The type B leukemogenic virus truncated superantigen is dispensable for T-cell lymphomagenesis

Type B leukemogenic virus (TBLV) is a variant of mouse mammary tumor virus (MMTV) that causes T-cell lymphomas in mice. We have constructed a TBLV-MMTV hybrid, pHYB-TBLV, in which 756 bp of the C3H MMTV long terminal repeat (LTR) was replaced with 438 bp of the TBLV LTR. Intraperitoneal injection of pHYB-TBLV transfectants consistently resulted in T-cell lymphomas in 50% of injected weanling BALB/c mice with an average latency period of 5.7 (+/- 1.5) months. Transfectants of pHYB-TBLV containing a double-frameshift mutation in the truncated superantigen gene (sag) induced T-cell lymphomas with similar incidences, latency periods, and phenotypes, suggesting that cis-acting elements in the TBLV LTR determine disease specificity.     

Study of Plasma Parameters and Deposition Rate of Titanium Thin Film in a DC Magnetron Sputtering Method

Plasma Physics Reports - The plasma parameters like electron temperature (Te) and electron density (ne) on the deposition rate in turn thickness of titanium thin film at different axial and radial...     

Molecular interplay of autophagy and endocytosis in human health and diseases

Autophagy, an evolutionarily conserved process for maintaining the physio‐metabolic equilibrium of cells, shares many common effector proteins with endocytosis. For example, tethering proteins involved in fusion like Ras‐like GTPases (Rabs), soluble N‐ethylmaleimide sensitive factor attachment protein receptors (SNAREs), lysosomal‐associated membrane protein (LAMP), and endosomal sorting complex required for transport (ESCRT) have a dual role in endocytosis and autophagy, and the trafficking routes of these processes converge at lysosomes. These common effectors indicate an association between budding and fusion of membrane‐bound vesicles that may have a substantial role in autophagic lysosome reformation, by sensing cellular stress levels. Therefore, autophagy–endocytosis crosstalk may be significant and implicates a novel endocytic regulatory pathway of autophagy. Moreover, endocytosis has a pivotal role in the intake of signalling molecules, which in turn activates cascades that can result in pathophysiological conditions. This review discusses the basic mechanisms of this crosstalk and its implications in order to identify potential novel therapeutic targets for various human diseases.     

Delta-Tocotrienol Suppresses Radiation-Induced MicroRNA-30 and Protects Mice and Human CD34+ Cells from Radiation Injury

We reported that microRNA-30c (miR-30c) plays a key role in radiation-induced human cell damage through an apoptotic pathway. Herein we further evaluated radiation-induced miR-30 expression and mechanisms of delta-tocotrienol (DT3), a radiation countermeasure candidate, for regulating miR-30 in a mouse model and human hematopoietic CD34+ cells. CD2F1 mice were exposed to 0 (control) or 7–12.5 Gy total-body gamma-radiation, and CD34+ cells were irradiated with 0, 2 or 4 Gy of radiation. Single doses of DT3 (75 mg/kg, subcutaneous injection for mice or 2 μM for CD34+ cell culture) were administrated 24 h before irradiation and animal survival was monitored for 30 days. Mouse bone marrow (BM), jejunum, kidney, liver and serum as well as CD34+ cells were collected at 1, 4, 8, 24, 48 or 72 h after irradiation to determine apoptotic markers, pro-inflammatory cytokines interleukin (IL)-1β and IL-6, miR-30, and stress response protein expression. Our results showed that radiation-induced IL-1β release and cell damage are pathological states that lead to an early expression and secretion of miR-30b and miR-30c in mouse tissues and serum and in human CD34+ cells. DT3 suppressed IL-1β and miR-30 expression, protected against radiation-induced apoptosis in mouse and human cells, and increased survival of irradiated mice. Furthermore, an anti-IL-1β antibody downregulated radiation-induced NFκBp65 phosphorylation, inhibited miR-30 expression and protected CD34+ cells from radiation exposure. Knockdown of NFκBp65 by small interfering RNA (siRNA) significantly suppressed radiation-induced miR-30 expression in CD34+ cells. Our data suggest that DT3 protects human and mouse cells from radiation damage may through suppression of IL-1β-induced NFκB/miR-30 signaling.     

Burden and Correlates of HIV among Men Who Have Sex with Men in West Bengal,India: Analysis of Sentinel Surveillance Data

BackgroundLittle is known about the socio-behavioral risk factors for HIV acquisition among hard-to-reach men who have sex with men (MSM) population in India, particularly from the densely populated eastern part. Thus to measure the burden and correlates of HIV among MSM in West Bengal state of eastern India, a cross-sectional analysis of the national HIV Sentinel Surveillance (HSS) data was conducted.MethodsIn 2011, between July and September, involving all sentinel sites of the state, 1237 consenting MSM were anonymously interviewed and tested for HIV following national guidelines. Using a short, structured questionnaire, information was collected on socio-behavioral factors along with sexual practices and was analyzed to determine burden of HIV and the role of its socio-behavioral correlates on HIV acquisition.ResultsAmong participants, mean age was 23.4 years, 44.55% were “Kothis” (usually receptive partner) and 25.1% admitted receiving money for sex with man. HIV sero-positivity was 5.09%. Using logistic regression method, for both bivariate and multivariate (with saturated model) analyses, transport-workers [adjusted odds ratio (AOR)=8.95, 95% confidence interval (95%CI): 1.09-73.71), large business-owners/self-employed (AOR=8.46, 95%CI: 1.25-57.49), small business-owners/cultivators (AOR=7.90, 95%CI: 1.67-37.38), those who visited the sentinel site for official purposes (AOR=7.60, 95%CI: 1.21-47.83) and paying money for having sex with men (AOR=3.03, 95%CI: 1.10-8.33) were strongly associated with higher HIV sero-positivity with than their counterparts. Using the parsimonious model for multivariate analysis, Kothis (AOR=4.64, 95%CI: 1.03-20.89), paying (AOR=2.96, 95%CI: 1.15-7.58) or receiving (AOR=2.06, 95%CI: 1.06-3.99) money for having sex with a man were associated with higher risk of HIV.ConclusionsFocused intervention targeting the high risk MSM subgroups including Kothis, transport-workers, business-owners/self-employed and those who exchanged money for having sex with men, seemed to be the need of the hour for preventing the spread of HIV infection within and from this understudied population.     

The N-terminus region of Drp1, a Rint1 family protein is essential for cell survival and its interaction with Rad50 protein in fission yeast S.pombe

BackgroundDefects in DNA repair pathway can lead to double-strand breaks leading to genomic instability. Earlier we have shown that S.pombe Drp1, a Rint1/Tip1 family protein is required for the recovery from DNA damage.MethodsVarious truncations of Drp1 protein were constructed and their role in DNA damage response and interaction with Rad50 protein has been studied by co-immunoprecipitation and pull-down assays.ResultsThe structural and functional analysis of Drp1 protein revealed that the N-terminus region of Drp1 is indispensable for the survival. The C-terminus truncation mutants, drp1C1Δ and drp1C2Δ exhibit temperature sensitive phenotype and are hypersensitive against DNA damaging agents with elevated level of Rad52-YFP foci at non-permissive temperature indicating the impairment for DNA damage repair pathway. The essential N-terminus region of Drp1 interacts with the C-terminus region of Rad50 and might be involved in influencing the MRN/X function. Small-angle X-ray (SAXS) analysis revealed three-domain like shapes in Drp1 protein while the C-terminus region of Rad50 exhibit unusual bulges. Computational docking studies revealed the amino acid residues at the C-terminus region of Rad50 that are involved in the interaction with the residues present at the N-terminal region of Drp1 indicating the importance of the N-terminal region of Drp1 protein.ConclusionsWe have identified the region of Drp1 and Rad50 proteins that are involved in the interaction and their role in the DNA damage response pathway has been analyzed.General significanceThe functional and structural aspects of fission yeast Drp1 protein and its interaction with Rad50 have been elucidated.     

Millifluidics for Chemical Synthesis and Time-resolved Mechanistic Studies

Procedures utilizing millifluidic devices for chemical synthesis and time-resolved mechanistic studies are described by taking three examples. In the first, synthesis of ultra-small copper nanoclusters is described. The second example provides their utility for investigating time resolved kinetics of chemical reactions by analyzing gold nanoparticle formation using in situ X-ray absorption spectroscopy. The final example demonstrates continuous flow catalysis of reactions inside millifluidic channel coated with nanostructured catalyst.     

Evaluation of Two Approaches for Assessing the Genetic Similarity of Virioplankton Populations as Defined by Genome Size

Viral production estimates show that virioplankton communities turn over rapidly in aquatic ecosystems. Thus, it is likely that the genetic identity of viral populations comprising the virioplankton also change over temporal and spatial scales, reflecting shifts in viral-host interactions. However, there are few approaches that can provide data on the genotypic identity of viral populations at low cost and with the sample throughput necessary to assess dynamic changes in the virioplankton. This study examined two of these approaches—T4-like major capsid protein (g23) gene polymorphism and randomly amplified polymorphic DNA-PCR (RAPD-PCR) fingerprinting—to ask how well each technique could track differences in virioplankton populations over time and geographic location. Seasonal changes in overall virioplankton composition were apparent from pulsed-field gel electrophoresis (PFGE) analysis. T4-like phages containing similar g23 proteins were found within both small- and large-genome populations, including populations from different geographic locations and times. The surprising occurrence of T4-like g23 within small genomic groups (23 to 64 kb) indicated that the genome size range of T4-like phages may be broader than previously believed. In contrast, RAPD-PCR fingerprinting detected high genotypic similarity within PFGE bands from the same location, time, and genome size class without the requirement for DNA sequencing. Unlike g23 polymorphism, RAPD-PCR fingerprints showed a greater temporal than geographic variation. Thus, while polymorphism in a viral signature gene, such as g23, can be a powerful tool for inferring evolutionary relationships, the degree to which this approach can capture fine-scale variability within virioplankton populations is less clear.