Weizmann Institute scienists find that stem cells in the bone marrow become l...( They still don't have a personality an...)

They still don't have a personality, and they're waiting for the maturity call. Stem cells in our bone marrow usually develop into blood cells, replenishing our blood system. However, in states of emergency, the destiny of some of these stem cells may change: They can become virtually any type of cell liver cells, muscle cells, nerve cells responding to the body's needs.

Prof. Tsvee Lapidot and Dr. Orit Kollet of the Weizmann Institute's Immunology Department have found how the liver, when damaged, sends a cry for help to these stem cells. "When the liver becomes damaged, it signals to stem cells in the bone marrow, which rush to it and help in its repair as liver cells," says Lapidot. His research team has found that certain molecules that govern normal development of the liver become overproduced when it is damaged, signaling to the stem cells in the bone marrow to come to the site. The scientists were able to pinpoint the signaling molecules HGF, MMP-9 and SDF-1 and describe the homing process. HGF is involved in liver cell development and, in irregular cases, can play a role in cancer metastasis. MMP-9 assists cell migration from the blood system into various types of tissue, including liver tissue. SDF-1 is a molecule that stem cells are attracted to. The scientists discovered that large amounts of HGF and MMP-9, when overproduced in the damaged liver, enter the blood flow and increase the sensitivity of stem cells in the bone marrow to SDF-1. Suddenly able to sense SDF-1's calling signal from the liver (which itself is amplified due to increased production and distribution of SDF-1), the stem cells migrate from the bone marrow into the blood and navigate their way to the liver. The findings could lead to new insights into organ repair and transplants, especially liver-related ones. They may also uncover a whole new stock of stem cells that can under certain conditions become liver cells. Until a few years ago only embryonic stem cells were though
'"/>

Contact: Alex Smith
Alex_smith@margeotes.com
212-460-0563
American Committee for the Weizmann Institute of Science
11-Aug-2003

Page: 1 2
Related biology news :

1. Weizmann scientists invention moves forward: Cancer diagnosis technique gets FDA clearance
2. Psoriasis treatment based on Weizmann Institute Research passes phase II clinical trials
3. Weizmann Institute scientists report why taste and smell differ among individuals
4. Weizmann institute scientists solve the 3-D structure of the enzyme involved in Gaucher disease
5. Prize to Weizmann Institute professor for landmark work in stem cell transplantation
6. New witchweed-fighting method, presented by CIMMYT and Weizmann Institute scientist
7. Weizmann Institute scientists win global competition in predicting protein-protein interactions
8. Vaccination following spinal cord injury: Innovative Weizmann Institute approach limits paralysis
9. Weizmann Institute scientists block loss of eyesight in animals with a glaucoma-like disease
10. Weizmann Institute researcher named to Israel Academy Of Sciences And Humanities
11. Weizmann Institute scientists develop a novel system for analyzing genetic data that mimics the human capacity for unsupervised learning