Stem Cells in the News - February 2018
Thursday, February 01, 2018 - 11:42
We have captured this month's most interesting, innovative, and maybe some of the strangest examples of stem cells in the news from around the world.
For the first time, trophoblast stem cells have been isolated and cultured by researchers in Japan. These cells line the outer layer of the blastocyst and eventually become the placenta for developing fetuses. The amount and location of these cells contribute to miscarriages, preeclampsia and other conditions during pregnancy. Previously, other cell lines have been used to mimic these stem cells, but they lack the same protein expression observed in native cells. The culture method, recently published in Cell Stem Cell, utilized genetic sequencing to determine the proper culture conditions.
Primary mesenchymal stem cells (MSCs) are delicate, which is why many researchers opt to use immortalized cell lines in their studies. However, these MSC lines lack a functional p53 gene and researchers from the Phinney lab at The Scripps Research Institute think that is a big issue. They tested varying levels of p53 expression in MSCs and found it to be the “master regulatory factor” that determines how MSCs grow and differentiate. Specifically, p53 can interact with two transcription factors, TWIST2 and PPARG, which determine the differentiation fate of MSCs.
A team of scientists from the OncoTrack Project have recently published findings that show cancer stem cells (CSCs) utilize a noncanonical signaling pathway, involving Hedgehog and a positive regulator of WNT, to improve their survival in colon cancer. The study demonstrates the use of a specific feature of this Hedgehog signaling pathway that allows the cell to respond to external signals as well as inhibit stem cell differentiation. They believe that targeting the Hedgehog signaling pathway in combination with other treatments could create a new strategy to eliminate CSCs and prevent the reoccurrence of cancer.
Scientists in the Crump lab at the University of Southern California have uncovered two genes that regulate the generation of skeletal cells from stem cells during zebrafish jaw development. Their findings demonstrate a fine balance between the development of cartilage and bone depending on what gene is more highly expressed. Previously, little had been known about the pathway of the development of the upper jaw, and these findings may one day improve our ability to correct craniofacial abnormalities in humans.
A recent study, published in Nature, has determined that acetaldehyde, a metabolite of alcohol, causes double-stranded breaks in the DNA of blood stem cells in mice. How exactly it causes the damage is still a point of controversy, but the study highlights the potentially damaging effects alcohol can have on stem cells, which repair and generate our tissues.
Cincinnati researchers have recently published a study that highlights the detrimental effects of obesity on our blood producing progenitors, hematopoietic stem cells (HSCs). Their findings show a reduced diversity of HSCs which can promote pre-leukemic fates of these cells observed in obese mice. They suggest that this reduction in diversity is correlated to the overexpression of a transcription factor, Gfi1. Their work reveals additional long-term alterations of HSCs which can help future exploration of more therapeutic stem cell treatments.
A method for a single injection of a new drug combination to harvest blood stem cells from donors of bone marrow has been published in Cell. This method is both faster and more effective at harvesting these cells than current standard methods. The study was done in mice, but the researchers from Indiana University are already looking toward clinical trials to test its safety in humans.
In a scientific first, researchers have reprogrammed mouse skin cells to induced pluripotent stem cells (iPSCs) using CRISPR gene regulation technology. This study provides a third reprogramming option for researchers, in addition to the Yamanaka Factors and chemical reprogramming previously established. The study shows activation of Sox2 or Oct4 led to the efficient reprogramming of skin cells in mice to iPSCs.
iPSC-derived cardiomyocytes from Cellular Dynamics were launched into space in late December 2017 to resupply a mission at the International Space Station that is developing NASA’s Bioculture System for automated cell culture in space. The cells will be used to study the effects of microgravity on human cardiac cell function.
Duke University researchers have successfully created functioning human muscle tissue from iPSCs in a study published in Nature Communications last month. This finding has been the most robust differentiation of skin cells to muscle to date. What helped them develop such a promising method? They attribute their success to the cell culture conditions and a 3-D Matrix they used to help the differentiated cells develop and grow much faster than 2-D culture methods.