Common viruses cause Alzheimer’s disease?
Scientists have been puzzling over the causes of Alzheimer’s for years, but have so far failed to identify what triggers the disease by. Scientists from the Icahn School of Medicine at Mount Sinai have published a study revisiting the more than 50-year-old idea that common viruses are behind Alzheimer’s disease.
– We were looking for a drugóin whichóre could be used to treat the patientów with Alzheimer’s disease, but the patterns które emerged from our analysis, point to viruses as the cause of the disease – said geneticist Joel Dudley, one of the authors of theóin the study, whichóre appeared in the pages of the journal „Neuron”.
The concept that viruses may contribute to the development of dementia emerged in 1950. Hypothesis móShe concluded that Alzheimer’s disease is "slow viral disease", in whichórej one or more virusesów steadily degrades neurological processes in mózgu after several decades of dormancy.
In recent years, researchers have been leaning toward the hypothesis that theóra indicated the presence of m in mózgu depositsów protein – beta-amyloidów. According to her, these proteins accumulate outside neurons in the mózgu killing them or blocking. This concept has been seriously weakened after analyzing decades of clinical trials of drugs targeting amyloid plaques, in which theórej it was found that the failure rate of the resultingósł 99.6 percent. The paper was published in 2014 in the pages of „Alzheimer's Research & Therapy”.
The concept pointing to viral causes of Alzheimer’s disease wróhas returned to favor. It seems to be supported by a recent study. New York researchers have discovered that mózgi 622 osób with Alzheimer’s symptoms had twice as high levels of harpesvirusesóin poróIn the case of the osób healthy.
Harpesviruses are a family of virusesóin whichóra contains more than 100 species ofów. These are common viruses in animals and humans. The best known of these are herpes simplex virus HHV-1 and HHV-2. But scientists in the mózgach osób with dementia have found elevated levels of the virusóin HHV-6A (erythema urgens virus) and HHV-7.
– I don’t think we can yet say that herpesviruses are the mainóThe main cause of Alzheimer’s disease. However, it is clear that they participate in changes in mózgu associated with Alzheimer’s disease and accelerate them – admitted Dudley.
It is possible that both concepts are correct. Perhaps herpesviruses in some wayób interact with human DNA and stimulate the growth of amyloid plaques. The authors of the publication in the journal „Neuron” acknowledged that in their study they noticed that herpewiruses were involved in networks that regulate the production of amyloid proteins.
HHV-6A and HHV-7 are extremely common viruses, often with no symptoms at allów. The researchers noted in their paper that in America Pónnocent about 90 percent. children have at least one of them in their blood early in life.
– While this is a solid study, it, like other research in the field, cannot prove that viruses are indeed responsible for the disease. Therefore, it does not change what we already know about the causes of dementia and does not mean that the common cold increases the risk of Alzheimer’s. People should not be overly concerned – said James Pickett of the Alzheimer's Society.
It is likely that there are many róThe complex mechanismóin the development of Alzheimer’s disease. But the authors of the new study hope that resurrecting the viral hypothesis may helpóc im in discovering new dróg, whichóre may lead to new therapies.