Breaking News
December 17, 2018 - Enlarged heart linked to a higher risk of dementia
December 17, 2018 - Prostate cancer detection using MRI now first-line investigation tool
December 17, 2018 - Adolescents who use cognitive reappraisal had better metabolic measures, shows study
December 17, 2018 - Probiotics may offer therapeutic benefits for biopolar patients
December 17, 2018 - Stealth BioTherapeutics Granted Fast Track Designation for Elamipretide for the Treatment of Dry Age-Related Macular Degeneration with Geographic Atrophy
December 17, 2018 - Studies reveal role of red meat in gut bacteria, heart disease development
December 17, 2018 - Eisai enters into agreement with Eurofarma for its anti-obesity agent lorcaserin
December 17, 2018 - Researchers use brain connectome to reassess neuroimaging findings of Alzheimer’s disease
December 17, 2018 - “Miracle” baby survives Ebola in Congo and rapid a new Ebola detection device
December 17, 2018 - AHF urges the WHO to expedite approval process for vaccine effective against Ebola
December 17, 2018 - Study finds misuse of benzodiazepines to be highest among young adults
December 17, 2018 - TGen receives PayPal grant to underwrite costs of genetic tests for children with rare disorders
December 17, 2018 - New research highlights why HIV-infected patients suffer higher rates of cancer
December 17, 2018 - Antibiotic-resistant bacteria could soon be targeted with Alzheimer’s drug
December 17, 2018 - Rutgers scientists take an important step in making diseased hearts heal themselves
December 17, 2018 - Tailored Feedback at CRC Screen Improves Lifestyle Behaviors
December 17, 2018 - Loss of two genes drives a deadly form of colorectal cancer, reveals a potential treatment
December 17, 2018 - How the Mediterranean Diet Can Help Women’s Hearts
December 17, 2018 - Sustained connections associated with symptoms of autism
December 17, 2018 - Concussion rates among young football players were higher than previously reported
December 17, 2018 - Cresco Labs granted approval to operate marijuana dispensary in Ohio
December 17, 2018 - Study provides insight into health risks facing new mothers
December 17, 2018 - AMSBIO expands Wnt signaling pathway product range to aid research
December 16, 2018 - Surgical treatment unnecessary for many prostate cancer patients
December 16, 2018 - Excess weight responsible for cancers globally finds report
December 16, 2018 - Regular sex associated with greater enjoyment of life in seniors
December 16, 2018 - Social stigma contributes to poor mental health in the autistic community
December 16, 2018 - Multidisciplinary team successfully performs complex surgery on patient suffering from enlarged skull
December 16, 2018 - Experts analyze data that can guide antidepressant discontinuation
December 16, 2018 - Menlo Therapeutics’ Successful Phase 2 Clinical Trial of Serlopitant Demonstrates Reduction of Pruritus Associated with Psoriasis
December 16, 2018 - Siblings of children with autism or ADHD are at elevated risk for both disorders
December 16, 2018 - New project aims to understand why and how metabolic disorders develop in patients
December 16, 2018 - Diets containing GM maize have no harmful effects on health or metabolism of rats
December 16, 2018 - Are doctors and teachers confusing immaturity and attention deficit?
December 16, 2018 - Hearing loss linked with increased risk for premature death
December 16, 2018 - Chromatrap buffer reagents for lysing cells offer many benefits
December 16, 2018 - Young Breast Cancer Patients Face Higher Risk for Osteoporosis
December 16, 2018 - 3-D printing offers helping hand to people with arthritis
December 16, 2018 - Community Health Choice helps manage complex and chronic care conditions
December 16, 2018 - Regular trips out could dramatically reduce depression in older age
December 16, 2018 - CWRU to use VivaLNK’s Vital Scout device for stress study in student athletes
December 16, 2018 - ‘Easy Way Out’? Stigma May Keep Many From Weight Loss Surgery
December 16, 2018 - Gout drug may protect against chronic kidney disease
December 16, 2018 - Talking about memories enhances the wellbeing of older and younger people
December 16, 2018 - Occupational exposure to pesticides increases risk for cardiovascular disease among Latinos
December 16, 2018 - A biomarker in the brain’s circulation system may be Alzheimer’s earliest warning
December 16, 2018 - Magnesium may play important role in optimizing vitamin D levels, study shows
December 16, 2018 - The effect of probiotics on intestinal flora of premature babies
December 16, 2018 - Parents spend more time talking with kids about mechanics of using mobile devices
December 16, 2018 - Biohaven Announces Positive Results from Ongoing Rimegepant Long-Term Safety Study
December 16, 2018 - Arterial stiffness may predict dementia risk
December 16, 2018 - Study explores link between work stress and increased cancer risk
December 16, 2018 - Sex work criminalization linked to incidences of violence finds study
December 16, 2018 - Johns Hopkins researchers discover swarming behavior in fish-dwelling parasite
December 16, 2018 - Schistosomiasis prevention and treatment could help control HIV
December 16, 2018 - Early postpartum opioids linked with persistent usage
December 16, 2018 - Johns Hopkins researchers identify molecular causes of necrotizing enterocolitis in preemies
December 16, 2018 - Advanced illumination expands capabilities of light-sheet microscopy
December 16, 2018 - Alzheimer’s could possibly be spread via contaminated neurosurgery
December 16, 2018 - Unraveling the complexity of cancer biology can prompt new avenues for drug development
December 16, 2018 - Inflammatory Bowel Disease, Prostate Cancer Linked
December 16, 2018 - Cannabis youth prevention strategy should target mental wellbeing
December 15, 2018 - Recent developments and challenges in hMAT inhibitors
December 15, 2018 - Sewage bacteria found lurking in Hudson River sediments
December 15, 2018 - CDC selects UMass Amherst biostatistician model that helps predict influenza outbreaks
December 15, 2018 - Researchers reveal brain mechanism that drives itch-evoked scratching behavior
December 15, 2018 - New computer model helps predict course of the disease in prostate cancer patients
December 15, 2018 - Obesity to Blame for Almost 1 in 25 Cancers Worldwide
December 15, 2018 - How the brain tells you to scratch that itch
December 15, 2018 - New findings could help develop new immunotherapies against cancer
December 15, 2018 - World’s largest AI-powered medical research network launched by OWKIN
December 15, 2018 - Young people suffering chronic pain battle isolation and stigma as they struggle to forge their identities
December 15, 2018 - Lifespan extension at low temperatures depends on individual’s genes, study shows
December 15, 2018 - New ingestible capsule can be controlled using Bluetooth wireless technology
December 15, 2018 - Researchers uncover microRNAs involved in the control of social behavior
December 15, 2018 - Research offers hope for patients with serious bone marrow cancer
December 15, 2018 - Link between poverty and obesity is only about 30 years old, study shows
December 15, 2018 - Mass spectrometry throws light on old case of intentional heavy metal poisoning
December 15, 2018 - BeyondSpring Announces Phase 3 Study 105 of its Lead Asset Plinabulin for Chemotherapy-Induced Neutropenia Meets Primary Endpoint at Interim Analysis
December 15, 2018 - Study finds that in treating obesity, one size does not fit all
Study opens up new avenues for stopping calcific aortic valve disease

Study opens up new avenues for stopping calcific aortic valve disease

image_pdfDownload PDFimage_print

The diminutive size of our aortic valve — just shy of a quarter — belies its essential role in pushing oxygen-rich blood from the heart into the aorta, our body’s largest vessel, and from there to all other organs. Yet for decades, researchers have focused less on damaged valves than on atherosclerosis, the gradual hardening of the blood vessels themselves.

Thanks, in part, to pigs at the University of Wisconsin-Madison’s Arlington Agricultural Research Station, scientists now are catching up on understanding the roots of calcific aortic valve disease (CAVD).

“For a long time, people thought CAVD was just the valvular equivalent of atherosclerosis,” says Kristyn Masters, a professor of biomedical engineering at UW-Madison. “Today, we know that valve cells are quite unique and distinct from the smooth muscle cells in our blood vessels, which explains why some treatments for atherosclerosis, such as statins, don’t work for CAVD, and why the search for drugs has to start from scratch.”

A team led by Masters has jumped a longstanding hurdle in that search with a study published today (Dec. 25, 2017) in the journal Proceedings of the National Academy of Sciences. The researchers teased apart, for the first time, the early cascade of events that may eventually cause stenosis, a severe narrowing of the aortic valve that reduces blood flow to body tissues and weakens the heart.

The only current treatment for stenosis is valve replacement, which typically requires risky and expensive open-heart surgery.

“Our study sheds new light on the differences between atherosclerosis and CAVD, especially in terms of bottleneck events that we can target with drugs,” says Masters, whose work is supported by the National Institutes of Health and the American Heart Association. “With a better understanding of how the disease progresses from early to later stages, we may eventually be able to stop CAVD in its tracks and avoid valve replacement surgery.”

Since the hearts of mice and other small animals are vastly different from the human organ, CAVD research has long been hampered by a lack of good animal models. That’s why the pigs — specifically those bred to have an overdose of fatty molecules in their arteries — were an important starting point for the current study.

Their valves provided a snapshot of early CAVD that is challenging to capture in humans, showing that it typically begins with the accumulation of certain sugar molecules called glycosaminoglycans (GAGs) in valve tissue. But to examine exactly how this tissue responds to increasing levels of GAGs, the researchers needed a greater amount of valve tissue than living pigs could provide.

That prompted them to create a first-of-its-kind platform mimicking hallmarks of early porcine CAVD in a lab dish. Key for this model was the ability to grow valve cells in their native healthy form, an important distinction from many previous studies that had focused on already diseased cells.

When the researchers changed only the amount of GAGs these native valve cells were exposed to, while keeping all other conditions the same, they observed surprising results that challenged previous assumptions.

“We thought the GAGs would play a major role in driving the disease process, but the more we added, the fewer inflammatory factors the cells produced and the happier they were,” says Masters. “When we examined this unexpected finding more closely, we noticed two distinct effects: GAGs directly increased a chemical needed to grow new blood vessels, and also trapped low-density lipoprotein (LDL) molecules.”

Neither of these effects was immediately detrimental for valve cells, but the trapping made it more likely for oxygen to react with LDL molecules, and the accumulation of oxidized LDL appeared to be a bottleneck event for a multi-stage process toward valve cell damage, Masters says. This multi-stage process may explain why 25 percent of adults over the age of 65 have CAVD with partially blocked aortic valves, but only one percent goes on to develop stenosis due to a valve that can no longer open and close properly. The fact that native valve cells cannot oxidize LDL themselves, while smooth muscle cells in blood vessels can, also highlights a key distinction between CAVD and atherosclerosis. The study, which included first author Ana Porras, a postdoctoral in Masters’ lab, has important implications for the development of new drugs that may prevent early CAVD from progressing to stenosis by making GAGs less likely to bind LDL. “The take-home message of our study is that CAVD is a multi-stage process and that healthy valve cells respond differently to LDL than blood vessel cells,” Masters says. “The ability to examine multiple steps in this novel in vitro model for early CAVD opens up several promising avenues for developing drugs that are distinct from those for atherosclerosis.”

Source:

New hope for stopping an understudied heart disease in its tracks

Tagged with:

About author

Related Articles