Hu, S;Wang, Y;Han, X;Dai, M;Zhang, Y;Ma, Y;Weng, S;Xiao, L;
PMID: 36127701 | DOI: 10.1186/s12915-022-01405-0
Oxytocin, secreted by oxytocin neurons in the hypothalamus, is an endogenous neuropeptide involved in modulating multiple sensory information processing pathways, and its roles in the brain have been associated with prosocial, maternal, and feeding-related behaviors. Visual information is necessary for initiating these behaviors, with the retina consisting of the first stage in the visual system mediating external stimulus perception. Oxytocin has been detected in the mammalian retina; however, the expression and possible function of oxytocin receptors (OxtR) in the retina remain unknown. Here, we explore the role of oxytocin in regulating visual information processing in the retina.We observed that OxtR mRNA and protein are expressed in the mouse retina. With Oxtr-Cre transgenic mice, immunostaining, and fluorescence in situ hybridization, we found that OxtRs are mainly expressed in GABAergic amacrine cells (ACs) in both the inner nuclear layer (INL) and ganglion cell layer (GCL). Further immunoreactivity studies showed that GABAergic OxtR+ neurons are mainly cholinergic and dopaminergic neurons in the INL and are cholinergic and corticotrophin-releasing hormone neurons in the GCL. Surprisingly, a high level of Oxtr mRNAs was detected in retinal dopaminergic neurons, and exogenous oxytocin application activated dopaminergic neurons to elevate the retinal dopamine level. Relying on in vivo electroretinographic recording, we found that activating retinal OxtRs reduced the activity of bipolar cells via OxtRs and dopamine receptors.These data indicate the functional expression of OxtRs in retinal GABAergic ACs, especially dopaminergic ACs, and expand the interactions between oxytocinergic and dopaminergic systems. This study suggests that visual perception, from the first stage of information processing in the retina, is modulated by hypothalamic oxytocin signaling.
Abdelmesih, B;Anderson, R;Bambah-Mukku, D;Carta, I;Autry, AE;
PMID: 36476733 | DOI: 10.1038/s41380-022-01902-2
Infant avoidance and aggression are promoted by activation of the Urocortin-3 expressing neurons of the perifornical area of hypothalamus (PeFAUcn3) in male and female mice. PeFAUcn3 neurons have been implicated in stress, and stress is known to reduce maternal behavior. We asked how chronic restraint stress (CRS) affects infant-directed behavior in virgin and lactating females and what role PeFAUcn3 neurons play in this process. Here we show that infant-directed behavior increases activity in the PeFAUcn3 neurons in virgin and lactating females. Chemogenetic inhibition of PeFAUcn3 neurons facilitates pup retrieval in virgin females. CRS reduces pup retrieval in virgin females and increases activity of PeFAUcn3 neurons, while CRS does not affect maternal behavior in lactating females. Inhibition of PeFAUcn3 neurons blocks stress-induced deficits in pup-directed behavior in virgin females. Together, these data illustrate the critical role for PeFAUcn3 neuronal activity in mediating the impact of chronic stress on female infant-directed behavior.
Lemos JC, Shin JH, Alvarez VA.
PMID: 31109960 | DOI: 10.1523/JNEUROSCI.0479-19.2019
Cholinergic interneurons (CINs) are critical regulators of striatal network activity and output. Changes in CIN activity are thought to encode salient changes in the environment and stimulus-response-outcome associations. Here we report that the stress-associated neuropeptide corticotropin releasing factor (CRF) produces a profound and reliable increase in the spontaneous firing of CINs in both dorsal striatum and nucleus accumbens (NAc) through activation of CRF type 1 receptors, production of cAMP and reduction in spike accommodation in male mice. The increase of CIN firing by CRF results in the activation muscarinic acetylcholine receptors type 5, which mediate potentiation of dopamine transmission in the striatum. This study provides critical mechanistic insight into how CRF modulates striatal activity and dopamine transmission in the NAc to likely account for CRF facilitation of appetitive behaviors.SIGNIFICANCE STATEMENT Although the presence of CRF receptors in the dorsal and ventral striatum has been acknowledged, the cellular identity and the functional consequences of receptor activation is unknown. Here we report that striatal cholinergic interneurons express CRF-R1 receptors and are acutely activated by the neuropeptide CRF that is released in response to salient environmental stimuli. Cholinergic interneurons make <1% of the cells in the striatum but are critical regulators of the striatal circuitry and its output. CRF's fast and potent activation of cholinergic interneurons could have far reaching behavioral implications across motivated behaviors controlled by the striatum.
Underwood, CF;Burke, PGR;Kumar, NN;Goodchild, AK;McMullan, S;Phillips, JK;Hildreth, CM;
PMID: 35654013 | DOI: 10.1159/000525337
Angiotensin (Ang) II signalling in the hypothalamic paraventricular nucleus (PVN) via angiotensin type-1a receptors (AT1R) regulates vasopressin release and sympathetic nerve activity - two effectors of blood pressure regulation. We determined the cellular expression and function of AT1R in the PVN of a rodent model of polycystic kidney disease (PKD), the Lewis Polycystic Kidney (LPK) rat, to evaluate its contribution to blood pressure regulation and augmented vasopressin release in PKD.PVN AT1R gene expression was quantified with fluorescent in-situ hybridisation in LPK and control rats. PVN AT1R function was assessed with pharmacology under urethane anaesthesia in LPK and control rats instrumented to record arterial pressure and sympathetic nerve activity.AT1R gene expression was upregulated in the PVN, particularly in CRH neurons, of LPK versus control rats. PVN microinjection of Ang II produced larger increases in systolic blood pressure in LPK versus control rats (36±5 vs. 17±2 mmHg; P<0.01). Unexpectedly, Ang II produced regionally heterogeneous sympathoinhibition (renal: -33%; splanchnic: -12%; lumbar no change) in LPK and no change in controls. PVN pre-treatment with losartan, a competitive AT1R antagonist, blocked the Ang II-mediated renal sympathoinhibition and attenuated the pressor response observed in LPK rats. The Ang II pressor effect was also blocked by systemic OPC-21268, a competitive V1A receptor antagonist, but unaffected by hexamethonium, a sympathetic ganglionic blocker.Collectively, our data suggest that upregulated AT1R expression in PVN sensitises neuroendocrine release of vasopressin in the LPK, identifying a central mechanism for the elevated vasopressin levels present in PKD.The Author(s).
Corticotropin-releasing factor neurons in the bed nucleus of the stria terminalis exhibit sex-specific pain encoding in mice
Yu, W;Caira, CM;Del R Rivera Sanchez, N;Moseley, GA;Kash, TL;
PMID: 34127705 | DOI: 10.1038/s41598-021-91672-8
The bed nucleus of the stria terminalis (BNST) plays an emerging role in pain regulation. Pharmacological studies have found that inhibiting corticotropin-releasing factor (CRF) signaling in the BNST can selectively mitigate the sensory and affective-motivational components of pain. However, mechanistic insight on the source of CRF that drives BNST responses to these harmful experiences remains unknown. In the present study, we used a series of genetic approaches to show that CRF in the BNST is engaged in the processing and modulation of pain. We conducted cell-type specific in vivo calcium imaging in CRF-Cre mice and found robust and synchronized recruitment of BNSTCRF neurons during acute exposures to noxious heat. Distinct patterns of recruitment were observed by sex, as the magnitude and timing of heat responsive activity in BNSTCRF neurons differed for male and female mice. We then used a viral approach in Floxed-CRF mice to selectively reduce CRF expression in the BNST and found it decreased nociceptive sensitivity for both sexes and increased paw attending for females. Together, these findings reveal that CRF in the BNST influences multiple facets of the pain experience to impact the sex-specific expression of pain-related behaviors.
Porcu, A;Nilsson, A;Booreddy, S;Barnes, SA;Welsh, DK;Dulcis, D;
PMID: 36054362 | DOI: 10.1126/sciadv.abn9867
Seasonal changes in day length (photoperiod) affect numerous physiological functions. The suprachiasmatic nucleus (SCN)-paraventricular nucleus (PVN) axis plays a key role in processing photoperiod-related information. Seasonal variations in SCN and PVN neurotransmitter expression have been observed in humans and animal models. However, the molecular mechanisms by which the SCN-PVN network responds to altered photoperiod is unknown. Here, we show in mice that neuromedin S (NMS) and vasoactive intestinal polypeptide (VIP) neurons in the SCN display photoperiod-induced neurotransmitter plasticity. In vivo recording of calcium dynamics revealed that NMS neurons alter PVN network activity in response to winter-like photoperiod. Chronic manipulation of NMS neurons is sufficient to induce neurotransmitter switching in PVN neurons and affects locomotor activity. Our findings reveal previously unidentified molecular adaptations of the SCN-PVN network in response to seasonality and the role for NMS neurons in adjusting hypothalamic function to day length via a coordinated multisynaptic neurotransmitter switching affecting behavior.
Activation of the hypothalamic-pituitary-adrenal axis by exogenous and endogenous GDF15
Proceedings of the National Academy of Sciences of the United States of America
Cimino, I;Kim, H;Tung, YCL;Pedersen, K;Rimmington, D;Tadross, JA;Kohnke, SN;Neves-Costa, A;Barros, A;Joaquim, S;Bennett, D;Melvin, A;Lockhart, SM;Rostron, AJ;Scott, J;Liu, H;Burling, K;Barker, P;Clatworthy, MR;Lee, EC;Simpson, AJ;Yeo, GSH;Moita, LF;Bence, KK;Jørgensen, SB;Coll, AP;Breen, DM;O'Rahilly, S;
PMID: 34187898 | DOI: 10.1073/pnas.2106868118
An acute increase in the circulating concentration of glucocorticoid hormones is essential for the survival of severe somatic stresses. Circulating concentrations of GDF15, a hormone that acts in the brain to reduce food intake, are frequently elevated in stressful states. We now report that GDF15 potently activates the hypothalamic-pituitary-adrenal (HPA) axis in mice and rats. A blocking antibody to the GDNF-family receptor α-like receptor completely prevented the corticosterone response to GDF15 administration. In wild-type mice exposed to a range of stressful stimuli, circulating levels of both corticosterone and GDF15 rose acutely. In the case of Escherichia coli or lipopolysaccharide injections, the vigorous proinflammatory cytokine response elicited was sufficient to produce a near-maximal HPA response, regardless of the presence or absence of GDF15. In contrast, the activation of the HPA axis seen in wild-type mice in response to the administration of genotoxic or endoplasmic reticulum toxins, which do not provoke a marked rise in cytokines, was absent in Gdf15 -/- mice. In conclusion, consistent with its proposed role as a sentinel hormone, endogenous GDF15 is required for the activation of the protective HPA response to toxins that do not induce a substantial cytokine response. In the context of efforts to develop GDF15 as an antiobesity therapeutic, these findings identify a biomarker of target engagement and a previously unrecognized pharmacodynamic effect, which will require monitoring in human studies.
Revue des Maladies Respiratoires
Tanguy, J;Boutanquoi, P;Dondaine, L;Burgy, O;Bellaye, P;Beltramo, G;Garrido, C;Bonniaud, P;Goirand, F;
| DOI: 10.1016/j.rmr.2022.11.068
Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and lethal disease of unknown aetiology. In France, it ranks among the most frequent interstitial pathologies and affects 6 out of 8 people per 100,000 each year. IPF is characterized by dysregulated healing mechanisms that leads to the accumulation of large amounts of collagen in the lung tissue that disrupts the alveolar architecture. Nintedanib and Pirfenidone are the only currently available treatments even though they are only able to slow down the disease without being curative. In this context, inhibiting HSPB5, a low molecular weight heat shock protein known to be involved in the development of fibrosis, could constitute a potential therapeutic target. Our aim consist to explore how NCI-41356 (a chemical inhibitor of HSPB5) can limit the development of pulmonary fibrosis. Methods In vivo, fibrosis was assessed in mice injected intratracheally (i.t.) with Bleomycin (BLM) and treated with NaCl or NCI-41356 (3 times i.t. or 3 times a week i.v.). Fibrosis was evaluated by collagen quantification (Sircol, Sirius Red staining), Immunofluorescence, TGF-β gene expression (RNAscope). In vitro, TGF-β1 signaling was evaluated in epithelial cells treated by TGF-β1 with or without NCI-41356 (Western Blot, Immunofluorescence, Proximity ligation assay). Results In vivo, NCI-41356 reduced the accumulation of collagen, the expression of TGF-β1 and several pro-fibrotic markers (PAI-1, α-SMA). In vitro, NCI-41356 decreased the interaction between HSPB5 and SMAD4 explaining NCI-41356 anti-fibrotic properties. Conclusion In this study, we determined that inhibition of HSPB5/SMAD4 could limit IPF in mice. NCI-41356 modulates SMAD4 nuclear translocation thus limiting TGF-β1 signaling and synthesis of collagen and pro-fibrotic markers. Further investigations with human fibrotic lung tissues are needed to determine if these results can be transposed in human.
Espinosa MG, Taber LA, Wagenseil JE.
PMID: 29696727 | DOI: 10.1002/dvdy.24635
Background Perturbations to embryonic hemodynamics are known to adversely affect cardiovascular development. Vitelline vein ligation (VVL) is a model of reduced placental blood flow used to induce cardiac defects in early chick embryo development. The effect of these hemodynamic interventions on maturing elastic arteries is largely unknown. We hypothesize that hemodynamic changes impact maturation of the dorsal aorta (DA). Results We examined the effects of VVL on hemodynamic properties well into the maturation process and the corresponding changes in aortic dimensions, wall composition, and gene expression. In chick embryos, we found that DA blood velocity was reduced immediately post-surgery at Hamburger-Hamilton stage (HH) 18 and later at HH36, but not in the interim. Throughout this period, DA diameter adapted to maintain a constant shear stress. At HH36, we found that VVL DAs showed a substantial decrease in elastin and modest increase in collagen protein content. In VVL DAs, upregulation of elastic fiber related genes followed the downregulation of flow-dependent genes. Together, these suggest the existence of a compensatory mechanism in response to shear induced delays in maturation. Conclusions The DA's response to hemodynamic perturbations invokes coupled mechanisms for shear regulation and matrix maturation, potentially impacting the course of vascular development.
Fujii Y, Suzuki K, Hasegawa Y, Nanba F, Toda T, Adachi T, Taira S, Osakabe N.
PMID: 29902479 | DOI: 10.1016/j.neulet.2018.06.015
We previously confirmed that postprandial alterations in the circulation and metabolism after a single oral dose of flavan 3-ols (mixture of catechin and catechin oligomers) were involved in an increase in sympathetic nervous activity. However, it is well known that, in response to various stresses, activation of the hypothalamic-pituitary-adrenal (HPA) axis occurs together with sympathetic nerve activity, which is associated with activation of the sympathetic-adrenal-medullary (SAM) axis. In this study, we examined whether the HPA axis was activated after a single dose of flavan 3-ols. We administered an oral dose of 10 or 50 mg/kg flavan 3-ols to male ICR mice, removed the brains, and fixed them in paraformaldehyde-phosphate buffer. Other animals that were treated similarly were decapitated, and blood was collected. In the paraventricular nucleus (PVN), c-fos mRNA expression increased significantly at 15 min after administration of either 10 or 50 mg/kg flavan 3-ols. Corticotropin-releasing hormone (CRH) mRNA expression levels significantly increased at 240 min after administration of 10 mg/kg flavan 3-ols, and at 60 min after administration of 50 mg/kg flavan 3-ols. Plasma corticosterone levels were also significantly increased at 240 min after ingestion of 50 mg/kg flavan 3-ols. In this experiment, we confirmed that the ingestion of flavan 3-ols acted as a stressor in mammals with activation both the SAM and HPA axes.
The American journal of pathology
Kobayashi, Y;Yokoi, A;Hashimura, M;Oguri, Y;Konno, R;Matsumoto, T;Tochimoto, M;Nakagawa, M;Ishibashi, Y;Ito, T;Ohhigata, K;Harada, Y;Fukagawa, N;Kodera, Y;Saegusa, M;
PMID: 37169340 | DOI: 10.1016/j.ajpath.2023.04.011
Epithelial-mesenchymal transition is a hallmark of uterine carcinosarcoma (UCS). Here, we used shotgun proteomics analysis to identify biomarkers associated with blebbistatin-mediated epithelial-mesenchymal transition in UCS, and found up-regulation of nucleobindin-2 (NUCB2) in endometrial carcinoma (Em Ca) cells. Expression of N-cadherin, Snail, Slug, and ZEB1 was reduced in NUCB2 knockout Em Ca cells, whereas ZEB1, Twist1, and vimentin were up-regulated in NUCB2-overexpressing Em Ca cells. NUCB2 knockout reduced cell proliferation and migration, whereas NUCB2 overexpression had the opposite effect. Treatment of Em Ca cells with transforming growth factor (TGF)-β1 dramatically altered morphology toward a fibroblastic appearance; concomitantly, expression of NUCB2 and ZEB1 increased. The NUCB2 promoter was also activated by transfection of Smad2. In UCS tissues, NUCB2 expression was significantly higher in sarcomatous compared with carcinomatous components; this was consistent with increased TGF-β1 mRNA expression in stromal and sarcomatous components compared with carcinomatous components. In addition, NUCB2 score correlated positively with ZEB1 and vimentin scores, whereas ZEB1 score correlated positively with Slug and vimentin scores and inversely with the E-cadherin score. We therefore suggest that TGF-β-dependent up-regulation of NUCB2 and ZEB1 contributes to the phenotypic characteristics of sarcomatous components in UCS.
Physiol Behav. 2014 Apr 2. pii: S0031-9384(14)00173-5.
Smith JA, Wang L, Hiller H, Taylor CT, de Kloet AD, Krause EG.
PMID: 24704193 | DOI: 10.1016/j.physbeh.2014.03.027.
Previous investigation by our laboratory found that acute hypernatremia potentiates an oxytocinergic tone that inhibits parvocellular neurosecretory neurons in the paraventricular nucleus of the hypothalamus (PVN), attenuates restraint-induced surges in corticosterone (CORT), and reduces anxiety-like behavior in male rats. To investigate the neural mechanisms mediating these effects and extend our findings to a more versatile species, we repeated our studies using laboratory mice. In response to 2.0M NaCl injections, mice had increased plasma sodium concentrations which were associated with a blunted rise in CORT subsequent to restraint challenge relative to 0.15M NaCl injected controls. Immunofluorescent identification of the immediate early gene product Fos found that 2.0M NaCl treatment increased the number of activated neurons producing oxytocin in the PVN. To evaluate the effect of acute hypernatremia on PVN neurons producing corticotropin-releasing hormone (CRH), we used the Cre-lox system to generate mice that produced the red fluorescent protein, tdTomato, in cells that had Cre-recombinase activity driven by CRH gene expression. Analysis of brain tissue from these CRH-reporter mice revealed that 2.0M NaCl treatment caused a dramatic reduction in Fos-positive nuclei specifically in CRH-producing PVN neurons. This altered pattern of activity was predictive of alleviated anxiety-like behavior as mice administered 2.0M NaCl spent more time exploring the open arms of an elevated-plus maze than 0.15M NaCl treated controls. Taken together, these results further implicate an oxytocin-dependent inhibition of CRH neurons in the PVN and demonstrate the impact that slight elevations in plasma sodium have on the hypothalamic-pituitary-adrenocortical axis output and anxiety-like behavior.
