Optimization of process parameters for improved production of bioactive metabolite by a novel endophytic fungus <Emphasis Type="Italic">Fusarium</Emphasis> sp. DF2 isolated from <Emphasis Type="Italic">Taxus wallichiana</Emphasis> of North East India

An endophytic fungus having antifungal and antibacterial properties was isolated from Taxus wallichiana of Arunachal Pradesh, India. On the basis of morphological and molecular characteristics, the fungus was identified as Fusarium sp. and designated as DF2. The fungus was optimized for growth and maximum production of the antimicrobial agent. Media with 5% leaf extract (w/v) supplemented with 0.1% dextrose as carbon and yeast extract as nitrogen source favored the growth with temperature optimum 25 ± 2°C and pH 6. Incubation period of 10 days was observed optimum for growth and production of antimicrobial agent. Phenylalanine and dextrose enriched basal medium promoted the antimicrobial agent production, whereas methionine amended in combination with glucose promoted higher biomass accumulation. The TLC purified active compound with UV λ-max 270 nm in ethyl acetate has got the lowest minimum inhibitory concentration (MIC) against Bacillus subtilis, Staphylococcus aureus and Escherichia coli and highest against Pseudomonas aeruginosa.     

The cytoplasmic tail of L-selectin interacts with members of the Ezrin-Radixin-Moesin (ERM) family of proteins: cell activation-dependent binding of Moesin but not Ezrin.

L-selectin regulates the recruitment of naive lymphocytes from the bloodstream to secondary lymphoid organs, mediating their initial capture and subsequent rolling along high endothelial cell surface-expressed ligands in peripheral lymph nodes. In vivo, distribution of L-selectin and cell surface levels determine the tethering efficiency and rolling velocity of leukocytes, respectively. Treatment of naive lymphocytes with phorbol myristate acetate (PMA) induces rapid ectodomain proteolytic down-regulation (shedding) of surface L-selectin via a protein kinase C (PKC)-dependent pathway. In an attempt to isolate proteins that are involved in regulating L-selectin expression, an affinity column was constructed using the 17-amino acid cytoplasmic tail of L-selectin. Affinity purification of extracts from lymphocytes, pre-treated with or without PMA, allowed identification of proteins that interact with the affinity column under one condition but not the other. By using this approach, members of the Ezrin-Radixin-Moesin family of proteins were found to interact specifically with the cytoplasmic tail of L-selectin. Moesin from PMA-stimulated lymphocytes, but not from unstimulated lymphocytes, bound to L-selectin tail. In contrast, ezrin from unstimulated or PMA-stimulated lymphocytes associated with L-selectin tail with equal affinity. Furthermore, the PKC inhibitor Ro 31-8220 significantly reduced the interaction of moesin, but not ezrin, with L-selectin. Alanine mutations of membrane-proximal basic amino acid residues in the cytoplasmic domain of L-selectin identified arginine 357 as a critical residue for both ezrin and moesin interaction. Finally, BIAcore affinity analysis confirmed that N-terminal moesin interacts specifically with L-selectin cytoplasmic tail, with relatively high affinity (K(d) approximately 40 nm). Based on these findings, although moesin and ezrin bind to a similar region of the cytoplasmic tail of L-selectin, moesin binding is dependent on PKC activation, which suggests that ezrin and moesin are regulated differently in lymphocytes.     

Genomic diversity at thirteen short tandem repeat loci in a substructured caste population, Golla, of southern Andhra Pradesh, India.

Genomic diversity based on 13 short tandem repeat (STR) loci was studied in seven population groups of a substructured Golla caste from Chittoor district in southern Andhra Pradesh, India. These groups are traditionally pastoral, culturally homogeneous, and strictly endogamous. Blood samples were drawn from 317 individuals from 30 Golla villages. The 13 STR loci analyzed in five standard multiplex polymerase chain reactions were: (1) CSF1R, TH01, and PLA2A; (2) F13A1, CYP19, and LPL; (3) D21S1446 and D21S1435; (4) D20S481, D20S473, and D20S604; and (5) D5S1453 and D6S1006. The average heterozygosity was found to be low among the Golla subgroups (0.64-0.70) in comparison to that of groups at the upper levels of the hierarchy. The coefficient of gene differentiation was found to be moderate (average GST = 0.031; range between 0.018 and 0.049 among the loci) when compared to that observed for a similar class of markers among populations with relatively higher levels of hierarchy, for example, among castes. It is, however, much higher when compared to the average observed for Indian caste and tribal populations, based on classical markers. Genetic distance measures revealed clusters of populations that are consistent with the known ethnohistorical and geographical backgrounds of the groups. We claim that these hypervariable markers are quite useful in understanding the process of substructuring within the Indian castes, leading to the formation of smaller breeding isolates, the basic Mendelian units within which microevolutionary forces operate.     

Crystal stuctures of MglB‐2 (TP0684), a topologically variant d‐glucose‐binding protein from Treponema pallidum,reveal a ligand‐induced conformational change

Previously, we determined the crystal structure of apo‐TpMglB‐2, a d ‐glucose‐binding component of a putative ABC transporter from the syphilis spirochete Treponema pallidum. The protein had an unusual topology for this class of proteins, raising the question of whether the d ‐glucose‐binding mode would be different in TpMglB‐2. Here, we present the crystal structures of a variant of TpMglB‐2 with and without d ‐glucose bound. The structures demonstrate that, despite its aberrant topology, the protein undergoes conformational changes and binds d ‐glucose similarly to other Mgl‐type proteins, likely facilitating d ‐glucose uptake in T. pallidum.     

Proliferation of canine bone marrow derived mesenchymal stem cells on different nanomaterial based thin film scaffolds

Stem cell niche research uses nanotechnologies to mimic the extra-cellular microenvironment to promote proliferation and differentiation. The aim of designing different scaffolds is to simulate the best structural and environmental pattern for extracellular matrix. This experiment was designed to study the proliferative behaviour of canine bone marrow deriver mesenchymal stem cells (MSCs) on different nanomaterial based thin film scaffolds of carbon nanotubes (CNT), chitosan and poly ε-caprolactone. Similar number of cells was seeded on the scaffolds and standard cell culture flask, taken as control. Cells were maintained on DMEM media and relative number of metabolically active cells was determined by MTT assay up to day six of culture. Cells proliferated on control and all the scaffolds as the days progressed. Although proliferation rate was slow but no decline of cell number was noticed on the scaffolds during the study period. Initially, the cell proliferation was lower on CNT but as time progressed no significant difference was observed compared to control. The result indicated that nanomaterial based scaffolds reduce the proliferation rate of canine MSCs. However, canine MSCs adapted and proliferated better on CNT substrate in vitro and may be used as a scaffold component in canine tissue engineering in future.     

Association of FTO Gene Variants With Adiposity in African‐American Adolescents

The prevalence of obesity continues to increase significantly, with the largest rise in the African‐American adolescents. Genetic contributions to obesity are being identified with the advent of genome‐wide association studies (GWAS). Specifically, variants of the fat mass and obesity associated (FTO) gene have been associated with obesity in populations of European descent. The studies in African Americans have been inconclusive. To further evaluate the association of the FTO gene and adiposity in African Americans, we genotyped 47 single‐nucleotide polymorphisms (SNPs), including seven SNPs previously reported to be significant in the literature in a cohort consisting of 561 non‐Hispanic white and 497 African‐American individuals. Analysis of our data showed 17 SNPs to be associated with BMI Z‐score (BMI‐Z) in our study population. The strongest association was found in the African Americans. The most significant SNP was rs8057044, which was associated with BMI‐Z in the African Americans (P = 0.00054). SNP rs9939609 was found to be significant in the non‐Hispanic white population (P = 0.028). Our data confirm the association between FTO and adiposity suggesting that FTO is a childhood obesity susceptibility gene. Our data also identify a novel SNP of the FTO gene (rs8057044) that is associated with measures of adiposity in the African‐American population.     

Structural, bioinformatic, and in vivo analyses of two Treponema pallidum lipoproteins reveal a unique TRAP transporter

Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of "tetratricopeptide repeat" (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).     

Diagnostic and Prognostic Biomarkers in ovarian cancer and the potential roles of cancer stem cells – An updated review

Ovarian carcinomas relate to highest death rate in gynecologic malignancies as absence of symptoms shield the disease in the early stage. Current evidences have been devoted to discovering early effective screening mechanism prior to the onset of clinical symptoms. Therefore, biomarkers are the crucial tools that are capable of predicting progression, risk stratification and overall therapeutic benefit to fight against this deadly disease. Although recent studies have revealed serum protein markers, CA-125, HE4, mesothelin etc. have higher sensitivity and specificity at the early stages of the cancer; the critical questions arise regarding the applicability and reproducibility of genomic profiling across different patient groups. Hence, our hypothesis is that the panels of signature biomarkers will be much more effective to improve the diagnosis and prediction of patient survival outcome with high sensitivity and specificity. Ovarian cancer is heterogeneous in nature and contain a sub-population of stem cell-like characteristics that has the ability to grow as anchorage-independent manner and subsequently is able to metastasize. Highly tumorigenic and chemotherapy-resistant cancer stem cells (CSCs)-specific biomarkers therefore reflects the interesting possibilities to be targeted to minimize the high frequency of relapse and resistance to drugs. Several putative ovarian CSC markers such as CD24, CD44, CD133, SSEA have already been proposed in recent studies, yet, a large panel of updated biomarkers have high clinical relevance to define the prospective isolation of viable circulating CSCs. Therefore, this review highlights current evidence based updated ovarian cancer specific prognostic and diagnostic biomarkers and potential importance of CSCs in context of tumorigenicity and metastatic activity for fundamental biological and clinical implications.     

Transformation techniques for metabolic engineering of diatoms and haptophytes: current state and prospects

Applied Microbiology and Biotechnology - Diatoms and haptophytes represent a key segment of the dominant phytoplankton communities that frequently form massive blooms in the photic zone of the...