RESUMEN
Mn(I) C-H functionalization of coumarins provides a versatile and practical method for the rapid assembly of fused polycyclic pyridinium-containing coumarins in a regioselective manner. The synthetic strategy enables application of bench-stable organomanganese reagents in both photochemical- and thermal-promoted reactions. The cyclomanganated intermediates, and global reaction system, provide an ideal testing ground for structural characterization of the active Mn(I) carbonyl-containing species, including transient species observable by ultra-fast time-resolved spectroscopic methods. The thermodynamic reductive elimination product, solely encountered from reaction between alkynes and air-stable organometallic cyclomanganated coumarins, has enabled characterization of a critical seven-membered Mn(I) intermediate, detected by time-resolved infrared spectroscopy, enabling the elucidation of the temporal profile of key steps in the reductive elimination pathway. Quantitative data are provided. Manganated polycyclic products are readily decomplexed by AgBF4 , opening-up an efficient route to the formation of π-extended hybrid coumarin-pyridinium compounds.
RESUMEN
OBJECTIVES: Oxytocin (OT) has a well-established role in reproductive behaviours; however, it recently emerged as an important regulator of energy homeostasis. In addition to central nervous system (CNS), OT is found in the plasma and OT receptors (OT-R) are found in peripheral tissues relevant to energy balance regulation. Here, we aim to determine whether peripheral OT-R activation is sufficient to alter energy intake and expenditure. METHODS AND RESULTS: We first show that systemic OT potently reduced food intake and food-motivated behaviour for a high-fat reward in male and female rats. As it is plausible that peripherally, intraperitoneally (IP) injected OT crosses the blood-brain barrier (BBB) to produce some of the metabolic effects within the CNS, we screened, with a novel fluorescently labelled-OT (fAF546-OT, Roxy), for the presence of IP-injected Roxy in CNS tissue relevant to feeding control and compared such with BBB-impermeable fluorescent OT-B12 (fCy5-OT-B12; BRoxy). While Roxy did penetrate the CNS, BRoxy did not. To evaluate the behavioural and thermoregulatory impact of exclusive activation of peripheral OT-R, we generated a novel BBB-impermeable OT (OT-B12 ), with equipotent binding at OT-R in vitro. In vivo, IP-injected OT and OT-B12 were equipotent at food intake suppression in rats of both sexes, suggesting that peripheral OT acts on peripheral OT-R to reduce feeding behaviour. Importantly, OT induced a potent conditioned taste avoidance, indistinguishable from that induced by LiCl, when applied peripherally. Remarkably, and in contrast to OT, OT-B12 did not induce any conditioned taste avoidance. Limiting the CNS entry of OT also resulted in a dose-dependent reduction of emesis in male shrews. While both OT and OT-B12 proved to have similar effects on body temperature, only OT resulted in home-cage locomotor depression. CONCLUSIONS: Together our data indicate that limiting systemic OT CNS penetrance preserves the anorexic effects of the peptide and reduces the clinically undesired side effects of OT: emesis, taste avoidance and locomotor depression. Thus, therapeutic targeting of peripheral OT-R may be a viable strategy to achieve appetite suppression with better patient outcomes.
Asunto(s)
Ingestión de Alimentos , Oxitocina , Ratas , Masculino , Femenino , Animales , Oxitocina/farmacología , Motivación , Gusto , Sistema Nervioso Central , VómitosRESUMEN
Recent developments suggest that increased glucagon and decreased somatostatin secretion from the pancreas contribute to hyperglycaemia in type-2 diabetes (T2D) patients. There is a huge need to understand changes in glucagon and somatostatin secretion to develop potential anti-diabetic drugs. To further describe the role of somatostatin in the pathogenesis of T2D, reliable means to detect islet δ-cells and somatostatin secretion are necessary. In this study, we first tested currently available anti-somatostatin antibodies against a mouse model that fluorescently labels δ-cells. We found that these antibodies only label 10-15% of the fluorescently labelled δ-cells in pancreatic islets. We further tested six antibodies (newly developed) that can label both somatostatin 14 (SST14) and 28 (SST28) and found that four of them were able to detect above 70% of the fluorescent cells in the transgenic islets. This is quite efficient compared to the commercially available antibodies. Using one of these antibodies (SST10G5), we compared the cytoarchitecture of mouse and human pancreatic islets and found fewer δ-cells in the periphery of human islets. Interestingly, the δ-cell number was also reduced in islets from T2D donors compared to non-diabetic donors. Finally, with the aim to measure SST secretion from pancreatic islets, one of the candidate antibodies was used to develop a direct-ELISA-based SST assay. Using this novel assay, we could detect SST secretion under low and high glucose conditions from the pancreatic islets, both in mice and humans. Overall, using antibody-based tools provided by Mercodia AB, our study indicates reduced δ-cell numbers and SST secretion in diabetic islets.
Asunto(s)
Diabetes Mellitus Tipo 2 , Islotes Pancreáticos , Humanos , Recuento de Células , Glucagón , Insulina , SomatostatinaRESUMEN
We investigated the associations between dietary patterns and chronic disease mortality in Switzerland using an ecological design and explored their spatial dependence, i.e. the tendency of near locations to present more similar and distant locations to present more different values than randomly expected. Data of the National Nutrition Survey menuCH (n 2057) were used to compute hypothesis- (Alternate Healthy Eating Index (AHEI)) and data-driven dietary patterns. District-level standardised mortality ratios (SMR) were calculated using the Swiss Federal Statistical Office mortality data and linked to dietary data geographically. Quasipoisson regression models were fitted to investigate the associations between dietary patterns and chronic disease mortality; Moran's I statistics were used to explore spatial dependence. Compared with the first, the fifth AHEI quintile (highest diet quality) was associated with district-level SMR of 0·95 (95 % CI 0·93, 0·97) for CVD, 0·91 (95 % CI 0·88, 0·95) for ischaemic heart disease (IHD), 0·97 (95 % CI 0·95, 0·99) for stroke, 0·99 (95 % CI 0·98, 1·00) for all-cancer, 0·98 (95 % CI 0·96, 0·99) for colorectal cancer and 0·93 (95 % CI 0·89, 0·96) for diabetes. The Swiss traditional and Western-like patterns were associated with significantly higher district-level SMR for CVD, IHD, stroke and diabetes (ranging from 1·02 to 1·08) compared with the Prudent pattern. Significant global and local spatial dependence was identified, with similar results across hypothesis- and data-driven dietary patterns. Our study suggests that dietary patterns partly contribute to the explanation of geographic disparities in chronic disease mortality in Switzerland. Further analyses including spatial components in regression models would allow identifying regions where nutritional interventions are particularly needed.
Asunto(s)
Enfermedades Cardiovasculares , Accidente Cerebrovascular , Enfermedad Crónica , Dieta , Humanos , Suiza/epidemiologíaRESUMEN
Manganese-mediated borylation of aryl/heteroaryl diazonium salts emerges as a general and versatile synthetic methodology for the synthesis of the corresponding boronate esters. The reaction proved an ideal testing ground for delineating the Mn species responsible for the photochemical reaction processes, that is, involving either Mn radical or Mn cationic species, which is dependent on the presence of a suitably strong oxidant. Our findings are important for a plethora of processes employing Mn-containing carbonyl species as initiators and/or catalysts, which have considerable potential in synthetic applications.
RESUMEN
PURPOSE: Diet is one of the most important modifiable risk factors for the development of type 2 diabetes. Here, we aim to identify dietary patterns and to investigate their association with prediabetes, undetected diabetes and prevalent diabetes. METHODS: The present study included 1305 participants of the cross-sectional population-based KORA FF4 study. Oral glucose tolerance test (OGTT) measurements together with a physician-confirmed diagnosis allowed for an accurate categorization of the participants according to their glucose tolerance status into normal glucose tolerance (n = 698), prediabetes (n = 459), undetected diabetes (n = 49), and prevalent diabetes (n = 99). Dietary patterns were identified through principal component analysis followed by hierarchical clustering. The association between dietary patterns and glucose tolerance status was investigated using multinomial logistic regression models. RESULTS: A Prudent pattern, characterized by high consumption of vegetables, fruits, wholegrains and dairy products, and a Western pattern, characterized by high consumption of red and processed meat, alcoholic beverages, refined grains and sugar-sweetened beverages, were identified. Participants following the Western pattern had significantly higher chances of having prediabetes (odds ratio [OR] 1.92; 95% confidence interval [CI] 1.35, 2.73), undetected diabetes (OR 10.12; 95% CI 4.19, 24.43) or prevalent diabetes (OR 3.51; 95% CI 1.85, 6.67), compared to participants following the Prudent pattern. CONCLUSION: To our knowledge, the present study is one of the few investigating the association between dietary patterns and prediabetes or undetected diabetes. The use of a reference group exclusively including participants with normal glucose tolerance might explain the strong associations observed in our study. These results suggest a very important role of dietary habits in the prevention of prediabetes and type 2 diabetes.
Asunto(s)
Diabetes Mellitus Tipo 2 , Estado Prediabético , Estudios Transversales , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiología , Dieta , Conducta Alimentaria , Humanos , Estado Prediabético/diagnóstico , Estado Prediabético/epidemiología , Factores de RiesgoRESUMEN
OBJECTIVE: To describe and analyse the sociodemographic, anthropometric, behavioural and dietary characteristics of different types of Swiss (no-)meat eaters. DESIGN: No-, low-, medium- and high-meat eaters were compared with respect to energy and total protein intake and sociodemographic, anthropometric and behavioural characteristics. SETTING: National Nutrition Survey menuCH, the first representative survey in Switzerland. PARTICIPANTS: 2057 participants, aged 18-75 years old, who completed two 24-h dietary recalls (24-HDR) and a questionnaire on dietary habits, sociodemographic and lifestyle factors. Body weight and height were measured by trained interviewers. No-meat eaters were participants who reported meat avoidance in the questionnaire and did not report any meat consumption in the 24-HDR. Remaining study participants were assigned to the group of low-, medium- or high-meat eaters based on energy contributions of total meat intake to total energy intake (meat:energy ratio). Fifteen percentage of the participants were assigned to the low- and high-meat eating groups, and the remaining to the medium-meat eating group. RESULTS: Overall, 4·4 % of the study participants did not consume meat. Compared with medium-meat eaters, no-meat eaters were more likely to be single and users of dietary supplements. Women and high-educated individuals were less likely to be high-meat eaters, whereas overweight and obese individuals were more likely to be high-meat eaters. Total energy intake was similar between the four different meat consumption groups, but no-meat eaters had lowest total protein intake. CONCLUSIONS: This study identified important differences in sociodemographic, anthropometric, behavioural and dietary factors between menuCH participants with different meat-eating habits.
Asunto(s)
Dieta Vegetariana , Carne , Adolescente , Adulto , Anciano , Suplementos Dietéticos , Femenino , Humanos , Persona de Mediana Edad , Encuestas Nutricionales , Obesidad/epidemiología , Suiza , Adulto JovenRESUMEN
Reduced activity of vagal efferents has long been implicated in schizophrenia and appears to be responsible for diminished parasympathetic activity and associated peripheral symptoms such as low heart rate variability and cardiovascular complications in affected individuals. In contrast, only little attention has been paid to the possibility that impaired afferent vagal signaling may be relevant for the disorder's pathophysiology as well. The present study explored this hypothesis using a model of subdiaphragmatic vagal deafferentation (SDA) in male rats. SDA represents the most complete and selective vagal deafferentation method existing to date as it leads to complete disconnection of all abdominal vagal afferents while sparing half of the abdominal vagal efferents. Using next-generation mRNA sequencing, we show that SDA leads to brain transcriptional changes in functional networks annotating with schizophrenia. We further demonstrate that SDA induces a hyperdopaminergic state, which manifests itself as increased sensitivity to acute amphetamine treatment and elevated accumbal levels of dopamine and its major metabolite, 3,4-dihydroxyphenylacetic acid. Our study also shows that SDA impairs sensorimotor gating and the attentional control of associative learning, which were assessed using the paradigms of prepulse inhibition and latent inhibition, respectively. These data provide converging evidence suggesting that the brain transcriptome, dopamine neurochemistry, and behavioral functions implicated in schizophrenia are subject to visceral modulation through abdominal vagal afferents. Our findings may encourage the further establishment and use of therapies for schizophrenia that are based on vagal interventions.SIGNIFICANCE STATEMENT The present work provides a better understanding of how disrupted vagal afferent signaling can contribute to schizophrenia-related brain and behavioral abnormalities. More specifically, it shows that subdiaphragmatic vagal deafferentation (SDA) in rats leads to (1) brain transcriptional changes in functional networks related to schizophrenia, (2) increased sensitivity to dopamine-stimulating drugs and elevated dopamine levels in the nucleus accumbens, and (3) impairments in sensorimotor gating and the attentional control of associative learning. These findings may encourage the further establishment of novel therapies for schizophrenia that are based on vagal interventions.
Asunto(s)
Abdomen/inervación , Química Encefálica/genética , Neuronas Aferentes/fisiología , Esquizofrenia/genética , Transcriptoma , Nervio Vago/fisiología , Anfetamina/farmacología , Animales , Aprendizaje por Asociación , Atención/efectos de los fármacos , Desnervación , Dopamina/metabolismo , Dopaminérgicos/farmacología , Masculino , ARN Mensajero/genética , Ratas , Ratas Sprague-Dawley , Reflejo de Sobresalto , Filtrado SensorialRESUMEN
OBJECTIVES: Our study aimed at assessing the prevalence and determinants of vitamin D deficiency (25-hydroxy-vitamin D [25(OH)D] < 20 ng/mL) in pregnant women in the first trimester living in Switzerland. METHODS: From September 2014 through December 2015, 204 pregnant women were conveniently recruited during their first clinical appointment at the Clinic of Obstetrics of the University Hospital Zurich (between week 6 and 12 of pregnancy). Blood samples were collected and a questionnaire focusing on lifestyle and skin colour was completed face-to-face with the responsible physician. Logistic regression analyses were performed with vitamin D status as dependent variable. RESULTS: 63.2% of the participating women were vitamin D deficient, and the median vitamin D concentration in the overall sample was 17.1 ng/mL [Q1, Q3: 9.78, 22.3]. The highest proportions of vitamin D deficiency were detected in women originating from Africa and Middle East (91.4% deficient, median vitamin D concentration of 10.7 ng/mL [Q1, Q3: 6.55, 14.45]) and from South-East Asia/Pacific (88.5% deficient, median vitamin D concentration of 8.4 ng/mL [Q1, Q3: 6.10, 14.88]). Multivariable logistic regression showed that significant risk factors of vitamin D deficiency were country of origin (women born in Switzerland and Germany had a lower risk than women born in other countries), smoking status (lower risk for former smokers) and intake of vitamin D supplements. CONCLUSIONS: Our results confirm a high prevalence of vitamin D deficiency in this Swiss cohort, in particular in women coming from Asian and African countries, and underline the importance of appropriate counseling and vitamin D supplementation in early pregnancy.
Asunto(s)
Complicaciones del Embarazo/epidemiología , Primer Trimestre del Embarazo/sangre , Deficiencia de Vitamina D/epidemiología , Vitamina D/análogos & derivados , Adulto , África/etnología , Asia Sudoriental/etnología , Femenino , Alemania/etnología , Voluntarios Sanos , Humanos , Modelos Logísticos , Medio Oriente/etnología , Análisis Multivariante , Estado Nutricional , Embarazo , Complicaciones del Embarazo/etnología , Primer Trimestre del Embarazo/etnología , Mujeres Embarazadas , Prevalencia , Factores de Riesgo , Suiza/epidemiología , Suiza/etnología , Vitamina D/sangre , Deficiencia de Vitamina D/etnologíaRESUMEN
Intestinal lymph supposedly provides a readout for the secretion of intestinal peptides. We here assessed how mesenteric lymph duct (MLD) lymph levels of glucagon-like peptide (GLP-1), insulin, and metabolites [glucose and triglycerides (TG)] evolve after isocaloric high- and low-fat diet (HFD and LFD) meals and how they compare with hepatic portal vein (HPV) plasma levels. Moreover, we examined the effects of intraperitoneally administered GLP-1 (1 or 10 nmol/kg) on these parameters. At 20 min after the HFD meal onset, GLP-1 levels were higher in MLD lymph than in HPV plasma. No such difference occurred with the LFD meal. Intraperitoneal injections of 10 nmol/kg GLP-1 before meals enhanced the meal-induced increases in MLD lymph and HPV plasma GLP-1 levels except for the MLD lymph levels after the HFD meal. Intraperitoneal injection of 1 nmol/kg GLP-1 only increased HPV plasma GLP-1 levels at 60 min after the HFD meal. GLP-1 injections did not increase the MLD lymph or HPV plasma GLP-1 concentrations beyond the physiological range, suggesting that intraperitoneal GLP-1 injections can recapitulate the short-term effects of endogenous GLP-1. Dipeptidyl peptidase IV (DPP-IV) activity in MLD lymph was lower than in HPV plasma, which presumably contributed to the higher levels of GLP-1 in lymph than in plasma. Insulin and glucose showed similar profiles in MLD lymph and HPV plasma, whereas TG levels were higher in lymph than in plasma. These results indicate that intestinal lymph provides a sensitive readout of intestinal peptide release and potential action, in particular when fat-rich diets are consumed.
Asunto(s)
Péptido 1 Similar al Glucagón/metabolismo , Secreciones Intestinales/metabolismo , Linfa/metabolismo , Vasos Linfáticos/metabolismo , Periodo Posprandial , Animales , Biomarcadores/metabolismo , Dieta con Restricción de Grasas , Dieta Alta en Grasa , Dipeptidil Peptidasa 4/metabolismo , Ingestión de Energía , Péptido 1 Similar al Glucagón/administración & dosificación , Péptido 1 Similar al Glucagón/sangre , Glucosa/metabolismo , Inyecciones Intraperitoneales , Insulina/metabolismo , Masculino , Ratas Sprague-Dawley , Vías Secretoras , Factores de Tiempo , Triglicéridos/metabolismoRESUMEN
Endogenous intestinal glucagon-like peptide-1 (GLP-1) controls satiation and glucose metabolism via vagal afferent neurons (VANs). Recently, VANs have received increasing attention for their role in brown adipose tissue (BAT) thermogenesis. It is, however, unclear whether VAN GLP-1 receptor (GLP-1R) signaling affects BAT thermogenesis and energy expenditure (EE) and whether this VAN mechanism contributes to energy balance. First, we tested the effect of the GLP-1R agonist exendin-4 (Ex4, 0.3 µg/kg ip) on EE and BAT thermogenesis and whether these effects require VAN GLP-1R signaling using a rat model with a selective Glp1r knockdown (kd) in VANs. Second, we examined the role of VAN GLP-1R in energy balance during chronic high-fat diet (HFD) feeding in VAN Glp1r kd rats. Finally, we used viral transsynaptic tracers to identify the possible neuronal substrates of such a gut-BAT interaction. VAN Glp1r kd attenuated the acute suppressive effects of Ex4 on EE and BAT thermogenesis. Consistent with this finding, the VAN Glp1r kd increased EE and BAT activity, diminished body weight gain, and improved insulin sensitivity compared with HFD-fed controls. Anterograde transsynaptic viral tracing of VANs infected major hypothalamic and hindbrain areas involved in BAT sympathetic regulation. Moreover, retrograde tracing from BAT combined with laser capture microdissection revealed that a population of VANs expressing Glp1r is synaptically connected to the BAT. Our findings reveal a novel role of VAN GLP-1R signaling in the regulation of EE and BAT thermogenesis and imply that through this gut-brain-BAT connection, intestinal GLP-1 plays a role in HFD-induced metabolic syndrome.
Asunto(s)
Tejido Adiposo Pardo/inervación , Sistema Nervioso Autónomo/metabolismo , Encéfalo/metabolismo , Metabolismo Energético , Péptido 1 Similar al Glucagón/metabolismo , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Intestinos/inervación , Termogénesis , Animales , Sistema Nervioso Autónomo/efectos de los fármacos , Dieta Alta en Grasa , Metabolismo Energético/efectos de los fármacos , Exenatida/farmacología , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/genética , Incretinas/farmacología , Masculino , Vías Nerviosas/metabolismo , Neuronas Aferentes/metabolismo , Ratas Sprague-Dawley , Transducción de Señal , Termogénesis/efectos de los fármacosRESUMEN
Vitamin D deficiency during pregnancy is associated with negative health consequences for mothers and their infants. Data on the vitamin D status of pregnant women in Switzerland are scarce. A three-centre study was conducted in the obstetric departments of Zurich, Bellinzona and Samedan (Switzerland) to investigate the prevalence and determinants of vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D)<50 nmol/l) in 3rd-trimester pregnant women living in Switzerland (n 305), and the correlation between 25(OH)D in pregnant women and their offspring at birth (n 278). Demographic and questionnaire data were used to explore the determinants of vitamin D deficiency. Median concentration of serum 25(OH)D in the third trimester of pregnancy was 46·0 nmol/l (1st-3rd quartiles: 30·5-68·5), representing a 53·4 % prevalence of vitamin D deficiency. 25(OH)D levels in the umbilcal cord blood (median: 50·0 nmol/l; 1st-3rd quartiles: 31·0-76·6) strongly correlated with mothers' serum 25(OH)D (Spearman's correlation ρ=0·79, P<0·001). Multivariable logistic regression analysis showed that significant determinants of vitamin D deficiency in pregnant women were centre of study, country of origin, season of delivery and vitamin D supplement intake. Near-term BMI, skin colour, use of sunscreen and mothers' education, although each not individually significant, collectively improved the ability of the model to explain vitamin D status. Low vitamin D levels were common in this sample of pregnant women and their newborns' cord blood. Vitamin D supplement intake was the most actionable determinant of vitamin D status, suggesting that vitamin D supplementation during pregnancy should receive more attention in clinical practice.
Asunto(s)
Complicaciones del Embarazo/epidemiología , Deficiencia de Vitamina D/epidemiología , Adulto , Suplementos Dietéticos , Femenino , Sangre Fetal/química , Humanos , Conceptos Meteorológicos , Estado Nutricional , Embarazo , Complicaciones del Embarazo/sangre , Tercer Trimestre del Embarazo , Estaciones del Año , Pigmentación de la Piel , Luz Solar , Suiza/epidemiología , Vitamina D/administración & dosificación , Vitamina D/análogos & derivados , Vitamina D/sangre , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/complicacionesRESUMEN
The small intestine is the main organ involved in the digestion and absorption of nutrients. It is in an ideal position to sense the availability of energy in the lumen in addition to its absorptive function. Consumption of a high-fat diet (HFD) influences the metabolic characteristics of the small intestine. Therefore, to better understand the metabolic features of the small intestine and their changes in response to dietary fat, we characterized the metabolism of duodenal, jejunal, and hepatic cell lines and assessed the metabolic changes in the enterocytes and the liver after short-term (3 days) or medium-term (14 days) HFD feeding in mice. Experiments with immortalized enterocytes indicated a higher glycolytic capacity in the duodenal cell line compared to the other two cell lines, whereas the jejunal cell line exhibited a high oxidative metabolism. Short-term HFD feeding induced changes in the expression of glucose and lipid metabolism-related genes in the duodenum and the jejunum of mice, but not in the liver. When focusing on fatty acid oxidation both, short- and medium-term HFD feeding induced an upregulation of 3-hydroxy-3-methylglutaryl-coenzyme A, the key enzyme of ketogenesis, at the protein level in the intestinal epithelial cells, but not in the liver. These results suggest that HFD feeding induces an early adaptation of the small intestine rather than the liver in response to a substantial fat load. This highlights the importance of the small intestine in the adaptation of the body to the metabolic changes induced by HFD exposure. J. Cell. Physiol. 232: 167-175, 2017. © 2016 Wiley Periodicals, Inc.
Asunto(s)
Dieta Alta en Grasa , Enterocitos/efectos de los fármacos , Intestino Delgado/efectos de los fármacos , Intestino Delgado/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Obesidad/metabolismo , Adaptación Fisiológica/efectos de los fármacos , Composición Corporal/efectos de los fármacos , Composición Corporal/fisiología , Grasas de la Dieta/metabolismo , Enterocitos/metabolismo , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Factores de TiempoRESUMEN
The first stable gold(III) formate and experimental evidence for its ß-hydride elimination are described. A catalytic dehydrogenation of formic acid together with mechanistic studies shed light on potential pathways operating in fundamental gold-catalyzed transformations.
RESUMEN
Macrocycles are arising considerable interest in medicinal chemistry. With the goal of harnessing C-H activation reactions for the development of efficient macrocyclization processes, the ruthenium(II)-catalyzed cyclization of O-methyl benzhydroxamates possessing an ω-acetylenic chain was investigated to access new structurally diverse macrocyclic isoquinolones. A slow addition of the substrate and the presence of Cu(OAc)2 â H2 O as an additive were crucial for the success of the macrocyclization that features an excellent functional-group compatibility, as illustrated by the successful synthesis of a library of 21â macrocyclic isoquinolones of different ring sizes and substitution patterns. These results contribute to significantly highlight the synthetic interest of C-H activation-mediated processes for the synthesis of new macrocyles incorporating heterocyclic scaffolds of potential interest in medicinal chemistry.
RESUMEN
With the goal of synthesizing new [n]paracyclophanes, the expansion of the scope of a strategy originally disclosed by Winterfeldt etâ al., was investigated. This approach involves sequential Diels-Alder/retro-Diels-Alder reactions, the applications of which have been constrained so far to steroid derivatives. An efficient access to new functionalized [9]-, [10]-, and [16]paracyclophanes, including original cage architectures, was developed from readily available building blocks using thermal electrocyclization and a cycloaddition/cycloreversion sequence as the key steps.
Asunto(s)
Éteres Cíclicos/química , Ciclización , Reacción de Cicloadición , Lactamas , Compuestos Macrocíclicos/químicaRESUMEN
The past decades have witnessed the rise and fall of several, largely unsuccessful, therapeutic attempts to bring the escalating obesity pandemic to a halt. Looking back to look ahead, the field has now put its highest hopes in translating insights from how the gastrointestinal (GI) tract communicates with the brain to calibrate behavior, physiology, and metabolism. A major focus of this review is to summarize the latest advances in comprehending the neuroendocrine aspects of this so-called 'gut-brain axis' and to explore novel concepts, cutting-edge technologies, and recent paradigm-shifting experiments. These exciting insights continue to refine our understanding of gut-brain crosstalk and are poised to promote the development of additional therapeutic avenues at the dawn of a new era of antiobesity therapeutics.
RESUMEN
Background and Objectives: Emerging preclinical evidence suggests that vagal signals contribute to the development of schizophrenia-related abnormalities in brain and behavior. Whether vagal communication in general, and its impairment in particular, is a risk factor for schizophrenia in humans remains, however, unclear. Vagotomy, the surgical lesion of the vagus nerve, was routinely performed as a treatment for peptic ulcer before modern treatment options were available. Hence, the primary aim of this study was to investigate whether vagotomy modulates the subsequent risk of developing schizophrenia. Moreover, given the existence of diverse vagotomy techniques (i.e., "truncal" or "selective"), our secondary goal was to test whether the extent of denervation modulates the risk of schizophrenia. Methods: Using a nationwide retrospective matched cohort design, we identified 8,315 vagotomized individuals from the Swedish National Patient Register during the period 1970-2020 and 40,855 non-vagotomized individuals matching for age, sex and type of peptic ulcer. The risk of being diagnosed with schizophrenia and associated psychoses (ICD10 codes F20-29) was analyzed using Cox proportional hazards regression models, including death as competing risk. Results: When considering all types of vagotomy together, vagotomy was not significantly associated with schizophrenia (HR: 0.91 [0.72; 1.16]). However, truncal vagotomy (which denervates all subdiaphragmatic organs) significantly increased the risk of developing schizophrenia by 69% (HR: 1.69 [1.08; 2.64]), whereas selective vagotomy (which only denervates the stomach) showed no significant association (HR: 0.80 [0.61; 1.04]). Discussion: Our results provide epidemiological support for the hypothesis that impairments in vagal functions could increase the risk of schizophrenia. Notably, the finding that truncal but not selective vagotomy is associated with an increased risk of schizophrenia raises the possibility that the activity of subdiaphragmatic non-gastric vagal branches may be of particular relevance for the development of schizophrenia.
RESUMEN
Food intake behavior is under the tight control of the central nervous system. Most studies to date focus on the contribution of neurons to this behavior. However, although previously overlooked, astrocytes have recently been implicated to play a key role in feeding control. Most of the recent literature has focused on astrocytic contribution in the hypothalamus or the dorsal vagal complex. The contribution of astrocytes located in the lateral parabrachial nucleus (lPBN) to feeding behavior control remains poorly understood. Thus, here, we first investigated whether activation of lPBN astrocytes affects feeding behavior in male and female rats using chemogenetic activation. Astrocytic activation in the lPBN led to profound anorexia in both sexes, under both ad-libitum feeding schedule and after a fasting challenge. Astrocytes have a key contribution to glutamate homeostasis and can themselves release glutamate. Moreover, lPBN glutamate signaling is a key contributor to potent anorexia, which can be induced by lPBN activation. Thus, here, we determined whether glutamate signaling is necessary for lPBN astrocyte activation-induced anorexia, and found that pharmacological N-methyl D-aspartate (NMDA) receptor blockade attenuated the food intake reduction resulting from lPBN astrocyte activation. Since astrocytes have been shown to contribute to feeding control by modulating the feeding effect of peripheral feeding signals, we further investigated whether lPBN astrocyte activation is capable of modulating the anorexic effect of the gut/brain hormone, glucagon like peptide -1, as well as the orexigenic effect of the stomach hormone - ghrelin, and found that the feeding effect of both signals is modulated by lPBN astrocytic activation. Lastly, we found that lPBN astrocyte activation-induced anorexia is affected by a diet-induced obesity challenge, in a sex-divergent manner. Collectively, current findings uncover a novel role for lPBN astrocytes in feeding behavior control.
Asunto(s)
Astrocitos , Ingestión de Alimentos , Núcleos Parabraquiales , Animales , Astrocitos/metabolismo , Astrocitos/fisiología , Masculino , Femenino , Ratas , Ingestión de Alimentos/fisiología , Núcleos Parabraquiales/fisiología , Anorexia/metabolismo , Conducta Alimentaria/fisiología , Ratas Sprague-Dawley , Ácido Glutámico/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismoRESUMEN
Polycystic ovary syndrome (PCOS) is associated with symptoms of moderate to severe anxiety and depression. Hyperandrogenism is a key feature together with lower levels of the adipocyte hormone adiponectin. Androgen exposure leads to anxiety-like behavior in female offspring while adiponectin is reported to be anxiolytic. Here we test the hypothesis that elevated adiponectin levels protect against the development of androgen-induced anxiety-like behavior. Pregnant mice overexpressing adiponectin (APNtg) and wildtypes were injected with vehicle or dihydrotestosterone to induce prenatal androgenization (PNA) in the offspring. Metabolic profiling and behavioral tests were performed in 4-month-old female offspring. PNA offspring spent more time in the closed arms of the elevated plus maze, indicating anxiety-like behavior. Intriguingly, neither maternal nor offspring adiponectin overexpression prevented an anxiety-like behavior in PNA-exposed offspring. However, adiponectin overexpression in dams had metabolic imprinting effects, shown as lower fat mass and glucose levels in their offspring. While serum adiponectin levels were elevated in APNtg mice, cerebrospinal fluid levels were similar between genotypes. Adiponectin overexpression improved metabolic functions but did not elicit anxiolytic effects in PNA-exposed offspring. These observations might be attributed to increased circulating but unchanged cerebrospinal fluid adiponectin levels in APNtg mice. Thus, increased adiponectin levels in the brain are likely needed to stimulate anxiolytic effects.