Enhancing the Function of CD34+ Cells by Targeting Plasminogen Activator Inhibitor-1

Abstract

Previously, we showed that transient inhibition of TGF- β1 resulted in correction of key aspects of diabetes-induced CD34+ cell dysfunction. In this report, we examine the effect of transient inhibition of plasminogen activator inhibitor-1 (PAI-1), a major gene target of TGF-β1 activation. Using gene array studies, we examined CD34+ cells isolated from a cohort of longstanding diabetic individuals, free of microvascular complications despite suboptimal glycemic control, and found that the cells exhibited reduced transcripts of both TGF-β1 and PAI-1 compared to age, sex, and degree of glycemic control-matched diabetic individuals with microvascular complications. CD34+ cells from diabetic subjects with microvascular complications consistently exhibited higher PAI-1 mRNA than age-matched non-diabetic controls. TGF- β1 phosphorodiamidate morpholino oligo (PMO) reduced PAI-1 mRNA in diabetic (p<0.01) and non-diabetic (p=0.05) CD34+ cells. To reduce PAI-1 in human CD34+ cells, we utilized PAI-1 siRNA, lentivirus expressing PAI-1 shRNA or PAI-1 PMO. We found that inhibition of PAI-1 promoted CD34+ cell proliferation and migration in vitro, likely through increased PI3(K) activity and increased cGMP production. Using a retinal ischemia reperfusion injury model in mice, we observed that recruitment of diabetic CD34+ cells to injured acellular retinal capillaries was greater after PAI-1-PMO treatment compared with control PMO-treated cells. Targeting PAI-1 offers a promising therapeutic strategy for restoring vascular reparative function in defective diabetic progenitors.

Collagen biomaterial stimulates the production of extracellular vesicles containing microRNA‐21 and enhances the proangiogenic function of CD34 + cells

“…This is not the first report on the importance of miRs in improving the function of CD34 + cells in the context of disease. A recent study showed that miR-92a corrects CD34 + cell dysfunction in diabetes by reducing the inflammatory phenotype of these cells (77), and the use of miR-146a to target plasminogen activator inhibitor-1 results in enhanced in vitro growth and migration of diabetic CD34 + cells (42). Given that CD34 + cells from donors with disease typically exhibit reduced number and function, a biomaterial culture strategy, such as the one reported herein, may be used to mediate proangiogenic miRs and improve the potency of such cells for autologous use in therapy.…”

“…For example, mobilization agents are effective at increasing the number of circulating CD34 + cells (reviewed in ref. 40), whereas in vitro cell culture expansion and genetic manipulation and stimulation have been tested to improve the yield and functionality of the cells (41)(42)(43)(44)(45)(46)(47). Notably, it has been shown that overexpression of the secreted angiogenic morphogen sonic hedgehog by CD34 + cells resulted in a superior therapy for treating myocardial infarction by limiting the infarct size and increasing vascular density (43).…”

Ataxia Telangiectasia Mutated Dysregulation Results in Diabetic Retinopathy

“…In this study, we demonstrate the critical role of ATM maintenance in the clinical setting by using a unique cohort of diabetic individuals protected from DR. We have previously reported that this patient population showed an increase in the protective arm of the renin‐angiotensin axis (Ang1‐7 and MAS1) and decease in TGF‐β1 expression . This study identifies a novel mechanism of protection of CD34 + cells from diabetic stress by recognizing the critical role of ATM in the long‐term survival of HSCs.…”

Loss of Angiotensin-Converting Enzyme 2 Exacerbates Diabetic Retinopathy by Promoting Bone Marrow Dysfunction

“…However, circulating angiogenic cells of diabetics, such as CD34 + cells, typically lose this ability and secrete proinflammatory and vasoconstrictive factors . Additionally, diabetic circulating angiogenic cells lose their ability to migrate into tissues in response to local injury .…”