4
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Protective effect of manganese treatment on insulin resistance in HepG2 hepatocytes Translated title: Efecto protector del tratamiento con manganeso sobre la resistencia a la insulina en hepatocitos HepG2

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Abstract Objectives: manganese (Mn) is closely related to type 2 diabetes mellitus and insulin resistance (IR), but the exact mechanism is unclear. This study aimed to explore the regulatory effects and mechanism of Mn on IR using hepatocyte IR model induced by high palmitate (PA), high glucose (HG) or insulin. Methods: HepG2 cells were exposed to PA (200 µM), HG (25 mM) or insulin (100 nM) respectively, alone or with 5 µM Mn for 24 hours. The expression of key proteins in insulin signaling pathway, intracellular glycogen content and glucose accumulation, reactive oxygen species (ROS) level and Mn superoxide dismutase (MnSOD) activity were detected. Results: compared with control group, the expression of phosphorylated protein kinase B (Akt), glycogen synthase kinase-3β (GSK-3β) and forkhead box O1 (FOXO1) in the three IR groups was declined, and this decrease was reversed by Mn. The reduction of intracellular glycogen content and increase in glucose accumulation in IR groups were also inhibited by Mn. Additionally, the production of ROS was increased in IR models, compared with normal control group, while Mn reduced the excessive production of ROS induced by PA, HG or insulin. However, Mn did not alter the activity of MnSOD in the three IR models. Conclusion: this study demonstrated that Mn treatment can improve IR in hepatocytes. The mechanism is probably by reducing the level of intracellular oxidative stress, enhancing the activity of Akt/GSK-3β/FOXO1 signal pathway, promoting glycogen synthesis, and inhibiting gluconeogenesis.

          Translated abstract

          Resumen Objetivos: el manganeso (Mn) está estrechamente relacionado con la diabetes mellitus tipo 2 y la resistencia a la insulina (RI), pero el mecanismo exacto aún no está claro. Este estudio tuvo como objetivo explorar los efectos reguladores y el mecanismo del Mn sobre la RI utilizando un modelo de RI en hepatocitos inducido por palmitato alto (PA), glucosa alta (HG) o insulina. Métodos: las células HepG2 se expusieron a PA (200 µM), HG (25 mM) o insulina (100 nM), solas o junto con 5 µM de Mn durante 24 horas. Se evaluó la expresión de proteínas clave en la vía de señalización de la insulina, el contenido intracelular de glucógeno y la acumulación de glucosa, el nivel de especies reactivas de oxígeno (ROS) y la actividad superóxido dismutasa del manganeso (MnSOD). Resultados: en comparación con el grupo de control, la expresión de proteína quinasa B fosforilada (Akt), la glucógeno sintasa quinasa-3β (GSK-3β) y la proteína forkhead box O1 (FOXO1) en los tres grupos de RI se redujo, y esta disminución fue revertida por el Mn. La reducción del contenido de glucógeno intracelular y el aumento de la acumulación de glucosa en los grupos de RI también fueron inhibidos por el Mn. Además, la producción de ROS aumentó en los modelos de RI en comparación con el grupo de control normal. Mientras que el Mn redujo la producción excesiva de ROS inducida por PA, HG o insulina. Sin embargo, el Mn no alteró la actividad de la MnSOD en los tres modelos de RI. Conclusión: este estudio demostró que el tratamiento con Mn puede mejorar la RI en hepatocitos. El mecanismo probablemente sea mediante la reducción del nivel de estrés oxidativo intracelular, mejorando la actividad de la vía de señalización Akt/GSK-3β/FOXO1, promoviendo la síntesis de glucógeno e inhibiendo la gluconeogénesis.

          Related collections

          Most cited references42

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          The PI3K/AKT pathway in obesity and type 2 diabetes

          Obesity and type 2 diabetes mellitus are complicated metabolic diseases that affect multiple organs and are characterized by hyperglycaemia. Currently, stable and effective treatments for obesity and type 2 diabetes mellitus are not available. Therefore, the mechanisms leading to obesity and diabetes and more effective ways to treat obesity and diabetes should be identified. Based on accumulated evidences, the PI3K/AKT signalling pathway is required for normal metabolism due to its characteristics, and its imbalance leads to the development of obesity and type 2 diabetes mellitus. This review focuses on the role of PI3K/AKT signalling in the skeletal muscle, adipose tissue, liver, brain and pancreas, and discusses how this signalling pathway affects the development of the aforementioned diseases. We also summarize evidences for recently identified therapeutic targets of the PI3K/AKT pathway as treatments for obesity and type 2 diabetes mellitus. PI3K/AKT pathway damaged in various tissues of the body leads to obesity and type 2 diabetes as the result of insulin resistance, and in turn, insulin resistance exacerbates the PI3K/AKT pathway, forming a vicious circle.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Insulin sensitivity: modulation by nutrients and inflammation.

            Insulin resistance is a major metabolic feature of obesity and is a key factor in the etiology of a number of diseases, including type 2 diabetes. In this review, we discuss potential mechanisms by which brief nutrient excess and obesity lead to insulin resistance and propose that these mechanisms of action are different but interrelated. We discuss how pathways that "sense" nutrients within skeletal muscle are readily able to regulate insulin action. We then discuss how obesity leads to insulin resistance via a complex interplay among systemic fatty acid excess, microhypoxia in adipose tissue, ER stress, and inflammation. In particular, we focus on the hypothesis that the macrophage is an important cell type in the propagation of inflammation and induction of insulin resistance in obesity. Overall, we provide our integrative perspective regarding how nutrients and obesity interact to regulate insulin sensitivity.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Reactive oxygen species have a causal role in multiple forms of insulin resistance.

              Insulin resistance is a cardinal feature of type 2 diabetes and is characteristic of a wide range of other clinical and experimental settings. Little is known about why insulin resistance occurs in so many contexts. Do the various insults that trigger insulin resistance act through a common mechanism? Or, as has been suggested, do they use distinct cellular pathways? Here we report a genomic analysis of two cellular models of insulin resistance, one induced by treatment with the cytokine tumour-necrosis factor-alpha and the other with the glucocorticoid dexamethasone. Gene expression analysis suggests that reactive oxygen species (ROS) levels are increased in both models, and we confirmed this through measures of cellular redox state. ROS have previously been proposed to be involved in insulin resistance, although evidence for a causal role has been scant. We tested this hypothesis in cell culture using six treatments designed to alter ROS levels, including two small molecules and four transgenes; all ameliorated insulin resistance to varying degrees. One of these treatments was tested in obese, insulin-resistant mice and was shown to improve insulin sensitivity and glucose homeostasis. Together, our findings suggest that increased ROS levels are an important trigger for insulin resistance in numerous settings.
                Bookmark

                Author and article information

                Journal
                nh
                Nutrición Hospitalaria
                Nutr. Hosp.
                Grupo Arán (Madrid, Madrid, Spain )
                0212-1611
                1699-5198
                August 2023
                : 40
                : 4
                : 746-754
                Affiliations
                [1] Shanghai orgnameShanghai University of Medicine and Health Sciences orgdiv1College of Medical Technology P. R. China
                [2] Shanghai orgnameShanghai University of Medicine and Health Sciences orgdiv1Collaborative Innovation Center P. R. China
                [4] Haerbin orgnameHarbin Medical University orgdiv1Publich Health College P. R. China
                [3] Hangzhou orgnameLinping District Center for Disease Control and Prevention P. R. China
                [5] Shanghai orgnameShanghai University of Medicine and Health Sciences orgdiv1College of Public Health P. R. China
                Article
                S0212-16112023000500010 S0212-1611(23)04000400010
                10.20960/nh.04521
                cf5038b7-a3c4-496f-ae2a-9e84ad181952

                This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

                History
                : 09 November 2022
                : 09 February 2023
                Page count
                Figures: 0, Tables: 0, Equations: 0, References: 43, Pages: 9
                Product

                SciELO Spain

                Categories
                Original Paper

                Manganese,Resistencia a la insulina,Diabetes tipo 2,Manganeso,Insulin resistance,Type 2 diabetes

                Comments

                Comment on this article