Effect of pH on the pore forming activity and conformational stability of ostreolysin, a lipid raft-binding protein from the edible mushroom Pleurotus ostreatus

Ostreolysin, a pore-forming protein from the edible oyster mushroom (Pleurotus ostreatus), is a member of the aegerolysin protein family, a novel group of small acidic proteins found in bacteria, molds, mushrooms, and plants. It binds to lipid rafts and interacts specifically with cholesterol-rich lipid domains. In this study, ostreolysin was classified as a single-domain all-beta-structured protein on the basis of cDNA sequencing. pH-induced and thermally induced unfolding of ostreolysin was studied by means of CD, UV absorption, and intrinsic tryptophan fluorescence to characterize conformational transitions associated with its functional properties, i.e., binding to lipid membranes, pore forming activity on lipid vesicles, and hemolysis. At 25 degrees C and between pH 6 and 9, ostreolysin adopted a monomeric and thermodynamically stable nativelike conformation, characterized by rigid tertiary structure and predominantly beta-sheet secondary structure. Between pH 2 and 3, the protein underwent an irreversible transition to a partially unfolded, molten globule-like state which bound ANS, and exhibited disrupted tertiary structure and enhanced non-native alpha-helical structure. Functional studies showed that, unlike colicins and some other bacterial pore-forming toxins, the acid-induced molten globule-like state of ostreolysin is not relevant for lipid binding and pore formation. Instead, the compact native state was necessary for binding to cholesterol/sphingomyelin multilamellar vesicles, optimally in the pH range from 6 to 7, and for pore formation and hemolysis, maximally between pH 7 and 8.     

Proteasome inhibition alters neural mitochondrial homeostasis and mitochondria turnover

Inhibition of proteasome activity occurs in normal aging and in a wide variety of neurodegenerative conditions including Alzheimer's disease and Parkinson's disease. Although each of these conditions is also associated with mitochondrial dysfunction potentially mediated by proteasome inhibition, the relationship between proteasome inhibition and the loss of mitochondrial homeostasis in each of these conditions has not been fully elucidated. In this study, we conducted experimentation in order to begin to develop a more complete understanding of the effects proteasome inhibition has on neural mitochondrial homeostasis. Mitochondria within neural SH-SY5Y cells exposed to low level proteasome inhibition possessed similar morphological features and similar rates of electron transport chain activity under basal conditions as compared with untreated neural cultures of equal passage number. Despite such similarities, maximal complex I and complex II activities were dramatically reduced in neural cells subject to proteasome inhibition. Proteasome inhibition also increased mitochondrial reactive oxygen species production, reduced intramitochondrial protein translation, and increased cellular dependence on glycolysis. Finally, whereas proteasome inhibition generated cells that consistently possessed mitochondria located in close proximity to lysosomes with mitochondria present in the cellular debris located within autophagosomes, increased levels of lipofuscin suggest that impairments in mitochondrial turnover may occur following proteasome inhibition. Taken together, these data demonstrate that proteasome inhibition dramatically alters specific aspects of neural mitochondrial homeostasis and alters lysosomal-mediated degradation of mitochondria with both of these alterations potentially contributing to aging and age-related disease in the nervous system.     

The mechanisms of morphological-motor functioning in elementary school female first- to fourth-graders

Four morphological and 7 motor variables were assessed in a sample of 2,235 female children (subdivided into 4 groups) aged 7-11 years, elementary school first- to fourth-graders from the Primorje-Gorski Kotar County, Republic of Croatia. The study objective was to analyze the morphological-motor structures according to age. Factor analysis was done for each of the four subject groups. Results clearly showed the morphological-motor functioning of the girls to change with age. Developmental processes lead to the formation of a general morphological factor defined as ectomesomorph and two general mechanisms responsible for motor efficiency in the form of strength regulation and speed regulation. The results obtained were found to be consistent with the existing relevant models related to the morphological, motor, functional and cognitive systems. The more so, these results allow for a supramodel to design, which will integrate relevant elements of all these models to define the function of the body as a whole.     

The -429 T/C and -374 T/A gene polymorphisms of the receptor of advanced glycation end products gene (RAGE) are not risk factors for coronary artery disease in Slovene population with type 2 diabetes

Receptor for advanced glycation end products (RAGE) plays a role in atherosclerosis in diabetics. There are two functional polymorphisms in the promoter of the RAGE gene (-429T/C and -374T/A). The aim of this study was to look for a relationship between the -429T/C and the -374T/A gene polymorphisms of the RAGE gene and the development of coronary artery disease (CAD) in the Slovene population with type 2 diabetes of duration longer than 10 years. One hundred and sixty-eight subjects with diabetes and CAD were compared to 241 diabetic subjects without CAD. The -429T/C and the -374T/A RAGE genotype distributions in patients with CAD (-429T/C: CC: 3%, TC: 31%, TT: 66.0%; -374T/A:AA: 7.7%, TA: 48.2%, TT: 44.1%) were not significantly different from those in patients without CAD (-429 T/C: CC: 1.7%, TC: 26.1%, TT: 72.2%; -374T/A: AA: 11.2%, TA: 43.2%, TT: 45.6%). Our study failed to demonstrate an association between either the -429T/C or the -374T/A gene polymorphism of the RAGE gene and CAD in the Slovene population with type 2 diabetes of duration longer than 10 years.     

Bacterial Vaginosis Is Associated with Loss of Gamma Delta T Cells in the Female Reproductive Tract in Women in the Miami Women Interagency HIV Study (WIHS): A Cross Sectional Study

Bacterial vaginosis (BV) is the most common female reproductive tract infection and is associated with an increased risk of acquiring and transmitting HIV by a mechanism that is not well understood. Gamma delta (GD) T cells are essential components of the adaptive and innate immune system, are present in the female reproductive tract, and play an important role in epithelial barrier protection. GD1 cells predominate in the mucosal tissue and are important in maintaining mucosal integrity. GD2 cells predominate in peripheral blood and play a role in humoral immunity and in the immune response to pathogens. HIV infection is associated with changes in GD T cells frequencies in the periphery and in the female reproductive tract. The objective of this study is to evaluate if changes in vaginal flora occurring with BV are associated with changes in endocervical GD T cell responses, which could account for increased susceptibility to HIV. Seventeen HIV-infected (HIV+) and 17 HIV-uninfected (HIV-) pre-menopausal women underwent collection of vaginal swabs and endocervical cytobrushes. Vaginal flora was assessed using the Nugent score. GD T cells were assessed in cytobrush samples by flow cytometry. Median Nugent score was 5.0 and 41% of women had abnormal vaginal flora. In HIV uninfected women there was a negative correlation between Nugent score and cervical GD1 T cells (b for interaction = - 0.176, p<0.01); cervical GD1 T cells were higher in women with normal vaginal flora than in those with abnormal flora (45.00% vs 9.95%, p = 0.005); and cervical GD2 T cells were higher in women with abnormal flora than in those with normal flora (1.70% vs 0.35%, p = 0.023). GD T cells in the genital tract are protective (GD1) and are targets for HIV entry (GD2). The decrease in cervical GD1 and increase in GD2 T cells among women with abnormal vaginal flora predisposes women with BV to HIV acquisition. We propose to use GD T cell as markers of female genital tract vulnerability to HIV.     

LAT Software Induced Savings on Medical Costs of Alcohol Addicts' Care - Results from a Matched-Pairs Case-Control Study

Lesch Alcoholism Typology (LAT) is one of the most widely used clinical typologies of alcohol addiction. Study tested whether introduction of LAT software in clinical practice leaded to improved outcomes and reduced costs. Retrospective matched-pairs case-control cost comparison study was conducted at the Regional Addiction Center of the University Clinic in Serbia involving 250 patients during the four-year period. Mean relapse frequency followed by outpatient detoxification was 0.42±0.90 vs. 0.70±1.66 (LAT/non-LAT; p = 0.267). Adding relapses after inpatient treatment total mean-number of relapses per patient was 0.70±1.74 vs. 0.97±1.89 (LAT/non-LAT; p = 0.201). However, these relapse frequency differentials were not statistically significant. Total hospital costs of Psychiatry clinic based non-LAT addicts'' care (€54,660) were significantly reduced to €36,569 after initiation of LAT. Mean total cost per patient was reduced almost by half after initiation of LAT based treatment: €331±381 vs. €626±795 (LAT/non-LAT; p = 0.001). Mean cost of single psychiatry clinic admission among non-LAT treatment group was €320±330 (CI 95% 262–378) and among LAT €197±165 (CI 95% 168–226) (p = 0.019). Mean LAT software induced net savings on psychiatric care costs were €144 per patient. Total net savings on hospital care including F10 associated somatic co-morbidities amounted to €295 per patient. More sensitive diagnostic assessment and sub-type specific pharmacotherapy and psychotherapy following implementation of LAT software lead to significant savings on costs of hospital care.