scholarly journals Leptin receptor neurons in the mouse hypothalamus are colocalized with the neuropeptide galanin and mediate anorexigenic leptin action

2013 ◽  
Vol 304 (9) ◽  
pp. E999-E1011 ◽  
Author(s):  
Amanda Laque ◽  
Yan Zhang ◽  
Sarah Gettys ◽  
Tu-Anh Nguyen ◽  
Kelly Bui ◽  
...  

Leptin acts centrally via leptin receptor (LepRb)-expressing neurons to regulate food intake, energy expenditure, and other physiological functions. LepRb neurons are found throughout the brain, and several distinct populations contribute to energy homeostasis control. However, the function of most LepRb populations remains unknown, and their contribution to regulate energy homeostasis has not been studied. Galanin has been hypothesized to interact with the leptin signaling system, but literature investigating colocalization of LepRb and galanin has been inconsistent, which is likely due to technical difficulties to visualize both. We used reporter mice with green fluorescent protein expression from the galanin locus to recapitulate the colocalization of galanin and leptin-induced p-STAT3 as a marker for LepRb expression. Here, we report the existence of two populations of galanin-expressing LepRb neurons (Gal-LepRb neurons): in the hypothalamus overspanning the perifornical area and adjacent dorsomedial and lateral hypothalamus [collectively named extended perifornical area (exPFA)] and in the brainstem (nucleus of the solitary tract). Surprisingly, despite the known orexigenic galanin action, leptin induces galanin mRNA expression and stimulates LepRb neurons in the exPFA, thus conflicting with the expected anorexigenic leptin action. However, we confirmed that intra-exPFA leptin injections were indeed sufficient to mediate anorexic responses. Interestingly, LepRb and galanin-expressing neurons are distinct from orexin or melanin-concentrating hormone (MCH)-expressing neurons, but exPFA galanin neurons colocalized with the anorexigenic neuropeptides neurotensin and cocaine- and amphetamine-regulated transcript (CART). Based on galanin's known inhibitory function, we speculate that in exPFA Gal-LepRb neurons galanin acts inhibitory rather than orexigenic.

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4600-4607 ◽  
Author(s):  
Alastair S. Garfield ◽  
Christa Patterson ◽  
Susanne Skora ◽  
Fiona M. Gribble ◽  
Frank Reimann ◽  
...  

Abstract The action of peripherally released leptin at long-form leptin receptors (LepRb) within the brain represents a fundamental axis in the regulation of energy homeostasis and body weight. Efforts to delineate the neuronal mediators of leptin action have recently focused on extrahypothalamic populations and have revealed that leptin action within the nucleus of the solitary tract (NTS) is critical for normal appetite and body weight regulation. To elucidate the neuronal circuits that mediate leptin action within the NTS, we employed multiple transgenic reporter lines to characterize the neurochemical identity of LepRb-expressing NTS neurons. LepRb expression was not detected in energy balance-associated NTS neurons that express cocaine- and amphetamine-regulated transcript, brain-derived neurotrophic factor, neuropeptide Y, nesfatin, catecholamines, γ-aminobutyric acid, prolactin-releasing peptide, or nitric oxide synthase. The population of LepRb-expressing NTS neurons was comprised of subpopulations marked by a proopiomelanocortin-enhanced green fluorescent protein (EGFP) transgene and distinct populations that express proglucagon and/or cholecystokinin. The significance of leptin action on these three populations of NTS neurons was assessed in leptin-deficient Ob/Ob mice, revealing increased NTS proglucagon and cholecystokinin, but not proopiomelanocortin, expression. These data provide new insight into the appetitive brainstem circuits engaged by leptin.


Endocrinology ◽  
2006 ◽  
Vol 147 (7) ◽  
pp. 3190-3195 ◽  
Author(s):  
Kate L. J. Ellacott ◽  
Ilia G. Halatchev ◽  
Roger D. Cone

The central melanocortin system plays a key role in the regulation of energy homeostasis. Neurons containing the peptide precursor proopiomelanocortin (POMC) are found at two sites in the brain, the arcuate nucleus of the hypothalamus (ARC) and the caudal region of the nucleus of the solitary tract (NTS). ARC POMC neurons, which also express cocaine- and amphetamine-regulated transcript (CART), are known to mediate part of the response to factors regulating energy homeostasis, such as leptin and ghrelin. In contrast, the physiological role(s) of the POMC neurons in the caudal brainstem are not well characterized. However, development of a transgenic mouse expressing green fluorescent protein under the control of the POMC promoter [POMC-enhanced green fluorescent protein (EGFP) mouse] has aided the study of these neurons. Indeed, recent studies have shown significant activation of NTS POMC-EGFP cells by the gut released satiety factor cholecystokinin (CCK). Here we show that peripheral leptin administration induces the expression of phospho-signal transducer and activator of transcription 3 immunoreactivity (pSTAT3-IR), a marker of leptin receptor signaling, in more than 50% of NTS POMC-EGFP neurons. Furthermore, these POMC-EGFP neurons comprise 30% of all pSTAT3-IR cells in the NTS. Additionally, we also show that in contrast to the ARC population, NTS POMC-EGFP neurons do not coexpress CART immunoreactivity. These data suggest that NTS POMC neurons may participate with ARC POMC cells in mediating some of the effects of leptin and thus comprise a novel cell group regulated by both long-term adipostatic signals and satiety factors such as CCK.


2008 ◽  
Vol 200 (1) ◽  
pp. 93-105 ◽  
Author(s):  
E Guillod-Maximin ◽  
A F Roy ◽  
C M Vacher ◽  
A Aubourg ◽  
V Bailleux ◽  
...  

Adiponectin is involved in the control of energy homeostasis in peripheral tissues through Adipor1 and Adipor2 receptors. An increasing amount of evidence suggests that this adipocyte-secreted hormone may also act at the hypothalamic level to control energy homeostasis. In the present study, we observed the gene and protein expressions of Adipor1 and Adipor2 in rat hypothalamus using different approaches. By immunohistochemistry, Adipor1 expression was ubiquitous in the rat brain. By contrast, Adipor2 expression was more limited to specific brain areas such as hypothalamus, cortex, and hippocampus. In arcuate and paraventricular hypothalamic nuclei, Adipor1, and Adipor2 were expressed by neurons and astrocytes. Furthermore, using transgenic green fluorescent protein mice, we showed that Adipor1 and Adipor2 were present in pro–opiomelanocortin (POMC) and neuropeptide Y (NPY) neurons in the arcuate nucleus. Finally, adiponectin treatment by intracerebroventricular injection induced AMP-activated protein kinase (AMPK) phosphorylation in the rat hypothalamus. This was confirmed byin vitrostudies using hypothalamic membrane fractions. In conclusion, Adipor1 and Adipor2 are both expressed by neurons (including POMC and NPY neurons) and astrocytes in the rat hypothalamic nuclei. Adiponectin is able to increase AMPK phosphorylation in the rat hypothalamus. These data reinforced a potential role of adiponectin and its hypothalamic receptors in the control of energy homeostasis.


Endocrinology ◽  
2014 ◽  
Vol 155 (6) ◽  
pp. 2314-2319 ◽  
Author(s):  
Zi Chen Wang ◽  
Michael B. Wheeler ◽  
Denise D. Belsham

The mouse insulin I promoter (MIP) construct was developed to eliminate the promoter activity detected with the rat insulin II promoter in specific hypothalamic neurons that may have unintended effects on glucose and energy homeostasis in transgenic models. Thus, the specificity of this novel construct must be validated prior to the widespread availability of derived Cre models. Although limited validation efforts have indicated a lack of MIP activity within neuronal tissue, the global immunohistochemical methodology used may not be specific enough to rule out the possibility of specific populations of neurons with MIP activity. To investigate possible MIP activity within the hypothalamus, primary hypothalamic isolates from MIP-green fluorescent protein reporter mice were analyzed after fluorescent-activated cell sorting. Primary hypothalamic neurons isolated from the MIP-green fluorescent protein mice were immortalized. Characterization detected the presence of hypothalamic neuropeptide Y (NPY) and agouti-related peptide, involved in the control of energy homeostasis, as well as confirmed insulin responsiveness in the cell lines. Moreover, because insulin was demonstrated to differentially regulate NPY expression within these MIP neurons, the promoter construct may be active in multiple hypothalamic NPY/agouti-related peptide subpopulations with unique physiological functions. MIP transgenic animals may therefore face similar limitations seen previously with rat insulin II promoter-based models.


2021 ◽  
Author(s):  
Mikkel Oernfeldt Noegaard ◽  
Lasse Bach Steffensen ◽  
Didde Hansen ◽  
Ernst-Martin Fuchtbauer ◽  
Morten Buch Engelund ◽  
...  

The in vivo function of cell-derived extracellular vesicles (EVs) is challenging to establish since cell-specific EVs are difficult to isolate. We therefore created an EV reporter using CD9 to display enhanced green fluorescent protein (EGFP) on the EV surface. CD9-EGFP expression in cells did not affect EV size and concentration, but allowed for co-precipitation of EV markers TSG101 and ALIX from cell-conditioned medium by anti-GFP immunoprecipitation. We created a transgenic mouse where CD9-EGFP was inserted in the inverse orientation and double-floxed, ensuring Cre recombinase-dependent EV reporter expression. We crossed the EV reporter mice with mice expressing Cre ubiquitously (CMV-Cre), in cardiomyocytes (AMHC-Cre) and kidney epithelium (Pax8-Cre), respectively. The mice showed tissue-specific EGFP expression, and plasma and urine samples were used to immunoprecipitate EVs. CD9-EGFP EVs was detected in plasma samples from CMV-Cre/CD9-EGFP and AMHC-Cre/CD9-EGFP mice, but not in PAX8-Cre/CD9-EGFP mice. On the other hand, CD9-EGFP EVs were detected in urine samples from CMV-Cre/CD9-EGFP and PAX8-Cre/CD9-EGFP mice, but not AMHC-Cre/CD9-EGFP, indicating that plasma EVs are not filtered to the urine. In conclusion, our EV reporter mouse model enables Cre-dependent EV labeling, providing a new approach to study cell-specific EVs in vivo and gain new insight into their physiological and pathophysiological function.


Endocrinology ◽  
2016 ◽  
Vol 157 (5) ◽  
pp. 1991-2001 ◽  
Author(s):  
Joon S. Kim ◽  
Mohammed Z. Rizwan ◽  
Deborah J. Clegg ◽  
Greg M. Anderson

Abstract Estradiol and leptin are critical hormones in the regulation of body weight. The aim of this study was to determine whether this cross talk between leptin receptor (LepRb) and estrogen receptor-α (ERα) signaling is critical for estradiol's anorexigenic effects. Leprb-Cre mice were crossed with Cre-dependent Tau-green fluorescent protein (GFP) reporter, Stat3-flox or Erα-flox mice to generate female mice with GFP expression, signal transducer and activator of transcription 3 (STAT3) knockout (KO), or ERα KO, specifically in LepRb-expressing cells. The proportion of Leprb-GFP cells colocalizing ERα was high (∼80%) in the preoptic area but low (∼10%) in the mediobasal hypothalamus, suggesting that intracellular cross talk between these receptors is minimal for metabolic regulation. To test whether estradiol enhanced arcuate leptin sensitivity, ovarectomized mice received varying levels of estradiol replacement. Increasing estrogenic states did not increase the degree of leptin-induced STAT3 phosphorylation. LepRb-specific STAT3 KO mice and controls were ovarectomized and given either chronic estradiol or vehicle treatment to test whether STAT3 is required for estrogen-induced body weight suppression. Both groups of estradiol-treated mice showed an equivalent reduction in body weight and fat content compared with vehicle controls. Finally, mice lacking ERα specifically in LepRb-expressing neurons also showed no increase in body weight or impairments in metabolic function compared with controls, indicating that estradiol acts independently of leptin-responsive cells to regulate body weight. However, fecundity was impaired in in Leprb-ERα KO females. Contrary to the current dogma, we report that estradiol has minimal direct actions on LepRb cells in the mediodasal hypothalamus and that its anorexigenic effects can occur entirely independently of LepRb-STAT3 signaling in female mice.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Bei Jia ◽  
Chenchen Zhao ◽  
Guoli Li ◽  
Yaxian Kong ◽  
Yaluan Ma ◽  
...  

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous subset of cells that expands dramatically in many disease states and can suppress T-cell responses. MDSCs mainly include monocytic and granulocytic subpopulations that can be distinguished in mice by the expression of Ly6G and Ly6C cell surface markers. This identification system has been validated in experimental tumor models, but not in models of inflammation-associated conditions such as sepsis. We challenged growth factor independent 1 transcription repressor green fluorescent protein (Gfi1:GFP) knock-in reporter mice with cecal ligation and puncture surgery and found that CD11b+Ly6GlowLy6Chigh MDSCs in this sepsis model comprised both monocytic and granulocytic MDSCs. The evidence that conventional Ly6G/Ly6C marker analysis may not be suited to study of inflammation-induced MDSCs led to the development of a novel strategy of distinguishing granulocytic MDSCs from monocytic MDSCs in septic mice by expression of CD48. Application of this novel model should help achieve a more accurate understanding of the inflammation-induced MDSC activity.


Endocrinology ◽  
2010 ◽  
Vol 151 (5) ◽  
pp. 2200-2210 ◽  
Author(s):  
Yukari Date ◽  
Muhtashan S. Mondal ◽  
Haruaki Kageyama ◽  
Masoud Ghamari-Langroudi ◽  
Fumiko Takenoya ◽  
...  

Neuropeptide W (NPW) is an anorectic peptide produced in the brain. Here, we showed that NPW was present in several hypothalamic nuclei, including the paraventricular hypothalamic nucleus, ventromedial hypothalamic nucleus, lateral hypothalamus, and hypothalamic arcuate nucleus. NPW expression was significantly up-regulated in leptin-deficient ob/ob and leptin receptor-deficient db/db mice. The increase in NPW expression in ob/ob mice was abrogated to control levels after leptin replacement. Leptin induced suppressors of cytokine signaling-3 after phosphorylation of signal transducer and activator of transcription-3 in NPW-expressing neurons. In addition, we demonstrated that NPW reduces feeding via the melanocortin-4-receptor signaling pathway. We also showed that NPW activates proopiomelanocortin and inhibits neuropeptide Y neurons using loose-patch extracellular recording of these neurons identified by promoter-driven green fluorescent protein expression. This study indicates that NPW may play an important role in the regulation of feeding and energy metabolism under the conditions of leptin insufficiency.


Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Deng F Guo ◽  
Donald A Morgan ◽  
Justin L Grobe ◽  
Darryl Nishimura ◽  
Charles Searby ◽  
...  

Bardet-Biedl syndrome (BBS) is a pleiotropic autosomal recessive disorder associated with several features including obesity and hypertension. Deletion of BBS genes globally or in the nervous system recapitulated many of the BBS phenotypes including obesity and hypertension. Here, we assessed the effect of ablating the Bbs1 gene from the neurons expressing the long signaling form of the leptin receptor (LepRb). Breeding Bbs1 flox with LepRb Cre mice created mice deficient in the Bbs1 gene only in LepRb-positive neurons (visualized by tdTomato expression) as indicated by loss of leptin activation of Stat3. Importantly, Bbs1 flox /LepR Cre mice display an obesity phenotype as indicated by the increased (P<0.05) body weight (39±2 vs. 30±1 g in controls) and fat mass measured by MRI (14±3 vs. 4±1 g in controls) associated with increased (P<0.05) food intake (3.4±0.1 vs. 2.9±0.1 g in controls) in 25 weeks old mice. However, body weight and fat pads of pair-fed LRb Cre /Bbs1 fl/fl mice remained significantly elevated compared to controls suggesting that LRb Cre /Bbs1 fl/fl mice have reduced energy expenditure. Consistent with this possibility, LRb Cre /Bbs1 fl/fl mice displayed decreased (P<0.05) O 2 consumption (2.6±0.1 vs. 3.1±0.1 mL/100g/min in controls) and heat production (8.1±0.3 vs. 9.6±0.3 kcal/kg/h in controls). These results indicate that hyperphagia and decreased energy expenditure contribute to the development of obesity in Bbs1 flox /LepR Cre mice. Next, we assessed the effect on arterial pressure (AP) and sympathetic nerve activity (SNA) of ablating the Bbs1 gene from the LepR-containing neurons. Interestingly, deletion of the Bbs1 gene in LepR neurons recapitulates the hypertension phenotype of BBS as indicated by elevated mean AP (125±4 vs 109±3 mmHg in controls, P=0.03). Conscious renal SNA was also elevated in LRb Cre /Bbs1 fl/fl mice relative to controls (97±8 vs 62±10 spikes/sec, P<0.05). Finally, the depressor effect of ganglionic blockade (hexamethonium) was exaggerated in Bbs1 flox /LepR Cre mice (-57±5 vs -38±5 mmHg in control, P=0.01). These findings demonstrate that the Bbs1 gene in LepR neurons is critical for energy homeostasis and arterial pressure regulation.


2016 ◽  
Vol 310 (1) ◽  
pp. R41-R54 ◽  
Author(s):  
Joel C. Geerling ◽  
Minjee Kim ◽  
Carrie E. Mahoney ◽  
Stephen B. G. Abbott ◽  
Lindsay J. Agostinelli ◽  
...  

The parabrachial nucleus is important for thermoregulation because it relays skin temperature information from the spinal cord to the hypothalamus. Prior work in rats localized thermosensory relay neurons to its lateral subdivision (LPB), but the genetic and neurochemical identity of these neurons remains unknown. To determine the identity of LPB thermosensory neurons, we exposed mice to a warm (36°C) or cool (4°C) ambient temperature. Each condition activated neurons in distinct LPB subregions that receive input from the spinal cord. Most c-Fos+ neurons in these LPB subregions expressed the transcription factor marker FoxP2. Consistent with prior evidence that LPB thermosensory relay neurons are glutamatergic, all FoxP2+ neurons in these subregions colocalized with green fluorescent protein (GFP) in reporter mice for Vglut2, but not for Vgat. Prodynorphin ( Pdyn)-expressing neurons were identified using a GFP reporter mouse and formed a caudal subset of LPB FoxP2+ neurons, primarily in the dorsal lateral subnucleus (PBdL). Warm exposure activated many FoxP2+ neurons within PBdL. Half of the c-Fos+ neurons in PBdL were Pdyn+, and most of these project into the preoptic area. Cool exposure activated a separate FoxP2+ cluster of neurons in the far-rostral LPB, which we named the rostral-to-external lateral subnucleus (PBreL). These findings improve our understanding of LPB organization and reveal that Pdyn- IRES- Cre mice provide genetic access to warm-activated, FoxP2+ glutamatergic neurons in PBdL, many of which project to the hypothalamus.


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