Ciliary neurotrophic factor corrects obesity and diabetes associated with leptin deficiency and resistance.
Ontology highlight
ABSTRACT:
SUBMITTER: Gloaguen I
PROVIDER: S-EPMC21071 | biostudies-literature | 1997 Jun
REPOSITORIES: biostudies-literature
Publications
Ciliary neurotrophic factor corrects obesity and diabetes associated with leptin deficiency and resistance.
Gloaguen I I Costa P P Demartis A A Lazzaro D D Di Marco A A Graziani R R Paonessa G G Chen F F Rosenblum C I CI Van der Ploeg L H LH Cortese R R Ciliberto G G Laufer R R
Proceedings of the National Academy of Sciences of the United States of America 19970601 12
Receptor subunits for the neurocytokine ciliary neurotrophic factor (CNTF) share sequence similarity with the receptor for leptin, an adipocyte-derived cytokine involved in body weight homeostasis. We report here that CNTF and leptin activate a similar pattern of STAT factors in neuronal cells, and that mRNAs for CNTF receptor subunits, similarly to the mRNA of leptin receptor, are localized in mouse hypothalamic nuclei involved in the regulation of energy balance. Systemic administration of CNT ...[more]
Similar Datasets
Project description:Ciliary neurotrophic factor, cardiotrophin-like cytokine, and neuropoietin are members of the four-helix bundle cytokine family. These proteins signal through a common tripartite receptor composed of leukemia inhibitory factor receptor, gp130, and ciliary neurotrophic factor receptor alpha. Binding to ciliary neurotrophic factor receptor alpha occurs through an interaction site located at the C terminus of the cytokine AB loop and alphaD helix, known as site 1. In the present study, we have generated a model of neuropoietin and identified a conserved binding site for the three cytokines interacting with ciliary neurotrophic factor receptor alpha. To identify the counterpart of this site on ciliary neurotrophic factor receptor alpha, its cytokine binding domain was modeled, and the physicochemical properties of its surface were analyzed. This analysis revealed an area displaying properties complementary to the site 1 of ciliary neurotrophic factor, cardiotrophin-like cytokine, and neuropoietin. Based on our computational predictions, residues were selected for their potential involvement in the ciliary neurotrophic factor receptor alpha binding epitope, and site-directed mutagenesis was carried out. Biochemical, cell proliferation, and cell signaling analyses showed that Phe(172) and Glu(286) of ciliary neurotrophic factor receptor alpha are key interaction residues. Our results demonstrated that ciliary neurotrophic factor, cardiotrophin-like cytokine, and neuropoietin share a conserved binding site on ciliary neurotrophic factor receptor alpha.
| S-EPMC2662086 | biostudies-literature
Project description:Ciliary neurotrophic factor (CNTF) promotes survival in vitro and in vivo of several neuronal cell types including sensory and motor neurons. The primary structure of CNTF suggests it to be a cytosolic protein with strong similarity to the alpha-helical cytokine family which is characterized by a bundle of four anti-parallel helices. CNTF exerts its activity via complexation with CNTF receptor (CNTF-R). This complex consists of a CNTF-binding protein (CNTF-R) and two proteins important for signal transduction [gp130 and leukaemia inhibitory factor receptor (LIF-R)]. We have shortened the cDNA coding for CNTF at both the 5' and the 3' end and expressed the truncated proteins in bacteria. Biological activities of the protein preparations were determined by their ability to induce proliferation of BAF/3 cells that were stably transfected with CNTF-R, gp130 and LIF-R cDNAs. CNTF proteins with 14 amino acid residues removed from the N-terminus were biologically active whereas the removal of 23 amino acids resulted in an inactive protein. In addition, 18 amino acid residues could be removed from the C-terminus of the CNTF protein without apparent loss of bioactivity, but further truncation at the C-terminus yielded biologically inactive proteins. The introduction of two point mutations into the CNTF protein at a site that presumably interacts with one of the two signal-transducing proteins resulted in a CNTF mutant with no measurable bioactivity. In addition, a model of the three-dimensional structure of human CNTF was constructed using the recently established structural co-ordinates of the related cytokine, granulocyte colony-stimulating factor. CD spectra of CNTF together with our mutational analysis and our three-dimensional model fully support the view that CNTF belongs to the family of alpha-helical cytokines. It is expected that our results will facilitate the rational design of CNTF mutants with agonistic or antagonistic properties.
| S-EPMC1135822 | biostudies-other
Project description:In humans and experimental animals, the administration of ciliary neurotrophic factor (CNTF) reduces food intake and body weight. To gain further insights into the mechanism(s) underlying its satiety effect, we: (i) evaluated the CNTF-dependent activation of the Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) pathway in mouse models where neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) neurons can be identified by green fluorescent protein (GFP); and (ii) assessed whether CNTF promotes leptin signaling in hypothalamic feeding centers. Immunohistochemical experiments enabled us to establish that intraperitoneal injection of mouse recombinant CNTF activated the JAK2-STAT3 pathway in a substantial proportion of arcuate nucleus (ARC) NPY neurons (18.68% ± 0.60 in 24-h fasted mice and 25.50% ± 1.17 in fed mice) but exerted a limited effect on POMC neurons (4.15% ± 0.33 in 24-h fasted mice and 2.84% ± 0.45 in fed mice). CNTF-responsive NPY neurons resided in the ventromedial ARC, facing the median eminence (ME), and were surrounded by albumin immunoreactivity, suggesting that they are located outside the blood-brain barrier (BBB). In both normally fed and high-fat diet (HFD) obese animals, CNTF activated extracellular signal-regulated kinase signaling in ME ?1- and ?2-tanycytes, an effect that has been linked to the promotion of leptin entry into the brain. Accordingly, compared to the animals treated with leptin, mice treated with leptin/CNTF showed: (i) a significantly greater leptin content in hypothalamic protein extracts; (ii) a significant increase in phospho-STAT3 (P-STAT3)-positive neurons in the ARC and the ventromedial hypothalamic nucleus of normally fed mice; and (iii) a significantly increased number of P-STAT3-positive neurons in the ARC and dorsomedial hypothalamic nucleus of HFD obese mice. Collectively, these data suggest that exogenously administered CNTF reduces food intake by exerting a leptin-like action on distinctive NPY ARC neurons and by promoting leptin signaling in hypothalamic feeding centers.
| S-EPMC7253709 | biostudies-literature
Project description:Despite treatment with agents that enhance beta-cell function and insulin action, reduction in beta-cell mass is relentless in patients with insulin resistance and type 2 diabetes mellitus. Insulin resistance is characterized by impaired signaling through the insulin/insulin receptor/insulin receptor substrate/PI-3K/Akt pathway, leading to elevation of negatively regulated substrates such as glycogen synthase kinase-3beta (Gsk-3beta). When elevated, this enzyme has antiproliferative and proapoptotic properties. In these studies, we designed experiments to determine the contribution of Gsk-3beta to regulation of beta-cell mass in two mouse models of insulin resistance. Mice lacking one allele of the insulin receptor (Ir+/-) exhibit insulin resistance and a doubling of beta-cell mass. Crossing these mice with those having haploinsufficiency for Gsk-3beta (Gsk-3beta+/-) reduced insulin resistance by augmenting whole-body glucose disposal, and significantly reduced beta-cell mass. In the second model, mice missing two alleles of the insulin receptor substrate 2 (Irs2-/-), like the Ir+/- mice, are insulin resistant, but develop profound beta-cell loss, resulting in early diabetes. We found that islets from these mice had a 4-fold elevation of Gsk-3beta activity associated with a marked reduction of beta-cell proliferation and increased apoptosis. Irs2-/- mice crossed with Gsk-3beta+/- mice preserved beta-cell mass by reversing the negative effects on proliferation and apoptosis, preventing onset of diabetes. Previous studies had shown that islets of Irs2-/- mice had increased cyclin-dependent kinase inhibitor p27(kip1) that was limiting for beta-cell replication, and reduced Pdx1 levels associated with increased cell death. Preservation of beta-cell mass in Gsk-3beta+/- Irs2-/- mice was accompanied by suppressed p27(kip1) levels and increased Pdx1 levels. To separate peripheral versus beta-cell-specific effects of reduction of Gsk3beta activity on preservation of beta-cell mass, mice homozygous for a floxed Gsk-3beta allele (Gsk-3(F/F)) were then crossed with rat insulin promoter-Cre (RIP-Cre) mice to produce beta-cell-specific knockout of Gsk-3beta (betaGsk-3beta-/-). Like Gsk-3beta+/- mice, betaGsk-3beta-/- mice also prevented the diabetes of the Irs2-/- mice. The results of these studies now define a new, negatively regulated substrate of the insulin signaling pathway specifically within beta-cells that when elevated, can impair replication and increase apoptosis, resulting in loss of beta-cells and diabetes. These results thus form the rationale for developing agents to inhibit this enzyme in obese insulin-resistant individuals to preserve beta-cells and prevent diabetes onset.
| S-EPMC2245985 | biostudies-literature
Project description:Administration of ciliary neurotrophic factor (CNTF) to experimental animals exerts anti-obesity effects by acting on multiple targets. In white adipose tissue CNTF reduces lipid content, promotes fatty acid (FA) oxidation and improves insulin sensitivity. This study was performed to establish whether CNTF exerts similar effects on human white adipocytes. To this end, adipose differentiation was induced in vitro in human multipotent adipose-derived stem (hMADS) cells. CNTF receptor ? (CNTFR?) expression was assessed in hMADS cells and adipocytes by qRT-PCR, Western blotting, and immunocytochemistry. After administration of human recombinant CNTF, signaling pathways and gene expression were evaluated by Western blotting and qRT-PCR. Glucose uptake was assessed by measuring 2-nitrobenzodeoxyglucose uptake with a fluorescence plate reader. Lastly, CNTF-induced anti-inflammatory responses were evaluated in hMADS adipocytes stressed with tumor necrosis factor ? (TNF?) for 24 h. Results showed that CNTFR? protein expression was higher in undifferentiated hMADS cells than in hMADS adipocytes, where it was however clearly detectable. In hMADS adipocytes, 1 nM CNTF strongly activated the JAK-STAT3 (Janus kinase-signaling transducer and activator of transcription 3) pathway and acutely and transiently activated the AMPK (AMP-activated protein kinase) and AKT (protein kinase B) pathways. Acute CNTF treatment for 20 min significantly increased basal glucose uptake and was associated with increased AKT phosphorylation. Longer-term (24 and 48 h) treatment reduced the expression of lipogenic markers (FA synthase and sterol regulatory element-binding protein-1) and increased the expression of lipolytic [hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL)] and mitochondrial (peroxisome proliferator-activated receptor ? coactivator-1? and carnitine palmitoyltransferase 1) markers. In TNF?-treated hMADS adipocytes, CNTF significantly reduced the expression of monocyte chemoattractant protein 1 and TNF?-induced AKT inhibition. Collectively, these findings demonstrate for the first time that CNTF plays a role also in human adipocytes, driving their metabolism toward a less lipid-storing and more energy-consuming phenotype.
| S-EPMC6861295 | biostudies-literature
Project description:Ciliary neurotrophic factor (Cntf) plays an essential role in postnatal maintenance of spinal motoneurons. Whereas the expression of this neurotrophic factor is low during embryonic development, it is highly up-regulated after birth in myelinating Schwann cells of rodents. To characterize the underlying transcriptional mechanisms, we have analyzed and compared the effects of various glial transcription factors. In contrast to Pit-1, Oct-1, Unc-86 homology region (POU) domain class 3, transcription factor 1 (Oct6/SCIP/Tst-1) and paired box gene 3 (Pax3), SRY-box-containing gene 10 (Sox10) induces Cntf expression in Schwann cells. Subsequent promoter analysis using luciferase reporter gene and EMSA identified the corresponding response elements within the Cntf promoter. Overexpression of Sox10 in primary sciatic nerve Schwann cells leads to a >100-fold up-regulation of Cntf protein, and suppression of Sox10 by RNA interference in the spontaneously immortalized Schwann cell line 32 reduces Cntf expression by >80%. Mice with heterozygous inactivation of the Sox10 gene show significantly reduced Cntf protein levels in sciatic nerves, indicating that Sox10 is necessary and sufficient for regulating Cntf expression in the peripheral nervous system.
| S-EPMC1472537 | biostudies-literature
Project description:Food restriction and weight loss result in reduced plasma leptin, which is associated with a pleiotropic biologic response. However, because weight loss itself is also associated with changes in numerous other humoral and metabolic signals, it can be difficult to determine the precise features of the biologic response to acute leptin deficiency. To study this response in the absence of changes in nutritional state, we have developed a protocol that allows such analysis in normal, non-food-restricted animals. Wild-type mice are treated with high-dose leptin until fat mass is depleted and, as a consequence, endogenous leptin production is reduced. At this point, exogenous leptin is abruptly withdrawn, thus inducing a state of leptin deficiency in otherwise normal mice. Leptin deficiency is sustained by feeding the animals only as much as they consumed voluntarily before leptin withdrawal. The biologic response to leptin deficiency induced in this manner includes altered neuropeptide levels, decreased energy expenditure, and impaired reproductive and immune function. Replacement of leptin at physiological concentrations after withdrawal of high-dosage leptin blunts, but does not completely block, the hyperphagia and weight regain caused by acute leptin deficiency, nor does it correct the resulting reproductive and immune dysfunction. This suggests that high-dosage leptin treatment induces a state of partial leptin resistance. In aggregate, these studies establish the role of acute hypoleptinemia in regulating energy balance, the immune system, and reproductive function, and further suggest that high-dosage leptin treatment can induce a state of acquired leptin resistance.
| S-EPMC548993 | biostudies-literature
Project description:ObjectiveIn this study, we aimed to investigate relationships between maternal prepregnancy obesity and gestational diabetes mellitus and placental leptin DNA methylation.Study designThis study comprises data on 535 mother-infant dyads enrolled in the Rhode Island Child Health Study, a prospective cohort study of healthy term pregnancies. Prepregnancy body mass index was calculated from self-reported anthropometric measures and gestational diabetes mellitus diagnoses gathered from inpatient medical records. DNA methylation of the leptin promoter region was assessed in placental tissue collected at birth using quantitative bisulfite pyrosequencing.ResultsIn a multivariable regression analysis adjusted for confounders, infants exposed to gestational diabetes mellitus had higher placental leptin methylation (β = 1.89, P = .04), as did those demonstrating prepregnancy obesity (β = 1.17, P = .06). Using a structural equations model, we observed that gestational diabetes mellitus is a mediator of the effects of prepregnancy obesity on placental leptin DNA methylation (β = 0.81, 95% confidence interval, 0.27-2.71).ConclusionOur results suggest that the maternal metabolic status before and during pregnancy can alter placental DNA methylation profile at birth and potentially contribute to metabolic programming of obesity and related conditions.
| S-EPMC4254188 | biostudies-literature
Project description:Obese subjects display elevated plasma levels of leptin reflecting the phenomenon of leptin resistance. Here, we aimed to determine whether leptin-reactive immunoglobulins (Ig) are present in obese and type 2 diabetes (T2D) patients and whether their plasma levels and affinity kinetics may correlate with obesity and diabetes markers. We show that leptin levels are increased in obese patients with and without T2D. Although mean plasma levels of leptin-reactive IgG were similar between study groups, IgG in obese non-diabetic patients had increased dissociation rate and lower affinity (increased dissociation equilibrium constant value; KD). In controls and diabetic patients, the association rates of leptin IgG correlated negatively with obesity and diabetes markers, respectively. In contrast, KD values correlated positively with plasma leptin levels and obesity traits in our cohort, and with diabetes markers in both the total cohort and in the obese T2D group. Taken together, our data reveal that leptin-reactive IgG are present in healthy subjects, obese, and diabetic patients but display altered affinity kinetics in obesity. Increased IgG binding to leptin in healthy subjects associated with lower body mass index (BMI) suggests an enhancing role of IgG in leptin signaling. Accordingly, a decreased affinity of IgG for leptin, found in obese patients, can be relevant to leptin resistance.
| S-EPMC5966443 | biostudies-literature
Project description:Introduction: The ascending prevalence of obesity in recent decades is commonly associated with soaring rates of morbidity and mortality resulting in increased health care costs and decreased quality of life. A systemic state of stress characterized by low grade inflammation and pathologic formation of reactive oxygen species (ROS) usually manifest in obesity. The transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) is the master regulator of the redox homeostasis and plays a critical role in the resolution of inflammation. Our results indicate that the natural isothiocyanate and potent NRF2 activator sulforaphane reverses the diet-induced obesity in rodents and implicate involvement of leptin receptor singling in this effect. Purpose: Here, we investigate molecular pathways underlying the effects of sulforaphane in reversing diet-induced obesity and interrogate potential pathways that link NRF2 with leptin receptor signaling by conducting whole transcriptome analysis in 6 metabolically active tissues from the diet-induced obese mice that were treated with SFN. Methods: Male 12-week-old C57/BJ wild type mice were fed with high fat diet for 16-20 weeks. Around 28 weeks of age, mice were treated with daily ip injections of either SFN (5 mg/kg) or vehicle for one week. We probed the whole transcriptome in several metabolic tissues including the hypothalamus, liver, brown adipose tissue (BAT), epididymal white adipose tissue (eWAT), inguinal white adipose tissue (iWAT), and skeletal muscle following peripheral SFN administration. Total RNA samples from each tissue were prepared with Trizol. Whole transcriptome were conducted by using Novogene sequencing platform NovaSeq 6000 PE150. The following bioinformatics analysis have been conducted. 1. Data Quality Control: filtering reads containing adapter or with low quality. 2. Statistics Analysis of Data Production and Quality. 3. Mapping Reads to Reference Genome. 4. Gene Expression Quantification. 5. Correlation analysis (For biological replicates only). 6. Differential Expression Analysis (two or more groups of samples). 7. GO Enrichment Analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples). 8. KEGG Pathway Enrichment Analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples). 9. GSEA Enrichment Analysis of Expressed Genes (two or more groups of samples). 10. Protein Protein Interaction Analysis. 11. Reactome Pathway Enrichment Analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples and only for mouse samples). 12. Oncogene Functional Annotation analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples and only for mouse sample). Results: RNAseq results indicated a significant upregulation of the NRF2 target gene HMOX1 only in the skeletal muscle. We also conducted an enrichment analysis to identify potential transcription factors for the significantly upregulated genes. NRF2 was identified as the most significant transcription factor only for the skeletal muscle gene set, providing further support for the skeletal muscle being a primary target tissue of SFN action. We thus conducted a KEGG and GO pathway analysis, and identified ribosome biogenesis, proteasome pathway, and the RNA transport as the significantly upregulated pathways in the SFN-treated muscle samples. In addition to HMOX1, the RNA seq results indicate upregulation of other genes involved in oxidative stress response capacity in SFN treated mice in the skeletal muscle. GCLM (glutamate-cysteine ligase), the first rate-limiting enzyme of glutathione synthesis, SRXN1 (Sulfiredoxin), an oxidoreductase that reduces cysteine-sulfinate, and GSR (glutathione-disulfide reductase), a central antioxidant enzyme, which reduces oxidized glutathione disulfide (GSSG) to the sulfhydryl form glutathione (GSH), and TXNRD1 (thioredoxin reductase 1) which reduces thioredoxins are all upregulated in the skeletal muscle of the SFN-treated DIO animals. Conclusions: Here, we show that the natural isothiocyanate and potent NRF2 activator sulforaphane reverses diet-induced obesity through an NRF2-dependent mechanism that requires a functional leptin receptor signaling and hyperleptinemia. Transcriptional profiling of six major metabolically relevant tissues highlights that sulforaphane suppresses fatty acid synthesis while promoting ribosome biogenesis, reducing ROS accumulation and resolving inflammation, therefore representing a unique transcriptional program that leads to protection from obesity. Our findings argue for clinical evaluation of sulforaphane for weight loss and obesity-associated metabolic disorders.
2022-01-22 | GSE181477 | GEO