Genetic defect leads to slower production of brain cells linked to one form of autism

Child with Fragile X syndrome

Fragile X syndrome (FXS) is a genetic disorder that is the most common form of inherited intellectual disability in children, and has also been linked to a form of autism. Uncovering the cause of FXS could help lead to a deeper understanding of autism, what causes it and ultimately, it’s hoped, to treating or even preventing it.

Researchers at Children’s Hospital in Chicago looked at FXS at the stem cell level and found how a genetic defect has an impact on the development of neurons (nerve cells in the brain) and how that in turn has an impact on the developing brain in the fetus.

In a news release on Eurekalert, Dr. Yongchao Ma, the senior author of the study, says this identified a problem at a critical point in the development of the brain:

“During embryonic brain development, the right neurons have to be produced at the right time and in the right numbers. We focused on what happens in the stem cells that leads to slower production of neurons that are responsible for brain functions including learning and memory. Our discoveries shed light on the earliest stages of disease development and offer novel targets for potential treatments.”

The team looked at neural stem cells and found that a lack of one protein, called FMRP, created a kind of cascade that impacted the ability of the cells to turn into neurons. Fewer neurons meant impaired brain development. 

The findings, published in the journal Cell Reports, help explain how genetic information flows in cells in developing babies and, according to Dr. Ma, could lead to new ideas on how to treat problems.

“Currently we are exploring how to stimulate FMRP protein activity in the stem cell, in order to correct the timing of neuron production and ensure that the correct amount and types of neurons are available to the developing brain. There may be potential for gene therapy for fragile X syndrome.”

Midwest universities are making important tools to advance stem cell research

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iPSCs are not just pretty, they’re also pretty remarkable

Two Midwest universities are making headlines for their contributions to stem cell research. Both are developing important tools to advance this field of study, but in two unique ways.

Scientists at the University of Michigan (UM), have compiled an impressive repository of disease-specific stem cell lines. Cell lines are crucial tools for scientists to study the mechanics of different diseases and allows them to do so without animal models. While animal models have important benefits, such as the ability to study a disease within the context of a living mammal, insights gained from such models can be difficult to translate to humans and many diseases do not even have good models to use.

The stem cell lines generated at the Reproductive Sciences Program at UM, are thanks to numerous individuals who donated extra embryos they did not use for in vitro fertilization (IVF). Researchers at UM then screened these embryos for abnormalities associated with different types of disease and generated some 36 different stem cell lines. These have been donated to the National Institute of Health’s (NIH) Human Embryonic Stem Cell Registry, and include cell lines for diseases such as cystic fibrosis, Huntington’s Disease and hemophilia.

Using one such cell line, Dr. Peter Todd at UM, found that the genetic abnormality associated with Fragile X Syndrome, a genetic mutation that results in developmental delays and learning disabilities, can be corrected by using a novel biological tool. Because Fragile X Syndrome does not have a good animal model, this stem cell line was critical for improving our understanding of this disease.

In the next state over, at the University of Wisconsin-Madison (UWM), researchers are doing similar work but using induced pluripotent stem cells (iPSCs) for their work.

The Human Stem Cell Gene Editing Service has proved to be an important resource in expediting research projects across campus. They use CRISPR-Cas9 technology (an efficient method to mutate or edit the DNA of any organism), to generate human stem cell lines that contain disease specific mutations. Researchers use these cell lines to determine how the mutation affects cells and/or how to correct the cellular abnormality the mutation causes. Unlike the work at UM, these stem cell lines are derived from iPSCs  which can be generated from easy to obtain human samples, such as skin cells.

The gene editing services at UWM have already proved to be so popular in their short existence that they are considering expanding to be able to accommodate off-campus requests. This highlights the extent to which both CRISPR technology and stem cell research are being used to answer important scientific questions to advance our understanding of disease.

CIRM also created an iPSC bank that researchers can use to study different diseases. The  Induced Pluripotent Stem Cell (iPSC) Repository is  the largest repository of its kind in the world and is used by researchers across the globe.

The iPSC Repository was created by CIRM to house a collection of stem cells from thousands of individuals, some healthy, but some with diseases such as heart, lung or liver disease, or disorders such as autism. The goal is for scientists to use these cells to better understand diseases and develop and test new therapies to combat them. This provides an unprecedented opportunity to study the cell types from patients that are affected in disease, but for which cells cannot otherwise be easily obtained in large quantities.

Stories that caught our eye: stem cell transplants help put MS in remission; unlocking the cause of autism; and a day to discover what stem cells are all about

multiple-sclerosis

Motor neurons

Stem cell transplants help put MS in remission: A combination of high dose immunosuppressive therapy and transplant of a person’s own blood stem cells seems to be a powerful tool in helping people with relapsing-remitting multiple sclerosis (RRMS) go into sustained remission.

Multiple sclerosis (MS) is an autoimmune disorder where the body’s own immune system attacks the brain and spinal cord, causing a wide variety of symptoms including overwhelming fatigue, blurred vision and mobility problems. RRMS is the most common form of MS, affecting up to 85 percent of people, and is characterized by attacks followed by periods of remission.

The HALT-MS trial, which was sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), took the patient’s own blood stem cells, gave the individual chemotherapy to deplete their immune system, then returned the blood stem cells to the patient. The stem cells created a new blood supply and seemed to help repair the immune system.

Five years after the treatment, most of the patients were still in remission, despite not taking any medications for MS. Some people even recovered some mobility or other capabilities that they had lost due to the disease.

In a news release, Dr. Anthony Fauci, Director of NIAID, said anything that holds the disease at bay and helps people avoid taking medications is important:

“These extended findings suggest that one-time treatment with HDIT/HCT may be substantially more effective than long-term treatment with the best available medications for people with a certain type of MS. These encouraging results support the development of a large, randomized trial to directly compare HDIT/HCT to standard of care for this often-debilitating disease.”

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Scripps Research Institute

Using stem cells to model brain development disorders. (Karen Ring) CIRM-funded scientists from the Scripps Research Institute are interested in understanding how the brain develops and what goes wrong to cause intellectual disabilities like Fragile X syndrome, a genetic disease that is a common cause of autism spectrum disorder.

Because studying developmental disorders in humans is very difficult, the Scripps team turned to stem cell models for answers. This week, in the journal Brain, they published a breakthrough in our understanding of the early stages of brain development. They took induced pluripotent stem cells (iPSCs), made from cells from Fragile X syndrome patients, and turned these cells into brain cells called neurons in a cell culture dish.

They noticed an obvious difference between Fragile X patient iPSCs and healthy iPSCs: the patient stem cells took longer to develop into neurons, a result that suggests a similar delay in fetal brain development. The neurons from Fragile X patients also had difficulty forming synaptic connections, which are bridges that allow for information to pass from one neuron to another.

Scripps Research professor Jeanne Loring said that their findings could help to identify new drug therapies to treat Fragile X syndrome. She explained in a press release;

“We’re the first to see that these changes happen very early in brain development. This may be the only way we’ll be able to identify possible drug treatments to minimize the effects of the disorder.”

Looking ahead, Loring and her team will apply their stem cell model to other developmental diseases. She said, “Now we have the tools to ask the questions to advance people’s health.”

A Day to Discover What Stem Cells Are All about.  (Karen Ring) Everyone is familiar with the word stem cells, but do they really know what these cells are and what they are capable of? Scientists are finding creative ways to educate the public and students about the power of stem cells and stem cell research. A great example is the University of Southern California (USC), which is hosting a Stem Cell Day of Discovery to educate middle and high school students and their families about stem cell research.

The event is this Saturday at the USC Health Sciences Campus and will feature science talks, lab tours, hands-on experiments, stem cell lab video games, and a resource fair. It’s a wonderful opportunity for families to engage in science and also to expose young students to science in a fun and engaging way.

Interest in Stem Cell Day has been so high that the event has already sold out. But don’t worry, there will be another stem cell day next year. And for those of you who don’t live in Southern California, mark your calendars for the 2017 Stem Cell Awareness Day on Wednesday, October 11th. There will be stem cell education events all over California and in other parts of the country during that week in honor of this important day.