Breaking News
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
December 15, 2018 - Tenacity and flexibility help maintain psychological well-being, mobility in older people
December 15, 2018 - Study reveals role of brain mechanism in memory recall
December 15, 2018 - High levels of oxygen encourage the brain to remain in deep, restorative sleep
December 15, 2018 - Experimental HIV vaccine strategy works in non-human primates, research shows
December 15, 2018 - Genetically modified pigs could limit replication of classical swine fever virus, study shows
December 15, 2018 - FDA Approves Herzuma (trastuzumab-pkrb), a Biosimilar to Herceptin
December 15, 2018 - Cost and weight-loss potential matter most to bariatric surgery patients
December 15, 2018 - Cancer Research UK and AstraZeneca open new Functional Genomics Centre
December 15, 2018 - New research lays out potential path for treatment of Huntington’s disease
December 15, 2018 - Prestigious R&D 100 Award presented to Leica Microsystems
December 15, 2018 - Study shows septin proteins detect and kill gut pathogen, Shigella
December 15, 2018 - Study sheds new light on disease-spreading mosquitoes
December 15, 2018 - 2017 Saw Slowing in National Health Care Spending
December 15, 2018 - Monitoring movement reflects efficacy of mandibular splint
December 15, 2018 - Study supports BMI as useful tool for assessing obesity and health
December 15, 2018 - Self-guided, internet-based therapy platforms effectively reduce depression
December 15, 2018 - Organically farmed food has bigger climate impact than conventional food production
December 15, 2018 - Faster, cheaper test has potential to enhance prostate cancer evaluation
December 15, 2018 - Researchers study abnormal blood glucose levels of patients after hospital discharge
December 15, 2018 - Swedish scientists explore direct association of dementia and ischemic stroke deaths
December 15, 2018 - Study finds 117% increase in number of dementia sufferers in 26 years
December 15, 2018 - Eczema Can Drive People to Thoughts of Suicide: Study
December 15, 2018 - Link between neonatal vitamin D deficiency and schizophrenia confirmed
December 15, 2018 - Nurse denied life insurance because she carries naloxone
December 15, 2018 - Ritalin drug affects organization of pathways that build brain networks used in attention, learning
December 15, 2018 - Research pinpoints two proteins involved in creation of stem cells
December 15, 2018 - Gut bacteria may modify effectiveness of anti-diabetes drugs
December 15, 2018 - A new type of ‘painless’ adhesive for biomedical applications
December 15, 2018 - Early physical therapy associated with reduction in opioid use
December 15, 2018 - Breast cancer protection from pregnancy begins many decades later, study finds
December 15, 2018 - How often pregnant women follow food avoidance strategy to prevent allergy in offspring?
December 15, 2018 - Using machine learning to predict risk of developing life-threatening infections
December 15, 2018 - How imaginary friends could boost children’s development
December 15, 2018 - Folate deficiency creates more damaging chromosomal abnormalities than previously known
December 15, 2018 - Study provides new insights into molecular mechanisms underlying role of amyloid in Alzheimer’s disease
December 15, 2018 - For the asking, a check is in the mail to help pay for costly drugs
December 15, 2018 - UA scientists uncover biological processes leading to rare brain disorder in babies
December 15, 2018 - The largest database on industrial poisons
December 15, 2018 - ESMO Immuno-Oncology Congress showcases novel technologies set to benefit many cancer patients
December 15, 2018 - Ovid Therapeutics Announces Plans to Move into a Phase 3 Trial in Pediatric Patients Based on End-of-Phase 2 Meeting for OV101 in Angelman Syndrome
December 15, 2018 - Left ventricular noncompaction – Genetics Home Reference
Researchers discover why exercise is good and high blood pressure is bad for the heart

Researchers discover why exercise is good and high blood pressure is bad for the heart

image_pdfDownload PDFimage_print

When the heart is put under stress during exercise, it is considered healthy. Yet stress due to high blood pressure is bad for the heart. Why? And is this always the case? Researchers of the German Centre for Cardiovascular Research (DZHK) and of Heidelberg University Hospital have obtained new findings which indicate that a previously undetected signal pathway causes or protects from heart failure – depending on the type of stress. They report their findings in the current issue of Nature Medicine.

The researchers examined a chain of metabolic processes in the heart that has an epigenetic switch called histone deacetylase 4 (HDAC4) at its outset. Epigenetics investigates how environmental influences regulate genes. The newly discovered signal transmission pathway can be upregulated or downregulated in mouse hearts depending on the stress. The researchers identified this, because at the end of the signal pathway, a fragment of HDAC4 is more prevalent in healthy mouse hearts after physiological stress, i.e. after exercise. Yet the mouse hearts that were subjected to pathological stress, for example permanent stress due to increased blood pressure, did not generate this fragment.

Temporary heart failure

The researchers aimed to investigate the effect more closely and therefore produced genetically modified mice that are not able to generate the HDAC4 fragment. The animals were subjected to physiological stress and, surprisingly, exercise no longer had the healthy effect on them. Instead, they developed temporary heart failure after the intensive workout which led to a distinctly reduced performance. This heart failure, however, regressed again.

“We found temporary cardiac fatigue”, says DZHK Professor Johannes Backs of Heidelberg University Hospital, Director of the newly established Department of Molecular Cardiology and Epigenetics (Internal Medicine VIII) since 2015. The syndrome is also found in patients, but is underestimated according to Dr. Lorenz Lehmann, the lead author of the study from the Department of Cardiology (Internal Medicine VIII) at Heidelberg University Hospital. Lehmann states that this is because it can only be detected if the cardiac function is examined during or in the minutes immediately after exercise.

It all depends on the breaks

The HDAC4 fragment can thus protect the heart from damage caused by temporary physiological stress. Yet why not also from stress caused by high blood pressure or other kinds of morbid stress? “The breaks make all the difference”, says Backs. During exercise, there are frequently rest periods for the heart. An enzyme called protein kinase A recovers during these periods and then ensures that the healthy path via the activation of the HDAC4 fragment is followed at a crossroads of the metabolic chain.

During permanent stress caused by severe high blood pressure, the signals in the heart cells, on the other hand, follow the newly discovered, morbid path: The protein kinase A’s activity eventually distinctly wanes under the permanent stress and the fragment disappears. The myocardial cells’ metabolism then uses more sugar than fat for producing energy. It is not, however, the change in energy production that makes the heart ill. Rather, it is because sugar residues attach to proteins too. Some of these proteins altered by sugar eventually inhibit the calcium metabolism and thus the myocardium’s contractile function, which leads to a deficiency in the heart’s pumping power.

“These findings are novel and change the way we think about how a myocardial cell can fail. We were able to demonstrate that there is a link from epigenetics via the metabolism through to contractility, i.e., through to cardiac function”, says Backs. The researchers also demonstrate that a gene therapy with the HDAC4 fragment protects against this pumping power deficiency in mice. This entirely new therapeutic principle is now being intensively investigated.

Extreme endurance sports can damage the heart

Even from an evolutionary perspective, the mechanism seems plausible to the researchers. Our ancestors, the gatherers and hunters, often had to be physically active for many hours to find food and bring it home. The newly discovered signal pathway could have protected the heart in this case. The results also explain why extreme endurance sports without rest periods can damage the heart. “We all intuitively know that breaks are important. Perhaps we have now found the molecular causes for this”, states Backs.

That prolonged stress on the heart leads to changes in the signal pathway may also be the cause of the broken heart syndrome (Takotsubo cardiomyopathy), in which temporary heart failure is brought on, in particular, by emotional stress. The researchers led by Johannes Backs are currently putting this phenomenon under the microscope.

Source:

https://dzhk.de/en/news/latest-news/article/exercise-is-good-for-the-heart-high-blood-pressure-is-bad-researchers-find-out-why/

Tagged with:

About author

Related Articles