Design of a Plasmonic Photocatalyst Structure Consisting of Metallic Nanogratings for Light-Trapping Enhancement

Plasmonics - In this paper, a novel SPP-based photocatalytic system with high photocatalytic performance consisting metallic nanograting elements is proposed and simulated numerically with...     

Two polypyrimidine tracts in the nitric oxide synthase 2 gene: similar regulatory sequences with different properties

We reported previously that the polymorphic polypyrimidine CCTTT-microsatellite in the regulatory region of nitric oxide synthase 2 (NOS2) bound nuclear proteins in vitro. In the present work, we aimed to characterize and investigate a potential regulatory role of the CCTTT-microsatellite in NOS2 expression. Therefore, we performed gel-shift, S1-nuclease, and chromatin immunoprecipitation (ChIP) assays. In vitro experiments showed that the microsatellite formed triplex-DNA both with and without superhelical constraint. We also found that the CCTTT-microsatellite and an apparently similar CT-repeat in the first intron of NOS2 were specifically cleaved by S1-nuclease, when cloned into a supercoiled plasmid. In vitro data suggested that the CCTTT-microsatellite bound both polypyrimidine tract-binding protein (PTBP1) and heterogeneous nuclear ribonucleoprotein K (hnRNPK). On the contrary, ChIP revealed binding of PTBP1 and hnRNPK rather to the CT-repeat in the first intron than to the CCTTT-microsatellite. Enrichment for RNA polymerase II and acetylated histones H3 and H4 was also detected at the intronic site. We suggest that both PTBP1 and hnRNPK binds the single strand of the triplex-DNA formed at the CT-repeat in the first intron and that this interaction could be involved in the regulation of NOS2 expression.     

Ovine fetal mesenchymal stem cell differentiation to cardiomyocytes,effects of co‐culture,role of small molecules; reversine and 5‐azacytidine

The aim of the present study was to investigate the effect of small molecules: Reversine and 5‐azacytidine (5‐AC), in an indirect co‐culture condition with the cardiac fibroblasts as well as non co‐culture condition, in order to explore the effect of such molecules in the process of differentiation of the ovine bone‐marrow mesenchymal stem cells (BM‐MSCs) towards cardiomyocytes. Surface antigens of the isolated cells were analysed using flow‐cytometry. In addition, following to three passages cells were examined for their differentiation capacity into osteocytes and adipose cells, in order to ensure the mesenchymal origin of the stem cells. Six types of treatments were carried out in the present investigation, such that, in the first treatment BM‐MSCs were cultured for 28 days as control group; the second treatment was composed of culturing ovine fetal cardiac fibroblasts on inserts, aiming to use these inserts for culturing plates which were seeded with BM‐MSCs (Chamber group). As the third treatment, BM‐MSCs were supplemented with 10‐μM 5‐AC and incubated for 48 h. The fourth treatment was composed of supplementing BM‐MSCs with the 600‐nM reversine, incubated for 48 h, and subsequently the incubation was further extended for another 48 h in the presence of 5‐AC. The fifth treatment was composed of supplementing the chamber group with 10‐μM 5‐AC and incubation for 48 h, and the last or the sixth treatment was such that chamber group was supplemented with 600‐nM reversine and an incubation period of 48 h. Following to the incubation, medium was replaced with 10‐μM 5‐AC and further incubated for another round of 48 h. In all treatments, following to addition of the small molecules incubations were carried out for 28 days; same as controls. Expression of cardiac alpha‐actinin was analysed by immunocytochemistry. BM‐MSCs have shown to express CD44 and CD166 along with a weak expression of the CD90, CD34, in addition to CD45. Multilineage differentiation has indicated that BM‐MSCs could differentiate into adipose and osteocytes cells as well. In the treatment 4 it was observed that FGF signalling involved genes and all cardiac‐related genes (ANP, MYH6 and Troponin I) were significantly expressed, except connexin 43 compared to other treatments. All treatments received small molecules, either alone or as a co‐culture were seen to express sarcomeric alpha‐actinin. This finding was partially supported by immunocytochemistry. These results validate that reversine and 5‐AC have an effect on ovine BM‐MSC differentiation into cardiomyocytes. Copyright © 2016 John Wiley & Sons, Ltd.     

Population ecological parameters and stock assessment of Russian sturgeon Acipenser gueldenstaedti Brandt & Ratzeburg, 1833 in the Southern Caspian Sea

Russian sturgeon (Acipenser gueldenstaedti Brandt & Ratzeburg, 1833) is one of the major commercial sturgeon species, but there is no adequate information and previous‐published about population dynamics and stock assessment of this species in the southern Caspian Sea. This paper examines the age structure, growth parameters, maturity, age at first capture, optimum length, natural and fishing mortality and amount of biomass in the southern Caspian Sea (Iranian waters), during a two decades time series period from 1990–1991 to 2008–2009. For a pooled data, the growth parameters were estimated as L_∞ = 214.0 cm, K = 0.054, t₀ = ?4.5 year. Size at fifty percent sexual maturity was at FL = 118 cm for females and 113 cm for males. The age at first capture (t_c) estimated to be 12.1 years. In the catch composition, bulk of the catch (75%) belonged to 13–17 years old. The instantaneous coefficient of natural mortality (M) was estimated as 0.120 year^?1 and the instantaneous coefficient of fishing mortality (F) varied during the 19‐year period between 0.130 to 0.505 year^?1. The biomass showed a descending trend from 1,941.2 mt in 1990–1991 collapsed to about 55 mt in 2004–2005, and then decreased to the lowest level and represented 18.5 mt in 2008–2009. The result revealed that, the stock of Russian sturgeon is being over‐fished. We concluded that to manage the sturgeons stocks, a coordinated regional and international effort are needed to provide immediate implementation of stock enhancement and management in the Caspian Sea.     

Signaling crosstalk of FHIT,CHK2 and p38 in etoposide induced growth inhibition in MCF-7 cells

FHIT (Fragile Histidin Triad) is a tumor suppressor gene involved in regulating cell death during DNA damage conditions. The exact mechanism of DNA damage-induced FHIT signaling is not well understood. It is known that p38 kinase and CHK2 kinase are being activated during stress-induced conditions and DNA damage, resulting in cell death. Since both CHK2 and FHIT are being influenced by DNA damage, we have evaluated the interplay of p38, CHK2 and FHIT in response to etoposide-induced cell death. DNA damage was induced by etoposide in MCF-7 cells and viability was examined using MTT. FHIT expression was blocked using siRNA. Protein expression was measured using western blotting. Our results indicated that etoposide induced cytotoxicity in MCF-7. Block of FHIT expression, completely reversed etoposide cytotoxicity. Besides, etoposide induced p38 and CHK2 phosphorylation and reduced FHIT expression in a time-dependent manner. The time-course study indicated that CHK2 had been phosphorylated prior to p38 activation. Knockdown of FHIT expression reduced CHK2 phosphorylation but had no significant effect on p38 activation. Inhibition of p38 kinase and CHK2 prevented etoposide induced alteration in FHIT expression. Furthermore, p38 inhibitors augmented etoposide-induced CHK2 phosphorylation. These results indicate that etoposide lowers FHIT expression and induces cell death via p38 and CHK2 phosphorylation. These results demonstrate a time dependent complex crosstalk of FHIT, p38 and CHK2 pathways in response to etoposide. Moreover, our findings suggest signaling interaction for these pathways which can be targeted for manipulating cell proliferation.     

Mitochondrial Threonyl-tRNA Synthetase TARS2 Is Required for Threonine-Sensitive mTORC1 Activation

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