On the repression of the biogenesis of respiratory enzymes inSaccharomyces cereuisiae andEscherichia coli by glucose

The effect of glucose on the respiratory metabolism of two facultative anaerobesSaccharomyces cerevisiae andEscherichia coli has been studied and a close similarity is reported. In both cases, there is disorganisation of the membrane bound electron transport components.     

Role of cyclic AMP in mitochondriogenesis in yeast

Cyclic AMP prevents the release of proteins from mitochondria (prelabelled with radioactive aminoacids) during glucose repression in yeast cells and chloramphenicol has no effect on this process. Using specific antisera, the release of the mitochondrially synthesised membrane factor of ATPase during repression and the blocking of this by cAMP has been demonstrated.     

Bio catalytic oxidation of sulphide laden wastewater from leather industry using sulfide: Quinone oxidoreductase immobilized bio reactor

Abstract

Anaerobic treatment of sulphate rich wastewater results in high amount of sulphide in liquid phase and gaseous phase. Sulphide is malodorous in gaseous phase and toxic even at very low concentrations in liquid phase and causes objectionable environmental issues. In the present investigation the sulphide present in the UASB treated post tanning wastewater was oxidised into elemental sulphur using Sulfide: Quinone oxidoreductase (SQR) immobilized Functionalized Carbon-silica matrix (FCSM) packed bed reactor. The variables employed for the production of Bacillus clausii biomass for the extraction of SQR were optimized using RSM. The purified SQR showed the maximum activity and stability at pH 6.0 to 8.0 and the percentage oxidation of sulphide at HRT of 24?h were 99.2%?±?0.2 at pH 6.0; 99.6%?±?0.2 at pH 7.0 and 99.6%?±?2.12 at pH 8.0. The effect of temperature on SQR activity was optimized and it established the maximum activity and stability at 40?°C with sulphide oxidation of 99.6%?±?0.8%. The optimum conditions for immobilization of SQR onto FCSM were time, 240?min; pH, 7.0; temperature, 40?°C and SQR concentration, 10?mg/g. The immobilization of SQR onto FCSM obeyed the Langmuir isotherm model. The immobilization of SQR onto FCSM was confirmed by SEM, FT-IR, XRD, TGA and DSC analyses. The SQR-FCSM packed bed reactor was operated separately for the oxidation of sulfide in UASB treated post-tanning wastewater under continuous mode at different HRTs and it recorded the maximum sulphide oxidation by 99?±?0.1% at HRT of 15?h with residual sulphide of 2.4?±?1.1?mg/L. The formation of elemental Sulphur was confirmed by XRD studies. The present investigation provides the scope for the removal of sulphide and thereby substantial reduction in Total Dissolved Solids from post tanning wastewater without addition of chemicals.     

Alteration of gene expression levels during osteogenic induction of human adipose derived stem cells in long-term culture

Adipose tissue is a source of multipotent stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic and adipogenic cells. Most studies on human adipose-derived stem cells (ASCs) have been carried out at the early passages. For clinical usage, ASCs need to be expanded in vitro for a period of time to get sufficient cells for transplantation into patients. However, the impact of long-term culture on ASCs molecular characteristics has not been established yet. Several studies have also shown that osteogenic and adipogenic cells have the ability to switch pathways during in vitro culture as they share the same progenitor cells. This data is important to ensure their functionality and efficacy before being used clinically in the treatment of bone diseases. Therefore, we aim to investigate the effect of long-term culture on the adipogenic, stemness and osteogenic genes expression during osteogenic induction of ASCs. In this study, the molecular characteristics of ASCs during osteogenic induction in long-term culture was analysed by observing their morphological changes during induction, analysis of cell mineralization using Alizarin Red staining and gene expression changes using quantitative RT-PCR. Morphologically, cell mineralization at P20 was less compared to P5, P10 and P15. Adipogenesis was not observed as negative lipid droplets formation was recorded during induction. The quantitative PCR data showed that adipogenic genes expression e.g. LPL and AP2 decreased but PPAR-γ was increased after osteogenic induction in long-term culture. Most stemness genes decreased at P5 and P10 but showed no significant changes at P15 and P20. While most osteogenic genes increased after osteogenic induction at all passages. When compared among passages after induction, Runx showed a significant increased at P20 while BSP, OSP and ALP decreased at later passage (P15 and P20). During long-term culture, ASCs were only able to differentiate into immature osteogenic cells.     

Differentiation of mesenchymal stem cells derived from human bone marrow and subcutaneous adipose tissue into pancreatic islet-like clusters in vitro

Although stem cells are present in various adult tissues and body fluids, bone marrow has been the most popular source of stem cells for treatment of a wide range of diseases. Recent results for stem cells from adipose tissue have put it in a position to compete for being the leading therapeutic source. The major advantage of these stem cells over their counterparts is their amazing proliferative and differentiation potency. However, their pancreatic lineage transdifferentiation competence was not compared to that for bone marrow-derived stem cells. This study aims to identify an efficient source for transdifferentiation into pancreatic islet-like clusters, which would increase potential application in curative diabetic therapy. The results reveal that mesenchymal stem cells (MSC) derived from bone marrow and subcutaneous adipose tissue can differentiate into pancreatic islet-like clusters, as evidenced by their islet-like morphology, positive dithizone staining and expression of genes such as Nestin, PDX1, Isl 1, Ngn 3, Pax 4 and Insulin. The pancreatic lineage differentiation was further corroborated by positive results in the glucose challenge assay. However, the results indicate that bone marrow-derived MSCs are superior to those from subcutaneous adipose tissue in terms of differentiation into pancreatic islet-like clusters. In conclusion, bone marrow-derived MSC might serve as a better alternative in the treatment of diabetes mellitus than those from adipose tissue.     

The changes of stemness biomarkers expression in human adipose-derived stem cells during long-term manipulation

One of the advantages of human adipose-derived stem cells (ASCs) in regenerative medicine is that they can be harvested in abundance. However, the stemness biomarkers, which marked the safety and efficacy of ASCs in accordance with the good manufacturing practice guidelines, is not yet well established. This study was designed to investigate the effect of long-term culture on the stemness properties of ASCs using quantitative real-time polymerase chain reaction and flow cytometry. Results showed the growth rate of ASCs was at its peak when they reached P10 (population doubling; PD = 26) but started to decrease when they were expanded to P15 (PD = 36) and P20 (PD = 46). The ASCs can be culture expanded with minimal alteration in the stemness genes and cluster of differentiation (CD) markers expression up to P10. Expression level of Sox2, Nestin, and Nanog3 was significantly decreased at later passage. CD31, CD45, CD117, and human leukocyte antigen DR, DQ, and DP were lowly expressed at P5 and P10 but their expressions increased significantly at P15 or P20. The differentiation ability of ASCs (adipogenesis, osteogenesis, and neurogenesis) also decreased in long-term culture. Our findings suggested that P10 (PD = 26) should be the "cutoff point" for clinical usage because ASCs at passage 15 onward showed significant changes in the stemness genes, CD markers expression, and differentiation capability.     

Absolute configuration of antifibrotic (+)-episesamin isolated from Lindera obtusiloba BLUME

Fractionation of a 70% ethanolic extract from twigs of Lindera obtusiloba BLUME (Japanese spicebush, Tohaku) yielded five fractions of different polarity. The antifibrotic activity within the chloroform phase was best assessed by an in vitro bioassay using rat hepatic stellate cell (HSC) proliferation and their autocrine transforming growth factor beta (TGF-beta) expression as sensitive fibrosis-associated read out. Chromatography of the chloroform extract on Sephadex LH-20 or liquid-liquid extractions yielded a crystalline compound as an active principle, which was identified from NMR and ESI-MS analyses, its melting point, and its optical rotation as (7S,7'R,8R,8'R)-3,4:3',4'-bis(methylenedioxy)-7,9':7',9-diepoxy-lignane [(+)-episesamin]. X-Ray diffraction confirmed the structure and provided, for the first time, directly its absolute configuration. (+)-Episesamin blocked proliferation and the profibrotic autocrine TGF-beta expression HSC without significant cytotoxicity.     

Chemopreventive effect of <Emphasis Type="BoldItalic">Padina boergesenii</Emphasis> extracts on ferric nitrilotriacetate (Fe-NTA)-induced oxidative damage in Wistar rats

The present study was designed to investigate the prophylactic effect of extracts of the brown alga Padina boergesenii against potent nephrotoxic agent ferric nitrilotriacetate (Fe-NTA), in blood circulation of rats. Administration of Fe-NTA for seven consecutive days significantly enhanced lipid peroxidation accompanied with reduction in glutathione content. Together with this, the level of antioxidant enzymes, glutathione peroxidase, superoxide dismutase, and catalase was significantly (P < 0.05) diminished. Pretreatment of rats with P. boergesenii (150 mg kg⁻¹ body weight) reversed Fe-NTA-induced oxidative damage in lipid peroxidation and glutathione content significantly (P < 0.05). Further, the activity of antioxidant enzymes was also restored significantly. In order to assess the role of polyphenolic components in the relevant activity, phenolic contents of the extract was found to be 1.78 ± 0.02% in the methanol extract and 1.30 ± 0.30% in the diethyl ether extract. Hence, the present results confirm that the brown alga P. boergesenii preclude its role in Fe-NTA-induced oxidative damage and hyperproliferative response in circulation.