NaHS·nH2O-induced umpolung: the synthesis of 2-acyl-3-aminoindoles from aryl methyl ketones and 2-aminobenzonitriles.

An efficient method for constructing 2-acyl-3-aminoindoles from methyl ketones and 2-aminobenzonitriles is described, in which NaHS·nH2O is used as a novel umpolung reagent for the first time in organic synthesis. Mechanistic studies revealed that the key step involved an Eschenmoser sulfide contraction reaction.

[Effect of p65 gene inhibited by siRNA on differention of rat marrow mesenchymal stem cells into neurons].

OBJECTIVE: To investigate the effect of p65 gene inhibited by siRNA on neuronic differentiation in the marrow mesenchymal stem cells (MSCs). METHODS: The MSCs were transfected with Rn-p65-siRNA. Fasudil hydrochloride induced MSCs differentiating into neurons. The non-transfected group and negative control group (transfected with negative control siRNA marked by Cy3) were used as controls. The fluorescence expressed by transfected MSCs were observed under inverted fluorescence microscope at 24 h,48 h and 72 h after transfected with negative control siRNA. The viability of MSCs was detected by MTT at 24 h, 48 h and 72 h after transfected with Rn-p65-siRNA. The expressions of p65 mRNA and protein in MSCs were detected by RT-PCR and Western blot respectively. The expressions of p65 protein, NSE, MAP-2 and glial fibrillary acidic protein (GFAP) were detected by immunocytochemical method after transfection for 6 h. RESULTS: The fluorescence of MSCs was mostly displayed after transfection of 72 hours and the efficiency of transfection was up to 83.3% ± 3.8%. Meanwhile, the p65 mRNA and p65 protein expressed by MSCs of transfected group were significantly decreased (P < 0.05); MTT displayed that the viability of MSCs was also significantly reduced (P < 0.05). The best efficiency of induction was observed in the transfected group. There were higher expressions of NSE and MAP-2 than the other group (P < 0.05). CONCLUSION: The p65 gene inhibited by siRNA can promote the marrow mesenchymal stem cells to differentiate into neurons.

Distribution of transglutaminase 6 in the central nervous system of adult mice.

Our previous study identified a new form of spinocerebellar ataxia (SCA), in which mutations in the gene coding for transglutaminase 6 (TG6) were suggested to be causative. However, the data concerning cellular distribution of TG6 in the brain is still fragmentary. Therefore, we now report a comprehensive immunohistochemical examination of the expression profile of TG6 in adult mouse brain. TG6 was abundantly expressed in the septal region, basal ganglia, hypothalamus and brainstem. Notably, numerous TG6-positive neurons were found in the key brain regions involved in regulating locomotion activity, including the globus pallidus, subthalamic nucleus, substantia nigra, cerebellum, some precerebellar nuclei, and spinal motor neurons. Double immunostaining showed that the vast majority of TG6-positive neurons in the reticular nigra were GABAergic and those in the compact nigra were not dopaminergic. In addition, double staining for TG6 with either anti-NeuN or glial fibrillary acidic protein (GFAP) antibodies demonstrated exclusive NeuN-TG6 co-localization. This study presents a comprehensive overview of TG6 expression in the mouse brain, and provides insight for investigating the role of TG6 in the development of SCA.

Gluten ataxia of sporadic and hereditary cerebellar ataxia in patients from mainland China.

BACKGROUND: Gluten sensitivity (GS) is a spectrum of disorders with diverse manifestations. Recent evidence suggests that ataxia may be the only manifestation of GS and that it may be one of the causes of sporadic ataxia. AIM: To investigate the prevalence of gluten ataxia among patients with ataxia in China. MATERIALS AND METHODS: Serum levels of anti-gliadin, anti-transglutaminase 2 (TG2), and anti-transglutaminase 6 (TG6) antibodies measured in 125 patients with ataxia (100 patients with sporadic ataxia and 25 patients with hereditary ataxia) and 51 healthy controls by enzyme-linked immunosorbent assay (ELISA). RESULTS: The serum concentrations of anti-gliadin, anti-TG2 IgG, IgA, and TG6-IgG antibodies were elevated in ataxia patients, but the increase was not statistically significant. However, TG6-IgA serum levels were significantly higher in sporadic ataxia as compared to those in healthy controls (P < 0.05). CONCLUSIONS: These results provide evidence that sporadic ataxia in a subgroup of patients may be due to gluten ataxia in mainland China. Measurement of serum anti-TG6 antibodies along with anti-TG2 and anti-gliadin antibodies may be useful for diagnosing gluten ataxia.

Transglutaminase 6 interacts with polyQ proteins and promotes the formation of polyQ aggregates.

A common feature of polyglutamine (polyQ) diseases is the presence of aggregates in neuronal cells caused by expanded polyglutamine tracts. PolyQ proteins are the substrates of transglutaminase 2, and the increased activity of transglutaminase in polyQ diseases suggests that transglutaminase may be directly involved in the formation of the aggregates. We previously identified the transglutaminase 6 gene to be causative of spinocerebellar ataxia type 35 (SCA35), and we found that SCA35-associated mutants exhibited reduced transglutaminase activity. Here we report that transglutaminase 6 interacts and co-localizes with both normal and expanded polyQ proteins in HEK293 cells. Moreover, the overexpression of transglutaminase 6 promotes the formation of polyQ aggregates and the conversion of soluble polyQ into insoluble polyQ aggregates. However, SCA35-associated mutants do not affect their interactions with polyQ proteins. These data suggest that transglutaminase 6 could be involved in polyQ diseases and there may exist a common pathological link between polyQ associated SCA and SCA35.

O-GlcNAcylation of BMAL1 regulates circadian rhythms in NIH3T3 fibroblasts.

Various physiological processes and behaviors show a circadian rhythm of approximately 24 h, which is crucial in coordinating internal metabolic processes and environmental signals. Post-translational modifications play an important role in regulating circadian core proteins. In this study, we demonstrated that BMAL1 was modified with an O-linked ß-N-acetylglucosamine (O-GlcNAc), which stabilized BMAL1 and enhanced its transcriptional activity. Conversely, inhibition of O-GlcNAcylation resulted in inhibition of circadian rhythms of clock gene expression. Because O-GlcNAcylation is sensitive to the glucose level, such a modification may provide a new mechanism connecting metabolism with circadian rhythms.

Spinocerebellar ataxia type 35 (SCA35)-associated transglutaminase 6 mutants sensitize cells to apoptosis.

Spinocerebellar ataxia type 35 (SCA35) is an autosomal dominant neurodegenerative disorder. In our previous study, using exome sequencing and linkage analysis, two missense mutations of the transglutaminase 6 (TGM6) gene were identified as causative for SCA35. TGM6 encodes transglutaminase 6 (TG6), a member of the transglutaminase family of enzymes that catalyze the formation of a covalent bond between a free amine group and the γ-carboxamide group of protein- or peptide-bound glutamine. However, the precise role of TG6 in contributing to SCA35 remains unclear. In this study, we analyzed the subcellular distribution, expression and in vitro activity of two missense mutations of TG6 (D327G, L517W) and found that both mutants exhibited decreased transglutaminase activity and stability. Furthermore, overexpressing the TG6 mutants sensitized cells to staurosporine-induced apoptosis by increasing the activity of caspases. We propose that the pro-apoptotic role of these mutants might underlie the pathogenesis of SCA35.

[Recent advance in genetic study of hereditary autosomal recessive cerebellar ataxia].

Autosomal recessive cerebellar ataxias (ARCA) are a highly heterogeneous group of rare neurodegenerative diseases affecting both central and peripheral nervous systems. Based on pathological mechanisms, five major types of ARCA may be distinguished, which include mitochondrial ataxia, metabolic disorder, DNA repair defect ataxia, congenital ataxias and degenerative ataxia. This review summarizes clinical features, molecular genetics and recent advances in DNA sequencing of common types of ARCA.

Spinocerebellar ataxia type 23 is an uncommon SCA subtype in the Chinese Han population.

The spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative diseases. In 2010, four missense mutations in the prodynorphin (PDYN) gene were found in two families and two sporadic cases of SCA type 23 (SCA23) from the Netherlands. In addition, one missense mutation in PDYN was also found in one sporadic SCA23 case in America in 2012. To date, there have been no reports of PDYN gene mutations in mainland China. To investigate the frequency of SCA23 among the Chinese Han population, we performed polymerase chain reaction (PCR) and DNA direct sequencing of the PDYN gene in 305 unrelated ataxia patients. Although no SCA23 mutation was identified, one novel single nucleotide polymorphism (c.255G>A, p.Lys85Lys) in exon 4 of the PDYN gene was found. This suggests that SCA23 is a rare form of dominant ataxia in the Chinese Han population.

[Expression of microRNA in neonatal rats with hypoxic-ischemic brain damage].

OBJECTIVE: To study the changes of microRNA expression in cortex tissues in neonatal rats with hypoxic-ischemic brain damage (HIBD)and the possible roles of microRNA in the pathogenesis of HIBD. METHODS Rat HIBD model was prepared. The cortex tissues were obtained 14 days after the HIBD event. The microRNA expression profiles were measured using microRNA microarray. Expression of 9 microRNAs (miR-126,-26a,-674-5p,-21,-25,-290, miR-124,-125b-5p and microRNA-9a) was determined by quantitative real-time PCR. RESULTS: he results of microRNA expression profiles indicated that 27 pieces of microRNA were up-regulated more than 2 folds and 60 pieces were down-regulated more than 2 folds compared with the normal control group. The results of the 9 microRNAs detected by quantitative real-time PCR were consistent with those detected by microRNA microarray. CONCLUSIONS: HIBD rats have significant changes in microRNA expression, suggesting that microRNA expression may play important roles in the pathogenesis of HIBD.

[Effect of notch signaling on differentiation of rat marrow mesenchymal stem cells into neurons induced by fasudil hydrochloride].

OBJECTIVE: To investigate the effect of notch signaling on differentiation of rat bone marrow mesenchymal stem cells (MSCs) into neurons induced by fasudil hydrochloride. METHODS: The experiments were divided into non-transfected group, transfected group (transfected with Rn-Notch1-siRNA), positive control group (transfected with Rn-MAPK-1 Control siRNA) and negative control group (transfected with negative control siRNA). Fasudil hydrochloride induced MSCs differentiating into neurons. The fluorescence expressed by transfected MSCs were observed under inverted fluorescence microscope. The expression of notch1 mRNA, Hes1 mRNA and MAPK1 mRNA in MSCs was detected by RT-PCR. The expression of Notch1 protein, NSE, neurofilament M (NF-M) and glial fibrillary acidic protein(GFAP)was detected by immunocytochemical method. The viability of MSCs was detected by MTT. RESULTS: (1) The fluorescence of MSCs was mostly displayed after transfection for 72 h and the efficiency of transfection was up to 91.3% +/- 4.2%. Meanwhile, the notch1 mRNA and Hes1 mRNA expressed by MSCs of transfected group were significantly decreased (P < 0.05) and MTT displayed that the viability of MSCs was also significantly reduced (P < 0.05). (2) Fasudil hydrochloride could induce MSCs differentiate into neurons and the best efficiency of induction was observed in the transfected group. There was higher expression of NSE and neurofilament-M (NF-M) than the other groups (P < 0.05). CONCLUSION: There may be notch1 signaling and Rho/Rho GTPase signaling synergy on differentiation of rat bone marrow stromal cell into neurons induced by fasudil hydrochloride and they jointly promote the differentiation of MSCs into neurons.

[Effects of DSCAM on differentiation of rat marrow mesenchymal stem cells into neurons in vitro].

OBJECTIVE: To study the effects of Down syndrome cellular adhesion molecule (DSCAM) on differentiation of rat marrow mesenchymal stem cells (MSCs) into neurons in vitro. METHODS: MSCs from Sprague-Dawley rats were induced into neurons by baicalin. The expression of DSCAM before and after induction was evaluated by immunocytochemical staining and Western blot assay. After knockdown of DSCAM by siRNA transfection, the differentiation rate of neurons derived from MSCs was measured. RESULTS: Before induction, the expression of DSCAM was not detectable in MSCs. After bFGF preinduction for 24 hrs, DSCAM was slightly expressed in MSCs (1.71+/- 0.67%). The DSCAM expression increased 6 hrs after baicalin induction (15.79+/- 4.24%), reached a peak at 3 days (53.16+/- 5.94%) and then decreased gradually. The DSCAM expression 6 days after baicalin induction (28.99+/- 6.72%) was significantly lower than that at 3 days (P<0.01). However, after DSCAM-siRNA transfection, the DSCAM expression in MSCs was significantly reduced. MSCs did not express neuron-specific beta-III-tubulin before induction. After baicalin induction for 6 hrs, 3 days and 6 days, the expression of beta-III-tubulin was 1.40+/- 0.79%, 41.59+/- 3.17% and 59.11+/- 4.76% respectively. But the beta-III-tubulin expression significantly decreased 3 and 6 days after DSCAM-siRNA transfection (28.57+/- 2.91% and 43.90+/- 12.31% respectively). CONCLUSIONS: DSCAM may play an important role in MSCs differentiation into neural cells.