Cyclic stretch induces PlGF expression in bronchial airway epithelial cells via nitric oxide release

Mechanical strain of lung tissue is an important stimulus for the production of growth factors that are critical for lung growth and development. However, excessive mechanical strain, as may occur during mechanical ventilation, may produce an increase in growth factors that may contribute to lung injury. We hypothesized that mechanical strain of primary bronchial airway epithelial cells (BAEpCs) induced the production of placental growth factor (PlGF), a member of the VEGF family. BAEpCs were cultured on a deformable silicoelastic membrane and exposed to different magnitudes of stretch. Stretch induced PlGF and nitric oxide (NO) production that increased with increasing magnitude of stretch. Stretch also induced PlGF and inducible NO synthase (iNOS) gene expression. The stretch-induced PlGF production and NO synthesis were attenuated by PD98059, a specific mitogen-activated protein kinase kinase-1 and -2 inhibitor. Inhibition of NO generation by l-NAME or l-NMMA or scavenging NO by carboxy-PTIO prevented stretch-mediated erk1/2 activation. In addition, in unstretched BAEpCs, exogenous NO enhanced erk1/erk2 activation. Our data suggest that mechanical stretch of BAEpCs induces iNOS expression and induces PlGF release in an erk1/2 activation-dependent manner.     

NF-kappaB in breast cancer cells promotes osteolytic bone metastasis by inducing osteoclastogenesis via GM-CSF

Advanced breast cancers frequently metastasize to bone, resulting in osteolytic lesions, yet the underlying mechanisms are poorly understood. Here we report that nuclear factor-kappaB (NF-kappaB) plays a crucial role in the osteolytic bone metastasis of breast cancer by stimulating osteoclastogenesis. Using an in vivo bone metastasis model, we found that constitutive NF-kappaB activity in breast cancer cells is crucial for the bone resorption characteristic of osteolytic bone metastasis. We identified the gene encoding granulocyte macrophage-colony stimulating factor (GM-CSF) as a key target of NF-kappaB and found that it mediates osteolytic bone metastasis of breast cancer by stimulating osteoclast development. Moreover, we observed that the expression of GM-CSF correlated with NF-kappaB activation in bone-metastatic tumor tissues from individuals with breast cancer. These results uncover a new and specific role of NF-kappaB in osteolytic bone metastasis through GM-CSF induction, suggesting that NF-kappaB is a potential target for the treatment of breast cancer and the prevention of skeletal metastasis.     

Ramachandran plot on the web (2.0)

The Ramachandran plot displays the main chain conformation angles (Phi and Psi) of the polypeptide chain of a protein molecule. The paper reports the updated version of the Ramachandran plot web server and has several improved options for displaying the conformation angles in various regions. In addition, options are provided to display the conformation angles in various secondary structural elements and regions within the user specified Phi and Psi values in the plot. The updated version is accessible at the following URL: http://dicsoft1.physics.iisc.ernet.in/rp/.     

DNMT1 and DNMT3B gene variants and their association with endometriosis in South Indian women

Background

Endometriosis is a multifactorial estrogen dependent gynecological disease characterized by implantation of functional endometrial tissue at ectopic positions. Though this disease is benign, it is associated with an increased risk of malignant transformation. Epigenetic disruptions like aberrant DNA methylation, resulting changes in gene expression capacity, are important in tumor progression and malignant cellular transformation. Therefore, variation in genes involved in DNA methylation might lead to disease susceptibility.

Purpose

To investigate the association between DNA methyl transferases (DNMT1 and DNMT3B) single nucleotide polymorphisms (SNPs) and the risk of endometriosis in South Indian women.

Methods

In the present study, we examined the genotypic and allele distribution of DNMT1 (rs10423341C/A, rs2228611G/Aandrs4804490C/A) and DNMT3B (rs1569686G/T) among the endometriosis patients (n?=?150) and controls (n?=?150). The genotypes were analyzed by polymerase chain reaction (PCR) and sequencing methods. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D?) for pairwise linkage disequilibrium (LD) were surveyed by Haploview Software.

Result

Significant increase in the frequencies of DNMT1 rs10423341 (P?=?0.04601), rs2228611 (P?=?0.00175) and DNMT3B rs1569686 (P?=?0.033) genotypes and alleles was observed in patients compared to controls. In addition, the frequency of A/A/C (P?=?0.0065) haplotype was significantly high in patients. But the DNMT1 (rs4804490) SNP did not show significant association with the disease.

Conclusion

The DNMT1 and DNMT3B polymorphism may constitute an inheritable risk factor for endometriosis in South Indian women. To the best of our knowledge there is no reported study on the association of polymorphisms in DNMT1 and DNMT3B with endometriosis risk.

     

Ability to use the diazo dye, C.I. Acid Black 1 as a nitrogen source by the marine cyanobacterium Oscillatoria curviceps BDU92191

Ten different strains of marine cyanobacteria were tested for their ability to decolourise and degrade a recalcitrant diazo dye, C.I. Acid Black 1. Of them, Oscillatoria curvicepsBDU92191 was able to grow up to a tested concentration of 500 mG L⁻¹. The organism degraded 84% of the dye at 100 mG L⁻¹ in 8 days in a medium free of combined nitrogen. The dye degrading ability is attributed to the activities of the enzymes: laccase, polyphenol oxidase and azoreductase. The absence of the doublet amine peak in addition to the overall reduction of absorption in the IR spectra confirmed the mineralisation of the tested azo dye. The nitrogen assimilating enzyme studies along with nitrogenase assay strongly suggested the ability of the non-heterocystous, filamentous marine cyanobacterium, O. curvicepsBDU92191 to use C.I. Acid Black 1 as a nitrogen source in an oligotrophic environment.     

Morphological and molecular identification of the metacestode parasitizing the liver of rodent hosts in bamboo growing areas of mizoram, northeast India

In Mizoram (Northeast India), rodent outbreaks are known to occur periodically with the onset of bamboo flowering causing a tremendous destruction to food grains and as per the folk belief, often resulting in famine. In an exploratory survey of rodent pests in bamboo growing atreas for their helminth parasite spectrum, metacestodes of tapeworms were frequently encountered infecting the liver lobes and body cavity of the host. The morphological criteria were found to be closely consistent with the metacestode of Taenia species. In molecular characterization of the parasite, the ribosomal DNA (ITS1, ITS2) and mitochondrial COI were amplified and sequenced. Based upon both morphological data and molecular analysis using bioinformatic tools, the metacestode is identified as confirmed to be representing Cysticercus fasciolaris. The adult form of which (Taenia taeniaeformis) commonly occurs in felid and canid mammalian hosts.     

Expression of catalase and glutathione S-transferase genes in Chironomus riparius on exposure to cadmium and nonylphenol

Antioxidant enzymes play important roles in the protection against oxidative damage caused by environmental pollutants by scavenging high levels of reactive oxygen species and have been quantified as oxidative stress markers. However, combining mRNA expressions of genes coding for detoxification enzymes along with enzyme activities will be more useful biomarkers of stress. Therefore, in this study the cDNA of the catalase gene from the aquatic midge, Chironomus riparius (CrCAT) was sequenced using 454 pyrosequencing. The 2139 bp CrCAT cDNA included an open reading frame of 1503 bp encoding a putative protein of 500 amino acids with a predicted molecular mass of 56.72 kDa. There was an 18 bp 5’ and a long 618 bp 3' untranslated region with a polyadenylation signal site (AATAAA). The deduced amino acid sequence of CrCAT contained several highly conserved motifs including the proximal heme–ligand signature sequence RLFSYNDTX and the proximal active site signature FXRERIPERVVHAKGXGA. A comparative analysis showed the presence of conserved amino acid residues and all of the catalytic amino acids (His⁷⁰, Asn¹⁴³, and Tyr³⁵³) were conserved in all species. The CrCAT contained three potential glycosylation sites and a peroxisome targeting signal of ‘AKM’. The mRNA was detected using RT-PCR at all developmental stages. The time-course expression of CrCAT was measured using quantitative real-time PCR after exposure to different concentration and durations of Paraquat (PQ), cadmium chloride (Cd) and nonylphenol (NP). The expression of CrCAT was significantly up regulated on exposure to 50 and 100 mg/L PQ for 12 and 24 h. Among the different concentrations and durations of Cd tested, significantly highest level of expression for CrCAT mRNA and catalase enzyme activity was observed on exposure to 10 mg/L for 24 h. In the case of NP, the highest level of CrCAT expression was observed after exposure to 100 μg/L for 24 h. The expression profiles of three selected C. riparius glutathione S-transferase genes (CrGSTs) viz. CrGSTdelta3, CrGSTsigma4 and CrGSTepsilon1 was also studied on exposure to NP and were up or down regulated at different time points and concentrations. Significantly highest level of expression for CrGSTdelta3 was observed after 48 h and for CrGSTsigma4 and CrGSTepsilon1 after 24 h exposure to 100 μg/L of NP. The results show that CrGSTs and CrCAT could be used as potential biomarkers in C. riparius for aquatic ecotoxicological studies.