Upregulation of KLF14 expression attenuates kidney fibrosis by inducing PPARα-mediated fatty acid oxidation.

Tubulointerstitial fibrosis (TIF) is essential during the development of end-stage kidney disease (ESKD) and is associated with the impairment of fatty acid oxidation (FAO). Kruppel-like factor 14 (KLF14) is an important gene in lipid metabolism, but its role in TIF remains unknown. TGF-ß-stimulated HK-2 cells and mouse unilateral ureteral obstruction (UUO) were used as renal fibrosis models. The role of KLF14 in the process of renal fibrosis was verified by gene knockout mice, genetic or pharmacological interference in animal model and cell model respectively. In the current study, we found that KLF14 expression increased after activation of the TGF-ß signaling pathway during TIF. In KLF14-/- mice, more severe fibrosis was observed after unilateral ureteral obstruction (UUO) was induced. In human HK2 cells, knockdown of KLF14 led to more severe fibrosis induced by TGF-ß1, while overexpression of KLF14 partially attenuated this process. Specifically, KLF14 deficiency decreased mitochondrial FAO activity, resulting in lipid accumulation. Thus, the energy supply to the cells was insufficient, finally resulting in TIF. We further proved that KLF14 could target peroxisome proliferator activated receptor alpha (PPARα) as a transcriptional activator. This study identified the upregulation of KLF14 expression in response to kidney stress during the process of fibrosis. Upon TIF, the activated TGF-ß signaling pathway can enhance KLF14 expression, while the upregulation of KLF14 expression can decrease the degree of TIF by improving FAO activity in tubular epithelial cells and recovering the energy supply mediated by PPARα.

Acyl-CoA Thioesterase 8 and 11 as Novel Biomarkers for Clear Cell Renal Cell Carcinoma.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is essentially a metabolic disorder characterized by reprogramming of several metabolic pathways. Acyl-coenzyme A thioesterases (ACOTs) are critical enzymes involved in fatty acid metabolism; however, the roles of ACOTs in ccRCC remain unclear. This study explored ACOTs expressions and their diagnostic and prognostic values in ccRCC. METHODS: Three online ccRCC datasets from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) were utilized to measure the expressions of ACOTs in paired normal and tumor tissues. Receiver operating characteristic (ROC) curves were depicted to assess the diagnostic values of ACOTs in ccRCC. Quantitative real-time PCR and immunohistochemical analysis were performed to validate the ACOT11 expression in ccRCC cell lines and clinical samples. Survival curves and Cox regression analysis were used to evaluate the predictive values of ACOTs in clinical outcome of ccRCC patients. Functional enrichment analyses and correlation analysis were carried out to predict the potential roles of ACOT8 in tumorigenesis and progression of ccRCC. RESULTS: ACOT1/2/8/11/13 were found to be significantly downregulated in ccRCC samples. In particular, ACOT11 was decreased in almost every matched normal-tumor pair, and had extremely high diagnostic value as shown by ROC curve analysis (AUC = 0.964). The expression of ACOT11 was further verified in ccRCC cell lines and clinical samples at mRNA and protein levels. Furthermore, clinical correlation analysis and survival analysis indicated that ACOT8 was correlated with disease progression and was an independent predictor of unfavorable outcome in ccRCC. Moreover, functional analyses suggested potential roles of ACOT8 in the regulation of oxidative phosphorylation (OXPHOS), and correlation analysis revealed an association between ACOT8 and ferroptosis-related genes in ccRCC. CONCLUSION: Our study revealed that ACOT11 and ACOT8 are promising biomarkers for diagnosis and prognosis of ccRCC, respectively, and ACOT8 may affect ccRCC development and progression through the regulation of OXPHOS and ferroptosis. These findings may provide new strategies for precise diagnosis and personalized therapy of ccRCC.

A preliminary study: the role of preoperative procalcitonin in predicting postoperative fever after mini-percutaneous nephrolithotomy in patients with a negative baseline urine culture.

To evaluate the role of preoperative procalcitonin (PCT) levels in predicting postoperative fever after mini-percutaneous nephrolithotomy (mini-PCNL) in patients with a negative baseline urine culture. Between January 2014 and October 2017, 329 patients with a negative baseline urine culture and who underwent mini-PCNL were enrolled in this study. Patients were stratified into the control or febrile group based on a body temperature either less than or greater than 38 °C, respectively. Demographic and perioperative data were compared between the groups, and variables found to be statistically significant were included in a binary logistic regression analysis. A total of 68 (20.6%) patients experienced postoperative fever. The univariate analysis revealed a statistically significant difference between groups in preoperative fever (p = 0.032), stone burden (p < 0.001), C-reactive protein (p = 0.011), PCT (p < 0.001) and interleukin-6 (p = 0.035) levels. Binary logistic regression analysis indicated that stone burden > 353 mm3 (p = 0.003) and PCT > 0.05 ng/mL (p < 0.001) are independent risk factors for postoperative fever in mini-PCNL-treated patients with a negative baseline urine culture. We concluded that patients with stone burden > 353 mm3 or PCT > 0.05 ng/mL were more likely to develop postoperative fever after mini-PCNL, though with a negative baseline urine culture.

Is the Preoperative Level of Procalcitonin a Valid Indicator for Predicting Postoperative Fever After Percutaneous Nephrolithotomy?

OBJECTIVE: To evaluate the risk factors for postoperative fever and to identify the value of preoperative procalcitonin (PCT) in predicting postoperative fever after percutaneous nephrolithotomy (PNL). PATIENTS AND METHODS: Patients who underwent PNL between January 2014 and March 2017 were studied. In total, 363 medical records with complete data were determined to be eligible for analysis. Patients were classified into a control or febrile group according to the presence of a body temperature over 38°C. Demographic and perioperative data were compared between the groups. Variables found to be statistically significant were included in a binary logistic regression analysis. RESULTS: Ninety-one (25.1%) patients experienced postoperative fever. Univariate analysis revealed a statistically significant difference between postoperative fever and factors, such as sex (p = 0.009), preoperative fever (p < 0.001), stone burden (p < 0.001), pyuria (p = 0.013), urine culture (p < 0.001), and serum levels of C-reactive protein (CRP) (p = 0.003), PCT (p < 0.001), and interleukin-6 (IL-6) (p = 0.003). Binary logistic regression analysis indicated the presence of preoperative fever (p = 0.037), stone burden >353 mm2 (p = 0.002), PCT >0.05 ng/mL (p < 0.001), or positive urine culture (p = 0.004) as independent risk factors for postoperative fever following PNL. CONCLUSIONS: We concluded that patients with preoperative fever, stone burden >353 mm2, PCT >0.05 ng/mL, or positive urine culture were more likely to develop postoperative fever and that routinely detecting PCT levels before PNL would be helpful in predicting postoperative fever.

Relaxin abrogates renal interstitial fibrosis by regulating macrophage polarization via inhibition of Toll-like receptor 4 signaling.

Renal fibrosis is a common feature of chronic kidney disease (CKD). To inhibit the CKD process, it is important to prevent renal fibrosis, though CKD remains incurable. Renal fibrosis can be inhibited by relaxin in several experimental models, but the mechanism of relaxin for antifibrotic potential is still not clear. And here we have studied the role of relaxin in macrophage polarization and renal inflammation after unilateral ureteral obstruction (UUO). Our results show that relaxin can downregulate the Toll-like receptor (TLR) 4 signaling, shift macrophage polarization toward the M2 phenotype and ameliorat renal fibrosis in the early stages of UUO. In vitro experiments, it has been confirmed that relaxin can downregulate the TLR4 signaling and induce the M2 macrophage transition. Furthermore, the transitional actions of macrophage phenotype induced by relaxin are significantly blocked by TAK-242, a TLR4 antagonist, in vitro experiments. Thus, there is a novel mechanism of relaxin for antifibrosis that shifts macrophage polarization toward the M2 phenotype via inhibition of TLR4 signaling.

HMGB1/TLR4 signaling induces an inflammatory response following high-pressure renal pelvic perfusion in a porcine model.

Percutaneous nephrolithotomy (PCNL) causes a rapid increase in renal pelvic pressure in the kidney, which induces an inflammatory response. High-mobility group box-1 (HMGB1) is known to trigger the recruitment of inflammatory cells and the release of proinflammatory cytokines following ischemia reperfusion injury in the kidney, but the contribution of HMGB1 to the inflammatory response following high-pressure renal pelvic perfusion has not been investigated. In this study, high-pressure renal pelvic perfusion was induced in anesthetized pigs to examine the effect of HMGB1 on the inflammatory response. HMGB1 levels in the kidney increased following high-pressure renal pelvic perfusion, together with elevated levels of inflammatory cytokines in the plasma and kidney and an accumulation of neutrophils and macrophages. Inhibition of HMGB1 alleviated this inflammatory response while perfusion with recombinant HMGB1 had an augmentative effect, confirming the involvement of HMGB1 in the inflammatory response to high-pressure renal pelvic perfusion. HMGB1 regulated the inflammatory response by activating Toll-like receptor 4 (TLR4) signaling. In conclusion, this study has demonstrated that HMGB1/TLR4 signaling contributes to the inflammatory response following high-pressure renal pelvic perfusion in a porcine model and has implications for the management of inflammation after PCNL.

Verapamil Inhibits the Pelvic Pressure Increase Corresponding to Flow Perfusion in the Porcine Percutaneous Renal Puncture Model.

PURPOSE: To estimate the effects of verapamil on pelvic pressure and investigate the possible systemic side effects in the porcine model during the procedure of increasing perfusion rates. MATERIALS AND METHODS: In the experimental group, the pelvic pressure was recorded with increasing perfusion rates of the renal pelvis (0, 2, 4, 6, 8, 10, 14 and 20 ml/min) in response to intraluminal administration of increasing concentrations of verapamil (0, 0.1, 1, 10 and 100 µg/ml) in isotonic saline. In the isotonic saline group, the pressure flow study was also done by increasing perfusion rates of the renal pelvis per animal using isotonic saline without verapamil. RESULTS: Perfusion with 1, 10 and 100 µg/ml verapamil caused a decrease in pelvic pressure as a response to increasing flow rates, whereas perfusion with 0.1 µg/ml verapamil did not obviously inhibit the increase of pelvic pressure at all perfusion rates compared with other concentrations. Importantly, the mean systolic blood pressure and mean heart rate were stable despite the increase of flow rates and verapamil concentrations. In the isotonic saline group, perfusion with isotonic saline resulted in an increase in the pelvic pressure with an increase in flow rates each time. CONCLUSIONS: Endoluminal administration of verapamil reduces pelvic pressure significantly without any untoward systemic cardiovascular side effects.

Increased B-type-natriuretic peptide promotes myocardial cell apoptosis via the B-type-natriuretic peptide/long non-coding RNA LSINCT5/caspase-1/interleukin 1ß signaling pathway.

Chronic heart failure (CHF) is the final stage of various heart diseases, and is increasingly recognized as a major health problem in the elderly. Previous studies demonstrated that B­type­natriuretic peptide (BNP) is an established biomarker of CHF. Furthermore, BNP also regulates cell proliferation, differentiation and apoptosis. Recent evidence has revealed that BNP affects myocardial cell apoptosis during myocardial ischemia­reperfusion injury. Long non­coding RNAs (lncRNAs) are emerging as novel molecular compounds involved in gene regulation, and have important roles in numerous human diseases. However, the mechanism underlying the BNP and lncRNA-induced regulation of myocardial cell apoptosis remains to be elucidated. The present study reported that lncRNA LSINCT5, upregulated by BNP, is able to regulate myocardial cell apoptosis via the activation of the caspase­1/interleukin (IL)­1ß signaling pathway. BNP-induced apoptosis of HCM cells was observed using flow cytometry, and involved caspase­1. In addition, expression profiling using a human lncRNA polymerase chain reaction array revealed that LSINCT5 was highly expressed in BNP-treated myocardial cells, as compared with untreated cells. The role of lncRNA LSINCT5 in HCM cell apoptosis was also investigated. The results of the present study indicated that LSINCT5 silencing by small interfering RNA inhibits caspase­1/IL­1ß signaling, and suppresses apoptosis in BNP-treated HCM cells. Therefore, high expression levels of BNP promote the apoptosis of myocardial cells through the lncRNA LSINCT5 mediator, which activates the caspase­1/IL­1ß signaling pathway. These findings uncovered a novel pathogenic mechanism, and provided a potential therapeutic target for CHF.

Effect of heat shock pretreatment on apoptosis and metallothionein expression in rat cardiomyocytes.

To investigate the effect of heat shock pretreatment on apoptosis and mitochondrial metallothionein (MT) expression in rat cardiomyocytes. In vitro cultured H9C2 cells were randomly divided into three groups: control, hydrogen peroxide (H2O2) injury, and H2O2 injury after heat shock pretreatment (n = 6 per group). Cardiomyocyte apoptosis and caspase-3 activity were assayed after treatment. Mitochondrial cytochrome (cyt) c and MT expression was assayed by Western blotting. Compared with the control group, the H2O2 injury group had a growing number of apoptotic cardiomyocytes (P < 0.01) and significantly elevated caspase-3 activity (P < 0.01) with markedly increased mitochondrial cyt c and MT expression (P < 0.01). After heat shock pretreatment, the numbers of apoptotic and necrotic cardiomyocytes (P < 0.01) and the caspase-3 activity significantly declined (P < 0.01), while mitochondrial cyt c and MT expression continued to increase (P < 0.01) compared with the H2O2 injury group. Heat shock pretreatment inhibits cardiomyocyte apoptosis, which may have a protective effect on cardiomyocytes by increasing the expression of myocardial protective MT and reducing the release of mitochondrial cyt c.