Role of sphingolipid metabolism in chondrogenesis

Background

Cartilage is a tissue with low self-repair capability, and therefore it is important to find therapeutic strategies that enable efficient cartilage repair. Mesenchymal stem cells (MSCs) are adult stem cells that have unique properties of self-renewal, proliferation and potential for multilineage differentiation [1]. Because of their chondrogenic potential, MSCs have been recognized as promising candidates for cell-based therapies of cartilage defects [2]. However, the lack of knowledge on the precise molecular mechanisms participating in this differentiation process, as well as the absence of well-defined markers for chondrogenesis, have hindered achievement of satisfactory results.

Several studies have demonstrated the importance of sphingolipid metabolism (SM) on cartilage homeostasis and chondrogenesis of MSCs [3-6]. Sphingolipids, a family of membrane lipids, are bioactive molecules that participate in diverse functions controlling fundamental cellular processes such as cell division, differentiation, and cell death. Although sphingolipids contribute to only a small proportion of the total cellular lipid pool, their accumulation in certain cells may be a trigger for pathology of many diseases.

The aim of this assignment is to unravel the role of SM on chondrogenic differentiation using diverse biochemical techniques, including mass spectrometry imaging. Mass spectrometry imaging (MSI) is a fairly new, powerful technique for determining and visualizing the molecular complexity of biological samples.

Approach

To study the role of SM on cartilage formation you will culture chondrocytes and MSCs and stimulate them with SM altering drugs and subsequently analyze their cartilage matrix production and SM.

Techniques

Monolayer and pellet cultures, pharmacological stimulation, histology, colorimetric assays, qPCR, and mass spectrometry imaging (such as MALDI IMS, ToF-SIMS, and DESI)

References

1. Koga, H., et al., Mesenchymal stem cell-based therapy for cartilage repair: a review. Knee Surg Sports Traumatol Arthrosc, 2009. 17(11): p. 1289-97.

2. Gupta, P.K., et al., Mesenchymal stem cells for cartilage repair in osteoarthritis. Stem Cell Res Ther, 2012. 3(4): p. 25.

3. Simonaro, C.M., et al., Acid ceramidase maintains the chondrogenic phenotype of expanded primary chondrocytes and improves the chondrogenic differentiation of bone marrow-derived mesenchymal stem cells. PLoS One, 2013. 8(4): p. e62715.

4. Gilbert, S.J., et al., Sphingomyelinase decreases type II collagen expression in bovine articular cartilage chondrocytes via the ERK signaling pathway. Arthritis Rheum, 2008. 58(1): p. 209-20.

5. Sabatini, M., et al., Effects of ceramide on apoptosis, proteoglycan degradation, and matrix metalloproteinase expression in rabbit articular cartilage. Biochem Biophys Res Commun, 2000. 267(1): p. 438-44.

6. Rocha, B., et al., Characterization of lipidic markers of chondrogenic differentiation using mass spectrometry imaging. Proteomics, 2015. 15(4): p. 702-13.

Daily supervisor: Brenda Bakker, MSc

If you are interested in this assignment, please contact: Dr. Janneke Alers, contact person for all DBE assignments

j.c.alers@utwente.nl