The influence of overexpression of NeuroD1 on transdifferentiation of spinal cord reactive astrocytes into neurons / 中国神经精神疾病杂志

Objective To investigate the effect of the overexpression of NeuroD1 on mediating transdifferentiation of spinal reactive astrocytes into neurons. Methods Spinal cord astrocytes were cultured from the SD rat, and reactive astrocytes were prepared by scratches treatment. Cells were divided into blank groups (NV group), control virus group (GFP group) and NeuroD1 virus group (NeuroD1 group). At 7 d after scratches treatment, GFP and NeuroD1 groups were infected with retroviruses carrying the GFP gene and and GFP gene plus NeuroD1 gene, respectively,whereas NV group was not infected with the virus. Twenty-four hours late, the culture medium were replaced by neuron conditioned medi?um. Cell morphology was examined at 1, 2, 3, 5, 7 and 14 d. DCX positive and NeuN positive cells were detected at 7 d and 14 d after infection by using immunofluorescence staining method, respectively. Results After replacement with the neuron conditioned medium, the nucleus was obviously plump, the cytoplasm was thin and neurites was reduced and ex?tended. Compared with the NeuroD1 group, neurites of NV group and GFP group were shorter with many branches and the nucleus was smaller. At 7 d after infection, cell morphology of NV group and GFP group gradually recovered, but cell morphology of NeuroD1 group did not. Compared with NV group and GFP group, NeuroD1 group had more DCX(9.84 ± 2.06%)and NeuN(8.25±2.78%)positive cells [F values 40.107 for DCX and 21.73 for NeuN (P<0.05)]. Conclusion The overexpression of NeuroD1 can mediate the transdifferentiation of spinal reactive astrocytes into neurons.

Parallel determination of NeuroD1, Chromogranin-A, KI67 and androgen receptor expression in surgically treated prostate cancers

PURPOSE: Neuroendocrine differentiation is a hallmark of prostate cancer. The aim of our study was the detection of the parallel expression of neuroendocrine related markers using a prostate tissue microarray (TMA). MATERIALS AND METHODS: Our study was aimed at detecting the parallel expression of NeuroD1, Chromogranin-A (ChrA), Androgen Receptor (AR) and Ki-67 by immunohistochemistry on prostate cancer tissue microarray. The data was analyzed using SAS version 8.2 (SAS Inc, Cary, NC). The relationships between NeuroD1, ChrA and AR expressions and patients' characteristics were investigated by multivariate logistic regression analysis. Progression and Overall Survival (OS) distributions were calculated using Kaplan-Meier method. RESULTS: Tissue reactivity for NeuroD1, ChrA and AR concerned 73 percent, 49 percent and 77 percent of the available cases, respectively. Regarding overall survival, there were 87 deaths and 295 patients alive/censored (6 years of median follow-up). Seventy-seven disease progressions occurred at the median follow-up 5.4y. A significant correlation between NeuroD1, ChrA and AR expression was observed (p < 0.001 and p < 0.03, respectively). Additionally, ChrA was strongly associated in multivariate analysis to Gleason score and Ki67 expression (p < 0.009 and p < 0.0052, respectively). Survival analysis showed no association between markers neither for overall nor for cancer-specific survival. CONCLUSIONS: The results highlight that NeuroD1, Chromogranin-A and Androgen Receptor are strongly associated, however their expression does not correlate with overall survival or disease progression.

Screening and functional analysis of variation in NeuroD1 gene in early-onset type 2 diabetic pedigrees / 中华内分泌代谢杂志

Objective To screen the variation in NeuroD1 gene and to study its function in vitro and its clinical phenotypes and genetic characteristics in Chinese early-onset type 2 diabetic probands. Methods PCR-direct sequencing of NeuroD1 gene was performed in 85 early-onset type 2 diabetic probands, 95 late-onset type 2 diabetics with strong diabetic history and 87 non-diabetic control subjects. Distributions of the identified variation were calculated and compared among the three groups. Expression vectors with mouse NeuroD1 (mND1)cDNA wild type or mutant type and reporter vectors with human insulin promotor-linked luciferase were constructed. Then the above vectors were co-transfected into rat INS-1 cells. Relative luciferase activities were measured to compare transcriptional activities of insulin gene between WT and MT. Results S159P (T→C), a new mutation was identified in a proband, which was co-segregated with diabetes in 4 carriers from the paternal side. The functional study showed that the S159P mutant exhibited a 25% reduction in transcriptional activity of insulin gene as compared with the wild type. A45T (G→A), a common variation was identified. The AA + GA genotypic frequencies were markedly increased in early-onset type 2 diabetic probands as compared with late-onset type 2 diabetic probands and non-diabetic control subjects (P=0.006 and P=0.014, respectively). Conclusion The novel S159P mutation in the NeuroDl gene seems to contribute to the development of diabetes in the Chinese early-onset type 2 diabetic family. The A45T variation may increase susceptibility to or be in disequilibrium with early-onset type 2 diabetes mellitus in Chinese population. In addition, the A45T variation may affect the onset pattern of type 2 diabetes mellitns, such as early-onset but not late-onset type 2 diabetes mellitus.