Protein Kinase D Is Implicated in the Reversible Commitment to Differentiation in Primary Cultures of Mouse Keratinocytes

Although commitment to epidermal differentiation is generally considered to be irreversible, differentiated keratinocytes (KCs) have been shown to maintain a regenerative potential and to reform skin epithelia when placed in a suitable environment. To obtain insights into the mechanism of reinitiation of this proliferative response in differentiated KCs, we examined the reversibility of commitment to Ca²⁺-induced differentiation. Lowering Ca²⁺ concentration to micromolar levels triggered culture-wide morphological and biochemical changes, as indicated by derepression of cyclin D1, reinitiation of DNA synthesis, and acquisition of basal cell-like characteristics. These responses were inhibited by Goedecke 6976, an inhibitor of protein kinase D (PKD) and PKCα, but not with GF109203X, a general inhibitor of PKCs, suggesting PKD activation by a PKC-independent mechanism. PKD activation followed complex kinetics with a biphasic early transient phosphorylation within the first 6 h, followed by a sustained and progressive phosphorylation beginning at 24 h. The second phase of PKD activation was followed by prolonged ERK1/2 signaling and progression to DNA synthesis in response to the low Ca²⁺ switch. Specific knockdown of PKD-1 by RNA interference or expression of a dominant negative form of PKD-1 did not have a significant effect on normal KC proliferation and differentiation but did inhibit Ca²⁺-mediated reinitiation of proliferation and reversion in differentiated cultures. The present study identifies PKD as a major regulator of a proliferative response in differentiated KCs, probably through sustained activation of the ERK-MAPK pathway, and provides new insights into the process of epidermal regeneration and wound healing.     

Synthesis and character investigation of new collagen Hydrolysate/polyvinyl alcohol/hydroxyapatite Polymer-Nano-Porous Membranes: I. Experimental design optimization in thermal and structural properties

Abstract

Development of bioorganic–inorganic composites has drawn eyes to extensive attention in biomedical fields and tissue engineering. So many attempts to prepare hydroxyapatite (HA), in conjunction with various binders including polyvinyl alcohol (PVA), and collagen has performed for late 20 years. We applied a method based on the phase separation for making of polymer porous membranes. This procedure is induced through the addition of a small quantity of water (polymer-rich phase) to a solution with HA precursors (polymer-poor phase). Thermal and structural composite properties of collagen Hydrolysate (CH)–PVA/HA Polymer-Nano-Porous Membranes were analyzed by Design of experiment that was undertaken using D-optimal approach, to select the optimal combination of nano composites precursor. The resulted composite characters were investigated by Fourier transform infrared, scanning electron microscopy (SEM) and thermal gravimetric analysis. Based on the SEM images, this new method could be clearly concluded to porous CH–PVA/HA hybrid materials. Finally the hemocompatibility of nanocomposite membranes were evaluated by the hemolysis study.

Graphical Abstract

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DNA interaction studies of sesamol (3,4-methylenedioxyphenol) food additive

The interaction of native calf thymus DNA (CT-DNA) with sesamol (3,4-methylenedioxyphenol) in Tris–HCl buffer at neutral pH 7.4 was monitored by absorption spectrophotometry, viscometry and spectrofluorometry. It is found that sesamol molecules could interact with DNA outside and/or groove binding modes, as are evidenced by: hyperchromism in UV absorption band, very slow decrease in specific viscosity of DNA, and small increase in the fluorescence of methylene blue (MB)-DNA solutions in the presence of increasing amounts of sesamol, which indicates that it is able to partially release the bound MB. Furthermore, the enthalpy and entropy of the reaction between sesamol and CT-DNA showed that the reaction is enthalpy-favored and entropy-disfavored (ΔH = ?174.08 kJ mol^?1; ΔS = ?532.92 J mol^?1 K^?1). The binding constant was determined using absorption measurement and found to be 2.7 × 10⁴ M^?1; its magnitude suggests that sesamol interacts to DNA with a high affinity.     

Maternal zinc intake of Wistar rats has a protective effect in the alloxan-induced diabetic offspring

Zinc has a role in the synthesis, storage, and secretion of insulin, and has been suggested to be beneficial when used in the diabetic state. Effect of zinc intake in pregnant rats has been studied here on diabetized offspring. Pregnant rats were divided in two groups; the control group received normal food and water, and the experimental group received zinc sulfate during pregnancy and 3 weeks after offspring birth. Male offspring from the control (C) and experimental (E) groups were divided each in three groups: C1, fed with normal food and water; C2, diabetized with alloxan; C3, received zinc sulfate; E1, fed with normal food and water; E2, diabetized with alloxan; and E3, receiving zinc sulfate. After 30 days, the histological changes of pancreatic tissues were investigated by light microscopy. Body weight, blood glucose, serum insulin levels, food intake, water intake, and urine quantity were also compared between the groups. Water intake and urine quantity were decreased significantly (p?<?0.01and p?<?0.001) in E2 (experimental diabetic group) in comparison with C2 (control diabetic group), but there was no significant difference in the body weight in C2 in comparison with E2, while blood glucose was decreased significantly (p?<?0.001) and blood insulin level was increased significantly (p?<?0.01) in E2 in comparison with C2. Microscopic evaluation of pancreas showed that E2 were protected against alloxan-induced beta-cell degeneration. In conclusion, this work showed that maternal zinc intake may influence subsequent deleterious effects of diabetes on alloxan-diabetized offspring.     

Application of magnetic nanoparticles in smart enzyme immobilization

Immobilization of enzymes enhances their properties for efficient utilization in industrial processes. Magnetic nanoparticles, due to their high surface area, large surface-to-volume ratio and easy separation under external magnetic fields, are highly valued. Significant progress has been made to develop new catalytic systems that are immobilized onto magnetic nanocarriers. This review provides an overview of recent developments in enzyme immobilization and stabilization protocols using this technology. The current applications of immobilized enzymes based on magnetic nanoparticles are summarized and future growth prospects are discussed. Recommendations are also given for areas of future research.     

Preparation of Effective and Safe Gene Carriers by Grafting Alkyl Chains to Generation 5 Polypropyleneimine

Gene therapy is a novel method to treat a variety of diseases including genetic disorders and cancer. Nonviral gene carriers have now gained considerable attention as gene carrier systems. Polyamidoamine (PAMAM) and polypropyleneimine (PPI) are the two most widely used denderimers in gene delivery studies. The aim of the current study was to investigate the effects of modification of generation 5 polypropyleneimine (G5 PPI) dendrimers with alkanoate groups as hydrophobic moieties on DNA transfection and cytotoxicity. Six, 10, and 16 carbon derivatives of bromoalkanoic acids were conjugated onto PPI with 10%, 30%, and 50% of surface amine grafting. Ethidium bromide exclusion assay results proved the ability of modified carriers to condense DNA. Transfection assay showed higher DNA delivery potential for 30% and 50% grafting with decanoate moieties compared to native G5 PPI and Superfect^TM. 3-(4,5-Dimethylthiazol-2-yl)-2,5-di phenyltetrazolium bromide (MTT) and apoptosis experiments showed lower toxicity for modified carriers compared to unmodified PPI. The hemolytic effect of grafted carriers was not significantly different from G5 PPI. Size and zeta potential measurements revealed that polyplex size was less than 200 nm and electrical charges were in the range 14–25 mV. The hydrophobic modifications improved transfection activity and toxicity of G5 PPI without negatively affecting hemocompatibility. These modified carriers are therefore promising candidates for further in vivo investigations.KEY WORDS: gene delivery, hydrophobic modification, nonviral vector, polypropyleneimine, transfection     

Association Between Trace Element Status and Depression in HTLV-1-Infected Patients: a Retrospective Cohort Study

Depression and Anxiety are two important public health problems that are known to be associated with viral infections. The association between the intake of nutrients such as zinc and copper with symptoms of depression has been studied previously. The aim of the current study was to investigate the association between depression with human T cell lymphotropic virus type 1 (HTLV-1) infection and serum content of zinc and copper in a large Iranian population cohort. The study population consisted of 279 HTLV-1-positive patients who were identified after recruitment as part of a large cohort study: the Mashhad Stroke and Heart Association Disorder (MASHAD) study. They were divided into two groups of diagnosed with or without depression based on their symptoms. Serum zinc and copper levels of all subjects were measured using the flame atomic absorption spectrometry. The population sample comprised of 279 individuals infected with HTLV-1 of whom 192 (68.8%) were women. The mean serum zinc in the group with and without depression was 78.69 ± 13.79 μg/dl and 86.87 ± 19.44 μg/dl, respectively (p < 0.001). Also, the serum copper level was higher in the depressive group (116.75 ± 39.56) than in the non-depressive group (104.76 ± 30.77) (p 0.004). The association between serum zinc and copper with depression in HTLV-1-infected patients which was shown in this study could be considered in the treatment strategies in these patients.

     

Melatonin-mediated regulation of autophagy: Making sense of double-edged sword in cancer

Much research has been conducted to discover novel techniques to reverse the process of tumorigenesis and, cure already stablished malignancies. One well-stablished approach has been the use of organic compounds and naturally found agents such as melatonin whose anticancer effects have been shown in multiple studies, signaling a unique opportunity regarding cancer prevention and treatment. Various agents use a variety of methods to exert their anticancer effects. Two of the most important of these methods are interfering with cell signaling pathways and changing cellular functions, such as autophagy, which is essential in maintaining cellular stability against multiple exogenous and endogenous sources of stress, and is a major tool to evade early cell death. In this study, the importance of melatonin and autophagy are discussed, and the effects of melatonin on autophagy, and its contribution in the process of tumorigenesis are then noted.     

A mechanism for anti-asialo GM 1 antibody-induced anaphylactoid response in mice infected with Trichinella pseudospiralis

Intravenous injection of anti-asialo GM 1 antibody into mice infected with Trichinella pseudospiralis resulted in rapid acute illness or death accompanied by a dramatic rise in hematocrit values in these animals. The described antibody-induced changes were reversible by intravenous infusion of Hanks' balanced salt solution (HBSS). These effects were not seen in uninfected mice or in Trichinella spiralis-infected mice injected with anti-asialo GM 1 antibody. Viability of T. spiralis or T. pseudospiralis infective L1 larvae, both isolated worms and those housed in muscle, was unaffected by exposure to anti-asialo GM 1 antibody and complement. Infectivity of larvae of T. pseudospiralis decreased significantly following exposure to anti-asialo GM 1 antibody. Release of protein by T. pseudospiralis infective L1 larvae during incubation in the presence of anti-asialo GM 1 antibody was significantly greater than that released by worms incubated in normal rabbit serum or HBSS. Protein released by infective L1 larvae of T. pseudospiralis was identified as Trichinella excretory/secretory antigens by immunoblot. Intravenous injection of T. pseudospiralis excretory/secretory products resulted in anaphylaxis in T. pseudospiralis-infected mice but not in uninfected or T. spiralis-infected mice. Excretory/secretory product-induced anaphylactoid response also was reversible by the intravenous injection of HBSS or by injection of an antihistamine. Significantly higher levels of total IgE were observed in sera from mice infected with T. pseudospiralis compared to uninfected or T. spiralis-infected mice. Binding of anti-asialo GM 1 antibody to the surface of T. pseudospiralis muscle larvae induced release of excretory/secretory antigen by the parasite.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preparation,Characterization, and Optimization of Folic Acid-Chitosan-Methotrexate Core-Shell Nanoparticles by Box-Behnken Design for Tumor-Targeted Drug Delivery

The objective of this study was to investigate the combined influence of independent variables in the preparation of folic acid-chitosan-methotrexate nanoparticles (FA-Chi-MTX NPs). These NPs were designed and prepared for targeted drug delivery in tumor. The NPs of each batch were prepared by coaxial electrospray atomization method and evaluated for particle size (PS) and particle size distribution (PSD). The independent variables were selected to be concentration of FA-chitosan, ratio of shell solution flow rate to core solution flow rate, and applied voltage. The process design of experiments (DOE) was obtained with three factors in three levels by Design expert software. Box-Behnken design was used to select 15 batches of experiments randomly. The chemical structure of FA-chitosan was examined by FTIR. The NPs of each batch were collected separately, and morphologies of NPs were investigated by field emission scanning electron microscope (FE-SEM). The captured pictures of all batches were analyzed by ImageJ software. Mean PS and PSD were calculated for each batch. Polynomial equation was produced for each response. The FE-SEM results showed the mean diameter of the core-shell NPs was around 304 nm, and nearly 30% of the produced NPs are in the desirable range. Optimum formulations were selected. The validation of DOE optimization results showed errors around 2.5 and 2.3% for PS and PSD, respectively. Moreover, the feasibility of using prepared NPs to target tumor extracellular pH was shown, as drug release was greater in the pH of endosome (acidic medium). Finally, our results proved that FA-Chi-MTX NPs were active against the human epithelial cervical cancer (HeLa) cells.