Critical hubs of renal ischemia-reperfusion injury: endoplasmic reticulum-mitochondria tethering complexes.

Mitochondrial injury and endoplasmic reticulum (ER) stress are considered to be the key mechanisms of renal ischemia-reperfusion (I/R) injury. Mitochondria are membrane-bound organelles that form close physical contact with a specific domain of the ER, known as mitochondrial-associated membranes. The close physical contact between them is mainly restrained by ER-mitochondria tethering complexes, which can play an important role in mitochondrial damage, ER stress, lipid homeostasis, and cell death. Several ER-mitochondria tethering complex components are involved in the process of renal I/R injury. A better understanding of the physical and functional interaction between ER and mitochondria is helpful to further clarify the mechanism of renal I/R injury and provide potential therapeutic targets. In this review, we aim to describe the structure of the tethering complex and elucidate its pivotal role in renal I/R injury by summarizing its role in many important mechanisms, such as mitophagy, mitochondrial fission, mitochondrial fusion, apoptosis and necrosis, ER stress, mitochondrial substance transport, and lipid metabolism.

Machine learning in nephrology: scratching the surface.

Machine learning shows enormous potential in facilitating decision-making regarding kidney diseases. With the development of data preservation and processing, as well as the advancement of machine learning algorithms, machine learning is expected to make remarkable breakthroughs in nephrology. Machine learning models have yielded many preliminaries to moderate and several excellent achievements in the fields, including analysis of renal pathological images, diagnosis and prognosis of chronic kidney diseases and acute kidney injury, as well as management of dialysis treatments. However, it is just scratching the surface of the field; at the same time, machine learning and its applications in renal diseases are facing a number of challenges. In this review, we discuss the application status, challenges and future prospects of machine learning in nephrology to help people further understand and improve the capacity for prediction, detection, and care quality in kidney diseases.

Corrosion resistance and antibacterial activity of zinc-loaded montmorillonite coatings on biodegradable magnesium alloy AZ31.

A Zinc-loaded montmorillonite (Zn-MMT) coating was hydrothermally prepared using Zn2+ ion intercalated sodium montmorillonite (Na-MMT) upon magnesium (Mg) alloy AZ31 as bone repairing materials. Biodegradation rate of the Mg-based materials was studied via potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and hydrogen evolution tests. Results revealed that both Na-MMT and Zn-MMT coatings exhibited better corrosion resistance in Dulbecco's modified eagle medium (DMEM) + 10% calf serum (CS) than bare Mg alloy AZ31 counterparts. Hemolysis results demonstrated that hemocompatibility of the Na-MMT and Zn-MMT coatings were 5%, and lower than that of uncoated Mg alloy AZ31 pieces. In vitro MTT tests and live-dead stain of osteoblast cells (MC3T3-E1) indicated a significant improvement in cytocompatibility of both Na-MMT and Zn-MMT coatings. Antibacterial properties of two representative bacterial strains associated with device-related infection, i.e. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), were employed to explore the antibacterial behavior of the coatings. The measured inhibitory zone and bacterial growth rate confirmed that Zn-MMT coatings exhibited higher suppression toward both E. coli and S. aureus than that of Na-MMT coatings. The investigation on antibacterial mechanism through scanning electron microscopy (SEM) and lactate dehydrogenase (LDH) release assay manifested that Zn-MMT coating led to severe breakage of bacterial membrane of E. coli and S. aureus, which resulted in a release of cytoplasmic materials from the bacterial cells. In addition, the good inhibition of Zn-MMT coatings against E. coli and S. aureus might be attributed to the slow but sustainable release of Zn2+ ions (up to 144 h) from the coatings into the culture media. This study provides a novel coating strategy for manufacturing biodegradable Mg alloys with good corrosion resistance, biocompatibility and antibacterial activity for future orthopedic applications. STATEMENT OF SIGNIFICANCE: The significance of the current work is to develop a corrosion-resistant and antibacterial Zn-MMT coating on magnesium alloy AZ31 through a hydrothermal method. The Zn-MMT coating on magnesium alloy AZ31 shows better corrosion resistance, biocompatibility and excellent antibacterial ability than magnesium alloy AZ31. This study provides a novel coating on Mg alloys for future orthopedic applications.

A non-invasive diagnostic model of immunoglobulin A nephropathy and serological markers for evaluating disease severity.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is the most common pathological type of glomerular disease. Kidney biopsy, the gold standard for IgAN diagnosis, has not been routinely applied in hospitals worldwide due to its invasion nature. Thus, we aim to establish a non-invasive diagnostic model and determine markers to evaluate disease severity by analyzing the serological parameters and pathological stages of patients with IgAN. METHODS: A total of 272 biopsy-diagnosed IgAN inpatients and 518 non-IgA nephropathy inpatients from the Department of Nephrology of Chinese People's Liberation Army General Hospital were recruited for this study. Routine blood examination, blood coagulation testing, immunoglobulin-complement testing, and clinical biochemistry testing were conducted and pathological stages were analyzed according to Lee grading system. The serological parameters and pathological stages were analyzed. The receiver operating characteristic (ROC) analysis was performed to estimate the diagnostic value of the clinical factors. Logistic regression was used to establish the diagnostic model. RESULTS: There were 15 significantly different serological parameters between the IgAN and non-IgAN groups (all P < 0.05). The ROC analysis was performed to measure the diagnostic value for IgAN of these parameters and the results showed that the area under the ROC curve (AUC) of total protein (TP), total cholesterol (TC), fibrinogen (FIB), D-dimer (D2), immunoglobulin A (IgA), and immunoglobulin G (IgG) were more than 0.70. The AUC of the "TC + FIB + D2 + IgA + age" combination was 0.86, with a sensitivity of 85.98% and a specificity of 73.85%. Pathological grades of I, II, III, IV, and V accounted for 2.21%, 17.65%, 62.50%, 11.76%, and 5.88%, respectively, with grade III being the most prevalent. The levels of urea nitrogen (UN) (13.57 ±â€Š5.95 vs. 6.06 ±â€Š3.63, 5.92 ±â€Š2.97, 5.41 ±â€Š1.73, and 8.41 ±â€Š3.72 mmol/L, respectively) and creatinine (Cr) (292.19 ±â€Š162.21 vs. 80.42 ±â€Š24.75, 103.79 ±â€Š72.72, 96.41 ±â€Š33.79, and 163.04 ±â€Š47.51 µmol/L, respectively) were significantly higher in grade V than in the other grades, and the levels of TP (64.45 ±â€Š7.56, 67.16 ±â€Š6.94, 63.22 ±â€Š8.56, and 61.41 ±â€Š10.86 vs. 37.47 ±â€Š5.6 mg/d, respectively), direct bilirubin (DB) (2.34 ±â€Š1.23, 2.58 ±â€Š1.40, 1.91 ±â€Š0.97, and 1.81 ±â€Š1.44 vs. 0.74 ±â€Š0.57 µmol/L, respectively), and IgA (310.35 ±â€Š103.78, 318.48 ±â€Š107.54, 292.58 ±â€Š81.85, and 323.29 ±â€Š181.67 vs. 227.17 ±â€Š68.12 g/L, respectively) were significantly increased in grades II-V compared with grade I (all P < 0.05). CONCLUSIONS: The established diagnostic model that combined multiple factors (TC, FIB, D2, IgA, and age) might be used for IgAN non-invasive diagnosis. TP, DB, IgA, Cr, and UN have the potential to be used to evaluate IgAN disease severity.

Analysis of chronic kidney disease staging with different estimated glomerular filtration rate equations in Chinese centenarians.

BACKGROUND: Accurate estimation of the glomerular filtration rate (GFR) and staging of chronic kidney disease (CKD) are important. Currently, there is no research on the differences in several estimated GFR equations for staging CKD in a large sample of centenarians. Thus, this study aimed to investigate the differences in CKD staging with the most commonly used equations and to analyze sources of discrepancy. METHODS: A total of 966 centenarians were enrolled in this study from June 2014 to December 2016 in Hainan province, China. The GFR with the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Berlin Initiative Study 1 (BIS1) equations were estimated. Agreement between these equations was investigated with the κ statistic and Bland-Altman plots. Sources of discrepancy were investigated by partial correlation analysis. RESULTS: The κ values of the MDRD and CKD-EPI equations, MDRD and BIS1 equations, and CKD-EPI and BIS1 equations were 0.610, 0.253, and 0.381, respectively. Serum creatinine (Scr) explained 10.96%, 41.60% and 17.06% of the variability in these three comparisons, respectively. Serum uric acid (SUA) explained 3.65% and 5.43% of the variability in the first 2 comparisons, respectively. Gender was associated with significant differences in these 3 comparisons (P < 0.001). CONCLUSIONS: The strengths of agreement between the MDRD and CKD-EPI equations were substantial, but those between the MDRD and BIS1 equations and the CKD-EPI and BIS1 equations were fair. The difference in CKD staging of the first 2 comparisons strongly depended on Scr, SUA and gender, and that of CKD-EPI and BIS1 equations strongly depended on Scr and gender. The incidence at various stages of CKD staging was quite different. Thus, a new equation that is more suitable for the elderly needs to be built in the future.

Risk Factors For Hyperuricemia In Chinese Centenarians And Near-Centenarians.

PURPOSE: Hyperuricemia is an important potential pathogenic factor for hypertension, cardiovascular disease and stroke. The current study aimed to investigate the prevalence of hyperuricemia and its relationship to lifestyle characteristics and dietary habits in centenarians and near-centenarians. PATIENTS AND METHODS: In total, 966 centenarians and 788 near-centenarians were included. Community-based surveys were conducted to collect information about lifestyle. Blood examinations were performed using enzymatic assays. T-tests and χ2 tests were used to investigate significant indicators of hyperuricemia, and multivariate logistic regression was used to analyze the related risk factors. A comprehensive analysis of nineteen modifiable factors, including lifestyle characteristics, dietary habits, general characteristics and blood test indexes, was conducted. RESULTS: The prevalence of hyperuricemia was 29.02%. The percentage of men, waist circumference (WC), waist-hip ratio, estimated glomerular filtration rate (eGFR), levels of total protein (TP), alanine aminotransferase, aspartate aminotransferase, triglycerides, high-density lipoprotein cholesterol, serum homocysteine, serum uric acid, serum urea and serum creatinine, passive smoking, alcohol consumption, snoring, preference for fried flavors, and meat, seafood and vegetable consumption were significantly different between the hyperuricemia group and the normouricemia group (p<0.05). Multivariate logistic regression analysis showed that WC (OR=1.020), eGFR (OR=0.960), TP level (OR=1.038), serum urea level (OR=1.154), passive smoking (OR=2.589), snoring (OR=2.003), meat consumption (OR=2.506), seafood consumption (OR=1.422) and vegetable consumption (OR=0.521) were significantly associated with the risk of hyperuricemia (p<0.05). CONCLUSION: Low eGFR and vegetable consumption, high WC, TP, and serum urea levels, passive smoking, snoring, and high meat and seafood consumption were independent risk factors for hyperuricemia. It is recommended that people at high risk for hyperuricemia should actively limit their intake of fried food, alcohol and purine-rich food, increase their intake of fresh vegetables, actively treat sleep apnea syndrome, avoid passive smoking, maintain a healthy WC and seek to improve their kidney and liver function.

catena-Poly[[bis-(3,5-dicarboxy-benzo-ato)cobalt(II)]-µ-4,4'-bipyridine].

In the title compound, [Co(C(9)H(5)O(6))(2)(C(10)H(8)N(2))](n), the asymmetric unit consists of one Co(2+) ion with site symmetry 2, one mono-deprotonated 1,3,5-benzene-tricarboxylic acid anion and one-half of a 4,4'-bipyridine (4,4'-bipy) mol-ecule, in which two N and two C atoms have site symmetry 2. In the crystal structure, the Co(2+) centre is coordinated by four O atoms from two bidentate carboxyl-ate groups of two anions and two N atoms of two 4,4'-bipy mol-ecules, resulting in infinite chains propagating in [010]. The cobalt coordination is distorted trans-CoO(4)N(2) octa-hedral and inter-chain O-H⋯O hydrogen bonds complete the structure.

Less toxic zinc(ii), diorganotin(iv), gallium(iii) and cadmium(ii) complexes derived from 2-benzoylpyridine N,N-dimethylthiosemicarbazone: synthesis, crystal structures, cytotoxicity and investigations of mechanisms of action.

Four metal complexes based on 2-benzoylpyridine N,N-dimethylthiosemicarbazone (Bp44mT) were designed. Free ligand and zinc(ii), diorganotin(iv), gallium(iii) and cadmium(ii) complexes all demonstrated pronounced activity, which was indicated using the growth inhibition test in vitro. Interestingly, most of the compounds were found to be selective against hepatocellular carcinoma (HepG2) cells but had little effect on normal hepatocyte (QSG7701) cells. In particular, Zn(Bp44mT)2 (1) exhibited toxicity on QSG7701 cells which approximately 12-fold lower than that on HepG2 cells. The studies of mechanisms of action indicated that 1 induced reactive oxygen species (ROS) generation in a dose-dependent manner via the mitochondria transduction pathway. Protein analyses showed that 1 significantly promoted p21 and p53 gene expression, causing caspase-3 activation.

Potential Value of Datura stramonium Agglutinin-recognized Glycopatterns in Urinary Protein on Differential Diagnosis of Diabetic Nephropathy and Nondiabetic Renal Disease.

BACKGROUND: Diabetic nephropathy (DN) is the most common and serious microvascular complication of diabetes. To date, the gold standard for identifying DN and nondiabetic renal disease (NDRD) is a renal biopsy; however, there is currently no reliable diagnostic marker to identify DN and NDRD in a noninvasive manner. This study aimed to investigate the different glycopatterns in urine specimens of DN patients and NDRD patients for a differential diagnosis. METHODS: In total, 19 DN patients and 18 NDRD patients who underwent renal biopsies between March 2015 and March 2016 at the Chinese People's Liberation Army General Hospital were enrolled in this study. A lectin microarray was used to investigate the glycopatterns in the urinary protein of the 37 patients. Ratio analysis and one-way analysis of variance were used to screen altered glycopatterns. Then, the altered glycopatterns between the DN and NDRD groups were verified by a urinary protein microarray among another 32 patients (15 with DN and 17 with NDRD), and receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic value of the altered glycopatterns in differentiating DN and NDRD. Finally, lectin blotting was used to evaluate the altered glycosylation in protein level. RESULTS: The result of lectin microarrays revealed that the relative abundance of the (ß-1,4)-linked N-acetyl-D-glucosamine (GlcNAc) recognized by lectin Datura stramonium agglutinin (DSA) was significantly higher in urinary protein in DN patients than that in NDRD patients (fold change >1.50, P < 0.001). Subsequently, the results of urinary protein microarrays were consistent with lectin microarrays (P < 0.05). Furthermore, the ROC curve showed that glycopatterns could effectively distinguish DN from NDRD patients (area under the ROC curve = 0.94, P < 0.001). DSA lectin blotting showed that glycoproteins, with a molecular weight of approximately 50,000, demonstrated a difference in urine samples between DN patients and NDRD patients. CONCLUSIONS: The relative abundance of (ß-1,4)-linked GlcNAc recognized by lectin DSA and urinary glycoprotein with a molecular weight of approximately 50,000 are significantly different between DN and NDRD patients, indicating that the glycopatterns could be used as potential biomarkers for a differential diagnosis.

Helicobacter pylori Infection is Associated with Occurrence of Proteinuria in Type 2 Diabetes Patients: A Systemic Review and Meta-Analysis.

BACKGROUND: Type 2 diabetes (T2DM) patients are susceptible to Helicobacter pylori (HP), and it has been reported that the occurrence of proteinuria is associated with HP infection in T2DM patients; however, this view remains controversial. This meta-analysis aimed to explore the association between HP infection and the occurrence of proteinuria in T2DM patients. In addition, we hope to provide some recommendations to readers in clinical or related fields. METHODS: Our meta-analysis was conducted with the methodology of the Cochrane Collaboration. Search strategies were formulated by relevant professionals. Case-control studies that compared the occurrence of proteinuria in T2DM patients with and without HP infection were involved in our meta-analysis. Relevant English or Chinese studies were searched on online databases before 2018, including PubMed, the Cochrane library, Medline, Google Scholar, the China National Infrastructure, and Wanfang database. The search strategies were "diabetic proteinuria, diabetic microalbuminuria, diabetic albuminuria, diabetic kidney disease, diabetic renal dysfunction, diabetic renal disease, diabetic nephropathy, diabetic complications, and diabetic mellitus, combined with HP." The quality of these involved articles was separately assessed by two investigators using the Newcastle-Ottawa Scale (NOS). Odds ratios (ORs) and associated 95% confidence intervals (CIs) were extracted and pooled using fixed-effects models. RESULTS: Seven studies involving 1029 participants were included. The quality of these seven articles was all above five stars as assessed by NOS, and there was no significant publication bias in our meta-analysis. We found that T2DM patients with HP infection had a 2.00 times higher risk of the occurrence of proteinuria than patients without HP infection (OR: 2.00, 95% CI: 1.48-2.69). CONCLUSIONS: Our analysis showed that HP infection was associated with the occurrence of proteinuria in T2DM patients. HP radical surgery might be a therapeutic option for protecting kidney function in patients with T2DM.

Cu(ii), Ga(iii) and In(iii) complexes of 2-acetylpyridine N(4)-phenylthiosemicarbazone: synthesis, spectral characterization and biological activities.

In this paper, synthesis and characterization of metal complexes [Cu2(L)3]ClO4 (1), [Ga(L)2]NO3·2H2O (2) and [In(L)2]NO3·H2O (3) (HL = 2-acetylpyridine N(4)-phenylthiosemicarbazone) was carried out, including elemental analysis, spectral analysis (IR, UV-vis, NMR), and X-ray crystallography. Complex 1 contains one S-bridged binuclear [Cu2(L)3]+ unit, where two Cu atoms display diverse coordination geometries: one being square planar geometry and the other octahedral geometry. Both 2 and 3 are mononuclear complexes, and the metal centers in 2 and 3 are chelated by two NNS tridentate ligands possessing a distorted octahedral geometry. Biological studies show that all the complexes possess a wide spectrum of modest to effective antibacterial activities and remarkable cytotoxicities against HepG2 cells, and 1, in particular, with an IC50 value of 0.19 ± 0.06 µM, is 113-fold and 28-fold more cytotoxic than HL and the antitumor drug mitoxantrone, respectively. In addition, 3 exhibits excellent photoluminescence properties. Upon the addition of 1 equiv of In3+ ions, a remarkable fluorescence intensity of HL and fluorescent color change (from transparent to light-green) could be observed with 365 nm light, indicating that this ligand may be used as a promising colorimetric and fluorescent probe for In3+ detection.