We are on a short break from our audio podcast, however we are still delivering our Science Round Ups in written form here on our blog.
Our Science Round Up is brought to you by Bio-techne. Bio-techne brings together the prestigious life science research brands of R&D Systems, Novus Biologicals, Tocris Bioscience, and Protein Simple to provide stem cell researchers with high quality reagents that will optimize and standardize their workflow.
This Science Round Up includes several research paper and article summaries including papers covering: the Zika Virus in Americas, toys and their relation to parent-child communication, the hottest year ever, transgenic monkeys, HIV testing, retinitis pigmentosa, the potential end of Type I Diabetes, stem cell sunscreen, NANOG, stem cell derived teratomas, and electrically stimulated cardiomyocytes (heart muscle cells). Enjoy.
Wow, what a crazy story and I’m sure you have heard about this on the news. This comes from a New England Journal of Medicine perspective story that came out on January 13th. The author of this story says the situation with Zika virus is a pandemic in progress and it is only getting worse with every passing day. Zika virus is an arbovirus that is part of the same disease family as Yellow Fever Virus and West Nile Virus. What has become increasingly scary is the connection between the infection of pregnant women and their babies being born with a disease called microcephaly; or an abnormally small head. Since November, Brazil has documented 4000 cases of microcephaly in babies born to women who were infected with Zika during their pregnancy. For perspective, in 2014, there were only 146 cases. Whoa. The virus is transmitted when a mosquito bites someone with an active infection and then spreads it by biting others. In most people, symptoms of the virus are mild and 80% of those infected never know they have the disease. That’s even more concerning for pregnant women as the virus has now been shown to pass through the placenta to the growing baby. In this article, Dr. Fauci summarizes the current situation about this emerging pandemic, the rapid spread of the virus, and what scientists are doing to help limit this spread.
If you have kids, you know how loud and sometimes annoying toys can be. Loud cars, talking dolls, beeping trucks are just some of them. However, in a new study, these electronic/noisy toys may be more than just annoying, and in fact may have consequences in terms of children’s development. The results of this study found that the quantity and quality of language exchange between parent and child decreased when playing with electronic/noisy toys compared to traditional toys and books. The study focused on children right on the cusp of speaking, 10-16 months old. The American Pediatric Association already suggests that children under the age of 2 should not engage in any media such as TV and smartphones etc. The authors here do not suggest a similar ban for these electronic toys, but do suggest they are played with in moderation.
Did it seem warmer this past year? Well, data from the National Oceanic and Atmospheric Administration clearly demonstrates that 2015 was the hottest year on earth since they started tracking this in the late 19th century. The data showed that the average worldwide surface temperature increased by 1.5 degrees fahrenheit compared to the 20th century average of 57°F. In 2014, the increase was 1.1 degrees and the difference from 2014 to 2015 is the largest margin by which an annual temperature record has ever been broken. The Earth has now seen 39 consecutive years of temperatures above average and heat-trapping greenhouse gases in the atmosphere largely contributed to this long-term rise in surface temperatures. Last year, however, got an additional temperature boost from the ongoing El Niño, a naturally occurring weather disruption caused by unusually warm seawater in the eastern Pacific. On last week’s show (Episode 62) we talked about how aging might be the biggest problem our world faces. We think climate change and global warming might be at the very top of the list as well.
For a decades now researchers have been performing numerous genetic studies on patients with autism to try and identify “Autism Genes”. While numerous candidates have been described, these studies have proved difficult to truly identify single genes responsible for autism. However, we do know that mutations or deletions in certain genes can lead to severe syndromes that render patients autistic. One of these diseases, Rett Syndrome is what we call a monogenic syndrome because its cause can be linked to the mutation of one gene; MeCP2. Researchers use monogenic, autism syndromes to gain insight into the behavior and pathology of autism. In a recent study, researchers in China engineered a monkey genome to express the mutated, human form of MeCP2 and report these monkeys exhibit autism like behaviors such as more repetitive behavior, increased anxiousness, and less social interaction amongst other monkeys. With this non-human, primate model of autism, researchers can now assess these animals brain function to gain more insight as to what goes on in the brains of autistic individuals and what molecular pathways are implicated.
For a long time, HIV was thought to be a death sentence. If you were to contract the virus, it would ultimately lead to AIDS and subsequently death. With the discovery of new medications, cocktails and treatments, this is no longer the case, and people are living very healthy lives with HIV. Despite this positive news, a new report out of the journal of Pediatrics shows that not only are HIV rates on the rise amongst teens, despite a dramatic increase in safe sex awareness, teenagers still refrain from getting tested for HIV. In this study it is reported that people ages 13 to 24 make up less than 17 percent of the U.S. population but account for 26 percent of all new HIV infections. What is worse about this, nearly half of them don’t even know they are infected. Despite the CDC recommending all teens over the age of 12 get tested for HIV, the rates of teen testing does not increase. The authors present data on this and offer potential reasons as to why these teens still do not get tested. We still can’t believe that the HIV rate amongst young people remains this high. With all of the talk and information available regarding safer sex measures, you would think the transmission rate would decrease. Please everyone, be safe and get tested.
STEM CELL SCIENCE
Retinitis pigmentosa (RP) is an inherited, degenerative eye disease that causes severe vision impairment due to the degeneration of the photoreceptor cells in the retina. RP is one of the most common forms of inherited retinal degeneration. There are many different ways to inherit this disease, and one of these is in an X-linked pattern. The genes associated with X-linked retinitis pigmentosa are located on the X chromosome, which is one of the two sex chromosomes. In this study, researchers wanted to assess if they can take induced pluripotent stem cells (iPSCs) generated from x-linked RP patient fibroblasts, correct the mutation with CRISPR technology, and thus repair the disease. This could potentially be used as a source of autologous cells for transplantation in retinal disease. In this case, the gene that was mutated was the RPGR gene, a mutation that is known to cause RP. This group of isolated fibroblasts is cultured from a skin-punch biopsy of an RP patient and generated iPSCs from them.. The iPSCs were then genetically modified to correct the mutation using CRISPR technology. Despite the gene’s repetitive sequences, 13% of RPGR gene copies showed mutation correction and conversion to the wild-type allele. The authors report this is the first report using CRISPR to correct a pathogenic mutation in iPSCs derived from a patient with photoreceptor degeneration and is an important proof-of-concept finding supporting the development of personalized, stem cell based therapies for genetic blinding disorders.
Type 1 diabetes results from the autoimmune destruction of the insulin-producing beta cells located in the pancreas. Insulin is needed to correctly regulate glucose levels, and without proper functioning beta cells, insulin levels in these patients decrease leading to increased blood and urine glucose. The current cause of type 1 diabetes is unknown. Patients diagnosed with type 1 diabetes require daily insulin administration, and this is done by injection multiple times per day. It has been a long standing idea that stem cells can be used to help this disease by generating functional pancreatic beta cells from stem cells, and then implanting those cells to regulate the patient’s insulin levels. For some time now, researchers at Harvard and MIT have done just that using stem cell derived insulin-producing cells to restore function in mice for an extended period of time. Recently this group reported the ability to generate these insulin producing cells from stem cells in very large quantities. In a recent study in Nature, this same group has now shown that these human stem cells derived beta cells cells after transplantation into mice, effectively “cure” or stop the disease for six months, without creating an immune response. This is a major breakthrough, and the co-author Daniel Anderson was quoted in MIT News as saying this approach “has the potential to provide diabetics with a new pancreas that is protected from the immune system, which would allow them to control their blood sugar without taking drugs.” If this process can be shown effective in humans, patients would just require a transfusion every few years, rather than daily injections of insulin.
We saw this and had to provide the link. Cosmetic companies have been trying to incorporate stem cells into their products and marketing campaigns for a while now. Why? Stem cells are hot and it sounds “sexy” when they are in the name or tagline for your product. Juice Beauty company has a new organic sunscreen that contains fruit stem cells and a bunch of other vitamins and antioxidants. Who is going to be the first to try this out? When you do, be sure to let us know how it worked.
Ok, for the hard core stem cel fans out there, this story is for you. If you know stem cells you know that NANOG is a master stem cell gene. It has been reported many times to be involved in regulating stem cell pluripotency, or their ability to turn into many different cells types. Interestingly, NANOG is also expressed in primordial germ cells, or the cells that go on to make sperm and egg cells. What it does in those cells has not been explored, and a new study published in Nature reports on exactly this. In short, the authors go on to show that NANOG expression alone is sufficient to induce primordial germ like cells in epiblast like stem cells but but not embryonic stem cells. The authors say this study demonstrates a mechanistic principle for how cells acquire competence for cell fate determination, resulting in the context-dependent roles of key transcription factors during development.
The major “problem” associated with using cells derived from pluripotent stem cells for a therapy is that there is a risk for tumor formation. These tumors are called teratomas. While strategies to purify these differentiated cells to remove the tumor forming cells have gotten better, there must be a way preclinically and clinically to assess and monitor tumor formation. In this study the authors generated human iPSCs and specifically selected colonies that continued to express reprogramming factors after differentiation into cardiomyocytes. The rationale here is that because they still express these factors they will go on to form teratomas after transplantation into cardiac tissue. They then compared MRI, cardiac ultrasound, and serum biomarkers for their ability to identify teratoma formation and growth. They found that MRI enabled the detection of teratomas with a volume >8 mm cubed and a combination of three plasma biomarkers was able to detect teratomas with a volume >17 mm cubed with a sensitivity of more than 87%. Based on these findings, the authors conclude a combination of serum biomarkers with MRI screening may offer the best sensitivity for teratoma detection and tracking.
A team of Columbia University researchers have found that electrical stimulation of human cardiomyocytes (heart muscle cells), derived from human stem cells can beat with electrical stimulation. For the first time, they show that this activity actually encouraged the newly generated cells to beat by themselves and then can transfer that to surrounding cardiomyocytes. The group states that this electrical conditioning has implications for cell-based reduction of arrhythmia during heart regeneration.
We hope you enjoyed this Science Round Up, brought to you by Biotechne. Please leave comments or questions you might have below.
The Stem Cell Podcast Team
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