O-GlcNAcase overexpression reverses coronary endothelial cell dysfunction in type 1 diabetic mice

Cardiovascular disease is the primary cause of morbidity and mortality in diabetes, and endothelial dysfunction is commonly seen in these patients. Increased O-linked N-acetylglucosamine ( O-GlcNAc) protein modification is one of the central pathogenic features of diabetes. Modification of proteins by O-GlcNAc ( O-GlcNAcylation) is regulated by two key enzymes: β- N-acetylglucosaminidase [ O-GlcNAcase (OGA)], which catalyzes the reduction of protein O-GlcNAcylation, and O-GlcNAc transferase (OGT), which induces O-GlcNAcylation. However, it is not known whether reducing O-GlcNAcylation can improve endothelial dysfunction in diabetes. To examine the effect of endothelium-specific OGA overexpression on protein O-GlcNAcylation and coronary endothelial function in diabetic mice, we generated tetracycline-inducible, endothelium-specific OGA transgenic mice, and induced OGA by doxycycline administration in streptozotocin-induced type 1 diabetic mice. OGA protein expression was significantly decreased in mouse coronary endothelial cells (MCECs) isolated from diabetic mice compared with control MCECs, whereas OGT protein level was markedly increased. The level of protein O-GlcNAcylation was increased in diabetic compared with control mice, and OGA overexpression significantly decreased the level of protein O-GlcNAcylation in MCECs from diabetic mice. Capillary density in the left ventricle and endothelium-dependent relaxation in coronary arteries were significantly decreased in diabetes, while OGA overexpression increased capillary density to the control level and restored endothelium-dependent relaxation without changing endothelium-independent relaxation. We found that connexin 40 could be the potential target of O-GlcNAcylation that regulates the endothelial functions in diabetes. These data suggest that OGA overexpression in endothelial cells improves endothelial function and may have a beneficial effect on coronary vascular complications in diabetes.

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ERK-containing microparticles from a diabetic mouse induce endothelial dysfunction

Journal of Endocrinology ◽

10.1530/joe-18-0616 ◽

2019 ◽

Vol 241 (3) ◽

pp. 221-233 ◽

Cited By ~ 4

Author(s):

Kumiko Taguchi ◽

Haruka Narimatsu ◽

Takayuki Matsumoto ◽

Tsuneo Kobayashi

Keyword(s):

Endothelial Cells ◽

Endothelial Dysfunction ◽

Endothelial Function ◽

Vascular Complications ◽

Diabetic Mouse ◽

Diabetic Rats ◽

Enzyme Linked Immunosorbent Assay ◽

Diabetic Mice ◽

Diabetic Vascular Complications ◽

Underlying Mechanisms

Endothelial dysfunction is a hallmark of diabetic vascular complications. Microparticles (MPs) are small vesicles shed from the surface of blood and vascular cells that act as stimuli and during apoptosis. Circulating MPs of diabetic rats have been shown to induce endothelial dysfunction. However, the underlying mechanisms require further study. In this study, we investigated how MPs from diabetic mice affect endothelial function. MPs were collected from streptozotocin-induced diabetic mice and Institute of Cancer Research (ICR) mice as controls. The levels of MPs were assessed and characterized by flow cytometry, enzyme-linked immunosorbent assay and dot blotting. Normal mice aortas were incubated with MPs and expressions of enzymes and vascular relaxation were analyzed. We found that (1) circulating MPs level increased in diabetic mice; (2) MPs impaired endothelial-dependent relaxation in mice aorta, but diabetic mice-derived MPs (diabetes mellitus (DM) MPs) were easier to attach to the endothelial cells than were control MPs; (3) DM MPs had more extracellular signal-regulated kinase (ERK)1/2 than did control mice-derived MPs, and they induced ERK1/2 activation in mice aortas; (4) DM MPs decreased endothelial nitric oxide synthase (eNOS) in mice aortas, and eNOS was emitted from endothelial cells to blood in the shape of endothelial MPs. DM MPs significantly altered endothelial function by activation of ERK1/2, which might provide a therapeutic target for diabetic vascular complications.

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Abstract 344: Endothelin-1 Overexpression Exaggerates Diabetes-induced Endothelial Dysfunction

Hypertension ◽

10.1161/hyp.64.suppl_1.344 ◽

2014 ◽

Vol 64 (suppl_1) ◽

Author(s):

Noureddine IDRIS KHODJA ◽

Muhammad Oneeb Rehman Mian ◽

Tlili Barhoumi ◽

Sofiane Ouerd ◽

Jordan Gornitsky ◽

...

Keyword(s):

Type 1 Diabetes ◽

Endothelial Dysfunction ◽

Vascular Complications ◽

Fold Increase ◽

Wild Type ◽

No Donor ◽

Meclofenamic Acid ◽

Fibronectin Expression ◽

Endothelium Dependent Relaxation

Objective: Vascular disease associated with endothelial dysfunction is a major cause of morbidity in patients with type-1 diabetes. Endothelin (ET)-1 plays a role in diabetes-induced vascular complications, since ET-1 type A receptor blockade reduces diabetes-induced vascular injury. However, whether ET-1 contributes to diabetes-induced endothelial dysfunction remains unproven. We hypothesized that vascular ET-1 overexpression will exaggerate diabetes-induced endothelial dysfunction. Methods: Diabetes was induced by streptozotocin treatment (STZ, 55 mg/kg/day, ip) for 5 days in 6-week-old male wild-type (WT) mice and in mice overexpressing ET-1 restricted to the endothelium (eET-1). Mice were studied 14 weeks later. Blood was collected to determine glucose. Mesenteric artery reactivity and remodeling were evaluated using pressurized myography and aortic fibronectin expression by immnunofluorescence. Results: STZ-induced diabetes was confirmed by a 3-fold increase in glycemia in WT and eET-1 ( P <0.001). Diabetes impaired endothelium-dependent relaxation (EDR) reponses to acetylcholine in WT (60.9±6.4% vs 83.9±3.4%, P <0.05) and eET-1 (48.6±5.1% vs 81.5±5.2%, P <0.001). EDR impairment was exaggerated in eET-1 compared to WT ( P <0.05). Meclofenamic acid, an inhibitor of cyclooxygenase, increased EDR in eET-1 compared to WT (78.4±9.4% vs 66.7±3.2%, P <0.01), which was not observed in diabetic mice. L-NAME, an inhibitor of nitric oxide (NO) synthase, completely blocked EDR in WT, eET-1 and diabetic WT, but not in diabetic eET-1 (4.1±1.6%, 6.4±5.7%, 2.2±4.6% and 26.6±4.6%, P <0.05). Apamin plus Tram34, inhibitors of endothelium-dependent hyperpolarization inhibited EDR in the four groups. Endothelium-independent relaxation to sodium nitroprusside, a NO donor, was similar in the four groups. Diabetes reduced media/lumen in WT (2.7±0.3 vs 3.6±0.3, P <0.05) and eET-1 (2.9±0.2 vs 3.8±0.3, P <0.05). Diabetes decreased aortic fibronectin expression in WT (94.0±11.0 vs. 151.9±21.8 RFU/μm 2 , P <0.05) and eET-1 (66.3±8.7 vs. 146.6±20.7 RFU/μm 2 , P <0.05). Conclusion: ET-1 contributes to alterations in several pathways mediating endothelium-dependent relaxation in type-1 diabetes, leading to exaggerated endothelial dysfunction.

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HuR-mediated posttranscriptional modification of Cx40 and coronary microvascular dysfunction in type 2 diabetes

10.21203/rs.3.rs-154496/v1 ◽

2021 ◽

Author(s):

Rui Si ◽

Jody Tori O. Cabrera ◽

Atsumi Tsuji-Hosokawa ◽

Lei Gao ◽

Rui Guo ◽

...

Keyword(s):

Type 2 Diabetes ◽

Endothelial Function ◽

Binding Protein ◽

Microvascular Disease ◽

Capillary Density ◽

Diabetic Patients ◽

Diabetic Mice ◽

Endothelium Dependent Relaxation

Abstract Background Diabetic patients with coronary microvascular disease (CMD) exhibit higher cardiac mortality than patients without CMD. However, the molecular mechanism by which diabetes promotes CMD is poorly understood. RNA-binding protein HuR is a key regulator of mRNA stability and translation of many genes, and there is growing evidence showing the potential role of HuR in cardiovascular disease. In this study, we investigated the role of HuR and its target genes in the development of CMD in type 2 diabetic mice. Methods Type 2 diabetes was induced in male mice by a high-fat diet combined with a single injection of low-dose streptozotocin. We assessed coronary flow velocity reserve (CFVR, a determinant of coronary microvascular function) in vivo and isolated cardiac endothelial cells (CECs) from those mice for in vitro experiment. Coronary endothelial function was evaluated in the 3rd order of coronary arteries using a wire myograph. Human CECs from 4 control subjects and 4 diabetic patients were purchased from the company. Results Diabetic mice exhibited decreases in CFVR and capillary density in the left ventricle (LV). HuR protein levels in CECs were significantly lower in diabetic mice and diabetic patients than in the controls. Endothelial-specific HuR-KO mice also displayed significant reductions in CFVR and capillary density. By examining mRNA levels of 92 genes associated with endothelial function, we found that HuR, Cx40, and Nox4 levels were decreased in CECs from diabetic and HuR-KO mice in comparison to control mice. Cx40 protein level and HuR binding to Cx40 mRNA were downregulated in CECs from diabetic mice, and Cx40-KO mice exhibited decreased CFVR, attenuated endothelium-dependent relaxation, and reduced capillary density in the LV. Furthermore, endothelium-specific Cx40 overexpression ameliorated endothelial functions by augmenting endothelium-dependent relaxation and increasing capillary density in the LV, and resulted in the improvement of CFVR in diabetic mice. Conclusions These data suggest that decreased HuR, a specific mRNA binding protein that downregulates gap junction protein Cx40 in CECs, plays an important role in the development of coronary microvascular disease in diabetes. Restoration of Cx40 expression and function is potentially a novel therapeutic strategy for diabetic cardiovascular complications.

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Fibroblast growth factor 21 Ameliorates diabetes-induced endothelial dysfunction in mouse aorta via activation of the CaMKK2/AMPKα signaling pathway

Cell Death and Disease ◽

10.1038/s41419-019-1893-6 ◽

2019 ◽

Vol 10 (9) ◽

Cited By ~ 7

Author(s):

Lei Ying ◽

Na Li ◽

Zhengyue He ◽

Xueqin Zeng ◽

Yan Nan ◽

...

Keyword(s):

Oxidative Stress ◽

Endothelial Dysfunction ◽

Endothelial Function ◽

Signaling Pathway ◽

Oxidative Capacity ◽

Fibroblast Growth Factor 21 ◽

Diabetic Mice

Abstract Endothelial dysfunction initiates and exacerbates hypertension, atherosclerosis and other cardiovascular complications in diabetic mellitus. FGF21 is a hormone that mediates a number of beneficial effects relevant to metabolic disorders and their associated complications. Nevertheless, it remains unclear as to whether FGF21 ameliorates endothelial dysfunction. Therefore, we investigated the effect of FGF21 on endothelial function in both type 1 and type 2 diabetes. We found that FGF21 reduced hyperglycemia and ameliorated insulin resistance in type 2 diabetic mice, an effect that was totally lost in type 1 diabetic mice. However, FGF21 activated AMPKα, suppressing oxidative stress and enhancing endothelium-dependent vasorelaxation of aorta in both types, suggesting a mechanism that is independent of its glucose-lowering and insulin-sensitizing effects. In vitro, we identified a direct action of FGF21 on endothelial cells of the aorta, in which it bounds to FGF receptors to alleviate impaired endothelial function challenged with high glucose. Furthermore, the CaMKK2-AMPKα signaling pathway was activated to suppress oxidative stress. Apart from its anti-oxidative capacity, FGF21 activated eNOS to dilate the aorta via CaMKK2/AMPKα activation. Our data suggest expanded potential uses of FGF21 for the treatment of vascular diseases in diabetes.

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Sphingosine-1-phosphate inhibits high glucose-mediated ERK1/2 action in endothelium through induction of MAP kinase phosphatase-3

AJP Cell Physiology ◽

10.1152/ajpcell.00293.2008 ◽

2009 ◽

Vol 296 (2) ◽

pp. C339-C345 ◽

Cited By ~ 13

Author(s):

Angela M. Whetzel ◽

David T. Bolick ◽

Catherine C. Hedrick

Keyword(s):

Endothelial Cells ◽

Type 1 Diabetes ◽

Vascular Complications ◽

Nod Mice ◽

Endothelial Activation ◽

Adhesion Assay ◽

Monocyte Adhesion ◽

Map Kinase Phosphatase ◽

Sphingosine 1 Phosphate

Endothelial activation is a key early event in vascular complications of Type 1 diabetes. The nonobese diabetic (NOD) mouse is a well-characterized model of Type 1 diabetes. We previously reported that Type 1 diabetic NOD mice have increased endothelial activation, with increased production of monocyte chemoattractant protein (MCP)-1 and IL-6, and a 30% increase of surface VCAM-1 expression leading to a fourfold increase in monocyte adhesion to the endothelium. Sphingosine-1-phosphate (S1P) prevents monocyte:endothelial interactions in these diabetic NOD mice. Incubation of diabetic NOD endothelial cells (EC) with S1P (100 nmol/l) reduced ERK1/2 phosphorylation by 90%, with no significant changes in total ERK1/2 protein. In the current study, we investigated the mechanism of S1P action on ERK1/2 to reduce activation of diabetic endothelium. S1P caused a significant threefold increase in mitogen-activated kinase phosphatase-3 (MKP-3) expression in EC. MKP-3 selectively regulates ERK1/2 activity through dephosphorylation. Incubation of diabetic NOD EC with S1P and the S1P1-selective agonist SEW2871 significantly increased expression of MKP-3 and reduced ERK1/2 phosphorylation, while incubation with the S1P1/S1P3 antagonist VPC23019 decreased the expression of MKP-3, both results supporting a role for S1P1 in MKP-3 regulation. To mimic the S1P-mediated induction of MKP-3 diabetic NOD EC, we overexpressed MKP-3 in human aortic endothelial cells (HAEC) cultured in elevated glucose (25 mmol/l). Overexpression of MKP-3 in glucose-cultured HAEC decreased ERK1/2 phosphorylation and resulted in decreased monocyte:endothelial interactions in a static monocyte adhesion assay. Finally, we used small interfering RNA to MKP-3 and observed increased monocyte adhesion. Moreover, S1P was unable to inhibit monocyte adhesion in the absence of MKP-3. Thus, one mechanism for the anti-inflammatory action of S1P in diabetic EC is inhibition of ERK1/2 phosphorylation through induction of MKP-3 expression via the S1P-S1P1 receptor axis.

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Circulating stem and progenitor cells as markers of inflammation, endothelial regeneration, and prediction of vascular complications in metabolic syndrome and type 1 and 2 diabetes mellitus

Nauchno-prakticheskii zhurnal «Patogenez» ◽

10.25557/2310-0435.2018.01.58-67 ◽

2018 ◽

pp. 58-67

Author(s):

О.В. Першина ◽

А.В. Пахомова ◽

Н.Н. Ермакова ◽

О.Ю. Рыбалкина ◽

В.А. Крупин ◽

...

Keyword(s):

Diabetes Mellitus ◽

Metabolic Syndrome ◽

Stem Cells ◽

Bone Marrow ◽

Endothelial Cells ◽

Progenitor Cells ◽

Vascular Complications ◽

Endothelial Regeneration

Цель исследования состояла в выявлении информативных клеточных маркеров сосудистых осложнений, регенерации микрососудистой сети и воспаления в венозной крови здоровых волонтеров, больных с метаболическим синдромом, сахарным диабетом 1 и 2 типа. Методы. Обследованы больные с метаболическим синдромом (МС), диабетом 2 типа без осложнений, диабетом 1 типа средней степени тяжести и здоровые волонтеры. Диагноз пациентов подтвержден общеклиническими, биохимическими, коагулометрическими и иммуноферментными методами исследования, для оценки экспрессии антигенов использовался многопараметрический цитометрический анализ. Результаты. При анализе экспрессии маркеров показано изменение числа эндотелиальных клеток, мезенхимальных стволовых клеток (МСК) и гемопоэтических стволовых клеток (ГСК) в крови в зависимости от патологии. Эндотелиальные клетки миелоидного (CD45CD14CD34CD309CD144CD31) и немиелоидного (CD45CD14CD34CD309CD144CD31) происхождения, CD309-эндотелиальные клетки и МСК (CD44CD73CD90CD105) предлагаются в качестве маркеров повреждения эндотелия при диабетической симптоматике. При этом ГСК (CD45CD34) могут выступать ценным диагностическим и прогностическим маркером воспаления. Заключение. Для подтверждения сосудистых повреждений и прогноза развития осложнений при диабете 1 и 2 типа в венозной крови пациентов целесообразно оценивать эндотелиальные прогениторные клетки (ЭПК) не костномозговой локализации (CD31CD309CD144) и костномозговой локализации (CD34CD309), и ЭПК c высоким регенеративным потенциалом (CD45CD34CD31CD144). Циркулирующие ЭПК, формирующие колонии in vitro (CD45CD34CD31), рекомендуется использовать в качестве дифференциального маркера состояния регенерации эндотелия при диабете 2 типа. The aim of this study was to identify mesenchymal stem cells (MSC), hematopoietic stem cells (HSC), mature endothelial cells, and endothelial progenitor cells (EPC) in the blood of healthy volunteers, patients with metabolic syndrome, and type 1 and 2 diabetes mellitus as new, informative cellular markers of vascular complications, endothelial regeneration, and inflammation. Methods. The diagnosis was confirmed by general clinical, biochemical, coagulometeric and ELISA studies; multi-parameter cytometric assay was used for evaluation of antigen expression. Results. Changes in the count of MSC, HSC, mature endothelial cells, and endothelial progenitor cells in blood of patients with metabolic syndrome and type 1 and 2 diabetes depended on the type of pathology. We propose using endothelial cells of myeloid (CD45CD14CD34CD309CD144CD31) and non-myeloid origin (CD45CD14CD34CD309CD144CD31), CD309-endothelial cells, and MSCs with the CD44CD73CD90CD105 phenotype as nonspecific markers of endothelial damage in presence of diabetic symptoms. Furthermore, HSCs (CD45CD34) can be used as a valuable diagnostic and prognostic marker of inflammation. Conclusions. It is relevant to evaluate EPCs of non-bone marrow localization (CD31CD309CD144) and bone marrow localization (CD34CD309) and EPCs with a high regenerative potential (CD45CD34CD31CD144) in the blood of patients with type 1 and 2 diabetes to confirm the presence of vascular damage and predict development of complications. Circulating, in vitro colony-forming EPCs (CD45CD34CD31) are recommended as a differential marker for inhibition of endothelial regeneration in type 2 diabetes.

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Endothelial Dysfunction in Fabry Disease Is Related to Glycocalyx Degradation

Frontiers in Immunology ◽

10.3389/fimmu.2021.789142 ◽

2021 ◽

Vol 12 ◽

Author(s):

Solvey Pollmann ◽

David Scharnetzki ◽

Dominique Manikowski ◽

Malte Lenders ◽

Eva Brand

Keyword(s):

Endothelial Cells ◽

Endothelial Dysfunction ◽

Endothelial Function ◽

Fabry Disease ◽

Specific Inhibitor ◽

Small Vessel ◽

Endothelial Glycocalyx ◽

Enzyme Replacement ◽

Anti Inflammatory

Fabry disease (FD) is an X-linked multisystemic lysosomal storage disease due to a deficiency of α-galactosidase A (GLA/AGAL). Progressive cellular accumulation of the AGAL substrate globotriaosylceramide (Gb3) leads to endothelial dysfunction. Here, we analyzed endothelial function in vivo and in vitro in an AGAL-deficient genetic background to identify the processes underlying this small vessel disease. Arterial stiffness and endothelial function was prospectively measured in five males carrying GLA variants (control) and 22 FD patients under therapy. AGAL-deficient endothelial cells (EA.hy926) and monocytes (THP1) were used to analyze endothelial glycocalyx structure, function, and underlying inflammatory signals. Glycocalyx thickness and small vessel function improved significantly over time (p<0.05) in patients treated with enzyme replacement therapy (ERT, n=16) and chaperones (n=6). AGAL-deficient endothelial cells showed reduced glycocalyx and increased monocyte adhesion (p<0.05). In addition, increased expression of angiopoietin-2, heparanase and NF-κB was detected (all p<0.05). Incubation of wild-type endothelial cells with pathological globotriaosylsphingosine concentrations resulted in comparable findings. Treatment of AGAL-deficient cells with recombinant AGAL (p<0.01), heparin (p<0.01), anti-inflammatory (p<0.001) and antioxidant drugs (p<0.05), and a specific inhibitor (razuprotafib) of angiopoietin-1 receptor (Tie2) (p<0.05) improved glycocalyx structure and endothelial function in vitro. We conclude that chronic inflammation, including the release of heparanases, appears to be responsible for the degradation of the endothelial glycocalyx and may explain the endothelial dysfunction in FD. This process is partially reversible by FD-specific and anti-inflammatory treatment, such as targeted protective Tie2 treatment.

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Differential effects of obesity on visceral vs. subcutaneous adipose arteries: role of shear activated Kir2.1 and alterations to the glycocalyx

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00399.2021 ◽

2021 ◽

Author(s):

Sang Joon Ahn ◽

Elizabeth Le Master ◽

James C. Lee ◽

Shane A. Phillips ◽

Irena Levitan ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Dysfunction ◽

Endothelial Function ◽

Ex Vivo ◽

Flow Chamber ◽

Dominant Negative ◽

Obese Mice ◽

Shear Sensitivity ◽

Electrophysiological Recordings ◽

Subcutaneous Adipose

Obesity imposes well-established deficits to endothelial function. We recently showed that obesity-induced endothelial dysfunction was mediated by disruption of the glycocalyx and a loss of Kir channel flow-sensitivity. However, obesity-induced endothelial dysfunction is not observed in all vascular beds: visceral adipose arteries (VAA), but not subcutaneous adipose arteries (SAA), exhibit endothelial dysfunction. Aim: To determine if differences in SAA vs. VAA endothelial function observed in obesity are attributed to differential impairment of Kir channels and alterations to the glycocalyx. Methods: Mice were fed a normal rodent diet, or a high fat Western diet to induce obesity. Flow-induced vasodilation (FIV) was measured ex vivo. Functional downregulation of endothelial Kir2.1 was accomplished by transducing adipose arteries from mice and obese humans with adenovirus containing a dominant-negative Kir2.1 construct. Kir function was tested in freshly isolated endothelial cells seeded in a flow chamber for electrophysiological recordings under fluid shear. Atomic force microscopy was used to assess biophysical properties of the glycocalyx. Results: Endothelial dysfunction was observed in VAA of obese mice and humans. Downregulating Kir2.1 blunted FIV in SAA, but had no effect on VAA, from obese mice and humans. Obesity abolished Kir shear-sensitivity in VAA endothelial cells and significantly altered the VAA glycocalyx. In contrast, Kir shear-sensitivity was observed in SAA endothelial cells from obese mice and effects on SAA glycocalyx were less pronounced. Conclusions: We reveal distinct differences in Kir function and alterations to the glycocalyx that we propose contribute to the dichotomy in SAA vs. VAA endothelial function with obesity.

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Abstract 14372: Identification of the Genes That Are Involved in Severe Pulmonary Hypertension in Type 2 Diabetic Mice

Circulation ◽

10.1161/circ.142.suppl_3.14372 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Qiuyu Zheng ◽

Atsumi Tsuji-Hosokawa ◽

Jody T Cabrera ◽

Jian Wang ◽

Ayako Makino

Keyword(s):

Pulmonary Hypertension ◽

Endothelial Function ◽

Protein Level ◽

Chronic Hypoxia ◽

Systolic Pressure ◽

Vascular Complications ◽

Hypoxic Exposure ◽

Diabetic Mice ◽

Type 2 Diabetic

Pulmonary hypertension (PH) is a progressive disease characterized by increased pulmonary vascular resistance. Increasing evidence shows that diabetes increases the risks of PH, and diabetic priming leads to severe PH. However, the molecular mechanism by which preconditioning of diabetes results in severe PH is still unknown. It has been shown that endothelium serves as a key regulator of vascular tone, and endothelial cell dysfunction is implicated in the development of PH and diabetes-related vascular complications. Therefore, we identified the genes that contribute to the development of severe PH in diabetic mice with a focus on endothelial function. We first determined the effect of chronic hypoxia (10% O 2 , 4 weeks) on hemodynamics in type 2 diabetic (T2D) mice. We used inducible T2D mice (generated by high-fat diet and a low-dose streptozotocin injection) and spontaneous T2D mice (TALLYHO/Jng). Diabetic mice exhibited a slight increase in right ventricular systolic pressure (RVSP), and chronic hypoxia led to a further rise in RVSP in both inducible and spontaneous T2D mice. We isolated pulmonary endothelial cells (MPEC) from normoxia-exposed control mice (CN), hypoxia-exposed control mice (CH), normoxia-exposed diabetic mice (DN), and hypoxia-exposed diabetic mice (DH) to examine the levels of 92 genes using real-time PCR. Nighty two genes were selected based on their functions, which are significantly related to endothelial function. We found that 27 genes were significantly changed among 4 groups. We then examined the protein levels of genes that were related to apoptosis and glycolysis. Western Blot data indicated that the protein level of GAPDH was significantly increased in CH and DH compared to CN and DN. In addition, hypoxic exposure in diabetic mice (DH) significantly increased HK2 protein level compare to hypoxia-exposed control mice (CH). These data suggest that precondition of diabetes increases susceptibility to developing PH due partly to altering gene expression of HK2 and Gapdh in MPECs. Since HK2 and GAPDH are a crucial regulator of glycolysis, alteration of glycolysis is expected in hypoxia-exposed diabetic mice. Our study revealed the key molecules which could be used for treating severe PH in diabetes.

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Icariin Attenuates High Glucose-Induced Apoptosis, Oxidative Stress, and Inflammation in Human Umbilical Venous Endothelial Cells

Planta Medica ◽

10.1055/a-0837-0975 ◽

2019 ◽

Vol 85 (06) ◽

pp. 473-482 ◽

Cited By ~ 8

Author(s):

Si Sun ◽

Le Liu ◽

Xiaojun Tian ◽

Yanghongyun Guo ◽

Yingkang Cao ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Dysfunction ◽

High Glucose ◽

Vascular Endothelial Cells ◽

Reactive Oxygen Species Generation ◽

Vascular Complications ◽

Flavonoid Glycoside ◽

Inflammatory Factors ◽

Diabetic Vascular Complications ◽

Induced Apoptosis

AbstractEndothelial dysfunction is closely associated with diabetic complications. Icariin, a flavonoid glycoside isolated from the Epimedium plant species, exhibits antidiabetic properties. However, its impact on endothelial function remains poorly understood, particularly under hyperglycemia. In this study, we investigated the potential protective effect of icariin on high glucose-induced detrimental effects on vascular endothelial cells. Human umbilical venous endothelial cells were incubated in media containing 5.5 mM glucose (normal glucose) or 25 mM glucose (high glucose) in the presence or absence of 50 µM icariin for 72 h. We found that high glucose markedly induced cell apoptosis, enhanced reactive oxygen species generation, and elevated expression levels of inflammatory factors and cell adhesion molecules, which were greatly subdued by icariin supplementation. In conclusion, icariin exerted a beneficial effect on high glucose-induced endothelial dysfunction. This new finding provides a promising strategy for future treatment of diabetic vascular complications.

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