Angiogenesis induced by autologous whole bone marrow stem cells transplantation

[Biotherapies for erectile dysfunction and Peyronie's disease: Where are we now?]

INTRODUCTION

Clinical trials of cell therapy for erectile dysfunction (ED) and Peyronie's disease (PD) were recently conducted after preclinical studies.

AIMS

The aims of this study are to give an update on biotherapy for ED and PD and to describe the regulatory framework for these therapies.

MATERIALS AND METHODS

A literature review was performed through PubMed and Clinical.trials.gov addressing cell therapy for ED and PD and using following keywords "erectile dysfunction", "Peyronie's disease", "stem cell", and "platelet-rich plasma".

RESULTS

Preclinical studies in rodent models have shown the potential benefit of cell therapy for ED after radical prostatectomy or caused by metabolic diseases, and PD. The tissues used to obtain the therapeutic product were bone marrow, adipose tissue and blood (PRP, platelet-rich plasma). Mechanism of action was shown to be temporary and mainly paracrine. Four clinical trials were published concerning ED after radical prostatectomy and in diabetic patients and one for PD. Eleven clinical trials including three randomized trials are currently going on. Preclinical and preliminary clinical results suggested the possibility to improve spontaneous erectile function and response to pharmaceutical treatment in initially non-responder patients. This effect is mediated by an improvement of penile vascularization. A reduction of penile curvature without side effect was noted after injections into the plaque of PD patients. Most of these therapeutic strategies using autologous cells were considered as "Advanced Therapy Medicinal Products" with strict regulatory frameworks imposing heavy constraints, in particular in case of "substantial" modification of the cells. The regulatory framework remains unclear and more permissive for PRP and cell therapy processes with extemporaneous preparation/injection and no "substantial" modifications.

CONCLUSIONS

First results on cell therapy for ED and PD are promising. The regulatory framework can significantly change according to cell preparations and origins leading to various constraints. This regulatory framework is crucial to consider for the choice of the procedure.

Development of a dual screening strategy to identify pro-angiogenic compounds from natural products: application on Tongmai Yangxin Pills

Establishment and application the dual-screening strategy to screen pro-angiogenic compounds from natural products for the first time.

Inhibitory effects of mesenchymal stem cells in intimal hyperplasia after balloon angioplasty

OBJECTIVE

Intimal hyperplasia is a major cause of restenosis after arterial bypass and balloon angioplasty. Induction of rapid re-endothelialization has been proposed to reduce intimal hyperplasia. The aim of this study was to evaluate the inhibitory effect of mesenchymal stem cells on intimal hyperplasia.

METHODS

Male New Zealand white rabbits were fed 1% cholesterol diets from 1 week before balloon angioplasty to the day of harvest. After dissection of rabbit carotid arteries, balloon angioplasty was performed with a 2F Fogarty embolectomy catheter. The injured carotid artery was coated with a mixture of 7 × 10(6) human umbilical cord mesenchymal stem cells (HUC-MSCs) and fibrin matrix. The carotid arteries were harvested 2, 4, and 8 weeks thereafter, and immunofluorescent staining and quantitative real-time polymerase chain reaction analysis were performed.

RESULTS

The intima/media ratio was significantly reduced in the group treated with HUC-MSCs compared with the nontreated group (Student t-tests, *P < .05). The area of re-endothelialization was significantly higher (Student t-tests, *P < .05) in the group treated with HUC-MSCs than in the nontreated group. Expression of angiogenic genes such as vascular endothelial growth factor, platelet-derived growth factor, kinase insert domain receptor 1, angiopoietin 1, and angio-associated migratory cell protein was increased (analysis of variance, P < .05) in the group treated with HUC-MSCs relative to the nontreated group.

CONCLUSIONS

Our study showed that HUC-MSCs reduce the formation of intimal hyperplasia through rapid re-endothelialization. This result might be applied to development of stem cell-coated stents as well as to development of a stem cell-containing sheet coat for inhibition of intimal hyperplasia after angioplasty or surgery.

Somatic cell dedifferentiation/reprogramming for regenerative medicine

The concept of dedifferentiation or reprogramming of a somatic cell into a pluripotent embryonic stem cell-like cell (ES-like cell), which give rise to three germ layers and differentiate various cell types, opens a new era in stem cell biology and provides potential therapeutic modality in regenerative medicine. Here, we outline current dedifferentiation/reprogramming methods and their technical hurdles, and the safety and therapeutic applications of reprogrammed pluripotent stem cells in regenerative medicine. This review summarizes the concept and data of somatic cell nuclear transfer, fusion of somatic cells with ES cells, viral or non-viral transduction of pluripotency-related genes into somatic cells, introduction of extract (or proteins) of pluripotent cells into somatic cells. Dedifferentiated/reprogrammed ES-like cells could be a perfect genetic match (autologous or tailored pluripotent stem cells) for future applications. Further studies regarding technical refinements as well as mechanistic analysis of dedifferentiation induction and re-differentiation into specific cell types will provide us with the substantial application of pluripotent stem cells to therapeutic purposes.

Clinical application of stem cells for therapeutic angiogenesis in patients with peripheral arterial disease

Peripheral arterial disease (PAD) may ultimately cause to the loss of the affected limb due to gangrene or infection. Some patients with PAD may have severe coexisting diseases and diffuse involvement of their distal arteries, and so they are poor candidates for revascularization procedures. Angiogenesis has recently been suggested to be a new emerging treatment strategy for patients with PAD. Angiogenesis is defined as the sprouting of new capillaries from pre-existing vascular structures; this process plays a major role in the development of collateral vessels in an ischemic limb. Yet, the exact mechanism of angiogenesis is currently poorly understood. It has been established that angiogenesis is initiated by hypoxia and it requires various pro-angiogenic factors such as vascular endothelial growth factor. Therapeutic angiogenesis is aimed at enhancing natural angiogenesis by the administration of the cells or genes that can trigger angiogenesis and this can lead to pain relief and wound healing by the development of collateral vessels. Most of the recent clinical trials have reported that stem cell therapy for promoting angiogenesis in patients with PAD improves the ischemic symptoms and enhances wound healing. However, there are several limitations to approve a standard treatment for PAD such as small sample size in several prevous studies, their diverse inclusion criteria and the lack of standard assessment methods for the safety and outcome. Therefore, multicenter, large-scale and randomized controlled studies are needed to prove the safety and efficacy of the clinically applying stem cells for therapeutic angiogenesis in patients with PAD.

Thromoboagiitis Obliterans (TAO)

Thromboangiitis obliterans (TAO) is nonatherosclerotic inflammatory disease of the peripheral blood vessels, and TAO affects the small and medium sized vessels of the extremities. TAO is mainly seen in young males who smoke, and smoking is strongly associated with the disease course and progression. The diagnosis is made on the basis of the history, the physical examination and the clinical diagnostic criteria. As the bedrock for treating patients with TAO, absolute abstinence from tobacco is most important factor, and patients with TAO are usually managed conservatively. Surgical bypass or endovascular therapy is usually not possible for patients with TAO because of the diffuse segmental involvement and the distal nature of the disease. Therefore, stem cell therapy is considered to be a novel therapeutic modality for treating patients with TAO and who are not eligible for conventional revascularization therapies. In this paper, I have summarized the recent knowledge about TAO and I have reviewed the recent studies that have focused on the treatment of TAO.

In Vitro Differentiation and Expansion of Intrathymic T Cell Progenitors from Human Umbilical Cord Blood-Derived CD34(+) Cells

BACKGROUND AND OBJECTIVES

CD4 positive cells play a central role in many lethal diseases, such as AIDS, cancer and autoimmunity diseases. CD4(-) commitment of hematopoietic stem cells involved in T cell lineage, monocyte and dendritic cells development. In this study, we showed that CD4 commitment out of thymus which may happen when hematopoietic cells undergo monocyte, dendritic cells or even earlier T cell progenitor differentiation.

METHODS AND RESULTS

after culturing in our medium for more than five weeks, CD4(-)CD34(+) fraction, isolated from human umbilical cord blood, decreased to 1%. However, the fraction expressing CD4 went up to 86.5%. After CD4(+) cells were cultured in methylcellulose-based CFU medium, about 40 colonies/2×10(4) cells could developed. An activation of notch-1 pathway in the freshly isolated CD34(+) cells and up-regulation of PI3K/JNK/c-Myc pathway may provide an explanation for the differentiation and proliferation of CD4(+) cells from CD34(+) hematopoietic stem cells respectively.

CONCLUSIONS

ACD4(+) enriched population was obtained after highly purified CD34(+) cells, isolated from human cord blood, underwent long term culture in a feeder layer-free culturing system. Colonigenic ability was maintained in the population of CD4(+) cells. This finding will be a benefit for the studies on the cell therapy for immune dysfunctions.