Amphetamine-regulated Transcript Peptide Research Articles

Action of cocaine- and amphetamine-regulated transcript (CART) peptide to attenuate cisplatin-induced emesis in Suncus murinus (house musk shrew)

Cocaine- and amphetamine-regulated transcript (CART) peptide is a brain-gut neuropeptide that has been implicated in a range of physiological functions including appetite, which is disturbed during chemotherapy. The aims of the present study were to identify the distribution and expression of CART mRNA and CART peptide, and to examine the potential of CART (55-102) to attenuate cisplatin-induced emesis in Suncus murinus. CART mRNA and peptide were detected throughout the entire brain, including the forebrain, hypothalamus, and brainstem, and also in the gut wall and stomach. In conscious, freely moving animals, intracerebroventricular administration of CART (55-102) did not modulate food and water intake or alter locomotor activity when administered alone. Cisplatin induced emesis and upregulated the expression of CART mRNA in the brainstem. However, CART (55-102) reduced the number of cisplatin-induced retches. Both CART (55-102) and cisplatin increased the number of c-Fos positive cells in the nucleus tractus solitarius, lateral hypothalamus, paraventricular hypothalamus, and bed nucleus of the stria terminalis (BNST), compared to saline-treated animals, whereas cisplatin also induced c-Fos expression in the area postrema (AP), arcuate nucleus, and central nucleus of the amygdala. Pre-treatment with CART (55-102) significantly attenuated the increased c-Fos positive cells in the BNST and AP. These data indicate that CART mRNA and peptide were localized to regions involved in reward/ enforcement, emotion, feeding and emesis. The anti-emetic effect of CART (55-102) against cisplatin-induced emesis may involve both the forebrain limbic system and the brainstem.

Cocaine- and Amphetamine-Regulated Transcript Peptide in the Central Nervous System of the Gecko, Hemidactylus leschenaultii: Molecular Characterization, Neuroanatomical Organization, and Regulation by Neuropeptide Y.

Neuropeptide cocaine- and amphetamine-regulated transcript (CART) is widely expressed in the brains of teleosts, amphibians, birds, and mammals and has emerged as a conserved regulator of energy balance across these vertebrate phyla. However, as yet, there is no information on CART in the reptilian brain. We characterized the cDNA encoding CART and mapped CART-containing elements in the brain of gecko, Hemidactylus leschenaultii (hl) using a specific anti-CART antiserum. We report a 683-bp hlcart transcript containing a 336-bp open reading frame, which encodes a putative 111-amino acid hl-preproCART. The 89-amino acid hl-proCART generated from hl-preproCART produced two putative bioactive hl-CART-peptides. These bioactive CART-peptides were >93% similar with those in rats/humans. Although reverse transcription-polymerase chain reaction (RT-PCR) detected hlcart-transcript in the brain, CART-containing neurons/fibers were widely distributed in the telencephalon, diencephalon, mesencephalon, rhombencephalon, spinal cord, and retina. The mitral cells in olfactory bulb, neurons in the paraventricular, periventricular, arcuate (Arc), Edinger-Westphal, and brainstem nuclei were intensely CART-positive. In view of antagonistic roles of neuropeptide Y (NPY) and CART in energy balance in the framework of mammalian hypothalamus, we probed CART-NPY interaction in the hypothalamus of H. leschenaultii. Double immunofluorescence showed a dense NPY-innervation of Arc CART neurons. Ex vivo hypothalamic slices treated with NPY/NPY-Y1-receptor agonist significantly reduced hlcart-mRNA levels in the Arc-containing tissues and CART-ir in the dorsal-Arc. However, CART-ir in ventral-Arc was unaffected. NPY via Y1-receptors may regulate energy balance by inhibiting dArc CART neurons. This study on CART in a reptilian brain fills the current void in literature and underscores the conserved feature of the neuropeptide across the entire vertebrate phyla.

Exploring a novel toxicological mechanism: Ammonia-N induces neurotoxicity, oxidative damage in brain tissue, and modulates the expression of central appetite factors to suppress feeding in juvenile Siberian sturgeon (Acipenser baerii Brandt)

Ammonia-N is a common toxic factor in aquatic environment, known to inhibit fish feeding, yet its mechanism remains unclear. To investigate the toxicological mechanism of ammonia-N in inhibiting fish feeding, this study conducted experiments exposing juvenile Siberian sturgeon (Acipenser baerii) to ammonia-N at concentrations of 0, 5, 10, and 15 mg/L for 14 days. The results revealed a significant reduction in both daily and cumulative food intake. Obviously decreased condition factor (CF), hepatosomatic index (HSI), and viscerosomatic index (VSI) at 15 mg/L (P < 0.05). Besides, the serum ammonia concentration significantly increased on the 14th day, while the neurotoxic marker acetylcholinesterase (AchE) showed a consistent increase over the 14-day period (P < 0.05). Pathological examination of brain tissue demonstrated that ammonia-N induced damage, particularly evident in 15 mg/L ammonia-N group, where severe nerve fiber dissolution was observed. Moreover, the activity of superoxide dismutase (SOD) was significantly increased in the brain on the 1st, 3rd, and 7th day (P < 0.05). RNA-seq analysis o revealed 1566, 2188, and 2026 differentially expressed genes (DEGs) were obtained in the 5, 10, and 15 mg/L ammonia-N groups, respectively, compared to the control group, and 30 DEGs related to appetite regulation were identified. Further quantitative real-time PCR (qPCR) analysis indicated that ammonia-N exposure changed the expressions of appetite factors, including downregulation of agouti-related protein (agrp) and neuropeptide Y (npy), and upregulation of pro-opiomelanocortin (pomc), cocaine-and amphetamine-regulated transcript peptide (cart), and corticotropin releasing factor (crf) (P < 0.05). Therefore, these results suggest that ammonia-N inhibits feeding via neurotoxicity induced oxidative damage which primarily by downregulating appetite promoting factors and upregulating appetite-inhibiting factors. This study lays the groundwork for deeper understanding of the toxicological mechanism of ammonia-N on aquatic animals, particularly its detrimental effects on fish brain function and feeding behavior.

Lipidized analogues of the anorexigenic CART (cocaine- and amphetamine-regulated transcript) neuropeptide show anorexigenic and neuroprotective potential in mouse model of monosodium-glutamate induced obesity

AimsThis study investigates the neuroprotective effects of lipidized analogues of 2-SS-CART(61–102) derived from anorexigenic neuropeptide cocaine- and amphetamine-regulated transcript peptide (CARTp) in light of the link between obesity, its comorbidities, and the development of Alzheimer's disease. MethodsWe introduce novel lipidized analogues derived from 2-SS-CART(61–102), a specific analogue of natural CART(61–102), with two disulfide bridges. Using hypothermic PC12 cells, we tested the effect of the most potent analogues on Tau phosphorylation. We further described the anorexigenic and neuroprotective potential of subcutaneously (SC) injected lipidized CARTp analogue in a mouse model with prediabetes and obesity induced by neonatal monosodium glutamate (MSG) administration. ResultsCompared to the non-lipidized 2-SS-CART(61–102), all lipidized analogues exhibited a potent binding affinity to PC12 cells and enhanced in vitro stability in rat plasma. Two most potent lipidized analogues attenuated hypothermia-induced Tau hyperphosphorylation at multiple epitopes. Subsequently, chronic SC treatment with palm-2-SS-CART(61–102) significantly decreased body weight and food intake, improved metabolic parameters, decreased level of pTau and increased neurogenesis in hippocampi of obese MSG mice. ConclusionOur unique CARTp analogue palm-2-SS-CART(61–102) shows promise as a potent anti-obesity and neuroprotective agent.

CREB-Binding Protein Regulates Cocaine- and Amphetamine-Regulated Transcript Peptide Expression in the Lateral Hypothalamus: Implication in Reward and Reinforcement.

Neuropeptide cocaine- and amphetamine-regulated transcript peptide (CARTp) is known to play an important role in reward processing. The rats conditioned to intra-cranial self-stimulation (ICSS) showed massive upregulation of CART protein and mRNA in the vicinity of the electrode implanted to deliver the electric current directly at the lateral hypothalamus (LH)-medial forebrain bundle (MFB) area. However, the underlying mechanisms leading to the upregulation of CART in ICSS animals remain elusive. We tested the putative role of CREB-binding protein (CBP), an epigenetic enzyme with intrinsic histone acetyltransferase (HAT) activity, in regulating CART expression during ICSS. An electrode was implanted in LH-MFB and the rats were conditioned to self-stimulation in an operant chamber. CBP siRNA was delivered ipsilaterally in the LH-MFB to knock-down CBP and the effects on lever press activity were monitored. While ICSS-conditioned rats showed distinct increase in CART, CBP and pCREB levels, enhanced CBP binding and histone acetylation (H3K9ac) were noticed on the CART promoter in chromatin immunoprecipitation assay. Direct infusion of CBP siRNA in the LH-MFB lowered lever press activity, CBP levels, histone acetylation at the CART promoter, and CART mRNA and peptide expression. Co-infusion of CARTp in LH-MFB rescued the waning effects of CBP siRNA on self-stimulation. We suggest that CBP-mediated histone acetylation may play a causal role in CART expression in LH, which in turn may drive the positive reinforcement of lever press activity.

Behavioral characterization of G-protein-coupled receptor 160 knockout mice.

Neuropathic pain is a devastating condition where current therapeutics offer little to no pain relief. Novel nonnarcotic therapeutic targets are needed to address this growing medical problem. Our work identified the G-protein-coupled receptor 160 (GPR160) as a potential target for therapeutic intervention. However, the lack of small-molecule ligands for GPR160 hampers our understanding of its role in health and disease. To address this void, we generated a global Gpr160 knockout (KO) mouse using CRISPR-Cas9 genome editing technology to validate the contributions of GPR160 in nociceptive behaviors in mice. Gpr160 KO mice are healthy and fertile, with no observable physical abnormalities. Gpr160 KO mice fail to develop behavioral hypersensitivities in a model of neuropathic pain caused by constriction of the sciatic nerve. On the other hand, responses of Gpr160 KO mice in the hot-plate and tail-flick assays are not affected. We recently deorphanized GPR160 and identified cocaine- and amphetamine-regulated transcript peptide (CARTp) as a potential ligand. Using Gpr160 KO mice, we now report that the development of behavioral hypersensitivities after intrathecal or intraplantar injections of CARTp are dependent on GPR160. Cocaine- and amphetamine-regulated transcript peptide plays a role in various affective behaviors, such as anxiety, depression, and cognition. There are no differences in learning, memory, and anxiety between Gpr160 KO mice and their age-matched and sex-matched control floxed mice. Results from these studies support the pronociceptive roles of CARTp/GPR160 and GPR160 as a potential therapeutic target for treatment of neuropathic pain.

Bisphenol A Effects on Neurons’ Neurochemical Character in the Urinary Bladder Intramural Ganglia of Domestic Pigs

Bisphenol A (BPA), a substance globally used to produce plastics, is part of many everyday items, including bottles, food containers, electronic elements, and others. It may penetrate the environment and living organisms, negatively affecting, among others, the nervous, immune, endocrine, and cardiovascular systems. Knowledge of the impact of BPA on the urinary bladder is extremely scarce. This study investigated the influence of two doses of BPA (0.05 mg/kg body weight (b.w.)/day and 0.5 mg/kg b.w./day) given orally for 28 days on the neurons situated in the ganglia located in the urinary bladder trigone using the typical double immunofluorescence method. In the study, an increase in the percentage of neurons containing substance P (SP), galanin (GAL), a neuronal isoform of nitric oxide synthase (nNOS—used as the marker of nitrergic neurons), and/or cocaine- and amphetamine-regulated transcript (CART) peptide was noted after BPA administration. The severity of these changes depended on the dose of BPA and the type of neuronal factors studied. The most visible changes were noted in the cases of SP- and/or GAL-positive neurons after administering a higher dose of BPA. The results have shown that oral exposure to BPA, lasting even for a short time, affects the intramural neurons in the urinary bladder wall, and changes in the neurochemical characterisation of these neurons may be the first signs of BPA-induced pathological processes in this organ.

Influence of bisphenol A and its analog bisphenol S on cocaine- and amphetamine-regulated transcript peptide-positive enteric neurons in the mouse gastrointestinal tract.

Bisphenol A (BPA) is used in large quantities for the production of plastics and is present in various everyday objects. It penetrates living organisms and shows multidirectional adverse influence on many internal organs. For this reason, BPA is often replaced in plastic production by other substances. One of them is bisphenol S (BPS), whose effects on the enteric nervous system (ENS) have not been explained. Therefore, the present study compares the influence of BPA and BPS on the number of enteric neurons immunoreactive to cocaine-and amphetamine-regulated transcript (CART) peptide located in the ENS of the stomach, jejunum and colon with the use of double immunofluorescence method. The obtained results have shown that both bisphenols studied induced an increase in the number of CART-positive enteric neurons, and the severity of changes depended on the type of enteric ganglion, the dose of bisphenols and the segment of the digestive tract. The most visible changes were noted in the myenteric ganglia in the colon. Moreover, in the colon, the changes submitted by BPS are more noticeable than those observed after BPA administration. In the stomach and jejunum, bisphenol-induced changes were less visible, and changes caused by BPS were similar or less pronounced than those noted under the impact of BPA, depending on the segment of the gastrointestinal tract and ganglion type studied. The results show that BPS affects the enteric neurons containing CART in a similar way to BPA, and the BPS impact is even stronger in the colon. Therefore, BPS is not neutral for the gastrointestinal tract and ENS.

Cocaine- and Amphetamine-Regulated Transcript (CART) Peptide Is Co-Expressed with Parvalbumin, Neuropeptide Y and Somatostatin in the Claustrum of the Chinchilla.

Although for many years, researchers have been working on understanding the function of the cocaine- and amphetamine-regulated transcript (CART) peptide at the central- and peripheral-nervous-system level, data describing the presence of CART in the claustrum are still missing. Therefore, the aim of the present study was to immunohistochemically investigate the CART expression in the claustrum neurons in chinchillas as well as the CART co-localization with somatostatin (SOM), parvalbumin (PV), and neuropeptide Y (NPY) using double-immunohistochemical staining. The claustrum is divided into two main parts: the dorsal segment (CL), which is located above the rhinal fissure, and the ventral segment (EN), located below the rhinal fissure. The presence of HU C/D-IR CART-IR-positive neurons was detected in both the insular claustrum (CL) and the endopiriform nucleus (EN). The vast majority of CART-IR neurons were predominantly small and medium in size and were evenly scattered throughout the claustrum. CART co-localization with selected neurotransmitters/neuromodulators (SOM, NPY, and PV) showed the presence of a CART-IR reaction only in the neurons, while the nerve fibers were, in all cases, devoid of the CART-IR response. Our research supplements missing knowledge about the distribution and co-localization pattern of CART with SOM, NPY, and PV in the chinchilla claustrum, and also provides a better understanding of the similarities and differences compared to other species of rodents and other mammals.

GPR-160 Receptor Signaling in the Dorsal Vagal Complex of Male Rats Modulates Meal Microstructure and CART-Mediated Hypophagia.

The g-protein coupled receptor GPR-160, recently identified as a putative receptor for the cocaine and amphetamine-regulated transcript (CART) peptide, shows abundant expression in the energy-balance control nuclei, including the dorsal vagal complex (DVC). However, its physiological role in the control of food intake has yet to be fully explored. Here, we performed a virally mediated, targeted knockdown (KD) of Gpr160 in the DVC of male rats to evaluate its physiological role in control of feeding. Our results indicate that DVC Gpr160 KD affects meal microstructure. Specifically, DVC Gpr160 KD animals consumed more frequent, but shorter meals during the dark phase and showed decreased caloric intake and duration of meals during the light phase. Cumulatively, however, these bidirectional effects on feeding resulted in no difference in body weight gain. We next tested the role of DVC GPR-160 in mediating the anorexigenic effects of exogenous CART. Our results show that DVC Gpr160 KD partially attenuates CART's anorexigenic effects. To further characterize Gpr160+ cells in the DVC, we utilized single-nucleus RNA sequencing data to uncover abundant GPR-160 expression in DVC microglia and only minimal expression in neurons. Altogether, our results suggest that DVC CART signaling may be mediated by Gpr160+ microglia, which in turn may be modulating DVC neuronal activity to control food intake.

GPR160 is not a receptor of anorexigenic cocaine- and amphetamine-regulated transcript peptide

Cocaine- and amphetamine-regulated transcript peptide (CARTp) is an anorexigenic neuropeptide whose receptor is undisclosed. Previously, we reported the specific binding of CART(61–102) to pheochromocytoma PC12 cells, where CART(61–102) affinity and the number of binding sites per cell corresponded to ligand-receptor binding. Recently, Yosten et al. designated orphan GPR160 as the CARTp receptor, because the GPR160 antibody abolished neuropathic pain and anorexigenic effects induced by CART(55–102) and exogenous CART(55–102) coimmunoprecipitated with GPR160 in KATOIII cells. As no direct evidence that CARTp is a ligand for GPR160 has been described, we decided to verify this hypothesis by testing CARTp affinity to the GPR160 receptor. We investigated the GPR160 expression in PC12 cells since it is cell line known to specifically bind CARTp. Moreover, we examined the specific CARTp binding in THP1 cells, with high endogenous GPR160 expression and GPR160-transfected cell lines U2OS and U-251 MG. In PC12 cells, the GPR160 antibody did not compete for specific binding with 125I-CART(61–102) or with 125I-CART(55–102), and GPR160 mRNA expression and GPR160 immunoreactivity were not detected. Moreover, THP1 cells did not show any 125I-CART(61–102) or 125I-CART(55–102) specific binding despite GPR160 detection by fluorescent immunocytochemistry (ICC). Finally, no 125I-CART(61–102) or 125I-CART(55–102) specific binding in the GPR160-transfected cell lines U2OS and U-251 MG, selected due to their negligible endogenous expression of GPR160, was detected, despite the detection of GPR160 by fluorescent ICC. Our binding studies clearly demonstrated that GPR160 cannot be a receptor for CARTp. Further studies are needed to identify true CARTp receptors.

Unique, Specific CART Receptor-Independent Regulatory Mechanism of CART(55-102) Peptide in Spinal Nociceptive Transmission and Its Relation to Dipeptidyl-Peptidase 4 (DDP4).

Cocaine- and amphetamine-regulated transcript (CART) peptides are involved in several physiological and pathological processes, but their mechanism of action is unrevealed due to the lack of identified receptor(s). We provided evidence for the antihyperalgesic effect of CART(55-102) by inhibiting dipeptidyl-peptidase 4 (DPP4) in astrocytes and consequently reducing neuroinflammation in the rat spinal dorsal horn in a carrageenan-evoked inflammation model. Both naturally occurring CART(55-102) and CART(62-102) peptides are present in the spinal cord. CART(55-102) is not involved in acute nociception but regulates spinal pain transmission during peripheral inflammation. While the full-length peptide with a globular motif contributes to hyperalgesia, its N-terminal inhibits this process. Although the anti-hyperalgesic effects of CART(55-102), CART(55-76), and CART(62-76) are blocked by opioid receptor antagonists in our inflammatory models, but not in neuropathic Seltzer model, none of them bind to any opioid or G-protein coupled receptors. DPP4 interacts with Toll-like receptor 4 (TLR4) signalling in spinal astrocytes and enhances the TLR4-induced expression of interleukin-6 and tumour necrosis factor alpha contributing to inflammatory pain. Depending on the state of inflammation, CART(55-102) is processed in the spinal cord, resulting in the generation of biologically active isoleucine-proline-isoleucine (IPI) tripeptide, which inhibits DPP4, leading to significantly decreased glia-derived cytokine production and hyperalgesia.

Glycogen Synthase Kinase 3β Is a Key Regulator in the Inhibitory Effects of Accumbal Cocaine- and Amphetamine-Regulated Transcript Peptide 55-102 on Amphetamine-Induced Locomotor Activity.

Microinjection of cocaine- and amphetamine-regulated transcript (CART) peptide 55-102 into the nucleus accumbens (NAcc) core significantly attenuates psychostimulant-induced locomotor activity. However, the molecular mechanism remains poorly understood. We examined the phosphorylation levels of Akt, glycogen synthase kinase 3β (GSK3β), and glutamate receptor 1 (GluA1) in NAcc core tissues obtained 60 min after microinjection of CART peptide 55-102 into this site, followed by systemic injection of amphetamine (AMPH). Phosphorylation levels of Akt at Thr308 and GSK3β at Ser9 were decreased, while those of GluA1 at Ser845 were increased, by AMPH treatment. These effects returned to basal levels following treatment with CART peptide 55-102. Furthermore, the negative regulatory effects of the CART peptide on AMPH-induced changes in phosphorylation levels and locomotor activity were all abolished by pretreatment with the S9 peptide, an artificially synthesized indirect GSK3β activator. These results suggest that the CART peptide 55-102 in the NAcc core plays a negative regulatory role in AMPH-induced locomotor activity by normalizing the changes in phosphorylation levels of Akt-GSK3β, and subsequently GluA1 modified by AMPH at this site. The present findings are the first to reveal GSK3β as a key regulator of the inhibitory role of the CART peptide in psychomotor stimulant-induced locomotor activity.

The neuropeptide landscape of human prefrontal cortex

Human prefrontal cortex (hPFC) is a complex brain region involved in cognitive and emotional processes and several psychiatric disorders. Here, we present an overview of the distribution of the peptidergic systems in 17 subregions of hPFC and three reference cortices obtained by microdissection and based on RNA sequencing and RNAscope methods integrated with published single-cell transcriptomics data. We detected expression of 60 neuropeptides and 60 neuropeptide receptors in at least one of the hPFC subregions. The results reveal that the peptidergic landscape in PFC consists of closely located and functionally different subregions with unique peptide/transmitter-related profiles. Neuropeptide-rich PFC subregions were identified, encompassing regions from anterior cingulate cortex/orbitofrontal gyrus. Furthermore, marked differences in gene expression exist between different PFC regions (>5-fold; cocaine and amphetamine-regulated transcript peptide) as well as between PFC regions and reference regions, for example, for somatostatin and several receptors. We suggest that the present approach allows definition of, still hypothetical, microcircuits exemplified by glutamatergic neurons expressing a peptide cotransmitter either as an agonist (hypocretin/orexin) or antagonist (galanin). Specific neuropeptide receptors have been identified as possible targets for neuronal afferents and, interestingly, peripheral blood-borne peptide hormones (leptin, adiponectin, gastric inhibitory peptide, glucagon-like peptides, and peptide YY). Together with other recent publications, our results support the view that neuropeptide systems may play an important role in hPFC and underpin the concept that neuropeptide signaling helps stabilize circuit connectivity and fine-tune/modulate PFC functions executed during health and disease.

Molecular and functional characterization of the mouse intrinsic cardiac nervous system.

The intrinsic cardiac nervous system (ICNS) refers to clusters of neurons, located within the heart, that participate in the neuronal regulation of cardiac functions and that are involved in the initiation of cardiac arrhythmias. Therefore, deciphering its role in cardiac physiology and physiopathology is mandatory. The aim of this study was to provide a phenotypic, electrophysiological, and pharmacological characterization of the mouse ICNS, which is still poorly characterized. Global cardiac innervation and phenotypic diversity were investigated using immunohistochemistry on cleared murine hearts and on tissue sections. The patch clamp technique was used for the electrophysiological and pharmacological characterization of isolated mouse intracardiac neurons. We have identified the expression of 7 distinct neuronal markers within the mouse ICNS, thus proving the neurochemical diversity of this network. Of note, it was the first time that the existenceof neurons expressing the calcium-binding protein calbindin, neuropeptide Y, and cocaine and amphetamine regulated transcript peptide was described in the mouse. Electrophysiology studies also revealed the existence of 4 different neuronal populations on the basis of their electrical behavior. Finally, we showed that these neurons can be modulated by several neuromodulators. This study showed that the mouse ICNS presents a molecular and functional complexity similar to other species and is therefore a suitable model to decipher the role of individual neuronal subtypes regarding the modulation of cardiac function and the initiation of cardiac arrhythmias.

Reproductive phase related variations in the expression of neuropeptide, cocaine- and amphetamine- regulated transcript (CART) in the brain and pituitary gland of adult male Microhyla ornata

Cocaine- and amphetamine-regulated transcript (CART) peptide is a multifaceted neuropeptide involved in several physiological functions including appetite and reproduction. While studies in mammals, aves and fishes suggest evolutionary conserved role of CART, the information in amphibian is scanty. We have investigated the reproductive phase related variations of CART in the brain of adult male Microhyla ornata. Seasonal changes in the expression of CART peptide were noticed in the brain and pituitary of M. ornata. Significant differences were observed in the nucleus infundibularis ventralis (NIV), epiphysis (E), anteroventral tegmental region (AV), raphe nucleus (Ra) of the brain and pars intermedia (PI), pars distalis (PD) of the pituitary. Compared to the pre-breeding and post-breeding seasons, increase in CART immunoreactivity was seen in E, NIV, AV, Ra of brain and PI, PD of pituitary gland of animals collected during breeding season. Similarly, highest mRNA levels of CART were also observed in the breeding season in the middle region of brain that includes hypothalamus and pituitary gland. Variation in the levels of CART peptide and mRNA in the brain of M. ornata suggests its conserved role in seasonal control of appetite and reproduction.

Variations of body mass and thermogenesis properties in Eothenomys olitor during cold acclimatization

Abstract The set-point hypothesis states that there is a biological control method in mammals that actively regulates weight toward a predetermined set weight for each individual, which may occur by regulation of energy intake or energy expenditure. In order to investigate the effects of low temperature on body mass regulation in Eothenomys olitor, body mass, body fat mass, food intake, resting metabolic rate (RMR), non-shivering thermogenesis (NST), serum leptin levels, morphology, biochemical indexes of liver and brown adipose tissue (BAT) and hypothalamic neuropeptide genes expression were measured during cold acclimatization. The results showed that there was no significant difference in body mass, but food intake, RMR and NST increased during cold acclimatization. Cytochrome c oxidase (COX) and α-glycerophosphate oxidase (α-GPO) activities in liver and BAT were significantly enhanced during cold acclimatization, and triiodothyronine (T3) and thyroxine (T4) levels in serum were significantly higher than those in the control group. Serum leptin levels decreased after cold acclimatization. Low temperature significantly increased the expression of neuropeptide Y (NPY) and agouti-related peptide (AgRP), while it decreased cocaine- and amphetamine-regulated transcript peptide (CART) and pro-opiomelanocortin (POMC) expressions. All of the above results suggested that body mass in E. olitor can remain relatively stable at low temperature, which conforms to the ‘set-point hypothesis’. However, the species showed differences with sympatric species, such as E. miletus, Apodemus chevrieri and Tupaia belangeri. Moreover, E. olitor can cope with low temperature by increasing its metabolic rate and thermogenesis properties.

Erasing m6A-dependent transcription signature of stress-sensitive genes triggers antidepressant actions

Emerging evidence has shown that stress responsivity and psychiatric diseases are associated with alterations in N6-methyladenosine (m6A) mRNA epigenetic modifications. Fat mass and obesity-associated protein (FTO) is an m6A demethylase that has been linked to increased body mass and obesity. Here, we show that tricyclic antidepressants (TCAs) with weight-gain side effects, such as imipramine and amitriptyline, directly increased FTO expression and activated its epigenetic function in the ventral tegmental area (VTA). VTA-specific genetic disruption of FTO increased stress vulnerability and abolished the antidepressant activity of TCAs, whereas erasing m6A modification in the VTA by FTO overexpression or cycloleucine led to significant antidepressant activity. Mechanistically, both transcriptome sequencing and quantitative PCR revealed that overexpression of FTO in the VTA decreased the transcription of stress-related neuropeptides, such as cocaine- and amphetamine-regulated transcript peptide and urocortin, in the social defeat model, which was mimicked by imipramine, suggesting an m6A-dependent transcription mechanism of stress-related neuropeptides may underlie the responses to antidepressant. Collectively, our results demonstrate that inhibiting m6A-dependent transcription of stress-related genes may work as a novel antidepressant strategy and highlight a previously unrecognized activator of FTO-dependent epigenetic function that may be used for the treatment of other neurological diseases.

The Ciji-Hua'ai-Baosheng II Formula Attenuates Chemotherapy-Induced Anorexia in Mice With H22 Hepatocellular Carcinoma.

Background: Ciji-Hua’ai-Baosheng II Formula (CHB-II-F) is a traditional Chinese medicine formula, which specifically targets different aspects of chemotherapy-induced adverse effects in patients with cancer. In our clinical application, CHB-II-F significantly alleviated chemotherapy-induced anorexia (loss of appetite) and improved the quality of life for patients with tumor during and after chemotherapy. However, the mechanism of CHB-II-F in alleviation of chemotherapy-induced anorexia remains to be further investigated.Aim of Study: To explore the therapeutic effect and mechanism of CHB-II-F on chemotherapy-induced anorexia in the mice model of H22 hepatoma.Materials and Methods: A total of 72 Kunming mice of SPF grade were inoculated subcutaneously with H22 hepatoma cells into the right anterior armpit of the mice. After 1 week of seeding, mice were injected intraperitoneally with a high dose of 5-fluorouracil (200 mg/kg 5-FU) to establish the model of chemotherapy. The mice were randomly divided into six groups: untreated group, 5-FU group, 5-FU plus Yangzheng Xiaoji capsule (YZXJC) group, and three groups of 5-FU plus different concentrations of CHB-II-F. All the mice in each group were treated for 14 days. The body weight, food intake, tumor volume, and tumor weight of mice were measured, and pathological examinations of tumor tissue, stomach, and duodenum were carried out. Expressions of serum Leptin, Neuropeptide Y (NPY), epidermal cell growth factor (EGF), Motilin (MTL), Orexin A (OXA), Gastrin (GAS), Ghrelin, Prostaglandin E2 (PGE2), and jejunum superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined. The protein and mRNA levels of proopiomelanocortin (POMC), Orexin receptor 1 (OX1R), neuropeptide Y (NPY), cocaine and amphetamine regulated transcript peptide (CART), Agouti gene-related protein (AgRP), Leptin receptor (Ob-R), and Ghrelin receptor (GHSR) were examined in hypothalamus, and the protein levels of substance P (SP) and 5-hydroxytryptamine (5-HT) in duodenum were measured.Results: The combination of CHB-II-F and 5-FU could enhance the inhibitory effect of 5-FU on tumor. The tumor inhibition rates of 5-FU group, YZXJC group, CHB-II-F(H) group, CHB-II-F(M) group, and CHB-II-F(L) group were 58.88, 28.08, 54.96, 37.69, and 28.61%, respectively. Compared with untreated group and 5-FU group, CHB-II-F significantly increased the body weight and food intake of tumor-bearing mice; increased the content of NPY, Orexin A, Ghrelin, GAS, MTL, EGF, and PGE2 in serum and the activity of SOD in jejunum; and decreased the content of Leptin in serum and the content of MDA in jejunum. Compared with untreated group and 5-FU group, CHB-II-F also enhanced the expression of OX1R, GHSR, NPY, and AgRP protein and gene and decreased the expression of Ob-R, POMC, and CART protein and gene in hypothalamus of mice, and the gene expression was consistent with the protein expression. In addition, CHB-II-F decreased the expression of 5-HT and SP protein in duodenum.Conclusion: In the murine model of H22 hepatocellular carcinoma (HCC) receiving chemotherapy, CHB-II-F enhances the inhibitory effect of 5-FU on tumor, significantly improves the pathological injury of gastrointestinal tract caused by chemotherapy, and regulates the secretion of gastrointestinal hormones. It may alleviate chemotherapy-induced anorexia by affecting appetite regulatory factors in the feeding area of hypothalamus central nervous system and peripheral appetite regulatory factors.

Cocaine- and amphetamine-regulated transcript peptide- and dopamine-containing systems interact in the ventral tegmental area of the zebra finch, Taeniopygia guttata, during dynamic changes in energy status.

The mesolimbic dopamine (DA)-pathway regulates food-reward, feeding-related behaviour and energy balance. Evidence underscores the importance of feeding-related neuropeptides in modulating activity of these DA neurons. The neuropeptide, CART, a crucial regulator of energy balance, modulates DA-release, and influences the activity of ventral tegmental area (VTA) DAergic neurons in the mammalian brain. Whether CART- and DA-containing systems interact at the level of VTA to regulate energy balance, however, is poorly understood. We explored the interaction between CART- and DA-containing systems in midbrain of the zebra finch, Taeniopygia guttata, an interesting model to study dynamic changes in energy balance due to higher BMR/daytime body temperature, and rapid responsiveness of the feeding-related neuropeptides to changes in energy state. Further, its midbrain DA-neurons share similarities with those in mammals. In the midbrain, tyrosine hydroxylase-immunoreactive (TH-i) neurons were seen in the substantia nigra (SN) and VTA [anterior (VTAa), mid (VTAm) and caudal (VTAc)]; those in VTA were smaller. In the VTA, CART-immunoreactive (CART-i)-fibers densely innervated TH-i neurons, and both CART-immunoreactivity (CART-ir) and TH-immunoreactivity (TH-ir) responded to energy status-dependent changes. Compared to fed and fasted birds, refeeding dramatically enhanced TH-ir and the percentage of TH-i neurons co-expressing FOS in the VTA. Increased prepro-CART-mRNA, CART-ir and a transient appearance of CART-i neurons was observed in VTAa of fasted, but not fed birds. To test the functional interaction between CART- and DA-containing systems, ex-vivo superfused midbrain-slices were treated with CART-peptide and changes in TH-ir analysed. Compared to control tissues, CART-treatment increased TH-ir in VTA but not SN. We propose that CART is a potential regulator of VTA DA-neurons and energy balance in T. guttata.