The road to pluripotence: the research response to the embryonic stem cell debate

Ginsenosides on stem cells fate specification-a novel perspective

Recent studies have demonstrated that stem cells have attracted much attention due to their special abilities of proliferation, differentiation and self-renewal, and are of great significance in regenerative medicine and anti-aging research. Hence, finding natural medicines that intervene the fate specification of stem cells has become a priority. Ginsenosides, the key components of natural botanical ginseng, have been extensively studied for versatile effects, such as regulating stem cells function and resisting aging. This review aims to summarize recent progression regarding the impact of ginsenosides on the behavior of adult stem cells, particularly from the perspective of proliferation, differentiation and self-renewal.

Mapping and driving the stem cell ecosystem

The stem cell and regenerative medicine arena has become increasingly complicated in recent years with thousands of people involved. There are as many as a dozen or more main groups of stakeholders, who together may be viewed as one ecosystem that is now rapidly evolving. The nature of the ecosystem and its evolution have major implications for not just those within it, but also for medicine and society at large. Here, I describe this ecosystem and its evolution, as well as the negative impacts within the ecosystem of a constellation of hundreds of unproven for-profit clinics and related businesses. Finally, I propose approaches for how to positively influence and drive the future of the global stem cell ecosystem.

The science and ethics of cell-based therapies for Parkinson's disease

Parkinson's Disease (PD) is an age-related, disabling neurodegenerative disorder. Although sufferers usually respond to dopamine agonists for extended periods, the disease remains progressive and adverse drug effects can compromise effective long term treatment. Cell-based therapies have been the subject of much hype and optimism with regard to PD. Proof of principle was provided in the 1980s with fetal tissue transplantation trials demonstrating successful graft survival. Embryonic stem cells and reprogrammed or transdifferentiated somatic cells may provide alternative sources of tissue with the potential to overcome the material shortages and technical difficulties that have hindered fetal neural transplants. This article will review the state of the science for cell based therapies and examine the ethical issues that societies must negotiate regarding their clinical use.

Human somatic cell nuclear transfer and reproductive cloning: an Ethics Committee opinion

This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer and cloning," last published in Fertil Steril 2012;98:804-7.

Human somatic cell nuclear transfer and cloning

This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer (cloning)," last published in Fertil Steril 2000;74:873-6.

A comparison of stem cells for therapeutic use

A critical comparison of the attributes of several types of stem cells is presented, with particular emphasis on properties that are critical for the application of these cells for therapeutic purposes. The importance of an autologous source of pluripotent stem cells is stressed. It is apparent that two sources currently exist for non-embryonic pluripotent stem cells--very small embryonic-like stem cells (VSELs) and induced pluripotent stem cells (iPS). The impact of the emerging iPS research on therapy is considered.

Testicular germline stem cells

Stem cells have the ability to both differentiate into other mature cell types and maintain an undifferentiated state by self-renewal. These unique properties form the basis for stem cell use in organ replacement and tissue regeneration in clinical medicine. Currently, embryonic stem cells are the best-studied stem cell type. However alternative stem cells such as induced pluripotent stem cells and other adult stem cells are also being actively investigated for their potential for cell-based therapy. Among adult stem cells, emerging research has focused on evaluating the pluripotency potential of testis stem cells. To date, stem cells with embryonic-like potential have been created from adult testis germ cells. These cells could provide patient-specific, non-embryo-derived stem cells for men in the future.

Stem cells and ethics: current issues

Much attention has recently turned to the promise and potential of human stem cells in therapeutic applications for the repair of cardiac tissue. The advances being made in the laboratory are exciting, and the pace at which research using human stem cells is moving from bench to bedside is extraordinary. The social, ethical, and policy considerations embedded within this area of research also require a large amount of attention and deliberation so that the scientific progress is able to successfully continue without social backlash.

Development of insulin-producing cells from primitive biologic precursors

PURPOSE OF REVIEW

The differentiation of pluripotent and multipotent stem cells into insulin-producing cells has the potential to create a renewable supply of replacement beta cells with tremendous utility in the treatment of diabetes. The purpose of this review is to summarize recent advancements in the field, with emphasis on the limitations of this technology as it relates to the beta cell.

RECENT FINDINGS

Multiple groups have developed successful in-vitro protocols to differentiate human embryonic stem cells and selected tissue specific stem cells into progenitors capable of insulin production and glucose-stimulated insulin secretion. The resulting cells are immature beta cell-like cells that coexpress multiple islet hormones and lack the full complement of genes necessary for normal function. Protocols that include in-vivo maturation in immune-compromised mice produce cells with a more mature phenotype.

SUMMARY

Although tremendous progress has been made in differentiating stem cells into insulin-producing cells, there is still more research needed to produce a fully functional adult beta cell.

Neural stem cells: mechanisms of fate specification and nuclear reprogramming in regenerative medicine

Recently, intense interest in the potential use of neural stem cells (NSC) in the clinical therapy of brain disease and injury has resulted in rapid progress in research on the properties of NSC, their innate and directed differentiation potential and the induced reprogramming of differentiated somatic cells to revert to a pluripotent NSC-like state. The aim of this review is to give an overview of our current operational definitions of the NSC lineage, the growing understanding of extrinsic and intrinsic mechanisms, including heritable but reversible epigenetic chromatin modifications that regulate the maintenance and differentiation of NSC in vivo, and to emphasize ground-breaking efforts of cellular reprogramming with the view to generating patient-specific stem cells for cell replacement therapy. This is set against a summary of current practical procedures for the isolation, research and application of NSC, and of the state of the art in NSC-based regenerative medicine of the nervous system. Both provide the backdrop for the translation of recent findings into innovative clinical applications, with the hope of increasing the safety, efficiency and ethical acceptability of NSC-based therapies in the near future.