Health and Medical News and Resources

General interest items edited by Janice Flahiff

Complex signaling between blood and stem cells controls regeneration in fly gut

Complex signaling between blood and stem cells controls regeneration in fly gut.

 

Buck Institute scientists say impaired interactions between macrophages and stem cells are likely players in human intestinal maladies like IBS, leaky gut and colorectal cancers 

May 25, 2015/NOVATO, CA:  Having a healthy gut may well depend on maintaining a complex signaling dance between immune cells and the stem cells that line the intestine. Scientists at the Buck Institute are now reporting significant new insight into how these complex interactions control intestinal regeneration after a bacterial infection. It’s a dance that ensures repair after a challenge, but that also goes awry in aging fruit flies — the work thus offers important new clues into the potential causes of age-related human maladies, such as irritable bowel syndrome, leaky gut and colorectal cancer.

“We’ve dissected a very complex signaling interaction,” said senior scientist and Buck faculty Heinrich Jasper, PhD. “By doing so temporally we’ve clearly established a role for the immune system both in initiating the regenerative process and in shutting it down – activities that are essential for maintaining tissue homeostasis.”

Publishing in the May 25, advance online edition of Nature Cell Biology, researchers in the Jasper lab show that the macrophage-like hemocytes (which comprise the cellular immune system in flies) go to the intestines ofDrosophila following damage. The hemocytes secrete the growth factor Dpp (a homologue of BMP, which has many functions, including the control of mobility, differentiation and invasiveness of normal cells), setting off the regenerative process by activating specific receptors in stem cells. In a fascinating twist, stem cells switch their response to Dpp in the middle of the regenerative response by turning on other Dpp-related receptors, which in turn instruct the stem cells to go back to a quiescent or quiet state.  Jasper says it’s a balancing act that both allows for healing and prevents excessive cell proliferation, which could lead to pre-cancerous dysplasia. “The temporal sequence of cell interactions during injury-induced regeneration is only beginning to be understood,” said Jasper. “The proper timing of these interactions may be key in maintaining a healthy gut.”

Jasper says aging makes it harder for the stem cells to switch gears between proliferation and quiescence and that flies suffer from age-related intestinal dysfunctions similar to those experienced by humans.

July 28, 2015 Posted by | Medical and Health Research News | , , , , , , , , , , , , , | Leave a comment

University Of Dayton Study Overturns 250-Year-Old Belief About Effects Of Age, Repeated Injury On Tissue Regeneratio

From the 19 July 2011 Medical News Today article

Scientists have been wrong for 250 years about a fundamental aspect of tissue regeneration, according to a University of Dayton biologist who says his recent discovery is good news for humans.

In research published in Nature Communications this month, Panagiotis Tsonis concludes repeated regeneration, even at old age, does not alter the capacity of newts to regenerate tissue. His findings overturn long-accepted theories proposed by regeneration scientists that age and repeated amputation negatively affect regeneration….

Click here to read the rest of the article

July 19, 2011 Posted by | Medical and Health Research News | , | Leave a comment

   

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