Erythrocytes Induce Endothelial Injury in Type 2 Diabetes Through Alteration of Vascular Purinergic Signaling

It is well established that altered purinergic signaling contributes to vascular dysfunction in type 2 diabetes (T2D). Red blood cells (RBCs) serve as an important pool for circulating ATP and the release of ATP from RBCs in response to physiological stimuli is impaired in T2D. We recently demonstrated that RBCs from patients with T2D (T2D RBC) serve as key mediators of endothelial dysfunction. However, it remains unknown whether altered vascular purinergic signaling is involved in the endothelial dysfunction induced by dysfunctional RBCs in T2D. Here, we evaluated acetylcholine-induced endothelium-dependent relaxation (EDR) of isolated rat aortas after 18 h ex vivo co-incubation with human RBCs, and aortas of healthy recipient rats 4 h after in vivo transfusion with RBCs from T2D Goto-Kakizaki (GK) rats. Purinergic receptor (PR) antagonists were applied in isolated aortas to study the involvement of PRs. EDR was impaired in aortas incubated with T2D RBC but not with RBCs from healthy subjects ex vivo, and in aortas of healthy rats after transfusion with GK RBCs in vivo. The impairment in EDR by T2D RBC was attenuated by non-selective P1R and P2R antagonism, and specific A1R, P2X7R but not P2Y6R antagonism. Transfusion with GK RBCs in vivo impaired EDR in aortas of recipient rats, an effect that was attenuated by A1R, P2X7R but not P2Y6R antagonism. In conclusion, RBCs induce endothelial dysfunction in T2D via vascular A1R and P2X7R but not P2Y6R. Targeting vascular purinergic singling may serve as a potential therapy to prevent endothelial dysfunction induced by RBCs in T2D.

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Downregulation of Erythrocyte miR-210 Induces Endothelial Dysfunction in Type 2 Diabetes

10.2337/figshare.16896523 ◽

2021 ◽

Author(s):

Zhichao Zhou ◽

Aida Collado ◽

Changyan Sun ◽

Yahor Tratsiakovich ◽

Ali Mahdi ◽

...

Keyword(s):

Type 2 Diabetes ◽

Endothelial Cells ◽

Endothelial Dysfunction ◽

Endothelial Function ◽

Ex Vivo ◽

Tyrosine Phosphatase ◽

Protective Role ◽

Diabetic Patients

Red blood cells (RBCs) act as mediators of vascular injury in type 2 diabetes mellitus (T2DM). miR-210 plays a protective role in cardiovascular homeostasis and is decreased in whole blood of T2DM mice. We hypothesized that downregulation of RBC miR-210 induces endothelial dysfunction in T2DM. RBCs were co-incubated with arteries and endothelial cells ex vivo and transfused in vivo to identify the role of miR-210 and its target protein tyrosine phosphatase 1B (PTP1B) in endothelial dysfunction. RBCs from patients with T2DM (T2DM RBC) and diabetic rodents induced endothelial dysfunction ex vivo and in vivo. miR-210 levels were lower in human T2DM RBC than in RBCs from healthy subjects (H RBC). Transfection of miR-210 in human T2DM RBC rescued endothelial function, whereas miR-210 inhibition in H RBC or RBCs from miR-210 knockout mice impaired endothelial function. Human T2DM RBC decreased miR-210 expression in endothelial cells. miR-210 expression in carotid artery plaques was lower in T2DM patients than in non-diabetic patients. Endothelial dysfunction induced by downregulated RBC miR-210 involved PTP1B and reactive oxygen species. miR-210 mimic attenuated endothelial dysfunction induced by RBCs via downregulating vascular PTP1B and oxidative stress in diabetic mice in vivo. These data reveal that the downregulation of RBC miR-210 is a novel mechanism driving the development of endothelial dysfunction in T2DM.

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Abstract 13373: Exercise Improves Angiogenic Function of Circulating Exosomes in Type 2 Diabetes: Role of Extracellular SOD

Circulation ◽

10.1161/circ.142.suppl_3.13373 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Kareem Abdelsaid ◽

Sudhahar Varadarajan ◽

Archita Das ◽

Yutao Liu ◽

Xuexiu Fang ◽

...

Keyword(s):

Type 2 Diabetes ◽

Wound Healing ◽

Endothelial Dysfunction ◽

Wound Repair ◽

Cell Communication ◽

Tube Formation ◽

Skin Wound ◽

Skin Wound Healing

Background: Exosomes, key mediators of cell-cell communication, derived from type 2 diabetes mellitus (T2DM) have detrimental effects. Exercise not only improves endothelial dysfunction and angiogenesis in T2DM but also induces secretion of exosomes into circulation. Extracellular superoxide dismutase (ecSOD) is a major secretory Cu containing antioxidant enzyme that catalyzes dismutation of O 2 •- to H 2 O 2 and its full activity requires Cu transporter ATP7A. We reported that ecSOD-derived H 2 O 2 in endothelial cells (ECs) enhances angiogenesis while impaired ATP7A-ecSOD axis in diabetes induces endothelial dysfunction. Here we examined whether exercise-derived exosomes (Exe-Exo) may have pro-angiogenic effects via regulating ATP7A-ecSOD axis in T2DM. Results: Two weeks of voluntary wheel exercise of control C57Bl6 mice increased plasma exosome levels (6.2-fold) characterized by Nanosight, TEM and exosome markers (CD63, CD81, Tsg101). Treatment of HUVECs with equal number of exosomes revealed that angiogenic responses such as EC migration (1.8-fold) and tube formation (1.7-fold) were significantly enhanced by Exe-Exo compared to sedentary-derived exosomes (Sed-Exo). This was associated with increased ATP7A (2.9-fold) and ecSOD (1.4-fold) expression in Exe-Exo. Sed-Exo from high fat-induced T2DM mice significantly decreased EC migration (40%) and tube formation (10%) as well as ATP7A expression (28%) compared to Sed-Exo from control mice, which were restored by T2DM Exe-Exo, but not by T2DM/ecSOD KO Exe-Exo. Furthermore, exosomes overexpressing ecSOD (ecSOD-Exo) which mimic exercise increased angiogenesis and H2O2 levels in ECs, which were inhibited by overexpression of catalase. In vivo, skin wound healing model showed that direct application of T2DM Sed-Exo delayed while T2DM Exe-Exo enhanced wound healing of control mice. Furthermore, defective wound healing in T2DM mice or ecSOD KO mice were rescued by ecSOD-Exo application. Conclusion: Exercise training improves pro-angiogenic function of circulating exosomes in T2DM via increasing ATP7A-ecSOD axis, which may provide an effective therapy for promoting angiogenesis and wound repair in metabolic and cardiovascular diseases.

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Altered Purinergic Receptor Sensitivity in Type 2 Diabetes-Associated Endothelial Dysfunction and Up4A-Mediated Vascular Contraction

International Journal of Molecular Sciences ◽

10.3390/ijms19123942 ◽

2018 ◽

Vol 19 (12) ◽

pp. 3942 ◽

Cited By ~ 6

Author(s):

Ali Mahdi ◽

Tong Jiao ◽

Yahor Tratsiakovich ◽

Jiangning Yang ◽

Claes-Göran Östenson ◽

...

Keyword(s):

Endothelial Dysfunction ◽

Endothelial Function ◽

Vascular Function ◽

Purinergic Receptor ◽

Purinergic Signaling ◽

Mesenteric Arteries ◽

Vascular Contraction ◽

Gk Rats ◽

Vasoconstrictor Response

Purinergic signaling may be altered in diabetes accounting for endothelial dysfunction. Uridine adenosine tetraphosphate (Up4A), a novel dinucleotide substance, regulates vascular function via both purinergic P1 and P2 receptors (PR). Up4A enhances vascular contraction in isolated arteries of diabetic rats likely through P2R. However, the precise involvement of PRs in endothelial dysfunction and the vasoconstrictor response to Up4A in diabetes has not been fully elucidated. We tested whether inhibition of PRs improved endothelial function and attenuated Up4A-mediated vascular contraction using both aortas and mesenteric arteries of type 2 diabetic (T2D) Goto Kakizaki (GK) rats vs. control Wistar (WT) rats. Endothelium-dependent (EDR) but not endothelium-independent relaxation was significantly impaired in both aortas and mesenteric arteries from GK vs. WT rats. Non-selective inhibition of P1R or P2R significantly improved EDR in aortas but not mesenteric arteries from GK rats. Inhibition of A1R, P2X7R, or P2Y6R significantly improved EDR in aortas. Vasoconstrictor response to Up4A was enhanced in aortas but not mesenteric arteries of GK vs. WT rats via involvement of A1R and P2X7R but not P2Y6R. Depletion of major endothelial component nitric oxide enhanced Up4A-induced aortic contraction to a similar extent between WT and GK rats. No significant differences in protein levels of A1R, P2X7R, and P2Y6R in aortas from GK and WT rats were observed. These data suggest that altered PR sensitivity accounts for endothelial dysfunction in aortas in diabetes. Modulating PRs may represent a potential therapy for improving endothelial function.

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Endothelial Dysfunction: Is There a Hyperglycemia-Induced Imbalance of NOX and NOS?

International Journal of Molecular Sciences ◽

10.3390/ijms20153775 ◽

2019 ◽

Vol 20 (15) ◽

pp. 3775 ◽

Cited By ~ 23

Author(s):

Cesar A. Meza ◽

Justin D. La Favor ◽

Do-Houn Kim ◽

Robert C. Hickner

Keyword(s):

Type 2 Diabetes ◽

Cardiovascular Disease ◽

Blood Flow ◽

Endothelial Dysfunction ◽

Endothelial Function ◽

Vascular Dysfunction ◽

Vascular Complications ◽

Enzymatic Production

NADPH oxidases (NOX) are enzyme complexes that have received much attention as key molecules in the development of vascular dysfunction. NOX have the primary function of generating reactive oxygen species (ROS), and are considered the main source of ROS production in endothelial cells. The endothelium is a thin monolayer that lines the inner surface of blood vessels, acting as a secretory organ to maintain homeostasis of blood flow. The enzymatic production of nitric oxide (NO) by endothelial NO synthase (eNOS) is critical in mediating endothelial function, and oxidative stress can cause dysregulation of eNOS and endothelial dysfunction. Insulin is a stimulus for increases in blood flow and endothelium-dependent vasodilation. However, cardiovascular disease and type 2 diabetes are characterized by poor control of the endothelial cell redox environment, with a shift toward overproduction of ROS by NOX. Studies in models of type 2 diabetes demonstrate that aberrant NOX activation contributes to uncoupling of eNOS and endothelial dysfunction. It is well-established that endothelial dysfunction precedes the onset of cardiovascular disease, therefore NOX are important molecular links between type 2 diabetes and vascular complications. The aim of the current review is to describe the normal, healthy physiological mechanisms involved in endothelial function, and highlight the central role of NOX in mediating endothelial dysfunction when glucose homeostasis is impaired.

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Rod phototransduction and light signal transmission during type 2 diabetes

BMJ Open Diabetes Research & Care ◽

10.1136/bmjdrc-2020-001571 ◽

2020 ◽

Vol 8 (1) ◽

pp. e001571

Author(s):

Silke Becker ◽

Lara S Carroll ◽

Frans Vinberg

Keyword(s):

Type 2 Diabetes ◽

Multiple Stressors ◽

Ex Vivo ◽

Light Signal ◽

Rod Photoreceptor ◽

Diabetic Mice ◽

Rod Photoreceptors ◽

Light Signals

IntroductionDiabetic retinopathy is a major complication of diabetes recently associated with compromised photoreceptor function. Multiple stressors in diabetes, such as hyperglycemia, oxidative stress and inflammatory factors, have been identified, but systemic effects of diabetes on outer retina function are incompletely understood. We assessed photoreceptor physiology in vivo and in isolated retinas to better understand how alterations in the cellular environment compared with intrinsic cellular/molecular properties of the photoreceptors, affect light signal transduction and transmission in the retina in chronic type 2 diabetes.Research design and methodsPhotoreceptor function was assessed in BKS.Cs-Dock7m+/+Lepr db/J mice, using homozygotes for Leprdb as a model of type 2 diabetes and heterozygotes as non-diabetic controls. In vivo electroretinogram (ERG) was recorded in dark-adapted mice at both 3 and 6 months of age. For ex vivo ERG, isolated retinas were superfused with oxygenated Ames’ media supplemented with 30 mM glucose or mannitol as iso-osmotic control and electrical responses to light stimuli were recorded.ResultsWe found that both transduction and transmission of light signals by rod photoreceptors were compromised in 6-month-old (n=9–10 eyes from 5 animals, ***p<0.001) but not in 3-month-old diabetic mice in vivo (n=4–8 eyes from 2 to 4 animals). In contrast, rod signaling was similar in isolated retinas from 6-month-old control and diabetic mice under normoglycemic conditions (n=11). Acutely elevated glucose ex vivo increased light-evoked rod photoreceptor responses in control mice (n=11, ***p<0.001), but did not affect light responses in diabetic mice (n=11).ConclusionsOur data suggest that long-term diabetes does not irreversibly change the ability of rod photoreceptors to transduce and mediate light signals. However, type 2 diabetes appears to induce adaptational changes in the rods that render them less sensitive to increased availability of glucose.

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Abstract P632: Nlrp3/inflammasome Activation Contributes To Aldosterone-induced Vascular Dysfunction In Type 2 Diabetes.

Hypertension ◽

10.1161/hyp.68.suppl_1.p632 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Nathanne S Ferreira ◽

Thiago Bruder-Nascimento ◽

Camila A Pereira ◽

Camila Z Zanotto ◽

Douglas S Prado ◽

...

Keyword(s):

Type 2 Diabetes ◽

Endothelial Dysfunction ◽

Nlrp3 Inflammasome ◽

Vascular Dysfunction ◽

Vascular Inflammation ◽

Diabetic Patients ◽

Inflammasome Activation ◽

Caspase 1

Diabetic patients and animal models of type 2 diabetes (DM2) display increased plasma aldosterone (aldo) levels. Aldo induces vascular inflammation and endothelial dysfunction. NOD-like receptors, which are pattern recognition receptors involved in a variety of host innate immune responses, promote vascular inflammation. We hypothesized that aldo via mineralocorticoid receptors (MR) activates the inflammasome platform in the vasculature of DM2 mice. Control (db/+) and diabetic (db/db) mice were treated with vehicle or spironolactone (spiro - MR antagonist, 50 mg/Kg/day). Mesenteric resistance arteries (MA) from db/db mice exhibited reduced acetylcholine (ACh) dilation, which was reversed by spiro [Emax (% of relaxation): db/+: 78.5±4.1; db/db: 40.5±6.4; db/+spiro: 77.0±3.8; db/db+spiro: 62.8±5.9 n=3-6 p<0.05]. Spiro treatment reduced caspase-1 and mature IL-1β content in MA from db/db mice. Spiro also reduced caspase-1 activity in macrophages from peritoneal lavage of db/db mice [% of activity: db/+: 33.9±2.5; db/db: 51.8±7.4; db/+spiro: 31.1±1.9; db/db+spiro: 34.8±3.8 n=4-7, p<0.05]. In vitro, aldo increased mature IL-1β in vascular smooth muscle cells (VSMC) (cont: 0.9±0.01 ; LPS+Nigericine: 6.1±2.1 ; Aldo 4h: 9.7±2.6; LPS+Aldo 4h: 12.8±1.9 n=3-5, p<0.05). To determine whether aldo in vivo directly activates NLRP3/inflammasome in the vasculature and whether NLRP3 activation contributes to aldo-induced vascular injury, aldo was infused (600 ug/Kg/day for 14 days) in wild type (WT) and NLRP3 knockout mice ( NLRP3-/- ) after bone marrow transplantation from WT donor. The groups were constituted: WT->WT, WT->WT+aldo and WT-> NLRP3 -/-+aldo. NLRP3 -/- mice were protected against aldo-induced endothelial dysfunction [Emax: WT: 89.3±2.9; WT+aldo: 39.8±1.8; NLRP3-/- +aldo: 87.7±4.2, p<0.05]. Aldo treatment leaded to endothelial dysfunction in WT ->WT mice, but WT-> NLRP3 -/- mice were protected from aldo-induced endothelial dysfunction [Emax: WT->WT: 95.1±3.1; WT->WT+aldo: 57.1±4.7; WT->NLRP3-/-+aldo: 85.3±3.1 p<0.05]. These results suggest that NLRP3/inflammasome in the vasculature plays a crucial role on aldo/MR-induced vascular damage and on DM2-associated vascular dysfunction. Financial Support: FAPESP, CAPES, CNPq.

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Abstract 211: The DPP-4 Inhibitor Linagliptan Reverses Endothelial Dysfunction of Mesenteric Arteries From Rats Fed a Western Diet

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.211 ◽

2014 ◽

Vol 34 (suppl_1) ◽

Author(s):

Salheen M Salheen ◽

Jason C Nguyen ◽

Trisha A Jenkins ◽

Owen L Woodman

Keyword(s):

Type 2 Diabetes ◽

Endothelial Dysfunction ◽

Western Diet ◽

Mesenteric Arteries ◽

Standard Diet ◽

High Fat ◽

Total Fat ◽

Endothelium Dependent Relaxation ◽

Superoxide Release

A high-fat ‘western’ diet (WD), a risk factor for the development of type 2 diabetes, may cause endothelial dysfunction one of the earliest events in atherogenesis. The dipeptidyl peptidase-4 (DPP-4) inhibitors are used to lower hyperglycemia in type 2 diabetes which is also associated with endothelial dysfunction. We tested whether consumption of a WD affected endothelium-dependent relaxation (EDR) of rat mesenteric arteries (MA) and whether the DPP-4 inhibitor linagliptin (1μM) improves EDR. Wistar Hooded rats were fed a standard diet (SD, 7% total fat) or WD (21% total fat) for 10 weeks. Consumption of the WD significantly increased superoxide release from MA assayed by lucigenin chemiluminescence (WD 1210±180 counts/mg versus SD 543±156 counts/mg, n=7-8, p<0.05) and linagliptin significantly reduced the vascular superoxide release (WD+linagliptin 432±102 counts/mg, p<0.05). Acetylcholine (ACh)-induced endothelium-dependent relaxation of MA was assessed using wire myography. WD significantly reduced the sensitivity to ACh (pEC50, SD 7.72±0.08, WD, 7.32±0.05 n=8, p<0.05) and treatment with linagliptin improved endothelial function (ACh pEC50 WD+linagliptin, 7.74±0.12, n=8, p<0.05). The contribution of EDHF to ACh-induced relaxation was determined in the presence of L-NNA and ODQ to block NOS and guanylate cyclase. EDHF-mediated relaxation was improved by linagliptin (pEC50, WD 6.24±0.06, WD+linagliptin 6.95±0.12, n=4-5, p<0.05). Linagliptin also significantly improved the contribution of NO (determined in the presence of TRAM-34 + apamin to block IKCa and SKCa) to relaxation (pEC50, WD 6.50±0.13, WD+linagliptin 7.30±0.10 n=4-6, p<0.05). Linagliptin significantly reduced vascular superoxide levels and improved the contribution of both NO and EDHF to preserve endothelium-dependent relaxation in rats fed a high fat diet. DPP-4 inhibition may have effects in addition to the lowering of plasma glucose to improve vascular function in diabetes.

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[18F]FDG Uptake in Adipose Tissue Is Not Related to Inflammation in Type 2 Diabetes Mellitus

Molecular Imaging and Biology ◽

10.1007/s11307-020-01538-0 ◽

2020 ◽

Vol 23 (1) ◽

pp. 117-126

Author(s):

Melanie Reijrink ◽

Stefanie A. de Boer ◽

Ines F. Antunes ◽

Daan S. Spoor ◽

Hiddo J. L. Heerspink ◽

...

Keyword(s):

Diabetes Mellitus ◽

Type 2 Diabetes ◽

Type 2 Diabetes Mellitus ◽

Mrna Expression ◽

Ex Vivo ◽

Expression Levels ◽

Fdg Uptake ◽

Mrna Expression Levels

Abstract Purpose 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) uptake is a marker of metabolic activity and is therefore used to measure the inflammatory state of several tissues. This radionuclide marker is transported through the cell membrane via glucose transport proteins (GLUTs). The aim of this study is to investigate whether insulin resistance (IR) or inflammation plays a role in [18F]FDG uptake in adipose tissue (AT). Procedures This study consisted of an in vivo clinical part and an ex vivo mechanistic part. In the clinical part, [18F]FDG uptake in abdominal visceral AT (VAT) and subcutaneous AT (SAT) was determined using PET/CT imaging in 44 patients with early type 2 diabetes mellitus (T2DM) (age 63 [54–66] years, HbA1c [6.3 ± 0.4 %], HOMA-IR 5.1[3.1–8.5]). Plasma levels were measured with ELISA. In the mechanistic part, AT biopsies obtained from 8 patients were ex vivo incubated with [18F]FDG followed by autoradiography. Next, a qRT-PCR analysis was performed to determine GLUT and cytokine mRNA expression levels. Immunohistochemistry was performed to determine CD68+ macrophage infiltration and GLUT4 protein expression in AT. Results In vivo VAT [18F]FDG uptake in patients with T2DM was inversely correlated with HOMA-IR (r = − 0.32, p = 0.034), and positively related to adiponectin plasma levels (r = 0.43, p = 0.003). Ex vivo [18F]FDG uptake in VAT was not related to CD68+ macrophage infiltration, and IL-1ß and IL-6 mRNA expression levels. Ex vivo VAT [18F]FDG uptake was positively related to GLUT4 (r = 0.83, p = 0.042), inversely to GLUT3 (r = − 0.83, p = 0.042) and not related to GLUT1 mRNA expression levels. Conclusions In vivo [18F]FDG uptake in VAT from patients with T2DM is positively correlated with adiponectin levels and inversely with IR. Ex vivo [18F]FDG uptake in AT is associated with GLUT4 expression but not with pro-inflammatory markers. The effect of IR should be taken into account when interpreting data of [18F]FDG uptake as a marker for AT inflammation.

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Knockout of vascular smooth muscle EGF receptor in a mouse model prevents obesity-induced vascular dysfunction and renal damage in vivo

Diabetologia ◽

10.1007/s00125-020-05187-4 ◽

2020 ◽

Vol 63 (10) ◽

pp. 2218-2234

Author(s):

Christian Stern ◽

Barbara Schreier ◽

Alexander Nolze ◽

Sindy Rabe ◽

Sigrid Mildenberger ◽

...

Keyword(s):

Type 2 Diabetes ◽

Smooth Muscle ◽

Mitochondrial Dysfunction ◽

Renal Damage ◽

Egf Receptor ◽

Vascular Dysfunction ◽

Cellular Level

Abstract Aims/hypothesis Obesity causes type 2 diabetes leading to vascular dysfunction and finally renal end-organ damage. Vascular smooth muscle (VSM) EGF receptor (EGFR) modulates vascular wall homeostasis in part via serum response factor (SRF), a major regulator of VSM differentiation and a sensor for glucose. We investigated the role of VSM-EGFR during obesity-induced renovascular dysfunction, as well as EGFR–hyperglycaemia crosstalk. Methods The role of VSM-EGFR during high-fat diet (HFD)-induced type 2 diabetes was investigated in a mouse model with inducible, VSM-specific EGFR-knockout (KO). Various structural and functional variables as well as transcriptome changes, in vivo and ex vivo, were assessed. The impact of hyperglycaemia on EGFR-induced signalling and SRF transcriptional activity and the underlying mechanisms were investigated at the cellular level. Results We show that VSM-EGFR mediates obesity/type 2 diabetes-induced vascular dysfunction, remodelling and transcriptome dysregulation preceding renal damage and identify an EGFR–glucose synergism in terms of SRF activation, matrix dysregulation and mitochondrial function. EGFR deletion protects the animals from HFD-induced endothelial dysfunction, creatininaemia and albuminuria. Furthermore, we show that HFD leads to marked changes of the aortic transcriptome in wild-type but not in KO animals, indicative of EGFR-dependent SRF activation, matrix dysregulation and mitochondrial dysfunction, the latter confirmed at the cellular level. Studies at the cellular level revealed that high glucose potentiated EGFR/EGF receptor 2 (ErbB2)-induced stimulation of SRF activity, enhancing the graded signalling responses to EGF, via the EGFR/ErbB2–ROCK–actin–MRTF pathway and promoted mitochondrial dysfunction. Conclusions/interpretation VSM-EGFR contributes to HFD-induced vascular and subsequent renal alterations. We propose that a potentiated EGFR/ErbB2–ROCK–MRTF–SRF signalling axis and mitochondrial dysfunction underlie the role of EGFR. This advanced working hypothesis will be investigated in mechanistic depth in future studies. VSM-EGFR may be a therapeutic target in cases of type 2 diabetes-induced renovascular disease. Data availability The datasets generated during and/or analysed during the current study are available in: (1) share_it, the data repository of the academic libraries of Saxony-Anhalt (10.25673/32049.2); and (2) in the gene expression omnibus database with the study identity GSE144838 (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE144838).

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Islet macrophages drive islet vascular remodeling and compensatory hyperinsulinemia in the early stages of diabetes

10.1101/584953 ◽

2019 ◽

Cited By ~ 1

Author(s):

Manesh Chittezhath ◽

Divya Gunaseelan ◽

Xiaofeng Zheng ◽

Riasat Hasan ◽

Vanessa SY Tay ◽

...

Keyword(s):

Type 2 Diabetes ◽

Insulin Secretion ◽

Vascular Remodeling ◽

Ex Vivo ◽

Vascular Density ◽

Rapid Progression ◽

List Type ◽

The Impact

Abstractβ-cells respond to peripheral insulin resistance by increasing circulating insulin in early type-2 diabetes (T2D). Islet remodeling supports this compensation but the drivers of this process remain poorly understood. Infiltrating macrophages have been implicated in late stage T2D but relatively little is known on islet resident macrophages, especially in early T2D. We hypothesize that islet resident macrophages contribute to islet vascular remodeling and hyperinsulinemia, the failure of which results in a rapid progression to T2D. Using genetic and diet-induced models of compensatory hyperinsulinemia we show that its depletion significantly compromises islet remodeling in terms of size, vascular density and insulin secretion capacity. Depletion of islet macrophages reduces VEGF-A secretion from both human and mouse islets ex vivo and the impact of reduced VEGF-A functionally translates to delayed re-vascularization upon transplantation in vivo. Hence, we show a new role of islet resident macrophages in the context of early T2D and suggest that there is considerable utility in harnessing islet macrophages to promote islet remodeling and islet insulin secretion capacity.HighlightsThe compensatory hyperinsulinemic phase of type-2 diabetes is accompanied with significant pancreatic islet remodeling.Bona fide islet resident macrophages are increased during the diabetic compensation phase by largely in situ proliferation.Ablating macrophages severely compromises the islet remodeling process and exacerbates glycemic control in vivo.Mouse and human islet macrophages contribute VEGF-A to the islet environment.Specific removal of islet macrophages delays islet vascularization in compensatory hyperinsulinemic mice.

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