Effects of iron oxide nanoparticles on cardiac differentiation of embryonic stem cells.

The therapeutic potential of transplantation of embryonic stem cells (ESCs) in animal model of myocardial infarction has been consistently demonstrated. The development of superparamagnetic iron oxide (SPIO) nanoparticles labeling and cardiac magnetic resonance imaging (MRI) have been increasingly used to track the migration of transplanted cells in vivo allowing cell fate determination. However, the impact of SPIO- labeling on cell phenotype and cardiac differentiation capacity of ESCs remains unclear. In this study, we demonstrated that ESCs labeled with SPIO compared to their unlabeled counterparts had similar cardiogenic capacity, and SPIO-labeling did not affect calcium-handling property of ESC-derived cardiomyocytes. Moreover, transplantation of SPIO-labeled ESCs via direct intra-myocardial injection to infarct myocardium resulted in significant improvement in heart function. These findings demonstrated the feasibility of in vivo ESC tracking using SPIO-labeling and cardiac MRI without affecting the cardiac differentiation potential and functional properties of ESCs.

Triiodothyronine promotes cardiac differentiation and maturation of embryonic stem cells via the classical genomic pathway.

Embryonic stem cells (ESCs) can differentiate into functional cardiomyocytes and thus represent a promising cell source for cardiac regenerative therapy. Nevertheless, the therapeutic application of ESC-derived cardiomyocytes is limited by the low efficacy of the current protocol for cardiac differentiation and their immature phenotypes. Although thyroid hormone is essential for normal cardiac development and function, its role in the cardiac differentiation of ESCs, as well as the maturation of ESC-derived cardiomyocytes, remains unclear. In this study, we examined the cardiac differentiation of murine ESCs in the presence of T(3) for 7 d using flow cytometry, RT-PCR, cellular electrophysiology study, and confocal calcium imaging. Compared with control conditions, T(3) supplementation increased the number of ESC-derived cardiomyocytes and was accompanied by up-regulation of a panel of cardiac markers, including Nkx2.5, myosin light chain-2V, as well as alpha- and beta-myosin heavy chain. More importantly, electrophysiological study revealed that ESC-derived cardiomyocytes exhibited more adult-like phenotypes after T(3) supplementation based on action potential characteristics. They also exhibited more adult-like calcium homeostasis properties. These phenotypic changes were associated with up-regulation of sarco(endo)plasmic reticulum calcium ATPase-2a and ryanodine receptor-2 expression. In addition, the classical (genomic) pathway was shown to be involved in T(3)-induced cardiac differentiation of ESCs. Our results show that T(3) supplementation promotes cardiac differentiation of ESCs and enhances maturation of electrophysiological, as well as calcium homeostasis, properties of ESC-derived cardiomyocytes.

The effectiveness of manual therapy in the management of musculoskeletal disorders of the shoulder: a systematic review.

A systematic review of randomised controlled trials (RCTs) was conducted to determine the effectiveness of manual therapy (MT) techniques for the management of musculoskeletal disorders of the shoulder. Seven electronic databases were searched up to January 2007, and reference lists of retrieved articles and relevant MT journals were screened. Fourteen RCTs met the inclusion criteria and their methodological qualities were assessed using the PEDro scale. Results were analyzed within diagnostic subgroups (adhesive capsulitis (AC), shoulder impingement syndrome [SIS], non-specific shoulder pain/dysfunction) and a qualitative analysis using levels of evidence to define treatment effectiveness was applied. For SIS, there was no clear evidence to suggest additional benefits of MT to other interventions. MT was not shown to be more effective than other conservative interventions for AC, however, massage and Mobilizations-with-Movement may be useful in comparison to no treatment for short-term outcomes for shoulder dysfunction.