Bone marrow-derived myeloid progenitors in the leptomeninges of adult mice.

Although the bone marrow contains most hematopoietic activity during adulthood, hematopoietic stem and progenitor cells can be recovered from various extramedullary sites. Cells with hematopoietic progenitor properties have even been reported in the adult brain under steady-state conditions, but their nature and localization remain insufficiently defined. Here, we describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice.

Generation of Cardiomyocytes From Vascular Adventitia-Resident Stem Cells.

Rationale: Regeneration of lost cardiomyocytes is a fundamental unresolved problem leading to heart failure. Despite several strategies developed from intensive studies performed in the past decades, endogenous regeneration of heart tissue is still limited and presents a big challenge that needs to be overcome to serve as a successful therapeutic option for myocardial infarction.

Objective: One of the essential prerequisites for cardiac regeneration is the identification of endogenous cardiomyocyte progenitors and their niche that can be targeted by new therapeutic approaches.

The vascular adventitia: An endogenous, omnipresent source of stem cells in the body.

Until a decade ago it was believed that the wall of adult blood vessels exclusively contains terminally differentiated cell types. A paradigm shift was unavoidable since studies from different groups convincingly showed the presence of vascular wall-resident stem and progenitor cells (VW-SCs) which were identified to particularly reside in the sub-endothelial space and the so-called adventitial "vasculogenic zone". Data published during the last decade uncloaked the fact that VW-SCs have the capacity to differentiate into both vascular and non-vascular cell types.

Robust Generation of Cardiomyocytes from Human iPS Cells Requires Precise Modulation of BMP and WNT Signaling.

Various strategies have been published enabling cardiomyocyte differentiation of human induced pluripotent stem (iPS) cells. However the complex nature of signaling pathways involved as well as line-to-line variability compromises the application of a particular protocol to robustly obtain cardiomyocytes from multiple iPS lines. Hence it is necessary to identify optimized protocols with alternative combinations of specific growth factors and small molecules to enhance the robustness of cardiac differentiation.

Thinking outside the liver: induced pluripotent stem cells for hepatic applications.

The discovery of induced pluripotent stem cells (iPSCs) unraveled a mystery in stem cell research, after identification of four re-programming factors for generating pluripotent stem cells without the need of embryos. This breakthrough in generating iPSCs from somatic cells has overcome the ethical issues and immune rejection involved in the use of human embryonic stem cells. Hence, iPSCs form a great potential source for developing disease models, drug toxicity screening and cell-based therapies.

Derivation, characterization and retinal differentiation of induced pluripotent stem cells.

Millions of people world over suffer visual disability due to retinal dystrophies which can be age-related or a genetic disorder resulting in gradual degeneration of the retinal pigmented epithelial (RPE) cells and photoreceptors. Therefore, cell replacement therapy offers a great promise in treating such diseases. Since the adult retina does not harbour any stem cells, alternative stem cell sources like the embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) offer a great promise for generating different cell types of the retina.

Identification of circulating CD90 CD73 cells in cirrhosis of liver.

Aim: To identify circulating CD90(+) CD73(+) CD45(-) cells and evaluate their in vitro proliferating abilities.

Methods: Patients with cirrhosis (n = 43), and healthy volunteers (n = 40) were recruited to the study. Mononuclear cells were isolated and cultured from the peripheral blood of controls and cirrhosis patients.

Characterization of hepatic progenitors from human fetal liver during second trimester.

Aim: To enrich hepatic progenitors using epithelial cell adhesion molecule (EpCAM) as a marker from human fetal liver and investigate the expression of human leukocyte antigen (HLA) and their markers associated with hepatic progenitor cells.

Methods: EpCAM +ve cells were isolated using magnetic cell sorting (MACS) from human fetuses (n = 10) at 15-25 wk gestation. Expression of markers for hepatic progenitors such as albumin, alpha-fetoprotein (AFP), CD29 (integrin beta1), CD49f (integrin alpha6) and CD90 (Thy 1) was studied by using flow cytometry, immunocytochemistry and RT-PCR; HLA class I (A, B, C) and class II (DR) expression was studied by flow cytometry only.