Regulation of alternative splicing of tau exon 10

The neuronal microtubule-associated protein tau is abnormally hyperphosphorylated and aggregated into neurofibrillary tangles in the brains of individuals with Alzheimer’s disease and related neurodegenerative disorders. The adult human brain expresses six isoforms of tau generated by alternative splicing of exons 2, 3, and 10 of its pre-mRNA. Exon 10 encodes the second microtubule-binding repeat of tau. Its alternative splicing produces tau isoforms with either three or four microtubule-binding repeats, termed 3R-tau and 4Rtau. In the normal adult human brain, the level of 3R-tau is approximately equal to that of 4R-tau. Several silent and intronic mutations of the tau gene associated with FTDP-17T (frontotemporal dementia with Parkinsonism linked to chromosome 17 and specifically characterized by tau pathology) only disrupt exon 10 splicing, but do not influence the primary sequence of the tau protein. Thus, abnormal exon 10 splicing is sufficient to cause neurodegeneration and dementia. Here, we review the regulation of tau exon 10 splicing by cis-elements and trans-factors and summarize all the mutations associated with FTDP-17T and related tauopathies. The findings suggest that correction of exon 10 splicing may be a potential target for tau exon 10 splicing-related tauopathies.     

康复期应用电动康复机对脑出血偏瘫病人下肢运动功能及生活质量的影响

目的探讨脑出血偏瘫病人在早期康复护理中应用电动康复机对下肢运动功能及生活质量的影响效果。方法 选取南通大学附属医院神经外科2015年2月至2016年2月收治行早期康复护理的脑出血偏瘫病人52例作为对照组,另选取2016年3月至2017年3月在对照组基础上行电动康复机训练的脑出血偏瘫病人52例作为观察组。两组护理8周,对比下肢运动功能、生活质量及临床疗效。结果 观察组护理4周、6周、8周后肢体运动功能评分(FMA)评分均高于对照组,差异有统计学意义(均P＜0.05)。观察组护理2周、4周、6周、8周后生活质量量表(QOL)评分均高于对照组,差异有统计学意义(均P＜0.05)。观察组治疗有效率高于对照组(94.23%比78.85%),差异有统计学意义(χ²=4.044,P=0.044)。结论 电动康复机应用于脑出血偏瘫病人早期康复护理效果显著,可有效提高下肢运动功能及临床疗效,改善生活质量,值得临床推广。     

HMGB1 gene silencing inhibits neuroinflammation via down-regulation of NF-κB signaling in primary hippocampal neurons induced by Aβ25–35

High mobility group box 1 protein (HMGB1) is potentially triggered by Aβ oligomers and other sterile injuries, and is a non-histone DNA binding nuclear protein with roles in neural development and neurodegeneration, which contribute to memory impairment and chronic neuroinflammation in the brain. However, the exact molecular mechanisms of HMGB1 activation in Alzheimer's disease (AD) were previously unknown. The present study aimed to elucidate the effects of HMGB1 in Aβ_25–35-induced neuroinflammation in hippocampal neuron cultures. RNA interference (RNAi) HMGB1 treatment significantly reduced Aβ_25–35-induced HMGB1 expression by almost 70% in primary hippocampal neurons. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and enzyme-linked immunosorbent assay (ELISA) demonstrated that short hairpin RNA (shRNA) for HMGB1 ameliorated Aβ_25–35-treated neuroinflammation, including activation of advanced glycosylation end product-specific receptor (RAGE), toll-like receptor 4 (TLR4), and nuclear factor-kappa B (NF-κB)-p65, as well as induced the release of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), IL-6, and HMGB1 in primary hippocampal neurons and the culture supernatant. In addition, pretreatment with HMGB1-shRNA dramatically reduced both the degree of nuclear-cytoplasmic HMGB1 translocation of HMGB1 and NF-κB DNA binding. Together, the data indicate that HMGB1 mediates the pathogenesis of AD by activating RAGE/TLR4 signaling and that shRNA targeting HMGB1 may be a promising therapeutic strategy for treating AD.     

A role for activator of G-protein signaling 3 (AGS3) in multiple myeloma

Previous studies have demonstrated that activator of G-protein signaling 3 (AGS3; also known as GPSM1), a member of the AGS family, plays an important anti-apoptotic role through enhancing the phosphorylation of cyclic AMP response element-binding protein (p-CREB). In this report, we delineate the anti-apoptotic role of AGS3 in multiple myeloma (MM). To do this, we developed a cell apoptotic model induced by doxorubicin in MM. Our data indicate that decreased expression of AGS3 is correlated with reduced levels of p-CREB in the apoptotic model. The negative role of AGS3 in cell apoptosis was further confirmed by knocking down AGS3. The microenvironment has been shown to influence tumor cell phenotype in response to chemotherapy. Since cell adhesion-mediated drug resistance remains a major obstacle for successful treatment of MM, we constructed a cell adhesion model in MM and detected the changing of AGS3 protein expression. AGS3 siRNA reversed the high rate of MM cell adhesion to either fibronectin or HS-5 cells. Consistent with the reduced adhesion rate, the cells also exhibited reduced drug resistance to doxorubicin, mitoxantrone, and dexamethasone. Collectively, these data indicate that AGS3 may be represented as a good candidate for pursuing clinical trials in MM. Moreover, our data provide a clinical therapeutic target for MM and potentially other tumors that home and/or metastasize to the bone.     

海马去神经支配损伤后放射状胶质细胞表达RUNX1T1的变化及向神经元分化的影响

目的 观察海马去神经支配损伤后,海马放射状胶质细胞表达RUNX相关转录因子1转位1（RUNX1T1）和向神经元分化的情况。方法 取6只大鼠,采用物理切割大鼠穹隆海马伞术制备海马去神经支配损伤模型,并制备海马提取液,海马放射状胶质细胞体外培养,培养液中加入海马提取液。实验分为去神经支配组、正常组和空白对照组,共6块24孔板,每组各48孔。采用Real-time PCR、Western blotting及免疫荧光技术检测各组放射状胶质细胞表达RUNX1T1 mRNA和蛋白的变化,以及分化成微管相关蛋白 2（MAP-2）阳性神经元比例。结果 体外培养的海马放射状胶质细胞具有细而长的突起,且表达RUNX1T1,去神经支配组中RUNX1T1阳性细胞的荧光强度高于正常组和空白对照组约1.8倍,细胞突起也较后两组长。去神经支配组RUNX1T1 mRNA和蛋白表的表达量各上调2.9倍和2.4倍,且39.33%细胞表达MAP-2,与正常组和空白对照组相比,阳性细胞数比例明显增高。结论 海马去神经支配损伤后海马放射状胶质细胞上调表达RUNX1T1,并可更多地向神经元分化。     

骨形态发生蛋白/维甲酸诱导的神经特异性蛋白3在丙戊酸钠诱导神经干细胞向神经元分化过程中的作用

目的 探讨骨形态发生蛋白/维甲酸诱导的神经特异性蛋白3（Brinp3）在丙戊酸钠（VPA）诱导神经干细胞向神经元分化过程中的作用。方法 体外培养大鼠海马神经干细胞,运用Real-time PCR和Western blotting技术在VPA诱导神经干细胞分化后24 h和48 h检测Brinp3的表达;Real-time PCR检测Brinp3在成年大鼠各组织中以及在神经干细胞、星形胶质细胞和神经元中的表达水平;在神经干细胞中转染Brinp3小干扰RNA（siRNA）并诱导分化24 h后,运用Real-time PCR、Western blotting和免疫荧光技术检测Brinp3和神经元标志分子的表达。以上实验均包含5次生物学重复。结果 与对照组相比,VPA处理组中Brinp3的mRNA和蛋白水平在24 h和48 h均显著上调（P<0.05）;Brinp3在脑组织中呈优势表达;Brinp3在星形胶质细胞中表达较低,而在神经元中表达较高（P<0.001）;在神经干细胞中转染Brinp3 siRNA,诱导分化24 h后,Brinp3的表达被显著抑制（P<0.001）,神经元标志分子的表达均显著下调（P<0.01）,第4天分化成的神经元比例减少（P<0.001）。结论 Brinp3表达的上调可能介导了VPA促神经干细胞向神经元分化的功能。     

Neural tissue engineering options for peripheral nerve regeneration

Tissue engineered nerve grafts (TENGs) have emerged as a potential alternative to autologous nerve grafts, the gold standard for peripheral nerve repair. Typically, TENGs are composed of a biomaterial-based template that incorporates biochemical cues. A number of TENGs have been used experimentally to bridge long peripheral nerve gaps in various animal models, where the desired outcome is nerve tissue regeneration and functional recovery. So far, the translation of TENGs to the clinic for use in humans has met with a certain degree of success. In order to optimize the TENG design and further approach the matching of TENGs with autologous nerve grafts, many new cues, beyond the traditional ones, will have to be integrated into TENGs. Furthermore, there is a strong requirement for monitoring the real-time dynamic information related to the construction of TENGs. The aim of this opinion paper is to specifically and critically describe the latest advances in the field of neural tissue engineering for peripheral nerve regeneration. Here we delineate new attempts in the design of template (or scaffold) materials, especially in the context of biocompatibility, the choice and handling of support cells, and growth factor release systems. We further discuss the significance of RNAi for peripheral nerve regeneration, anticipate the potential application of RNAi reagents for TENGs, and speculate on the possible contributions of additional elements, including angiogenesis, electrical stimulation, molecular inflammatory mediators, bioactive peptides, antioxidant reagents, and cultured biological constructs, to TENGs. Finally, we consider that a diverse array of physicochemical and biological cues must be orchestrated within a TENG to create a self-consistent coordinated system with a close proximity to the regenerative microenvironment of the peripheral nervous system.     

A low level of GPR37 is associated with human hepatocellular carcinoma progression and poor patient survival

GPR37, also known as parkin-associated endothelin-like receptor (Pael-R), is an orphan G protein-coupled receptor (GPCR). It has been reported that GPCRs play vital roles in the development and progression of cancer. To investigate the potential roles of GPR37 in hepatocellular carcinoma (HCC), expression of GPR37 was examined in human HCC samples. Immunohistochemistry and Western blot analyses were performed for GPR37 in 57 hepatocellular carcinoma samples. GPR37 expression was low in hepatocellular carcinoma as compared with the adjacent non-tumorous tissues. Clinicopathological analysis showed that GPR37 expression was significantly correlated with histological grade and the level of alpha fetal protein (AFP) (P = 0.000 and 0.002, respectively). The Kaplan–Meier survival curves revealed that decreasing GPR37 expression was associated with poor prognosis in HCC patients, while in vitro, following the release from serum starvation of HuH7 HCC cell, the expression of GPR37 was downregulated. In addition, the transient GPR37 knockdown by siRNA in HuH7 cells significantly decreased the apoptosis of hepatoma cells with activation of the phosphatidylinositol 3-kinase-Akt signaling pathway. Our data suggest that GPR37 may play an important role in the pathogenesis of hepatocellular carcinoma by affecting the proliferation of H CC cells, and it could be a novel potential molecular therapy target for HCC.     

The expression levels and prognostic value of high temperature required A2 (HtrA2) in NSCLC

High temperature required A2 (HtrA2) is a serine kinase that is released from mitochondria into the cytosol upon apoptotic stimuli, inducing apoptosis in various cancers. Thus, analysis of the expression of HtrA2 in non-small-cell lung cancer (NSCLC) tissues is needed for the understanding of this malignancy. In this study we firstly analyzed the apoptosis effect of HtrA2 in A549 cells by RNA interference and cisplatin with Western blot and flow cytometry. Then HtrA2 expression was evaluated by Western blot and immunohistochemistry in NSCLC tissues. Western blot and flow cytometry analyses indicated that deletion of HtrA2 was negatively correlated with apoptosis-induced protein in A549 cells. HtrA2 was lowly expressed in NSCLC and significantly associated with histological differentiation and clinical stage. Besides, low expression of HtrA2 was a prognostic factor for NSCLC patients’ inferior survival. In conclusion, HtrA2 might promote the apoptosis of NSCLC cells, and serve as a target for NSCLC's treatment.     

Erythropoietin and retinopathy of prematurity: a meta-analysis

We performed a meta-analysis to study the association between erythropoietin (EPO) and the development of retinopathy of prematurity (ROP) in preterm newborn infants. Studies were identified through PubMed (1966–) and ISI databases (1965–) literature searches. Results and effect sizes are expressed as odds ratio (OR) with 95 % confidence intervals (CI). Fourteen studies identified to the meta-analysis, including 3,484 preterm newborn infants. A total of 563 of 1,221 babies treated with EPO had ROP (46.1 %) vs. 420 of 1,134 babies without EPO (37.0 %). No significant difference was found in the ROP risk between the two groups, with the OR 1.592 (95 % CI 0.901–2.812). A total of 192 of 1,298 babies treated with EPO had severe ROP (stage 3–4) (14.8 %) vs. 166 of 1,199 babies without EPO (13.8 %). The OR was 1.203 (95 % CI 0.763–1.896). No significant publication bias was found. Sensitivity analyses showed the results were robust. Conclusion: Our meta-analysis indicates that EPO treatment is not associated with the development of ROP in preterm infants. But this conclusion should be confirmed by further high-quality researches.