Transplanted Donor Cells Rescue Contra-Lateral Chemo-ablated Muscle Bed

Only 25% of Nuclei are of Donor Origin! R + BCNU DONOR (i.m.) or MGMTP140K WT L + BCNU SALINE (i.m.) O6BG (i.p.) Transplanted Donor Cells Rescue Contra-Lateral Chemo-ablated Muscle Bed

Transplanted Donor Cells Rescue Contra-Lateral Chemo-ablated Muscle Bed R L BCNU BCNU NO Images have been removed for the printing purpose. R L R L 14 Days Post-Transplantation (n = 8 /4) Muscle Injected with MGMT Donor Cells Muscle Injected with Wild-Type Donor Cells

pr in tin g BCNU L BCNU he R pu rp os e. Rescue of Contra-Lateral Chemo-ablated Muscle Bed with Negligible Donor Cell Contribution ov ed ag es ha v e be en re m Left EDL Im Right EDL fo rt NO MGMT(P140K) D14 Post-Transplantation

Heterogeneity within CD34 +ve Cells from Regenerating Skeletal Muscle Sca-1(-)/CD45(-)/CD34(+) Expressed by Satellite cell progenitor cells Images have been removed for the printing purpose. Intramuscular transplantation has been shown to result in successful engraftment Sca-1(+)/CD45(-)/CD34(+) Expressed by Muscle Derived Stem Cells (MDSCs) Sca-1(-) / CD45(-) Sca-1(+) / CD45(-) Intramuscular injection has been shown to result in successful engraftment Also expressed by Mesoangioblasts and skeletal muscle SP cells

Heterogeneity within CD34 +ve Cells from Regenerating Skeletal Muscle CD56(-)/ALP(+)/CD34(+) Pericyte marker Images have been removed for the printing purpose. Intra-arterial injection has been shown to result in successful engraftment in down stream muscles CD144(+)/CD56(+)/CD34(+) Myo-endothelial marker Sca-1(-) / CD45(-) Sca-1(+) / CD45(-) CD56(-) / ALP(+) CD144(+) / CD56 (+) CD144(+) / CD56 (-) Successful engraftment upon intra-muscular injection CD144(+)/CD56(-)/CD34(+) Endothelial cell marker

Heterogeneity within CD34 +ve Cells from Regenerating Skeletal Muscle Pax7(+)/CD34(+) Satellite cell marker Images have been removed for the printing purpose. Expressed in both quiescent and proliferating Satellite cells CD133 (+)/CD34(+) Endothelial progenitor marker but shown to have myogenecity Sca-1(-) / CD45(-) Sca-1(+) / CD45(-) CD56(-) / ALP(+) CD144(+) / CD56 (+) CD144(+) / CD56 (-) Pax7(+) CD133(+) Systemic injection resulted in successful engraftment into downstream muscles

Heterogeneity within CD34 +ve Cells from Regenerating Skeletal Muscle CD11b(+)/CD34(+) Monocyte marker Shown to aid in phagocytosis Images have been removed for the printing purpose. Promotes muscle stem cell proliferation and muscle regeneration CXCR4(+)/CD34(+) Receptor for SDF-1 and expressed in endothelial progenitors Sca-1(-) / CD45(-) Sca-1(+) / CD45(-) CD56(-) / ALP(+) CD144(+) / CD56 (+) CD144(+) / CD56 (-) Pax7(+) CD133(+) CD11b(+) CXCR4(+) SDF-1 is secreted from injured skeletal muscles Has been shown to contribute to myofiber formation

Peault et al. (2007) Molecular Therapy

3. Adult (Somatic) Stem Cells - Plasticity? 1. Neural Stem Cells for Blood. 2. Bone-Marrow Stem Cells for Liver, Skin and Neurons. 3. Blood Vessel Stem Cells for Fat and Muscles.

Questions & Future Direction: What is the Identity and Location of the Responding Stem Cells? 1. Cells recruited from systemic circulation? WT GFP+: Near ubiquitous expression of EGFP in cardiac and skeletal muscle BCNU MGMT(P140K) NO

Parabiosis UNSW ACEC Approval 09/27A From An improved method of parabiosis Bunster E. & Meyer R., Anat Rec 1933;57:339-343. Peripheral blood equilibrium is established 2-3 weeks post-surgery Bunster & Meyer (1933) Anatomical Records

Parabiosis Model Brack (2007) Science Conboy (2005) Nature

Parabiosis Model Is the Pro-Regenerative Signal Systemic? Are the Responding Progenitors Recruited from Circulation? Images have been removed for the printing purpose. WT BCNU NO BCNU MGMT(P140K) GFP+: Near-ubiquitous expression of EGFP

Parabiosis Model Is the Pro-Regenerative Signal Systemic? Are the Responding Progenitors Recruited from Circulation? WT GFP+: Near-ubiquitous expression of EGFP Day -3 Day 0 Male Donor Cells MGMT(tg/tg) - into TA & EDL - 3 Days of regeneration Selectionof Donor Cells -CD34(+ve) cells - 6 x 10 4 donor cells BCNU NO BCNU MGMT(P140K)

Systemic Stem Cell Activation Signals What is the Identity and Location of the Responding Stem Cells? 1. Cells recruited from systemic circulation? 2. Local stem cells activated upon receiving signal in systemic circulation? WT GFP+: Near ubiquitous expression of EGFP in cardiac and skeletal muscle BCNU MGMT(P140K) NO

Future Directions Candidate chemokine/cytokine & receptor screening SDF-1, VEGF, TNF-α, IGF-1 etc. Quantitative RT-PCR FACS analyses Transplantation of various donor sub-populations. Identify population(s) responsible for the systemic pro-regenerative signal Implantation of bio-degradable gels releasing recombinant protein(s) Alginate Gel, Atelocollagen, Fmoc-L-Phenylalanine-L-Phenylalanine (Fmoc- Phe-Phe)

Work in Progress Screening of Candidate Cytokines & Chemokines using qrt-pcr - Honours Project, Animesh Singla SDF-1, VEGF, TNF-α, IGF-1 etc. Multiple time-point analyses (D1 - D2 - D3 - D4 - D5 - D7 - D14) injured vs Chemo-ablated alpha-sg null (dystrophic muscle under long-term de/regeneration cycle)

Work in Progress Screening of Candidate Cytokines & Chemokines using qrt-pcr - Honours Project, Animesh Singla SDF-1, VEGF, TNF-α, IGF-1 etc. Multiple time-point analyses (D1 - D2 - D3 - D4 - D5 - D7 - D14) Images have been removed for the printing purpose. Sca-1(-) / CD45(-) Sca-1(+) / CD45(-) CD56(-) / ALP(+) CD144(+) / CD56 (+) CD144(+) / CD56 (-) Pax7(+) CD133(+) CD11b(+) CXCR4(+)

Work in Progress Screening of Candidate Cytokines & Chemokines using qrt-pcr - Honours Project, Animesh Singla SDF-1, VEGF, TNF-α, IGF-1 etc. Multiple time-point analyses (D1 - D2 - D3 - D4 - D5 - D7 - D14) Mouse gastrocnemius 5 days post freeze injury showing VEGF (brown) staining. (Wagatsuma, Mol Cell Biochem 2007) Muscle biopsy from DMD paqent (Christov et. al., Mol Biol Cell 2007)