Killion, EA;Hussien, R;Shkumatov, A;Davies, R;Lloyd, DJ;Véniant, MM;Lebrec, H;Fort, MM;
PMID: 35224888 | DOI: 10.1111/andr.13166
Glucose-dependent insulinotropic polypeptide receptor (Gipr) gene expression has been reported in mouse spermatids and Gipr knockout male mice have previously been reported to have decreased in vitro fertilization, although the role of Gipr signaling in male mouse fertility is not well understood.The purposes of these studies were to determine the role of glucose-dependent insulinotropic polypeptide receptor in male fertility using Gipr knockout mice and anti-glucose-dependent insulinotropic polypeptide receptor antibody-treated wild-type mice and to determine if the expression of Gipr in mouse testes is similar in non-human and human primates.Adiponectin promoter-driven Gipr knockout male mice (GiprAdipo-/- ) were assessed for in vitro and in vivo fertility, sperm parameters, and testicular histology. CD1 male mice were administered an anti-glucose-dependent insulinotropic polypeptide receptor antibody (muGIPR-Ab) prior to and during mating for assessment of in vivo fertility and sperm parameters. Expression of Gipr/GIPR mRNA in the mouse, cynomolgus monkey, and human testes was assessed by in situ hybridization methods using species-specific probes.GiprAdipo-/- male mice are infertile in vitro and in vivo, despite normal testis morphology, sperm counts, and sperm motility. In contrast, administration of muGIPR-Ab to CD1 male mice did not impact fertility. While Gipr mRNA expression is detectable in the mouse testes, GIPR mRNA expression is not detectable in monkey or human testes.The infertility of GiprAdipo-/- male mice correlated with the lack of Gipr expression in the testis and/or adipocyte tissue. However, as administration of muGIPR-Ab did not impact the fertility of adult male mice, it is possible that the observations in genetically deficient male mice are related to Gipr deficiency during development.Our data support a role for Gipr expression in the mouse testis during the development of sperm fertilization potential, but based on gene expression data, a similar role for glucose-dependent insulinotropic polypeptide receptor in non-human primate or human male fertility is unlikely.
Wang, W;Xu, M;Yue, J;Zhang, Q;Nie, X;Jin, Y;Zhang, Z;
PMID: 35894166 | DOI: 10.1210/endocr/bqac115
Increasing incidence of metabolic disturbances has become a severe public healthcare problem. Ion channels and receptors in the paraventricular nucleus (PVN) of the hypothalamus serve vital roles in modulating neuronal activities and endocrine functions, which are linked to the regulation of energy balance and glucose metabolism. In this study, we found that acid-sensing ion channel 1a (ASIC1a), a Ca2+-permeable cationic ion channel was localized in the PVN. Knockdown of ASIC1a in this region led to significant body weight gain, glucose intolerance, and insulin resistance. Pharmacological inhibition of ASIC1a resulted in an increase in food intake and a decrease in energy expenditure. Our findings suggest ASIC1a in the PVN as a potential new target for the therapeutic intervention of metabolic disorders.
Brix, LM;Toksöz, I;Aman, L;Kovarova, V;Springer, M;Bordes, J;van Doeselaar, L;Engelhardt, C;Häusl, AS;Narayan, S;Sterlemann, V;Yang, H;Deussing, JM;Schmidt, MV;
PMID: 36007872 | DOI: 10.1016/j.molmet.2022.101579
Steroidogenic factor 1 (SF1) expressing neurons in the ventromedial hypothalamus (VMH) have been directly implicated in whole-body metabolism and in the onset of obesity. The co-chaperone FKBP51 is abundantly expressed in the VMH and was recently linked to type 2 diabetes, insulin resistance, adipogenesis, browning of white adipose tissue (WAT) and bodyweight regulation.We investigated the role of FKBP51 in the VMH by conditional deletion and virus-mediated overexpression of FKBP51 in SF1-positive neurons. Baseline and high fat diet (HFD)-induced metabolic- and stress-related phenotypes in male and female mice were obtained.In contrast to previously reported robust phenotypes of FKBP51 manipulation in the entire mediobasal hypothalamus (MBH), selective deletion or overexpression of FKBP51 in the VMH resulted in only a moderate alteration of HFD-induced bodyweight gain and body composition, independent of sex.Overall, this study shows that animals lacking and overexpressing Fkbp5 in Sf1-expressing cells within the VMH display only a mild metabolic phenotype compared to an MBH-wide manipulation of this gene, suggesting that FKBP51 in SF1 neurons within this hypothalamic nucleus plays a subsidiary role in controlling whole-body metabolism.
Journal of the Endocrine Society
Lizneva, D;Ievleva, K;Gumerova, A;Shelly, E;Korkmaz, F;Muradova, V;Netto, J;Kuo, T;Sultana, F;Kumar, P;Kramskiy, N;Ryu, V;Padilla, A;Hutchison, S;Yuen, T;Zaidi, M;
| DOI: 10.1210/jendso/bvac150.058
Menopause is associated with the loss of LH ovulatory surges and enhanced visceral adiposity. Visceral fat depots increase from 5-8% at premenopause to 15-20% of total body fat at postmenopause. Here, we report that high-dose LH, hCG, or small molecule LH/CGR agonist ORG43553 injected twice-a-week into 14-weeks-old C57BL/6 male mice protects them from diet-induced obesity. Testosterone levels were elevated in mice treated with LH or hCG, but not with ORG43553. Notably, the anti-obesity action of LH/hCG is independent of testosterone, as blocking the androgen receptor using flutamide yielded similar results. Importantly, male Lhcgr knockout mice on a high-fat diet treated with LH failed to display a reduction in adiposity, confirming the in vivo specificity of action. Furthermore, our data phenocopied Lhcgr haploinsufficiency in mice. We confirmed the presence of Lhcgr in mouse genital and inguinal fat pads, adipose-derived stromal vascular cells, as well as in differentiated and undifferentiated 3T3-L1 murine adipocytes by qPCR, RNAscope in situ hybridization, and immunohistochemistry. Sanger sequencing showed that the extracellular domain of Lhcgr in genital fat depot was identical to the ovarian receptor. Similarly, we identified LHCGR in human subcutaneous and visceral fat depots. Binding of intraperitoneally injected AlexaFluor-488-labeled hCG was found not only in mouse ovary, but also in genital and subcutaneous fat pad, further confirming the presence of LHCGR in adipose tissue. This binding could be competitively displaced in 3T3-L1 cells using unlabeled hCG. LH, hCG and ORG43553 activated ERK1/2 in a dose-dependent manner in undifferentiated and differentiated 3T3-L1 cells, suggesting that the adipose LHCGR is fully functional. LH, hCG, and ORG43553 reduced adipogenic differentiation in 3T3-L1 cells, which is further confirmed by RNA sequencing. Moreover, we observed, that LH and hCG also alters several aspects of immune response in adipose tissue, including inflammatory response and adaptive immunity. In conclusion, we demonstrated that LH/CG receptors are present and fully functional in adipose tissue, and that high-dose intermittent activation of LHCGR in mouse fat depots protects mice from diet-induced obesity and modifies adipose tissue immune response. Presentation: Saturday, June 11, 2022 1:42 p.m. - 1:47 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
Patel, S;Haider, A;Alvarez-Guaita, A;Bidault, G;El-Sayed Moustafa, JS;Guiu-Jurado, E;Tadross, JA;Warner, J;Harrison, J;Virtue, S;Scurria, F;Zvetkova, I;Blüher, M;Small, KS;O'Rahilly, S;Savage, DB;
PMID: 36064109 | DOI: 10.1016/j.molmet.2022.101589
Obesity in humans and mice is associated with elevated levels of two hormones responsive to cellular stress, namely GDF15 and FGF21. Over-expression of each of these is associated with weight loss and beneficial metabolic changes but where they are secreted from and what they are required for physiologically in the context of overfeeding remains unclear.Here we used tissue selective knockout mouse models and human transcriptomics to determine the source of circulating GDF15 in obesity. We then generated and characterized the metabolic phenotypes of GDF15/FGF21 double knockout mice.Circulating GDF15 and FGF21 are both largely derived from the liver, rather than adipose tissue or skeletal muscle, in obese states. Combined whole body deletion of FGF21 and GDF15 does not result in any additional weight gain in response to high fat feeding but it does result in significantly greater hepatic steatosis and insulin resistance than that seen in GDF15 single knockout mice.Collectively the data suggest that overfeeding activates a stress response in the liver which is the major source of systemic rises in GDF15 and FGF21. These hormones then activate pathways which reduce this metabolic stress.
The Journal of experimental medicine
Li, L;Wyler, SC;León-Mercado, LA;Xu, B;Oh, Y;Swati, ;Chen, X;Wan, R;Arnold, AG;Jia, L;Wang, G;Nautiyal, K;Hen, R;Sohn, JW;Liu, C;
PMID: 35796804 | DOI: 10.1084/jem.20212307
Triptans are a class of commonly prescribed antimigraine drugs. Here, we report a previously unrecognized role for them to suppress appetite in mice. In particular, frovatriptan treatment reduces food intake and body weight in diet-induced obese mice. Moreover, the anorectic effect depends on the serotonin (5-HT) 1B receptor (Htr1b). By ablating Htr1b in four different brain regions, we demonstrate that Htr1b engages in spatiotemporally segregated neural pathways to regulate postnatal growth and food intake. Moreover, Htr1b in AgRP neurons in the arcuate nucleus of the hypothalamus (ARH) contributes to the hypophagic effects of HTR1B agonists. To further study the anorexigenic Htr1b circuit, we generated Htr1b-Cre mice. We find that ARH Htr1b neurons bidirectionally regulate food intake in vivo. Furthermore, single-nucleus RNA sequencing analyses revealed that Htr1b marks a subset of AgRP neurons. Finally, we used an intersectional approach to specifically target these neurons (Htr1bAgRP neurons). We show that they regulate food intake, in part, through a Htr1bAgRP→PVH circuit.
Tissue-specific expression of insulin receptor isoforms in obesity/type 2 diabetes mouse models
Journal of cellular and molecular medicine
Moruzzi, N;Lazzeri-Barcelo, F;Valladolid-Acebes, I;Moede, T;Paschen, M;Leibiger, B;Berggren, PO;Leibiger, IB;
PMID: 33742502 | DOI: 10.1111/jcmm.16452
The two insulin receptor (IR) isoforms IR-A and IR-B are responsible for the pleiotropic actions of insulin and insulin-like growth factors. Consequently, changes in IR isoform expression and in the bioavailability of their ligands will impact on IR-mediated functions. Although alteration of IR isoform expression has been linked to insulin resistance, knowledge of IR isoform expression and mechanisms underlying tissue/cell-type-specific changes in metabolic disease are lacking. Using mouse models of obesity/diabetes and measuring the mRNA of the IR isoforms and mRNA/protein levels of total IR, we provide a data set of IR isoform expression pattern that documents changes in a tissue-dependent manner. Combining tissue fractionation and a new in situ mRNA hybridization technology to visualize the IR isoforms at cellular resolution, we explored the mechanism underlying the change in IR isoform expression in perigonadal adipose tissue, which is mainly caused by tissue remodelling, rather than by a shift in IR alternative splicing in a particular cell type, e.g. adipocytes.
Pena-Leon, V;Folgueira, C;Barja-Fernández, S;Pérez-Lois, R;Da Silva Lima, N;Martin, M;Heras, V;Martinez-Martinez, S;Valero, P;Iglesias, C;Duquenne, M;Al-Massadi, O;Beiroa, D;Souto, Y;Fidalgo, M;Sowmyalakshmi, R;Guallar, D;Cunarro, J;Castelao, C;Senra, A;González-Saenz, P;Vázquez-Cobela, R;Leis, R;Sabio, G;Mueller-Fielitz, H;Schwaninger, M;López, M;Tovar, S;Casanueva, FF;Valjent, E;Diéguez, C;Prevot, V;Nogueiras, R;Seoane, LM;
PMID: 35879461 | DOI: 10.1038/s42255-022-00602-z
Early-life determinants are thought to be a major factor in the rapid increase of obesity. However, while maternal nutrition has been extensively studied, the effects of breastfeeding by the infant on the reprogramming of energy balance in childhood and throughout adulthood remain largely unknown. Here we show that delayed weaning in rat pups protects them against diet-induced obesity in adulthood, through enhanced brown adipose tissue thermogenesis and energy expenditure. In-depth metabolic phenotyping in this rat model as well as in transgenic mice reveals that the effects of prolonged suckling are mediated by increased hepatic fibroblast growth factor 21 (FGF21) production and tanycyte-controlled access to the hypothalamus in adulthood. Specifically, FGF21 activates GABA-containing neurons expressing dopamine receptor 2 in the lateral hypothalamic area and zona incerta. Prolonged breastfeeding thus constitutes a protective mechanism against obesity by affecting long-lasting physiological changes in liver-to-hypothalamus communication and hypothalamic metabolic regulation.
Xie, B;Murali, A;Vandevender, A;Chen, J;Silva, A;Bello, F;Chuan, B;Bahudhanapati, H;Sipula, I;Dedousis, N;Shah, F;O’Donnell, C;Alder, J;Jurczak, M;
| DOI: 10.1016/j.isci.2022.105569
Growth differentiation factor 15 (GDF15) is a stress-induced secreted protein whose circulating levels are increased in the context of obesity. Recombinant GDF15 reduces body weight and improves glycemia in obese models, which is largely attributed to the central action of GDF15 to suppress feeding and reduce body weight. Despite these advances in knowledge, the tissue-specific sites of GDF15 production during obesity are unknown, and the effects of modulating circulating GDF15 levels on insulin sensitivity have not been evaluated directly. Here, we demonstrate that hepatocyte Gdf15 expression is sufficient for changes in circulating levels of GDF15 during obesity and that restoring Gdf15 expression specifically in hepatocytes of Gdf15 knockout mice results in marked improvements in hyperinsulinemia, hepatic insulin sensitivity, and to a lesser extent peripheral insulin sensitivity. These data support that liver hepatocytes are the primary source of circulating GDF15 in obesity.
Calco, GN;Maung, JN;Jacoby, DB;Fryer, AD;Nie, Z;
PMID: 36107629 | DOI: 10.1172/jci.insight.161898
Obesity-induced asthma responds poorly to all current pharmacological interventions, including steroids; suggesting that classic, eosinophilic inflammation is not a mechanism. As insulin resistance and hyperinsulinemia are common in obese individuals and associated with increased risk of asthma, we used diet-induced obese mice to study how insulin induces airway hyperreactivity. Inhaled 5-HT or methacholine induced dose dependent bronchoconstriction that was significantly potentiated in obese mice. Cutting the vagus nerves eliminated bronchoconstriction in both obese and non-obese animals indicating it was mediated by a neural reflex. There was significantly greater density of airway sensory nerves in obese than in non-obese mice. Deleting insulin receptors on sensory nerves prevented the increase in sensory nerve density and prevented airway hyperreactivity in obese mice with hyperinsulinemia. Our data demonstrate that high levels of insulin drives obesity-induced airway hyperreactivity by increasing sensory innervation of the lung. Therefore, pharmacological interventions to control metabolic syndrome and limit reflex-mediated bronchoconstriction may be a more effective approach to reduce asthma exacerbations in obese and asthmatic patients.
Hwang, E;Scarlett, JM;Baquero, AF;Bennett, C;Dong, Y;Chau, D;Brown, JM;Mercer, AJ;Meek, TH;Grove, KL;Phan, BAN;Morton, GJ;Williams, KW;Schwartz, MW;
PMID: 35917179 | DOI: 10.1172/jci.insight.160891
In rodent models of type 2 diabetes (T2D), central administration of fibroblast growth factor 1 (FGF1) normalizes elevated blood glucose levels in a manner that is sustained for weeks or months. Increased activity of NPY/AgRP neurons in the hypothalamic arcuate nucleus (ARC) is implicated in the pathogenesis of hyperglycemia in these animals, and the ARC is a key brain area for the antidiabetic action of FGF1. We therefore sought to determine whether FGF1 inhibits NPY/AgRP neurons, and if so whether this inhibitory effect is sufficiently durable to offer a feasible explanation for sustained diabetes remission induced by central administration of FGF1. Here we show that FGF1 inhibits ARC NPY/AgRP neuron activity, both after icv injection in vivo and when applied ex vivo in a slice preparation, and that the underlying mechanism involves increased input from presynaptic GABAergic neurons. Following central administration, the inhibitory effect of FGF1 on NPY/AgRP neurons is also highly durable, lasting for at least two weeks. To our knowledge, no precedent for such a prolonged inhibitory effect exists. Future studies are warranted to determine whether NPY/AgRP neuron inhibition contributes to the sustained antidiabetic action elicited by icv FGF1 injection in rodent models of T2D. .
Cho, JH;Kim, K;Cho, HC;Lee, J;Kim, EK;
PMID: 36064426 | DOI: 10.1186/s13041-022-00962-3
Fibroblast growth factor 11 (FGF11) is a member of the intracellular fibroblast growth factor family. Here, we report the central role of FGF11 in the regulation of metabolism. Lentiviral injection of Fgf11 shRNA into the arcuate nucleus of the mouse hypothalamus decreased weight gain and fat mass, increased brown adipose tissue thermogenesis, and improved glucose and insulin intolerances under high-fat diet conditions. Fgf11 was expressed in the NPY-expressing neurons, and Fgf11 knockdown considerably decreased Npy expression and projection, leading to increased expression of tyrosine hydroxylase in the paraventricular nucleus. Mechanistically, FGF11 regulated Npy gene expression through the glycogen synthase kinase 3-cAMP response element-binding protein pathway. Our study defines the physiological significance of hypothalamic FGF11 in the regulation of metabolism in response to overnutrition such as high-fat diet.