Differential expression of Zymomonas mobilis sucrase genes (sacB and sacC) in Escherichia coli and sucrase mutants of Zymomonas mobilis

The sacB and sacC genes encoding levansucrase and extracellular sucrase respectively were independently subcloned in pBluescript (high copy number) and in Z. mobilis-E. coli shuttle vector, pZA22 (low copy number). The expression of these genes were compared under identical background of E. coli and Z. mobilis host. The level of sacB gene expression in E. coli was almost ten fold less than the expression of sacC gene, irrespective of the growth medium or the host strain. In Z. mobilis the expression of sacB and sacC genes was shown to be subject to carbon source dependent regulation. The transcript of sacB and sacC was three fold higher in cells grown on sucrose than in cells grown on glucose/fructose. Northern blot analysis revealed that the transcript levels of sacC was approximately 2-3 times higher than that of sacB. These results suggested that the expression of sacC gene was more pronounced than sacB

Silver nanoparticles inhibit VEGF-and IL-1β-induced vascular permeability via Src dependent pathway in porcine retinal endothelial cells

The aim of this study is to determine the effects of silver nanoparticles (Ag-NP) on vascular endothelial growth factor (VEGF)-and interleukin-1 beta (IL-1β)-induced vascular permeability, and to detect the underlying signaling mechanisms involved in endothelial cells. Porcine retinal endothelial cells (PRECs) were exposed to VEGF, IL-1β and Ag-NP at different combinations and endothelial cell permeability was analyzed by measuring the flux of RITC-dextran across the PRECs monolayer. We found that VEGF and IL-1β increase flux of dextran across a PRECs monolayer, and Ag-NP block solute flux induced by both VEGF and IL-1β. To explore the signalling pathway involved VEGF- and IL-1β-induced endothelial alteration, PRECs were treated with Src inhibitor PP2 prior to VEGF and IL-1β treatment, and the effects were recorded. Further, to clarify the possible involvement of the Src pathways in endothelial cell permeability, plasmid encoding dominant negative(DN) and constitutively active(CA) form of Src kinases were transfected into PRECs, 24 h prior to VEGF and IL-1β exposure and the effects were recorded. Overexpression of DN Src blocked both VEGF-and IL-1β-induced permeability, while overexpression of CA Src rescues the inhibitory action of Ag-NP in the presence or absence of VEGF and IL-1β. Further, an in vitro kinase assay was performed to identify the presence of the Src phosphorylation at Y419. We report that VEGF and IL-1β-stimulate endothelial permeability via Src dependent pathway by increasing the Src phosphorylation and Ag-NP block the VEGF-and IL-1β-induced Src phosphorylation at Y419. These results demonstrate that Ag-NP may inhibit the VEGF-and IL-1β-induced permeability through inactivation of Src kinase pathway and this pathway may represent a potential therapeutic target to inhibit the ocular diseases such as diabetic retinopathy

Genomic instability and tumor-specific alterations in oral squamous cell carcinomas assessed by inter- (simple sequence repeat) PCR

Purpose: Genomic instability plays a major role in the genesis and progression of tumors, and in the evolution of tumor heterogeneity. To determine the role of genomic instability in the genesis and progression of oral cancer, we assessed the extent of genomic alterations in oral squamous cell carcinomas (OSCCs). Experimental Design: We used the recently developed inter-(simple sequence repeat) PCR technique to quantitate genomic instability using matched tumor and normal OSCC samples (n = 25). The inter-repeat region bands of similar molecular size observed to be altered in more than one case were sequenced and analyzed to identify probable OSSC-associated specific genetic lesions. Results: Of the four base-anchored, dinucleotide repeat-based primers used for the study, the most informative profile in OSCCs was generated by the (CA)8RG primer. Measurement of genomic instability index using the (CA)8RG primer revealed a high incidence of genomic instability in OSCCs. No significant correlation between the extent of alterations and stage or location of the tumor was observed. Sequencing analysis of the altered bands revealed gains/losses in several chromosomal regions. Of the matched tumor and corresponding normal tissue DNA studied, hitherto unreported losses were seen in 11p15 and 17q25 chromosomal regions. Sequencing of some of the tumor-specific altered regions indicated that they code for regions of UDP-GalNAc and hRAD 17 genes, which were lost (deleted) in oral cancer. Conclusions: Our results indicate that the extent of genomic instability in OSCC is not correlated to the tumor stage or location. For the first time, we have shown that chromosomal alterations detected by inter-(simple sequence repeat) PCR could be correlated to genes associated with cancer development

Anti-oxidant effect of gold nanoparticles restrains hyperglycemic conditions in diabetic mice

<p>Abstract</p> <p>Background</p> <p>Oxidative stress is imperative for its morbidity towards diabetic complications, where abnormal metabolic milieu as a result of hyperglycemia, leads to the onset of several complications. A biological antioxidant capable of inhibiting oxidative stress mediated diabetic progressions; during hyperglycemia is still the need of the era. The current study was performed to study the effect of biologically synthesized gold nanoparticles (AuNPs) to control the hyperglycemic conditions in streptozotocin induced diabetic mice.</p> <p>Results</p> <p>The profound control of AuNPs over the anti oxidant enzymes such as GSH, SOD, Catalase and GPx in diabetic mice to normal, by inhibition of lipid peroxidation and ROS generation during hyperglycemia evidence their anti-oxidant effect during hyperglycemia. The AuNPs exhibited an insistent control over the blood glucose level, lipids and serum biochemical profiles in diabetic mice near to the control mice provokes their effective role in controlling and increasing the organ functions for better utilization of blood glucose. Histopathological and hematological studies revealed the non-toxic and protective effect of the gold nanoparticles over the vital organs when administered at dosage of 2.5 mg/kilogram.body.weight/day. ICP-MS analysis revealed the biodistribution of gold nanoparticles in the vital organs showing accumulation of AuNPs in the spleen comparatively greater than other organs.</p> <p>Conclusion</p> <p>The results obtained disclose the effectual role of AuNPs as an anti-oxidative agent, by inhibiting the formation of ROS, scavenging free radicals; thus increasing the anti-oxidant defense enzymes and creating a sustained control over hyperglycemic conditions which consequently evoke the potential of AuNPs as an economic therapeutic remedy in diabetic treatments and its complications.</p

Comprehensive review on the positive and negative effects of various important regulators on male spermatogenesis and fertility

With the increasing global incidence of infertility, the influence of environmental factors, lifestyle habits, and nutrients on reproductive health has gradually attracted the attention of researchers. The quantity and quality of sperm play vital roles in male fertility, and both characteristics can be affected by external and internal factors. In this review, the potential role of genetic, environmental, and endocrine factors; nutrients and trace elements in male reproductive health, spermatozoa function, and fertility potency and the underlying mechanisms are considered to provide a theoretical basis for clinical treatment of infertility