Endothelial Hyaluronan Synthase 3 Augments Postischemic Arteriogenesis Through CD44/eNOS Signaling.
Rebekka SchneckmannTatsiana SuvoravaChristian HundhausenDominik SchulerChristin LorenzTill FreudenbergerMalte KelmJens W FischerUlrich FlögelMaria GrandochPublished in: Arteriosclerosis, thrombosis, and vascular biology (2021)
Objective: The dominant driver of arteriogenesis is elevated shear stress sensed by the endothelial glycocalyx thereby promoting arterial outward remodeling. Hyaluronan, a critical component of the endothelial glycocalyx, is synthesized by 3 HAS isoenzymes (hyaluronan synthases 1-3) at the plasma membrane. Considering further the importance of HAS3 for smooth muscle cell and immune cell functions we aimed to evaluate its role in collateral artery growth.
Approach and Results: Male Has3-deficient (Has3-KO) mice were subjected to hindlimb ischemia. Blood perfusion was monitored by laser Doppler perfusion imaging and endothelial function was assessed by measurement of flow-mediated dilation in vivo. Collateral remodeling was monitored by high resolution magnetic resonance angiography. A neutralizing antibody against CD44 (clone KM201) was injected intraperitoneally to analyze hyaluronan signaling in vivo. After hindlimb ischemia, Has3-KO mice showed a reduced arteriogenic response with decreased collateral remodeling and impaired perfusion recovery. While postischemic leukocyte infiltration was unaffected, a diminished flow-mediated dilation pointed towards an impaired endothelial cell function. Indeed, endothelial AKT (protein kinase B)-dependent eNOS (endothelial nitric oxide synthase) phosphorylation at Ser1177 was substantially reduced in Has3-KO thigh muscles. Endothelial-specific Has3-KO mice mimicked the hindlimb ischemia-induced phenotype of impaired perfusion recovery as observed in global Has3-deficiency. Mechanistically, blocking selectively the hyaluronan binding site of CD44 reduced flow-mediated dilation, thereby suggesting hyaluronan signaling through CD44 as the underlying signaling pathway.
Conclusions: In summary, HAS3 contributes to arteriogenesis in hindlimb ischemia by hyaluronan/CD44-mediated stimulation of eNOS phosphorylation at Ser1177. Thus, strategies augmenting endothelial HAS3 or CD44 could be envisioned to enhance vascularization under pathological conditions.
Keyphrases
- endothelial cells
- nitric oxide synthase
- high resolution
- magnetic resonance
- signaling pathway
- high glucose
- smooth muscle
- pi k akt
- protein kinase
- nitric oxide
- contrast enhanced
- magnetic resonance imaging
- high fat diet induced
- oxidative stress
- single cell
- mesenchymal stem cells
- bone marrow
- computed tomography
- epithelial mesenchymal transition
- cell proliferation
- type diabetes
- high speed
- photodynamic therapy
- peripheral blood