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1.
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
2.
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
3.
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
4.
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
5.
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
6.
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
8.
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
9.
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
10.
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
11.
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
12.
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
13.
Commun Biol ; 5(1): 1232, 2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36371562

RESUMO

Here we use a combination of two-photon Fluorescence Lifetime Imaging Microscopy (FLIM) of NAD(P)H free/bound ratio in living HIs with post-fixation, immunofluorescence-based, cell-type identification. FLIM allowed to measure variations in the NAD(P)H free/bound ratio induced by glucose; immunofluorescence data allowed to identify single α and ß cells; finally, matching of the two datasets allowed to assign metabolic shifts to cell identity. 312 α and 654 ß cells from a cohort of 4 healthy donors, 15 total islets, were measured. Both α and ß cells display a wide spectrum of responses, towards either an increase or a decrease in NAD(P)H free/bound ratio. Yet, if single-cell data are averaged according to the respective donor and correlated to donor insulin secretion power, a non-random distribution of metabolic shifts emerges: robust average responses of both α and ß cells towards an increase of enzyme-bound NAD(P)H belong to the donor with the lowest insulin-secretion power; by contrast, discordant responses, with α cells shifting towards an increase of free NAD(P)H and ß cells towards an increase of enzyme-bound NAD(P)H, correspond to the donor with the highest insulin-secretion power. Overall, data reveal neat anti-correlation of tissue metabolic responses with respect to tissue insulin secretion power.


Assuntos
Glucose , Ilhotas Pancreáticas , Humanos , Glucose/metabolismo , NAD/metabolismo , NADP/metabolismo , Ilhotas Pancreáticas/metabolismo , Insulina/metabolismo
14.
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
15.
Cell Commun Signal ; 20(1): 179, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376971

RESUMO

BACKGROUND: The aim of the present study was to determine the role of individual PHLPP isoforms in insulin signaling and insulin resistance in neuronal cells. METHODS: PHLPP isoforms were either silenced or overexpressed individually, and the effects were observed on individual Akt isoforms, AS160 and on neuronal glucose uptake, under insulin sensitive and resistant conditions. To determine PHLPP regulation itself, we tested effect of scaffold protein, Scribble, on PHLPP isoforms and neuronal glucose uptake. RESULTS: We observed elevated expression of both PHLPP1 and PHLPP2 in insulin resistant neuronal cells (Neuro-2A, mouse neuroblastoma; SHSY-5Y, human neuroblastoma) as well as in the whole brain lysates of high-fat-diet mediated diabetic mice. In insulin sensitive condition, PHLPP isoforms differentially affected activation of all Akt isoforms, wherein PHLPP1 regulated serine phosphorylation of Akt2 and Akt3, while PHLPP2 regulated Akt1 and Akt3. This PHLPP mediated Akt isoform specific regulation activated AS160 affecting glucose uptake. Under insulin resistant condition, a similar trend of results were observed in Akt isoforms, AS160 and glucose uptake. Over-expressed PHLPP isoforms combined with elevated endogenous expression under insulin resistant condition drastically affected downstream signaling, reducing neuronal glucose uptake. No compensation was observed amongst PHLPP isoforms under all conditions tested, indicating independent roles and pointing towards possible scaffolding interactions behind isoform specificity. Silencing of Scribble, a scaffolding protein known to interact with PHLPP, affected cellular localization of both PHLPP1 and PHLPP2, and caused increase in glucose uptake. CONCLUSIONS: PHLPP isoforms play independent roles via Scribble in regulating Akt isoforms differentially, affecting AS160 and neuronal glucose uptake. Video abstract.


Assuntos
Diabetes Mellitus Experimental , Resistência à Insulina , Neuroblastoma , Animais , Humanos , Camundongos , Glucose , Insulina/farmacologia , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Fosforilação , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
16.
Biol Sex Differ ; 13(1): 65, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36348465

RESUMO

BACKGROUND: The receptor for advanced glycation end products (RAGE) plays an important role in obesity-associated insulin sensitivity. We have also previously reported that RAGE deficiency improved insulin resistance in obesity-induced adipose tissue. The current study was aimed to elucidate the sex-specific mechanism of RAGE deficiency in adipose tissue metabolic regulation and systemic glucose homeostasis. METHODS: RAGE-deficient (RAGE-/-) mice were fed a high-fat diet (HFD) and subjected to glucose and insulin tolerance tests. Subcutaneous adipose tissue (sAT) was collected, and macrophage polarization was assessed by quantitative real-time PCR. Immunoblotting was performed to evaluate the insulin signaling in adipose tissues. RESULTS: Under HFD feeding conditions, body weight and adipocyte size of female RAGE deficient (RAGE-/-) were markedly lower than that of male mice. Female RAGE-/- mice showed significantly improved glucose and insulin tolerance compared to male RAGE-/- mice, accompanied with increased M2 macrophages polarization. Expressions of genes involved in anti-oxidant and browning were up-regulated in adipose tissues of female RAGE-/- mice. Moreover, insulin-induced AKT phosphorylation was significantly elevated in adipose tissue in female RAGE-/- mice compared to male RAGE-/- mice. CONCLUSIONS: Our findings suggest that RAGE-mediated adipose tissue insulin resistance is sex-specific, which is associated with different expression of genes involved in anti-oxidant and browning and insulin-induced AKT phosphorylation.


Assuntos
Resistência à Insulina , Masculino , Feminino , Camundongos , Animais , Resistência à Insulina/genética , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Antioxidantes/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Camundongos Endogâmicos C57BL , Tecido Adiposo/metabolismo , Obesidade/metabolismo , Insulina/metabolismo , Glucose/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-36351678

RESUMO

INTRODUCTION: Pregnancy entails both pancreatic adaptations with increasing ß-cell mass and immunological alterations in healthy women. In this study, we have examined the effects of pregnancy on ß-cell function and immunological processes in long-standing type 1 diabetes (L-T1D). RESEARCH DESIGN AND METHODS: Fasting and stimulated C-peptide were measured after an oral glucose tolerance test in pregnant women with L-T1D (n=17) during the first trimester, third trimester, and 5-8 weeks post partum. Two 92-plex Olink panels were used to measure proteins in plasma. Non-pregnant women with L-T1D (n=30) were included for comparison. RESULTS: Fasting C-peptide was detected to a higher degree in women with L-T1D during gestation and after parturition (first trimester: 64.7%, third trimester: 76.5%, and post partum: 64.7% vs 26.7% in non-pregnant women). Also, total insulin secretion and peak C-peptide increased during pregnancy. The plasma protein levels in pregnant women with L-T1D was dynamic, but few analytes were functionally related. Specifically, peripheral levels of prolactin (PRL), prokineticin (PROK)-1, and glucagon (GCG) were elevated during gestation whereas levels of proteins related to leukocyte migration (CCL11), T cell activation (CD28), and antigen presentation (such as CD83) were reduced. CONCLUSIONS: In summary, we have found that some C-peptide secretion, that is, an indirect measurement of endogenous insulin production, is regained in women with L-T1D during pregnancy, which might be attributed to elevated peripheral levels of PRL, PROK-1, or GCG.


Assuntos
Diabetes Mellitus Tipo 1 , Insulina , Gravidez , Feminino , Humanos , Insulina/metabolismo , Secreção de Insulina , Peptídeo C , Teste de Tolerância a Glucose , Insulina Regular Humana/metabolismo
18.
PLoS One ; 17(11): e0277457, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36374861

RESUMO

BACKGROUND: Type-II diabetes mellitus (T2DM) is a major risk factor for cognitive impairment. Protecting the brain environment against inflammation, and neurodegeneration, as well as preservation of the BBB veracity through modulating the crosstalk between insulin/AKT/GSK-3ß and Wnt/ß-catenin signaling, might introduce novel therapeutic targets. PURPOSE: This study aimed at exploring the possible neuroprotective potential of vitamin D3 (VitD) and/or rosuvastatin (RSV) in T2DM-induced cognitive deficits. METHODS: T2DM was induced by a high-fat sucrose diet and a single streptozotocin (STZ) dose. Diabetic rats were allocated into a diabetic control and three groups treated with RSV (15 mg/kg/day, PO), VitD (500 IU/kg/day, PO), or their combination. RESULTS: Administration of VitD and/or RSV mitigated T2DM-induced metabolic abnormalities and restored the balance between the anti-inflammatory, IL 27 and the proinflammatory, IL 23 levels in the hippocampus. In addition, they markedly activated both the canonical and noncanonical Wnt/ß-catenin cassettes with stimulation of their downstream molecular targets. VitD and/or RSV upregulated insulin and α7 nicotinic acetylcholine (α7nACh) receptors gene expression, as well as blood-brain barrier integrity markers including Annexin A1, claudin 3, and VE-cadherin. Also, they obliterated hippocampal ApoE-4 content, Tau hyperphosphorylation, and Aß deposition. These biochemical changes were reflected as improved behavioral performance in Morris water maze and novel object recognition tests and restored hippocampal histological profile. CONCLUSION: The current findings have accentuated the neuroprotective potential of VitD and RSV and provide new incentives to expand their use in T2DM-induced cognitive and memory decline. This study also suggests a superior benefit of combining both treatments over either drug alone.


Assuntos
Disfunção Cognitiva , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Ratos , Animais , beta Catenina/metabolismo , Rosuvastatina Cálcica/uso terapêutico , Aprendizagem em Labirinto/fisiologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Vitamina D/farmacologia , Vitamina D/uso terapêutico , Vitamina D/metabolismo , Doenças Neuroinflamatórias , Glicogênio Sintase Quinase 3 beta/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Via de Sinalização Wnt , Hipocampo/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Insulina/metabolismo
19.
Nat Commun ; 13(1): 6754, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376280

RESUMO

Chronic hyperglycaemia causes a dramatic decrease in mitochondrial metabolism and insulin content in pancreatic ß-cells. This underlies the progressive decline in ß-cell function in diabetes. However, the molecular mechanisms by which hyperglycaemia produces these effects remain unresolved. Using isolated islets and INS-1 cells, we show here that one or more glycolytic metabolites downstream of phosphofructokinase and upstream of GAPDH mediates the effects of chronic hyperglycemia. This metabolite stimulates marked upregulation of mTORC1 and concomitant downregulation of AMPK. Increased mTORC1 activity causes inhibition of pyruvate dehydrogenase which reduces pyruvate entry into the tricarboxylic acid cycle and partially accounts for the hyperglycaemia-induced reduction in oxidative phosphorylation and insulin secretion. In addition, hyperglycaemia (or diabetes) dramatically inhibits GAPDH activity, thereby impairing glucose metabolism. Our data also reveal that restricting glucose metabolism during hyperglycaemia prevents these changes and thus may be of therapeutic benefit. In summary, we have identified a pathway by which chronic hyperglycaemia reduces ß-cell function.


Assuntos
Diabetes Mellitus , Hiperglicemia , Ilhotas Pancreáticas , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Glucose/metabolismo , Glicólise/fisiologia , Insulina/metabolismo , Hiperglicemia/metabolismo , Ácido Pirúvico/metabolismo , Ilhotas Pancreáticas/metabolismo , Diabetes Mellitus/metabolismo
20.
Cell Mol Life Sci ; 79(12): 587, 2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36370223

RESUMO

Type 1 diabetes (T1D) is characterized by an immune-mediated progressive destruction of the insulin-producing ß-cells. Proinflammatory cytokines trigger endoplasmic reticulum (ER) stress and subsequent insulin secretory deficiency in cultured ß-cells, mimicking the islet microenvironment in T1D. ß-cells undergo physiologic ER stress due to the high rate of insulin production and secretion under stimulated conditions. Severe and uncompensated ER stress in ß-cells is induced by several pathological mechanisms before onset and during T1D. We previously described that the small drug Compound A (CpdA), a selective glucocorticoid receptor (GR/NR3C1, nuclear receptor subfamily 3, group C, member 1) ligand with demonstrated inflammation-suppressive activity in vivo, is an effective modulator of effector T and dendritic cells and of macrophages, yet, in a GR-independent manner. Here, we focus on CpdA's therapeutic potential in T1D cellular and animal models. We demonstrate that CpdA improves the unfolded protein response (UPR) by attenuating ER stress and favoring the survival and function of ß-cells exposed to an environment of proinflammatory cytokines. CpdA administration to NODscid mice adoptively transferred with diabetogenic splenocytes (from diabetic NOD mice) led to a delay of disease onset and reduction of diabetes incidence. Histological analysis of the pancreas showed a reduction in islet leukocyte infiltration (insulitis) and preservation of insulin expression in CpdA-treated normoglycemic mice in comparison with control group. These new findings together with our previous reports justify further studies on the administration of this small molecule as a novel therapeutic strategy with dual targets (effector immune and ß-cells) during autoimmune diabetes.


Assuntos
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Camundongos , Animais , Camundongos Endogâmicos NOD , Estresse do Retículo Endoplasmático , Citocinas/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Modelos Animais de Doenças
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