Regenerative Medicine: 4/19 TE-RegenMed-StemCell feed

Tuesday, April 19, 2011

4/19 TE-RegenMed-StemCell feed

TE-RegenMed-StemCell feed

Mesenchymal stem cells facilitate axon sorting, myelination, and functional recovery in paralyzed mice deficient in Schwann cell-derived laminin.

April 18, 2011 at 9:10 AM

Mesenchymal stem cells facilitate axon sorting, myelination, and functional recovery in paralyzed mice deficient in Schwann cell-derived laminin.

Glia. 2011 Feb;59(2):267-77

Authors: Carlson KB, Singh P, Feaster MM, Ramnarain A, Pavlides C, Chen ZL, Yu WM, Feltri ML, Strickland S

Peripheral nerve function depends on a regulated process of axon and Schwann cell development. Schwann cells interact with peripheral neurons to sort and ensheath individual axons. Ablation of laminin γ1 in the peripheral nervous system (PNS) arrests Schwann cell development prior to radial sorting of axons. Peripheral nerves of laminin-deficient animals are disorganized and hypomyelinated. In this study, sciatic nerves of laminin-deficient mice were treated with syngenic murine adipose-derived stem cells (ADSCs). ADSCs expressed laminin in vitro and in vivo following transplant into mutant sciatic nerves. ADSC-treatment of mutant nerves caused endogenous Schwann cells to differentiate past the point of developmental arrest to sort and myelinate axons. This was shown by (1) functional, (2) ultrastructural, and (3) immunohistochemical analysis. Treatment of laminin-deficient nerves with either soluble laminin or the immortalized laminin-expressing cell line 3T3/L1 did not overcome endogenous Schwann cell developmental arrest. In summary, these results indicate that (1) laminin-deficient Schwann cells can be rescued, (2) a cell-based approach is beneficial in comparison with soluble protein treatment, and (3) mesenchymal stem cells modify sciatic nerve function via trophic effects rather than transdifferentiation in this system.

PMID: 21125647 [PubMed - indexed for MEDLINE]

The Effect of Storage Time on Adipose-Derived Stem Cell Recovery from Human Lipoaspirates.

April 18, 2011 at 9:10 AM

The Effect of Storage Time on Adipose-Derived Stem Cell Recovery from Human Lipoaspirates.

Cells Tissues Organs. 2011 Apr 14;

Authors: Carvalho PP, Wu X, Yu G, Dias IR, Gomes ME, Reis RL, Gimble JM

Multipotent adipose-derived stromal/stem cells (ASCs) can be isolated with high yield from human subcutaneous lipoaspirates. This study reports our experience isolating, expanding, differentiating and immunophenotypically characterizing ASCs over a period of 4 days after having surgically obtained the lipoaspirate samples. The ultimate goal is to understand how to optimize the consistent isolation of ASCs from lipoaspirates. The length of time between adipose tissue harvest and processing will need to be systematically evaluated with respect to cell yield, viability, and function since some distance is likely to exist between the plastic surgeon's office where lipoaspiration is performed and the current Good Manufacturing Practices (cGMP) laboratory where the ASCs are isolated. The objective of this study was to determine the effect of time delays on the yield and function of ASCs after collagenase digestion. We were able to isolate ASCs from lipoaspirates up to 72 h after the surgical procedure. The ASCs isolated on sequential days after the original tissue harvest proliferated, differentiated and maintained cell surface markers. We found that the initial 24-hour period is optimal for isolating ASCs with respect to cell yield and that there was no significant difference between ASC cell proliferation and differentiation ability within this period of time. In contrast, each of these parameters declined significantly for tissues maintained at room temperature for 48 or 72 h prior to isolation. These findings should be considered in the future development of standard operating procedures for cGMP processing of clinical-grade human ASCs.

PMID: 21494019 [PubMed - as supplied by publisher]