Dietary restriction of amino acids other than methionine prevents oxidative damage during aging: involvement of telomerase activity and telomere length

AimsIt has been suggested that variations in the proportions of some dietary amino acids can slow down aging. In this study, the influence of amino acids other than methionine on aging was investigated.Main methodsRats were fed either with normal (ND) or except methionine, protein restricted diet (PREMD) for 4 months and oxygen radical production, oxidative protein and DNA damage along with telomere length and telomerase activity were evaluated in the liver.Key findingsExcept mitochondrial superoxide production rate, feeding with PREMD significantly decreased the oxygen radical production rate and protein carbonyl levels in the homogenate and mitochondria of 16-month-old rats. Feeding with PREMD prevented 8-OHdG formation in mitochondrial DNA but not in the genomic DNA. Although liver telomerase activities of rats receiving either ND or PREMD seemed to have some variations, these did not reach a statistical significance. Feeding with PREMD conserved the telomere length in the liver. The telomere length of 8- and 16-month-old rats fed PREMD was similar, 16-month-old rats fed ND had telomeres shortened by 36% (p < 0.05).SignificanceLong-term restriction of the amino acids other than methionine may decrease oxygen radical generation and oxidative damage of cellular constituents, and may also prevent telomere shortening in rat liver.     

Effect of Strontium Ranelate on Hydrogen Peroxide-Induced Apoptosis of CRL-11372 Cells

In vitro and in vivo studies have proven strontium to be an osteoinductive trace element. The effect of strontium ranelate (SR) on H₂O₂-induced apoptosis of CRL-11372 cells and optimization of its anti-apoptotic dose were the aims of this study. After 1 h of pretreatment with SR 1 μM, 50 μM, 100 μM, 500 μM, and 1,000 μM concentrations, CRL-11372 osteoblasts were exposed to 100 μM H₂O₂ for periods of 6–12 h. The same experiments were repeated without H₂O₂. The apoptotic index and viability of cells were assessed quantitatively with a fluorescent dye and qualitatively with agarose gel electrophoresis. Concentrations of 1–100 μM of SR with a 6-h treatment and only 1 μM concentration with a 12-h treatment inhibited the apoptotic effect of H₂O₂ on cultured osteoblasts significantly (P < 0.05). SR was shown to inhibit H₂O₂-induced apoptosis of CRL-11372 cells in a dose-dependent manner.     

Melanocortin-4 Receptor Gene Polymorphisms in Obese Patients

Obesity is a complex disease caused by both genetics and environmental factors. Melanocortin-4 receptor (MC4R) (MIM 155541) gene polymorphisms were reported to be the cause of monogenic obesity in humans. We studied three polymorphisms (Val50Met, Val103Ile, and Ser58Cys) and a mutation (Asn274Ser) of the MC4R gene in 203 obese patients and in 110 healthy subjects in the Turkish population. A high incidence of Val103Ile and Val50Met polymorphisms as well as the Asn274Ser mutation was found in the obese patients, whereas no significant correlation was found regarding the Ser58Cys polymorphism. We conclude that there is a concordance between the polymorphisms (Val103Ile, Val50Met, Ser58Cys) that were first studied in the Turkish population with obesity.     

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.     

Apoptotic effect of gossypol on human lymphocytes

The overall objective of this study was to determine the effect of gossypol on human lymphocytes. Blood samples were taken from healthy donors and lymphocytes were cultured with various concentrations of gossypol (25-150 microM). The percentage of apoptotic cells was determined by assessing DNA fragmentation by agarose gel electrophoresis; morphological features of apoptosis were assessed by light microscopy. The concentrations of gossypol required to induce apoptosis in human lymphocytes without causing necrosis through cytotoxic effects were between 25-50 microM.     

Bioengineering functional copolymers. XIV. Synthesis and interaction of poly(N-isopropylacrylamide-co-3,4-dihydro-2H-pyran-alt-maleic anhydride)s with SCLC cancer cells

Novel antitumor active functional polymers with supramacromolecular structures were synthesized by a complex-radical terpolymerization of N-isopropylacrylamide (NIPAm), 3,4-dihydro-2H-pyran (DHP), and maleic anhydride (MA) with 2,2'-azoisobisbutyronitrile as a radical initiator in 1,4-dioxane at 65°C under nitrogen atmosphere. The structure and composition of terpolymers were investigated by (1)H ((13)C) NMR spectroscopy. Interaction of terpolymers with human lung small cell carcinoma (SCLC) were investigated by using different methods such as cytotoxicity, statistical, apoptotic and necrotic cell indexes, double staining and caspase-3 immunostaining, light and fluorescence inverted microscopy analyses. Investigations into structure, composition, and antitumor activity relationships revealed that terpolymers containing a combination of ionisable amide-pyran linkages and H-bonded carboxylic groups exhibited higher cytotoxicity. It was observed that terpolymer with nearly alternating structure provides a maximum concentration of ionisable and H-bonded antitumor sites, and therefore, exhibits higher in vitro cytotoxicity, apoptotic and necrotic effects towards SCLC cancer cells.     

Restless legs syndrome and pregnancy in Kayseri,Turkey: A hospital based survey

Sleep and Biological Rhythms - The prevalence of restless legs syndrome (RLS) is low in the general population in Turkey. To assess the prevalence of RLS in pregnancy, a hospital-based survey...     

Biological parameters of the predatory mite Cheletomimus bakeri (Acari: Cheyletidae) feeding on Tetranychus cinnabarinus (Acari: Tetranychidae)

Developmental periods of egg, larva and nymphal stages and fecundity as well as predation of Cheletomimus bakeri (Acari: Cheyletidae) feeding on Tetranychus cinnabarinus (Acari: Tetranychidae) were evaluated at different temperatures (15, 20, 25, 30 and 35°C) at 65 ± 10% relative humidity and 16 L: 8D in the laboratory. The development periods of C. bakeri from egg through adult decreased significantly when the temperature was increased from 20°C to 35°C. Egg and total development periods of C. bakeri at 20, 25, 30 and 35°C were 13.86, 7.98, 5.07, 4.08 days and 58.66, 41.51, 21.21, 22.92 days, respectively. The highest numbers of total and daily egg production were found at 20°C and 30°C, respectively. Net reproductive rate (R₀ = 13.29), mean generation time (T = 88.30), gross reproductive rate (GRR = 17.46) and doubling time (DT = 23.66) were the highest at 20°C. The intrinsic rate of increase (r_m = 0.0592) and finite capacity for increase (λ = 1.061) for C. bakeri were the highest at 30°C. Predation of C. bakeri increased throughout the range of prey densities. The highest consumption number of C. bakeri feeding on T. cinnabarinus males per day was 4.63, 4.70 and 4.60 when confined to 40, 80 and 160 individuals, respectively. Our data suggest that C. bakeri does not appear to have much promise for the control of spider mites because of the characteristics of the predator such as slow development period, poor searching capacity and low intrinsic rate of increase.     

Altered biological activity associated with C-terminal modifications of IL-7

Interleukin 7 (IL-7) is a pleiotropic cytokine which plays a role in both T and B cell function as well as in establishment and maintenance of immunological barriers in epithelial tissues. The heterodimeric IL-7 receptor (IL-7R) consists of the p76 IL-7Ralpha subunit and the p64 common gamma (gammac) subunit. Ligand-binding induces signal transduction through tyrosine phosphorylation of the janus (Jak) and src-related kinases as well as by activation of phosphatidinositol-3 kinase (P13-kinase). In an effort to further define the requirements for ligand-receptor interactions and to subsequently develop candidate receptor binding antagonists with selective biological activities, we examined a series of IL-7 mutants in which the carboxy terminal hydrophobic residues were substituted with aliphatic amino acids. In this study we describe abrogation of IL-7 driven proliferation and attenuated phosphotyrosine signaling by IL-7(143) (Trp-Ala) and IL-7(143) (Trp-His) in IL-7R expressing T and B leukemia cells. Decreased phosphorylation of Jak3 kinase by IL-7W143A, IL-7W143P and IL-7W143H suggest that alterations in this region of the carboxyterminal region of IL-7 affects its interaction with the gammac subunit of the IL-7R.