The association between low-carbohydrate diet score and sleep duration among Iranian adults

Sleep and Biological Rhythms - Sleep disorders are linked to obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). The evidence suggests that dietary carbohydrate content may...     

Neuropathological and genomic characterization of glioblastoma-induced rat model: How similar is it to humans for targeted therapy?

Glioblastoma multiforme (GBM) is a unique aggressive tumor and mostly develops in the brain, while rarely spreading out of the central nervous system. It is associated with a high mortality rate; despite tremendous efforts having been made for effective therapy, tumor recurrence occurs with high prevalence. To elucidate the mechanisms that lead to new drug discovery, animal models of tumor progression is one of the oldest and most beneficial approaches to not only investigating the aggressive nature of the tumor, but also improving preclinical research. It is also a useful tool for predicting novel therapies' effectiveness as well as side effects. However, there are concerns that must be considered, such as the heterogeneity of tumor, biological properties, pharma dynamic, and anatomic shapes of the models, which have to be similar to humans as much as possible. Although several methods and various species have been used for this approach, the real recapitulation of the human tumor has been left under discussion. The GBM model, which has been verified in this study, has been established by using the Rat C6 cell line. By exploiting bioinformatic tools, the similarities between aberrant gene expression and pathways have been predicted. In this regard, 610 common genes and a number of pathways have been detected. Moreover, while magnetic resonance imaging analysis enables us to compare tumor features between these two specious, pathological findings provides most of the human GBM characteristics. Therefore, the present study provides genomics, pathologic, and imaging evidence for showing the similarities between human and rat GBM models.     

Neuroscience goes on a chip

Advances in microelectronics, microfluidics, polymers and microfabrication have enabled the creation of disposable lab-on-a-chips (LOCs) as the new tools for neuroscience research. The LOCs have been applied for a wide range of neurobiology studies, including cellular and molecular biochemical experimentations, morphological observations and electrophysiological investigations. The integration of miniaturised components leads to analytical instrumentations with unprecedented automation, speed of analysis, and flexibility. These features make LOCs capable enough to replace their bulky and expensive bench-top counterparts. LOCs can be useful for genomic, proteomic, epigenomic, peptidomic, connectomic and electrophysiological studies and also as effective tools for reductionist neuroscientists. Moreover, they can be applied at higher level studies such as developmental neurobiology and behavioural investigations. This work provides an in-depth review of LOC platforms for neuroscience research. First, we review the essential bench-top neuroscience instrumentation as per their functions and features. Next, we present LOC counterparts for those bench-top instrumentations. Finally, we offer perspectives on persistent challenges and our perception of opportunities based on LOC instrumentations in neuroscience research.     

Ethnic and Geographic Differentiation of Helicobacter pylori within Iran

The bacterium Helicobacter pylori colonizes the human stomach, with individual infections persisting for decades. The spread of the bacterium has been shown to reflect both ancient and recent human migrations. We have sequenced housekeeping genes from H. pylori isolated from 147 Iranians with well-characterized geographical and ethnic origins sampled throughout Iran and compared them with sequences from strains from other locations. H. pylori from Iran are similar to others isolated from Western Eurasia and can be placed in the previously described HpEurope population. Despite the location of Iran at the crossroads of Eurasia, we found no evidence that the region been a major source of ancestry for strains across the continent. On a smaller scale, we found genetic affinities between the H. pylori isolated from particular Iranian populations and strains from Turks, Uzbeks, Palestinians and Israelis, reflecting documented historical contacts over the past two thousand years.     

Proteomic signature of human embryonic stem cells

Human embryonic stem cells (hESC) represent a population of undifferentiated pluripotent cells with both self-renewal and multilineage differentiation characteristics. Proteomics provides a powerful approach for studying the characteristics of hESC and discovering molecular markers. We have analyzed proteome profiles of three hESC lines using 2-DE and MALDI TOF-TOF. Out of 844 spots analyzed with MALDI TOF-TOF, 685 proteins were identified of which 60 proteins were classified as the most abundant proteins on 2-D gels. A large number of proteins particularly high abundant ones were identified as chaperones, heat shock proteins, ubiquitin/proteasome, and oxidative stress responsive proteins underscoring the ability of these cells to resist oxidative stress and increase the life span. Several proteins involved in cell proliferation and differentiation were also among the highly expressed proteins. Although overall expression pattern of three hESC were similar, 54 spots changed quantitatively and 14 spots changed qualitatively among the hESC cell lines. Most of these proteins were identified as proteins involved in cell growth, metabolism and signal transduction, which may affect the self-renewal and pluripotency. To our knowledge, this study represents the first proteomic dataset for hESC and provides a better insight into the biology of hESC. Proteome maps of hESC are accessible at http://www.RoyanProteomics.ir.     

Arabidopsis AtGSTF2 is regulated by ethylene and auxin, and encodes a glutathione S-transferase that interacts with flavonoids

Expression of the Arabidopsis glutathione S-transferase (GST) gene AtGSTF2 is induced by several stimuli, but the function of this GST remains unknown. We demonstrate that AtGSTF2 expression is also induced by glutathione, paraquat, copper, and naphthalene acetic acid (NAA) via a mechanism independent of ethylene perception, as determined by analysis of the ethylene-insensitive etr1 mutant. Deletion analyses identified two promoter regions important for regulation of AtGSTF2 expression in response to several of these inducers. Previous studies have suggested that AtGSTF2 interacts with indole-3-acetic acid (IAA) and the auxin transport inhibitor 1-N-naphthylphthalamic acid (NPA). We show that recombinant AtGSTF2 directly binds IAA, NPA, and the artificial auxin NAA. As NPA may act as an endogenous flavonoid regulator of auxin transport, competition between NPA and flavonoids for binding to AtGSTF2 was examined. Both quercetin and kaempferol competed with NPA for AtGSTF2 binding, indicating that all three compounds bind AtGSTF2 at the same site. In transgenic Arabidopsis seedlings, AtGSTF2::GUS expression occurred at the root-shoot transition zone and was induced in this region, as well as at the root distal elongation zone, after treatment with IAA. In wild-type seedlings, AtGSTF2 is localized near the plasma membrane of cells in the root-shoot transition zone. However, both AtGSTF2::GUS expression and localization of AtGSTF2 protein were disrupted in flavonoid-deficient tt4 seedlings. Our results indicate that AtGSTF2 is involved not only in stress responses but also in development under normal growth conditions.     

Expression of senescence-enhanced genes in response to oxidative stress

Expression of the LSC54 gene, encoding a metallothionein protein, has been shown previously to increase during leaf senescence and cell death. Evidence is presented in this paper to indicate that the extent of LSC54 expression is related to levels of oxidative stress in the tissues. Treatment of Arabidopsis cotyledon and leaf tissues with the catalase inhibitor, 3-amino-1,2,4-triazole, or with silver nitrate result in the enhanced expression of LSC54. Combined treatments with quenchers of reactive oxygen species (ROS), such as ascorbate, tiron and benzoic acid indicated that this induced expression was due to increased levels of ROS. The expression of many other senescence-enhanced genes was also found to be inducible by the increase in ROS. Treatment of plant tissue with 3-amino-1,2,4-triazole, followed by silver nitrate, resulted in protection from the severe damage caused by the silver nitrate treatment and reduced expression of many of the genes examined. However, one gene, encoding a lipid hydroperoxide-dependent glutathione peroxidase, showed increased expression in the protected tissue, which may indicate a role for this enzyme in the protection of plant tissue from oxidative stress. ROS-enhanced expression of at least one of the genes investigated required the presence of the salicylic acid signalling pathway, which was not required for the expression of LSC54.