Breaking News
March 22, 2018 - Vitamin D deficiency linked to metabolic syndrome in postmenopausal women
March 22, 2018 - Changes in the intestines may be responsible for reversal of diabetes after bariatric surgery
March 22, 2018 - iPads and Cancer; Clot Retrieval and Stroke: It’s PodMed Double T!
March 22, 2018 - Premature births linked to changes in mother’s bacteria
March 22, 2018 - Brain SPECT scans predict treatment outcomes in patients with depression
March 21, 2018 - Researchers succeed in integrating artificial organelles into cells of living organism
March 21, 2018 - Researchers discover ‘missing mutation’ in severe infant epilepsy
March 21, 2018 - Researchers develop statistics-based computational scheme to zoom in on brain function
March 21, 2018 - Verge joins Genomics England’s Discovery Forum industry partnership
March 21, 2018 - Trovagene Announces First Patient Successfully Completes Cycle 1 of Treatment with PCM-075 in Combination with Low Dose Cytarabine (LDAC) in AML Trial
March 21, 2018 - Congenital Cardiac Cath Tx Often Strays from Guidelines
March 21, 2018 - Marked increase in cardiovascular risk factors in women after preeclampsia
March 21, 2018 - New app may help predict, track manic and depressive episodes in bipolar patients
March 21, 2018 - Discovery of genes could lead to development of novel therapies for EBV-related cancers
March 21, 2018 - High-fat, high-cholesterol diet depletes ranks of artery-protecting immune cells
March 21, 2018 - Research misconduct allegations shadow likely CDC appointee
March 21, 2018 - Most Breast Ca Patients Fail to Get Genetic Counseling
March 21, 2018 - Lopsided ear function can lead to lopsided brain development
March 21, 2018 - Acupuncture helps manage menopausal symptoms, review finds
March 21, 2018 - Motor skill training may contribute to reading skills in obese children
March 21, 2018 - Poor dental health may be related to increased diabetes risk
March 21, 2018 - Chronic opioid users at increased risk of complications after spinal fusion surgery
March 21, 2018 - NSAID use linked to increased risk of atrial fibrillation
March 21, 2018 - Scientists develop brain “stethoscope” that can detect silent seizures
March 21, 2018 - New method predicts effects of global warming on disease
March 21, 2018 - Insurance Company Hurdles Burden Doctors, May Harm Patients
March 21, 2018 - Renal Transplant from HCV-Positive Donors Feasible
March 21, 2018 - Myelodysplastic syndrome: MedlinePlus Medical Encyclopedia
March 21, 2018 - Research reveals brain mechanism involved in language learning
March 21, 2018 - Many parents still hesitate to try early peanut introduction, survey finds
March 21, 2018 - Audiologist urges tinnitus sufferers facing ‘revolving door healthcare’ to seek support
March 21, 2018 - Study reveals impact of prostate cancer on wives and partners of sufferers
March 21, 2018 - ‘Almost a Miracle Drug’: What We Heard This Week
March 21, 2018 - Study shows NIH spent >$100 billion on basic science for new medicines
March 21, 2018 - Columbia researchers identify nerve cells that drive fruit fly’s escape behavior
March 21, 2018 - Sartorius Stedim Biotech selected by ABL Europe to supply single-use process technologies
March 21, 2018 - Increase in coffee consumption may help battle against colon cancer
March 21, 2018 - Hydrogel may accelerate healing of diabetic ulcers
March 21, 2018 - Dermira’s Two Phase 3 Trials Evaluating Olumacostat Glasaretil in Patients with Acne Vulgaris Did Not Meet Co-Primary Endpoints
March 21, 2018 - DePuy Synthes introduces ACTIS Total Hip System for improving initial implant stability
March 21, 2018 - ‘Oh, It Was Nothing’
March 21, 2018 - Herbal drug kratom linked to salmonella illnesses, CDC says
March 21, 2018 - New optical point-of-care device could enhance screening for thyroid nodules
March 21, 2018 - FDA Expands Approval of Adcetris (brentuximab vedotin) for First-Line Treatment of Stage III or IV Classical Hodgkin Lymphoma in Combination with Chemotherapy
March 21, 2018 - Eosinophilic Esophagitis: Late Manifestation of Allergic March
March 21, 2018 - Signaling pathway involving the Golgi apparatus identified in cells with Huntington’s disease
March 21, 2018 - Quintupling inhaled steroid doses may not benefit children with asthma
March 21, 2018 - Study shows clear connection between cardiovascular fitness in middle age and dementia risk
March 21, 2018 - Premature babies have higher risks of health complications in Bangladesh
March 21, 2018 - Child’s temperament and parenting influence weight gain in babies
March 21, 2018 - Researchers find the heart to be capable of arrhythmia termination after local gene therapy
March 21, 2018 - Inhealthcare to provide digital infrastructure for NHS to help protect people from falls
March 21, 2018 - Flu Season Finally Slowing Down
March 21, 2018 - Mixed Results for Shorter DAPT in ACS Patients
March 21, 2018 - Scientists discover fish scale-derived collagen effective for healing wounds
March 21, 2018 - Genomics England announces new partnership to improve efficiency of next-generation sequencing analysis
March 21, 2018 - Adjuvant AC chemotherapy found to be effective in treating HRD-positive breast cancer patients
March 21, 2018 - Researchers identify new treatment targets for lung diseases using big data
March 21, 2018 - Kids see more women in science than five decades ago
March 21, 2018 - Research shows link between chronic fatigue syndrome and lower thyroid hormone levels
March 21, 2018 - Alzheimer’s disease on the rise
March 21, 2018 - Two Agents Equal as Pretreatment for Adrenal Tumor Surgery
March 21, 2018 - ‘Icebreaker’ protein opens genome for T cell development, researchers find
March 21, 2018 - Women in medicine shout #Metoo about sexual harassment at work
March 21, 2018 - Mother’s pre-pregnancy waist size may be linked to child’s autism risk
March 21, 2018 - Second hand marijuana smoke can cause serious damage
March 21, 2018 - International study shows benefits of using MRI at the start of prostate cancer diagnosis
March 20, 2018 - Santhera Reports Outcome of Exploratory Trial with Idebenone in PPMS Conducted at the NIH
March 20, 2018 - ECG Patch Ups At-Home Afib Diagnosis in mSToPS Trial
March 20, 2018 - ROS-scavenging nanozymes for anti-inflammation therapeutics
March 20, 2018 - Genomics England announces appointment of global genomics pioneer as first CEO
March 20, 2018 - Test flight at German Aerospace Center in Cologne demonstrates functionality of deficopter
March 20, 2018 - Music therapy helps treat combat-related psychological injuries in military personnel
March 20, 2018 - Innovative psychotherapeutic treatment protocol for obsessive-compulsive disorders
March 20, 2018 - Weight loss after lap-band surgery alleviates arthritic knee pain
March 20, 2018 - New diabetes drug may help obese people shed body weight
March 20, 2018 - Novel Peanut OIT a Winner in Phase III Trial
March 20, 2018 - Can gene therapy be harnessed to fight the AIDS virus?
March 20, 2018 - Education and academic achievement can lessen effects of child abuse, neglect
March 20, 2018 - Researchers develop new algorithm to make CPR more effective
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.


Tagged with:

About author

Related Articles