New possibilities for the use of stem cell based therapies in bone and heart
repair.
Zsombor Lacza, Miklós Weszl, Attila Cselenyák, Eszter Pankotai, Gabriella Vácz,
Dénes Horváthy, Gábor Skaliczki, Viktor Izápy, Levente Kiss
Laboratory of tissue engineering, Dept. of Human Physiology and Clinical
Experimental Research, Semmelweis University, Budapest, Hungary
Stem cells povide a good opportunity for the development of new regenerative
apporaches and several protocols are under clinical trials. However, it is becoming
clear that understanding the mechanisms by which grafted or resident stem cells
repair damaged tissues is crucial for designing effective therapies. I present new
results of stem cell-based therapies in two distinct fields: hearts and bones.
Cell implantation is already used in cardiac repair after myocardial infarction.
However, little is known about the cellular mechanisms by which the cells improve
cardiac performance. We used an in vitro model of ishcemia and investigated cell-tocell contacts with multi-channel time-lapse confocal microscopy during and after
ischemia and cell implantation. We showed that the addition of healthy cells to
postishcemic cultures significantly increases the survival rate, which is not dependent
on either differentiation, cell fusion or soluble factors. We observed that mitochondria
are transferred form one cell to the other through cellular filaments (nanotubes), and
that inhibition of mitochondrial function abolishes the salvage effect.
The other field where cell therapy is closest to clinical use is musculoskeletal
repair. There are numerous bone replacement meterials available, however, none of
them is optimal. We developed a coating technique which enables better seeding and
proliferation of bone marrow or dental pulp derived stem cells on the surface of
human bone allografts and tested it in an animal model of bone defect. Osteoblast
activity was monitored with NANO-SPECT-CT, while osteointegration with high
resolution microCT.
This study was supported by TÉT ARG and SIN, Bolyai Fellowship, OTKA
83803 and TÁMOP-4.2.2/08/1/KMR-2008-0004.