RESUMEN

High-intensity interval training (HIIT) has been found to be more effective in relieving heart failure (HF) symptoms, than moderate-intensity continuous aerobic training (MICT). Additionally, higher meteorin-like protein (Metrnl) levels are seen after HIIT versus MICT. We investigated whether Metrnl contributed to post-HF cardiac functional improvements, and the signaling pathways involved. 50 HF patients underwent MICT, and another 50, HIIT, which was followed by cardiac function and serum Metrnl measurements. Metrnl was also measured in both blood and skeletal muscle samples of mice with transverse aortic constriction-induced HF after undergoing HIIT. Afterward, shRNA-containing adenovectors were injected into mice, yielding five groups: control, HF, HF + HIIT + scrambled shRNA, HF + HIIT + shMetrnl, and HF + Metrnl (HF + exogenous Metrnl). Mass spectrometry identified specific signaling pathways associated with increased Metrnl, which was confirmed with biochemical analyses. Glucose metabolism and mitochondrial functioning were evaluated in cardiomyocytes from the five groups. Both HF patients and mice had higher circulating Metrnl levels post-HIIT. Metrnl activated AMPK in cardiomyocytes, subsequently increasing histone deacetylase 4 (HDAC4) phosphorylation, leading to its cytosolic sequestration and inactivation via binding with chaperone protein 14-3-3. HDAC4 inactivation removed its repression on glucose transporter type 4, which, along with increased mitochondrial complex I-V expression, yielded improved aerobic glucose respiration and alleviation of mitochondrial dysfunction. All these changes ultimately result in improved post-HF cardiac functioning. HIIT increased skeletal muscle Metrnl production, which then operated on HF hearts to alleviate their functional defects, via increasing aerobic glucose metabolism through AMPK-HDAC4 signaling.

RESUMEN

The glucose transporter GLUT4 is integral for optimal skeletal muscle performance during exercise, as well as for metabolic health. Physiological regulation of GLUT4 translocation during exercise and increased GLUT4 expression following exercise involves multiple, redundant signalling pathways. These include effects of reactive oxygen species (ROS). ROS contribute to GLUT4 translocation that increases skeletal muscle glucose uptake during exercise and stimulate signalling pathways that increase GLUT4 expression. Conversely, ROS can also inhibit GLUT4 translocation and expression in metabolic disease states. The opposing roles of ROS in GLUT4 regulation are ultimately linked to the metabolic state of skeletal muscle and the intricate mechanisms involved give insights into pathways critical for exercise performance and implicated in metabolic health and disease.

RESUMEN

AIMS/HYPOTHESIS: Appropriate management of blood glucose levels and the prevention of complications are important in the treatment of diabetes. We have previously reported on a compound named HPH-15 that is not only antifibrotic but also AMP-activated protein kinase (AMPK)-activating. In this study, we evaluated whether HPH-15 is useful as a therapeutic medication for diabetes. METHODS: We examined the effects of HPH-15 on AMPK activation, glucose uptake, fat accumulation and lactic acid production in L6-GLUT4, HepG2 and 3T3-L1 cells, as a model of muscle, liver and fat tissue, respectively. Additionally, we investigated the glucose-lowering, fat-accumulation-suppressing, antifibrotic and AMPK-activating effect of HPH-15 in mice fed a high-fat diet (HFD). RESULTS: HPH-15 at a concentration of 10 µmol/l increased AMPK activation, glucose uptake and membrane translocation of GLUT4 in each cell model to the same extent as metformin at 2 mmol/l. The production of lactic acid (which causes lactic acidosis) in HPH-15-treated cells was equal to or less than that observed in metformin-treated cells. In HFD-fed mice, HPH-15 lowered blood glucose from 11.1±0.3 mmol/l to 8.2±0.4 mmol/l (10 mg/kg) and 7.9±0.4 mmol/l (100 mg/kg) and improved insulin resistance. The HPH-15 (10 mg/kg) group showed the same level of AMPK activation as the metformin (300 mg/kg) group in all organs. The HPH-15-treated HFD-fed mice also showed suppression of fat accumulation and fibrosis in the liver and fat tissue; these effects were more significant than those obtained with metformin. Mice treated with high doses of HPH-15 also exhibited a 44% reduction in subcutaneous fat. CONCLUSIONS/INTERPRETATION: HPH-15 activated AMPK at lower concentrations than metformin in vitro and in vivo and improved blood glucose levels and insulin resistance in vivo. In addition, HPH-15 was more effective than metformin at ameliorating fatty liver and adipocyte hypertrophy in HFD-fed mice. HPH-15 could be effective in preventing fatty liver, a common complication in diabetic individuals. Additionally, in contrast to metformin, high doses of HPH-15 reduced subcutaneous fat in HFD-fed mice. Presumably, HPH-15 has a stronger inhibitory effect on fat accumulation and fibrosis than metformin, accounting for the reduction of subcutaneous fat. Therefore, HPH-15 is potentially a glucose-lowering medication that can lower blood glucose, inhibit fat accumulation and ameliorate liver fibrosis.

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

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

BACKGROUND/AIM: Over-expression of glucose transporters (GLUTs), membrane proteins that facilitate glucose transport, has been implicated in cutaneous melanomas. Our prior studies have demonstrated increased expression of GLUT1 and GLUT3 in melanomas and their association with poorer prognosis. This study aimed to investigate the expression of GLUT isoforms 4 and 8 in melanocytic lesions, examine the co-expression status of multiple GLUTs, and evaluate their prognostic significance. MATERIALS AND METHODS: We analyzed 171 melanocytic lesions (97 primary melanomas, 19 metastatic melanomas, and 55 nevi) using a tissue microarray and immunohistochemistry using antibodies against GLUT4 and GLUT8. Membranous expression of GLUTs was scored using a semi-quantitative method. A combined GLUT total score was generated by summing scores from GLUT1, GLUT3, GLUT4, and GLUT8 (including data from previous studies). RESULTS: A significant up-regulation of GLUT4 and GLUT8 expression was found in melanomas compared to nevi (p<0.0001 for both). Concurrent over-expression of multiple GLUTs was more prevalent in melanomas compared to nevi (p<0.0001), and it was also more frequent in metastatic melanomas compared to primary melanomas (p=0.047). Importantly, high total GLUT expression scores were significantly correlated with negative prognostic factors, such as ulceration and mitoses (p=0.03 and p=0.008 respectively). Additionally, Kaplan-Meier survival curves revealed that patients with elevated GLUT total score in their melanomas had a lower disease-specific survival (p=0.006). Furthermore, analysis of multiple GLUTs improved diagnostic sensitivity. CONCLUSION: Similar to GLUT1 and GLUT3, melanoma exhibits up-regulation of GLUT 4 and GLUT8 compared to nevi. Evaluation of multiple GLUT isoforms improves diagnostic and prognostic values.

Asunto(s)

Proteínas Facilitadoras del Transporte de la Glucosa , Melanoma , Neoplasias Cutáneas , Humanos , Melanoma/metabolismo , Melanoma/patología , Melanoma/mortalidad , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/mortalidad , Pronóstico , Femenino , Masculino , Persona de Mediana Edad , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Anciano , Adulto , Biomarcadores de Tumor/metabolismo , Anciano de 80 o más Años , Melanoma Cutáneo Maligno , Inmunohistoquímica , Análisis de Matrices Tisulares , Adulto Joven

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

CONTEXT: Housing temperature is a critical regulator of mouse metabolism and thermoneutral housing can improve model translation to humans. However, the impact of housing temperature on the ability of wheel running exercise training to rescue the detrimental effect of diet-induced obese mice is currently not fully understood. OBJECTIVE: To investigate how housing temperature affects muscle metabolism in obese mice with regard to calcium handling and exercise training (ET) adaptations in skeletal muscle, and benefits of ET on adiposity and glucometabolic parameters. METHODS: Lean or obese female mice were housed at standard ambient temperature (22 °C) or thermoneutrality (30 °C) with/without access to running wheels. The metabolic phenotype was investigated using glucose tolerance tests, indirect calorimetry, and body composition. Molecular muscle adaptations were measured using immunoblotting, qPCR, and spectrophotometric/fluorescent assays. RESULTS: Obese female mice housed at 22 °C showed lower adiposity, lower circulating insulin levels, improved glucose tolerance, and elevated basal metabolic rate compared to 30 °C housing. Mice exposed to voluntary wheel running exhibited a larger fat loss and higher metabolic rate at 22 °C housing compared to thermoneutrality. In obese female mice, glucose tolerance improved after ET independent of housing temperature. Independent of diet and training, 22 °C housing increased skeletal muscle sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) activity. Additionally, housing at 22 °C elevated the induction of training-responsive muscle proteins in obese mice. CONCLUSION: Our findings highlight that housing temperature significantly influences adiposity, insulin sensitivity, muscle physiology, and exercise adaptations in diet-induced obese female mice.

Asunto(s)

Adaptación Fisiológica , Calcio , Músculo Esquelético , Obesidad , Condicionamiento Físico Animal , Animales , Femenino , Condicionamiento Físico Animal/fisiología , Músculo Esquelético/metabolismo , Ratones , Obesidad/metabolismo , Obesidad/fisiopatología , Calcio/metabolismo , Adaptación Fisiológica/fisiología , Ratones Endogámicos C57BL , Respuesta al Choque por Frío/fisiología , Ratones Obesos , Frío , Adiposidad/fisiología

RESUMEN

Deuterium-depleted water (DDW) is used in the treatment of many diseases, including cancer and diabetes. To detect the effect of DDW on gene expression and activation of the insulin-responsive transporter GLUT4 as a mechanism for improving the pathology of diabetes, we investigated the GLUT4 expression and glucose uptake at various concentrations of DDW using the myoblast cell line C2C12 differentiated into myotubes. GLUT4 gene expression significantly increased under deuterium depletion, reaching a maximum value at a deuterium concentration of approximately 50 ppm, which was approximately nine times that of natural water with a deuterium concentration of 150 ppm. GLUT4 protein also showed an increase at similar DDW concentrations. The membrane translocation of GLUT4 by insulin stimulation reached a maximum value at a deuterium concentration of approximately 50-75 ppm, which was approximately 2.2 times that in natural water. Accordingly, glucose uptake also increased by up to 2.2 times at a deuterium concentration of approximately 50 ppm. Drug-induced insulin resistance was attenuated, and the glucose uptake was four times higher in the presence of 10 ng/mL TNF-α and three times higher in the presence of 1 µg/mL resistin at a deuterium concentration of approximately 50 ppm relative to natural water. These results suggest that DDW promotes GLUT4 expression and insulin-stimulated activation in muscle cells and reduces insulin resistance, making it an effective treatment for diabetes.

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

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

Maternal hypoxia is strongly linked to insulin resistance (IR) in adult offspring, and altered insulin signaling for muscle glucose uptake is thought to play a central role. However, whether the SIRT3/GSK-3ß/GLUT4 axis is involved in maternal hypoxia-induced skeletal muscle IR in old male rat offspring has not been investigated. Maternal hypoxia was established from Days 5 to 21 of pregnancy by continuous infusion of nitrogen and air. The biochemical parameters and levels of key insulin signaling molecules of old male rat offspring were determined through a series of experiments. Compared to the control (Ctrl) old male rat offspring group, the hypoxic (HY) group exhibited elevated fasting blood glucose (FBG) (∼30%), fasting blood insulin (FBI) (∼35%), total triglycerides (TGs), and low-density lipoprotein cholesterol (LDL-C), as well as results showing impairment in the glucose tolerance test (GTT) and insulin tolerance test (ITT). In addition, hematoxylin-eosin (HE) staining and transmission electron microscopy (TEM) revealed impaired cellular structures and mitochondria in the longitudinal sections of skeletal muscle from HY group mice, which might be associated with decreased SIRT3 expression. Furthermore, the expression of insulin signaling molecules, such as GSK-3ß and GLUT4, was also altered. In conclusion, the present results indicate that the SIRT3/GSK-3ß/GLUT4 axis might be involved in maternal hypoxia-induced skeletal muscle IR in old male rat offspring.

Asunto(s)

Transportador de Glucosa de Tipo 4 , Glucógeno Sintasa Quinasa 3 beta , Hipoxia , Resistencia a la Insulina , Músculo Esquelético , Sirtuina 3 , Animales , Masculino , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Resistencia a la Insulina/fisiología , Músculo Esquelético/metabolismo , Femenino , Transportador de Glucosa de Tipo 4/metabolismo , Embarazo , Sirtuina 3/metabolismo , Ratas , Hipoxia/metabolismo , Transducción de Señal , Efectos Tardíos de la Exposición Prenatal/metabolismo , Ratas Sprague-Dawley , Insulina/sangre , Insulina/metabolismo , Glucemia/metabolismo , Sirtuinas

RESUMEN

BACKGROUND: Human beings consume different chemical forms of iodine in their diet. These are transported by different mechanisms in the cell. The forms of iodine can be part of thyroid hormones, bind to lipids, be an antioxidant, or be an oxidant, depending on their chemical form. The excessive consumption of iodine has been associated with pancreatic damage and diabetes mellitus type 2, but the association between disease and the chemical form consumed in the diet is unknown. This research analyzes the effect of excessive iodine consumption as Lugol (molecular iodine/potassium iodide solution) and iodate on parameters of pancreatic function, thyroid and lipid profiles, antioxidant and oxidant status, the expression of IR/Akt/P-Akt/GLUT4, and transcription factors PPAR-γ and CEBP-ß. METHODS: Three groups of Wistar rats were treated with 300 µg/L of iodine in drinking water: (1) control, (2) KIO3, and (3) Lugol. RESULTS: Lugol and KIO3 consumption increased total iodine levels. Only KIO3 increased TSH levels. Both induced high serum glucose levels and increased oxidative stress and pancreatic alpha-amylase activity. Insulin levels and antioxidant status decreased significantly. PPAR-γ and C/EBP-ß mRNA expression increased. CONCLUSION: The pancreatic damage, hypertriglyceridemia, and oxidative stress were independent of the chemical form of iodine consumed. These effects depended on PPAR-γ, C/EBP-ß, GLUT-4, and IR.

RESUMEN

Diabetes mellitus is a spreading global pandemic. Type 2 diabetes mellitus (T2DM) is the predominant form of diabetes, in which a reduction in blood glucose uptake is caused by impaired glucose transporter 4 (GLUT4) translocation to the plasma membrane in adipose and muscle cells. Antihyperglycemic drugs play a pivotal role in ameliorating diabetes symptoms but often are associated with side effects. Hence, novel antidiabetic compounds and nutraceutical candidates are urgently needed. Phytogenic therapy can support the prevention and amelioration of impaired glucose homeostasis. Using total internal reflection fluorescence microscopy (TIRFM), 772 plant extracts of an open-access plant extract library were screened for their GLUT4 translocation activation potential, resulting in 9% positive hits. Based on commercial interest and TIRFM assay-based GLUT4 translocation activation, some of these extracts were selected, and their blood glucose-reducing effects in ovo were investigated using a modified hen's egg test (Gluc-HET). To identify the active plant part, some of the available candidate plants were prepared in-house from blossoms, leaves, stems, or roots and tested. Acacia catechu (catechu), Pulmonaria officinalis (lungwort), Mentha spicata (spearmint), and Saponaria officinalis (common soapwort) revealed their potentials as antidiabetic nutraceuticals, with common soapwort containing GLUT4 translocation-activating saponarin.

Asunto(s)

Transportador de Glucosa de Tipo 4 , Hipoglucemiantes , Insulina , Microscopía Fluorescente , Extractos Vegetales , Extractos Vegetales/farmacología , Transportador de Glucosa de Tipo 4/metabolismo , Hipoglucemiantes/farmacología , Animales , Insulina/metabolismo , Ratones , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Humanos , Transporte de Proteínas/efectos de los fármacos

RESUMEN

Background: Diabetic nephropathy represents a significant microvascular complication of diabetes, characterized by extracellular matrix accumulation, loss of cell-cell junctions, microalbuminuria, and diminished creatinine clearance. Despite its prevalence, therapeutic options dedicated to this condition are currently lacking. Natural products like bioflavonoids have garnered attention for their potential therapeutic benefits. The present study aimed to evaluate the efficacy of a bioflavonoid combination, including ginger extract, soy extract, and hesperetin, in a diabetic rat model. Methods: Diabetes was initiated in the rat pups via intraperitoneal injection of streptozotocin on the fifth postnatal day. After six weeks, rats exhibiting blood sugar levels exceeding 160 mg/dL were allocated into diabetic control and treatment groups, with eight animals each. A subset of rats received citrate buffer as a control. The treatment group received the bioflavonoid combination orally for twenty-four weeks. Various parameters, including glycemic levels, urinary parameters, antioxidant status, mRNA expression via Western blot, gel zymography, and immunohistochemistry, were assessed at the study's conclusion. Results: The bioflavonoid combination demonstrated significant reductions in hyperglycemia and various urinary parameters compared to controls. Notably, it modulated MMP-9/TIMP-1 expression, upregulated GLUT-4, and downregulated TGF-ß. Additionally, the combination enhanced total antioxidant capacity, indicating potential antioxidative benefits. Conclusions: This study highlights the therapeutic potential of a bioflavonoid combination (ginger extract, soy extract, and hesperetin) in improving renal function in diabetic nephropathy. By modulating key factors such as MMP-9/TIMP-1, TGF-ß, and GLUT-4, this combination presents a promising avenue for further exploration in managing diabetic nephropathy. These findings underscore the importance of natural products as potential therapeutic agents in addressing diabetic complications.

RESUMEN

From the fruits of Cordia dichotoma, 11 new phenolic compounds, dichotomins A-K, were isolated, together with 19 known compounds. Through the analysis of detailed NMR data and HRESIMS data, the planar structures of all compounds were confirmed. Using NMR calculations, the absolute configuration of dichotomins A-K was elucidated by comparing their observed and computed electronic circular dichroism (ECD) spectra. Dichotomin H (8) and dichotomin I (9) were determined as two pairs of enantiomers. The enantiomers of compounds 8 and 9 were separated using chiral-phase high-performance liquid chromatography (HPLC), and the stereostructure of each enantiomer was determined by similarly calculating the ECD. Compounds 3, 5, 7, 17, 18, 23-25, and 27-30 increased glucose uptake by 1.04- to 2.85-folds at concentrations of 30 µg/mL. Further studies revealed that compounds 3 and 5 had a moderate effect on glucose transporter 4 (GLUT4) translocation activity in L6 cells. At 30 µg/mL, compound 3 significantly enhanced AMPK phosphorylation and GLUT4 expression. As a whole, compound 3 has the potential to be a drug candidate for the treatment of type 2 diabetes mellitus (T2DM).

Asunto(s)

Frutas , Transportador de Glucosa de Tipo 4 , Glucosa , Fenoles , Extractos Vegetales , Transportador de Glucosa de Tipo 4/metabolismo , Transportador de Glucosa de Tipo 4/genética , Frutas/química , Glucosa/metabolismo , Fenoles/química , Fenoles/farmacología , Fenoles/metabolismo , Animales , Ratas , Extractos Vegetales/química , Extractos Vegetales/farmacología , Extractos Vegetales/metabolismo , Transporte Biológico/efectos de los fármacos , Estructura Molecular , Línea Celular , Transporte de Proteínas , Humanos , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/química

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

The cell-free aqueous extract from the coelomic fluid of Holothuria tubulosa was prepared and examined for its glucose-lowering effect on HepG2 cells in vitro. In particular, employing a combination of cytochemical, flow cytometric, PCR, and protein blot techniques, we evaluated its role on glucose internalization and storage and on the upregulation and surface translocation of the two glucose transporters GLUT-2 and -4. The changes in expression, synthesis, and/or activation of the GLUT2-related transcription factor hepatocyte nuclear factor-1 alpha (HNF1α) and the GLUT-4-translocation regulatory factors insulin receptor substrate-1 (IRS-1) and AKT were also studied. Our results showed the improved glucose response by HepG2 cells, leading to an evident increase in glucose consumption/uptake and glycogen storage upon exposure. Moreover, the extract induced molecular reprogramming involving the upregulation of (i) IRS1 gene expression, (ii) the transcription and translation levels of HNF1α, AKT, and GLUT-4, (iii) the phosphorylation level of AKT, (iv) the synthesis of GLUT-2 protein, and (v) the translocation of GLUT-2 and -4 transporters onto the plasma membrane. Cumulatively, our results suggest that the coelomic fluid extract from H. tubulosa can be taken into consideration for the development of novel treatment agents against diabetes mellitus.