Conditions to improve expansion of human mesenchymal stem cells based on rat samples

AIM: To improve the isolation and expansion of human marrow-derived mesenchymal stem cells (MSCs) based on rat samples. METHODS: Based on the fact that rat MSCs are relatively easy to obtain from a small aspirate, bone marrow-derived MSCs from rat were cultured and characterized to set up the different protocols used in this study. Then, accordingly, almost the same protocols were performed on human healthy bone marrow samples, after obtaining approval of the ethics committee and gaining informed consent. We used different protocols and culture conditions, including the type of basal media and the culture composition. The MSCs were characterized by immunophenotyping and differentiation. RESULTS: There was no difference in morphology and proliferation capacity between different culture media at the first passage. During the 5-7th passages, the cells gradually lost their morphology and proliferation potential on Dulbecco’s modified Eagle’s medium (DMEM) high glucose and α modified Eagle’s medium. Although the cells expanded rapidly for up to 10 passages on DMEM low glucose containing 10% to 15% fetal calf serum (FCS), their proliferation was arrested without change in morphology and differentiation capacity at the third passage on 5% FCS. Flow cytometric analysis and functional tests confirmed that more than 90% of marrow cells which were isolated and expanded by our selective protocols were MSCs. CONCLUSION: We improved the isolation and expansion of human bone marrow derived MSCs, based on rat sample experiments, for further experimental and clinical use.     

Interactions of human serum albumin with bioactive 3<Emphasis Type="Italic">H</Emphasis>-imidazo[4,5-<Emphasis Type="Italic">a</Emphasis>]acridines: Insights from fluorescence spectroscopic studies

Several 3H-imidazo[4,5-a]acridine derivatives were conveniently synthesized by the reaction of imidazo[4,5-a]acridones in boiling POCl3. The imidazoacridones were obtained by rearrangement of 3H-imidazo[4',5':3,4]benzo[c]isoxazoles in concentrated sulfuric acid containing nitrous acid at room temperature. The structures of all newly synthesized compounds were confirmed by IR, ¹H NMR, and mass spectral data. The interactions of 3H-imidazo[4,5-a]acridines with human serum albumin (HSA) were studied by fluorescence spectroscopy. The binding of 3H-imidazo[4,5-a]acridines quenches the HSA fluorescence, revealing a 1: 1 interaction with a binding constant of about 2.34 × 10⁵–3.16 × 10⁶ M^–1. A decrease in fluorescence intensity at 339 nm, when excited at 280 nm, is attributed to changes in the environment of the protein fluorophores caused by the presence of the ligand. The differences in interactions of 3H-imidazo[4,5-a]acridines with HSA were observed using spectrofluorimetry technique.     

Dendritic Cell IL-1α and IL-1β Are Polyubiquitinated and Degraded by the Proteasome

IL-1α and β are key players in the innate immune system. The secretion of these cytokines by dendritic cells (DC) is integral to the development of proinflammatory responses. These cytokines are not secreted via the classical secretory pathway. Instead, 2 independent processes are required; an initial signal to induce up-regulation of the precursor pro-IL-1α and -β, and a second signal to drive cleavage and consequent secretion. Pro-IL-1α and -β are both cytosolic and thus, are potentially subject to post-translational modifications. These modifications may, in turn, have a functional outcome in the context of IL-1α and -β secretion and hence inflammation. We report here that IL-1α and -β were degraded intracellularly in murine bone marrow-derived DC and that this degradation was dependent on active cellular processes. In addition, we demonstrate that degradation was ablated when the proteasome was inhibited, whereas autophagy did not appear to play a major role. Furthermore, inhibition of the proteasome led to an accumulation of polyubiquitinated IL-1α and -β, indicating that IL-1α and -β were polyubiquitinated prior to proteasomal degradation. Finally, our investigations suggest that polyubiquitination and proteasomal degradation are not continuous processes but instead are up-regulated following DC activation. Overall, these data highlight that IL-1α and -β polyubiquitination and proteasomal degradation are central mechanisms in the regulation of intracellular IL-1 levels in DC.     

Plant-mediated vulnerability of an insect herbivore to Bacillus thuringiensis in a plant-herbivore-pathogen system

Laboratory studies were performed to explore the effects of host-plant quality on the vulnerability of Plutella xylostella to Bacillus thuringiensis. P. xylostella were kept on different host plants, including Brassica pekinensis (Chinese cabbage) cv. Hero, Brassica oleracea var. botrytis (cauliflower) cv. Royal, and B. oleracea var. capitata (common cabbage) cv. Globe Master (white cabbage) and cv. Red Dynasty (red cabbage) for at least two generations. These host plants are considered as the high (Chinese cabbage), intermediate (cauliflower and white cabbage) and low-quality (red cabbage) hosts for P. xylostella. The vulnerability of the pest larvae was then tested using two formulation of B. thuringiensis var. kurstaki, including Biolarv^® and Biolep^®. The results demonstrated that the susceptibility of P. xylostella to B. thuringiensis was influenced by host-plant quality. Indeed, B. thuringiensis acted better on the pest fed on the low-quality host plant compared with that on the high-quality host plant. The interaction between the pathogen and plant quality/resistance resulted in more mortality of the pest larvae, implying a synergistic effect. From a pest management viewpoint, these findings may be promising for the integration of the pathogen and the low-quality/partially resistant host plants against P. xylostella in field studies.     

Plant protein-based hydrophobic fine and ultrafine carrier particles in drug delivery systems

For thousands of years, plants and their products have been used as the mainstay of medicinal therapy. In recent years, besides attempts to isolate the active ingredients of medicinal plants, other new applications of plant products, such as their use to prepare drug delivery vehicles, have been discovered. Nanobiotechnology is a branch of pharmacology that can provide new approaches for drug delivery by the preparation of biocompatible carrier nanoparticles (NPs). In this article, we review recent studies with four important plant proteins that have been used as carriers for targeted delivery of drugs and genes. Zein is a water-insoluble protein from maize; Gliadin is a 70% alcohol-soluble protein from wheat and corn; legumin is a casein-like protein from leguminous seeds such as peas; lectins are glycoproteins naturally occurring in many plants that recognize specific carbohydrate residues. NPs formed from these proteins show good biocompatibility, possess the ability to enhance solubility, and provide sustained release of drugs and reduce their toxicity and side effects. The effects of preparation methods on the size and loading capacity of these NPs are also described in this review.     

Effects of gamma radiation on the reproduction biology and mating competitiveness of citrus leafminer Phyllocnistis citrella Stainton

The citrus leafminer (CLM), Phyllocnistis citrella Stainton, is one of the most serious pests of Iran's citrus nursery stocks. In this study, the effects of gamma radiation at doses of 100–450?Gy on the biological and reproductive parameters of P. citrella were determined. The results showed that the mean percentage of pupal mortality increases with a rise in the dose. Also, the mean values of this parameter were higher for irradiated females, indicating higher sensitivity. The mean fertility of the irradiated females mated with normal males was affected drastically and reached zero at 300?Gy. The hatchability of the eggs laid by normal females mated with irradiated males dropped to 2% at the highest irradiation dose of 450?Gy. The results of this test showed that females have a higher radio-sensitivity than males. The competitiveness values fluctuated from 0.2 to 0.6 at doses higher than 200?Gy. The results showed that the male CLMs irradiated with sterilizing doses could compete suitably with the untreated males in laboratory conditions.     

Epigenetic changes of <Emphasis Type="Italic">CDX2</Emphasis> in gastric adenocarcinoma

Gastric cancer is one of the most commonplace and lethal cancers in the world. Molecular investigation of this disease, in order to obtain diagnostic and treatments achievements is important and vital. Relatively, in this research study, one of the most important epigenetic factors, the methylation of CDX2 gene was investigated in tumoral and non-tumoral tissues of gastric cancer patients by bisulfite treatment followed by sequencing of the 5’UTR region of CDX2 in both tissues. The results indicated a hypomethylation in tumoral tissues of adenocarcinoma. Consequently, the methylation amount of CDX2 in tumoral tissues was significantly reduced compared with non-tumoral tissues.