Researcher creates cell lines to help treat mitochondrial disease in children – sciencedaily
The mitochondria have acquired all the reputation of their role as the “powerhouse of the cell”. These tiny but powerful organelles play a variety of life sustaining roles, from feeding our own cells and organs to fueling chemical and biological processes. But when they don’t work properly, a number of rare diseases can occur.
Mitochondrial diseases are a group of debilitating genetic disorders that affect one in 5,000 people worldwide, most of them children. These illnesses are accompanied by a variety of health problems including, but not limited to, heart disease, developmental and cognitive impairment, breathing problems, poor growth, and even premature death. From this moment there is no cure.
But recent work published in journals Mitochondria and BMC Molecular and Cellular Biology by Aloka Abey Bandara, associate research professor in the Department of Biomedical Sciences and Pathobiology at the Virginia-Maryland College of Veterinary Medicine, and her team offer patients with mitochondrial diseases and their parents a silver lining.
With a team of researchers from Virginia Tech in Blacksburg and Roanoke, Bandara succeeded in creating living cell models that mimic mitochondrial disease cells. These cells will lay the foundation for drug studies and future studies of mitochondrial diseases.
“Our cell models will allow us to see what exactly happens to cells and its processes when a child develops mitochondrial disease. In addition to these factors, we will be able to conduct further studies on the toxicity and efficacy of new candidates. -medicines. ”said Bandara, who is also an affiliate faculty member of the Fralin Life Sciences Institute.
Our bodies produce vital energy from the food we eat and the air we breathe. Oxygen and nutrients, like glucose, travel through the body’s organs, tissues, and cells until they reach their final destination: the mitochondria. When nutrients reach the inner membrane of the mitochondria, a unique series of protein complexes, called an electron transport chain, kick in.
Through a series of reactions, the electron transport chain is able to remove electrons from nutrients and push them through the mitochondrial membrane, which forms a proton gradient. When this happens, the body generates adenosine triphosphate, better known as ATP, a molecule that carries energy within cells.
“Sometimes you can see disruptions or mutations in proteins in the electron transport chain,” Bandara said. “As a result, protein complexes cannot transport electrons, and energy production is disrupted. Almost every organ in the body will be affected – heart, eyes and muscles – and they will not be able to function properly. “
The electron transport chain is made up of five protein complexes or groups of proteins. Complex I and Complex II are two protein complexes primarily responsible for removing electrons from nutrients. If they don’t do their duty, the whole electron transport chain fails and the body cannot produce ATP.
Patients with mitochondrial disease may have defects in Complex I or Complex II. Patients with Complex I disturbances usually have neurological problems, such as seizures and abnormal brain functions. People with complex II disturbances can develop many other diseases and are more likely to develop several cancers.
While researchers are able to pinpoint the exact locations of the defects, creating treatments for these mitochondrial diseases has been a challenge. Therapies, vitamins, and dietary adjustments may have helped relieve symptoms and slow disease progression; but, mitochondrial disease itself has no cure. Therefore, new drugs must be created, tested and refined.
Bandara hopes his cell lines will not only support future research, but also patients and their families, who directly experience mitochondrial disease and all of its impacts.
“Parents are often helpless because they can’t just go to the pharmacy and get a medicine,” Bandara said. “I hope they can see that Virginia Tech is making tremendous strides in finding a cure for these diseases. Maybe they can feel that they are no longer alone – that universities, government and science fight with them. “
In order to test drug candidates, researchers must first create cell models, which act like artificial “sick” cells. Cell models are a great tool for drug discovery because mitochondrial disease can be studied without actually needing to extract cells from patients.
To create cells that mimic mitochondrial disease, Bandara had to “remove” parts of the genome that create the coding for Complex I and Complex II using CRISPR / Cas9 technology.
First, the researchers identified the part of the genome that needed to be deleted. Then they designed a piece of RNA that made this point its “home base”. The RNA then “guided” an enzyme called Cas9 back to its original base on the gene. Cas9 is then able to bind at that point and “cut” it.
Once this process was completed, Bandara performed genomic sequencing to confirm that the part had been successfully removed from the genome. Over the course of several months of hard work, Bandara and her team created two mutant cell lines, one without Complex I and one without Complex II.
Bandara is one of the few researchers at Virginia Tech’s Blacksburg campus to use CRISPR / Cas9 technology to treat mitochondrial disease.
Once the mutant cell lines were created, Bandara subjected them to a disease model, where he tested the functions of the “diseased” cell line against the “parent” cell line, which is made up of healthy cells. Through extensive analysis, Bandara confirmed that diseased cells consume much less oxygen, grow very slowly, and do not produce enough ATP for cells to function properly – the three hallmarks of cells with the disease. mitochondrial.
Once they confirmed that the knockout cell lines correctly mimicked mitochondrial disease cell dysfunctions, they were able to test a new drug called Idebenone. With this treatment, Bandara has shown that cell growth and oxygen uptake can be restored to some extent.
These cell lines were the product of a successful collaboration of experts from the Department of Human Nutrition, Food and Exercise and the Virginia Tech Carilion School of Medicine.
The construction of mutant cell lines was guided and supported by David Brown, former Associate Professor in the Department of Human Nutrition, Diet and Exercise at Virginia Tech College of Agriculture and Life Sciences, now Senior Director of Scientific Innovation and technique at Stealth BioTherapeutics, a Boston-based biotechnology company.
From this work, the team received two provisional patents for their cells. One of the cell lines has already been patented and licensed to a pharmaceutical company, which will develop new therapies for people with mitochondrial diseases.
These cells have been made available for global use by interested researchers and pharmaceutical companies through Ximbio, the world’s largest non-profit organization specializing in life science research tools of all types.
“Cellular models of mitochondrial complex I and II defects have high societal and economic impact as models to test drug candidates cost-effectively and rapidly for the treatment of mitochondrial dysfunction,” said Justin Perry, Virginia graduate. Tech, and now a Business Development Manager at Ximbio.