45 research outputs found
Dual-Acting Small Molecules: Subtype-Selective Cannabinoid Receptor 2 Agonist/Butyrylcholinesterase Inhibitor Hybrids Show Neuroprotection in an Alzheimer's Disease Mouse Model.
We present the synthesis and characterization of merged human butyrylcholinesterase (hBChE) inhibitor/cannabinoid receptor 2 (hCB2R) ligands for the treatment of neurodegeneration. In total, 15 benzimidazole carbamates were synthesized and tested for their inhibition of human cholinesterases, also with regard to their pseudoirreversible binding mode and affinity toward both cannabinoid receptors in radioligand binding studies. After evaluation in a calcium mobilization assay as well as a ÎČ-arrestin 2 (ÎČarr2) recruitment assay, two compounds with balanced activities on both targets were tested for their immunomodulatory effect on microglia activation and regarding their pharmacokinetic properties and blood-brain barrier penetration. Compound 15d, containing a dimethyl carbamate motif, was further evaluated in vivo, showing prevention of AÎČ25-35-induced learning impairments in a pharmacological mouse model of Alzheimer's disease for both short- and long-term memory responses. Additional combination studies proved a synergic effect of BChE inhibition and CB2R activation in vivo
Controls on gut phosphatisation : the trilobites from the Weeks Formation LagerstÀtte (Cambrian; Utah)
Despite being internal organs, digestive structures are frequently preserved in Cambrian LagerstÀtten. However, the reasons for their fossilisation and their biological implications remain to be thoroughly explored. This is particularly true with arthropods--typically the most diverse fossilised organisms in Cambrian ecosystems--where digestive structures represent an as-yet underexploited alternative to appendage morphology for inferences on their biology. Here we describe the phosphatised digestive structures of three trilobite species from the Cambrian Weeks Formation LagerstÀtte (Utah). Their exquisite, three-dimensional preservation reveals unique details on trilobite internal anatomy, such as the position of the mouth and the absence of a differentiated crop. In addition, the presence of paired pygidial organs of an unknown function is reported for the first time. This exceptional material enables exploration of the relationships between gut phosphatisation and the biology of organisms. Indeed, soft-tissue preservation is unusual in these fossils as it is restricted to the digestive structures, which indicates that the gut played a central role in its own phosphatisation. We hypothesize that the gut provided a microenvironment where special conditions could develop and harboured a source of phosphorus. The fact that gut phosphatization has almost exclusively been observed in arthropods could be explained by their uncommon ability to store ions (including phosphorous) in their digestive tissues. However, in some specimens from the Weeks Formation, the phosphatisation extends to the entire digestive system, suggesting that trilobites might have had some biological particularities not observed in modern arthropods. We speculate that one of them might have been an increased capacity for ion storage in the gut tissues, related to the moulting of their heavily-mineralised carapace
Expression of the Splicing Factor Gene SFRS10 Is Reduced in Human Obesity and Contributes to Enhanced Lipogenesis
SummaryAlternative mRNA splicing provides transcript diversity and may contribute to human disease. We demonstrate that expression of several genes regulating RNA processing is decreased in both liver and skeletal muscle of obese humans. We evaluated a representative splicing factor, SFRS10, downregulated in both obese human liver and muscle and in high-fat-fed mice, and determined metabolic impact of reduced expression. SFRS10-specific siRNA induces lipogenesis and lipid accumulation in hepatocytes. Moreover, Sfrs10 heterozygous mice have increased hepatic lipogenic gene expression, VLDL secretion, and plasma triglycerides. We demonstrate that LPIN1, a key regulator of lipid metabolism, is a splicing target of SFRS10; reduced SFRS10 favors the lipogenic ÎČ isoform of LPIN1. Importantly, LPIN1ÎČ-specific siRNA abolished lipogenic effects of decreased SFRS10 expression. Together, our results indicate that reduced expression of SFRS10, as observed in tissues from obese humans, alters LPIN1 splicing, induces lipogenesis, and therefore contributes to metabolic phenotypes associated with obesity
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
The selective butyrylcholinesterase inhibitor UWâMDâ95 shows symptomatic and neuroprotective effects in a pharmacological mouse model of Alzheimer's disease
International audienceAims Alzheimer's disease (AD) is a devastating dementia characterized by extracellular amyloidâÎČ (AÎČ) protein aggregates and intracellular tau protein deposition. Clinically available drugs mainly target acetylcholinesterase (AChE) and indirectly sustain cholinergic neuronal tonus. Butyrylcholinesterase (BChE) also controls acetylcholine (ACh) turnover and is involved in the formation of AĂ aggregates and senile plaques. UWâMDâ95 is a novel carbamateâbased compound acting as a potent pseudoâirreversible BChE inhibitor, with high selectivity versus AChE, and showing promising protective potentials in AD. Methods We characterized the neuroprotective activity of UWâMDâ95 in mice treated intracerebroventricularly with oligomerized AÎČ 25â35 peptide using behavioral, biochemical, and immunohistochemical approaches. Results When injected acutely 30âmin before the behavioral tests (spontaneous alternation in the Yâmaze, object recognition, or passive avoidance), UWâMDâ95 (0.3â3âmg/kg) showed antiâamnesic effects in AÎČ 25â35 âtreated mice. When injected once a day over 7âdays, it prevented AÎČ 25â35 âinduced memory deficits. This effect was lost in BChE knockout mice. Moreover, the compound prevented AÎČ 25â35 âinduced oxidative stress (assessed by lipid peroxidation or cytochrome c release), neuroinflammation (ILâ6 and TNFα levels or GFAP and IBA1 immunoreactivity) in the hippocampus and cortex, and apoptosis (Bax level). Moreover, UWâMDâ95 significantly reduced the increase in soluble AÎČ 1â42 level in the hippocampus induced by AÎČ 25â35 . Conclusion UWâMDâ95 appeared as a potent neuroprotective compound in the AÎČ 25â35 model of AD, with potentially an impact on AÎČ 1â42 accumulation that could suggest a novel mechanism of neuroprotection
Dual-Acting Small Molecules: Subtype-Selective Cannabinoid Receptor 2 Agonist/Butyrylcholinesterase Inhibitor Hybrids Show Neuroprotection in an Alzheimerâs Disease Mouse Model
We present the synthesis and characterization of merged
human butyrylcholinesterase
(hBChE) inhibitor/cannabinoid receptor 2 (hCB2R) ligands for the treatment of neurodegeneration.
In total, 15 benzimidazole carbamates were synthesized and tested
for their inhibition of human cholinesterases, also with regard to
their pseudoirreversible binding mode and affinity toward both cannabinoid
receptors in radioligand binding studies. After evaluation in a calcium
mobilization assay as well as a ÎČ-arrestin 2 (ÎČarr2) recruitment
assay, two compounds with balanced activities on both targets were
tested for their immunomodulatory effect on microglia activation and
regarding their pharmacokinetic properties and bloodâbrain
barrier penetration. Compound 15d, containing a dimethyl
carbamate motif, was further evaluated in vivo, showing prevention
of AÎČ25â35-induced learning impairments in
a pharmacological mouse model of Alzheimerâs disease for both
short- and long-term memory responses. Additional combination studies
proved a synergic effect of BChE inhibition and CB2R activation
in vivo
Dual-Acting Small Molecules: Subtype-Selective Cannabinoid Receptor 2 Agonist/Butyrylcholinesterase Inhibitor Hybrids Show Neuroprotection in an Alzheimerâs Disease Mouse Model
We present the synthesis and characterization of merged
human butyrylcholinesterase
(hBChE) inhibitor/cannabinoid receptor 2 (hCB2R) ligands for the treatment of neurodegeneration.
In total, 15 benzimidazole carbamates were synthesized and tested
for their inhibition of human cholinesterases, also with regard to
their pseudoirreversible binding mode and affinity toward both cannabinoid
receptors in radioligand binding studies. After evaluation in a calcium
mobilization assay as well as a ÎČ-arrestin 2 (ÎČarr2) recruitment
assay, two compounds with balanced activities on both targets were
tested for their immunomodulatory effect on microglia activation and
regarding their pharmacokinetic properties and bloodâbrain
barrier penetration. Compound 15d, containing a dimethyl
carbamate motif, was further evaluated in vivo, showing prevention
of AÎČ25â35-induced learning impairments in
a pharmacological mouse model of Alzheimerâs disease for both
short- and long-term memory responses. Additional combination studies
proved a synergic effect of BChE inhibition and CB2R activation
in vivo
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Defects in muscle branched-chain amino acid oxidation contribute to impaired lipid metabolism
Objective: Plasma levels of branched-chain amino acids (BCAA) are consistently elevated in obesity and type 2 diabetes (T2D) and can also prospectively predict T2D. However, the role of BCAA in the pathogenesis of insulin resistance and T2D remains unclear. Methods: To identify pathways related to insulin resistance, we performed comprehensive gene expression and metabolomics analyses in skeletal muscle from 41 humans with normal glucose tolerance and 11 with T2D across a range of insulin sensitivity (SI, 0.49 to 14.28). We studied both cultured cells and mice heterozygous for the BCAA enzyme methylmalonyl-CoA mutase (Mut) and assessed the effects of altered BCAA flux on lipid and glucose homeostasis. Results: Our data demonstrate perturbed BCAA metabolism and fatty acid oxidation in muscle from insulin resistant humans. Experimental alterations in BCAA flux in cultured cells similarly modulate fatty acid oxidation. Mut heterozygosity in mice alters muscle lipid metabolism in vivo, resulting in increased muscle triglyceride accumulation, increased plasma glucose, hyperinsulinemia, and increased body weight after high-fat feeding. Conclusions: Our data indicate that impaired muscle BCAA catabolism may contribute to the development of insulin resistance by perturbing both amino acid and fatty acid metabolism and suggest that targeting BCAA metabolism may hold promise for prevention or treatment of T2D