Cocaine-amphetamine-regulated Transcript Research Articles

Expression and role of cocaine-amphetamine regulated transcript (CART) in the proliferation of biliary epithelium.

Cholangiocytes, the epithelial cells that line the biliary tree, can proliferate under the stimulation of several factors through both autocrine and paracrine pathways. The cocaine-amphetamine-regulated-transcript (CART) peptide has several physiological functions, and it is widely expressed in several organs. CART increases the survival of hippocampal neurons by upregulating brain-derived neurotrophic factor (BDNF), whose expression has been correlated to the proliferation rate of cholangiocytes. In the present study, we aimed to evaluate the expression of CART and its role in modulating cholangiocyte proliferation in healthy and bile duct ligated (BDL) rats in vivo, as well as in cultured normal rat cholangiocytes (NRC) in vitro. Liver samples from both healthy and BDL (1 week) rats, were analyzed by immunohistochemistry and immunofluorescence for CART, CK19, TrkB and p75NTR BDNF receptors. PCNA staining was used to evaluate the proliferation of the cholangiocytes, whereas TUNEL assay was used to evaluate biliary apoptosis. NRC treated or not with CART were used to confirm the role of CART on cholangiocytes proliferation and the secretion of BDNF. Cholangiocytes proliferation, apoptosis, CART and TrkB expression were increased in BDL rats, compared to control rats. We found a higher expression of TrkB and p75NTR, which could be correlated with the proliferation rate of biliary tree during BDL. The in vitro study demonstrated increased BDNF secretion by NRC after treatment with CART compared with control cells. As previously reported, proliferating cholangiocytes acquire a neuroendocrine phenotype, modulated by several factors, including neurotrophins. Accordingly, CART may play a key role in the remodeling of biliary epithelium during cholestasis by modulating the secretion of BDNF.

Effects of Extreme Light Cycle and Density on Melatonin, Appetite, and Energy Metabolism of the Soft-Shelled Turtle (Pelodiscus sinensis).

Simple SummaryLight is an important factor that affects a variety of physiological functions of animals. Melatonin is known as the hormonal mediator of photoperiodic information to the central nervous system in vertebrates and plays a key role in food intake and energy balance regulation. The present work aimed to examine the effect of extreme light cycles (herein meaning constant darkness and constant light) that animals may encounter under dark culture situations or light pollution on melatonin secretion and melatonin-modulated appetite and energy metabolism of the soft-shelled turtle Pelodiscus sinensis. We measured melatonin level, appetite, and energy metabolism-related parameters under various photoperiods and stocking densities during daytime and nighttime. The results demonstrated that (1) melatonin secretion of the turtle was not only affected by light, but also likely to be regulated by unknown endogenous factors and density; and (2) altered plasma melatonin induced by constant darkness and density seemed to be involved in the modulation of energy metabolism (elevated thyroid activity and standard metabolic rate) rather than appetite (unchanged leptin and ghrelin contents, kisspeptin 1, cocaine amphetamine-regulated transcript, and neuropeptide Y mRNA) in Chinese soft-shelled turtles. Our results shed light on the physiological responses of freshwater turtles to extreme light cycles and also contribute important data for turtle culture.Constant darkness and constant light exposure often disturb the circadian rhythm in the behavior and energy metabolism of vertebrates. Melatonin is known as the hormonal mediator of photoperiodic information to the central nervous system and plays a key role in food intake and energy balance regulation in vertebrates. The popularly cultured soft-shelled turtle Pelodiscus sinensis has been reported to grow better under constant darkness; however, the underlying physiological mechanism by which darkness benefits turtle growth is not clear yet. We hypothesized that increased melatonin levels induced by darkness would increase appetite and energy metabolism and thus promote growth in P. sinensis. In addition, in order to elucidate the interaction of photoperiod and density, juvenile turtles were treated under three photoperiods (light/dark cycle: 24L:0D, 12L:12D, 0L:24D, light density 900 lux) and two stocking densities (high density: 38.10 ind./m2, low density: 6.35 ind./m2) for 4 weeks, and then the blood and brain tissues of turtles were collected during the day (11:00–13:00) and at night (23:00–1:00) after 2 days of fasting. We examined changes in plasma melatonin levels, food intake (FI), and appetite-related hormones (plasma ghrelin and leptin), as well as growth and energy metabolism parameters such as specific growth rate (SGR), standard metabolic rate (SMR), plasma growth hormone (GH), and thyroid hormone/enzyme activity (plasma triiodothyronine T3, thyroxine T4, and T45′-deiodinase activity). Moreover, we also assessed the responses of mRNA expression levels of food intake-related genes (kisspeptin 1 (Kiss1); cocaine amphetamine-regulated transcript (CART); neuropeptide Y (NPY)) in the brain. The results showed that under high density, SGR was the lowest in 24L:0D and the highest in 0L:24D. FI was the highest in 0L:24D regardless of density. Plasma melatonin was the highest in 0L:24D under high density at night. SMR increased with decreasing light time regardless of density. Most expressions of the measured appetite-related genes (Kiss1, CART, and NPY) were not affected by photoperiod, nor were the related hormone levels, such as plasma leptin, ghrelin, and GH. However, thyroid hormones were clearly affected by photoperiod. T3 level in 0L:24D under high density during the day was the highest among all treatment groups. T4 in 24L:0D under high density during the day and T45′-deiodinase activity in 24L:0D under low density at night were significantly reduced compared with the control. Furthermore, the energy metabolism-related hormone levels were higher under higher density, especially during the day. Together, melatonin secretion is not only modulated by light but also likely to be regulated by unknown endogenous factors and density. Altered plasma melatonin induced by constant darkness and density seems to be involved in the modulation of energy metabolism rather than appetite in the soft-shelled turtle.

Cocaine-amphetamine regulated transcript (CART) - promising omics breakthrough in the endocrinology

The cocaine-amphetamine regulated transcript has been discovered long time ago (circa over 25 years ago) but still stays not enough investigated. Just during last five years scientist's society started providing interest to the genomic, proteomic and metabolic essence of the cocaine-amphetamine regulated transcript. The evaluation of historical pathway and perspectives of the cocaine-amphetamine regulated transcript medical investigations. The literature search has been provided via Russian (eLibrary, CyberLeninka.ru) and international (PubMed, Cochrane Library) databases and among articles on Russian and English languages. The main criteria for article selection was free access and 2019-2021 years of publishing. Although the introduction is based on the articles published in 1989. The present article was created according to the federal project «Central and peripheral pathophysiological mechanisms of adipose tissue diseases and their clinical and hormonal manifestations патофизиологические механизмы развития болезней жировой ткани с учетом клинических и гормональных характеристик» (2020-2022)RESULTS AND CONCLUISON:It is necessary to keep on investigating genomic, proteomic and metabolomic markers because they contain important clues for successful resistance against human diseases. The 21stcentury is the era of transformation from simple clinical medicine to personalized science. For example, researches in the area of cocaine-amphetamine regulated transcript may result in invention of genetic medicine against dangerous metabolic diseases.

Effect of Chemically-Induced Diabetes Mellitus on Phenotypic Variability of the Enteric Neurons in the Descending Colon in the Pig

Abstract Gastrointestinal neuropathy in diabetes is one of numerous diseases resulting in abnormal functioning of the gastrointestinal tract (GIT), and it may affect any section of the GIT, including the descending colon. In the gastrointestinal system, the neurons are arranged in an interconnecting network defined as the enteric nervous system (ENS) which includes the myenteric plexus and the submucosal plexuses: inner and outer. Regular functioning of the ENS is determined by normal synthesis of the neurotransmitters and neuromodulators. This paper demonstrates the effect of hyperglycaemia on the number of enteric neurons which are immunoreactive to: neural isoform of nitric oxide synthase (nNOS), vasoactive intestinal peptide (VIP), galanin (GAL), calcitonin generelated peptide (CGRP) and cocaine amphetamine-regulated transcript (CART) in the porcine descending colon. It was demonstrated that there was a statistically significant increase in the number of neurons within the myenteric plexus immunoreactive to all investigated substances. In the outer submucosal plexus, the CART-positive neurons were the only ones not to change, whereas no changes were recorded for nNOS or CART in the inner submucosal plexus. This study is the first study to discuss quantitative changes in the neurons immunoreactive to nNOS, VIP, GAL, CGRP and CART in the descending colon in diabetic pigs.

CART mitigates oxidative stress and DNA damage in memory deficits of APP/PS1 mice via upregulating β‑amyloid metabolism‑associated enzymes.

Alzheimer's disease (AD) is the most common form of dementia that is primarily characterized by progressive cognitive deficits. The toxicity of amyloid β-protein (Aβ) serves an important role in the progression of AD, resulting in neuronal loss via a number of possible mechanisms, including oxidative stress, mitochondrial dysfunction, energy depletion, apoptosis and neuroinflammation. Previous studies have reported that cocaine amphetamine regulated transcript (CART) treatment improves memory and synaptic structure in APP/PS1 mice. Therefore, the present study aimed to investigate whether CART served a protective role against memory deficits in AD. APP/PS1 mice were treated with CART or PBS. Spatial memory was assessed using the Morris water maze. Oxidative stress and DNA damage were compared among wild-type, APP/PS1 and CART-treated APP/PS1 mice. The mRNA and protein expression levels of Aβ metabolism-associated enzymes, including neprilysin (NEP), insulin-degrading enzyme (IDE), receptor for advanced glycation end products (RAGE) and low-density lipoprotein receptor-related protein 1 (LRP-1), in the hippocampus were measured via reverse transcription-quantitative PCR and western blotting, respectively. CART improved the memory impairment of APP/PS1 mice by reducing oxidative stress, inhibiting DNA damage and protecting against mitochondrial dysfunction in the cerebral cortex and hippocampus. CART also reduced cell senescence and oxidative stress in Aβ1-42-exposed primary cortical neurons in APP/PS1 mice. Moreover, CART promoted Aβ degradation via modulating Aβ metabolism-associated enzymes, including IDE, NEP, LRP-1 and RAGE. Collectively, the present study indicated that CART improved the learning and memory capacity of APP/PS mice, thus may have potential to serve as a novel therapeutic agent for AD.

Khat (Catha edulis) upregulates lipolytic genes in white adipose tissue of male obese mice (C57BL/6J)

Ethnopharmacological relevanceKhat (Catha edulis (Vahl) Forssk.) is a herb from the Celastraceae family (also known as qat, gaad, or mirra) that is widely-consumed in East Africa and in the Arabian peninsula. The green leaves and small stems are consumed primarily at recreational and social gatherings, and medicinally for their antidiabetic and appetite-suppression effects. AimsThe objectives of this study were to determine the effects of khat and its active alkaloid, cathinone, on food intake and body weight in mice maintained on a high-fat diet, and to investigate its mechanism of action in white adipose tissue and in the hypothalamus.Materials & Method: Adult male mice (C57BL/6J) were fed a high fat diet (HFD) for 8 weeks (n = 30), then divided into 5 groups and treated daily for a further 8 weeks with HFD + vehicle [control (HFD)], HFD + 15 mg/kg orlistat (HFDO), HFD + 200 mg/kg khat extract (HFDK200), HFD + 400 mg/kg khat extract (HFDK400) and HFD + 3.2 mg/kg cathinone (HFDCAT). Treatments were carried out once daily by gastric gavage. Blood and tissue samples were collected for biochemical, hormonal and gene expression analyses. ResultsKhat extracts and orlistat treatment significantly reduced weight gain as compared to control mice on HFD, and cathinone administration completely prevented weight gain in mice fed on HFD. Khat treatment caused a marked reduction in body fat and in serum triglycerides. A dose-dependent effect of khat was observed in reducing serum leptin concentrations. Analysis of gene expression in adipose tissue revealed a significant upregulation of two lipolysis pathway genes:(adipose triglyceride lipase (PNPLA-2) and hormone-sensitive lipase (LIPE). In the hypothalamic there was a significant (P < 0.05) upregulation of agouti-related peptide (AgRP) and cocaine-amphetamine regulated transcript (CART) genes in the HFDK400 and HFDCAT groups. ConclusionCathinone treatment blocked body weight gain, while high dose khat extract significantly reduced the weight gain of mice on an obesogenic diet through stimulation of lipolysis in white adipose tissue.

The neuroprotective effect of NeuroAid on morphine-induced amnesia with respect to the expression of TFAM, PGC-1α, ΔfosB and CART genes in the hippocampus of male Wistar rats.

Morphine is a natural alkaloid which derived from the opium poppy Papaver somniferum. Many studies have reported the effect of morphine on learning, memory and gene expression. CART (cocaine-amphetamine regulated transcript)is an important neuropeptide which has a critical role in physiological processes including drug dependence and antioxidant activity. ΔfosB is a transcription factor which modulates synaptic plasticity and affects learning and memory. TFAM (the mitochondrial transcription factor A) and PGC-1α (Peroxisome proliferator-activated receptor γ coactivator-1α) are critically involved in mitochondrial biogenesis and antioxidant pathways. NeuroAid is a Chinese medicine that induces neuroprotective and anti-apoptotic effects. In this research, we aimed to investigate the effect of NeuroAid on morphine-induced amnesia with respect to the expression of TFAM, PGC-1α, ΔfosB and CART in the rat's hippocampus. In this study, Morphine sulfate (at increasing doses), Naloxone hydrochloride (2.5mg/kg) and NeuroAid (2.5mg/kg) were administered intraperitoneal and real-time PCR reactions were done to assess gene expression. The results showed, morphine impaired memory of step-through passive avoidance, while NeuroAid had no effect. NeuroAid attenuated (but not reversed) morphine-induced memory impairment in morphine-addicted rats. Morphine increased the expression of PGC-1α and decreased the expression of CART. However, NeuroAid increased the expression of TFAM, PGC-1α, ΔfosB and CART. NeuroAid restored the effect of morphine on the expression of CART and PGC-1α. In conclusion, morphine impaired memory of step-through passive avoidance and NeuroAid attenuated this effect. The effect of NeuroAid on morphine-induced memory impairment/gene expression may be related to its anti-apoptotic and neuroprotective effects.

Goldfish Leptin-AI and Leptin-AII: Function and Central Mechanism in Feeding Control.

In mammals, leptin is a peripheral satiety factor that inhibits feeding by regulating a variety of appetite-related hormones in the brain. However, most of the previous studies examining leptin in fish feeding were performed with mammalian leptins, which share very low sequence homologies with fish leptins. To elucidate the function and mechanism of endogenous fish leptins in feeding regulation, recombinant goldfish leptin-AI and leptin-AII were expressed in methylotrophic yeast and purified by immobilized metal ion affinity chromatography (IMAC). By intraperitoneal (IP) injection, both leptin-AI and leptin-AII were shown to inhibit the feeding behavior and to reduce the food consumption of goldfish in 2 h. In addition, co-treatment of leptin-AI or leptin-AII could block the feeding behavior and reduce the food consumption induced by neuropeptide Y (NPY) injection. High levels of leptin receptor (lepR) mRNA were detected in the hypothalamus, telencephalon, optic tectum and cerebellum of the goldfish brain. The appetite inhibitory effects of leptins were mediated by downregulating the mRNA levels of orexigenic NPY, agouti-related peptide (AgRP) and orexin and upregulating the mRNA levels of anorexigenic cocaine-amphetamine-regulated transcript (CART), cholecystokinin (CCK), melanin-concentrating hormone (MCH) and proopiomelanocortin (POMC) in different areas of the goldfish brain. Our study, as a whole, provides new insights into the functions and mechanisms of leptins in appetite control in a fish model.

Injection of Cocaine-Amphetamine Regulated Transcript (CART) peptide into the nucleus accumbens does not inhibit caffeine-induced locomotor activity: Implications for CART peptide mechanism

Much evidence suggests that intra-nucleus accumbens (NAc) CART peptide (CART 55-102) injection inhibits locomotor activity (LMA) when there is an increase in the release and activity of dopamine (DA) in the NAc. However, this hypothesis has not been fully tested. One way to examine this is to determine if there is a lack of effect of intra-NAc CART peptide on LMA that does not involve increases in DA release in the NAc. Several studies have suggested that caffeine-induced LMA does not involve extracellular DA release in the NAc core. Therefore, in this study, we have examined the effect of injections of CART peptide (2.5μg) into the NAc core on the locomotor effects of caffeine in male Sprague-Dawley rats. Several LMA relevant doses of caffeine were used (0, 10, 20mg/kg i.p.), and an inverted U response curve was found as expected. We determined, in the same animals, that intra-NAc CART peptide had no effect on caffeine-induced LMA whereas it blunted cocaine-mediated LMA, as shown by other reports. We also extended a previous observation in mice by showing that at a LMA activating dose of caffeine there is no alteration of CART peptide levels in the NAc of rats. Our study supports the hypothesis that the inhibitory effects of CART peptide in the NAc may be exerted only under conditions of increased extracellular DA release and activity in this region. Our results also suggest that intra-NAc CART 55-102 does not generally inhibit increases in LMA due to all drugs, but has a more specific inhibitory effect on dopaminergic neurotransmission.

Nucleus accumbens cocaine-amphetamine regulated transcript mediates food intake during novelty conflict

Obesity is a persistent and pervasive problem, particularly in industrialized nations. It has come to be appreciated that the metabolic health of an individual can influence brain function and subsequent behavioral patterns. To examine the relationship between metabolic phenotype and central systems that regulate behavior, we tested rats with divergent metabolic phenotypes (Low Capacity Runner: LCR vs. High Capacity Runner: HCR) for behavioral responses to the conflict between hunger and environmental novelty using the novelty suppressed feeding (NSF) paradigm. Additionally, we measured expression of mRNA, for peptides involved in energy management, in response to fasting. Following a 24-h fast, LCR rats showed lower latencies to begin eating in a novel environment compared to HCR rats. A 48-h fast equilibrated the latency to begin eating in the novel environment. A 24-h fast differentially affected expression of cocaine-amphetamine regulated transcript (CART) mRNA in the nucleus accumbens (NAc), where 24-h of fasting reduced CART mRNA in LCR rats. Bilateral microinjections of CART 55-102 peptide into the NAc increased the latency to begin eating in the NSF paradigm following a 24-h fast in LCR rats. These results indicate that metabolic phenotype influences how animals cope with the conflict between hunger and novelty, and that these differences are at least partially mediated by CART signaling in the NAc. For individuals with poor metabolic health who have to navigate food-rich and stressful environments, changes in central systems that mediate conflicting drives may feed into the rates of obesity and exacerbate the difficulty individuals have in maintaining weight loss.

Lack of Hypophagia in CB1 Null Mice is Associated to Decreased Hypothalamic POMC and CART Expression.

Background:Cumulative data indicate that the endocannabinoid system plays a major role in feeding behavior and energy balance. Genetic silencing of cannabinoid receptor type 1 (CB1) reduces body weight gain, independently of food intake.Methods:In this work, we investigated whether the hypothalamic neuropeptide expression pattern supports the absence of the anorexigenic response observed under constitutive CB1 ablation, by using neuronal CB1 conditional null mice (CamK-CB1-KO) and whole body CB1 null mice (CB1-KO).Results:Our data showed that both CB1 null models display a marked decrease in proopiomelanocortin (POMC) and cocaine-amphetamine-regulated transcript (CART) expression in the arcuate nucleus of the hypothalamus (ARC).Conclusions:This evidence suggests that a lack of hypophagia is associated with the suppression of ARC anorexigenic neuropeptides and that behavioral changes in food intake (or lack thereof) after constitutive CB1 ablation are likely mediated by impaired melanocortin and CART signaling in the hypothalamus.

Up-regulation of orexigenic and down-regulation of anorexigenic neuropeptide gene expression in rat hypothalamus after partial lipectomy

Leptin down-regulates orexigenic and up-regulates anorexigenic neuropeptide gene expression in hypothalamus. Surgical removal of adipose tissue leads to decrease in circulating leptin concentrations in rats. In the present study, we tested: (a) regulation of neuropeptide gene expression in hypothalamus, (b) food intake, and (c) standard growth rate after removal of adipose tissue in rats. Partial lipectomy caused an approximately 10-fold reduction of subcutaneous, retroperitoneal and epididymal adipose tissue weight (at the end of experiments adipose tissue weight was 1.5±0.9 in lipectomy and 15±3.9g in control rats; statistically significant). Compared to control rats, the animals subjected to lipectomy presented increased food intake, standard growth rate, and decreased serum leptin concentrations (2.6±0.8 vs. 3.7±1.2ng/mL in the controls, statistically significant). These changes were associated with approximately twofold increase in neuropeptide Y, threefold increase in agouti-related peptide (orexigenic neuropeptides) and about 50% decrease in pro-opiomelanocortin and cocaine–amphetamine-regulated transcript peptide (anorexigenic neuropeptides) mRNA levels in the hypothalamus. These results suggest that partial lipectomy, leading to a decrease in circulating leptin concentrations, may exert an effect on hypothalamic orexigenic and anorexigenic neuropeptide gene expression, and consequently modulate food intake and standard growth rate in rats.

Leptin Stimulates Neuropeptide Y and Cocaine Amphetamine-Regulated Transcript Coexpressing Neuronal Activity in the Dorsomedial Hypothalamus in Diet-Induced Obese Mice

Neuropeptide Y (NPY) neurons in both the arcuate nucleus of the hypothalamus (ARH) and the dorsomedial hypothalamus (DMH) have been implicated in food intake and obesity. However, while ARH NPY is highly expressed in the lean animal, DMH NPY mRNA expression is observed only after diet-induced obesity (DIO). Furthermore, while ARH NPY neurons are inhibited by leptin, the effect of this adipokine on DMH NPY neurons is unknown. In this study we show that in contrast to the consistent expression in the ARH, DMH NPY mRNA expression was undetectable until after 10 weeks in mice fed a high-fat diet, and peaked at 20 weeks. Surprisingly, electrophysiological experiments demonstrated that leptin directly depolarized and increased the firing rate of DMH NPY neurons in DIO mice. To further differentiate the regulation of DMH and ARH NPY populations, fasting decreased expression of DMH NPY expression, while it increased ARH NPY expression. However, treatment with a leptin receptor antagonist failed to alter DMH NPY expression, indicating that leptin may not be the critical factor regulating mRNA expression. Importantly, we also demonstrated that DMH NPY neurons coexpress cocaine amphetamine-regulated transcript (CART); however, CART mRNA expression in the DMH peaked earlier in the progression of DIO. This study demonstrates novel and important findings. First, NPY and CART are coexpressed in the same neurons within the DMH, and second, leptin stimulates DMH NPY neurons. These studies suggest that during the progression of DIO, there is an unknown signal that drives the expression of the orexigenic NPY signal within the DMH, and that the chronic hyperleptinemia increases the activity of these NPY/CART neurons.

Ablation of Neurons Expressing Melanin-Concentrating Hormone (MCH) in Adult Mice Improves Glucose Tolerance Independent of MCH Signaling

Melanin-concentrating hormone (MCH)-expressing neurons have been ascribed many roles based on studies of MCH-deficient mice. However, MCH neurons express other neurotransmitters, including GABA, nesfatin, and cocaine-amphetamine-regulated transcript. The importance of these other signaling molecules made by MCH neurons remains incompletely characterized. To determine the roles of MCH neurons in vivo, we targeted expression of the human diphtheria toxin receptor (DTR) to the gene for MCH (Pmch). Within 2 weeks of diphtheria toxin injection, heterozygous Pmch(DTR/+) mice lost 98% of their MCH neurons. These mice became lean but ate normally and were hyperactive, especially during a fast. They also responded abnormally to psychostimulants. For these phenotypes, ablation of MCH neurons recapitulated knock-out of MCH, so MCH appears to be the critical neuromodulator released by these neurons. In contrast, MCH-neuron-ablated mice showed improved glucose tolerance when compared with MCH-deficient mutant mice and wild-type mice. We conclude that MCH neurons regulate glucose tolerance through signaling molecules other than MCH.

Neurotransmitter CART as a New Therapeutic Candidate for Parkinson’s Disease

Parkinson’s disease (PD) is one of the most common neurodegenerative diseases. To date, there is no effective treatment that halts its progression. Increasing evidence indicates that mitochondria play an important role in the development of PD. Hence mitochondria-targeted approaches or agents may have therapeutic promise for treatment of the disease. Neuropeptide CART (cocaine-amphetamine-regulated transcript), a hypothalamus and midbrain enriched neurotransmitter with an antioxidant property, can be found in mitochondria, which is the main source of reactive oxygen species. Systemic administration of CART has been found to ameliorate dopaminergic neuronal loss and improve motor functions in a mouse model of PD. In this article, we summarize recent progress in studies investigating the relationship between CART, dopamine, and the pathophysiology of PD, with a focus on mitochondria-related topics.

The arcuate NPY, POMC, and CART expressions responding to food deprivation are exaggerated in young female rats that experienced neonatal maternal separation

This study was conducted to examine the effect of neonatal maternal separation on the hypothalamic feeding peptides expression in young female offspring. Sprague-Dawley pups were separated from dam for 3h daily during PND 1-14 (MS), or left undisturbed except routine cage cleaning (NH). Weanling female pups were housed in group and the arcuate mRNA levels of neuropeptide Y (NPY), proopiomelanocortin (POMC), and cocaine-amphetamine regulated transcript (CART) were examined at two months of age with or without food deprivation. The basal arcuate expression levels of these peptides did not differ between NH and MS group. However, a 48 h of food deprivation significantly increased NPY mRNA level, and decreased POMC and CART, in the arcuate nucleus of MS females, but not in NH females. Fasting-induced elevation of the plasma corticosterone tended to be greater in MS group than in NH, but the basal levels did not differ between the groups. Plasma leptin levels were decreased in MS females compared with NH, and food deprivation significantly suppressed the leptin levels both in NH and MS groups. Results suggest that MS experience may increase stress vulnerability in female rats and exaggerate the feeding peptides expression in the arcuate nucleus responding to metabolic stress food deprivation.

Polymorphisms of the cocaine-amphetamine-regulated transcript (CART) gene and their association with reproductive traits in Chinese goats

Polymorphisms of the CART gene were investigated by PCR-single-strand conformation polymorphism analysis in 540 samples from 10 goat breeds. Ten novel single-nucleotide polymorphisms as well as three microsatellites were detected; a mutation, 77T → C, led to an amino acid change (Leu → Ser). Associations between polymorphic loci and reproductive traits were analyzed in Chuandong White, Guizhou White and Gulin Ma breeds. Mutation at position 524 had no significant effect on litter size in these three goat breeds. The polymorphism 539C → A differed significantly among the three breeds (P < 0.05); C(7)T(8)/C(9)T(8) at 939 was associated with larger litter size (P < 0.05) than genotypes C(7)T(8)/C(7)T(8) and C(7)T(8)/C(8)T(8). No significant association of birth weight was found with gene variation (524C → T, 539C → A and 939 CnTn). These findings could be valuable for marker-assisted selection for goat breeding.

Action Profile of the Antiobesity Drug Candidate Oleoyl-Estrone in Rats

Oleoyl-estrone (OE) has been presented as a potential antiobesity therapeutic, but the published series of studies from one laboratory has not yet been independently confirmed, and the exact mechanism of action is unknown. Based on the hypothesis that OE has potential for the treatment of obesity, male and female rats were chronically treated with several doses of OE to evaluate the impact of this compound on energy metabolism. Body weight, body composition, energy balance parameters and the expression of hypothalamic neuropeptides regulating food intake as well as key markers of the reproductive system were examined. OE impressively reduced food consumption and body weight gain in both sexes. Although a major part of the loss in body weight could be explained by decreased fat mass, a substantial loss of lean mass also occurred after OE administration. The loss of weight can be sufficiently explained by the suppression of food consumption, as there were no major changes in energy expenditure, locomotor activity or respiratory quotient. In situ hybridization data showed no significant change in the expression of key neuropeptides and hormone receptors regulating feeding behavior after OE treatment. Cocaine-amphetamine-regulated transcript (CART) mRNA levels were decreased in the arcuate nucleus of OE-treated rats. Hypogonadism and low plasma testosterone levels were found in OE-treated males, whereas females showed substantially increased liver size. The present data suggest that OE decreases food intake and body weight but also appears to cause a significant impact on the hypothalamus-pituitary-reproductive axis.

Double disruption of α2A- and α2C -adrenoceptors results in sympathetic hyperactivity and high-bone-mass phenotype

Evidence demonstrates that sympathetic nervous system (SNS) activation causes osteopenia via β(2)-adrenoceptor (β2-AR) signaling. Here we show that female mice with chronic sympathetic hyperactivity owing to double knockout of adrenoceptors that negatively regulate norepinephrine release, α(2A)-AR and α(2C)-AR (α(2A) /α(2C)-ARKO), present an unexpected and generalized phenotype of high bone mass with decreased bone resorption and increased formation. In α(2A) /α(2C)-ARKO versus wild-type (WT) mice, micro-computed tomographic (µCT) analysis showed increased, better connected, and more plate-shaped trabeculae in the femur and vertebra and increased cortical thickness in the vertebra, whereas biomechanical analysis showed increased tibial and femoral strength. Tibial mRNA expression of tartrate-resistant acid phosphatase (TRACP) and receptor activator of NF-κB (RANK), which are osteoclast-related factors, was lower in knockout (KO) mice. Plasma leptin and brain mRNA levels of cocaine amphetamine-regulated transcript (CART), which are factors that centrally affect bone turnover, and serum levels of estradiol were similar between mice strains. Tibial β(2)-AR mRNA expression also was similar in KO and WT littermates, whereas α(2A)-, α(2B)- and α(2C)-AR mRNAs were detected in the tibia of WT mice and in osteoblast-like MC3T3-E1 cells. By immunohistochemistry, we detected α(2A)-, α(2B)-, α(2C)- and β(2)-ARs in osteoblasts, osteoclasts, and chondrocytes of 18.5-day-old mouse fetuses and 35-day-old mice. Finally, we showed that isolated osteoclasts in culture are responsive to the selective α(2)-AR agonist clonidine and to the nonspecific α-AR antagonist phentolamine. These findings suggest that β(2)-AR is not the single adrenoceptor involved in bone turnover regulation and show that α(2)-AR signaling also may mediate the SNS actions in the skeleton.

The Inhibitory Effect of Baicalin on the Short-Term Food Intake in C57BL/6J Mice

Abstract － Appetite is inhibited by the anorexigenic neuropeptides POMC (proopiomelanocortin) and CART (cocaine-amphetamine-regulated transcript) in the hypothalamus. The present study was performed to examine the inhibitory effects of baicalin against food intake and the upregulation of POMC/CART. Short-term food intake (48 h) was significantly inhibited by treatment with baicalin (10 mg/kg, p ＜0.05) in C57BL/6 mice. Immunohistochemical analysis showed that baicalin upregulated POMC and CART levels in the arcuate nucleus of the hypothalamus. These effects were also examined using an in vitro system. pPOMC-Luc or pCART-Luc plasmids were transformed into mouse N29-2 neuronal and human SH-SY5Y cells, and the activities of baicalin were examined in these cells. Baicalin increased POMC and CART promoter-driven luciferase activity in a dose-dependent manner without cytotoxic effects. These results suggest that baicalin downregulates short-term food intake while upregulating POMC and CART expression.Keywords: Baicalin,