Improvement of diabetes-induced spinal cord axon injury with taurine via nerve growth factor-dependent Akt/mTOR pathway.

Diabetic neuropathy (DN) is a common neurological complication caused by diabetes mellitus (DM). Axonal degeneration is generally accepted to be the major pathological change in peripheral DN. Taurine has been evidenced to be neuroprotective in various aspects, but its effect on spinal cord axon injury (SCAI) in DN remains barely reported. This study showed that taurine significantly ameliorated axonal damage of spinal cord (SC), based on morphological and functional analyses, in a rat model of DN induced by streptozotocin (STZ). Taurine was also found to induce neurite outgrowth in cultured cerebral cortex neurons with high glucose exposure. Moreover, taurine up-regulated the expression of nerve growth factor (NGF) and neurite outgrowth relative protein GAP-43 in rat DN model and cultured cortical neurons/VSC4.1 cells. Besides, taurine increased the activating phosphorylation signals of TrkA, Akt, and mTOR. Mechanistically, the neuroprotection by taurine was related to the NGF-pAKT-mTOR axis, because either NGF-neutralizing antibody or Akt or mTOR inhibitors was found to attenuate its beneficial effects. Together, our results demonstrated that taurine promotes spinal cord axon repair in a model of SCAI in STZ-induced diabetic rats, mechanistically associating with the NGF-dependent activation of Akt/mTOR pathway.

Practice of dialysis access interventional nephrology procedures in the Asia-Pacific region: Getting lay of the land.

AIM: This cross-sectional survey aimed to determine the prevalence of Interventional Nephrology (IN) practice amongst nephrologists in the Asia-Pacific Region (APR), specifically related to dialysis access (DA). METHODS: The Association of VA and intervenTionAl Renal physicians (AVATAR) Foundation from India conducted a multinational online survey amongst nephrologists from the Asia-Pacific to determine the practice of IN in the planning, creation, and management of dialysis access. The treatment modalities, manpower and equipment availability, monthly cost of treatment, specifics of dialysis access interventions, and challenges in the training and practice of IN by nephrologists were included in the survey. RESULTS: Twenty-one countries from the APR participated in the survey. Nephrologists from 18 (85.7%) countries reported performing at least one of the basic dialysis access-related IN procedures, primarily the placement of non-tunnelled central catheters (n-TCC; 71.5%). Only 10 countries (47.6%) reported having an average of <4% of nephrologists performing any of the advanced IN access procedures, the most common being the placement of a peritoneal dialysis (PD) catheter (20%). Lack of formal training (57.14%), time (42.8%), incentive (38%), institutional support (38%), medico-legal protection (28.6%), and prohibitive cost (23.8%) were the main challenges to practice IN. The primary obstacles to implementing the IN training were a lack of funding and skilled personnel. CONCLUSION: The practice of dialysis access-related IN in APR is inadequate, mostly due to a lack of training, backup support, and economic constraints, whereas training in access-related IN is constrained by a lack of a skilled workforce and finances.

Taurine Ameliorates Oxidative Stress in Spinal Cords of Diabetic Rats via Keap1-Nrf2 Signaling.

Hyperglycemia associated with diabetes mellitus (DM) causes oxidative stress, which is involved in the onset and development of diabetic neuropathy. Taurine, a powerful antioxidant, is an effective inhibitor of oxidative stress. The present experiment was conducted to explore the effect of taurine treatment on alterations in body weight, blood glucose, oxidative stress, and Keap1-Nrf2 signaling in the spinal cords of DM rats. The DM rat model was established by STZ injection, and taurine was administered in the drinking water. Body weight and blood glucose were recorded during the experiment. The expression of Gap-43 and MBP proteins was examined by Western blot. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined as indicators of oxidative stress. The expression of Keap1, Nrf2, and HO-1 gene was examined by real-time PCR. The results showed that compared with the control group, the body weight was decreased, blood glucose was increased, and both Gap-43 and MBP expression were decreased in DM rats, which were all remarkably reversed by taurine treatment. Oxidative stress, as reflected by lower SOD activity and higher MDA concentration, was inhibited in taurine-treated DM rats. Supplemental taurine also downregulated the mRNA level of Keap1, while upregulating Nrf2 and HO-1 mRNA levels. These results showed that taurine inhibits oxidative stress in the spinal cords of DM rats, an effect that might involve the regulation of Keap1-Nrf2 signaling.

A strategy for the rapid discovery and validation of active diterpenoids as quality markers in different habitats of Langdu using ultrahigh-performance liquid chromatography-tandem mass spectrometry with multivariate statistical analysis.

Langdu, known as a traditional Chinese medicine, was identified as the roots of species of Euphorbia ebracteolata Hayata and Euphorbia fischeriana Steud, displaying anti-tuberculosis activity. To clarify the potent quality markers of Langdu, this research first developed a fast and sensitive ultrahigh-performance liquid chromatography-tandem mass spectrometry method for the quantification of 13 diterpenoids in Langdu. The developed method was further applied in the analyses of 12 authentic E. ebracteolata and E. fischeriana samples collected in northern and southeastern China. Then, the anti-tuberculosis evaluation of 12 batches of Langdu samples was performed in vitro. Finally, partial least squares discrimination analysis was used in the discrimination of E. ebracteolata and E. fischeriana from different origins and processing methods. Jolkinolide A (1), jolkinolide E (3), yuexiandajisu D (6), and ebractenone A (11) were identified as key, potent diterpenoids for the quality control of E. ebracteolata Hayata and E. fischeriana Steud. The present study established a qualitative chemical analysis method for Langdu (E. ebracteolata and E. fischeriana) and suggested the key bioactive components that will improve qualitative control methodology for this important medicine.

Identification of 8 Feature Genes Related to Clear Cell Renal Cell Carcinoma Progression Based on Co-Expression Analysis.

BACKGROUND: The aim of the study was to screen biomarkers related to clear cell renal cell carcinoma (ccRCC) progression and prognosis. METHODS: 1,026 ccRCC-related genes were dug from 494 ccRCC samples in TCGA based on weighted gene co-expression network analysis, and 7 modules were identified. Afterward, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were conducted on modules of interest. Genes in these modules were taken as the input to construct a protein-protein interaction network. Thereafter, 30 genes with the highest connectivity were taken as core genes. Univariate Cox regression, LASSO Cox regression, and multivariate Cox regression analyses were performed on core genes. Univariate and multivariate Cox regression analyses were performed on patients' clinical characteristics and risk scores. RESULTS: Stage displayed significantly strong correlations with green module and red module (p < 0.001). Genes in modules participated in biological functions including T-cell proliferation and regulation of lymphocyte activation. GSEA showed that high- and low-risk groups exhibited significant enrichment differences in pathways related to immunity, cell migration, and invasion. Immune infiltration analysis also presented a strong correlation between the expression of these 8 genes and immune cell infiltration in ccRCC samples. It was displayed that risk score could be an independent factor to assess patients' prognosis. CONCLUSION: We determined biomarkers relevant to ccRCC progression, offering candidate targets for ccRCC treatment.

Urinary proteomics investigations into contrast-induced acute kidney injury.

Some patients have a decline in renal function after contrast medium injection, and this phenomenon is called contrast-induced acute kidney injury (CI-AKI); a small number of people even suffer severe renal failure. To date, the mechanism of CI-AKI remains unclear. We aimed to identify novel potential biomarkers in the urine of patients with CI-AKI through LC-MS/MS and bioinformatics analysis. We enrolled patients who underwent coronary angiography (contrast agent: iohexol). The CI-AKI group included 4 cases, and the non-CI-AKI group included 20 cases. We mixed the 4 CI-AKI samples and 20 non-CI-AKI samples. Then, a 0.6 ml urine sample was used for proteome analysis with LC-MS/MS approach. Metascape, ExPASy, and the Human Protein Atlas were utilized for bioinformatics analysis. We obtained 724 and 830 urine proteins from the CI-AKI and non-CI-AKI groups, respectively. The distribution of the pI values and molecular weights (MWs) of postoperative urine proteins showed no significant difference between the CI-AKI group and the non-CI-AKI group. A total of 99differentially expressed proteins (DEPs) were detected, among which 18 proteins were detected only in tubule cells, and 19 proteins were detected in both tubule cells and glomeruli. With GO analysis, the GEPs were mainly associated with immune response and inflammation. Although biomarkers cannot be asserted from this single pilot study, our results may help advance the understanding of the mechanisms of CI-AKI and identify potential novel biomarkers for further investigation.

NGF mediates protection of mesenchymal stem cells-conditioned medium against 2,5-hexanedione-induced apoptosis of VSC4.1 cells via Akt/Bad pathway.

It has been shown that the conditioned medium of bone mesenchymal stem cells (BMSC-CM) can inhibit apoptosis of neural cells exposed to 2,5-hexanedione (HD), but its protective mechanism remains unclear. To investigate the underlying mechanism, VSC4.1 cells were given HD and 5, 10 and 15% BMSC-CM (v/v) in the current experiment. Our data showed that BMSC-CM concentration-dependently attenuated HD-induced cell apoptosis. Moreover, BMSC-CM remarkably decreased the mitochondrial cytochrome c (Cyt C) release and the caspase-3 activity in HD-given VSC4.1 cells. Given a relatively high expression of NGF in BMSCs and BMSC-CM, we hypothesized that NGF might be an important mediator of the protection of BMSC-CM against apoptosis induced by HD. To verify our hypothesis, the VSC4.1 cells were administrated with NGF and anti-NGF antibody in addition to HD. As expected, NGF could perfectly mimic BMSC-CM's protective role and these beneficial effects were abolished by anti-NGF antibody intervention. To further explore its mechanism, inhibitors of TrkA and Akt were given to the VSC4.1 cells and NGF/Akt/Bad pathway turned out to be involved in anti-apoptotic role of BMSC-CM. Based on these findings, it was revealed that BMSC-CM beneficial role was mediated by NGF and relied on the Akt/Bad pathway.

Overexpression of miR­30c­5p reduces cellular cytotoxicity and inhibits the formation of kidney stones through ATG5.

MicroRNAs (miRNAs or miRs) are critical regulators in various diseases. In the current study, the role of miR­30c­5p in the formation of sodium oxalate­induced kidney stones was investigated. For this purpose, human renal tubular epithelial cells (HK­2 cells) were incubated with sodium oxalate at the concentrations of 100, 250, 500, 750 and 1,000 µM. Cell viability and the miR­30c­5p expression level were respectively measured by CCK­8 assay and RT­qPCR. After separately transfecting miR­30c­5p mimic and inhibitor into the HK­2 cells, the cell apoptotic rate, the levels of mitochondrial membrane potential (MMP) and ROS were determined by flow cytometry. The levels of oxidative stress indicators [lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT)] were determined using commercial kits. Crystal­cell adhesion assay was performed to evaluate the crystal adhesion capacity in vitro. miR­30c­5p binding at autophagy related 5 (ATG5) was predicted by TargetScan7.2 and further verified by dual­luciferase reporter assay. Rescue experiments were performed to confirm the molecular mechanisms underlying sodium oxalate­induced kidney formation in HK­2 cells. The results revealed that sodium oxalate decreased the viability of HK­2 cells in a concentration­dependent manner, and that miR­30c­5p expression was significantly downregulated by exposure to 750 µM sodium oxalate. In addition, the increase in cell apoptosis and crystal number, and the upregulated levels of LDH, MDA and ROS were reversed by the overexpression of miR­30c­5p. Moreover, the overexpression of miR­30c­5p upregulated the levels of SOD, CAT and MMP induced by sodium oxalate. ATG5 was directly regulated by miR­30c­5p, and the inhibition of cell cytotoxicity and crystal­cell adhesion induced by miR­30c­5p mimic was blocked by ATG5. These data indicated that the overexpression of miR­30c­5p alleviated cell cytotoxicity and crystal­cell adhesion induced by sodium oxalate through ATG5. Thus, the current study provides a better understanding of the role of miR­30c­5p in sodium oxalate­induced kidney stones.

2,5-hexanedione-induced deregulation of axon-related microRNA expression in rat nerve tissues.

Exposure to organic solvent in industry, including n-hexane is correlated with central-peripheral axonopathy, which is mediated by its active metabolite, 2,5-hexanedione (HD). However, the underlying mechanism is still largely unknown. Recently identified microRNAs (miRNAs) may play important roles in toxicant exposure and in the process of toxicant-induced neuropathys. To examine the role of miRNAs in HD-induced toxicity, neuropathic animal model was successfully built. miRNA microarray analysis revealed 105 differentially expressed miRNAs after HD exposure. Bioinformatics analysis showed that "Axon" and "Neurotrophin Signaling Pathway" was the top significant GO term and pathway, respectively. 7 miRNAs both related to "Axon" and "Neurotrophin Signaling Pathway" were screened out and further confirmed by Real-Time PCR. Correspondingly, the deregulation expression levels of proteins of four target genes (GSK3ß, Map3k1, BDNF and MAP1B) were further confirmed via western blot, verifying the results of gene target analysis. Taken together, our results showed that the axon-related miRNAs to be associated with MAP1B or neurotrophin signal pathways changed in nerve tissues following HD exposure. These miRNAs may play important roles in HD-induced neurotoxicity.

Assessment of dialysis initiation by a fuzzy mathematics equation (ADIFE): a study protocol for a randomised controlled trial.

INTRODUCTION: Starting dialysis early or late both result in a low quality of life and a poor prognosis in patients undergoing haemodialysis. However, there remains no consensus on the optimal timing of dialysis initiation, mainly because of a lack of suitable methods to assess variations in dialysis initiation time. We have established a novel equation named DIFE (Dialysis Initiation based on Fuzzy-mathematics Equation) through a retrospective, multicentre clinical cohort study in China to determine the most suitable timing of dialysis initiation. The predictors of the DIFE include nine biochemical markers and clinical variables that together influence dialysis initiation. To externally validate the clinical accuracy of DIFE, we designed the assessment of DIFE (ADIFE) study as a prospective, open-label, multicentre, randomised controlled trial to assess the clinical outcomes among patients who initiate dialysis in an optimal start dialysis group and a late-start dialysis group, based on DIFE. METHODS AND ANALYSIS: A total of 388 enrolled patients with end-stage renal disease will be randomised 1:1 to the optimal start dialysis group, with a DIFE value between 30 and 35, or the late-start dialysis group, with a DIFE value less than 30, using the Randomization and Trial Supply Management system. Participants will be assessed for changes in signs and symptoms, dialysis mode and parameters, biochemical and inflammatory markers, Subjective Global Assessment, Kidney Disease Quality of Life Short Form, Cognitive Assessment, medical costs, adverse events and concomitant medication at baseline, predialysis visiting stage and postdialysis visiting stage, every 12-24 weeks. The following data will be recorded on standardised online electronic case report forms. The primary endpoint is 3-year all-cause mortality. The secondary endpoints include non-fatal cerebrocardiovascular events, annual hospitalisation rate, quality of life, medical costs and haemodialysis related complications. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Ethics Committee of the First Affiliated Hospital of Dalian Medical University China (registration no: YJ-KY-2017-119) and the ethics committees of all participating centres. The final results of the ADIFE trial will be presented to the study sponsor, clinical researchers and the patient and public involvement reference group. Findings will be disseminated through peer-reviewed journals, Clinical Practice Guidelines and at scientific meetings. TRIAL REGISTRATION NUMBER: ClinicalTrial.gov. Registry (NCT03385902); pre-results.

An Equation Based on Fuzzy Mathematics to Assess the Timing of Haemodialysis Initiation.

In order to develop an equation that integrates multiple clinical factors including signs and symptoms associated with uraemia to assess the initiation of dialysis, we conducted a retrospective cohort study including 25 haemodialysis centres in Mainland China. Patients with ESRD (n = 1281) who commenced haemodialysis from 2008 to 2011 were enrolled in the development cohort, whereas 504 patients who began haemodialysis between 2012 and 2013 were enrolled in the validation cohort comprised. An artificial neural network model was used to select variables, and a fuzzy neural network model was then constructed using factors affecting haemodialysis initiation as input variables and 3-year survival as the output variable. A logistic model was set up using the same variables. The equation's performance was compared with that of the logistic model and conventional eGFR-based assessment. The area under the bootstrap-corrected receiver-operating characteristic curve of the equation was 0.70, and that of two conventional eGFR-based assessments were 0.57 and 0.54. In conclusion, the new equation based on Fuzzy mathematics, covering laboratory and clinical variables, is more suitable for assessing the timing of dialysis initiation in a Chinese ESRD population than eGFR, and may be a helpful tool to quantitatively evaluate the initiation of haemodialysis.

Impacts of parathyroidectomy on renal anemia and nutritional status of hemodialysis patients with secondary hyperparathyroidism.

The aim of this study was to investigate the impacts of parathyroidectomy (PTX) towards the renal anemia and nutritional status of hemodialysis patients with secondary hyperparathyroidism (SHPT). 32 patients, enrolled into the blood purification center of our hospital for the hemodialysis treatment, were collected and divided into the PTX group and the non-PTX group, with 16 patients in each group. The changes of relevant indicators such as immunoreactive parathyroid hormone (iPTH), anemia and nutrition were observed before, 1-, 3-, 6-month after the treatment. The contents of iPTH, Ca, P and Ca × P of the PTX group decreased rapidly 1 month after the surgery; while Hb and Hct increased significantly from the 1st postoperative month; the dosage of EPO was significantly reduced 3-month after the surgery; the content of Alb gradually increased from the 3(rd) postoperative month; the content of TG decreased significantly from the 6(th) postoperative month; while the contents of BMI and TSF increased significantly from the 6(th) postoperative month, which exhibited the statistically significant differences when compared with the preoperative and the non-PTX group (P < 0.05). PTX could quickly reduce the iPTH level and significantly improve the renal anemia and nutritional status; SHPT was the important factor that would affect the renal anemia and malnutrition; PTX could reduce the amount of EPO, and reduce the economic burden of patients.

Angiogenesis inhibitor, TNP-470, prevents diet-induced and genetic obesity in mice.

Adipose tissue growth has been proposed to involve recruitment of new blood vessels. Here, we test the hypothesis that delivery of an angiogenesis inhibitor in mice may prevent diet-induced obesity, the most common type of obesity in humans. We show that systemic administration of a selective angiogenesis inhibitor, TNP-470 (AGM-1470), prevents obesity in high caloric diet-fed wt mice as well as in genetically leptin-deficient ob/ob mice. Inhibition of obesity in mice by TNP-470 involves a reduction of vascularity in the adipose tissue. This therapeutic strategy appears to selectively affect the growth of adipose tissue as measured by the ratio between total fat and lean body mass. Interestingly, the treatment with TNP-470 results in decreased serum levels of low-density lipoprotein cholesterol. Furthermore, insulin levels are reduced, which indicates increased insulin sensitivity, suggesting that angiogenesis inhibitors may prevent the development of type II diabetes. Our findings suggest that similarly to growth and organogenesis in other tissues, adipose tissue growth is dependent on angiogenesis. Our observations may have conceptual implications for the prevention of obesity and related disorders.

Repeated immobilization stress increases uncoupling protein 1 expression and activity in Wistar rats.

Repeat immobilization-stressed rats are leaner and have improved cold tolerance due to enhancement of brown adipose tissue (BAT) thermogenesis. This process likely involves stress-induced sympathetic nervous system activation and adrenocortical hormone release, which dynamically enhances and suppresses uncoupling protein 1 (UCP1) function, respectively. To investigate whether repeated immobilization influences UCP1 thermogenic properties, we assessed UCP1 mRNA, protein expression, and activity (GDP binding) in BAT from immobilization-naive or repeatedly immobilized rats (3 h daily for 4 weeks) and sham operated or adrenalectomized (ADX) rats. UCP1 properties were assessed before (basal) and after exposure to 3 h of acute immobilization. Basal levels of GDP binding and UCP1 expression was significantly increased (140 and 140%) in the repeated immobilized group. Acute immobilization increased GDP binding in both naive (180%) and repeated immobilized groups (220%) without changing UCP1 expression. In ADX rats, basal GDP binding and UCP1 gene expression significantly increased (140 and 110%), and acute immobilization induced further increase. These data demonstrate that repeated immobilization resulted in enhanced UCP1 function, suggesting that enhanced BAT thermogenesis contributes to lower body weight gain through excess energy loss and an improved ability to maintain body temperature during cold exposure.

Enhanced gene expression of endothelial nitric oxide synthase in brown adipose tissue during cold exposure.

It has been shown that norepinephrine (NE) can mediate vasodilatation by stimulating the production of nitric oxide (NO) in brown adipose tissue (BAT), resulting in an increase in BAT blood flow. We speculated that constitutive NO synthase (NOS) is involved in this NO production. However, it is not known whether constitutive NOS is expressed in BAT. To answer this question, we assessed the expression of two types of constitutive NOS, endothelial (eNOS) and neuronal NOS (nNOS), in BAT of rats. eNOS was abundantly expressed in both BAT and isolated brown adipocytes, whereas nNOS was not. Cold exposure, which is known to stimulate NE release from sympathetic nerve terminals in BAT, led to a significant increase in eNOS mRNA in this tissue. In contrast, very low levels of inducible NOS (iNOS) mRNA were expressed, and cold stimulation failed to increase iNOS mRNA levels in BAT. These results suggest that eNOS is the primary isoform that is responsible for NO production in BAT and that its expression may be under sympathetic control.