Time‐dependent regulation of muscle caveolin activation and insulin signalling in response to high‐fat diet

Gómez-Ruiz, Ana; Miguel, Carlos de; Campión, Javier; Martínéz, J. Alfredo; Milagro, Fermı́n I.

doi:10.1016/j.febslet.2009.09.016

Cited by 13 publications

(12 citation statements)

References 31 publications

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“…In the current study, we demonstrated that cardiomyocyte Cav-3 expression increased 6–12 h after HG exposure but reduced to basal levels within 24 h and progressively further reduced to lower than basal levels after 36–48 h of HG exposure. The initial increase in Cav-3 expression after HG exposure observed in our study is an acute response to the calorie surplus similar to that reported by other researchers (40). The significant reduction of Cav-3 expression in cardiomyocytes after prolonged HG exposure is consistent with our results from the intact rats, which showed that Cav-3 expression was decreased in isolated cardiomyocytes from rats of 8- and 5-week duration of diabetes.…”

Section: Discussionsupporting

confidence: 92%

Hyperglycemia-Induced Protein Kinase C β2 Activation Induces Diastolic Cardiac Dysfunction in Diabetic Rats by Impairing Caveolin-3 Expression and Akt/eNOS Signaling

et al. 2013

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Protein kinase C (PKC)β2 is preferably overexpressed in the diabetic myocardium, which induces cardiomyocyte hypertrophy and contributes to diabetic cardiomyopathy, but the underlying mechanisms are incompletely understood. Caveolae are critical in signal transduction of PKC isoforms in cardiomyocytes. Caveolin (Cav)-3, the cardiomyocyte-specific caveolar structural protein isoform, is decreased in the diabetic heart. The current study determined whether PKCβ2 activation affects caveolae and Cav-3 expression. Immunoprecipitation and immunofluorescence analysis revealed that high glucose (HG) increased the association and colocalization of PKCβ2 and Cav-3 in isolated cardiomyocytes. Disruption of caveolae by methyl-β-cyclodextrin or Cav-3 small interfering (si)RNA transfection prevented HG-induced PKCβ2 phosphorylation. Inhibition of PKCβ2 activation by compound CGP53353 or knockdown of PKCβ2 expression via siRNA attenuated the reductions of Cav-3 expression and Akt/endothelial nitric oxide synthase (eNOS) phosphorylation in cardiomyocytes exposed to HG. LY333531 treatment (for a duration of 4 weeks) prevented excessive PKCβ2 activation and attenuated cardiac diastolic dysfunction in rats with streptozotocin-induced diabetes. LY333531 suppressed the decreased expression of myocardial NO, Cav-3, phosphorylated (p)-Akt, and p-eNOS and also mitigated the augmentation of O2−, nitrotyrosine, Cav-1, and iNOS expression. In conclusion, hyperglycemia-induced PKCβ2 activation requires caveolae and is associated with reduced Cav-3 expression in the diabetic heart. Prevention of excessive PKCβ2 activation attenuated cardiac diastolic dysfunction by restoring Cav-3 expression and subsequently rescuing Akt/eNOS/NO signaling.

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Section: Discussionsupporting

confidence: 92%

Hyperglycemia-Induced Protein Kinase C β2 Activation Induces Diastolic Cardiac Dysfunction in Diabetic Rats by Impairing Caveolin-3 Expression and Akt/eNOS Signaling

et al. 2013

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“…As previously reported using the same dietary model [17], body and adipose depot weights of the animals fed on the HF-diet were significantly higher than those fed on the control diet. However, no differences were found between the fasted (F) and non-fasted (NF) groups of animals (Table 1).…”

Section: Resultssupporting

confidence: 81%

“…In a late phase, after a prolonged time feeding on a high-fat diet, insulin resistance becomes apparent, accompanied by an impairment of Cav-3 and Cav-1 in skeletal muscle [17], whereas in adipocytes, Cav-1 and Cav-2 expression are increased, together with an inhibition of insulin signalling intermediaries [18]. …”

Section: Introductionmentioning

confidence: 99%

High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling

et al. 2011

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BackgroundThe effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP) and subcutaneous (SC) adipose tissue, comparing fasted (F) to not fasted (NF) rats that had been fed a control or high-fat (HF) diet for 72 days.MethodsSerum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4) were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test.ResultsHigh-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF) induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF) also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF) in animals fed either diet. In RP adipocytes of control animals, food intake (NF) decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF) did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF) decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet.ConclusionsAnimals fed a control-diet show a normal response to food intake (NF), with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase of caveolin-3 in muscle. Animals fed a high-fat diet develop metabolic changes that result in insulin signalling impairment. In these animals, caveolin expression in muscle and adipocytes seems to be regulated independently of insulin signalling.

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“…Our study showed that when the cardiomyocytes were exposed to high glucose for a long time (48 h), expression of Cav-3 decreased significantly. However, some studies showed that when the myocardial cells were exposed to high glucose for a short duration (6-12h), expression of Cav-3 in myocardial cells increased [28]. It is believed that the myocardial cells regulate the expression of Cav-3 as the acute stress reaction for self-protection when being exposed to high glucose.…”

Section: Discussionmentioning

confidence: 99%

Propofol Through Upregulating Caveolin-3 Attenuates Post-Hypoxic Mitochondrial Damage and Cell Death in H9C2 Cardiomyocytes During Hyperglycemia

Deng

Wang

Zhang

et al. 2017

Cell Physiol Biochem

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Background/Aims: Hearts from diabetic subjects are susceptible to myocardial ischemia reperfusion (I/R) injury. Propofol has been shown to protect against myocardial I/R injury due to its antioxidant properties while the underlying mechanism remained incompletely understood. Thus, this study aimed to determine whether or not propofol could attenuate myocardial I/R injury by attenuating mitochondrial dysfunction/damage through upregulating Caveolin (Cav)-3 under hyperglycemia. Methods: Cultured rat cardiomyocyte H9C2 cells were subjected to hypoxia/reoxygenation (H/R) in the absence or presence of propofol under high glucose (HG), and cell viability, lactate dehydrogenase (LDH) and mitochondrial viability as well as creatine kinase-MB (CK-MB), cardiac troponin I (cTnI) and intracellular adenosine triphosphate (ATP) content were measured with colorimetric Enzyme-Linked Immunosorbent Assays. Intracellular levels of oxidative stress was assessed using 2,7-dichlorodihydrofluorescein diacetate (DCF-DA) fluorescent staining and mitochondrial-dependent apoptosis was assessed by detecting mitochondrial membrane potential and the activation of apoptotic caspases 3 and 9. Results: Exposure of cells to HG without or with H/R both significantly increased cell injury, cell apoptosis and enhanced oxidative stress that were associated with mitochondrial dysfunction and decreased Cav-3 protein expression. All these changes were further exacerbated following H/R under HG. Administration of propofol at concentrations from 12.5 to 50 µM but not 100 µM significantly attenuated H/R injury that was associated with increased Cav-3 expression and activation of the prosurvival proteins Akt and STAT3 with the optimal protective effects seen at 50 µM of propofol (P25). The beneficial effects of propofol(P25) were abrogated by Cav-3 disruption with β-methyl-cyclodextrin. Conclusion: Propofol counteracts cardiomyocyte H/R injury by attenuating mitochondrial damage and improving mitochondrial biogenesis through upregulating Cav-3 during hyperglycemia.

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Time‐dependent regulation of muscle caveolin activation and insulin signalling in response to high‐fat diet

Cited by 13 publications

References 31 publications

Hyperglycemia-Induced Protein Kinase C β2 Activation Induces Diastolic Cardiac Dysfunction in Diabetic Rats by Impairing Caveolin-3 Expression and Akt/eNOS Signaling

Hyperglycemia-Induced Protein Kinase C β2 Activation Induces Diastolic Cardiac Dysfunction in Diabetic Rats by Impairing Caveolin-3 Expression and Akt/eNOS Signaling

High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling

Propofol Through Upregulating Caveolin-3 Attenuates Post-Hypoxic Mitochondrial Damage and Cell Death in H9C2 Cardiomyocytes During Hyperglycemia

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