Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Biotech / Medical : STEM -- StemCells, Inc. -- Ignore unavailable to you. Want to Upgrade?

To: scaram(o)uche who wrote (476)	6/6/2000 12:26:00 PM
From: redbird	Read Replies (1) \| Respond to of 805

Are the NYT articles the reason for today's run in STEM and NEXL? The whole group seems to be up. Redbird

To: scaram(o)uche who wrote (476)	6/10/2000 11:28:00 AM
From: scaram(o)uche	Read Replies (2) \| Respond to of 805

[ just parking ] Abstract from a group at Wisconsin that has interests in the migration and differentiation of stem cells, particularly as they relate to the pancreas..... Pancreatic Gene Expression in Differentiating Embryonic Stem Cells JON S. ODORICO, LYNN M. JACOBSON, NADYA LUMELSKY, DEBRA A. HULLETT, JAMES A. THOMSON, BRENDA W. KAHAN Embryonic stem (ES) cells possess the potential to develop into multiple cell lineages in vitro, the differentiated progeny of which might be used for cell-based transplantation therapies. Neural, hematopoeitic, myogenic, chondrogenic, and vascular endothelial precursors have been derived which express many of the morphologic and physiologic characteristics of terminally differentiated cell types. The differentiation of ES cells into endodermally-derived tissues, such as pancreas or pancreatic islets, has not been reported. Thus, we sought out to determine if ES cells are capable of differentiating into pancreatic islet cells. Methods: Murine D3 ES cells were allowed to spontaneously differentiate into embryoid bodies (EBs) in suspension cultures in 10% fetal calf serum and 5% CO2 without specific growth factors or additives. After 7 days, EBs were plated on adhesive plastic and cultured for up to 4 weeks. Total RNA was isolated from cultures and RT-PCR performed using endoderm and pancreatic endocrine gene-specific primers to determine if pancreatic islet-specific transcripts were expressed during differentiation. Parallel cultures were fixed and labeled with anti-insulin and anti-islet amyloid polypeptide (IAPP) antibodies and studied under confocal immunofluorescence microscopy. Results: ES cells induced to differentiate actively transcribed endoderm-specific genes including hepatocyte nuclear factor 3b, liver and intestinal fatty acid binding proteins, alpha-fetoprotein, and albumin. De novo expression of pancreas-specific gene products was also demonstrated in ES cell cultures. These include expression of pancreatic transcription factor PDX-1, insulin I and II, glucagon, somatostatin, PP, IAPP, glucose transporter 2, a-amylase, and carboxypeptidase A. None of these genes were transcribed in undifferentiated ES cells. Immunofluorescence studies demonstrated a subset of cells in 4 week cultures co-expressing both b cell hormones, insulin, and IAPP. Conclusions: This study demonstrates: 1) consistent de novo expression of endoderm and pancreas-specific genes in ES cells in vitro and 2) the ability of pluripotent murine ES cells to differentiate into endoderm and pancreatic islet precursors.