Nicotinamide adenine dinucleotide (NAD+) and its metabolites function as critical regulators to maintain physiologic processes, enabling the plastic cells to adapt to environmental changes including nutrient perturbation, genotoxic factors, circadian disorder, infection, inflammation and xenobiotics. These effects are mainly achieved by the driving effect of NAD+ on metabolic pathways as enzyme cofactors transferring hydrogen in oxidation-reduction reactions. Besides, multiple NAD+-dependent enzymes are involved in physiology either by post-synthesis chemical modification of DNA, RNA and proteins, or releasing second messenger cyclic ADP-ribose (cADPR) and NAADP+. Prolonged disequilibrium of NAD+ metabolism disturbs the physiological functions, resulting in diseases including metabolic diseases, cancer, aging and neurodegeneration disorder. In this review, we summarize recent advances in our understanding of the molecular mechanisms of NAD+-regulated physiological responses to stresses, the contribution of NAD+ deficiency to various diseases via manipulating cellular communication networks and the potential new avenues for therapeutic intervention.
The induction of autophagy by nanoparticles causes nanotoxicity, but appropriate modulation of autophagy by nanoparticles may have therapeutic potential. Multiwalled carbon nanotubes (MWCNTs) interact with cell membranes and membrane-associated molecules before and after internalization. These interactions alter cellular signaling and impact major cell functions such as cell cycle, apoptosis, and autophagy. In this work, we demonstrated that MWCNT-cell interactions can be modulated by varying densely distributed surface ligands on MWCNTs. Using a fluorescent autophagy-reporting cell line, we evaluated the autophagy induction capability of 81 surface-modified MWCNTs. We identified strong and moderate autophagy-inducing MWCNTs as well as those that did not induce autophagy. Variation of the surface ligand structure of strong autophagy nanoinducers led to the induction of different autophagy-activating signaling pathways, presumably through their different interactions with cell surface receptors.
Since late 2010, porcine epidemic diarrhea virus (PEDV) has rapidly disseminated all over the China and caused considerable morbidity and high mortality (up to 100%) in neonatal piglets. 79.66% (141 of 177) pig farms in 29 provinces (excluding Tibet and Hainan, China) and 72.27% (417 of 577) samples were positive for PEDV confirmed by reverse transcription-polymerase chain reaction (RT-PCR). The full-length S genes of representative field strains were sequenced. 33 field strains share 93.5%–99.9% homologies with each other at the nucleotide sequence level and 92.3%–99.8% homologies with each other at the amino acids sequence level. Most field strains have nucleotide deletion and insertion regions, and show lower homologies (93.5%–94.2%) with Chinese classical strain CH/S, however higher homologies (97.1%–99.3%) with recent strain CHGD-1. The phylogenetic analysis showed there are classical strains and variants prevailing in pig herd in China. PEDV has a high detection rate in pig herds in China. Sequence analysis indicated the S genes of recent field strains have heterogeneity and the variants are predominant.
. Influence of dietary conjugated linoleic acid and fat source on body fat and apoptosis in mice. Obes Res. 2004;12:1435-1444. Objective: To determine whether altered dietary essential fatty acid (linoleic and arachidonic acid) concentrations alter sensitivity to conjugated linoleic acid (CLA)-induced body fat loss or DNA fragmentation. Research Methods and Procedures: Mice were fed diets containing soy oil (control), coconut oil [essential fatty acid deficient (EFAD)], or fish oil (FO) for 42 days, and then diets were supplemented with a mixture of CLA isomers (0.5% of the diet) for 14 days. Body fat index, fat pad and liver weights, DNA fragmentation in adipose tissue, and fatty acid profiles of adipose tissue were determined. Results: The EFAD diet decreased (p Ͻ 0.05) linoleic and arachidonic acid in mouse adipose tissue but did not affect body fat. Dietary CLA caused a reduction (p Ͻ 0.05) in body fat. Mice fed the EFAD diet and then supplemented with CLA exhibited a greater reduction (p Ͻ 0.001) in body fat (20.21% vs. 6.94% in EFAD and EFAD ϩ CLA-fed mice, respectively) compared with mice fed soy oil. Dietary FO decreased linoleic acid and increased arachidonic acid in mouse adipose tissue. Mice fed FO or CLA were leaner (p Ͻ 0.05) than control mice. FO ϩ CLA-fed mice did not differ in body fat compared with FO-fed mice. Adipose tissue apoptosis was increased (p Ͻ 0.001) in CLA-supplemented mice and was not affected by fat source. Discussion: Reductions in linoleic acid concentration made mice more sensitive to CLA-induced body fat loss only when arachidonic acid concentrations were also reduced. Dietary essential fatty acids did not affect CLA-induced DNA fragmentation.
ObjectiveTo investigate the effect of dexmedetomidine in the prevention of etomidate-induced myoclonus.MethodsWe searched for randomized controlled trials (RCTs) regarding the use of dexmedetomidine in preventing etomidate-induced myoclonus in the databases PubMed, EMBASE, the Cochrane Library, and CNKI. We extracted data and assessed the quality of the literature and adopted RevMan 5.2 to conduct meta-analysis on each effective index and employed funnel plot to test publication bias.ResultsThe results showed that the incidence of etomidate-induced myoclonus in the dexmedetomidine treated groups was significantly lower than that of the control groups (risk ratio [RR]=0.27, 95% confidence interval [CI] [0.15, 0.47], P<0.00001). With regard to the severity of etomidate-induced myoclonus, incidences of etomidate-induced myoclonus in the dexmedetomidine treated groups resulting in mild myoclonus (RR=0.37, 95% CI [0.19, 0.75], P=0.006), moderate myoclonus (RR=0.21, 95% CI [0.12, 0.37], P<0.00001), or severe myoclonus (RR=0.18, 95% CI [0.08, 0.38], P<0.00001) were significantly lower than those of the control groups. No statistically significant difference was found (RR=0.70, 95% CI [0.47, 1.04], P=0.08) between etomidate-induced myoclonus in the dexmedetomidine treated groups and that of the midazolam treated groups.ConclusionDexmedetomidine can effectively prevent the incidence of etomidate-induced myoclonus and reduce the severity of etomidate-induced myoclonus. In addition, there were no significant differences between the effects of dexmedetomidine and midazolam in preventing etomidate-induced myoclonus.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.