Protein kinase C deficiency increases fatty acid oxidation and reduces fat storage

Metabolic syndrome is common in the general population, but there is little information available on the underlying signaling mechanisms regulating triglyceride (TG) content in the body. In the current study, we have uncovered a role for protein kinase Cbeta (PKCbeta) in TG homeostasis by studying the consequences of a targeted disruption of this kinase. PKCbeta(-/-) mutant mice were considerably leaner and the size of white fat depots was markedly decreased compared with wild-type littermates. TG content in the liver and skeletal muscle of PKCbeta(-/-) mice was also significantly low. Interestingly, mutant animals were hyperphagic and exhibited higher food intake and reduced feed efficiency versus wild type. The protection from obesity involves elevated oxygen consumption/energy expenditure and increased fatty acid oxidation in adipose tissue with concurrent increased mitochondria genesis, up-regulation of PGC-1alpha and UCP-2, and down-regulation of perilipin. The ability of PKCbeta deficiency to promote fat burning in adipocytes may suggest novel therapeutic strategies for obesity and obesity-related disorders.     

Oil pipeline corridor through an intact forest alters ground beetle (Coleoptera: Carabidae) assemblages in southeastern Ohio

Litter-dwelling ground beetle (Coleoptera: Carabidae) assemblages were monitored 1 yr after the construction of a corridor for installation of an oil pipeline along a xeric ridge-top forest in southeastern Ohio. After the creation of the corridor, three distinct habitats were evident in these sites: open corridor, ecotone areas around the corridor, and undisturbed forest interior. Carabidae were collected using directional pitfall traps that were placed parallel and perpendicular to the corridor in each of the three habitats. Results indicate that more carabids were present in the ecotone than in the other two habitats. Carabid diversity as estimated by rarefaction was highest in the corridor followed by ecotone and forest interior. Generalist and forest specialists such as Synuchus impunctatus (Say), Carabus goryi Dejean, and Pterostichus trinarius (Casey) were present in greater numbers in the forest interior and ecotone assemblages. In contrast, open-habitat specialists such as Harpalus pensylvanicus (DeGeer) and Selenophorus opalinus (LeConte) were present in greater numbers in the corridor assemblages. Carabid assemblages of the corridor were distinct from those of the ecotone and forest interior, whereas the latter two habitats had very similar assemblages. The successional pathway of the corridor carabid assemblage will therefore be likely different from that of the forest interior and ecotone. Overall, results indicate that construction of the oil pipeline corridor had significant short-term effects on the carabid numbers, diversity, and species composition because of ensuing habitat changes and fragmentation of the forest.     

Thrombomodulin exerts cytoprotective effect on low-dose UVB-irradiated HaCaT cells

Thrombomodulin (TM) is an endothelial cell surface anticoagulant glycoprotein that performs antimetastatic, angiogenic, adhesive, and anti-inflammatory functions in various tissues. It is also expressed in epidermal keratinocytes. We found that a physiological dose (10 mJ/cm²) of mid-wavelength ultraviolet irradiation (UVB) significantly induced TM expression via the p38mitogen-activated protein kinase (MAPK)/cyclic AMP response element (CRE) signaling pathway in the epidermal keratinocyte cell line HaCaT; this shows that TM regulates the survival of HaCaT cells. SB203580, a p38MAPK inhibitor, significantly decreased TM expression and the viability of cells exposed to UVB. Furthermore, overexpression of TM markedly increased cell viability, and it was abrogated by TM small interfering RNA (siRNA), suggesting that TM may play an important role in exerting cytoprotective effect on epidermal keratinocytes against low-dose UVB.     

Oxidative stress in primary glomerular diseases: a comparative study

Objective To evaluate the status of oxidative stress in patients with different primary glomerular diseases (PGD) which have differential predisposition to renal failure. Methods Seventy-three patients with PGD and 50 controls were enrolled in the study. They were sub-grouped into non-proliferative glomerulonephritis (NPGN) and proliferative glomerulonephritis (PGN). Levels of serum malondialdehyde (MDA), reactive nitrogen intermediates (RNI), plasma total homocysteine (tHcy), urine 8-isoprostane (8-IP), RBC thiols, glutathione-S-transferase (GST) and serum superoxide dismutase (SOD) were measured spectrophotometrically. Results PGD patients showed a significant increase in MDA, RNI, tHcy, 8-IP levels (P < 0.05) and decreased SOD, total thiols and protein bound thiol levels as compared to controls (P < 0.05). Significantly higher levels of tHcy, MDA and 8-IP (P < 0.05) and lower SOD enzyme activity (P < 0.05) were observed in PGN group as compared to NPGN and control groups. These changes remained significant even after adjustment was made for creatinine. Conclusions Oxidative stress in PGN is significantly higher than NPGN, indicating higher oxidative stress in these patients, independent of degree of renal dysfunction.     

Kinetics of Human Serum Butyrylcholinesterase Inhibition by a Novel Experimental Alzheimer Therapeutic,Dihydrobenzodioxepine Cymserine

Cholinergic loss is the single most replicated neurotransmitter deficiency in Alzheimer’s disease (AD) and has led to the use of acetylcholinesterase inhibitors (AChE-Is) and unselective cholinesterase inhibitors (ChE-Is) as the mainstay of treatment. AChE-Is and ChE-Is, however, induce dose-limiting adverse effects. Recent studies indicate that selective butyrylcholinesterase inhibitors (BuChE-Is) elevate acetylcholine (ACh) in brain, augment long-term potentiation, and improve cognitive performance in rodents without the classic adverse actions of AChE-Is and ChE-Is. BuChE-Is thereby represent a new strategy to ameliorate AD, particularly since AChE activity is depleted in AD brain, in line with ACh levels, whereas BuChE activity is elevated. Our studies have focused on the design and development of cymserine analogues to induce selective time-dependent brain BuChE inhibition, and on the application of innovative and quantitative enzyme kinetic analyses to aid selection of drug candidates. The quantitative interaction of the novel inhibitor, dihydrobenzodioxepine cymserine (DHBDC), with human BuChE was characterized. DHBDC demonstrated potent concentration-dependent binding with BuChE. The IC₅₀ and specific new kinetic constants, such as K_T50, P_PC, K_T1/2 and R_I, were determined at dual substrate concentrations of 0.10 and 0.60 mM butyrylthiocholine and reaction times, and are likely attainable in humans. Other classical kinetic parameters such as K_ia, K_ma, V_ma and V_mi were also determined. In synopsis, DHBDC proved to be a highly potent competitive inhibitor of human BuChE in comparison to its structural analogue, cymserine, and represents an interesting drug candidate for AD. Dedicated to Professor Moussa Youdim, Dept. Pharmacology, Technion, Haifa, Israel, in celebrating 45 years in scientific research focused on drug discovery and 30 years at Technion.     

Compositional and enzymatic changes in guava (Psidium guajava L.) fruits during ripening

Changes in chemical composition and hydrolytic enzyme activities in guava fruits cv. Lucknow-49 have been reported at four different stages of maturity, viz., mature green (MG), color turning (CT), ripe (R) and over ripe (OR). Chlorophyll content decreased, while carotenoid content increased with advancement of ripening. Starch content decreased with concomitant increase in alcohol soluble sugars. The cell wall constituents viz., cellulose, hemicellulose, and lignin decreased up to R stage, while the pectin content decreased throughout up to OR stage. Among the cell wall hydrolyzing enzymes, polygalacturonase (PG) and cellulase exhibited progressive increase in activity throughout ripening, while pectin methyl esterase (PME) activity increased up to CT stage and then decreased up to OR stage. The maximum increase in the activities of cell wall hydrolysing enzymes was observed between MG and CT stages. The activities of starch hydrolyzing enzymes, α-amylase and β-amylase decreased significantly with advancement of ripening. These changes in the activities of hydrolyzing enzymes could be considered good indicators of ripening in guava.     

Occurrence of cestodes and comparative efficacy of Typha angustata and sulphadimidine against cestodes in Columba livia domestica (Domestic Pigeon)

The occurrence of intestinal parasites of Columba livia domestica has been on the increase, leading to high economic and production losses with more fatal cases. This study was designed to investigate the prevalence of cestodes in pigeons and determine the efficacy of Typha angustata extract and sulphadimidine against these cestodes in the domestic pigeon. A total of 30 pigeons were examined. 18 (60%) pigeons were found infected with only one type of cestode species (Raillietina spp.). The difference in prevalence between males and females was statistically significant (χ² = 8.167, p = 0.004). The mean EPG count in group A (treated with T. angustata extract) before treatment and after treatment was 176 ± 4.33 and 155 ± 4.24, respectively. In group B (treated with sulphadimidine), the mean EPG calculated before treatment and after treatment was 184 ± 6.74 and 35 ± 3.53, respectively. The efficacy at day 28 of T. angustata and Sulphadimidine was 11.93% and 80.97%, respectively. It was concluded on the basis of the EPG and efficacy data that T. angustata extract had low efficacy against raillietiniasis, while as sulphadimidine, which is also used before to treat different intestinal parasites, had a good efficacy against raillietiniasis. Further studies are required to know the prevalence of other gastrointestinal parasites in pigeons and efficacy of different medicinal plants against such parasites.     

Genome-wide analysis of histone modifications by ChIP-on-chip

Post-translational modifications to histone proteins regulate the packaging of genomic DNA into chromatin, gene activity and other functions of the genome. They are understood to play key roles in embryonic development and disease pathogenesis. Recent advances in technology have made it possible to analyze chromatin structure genome-wide in mammalian cells. Global patterns of histone modifications can be observed using a technique called ChIP-on-chip, which combines the specificity of chromatin immunoprecipitation with the unbiased, high-throughput capabilities of microarrays. The resulting maps provide insight into the functions of, and relationships between, different modifications. Here, we provide validated ChIP-on-chip methods for analyzing histone modification patterns at genome-scale in mammalian cells.     

Enhanced intestinal tumor multiplicity and grade in vivo after HZE exposure: mouse models for space radiation risk estimates

Carcinogenesis induced by space radiation is considered a major risk factor in manned interplanetary and other extended missions. The models presently used to estimate the risk for cancer induction following deep space radiation exposure are based on data from A-bomb survivor cohorts and do not account for important biological differences existing between high-linear energy transfer (LET) and low-LET-induced DNA damage. High-energy and charge (HZE) radiation, the main component of galactic cosmic rays (GCR), causes highly complex DNA damage compared to low-LET radiation, which may lead to increased frequency of chromosomal rearrangements, and contribute to carcinogenic risk in astronauts. Gastrointestinal (GI) tumors are frequent in the United States, and colorectal cancer (CRC) is the third most common cancer accounting for 10% of all cancer deaths. On the basis of the aforementioned epidemiological observations and the frequency of spontaneous precancerous GI lesions in the general population, even a modest increase in incidence by space radiation exposure could have a significant effect on health risk estimates for future manned space flights. Ground-based research is necessary to reduce the uncertainties associated with projected cancer risk estimates and to gain insights into molecular mechanisms involved in space-induced carcinogenesis. We investigated in vivo differential effects of γ-rays and HZE ions on intestinal tumorigenesis using two different murine models, ApcMin/+ and Apc1638N/+. We showed that γ- and/or HZE exposure significantly enhances development and progression of intestinal tumors in a mutant-line-specific manner, and identified suitable models for in vivo studies of space radiation–induced intestinal tumorigenesis.