Explore the vast range of titles available.

Background MicroRNAs (miRNAs) play crucial roles in regulating inflammation and cellular senescence. Among them, miR-146a has emerged as a key modulator of inflammation, but its role in obesity-induced senescence remains unexplored. This study investigates the involvement of miR-146a in high-fat diet (HFD)-induced hypothalamic senescence and in protective effects of elocalcitol (Elo), a non-hypercalcemic, fluorinated vitamin D analog on HFD-induced senescence. Results Wild-type ( WT ) HFD-fed mice exhibited increased body weight, impaired locomotor activity, and cognitive decline compared to low-fat diet (LFD) controls. In the brain, HFD induced senescence markers ( p16 , p21 ), β-galactosidase activity (β-gal) of microglia, and increased expression of senescence associated secretory phenotype (SASP) cytokines ( Il1b , Il18 , Tnf , Il6 ) in activated hypothalamic microglia. In the liver, increased p21 and SASP cytokines were detected, although p16 and β-gal levels remained unchanged. Importantly, miR-146a expression was significantly downregulated in the hypothalamus following HFD exposure in WT mice, while miR-146a knockout ( Mir146a-/- ) mice subjected to HFD showed augmented hypothalamic senescence characterized by higher levels of p16 , p21 , and β-gal + microglial cells as compared to WT mice. The SASP profile remained similar between Mir146a-/- HFD and WT HFD mice. Among miR-146a target genes, smad4 was upregulated the hypothalamus of HFD-fed mice, with a more pronounced increase in the hypothalamus of HFD-fed Mir146a-/- mice. Further, treatment with Elo upregulated miR-146a expression in both the hypothalamus and the liver, lowered body weight and improved cognitive function, while reducing senescence markers and SASP cytokines in WT HFD mice. These effects were absent in Mir146a-/- HFD mice when treated with Elo, indicating the dependence of Elo’s therapeutic efficacy on miR-146a. Conclusion Elocalcitol prevents development of senescence in microglia via modulation of miR-146a expression, while miR-146a provides protection against HFD-induced cellular senescence in the hypothalamus most probably via inhibition of TGF/Smad4 pathway. These findings highlight Elo and miR-146a as promising therapeutic candidates for ameliorating obesity-related neuroinflammation and senescence.

Obesity is an emerging health problem worldwide as it is associated with increased risk of cardiovascular, metabolic, mental disorders, and cancer. Therapeutic weight management remains one of the options for the treatment of excess weight and associated comorbidities. In this study, the therapeutic potential of elocalcitol, a fluorinated derivative of vitamin D, was studied on the model of high-fat diet (HFD)-induced obesity in mice. It was demonstrated that co-administration of elocalcitol in the doses 15 ug/kg (i.p.) twice a week for 16 weeks prevented body weight gain by approximately 15%. The significant retardation in the body weight gain was observed already on the second week of elocalcitol treatment. Administration of elocalcitol also reduced visceral and epididymal fat accumulation by 55% and 35%, respectively, metabolic syndrome development, and lipid droplets accumulation in the liver of mice exposed to HFD. In contrast, the administration of cholecalciferol (vitamin D)-a precursor to calcitriol, the biologically active form of vitamin D, did not affect significantly the signs of obesity and metabolic syndrome, suggesting that the anti-obese effects of elocalcitol are not related to the canonical vitamin D receptor (VDR). Further studies have demonstrated that the preventive effect of elocalcitol is associated with the decreased levels of sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) and upregulation insulin-inducing gene-1 ( ) mRNA expression suggesting that the anti-obese effect of elocalcitol is mediated via inhibition of SREBP-mediated lipogenesis. We also demonstrated that elocalcitol prevents an increase in the expression of proinflammatory cytokines such as interleukin-1 beta ( ), tumor necrosis factor-alpha ( ), and interleukin-18 ( ), and this effect was associated with upregulation of microRNA-146a (miR-146a). Deletion of the miR-146a gene reduced the anti-obese effects of elocalcitol and prevented its actions on the SCAP levels. The data indicate that elocalcitol's reduction of SCAP is at least partly mediated by miR-146a modulation. The study demonstrates that elocalcitol prevents HFD-induced obesity and metabolic syndrome in mice, likely by inhibiting SREBP-mediated lipogenesis and upregulating miR-146a. These findings provide valuable insights into the anti-obesity mechanisms of fluorinated D-vitamin analogs and suggest potential therapeutic strategies for obesity prevention.

We generated mouse mutants with targeted AMPA receptor (AMPAR) GluR–B subunit alleles, functionally expressed at different levels and deficient in Q/R–site editing. All mutant lines had increased AMPAR calcium permeabilities in pyramidal neurons, and one showed elevated macroscopic conductances of these channels. The AMPAR–mediated calcium influx induced NMDA–receptor–independent long–term potentiation (LTP) in hippocampal pyramidal cell connections. Calcium–triggered neuronal death was not observed, but mutants had mild to severe neurological dysfunctions, including epilepsy and deficits in dendritic architecture. The seizure–prone phenotype correlated with an increase in the macroscopic conductance, as independently revealed by the effect of a transgene for a Q/R–site–altered GluR–B subunit. Thus, changes in GluR–B gene expression and Q/R site editing can affect critical architectural and functional aspects of excitatory principal neurons.

Calcium permeability of L-α -amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPARs) in excitatory neurons of the mammalian brain is prevented by coassembly of the GluR-B subunit, which carries an arginine (R) residue at a critical site of the channel pore. The codon for this arginine is created by site-selective adenosine deamination of an exonic glutamine (Q) codon at the pre-mRNA level. Thus, central neurons can potentially control the calcium permeability of AMPARs by the level of GluR-B gene expression as well as by the extent of Q/R-site editing, which in postnatal brain, positions the R codon into >99% of GluR-B mRNA. To study whether the small amount of unedited GluR-B is of functional relevance, we have generated mice carrying GluR-B alleles with an exonic arginine codon. We report that these mutants manifest no obvious deficiencies, indicating that AMPAR-mediated calcium influx into central neurons can be solely regulated by the levels of Q/R site-edited GluR-B relative to other AMPAR subunits. Notably, a targeted GluR-B gene mutant with 30% reduced GluR-B levels had 2-fold higher AMPAR-mediated calcium permeability in hippocampal pyramidal cells with no sign of cytotoxicity. This constitutes proof in vivo that elevated calcium influx through AMPARs need not generate pathophysiological consequences.

We introduce the concept of local bucket error for the mini-bucket heuristics and show how it can be used to improve the power of AND/OR search for combinatorial optimization tasks in graphical models (e.g. MAP/MPE or weighted CSPs). The local bucket error illuminates how the heuristic errors are distributed in the search space, guided by the mini-bucket heuristic. We present and analyze methods for compiling the local bucket-errors (exactly and approximately) and show that they can be used to yield an effective tool for balancing look-ahead overhead during search. This can be especially instrumental when memory is restricted, accommodating the generation of only weak compiled heuristics. We illustrate the impact of the proposed schemes in an extensive empirical evaluation for both finding exact solutions and anytime suboptimal solutions.

The paper investigates parameterized approximate message-passing schemes that are based on bounded inference and are inspired by Pearl’s belief propagation algorithm (BP). We start with the bounded inference mini-clustering algorithm and then move to the iterative scheme called Iterative Join-Graph Propagation (IJGP), that combines both iteration and bounded inference. Algorithm IJGP belongs to the class of Generalized Belief Propagation algorithms, a framework that allowed connections with approximate algorithms from statistical physics and is shown empirically to surpass the performance of mini-clustering and belief propagation, as well as a number of other state-of-the-art algorithms on several classes of networks. We also provide insight into the accuracy of iterative BP and IJGP by relating these algorithms to well known classes of constraint propagation schemes.

Retrospective pharmacogenetic analysis was performed on 120 Caucasian subjects. Subjects were obtained in collaboration with the Estonian Genome Project and Egeen Inc. (CA, USA), who provided blinded medical record and genetic data to the researchers, respectively. Subjects selected from the Estonian Genome Project had a diagnosis of hypertension confirmed by at least two blood pressure measurements and multiple follow-up measurements for assessing calcium channel blocker antihypertensive treatment outcome. Treatment outcome was scored positive if at least three follow-up blood pressure measurements were nonhypertensive and no more than one follow-up measurement was hypertensive (>140/90). The genotypes of 62 single nucleotide polymorphisms (SNPs) in the calcium channel, voltage-dependent, L type, alpha 1C subunit (CACNA1C) gene were obtained for each subject from a blood sample. Univariate analyses with multiple test correction were conducted using family-wise error rate and false discovery rate methods. Three SNPs in CANCA1C had significant associations with antihypertensive outcome, combining to yield a positive treatment outcome of less than 15 to 80%.

Retrospective pharmacogenetic analysis was performed on 120 Caucasian subjects. Subjects were obtained in collaboration with the Estonian Genome Project and Egeen Inc. (CA, USA), who provided blinded medical record and genetic data to the researchers, respectively. Subjects selected from the Estonian Genome Project had a diagnosis of hypertension confirmed by at least two blood pressure measurements and multiple follow-up measurements for assessing calcium channel blocker antihypertensive treatment outcome. Treatment outcome was scored positive if at least three follow-up blood pressure measurements were nonhypertensive and no more than one follow-up measurement was hypertensive (>140/90). The genotypes of 62 single nucleotide polymorphisms (SNPs) in the calcium channel, voltage-dependent, L type, α 1C subunit ( ) gene were obtained for each subject from a blood sample. Univariate analyses with multiple test correction were conducted using family-wise error rate and false discovery rate methods. Three SNPs in had significant associations with antihypertensive outcome, combining to yield a positive treatment outcome of less than 15 to 80%.

Most automated reasoning problems in artificial intelligence are computationally hard (NP-hard). Therefore the design of approximation algorithms that trade accuracy for efficiency has great practical importance. The focus of this thesis is on the design and analysis of efficient algorithms for graphical models, such as constraint networks and belief networks. Our approach is to combine conditioning (such as backtracking search) with inference (such as variable elimination), where either conditioning, or inference, or both are being approximated. The central idea of this thesis is that efficiency can be gained by taking advantage of structural properties of graphical models. This thesis presents a new methodology for combining approximated inference with search. Specifically two schemes for automatically generating search heuristics by inference are proposed. The first uses the mini-bucket approximation method for generating a static heuristic function to be used subsequently by the search algorithm. The second explores an extension of inference-based approximations to a wider class of optimization tasks which allow dynamic heuristic generation throughout the search process. Both approaches dramatically improve Branch-and-Bound and Best-First search. Subsequently, we also explore several ways of improving stochastic local search methods using inference and demonstrate a significant impact on some classes of constraint problems. On probabilistic optimization tasks we showed that approximating inference is generally superior to approximating conditioning, while some hybrid is superior to both.

The paper is a second in a series of two papers evaluating the power of a new scheme that generates search heuristics mechanically. The heuristics are extracted from an approximation scheme called mini-bucket elimination that was recently introduced. The first paper introduced the idea and evaluated it within Branch-and-Bound search. In the current paper the idea is further extended and evaluated within Best-First search. The resulting algorithms are compared on coding and medical diagnosis problems, using varying strength of the mini-bucket heuristics. Our results demonstrate an effective search scheme that permits controlled tradeoff between preprocessing (for heuristic generation) and search. Best-first search is shown to outperform Branch-and-Bound, when supplied with good heuristics, and sufficient memory space.