RESUMEN

Fucoxanthin (Fx) has garnered significant interest due to its exceptional biological properties. However, its efficacy in enhancing food quality and human health is contingent upon the solubility of the compound in water and its physicochemical stability. Therefore, nanocarriers must be developed to enhance the stability and biocompatibility of Fx. In this study, oxidized paramylon and Fx self-assembled nanoparticles (Fx-OEP) were prepared via the anti-solvent method, with a loading rate of 82.47 % for Fx. The Fx-OEP exhibited robust storage and photostability. In vitro simulated digestion assays demonstrated that Fx-OEP effectively protected Fx from premature gastric release, while achieving a release efficiency of 72.17 % in the intestinal phase. Fx-OEP has the capacity to scavenge a range of reactive oxygen species (ROS) induced by cellular oxidative stress. Treatment with Fx-OEP resulted in a significant reduction in ROS accumulation in insulin-resistant HepG2 cells, which was attributed to the activation of the nuclear factor E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway. This, in turn, activated insulin receptor substrate 1/glucose transporter type 4 (IRS1/GLUT4), promoting cellular glucose absorption and utilization. These findings indicate the potential of self-assembled nanoparticles based on oxidized paramylon as a new type of nanocarrier for delivering hydrophobic substances.

Asunto(s)

Resistencia a la Insulina , Nanopartículas , Xantófilas , Humanos , Xantófilas/farmacología , Xantófilas/química , Nanopartículas/química , Células Hep G2 , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Portadores de Fármacos/química , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/efectos de los fármacos , Hemo-Oxigenasa 1/metabolismo , Transportador de Glucosa de Tipo 4/metabolismo , Proteínas Sustrato del Receptor de Insulina/metabolismo , Liberación de Fármacos , Glucanos/química , Glucanos/farmacología

RESUMEN

ABSTRACT: The role of intravenous immunoglobulin in protecting the diabetic heart from ischemia/reperfusion (I/R) injury is unclear. Hearts isolated from adult diabetic and nondiabetic Wistar rats (n = 8 per group) were treated with intravenous immunoglobulin (IVIG) either 2 hours before euthanasia, before ischemia, or at reperfusion. Hemodynamic data were acquired using the Isoheart software version 1.524-S. Ischemia/reperfusion (I/R) injury was evaluated by 2,3,5-triphenyltetrazolium chloride staining and troponin T levels. The levels of apoptosis markers, caspases-3/8, antioxidant enzymes, superoxide dismutase and catalase, glucose transporters, GLUT-1 and GLUT-4, phosphorylated ERK1/2, and phosphorylated eNOS were estimated by Western blotting. Proinflammatory and anti-inflammatory cytokine levels were evaluated using enzyme-linked immunosorbent assays. Intravenous immunoglobulin administration abolished the effects of I/R injury in hearts subjected to hyperglycemia when infused at reperfusion, before ischemia, or at reperfusion in 4-week diabetic rat hearts and only at reperfusion in 6-week diabetic rat hearts. IVIG infusion resulted in a significant (P < 0.05) recovery of cardiac hemodynamics and decreased infarct size. IVIG also reduced the levels of troponin T, apoptotic enzymes, and proinflammatory cytokines. IVIG significantly (P < 0.05) increased the levels of anti-inflammatory cytokines, antioxidant enzymes, GLUT-4, and phosphorylated eNOS. Intravenous immunoglobulin protected the hearts from I/R injury if infused at reperfusion in the presence of hyperglycemia, in 4- and 6-week diabetic rat hearts, and when infused before ischemia in 4-week diabetic rat hearts. IVIG exerts its cardioprotective effects associated with the upregulated phosphorylated eNOS/GLUT-4 pathway.

Asunto(s)

Diabetes Mellitus Experimental , Transportador de Glucosa de Tipo 4 , Daño por Reperfusión Miocárdica , Óxido Nítrico Sintasa de Tipo III , Ratas Wistar , Transducción de Señal , Animales , Daño por Reperfusión Miocárdica/prevención & control , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/fisiopatología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/tratamiento farmacológico , Transportador de Glucosa de Tipo 4/metabolismo , Masculino , Inmunoglobulinas Intravenosas/farmacología , Apoptosis/efectos de los fármacos , Miocardio/patología , Miocardio/metabolismo , Miocardio/enzimología , Infarto del Miocardio/patología , Infarto del Miocardio/metabolismo , Infarto del Miocardio/prevención & control , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/tratamiento farmacológico , Ratas , Estrés Oxidativo/efectos de los fármacos , Citocinas/metabolismo , Preparación de Corazón Aislado , Mediadores de Inflamación/metabolismo

RESUMEN

The Target-Based Virtual Screening approach is widely employed in drug development, with docking or molecular dynamics techniques commonly utilized for this purpose. This systematic review (SR) aimed to identify in silico therapeutic targets for treating Diabetes mellitus (DM) and answer the question: What therapeutic targets have been used in in silico analyses for the treatment of DM? The SR was developed following the guidelines of the Preferred Reporting Items Checklist for Systematic Review and Meta-Analysis, in accordance with the protocol registered in PROSPERO (CRD42022353808). Studies that met the PECo strategy (Problem, Exposure, Context) were included using the following databases: Medline (PubMed), Web of Science, Scopus, Embase, ScienceDirect, and Virtual Health Library. A total of 20 articles were included, which not only identified therapeutic targets in silico but also conducted in vivo analyses to validate the obtained results. The therapeutic targets most frequently indicated in in silico studies were GLUT4, DPP-IV, and PPARγ. In conclusion, a diversity of targets for the treatment of DM was verified through both in silico and in vivo reassessment. This contributes to the discovery of potential new allies for the treatment of DM.

Asunto(s)

Simulación por Computador , Diabetes Mellitus , Suplementos Dietéticos , Hipoglucemiantes , Humanos , Diabetes Mellitus/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Hipoglucemiantes/farmacología , Transportador de Glucosa de Tipo 4/metabolismo , Animales , Desarrollo de Medicamentos/métodos , PPAR gamma/metabolismo , Simulación del Acoplamiento Molecular , Terapia Molecular Dirigida/métodos

RESUMEN

Hypertension (HP) is a health condition that overloads the heart and increases the risk of heart attack and stroke. In an infarction, the lack of oxygen causes an exclusive use of glycolysis, which becomes a crucial source of ATP for the heart with a higher glucose uptake mediated by glucose transporters (GLUTs). Due to the unpleasant effects of antihypertensives, new drugs need to be researched to treat this disease. This study aimed to evaluate the cardioprotective effect of three novel antihypertensive compounds (LQMs, "Laboratorio de Química Medicinal") synthesized from Changrolin under hypoxic conditions with the participation of two primary cardiac GLUT1 and GLUT4 using a high-salt diet HP model. The model used a diet with 10% salt to increase arterial blood pressure in Wistar rats. In isolated cardiomyocytes from these rats, glucose uptake was measured during hypoxia, evaluating the participation of GLUTs with or without the animals' previous treatment with LQM312, 319, and 345 compounds. In silico calculations were performed to understand the affinity of the compounds for the trafficking of GLUTs. Results: Control cells do shift to glucose uptake exclusively in hypoxia (from 1.84 ± 0.09 µg/g/h to 2.67 ± 0.1 µg/g/h). Meanwhile, HP does not change its glucose uptake (from 2.38 ± 0.24 µg/g/h to 2.33 ± 0.26 µg/g/h), which is associated with cardiomyocyte damage. The new compounds lowered the systolic blood pressure (from 149 to 120 mmHg), but only LQM312 and LQM319 improved the metabolic state of hypoxic cardiomyocytes mediated by GLUT1 and GLUT4. In silico studies suggested that Captopril and LQM312 may mimic the interaction with the AMPK γ-subunit. Therefore, these compounds could activate AMPK, promoting the GLUT4 trafficking signaling pathway. These compounds are proposed to be cardioprotective during hypoxia under HP.

Asunto(s)

Antihipertensivos , Transportador de Glucosa de Tipo 4 , Glucosa , Hipertensión , Miocitos Cardíacos , Ratas Wistar , Animales , Ratas , Antihipertensivos/farmacología , Hipertensión/metabolismo , Hipertensión/tratamiento farmacológico , Glucosa/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Transportador de Glucosa de Tipo 4/metabolismo , Masculino , Cardiotónicos/farmacología , Cardiotónicos/uso terapéutico , Transportador de Glucosa de Tipo 1/metabolismo , Cloruro de Sodio Dietético/efectos adversos , Hipoxia/metabolismo , Hipoxia/tratamiento farmacológico , Transporte Biológico/efectos de los fármacos , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Presión Sanguínea/efectos de los fármacos

RESUMEN

Rosa davurica Pall. is widely used in traditional oriental herbal therapy, but its components and molecular mechanisms of action remain unclear. This study investigates the antidiabetic potential of Rosa davurica Pall. root extract (RDR) and elucidates its underlying molecular mechanisms with in vitro and in vivo models. Data from the current study show that RDR exhibits strong antioxidant activity and glucose homeostasis regulatory effects. It significantly impacts glucose homeostasis in C2C12 skeletal muscle cells by inhibiting α-glucosidase activity. Further molecular mechanistic studies revealed that RDR promoted glucose uptake by phosphorylation of AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC), but not Phosphatidylinositol 3-kinase (PI 3-kinase)/Akt in C2C12 skeletal muscle cells. These actions increased the expression and translocation of glucose transporter type 4 (GLUT4) to the plasma membrane. In addition, RDR treatment in the STZ-induced diabetic rats remarkably improved the low body weight, polydipsia, polyphagia, hyperglycemia, and islet architecture and increased the insulin/glucose ratio. The liver (ALT and AST) and kidney marker enzyme (BUN and creatinine) levels were restored by RDR treatment as well. Phytochemical analysis identified eight major constituents in RDR, crucial for its antioxidant and antidiabetic activity. Through the molecular docking of representative glucose transporter GLUT4 with these compounds, it was confirmed that the components of RDR had a significantly high binding score in terms of structural binding. These findings from the current study highlight the antidiabetic effects of RDR. Collectively, our data suggest that RDR might be a potential pharmaceutical natural product for diabetic patients.

Asunto(s)

Diabetes Mellitus Experimental , Transportador de Glucosa de Tipo 4 , Hipoglucemiantes , Extractos Vegetales , Raíces de Plantas , Rosa , Hipoglucemiantes/farmacología , Hipoglucemiantes/química , Hipoglucemiantes/uso terapéutico , Extractos Vegetales/farmacología , Extractos Vegetales/química , Animales , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Raíces de Plantas/química , Rosa/química , Ratas , Transportador de Glucosa de Tipo 4/metabolismo , Masculino , Ratones , Antioxidantes/farmacología , Antioxidantes/química , Glucemia/metabolismo , Glucemia/efectos de los fármacos , Línea Celular , Glucosa/metabolismo , Simulación del Acoplamiento Molecular , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo

RESUMEN

The aim was to investigate the long-term effects of metformin ingestion on high-intensity interval training on performance, glycogen concentration (GC), GLUT-4 content, and metabolomics outcomes in rats. Fifty male Wistar rats were randomly divided into baseline, metformin (500 mg daily), and control groups. Training consisted of 4 sets of 10 jumps with 30 s of passive recovery per day, 5 days/week for 8 weeks. The intensity equivalent was 50% of body mass (BM) in the first four weeks and 70% of BM in the last four weeks. The animals were submitted to a weekly jump test until exhaustion at 50% of BM. Serum and tissues were collected at baseline and after 4 and 8 weeks for biochemical and metabolomics analysis. The number of jumps increased in the Control group without a significant difference between groups at 4 and 8 weeks. GLUT4 was lower in the gastrocnemius muscle in the Metformin at the fourth week compared to Control (P=0.03) and compared to Metformin (P=0.02) and Control (P=0.01) at eight weeks. Hepatic and soleus GC were not altered by metformin. Gastrocnemius GC was lower after 8 weeks in the Metformin group compared to Control (P=0.01). Significantly lower levels of pyruvate and phenylalanine and higher levels of ethanol, formate, betaine, very low-density lipoprotein, low-density lipoprotein, and creatine were found in the Metformin compared to the Control. Although chronic administration of metformin decreased food intake and negatively influenced the synthesis of muscle glycogen, it did not significantly change physical performance compared to the Control.

Asunto(s)

Transportador de Glucosa de Tipo 4 , Glucógeno , Entrenamiento de Intervalos de Alta Intensidad , Hipoglucemiantes , Metabolómica , Metformina , Condicionamiento Físico Animal , Animales , Masculino , Ratas , Transportador de Glucosa de Tipo 4/metabolismo , Glucógeno/metabolismo , Glucógeno/análisis , Entrenamiento de Intervalos de Alta Intensidad/métodos , Hipoglucemiantes/farmacología , Hipoglucemiantes/administración & dosificación , Espectroscopía de Resonancia Magnética/métodos , Metformina/farmacología , Metformina/administración & dosificación , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Condicionamiento Físico Animal/fisiología , Rendimiento Físico Funcional , Distribución Aleatoria , Ratas Wistar , Factores de Tiempo

RESUMEN

Chronic lipid overconsumption, associated with the Western diet, causes excessive cardiac lipid accumulation, insulin resistance, and contractile dysfunction, altogether termed lipotoxic cardiomyopathy (LCM). Existing treatments for LCM are limited. Traditional Chinese Medicine (TCM) has been shown as beneficial in diabetes and its complications. The following compounds-Resveratrol, Quercetin, Berberine, Baicalein, and Isorhamnetin-derived from TCM and often used to treat type 2 diabetes. However, virtually nothing is known about their effects in the lipid-overexposed heart. Lipid-induced insulin resistance was generated in HL-1 cardiomyocytes and adult rat cardiomyocytes by 24 h exposure to high palmitate. Upon simultaneous treatment with each of the TCM compounds, we measured myocellular lipid accumulation, insulin-stimulated fatty acid and glucose uptake, phosphorylation levels of AKT and ERK1/2, plasma membrane appearance of GLUT4 and CD36, and expression of oxidative stress-/inflammation-related genes and contractility. In lipid-overloaded cardiomyocytes, all the selected TCM compounds prevented lipid accumulation. These compounds also preserved insulin-stimulated CD36 and GLUT4 translocation and insulin-stimulated glucose uptake in an Akt-independent manner. Moreover, all the TCM compounds prevented and restored lipid-induced contractile dysfunction. Finally, some (not all) of the TCM compounds inhibited oxidative stress-related SIRT3 expression, and others reduced inflammatory TNFα expression. Their ability to restore CD36 trafficking makes all these TCM compounds attractive natural supplements for LCM treatment.

Asunto(s)

Medicina Tradicional China , Miocitos Cardíacos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Animales , Ratas , Medicina Tradicional China/métodos , Resistencia a la Insulina , Contracción Miocárdica/efectos de los fármacos , Glucosa/metabolismo , Medicamentos Herbarios Chinos/farmacología , Metabolismo de los Lípidos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Ratones , Línea Celular , Antígenos CD36/metabolismo , Antígenos CD36/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Masculino

RESUMEN

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are a cell model now widely used to investigate pathophysiological features of cardiac tissue. Given the invaluable contribution hiPSC-CM could make for studies on cardio-metabolic disorders by defining a postnatal metabolic phenotype, our work herein focused on monitoring the insulin response in CM derived from the hiPSC line UKBi015-B. Western blot analysis on total cell lysates obtained from hiPSC-CM showed increased phosphorylation of both AKT and AS160 following insulin treatment, but failed to highlight any changes in the expression dynamics of the glucose transporter GLUT4. By contrast, the Western blot analysis of membrane fractions, rather than total lysates, revealed insulin-induced plasma membrane translocation of GLUT4, which is known to also occur in postnatal CM. Thus, these findings suggest that hiPSC-derived CMs exhibit an insulin response reminiscent to that of adult CMs regarding intracellular signaling and GLUT4 translocation to the plasma membrane, representing a suitable cellular model in the cardio-metabolic research field. Moreover, our studies also demonstrate the relevance of analyzing membrane fractions rather than total lysates in order to monitor GLUT4 dynamics in response to metabolic regulators in hiPSC-CMs.

Asunto(s)

Membrana Celular , Transportador de Glucosa de Tipo 4 , Células Madre Pluripotentes Inducidas , Insulina , Miocitos Cardíacos , Transporte de Proteínas , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Transportador de Glucosa de Tipo 4/metabolismo , Miocitos Cardíacos/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Insulina/metabolismo , Insulina/farmacología , Membrana Celular/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosforilación , Diferenciación Celular , Proteínas Activadoras de GTPasa/metabolismo , Línea Celular

RESUMEN

Advanced glycated end products (AGEs) are cytotoxic compounds that are mainly increased in diabetes mellitus (DM), kidney failure, inflammation, and in response to the ingestion of AGE-rich diets. AGEs can also impair glycemic homeostasis by decreasing the expression of the Slc2a4 (solute carrier family 2 member 4) gene and its GLUT4 (solute carrier family 2, facilitated glucose transporter member 4) protein in muscle. However, the mechanisms underlying AGE's effect on adipocytes have not been demonstrated yet. This study investigated the effects of AGEs upon Slc2a4/GLUT4 expression in 3T3-L1 adipocytes, as well as the potential role of NFKB (nuclear factor NF-kappa-B) activity in the effects observed. Adipocytes were cultured in the presence of control albumin (CA) or advanced glycated albumin (GA) at concentrations of 0.4, 3.6, and 5.4 mg/mL for 24 h or 72 h. Slc2a4, Rela, and Nfkb1mRNAs were measured by RT-qPCR, GLUT4, IKKA/B, and p50/p65 NFKB subunits using Western blotting, and p50/p65 binding into the Slc2a4 promoter was analyzed by chromatin immunoprecipitation (ChIP) assay. GA at 0.4 mg/mL increased Slc2a4/GLUT4 expression after 24 h and 72 h (from 50% to 100%), but at 5.4 mg/mL, Slc2a4/GLUT4 expression decreased at 72 h (by 50%). Rela and Nfkb1 expression increased after 24 h at all concentrations, but this effect was not observed at 72 h. Furthermore, 5.4 mg/mL of GA increased the p50/p65 nuclear content and binding into Slc2a4 at 72 h. In summary, this study reveals AGE-induced and NFKB-mediated repression of Slc2a4/GLUT4 expression. This can compromise the adipocyte glucose utilization, contributing not only to the worsening of glycemic control in DM subjects but also the impairment of glycemic homeostasis in non-DM subjects under the high intake of AGE-rich foods.

Asunto(s)

Células 3T3-L1 , Adipocitos , Transportador de Glucosa de Tipo 4 , Productos Finales de Glicación Avanzada , Factor de Transcripción ReIA , Animales , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Ratones , Productos Finales de Glicación Avanzada/metabolismo , Productos Finales de Glicación Avanzada/farmacología , Adipocitos/metabolismo , Adipocitos/efectos de los fármacos , Factor de Transcripción ReIA/metabolismo , Factor de Transcripción ReIA/genética , FN-kappa B/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Regiones Promotoras Genéticas , Subunidad p50 de NF-kappa B/metabolismo , Subunidad p50 de NF-kappa B/genética

RESUMEN

Our recent studies have identified p21-activated kinase 4 (PAK4) as a key regulator of lipid catabolism in the liver and adipose tissue, but its role in glucose homeostasis in skeletal muscle remains to be explored. In this study, we find that PAK4 levels are highly upregulated in the skeletal muscles of diabetic humans and mice. Skeletal muscle-specific Pak4 ablation or administering the PAK4 inhibitor in diet-induced obese mice retains insulin sensitivity, accompanied by AMPK activation and GLUT4 upregulation. We demonstrate that PAK4 promotes insulin resistance by phosphorylating AMPKα2 at Ser491, thereby inhibiting AMPK activity. We additionally show that skeletal muscle-specific expression of a phospho-mimetic mutant AMPKα2S491D impairs glucose tolerance, while the phospho-inactive mutant AMPKα2S491A improves it. In summary, our findings suggest that targeting skeletal muscle PAK4 may offer a therapeutic avenue for type 2 diabetes.

Asunto(s)

Proteínas Quinasas Activadas por AMP , Diabetes Mellitus Tipo 2 , Glucosa , Resistencia a la Insulina , Músculo Esquelético , Quinasas p21 Activadas , Animales , Quinasas p21 Activadas/metabolismo , Quinasas p21 Activadas/genética , Glucosa/metabolismo , Fosforilación , Músculo Esquelético/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Humanos , Ratones , Diabetes Mellitus Tipo 2/metabolismo , Masculino , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Obesidad/metabolismo

RESUMEN

BACKGROUND: The fruit of Phyllanthus emblica L., a traditional medicine in China and India, is used to treat diabetes mellitus. Its water extract (WEPE) has demonstrated hypoglycemic effects in diabetic rats, but its mechanisms on glucose utilization and insulin resistance in skeletal muscle remain unclear. Therefore, this study aims to investigate the effects and underlying mechanisms of WEPE on glucose utilization and insulin resistance using C2C12 myotubes. METHODS: Effects of WEPE on glucose uptake, GLUT4 translocation, and AMPK and AKT phosphorylation were investigated in C2C12 myotubes and palmitate-treated myotubes. An AMPK inhibitor and siRNA were used to explore the mechanisms of WEPE. Glucose uptake was determined using a 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2-deoxyglucose (2-NBDG) uptake assay, and protein expression and GLUT4 translocation were assessed via western blotting. RESULTS: In normal myotubes, WEPE significantly stimulated glucose uptake and GLUT4 translocation to the plasma membrane at concentrations of 125 and 250 µg/mL. This was accompanied by an increase in the phosphorylation of AMPK and its downstream targets. However, both compound C and AMPK siRNA blocked the WEPE-induced GLUT4 translocation and glucose uptake. Moreover, pretreatment with STO-609, a calcium/calmodulin-dependent protein kinase kinase ß (CaMKKß) inhibitor, inhibited WEPE-induced AMPK phosphorylation and attenuated the WEPE-stimulated glucose uptake and GLUT4 translocation. In myotubes treated with palmitate, WEPE prevented palmitate-induced insulin resistance by enhancing insulin-mediated glucose uptake and AKT phosphorylation. It also restored the insulin-mediated translocation of GLUT4 from cytoplasm to membrane. However, these effects of WEPE on glucose uptake and GLUT4 translocation were blocked by pretreatment with compound C. CONCLUSIONS: WEPE significantly stimulated basal glucose uptake though CaMKKß/AMPK pathway and markedly ameliorated palmitate-induced insulin resistance by activating the AMPK pathway in C2C12 myotubes.

Asunto(s)

Proteínas Quinasas Activadas por AMP , Glucosa , Resistencia a la Insulina , Fibras Musculares Esqueléticas , Phyllanthus emblica , Extractos Vegetales , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/metabolismo , Animales , Ratones , Glucosa/metabolismo , Extractos Vegetales/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Frutas , Transportador de Glucosa de Tipo 4/metabolismo , Línea Celular , Palmitatos/farmacología , Ácido Palmítico/farmacología

RESUMEN

OBJECTIVE: Picalm (phosphatidylinositol-binding clathrin assembly protein), a ubiquitously expressed clathrin-adapter protein, is a well-known susceptibility gene for Alzheimer's disease, but its role in white adipose tissue (WAT) function has not yet been studied. Transcriptome analysis revealed differential expression of Picalm in WAT of diabetes-prone and diabetes-resistant mice, hence we aimed to investigate the potential link between Picalm expression and glucose homeostasis, obesity-related metabolic phenotypes, and its specific role in insulin-regulated GLUT4 trafficking in adipocytes. METHODS: Picalm expression and epigenetic regulation by microRNAs (miRNAs) and DNA methylation were analyzed in WAT of diabetes-resistant (DR) and diabetes-prone (DP) female New Zealand Obese (NZO) mice and in male NZO after time-restricted feeding (TRF) and alternate-day fasting (ADF). PICALM expression in human WAT was evaluated in a cross-sectional cohort and assessed before and after weight loss induced by bariatric surgery. siRNA-mediated knockdown of Picalm in 3T3-L1-cells was performed to elucidate functional outcomes on GLUT4-translocation as well as insulin signaling and adipogenesis. RESULTS: Picalm expression in WAT was significantly lower in DR compared to DP female mice, as well as in insulin-sensitive vs. resistant NZO males, and was also reduced in NZO males following TRF and ADF. Four miRNAs (let-7c, miR-30c, miR-335, miR-344) were identified as potential mediators of diabetes susceptibility-related differences in Picalm expression, while 11 miRNAs (including miR-23a, miR-29b, and miR-101a) were implicated in TRF and ADF effects. Human PICALM expression in adipose tissue was lower in individuals without obesity vs. with obesity and associated with weight-loss outcomes post-bariatric surgery. siRNA-mediated knockdown of Picalm in mature 3T3-L1-adipocytes resulted in amplified insulin-stimulated translocation of the endogenous glucose transporter GLUT4 to the plasma membrane and increased phosphorylation of Akt and Tbc1d4. Moreover, depleting Picalm before and during 3T3-L1 differentiation significantly suppressed adipogenesis, suggesting that Picalm may have distinct roles in the biology of pre- and mature adipocytes. CONCLUSIONS: Picalm is a novel regulator of GLUT4-translocation in WAT, with its expression modulated by both genetic predisposition to diabetes and dietary interventions. These findings suggest a potential role for Picalm in improving glucose homeostasis and highlight its relevance as a therapeutic target for metabolic disorders.

Asunto(s)

Células 3T3-L1 , Transportador de Glucosa de Tipo 4 , Obesidad , Animales , Ratones , Femenino , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Masculino , Humanos , Obesidad/metabolismo , Obesidad/genética , Tejido Adiposo Blanco/metabolismo , MicroARNs/metabolismo , MicroARNs/genética , Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Ratones Obesos , Adipogénesis , Epigénesis Genética , Resistencia a la Insulina , Metilación de ADN , Transporte de Proteínas

RESUMEN

Prenatal stress (PNS), which alters the hypothalamic-pituitary-adrenal axis function in the offspring, predisposes to insulin resistance (IR) in later life and is associated with numerous disorders, including cognitive and memory impairments. At present, our main goal is to assess the effects of chronic piromelatine (Pir) administration, a melatonin analogue, on PNS-provoked IR in the periphery and the hippocampus in male and female offspring. Pregnant Sprague-Dawley rats were exposed to chronic stress (one short-term stressor on a daily basis and one long-term stressor on a nightly basis) from the first gestation week until birth. Vehicle or Pir 20 mg/kg were administered intraperitoneally for 21 days. Plasma glucose, serum insulin levels, and the homeostasis model assessment of insulin resistance (HOMA-IR) were determined as markers of peripheral IR. For the hippocampal IR assessment, insulin receptors (IRs) and glucose transporter 4 (GLUT4) were examined. Prenatally stressed offspring of both sexes indicated enhanced plasma glucose and serum insulin concentrations, increased HOMA-IR, and decreased hippocampal GLUT4 only in male rats. The PNS-induced changes were corrected by chronic treatment with Pir. The present results suggest that the melatoninergic compound Pir exerts beneficial effects on altered glucose/insulin homeostasis in PNS-exposed offspring.

Asunto(s)

Hipocampo , Resistencia a la Insulina , Insulina , Efectos Tardíos de la Exposición Prenatal , Ratas Sprague-Dawley , Animales , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Femenino , Embarazo , Masculino , Ratas , Efectos Tardíos de la Exposición Prenatal/metabolismo , Insulina/metabolismo , Insulina/sangre , Glucemia/metabolismo , Estrés Psicológico/metabolismo , Transportador de Glucosa de Tipo 4/metabolismo , Receptor de Insulina/metabolismo , Melatonina/farmacología

RESUMEN

Diabetic cardiomyopathy (DCM) is one of the serious complications of type 2 diabetes mellitus. Vasant Kusumakar Rasa (VKR) is a Herbo-metallic formulation reported in Ayurveda, an Indian system of medicine. The present work was designed to study the effect of VKR in cardiomyopathy in type 2 diabetic rats. Diabetes was induced by feeding a high-fat diet (HFD) for 2 weeks followed by streptozotocin (STZ) administration (35 mg/kg i.p.). VKR was administered orally at dose of 28 and 56 mg/kg once a day for 16 weeks. The results of the study indicated that VKR treatment significantly improved the glycemic and lipid profile, serum insulin, CK-MB, LDH, and cardiac troponin-I when compared to diabetic control animals. VKR treatment in rats significantly improved the hemodynamic parameters and cardiac tissue levels of TNF-α, IL-1ß, and IL- 6 were also reduced. Antioxidant enzymes such as GSH, SOD, and catalase were improved in all treatment groups. Heart sections stained with H & E and Masson's trichome showed decreased damage to histoarchitecture of the myocardium. Expression of PI3K, Akt, and GLUT4 in the myocardium was upregulated after 16 weeks of VKR treatment. The study data suggested the cardioprotective capability of VKR in the management of diabetic cardiomyopathy in rats.

Asunto(s)

Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Cardiomiopatías Diabéticas , Estrés Oxidativo , Animales , Cardiomiopatías Diabéticas/prevención & control , Cardiomiopatías Diabéticas/fisiopatología , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/etiología , Cardiomiopatías Diabéticas/patología , Cardiomiopatías Diabéticas/tratamiento farmacológico , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/complicaciones , Masculino , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/complicaciones , Estrés Oxidativo/efectos de los fármacos , Ratas Wistar , Miocardio/patología , Miocardio/metabolismo , Antioxidantes/farmacología , Glucemia/metabolismo , Glucemia/efectos de los fármacos , Biomarcadores/sangre , Medicina Ayurvédica , Ratas , Mediadores de Inflamación/metabolismo , Transportador de Glucosa de Tipo 4/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Citocinas/metabolismo , Transducción de Señal

RESUMEN

Mitoxantrone (MTX) is a therapeutic agent used in the treatment of solid tumors and multiple sclerosis, recognized for its cardiotoxicity, with underlying molecular mechanisms not fully disclosed. The cardiotoxicity is influenced by risk factors, including age. Our study intended to assess the molecular effect of MTX on the cardiac muscle of old male CD-1 mice. Mice aged 19 months received a total cumulative dose of 4.5 mg/kg of MTX (MTX group) or saline solution (CTRL group). Two months post treatment, blood was collected, animals sacrificed, and the heart removed. MTX caused structural cardiac changes, which were accompanied by extracellular matrix remodeling, as indicated by the increased ratio between matrix metallopeptidase 2 and metalloproteinase inhibitor 2. At the metabolic level, decreased glycerol levels were found, together with a trend towards increased content of the electron transfer flavoprotein dehydrogenase. In contrast, lower glycolysis, given by the decreased content of glucose transporter GLUT4 and phosphofructokinase, seemed to occur. The findings suggest higher reliance on fatty acids oxidation, despite no major remodeling occurring at the mitochondrial level. Furthermore, the levels of glutamine and other amino acids (although to a lesser extent) were decreased, which aligns with decreased content of the E3 ubiquitin-protein ligase Atrogin-1, suggesting a decrease in proteolysis. As far as we know, this was the first study made in old mice with a clinically relevant dose of MTX, evaluating its long-term cardiac effects. Even two months after MTX exposure, changes in metabolic fingerprint occurred, highlighting enduring cardiac effects that may require clinical vigilance.

Asunto(s)

Cardiotoxicidad , Mitoxantrona , Miocardio , Animales , Ratones , Mitoxantrona/farmacología , Masculino , Cardiotoxicidad/etiología , Cardiotoxicidad/metabolismo , Cardiotoxicidad/patología , Miocardio/metabolismo , Miocardio/patología , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Envejecimiento/metabolismo , Envejecimiento/efectos de los fármacos , Glucólisis/efectos de los fármacos , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 2 de la Matriz/genética

RESUMEN

Energy metabolism is essential for insect development, reproduction and detoxification. Insects often reallocate energy and resources to manage external stress, balancing the demands of detoxification and reproduction. Glucose transport 4 (Glut4), a glucose transporter, is involved in glucose and lipid metabolism. However, the specific molecular mechanism of Glut4 in insect reproduction, and its role in the response to insecticide-induced oxidative stress remain unclear. In this study, LmGlut4 was identified and analyzed in Locusta migratoria. Silencing of LmGlut4 significantly reduced vitellogenin (Vg) biosynthesis in the fat body and Vg absorption by oocytes, ultimately hindering ovarian development and oocyte maturation. Knockdown of LmGlut4 also inhibited the biosynthesis of key insect hormones, such as juvenile hormone (JH), 20-hydroxyecdysone (20E) and insulin. Furthermore, LmGlut4 knockdown led to reduced triglyceride (TG) and glycogen content in the fat body and ovary, as well as decreased capacity for trehalose biosynthesis in adipocytes. Additionally, dsLmGlut4-treated locusts showed heightened sensitivity to deltamethrin, leading to increased triglyceride depletion during detoxification. This study sheds light on the biological function of LmGlut4 in the ovary and provides potential target genes for exploring biological pest management strategies.

Asunto(s)

Transportador de Glucosa de Tipo 4 , Insecticidas , Locusta migratoria , Nitrilos , Ovario , Piretrinas , Interferencia de ARN , Animales , Piretrinas/farmacología , Femenino , Nitrilos/farmacología , Ovario/metabolismo , Ovario/efectos de los fármacos , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Locusta migratoria/genética , Locusta migratoria/efectos de los fármacos , Locusta migratoria/metabolismo , Insecticidas/farmacología , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Vitelogeninas/metabolismo , Vitelogeninas/genética , Metabolismo Energético/efectos de los fármacos , Cuerpo Adiposo/metabolismo , Cuerpo Adiposo/efectos de los fármacos , Hormonas Juveniles/metabolismo , Hormonas Juveniles/farmacología , Oocitos/metabolismo , Oocitos/efectos de los fármacos , Triglicéridos/metabolismo

RESUMEN

Cellular heterogeneity is a well-accepted feature of tissues, and both transcriptional and metabolic diversity have been revealed by numerous approaches, including optical imaging. However, the high magnification objective lenses needed for high-resolution imaging provides information from only small layers of tissue, which can result in poor cell statistics. There is therefore an unmet need for an imaging modality that can provide detailed molecular and cellular insight within intact tissue samples in 3D. Using GFP-tagged GLUT4 as proof of concept, we present here a novel optical mesoscopy approach that allows precise measurement of the spatial location of GLUT4 within specific anatomical structures across the myocardium in ultrathick sections (5 mm×5 mm×3 mm) of intact mouse heart. We reveal distinct GLUT4 distribution patterns across cardiac walls and highlight specific changes in GLUT4 expression levels in response to high fat diet-feeding, and we identify sex-dependent differences in expression patterns. This method is applicable to any target that can be labelled for light microscopy, and to other complex tissues when organ structure needs to be considered simultaneously with cellular detail.

Asunto(s)

Transportador de Glucosa de Tipo 4 , Imagenología Tridimensional , Miocardio , Animales , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Imagenología Tridimensional/métodos , Miocardio/metabolismo , Ratones , Masculino , Femenino , Ratones Endogámicos C57BL , Dieta Alta en Grasa

RESUMEN

Doxorubicin (DOX) is a highly effective chemotherapeutic agent whose clinical use is hindered by the onset of cardiotoxic effects, resulting in reduced ejection fraction within the first year from treatment initiation. Recently it has been demonstrated that DOX accumulates within mitochondria, leading to disruption of metabolic processes and energetic imbalance. We previously described that phosphoinositide 3-kinase γ (PI3Kγ) contributes to DOX-induced cardiotoxicity, causing autophagy inhibition and accumulation of damaged mitochondria. Here we intend to describe the maladaptive metabolic rewiring occurring in DOX-treated hearts and the contribution of PI3Kγ signalling to this process. Metabolomic analysis of DOX-treated WT hearts revealed an accumulation of TCA cycle metabolites due to a cycle slowdown, with reduced levels of pyruvate, unchanged abundance of lactate and increased Acetyl-CoA production. Moreover, the activity of glycolytic enzymes was upregulated, and fatty acid oxidation downregulated, after DOX, indicative of increased glucose oxidation. In agreement, oxygen consumption was increased in after pyruvate supplementation, with the formation of cytotoxic ROS rather than energy production. These metabolic changes were fully prevented in KD hearts. Interestingly, they failed to increase glucose oxidation in response to DOX even with autophagy inhibition, indicating that PI3Kγ likely controls the fuel preference after DOX through an autophagy-independent mechanism. In vitro experiments showed that inhibition of PI3Kγ inhibits pyruvate dehydrogenase (PDH), the key enzyme of Randle cycle regulating the switch from fatty acids to glucose usage, while decreasing DOX-induced mobilization of GLUT-4-carrying vesicles to the plasma membrane and limiting the ensuing glucose uptake. These results demonstrate that PI3Kγ promotes a maladaptive metabolic rewiring in DOX-treated hearts, through a two-pronged mechanism controlling PDH activation and GLUT-4-mediated glucose uptake.

Asunto(s)

Cardiotoxicidad , Doxorrubicina , Metabolismo Energético , Ácidos Grasos , Glucosa , Oxidación-Reducción , Animales , Doxorrubicina/toxicidad , Glucosa/metabolismo , Ácidos Grasos/metabolismo , Metabolismo Energético/efectos de los fármacos , Fosfatidilinositol 3-Quinasa Clase Ib/metabolismo , Glucólisis/efectos de los fármacos , Autofagia/efectos de los fármacos , Masculino , Transducción de Señal/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Ciclo del Ácido Cítrico/efectos de los fármacos , Ratones Endogámicos C57BL , Cardiopatías/inducido químicamente , Cardiopatías/metabolismo , Cardiopatías/patología , Cardiopatías/prevención & control , Cardiopatías/fisiopatología , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Cardíacas/patología , Mitocondrias Cardíacas/enzimología , Ratones Noqueados , Modelos Animales de Enfermedad , Especies Reactivas de Oxígeno/metabolismo , Transportador de Glucosa de Tipo 4/metabolismo , Antibióticos Antineoplásicos/toxicidad , Antibióticos Antineoplásicos/efectos adversos

RESUMEN

Insulin resistance, the hallmark of type 2 diabetes mellitus (T2DM), has emerged as a pathological feature in Alzheimer's disease (AD). Given the shared role of insulin resistance in T2DM and AD, repurposing peripheral insulin sensitizers is a promising strategy to preserve neuronal insulin sensitivity and prevent AD. 1-Deoxynojirimycin (DNJ), a bioactive iminosugar, exhibited insulin-sensitizing effects in metabolic tissues and was detected in brain tissue post-oral intake. However, its impact on brain and neuronal insulin signaling has not been described. Here, we investigated the effect of DNJ treatment on insulin signaling and AD markers in insulin-resistant human SK-N-SH neuroblastoma, a cellular model of neuronal insulin resistance. Our findings show that DNJ increased the expression of insulin signaling genes and the phosphorylation status of key molecules implicated in insulin resistance (Y1146-pIRß, S473-pAKT, S9-GSK3B) while also elevating the expression of glucose transporters Glut3 and Glut4, resulting in higher glucose uptake upon insulin stimuli. DNJ appeared to mitigate the insulin resistance-driven increase in phosphorylated tau and Aß1-42 levels by promoting insulin-induced phosphorylation of GSK3B (a major tau kinase) and enhancing mRNA expression of the insulin-degrading enzyme (IDE) pivotal for insulin and Aß clearance. Overall, our study unveils probable mechanisms underlying the potential benefits of DNJ for AD, wherein DNJ attenuates tau and amyloid pathologies by reversing neuronal insulin resistance. This provides a scientific basis for expanding the use of DNJ-containing products for neuroprotective purposes and prompts further research into compounds with similar mechanisms of action.

Asunto(s)

1-Desoxinojirimicina , Enfermedad de Alzheimer , Resistencia a la Insulina , Neuronas , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Humanos , 1-Desoxinojirimicina/farmacología , 1-Desoxinojirimicina/análogos & derivados , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Línea Celular Tumoral , Péptidos beta-Amiloides/metabolismo , Proteínas tau/metabolismo , Transportador de Glucosa de Tipo 3/metabolismo , Transportador de Glucosa de Tipo 3/genética , Insulina/metabolismo , Transducción de Señal/efectos de los fármacos , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Fosforilación/efectos de los fármacos , Biomarcadores/metabolismo

RESUMEN

Obesity is associated with a low-grade chronic inflammatory process characterized by higher circulating TNFα levels, thus contributing to insulin resistance. This study evaluated the effect of silybin, the main bioactive component of silymarin, which has anti-inflammatory properties, on TNFα levels and its impact on glucose uptake in the adipocyte cell line 3T3-L1 challenged with two different inflammatory stimuli, TNFα or lipopolysaccharide (LPS). Silybin's pre-treatment effect was evaluated in adipocytes pre-incubated with silybin (30 or 80 µM) before challenging with the inflammatory stimuli (TNFα or LPS). For the post-treatment effect, the adipocytes were first challenged with the inflammatory stimuli and then post-treated with silybin. After treatments, TNFα production, glucose uptake, and GLUT4 protein expression were determined. Both inflammatory stimuli increased TNFα secretion, diminished GLUT4 expression, and significantly decreased glucose uptake. Silybin 30 µM only reduced TNFα secretion after the LPS challenge. Silybin 80 µM as post-treatment or pre-treatment decreased TNFα levels, improving glucose uptake. However, glucose uptake enhancement induced by silybin did not depend on GLUT4 protein expression. These results show that silybin importantly reduced TNFα levels and upregulates glucose uptake, independently of GLUT4 protein expression.

Asunto(s)

Células 3T3-L1 , Adipocitos , Glucosa , Lipopolisacáridos , Silibina , Factor de Necrosis Tumoral alfa , Animales , Silibina/farmacología , Ratones , Factor de Necrosis Tumoral alfa/metabolismo , Glucosa/metabolismo , Adipocitos/metabolismo , Adipocitos/efectos de los fármacos , Lipopolisacáridos/farmacología , Transportador de Glucosa de Tipo 4/metabolismo , Silimarina/farmacología