Reproduction de : Thèse de doctorat : Géographie : Lyon 2 : 1998. / Titre provenant de l'écran-titre. Notes bibliographiques.

Diss.--Geisteswissenschaftlichen Fak.--Innsbruck--Universität, 1992. / Bibliogr. p. 217-237.

Liver failure, which is the result of liver injury and pathological inflammation, is currently only successfully treated by organ transplantation. However donor organ shortages preclude transplantation for many patients in need. Thus, bioartificial liver systems (BALS) are being developed as a bridge to transplantation, or to create an environment conducive to liver regeneration. Hepatocytes, the main functional cells of the liver, are the cells of choice for BALSs, but in standard conditions ex vivo, they rapidly suffer from a reduction of their functionality and viability. Coculture with stromal cells, for example bone marrow mesenchymal stromal cells (BM-MSC), has been shown to improve, and extend, hepatocyte function ex vivo up to 21 days. But, only small numbers of BM-MSCs can be harvested from adult volunteers. We have previously described an alternative, more plentiful, source of MSCs — human umbilical cord perivascular cells (HUCPVC) — that are easily expanded and non-alloreactive. Our hypothesis was that HUCPVCs are putative stromal cells for hepatocytes. Our results show that HUCPVCs improved hepatocyte albumin secretion, urea synthesis and maintained hepatocyte cytochrome activity and the expression of hepato-specific genes. Furthermore, there was a net proliferation of hepatocytes, which were polarized in coculture with HUCPVCs, as judged by functional bile canaliculi that were present for up to 40 days. We found that both soluble and non-soluble factors contributed to these effects, while neither was able to allow net proliferation individually. Moreover, HUCPVCs expressed both hepato-trophic and anti-inflammatory factors, at different levels to BM-MSCs, indicating the potential for differential hepato-therapeutics. We conclude that HUCPVCs are putative stromal cells for hepatocytes; they improve hepatocyte functionality, polarity, morphology and net proliferation, and thus present an opportunity for the improvement of both BALS function and liver therapy.

Liver failure, which is the result of liver injury and pathological inflammation, is currently only successfully treated by organ transplantation. However donor organ shortages preclude transplantation for many patients in need. Thus, bioartificial liver systems (BALS) are being developed as a bridge to transplantation, or to create an environment conducive to liver regeneration. Hepatocytes, the main functional cells of the liver, are the cells of choice for BALSs, but in standard conditions ex vivo, they rapidly suffer from a reduction of their functionality and viability. Coculture with stromal cells, for example bone marrow mesenchymal stromal cells (BM-MSC), has been shown to improve, and extend, hepatocyte function ex vivo up to 21 days. But, only small numbers of BM-MSCs can be harvested from adult volunteers. We have previously described an alternative, more plentiful, source of MSCs — human umbilical cord perivascular cells (HUCPVC) — that are easily expanded and non-alloreactive. Our hypothesis was that HUCPVCs are putative stromal cells for hepatocytes. Our results show that HUCPVCs improved hepatocyte albumin secretion, urea synthesis and maintained hepatocyte cytochrome activity and the expression of hepato-specific genes. Furthermore, there was a net proliferation of hepatocytes, which were polarized in coculture with HUCPVCs, as judged by functional bile canaliculi that were present for up to 40 days. We found that both soluble and non-soluble factors contributed to these effects, while neither was able to allow net proliferation individually. Moreover, HUCPVCs expressed both hepato-trophic and anti-inflammatory factors, at different levels to BM-MSCs, indicating the potential for differential hepato-therapeutics. We conclude that HUCPVCs are putative stromal cells for hepatocytes; they improve hepatocyte functionality, polarity, morphology and net proliferation, and thus present an opportunity for the improvement of both BALS function and liver therapy.

No description available.