on intricate interactions between genetically altered tumor cells and their surrounding microenvironment. It is, however, unclear regarding the molecular mechanisms underlying the progress and metastasis of human clear-cell renal cell carcinoma in the microenvironment with fibroblasts. In this work, we investigated the effect of normal fibroblasts on the metastasis of renal cancer and the relevant signaling pathways. We isolated normal fibroblasts from normal renal tissues and used normal fibroblast-conditioned medium culture renal cancer cells. The CCK-8 and transwell assays showed that normal fibroblasts conditioned medium significantly enhanced ccRCC cell migration. IL6 mediated the cross talk between normal fibroblasts and the cancer cells, and promoted tumor cell migration through the STAT3 pathway. In contrast, GATA3 was downregulated at both mRNA and protein levels in the normal fibroblast-conditioned medium treated with renal cancer cells, but upregulated in adjacent normal tissues. GATA3 overexpression significantly reduced STAT3 phosphorylation and attenuated the migration in both renal cancer cell and IL6-stimulated renal cancer cell. Taken together, our findings suggest that the IL6/STAT3 pathway plays a crucial role in the normal fibroblast-enhanced clear-cell renal cell carcinoma metastasis, while GATA3 may mitigate this effect by inhibiting IL6/STAT3 signaling.

The δ-Opioid Receptor Differentially Regulates MAPKs and Anti-inflammatory Cytokines in Rat Kidney Epithelial Cells Under Hypoxia.

Hypoxic injury is one of the most important factors in progressive kidney disorders. Since we have found that δ-opioid receptor (DOR) is neuroprotective against hypoxic stress through a differential regulation of mitogen-activated protein kinases (MAPKs) and anti-inflammatory cytokines, we asked if DOR that is highly expressed in the kidney can modulate renal MAPKs and anti-inflammatory cytokines under hypoxia. We exposed cultured rat kidney epithelial cells (NRK-52E) to prolonged hypoxia (1% O2) with applications of specific DOR agonist or/and antagonist to examine if DOR affects hypoxia-induced changes in MAPKs and anti-inflammatory cytokines. The results showed that endogenous DOR expression remained unchanged under hypoxia, while DOR activation with UFP-512 (a specific DOR agonist) reversed the hypoxia-induced up-regulation of ERK1/2 and p38 phosphorylation. DOR inhibition with naltrindole had no appreciable effect on the hypoxia-induced changes in ERK1/2 phosphorylation, but increased p38 phosphorylation. DOR inhibition with naltrindole attenuated the effects of DOR activation on the changes in ERK1/2 and p38 phosphorylation in hypoxia. Moreover, DOR activation/inhibition differentially affected the expression of transcriptional repressor B-cell lymphoma 6 (Bcl-6), anti-inflammatory cytokines tristetraprolin (TTP), and interleukin-10 (IL-10). Taken together, our novel data suggest that DOR activation differentially regulates ERK1/2, p38, Bcl-6, TTP, and IL-10 in the renal cells under hypoxia.

Transperitoneal versus extraperitoneal approach in laparoscopic radical prostatectomy: A meta-analysis.

BACKGROUND: To compare the transperitoneal approach with extraperitoneal approach in laparoscopic radical prostatectomy (LRP) (including pure and robotic-assisted LRP) using meta-analytic techniques. METHODS: Medline (PubMed), Embase, Ovid, CMB, and Cochrane databases were searched for studies that compared the transperitoneal and extraperitoneal approaches in LRP from January 2000 to January 2017. Outcomes included were operative time, operative bloods joss (milliliters), rate of transfusion, rate of open conversion, rate of intraoperative complications, rate of postoperative complications, and time of postoperative catheterization. RESULTS: Thirteen studies including 1674 patients were selected for the meta-analysis. 850 (50.8%) cases had undergone transperitoneal LRP (TLRP) and 824 (49.2%) cases had undergone the extraperitoneal LRP (ELRP). Comparison of operative time between the TLRP group and the ELRP group showed no significant differences (weighted mean difference [WMD] = 21.21,95%CI = -1.16-43.57, P = .06). No significant differences were observed in blood loss (WMD = -6.04, 95%CI = -43.38-31.29, P = .75) and the rate of transfusion (odds ratio [OR] = 1.03, 95%CI = 0.55-1.96, P = .92) between the 2 groups. No significant differences were observed for the rate of intraoperative complications (OR = 1.25, 95%CI = 0.57-2.21, P = .75) and the rate of open conversion (OR = 1.12, 95%CI = 0.32-4.97, P = .75). Significant differences were observed in the TLRP group compared with the ELRP group (OR = 1.69, 95%CI: 1.23-2.32, P = .001) regarding the rate of postoperative complications. CONCLUSIONS: Our meta-analysis findings revealed that the TLRP group showed no significant differences in most important indicators compared with ELRP. Moreover, TLRP showed higher rate of postoperative complications compared with ELRP.

Major Differences in Hypoxia Tolerance and P38 Regulation Among Different Renal Cells.

BACKGROUND/AIMS: Mitogen-activated protein kinases (MAPKs) are involved in the cellular response to hypoxia and their dysregulation may contribute to the progression and pathology of diverse human renal diseases. Recent studies suggest that the regulation of MAPK responses to hypoxic stress may be different in different cells, even within the same organ. However, it is unclear if MAPKs are differentially regulated in different renal cells in hypoxia. This work was carried out to clarify this fundamental issue. METHODS: We cultured normal rat kidney epithelial (NRK-52E) cells, human kidney epithelial (HK-2) cells and human renal cell adenocarcinoma (769-P) cells simultaneously under normoxia and hypoxia (1% O2) for 24-72 hours. The protein levels of P-ERK1/2, ERK1/2, P-p38, p38 and eEF2K were detected by western blotting. The morphology of all cells was examined using light microscopy. RESULTS: Under the same hypoxic condition, P-ERK1/2 was up-regulated in all renal cells. Meanwhile,P-p38 in NRK-52E cells was markedly increased after hypoxia for 24-72 hours, while it appeared to show no appreciable change in HK-2 and 769-P cells exposed to hypoxia for 24-48 hours and significantly decreased in these cells after 72 hours hypoxia. On the other hand, hypoxia markedly down-regulated the expression of eukaryotic elongation factor-2 kinase (eEF2K) in all three cells. Under microscopy, NRK-52E cells had no visible injury after 72 hours hypoxia, while HK-2 and 769-P cells were mostly damaged under the same condition. CONCLUSIONS: Our data suggest that in response to prolonged hypoxic stress, ERK1/2 and p38 are differentially regulated in three renal cells, while eEF2K is largely down-regulated in all of these cells.