Insulin and IGF1 receptors in human cardiac microvascular endothelial cells: metabolic, mitogenic and anti-inflammatory effects

Diabetes is associated with microcirculatory dysfunction and heart failure and changes in insulin and IGF1 levels. Whether human cardiac microvascular endothelial cells (HMVEC-Cs) are sensitive to insulin and/or IGF1 is not known. We studied the role of insulin receptors (IRs) and IGF1 receptors (IGF1Rs) in metabolic, mitogenic and anti-inflammatory responses to insulin and IGF1 in HMVEC-Cs and human umbilical vein endothelial cells (HUVECs). IR and IGF1R gene expression was studied using real-time RT-PCR. Receptor protein expression and phosphorylation were determined by western blot and ELISA. Metabolic and mitogenic effects were measured as glucose accumulation and thymidine incorporation. An E-selectin ELISA was used to investigate inflammatory responses. According to gene expression and protein in HMVEC-Cs and HUVECs, IGF1R is more abundant than IR. Immunoprecipitation with anti-IGF1R antibody and immunoblotting with anti-IR antibody and vice versa, showed insulin/IGF1 hybrid receptors in HMVEC-Cs. IGF1 at a concentration of 10−8 mol/l significantly stimulated phosphorylation of both IGF1R and IR in HMVEC-Cs. In HUVECs IGF1 10−8 mol/l phosphorylated IGF1R. IGF1 stimulated DNA synthesis at 10−8 mol/l and glucose accumulation at 10−7 mol/l in HMVEC-Cs. TNF-α dramatically increased E-selectin expression, but no inflammatory or anti-inflammatory effects of insulin, IGF1 or high glucose were seen. We conclude that HMVEC-Cs express more IGF1Rs than IRs, and mainly react to IGF1 due to the predominance of IGF1Rs and insulin/IGF1 hybrid receptors. TNF-α has a pronounced pro-inflammatory effect in HMVEC-Cs, which is not counteracted by insulin or IGF1.

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Anti-Inflammatory Effect and Cellular Uptake Mechanism of Carbon Nanodots in in Human Microvascular Endothelial Cells

Nanomaterials ◽

10.3390/nano11051247 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1247

Author(s):

Sarah Belperain ◽

Zi Yae Kang ◽

Andrew Dunphy ◽

Brandon Priebe ◽

Norman H. L. Chiu ◽

...

Keyword(s):

Endothelial Cells ◽

Interleukin 1 ◽

Antioxidant Properties ◽

Synthesis Method ◽

Microvascular Endothelial Cells ◽

Carbon Nanodots ◽

Uptake Mechanism ◽

Tnf Α ◽

Anti Inflammatory ◽

Microvascular Endothelial

Cardiovascular disease (CVD) has become an increasingly important topic in the field of medical research due to the steadily increasing rates of mortality caused by this disease. With recent advancements in nanotechnology, a push for new, novel treatments for CVD utilizing these new materials has begun. Carbon Nanodots (CNDs), are a new form of nanoparticles that have been coveted due to the green synthesis method, biocompatibility, fluorescent capabilities and potential anti-antioxidant properties. With much research pouring into CNDs being used as bioimaging and drug delivery tools, few studies have been completed on their anti-inflammatory potential, especially in the cardiovascular system. CVD begins initially by endothelial cell inflammation. The cause of this inflammation can come from many sources; one being tumor necrosis factor (TNF-α), which can not only trigger inflammation but prolong its existence by causing a storm of pro-inflammatory cytokines. This study investigated the ability of CNDs to attenuate TNF-α induced inflammation in human microvascular endothelial cells (HMEC-1). Results show that CNDs at non-cytotoxic concentrations reduce the expression of pro-inflammatory genes, mainly Interleukin-8 (IL-8), and interleukin 1 beta (IL-1β). The uptake of CNDs by HMEC-1s was examined. Results from the studies involving channel blockers and endocytosis disruptors suggest that uptake takes place by endocytosis. These findings provide insights on the interaction CNDs and endothelial cells undergoing TNF-α induced cellular inflammation.

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Mechanisms of MAdCAM-1 gene expression in human intestinal microvascular endothelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.00406.2003 ◽

2005 ◽

Vol 288 (2) ◽

pp. C272-C281 ◽

Cited By ~ 39

Author(s):

Hitoshi Ogawa ◽

David G. Binion ◽

Jan Heidemann ◽

Monica Theriot ◽

Pamela J. Fisher ◽

...

Keyword(s):

Gene Expression ◽

Endothelial Cells ◽

Protein Expression ◽

Molecular Mechanisms ◽

Primary Cultures ◽

Microvascular Endothelial Cells ◽

Cellular Density ◽

Tnf Α ◽

Gene And Protein Expression ◽

Microvascular Endothelial

Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is a homing receptor preferentially expressed on gut-associated endothelial cells that plays a central role in leukocyte traffic into the mucosal immune compartment. Although the molecular mechanisms underlying endothelial ICAM-1 or E-selectin expression have been intensively investigated, the mechanisms that regulate human MAdCAM-1 expression have not been defined. We report MAdCAM-1 gene and protein expression in primary cultures of human intestinal microvascular endothelial cells (HIMEC) that was not demonstrated in human umbilical vein endothelial cells. Similar to ICAM-1 and E-selectin expression, MAdCAM-1 gene expression in HIMEC was inducible with TNF-α, IL-1β, or LPS activation. However, in striking contrast to ICAM-1 and E-selectin expression, MAdCAM-1 mRNA and protein expression in HIMEC was heavily dependent on culture duration and/or cellular density, suggesting a prominent role for cell-cell interaction among these endothelial cells in the expression of the mucosal addressin. MAdCAM-1 expression was inhibited by both SN-50 (NF-κB inhibitor) and LY-294002 [phosphatidylinositol 3-kinase (PI3-K) inhibitor], whereas ICAM-1 and E-selectin expression was inhibited by SN-50 but not by LY-294002. The Akt phosphorylation by TNF-α or LPS was greater at higher cell density, demonstrating a pattern similar to that of MAdCAM-1 expression. NF-κB activation was not affected by cellular density in HIMEC. MAdCAM-1 expression in human gut endothelial cells is regulated by distinct signaling mechanisms involving both NF-κB and PI3-K/Akt. These data also suggest that PI3-K/Akt is involved in the gut-specific differentiation of HIMEC, which results in expression of the mucosal addressin MAdCAM-1.

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Age-associated impairment in TNF-α cardioprotection from myocardial infarction

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00144.2003 ◽

2003 ◽

Vol 285 (2) ◽

pp. H463-H469 ◽

Cited By ~ 34

Author(s):

Dongqing Cai ◽

Munira Xaymardan ◽

Jacquelyne M. Holm ◽

Jingang Zheng ◽

Jorge R. Kizer ◽

...

Keyword(s):

Endothelial Cells ◽

Left Ventricular ◽

Microvascular Endothelial Cells ◽

Older Individuals ◽

Aging Heart ◽

Functional Studies ◽

Tnf Α ◽

Microvascular Endothelial ◽

Cardiac Microvascular Endothelial Cells

Age-associated dysfunction in cardiac microvascular endothelial cells with impaired induction of cardioprotective platelet-derived growth factor (PDGF)-dependent pathways suggests that alterations in critical vascular receptor(s) may contribute to the increased severity of cardiovascular pathology in older persons. In vivo murine phage-display peptide library biopanning revealed a senescent decrease in cardiac microvascular binding of phage epitopes homologous to tumor necrosis factor-α (TNF-α), suggesting that its receptor(s) may be downregulated in older cardiac endothelial cells. Immunostaining demonstrated that TNF-receptor 1 (TNF-R1) density was significantly lower in the subendocardial endothelium of the aging murine heart. Functional studies confirmed the senescent dysregulation of TNF-α receptor pathways, demonstrating that TNF-α induced PDGF-B expression in cardiac microvascular endothelial cells of 4-mo-old, but not 24-mo-old, rats. Moreover, TNF-α mediated cardioprotective pathways were impaired in the aging heart. In young rat hearts, injection of TNF-α significantly reduced the extent of myocardial injury after coronary ligation: TNF-α, 7.9 ± 1.9% left ventricular injury ( n = 4) versus PBS, 16.2 ± 7.9% ( n = 10; P < 0.05). The addition of PDGF-AB did not augment the cardioprotective action of TNF-α. In myocardial infarctions of older hearts, however, TNF-α induced significant postcoronary occlusion mortality (TNF-α 80% vs. PBS 0%; n = 10 each, P < 0.05) that was reversed by the coadministration of PDGF-AB. Overall, these studies demonstrate that aging-associated alterations in TNF-α receptor cardiac microvascular pathways may contribute to the increased cardiovasular pathology of the aging heart. Strategies targeted at restoring TNF-α receptor-mediated expression of PDGF-B may improve cardiac microvascular function and provide novel approaches for treatment and possible prevention of cardiovascular disease in older individuals.

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