Journal of Neuroendocrinology

ObjectiveGlucagon-like peptide-1 (GLP-1), a peptide neurotransmitter in the brain, is synthesized from proglucagon, encoded by the glucagon gene (Gcg). Besides medullary GLP-1 neurons, Gcg-expressing neuron populations were identified in the olfactory bulb and basolateral amygdala. However, several lines of evidence suggest that additional Gcg neuron populations might exist. MethodsWe conducted a brain-wide mapping of Gcg-expressing cells by fluorescent in situ hybridization in C57BL/6J and FVB/Ant mice. Proglucagon and GLP-1 expression were studied with immunofluorescence. We characterized a Gcg-Cre;tdTomato mouse line and studied the expression of proglucagon-processing enzymes in Gcg-expressing neuron populations. We used adeno-associated virus-mediated tracing in Gcg-Cre mice to map the projections of hypothalamic Gcg neurons. ResultsGcg-expressing neuron populations were identified in the olfactory bulb, claustrum, piriform cortex, basolateral amygdala, posterior hippocampus, posterior hypothalamic nucleus (PH), periaqueductal gray/dorsal raphe, and dorsal nucleus of the lateral lemniscus. These neurons express lower Gcg mRNA levels than medullary GLP-1 neurons. Proglucagon and GLP-1-immunoreactivity (C-terminus) were detected in almost all Gcg-expressing neuron populations, along with the mRNAs for prohormone convertases 1/3 and 2, enzymes generating GLP-1 or glucagon, respectively. Fasting markedly increased Gcg mRNA, proglucagon and GLP-1 synthesis in the PH. PH Gcg neurons project densely to the ventral and intermediate lateral septum, preoptic region, ventrolateral preoptic nucleus, lateral hypothalamus and zona incerta, establishing close contacts with both GLP-1 receptor-positive and -negative neurons. ConclusionsProglucagon is expressed in 9 distinct neuron populations. Feeding status regulates GLP-1 synthesis in PH neurons that likely control feeding- or energy balance-related functions.

Introduction: Central regulation of energy homeostasis is essential for balancing lipid storage and reproductive investment; however, the hypothalamic factors governing this trade-off remain incompletely defined in birds. Neurosecretory protein GM (NPGM), an 83-amino acid hypothalamic factor, was investigated for its role in energy allocation during sexual maturation in Japanese quail (Coturnix japonica). Methods: Male and female quails at the onset of sexual maturation received chronic intracerebroventricular administration of NPGM for 13 days via osmotic pumps, during which their body mass, food intake, and water intake were monitored daily. At the endpoint, peripheral tissue and muscle masses, serum metabolite levels (glucose, fatty acids, triglycerides, testosterone, and 17{beta}-estradiol), hepatic triglyceride content, and gene expression profiles of hypothalamic feeding/reproductive genes and hepatic/adipose lipid metabolic genes were evaluated. Results: NPGM increased subcutaneous and abdominal fat in both sexes and was associated with suppressed gonadal maturation, as indicated by reduced testicular mass relative to body mass and lower testosterone levels in males, as well as a trend toward reduced ovarian mass and lower 17{beta}-estradiol levels in females. Sex-dependent metabolic phenotypes emerged: males exhibited increased body mass gain, hyperphagia, elevated water intake, enlarged liver, pancreas, and heart, higher serum and hepatic triglyceride levels, increased hepatic SCD1 expression, and reduced hepatic CGI-58, PPAR{gamma}, SLC2A2, and CD36. In contrast, females showed fat accumulation without hyperphagia or hepatic triglyceride elevation, accompanied by reduced hepatic VTG2 and APOV1 and decreased adipose ATGL, LPL, and FATP. Hypothalamic AGRP expression decreased in males, whereas both NPY and AGRP decreased in females. Discussion: These findings demonstrate that central NPGM shifts energy allocation from reproduction toward lipid storage through sex-dependent endocrine and metabolic mechanisms, identifying NPGM as a neuroendocrine regulator of energy allocation during sexual maturation in Japanese quails.

Glucagon is a key metabolic hormone regulating blood glucose and appetite, yet little is known about its actions within the brain. Here, we investigated its receptor (GCGR) localization in periventricular brain barrier interfaces in young rats using immunohistochemical and immunofluorescence approaches. GCGR was enriched in the proximal region of motile ependymal cilia lining the ventricles, as well as in tanycytic primary cilia and cytoplasmic extensions within the hypothalamus. Additional immunostaining was observed in ciliated cells of the subcommissural organ and, more heterogeneously, in choroid plexus epithelium and associated primary cilia, while other circumventricular organs lacked detectable GCGR. These findings identify brain cilia and tanycytes as previously unrecognized sites of glucagon receptor localization and suggest that glucagon signaling at brain barrier interfaces may contribute to integrating peripheral metabolic cues with central homeostatic circuits.

The prevalence of neurodevelopmental disorders (NDDs) has increased dramatically, with growing evidence linking prenatal maternal stress exposure to NDDs. Across diverse maternal stressors, immune dysregulation emerges as a common feature, suggesting that fetal microglia may detect changes in the intrauterine environment and influence neurodevelopment. Accordingly, we utilized a mouse model of prenatal maternal cold stress to investigate the impact of maternal stress during pregnancy on fetal microglia morphology, cellular interactions, and phagocytic behaviors. Pregnant mice were exposed to cold stress from embryonic day 11.5 (E11.5) to E15.5 and fetal hypothalamic tissue was assessed from both male and female embryos. By adapting the morphology analysis toolset MicrogliaMorphology to assess fetal microglia, we demonstrate regional differences in microglial morphology in the fetal hypothalamus at baseline, with hypothalamic nuclei such as the paraventricular nucleus (PVN) containing fewer rod-like microglia compared to the broader hypothalamus. Interestingly, prenatal maternal cold stress induced a male-specific shift in microglial morphology from ameboid to ramified within the E15.5 PVN. Male embryos also displayed increased microglial-arginine vasopressin (AVP) neuronal interactions and microglial phagocytosis within the E15.5 PVN, but these changes were unique to microglia with a ramified morphology and were not observed when microglia with an ameboid or rod-like morphology were assessed. Using pHrodo bioparticles and flow cytometry, we further illustrate that prenatal maternal cold stress drives increased phagocytic activity in the E15.5 hypothalamus of male embryos, but not females. Together, these data demonstrate that prenatal maternal cold stress alters microglia morphology and drives morphology-dependent microglial interactions and phagocytic behaviors in male embryos which are unique to the hypothalamic PVN--a nuclei critical for social behaviors. Our findings also suggest that specific hypothalamic nuclei such as the PVN may be more sensitive to prenatal maternal stress, which has the potential to provide a cellular basis underlying the sex differences in microglia-dependent social deficits that were previously reported for this model.

INTRODUCTIONSex differences in mental health emerge during adolescence, a period marked by the onset and the establishment of menstrual cycle. However, is rarely examined how menstrual cycle regularity, a marker of hormonal function, modulates mental health. OBJECTIVEto analyse sex differences in mental health symptoms among adolescents considering the menstrual cycle regularity and sleep. METHODSA three-group design (female students with regular cycles/FR, n=77; with irregular cycles/FI, n=59; and male students/M, n=76) in a sample of Brazilian high-school adolescents (n=212; 14-18 years) enrolled in morning and full-time classes was used to test the hypothesis that mental health symptoms follow a graded pattern across these groups. RESULTSMean DASS-21 scores across all groups fell at or above the Mild severity threshold for mental health subscales. GLMs confirmed a monotonic gradient increase in group order (M[-&gt;]FR[-&gt;]FI) which was associated with higher scores on all outcomes (stress {beta}/step=4.33, p<.001; anxiety {beta}/step=4.08, p<.001; and depression {beta}/step=2.34, p=.010; model R{superscript 2}=.16, .13, .08 respectively). However, no differences were observed in sleep duration, social jetlag, chronotype, sleep quality, or sleep-debt. Then, a secondary analysis assessed sex-specific associations between socioeconomic status (SES) and mental health; higher SES was inversely related to stress, anxiety, and depression, being protective only in males (stress Males {beta}=-2.68, p=.011/Females {beta}=0.46, p=.614). CONCLUSIONThese findings support the reframing of menstrual irregularity not only as a reproductive health concern but also as a biological determinant of mental health risk in female adolescents, a vulnerability that sleep disruption and socioeconomic resources do not adequately explain.

Interactions between melanin-concentrating hormone (MCH) neurons and oxytocin neurons are crucial for parental care. Whole-cell patch-clamp recordings demonstrated that MCH inhibits paraventricular hypothalamic nucleus (PVN)-oxytocin neurons through activation of barium-sensitive inwardly rectifying potassium channels, potentially G-protein coupled inwardly rectifying potassium channels, and pup-directed aggression was positively related to loss of MCH neurons. Our findings offer a glimpse into the neural mechanisms underlying the evolutionary regulation of offspring caregiving and abuse in males.

Stress-related experiences alter glutamatergic signaling and neuronal excitability, but the mechanisms that couple experience to dentate granule cell function remain incompletely understood. Here, we examined how protein kinase N1a (PKN1a), a protein kinase C-like serine/threonine kinase, and repeated swim exposure regulate mouse hippocampal dentate granule cell excitability, with a focus on the neuronal glutamate transporter excitatory amino acid transporter 3 (EAAT3) and group I metabotropic glutamate receptors (mGluRs). Five days of repeated swim exposure increased spike firing in mature dentate granule cells from wild-type mice. PKN1a knockout produced a similar increase, and repeated swim did not further enhance firing in knockout mice. The enhanced firing observed after repeated swim exposure and in PKN1a knockout mice was reduced by co-application of an mGluR1 antagonist (LY367385) and an mGluR5 antagonist (MPEP). Inhibition of glutamate transporters with DL-TBOA increased granule cell firing in control wild-type mice but did not further increase firing in repeated-swim wild-type or PKN1a knockout mice, suggesting occlusion of transporter-dependent regulation of excitability. Repeated swim exposure and PKN1a knockout also reduced total and surface expression of EAAT3 in the hippocampus, whereas expression of the glial glutamate transporter EAAT2 was not significantly altered. Finally, PKN1a knockout and repeated swim exposure reduced anxiety-related behavior in the elevated plus maze test. Thus, PKN1a-dependent regulation of EAAT3 may restrain group I mGluR-dependent excitability in dentate granule cells, whereas repeated swim exposure and PKN1a knockout shift this system toward a lower-EAAT3, higher-excitability state accompanied by reduced anxiety-related behavior.

Prolactinomas, the most common secretory pituitary tumour subtype, frequently occur in patients with Multiple Endocrine Neoplasia type 1, caused by germline MEN1 mutations encoding menin. While menin loss is well established in MEN1-associated prolactinomas, its role in sporadic tumours remains unclear. We investigated menin expression, subcellular localization, and downstream signalling in two murine models of non-MEN1 prolactinomas, the dopamine D2-receptor knockout and the hCG{beta}-subunit-overexpressing mice, in which only females develop prolactinoma. Pituitary Men1 expression, analysed by qPCR, remained unchanged despite the genotype, in both sexes. However, in prolactinomas, lactotrophs exhibited a marked loss of nuclear MEN1 immunostained, with protein restricted to the cytoplasm. Male mice pituitaries retained nuclear MEN1 localization regardless their genotype. Loss of nuclear menin in prolactinomas was associated with reduced p27 and Pten expression, increased Ccnd1 expression, and enhanced pAKT. Moreover, by using in vivo pharmacological and surgical approaches we demonstrated that dopamine-agonist treatment preserved nuclear menin in lactotrophs, whereas dopamine blockade or estradiol induced its nuclear loss. Importantly, analysis of human pituitary biopsies confirmed nuclear and cytoplasmic menin localization in lactotrophs from normal pituitaries, and in prolactinomas from both genders following dopamine agonist therapy. However, in a prolactinoma from an untreated female, nuclear menin was partially lost. Therefore, our findings identify a state of functional MEN1-deficiency in sporadic prolactinomas (characterized by preserved MEN1 expression), but its exclusion from the nucleus (linked to activation of proliferative pathways, impaired tumour suppressor signalling, and tumour development) highlights the restoration of nuclear MEN1 localization as a potential therapeutic strategy.

Nitrogenous waste excretion is essential for all developmental stages of fish. Embryonic fish excrete urea, transitioning to cutaneous and later branchial ammonia excretion. In zebrafish, ammonia excretion involves rhesus glycoproteins Rhbg and Rhcgb in keratinocytes and ionocytes, but the developmental moment they appear in the gill remains unclear. Potential redundancy between Rhbg and Rhcgb in ammonia excretion is also not fully investigated, nor is the difference in response to low pH. We hypothesized that rhesus glycoproteins are partially redundant, and that they differ in their response to low pH as ammonia excretion enables ionocytes to exchange Na+ and H+ (Rh-NHE-metabolon). We predicted that a loss of rhbg or rhcgb induces compensatory responses. We characterized the transition from urea to branchial ammonia excretion from 0 to 8 days-post fertilization (dpf) and the response to pH 5.0 on the expression and localization of rhesus glycoproteins in control zebrafish and rhbg or rhcgb-crispants. Effects of high external ammonia (HEA, 500 M NH4Cl) and 10 mM HEPES-buffering were further characterized in rhcgb-crispants. Rhag and Rhbg appeared in the gill at 5 dpf, while Rhcgb appeared at 6 dpf. A loss of rhbg or rhcgb did not impact baseline N-excretion, illustrating that zebrafish can maintain ammonia excretion without the full complement of rhesus glycoproteins. We observed no compensatory increase in rhesus glycoproteins, but expression of the transporter hippocampus-abundant transcript 1b increased. HEA-exposed rhcgb-crispants switched to urea as primary nitrogen waste. Together, these findings underline the plasticity of the larval in dealing with nitrogenous waste.

In mammals, sex differences in the brain arise from genetic and hormonal factors, including organizational effects of perinatal testosterone. Epigenetic mechanisms including DNA methylation and demethylation have emerged as critical mediators of brain masculinization; specifically, their regulatory enzymes are upregulated in neonatal mice during the critical period of sexual differentiation, with their inhibition abolishing sex-specific cellular phenotypes. Here, we assessed sex differences in gene expression of the DNA demethylation machinery (Tet1, Tet2, Tet3, Gadd45a, Gadd45b and Tdg) during and after the critical period, and examined how these differences relate to the oxytocinergic system. mRNA expression was measured in the prefrontal cortex (PFC), preoptic area (POA) and paraventricular nucleus of the hypothalamus (PVN) at postnatal day (P) 7 and P18. At P7, males showed higher expression of all six genes than females in PFC, with no differences in POA or PVN; by P18, no regional differences remained. Oxytocin (OXT) immunoreactivity was surveyed across periventricular nucleus (Pe), anteroventral periventricular nucleus (AVPe), POA, PVN and supraoptic nucleus (SON). OXT was undetectable in the POA, AVPe and Pe at P7, and no sex differences were found in PVN or SON at either age, or in AVPe at P18. At P18, females showed higher OXT-immunoreactivity in the Pe and POA, than males. For Oxtr, qPCR revealed higher mRNA expression in the PFC of males at P7, with no other regional differences and none remaining at P18. Together, these findings suggest that sex differences in oxytocinergic regions arise from sex-specific epigenetic regulation during the critical period, and that perinatal testosterone may program DNA methylation dynamics underlying sex-specific gene expression in the developing brain. Our results support a model in which testosterone-dependent epigenetic mechanisms contribute to the sexual differentiation of neuroendocrine circuits, linking hormonal signals to long-term brain organization.

Lysophosphatidic acid (LPA) is widely recognized as an extracellular lipid mediator; however, the functional significance of intracellularly produced LPA remains poorly understood. Here, we investigated the regulatory mechanism and functional role of a LPA-producing lysophospholipase D GDE4, also known as GDPD1, in prostate cancer cells. GDE4 expression is induced under ER stress conditions in a PERK-dependent manner and requires the transcription factor ATF3. Disruption of GDE4 expression resulted in altered intracellular levels of LPA and LPA precursor lysophosphatidylethanolamine, accompanied by reduced cell proliferation. RNA sequencing and subsequent validation identified a set of genes downregulated in GDE4-depleted cells. Pharmacological inhibition experiments indicated that peroxisome proliferator-activated receptor and {gamma} (PPAR and PPAR{gamma}) signaling pathways contribute to the regulation of these GDE4-dependent genes. Collectively, our findings suggest that GDE4-dependent lipid remodeling is associated with PPAR/{gamma}-mediated transcriptional regulation under ER stress conditions. These results provide a potential framework for understanding the link between intracellular lipid metabolism and stress-responsive gene regulation.

Astrocytes play an important role in neuronal health. A critical function of astrocytes is to clear excess extracellular glutamate and prevent excitotoxicity. STAT3 is a transcription factor that promotes astrocyte development and astrocyte reactivity in neurodegenerative diseases and following central nervous system injury. To determine the innate molecular and behavioral functions of adult astrocyte-expressed STAT3 in a non-pathological state, we created conditional Stat3 astrocyte knockout mice (Stat3 aKO) using Stat3flox and the tamoxifen-activated Cre line, Aldh1l1-Cre/ERT2. We measured transcript levels of Gfap, a known STAT3 target gene, and glutamate transporter genes in the medial prefrontal cortex (PFC) of Stat3 aKO. Gfap, Slc1a2 and Slc17a8 transcripts were decreased in the PFC of Stat3 aKO of both sexes. GLT-1 protein, encoded by Slc1a2, was also reduced in the PFC of male Stat3 aKO. We recorded spontaneous excitatory post-synaptic currents (sEPSCs) in male Stat3 aKO and control prelimbic pyramidal neurons and found increased sEPSC amplitude, consistent with a hyper-glutamatergic state due to impaired glutamate clearance. To determine the behavioral consequences of STAT3 depletion in astrocytes, Stat3 aKO were tested for locomotor activity, anxiety-like behavior and binge ethanol consumption, behaviors linked to dysregulation of glutamate homeostasis. Stat3 aKO mice did not differ in locomotor activity or anxiety-like behavior; however, male Stat3 aKO mice consumed significantly less ethanol than controls. These results indicate that STAT3 in adult astrocytes is crucial for maintaining glutamate transporter levels in the adult brain and that astrocytic STAT3 promotes ethanol consumption in male mice. Main pointsO_LIGfap, Slc1a2 and Slc17a8 expression are lower in the cortex of Stat3 astrocyte knockout mice (Stat3 aKO) C_LIO_LIGLT-1 protein is decreased and glutamate neurotransmission is elevated in the cortex of male Stat3 aKO C_LIO_LIMale Stat3 aKO consume less ethanol C_LI

Mammalian reproductive function is driven by arcuate kisspeptin neurons, pacemakers of gonadotropin secretion. During energy shortages, animals reallocate resources from reproduction to survival; however, the underlying neural mechanisms remain elusive. Here we used fiber photometry to chronically monitor synchronized episodes of arcuate kisspeptin neuron activity (SEskiss) in adult mice under various energy-saving conditions. In both sexes, SEskiss frequency was markedly suppressed during fasting-induced torpor and pharmacologically induced hypothermia, whereas hypometabolism alone had no discernible effect. A Q neuron-induced hypothermic state (QIH) robustly suppressed SEskiss, leading to impaired gamete maturation, whereas warming the body temperature during QIH fully restored SEskiss frequency. These findings demonstrate that hypothermia, rather than hypometabolism, is the primary driver of suppression of the hypothalamic reproductive axis during energy-saving conditions. This study provides insights into how thermal signals act as critical gatekeepers in the mammalian reproductive system.

The cerebellar nuclei (CN) has demonstrated its influence on cognitive behavior via the cerebello-cortico circuit, yet the role of CN critical period mechanisms and how they may influence cognitive behavior, such as parvalbumin (PV) expressing interneurons enwrapped by perineuronal nets (PNNs), is still unclear. Therefore, we investigated the role of the lateral CN (LCN) PV cell calcium activity while animals performed a visual discrimination touchscreen cognitive task. All animals received the PV cell calcium indicator GCaMP6f at postnatal day 21 (P21). We targeted the LCN critical period by manipulating neural activity in male mice using the inhibitory Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) from postnatal day 21 to 35 or by injecting an Hapln1-AAV vector to selectively target LCN PNN development. After animals completed the visual discrimination task, cerebellar tissue was collected for viral recovery and antibody staining for PNN components, Hapln1 and aggrecan. Results revealed DREADD animals showed improved reversal learning, an increase in calcium response to learning-related activity and altered PNN expression (Hapln1 and aggrecan). Hapln1 treated animals displayed a decrease in final day acquisition performance, lower reversal performance compared to DREADD groups, a decrease in reversal calcium learning-related activity, and an increase in PNN expression (Hapln1). Together, these data provide further evidence of LCN mechanisms associated with learning as well as the importance of understanding region-specific critical periods of plasticity.

Black carbon (BC), a combustion-derived component of fine particulate matter, has been linked to depressive symptoms, but controlled experimental evidence remains limited. We established a controlled BC inhalation model combined with chronic restraint stress (CRS) to determine whether inhaled BC alone induces depressive-like behavior and whether concurrent stress enhances behavioral and molecular vulnerability. Male C57BL/6J mice were assigned to Control, CRS, BC, or BC+CRS groups and exposed for 21 consecutive days, followed by behavioral testing and molecular analyses of plasma-depleted whole blood and stress-related brain regions. BC exposure alone induced depressive-like behavior, and the combined BC+CRS condition showed the most pronounced phenotype. These findings indicate that inhaled BC is sufficient to influence stress-relevant behavior and may heighten vulnerability under chronic stress. At the molecular level, BC shifted peripheral responses toward a stress- and inflammation-associated state with reduced plasticity-related signaling, whereas CRS preferentially engaged glucocorticoid-responsive regulation. Combined BC+CRS exposure further altered plasticity- and transcription-related regulatory programs in blood and stress-related brain regions, with prominent changes in the nucleus accumbens. These condition-dependent molecular patterns suggest that BC engages blood-brain stress-related pathways in a context- and region-specific manner. Together, these findings identify inhaled BC as a neurobehaviorally relevant environmental hazard.

Lateral hypothalamic GABAergic (LHAGABA) neurons regulate arousal, feeding, and reward-related behaviors, but how their downstream projections coordinate motivated behaviors across domains remains incompletely defined. Our histological analyses revealed that LHAGABA fibers were distributed across the dorsal pons (DP) subregions, including the peri-locus coeruleus, laterodorsal tegmentum, and Barringtons nucleus, and extend throughout the lateral preoptic area (LPO), thereby refining existing anatomical descriptions. We then used optogenetics to systematically compare the effects of activating LHAGABA somata and their projections to the DP and LPO across assays of feeding, non-food-directed gnawing, predatory behavior, real-time place preference, and operant self-stimulation. In sated mice, optogenetic activation of LHAGABA somata or their terminals in the DP or LPO increased caloric food intake, whereas non-caloric cellulose intake was minimally affected during terminal stimulation. Across conditions, activation increased gnawing and shredding of non-food objects while reducing inactivity. In cricket hunting, stimulation increased cricket killing and consumption relative to controls. Similarly, all stimulation conditions supported positive-valence and reinforcement-related responding, as indicated by real-time place preference and operant self-stimulation. Together, these results provide new functional evidence that activation of LHAGABA somata and projections to both the DP and LPO recruit largely overlapping behavioral responses across feeding, non-food behavior, predatory hunting, and reinforcement-related assays. These findings support a distributed hypothalamic output architecture in which major ascending and descending LHAGABA pathways contribute to a shared motivational repertoire rather than wholly discrete behavioral functions.

Preeclampsia is a pregnancy complication characterized by hypertension, proteinuria, and end-organ dysfunction. Abnormal placentation leading to reduced placental perfusion may contribute to its development. Previous studies demonstrated that the activation of the apelin receptor (APJ) system has hypotensive, renoprotective, and antioxidant effects in preeclamptic rat models. Apelin and elabela (ELA) can stimulate the proliferation of trophoblast cells, suggesting a role in embryonic development. However, the mechanisms underlying the actions of apelin or ELA in trophoblast cells are not well understood, particularly in hypoxic settings. The immortalized HTR-8/SVneo trophoblastic cells were treated with cobalt chloride (CoCl2) at 0.2 mM for 24 hours to mimic hypoxic conditions. RT-qPCR, ELISA or Western blotting was used to measure mRNA or protein levels of apelin, elabela, and the components of IL-6 signaling in cell lysates or conditioned media. The exposure to CoCl2 increased total apelin and elabela content approximately 2-fold in the conditioned media but did not affect APJ levels. CoCl2 upregulated proinflammatory cytokine concentrations: soluble fms-like tyrosine kinase 1 (sFlt-1), soluble gp130 (sgp130), interleukin-6 (IL-6), and sIL-6 receptor (IL-s6R). Both apelin and elabela downregulated IL-6 mRNA but had no effect on sFlt-1 mRNA. Apelin attenuated sgp130, while ELA decreased the membrane form of IL-s6R. Apelin also decreased the pSTAT3/STAT3 ratio. CoCl2-induced hypoxia upregulated the pro-inflammatory milieu in HTR-8/SVneo cells. Local activation of this peptidergic system may be a compensatory response of the trophoblast cells to hypoxia as exogenous apelin and elabela treatment ameliorated the hypoxia-induced pro-inflammatory milieu.

BackgroundInflammation-associated depression is a subtype of major depressive disorder that is often resistant to conventional pharmacotherapies, which act in a regionally non-specific manner and therefore also produce unwanted side effects. Here we test GPR151, an orphan GPCR associated with inflammation and highly expressed in the habenula--a region linked to negative valence and depression--as a therapeutic target for inflammation-associated depression. MethodsWe integrated mouse and human habenular expression analyses with genetic loss-of-function and adult habenular re-expression approaches in mice. Gpr151 knockout mice and littermate controls were exposed to lipopolysaccharide (LPS) inflammatory challenge and assessed for stress coping and motivated behavior, body weight loss, and peripheral immune activation. To test whether adult habenular GPR151 expression is sufficient to restore inflammation-associated behavioral vulnerability, GPR151 was re-expressed in the habenula of knockout mice. ResultsGPR151 was exceptionally enriched in the habenula and showed conserved topographic organization and similar expression relationships with habenular marker genes in mice and humans. Following LPS challenge, male Gpr151 knockout mice showed reduced passive coping despite body weight loss and immune activation comparable to littermate controls. Adult habenular GPR151 re-expression increased LPS-induced amotivation in male knockout mice without increasing LPS-induced weight loss or immune activation. Female Gpr151 knockout mice also showed reduced passive coping after LPS challenge; however, habenular GPR151 re-expression was insufficient to increase LPS-induced amotivation in females. ConclusionsThese findings identify GPR151 as a conserved, regionally enriched regulator of behavioral sensitivity to inflammatory challenge and support GPR151 as a candidate therapeutic target for inflammation-associated depression.

Exposure to chemical cues released by predator or pathogen can evoke anxiety or fear responses in prey/host animals such as fight, flight or freeze both at behavioral and molecular levels. Freezing is a fundamental anxiety response when fighting or fleeing arent feasible. Despite the potential relevance of freezing as a stress-coping mechanism, its behavioral and molecular underpinnings are not understood yet. At molecular level danger cues are perceived by chemosensory receptors expressed in sensory neurons which may further regulate the animals behavioral responses(Ye et al., 2024){Citation}. 2-nonanone (2-NA) is one of the principal volatile organic compounds secreted by many pathogenic bacteria infecting Caenorhabditis elegans as well as humans and may signal danger to worms. Here, we show that olfactory exposure to threat-associated cue 2-NA induces a reversible fear-like freezing response characterized by immobility and halted feeding in C. elegans. With the application of in silico and behavioral approaches we showed that 2-NA is one of the ligands for an olfactory G-protein Coupled Receptor (GPCR) STR-211 and RNAi knockdown of the receptor leads to a defect in 2-NA induced avoidance behavior in worms. We next discovered that STR-211 is required for immediate behavioral changes in C. elegans during freezing response against 2-NA. The study proposes an environment relevant animal model to mimic human anxiety and fear-like behavior, along with the identification of one of the olfactory GPCRs mediating this behavior. The model may help in understanding the neuromolecular basis of freezing response in human anxiety, contributing towards treatment of mental health disorders.

BackgroundCircadian disruption is strongly associated with alcohol use disorder (AUD), but insight into the underlying brain-region and sex-specific mechanisms is limited. The function of the circadian clock gene Bmal1 within the striatum has been linked to alcohol drinking, yet its role within functionally distinct striatal subregions has not been systematically examined. MethodsWe deleted Bmal1 in medium spiny neurons of the dorsomedial striatum (DMS) or dorsolateral striatum (DLS). Male and female mice were tested for anxiety-like behavior, depressive-like behavior, and motor coordination. Voluntary alcohol intake was measured with an intermittent two-bottle choice paradigm, followed by sucrose preference and quinine-adulterated alcohol tests. To assess hormonal contributions, a subset of female mice underwent ovariectomy before behavioral testing. ResultsDeletion of Bmal1 in the DLS did not alter alcohol intake, alcohol preference, or quinine-adulterated alcohol intake in either sex. In contrast, DMS Bmal1 deletion significantly reduced alcohol consumption and alcohol preference in female mice, with no effect in males. These effects were not accompanied by changes in depressive-like behavior or motor coordination and were not explained by generalized reward changes, as sucrose preference was unaffected. Ovariectomy eliminated the effect of DMS Bmal1 deletion on alcohol intake, indicating dependence on ovarian hormones. ConclusionsThe DMS is a critical site at which Bmal1 regulates alcohol consumption in a sex-specific manner. These findings support an interaction between local circadian mechanisms and ovarian hormones in controlling alcohol drinking and highlight a potential target for sex-specific therapeutics in AUD.