Risk Factors and Clinical Outcomes of Renal Thrombotic Microangiopathy in Children with Lupus Nephritis in Terms of Pathological and Clinical Features.

BACKGROUND: Thrombotic microangiopathy (TMA) is an important risk factor for the prognosis of lupus nephritis (LN). Patients with LN complicated with TMA tend to be critically ill with high mortality and poor prognosis. In the present study, we retrospectively analyzed the clinical manifestations, laboratory results, renal pathological manifestations, and prognosis of children with LN-TMA and analyzed the risk factors for end-stage renal disease (ESRD) in children with LN-TMA. METHODS: Seventy-four patients with LN and renal TMA (rTMA) were selected and compared to 128 LN controls without TMA (1:2 ratio) matched according to demographics, pathological type and treatments. RESULTS: The mean values of systolic blood pressure, diastolic blood pressure (DBP), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), urinary protein quantitation (PRO), urine red blood cells, N-acetyl-ß-D-glucosidase (NAG), retinol-binding protein, systemic lupus erythematosus disease activity score (SLEDAI), and activity index (AI) scores in the TMA group were all higher than those in the non-TMA group (p < 0.05 and p < 0.01). The mean values of complement C3, hemoglobin, platelets, estimated glomerular filtration rate, and chronic index (CI) score in the TMA group were all lower than those in the non-TMA group (p < 0.05 and p < 0.01). The number of cases of glomerular crescent, fibrous crescent, endocapillary proliferation, tubular atrophy, interstitial fibrosis, C3 and C1q deposition in the TMA group was higher than that in the non-TMA group (p < 0.05 and p < 0.01). The 3-year and 5-year renal survival rates in the TMA group (88.93% vs. 97.00%, p < 0.05) and TMA group (61.41% vs. 82.31%, p < 0.05) were significantly lower than those in the non-TMA group. Multivariate Cox regression analysis showed that serum creatinine before treatment (≥110 µmol/L), TMA and interstitial fibrosis were independent risk factors for the development of ESRD in LN children. CONCLUSION: The general condition of children with TMA is critical, and the prognosis is poor. Early detection, early treatment and the development of new treatments are key to improving LN-TMA outcomes in children.

Clinical outcomes and clinico-pathological correlations in children with MPO-ANCA-associated glomerulonephritis showing renal arteritis.

The aim of this study was to evaluate the clinical features, pathological characteristics, and prognosis in myeloperoxidase (MPO)-antineutrophil cytoplasmic antibodies (ANCA)-associated glomerulonephritis (AAGN) with renal arteritis. The study involved 97 children from five pediatric clinical centers with MPO-AAGN who exhibited distinct clinical features. The patients were divided into AAGN-A+ and AAGN-A-, based on the presence or absence of arteritis, and the disparities in clinical, histopathological characteristics, and prognosis between the two groups was evaluated. In contrast to the AAGN-A- group, the children in the AAGN-A+ group exhibited more pronounced clinical symptoms and renal pathological injury. Arteritis positively moderately correlated with the serum creatinine, interleukin-6, urinary neutrophil gelatinase-associated lipocalin, negatively moderately correlated with serum complement C3. The renal survival rate in the AAGN-A+ group was significantly poorer than AAGN-A- group (χ2 = 4.278, p = 0.039). Arteritis showed a good predictive value for end-stage kidney disease (ESKD), and C3 deposition, ANCA renal risk score and arteritis were independent risk factors for the development of ESKD in children with MPO-AAGN. Arteritis is a significant pathological change observed in children with MPO-AAGN, and the formation of arteritis may be related to the inflammatory response and activation of the complement system.

Bowman capsule rupture in children with myeloperoxidase-antineutrophil cytoplasmic antibody-associated glomerulonephritis predicts poor renal survival.

Background: Recent developments indicated that Bowman capsule rupture (BCR) is observed in antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (AAGN). We aimed to explore the relationship between BCR and clinical manifestations, pathological changes, and prognosis in children with myeloperoxidase (MPO)-AAGN. Methods: A total of 56 children with MPO-AAGN were divided into BCR (+) and BCR (-) groups according to the status of Bowman's capsule. Clinical and histological features and renal outcomes were compared, and the predictive value of BCR for end-stage kidney disease (ESKD) of MPO-AAGN was evaluated. Results: After retrospective analysis of the data, 24 children (42.9%) were found to have BCR. The results showed that BCR positively correlated with intrarenal immune cell infiltrates, obsolescence and crescents in glomeruli, tubulointerstitial inflammation, tubulitis, and tubular atrophy negatively correlated with normal glomeruli and immunoglobulin G deposition in the kidney. The clinical features and kidney pathological changes were more severe in the BCR (+) group than BCR (-) group, and the renal survival rate was significantly poorer in the BCR (+) group than BCR (-) group (χ2 = 5.45, p = 0.02). Moreover, estimated glomerular filtration rate (≤15 mL/min/1.73 m2), BCR and ANCA renal risk score (ARRS) were independent risk factors for the development of ESKD in children with MPO-AAGN. After combining BCR with the Berden classification and ARRS, our data suggested that the Berden classification + BCR and ARRS + BCR showed better predictive values for ESKD than those of the Berden classification and ARRS, respectively. Conclusion: BCR is an important pathological lesion that correlates with severe clinical manifestations, pathological changes, and poor prognosis in children with MPO-AAGN.

Risk factors for renal outcomes in children with antineutrophil cytoplasmic antibody-associated vasculitis: a nationwide retrospective study in China.

BACKGROUND: Pediatric antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a life-threatening systemic vasculitis featured by liability to renal involvement. However, there are few studies on the risk factors and predictive models for renal outcomes of AAV in children. METHODS: Data from 179 AAV children in multiple centers between January 2012 and March 2020 were collected retrospectively. The risk factors and predictive model of end-stage renal disease (ESRD) in AAV were explored. RESULTS: Renal involvement was the most typical manifestation (95.5%), and the crescent was the predominant pathological lesion (84.9%). The estimated glomerular filtration rate (eGFR) was evaluated in 114 patients, of whom 59.6% developed ESRD, and the median time to ESRD was 3.20 months. The eGFR [P = 0.006, odds ratio (OR) = 0.955, 95% confidence interval (CI) = 0.924-0.987] and the percentages of global glomerulosclerosis (pGGS; P = 0.018, OR = 1.060, 95% CI = 1.010-1.112) were independent risk factors for ESRD of renal biopsy. Based on the pGGS and eGFR at renal biopsy, we developed three risk grades of ESRD and one predictive model. The Kaplan‒Meier curve indicated that renal outcomes were significantly different in different risk grades (P < 0.001). Compared with serum creatinine at baseline, the predictive model had higher accuracy (0.86 versus 0.58, P < 0.001) and a lower coefficient of variation (0.07 versus 0.92) in external validation. CONCLUSIONS: Renal involvement is the most common manifestation of pediatric AAV in China, of which more than half deteriorates into ESRD. The predictive model based on eGFR at renal biopsy and the pGGS may be stable and accurate in speculating the risk of ESRD in AAV children. Supplementary file 2 (MP4 18937 KB).

Clinical significance of kidney immune complex deposition in children with acute interstitial nephritis disease.

BACKGROUND: Acute interstitial nephritis (AIN) is a relatively rare cause of acute kidney injury (AKI) in children. Immune complex (IC) deposition was rare in renal pathology of AIN. METHODS: Based on the status and position of IC deposition, a total of 78 children with AIN were divided into two groups: the non-IC group and IC group. IC group was further divided into two subgroups: intraglomerular (IG)-IC group and extraglomerular (EG)-IC group. To compare the clinical and histological features, renal outcomes between groups. RESULTS: The IC deposition, IG-IC and EG-IC deposition were observed in 22 (28.21%), 12 (15.38%) and 10 (12.82%) children, respectively. The IC group demonstrated a higher frequency of AKI, higher level of Scr, urine N-acetyl-ß-D-glucosidase (NAG) enzyme, retinol-binding protein (RBP), neutrophil gelatinase-associated lipocalin (NGAL), higher frequency of neutrophils, plasma cells and eosinophils infiltrate, higher scores of interstitial inflammation (i), total inflammation (ti) and interstitial edema, lower level of estimated glomerular filtration rate (eGFR) as compared to non-IC group (p < 0.05, p < 0.01). EG-IC deposition positively moderate correlated with levels of RBP, IG-IC deposition positively moderate correlated with plasma cell infiltrate, interstitial inflammation (i), total inflammation (ti) and interstitial edema. Interstitial inflammation, EG-IC deposition and interstitial edema were risk factors for AKD in AIN, and interstitial fibrosis/tubular atrophy (IF/TA) was a risk factor for CKD in children with AIN. CONCLUSION: IG-IC and EG-IC deposition positively correlated with severe clinical manifestations, glomerular and tubular injuries, and EG-IC deposition was risk factor for the progression of AIN in children.

Crescentic glomerulonephritis in children: short-term follow-up predicts long-term outcome.

Background: Crescentic glomerulonephritis (CrGN) is a relatively rare but severe condition in childhood with the clinical feature of rapidly progressive glomerulonephritis (RPGN). The aim of this study is to investigate the clinicopathological features and prognosis of CrGN in children. Methods: We retrospectively analyzed the clinical and laboratory data, renal pathological results, treatment, and outcome of 147 CrGN in two Chinese pediatric nephrology centers. Results: Among the 147 children, there were 22 cases of type I (15.0%), 69 cases of type II (46.9%), and 56 cases of type III (38.1%). The mean percentages of crescents in CrGN I, II, and III were 85.3%, 68.7%, and 73.6%, respectively. The children with type I CrGN presented with more severe clinical manifestations and pathological lesions. The 3-month cumulative renal survival rates of types I, II, and III CrGN were 66.3%, 93.6%, and 75.6%, respectively. The 1-year cumulative renal survival rates of types I, II, and III CrGN were 56.9%, 85.3%, and 73.1%, respectively, and the 5-year cumulative renal survival rates of types I, II, and III CrGN were 33.8%, 73.5%, and 47.1%, respectively. The Kappa Consistency Test between the 3-month and 1-year total renal survival (82.1% vs. 74.7%) of the children was 0.683 (P < 0.001), and between the 1-year and 5-year total renal-free survival (78.3% vs. 69.1%) of the children was 0.476 (P < 0.001). The Bowman's Capsule Rupture (BCR), crescent, interstitial inflammation, and interstitial fibrosis/tubular atrophy (IF/TA) score were predictors of end-stage kidney disease (ESKD) risk but BCR showed better predictive value for ESKD than interstitial inflammation score (P = 0.027) and IF/TA score (P = 0.047). Conclusion: Patients with type I tended to have the worst renal survival rates. The three-month renal prognosis could partially reflect the 1-year renal prognosis, and the 1-year mortality rate could partially reflect the 5-year mortality rate of children with CrGN.

Validation of a renal risk score in a cohort of children with ANCA-associated glomerulonephritis.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is extremely rare in children. Renal involvement is a common and severe complication of AAV as it can cause end stage kidney disease (ESKD). ANCA renal risk score (ARRS) is helpful in predicting long-term ESKD in patients with ANCA-associated glomerulonephritis (AAGN). This retrospective study included 61 consecutive patients with kidney biopsy specimen-proven AAGN from Clinical Center for Children's Kidney Disease in China. Each patient was assessed by eGFR, normal glomeruli, and tubular atrophy/interstitial fibrosis, and the renal outcome was evaluated using the ARRS. Based on the ARRS, 27 (44.26%), 21 (34.43%), and 13 (21.31%) patients were divided into the low-risk, medium-risk, and high-risk groups, respectively. The median follow-up period was 46.36 (14.58-95.62) months. The high-risk group had worse renal outcomes than the low-risk group (p< 0.05) and the medium-risk group (p < 0.05). COX multivariate regression analysis showed that eGFR ≤ 15 ml/min/1.73 m2 (p = 0.015, Hazard Ratio (HR) = 9.574, 95% CI 4.205-25.187) and ARRS (p = 0.012, HR = 2.115, 95% CI 1.206-4.174) were independent risk factors for ESKD.The area under the curve for ESKD prediction of ARRS was 0.880, and the best cutoff value was 5.50. Delong test result showed that ARRS exhibited better predictive value for ESKD than the Berden classification (p < 0.001) and rapidly progressive glomerulonephritis (p < 0.001). This is the first study to investigate the value of the ARRS for predicting renal prognosis among Chinese children. The ARRS is a preferred index that can predict ESKD in Chinese children with AAGN.

The novel HLA-A*68:302 allele, identified by Sanger dideoxynucleotide sequencing in a Chinese individual.

HLA-A*68:302 differs from HLA-A*68:01:02:01 by one nucleotide in exon 4.

Relationship between Renal Damage and Serum Complement C3 in Children with Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis.

BACKGROUND: Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) disease is a well-known antibody-induced autoimmune disease. The pathogenesis of AAV has not yet been completely clarified, but may be related to heredity, infection, environmental factors, cellular immunity, etc. In recent years, complement in AAV pathogenesis has become the latest research hotspot, and the decrease of serum complement C3 is associated with poor prognosis of anti-neutrophil cytoplasmic antibody-associated glomerulonephritis. In the current study, we investigated the associations between serum complement C3 and kidney injury in AAV children. METHODS: Twenty-four children with AAV admitted to our hospital from June 2014 to June 2019 were divided into the low C3 group and the normal C3 group. All the children have undergone renal biopsy. The clinical manifestations, laboratory tests, renal pathology, treatment, and prognosis of the 2 groups were observed. The primary end point was end-stage renal disease (ESRD). RESULTS: It was shown that kidney injury was more obvious in patients with low C3 than in patients with normal C3 serum. The values of ESR, Scr, and UA before treatment in the low C3 group were higher than those in the normal C3 group (p < 0.01); the values of RBC, Hb, PLT, ALB, LDH, and eGFR in the normal C3 group were higher than those in the low C3 group (p < 0.01). The values of urinary protein and NAG enzyme in the low C3 group were higher than those in the normal C3 group (p < 0.01). The area of glomerular abandonment, sclerosis, segmental sclerosis, crescent, cellular crescent, cellular fibrous crescent, fibrous crescent, segmental loop necrosis, and the number of cases with acute renal tubulointerstitial lesions in the low C3 group were bigger than those in the normal C3 group (p < 0.05 and < 0.01). The number of cases with C3 deposition in the low C3 group was higher than that in the normal C3 group (p < 0.05). The number of patients receiving CRRT and PE in the low C3 group was higher than that in the normal C3 group (p < 0.05 and < 0.01). In this study, 3 children entered the stage of ESRD and 1 died in the low C3 group. CONCLUSION: The kidney injury of AAV children with low complement C3 is serious, and the prognosis is poor. We should pay attention to the influence of decreased complement C3 on the condition and prognosis of AAV children.

The COL4A3 and COL4A4 Digenic Mutations in cis Result in Benign Familial Hematuria in a Large Chinese Family.

Mutations in the COL4A5 gene result in X-linked Alport syndrome, homozygous or compound heterozygous mutations in COL4A3 or COL4A4 are responsible for autosomal recessive Alport syndrome, and heterozygous mutations in COL4A3 or COL4A4 cause autosomal dominant Alport syndrome or benign familial hematuria. Recently, the existence of a digenic inheritance in Alport syndrome has been demonstrated. We here report heterozygous COL4A3 and COL4A4 digenic mutations in cis responsible for benign familial hematuria. Using bioinformatics analyses and pedigree verification, we showed that COL4A4 c.1471C>T and COL4A3 c.3418 + 1G>T variants in cis are pathogenic and co-segregate with the benign familial hematuria. This result suggests that COL4A3 and COL4A4 digenic mutations in cis mimicking an autosomal dominant inheritance should be considered as a novel inheritance pattern of benign familial hematuria, although the disease-causing mechanism remains unknown.

Three Novel Heterozygous COL4A4 Mutations Result in Three Different Collagen Type IV Kidney Disease Phenotypes.

Thin basement membrane nephropathy (TBMN), autosomal dominant Alport syndrome (ADAS), and focal segmental glomerulosclerosis (FSGS) are kidney diseases that differ in clinical diagnosis, treatment, and prognosis. Nevertheless, they may result from the same causative genes. Here, we report 3 COL4A4 heterozygous mutations (p.Gly208Arg, p.Ser513Glufs*2, and p.Met1617Cysfs*39) that lead to 3 different collagen type IV kidney disease phenotypes, manifesting as TBMN, ADAS, and FSGS. Using bioinformatics analyses and pedigree verification, we show that these novel variants are pathogenetic and cosegregate with TBMN, ADAS, and FSGS. Furthermore, we found that the collagen type IV-associated kidney disease phenotypes are heterogeneous, with overlapping pathology and genetic mutations. We propose that COL4A4-associated TBMN, ADAS, and FSGS should be considered as collagen type IV kidney disease subtypes that represent different phases of disease progression.

Karyopherin subunit-α 2 expression accelerates cell cycle progression by upregulating CCNB2 and CDK1 in hepatocellular carcinoma.

Different types of cancer exhibit distinct gene expression profiles. The present study aimed to identify a specific gene dysregulated in hepatocellular carcinoma (HCC) that was essential for cancer progression. The whole transcriptomes of primary HCC tissue samples were analyzed with microarrays. The most significantly differentially expressed gene was identified, specifically karyopherin subunit-α 2 (KPNA2), and an analysis using the Oncomine online tool was performed with data from The Cancer Genome Atlas to predict associated genes in HCC. Reverse transcription-quantitative polymerase chain reaction was performed to confirm the gene expression levels of KPNA2, and the RNA interference knockdown of KPNA2 was performed to identify the effect on putative downstream target genes. A proliferation assay and flow cytometry analysis was used to assess the function of KPNA2 in the regulation of the cell cycle. The results demonstrated that KPNA2 expression was significantly upregulated in HCC tumor tissues compared with liver tissues and was associated with cyclin B2 (CCNB2) and cyclin-dependent kinase 1 (CDK1) expression. KPNA2 expression was identified a novel marker to predict the outcome of patients. In addition, KPNA2 knockdown downregulated CCNB2 and CDK1, inhibited cell proliferation and induced cell cycle arrest in the G2/M phase. In conclusion, it was demonstrated that KPNA2 may promote tumor cell proliferation by increasing the expression of CCNB2/CDK1. KPNA2 could be a target for therapeutic intervention in HCC.

MicroRNA­106b regulates skeletal muscle insulin sensitivity and glucose homeostasis by targeting mitofusion­2.

MicroRNA­106b (miR­106b) is reported to be closely associated with skeletal muscle insulin resistance. The present study further investigated the role of miR­106b in skeletal muscle insulin sensitivity and glucose homeostasis in vivo. Mice were randomly divided into 4 groups and infected with lentivirus expressing miR­106b (miR­106b mice), miR­106b sponge (miR­106b inhibition mice) or the corresponding empty vectors. Mitofusion­2 (Mfn2) protein expression levels and glucose transporter (Glut)­4 protein translocation were significantly reduced in the muscle of miR­106b mice, whereas they were unaffected in miR­106b inhibition mice. miR­106b mice had significantly increased blood glucose levels following 12 h of fasting and impaired glucose tolerance, whereas miR­106b inhibition mice had no significant alterations in fasting blood glucose levels and glucose tolerance. In vitro, the suppressive effect of miR­106b on glucose uptake and Glut4 translocation was completely inhibited in C2C12 myotubes infected with Mfn2 plasmids. Following treatment of C2C12 myotubes with Mfn2 small interfering RNA, miR­106b inhibition consistently increased Mfn2 protein levels and improved glucose uptake and Glut4 translocation. These results indicated that miR­106b targeted Mfn2 and regulated skeletal muscle insulin sensitivity and glucose tolerance. Therefore, increased miR­106b expression may be a potential mechanism underlying insulin resistance and type 2 diabetes.

MicroRNA-30e-5p promotes cell growth by targeting PTPN13 and indicates poor survival and recurrence in lung adenocarcinoma.

Aberrant microRNA expression is involved in the regulation of various cellular processes, such as proliferation and metastasis in multiple diseases including cancers. MicroRNA-30e-5p (miR-30e) was previously reported as an oncogenic or tumour suppressing miRNA in some malignancies, but its function in lung adenocarcinoma (LAC) remains largely undefined. In this study, we found that the expression of miR-30e was increased in LAC tissues and cell lines, associated with tumour size and represented an independent prognostic factor for overall survival and recurrence of LAC patients. Further functional experiments showed that knockdown of miR-30e suppressed cell growth while its overexpression promoted growth of LAC cells and xenografts in vitro and in vivo. Mechanistically, PTPN13 was identified as the direct target of miR-30e in LAC, in which PTPN13 expression was down-regulated in LAC tissues and showed the inverse correlation with miR-30e expression. Overexpression of PTPN13 inhibited cell growth and rescued the proliferation-promoting effect of miR-30e through inhibition of the EGFR signalling. Altogether, our findings suggest that miR-30e could function as an oncogene in LAC via targeting PTPN13 and act as a potential therapeutic target for treating LAC.

Novel mutations in COL4A3, COL4A4, and COL4A5 in Chinese patients with Alport Syndrome.

Alport syndrome (AS) is a clinically and genetically heterogeneous, progressive nephropathy caused by mutations in COL4A3, COL4A4, and COL4A5, which encode type IV collagen. The large sizes of these genes and the absence of mutation hot spots have complicated mutational analysis by routine polymerase chain reaction (PCR)-based approaches. Here, in order to design a rapid and effective method for the genetic diagnosis of AS, we developed a strategy by utilizing targeted capture associated with next-generation sequencing (NGS) to analyze COL4A3, COL4A4, and COL4A5 simultaneously in 20 AS patients. All the coding exons and flanking sequences of COL4A3, COL4A4, and COL4A5 from the probands were captured followed by HiSeq 2500 sequencing. Candidate mutations were validated by classic Sanger sequencing and quantitative (q)PCR. Sixteen patients (16/20, 75%) showed X-linked inheritance, and four patients (4/20, 20%) showed autosomal recessive inheritance. None of the individuals had autosomal-dominant AS. Fifteen novel mutations, 6 known mutations, and 2 novel fragment deletions were detected by targeted capture and NGS. Of these novel mutations, 12, 3, and 2 mutations were detected in COL4A5, COL4A4, and COL4A3, respectively. A comparison of the clinical manifestations caused by different types of mutations in COL4A5 suggested that nonsense mutations and glycine substitution by an acidic amino acid are more severe than the other missense mutations. Pathogenic mutations were detected in 20 patients. These novel mutations can expand the genotypic spectrum of AS. Our results demonstrated that targeted capture and NGS technology are effective in the genetic diagnosis of AS.

Inhibition of livin expression suppresses cell proliferation and enhances chemosensitivity to cisplatin in human lung adenocarcinoma cells.

Livin is a novel member of the inhibitor of apoptosis protein family that has been reported to be overexpressed in various types of human malignancy. Although several studies have demonstrated that livin may be used as an effective target for tumor therapy, few studies have investigated its role in human lung adenocarcinoma. In the present study, two different methods were used in order to investigate the tumor­suppressing effect of livin in human lung adenocarcinoma cells. Firstly, small interfering (si)RNA technology was used to down regulate livin expression; siRNA-mediated knockdown of livin was confirmed using reverse transcription quantitative polymerase chain reaction and western blot analysis, and cell proliferations was assessed using an MTT assay in vitro. Secondly, inhibition of livin expression was induced through the synergistic inhibitory effect between flavopiridol and tumor necrosis factor­related apoptosis-inducing ligand (TRAIL). Experimental results revealed that, following transfection of the livin gene-silencing vector, the gene expression of livin was markedly decreased, SPC-A1 cell proliferation was significantly reduced and the therapeutic effect of the chemotherapy drug cisplatin was markedly improved. This growth inhibitory effect was also observed in the flavopiridol and TRAIL combination treatment group. In the flavopiridol and TRAIL combination treatment group, the protein expression of livin was significantly reduced and the survival rate of SPC­A1 cells was significantly lower than the flavopiridol and TRAIL single operation group. In conclusion, the RNA silencing and the synergistic inhibitory effect between flavopiridol with TRAIL was able to effectively inhibit the expression of livin, significantly decrease SPC-A1 tumor cell proliferation and significantly enhance sensitivity to the chemotherapy drug cisplatin. These findings suggest that livin may be used as a novel target for tumor gene therapy.

Silencing miR-106b improves palmitic acid-induced mitochondrial dysfunction and insulin resistance in skeletal myocytes.

MicroRNA­106b (miR­106b) is reported to correlate closely with skeletal muscle insulin resistance. In the current study the effect of miR­106b on palmitic acid (PA)­induced mitochondrial dysfunction and insulin resistance was investigated in C2C12 myotubes via the silencing of miR­106b. MiR­106b expression was increased under PA treatment, while miR­106b loss of function improved insulin sensitivity by upregulating its target mitofusin­2 (Mfn2) in C2C12 myocytes. Furthermore, miR­106b loss of function partly improved mitochondrial morphological lesions and increased the levels of mitochondial DNA and intracellular adenosine triphosphate that had been impaired by PA exposure in C2C12 myocytes. MiR­106b loss of function attenuated the levels of intracellular reactive oxygen species (ROS), and upregulated the expression levels of the estrogen­related receptor (ERR)­α/peroxisome proliferative activated receptor γ coactivator (PGC)­1α/Mfn2 axis under PA exposure. In addition, miR­106b negatively regulated skeletal muscle mitochondrial function and insulin sensitivity under PA­induced insulin resistance by targeting Mfn2, which may be associated with reduced ROS and upregulation of the ERR­α/PGC­1α/Mfn2 axis.

MicroRNA-106b induces mitochondrial dysfunction and insulin resistance in C2C12 myotubes by targeting mitofusin-2.

MicroRNA-106b (miR-106b) is reported to correlate closely with skeletal muscle insulin resistance and type 2 diabetes. The aim of this study was to identify an mRNA targeted by miR-106b which regulates skeletal muscle insulin sensitivity. MiR-106b was found to target the 3' untranslated region (3' UTR) of mitofusin-2 (Mfn2) through miR-106b binding sites and to downregulate Mfn2 protein abundance at the post-transcriptional level by luciferase activity assay combined with mutational analysis and immunoblotting. Overexpression of miR-106b resulted in mitochondrial dysfunction and insulin resistance in C2C12 myotubes. MiR-106b was increased in insulin-resistant cultured C2C12 myotubes induced by TNF-α, and accompanied by increasing Mfn2 level, miR-106b loss of function improved mitochondrial function and insulin sensitivity impaired by TNF-α in C2C12 myotubes. In addition, both overexpression and downregulation of miR-106b upregulated peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α and estrogen-related receptor (ERR)-α expression. MiR-106b targeted Mfn2 and regulated skeletal muscle mitochondrial function and insulin sensitivity. Therefor, Inhibition of miR-106b may be a potential new strategy for treating insulin resistance and type 2 diabetes.

[Daily intake of plain water and beverages of primary and middle school students in four cities of China].

OBJECTIVE: To describe the daily consumption of plain water and beverages of primary and middle school students in four cities of China. METHODS: A total of 5914 students from Beijing, Shanghai, Guangzhou and Chengdu were selected using multiple-stage random sampling method, and 5868 students completed the study from September to October 2011. The information on amounts and types of drinking water was recorded using a 24 hour measurement for seven consecutive days. The amount of plain water and beverages was analyzed for subjects in different gender, grades and cities. RESULTS: The daily consumption of plain water of subjects was (744 ± 484) ml (68.3% of total drinking water) with statistically significant difference among the Guangzhou, Beijing, Shanghai and Chengdu ((869 ± 528), (818 ± 518), (702 ± 471), and (573 ± 333) ml; F = 113.74, P < 0.05). The amount of plain water in boys (809 ± 534) ml was significantly higher than in girls (683 ± 436) ml (Z = 9.58, P < 0.05) while higher in urban (792 ± 531) ml than in rural (695 ± 427) ml (Z = -6.09, P < 0.05). The consumption of plain water in high school students was the highest (829 ± 513) ml, and that in primary students was the lowest (672 ± 426) ml (F = 55.23, P < 0.05). The average daily consumption of beverages was (345 ± 287) ml (31.7% of total drinking water) and the highest in Shanghai (424 ± 304) ml, then in Beijing (347 ± 303) ml and in Guangzhou (316 ± 267) ml, the lowest in Chengdu (293 ± 255) ml (F = 58.94, P < 0.05). The consumption of beverages for students in urban areas (394 ± 301) ml was higher than that in rural areas (296 ± 264) ml (Z = -14.48, P < 0.05), but no significant difference between boys (348 ± 306) ml and girls (342 ± 269) ml (Z = -1.44, P > 0.05). The consumption of beverages of high school students (356 ± 309) ml and middle school students (360 ± 301) ml were higher than primary school students (328 ± 263) ml (F = 8.37, P < 0.05). CONCLUSION: The major drinking water of primary and middle school students in four cities of China was plain water. The amounts of consumption of plain water and beverages varied in different cities, urban and rural and levels of education.

Regulation of LYRM1 gene expression by free fatty acids, adipokines, and rosiglitazone in 3T3-L1 adipocytes.

LYR motif containing 1 (LYRM1) is a novel gene that is abundantly expressed in the adipose tissue of obese subjects and is involved in insulin resistance. In this study, free fatty acids (FFAs) and tumor necrosis factor-α (TNF-α) are shown to upregulate LYRM1 mRNA expression in 3T3-L1 adipocytes. Conversely, resistin and rosiglitazone exert an inhibitory effect on LYRM1 mRNA expression. These results suggest that the expression of LYRM1 mRNA is affected by a variety of factors that are related to insulin sensitivity. LYRM1 may be an important mediator in the development of obesity-related insulin resistance.