High-throughput sequencing analysis of lncRNAs in hippocampus tissues with hypoxic-ischemic brain damage.

LncRNAs abundantly expressed in the brain have vital and wide-ranging functions in different biological processes. However, little is currently known regarding the influence of lncRNAs in developing brains after hypoxic-ischemic brain damage (HIBD). In this study, to investigate the lncRNAs expression signatures and the co-expression network of lncRNAs and mRNAs in the brain after HIBD, we established a neonatal rat HIBD model and detected the expression profiles of lncRNAs in the HIBD brain and a sham control using high-throughput sequencing. Further, highly differentially expressed lncRNAs were selected and validated by qRT-PCR. Finally, the biological functions of the selected lncRNAs were investigated by over-expressing or silencing the target genes through lentivirus transfection in hippocampal neuron cells. Our results revealed that the expression profile of lncRNAs was dramatically different between the HIBD brains and the sham control, showing as the aberrant expression of 617 lncRNA transcripts and 441 mRNA transcripts at 24 hours after HIBD. GO and KEGG analyses indicated that the differentially expressed mRNAs were mostly involved in the apoptosis signaling pathway. After validating the expression of 8 randomly selected lncRNA transcripts by qRT-PCR, we found that the TNFRSF17 gene (ID: ENSRNOG00000021987) was down-regulated in HI brains. After stable over-expression and silencing of TNFRSF17, the apoptosis rate of hippocampal neuron cells exhibited obvious changes under hypoxia or normaxia. The over-expression of TNFRSF17 could significantly up-regulate Bcl-2 but down-regulate Bax, caspase-3, and caspase-9 at the mRNA and protein levels, while the silencing of TNFRSF17 led to just the opposite phenomenon. Notably, the regulation effects of TNFRSF17 on apoptotic related genes and proteins under hypoxia were more obvious than those under normaxia. Moreover, the over-expression of TNFRSF17 reduced the apoptotic rate, but the loss of TNFRSF17 led to a high rate of apoptosis under hypoxia. Taken together, the silencing of TNFRSF17 exacerbated, while over-expression attenuated, neuron apoptosis induced by HI injury, suggesting that TNFRSF17 may be a target for the prognosis, diagnosis, and treatment of HIBD.

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.

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.

Validation of the Oxford classification of IgA nephropathy for pediatric patients from China.

BACKGROUND: The Oxford classification of IgA nephropathy (IgAN) provides a useful tool for prediction of renal prognosis. However, the application of this classification in children with IgAN needs validation in different patient populations. METHODS: A total of 218 children with IgAN from 7 renal centers in China were enrolled. The inclusion criteria was similar to the original Oxford study. RESULTS: There were 98 patients (45%) with mesangial proliferation (M1), 51 patients (23%) with endocapillary proliferation (E1), 136 patients (62%) with segmental sclerosis/adhesion lesion (S1), 13 patients (6%) with moderate tubulointerstitial fibrosis (T1 26-50% of cortex scarred), and only 2 patients (1%) with severe tubulointerstitial fibrosis (T2, >50% of cortex scarred). During a median follow-up duration of 56 months, 24 children (12.4%) developed ESRD or 50% decline in renal function. In univariate COX analysis, we found that tubular atrophy/interstitial fibrosis (HR 4.3, 95%CI 1.8-10.5, P < 0.001) and segmental glomerulosclerosis (HR 9.2 1.2-68.6, P = 0.03) were significant predictors of renal outcome. However, mesangial hypercellularity, endocapillary proliferation, crescents, and necrosis were not associated with renal prognosis. In the multivariate COX regression model, none of these pathologic lesions were shown to be independent risk factors of unfavorable renal outcome except for tubular atrophy/interstitial fibrosis (HR 2.9, 95%CI 1.0-7.9 P = 0.04). CONCLUSIONS: We confirmed tubular atrophy/interstitial fibrosis was the only feature independently associated with renal outcomes in Chinese children with IgAN.

[Nephrotic syndrome complicated with intracranial venous thrombosis treated with urokinase: report of 5 cases].

OBJECTIVE: To explore the effect of urokinase and low molecular weight heparin in children with nephrotic syndrome complicated with intracranial venous thrombosis. METHODS: Urokinase and low molecular weight heparin were administered to the 5 patients intravenously. The initial dose of urokinase was 2000 - 4000 U/(kg.d), the initial pulse dose was 20 000 - 40 000 U given within 15 - 30 minutes, and the left was infused by using a pump, from the second day 2000 U/(kg.d) urokinase was infused daily for 3 to 7 days. During the treatment thrombin time (TT), activated partial thromboplastin time (APTT) were tested 3 times every week, with particular attention to bleeding. Low molecular weight heparin 100 - 120 AXaIU/kg, 1 or 2 times per day was hypodermally injected for a course of two weeks. Anti-platelet drugs: long-term oral administration of dipyridamole 3 - 5 mg/(kg.d) was applied 2 - 3 times every day for 3 months. RESULTS: The clinical symptoms disappeared after one month of the combined therapy of urokinase, low molecular weight heparin and dipyridamole in 5 cases of nephrotic syndrome complicated with intracranial venous thrombosis in children, the plasma viscosity returned to normal in 1 month, activated partial thromboplastin time, prothrombin time, fibrinogen degradation products returned to normal in 1 to 2 months, venous thrombosis disappeared after 1 to 3 months in head CT or MRI examination, showing the cerebral venous sinus thrombosis complete recanalization without relapse cases in follow-up. CONCLUSION: The early application of urokinase and low molecular heparin and anti-platelet coagulation drugs was effective. The early diagnosis, treatment and prevention of intracranial vein thrombosis in patients with nephrotic syndrome is important.

[Clinical and pathological study of 47 cases with Alport syndrome].

OBJECTIVE: To analyze the clinical and pathological features of children with Alport syndrome (AS). METHODS: A series of 47 patients with AS from unrelated families hospitalized from Jan. 1990 to Jan. 2007 were involved in this study. The clinical and histopathological data were collected and analyzed. RESULTS: Of the 47 cases, 32 were male and 15 female, M/F: 2.1:1. The patient's age ranged from 15 months to 13 years, mean 9 years. Thirty-nine of the 47 cases had positive family history, X-linked dominant inheritance AS was diagnosed in 37 cases, autosomal recessive inheritance AS in 2 cases. Gross hematuria or microscopic hematuria were found in 59.3% of the cases as the first manifestations, while 29.8% showed edema or proteinuria. The major clinical manifestations were isolated hematuria (23.4%), hematuria and proteinuria (36.2%), nephrotic syndrome (29.8%), and renal failure (10.6%). Hematuria and proteinuria existed in all the cases, while only 7 to 13 years children had nephrotic syndrome and renal failure. Of the 47 patients, 33 (70.2%) showed mesangial proliferative glomerulonephritis (MsPGN) under the light microscope, 13 (27.6%) focal segmental glomerulosclerosis (FSGS), 1 (2.1%) membrane proliferative glomerulonephritis (MPGN). For immunofluorescence, there was IgM (40.4%) as the dominant deposition in 19 patients, IgA in 9 (19.1%), IgG in 9 (19.1%), and 10 (21.4%) were negative. Thirty-nine cases showed typical glomerular basement membrane (GBM) pathological changes under electron microscope, while thin basement membrane in 8 cases; 46 showed abnormal skin and/or renal alpha-chain distribution. CONCLUSION: For Alport syndrome, number of male patients was higher than that of female patients. There was a significant difference among different age groups. Hematuria might be present throughout the course, while urine protein increases gradually. MsPGN was the dominant pathological change. The GBM pathological changes in younger children is not typical, so the immunofluorescence test of alpha-chain in collagen IV should be used as an important diagnostic method.

[Cyclosporin A treatment of 83 children with nephrotic syndrome of different pathological types].

OBJECTIVE: To evaluate the efficacy of cyclosporin A (CyA) therapy in 83 children with nephrotic syndrome of different pathological types. METHODS: Eighty-three children enrolled in this study were all hospitalized children with idiopathic nephrotic syndrome, aged 3 to 14 yrs (average 8.3 yrs) and included 52 males and 31 females. There were 35 cases with steroid-dependent, 17 with steroid resistant and 26 with frequent relapses. CyA was given to each patient with dosage of 5 mg/(kg.d) during the corticosteroid was diminished. The renwal biopsy was performed in all patients before the administration of CyA. The duration of CyA therapy lasted for about 3 to 6 months. The plasma concentration of CyA was monitored. RESULTS: Eighty-three children with nephrotic syndrome of different pathological types were treated with CyA, including 42 cases of minimal change nephrotic syndrome (MCNS), 31 cases of mesangioproliferative glomerulonephritis (MsPGN), 5 cases of membranoproliferative glomerulonephritis (MPGN) and 4 cases of focal segmental glomerular sclerosis (FSGS). All the 83 patients tolerated well to the CyA treatment. Forty-five cases got complete remission, 23 partial remission, 15 cases no change after one month treatment with CyA in the hospital. The overall response rate was 82%. Patients with different renal pathological types showed different responses. Among them, MCNS and MsPGN exhibited the best response rates of 86% and 84%, respectively; MPGN cases showed a lower response rate and FSGS cases showed the lowest rate. The response time was 7 to 45 days. The blood concentration of CyA was monitored for 1 week and 2 weeks after the drug was given. The effective drug concentration was maintained at 100 to 200 microg/L, and the course lasted for 3 to 6 months. During the follow-up of 83 cases, in 17 of 68 cases the disease relapsed when therapy was tapered or discontinued. The relapse rate was 25%. The results indicated that CyA would be effective to the relapsed cases. The serum creatinine increased temporarily after administration of CyA in 5 cases, N-acetyl-beta-D-glucosaminidase (NAG) in 8 cases and eventually reached the normal range after the adjustment of dosage. The side effects included anorexia, nausea, vomiting and so on. CONCLUSION: CyA is one of the effective substitutes for the treatment of nephrotic syndrome, especially for the cases with MCNS and MsPGN. And CyA could control refractory nephrotic syndrome effectively and rapidly. The clinical effect was related to the blood concentration of CyA and pathological types.