Modification of radiation induced damage in mouse intestine by WR-2721

Intestinal protection in mice against radiation injury by WR-2721 (300 mg/kg body wt, i.p., 30 min before irradiation) was studied after whole body gamma irradiation (0.5, 1.5, 3.0, 4.5, or 6.0 Gy). Crypt survival and induction of apoptosis, and abnormal mitoses in crypt cells in the jejunum were studied on day 1, 3 and 7 after irradiation. Irradiation produced a significant decrease in crypt survival, whereas apoptosis and abnormal mitoses showed a significant increase from sham-treated control animals. Maximum changes in all the parameters were observed on day 1 after irradiation and the effect increased linearly with radiation dose. There was recovery at later intervals, which was inversely related to radiation dose. WR-2721 pre-treatment resulted in a significant increase in the number of surviving crypts, whereas the number of apoptotic cells in the crypts showed a significant decrease from respective irradiated controls on day 1 after exposure. The recovery was also faster in WR-2721 pre- treated animals. It is concluded that WR-2721 protects against gastrointestinal death by reducing radiation induced cell death, thereby maintaining a higher number of stem cells in the proliferating compartment.     

Sodium butyrate modulates pRb phosphorylation and induces cell death in human vestibular schwannomas in vitro

In the present study, effect of Na-Bu on the pRb phosphorylation was analysed in the primary cultures of 12 VS tumors. Primary cultures of VS tumors were established from the fresh tumor tissues removed surgically and were treated with Na-Bu. Na-Bu treatment for 48 h led to morphological changes and apoptotic cell death in VS tumor cells. Na-Bu treatment decreased level of total pRb and phosphorylated form of pRb and caused specific dephosphorylation at Ser 249/Thr 252 and Ser 567. In the untreated and Na-Bu treated cells (when present), pRb was localised in the nucleus. Moreover, in Na-Bu treated cells the nucleus appeared highly condensed as compared to untreated cells. Results of the present study indicated that Na-Bu treatment modulated pRb phosphorylation status and caused apoptotic cell death in VS tumors.     

Amycolatopsis bartoniae sp. nov. and Amycolatopsis bullii sp. nov., mesophilic actinomycetes isolated from arid Australian soils

The status of two mesophilic filamentous actinomycetes isolated from an arid Australian soil sample was determined using a polyphasic taxonomic approach. The isolates had chemical and morphological properties consistent with their classification in the genus Amycolatopsis, assignments that were supported by analysis of 16S rRNA gene sequence data. Isolate SF26^T formed a distinct phyletic line and hence was sharply separated from its nearest phylogenetic neighbour, Amycolatopsis sacchari DSM 44468^T. In contrast, isolate SF27^T formed a subclade in the Amycolatopsis tree with Amycolatopsis vancoresmycina DSM 44592^T but was separated readily from the latter by DNA:DNA pairing data. The two isolates were distinguished from one another and from their respective nearest phylogenetic neighbours using a range of phenotypic properties. These data indicate that the two isolates should be recognized as new species in the genus Amycolatopsis. The names proposed for these new taxa are Amycolatopsis bartoniae sp. nov. and Amycolatopsis bullii sp. nov. with isolates SF26^T (=NCIMB 14706^T = NRRL B-2846^T) and SF27^T (=NCIMB 14707^T = NRRL B-24847^T) as the respective type strains.     

The energetic cost of mating in a promiscuous cephalopod

Costs that individuals incur through mating can play an important role in understanding the evolution of life histories and senescence, particularly in promiscuous species. Copulation costs, ranging from energy expenditure to reduced longevity, are widely studied in insects but have received substantially less attention in other taxa. One cost of mating, the energetic cost, is poorly studied across all taxa despite its potential importance for the many species where copulation is physically demanding and/or frequent. Here, we investigated the energetic cost of mating in both male and female dumpling squid (Euprymna tasmanica). In this species, copulation can last up to 3 h and requires that the male physically restrains the female. We report that the act of copulation halves the swimming endurance of both sexes, and that they take up to 30 min to recover. Such a reduction in post-copulatory performance may have important implications for predator avoidance, foraging ability and energy allocation. Therefore, quantifying this cost is essential to understand the evolution of reproductive strategies and behaviours such as female receptivity and male and female mating frequency.     

The endosomal adaptor protein APPL1 impairs the turnover of leading edge adhesions to regulate cell migration

Cell migration is a complex process that requires the integration of signaling events that occur in distinct locations within the cell. Adaptor proteins, which can localize to different subcellular compartments, where they bring together key signaling proteins, are emerging as attractive candidates for controlling spatially coordinated processes. However, their function in regulating cell migration is not well understood. In this study, we demonstrate a novel role for the adaptor protein containing a pleckstrin-homology (PH) domain, phosphotyrosine-binding (PTB) domain, and leucine zipper motif 1 (APPL1) in regulating cell migration. APPL1 impairs migration by hindering the turnover of adhesions at the leading edge of cells. The mechanism by which APPL1 regulates migration and adhesion dynamics is by inhibiting the activity of the serine/threonine kinase Akt at the cell edge and within adhesions. In addition, APPL1 significantly decreases the tyrosine phosphorylation of Akt by the nonreceptor tyrosine kinase Src, which is critical for Akt-mediated cell migration. Thus, our results demonstrate an important new function for APPL1 in regulating cell migration and adhesion turnover through a mechanism that depends on Src and Akt. Moreover, our data further underscore the importance of adaptor proteins in modulating the flow of information through signaling pathways.     

Impact of Aromatase protein variants and drug interactions in breast cancer: a molecular docking approach

Breast cancer is a frequently reported cancer in women all over the world. Several methods available to cure the breast cancer based on stage. This study focused on chemoprevention drugs of Aromatase, a potential target in breast cancer. Natural variants of Aromatase are very common; they have been collected and modeled, optimized the energy of mutated Aromatase protein. Reversible (Anastrozole) and irreversible (Exemestane) Aromatase inhibitors are selected and performed molecular docking studies of each drug against each variant to see the binding affinity impact on protein variant and drugs. In this comparative study, Anastrozole, a cumene derivative showed more binding affinity and Diethylstilbestrol showed weak binding affinity against among all drugs. The comparative molecular docking revealed that the binding affinity between drug and Aromatase protein variant is imprecise but fairly close; therefore the protein variants of Aromatase can be conceived to be equal for chemoprevention of breast cancer therapy.     

The effects of low levels of dystrophin on mouse muscle function and pathology

Duchenne muscular dystrophy (DMD) is a severe progressive muscular disorder caused by reading frame disrupting mutations in the DMD gene, preventing the synthesis of functional dystrophin. As dystrophin provides muscle fiber stability during contractions, dystrophin negative fibers are prone to exercise-induced damage. Upon exhaustion of the regenerative capacity, fibers will be replaced by fibrotic and fat tissue resulting in a progressive loss of function eventually leading to death in the early thirties. With several promising approaches for the treatment of DMD aiming at dystrophin restoration in clinical trials, there is an increasing need to determine more precisely which dystrophin levels are sufficient to restore muscle fiber integrity, protect against muscle damage and improve muscle function.To address this we generated a new mouse model (mdx-Xist ^Δhs) with varying, low dystrophin levels (3–47%, mean 22.7%, stdev 12.1, n = 24) due to skewed X-inactivation. Longitudinal sections revealed that within individual fibers, some nuclei did and some did not express dystrophin, resulting in a random, mosaic pattern of dystrophin expression within fibers. Mdx-Xist ^Δhs, mdx and wild type females underwent a 12 week functional test regime consisting of different tests to assess muscle function at base line, or after chronic treadmill running exercise. Overall, mdx-Xist ^Δhs mice with 3–14% dystrophin outperformed mdx mice in the functional tests. Improved histopathology was observed in mice with 15–29% dystrophin and these levels also resulted in normalized expression of pro-inflammatory biomarker genes, while for other parameters >30% of dystrophin was needed. Chronic exercise clearly worsened pathology, which needed dystrophin levels >20% for protection. Based on these findings, we conclude that while even dystrophin levels below 15% can improve pathology and performance, levels of >20% are needed to fully protect muscle fibers from exercise-induced damage.     

Phenotypic and genetic characterization of Vibrio cholerae O1 clinical isolates collected through national antimicrobial resistance surveillance network in Nepal

Cholera occurs in sporadic cases and outbreaks in Nepal each year. Vibrio cholerae O1 (n = 522) isolated during 2007-2010 from diarrheal patients at 10 different hospital laboratories in Nepal were characterized. Biochemical and serologic identifications showed that all the isolates belonged to serogroup O1, El Tor biotype. Except 72 isolates of Inaba serotype isolated in the year 2007, all the remaining isolates were of Ogawa serotype. All isolates were resistant to nalidixic acid and furazolidone. Resistance to tetracycline, ciprofloxacin, erythromycin and co-trimoxazole were 21, 4, 16 and 90 % respectively. Seventy-seven of these isolates were selected for further characterization for ctxB gene and MLVA typing. Two different variants of classical type cholera toxin were observed. Ogawa strains from 2007 and 2010-Western Nepal outbreak harbored CTX-3 type cholera toxin, whereas Inaba serotypes in 2007 and the remaining Ogawa serotypes in 2008-2010 harbored CTX 3b-type toxin. MLVA analysis showed circulation of four different groups of altered V. cholerae O1 El Tor strains. Two different profiles were seen among 2007 Inaba (9, 3, 6, x, x) and Ogawa (10, 7, 6, x, x) isolates. The MLVA profile of 2008 and 2009 Ogawa isolates were similar to those of Inaba strains of 2007. Isolates from 2010 also showed three different MLVA profiles; profile 9, 3, 6, x, x in 3 isolates, 11, 7, 6, x, x among 2010 Western Nepal outbreak strains and profile 8, 3, 6, x, x among isolates from Butwal and Kathmandu.     

Functional polymorphisms in promoter survivin gene and its association with susceptibility to bladder cancer in North Indian cohort

Survivin is a member of novel inhibitor of apoptosis protein family which expressed in human cancers. The molecular detection of bladder cancer by targeting Survivin as a novel marker may be useful in the occurrence and progression of cancer. We genotyped Survivin −31G>C, −1547A>G and −241C>T by PCR-restriction fragment length polymorphism to evaluate the risk of bladder cancer (BC) in 200 BC patients and 200 healthy controls from North Indian cohort. We observed significant increased BC risk associated with variant CC genotype of Survivin −31G>C having 2.6 fold risk. The variant genotype of Survivin −1547A>G was significantly associated with BC risk (P = 0.047). In case of Survivin −241C>T the protective genotype for BC was heterozygous (P = 0.035). Smoking significantly modulated the risk in patients with Survivin −1547A>G polymorphism. Variant as well as hetero genotype of Survivin −31G>C was associated with reduced risk of recurrence (HR = 0.22 and 0.35) in BC patients receiving BCG treatment thus showing least survival. Furthermore, the haplotype analysis revealed C–A–T haplotype to be associated with reduced BC risk. Our findings suggested that the functional polymorphism −31G>C, −1547A>G and −241C>T in the promoter of Survivin gene may play a significant role in mediating the BC risk among North Indian cohort.     

Identification of a region that assists membrane insertion and translocation of the catalytic domain of Bordetella pertussis CyaA toxin

The adenylate cyclase (CyaA) toxin, one of the virulence factors secreted by Bordetella pertussis, the pathogenic bacteria responsible for whooping cough, plays a critical role in the early stages of respiratory tract colonization by this bacterium. The CyaA toxin is able to invade eukaryotic cells by translocating its N-terminal catalytic domain directly across the plasma membrane of the target cells, where, activated by endogenous calmodulin, it produces supraphysiological levels of cAMP. How the catalytic domain is transferred from the hydrophilic extracellular medium into the hydrophobic environment of the membrane and then to the cell cytoplasm remains an unsolved question. In this report, we have characterized the membrane-interacting properties of the CyaA catalytic domain. We showed that a protein covering the catalytic domain (AC384, encompassing residues 1-384 of CyaA) displayed no membrane association propensity. However, a longer polypeptide (AC489), encompassing residues 1-489 of CyaA, exhibited the intrinsic property to bind to membranes and to induce lipid bilayer destabilization. We further showed that deletion of residues 375-485 within CyaA totally abrogated the toxin's ability to increase intracellular cAMP in target cells. These results indicate that, whereas the calmodulin dependent enzymatic domain is restricted to the amino-terminal residues 1-384 of CyaA, the membrane-interacting, translocation-competent domain extends up to residue 489. This thus suggests an important role of the region adjacent to the catalytic domain of CyaA in promoting its interaction with and its translocation across the plasma membrane of target cells.