Breaking News
May 3, 2019 - Vaping and Smoking May Signal Greater Motivation to Quit
May 3, 2019 - Dementia looks different in brains of Hispanics
May 3, 2019 - Short-Staffed Nursing Homes See Drop In Medicare Ratings
May 3, 2019 - Study of teens with eating disorders explores how substance users differ from non-substance users
May 3, 2019 - Scientists develop new video game that may help in the study of Alzheimer’s
May 3, 2019 - Arc Bio introduces Galileo Pathogen Solution product line at ASM Clinical Virology Symposium
May 3, 2019 - Cornell University study uncovers relationship between starch digestion gene and gut bacteria
May 3, 2019 - How to Safely Use Glucose Meters and Test Strips for Diabetes
May 3, 2019 - Anti-inflammatory drugs ineffective for prevention of Alzheimer’s disease
May 3, 2019 - Study tracks Pennsylvania’s oil and gas waste-disposal practices
May 3, 2019 - Creating a better radiation diagnostic test for astronauts
May 3, 2019 - Vegans are often deficient in these four nutrients
May 3, 2019 - PPDC announces seed grants to develop medical devices for children
May 3, 2019 - Study maps out the frequency and impact of water polo head injuries
May 3, 2019 - Research on Reddit identifies risks associated with unproven treatments for opioid addiction
May 3, 2019 - Good smells may help ease tobacco cravings
May 3, 2019 - Medical financial hardship found to be very common among people in the United States
May 3, 2019 - Researchers develop multimodal system for personalized post-stroke rehabilitation
May 3, 2019 - Study shows significant mortality benefit with CABG over percutaneous coronary intervention
May 3, 2019 - Will gene-editing of human embryos ever be justifiable?
May 3, 2019 - FDA Approves Dengvaxia (dengue vaccine) for the Prevention of Dengue Disease in Endemic Regions
May 3, 2019 - Why Tonsillitis Keeps Coming Back
May 3, 2019 - Fighting the opioid epidemic with data
May 3, 2019 - Maggot sausages may soon be a reality
May 3, 2019 - Deletion of ATDC gene prevents development of pancreatic cancer in mice
May 2, 2019 - Targeted Therapy Promising for Rare Hematologic Cancer
May 2, 2019 - Alzheimer’s disease is a ‘double-prion disorder,’ study shows
May 2, 2019 - Reservoir bugs: How one bacterial menace makes its home in the human stomach
May 2, 2019 - Clinical, Admin Staff From Cardiology Get Sneak Peek at Epic
May 2, 2019 - Depression increases hospital use and mortality in children
May 2, 2019 - Vicon and NOC support CURE International to create first gait lab in Ethiopia
May 2, 2019 - Researchers use 3D printer to make paper organs
May 2, 2019 - Viral infection in utero associated with behavioral abnormalities in offspring
May 2, 2019 - U.S. Teen Opioid Deaths Soaring
May 2, 2019 - Opioid distribution data should be public
May 2, 2019 - In the Spotlight: “I’m learning every single day”
May 2, 2019 - 2019 Schaefer Scholars Announced
May 2, 2019 - Podcast: KHN’s ‘What The Health?’ Bye-Bye, ACA, And Hello ‘Medicare-For-All’?
May 2, 2019 - Study describes new viral molecular evasion mechanism used by cytomegalovirus
May 2, 2019 - SLU study suggests a more equitable way for Medicare reimbursement
May 2, 2019 - Scientists discover first gene involved in lower urinary tract obstruction
May 2, 2019 - Researchers identify 34 genes associated with increased risk of ovarian cancer
May 2, 2019 - Many low-income infants receive formula in the first few days of life, finds study
May 2, 2019 - Global study finds high success rate for hip and knee replacements
May 2, 2019 - Taking depression seriously: What is it?
May 2, 2019 - With Head Injuries Mounting, Will Cities Put Their Feet Down On E-Scooters?
May 2, 2019 - Scientists develop small fluorophores for tracking metabolites in living cells
May 2, 2019 - Study casts new light into how mothers’ and babies’ genes influence birth weight
May 2, 2019 - Researchers uncover new brain mechanisms regulating body weight
May 2, 2019 - Organ-on-chip systems offered to Asia-Pacific regions by Sydney’s AXT
May 2, 2019 - Adoption of new rules drops readmission penalties against safety net hospitals
May 2, 2019 - Kids and teens who consume zero-calorie sweetened beverages do not save calories
May 2, 2019 - Improved procedure for cancer-related erectile dysfunction
May 2, 2019 - Hormone may improve social behavior in autism
May 2, 2019 - Alzheimer’s disease may be caused by infectious proteins called prions
May 2, 2019 - Even Doctors Can’t Navigate Our ‘Broken Health Care System’
May 2, 2019 - Study looks at the impact on criminal persistence of head injuries
May 2, 2019 - Honey ‘as high in sugars as table sugar’
May 2, 2019 - Innovations to U.S. food system could help consumers in choosing healthy foods
May 2, 2019 - FDA Approves Mavyret (glecaprevir and pibrentasvir) as First Treatment for All Genotypes of Hepatitis C in Pediatric Patients
May 2, 2019 - Women underreport prevalence and intensity of their own snoring
May 2, 2019 - Concussion summit focuses on science behind brain injury
May 2, 2019 - Booker’s Argument For Environmental Justice Stays Within The Lines
May 2, 2019 - Cornell research explains increased metastatic cancer risk in diabetics
May 2, 2019 - Mount Sinai study provides fresh insights into cellular pathways that cause cancer
May 2, 2019 - Researchers to study link between prenatal pesticide exposures and childhood ADHD
May 2, 2019 - CoGEN Congress 2019: Speakers’ overviews
May 2, 2019 - A new strategy for managing diabetic macular edema in people with good vision
May 2, 2019 - Sagent Pharmaceuticals Issues Voluntary Nationwide Recall of Ketorolac Tromethamine Injection, USP, 60mg/2mL (30mg per mL) Due to Lack of Sterility Assurance
May 2, 2019 - Screen time associated with behavioral problems in preschoolers
May 2, 2019 - Hormone reduces social impairment in kids with autism | News Center
May 2, 2019 - Researchers synthesize peroxidase-mimicking nanozyme with low cost and superior catalytic activity
May 2, 2019 - Study results of a potential drug to treat Type 2 diabetes in children announced
May 2, 2019 - Multigene test helps doctors to make effective treatment decisions for breast cancer patients
May 2, 2019 - UNC School of Medicine initiative providing unique care to dementia patients
May 2, 2019 - Nestlé Health Science and VHP join forces to launch innovative COPES program for cancer patients
May 2, 2019 - Study examines how our brain generates consciousness and loses it during anesthesia
May 2, 2019 - Transition Support Program May Aid Young Adults With Type 1 Diabetes
May 2, 2019 - Study shows how neutrophils exacerbate atherosclerosis by inducing smooth muscle-cell death
May 2, 2019 - Research reveals complexity of how we make decisions
Extracellular RNA in urine may provide useful biomarkers for muscular dystrophy

Extracellular RNA in urine may provide useful biomarkers for muscular dystrophy

Massachusetts General Hospital (MGH) researchers have found that extracellular RNA (exRNA) in urine may be a source of biomarkers for the two most common forms of muscular dystrophy, noninvasively providing information about whether therapeutic drugs are having the desired effects on a molecular level. The report published in online journal Nature Communications, is the first to show that urine exRNA can be used to monitor systemic diseases that do not directly affect the urinary tract.

“Our findings could facilitate drug development by offering a convenient, painless and relatively low-cost assay that may reduce and perhaps eventually eliminate the need for multiple invasive muscle biopsies to track disease activity and therapeutic response,” says Thurman Wheeler, MD, MGH Department of Neurology, senior author of the report. “Urine exRNA monitoring could determine whether a drug is reaching its target long before clinical effects on muscle function could be detected and may enable early identification of whether dosage adjustments may be required, something that would be impossible with invasive muscle biopsies.”

There are several types of muscular dystrophy, all of which lead to progressive muscle weakness and loss of muscle mass. Duchenne muscular dystrophy (DMD) is the most common form, with symptoms that usually begin in children under the age of 5. Myotonic muscular dystrophy (DM) is the most common adult-onset form and has two subtypes—DM1 and DM2. Each form is caused by a different gene mutation. In DMD, the mutation affects the gene for dystrophin, a protein essential to the strength of muscle fibers. DM-associated mutations—in the DMPK gene for DM1 and in the CNBP gene for DM2—involve excessive repeats of nucleotides, leading to abnormal processing of RNA molecules.

The mutation associated with DM1 affects RNA splicing, the process that removes non-coding segments from an RNA molecule. A single gene can normally give rise to several different proteins, with the differences being determined by alternative RNA splicing patterns. The DM1 mutation interferes with appropriate splicing of RNAs encoding several other proteins, and analysis of RNA splice variants in muscle biopsies has been used to determine disease severity in patients. In animal models, splice variants in muscle tissue have been used to indicate whether potential therapies are reaching their molecular target. A less invasive way of assessing disease severity and therapeutic response could expand the number of patients who could receive therapeutic drugs or participate in clinical trials. For example, a recent clinical trial for a DM1 drug was restricted to adult patients partially because of the need for repeat muscle biopsies.

Carried through bodily fluids like blood and urine in membrane bubbles called vesicles, exRNA encompasses messenger, non-coding, and microRNA molecules and can reflect mutations, deletions and other molecular variants. A few muscular-dystrophy-associated RNA or protein biomarkers have been identified in the blood of patients. Even though it seemed unlikely that exRNA from the skeletal and cardiac muscle tissues affected by DM1 could pass through the kidney’s filtration system into the urine, urine is such an easily accessible fluid that Wheeler’s team analyzed vesicles from both blood and urine for exRNAs that could reflect results of the DM1 mutation.

Their experiments comparing urine exRNAs from DM1 patients, patients with two other forms of muscular dystrophy and unaffected control volunteers identified 10 transcripts that are alternatively spliced in a pattern unique to DM1 patients, most of which had been previously found in patient muscle biopsies. A composite biomarker incorporating these 10 transcripts was 100 percent accurate in distinguishing DM1 patients from unaffected controls in a different group of participants. Samples taken from untreated DM1 patients over several months indicated consistency of splicing patterns within an individual, suggesting that repeat sampling could accurately reflect disease state and treatment response.

Along with developing a more precise assay for rapid measurement of alternative RNA splicing in urine and other bodily fluids, the team showed that splicing patterns in total RNA from the cells in the urine were different from and less useful as biomarkers than those from exRNAs and found that exRNAs in blood could not distinguish between DM1 patients and controls. They also found that the splicing patterns of some urine exRNA transcripts reflected the severity of DM1 symptoms, and that a small group of asymptomatic patients with the DM1 mutation had urine exRNA splicing patterns midway between those of symptomatic patients and unaffected controls.

A group of drugs being evaluated for the treatment of DMD manipulate splicing of the dystrophin gene in order to remove a specific exon—a protein-coding segment of RNA—producing a shortened but partially functional version of the dystrophin protein. The MGH team showed that urine exRNAs from six untreated DMD patients accurately reflected the specific gene mutation in each patient. In two DMD patients being treated with eteplirsen—an FDA-approved DMD drug that induces skipping of the target exon—analysis of urine exRNA was able to confirm the drug was reaching its molecular target, the first such confirmation not provided by muscle biopsy.

“Our demonstration of disease-specific splice variants in urine exRNA suggests the value of biofluids as a means of identifying novel splice variants that may help correlate gene variants with symptoms for several diseases for which noninvasive biomarkers are unavailable,” says Wheeler, an assistant professor of Neurology at Harvard Medical School. “These findings support studies of exRNA from urine, blood or cerebrospinal fluid as biomarker replacements for tissue biopsies in other conditions with altered RNA splicing—including other types of muscular dystrophy, spinal muscular atrophy and amyotrophic lateral sclerosis.”


Explore further:
New research increases understanding of Duchenne muscular dystrophy

More information:
Layal Antoury et al, Analysis of extracellular mRNA in human urine reveals splice variant biomarkers of muscular dystrophies, Nature Communications (2018). DOI: 10.1038/s41467-018-06206-0

Journal reference:
Nature Communications

Provided by:
Massachusetts General Hospital

Tagged with:

About author

Related Articles