Abstract 23: Exosome Inhibition Improved Blood Perfusion in Ischemic Hindlimb of db/db Diabetic Mice

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Zhongjian Cheng ◽  
Venkata Naga Srikanth Garikipati ◽  
Maria Cimini ◽  
Chunlin Wang ◽  
May Trungcao ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Blood Perfusion ◽  
Limb Ischemia ◽  
Tube Formation ◽  
Tissue Loss ◽  
Diabetic Patients ◽  
Post Injury ◽  
Patients With Diabetes

Background: Critical limb ischemia (CLI), a life-threatening condition characterized by pain at rest and tissue loss with ulcer and gangrene, imposes a major public healthy burden, resulting in high mortality and disability. The occurrence of CLI in patients with diabetes mellitus is very frequent. However, the effective therapy for CLI in diabetic patients is absent. Recent studies demonstrated that exosome from diabetic animals/cells has detrimental effects on the post-injury cardiovascular repair. Here, we tested the hypotheses that exosome inhibition in vivo improves blood flow recovery and protects skeletal muscle in ischemic hindlimbs of diabetic db/db mice following surgical ischemia. Methods and Results: Exosomes were isolated from bone-marrow derived progenitor cells or plasma in non-diabetic db/+ and diabetic db/db mice by ultracentrifugation. Diabetic exosome (5 ug/ml) inhibited tube formation of human cardiac microvascular endothelial cells. Unilateral hindlimb ischemia surgery was conducted by ligation of left femoral artery in 12-week old, male db/+ and db/db mice. Exosome inhibitor GW4869 (2 μg/g body weight) was given by intraperitoneal injection every other day for 4 weeks starting from one week before the HLI surgery. HLI mice injected with vehicle served as controls. Mice were divided into four groups: 1) db/+ + vehicle; 2) db/db+ vehicle; 3) db/+ GW4869; 4) db/db + GW4869. GW4869 decreased necrosis and loss of toe/toenail, improved blood flow, enhanced capillary/arterial density, skeletal muscle architecture and cell survival in ischemic hindlimb of diabetic db/db mice 21 days post-ligation. Conclusions: Although preliminary, our experiments suggest that therapeutic targeting of dysfunctional exosome secretion could represent a new avenue for the prevention and treatment of ischemic injury in diabetic patients.

Abstract 249: Plasma Exosomes Impair Angiogenesis in Ischemic Hind Limb of Diabetic Mice- Role of Histone Methylation

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Zhongjian Cheng ◽  
May M Truongcao ◽  
Chunlin Wang ◽  
Venkata NS Garikipati ◽  
Yan Tang ◽  
...  
Keyword(s):  
Hind Limb ◽  
Blood Perfusion ◽  
Limb Ischemia ◽  
Capillary Density ◽  
Cardiovascular Complications ◽  
Tube Formation ◽  
Angiogenic Factor ◽  
Diabetic Patients ◽  
Doppler Imager ◽  
Novel Target

Background: Critical limb ischemia (CLI) is one of most prevenient cardiovascular disease in diabetic patients. Recent evidence suggests that altered cargo and function of plasma exosomes (plasma-Exo) may play an important role in diabetes-induced cardiovascular complications. Here, we tested the hypotheses that inhibition of exosome biosynthesis/release improves ischemic hind limb (IHL) repair in db/db mice. Methods: Plasma-Exo from db/+ and db/db mice were isolated by density-gradient ultracentrifugation. Unilateral IHL in mice was conducted by ligation of left femoral artery. Blood perfusion in IHL was measured by Laser Doppler Imager. Results: Diabetic plasma-Exo impaired tube formation/migration of human microvascular endothelial cells (HMVECs) and blood perfusion in IHL of C57BL/6J mice. Exosome inhibitor GW4869 improved blood flow, capillary density, cell survival, and rescued necrosis of toe/toenail and fibrosis in IHL muscle of db/db mice. Mechanistically, diabetic plasma-Exo decreased secretion of pro-angiogenic factor Ang I&II, artemin, FGF2 and IGFBP1&2, and increased repressive transcriptional mark H3K27me3 and its methylase enhancer of zest homolog-2 (EZH2) in HMVECs. EZH2 inhibitor GSK343 rescued diabetic plasma-Exo-impaired tube formation and secretion of FGF2/artemin from HMVECs. Moreover, GW4869 reduced EZH2 and H3K27me3 protein expression in lung microvascular ECs of IHL db/db mice. Finally, diabetic plasma-Exo increased H3K27me3 level at promoter of artemin and FGF2. Conclusions: Diabetic plasma-Exo impair angiogenesis and IHL injury repair. Diabetic plasma-Exo impair reparative property of ECs via, at least in part, enhancement of EZH2/H3K27me3/artemin and FGF2 cascade. Inhibition of plasma-Exo biosynthesis/secretion improve IHL repair in db/db mice. Plasma-Exo may be a novel target for prevention/treatment of CLI in diabetic patients.

scholarly journals Functional recovery of the microcirculation during skeletal muscle regeneration

2018 ◽  
Author(s):  
◽  
Charmain Angela Fernando
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Regeneration ◽  
Flow Regulation ◽  
Skeletal Muscle Regeneration ◽  
Post Injury ◽  
Skeletal Muscle Function ◽  
Vasomotor Responses ◽  
Blood Flow Regulation

Skeletal muscle has a remarkable capacity to regenerate following injury, and although muscle regeneration has been studied extensively, little is known about the recovery of the skeletal muscle microcirculation during regeneration. To determine the restoration of blood flow regulation during skeletal muscle regeneration, this dissertation explored the recovery of vasomotor responses to physiological agonists and of functional vasodilation in response to muscle contraction. A novel injury model in the mouse gluteus maximus muscle was developed to study the microcirculation in vivo using intravital microscopy at welldefined time points (5, 10, 21 and 35 days) post injury compared to uninjured Control muscles. Studies encompassed feed arteries and the principal branches (1st, 2nd and 3rd order) of arteriolar networks comprising the resistance vasculature. Vasomotor responses to agonists and active force developed by muscle fibers recovered by 21d, however functional vasodilation required [about]35d to recover. This research provides novel insight into when and to what extent blood flow regulation is restored during skeletal muscle regeneration and provides novel perspective towards developing therapeutic strategies for restoring skeletal muscle function during recovery from injury.

scholarly journals Effects of aging and exercise training on spinotrapezius muscle microvascular Po2 dynamics and vasomotor control

2011 ◽  
Vol 110 (3) ◽  
pp. 695-704 ◽  
Author(s):  
Danielle J. McCullough ◽  
Robert T. Davis ◽  
James M. Dominguez ◽  
John N. Stabley ◽  
Christian S. Bruells ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Training ◽  
Sodium Nitroprusside ◽  
Vascular Function ◽  
Treadmill Running ◽  
Aged Rats ◽  
Phosphorescence Quenching

With advancing age, there is a reduction in exercise tolerance, resulting, in part, from a perturbed ability to match O2 delivery to uptake within skeletal muscle. In the spinotrapezius muscle (which is not recruited during incline treadmill running) of aged rats, we tested the hypotheses that exercise training will 1) improve the matching of O2 delivery to O2 uptake, evidenced through improved microvascular Po2 (PmO2), at rest and throughout the contractions transient; and 2) enhance endothelium-dependent vasodilation in first-order arterioles. Young (Y, ∼6 mo) and aged (O, >24 mo) Fischer 344 rats were assigned to control sedentary (YSED; n = 16, and OSED; n = 15) or exercise-trained (YET; n = 14, and OET; n = 13) groups. Spinotrapezius blood flow (via radiolabeled microspheres) was measured at rest and during exercise. Phosphorescence quenching was used to quantify PmO2 in vivo at rest and across the rest-to-twitch contraction (1 Hz, 5 min) transition in the spinotrapezius muscle. In a follow-up study, vasomotor responses to endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) stimuli were investigated in vitro. Blood flow to the spinotrapezius did not increase above resting values during exercise in either young or aged groups. Exercise training increased the precontraction baseline PmO2 (OET 37.5 ± 3.9 vs. OSED 24.7 ± 3.6 Torr, P < 0.05); the end-contracting PmO2 and the time-delay before PmO2 fell in the aged group but did not affect these values in the young. Exercise training improved maximal vasodilation in aged rats to acetylcholine (OET 62 ± 16 vs. OSED 27 ± 16%) and to sodium nitroprusside in both young and aged rats. Endurance training of aged rats enhances the PmO2 in a nonrecruited skeletal muscle and is associated with improved vascular smooth muscle function. These data support the notion that improvements in vascular function with exercise training are not isolated to the recruited muscle.

scholarly journals Myocardial revascularization in diabetic patients presenting with critical limbischemia

2010 ◽  
Vol 13 (4) ◽  
pp. 25-29
Author(s):  
Ivan Ivanovich Dedov ◽  
Victor Yur'evich Kalashnikov ◽  
Konstantin Vladimirovich Melkozerov
Keyword(s):  
Coronary Heart Disease ◽  
Heart Disease ◽  
Critical Limb Ischemia ◽  
Myocardial Revascularization ◽  
Limb Ischemia ◽  
Diabetic Patients ◽  
Preoperative Risk Assessment ◽  
Therapeutic Modalities ◽  
Optimal Drug ◽  
Patients With Diabetes

The frequency of diabetic complications remains high despite the development of improved therapeutic modalities. Macroangiopathy continues to bethe predominant complication while coronary heart disease is the main cause of mortality.This paper considers clinical features of diabetic patientswith coronary heart disease and critical limb ischemia; various aspects of optimal drug therapy, preoperative examination and diagnostics precedingvascular non-cardiac surgery; preoperative risk assessment; indications for coronary angiography and myocardial revascularization. The authors emphasizethe importance of development of algorithms for the treatment of patients with diabetes, critical limb ischemia, and coronary heart disease.

scholarly journals Microdialysis of skeletal muscle at rest

1999 ◽  
Vol 58 (4) ◽  
pp. 919-923 ◽  
Author(s):  
Jan Henriksson
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Human Skeletal Muscle ◽  
Human Metabolism ◽  
High Expectations ◽  
Perfusate Flow ◽  
Muscle Research ◽  
Interstitial Glucose

Techniques in human skeletal muscle research are by necessity predominantly 'descriptive'.Microdialysis has raised high expectations that it could meet the demand for a method that allows 'mechanistic' investigations to be performed in human skeletal muscle. In the present review, some views are given on how well the initial expectations on the use of the microdialysis technique in skeletal muscle have been fulfilled, and the areas in which additional work is needed in order to validate microdialysis as an important metabolic technique in this tissue. The microdialysis catheter has been equated to an artificial blood vessel, which is introduced into the tissue. By means of this 'vessel' the concentrations of compounds in the interstitial space can be monitored. The concentration of substances in the collected samples is dependent on the rate of perfusate flow. When perfusate flow is slow enough to allow complete equilibration between interstitial and perfusate fluids, the concentration in the perfusate is maximal and identical to the interstitial concentration. Microdialysis data may be influenced by changes in blood flow, especially in instances where the tissue diffusivity limits the recovery in vivo, i.e. when recovery in vitro is 100 %, whereas the recovery in vivo is less than 100 %. Microdialysis data indicate that a significant arterial-interstitial glucose concentration gradient exists in skeletal muscle but not in adipose tissue at rest. While the concentrations of glucose and lactate in the dialysate from skeletal muscle are close to the expected values, the glycerol values obtained for muscle are still puzzling. Ethanol added to the perfusate will be cleared by the tissue at a rate that is determined by the nutritive blood flow (the microdialysis ethanol technique). It is concluded that microdialysis of skeletal muscle has become an important technique for mechanistic studies in human metabolism and nutrition.

Capillary Permeability and Blood Flow in Skeletal Muscle of Patients with Diabetes Mellitus and Genetic Prediabetes

1972 ◽  
Vol 286 (9) ◽  
pp. 454-460 ◽  
Author(s):  
Joseph S. Alpert ◽  
Jay D. Coffman ◽  
Marios C. Balodimos ◽  
Lajos Koncz ◽  
J. Stuart Soeldner
Keyword(s):  
Diabetes Mellitus ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Capillary Permeability ◽  
Patients With Diabetes

Abstract 274: Polarization of Macrophage Confers Regenerative Capacity of Using Adipose Derived Regenerative Cells

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Satoshi Shintani ◽  
Yuuki Shimizu ◽  
Changning Hao ◽  
Kazuhisa Kondo ◽  
Ryo Hayashida ◽  
...  
Keyword(s):  
Umbilical Vein ◽  
Lymphatic Endothelial Cell ◽  
Limb Ischemia ◽  
Treated Group ◽  
Tube Formation ◽  
Mice Model ◽  
Ischemic Tissue ◽  
Regenerative Cells ◽  
Anti Inflammatory

Background: Recent studies indicate that macrophages (Mφ) have conflicting characteristics, pro-inflammatory or anti-inflammatory phenotypes. We previously demonstrated that implantation of adipose derived regenerative cells (ADRCs) augmented angiogenesis and lymph angiogenesis by modulating Mφ phenotype in animal models. We thus examine whether Mφ polarization to M2 type is important for neovascularization in various models. Methods and Results: Culture medium of ADRCs accelerated not only migration of human umbilical vein endothelial cells (HUVECs) but also polarization of M2 type Mφ. Cultured ADRCs released SDF-1, VEGF-C, and prostaglandin E2 (PGE2). PGE2 plays a key role for the polarization of M2 type Mφ via EP2/4 receptors. Matrigel tube formation assay conformed that ADRCs were incorporated into HUVEC network. In vivo, implanted ADRCs participated in the formation of capillary networks in ischemic tissue. In a mice model of tail lymphedema, the number of bone marrow derived Mφ was significantly higher in the ADRCs treated group than in the un-treated group. Most of Mφ differentiated into lymphatic endothelial cell in the edematous tissue and were polarized to M2 phenotype. Moreover, in a mice model of hind limb ischemia, implantation of ADRCs facilitated the polarization of Mφ into M2 type Mφ and up regulated IL-10 expression to suppress inflammation at ischemic tissue. Conclusion: Polarization into anti-inflammatory phenotype of Mφ plays an important role for regenerative action of ADRCs.

Abstract 14820: Sirt7 Deficiency in Blood Vessel Components Impairs Vascular Function by Inhibiting Cell Cycle- and Inflammatory-Related Protein Expression

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yuichi Kimura ◽  
Yasuhiro Izumiya ◽  
Satoshi Araki ◽  
Satoru Yamamura ◽  
Yoshiro Onoue ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Blood Flow ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Vascular Diseases ◽  
Tube Formation ◽  
Hindlimb Ischemia ◽  
Proliferation Assay

Introduction: Aging is a well-established cardiovascular risk factor and associated with vascular dysfunction. Sirt7, one of the members of mammalian sirtuin family, is thought to be involved in age-related diseases. However, little is known about the relative contribution of Sirt7 in vascular dysfunction. Hypothesis: Sirt7 maintains vascular cell functions and its deficiency plays a critical role in vascular diseases. Methods: Sirt7 loss- and gain-of-function experiments were performed with human aortic smooth muscle cells (HAoSMCs) and human umbilical vein endothelial cells (HUVECs). In vivo, blood flow recovery was evaluated by hindlimb ischemia model in homozygous Sirt7 deficient (Sirt7-/-) and wild-type (WT) mice. Irradiated WT mice were intravenously received bone marrow (BM) cells from WT or Sirt7 -/- mouse to achieve BM transfer. Results: An RNAi-medicated Sirt7 knockdown resulted in a significant inhibition of HAoSMCs proliferation following serum or Platelet-derived growth factor BB (PDGF-BB) stimulation as determined by cell count, BrdU cell proliferation assay and MTS proliferation assay. Knockdown of endogenous Sirt7 also reduced cell migration as revealed by Boyden chamber migration assay. The Cyclin D1 and Cyclin dependent kinase 2 (CDK2) protein levels were significantly decreased in Sirt7 siRNA-treated HAoSMCs in response to serum or PDGF-BB stimulation. In endothelial cells, knockdown of Sirt7 attenuated tube formation, proliferation and migration. These changes were accompanied by reduced ERK activation and VCAM-1 mRNA and protein expression in Sirt7 siRNA-treated HUVECs. Conversely, overexpression of Sirt7 by adenovirus enhanced tube formation and cell proliferation. In vivo, blood flow recovery in response to hindlimb ischemia was significantly attenuated in Sirt7-/- mice compared with WT mice. There was no difference in blood flow recovery between WT mice transplanted with WT or Sirt7-/- BM cells suggesting that Sirt7 deficiency in vascular cells have a predominant effect on attenuated blood flow recovery in response to hindlimb ischemia. Conclusions: Sirt7 in blood vessel components have an important role in maintenance of vascular function. Sirt7 could be a promising therapeutic target for vascular diseases.

scholarly journals The Functionality of Endothelial-Colony-Forming Cells from Patients with Diabetes Mellitus

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1731
Author(s):  
Caomhán J. Lyons ◽  
Timothy O'Brien
Keyword(s):  
Diabetes Mellitus ◽  
Cell Therapy ◽  
Diabetic Patients ◽  
Angiogenic Potential ◽  
Endothelial Colony Forming Cells ◽  
Allogeneic Cell Therapy ◽  
Patients With Diabetes ◽  
Pre Treatment

Endothelial-colony-forming cells (ECFCs) are a population of progenitor cells which have demonstrated promising angiogenic potential both in vitro and in vivo. However, ECFCs from diabetic patients have been shown to be dysfunctional compared to ECFCs from healthy donors. Diabetes mellitus itself presents with many vascular co-morbidities and it has been hypothesized that ECFCs may be a potential cell therapy option to promote revascularisation in these disorders. While an allogeneic cell therapy approach would offer the potential of an ‘off the shelf’ therapeutic product, to date little research has been carried out on umbilical cord-ECFCs in diabetic models. Alternatively, autologous cell therapy using peripheral blood-ECFCs allows the development of a personalised therapeutic approach to medicine; however, autologous diabetic ECFCs are dysfunctional and need to be repaired so they can effectively treat diabetic co-morbidities. Many different groups have modified autologous diabetic ECFCs to improve their function using a variety of methods including pre-treatment with different factors or with genetic modification. While the in vitro and in vivo data from the literature is promising, no ECFC therapy has proceeded to clinical trials to date, indicating that more research is needed for a potential ECFC therapy in the future to treat diabetic complications.

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