The prevalence of asthma has increased in recent years, and is characterized by airway hyperresponsiveness and inflammation. Many patients report using alternative therapies to self-treat asthma symptoms as adjuncts to short-acting and long-acting b-agonists and inhaled corticosteroids (ICS). As many as 40% of patients with asthma use herbal therapies to manage asthma symptoms, often without proven efficacy or known mechanisms of action. Therefore, investigations of both the therapeutic and possible detrimental effects of isolated components of herbal treatments on the airway are important. We hypothesized that ginger and its active components induce bronchodilation by modulating intracellular calcium ([Ca 21 ] i ) in airway smooth muscle (ASM). In isolated human ASM, ginger caused significant and rapid relaxation. Four purified constituents of ginger were subsequently tested for ASM relaxant properties in both guinea pig and human tracheas: ] i regulation. These purified compounds may provide a therapeutic option alone or in combination with accepted therapeutics, including b 2 -agonists, in airway diseases such as asthma.
Selective targeting of the ␣5-subunit of GABAA receptors relaxes airway smooth muscle and inhibits cellular calcium handling. Am J Physiol Lung Cell Mol Physiol 308: L931-L942, 2015. First published February 6, 2015 doi:10.1152/ajplung.00107.2014The clinical need for novel bronchodilators for the treatment of bronchoconstrictive diseases remains a major medical issue. Modulation of airway smooth muscle (ASM) chloride via GABA A receptor activation to achieve relaxation of precontracted ASM represents a potentially beneficial therapeutic option. Since human ASM GABAA receptors express only the ␣4-and ␣5-subunits, there is an opportunity to selectively target ASM GABAA receptors to improve drug efficacy and minimize side effects. Recently, a novel compound (R)-) with allosteric selectivity for ␣5-subunit containing GABAA receptors has become available. We questioned whether this novel GABAA ␣5-selective ligand relaxes ASM and affects intracellular calcium concentration ([Ca 2ϩ ]i) regulation. Immunohistochemical staining localized the GABAA ␣5-subunit to human ASM. The selective GABAA ␣5 ligand SH-053-2=F-R-CH3 relaxes precontracted intact ASM; increases GABA-activated chloride currents in human ASM cells in voltage-clamp electrophysiology studies; and attenuates bradykinin-induced increases in [Ca 2ϩ ]i, store-operated Ca 2ϩ entry, and methacholine-induced Ca 2ϩ oscillations in peripheral murine lung slices. In conclusion, selective subunit targeting of endogenous ␣5-subunit containing GABAA receptors on ASM may represent a novel therapeutic option to treat severe bronchospasm.GABAA ␣5-subunit; SH-053-2=F-R-CH3; airway relaxation DESPITE A PRESSING CLINICAL need for novel bronchodilators in the treatment of asthma and other bronchoconstrictive diseases, only three drug classes are currently in clinical use as acute bronchodilators in the United States (methylxanthines, anticholinergics, and -adrenoceptor agonists) (6). An emerging novel pathway to achieve bronchodilation involves modulating airway smooth muscle (ASM) chloride conductance via GABA A receptors to achieve relaxation of human precontracted ASM (15). Although there is legitimate concern that widespread activation of all GABA A receptors may lead to undesirable side effects (sedation, hypnosis, etc.), we have shown that human ASM cells express a limited repertoire of GABA A receptor subunits, with the ␣4-and ␣5-subunits the only ␣-subunits expressed, thereby allowing for potential selective pharmacological tissue specific receptor targeting to minimize side effects (18,33). Inhaled delivery of these selective compounds may also serve to obviate concerns of systemic effects. Concern regarding nonselective GABA A receptor activation is not limited to the airway. GABA A receptor ligands active in the central nervous system (CNS) can have many effects including anxiolytic, sedative, hypnotic, amnesic, anticonvulsant, and muscle relaxant effects. This motivated a search for benzodiazepine (BDZ) ligands that discriminate among the ␣-subunits of ...
Our objective was to characterize lipid profiles in cell models of adipocyte differentiation in comparison to mouse adipose tissues in vivo. A novel lipid extraction strategy was combined with global lipid profiling using direct infusion and sequential precursor ion fragmentation, termed MS/MSALL. Perirenal and inguinal white adipose tissue and interscapular brown adipose tissues from adult C57BL/6J mice were analyzed. 3T3-L1 preadipocytes, ear mesenchymal progenitor cells, and brown adipose-derived BAT-C1 cells were also characterized. Over 3000 unique lipid species were quantified. Principal component analysis showed that perirenal versus inguinal white adipose tissues varied in lipid composition of triacyl- and diacylglycerols, sphingomyelins, glycerophospholipids and, notably, cardiolipin CL 72:3. In contrast, hexosylceramides and sphingomyelins distinguished brown from white adipose. Adipocyte differentiation models showed broad differences in lipid composition among themselves, upon adipogenic differentiation, and with adipose tissues. Palmitoyl triacylglycerides predominate in 3T3-L1 differentiation models, whereas cardiolipin CL 72:1 and SM 45:4 were abundant in brown adipose-derived cell differentiation models, respectively. MS/MSALL data suggest new lipid biomarkers for tissue-specific lipid contributions to adipogenesis, thus providing a foundation for using in vitro models of adipogenesis to reflect potential changes in adipose tissues in vivo.
Objective This study investigated the effects of loss of Cthrc1 on adipogenesis, body composition, metabolism, physical activity and muscle physiology. Methods Complete metabolic and activity monitoring as well as grip strength measurements and muscle myography were performed in Cthrc1 null and wildtype mice. Results Compared to wildtypes, Cthrc1 null mice had similar body weights but significantly reduced energy expenditure, decreased lean mass and increased fat mass, especially visceral fat. In vitro studies demonstrated that Cthrc1 inhibited adipocyte differentiation as well as PPAR and CREB reporter activity, while preadipocytes isolated from Cthrc1 null mice exhibited enhanced adipogenic differentiation. Voluntary physical activity in Cthrc1 null mice as assessed by wheel running was reduced to approximately half the distance covered by wildtypes. Reduced grip strength was observed in Cthrc1 null mice at the age of 15 weeks or older with reduced performance and mass of fast twitch muscle. In the brain, Cthrc1 expression was most prominent in neurons of thalamic and hypothalamic nuclei with evidence for secretion into the circulation in the median eminence. Conclusions Our data indicate that Cthrc1 regulates body composition through inhibition of adipogenesis. In addition, central Cthrc1 may be a mediator of muscle function and physical activity.
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.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.