#cellular tech.

[ivmja]

Extracellular matrix components direct porcine muscle stem cell behavior

Karlijn J. Wilschuta, Henk P. Haagsmanb, Bernard A.J. Roelena,␣

Received 31 March 2009 Revised version received 2 October 2009 Accepted 16 October 2009 Available online 22 October 2009

...Apparently, the niche important for cell identity and behavior provides a suitable environment to sustain the self-renewal and differentiation capacity of primary stem cells. Therefore, by using the ECM components of the muscle niche we can enrich for muscle stem cells, optimize the myogenic capacity of the cells and investigate regulation of signaling pathways involved in muscle differentiation. Since pigs are more homologous to human than rodents in terms of physiology, organ size and life span, porcine stem cells can be of interest for tissue engineering and transplantation studies and in vitro culture of meat for human consumption [37]. In this study, we have examined the ECM components collagen, laminin, fibronectin, and also gelatin and Matrigel for their capacity to improve the proliferation and differentiation capacities of isolated primary porcine muscle stem cells.

Continued at:

www.ncbi.nlm.nih.gov/pubmed/19853598

[ivmja]

Algal Photosynthesis as the Primary Driver for a Sustainable Development in Energy, Feed, and Food Production

Ida G. Anemaet & Martijn Bekker & Klaas J. Hellingwerf Received: 26 February 2010 / Accepted: 30 June 2010 / Published online: 20 July 2010

Algal Biomass for “Vitromeat” A sustainable development of society in general may also require drastic changes in human consumption. To give an example: The environmental load of the level of meat consumption in the Western world is such that it will not be maintainable for the entire world population because of its very high energy (e.g., fertilizer) and fresh-water require- ment. Therefore, various initiatives are being taken to provide alternatives for this component of the human diet. One of these is often referred to as the “vitromeat” approach and implies the in vitro culturing of cells preferably derived from the muscle of a mammal to form an edible product (Edelman et al. 2005). Success in this approach heavily depends on finding a suitable cheap growth medium for these mammalian myoblasts. An important component in such media is the source of amino acids. Hydrolysates of plants are already in use to substitute the fetal calf serum (Chun et al. 2005; George et al. 2009). Algal biomass, also because of its high protein content, is an attractive starting point for the development of such medium constituents. Initial results in this approach, obtained in our research group hold great promise for success (M. Daniels et al., unpublished).

Continued at:

www.ncbi.nlm.nih.gov/pubmed/20640935

[ivmja]

Extracellular matrix components direct porcine muscle stem cell behavior

Karlijn J. Wilschuta, Henk P. Haagsmanb, Bernard A.J. Roelena,⁎

aDepartment of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht, The Netherlands bDepartment of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, The Netherlands

Received 31 March 2009 Revised version received 2 October 2009 Accepted 16 October 2009 Available online 22 October 2009

Abstract

In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle- residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

Introduction

When postnatal skeletal muscle growth and regeneration are needed, stem cells become activated after which they begin to proliferate and differentiate to contribute to muscle tissue. The activity of muscle stem cells is governed by the micro-environ- ment, or ‘niche’, consisting of the basement membrane of the myofiber, resident supporting cells, vascular system and the extracellular matrix (ECM). The ECM surrounding each muscle fiber consists of a network of glycoproteins like collagens, laminin and fibronectin organized by proteoglycans such as heparin sulfate. This network provides the muscle structural support for bearing force transmissions, mediates in cell–cell adhesion through integrin receptors and improves the binding of molecules to activate signaling mechanisms for the regulation of myogenesis [1,2].

Continued at:

http://www.sciencedirect.com/science/article/pii/S0014482709004431