New study into bladder regeneration heralds organ replacement treatment

Researchers in the United States have developed a medical model for regenerating bladders using stem cells harvested from a patient’s own bone marrow. The research, published in STEM CELLS, is especially relevant for paediatric patients suffering from abnormally developed bladders, but also represents another step towards new organ replacement therapies.

The research, led by Dr Arun Sharma and Earl Cheng from the Feinberg School of Medicine at Northwestern University and Children’s Memorial Research Center, focused on bone marrow mesenchymal stem cells (MSCs) taken from the patient. Previously studies into the regenerative capacity of cells in bladders have focused on animal models, but these have translated poorly in clinical settings. Continue reading “New study into bladder regeneration heralds organ replacement treatment”

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Researchers successfully reprogram keratinocytes attached to a single hair

The first reports of the successful reprogramming of adult human cells back into so-called induced pluripotent stem (iPS) cells, which by all appearances looked and acted liked embryonic stem cells created a media stir. But the process was woefully inefficient: Only one out of 10,000 cells could be persuaded to turn back the clock.

Now, a team of researchers led by Juan Carlos Izpisúa Belmonte at the Salk Institute for Biological Studies, succeeded in boosting the reprogramming efficiency more than 100fold, while cutting the time it takes in half. In fact, they repeatedly generated iPS cells from the tiny number of keratinocytes attached to a single hair plucked from a human scalp. Continue reading “Researchers successfully reprogram keratinocytes attached to a single hair”

Scientists eliminate viral vector in stem cell reprogramming

Previously, Dr. Shinya Yamanaka of Kyoto University and the Gladstone Institute of Cardiovascular Disease, had shown that adult cells can be reprogrammed to become embryonic stem cell–like using a cancer-causing oncogene as one of the four genes required to reprogram the cells, and a virus to transfer the genes into the cells. In the last year, Dr. Yamanaka and other labs showed that the oncogene, c-Myc, is not needed. However the use of viruses that integrate into the genome prohibit use of iPS cells for regenerative medicine because of safety concerns: its integration into the cell’s genome might activate or inactivate critical host genes.

Now Dr. Yamanaka’s laboratory in Kyoto has eliminated the need for the virus. In a report published this week in Science, they showed that the critical genes can be effectively introduced without using a virus. The ability to reprogram adult cells into iPS cells without viral integration into the genome also lays to rest concerns that the reprogramming event might be dependent upon viral integration into specific genomic loci that could mediate the genetic switch. Continue reading “Scientists eliminate viral vector in stem cell reprogramming”

Study unlocks stem cell DNA secrets

In a groundbreaking study led by an eminent molecular biologist at Florida State University, researchers have discovered that as embryonic stem cells turn into different cell types, there are dramatic corresponding changes to the order in which DNA is replicated and reorganized.

The findings bridge a critical knowledge gap for stem cell biologists, enabling them to better understand the enormously complex process by which DNA is repackaged during differentiation — when embryonic stem cells, jacks of all cellular trades, lose their anything-goes attitude and become masters of specialized functions.

Continue reading “Study unlocks stem cell DNA secrets”

Fat-regenerating ‘stem cells’ found in mice

Researchers have identified stem cells with the capacity to build fat, according to a report in the October 17th issue of the journal Cell, a Cell Press publication. Although they have yet to show that the cells can renew themselves, transplants of the progenitor cells isolated from the fat tissue of normal mice can restore normal fat tissue in animals that are otherwise lacking it.

The findings may yield insight into the causes of obesity, a condition characterized by an increase in both the size and number of fat cells. Continue reading “Fat-regenerating ‘stem cells’ found in mice”

The role of stem cells in renewing the cornea

A group of researchers in Switzerland has published a study appearing in the Oct 1 advance online edition of the Journal Nature that shows how the cornea uses stem cells to repair itself.

Using mouse models they demonstrate that everyday wear and tear on the cornea is repaired from stem cells residing in the corneal epithelium, and that more serious repair jobs require the involvement of other stem cells that migrate from the limbus, a region between the cornea and the conjunctiva, the white part of the eye. Continue reading “The role of stem cells in renewing the cornea”

New method for creating inducible stem cells is remarkably efficient

Some of the most challenging obstacles limiting the reprogramming of mature human cells into stem cells may not seem quite as daunting in the near future. Two independent research papers, published by Cell Press in the September 11th issue of the journal Cell Stem Cell, describe new tools that provide invaluable platforms for elucidating the molecular, genetic, and biochemical mechanisms associated with reprogramming. The new findings also offer considerable hope toward making the reprogramming process more therapeutically relevant.
Continue reading “New method for creating inducible stem cells is remarkably efficient”