296 research outputs found

    Multiple cell signalling pathways of human proinsulin c-peptide in vasculopathy protection

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    A major hallmark of diabetes is a constant high blood glucose level (hyperglycaemia), resulting in endothelial dysfunction. Transient or prolonged hyperglycemia can cause diabetic vasculopathy, a secondary systemic damage. C-Peptide is a product of cleavage of proinsulin by a serine protease that occurs within the pancreatic -cells, being secreted in similar amounts as insulin. The biological activity of human C-peptide is instrumental in the prevention of diabetic neuropathy, nephropathy and other vascular complications. The main feature of type 1 diabetes mellitus is the lack of insulin and of C-peptide, but the progressive -cell loss is also observed in later stage of type 2 diabetes mellitus. C-peptide has multifaceted effects in animals and diabetic patients due to the activation of multiple cell signalling pathways, highlighting p38 mitogen-activated protein kinase and extracellular signalregulated kinase ½, Akt, as well as endothelial nitric oxide production. Recent works highlight the role of C-peptide in the prevention and amelioration of diabetes and also in organ-specific complications. Benefits of C-peptide in microangiopathy and vasculopathy have been shown through conservation of vascular function, and also in the prevention of endothelial cell death, microvascular permeability, neointima formation, and in vascular inflammation. Improvement of microvascular blood flow by replacing a physiological amount of C-peptide, in several tissues of diabetic animals and humans, mainly in nerve tissue, myocardium, skeletal muscle, and kidney has been described. A review of the multiple cell signalling pathways of human proinsulin C-peptide in vasculopathy protection is proposed, where the approaches to move beyond the state of the art in the development of innovative and effective therapeutic options of diabetic neuropathy and nephropathy are discussed.The authors acknowledge the financial support received from Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project references M-ERA-NET/0004/2015-PAIRED and UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020. The authors acknowledge the support of the research project: Nutraceutica come supporto nutrizionale nel paziente oncologico, CUP: B83D18000140007.info:eu-repo/semantics/publishedVersio

    Ocular cell lines and genotoxicity assessment

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    Genotoxicity screening tests aim to evaluate if and to what extent a compound in contact with the human body (e.g., a drug molecule, a compound from the environment) interacts with DNA. The comet assay is a sensitive method used to predict the risk of DNA damage in individual cells, as it quantifies the tape breaks, being the alkaline version (pH > 13) the most commonly used in the laboratory. Epithelial cells serve as biomatrices in genotoxicity assessments. As ca. 80% of solid cancers are of epithelial origin, the quantification of the DNA damage upon exposure of epithelial cells to a drug or drug formulation becomes relevant. Comet assays run in epithelial cells also have clinical applications in human biomonitoring, which assesses whether and to what extent is the human body exposed to environmental genotoxic compounds and how such exposure changes over time. Ocular mucosa is particularly exposed to environmental assaults. This review summarizes the published data on the genotoxicity assessment in estimating DNA damage in epithelial cells with a special focus on ocular cell lines. General comet assay procedures for ex vivo and in vivo epithelium samples are also described.The authors acknowledge the financial support received from the Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) for the projects M-ERA-NET/0004/2015-PAIRED and UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020. The FCT Grant to CMG (SFRH/BD/145855/2019) and project PEst-OE/UID/AGR/04033/2019 (CITAB strategic fund) are also acknowledged.info:eu-repo/semantics/publishedVersio

    Statin short-term inhibition of insulin sensitivity and secretion during acute phase of ST-elevation myocardial infarction

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    Hyperglycemia during myocardial infarction (MI) has a strong and direct association with mortality. In stable patients and experimental models, statins favor the elevation of glycaemia. The present study investigated whether short-course treatment with statins during MI can influence glucose homeostasis and thus the clinical outcome. In this prospective study, euglycemic hyperinsulinemic clamp (EHC) was performed at second (D2) and sixth (D6) day after MI in patients randomized to simvastatin (S)10 or 80 mg/day during hospitalization (n = 27). In addition, patients (n = 550) were treated without (WS) or with simvastatin (S) at 20, 40 or 80 mg/day had HOMA2S on admission (D1) and fifth (D5) day after MI. According to EHC, insulin sensitivity increased by 20 +/- 60% in S10 and decreased by -6 +/- 28% in S80 (p = 0.025). Consistently, the changes in HOMA2S between D1 and D5 were 40 +/- 145% (WS), 22 +/- 117% (S20), 16 +/- 61% (S40) and -2% +/- 88% (S80) (p = 0.001). In conclusion, statin during the acute phase of MI reduces insulin sensitivity in a dose-dependent manner.9CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂŤFICO E TECNOLĂ“GICO - CNPQ301465/2017-

    The role of SGLT2i in attenuating residual cardiovascular risk through blood pressure-lowering: mechanistic insights and perspectives

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    Sodium glucose cotransporter 2 inhibitors (SGLT2) have been increasingly pursued as a promising target for addressing residual cardiovascular risk. Prior trials demonstrated that SGLT2i not only promotes glucose-lowering, but also improves endothelial dysfunction, adiposity, fluid overload, and insulin sensitivity thus contributing to hemodynamic changes implicated in its cardiorenal benefits. The mechanisms in the effect of SGLT2i on blood pressure and their potential role in preventing cardiovascular events are hereby revised

    Omega-3 intake is associated with attenuated inflammatory response and cardiac remodeling after myocardial infarction

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    Myocardial infarction (MI) elicits an intense acute inflammatory response that is essential for cardiac repair. However, an excessive inflammatory response also favors myocardial apoptosis, cardiac remodeling, and cardiovascular mortality. Omega-3 polyunsaturated fatty acids (-3) bear anti-inflammatory effects, which may mitigate the inflammatory response during MI. This study investigated whether -3 intake is associated with attenuation of the MI-related inflammatory response and cardiac remodeling. ST-elevation MI (STEMI) patients (n=421) underwent clinical, biochemical, nutritional, 3D echocardiogram, Cardiac Magnetic Resonance imaging (CMRi) at 30 days and 3D echocardiogram imaging at six months after the MI. Blood tests were performed at day one (D1) and day five (D5) of hospitalization. Changes in inflammatory markers (D5-D1) were calculated. A validated food frequency questionnaire estimated the nutritional consumption and -3 intake in the last 3months before admission. The intake of -3 below the median (<1.7g/day) was associated with a short-term increase in hs-C-reactive protein [OR:1.96(1.24-3.10); p=0.004], Interleukin-2 [OR:2.46(1.20-5.04); p=0.014], brain-type natriuretic peptide [OR:2.66(1.30-5.44); p=0.007], left-ventricle end-diastolic volume [OR:5.12(1.11-23.52)]; p=0.036] and decreases in left-ventricle ejection fraction [OR:2.86(1.47-6.88); p=0.017] after adjustment for covariates. No differences were observed in the extension of infarcted mass obtained by CMRi. These findings suggest that a reduced daily intake of -3 may intensify outcome-determining mechanisms after STEMI, such as acute inflammatory response and late left ventricular remodeling.18CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂŤFICO E TECNOLĂ“GICO - CNPQ308550/2010-

    Diabetic retinopathy and ocular melanoma: how far we are?

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    Diabetic retinopathy causes vascular damage to retinal neurons, presenting characteristics of chronic inflammation. The development of new therapies capable of combating vision loss involves knowledge of inflammatory retinal changes. Studies in animal models and patients with diabetes have shown a high expression of the inflammatory molecules that are involved in the progression of diabetic retinopathy. Uveal melanoma is an eye tumour that remains highly deadly, because despite the correct treatment, it still causes metastasis in about 50% of patients. This type of tumour has the ability to produce and store melanin, which may result in resistance to therapy. Over time there has been development of new therapies for this disease, such as radiotherapy and surgical resection. In this review, we discuss diabetic retinopathy and ocular melanoma, their relationship with angiogenesis and the current anti-angiogenic therapies for their treatment.The authors acknowledge the financial support received from the Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project references M-ERANET/0004/2015-PAIRED, UIDB/04469/2020 (strategic fund) and UID/AGR/04033/2019 (CITAB), co-financed by FEDER, under the Partnership Agreement PT2020. The authors also acknowledge the support of the research project: Nutraceutica come supporto nutrizionale nel paziente oncologico, CUP: B83D18000140007.info:eu-repo/semantics/publishedVersio

    Nanoparticle delivery systems in the treatment of diabetes complications

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    Diabetes mellitus, an incurable metabolic disease, is characterized by changes in the homeostasis of blood sugar levels, being the subcutaneous injection of insulin the first line treatment. This administration route is however associated with limited patients compliance, due to the risk of pain, discomfort and local infection. Nanoparticles have been proposed as insulin carriers to make possible the administration of the peptide via friendlier pathways without the need of injection, i.e., via oral or nasal routes. Nanoparticles stand for particles in the nanometer range that can be obtained from different materials (e.g., polysaccharides, synthetic polymers, lipid) and are commonly used with the aim to improve the physicochemical stability of the loaded drug and thereby its bioavailability. This review discusses the use of different types of nanoparticles (e.g., polymeric and lipid nanoparticles, liposomes, dendrimers, niosomes, micelles, nanoemulsions and also drug nanosuspensions) for improved delivery of different oral hypoglycemic agents in comparison to conventional therapies.The authors acknowledge the financial support received from Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project reference M-ERA-NET/0004/2015-PAIRED, co-financed by FEDER, under the Partnership Agreement PT2020. The authors also acknowledge the support of the research project: “Nutraceutica come supporto nutrizionale nel paziente oncologico”, CUP: B83D18000140007.info:eu-repo/semantics/publishedVersio
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