Description: Publication date: Available online 8 September 2015 Source: FEBS Open Bio Author(s): Saori Takahashi, Isao Suetake, Jan Engelhardt, Shoji Tajima Hydroxymethylcytosine has been shown to be involved in DNA demethylation and gene expression. Although methods to determine the position of hydroxymethylcytosine at single-base resolution have been reported, these methods involve some difficulties. Here, we report a simple method to analyze hydroxymethylcytosine in the CpG sequence utilizing the maintenance DNA methylation activity of DNMT1, which selectively methylates hemi-methylated but not hemi-hydroxymethylated CpG sequences. The method enables monitoring of the dynamics of the hydroxymethylation state of a specific genome site.

Description: Publication date: Available online 6 September 2015 Source: FEBS Open Bio Author(s): Marie Decock, Laetitia El Haylani, Serena Stanga, Ilse Dewachter, Jean Noël Octave, Steven O. Smith, Stefan N. Constantinescu, Pascal Kienlen-Campard Alzheimer’s disease (AD) is a neurodegenerative disease that causes progressive loss of cognitive functions, leading to dementia. Two types of lesions are found in AD brains: neurofibrillary tangles and senile plaques. The latter are composed mainly of the β-amyloid peptide (Aβ) generated by amyloidogenic processing of the amyloid precursor protein (APP). Several studies have suggested that dimerization of APP is closely linked to Aβ production. Nevertheless, the mechanisms controlling APP dimerization and their role in APP function are not known. Here we used a new luciferase complementation assay to analyze APP dimerization and unravel the involvement of its three major domains: the ectodomain, the transmembrane domain and the intracellular domain. Our results indicate that within cells full-length APP dimerizes more than its α and β C-terminal fragments, confirming the pivotal role of the ectodomain in this process. Dimerization of the APP transmembrane (TM) domain has been reported to regulate processing at the γ-cleavage site. We show that both non-familial and familial AD mutations in the TM GXXXG motifs strongly modulate Aβ production, but do not consistently change dimerization of the C-terminal fragments. Finally, we found for the first time that removal of intracellular domain strongly increases APP dimerization. Increased APP dimerization is linked to increased non-amyloidogenic processing.

Description: Publication date: Available online 3 September 2015 Source: FEBS Open Bio Author(s): Kao-Chang Lin, Hung-Jung Lin, Ching-Ping Chang, Mao-Tsun Lin Heat shock protein (HSP) 72 in serum was decreased to a greater degree in patients with serious heat stroke than in those with mild heat stroke. Thus, increased levels of HSP72 appeared to correlate with a better outcome for the patient. Nevertheless, the function of HSP72 in the heat-induced hypothalamic cell death has not been assessed. In this study, we found that increasing HSP72 levels with mild heat preconditioning or decreasing HSP72 levels with pSUPER plasmid expressing HSP72 small interfering RNA significantly attenuated or exacerbated heat-induced cell death in cultured primary hypothalamic cells, respectively. Our findings suggest that HSP72 plays a pivotal role in heat-induced cell death and may be associated with heat tolerance.

Description: Publication date: Available online 31 August 2015 Source: FEBS Open Bio Author(s): Melissa T. Manners, Yuzhen Tian, Zhaolan Zhou, Seena K. Ajit Nerve injury induces chronic pain and dysregulation of microRNAs in dorsal root ganglia (DRG). Several downregulated microRNAs are predicted to target Mecp2. MECP2 mutations cause Rett syndrome and these patients report decreased pain perception. We confirmed MeCP2 upregulation in DRG following nerve injury and repression of MeCP2 by miRNAs in vitro. MeCP2 regulates brain-derived neurotrophic factor (BDNF) and downregulation of MeCP2 by microRNAs decreased Bdnf in vitro . MeCP2 T158A mice exhibited reduced mechanical sensitivity and Mecp2 -null and MeCP2 T158A mice have decreased Bdnf in DRG. MeCP2-mediated regulation of Bdnf in the DRG could contribute to altered pain sensitivity.

Description: Publication date: Available online 1 September 2015 Source: FEBS Open Bio Author(s): Jen Y. Lee, Dede Lori, Dominic J. Wells, Paul R. Kemp Myostatin is a TGFβ family ligand that reduces muscle mass. In cancer cells, TGFβ signalling is increased by the protein FHL1. Consequently, FHL1 may promote signalling by myostatin. We therefore tested the ability of FHL1 to regulate myostatin function. FHL1 increased the myostatin activity on a SMAD reporter and increased myostatin dependent myotube wasting. In mice, independent expression of myostatin reduced fibre diameter whereas FHL1 increased fibre diameter, both consistent with previously identified effects of these proteins. However, co-expression of FHL1 and myostatin reduced fibre diameter to a greater extent than myostatin alone. Together, these data suggest that the expression of FHL1 may exacerbate muscle wasting under the appropriate conditions.

Description: Publication date: Available online 31 August 2015 Source: FEBS Open Bio Author(s): Danilo Ranieri, Alessandra Cucina, Mariano Bizzarri, Maurizio Alimandi, Maria Rosaria Torrisi Microgravity and sudden changes of gravitational forces exert numerous effects on tissues, organs and apparatus. Responses to these forces variably applied to cells indicate the existence of mechanotransduction pathways able to modulate transcription. Oscillation of circadian clocks similarly influences many cellular and metabolic processes. Here we hypothesized that signals derived from changes of gravitational forces applied to epidermal cells might influence their physiology in harmony with the oscillation of the molecular clock. In this study, we describe amplified oscillations of Bmal1 circadian clock gene in human keratinocytes exposed to short simulated microgravity and to rapid variation of gravitational forces. We found that exposure to microgravity enhances the amplitude of the Bmal1 feedback loop sustained by an apparently lower variability of Rev-erb α transcription, while recovery from microgravity is characterized by increased amplitude of Bmal1 expression and elongation of the oscillatory periods of Bmal1 and Rev-erbα. These data highlight the existence of integrated signaling network connecting mechanosensitive pathways to circadian gene regulation.

Description: Publication date: Available online 29 August 2015 Source: FEBS Open Bio Author(s): Antonio Filippi, Elisa Petrussa, Carlo Peresson, Alberto Bertolini, Angelo Vianello, Enrico Braidot Flavonoids represent one of the most important molecules of plant secondary metabolism, playing many different biochemical and physiological roles. Although their essential role in plant life and human health has been elucidated by many studies, their subcellular transport and accumulation in plant tissues remains unclear. This is due to the absence of a convenient and simple method to monitor their transport. In the present work, we suggest an assay able to follow in vivo transport of quercetin, the most abundant flavonoid in plant tissues. This uptake was monitored using 2-aminoethoxydiphenyl borate (DPBA), a fluorescent probe, in non-pigmented Vitis vinifera cell cultures.

Description: Publication date: Available online 28 August 2015 Source: FEBS Open Bio Author(s): Ya-Jun Sun, Ying Yu, Gao-Ceng Zhu, Zhu-Hua Sun, Jian-Xin Ge Schizophrenia is one of the most common mental disorders to severely affect human health worldwide. Single nucleotide polymorphisms (SNPs) within related genes are candidate susceptible factors for the disorder. Rs107822 within MiR219-1 and rs1625579 within MiR137 were genotyped in 589 cases and 622 controls to investigate the possible association between the loci and schizophrenia in a Chinese population. Our results showed significant association between rs107822 and the disorder in allele (C vs. T: adjusted OR=0.773, 95%CI=0.655-0.912), co-dominant (TC vs. TT: adjusted OR=0.734, 95%CI=0.571-0.943; CC vs. TT: adjusted OR=0.655, 95%CI=0.459-0.936), dominant (TC+CC vs. TT: adjusted OR=0.707, 95%CI= 0.559-0.895), and recessive (CC vs. TC+TT: adjusted OR=0.724, 95%CI=0.524 -0.999) models, respectively. Meanwhile, negative associations were also observed between rs107822 and the disorder in male and female subgroups, and genotype CC of the locus was significantly associated with a lower positive symptom score of PANSS compared to genotype TT carrier in the cases group. However, we didn’t observe a significant association between rs1625579 and the disorder. These findings indicate that rs107822 within MiR219-1 might be involved in pathogenesis of schizophrenia and that genotypes TC, CC and allele C of the locus are protective factors for schizophrenia in a Chinese population.

Description: Publication date: Available online 19 August 2015 Source: FEBS Open Bio Author(s): Ajay Srivastava Malignant pleural mesothelioma (MPM) is an aggressive form of thoracic cancer with poor prognosis. While some studies have identified the molecular alterations associated with MPM, little is known about their role in MPM. For example, fragile X mental retardation ( FMR ) gene is up-regulated in MPM but its role in MPM is unknown. Here, utilizing Drosophila genetics, I investigate the possible role FMR may be playing in MPM. I provide evidence which suggests that FMR may contribute to tumorigenesis by up-regulating a matrix metalloprotease (MMP) and by degrading the basement membrane (BM), both important for tumor metastasis. I also demonstrate a novel link between FMR and the JNK pathway and suggest that the effects of FMR in MPM could in part be mediated by up-regulation of the JNK pathway.

Description: Publication date: Available online 12 August 2015 Source: FEBS Open Bio Author(s): Yang Song, Yonghong Zhang, Haoxiang Jiang, Yanting Zhu, Lu Liu, Wei Feng, Lan Yang, Yibin Wang, Manxiang Li Activation of the Notch3 cascade is involved in the development of pulmonary arterial hypertension by stimulating the proliferation of vascular smooth muscle cells. However, the detailed molecular mechanisms underlying this effect are still unclear. The present study aims to address this issue. We demonstrated that over-expression of intracellular domain of the Notch3 receptor (NICD3) by adenovirus transfection dramatically induced proliferation of primary cultured pulmonary artery smooth muscle cells. This was accompanied with up-regulation of Hes1 protein and down-regulation of p27Kip1protein. More importantly, we observed that prior silencing of Hes1 with siRNA blocked NICD3 over-expression-induced p27Kip1 reduction and cell proliferation. The present study suggests that Hes1 lies downstream of NICD3 and particularly mediates Notch3 signaling-induced proliferation of pulmonary arterial smooth muscle cells by down-regulation of p27Kip1 expression.