Oxidative stress tolerance of early stage diabetic endothelial progenitor cell. Regen Ther. 2015;1:38-44. [PMID: 31245440 PMCID: PMC6581786 DOI: 10.1016/j.reth.2014.11.001]

Bioactives of Momordica charantia as Potential Anti-Diabetic/Hypoglycemic Agents

Momordica charantia L., a member of the Curcubitaceae family, has traditionally been used as herbal medicine and as a vegetable. Functional ingredients of M. charantia play important roles in body health and human nutrition, which can be used directly or indirectly in treating or preventing hyperglycemia-related chronic diseases in humans. The hypoglycemic effects of M. charantia have been known for years. In this paper, the research progress of M. charantia phytobioactives and their hypoglycemic effects and related mechanisms, especially relating to diabetes mellitus, has been reviewed. Moreover, the clinical application of M. charantia in treating diabetes mellitus is also discussed, hoping to broaden the application of M. charantia as functional food.

Mobilization of endothelial progenitor cells promotes angiogenesis after full thickness excision by AMD3100 combined with G-CSF in diabetic mice by SDF-1/CXCR4 axis

AIM

The aim of the present study was to investigate the effect of the mobilization of EPCs by AMD3100 combined with G-CSF on wound healing in diabetic mice.

METHODS

The full-thickness excisional wounds model of diabetic mice (db/db) was examined by hematoxylin and eosin staining, immunohistochemical staining, and western blotting to compare the wound healing and neovascularization among the combination, AMD3100 alone, G-CSF alone, and control groups.

RESULTS

The wounds reached the complete closure in the combination, AMD3100 alone, G-CSF alone, and control groups on days 17, 20, 21, 21 after surgery, respectively. In addition, the combination group promoted the inflammatory cell recruitment and glandular formation. On day 10 from injury, the protein expression of CD31 in the combination group was significantly higher compared with the other three groups (p < 0.001). The level of SDF-1 protein remained high in the combined group until on day 10 after surgery (p < 0.001).

CONCLUSION

The mobilization of endogenous EPCs by AMD3100 combine with G-CSF is able to enhance the complete healing of full-thickness wounds and neovascularization in db/db mice may by SDF-1/CXCR4 axis. These findings provided a novel method and indication of duration of mobilization on diabetic wound healing and tissue regeneration.

Procyanidin B2 improves endothelial progenitor cell function and promotes wound healing in diabetic mice via activating Nrf2

One of the major reasons for the delayed wound healing in diabetes is the dysfunction of endothelial progenitor cells (EPCs) induced by hyperglycaemia. Improvement of EPC function may be a potential strategy for accelerating wound healing in diabetes. Procyanidin B2 (PCB2) is one of the major components of procyanidins, which exhibits a variety of potent pharmacological activities. However, the effects of PCB2 on EPC function and diabetic wound repair remain elusive. We evaluated the protective effects of PCB2 in EPCs with high glucose (HG) treatment and in a diabetic wound healing model. EPCs derived from human umbilical cord blood were treated with HG. The results showed that PCB2 significantly preserved the angiogenic function, survival and migration abilities of EPCs with HG treatment, and attenuated HG‐induced oxidative stress of EPCs by scavenging excessive reactive oxygen species (ROS). A mechanistic study found the protective role of PCB2 is dependent on activating nuclear factor erythroid 2‐related factor 2 (Nrf2). PCB2 increased the expression of Nrf2 and its downstream antioxidant genes to attenuate the oxidative stress induced by HG in EPCs, which were abolished by knockdown of Nrf2 expression. An in vivo study showed that intraperitoneal administration of PCB2 promoted wound healing and angiogenesis in diabetic mice, which was accompanied by a significant reduction in ROS level and an increase in circulating EPC number. Taken together, our results indicate that PCB2 treatment accelerates wound healing and increases angiogenesis in diabetic mice, which may be mediated by improving the mobilization and function of EPCs.

Quality-Quantity Control Culture Enhances Vasculogenesis and Wound Healing Efficacy of Human Diabetic Peripheral Blood CD34+ Cells

Autologous endothelial progenitor cell (EPC) therapy is commonly used to stimulate angiogenesis in ischemic repair and wound healing. However, low total numbers and functional deficits of EPCs make autologous EPC therapy ineffective in diabetes. Currently, no known ex vivo culture techniques can expand and/or ameliorate the functional deficits of EPCs for clinical usage. Recently, we showed that a quality‐quantity culture (QQc) system restores the vasculogenic and wound‐healing efficacy of murine diabetic EPCs. To validate these results and elucidate the mechanism in a translational study, we evaluated the efficacy of this QQc system to restore the vasculogenic potential of diabetic human peripheral blood (PB) CD34+ cells. CD34+ cells purified from PB of diabetic and healthy patients were subjected to QQc. Gene expression, vascular regeneration, and expression of cytokines and paracrine mediators were analyzed. Pre‐ or post‐QQc diabetic human PB‐CD34+ cells were transplanted into wounded BALB/c nude mice and streptozotocin‐induced diabetic mice to assess functional efficacy. Post‐QQc diabetic human PB‐CD34+ cell therapy significantly accelerated wound closure, re‐epithelialization, and angiogenesis. The higher therapeutic efficacy of post‐QQc diabetic human PB‐CD34+ cells was attributed to increased differentiation ability of diabetic CD34+ cells, direct vasculogenesis, and enhanced expression of angiogenic factors and wound‐healing genes. Thus, QQc can significantly enhance the therapeutic efficacy of human PB‐CD34+ cells in diabetic wounds, overcoming the inherent limitation of autologous cell therapy in diabetic patients, and could be useful for treatment of not only wounds but also other ischemic diseases. Stem Cells Translational Medicine2018;7:428–438

Insights into the molecular mechanisms of diabetes-induced endothelial dysfunction: focus on oxidative stress and endothelial progenitor cells

Diabetes mellitus is a heterogeneous, multifactorial, chronic disease characterized by hyperglycemia owing to insulin insufficiency and insulin resistance (IR). Recent epidemiological studies showed that the diabetes epidemic affects 382 million people worldwide in 2013, and this figure is expected to be 600 million people by 2035. Diabetes is associated with microvascular and macrovascular complications resulting in accelerated endothelial dysfunction (ED), atherosclerosis, and cardiovascular disease (CVD). Unfortunately, the complex pathophysiology of diabetic cardiovascular damage is not fully understood. Therefore, there is a clear need to better understand the molecular pathophysiology of ED in diabetes, and consequently, better treatment options and novel efficacious therapies could be identified. In the light of recent extensive research, we re-investigate the association between diabetes-associated metabolic disturbances (IR, subclinical inflammation, dyslipidemia, hyperglycemia, dysregulated production of adipokines, defective incretin and gut hormones production/action, and oxidative stress) and ED, focusing on oxidative stress and endothelial progenitor cells (EPCs). In addition, we re-emphasize that oxidative stress is the final common pathway that transduces signals from other conditions-either directly or indirectly-leading to ED and CVD.

Signaling involved in stem cell reprogramming and differentiation

Stem cell differentiation is regulated by multiple signaling events. Recent technical advances have revealed that differentiated cells can be reprogrammed into stem cells. The signals involved in stem cell programming are of major interest in stem cell research. The signaling mechanisms involved in regulating stem cell reprogramming and differentiation are the subject of intense study in the field of life sciences. In this review, the molecular interactions and signaling pathways related to stem cell differentiation are discussed.