591-P: Macrophage IL-1beta–Dependent VEGF-A Expression Is Required for Inflammatory Arteriogenesis and Wound Healing in Type 2 Diabetes

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 591-P
Author(s):  
CHRIS S. MANTSOUNGA
Keyword(s):  
Type 2 Diabetes ◽  
Wound Healing

Abstract 199: Type 2 Diabetes Impairs Wound Healing By DNMT1-dependent Reduction of Hematopoietic Stem Cell Differentiation towards Monocytes/Macrophages and Skewing of the M1/M2 Polarization

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Jinglian Yan ◽  
Guodong Tie ◽  
Lyne Khair ◽  
Elena Filippova ◽  
Louis Messina
Keyword(s):  
Type 2 Diabetes ◽  
Wound Healing ◽  
Epigenetic Modification ◽  
Stem Cell Differentiation ◽  
M1 Macrophages ◽  
Hematopoietic Stem ◽  
Impaired Wound Healing ◽  
Inflammatory Phase ◽  
M2 Polarization

Rationale: People with Type 2 Diabetes Mellitus (T2DM) have a 25x higher risk of limb loss than non-diabetics due in large part to impaired wound healing. The mechanisms that cause impaired wound healing remain incompletely characterized. Objective: We hypothesize that T2DM impairs wound healing by epigenetic modifications in hematopoietic stem cells (HSC) that reduce their differentiation towards monocytes/macrophages and disrupts the balance in M1/M2 polarization during the three phases of wound healing. Methods and Results: Wounds were created on the back of mice. Wound healing was significantly slower in diabetic db/db than in WT mice. During the early inflammatory phase, db/db wounds exhibited a significant decrease in total macrophages and M1 macrophages. Then, total macrophages and M2 macrophages were decreased, while M1 macrophages increased in tissue formation phase. In the late tissue remodeling phase, total macrophages and M1 macrophages were persistently increased. The impaired wound healing phenotype of db/db mice was recapitulated in WT recipients which were resconstituted with db/db HSCs, demonstrating that the impaired differentiation of HSCs towards macrophages as well as their M1/M2 polarization was due to a cell autonomous mechanism. Epigenetic studies indicated that DNMT1-dependent hypermethylation of Notch1, Pu.1 and KLF4 in T2D HSCs was responsible for the impaired differentiation towards monocytes/macrophages as well as the skewed M1/M2 polarization. Knockdown of DNMT1 in HSCs from db/db mice transplanted into lethally irradiated WT mice led to improved wound healing by an increase in macrophage infiltration as well as a normalization of the M1/M2 polarization. Conclusion: This study indicates that the dynamic changes of macrophage concentration and M1/M2 polarization in wound healing are regulated at the level of HSCs. Moreover, T2DM impairs wound healing by inducing DNMT1-dependent reduction of HSCs’ differentiation towards macrophages and their M1/M2 polarization. This novel finding indicates that inflammation is regulated at the level of HSCs, which creates new opportunities to develop epigenetic modification related therapies for T2DM and potentially other conditions that result from dysinflammation.

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

Circulation ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document