DNA intercalative 4-butylaminopyrimido4',5':4,5]thieno(2,3-b)quinoline induces cell cycle arrest and apoptosis in leukemia cells

DNA intercalators are one of the interesting groups in cancer chemotherapy. The development of novel anticancer small molecule has gained remarkable interest over the last decade. In this study, we synthesized and investigated the ability of a tetracyclic-condensed quinoline compound, 4-butylaminopyrimido4',5':4,5]thieno(2,3-b)quinoline (BPTQ), to interact with double-stranded DNA and inhibit cancer cell proliferation. Circular dichroism, topological studies, molecular docking, absorbance, and fluorescence spectral titrations were employed to study the interaction of BPTQ with DNA. Cytotoxicity was studied by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assay. Further, cell cycle analysis by flow cytometry, annexin V staining, mitochondrial membrane potential assay, DNA fragmentation, and western blot analysis were used to elucidate the mechanism of action of BPTQ at the cellular level. Spectral, topological, and docking studies confirmed that BPTQ is a typical intercalator of DNA. BPTQ induces dose-dependent inhibitory effect on the proliferation of cancer cells by arresting cells at S and G2/M phase. Further, BPTQ activates the mitochondria-mediated apoptosis pathway, as explicated by a decrease in mitochondrial membrane potential, increase in the Bax:Bcl-2 ratio, and activation of caspases. These results confirmed that BPTQ is a DNA intercalative anticancer molecule, which could aid in the development of future cancer therapeutic agents.

Haloarchaeal gas vesicle nanoparticles displaying Salmonella antigens as a novel approach to vaccine development

A safe, effective, and inexpensive vaccine against typhoid and other Salmonella diseases is urgently needed. In order to address this need, we are developing a novel vaccine platform employing buoyant, self-adjuvanting gas vesicle nanoparticles (GVNPs) from the halophilic archaeon Halobacterium sp. NRC-1, bioengineered to display highly conserved Salmonella enterica antigens. As the initial antigen for testing, we selected SopB, a secreted inosine phosphate effector protein injected by pathogenic S. enterica bacteria during infection into the host cells. Two highly conserved sopB gene segments near the 3'- region, named sopB4 and sopB5, were each fused to the grIpC gene, and resulting SopB-GVNPs were purified by centrifugally accelerated flotation. Display of SopB4 and SopB5 antigenic epitopes on GVNPs was established by Western blotting analysis using antisera raised against short synthetic peptides of SopB. Immunostimulatory activities of the SopB4 and B5 nanoparticles were tested by intraperitoneal administration of SopB-GVNPs to BALB/c mice which had been immunized with S. enterica serovar Typhimurium 14028 ApmrG-H111-D (DV-STM-07), a live attenuated vaccine strain. Proinflammatory cytokines IFN-y, IL-2, and IL-9 were significantly induced in mice boosted with SopB5-GVNPs, consistent with a robust Thl response. After challenge with virulent S. enterica serovar Typhimurium 14028, bacterial burden was found to be diminished in spleen of mice boosted with SopB4-GVNPs and absent or significantly diminished in liver, mesenteric lymph node, and spleen of mice boosted with SopB5GVNPs, indicating that the C-terminal portions of SopB displayed on GVNPs elicit a protective response to Salmonella infection in mice. SopB antigen-GVNPs were also found to be stable at elevated temperatures for extended periods without refrigeration. The results show that bioengineered GVNPs are likely to represent a valuable platform for antigen delivery and development of improved vaccines against Salmonella and other diseases.

Neonatal exposure to 17 beta-estradiol down-regulates the expression of synaptogenesis related genes in selected brain regions of adult female rats

Aims: Administration of estradiol or compounds with estrogenic activity to newborn female rats results in irreversible masculinization as well as defeminization in the brain and the animals exhibit altered reproductive behavior as adults. The cellular and molecular mechanism involved in inducing the irreversible changes is largely unknown. In the present study, we have monitored the changes in the expression of selected synaptogenesis related genes in the sexually dimorphic brain regions such as POA, hypothalamus and pituitary following 17 beta-estradiol administration to neonatal female rats. Main methods: Female Wistar rats which were administered 17 beta-estradiol on day 2 and 3 after birth were sacrificed 120 days later and the expression levels of genes implicated in synaptogenesis were monitored by semi-quantitative reverse transcription PCR. Since estradiol induced up-regulation of COX-2 in POA is a marker for estradiol induced masculinization as well as defeminization, in the present study only animals in which the increase in expression of COX-2 gene was observed in POA were included in the study. Key findings: Down-regulation of genes such as NMDA-2B, NETRIN-1, BDNF, MT-5 MMP and TNF-alpha was observed in the pre-optic area of neonatally E2 treated female rat brain but not in hypothalamus and pituitary compared to the vehicle- treated controls as assessed by RT-PCR and Western blot analysis. Significance: Our results suggest a possibility that down-regulation of genes associated with synaptogenesis in POA, may be resulting in disruption of the cyclical regulation of hormone secretion by pituitary the consequence of which could be infertility and altered reproductive behavior. (C) 2015 Elsevier Inc. All rights reserved.

Differential proteomic and genomic profiling of mouse striatal cell model of Huntington's disease and control; probable implications to the disease biology

Huntington's disease (HD) is an autosomal dominant disorder of central nervous system caused by expansion of CAG repeats in exon1 of the huntingtin gene (Htt). Among various dysfunctions originated from the mutation in Htt gene, transcriptional deregulation has been considered to be one of the most important abnormalities. Large numbers of investigations identified altered expressions of genes in brains of HD patients and many models of HD. In this study we employed 2D SDS-PAGE/MALDI-MS coupled with 2D-DIGE and real-time PCR experiments of an array of genes focused to HD pathway to determine altered protein and gene expressions in STHdh(Q111)/Hdh(Q111) cells, a cell model of HD and compared with STHdh(Q7)/Hdh(Q7) cells, its wild type counterpart. We annotated 76 proteins from these cells and observed differential expressions of 31 proteins (by 2D-DIGE) involved in processes like unfolded protein binding, negative regulation of neuron apoptosis, response to superoxides etc. Our PCR array experiments identified altered expressions of 47 genes. Altogether significant alteration of 77 genes/proteins could be identified in this HD cell line with potential relevance to HD biology. Biological significance: In this study we intended to find out differential proteomic and genomic profiles in HD condition. We used the STHdh cells, a cellular model for HD and control. These are mouse striatal neuronal cell lines harboring 7 and 111 knock -in CAG repeats in their two alleles. The 111Q containing cell line (STHdh(Q111)/Hdh(Q111)) mimics diseased condition, whereas the 7Q containing ones (STHdh(Q7)/Hdh(Q7)), serves as the proper control cell line. Proteomic experiments were performed earlier to obtain differential expressions of proteins in R6/2 mice models, Hdh(Q) knock -in mice and in plasma and CSF from HD patients. However, no earlier report on proteomic alterations in these two HD cell lines and control was available in literature. It was, therefore, an important objective to find out differential expressions of proteins in these two cell lines. In this study, we annotated 76 proteins from STHdh(Q7)/Hdh(Q7) and STHdh(Q111)/Hdh(Q111) cells using 2D-gel/mass spectrometry. Next, by performing 2D-DIGE, we observed differential expressions of 31 proteins (16 upregulated and 15 downregulated) between these two cell lines. We also performed customized qRT-PCR array focused to HD pathway and found differential expressions of 47 genes (8 gene exptessions increased and 39 genes were decreased significantly). A total of 77 genes/proteins (Htt downregulated in both the studies) were found to be significantly altered from both the experimental paradigms. We validated the differential expressions of Vim, Hypk, Ran, Dstn, Hspa5 and Sod2 either by qRT-PCR or Western blot analysis or both. Out of these 77, similar trends in alteration of 19 out of 31 and 38 out of 47 proteins/genes were reported in earlier studies. Thus our study confirmed earlier observations on differential gene/protein expressions in HD and are really useful. Additionally, we observed differential expression of some novel genes/proteins. One of this was Hypk, a Htt-interacting chaperone protein with the ability to solubilize mHtt aggregated structures in cell lines. We propose that downregulation of Hypk in STHdh-Qm (Q111)/Hdh(Q111) has a causal effect towards HD pathogenesis. Thus the novel findings from our study need further research and might be helpful to understand the molecular mechanism behind HD pathogenesis. (C) 2015 Elsevier B.V. All rights reserved.

Air-pollution and economics: diesel bus versus electric bus

The Bangalore Metropolitan Transport Corporation (BMTC) took an initiative to check the overall benefits of introducing electric buses as a suitable replacement for the diesel buses to tackle the burgeoning pollution in the city of Bengaluru, India. For a trial run of three months, an electric bus was procured from a Chinese company `Build Your Dreams' (BYD). Data were collected by BMTC on the operation and maintenance of the bus. This new initiative, if rightly guided, could have a direct impact on the lives of those in the city. An economic analysis of the running as well as maintenance of the electric buses within the city limits was performed. For comparison, the same analysis was performed for the data from the existing diesel bus operating on the same route. On the basis of the study, it can be concluded that the introduction of electric buses as a means of public transport in the city would be beneficial both economically as well as environmentally. The electric bus also makes much less noise, thereby helping reduce noise pollution and makes less vibration when compared to the diesel bus. This results in a more comfortable journey for the passengers.