An in vitro examination of the antioxidant, cytoprotective and anti-inflammatory properties of chrysin-loaded nanofibrous mats for potential wound healing applications.

Chrysin (Chr) is a naturally occurring flavone with a wide spectrum of biological functions including anti-cancer, anti-inflammatory and anti-oxidant properties. Due to the low bioavailability and in vivo stability of Chr at therapeutic levels for wound-healing applications, Chr-loaded PCL/PEG nanofibrous mats were successfully fabricated by optimizing the electrospinning parameters and characterized using FE-SEM and FTIR. Results of MTT showed that Human foreskin fibroblast cells (HFF-1) have more than 80% viability on Chr-loaded nanofibers. The antioxidant activity of Chr-loaded PCL/PEG electrospun nanofibers was demonstrated applying an ORAC assay and by the capability of the nanofibers to maintain the viability of HFF-1 cells on the mats under an oxidative stress condition. The Chr-blended PCL/PEG nanofibrous mats also reduced overexpression of IL-6, IL-1ß, TNF-α and excessive production of nitric oxide (NO) in J774A1 following stimulation by lipopolysaccharide (LPS). These results suggest that the proposed natural substance based nanofibrous mats can accelerate wound healing process with cell proliferation, antioxidative and anti-inflammatory activities.

Conditioned Medium of Wharton's Jelly Derived Stem Cells Can Enhance the Cartilage Specific Genes Expression by Chondrocytes in Monolayer and Mass Culture Systems.

Purpose: Mesenchymal stem cells (MSCs) have been introduced for cell therapy strategies in osteoarthritis (OA). Despite of their capacity for differentiation into chondrocyte, there are some evidences about their life-threatening problem after transplantation. So, some researchers shifted on the application of stem cells conditioned medium. The goal of this study is to evaluate whether Wharton's jelly derived stem cell conditioned medium (WJSCs-CM) can enhance the gene expression profile by chondrocytes in monolayer and mass culture systems. Methods: Conditioned medium was obtained from WJSCs at fourth passage. Isolated chondrocytes were plated at density of 1×106 for both monolayer and high density culture. Then cells in both groups were divided into control (received medium) and experiment group treated with WJ-CM for 3 and 6 days. Samples were prepared to evaluate gene expression profile of collagen II, aggrecan, cartilage oligomeric matrix protein (COMP) and sox-9 using real-time RT-PCR. Results: After 3 days, Chondrocytes treated with WJSCs-CM expressed significantly higher level of genes compared to the control group in both culture systems. After 6 days, the expression of genes in monolayer cultivated chondrocytes was decreased but that of the mass culture were up-regulated significantly. Conclusion: WJ-SCs-CM can increase the expression of cartilage-specific genes and can be introduced as a promoting factor for cartilage regeneration.

Key Immune Cell Cytokines Affects the Telomere Activity of Cord Blood Cells In vitro.

PURPOSE: Telomere is a nucleoprotein complex at the end of eukaryotic chromosomes and its length is regulated by telomerase. The number of DNA repeat sequence (TTAGGG)n is reduced with each cell division in differentiated cells. The aim of this study was to evaluate the effect of SCF (Stem Cell Factor), Flt3 (Fms- Like tyrosine kinase-3), Interleukin-2, 7 and 15 on telomere length and hTERT gene expression in mononuclear and umbilical cord blood stem cells (CD34+ cells) during development to lymphoid cells. METHODS: The mononuclear cells were isolated from umbilical cord blood by Ficoll-Paque density gradient. Then cells were cultured for 21 days in the presence of different cytokines. Telomere length and hTERT gene expression were evaluated in freshly isolated cells, 7, 14 and 21 days of culture by real-time PCR. The same condition had been done for CD34+ cells but telomere length and hTERT gene expression were measured at initial and day 21 of the experiment. RESULTS: Highest hTERT gene expression and maximum telomere length were measured at day14 of MNCs in the presence of IL-7 and IL-15. Also, there was a significant correlation between telomere length and telomerase gene expression in MNCs at 14 days in a combination of IL-7 and IL-15 (r = 0.998, p =0.04). In contrast, IL-2 showed no distinct effect on telomere length and hTERT gene expression in cells. CONCLUSION: Taken together, IL-7 and IL-15 increased telomere length and hTERT gene expression at 14 day of the experiment. In conclusion, it seems likely that cells maintain naïve phenotype due to prolonged exposure of IL-7 and IL-15.

Molecular Cloning and Characterization of P4 Nuclease from Leishmania infantum.

Parasite of the genus Leishmania is reliant on the salvage pathway for recycling of ribonucleotides. A class I nuclease enzyme also known as P4 nuclease is involved in salvage of purines in cutaneous Leishmania species but the relevant enzymes have not been characterized in Leishmania infantum (L. infantum). The aim of this study was to clone and characterize the gene encoding class I nuclease in L. infantum. DNA extracted from L. infantum was used for amplification of P4 nuclease gene (Li-P4) by PCR. The product was cloned, sequenced, and expressed in E. coli for further characterization. Analysis of the sequence of Li-P4 revealed that the gene consists of an ORF of 951 bp. Sequence similarity analysis indicated that Li-P4 has a high homology to relevant enzymes of other kintoplastids with the highest homology (88%) to p1/s1 class I nuclease from L. donovani. Western blotting of antirecombinant Li-P4 with promastigote and amastigote stages of L. infantum showed that this nuclease is present in both stages of parasite with higher expression in amastigote stage. The highly conserved nature of this essential enzyme in Leishmania parasites suggests it as a promising drug target for leishmaniasis.

C-reactive protein level following treatment and withdrawal of lovastatin in diabetic nephropathy.

INTRODUCTION: We aimed to evaluate the high-sensitivity C-reactive protein (HS-CRP) level changes at the beginning and after withdrawal of lovastatin therapy in patients with diabetic nephropathy. MATERIALS AND METHODS: Thirty male patients with type 2 diabetes mellitus and diabetic nephropathy were enrolled in the study. Lovastatin, 20 mg/d, was administered for 90 days. Afterwards, Lovastatin was withdrawn for the next 30 days. Blood samples were obtained before the intervention, on the 90th day, and days 1, 7, and 30 after withdrawal of Lovastatin. Serum level of HS-CRP was determined by enzyme-linked immunosorbent assay. Alterations in lipid profile was assessed, as well, and compared with that of HS-CRP. RESULTS: Serum level of HS-CRP was significantly reduced after 90 days of lovastatin therapy (P < .001). Then, the HS-CRP reached the pretreatment baseline level on the 7th day after lovastatin withdrawal and maintained until the 30th day (P < .001). Serum HS-CRP changes showed no significant association with lipid profile except for serum total cholesterol level (r = 0.9, P = .006) after 3 months of lovastatin therapy. Their association was re-evaluated after 7 days and 1 month of treatment withdrawal and no significant correlations were found. CONCLUSIONS: Our findings suggest that lovastatin decreases serum CRP level in patients with diabetic nephropathy, and 7 days after lovastatin cessation, CRP level increases again.