Cytoglobin: a potential marker for adipogenic differentiation in preadipocytes in vitro

Obesity, mainly characterized by the excess fat storage, is a global health problem resulting in serious morbidity and mortality. Identification of molecular mechanisms in adipogenic differentiation pathway might lead to development of new strategies for diagnosis, prevention and therapy of obesity and associated diseases. Discovery of new genes and proteins in the differentiation pathway could help to understand the key specific regulators of the adipogenesis. Cytoglobin (Cygb), identified as a new globin family member protein, is expressed in various tissues. Although its interaction with oxygen and nitric oxide indicates the potential role in antioxidant pathways, the exact role remains unclear. In the current study, expression level of Cygb was determined in proliferating and differentiating 3T3-F442A cells by gene expression and protein expression analysis. Results revealed that Cygb expression up-regulated in differentiated cells in parallel with adipogenic differentiation markers; PPARγ, CEBPα and FABP4 expressions. Besides, Cygb overexpression in preadipocytes contributed to the adipogenic differentiation as verified by detection of higher lipid droplets and increased PPARγ, CEBPα and FABP4 expressions with respect to control cells. These findings will shed light on the unknown roles of Cygb in adipogenesis and obesity.     

CaCO3 and MgCO3 Dissolving Halophilic Bacteria

In the current study, fifteen halophilic and halotolerant bacteria were isolated from salt-affected soil of ?anl?urfa, Turkey. The isolates were characterized by conventional and molecular techniques (16S rDNA sequence analyses) as belonging to seven different genus including Bacillus (5 isolates), Halobacillus (1 isolate), Oceanobacillus (2 isolates), Halomonas (3 isolate), Nesterenkonia (1 isolate), Chromohalobacter (2 isolates) and Jeotgalibacillus (2 isolates). According to the results obtained, the investigated bacterial strains have high salt tolerance and significant enzyme activities which can improve soil nutrient cycling and fertility. Furthermore, these bacterial strains have been investigated for their ability to dissolve common salts available in salt-affected soils. Salt dissolving experiments showed that two Chromohalobacter isolates were able to dissolve CaCO₃ and one of the Halomonas isolate was able to dissolve both CaCO₃ and MgCO₃. As these bacterial isolates can dissolve CaCO₃ and MgCO₃, the availability of Ca²⁺ and Mg²⁺ ions may increase which can enhance the removal of the excess Na⁺ in soil profile.     

Single-stage photofermentative biohydrogen production from sugar beet molasses by different purple non-sulfur bacteria

Bioprocess and Biosystems Engineering - Biohydrogen production via fermentative routes offers considerable advantages in waste recycling and sustainable energy production. This can be realized by...     

Multiple-site trimethylation of ribosomal protein L11 by the PrmA methyltransferase

Ribosomal protein L11 is a universally conserved component of the large subunit, and plays a significant role during initiation, elongation, and termination of protein synthesis. In Escherichia coli, the lysine methyltransferase PrmA trimethylates the N-terminal alpha-amino group and the epsilon-amino groups of Lys3 and Lys39. Here, we report four PrmA-L11 complex structures in different orientations with respect to the PrmA active site. Two structures capture the L11 N-terminal alpha-amino group in the active site in a trimethylated post-catalytic state and in a dimethylated state with bound S-adenosyl-L-homocysteine. Two other structures show L11 in a catalytic orientation to modify Lys39 and in a noncatalytic orientation. The comparison of complex structures in different orientations with a minimal substrate recognition complex shows that the binding mode remains conserved in all L11 orientations, and that substrate orientation is brought about by the unusual interdomain flexibility of PrmA.     

Pregnenolone protects the PC-12 cell line against amyloid beta peptide toxicity but its sulfate ester does not

Pregnenolone (P), the main precursor of the steroids, and its sulfate ester, pregnenolone sulfate (PS), are the major neurosteroids produced in the neural tissue. Many neuroendocrinological studies stressed the neuroprotective role of neurosteroids although it has been suggested that the inhibition of P and PS synthesis can delay neuronal cell death. The potential roles of P and PS in vital neuronal functions and in amyloid beta peptide (Aβ) toxicity are not clearly identified. This work aims to investigate the effects of P and PS on cell viability and Aβ peptide toxicity in a concentration and exposure time-dependent manner in rat PC-12 cells. The cells were treated with 20 μM Aβ peptide 25-35 and variable concentrations of P and PS ranging from 0.5 μM to 100 μM. To examine the effects of steroid treatment on Aβ peptide toxicity, 0.5 μM (low) and 50 μM (high) neurosteroids were used. The cell viability and lactate dehydrogenase release of cells were evaluated after 24, 48 and 72 h. Morphological changes of cells were also examined. The treatment with higher than 1 μM concentrations of P and PS significantly decreased the cell viability comparing to untreated cells. At lower concentrations, P and PS had no toxic actions until 72 h. The Aβ treatment resulted in a significant decrease in cell viability comparing to untreated cells. P showed a dose-dependent protective effect against Aβ peptide in PC-12 cells. But its sulfate ester did not have the same effect on Aβ peptide toxicity, even it significantly decreased cell viability in Aβ-treated cells. Consequently, the discrepant effects of P and PS on Aβ peptide toxicity may provide insight on the pathogenesis of Alzheimer’s disease.     

The molecular basis of human keratin disorders

Keratins are cytoskeletal proteins that provide structural support to epithelial cells and tissues. Perturbation causes cell and tissue fragility and accounts for a large number of genetic disorders in humans. In humans, 54 functional keratin genes exist and 21 different keratin genes including hair keratins and hair follicle-specific epithelial keratins have been associated with hereditary disorders. Moreover, keratins have been implicated in more complex traits such as liver disease and inflammatory bowel disease. Understanding the molecular basis of keratin disorders has been the basis for improved diagnosis with prognostic implications, genetic counseling and prenatal testing for severe disorders. Besides their mechanical role, keratins have newly identified functions in apoptosis, cell growth, tissue polarity, wound healing and tissue remodeling. Improved understanding of the regulatory functions of keratins may offer novel approaches to overcome current treatment limitations.     

Both endothelium and afferent nerve endings play a role in acetylcholine-induced renal vasodilation

We investigated the nature and signaling pathways of endothelium- and sensory-nerve ending-derived substances involved in acetylcholine-induced vasodilation in rat isolated perfused kidney. Endothelial denudation by Triton X-100 (0.2%, 0.1 ml) or depletion of afferent nerve endings by capsaicin (10(-6) mol/l) attenuated acetylcholine-induced vasodilation. When these two agents were administered together, the response to acetylcholine was completely inhibited. CGRP1 receptor blocker CGRP 8-37 (10(-7) mol/l) and adenosine A(2) receptor antagonist ZM 241 385 (10(-7) mol/l) inhibited acetylcholine-induced dilation. When indomethacin (10(-5) mol/l), a cyclooxygenase inhibitor, l-NOARG (10(-4) mol/l), a nitric oxide (NO) synthase inhibitor, and potassium chloride (30 mmol/l), to test EDHF response, were perfused simultaneously, the inhibition was greater than that was observed with each agent alone. Guanylate cyclase inhibitor ODQ (10(-5) mol/l) or protein kinase A inhibitor KT 5720 (5x10(-7) mol/l) inhibited acetylcholine-induced dilation. Gap junction uncoupler 18alpha-glycyrrhetinic acid (10(-4) mol/l) caused an uncontrollable increase in basal perfusion pressure making it impossible to test against acetylcholine-induced dilation. Our data suggest that NO, prostanoids, EDHF, and CGRP released from vascular endothelium and afferent nerve endings participate in acetylcholine-induced vasodilation and their signal transduction molecules include protein kinase A and guanylate cyclase.     

Inhibition of angiogenesis by S-adenosylmethionine

Metastasis is a leading cause of mortality and morbidity in cancer. One of the steps in metastasis process is the formation of new blood vessels. Aberrant DNA methylation patterns are common in cancer cells. In recent studies, S-adenosylmethionine (SAM), which is a DNA methylating agent, has been found to have inhibitory effects on some carcinoma cells in vivo and in vitro. In the present study, we have used SAM to investigate whether it is effective against angiogenesis in vitro. Our results have shown that SAM can reduce the formation and organization of capillary-like structures of endothelial cells in tumoral environment. Besides, we have found SAM can block endothelial cell proliferation and the migration of cells towards growth factors-rich media. In conclusion, our study suggests that SAM may be used against angiogenesis as a natural bio-product.     

PON1 55 and 192 Gene Polymorphisms in Type 2 Diabetes Mellitus Patients in a Turkish Population

Diabetes mellitus is a multifactorial metabolic disease, caused by the complete or relative absence of insulin hormone, which results in the deterioration of carbohydrate, protein, and lipid metabolism. The PON1 55 and 192 polymorphisms have been reported to be associated with type 2 diabetes and its complications. In this study, the involvement of the PON1 55 and 192 polymorphisms and paraoxonase enzyme activity in diabetic complications was assessed. The MM and QQ genotypes were the most frequent in complications of type 2 diabetes in both of the polymorphisms. PON enzyme activity was lower in the type 2 diabetes group with respect to the control group. Regarding both genotypes and enzyme activity, correlations were found between the PON1 55 and 192 genotypes and diabetic complications. This study thus helps to outline a genotype?Cphenotype relation for the PON1 gene in a Turkish population.     

Determination of stress responses induced by aluminum in maize (Zea mays)

To assess the alternative responses to aluminum toxicity, maize (Zea mays L. cv Karadeniz y?ld?z?) roots were exposed to different concentrations of AlCl3 (150, 300 and 450 μM). Aluminum reduced the root elongation by 39.6% in 150 μM, 44.1% in 300 μM, 50.1% in 450 μM AlCl3 after 96 h period. To correlate the root elongation with the alternative stress responses including aluminum accumulation, lipid peroxidation, mitotic abnormalities, reduction of starch content, intracellular Ca2+ accumulation, callose formation, lignin deposition and peroxidase activity, cytochemical and biochemical tests were performed. The results indicated that aluminum accumulation and lipid peroxidation were observed more densely on the root cap and the outer cortex cells. In addition to morphological deformations, cytochemical analysis displayed cellular deformations. Furthermore, mitotic abnormalities were observed such as c-mitosis, micronuclei, bi- and trinucleated cells in aluminum treated root tips. Aluminum treatment induced starch reduction, callose formation, lignin accumulation and intracellular Ca2+ increase. Moreover, the peroxidase activity increased significantly by 3, 4.4 and 7.7 times higher than in that of control after 96 h, respectively. In conclusion, aluminum is significantly stressful in maize culminating in morphological and cellular alterations.