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1.
J Ethnopharmacol ; 300: 115688, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36067838

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese medicine, a long term of improper diet causes the Dampness and disturbs Zang-Fu's functions including Kidney deficiency. Atractylodes lancea (Atr) and Magnolia officinalis (Mag) as a famous herb pair are commonly used to transform Dampness, with kidney protection. AIM OF THE STUDY: To explore how Atr and Mag protected against insulin signaling impairment in glomerular podocytes induced by high dietary fructose feeding, a major contributor for insulin resistance in glomerular podocyte dysfunction. MATERIALS AND METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyze constituents of Atr and Mag. Rat model was induced by 10% fructose drinking water in vivo, and heat-sensitive human podocyte cells (HPCs) were exposed to 5 mM fructose in vitro. Animal or cultured podocyte models were treated with different doses of Atr, Mag or Atr and Mag combination. Western blot, qRT-PCR and immunofluorescence assays as well as other experiments were performed to detect adiponectin receptor protein 1 (AdipoR1), protein kinase B (AKT), Sirt1, p53 and miR-221 levels in rat glomeruli or HPCs, respectively. RESULTS: Fifty-five components were identified in Atr and Mag combination. Network pharmacology analysis indicated that Atr and Mag combination might affect insulin signaling pathway. This combination significantly improved systemic insulin resistance and prevented glomerulus morphological damage in high fructose-fed rats. Of note, high fructose decreased IRS1, AKT and AdipoR1 in rat glomeruli and cultured podocytes. Further data from cultured podocytes with Sirt1 inhibitor/agonist, p53 agonist/inhibitor, or miR-221 mimic/inhibitor showed that high fructose downregulated Sirt1 to stimulate p53-driven miR-221, resulting in insulin signaling impairment. Atr and Mag combination effectively increased Sirt1, and decreased p53 and miR-221 in in vivo and in vitro models. CONCLUSIONS: Atr and Mag combination improved insulin signaling in high fructose-stimulated glomerular podocytes possibly through upregulating Sirt1 to inhibit p53-driven miR-221. Thus, the regulation of Sirt1/p53/miR-221 by this combination may be a potential therapeutic approach in podocyte insulin signaling impairment.


Assuntos
Atractylodes , Água Potável , Resistência à Insulina , Magnolia , MicroRNAs , Podócitos , Animais , Proteínas de Transporte/metabolismo , Cromatografia Líquida , Água Potável/metabolismo , Frutose/efeitos adversos , Humanos , Insulina/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Receptores de Adiponectina/metabolismo , Transdução de Sinais , Sirtuína 1/metabolismo , Espectrometria de Massas em Tandem , Proteína Supressora de Tumor p53/metabolismo
2.
J Ethnopharmacol ; 301: 115788, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36223844

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Antidesma acidum Retz, a perennial herb is known for its anti-diabetic potential among the traditional health care providers of the tribal communities of Manipur, India. Scientific validation of the ancient knowledge on traditional use of this plant with the help of modern tools and techniques can promote further research and its use in health care. AIM OF THE STUDY: Type 2 Diabetes (T2D) is a complex metabolic disorder and linked with hyperglycemia occurring from insufficiency in insulin secretion, action, or both. The aim of this study was to scientifically validate the traditional myth behind the uses of this plant material against diabetes. More specifically, it was aimed to determine the effect of methanolic extract of A. acidum leaves and/or any of its bioactive phytochemical(s), in enhancing insulin sensitization and subsequently stimulating the insulin signaling cascade of glucose metabolism. MATERIALS AND METHODS: Methanol was used for extraction from the leaf powder of A. acidum followed by bioactivity guided fractionation and isolation of most active component. Biological evaluation was performed to determine the glucose uptake ability against insulin resistance in skeletal muscle (L6) cells. To understand the detailed mechanism of actions of the purified compound, several molecular biology and structural biology experiments such as Western blot, siRNA transfection assay and molecular docking study were performed. RESULTS AND DISCUSSION: Bioactivity guided isolation of pure compound and spectral data analysis led us to identify the active component as Kaempferol 3-O-rutinoside (KOR) for the first time from the leaf of A. acidum. Over expression of NAD-dependent histone deacetylase, Sirtuin 1 (SIRT1) was observed following KOR treatment. SIRT1 plays an important role in the metabolic pathway and over expression of SIRT implies that it involves in insulin signaling directly or indirectly. Molecular docking and simulation study showed the strong involvement between KOR and SIRT1.Treatment with KOR resulted in significant over expression of SIRT1followed by upregulation of insulin-dependent p-IRS, AKT and AMPK signaling molecules, and stimulation of the GLUT4 translocation, which ultimately enhanced the glucose uptake in sodium palmitate-treated insulin resistant L6 myotubes. Further, the effect of KOR on IRS1, AKT and AMPK phosphorylation, GLUT4 translocation, and glucose uptake was attenuated in SIRT1-knockdown myotubes. CONCLUSION: Overall, the results of this study suggest that Kaempferol 3-O-rutinoside is the active component presents in the leaf of A. acidum which increases glucose consumption by inducing SIRT1 activation and consequently improves insulin sensitization. These results may find future applications in drug discovery research against T2DM.


Assuntos
Diabetes Mellitus Tipo 2 , Sirtuína 1 , Humanos , Sirtuína 1/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quempferóis/farmacologia , Quempferóis/uso terapêutico , Simulação de Acoplamento Molecular , Índia , Fibras Musculares Esqueléticas , Insulina/metabolismo , Glucose/metabolismo , Músculo Esquelético , Transportador de Glucose Tipo 4/metabolismo
3.
Chemosphere ; 311(Pt 1): 137066, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36328321

RESUMO

Bisphenol F (BPF) is a widely used bisphenol A (BPA) substitute plastic additive that has attracted increasing public concerns due to its potential toxic effects on animal and human health. Although previous studies have indicated that BPF might have harmful effects on metabolic homeostasis, the systematic effects of BPF on glucose disorders remain controversial. In this study, mice fed a normal chow diet (ND) and high-fat diet (HFD) were administered BPF at a dose of 100 µg/kg of body weight, and glucose metabolism was monitored after both short- and long-term treatment. Little change in glucose metabolism was observed in BPF-treated ND mice, but improved glucose metabolism was observed in BPF-treated HFD mice. Consistently, BPF treatment led to increased insulin signalling in the skeletal muscle of HFD mice. Additionally, liver metabolite levels also revealed increased carbohydrate digestion and improved TCA cycle progression in BPF-treated HFD mice. Our results demonstrate that sustained BPF exposure at an environmentally relevant dosage may substantially improve glucose metabolism and enhance insulin sensitivity in mice fed a high-fat diet.


Assuntos
Dieta Hiperlipídica , Hipoglicemiantes , Humanos , Camundongos , Animais , Compostos Benzidrílicos/farmacologia , Insulina/metabolismo , Glucose/metabolismo
4.
Mol Cell Endocrinol ; 559: 111778, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36162635

RESUMO

During lactation, the maternal physiology adapts to bear the nutritional requirements of the offspring. The exocrine and endocrine pancreas are central to nutrient handling, promoting digestion and metabolism. In concert with prolactin, insulin is a determinant factor for milk synthesis. The investigation of the pancreas during lactation has been scattered over several periods. The investigations that laid the foundation of lactating pancreatic physiology and glucose homeostasis were conducted in the decades of 1970-1980. With the development of molecular biology, newer studies have revealed the molecular mechanisms involved in the endocrine pancreas during breastfeeding. There has been a surge of information recently about unexpected changes in the pancreas at the end of the lactation period and after weaning. In this review, we aim to gather information on the changes in the pancreas and glucose homeostasis during and after lactation and discuss the outcomes derived from the current discoveries.


Assuntos
Lactação , Pâncreas , Feminino , Humanos , Lactação/metabolismo , Pâncreas/metabolismo , Insulina/metabolismo , Glucose/metabolismo , Homeostase
6.
J Steroid Biochem Mol Biol ; 225: 106198, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36181990

RESUMO

To evaluate the effects of long-term vitamin D supplementation on metabolic profiles in middle-aged to elderly patients with type 2 diabetes (T2D), a randomized controlled trial was conducted among patients with T2D aged 50-70 years. A total of 270 patients underwent randomization with 135 being allocated to the vitamin D group and 135 to the control group, and participants in the vitamin D group received oral vitamin D3 (800 IU/day) for 30 months. Serum 25(OH)D and metabolic variables were measured at baseline, and after 6, 12, 18, and 30 months of intervention. After 30 months, the vitamin D group showed a greater increase in serum 25(OH)D than the control group (12.39 ± 6.99 vs 5.35 ± 5.29 ng/ml, P < 0.001). Meanwhile, changes in the levels of fasting insulin, HOMA-IR, non-high-density-lipoprotein cholesterol (non-HDL-C), high-sensitivity C-reactive protein (hs-CRP), and uric acid differed significantly between the two groups (all P < 0.05). Stratified analysis indicated that change in uric acid differed significantly between the two groups in subgroup with baseline 25(OH)D ≥ 20 ng/ml (P = 0.042) or subgroup with female patients (P = 0.034). And the change in fasting blood glucose (FBG) differed significantly between the vitamin D group (-0.30 ± 2.52 mmol/L) and the control group (0.49 ± 1.78 mmol/L, P = 0.049) among patients achieving 25(OH)D concentrations of 30 ng/ml at the end of this trial. A significant difference in the change of triglyceride was observed between the two groups among patients with obesity at baseline [0.05(-0.59, 0.23) vs 0.41(-0.01, 0.80) mmol/L, P = 0.023]. These findings suggested that long-term vitamin D supplementation significantly reduced fasting insulin, HOMA-IR, and serum concentrations of non-HDL-C, hs-CRP, and uric acid among middle-aged to elderly patients with T2D. And vitamin D status, gender, and baseline obesity may modify the effects of vitamin D supplementation.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Pessoa de Meia-Idade , Idoso , Humanos , Feminino , Vitamina D/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Proteína C-Reativa/metabolismo , Ácido Úrico , Glicemia/metabolismo , Suplementos Nutricionais , Vitaminas/uso terapêutico , Insulina/metabolismo , Obesidade , Metaboloma , Método Duplo-Cego
7.
Neurosci Lett ; 792: 136955, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36347339

RESUMO

GPR139 is an orphan G-protein-coupled receptor that is expressed in restricted areas of the nervous system, including the hypothalamus. In this study, we hypothesized that GPR139 could be involved in the regulation of energy balance and metabolism. In the first part of the study, we confirmed that GPR139 is expressed in the hypothalamus and particularly in proopiomelanocortin and agouti-related peptide neurons of the mediobasal hypothalamus. Using a lentivirus with a short-hairpin RNA, we inhibited the expression of GPR139 bilaterally in the mediobasal hypothalamus of mice. The intervention promoted a 40% reduction in the hypothalamic expression of GPR139, which was accompanied by an increase in body mass, a reduction in fasting blood glucose levels, and an increase in insulin levels. In the hypothalamus, inhibition of GPR139 was accompanied by a reduction in the expression of orexin. As previous studies using a pharmacological antagonist of orexin showed a beneficial impact on type 2 diabetes and glucose metabolism, we propose that the inhibition of hypothalamic GPR139 could be acting indirectly through the orexin system to control systemic glucose and insulin. In conclusion, this study advances the characterization of GPR139 in the hypothalamus, demonstrating its involvement in the regulation of body mass, blood insulin, and glycemia.


Assuntos
Diabetes Mellitus Tipo 2 , Insulina , Camundongos , Animais , Orexinas/metabolismo , Insulina/metabolismo , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Hipotálamo/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Proteínas do Tecido Nervoso/metabolismo
8.
J Nutr Biochem ; 111: 109157, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36150682

RESUMO

Gata4 is a member of the zinc finger GATA transcription factor family and is required for liver development during the embryonic stage. Gata4 expression is repressed during NAFLD progression, however how it functions in this situation remains unclear. Here, Gata4 was deleted specifically in hepatocytes via Cre recombinase driven by the Alb promoter region. Under a high-fat diet (HFD) or methionine and choline deficient diet (MCD), Gata4 knockout (KO) male, but not female, mice displayed more severe NAFLD or NASH, evidenced by increased steatosis, fibrosis, as well as a higher NAS score and serum ALT level. The Gata4KO male liver exposed to a HFD or MCD had a reduced ratio of pACC/ACC, similar to the Gata4KO hepatocytes treated with palmitic acid. More cell apoptosis, which is associated with activated JNK signaling and inhibited NFκB signaling, was observed in the Gata4KO male liver and isolated hepatocytes. However, the inflammatory status in the Gata4KO male liver was similar to the control liver. Importantly, lower activation of AKT signaling in the liver, which is consistent with de-sensitized insulin signaling in isolated hepatocytes, was found in the Gata4KO male. In summary, our data demonstrated that loss of Gata4 in hepatocytes promoted NAFLD progression in male mice.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Masculino , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Insulina/metabolismo , Camundongos Endogâmicos C57BL , Hepatócitos/metabolismo , Fígado/metabolismo , Dieta Hiperlipídica/efeitos adversos , Apoptose , Metionina/metabolismo , Colina/farmacologia , Camundongos Knockout , Fator de Transcrição GATA4/genética , Fator de Transcrição GATA4/metabolismo
9.
Mol Med Rep ; 27(1)2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36367173

RESUMO

Increasing endogenous secretion of glucagon­like peptide (GLP)­1 is considered a promising therapeutic approach for type 2 diabetes because decreased GLP­1 plasma concentrations have been observed in patients with this condition. Nesfatin­1, which is a central and peripheral anorexigenic peptide, has been reported to release GLP­1 from enteroendocrine STC­1 cells, although whether nesfatin­1 stimulates GLP­1 secretion in vivo remains to be elucidated. Previous studies have indicated that nesfatin­1 has glucose­lowering and insulinotropic effects in mice and rats; however, the in vivo mechanism remains unclear. The present study aimed to investigate whether peripheral administration of nesfatin­1 increased blood concentrations of GLP­1 and insulin in food­deprived mice. Nesfatin­1 was administered intraperitoneally to 18­h fasted mice. Plasma GLP­1 and insulin concentrations in the mice administered 2.5 µmol/kg nesfatin­1 were higher than those in saline­treated mice. Blood glucose concentrations in mice treated with 1.25 and 2.5 µmol/kg nesfatin­1 were lower than those in saline­treated mice. The mRNA expression of preproglucagon in mouse ilea after treatment with 1.25 µmol/kg nesfatin­1 was higher than that in saline­treated mice. The administration of 1.25 µmol/kg nesfatin­1 raised GLP­1 concentrations at 30 and 60 min and insulin concentrations at 30 and 60 min after injection. Furthermore, the higher level of nesfatin­1­induced insulin was diminished by pre­administration of anti­GLP­1 antiserum. Intraperitoneally administered nesfatin­1 increased insulin concentrations by accelerating GLP­1 secretion. The results are the first in vivo demonstration of promotion of GLP­1 secretion by nesfatin­1 in the mouse, suggesting the developmental potential of nesfatin­1 for GLP­1 release.


Assuntos
Diabetes Mellitus Tipo 2 , Peptídeo 1 Semelhante ao Glucagon , Camundongos , Ratos , Animais , Diabetes Mellitus Tipo 2/metabolismo , Células Enteroendócrinas , Insulina/metabolismo , Glucose/metabolismo , Glicemia/metabolismo
10.
Gen Comp Endocrinol ; 330: 114146, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36270337

RESUMO

Since practically a century ago, the insulin pathway was discovered in both vertebrates and invertebrates, implying an evolutionarily ancient origin. After a century of research, it is now clear that the insulin signal transduction pathway is a critical, flexible and pleiotropic pathway, evolving into multiple anabolic functions besides glucose homeostasis. It regulates paramount aspects of organismal well-being like growth, longevity, intermediate metabolism, and reproduction. Part of this diversification has been attained by duplications and divergence of both ligands and receptors riding on a common general signal transduction system. One of the aspects that is strikingly different is its usage in reproduction, particularly in male versus female development and fertility within the same species. This review highlights sexual divergence in metabolism and reproductive tract differences, the occurrence of sexually "exaggerated" traits, and sex size differences that are due to the sexes' differential activity/response to the insulin signaling pathway.


Assuntos
Insulina , Caracteres Sexuais , Animais , Masculino , Feminino , Insulina/metabolismo , Transdução de Sinais/fisiologia , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Reprodução/fisiologia
11.
J Nutr Biochem ; 111: 109175, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36223834

RESUMO

Increased body iron stores and inflammation in adipose tissue have been implicated in the pathogenesis of insulin resistance (IR) and type 2 diabetes mellitus. However, the underlying basis of these associations is unclear. To attempt to investigate this, we studied the development of IR and associated inflammation in adipose tissue in the presence of increased body iron stores. Male hepcidin knock-out (Hamp1-/-) mice, which have increased body iron stores, and wild-type (WT) mice were fed a high-fat diet (HFD) for 12 and 24 weeks. Development of IR and metabolic parameters linked to this, insulin signaling in various tissues, and inflammation and iron-related parameters in visceral adipose tissue were studied in these animals. HFD-feeding resulted in impaired glucose tolerance in both genotypes of mice. In response to the HFD for 24 weeks, Hamp1-/- mice gained less body weight and developed less systemic IR than corresponding WT mice. This was associated with less lipid accumulation in the liver and decreased inflammation and lipolysis in the adipose tissue in the knock-out mice, than in the WT animals. Fewer macrophages infiltrated the adipose tissue in the knockout mice than in wild-type mice, with these macrophages exhibiting a predominantly anti-inflammatory (M2-like) phenotype and indirect evidence of a possible lowered intracellular iron content. The absence of hepcidin was thus associated with attenuated inflammation in the adipose tissue and increased whole-body insulin sensitivity, suggesting a role for it in these processes.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Masculino , Camundongos , Animais , Resistência à Insulina/fisiologia , Dieta Hiperlipídica/efeitos adversos , Hepcidinas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Camundongos Endogâmicos C57BL , Tecido Adiposo/metabolismo , Inflamação/metabolismo , Insulina/metabolismo , Camundongos Knockout , Ferro/metabolismo
12.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1868(1): 159236, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36179802

RESUMO

Diet-induced obesity (OB) is usually accompanied by hypertriglyceridemia, which is characterized by the accumulation of triglyceride (TG)-rich lipoprotein (TRL) particles in the circulation. We previously found that postprandial TRL combined with insulin induced the adipogenic differentiation of 3T3-L1 preadipocytes, which may represent a key mechanism underlying obesity. However, the specific mechanism and signaling pathway involved in this process remain to be fully elucidated. In this study, we found that, in the postprandial state, patients with obesity had significantly higher levels of TG and remnant cholesterol (RC) than normal-weight controls. In vitro, we found that postprandial TRL, together with insulin, promoted the adipogenic differentiation of adipose-derived mesenchymal stem cells (AMSCs), as evidenced by the increased expression of lipogenesis-related genes and their protein products, including low-density lipoprotein related protein 1 (LRP1). Besides, caveolin-1 (Cav-1) expression was also significantly upregulated under this condition. Cav-1 and LRP1 were observed to interact, and then led to the activation of the PI3K/AKT1 signaling pathway. Meanwhile, the inhibition of LRP1 or Cav-1 significantly attenuated the adipogenic differentiation of AMSCs and downregulated AKT1 phosphorylation levels. Moreover, treatment with a selective AKT1 inhibitor significantly suppressed postprandial TRL and insulin-induced adipogenesis in AMSCs. Combined, our results demonstrated that, in association with insulin, postprandial TRL can promote the adipogenic differentiation of AMSCs in a manner that is dependent on the LRP1/Cav-1-mediated activation of the PI3K/AKT1 signaling pathway. Our findings indicated that a postprandial increase in TRL content is a critical factor in the pathogenesis of hypertriglyceridemia and diet-induced obesity.


Assuntos
Hipertrigliceridemia , Células-Tronco Mesenquimais , Humanos , Adipogenia , Caveolina 1/metabolismo , Triglicerídeos/metabolismo , Lipoproteínas/metabolismo , Hipertrigliceridemia/complicações , Insulina/metabolismo , Obesidade/metabolismo , Lipoproteínas LDL/metabolismo , Células-Tronco Mesenquimais/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo
13.
J Cell Biol ; 222(1)2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36350286

RESUMO

The primary cilium is an organelle present in most adult mammalian cells that is considered as an antenna for sensing the local microenvironment. Here, we use intact mouse pancreatic islets of Langerhans to investigate signaling properties of the primary cilium in insulin-secreting ß-cells. We find that GABAB1 receptors are strongly enriched at the base of the cilium, but are mobilized to more distal locations upon agonist binding. Using cilia-targeted Ca2+ indicators, we find that activation of GABAB1 receptors induces selective Ca2+ influx into primary cilia through a mechanism that requires voltage-dependent Ca2+ channel activation. Islet ß-cells utilize cytosolic Ca2+ increases as the main trigger for insulin secretion, yet we find that increases in cytosolic Ca2+ fail to propagate into the cilium, and that this isolation is largely due to enhanced Ca2+ extrusion in the cilium. Our work reveals local GABA action on primary cilia that involves Ca2+ influx and depends on restricted Ca2+ diffusion between the cilium and cytosol.


Assuntos
Cálcio , Cílios , Ilhotas Pancreáticas , Receptores de GABA-B , Ácido gama-Aminobutírico , Animais , Camundongos , Cálcio/metabolismo , Células Cultivadas , Cílios/metabolismo , Ácido gama-Aminobutírico/metabolismo , Glucose/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Receptores de GABA-B/metabolismo , Citosol
14.
Methods Mol Biol ; 2551: 297-309, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36310211

RESUMO

Inducing protein aggregation in vitro under various formulation and stress conditions may lead to an increased understanding of the different association routes a protein can undergo. However, a range of factors can affect the aggregation process, often leading to heterogenous samples and experimental irreproducibility between labs. Here, we present detailed methods to reproducibly form homogenous samples of superstructures: amyloid-like fibrils, spherulites, and particulates from human insulin. We discuss pitfalls and good practice in the lab, with the aim of creating awareness on the potential sources of artefacts for protein stability and aggregation studies.


Assuntos
Amiloide , Insulina , Humanos , Insulina/metabolismo , Agregados Proteicos
15.
Life Sci Alliance ; 6(1)2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36283703

RESUMO

Insulin-induced GLUT4 translocation to the plasma membrane in muscle and adipocytes is crucial for whole-body glucose homeostasis. Currently, GLUT4 trafficking assays rely on overexpression of tagged GLUT4. Here we describe a high-content imaging platform for studying endogenous GLUT4 translocation in intact adipocytes. This method enables high fidelity analysis of GLUT4 responses to specific perturbations, multiplexing of other trafficking proteins and other features including lipid droplet morphology. Using this multiplexed approach we showed that Vps45 and Rab14 are selective regulators of GLUT4, but Trarg1, Stx6, Stx16, Tbc1d4 and Rab10 knockdown affected both GLUT4 and TfR translocation. Thus, GLUT4 and TfR translocation machinery likely have some overlap upon insulin-stimulation. In addition, we identified Kif13A, a Rab10 binding molecular motor, as a novel regulator of GLUT4 traffic. Finally, comparison of endogenous to overexpressed GLUT4 highlights that the endogenous GLUT4 methodology has an enhanced sensitivity to genetic perturbations and emphasises the advantage of studying endogenous protein trafficking for drug discovery and genetic analysis of insulin action in relevant cell types.


Assuntos
Adipócitos , Proteínas rab de Ligação ao GTP , Camundongos , Animais , Células 3T3-L1 , Proteínas rab de Ligação ao GTP/metabolismo , Adipócitos/metabolismo , Insulina/metabolismo , Transportador de Glucose Tipo 4/genética , Transportador de Glucose Tipo 4/metabolismo , Glucose/metabolismo , Biologia
16.
Nat Commun ; 13(1): 6700, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36335114

RESUMO

Lymphocystis disease virus-1 (LCDV-1) and several other Iridoviridae encode viral insulin/IGF-1 like peptides (VILPs) with high homology to human insulin and IGFs. Here we show that while single-chain (sc) and double-chain (dc) LCDV1-VILPs have very low affinity for the insulin receptor, scLCDV1-VILP has high affinity for IGF1R where it can antagonize human IGF-1 signaling, without altering insulin signaling. Consequently, scLCDV1-VILP inhibits IGF-1 induced cell proliferation and growth hormone/IGF-1 induced growth of mice in vivo. Cryo-electron microscopy reveals that scLCDV1-VILP engages IGF1R in a unique manner, inducing changes in IGF1R conformation that led to separation, rather than juxtaposition, of the transmembrane segments and hence inactivation of the receptor. Thus, scLCDV1-VILP is a natural peptide with specific antagonist properties on IGF1R signaling and may provide a new tool to guide development of hormonal analogues to treat cancers or metabolic disorders sensitive to IGF-1 without affecting glucose metabolism.


Assuntos
Fator de Crescimento Insulin-Like I , Receptor IGF Tipo 1 , Humanos , Camundongos , Animais , Receptor IGF Tipo 1/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Insulina/metabolismo , Microscopia Crioeletrônica , Peptídeos/farmacologia
17.
Int J Mol Sci ; 23(21)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36362447

RESUMO

The longevity phenomenon is entirely controlled by the insulin signaling pathway (IIS-pathway). Both vertebrates and invertebrates have IIS-pathways that are comparable to one another, though no one has previously described de novo transcriptome assembly of IIS-pathway-associated genes in termites. In this research, we analyzed the transcriptomes of both reproductive (primary kings "PK" and queens "PQ", secondary worker reproductive kings "SWRK" and queens "SWRQ") and non-reproductive (male "WM" and female "WF" workers) castes of the subterranean termite Reticulitermes chinensis. The goal was to identify the genes responsible for longevity in the reproductive and non-reproductive castes. Through transcriptome analysis, we annotated 103,589,264 sequence reads and 184,436 (7G) unigenes were assembled, GC performance was measured at 43.02%, and 64,046 sequences were reported as CDs sequences. Of which 35 IIS-pathway-associated genes were identified, among 35 genes, we focused on the phosphoinositide-dependent kinase-1 (Pdk1), protein kinase B2 (akt2-a), tuberous sclerosis-2 (Tsc2), mammalian target of rapamycin (mTOR), eukaryotic translation initiation factor 4E (EIF4E) and ribosomal protein S6 (RPS6) genes. Previously these genes (Pdk1, akt2-a,&nbsp;mTOR, EIF4E, and RPS6) were investigated in various organisms, that regulate physiological effects, growth factors, protein translation, cell survival, proliferation, protein synthesis, cell metabolism and survival, autophagy, fecundity rate, egg size, and follicle number, although the critical reason for longevity is still unclear in the termite castes. However, based on transcriptome profiling, the IIS-pathway-associated genes could prolong the reproductive caste lifespan and health span. Therefore, the transcriptomic shreds of evidence related to IIS-pathway genes provide new insights into the maintenance and relationships between biomolecular homeostasis and remarkable longevity. Finally, we propose a strategy for future research to decrypt the hidden costs associated with termite aging in reproductive and non-reproductive castes.


Assuntos
Isópteros , Animais , Feminino , Masculino , Fator de Iniciação 4E em Eucariotos/genética , Insulina/metabolismo , Isópteros/genética , Isópteros/metabolismo , Longevidade/genética , Serina-Treonina Quinases TOR/metabolismo , Transcriptoma
18.
Cell Rep ; 41(8): 111685, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36417877

RESUMO

Insulin/insulin-like growth factor (IGF) receptor signaling (IIS) supports context-dependent learning in vertebrates and invertebrates. Here, we identify cell-specific mechanisms of IIS that integrate sensory information with food context to drive synaptic plasticity and learning. In the nematode Caenorhabditis elegans, pairing food deprivation with an odor such as butanone suppresses attraction to that odor. We find that aversive olfactory learning requires the insulin receptor substrate (IRS) protein IST-1 and atypical signaling through the insulin/IGF-1 receptor DAF-2. Cell-specific knockout and rescue demonstrate that DAF-2 acts in the AWCON sensory neuron, which detects butanone, and that learning preferentially depends upon the axonally localized DAF-2c isoform. Acute food deprivation increases DAF-2 levels in AWCON post-transcriptionally through an insulin- and insulin receptor substrate-1 (ist-1)-dependent process. Aversive learning alters the synaptic output of AWCON by suppressing odor-regulated glutamate release in wild-type animals, but not in ist-1 mutants, suggesting that axonal insulin signaling regulates synaptic transmission to support aversive memory.


Assuntos
Proteínas de Caenorhabditis elegans , Somatomedinas , Animais , Insulina/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Ácido Glutâmico , Caenorhabditis elegans/metabolismo , Células Receptoras Sensoriais/metabolismo , Butanonas
19.
FASEB J ; 36(12): e22667, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36421020

RESUMO

The regulation of muscle glucose utilization has significant potential for the treatment of type 2 diabetes mellitus (T2DM) and obesity. Heat shock factor 1 (HSF1) is involved in cellular metabolism and regulation of muscle metabolism. However, it is unclear how HSF1 regulates muscle glucose metabolism. In the present study, the development of obesity in mice was associated with HSF1 downregulation. Serum samples and muscle biopsies were obtained from obese and healthy humans. Fasting glucose and insulin levels and the homeostasis model assessment of insulin resistance value showed that obesity was associated with insulin resistance. The skeletal muscle level of HSF1 was decreased in obese and ob/ob mice. HSF1 was selectively over-expressed in the skeletal muscles of high fat diet (HFD)-fed mice. Muscle HSF1 over-expression successfully triggered glycolytic-to-oxidative myofiber switch and increased fatty acid metabolism and insulin sensitivity in the skeletal muscles of HFD-fed mice. Moreover, HSF1 improved energy expenditure and blocked muscle accumulation of triglycerides in HFD-fed mice. Consequently, muscle HSF1 mitigated the impaired muscle insulin signaling and insulin resistance in HFD-fed mice. In conclusion, T2DM and obesity in HFD-fed mice may be treated with selective HSF1-directed programming of exercise-like effects in skeletal muscle. These findings may aid the development of a new therapeutic approach for obesity and T2DM.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Humanos , Camundongos , Animais , Resistência à Insulina/fisiologia , Glucose/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Insulina/metabolismo , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/metabolismo
20.
Front Immunol ; 13: 951381, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36405687

RESUMO

The diabetic population has been increasing in the past decades and diabetic cardiomyopathy (DCM), a pathology that is defined by the presence of cardiac remodeling and dysfunction without conventional cardiac risk factors such as hypertension and coronary heart diseases, would eventually lead to fatal heart failure in the absence of effective treatment. Impaired insulin signaling, commonly known as insulin resistance, plays an important role in the development of DCM. A family of integral membrane proteins named caveolins (mainly caveolin-1 and caveolin-3 in the myocardium) and a protein hormone adiponectin (APN) have all been shown to be important for maintaining normal insulin signaling. Abnormalities in caveolins and APN have respectively been demonstrated to cause DCM. This review aims to summarize recent research findings of the roles and mechanisms of caveolins and APN in the development of DCM, and also explore the possible interplay between caveolins and APN.


Assuntos
Diabetes Mellitus , Cardiomiopatias Diabéticas , Resistência à Insulina , Humanos , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/prevenção & controle , Caveolina 1 , Miocárdio/patologia , Insulina/metabolismo , Adiponectina/metabolismo , Diabetes Mellitus/patologia
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