Meningeal Multipotent Cells: A Hidden Target for CNS Repair?

Traditionally, the primary role of the meninges is thought to be structural, i.e., to act as a surrounding membrane that contains and cushions the brain with cerebrospinal fluid. During development, the meninges is formed by both mesenchymal and neural crest cells. There is now emerging evidence that subsets of undifferentiated stem cells might persist in the adult meninges. In this mini-review, we survey representative studies of brain-meningeal interactions and discuss the hypothesis that the meninges are not just protective membranes, but instead contain multiplex stem cell subsets that may contribute to central nervous system (CNS) homeostasis. Further investigations into meningeal multipotent cells may reveal a "hidden" target for promoting neurovascular remodeling and repair after CNS injury and disease.

CD271+ Human Mesenchymal Stem Cells Show Antiarrhythmic Effects in a Novel Murine Infarction Model.

BACKGROUND: Ventricular arrhythmias (VA) are a common cause of sudden death after myocardial infarction (MI). Therefore, developing new therapeutic methods for the prevention and treatment of VA is of prime importance. METHODS: Human bone marrow derived CD271+ mesenchymal stem cells (MSC) were tested for their antiarrhythmic effect. This was done through the development of a novel mouse model using an immunocompromised Rag2-/- γc-/- mouse strain subjected to myocardial "infarction-reinfarction". The mice underwent a first ischemia-reperfusion through the left anterior descending (LAD) artery closure for 45 minutes with a subsequent second permanent LAD ligation after seven days from the first infarct. RESULTS: This mouse model induced various types of VA detected with continuous electrocardiogram (ECG) monitoring via implanted telemetry device. The immediate intramyocardial delivery of CD271+ MSC after the first MI significantly reduced VA induced after the second MI. CONCLUSIONS: In addition to the clinical relevance, more closely reflecting patients who suffer from severe ischemic heart disease and related arrhythmias, our new mouse model bearing reinfarction warrants the time required for stem cell engraftment and for the first time enables us to analyze and verify significant antiarrhythmic effects of human CD271+ stem cells in vivo.

Diabetes impairs the angiogenic capacity of human adipose-derived stem cells by reducing the CD271+ subpopulation in adipose tissue.

Type 2 diabetes mellitus is an important risk factor for cardiovascular diseases (CVDs). Therapeutic angiogenesis using adipose-derived stem cells (ADSCs) is attractive for CVD therapy. However, although it would be critical for ADSC application on CVD therapy, whether and how diabetes impairs human ADSC therapeutic potential is still uncertain. In this study, we aimed to investigate the impact of diabetes on the angiogenic potential of ADSCs in patients with CVDs, with special focus on stemness-related genes and cellular alteration of ADSCs. We established cultured ADSCs from diabetic (DM-ADSCs) and non-diabetic patients (nonDM-ADSCs) with CVDs. DM-ADSCs demonstrated limited proliferative capacity and reduced paracrine capacity of VEGF, with lower expression of the stemness gene SOX2. Angiogenic capacity and ADSC engraftment were assessed using xenograft experiments in a hindlimb ischemia model of athymic nude mice. Consistent with the results of in vitro assays, DM-ADSCs did not rescue limb ischemia. In contrast, nonDM-ADSCs induced neovascularization with enhanced engraftment. To elucidate the mechanism underlying these ADSC changes, we compared the surface marker profiles of freshly isolated ADSCs obtained from diabetic and non-diabetic patients by flow cytometry. Among studied subsets, the CD34+CD31-CD271+ subpopulation was reduced in the adipose tissues of diabetic patients. In addition, SOX2 expression and proliferative capacity were considerably reduced in nonDM-ADSCs derived from the stromal vascular fraction (SVF) with depletion of CD271+ cells (p < 0.01). Our observations elucidated that reduced CD271+ subpopulation is critical for the impairment of ADSCs in diabetic patients. Further investigations on the CD271+ subset of ADSCs might provide novel insights into the mechanisms and solutions for diabetes-related ADSC dysfunction in cell therapy.

Marker Expression of Interstitial Cells in Human Skeletal Muscle: An Immunohistochemical Study.

There is a growing recognition that myogenic stem cells are influenced by their microenvironment during regeneration. Several interstitial cell types have been described as supportive for myoblasts. In this role, both the pericyte as a possible progenitor for mesenchymal stem cells, and interstitial cells in the endomysium have been discussed. We have applied immunohistochemistry on normal and pathological human skeletal muscle using markers for pericytes, or progenitor cells and found a cell type co-expressing CD10, CD34, CD271, and platelet-derived growth factor receptor α omnipresent in the endomysium. The marker profile of these cells changed dynamically in response to muscle damage and atrophy, and they proliferated in response to damage. The cytology and expression profile of the CD10+ cells indicated a capacity to participate in myogenesis. Both morphology and indicated function of these cells matched properties of several previously described interstitial cell types. Our study suggests a limited number of cell types that could embrace many of these described cell types. Our study indicate that the CD10+, CD34+, CD271+, and platelet-derived growth factor receptor α+ cells could have a supportive role in human muscle regeneration, and thus the mechanisms by which they exert their influence could be implemented in stem cell therapy.

Fast isolation and expansion of multipotent cells from adipose tissue based on chitosan-selected primary culture.

Adipose-derived adult stem cells (ASCs) have gained much attention because of their multipotency and easy access. Here we describe a novel chitosan-based selection (CS) system instead of the conventional plastic adherence (PA) to obtain the primary ASCs. The minimal amount of adipose tissue for consistent isolation of ASCs is reduced from 10 mL to 5 mL. The selection is based on the specific interaction between cells and chitosan materials, which separate ASCs by forming spheroids during primary culture. The primary culture period was reduced from 4 days to one day and more ASCs (ten-fold expansion) were achieved in a week. The average duration for obtaining 1 × 10(7) cells takes about seven days from 5 mL of adipose tissue, compared to 14 days using the conventional PA method from 10 mL of adipose tissue. The replicative senescence of CS-ASCs is not evident until the fifteenth passage (vs. eighth for the PA-ASCs). The obtained ASCs (CS-ASCs) have less doubling time for the same passage of cells and show greater stemness than those obtained from the conventional PA method (PA-ASCs). Moreover, CS-ASCs undergo trilineage differentiation more effectively than PA-ASCs. The greater differentiation potential of CS-ASCs may be associated with the enrichment and maintenance of CD271 positive cells by chitosan selection of primary culture.

Optimization and validation of high-performance chromatographic condition for simultaneous determination of adapalene and benzoyl peroxide by response surface methodology.

The aim of this study was to develop a simple and reliable high-performance chromatographic (HPLC) method for simultaneous analysis of adapalene and benzoyl peroxide in pharmaceutical formulation by response surface methodology (RSM). An optimized mobile phase composed of acetonitrile, tetrahydrofuran and water containing 0.1% acetic acid at a ratio of 25:50:25 by volume was successfully predicted by using RSM. An isocratic separation was achieved by using the condition. Furthermore, the analytical method was validated in terms of specificity, linearity, accuracy and precision in a range of 80% to 120% of the expected concentration. Finally, the method was successfully applied to the analysis of a commercial product.