Fibroblast-derived exosomal miRNA-133 promotes cardiomyocyte-like differentiation.

OBJECTIVE: To investigate the role of exosomal miRNA-133 secreted by cardiac fibroblasts (CFs) in promoting cardiomyocyte differentiation. METHODS: Neonatal rat CFs were cultured in vitro, and the cultured CFs were divided into three groups as follows: induction, miRNA-133 high expression, and miRNA-133 inhibition. miRNA-133 was transfected into CFs with lentivirus as a vector. CFs were transfected with the miRNA-133 inhibitor, and the markers of cardiomyocyte were detected through immunofluorescence staining, Western blotting, and real-time quantitative polymerase chain reaction (qRT-PCR) at 3, 8, and 14 days, respectively. The expression levels of cardiac troponin T (cTnT) and cardiac actin (α-actin) were determined, and qRT-PCR was used to detect the expression of miRNA-133 in the fibroblast exosomes. RESULTS: CFs subjected to immunofluorescence staining expressed vimentin and discoid domain receptor 2. The exosomes secreted by CFs were observed as small vesicles of 30-100 nm via transmission electron microscopy, and Western blotting was used to detect exosome-specific protein CD63 and CD9 expression. The expression levels of cTnT, α-actin, and exosomal miRNA-133 secreted into the supernatant of the miRNA-133 high-expression group increased gradually at different time points and reached the highest level at 14 days. The expression levels of cTnT, α-actin, and exosome miRNA-133 in the miRNA-133 inhibition group were the lowest. CONCLUSION: The exosomal miRNA-133, which is derived from CFs, can promote the differentiation of fibroblasts into cardiomyocyte-like cells.

Optimization of noni callus induction and establishment of callus suspension system / 生物工程学报

The aim of the study was to obtain the secondary metabolites in the stem segment of noni and to establish genetic transformation system. The stem segments (no axillary buds) of noni were used as explants to induce the callus, and then to establish the cell suspension system. The factors affecting callus induction and cell suspension were studied. The results showed that the optimal culture medium for induction was MS with 1.0 mg/L 6-Benzylaminopurine (6-BA) and 0.1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), and the optimum culture medium for suspension was MS with 1.0 mg/L 6-BA and 0.1 mg/L 2,4-D, 3% sucrose and the pH of 5.85, with the initial inoculation amount of 37.5 g/L, and the speed of 110 r/min and 25±2 °C applying darkness culture. The suspension cells grew well and showed the maximum growth rate. The growth curve of the suspension cells from the stem segment of noni was in "S-typed" trend, and it should be transformed to the fresh medium between 12 and 20 d. During the culture, the pH of the culture medium decreased and then slowly increased, and the optimum pH for the suspension cells culture of callus from noni's stem segments was 4.5-5.0. In this study, the stable cell suspension system of the stem segment of noni was successfully established.

CRD-BP and β-TrCP in colorectal cancer / 国际肿瘤学杂志

Coding region instability determinant (CRD) is one of the influence factors of oncogene c-myc.Coding region instability determinant-binding protein (CRD-BP) can connect with CRD in order to protect CRD from nuclease attack,prevent rapid degradation of c-myc mRNA,and increase c-myc protein content.Beta-transducin repeats-containing protein (β-TrCP) can affect cell growth,differentiation,apoptosis and oncogenesis by regulating multiple signaling pathways and cell cycle.The overexpression of CRD-BP can upregulate the expression of β-TrCP and both of them play important roles in the tumorigenesis,progression,metastasis and invasion of colorectal cancer.

Survey and analysis of testing capabilities of clinical transfusion laboratories in medical institutions in Beijing / 中华医院管理杂志

Objective To investigate the testing capabilities of clinical transfusion laboratories in medical institutions in Beijing for the regulatory authorities to formulate administrative policies in this regard.Methods Experts assigned by Beijing Clinical Transfusion Quality Control Center made on-site inspections at the transfusion laboratories in medical institutions using quality control products.They recorded the complete testing process of the operators as well as the instruments,detection reagents in use and the testing results,with statistics and analysis made to the data so collected.Results The pass rate of these on-site inspections was lower than that of the external quality assessment.Some laboratories failed to complete the testing of the quality control products in time and the actual operations in some laboratories were inconsistent to the guidelines.55.9％ of level Ⅰ hospitals and 25.6％ of level Ⅱ hospitals were found with insufficient and inadequate instruments and process layout to meet the needs of clinical blood transfusion.Some of the technicians were found without sufficient trainings in their professional knowledge and basic skills,resulting in their poor competence against emergency cases and weakness in independent problem solving.In addition,the records of detection process and results were found to be substandard.Conclusions Transfusion laboratories in Beijing need to improve their testing capabilities in general.

Histone deacetylase inhibitors as therapeutic agents for polyglutamine disorders / 中华医学遗传学杂志

During the past few years, gene expression studies have shown that the perturbation of transcription frequently results in neuronal dysfunction in polyglutamine (PolyQ) diseases such as Huntington's disease (HD). Histone deacetylases (HDACs) act as repressors of transcription through interaction with co-repressor complexes, leading to chromatin remodelling. Aberrant interaction between PolyQ proteins and regulators of transcription could be one mechanism by which transcriptional dysregulation occurs. Here, the authors discuss the possible mechanism of transcriptional dysfunction in PolyQ disease, including the effect of histone acetyltransferases (HATs) and HDACs on pathogenesis, and the potential therapeutic pathways through which histone deacetylase inhibitors (HDACIs) might act to correct the aberrant transcription observed in HD and other PolyQ diseases.

Recent advances in molecular genetics of spinocerebellar ataxia type 3/Machado-Joseph disease / 中华医学遗传学杂志

To date, nearly 28 distinct genetic loci of autosomal dominant cerebellar ataxias have been identified, among them 18 disease-causing genes have been cloned. Of these, Machado-Joseph disease (MJD), also named as spinocerebellar ataxia type 3 (SCA3), is perhaps the most common subtype among different races and origins in the world. It is a neurodegenerative disease caused by the expansion of a CAG repeat in the coding region of the MJD1 gene, with obvious clinical and genetic heterogeneity. In this review, authors covered the recent advances in molecular genetic of SCA3/MJD.