Author: Joseph Caputo

Getting the most of mesenchymal stem cell transplants

Fat cells from mesenchymal stem cell transplant
The fat cells shown in yellow are descended from transplanted human mesenchymal stem cells (green) inside of a mouse after co-transplantation. The red stain shows native mouse fat cells.(Courtesy Juan Melero-Martin)
Joseph Caputo originally wrote this post for the Harvard Stem Cell Institute (HSCI). Vector editor Nancy Fliesler contributed.

Stem cell scientists had what first appeared to be an easy win for regenerative medicine when they discovered mesenchymal stem cells several decades ago. These cells, found in the bone marrow, can give rise to bone, fat and muscle tissue, and have been used in hundreds of clinical trials for tissue repair.

Uses range from tissue protection in heart attack and stroke to immune modification in multiple sclerosis and diabetes. Unfortunately, the results of these trials have been underwhelming. One challenge is that these stem cells don’t stick around in the body long enough to benefit the patient.

Read Full Story | Leave a Comment

Recapturing the liver’s fountain of youth

fountain of youth stem cellsThis post is condensed from a report from the Harvard Stem Cell Institute.

The liver has been a model of tissue regeneration for decades, and it’s well known that a person’s liver cells can duplicate in response to injury. Even if three-quarters of the liver is surgically removed, duplication alone can return the organ to its normal functioning mass. It’s why people are able to donate part of their liver to someone in need—like this mother to her son who was born with biliary atresia.

But what about people with more chronic liver damage? Researchers led by Fernando Camargo, PhD, of the Harvard Stem Cell Institute and Boston Children’s Hospital’s Stem Cell Program, have new evidence in mice that it may be possible to repair such liver disease by forcing mature liver cells to turn back the clock and revert to a stem cell-like state, able to generate functional liver progenitor cells to replace damaged tissue.

Read Full Story | Leave a Comment

Adrenal gland offers a new view of tissue regeneration and maintenance

A confocal micrograph of a mouse adrenal gland. The green stripes radiating from the outer region containing the zona glomerulosa (zG) to the inner region containing the zona fasiculata (zF) provide evidence for direct lineage conversion of these two differentiated cell types.
In this mouse adrenal gland, the green stripes radiating from the outer region containing the zona glomerulosa (zG) to the inner region containing the zona fasiculata (zF) provide evidence for direct lineage conversion of these two cell types.

In 2006, Shinya Yamanaka, MD, PhD, discovered a way to reprogram mature skin cells back to a stem cell state so they can be converted into any cell type a scientist is interested in studying. That work earned him last year’s Nobel Prize in Physiology or Medicine.

Yamanaka’s discovery raised the tantalizing question of whether similar reprogramming ever occurs in nature. In fact, it does, discovered David Breault, MD, PhD, an endocrinologist at Boston Children’s Hospital and a member of the Harvard Stem Cell Institute. In the journal Developmental Cell, Breault recently showed that the adrenal gland uses cellular reprogramming (called lineage conversion) for daily maintenance and to repair itself after injury.

“This is going to be important for how we think of tissue maintenance and regeneration,” Breault says.

Read Full Story | Leave a Comment