Nerve cell communication mechanisms uncovered, may lead to new therapeutic approaches for neurodegenerative diseases

 

Story by Madison Knapp/ Bond Life Sciences summer intern

Simple actions like walking, swallowing and breathing are the result of a complex communication system between cells. When we touch something hot, our nerve cells tell us to take our hand off the object.

This happens in a matter of milliseconds.

This hyperspeed of communication is instrumental in maintaining proper muscle function. Many degenerative diseases affecting millions of people worldwide result from reduced signaling speed or other cellular miscommunications within this intricate network.

Michael Garcia, investigator at the Christopher S. Bond Life Sciences Center and associate professor of biology at the University of Missouri, conducts basic research to answer fundamental questions of nerve cell mechanics.

“In order to fix something, you need to first understand how it works,” Garcia said.

Garcia’s research illuminates relationships between nerve cells to find factors affecting function.  His goal is to provide insight on fundamental cellular mechanisms that aren’t fully understood.

Garcia’s research has been funded partly by the National Science Foundation and National Institutes of Health.

Technological advancements have made it possible to better understand disease development in the human body to create more effective treatments. Alas, a scientist’s work is never finished— when the answer to one question is found, ten more crop up in its wake.

Garcia’s research, which appeared in several journals including Human Molecular Genetics andthe Journal of Neuroscience Research initially sought to shed light on the neuronal response to myelination, the development of an insulating border around a nerve cell, called a myelin sheath, which is critical in rapid communication between cells.

Eric Villalon, a graduate student in Michael Garcia's lab at the Bond Life Sciences Center, examines results. The Garcia Lab is answering news questions in cell mechanics. | PAIGE BLANKENBUEHLER

Eric Villalon, a graduate student in Michael Garcia’s lab at the Bond Life Sciences Center, examines results. The Garcia Lab is answering news questions in cell mechanics. | PAIGE BLANKENBUEHLER

How it works: Rebuilding cell theory

Garcia’s early research disproved a long-standing hypothesis concerning this cellular feature.

Mammals’ nervous systems are uniquely equipped with myelination, which has been shown to increase conduction velocity, or the speed at which nerve cells pass signals. Low velocity is often associated with neurodegenerative diseases, so research exploring why could later have application in therapeutic technology.

In addition to myelination, cell size makes a big difference in conduction velocity — the bigger the nerve cells, the faster they can pass and receive signals. Garcia’s findings disproved a hypothesis that related myelination to this phenomenon.

The hypothesis, published in a 1992 edition of Cell, claimed that myelination causes a cellular process called phosphorylation which then causes an increase in the axonal diameter (width of the communicating part of a nerve cell), leading to faster nerve cell communication. Garcia found that myelination did cause an increase in axonal diameter, and myelination was required for phosphorylation, but that the two results were independent of one another.

To narrow in on the processes affecting axonal diameter, Garcia identified the protein responsible for growth.

Garcia followed earlier work, showing that one subunit controls whether there is growth at all with myelination, by identifying the domain of this protein that determines how much growth.

After clarifying this part of the process, a question still remains: If not to control myelination, why does phosphorylation happen?

 

Looking forward

Jeffrey Dale, a recent PhD graduate from Garcia’s lab, said current research is in part geared toward finding a connection between phosphorylation and a process called remyelination.

Remyelination could be key to new therapeutic approaches. When a cell is damaged (as in neurodegenerative disease) the myelin sheath can be stripped away. Remyelination is the process a cell goes through to replace the myelin.

Imagine you have a new wooden toy boat, painted and smooth. If you take a knife and whittle away all the paint and then repaint it—even exactly how it was painted before—the boat is not going to be as shiny and smooth as it was before. This is how remyelination works (or rather, doesn’t).  When nerve cells are damaged, the myelin sheath is stripped away and even after the cell rebuilds it, the cell can’t conduct signals at the same speed it was able to before.

“If you can learn what controls myelination, maybe you can improve effectiveness of remyelination,” Dale said.

Garcia said it is possible that revealing the mechanics involved in phosphorylation could lead to better treatments. In context of neurodegenerative diseases, the question why don’t axons function properly might be wrapped up in Garcia’s question: In healthy cells, why do they?

Supervising editor: Paige Blankenbuehler

SoyKB: Leading the convergence of wet and dry science in the era of Big Data

Yaya Cui, an investigator in plant sciences at the Bond Life Sciences Center examines data on fast neuron soybean mutants that are represented on the SoyKB database.

Yaya Cui, an investigator in plant sciences at the Bond Life Sciences Center examines data on fast neuron soybean mutants that are represented on the SoyKB database.

The most puzzling scientific mysteries may be solved at the same machine you’re likely reading this sentence.

In the era of “Big Data” many significant scientific discoveries — the development of new drugs to fight diseases, strategies of agricultural breeding to solve world-hunger problems and figuring out why the world exists — are being made without ever stepping foot in a lab.

Developed by researchers at the Bond Life Sciences Center, SoyKB.org allows international researchers, scientists and farmers to chart the unknown territory of soybean genomics together — sometimes continents away from one another — through that data.

 

Digital solutions to real-world questions

As part of the Obama Administration’s $200 million “Big Data” Initiative, SoyKB (Soy Knowledge Base) was born.

The digital infrastructure changes the way researchers conduct their experiments dramatically, according to plant scientists like Gary Stacey, Bond LSC researcher, endowed professor of soybean biotechnology and professor of plant sciences and biochemistry.

“It’s very powerful,” Stacey said. “Humans can only look at so many lines in an excel spreadsheet — then it just kind of blurs. So we need these kinds of tools to be able to deal with this high-throughput data.”

The website, managed by Trupti Joshi, an assistant research professor in computer science at MU’s College of Engineering, enables researchers to develop important scientific questions and theories.

“There are people that during their entire career, don’t do any bench work or wet science, they just look at the data,” Stacey said.

The Gene Pathway Viewer available on SoyKB, shows different signaling pathways and points to the function of specific genes so that researchers can develop improvements for badly performing soybean lines.

“It’s much easier to grasp this whole data and narrow it down to basically what you want to focus on,” Joshi said.

A 3D-protein modeling tool lends itself especially to drug design. A pharmaceutical company could test the hypothesis and in some situations, the proposed drug turns out to yield the expected results — formulated solely by data analysis.

The Big Data initiative drives a blending of “wet science” — conducting experiments in the lab and gathering original data — and “dry science” — using computational methods.

Testament of the times?

“Oh, absolutely,” Joshi said.

 

Collaboration between the “wet” and “dry” sciences

Before SoyKB, data from numerous experiments would be gathered and disregarded, with only the desired results analyzed. The website makes it easy to dump all of the data gathered to then be repurposed by other researchers.

“With these kinds of databases now, all the data is put there so something that’s not valuable to me may be valuable to somebody else,” Stacey said,

Joshi said infrastructure like SoyKB is becoming more necessary in all realms of scientific discovery.

“(SoyKB) has turned out to be a very good public resource for the soybean community to cross reference that and check the details of their findings,” she said.

Computer science prevents researchers having to reinvent the wheel with their own digital platforms. SoyKB has a translational infrastructure with computational methods and tools that can be used for many disciplines like health sciences, animal sciences, physics and genetic research.

“I think there’s more and more need for these types of collaborations,” Joshi said. “It can be really difficult for biologists to handle the large scope of data by themselves and you really don’t want to spend time just dealing with files — You want to focus more on the biology, so these types of collaborations work really well.

It’s a win-win situation for everyone,” she said.

The success of SoyKB was perhaps catalyzed by Joshi. She adopted the website and the compilation of data in its infant stages as her PhD dissertation.

Joshi is unique because she has both a biology degree and a computer science background. Stacey said Joshi, who has “had a foot in each camp,” serves as an irreplaceable translator.

Most recently, the progress of SoyKB as part of the Big Data Initiative was presented at the International Conference on Bioinformatics and Biomedicine Dec. 2013 in Shanghai. The ongoing project is funded by NSF grants.

MU Scientists Successfully Transplant, Grow Stem Cells in Pigs

New line of pigs do not reject transplants, will allow for future research on stem cell therapies

Story by Nathan Hurst/MU News Bureau

COLUMBIA, Mo. – One of the biggest challenges for medical researchers studying the effectiveness of stem cell therapies is that transplants or grafts of cells are often rejected by the hosts. This rejection can render experiments useless, making research into potentially life-saving treatments a long and difficult process. Now, researchers at the University of Missouri have shown that a new line of genetically modified pigs will host transplanted cells without the risk of rejection.

Roberts, Mike

Mike Roberts, courtesy of MU News Bureau

“The rejection of transplants and grafts by host bodies is a huge hurdle for medical researchers,” said R. Michael Roberts, Curators Professor of Animal Science and Biochemistry and a researcher in the Bond Life Sciences Center. “By establishing that these pigs will support transplants without the fear of rejection, we can  move stem cell therapy research forward at a quicker pace.”

In a published study, the team of researchers implanted human pluripotent stem cells in a special line of pigs developed by Randall Prather, an MU Curators Professor of reproductive physiology. Prather specifically created the pigs with immune systems that allow the pigs to accept all transplants or grafts without rejection. Once the scientists implanted the cells, the pigs did not reject the stem cells and the cells thrived. Prather says achieving this success with pigs is notable because pigs are much closer to humans than many other test animals.

Randall Prather, courtesy of MU News Bureau

Randall Prather, courtesy of MU News Bureau

“Many medical researchers prefer conducting studies with pigs because they are more anatomically similar to humans than other animals, such as mice and rats,” Prather said. “Physically, pigs are much closer to the size and scale of humans than other animals, and they respond to health threats similarly. This means that research in pigs is more likely to have results similar to those in humans for many different tests and treatments.”

“Now that we know that human stem cells can thrive in these pigs, a door has been opened for new and exciting research by scientists around the world,” Roberts said. “Hopefully this means that we are one step closer to therapies and treatments for a number of debilitating human diseases.”

Roberts and Prather published their study, “Engraftment of human iPS cells and allogeneic porcine cells into pigs with inactivated RAG2 and accompanying severe combined immunodeficiency” in the Proceedings of the National Academy of Sciences.

This study was made possible through grants from Konkuk University in South Korea and the National Institutes of Health.

Roberts has appointments in the MU College of Food, Agriculture and Natural Resources (CAFNR) and the MU School of Medicine and is a member of the National Academy of Sciences. Prather has an appointment in CAFNR and is the director of the NIH-funded National Swine Resource and Research Center.