Metallic silver nanoparticle: a therapeutic agent in combination with antifungal drug against human fungal pathogen

Silver nanoparticles (Ag-NPs) are known to have inhibitory and fungicidal effects. Resistance against fungal infection has emerged as a major health problem in recent years, which needs great and immediate concern. Here, we report the extracellular biological synthesis of silver nanoparticles through a simple green route approach using a marine mangrove (Rhizophora mucronata) and silver nitrate. Aqueous extract of marine mangrove helped in reduction and was used as capping agent in biological synthesis. Nanoparticles were characterized using microscopy and spectroscopy techniques such as HRTEM, UV–Vis absorption spectroscopy and FTIR spectroscopy. X-ray diffraction analysis showed that the nanoparticles had face centered cubic structure with crystalline nature. FTIR spectroscopy showed the presence of different functional groups, such as hydroxyl and carbonyl, involved in the synthesis of nanoparticles. The antifungal activity of fluconazole and itraconazole was enhanced against the tested pathogenic fungi in the presence of Ag-NP and confirmed from increase in fold area of inhibition. This environmentally friendly method of biological synthesis can be easily integrated for various medical applications.     

Plasmon-Enhanced Light Trapping to Improve Efficiency of TiO2 Nanorod-Based Dye-Sensitized Solar Cell

Localized surface plasmon resonance incurred by silver nanoparticles is used to enhance the photoelectric conversion efficiency of a TiO₂ nanorod-based dye-sensitized solar cell (DSSC). Improved light transmission is observed experimentally in silver nanoparticle-coated FTO glass. The transmission data are used to explore the effect on electrical parameters of DSSC using theoretical model. Current density increased from 11.7 to 12.34 mA/cm² and open-circuit voltage increased from 704 to 709.5 mV. Overall efficiency enhancement of 6.67 % is observed in TiO₂ nanorod-based DSSC due to plasmon-induced light trapping.     

Piriformospora indica?rescues growth diminution of rice seedlings during high salt stress

Piriformospora indica association has been reported to increase biotic as well as abiotic stress tolerance of its host plants. We analyzed the beneficial effect of P. indica association on rice seedlings during high salt stress conditions (200 and 300 mM NaCl). The growth parameters of rice seedlings such as root and shoot lengths or fresh and dry weights were found to be enhanced in P. indica-inoculated rice seedlings as compared with non-inoculated control seedlings, irrespective of whether they are exposed to salt stress or not. However, salt-stressed seedlings performed much better in the presence of the fungus compared with non-inoculated control seedlings. The photosynthetic pigment content [chlorophyll (Chl) a, Chl b, and carotenoids] was significantly higher in P. indica-inoculated rice seedlings under high salt stress conditions as compared with salt-treated non-inoculated rice seedlings, in which these pigments were found to be decreased. Proline accumulation was also observed during P. indica colonization, which may help the inoculated plants to become salt tolerant. Taken together, P. indica rescues growth diminution of rice seedlings under salt stress.     

Induction and establishment of somatic embryogenesis in elite Indian cotton cultivar (Gossypium hirsutumL. cv Khandwa-2)

Embryogenesis in cotton is a difficult task due its genome dependency. We used 3 cotton cultivars (Khandwa-2, G. Cot. 10, and BC-68–2) and Coker-312 as control for regeneration. Efficient somatic embryogenesis was induced in agronomically important Indian cotton cultivars, Khandwa-2 and G. Cot. 10. For callusing in all the cultivars, different media combinations were tried. Embryogenesis was initiated on a hormone-free MS medium (MSB). For embryo maturation and recovery excess of L-glutamine and l-asparagine were used. Khandwa-2 somatic embryos were successfully regenerated into plants. However, no plantlet was obtained in case of G. Cot. 10. Callus induction was also observed in BC-68–2 but there was no embryogenesis observed. The study indicated that the medium and genotype significantly effects embryogenesis. An efficient protocol is described here for regenerating plants via somatic embryogenesis in an elite Indian cotton cultivar Khandwa-2.     

Phenotypic Switching Induced by Damaged Matrix Is Associated with DNA Methyltransferase 3A (DNMT3A) Activity and Nuclear Localization in Smooth Muscle Cells (SMC)

Extracellular matrix changes are often crucial inciting events for fibroproliferative disease. Epigenetic changes, specifically DNA methylation, are critical factors underlying differentiated phenotypes. We examined the dependency of matrix-induced fibroproliferation and SMC phenotype on DNA methyltransferases. The cooperativity of matrix with growth factors, cell density and hypoxia was also examined. Primary rat visceral SMC of early passage (0–2) were plated on native collagen or damaged/heat-denatured collagen. Hypoxia was induced with 3% O₂ (balanced 5% CO₂ and 95% N₂) over 48 hours. Inhibitors were applied 2–3 hours after cells were plated on matrix, or immediately before hypoxia. Cells were fixed and stained for DNMT3A and smooth muscle actin (SMA) or smooth muscle myosin heavy chain. Illumina 450 K array of CpG sites was performed on bisulfite-converted DNA from smooth muscle cells on damaged matrix vs native collagen. Matrix exquisitely regulates DNMT3A localization and expression, and influences differentiation in SMCs exposed to denatured matrix +/− hypoxia. Analysis of DNA methylation signatures showed that Matrix caused significant DNA methylation alterations in a discrete number of CpG sites proximal to genes related to SMC differentiation. Matrix has a profound effect on the regulation of SMC phenotype, which is associated with altered expression, localization of DNMTs and discrete changes DNA methylation.     

HCMV Activates the IL-6-JAK-STAT3 Axis in HepG2 Cells and Primary Human Hepatocytes

Objectives

There has been increased interest in the possible role of human cytomegalovirus (HCMV) in carcinogenesis during the last decade. HCMV seroprevalence was enhanced in patients with hepatocellular carcinoma (HCC) but a possible relationship between HCC and HCMV infection remained to be assessed. The aim of this work was to investigate the pro-tumor influence of HCMV on primary human hepatocytes (PHH) and HepG2 cells.

Methods

Following infection of PHH and HepG2 cells by two different strains of HCMV, we measured the production of IL-6 in culture supernatants by ELISA and the protein levels of STAT3, pSTAT3, JAK, cyclin D1, survivin, p53, p21, and Mdm2 by western Blotting in infected and uninfected cells. Cell proliferation and transformation were investigated using Ki67Ag expression measurement and soft-agar colony formation assay respectively.

Results

Infection of HepG2 cells and PHH by HCMV resulted in the production of IL-6 and the subsequent activation of the IL-6R-JAK-STAT3 pathway. HCMV increased the expression of cyclin D1 and survivin. Cell proliferation was enhanced in HepG2 and PHH infected with HCMV, despite a paradoxical overexpression of p53 and p21. More importantly, we observed the formation of colonies in soft agar seeded with PHH infected with HCMV and when we challenged the HepG2 cultures to form tumorspheres, we found that the HCMV-infected cultures formed 2.5-fold more tumorspheres than uninfected cultures.

Conclusion

HCMV activated the IL-6-JAK-STAT3 pathway in PHH and HepG2 cells, favored cellular proliferation, induced PHH transformation and enhanced HepG2 tumorsphere formation. Our observations raise the possibility that HCMV infection might be involved in the genesis of hepatocellular carcinoma.