uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Publications (3 of 3) Show all publications
Elksnis, A., Martinell, M., Eriksson, O. & Espes, D. (2019). Heterogeneity of Metabolic Defects in Type 2 Diabetes and Its Relation to Reactive Oxygen Species and Alterations in Beta-Cell Mass. Frontiers in Physiology, 10, Article ID 107.
Open this publication in new window or tab >>Heterogeneity of Metabolic Defects in Type 2 Diabetes and Its Relation to Reactive Oxygen Species and Alterations in Beta-Cell Mass
2019 (English)In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 10, article id 107Article, review/survey (Refereed) Published
Abstract [en]

Type 2 diabetes (T2D) is a complex and heterogeneous disease which affects millions of people worldwide. The classification of diabetes is at an interesting turning point and there have been several recent reports on sub-classification of T2D based on phenotypical and metabolic characteristics. An important, and perhaps so far underestimated, factor in the pathophysiology of T2D is the role of oxidative stress and reactive oxygen species (ROS). There are multiple pathways for excessive ROS formation in T2D and in addition, beta-cells have an inherent deficit in the capacity to cope with oxidative stress. ROS formation could be causal, but also contribute to a large number of the metabolic defects in T2D, including beta-cell dysfunction and loss. Currently, our knowledge on beta-cell mass is limited to autopsy studies and based on comparisons with healthy controls. The combined evidence suggests that beta-cell mass is unaltered at onset of T2D but that it declines progressively. In order to better understand the pathophysiology of T2D, to identify and evaluate novel treatments, there is a need for in vivo techniques able to quantify beta-cell mass. Positron emission tomography holds great potential for this purpose and can in addition map metabolic defects, including ROS activity, in specific tissue compartments. In this review, we highlight the different phenotypical features of T2D and how metabolic defects impact oxidative stress and ROS formation. In addition, we review the literature on alterations of beta-cell mass in T2D and discuss potential techniques to assess beta-cell mass and metabolic defects in vivo.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2019
Keywords
type 2 diabetes, diabetes classification, oxygen stress, reactive oxygen species, beta-cell, beta-cell mass, imaging, positron emission tomography
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:uu:diva-378233 (URN)10.3389/fphys.2019.00107 (DOI)000458732800001 ()
Funder
Swedish Child Diabetes FoundationSwedish Society for Medical Research (SSMF)Science for Life Laboratory - a national resource center for high-throughput molecular bioscienceErnfors FoundationSwedish Diabetes AssociationGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology
Available from: 2019-03-15 Created: 2019-03-15 Last updated: 2019-03-15Bibliographically approved
Wang, X., Elksnis, A., Wikström, P., Walum, E., Welsh, N. & Carlsson, P.-O. (2018). The novel NADPH oxidase 4 selective inhibitor GLX7013114 counteracts human islet cell death in vitro. PLoS ONE, 13(9), Article ID e0204271.
Open this publication in new window or tab >>The novel NADPH oxidase 4 selective inhibitor GLX7013114 counteracts human islet cell death in vitro
Show others...
2018 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 9, article id e0204271Article in journal (Refereed) Published
Abstract [en]

It has been proposed that pancreatic beta-cell dysfunction in type 2 diabetes is promoted by oxidative stress caused by NADPH oxidase (Nox) over-activity. The aim of the present study was to evaluate the efficacy of novel Nox inhibitors as protective agents against cytokine- or high glucose + palmitate-induced human beta-cell death. The Nox2 protein was present mainly in the cytoplasm and was induced by cytokines. Nox4 protein immunoreactivity, with some nuclear accumulation, was observed in human islet cells, and was not affected by islet culture in the presence of cytokines or high glucose + palmitate. Nox inhibitors with partial or no isoform selectivity (DPI, dapsone, GLX351322, and GLX481372) all reduced ROS production of human islet cells exposed to high glucose + palmitate. This was paralleled by improved viability and reduced caspase 3 activation. The Nox1 selective inhibitor ML171 failed to reduce human islet cell death in response to both cytokines and high glucose + palmitate. The selective Nox2 inhibitor Phox-12 also failed to protect against cytokines, but protected partially against high glucose + palmitate-induced cellular death. The highly selective Nox4 inhibitor GLX7013114 protected islet cells against both cytokines and high glucose + palmitate. However, as no osmotic control for high glucose was used, we cannot exclude the possibility that the high glucose effect was due to osmosis. It is concluded that Nox4 may participate in stress-induced islet cell death in human islets in vitro. We propose that Nox4 mediates pro-apoptotic effects in intact islets under stressful conditions and that selective Nox4-inhibition may be a therapeutic strategy in type 2 diabetes.

Place, publisher, year, edition, pages
PUBLIC LIBRARY SCIENCE, 2018
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:uu:diva-368106 (URN)10.1371/journal.pone.0204271 (DOI)000446005500024 ()30265686 (PubMedID)
Funder
Swedish Research Council, 2017-01343Stiftelsen Olle Engkvist ByggmästareSwedish Diabetes AssociationNovo NordiskErnfors FoundationSwedish Child Diabetes Foundation
Available from: 2018-12-03 Created: 2018-12-03 Last updated: 2018-12-03Bibliographically approved
Krizhanovskii, C., Kristinsson, H., Elksnis, A., Wang, X., Gavali, H., Bergsten, P., . . . Welsh, N. (2017). EndoC-beta H1 cells display increased sensitivity to sodium palmitate when cultured in DMEM/F12 medium. Islets, 9(3), 43-48
Open this publication in new window or tab >>EndoC-beta H1 cells display increased sensitivity to sodium palmitate when cultured in DMEM/F12 medium
Show others...
2017 (English)In: Islets, ISSN 1938-2014, E-ISSN 1938-2022, Vol. 9, no 3, p. 43-48Article in journal (Refereed) Published
Abstract [en]

Aims - Human pancreatic islets are known to die in response to the free fatty acid of sodium palmitate when cultured in vitro. This is in contrast to EndoC-beta H1 cells, which in our hands are not sensitive to the cell death-inducing effects sodium palmitate, making these cells seemingly unsuitable for lipotoxicity studies. However, the EndoC-beta H1 cells are routinely cultured in a nutrient mixture based on Dulbecco's Modified Eagle Medium (DMEM), which may not be the optimal choice for studies dealing with lipotoxicity. The aim of the present investigation was to define culture conditions that render EndoC-beta H1 cells sensitive to toxic effects of sodium palmitate. Methods - EndoC-beta H1 cells were cultured at standard conditions in either DMEM or DMEM/F12 culture medium. Cell death was analyzed using propidium iodide staining and flow cytometry. Insulin release and content was quantified using a human insulin ELISA. Results - We presently observe that substitution of DMEM for a DMEM/Ham's F12 mixture (50%/50% vol/vol) renders the cells sensitive to the apoptotic effects of sodium palmitate and sodium palmitate + high glucose leading to an increased cell death. Supplementation of the DMEM culture medium with linoleic acid partially mimicked the effect of DMEM/F12. Culture of EndoC-beta H1 cells in DMEM/F12 resulted also in increased proliferation, ROS production and insulin contents, but markers for metabolic stress, autophagy or amyloid deposits were unaffected. Conclusions - The culture conditions for EndoC-beta H1 cells can be modified so these cells display signs of lipotoxicity in response to sodium palmitate.

Keywords
cell death, EndoC-beta H1 cells, insulin, ROS production, sodium palmitate
National Category
Endocrinology and Diabetes
Identifiers
urn:nbn:se:uu:diva-331910 (URN)10.1080/19382014.2017.1296995 (DOI)000405586500001 ()
Funder
EXODIAB - Excellence of Diabetes Research in SwedenSwedish Diabetes AssociationSwedish Child Diabetes Foundation
Available from: 2017-10-23 Created: 2017-10-23 Last updated: 2017-10-23Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0353-326x

Search in DiVA

Show all publications