High glucose concentration induces endothelial cell proliferation by regulating cyclin‐D2‐related miR‐98

Cyclin D2 is involved in the pathology of vascular complications of type 2 diabetes mellitus (T2DM). This study investigated the role of cyclin‐D2‐regulated miRNAs in endothelial cell proliferation of T2DM. Results showed that higher glucose concentration (4.5 g/l) significantly promoted the proliferation of rat aortic endothelial cells (RAOECs), and significantly increased the expression of cyclin D2 and phosphorylation of retinoblastoma 1 (p‐RB1) in RAOECs compared with those under low glucose concentration. The cyclin D2‐3′ untranslated region is targeted by miR‐98, as demonstrated by miRNA analysis software. Western blot also confirmed that cyclin D2 and p‐RB1 expression was regulated by miR‐98. The results indicated that miR‐98 treatment can induce RAOEC apoptosis. The suppression of RAOEC growth by miR‐98 might be related to regulation of Bcl‐2, Bax and Caspase 9 expression. Furthermore, the expression levels of miR‐98 decreased in 4.5 g/l glucose‐treated cells compared with those treated by low glucose concentration. Similarly, the expression of miR‐98 significantly decreased in aortas of established streptozotocin (STZ)‐induced diabetic rat model compared with that in control rats; but cyclin D2 and p‐RB1 levels remarkably increased in aortas of STZ‐induced diabetic rats compared with those in healthy control rats. In conclusion, this study demonstrated that high glucose concentration induces cyclin D2 up‐regulation and miR‐98 down‐regulation in the RAOECs. By regulating cyclin D2, miR‐98 can inhibit human endothelial cell growth, thereby providing novel therapeutic targets for vascular complication of T2DM.     

Preparation of chicken IgY against recombinant E2 protein of bovine viral diarrhea virus (BVDV) and development of ELISA and ICA for BVDV detection

Bovine viral diarrhea virus (BVDV) infects cattle and may lead to persistent infection (PI). The PI animals harbor BVDV throughout their life and become immune tolerant against BVDV. Thus, diagnosis of this virus in herd is highly important. Recombinant E2 protein expression (using pET-32a in Escherichia coli) was confirmed by SDS-PAGE and Western blotting; then purified by Ni⁺ affinity chromatography. Chickens were immunized with BVDV-E2 protein, and IgY antibodies were extracted from egg yolk by PEG-6000. The peak titer of anti-BVDV-E2-IgY was 1:128,000 after the fifth immunization. IgY-based enzyme-linked immuno sorbent assay (ELISA) and immunochromatographic assay (ICA) were further developed. Coincidence of ELISA and ICA test with RT-PCR was 95.45 and 90.91%, respectively. The anti-BVDV-E2 IgY could be used in routine screening of BVDV infection. Besides, it can also be applicable while licensing and/or using live vaccines; screening of imported products containing bovine serum and strong surveillance of BVDV outbreaks.     

Serum pleiotrophin as a diagnostic and prognostic marker for small cell lung cancer

Pleiotrophin (PTN) is involved in tumour progression, angiogenesis and metastasis. The purpose of this study was to investigate the expression level of PTN in the serum of patients with small cell lung cancer (SCLC) and to explore the clinical significance of PTN. Serum samples from 128 patients with SCLC, 120 healthy volunteers (HV) and 60 patients with benign lung disease (BLD) were collected. The levels of serum PTN were determined with ELISA and its correlation with the clinical data was examined. The serum PTN levels in SCLC patients were significantly higher than that in BLD patients (P < 0.05) or HV (P < 0.05). With a cutoff value of 258.18 ng/mL, the sensitivity and specificity of PTN to SCLC patients and BLD patients, SCLC patients and HV were 79.2% and 91.7%, 86.7% and 95.8% respectively. An area under the curve for all stages of SCLC resulting from PTN, which was significantly better than the other tumour markers tested including progastrin‐releasing peptide and neuron‐specific enolase. High serum PTN levels appear to correlate with poor survival in patients with SCLC. These results suggest that PTN levels in the serum could be a new effective biomarker for the diagnosis and prognosis of SCLC.     

MiR‐802 causes nephropathy by suppressing NF‐κB‐repressing factor in obese mice and human

Obesity is associated with significant microvascular complications including renal injuries and may induce end‐stage renal disease. Emerging studies have demonstrated microRNAs (miRNAs) are potential mediators in the pathophysiological process of nephropathy. The present study aimed to investigate the role of miR‐802 in obesity‐related nephropathy and potential molecular mechanisms. Through utilizing obese mouse model and human subjects, we explored the therapeutic benefits and clinical application of miR‐802 in protecting against nephropathy. Renal miR‐802 level was positively correlated with functional parameters, including blood urea nitrogen and creatinine in obese mice. Specific silencing of renal miR‐802 improved high fat diet (HFD)‐induced renal dysfunction, structural disorders and fibrosis. The up‐regulated inflammatory response and infiltrated macrophages were also significantly decreased in miR‐802 inhibitor‐treated obese mice. Mechanistically, miR‐802 directly bond to 3?‐UTR of NF‐κB‐repressing factor (NRF) and suppressed its expression. In clinical study, the circulating miR‐802 level was significantly increased in obese subjects, and positively correlated with plasma creatinine level but negatively correlated with creatinine clearance. Taken together, our findings provided evidence that miR‐802/NRF signalling was an important pathway in mediating obesity‐related nephropathy. It is a possible useful clinical approach of treating miR‐802 inhibitor to combat nephropathy.     

β‐arrestin 2 negatively regulates NOD2 signalling pathway through association with TRAF6 in microglia after cerebral ischaemia/reperfusion injury

We previously reported that nucleotide‐binding oligomerization domain‐containing protein (NOD) 2 was involved in the inflammatory responses to cerebral ischaemia/reperfusion (I/R) insult. However, the mechanism by which NOD2 participates in brain ischaemic injury and the regulation of NOD2 in the process are still obscure. Increased β‐arrestin 2 (ARRB2) expression was observed in microglia following cerebral I/R in wild‐type mice besides the up‐regulation of NOD2 and TRAF6. Stimulation of NOD2 by muramyl dipeptide (MDP) in BV2 cells induced the activation of NF‐κB by the phosphorylation of p65 subunit and the degradation of IκBα. Meanwhile, the protein level of Cyclooxygenase‐2 (COX‐2), the protein expression and activity of MMP‐9 were significantly increased in BV2 cells after administration of MDP. Furthermore, overexpression of ARRB2 significantly suppressed the inflammation induced by MDP, silence of ARRB2 significantly enhanced the inflammation induced by MDP in BV2 cells. In addition, we observed endogenous interaction of TRAF6 and ARRB2 after stimulation of MDP or cerebral I/R insult, indicating ARRB2 negatively regulates NOD2‐triggered inflammatory signalling pathway by associating with TRAF6 in microglia after cerebral I/R injury. Finally, the in vivo study clearly confirmed that ARRB2 negatively regulated NOD2‐induced inflammatory response, as ARRB2 deficiency exacerbated stroke outcomes and aggravated the NF‐κB signalling pathway induced by NOD2 stimulation after cerebral I/R injury. These findings revealed ARRB2 negatively regulated NOD2 signalling pathway through the association with TRAF6 in cerebral I/R injury.     

Site-directed RNA editing (SDRE): Off-target effects and their countermeasures

Site-directed RNA editing (SDRE) is invaluable to basic research and clinical applications and has emerged as a new frontier in genome editing. The past few years have witnessed a surge of interest in SDRE, with SDRE tools emerging at a breathtaking pace. However, off-target effects of SDRE remain a tough problem, which constitutes a major hurdle to their clinical applications. Here we discuss the diverse strategies for combating off-target editing, drawing lessons from the published studies as well as our ongoing research. Overall, SDRE is still at its infancy, with significant challenges and exciting opportunities ahead.