Way back in clock time , ancient viruses are believed to have infect the generative cells of our ancestor , leave behind fossils of their genomes that we still see in our deoxyribonucleic acid today . In fact , as much as 8 % of our DNA is made up of the remnants of these infections , make out asendogenous retroviruses . Usually they lie sleeping , but they can be awoken , reigniting the output of viral constituent .
Controversially , such reactivation of these sleepyheaded sequence has now been connect with a reformist disease of the nervous system , call in Lou Gehrig ’s disease . We ’re right smart off from confirming that these viral genes play a causative role in this precondition , but if this turns out to be the case , then it may be that some affected role can be helped with drugs that we already use to treat infections with similar viruses .
This determination followed a series of observations regarding the status , also calledamyotrophic lateral sclerosis(ALS ) or motor neuron disease , which slowly destroys the nerves require in movement . While roughly10%of ALS patients also have a congenator afflicted with the disease , indicate heritability , some have no crime syndicate history , hence the name sporadic ALS .
Interestingly , some patients with AIDS – induce by the retrovirus HIV – show symptoms evocative of ALS , but they can often be revoke using antiviral drugs . slight to some , but another pinch of a potential connexion come from parentage samples of ALS patient , which in some cases show the presence of a retroviral protein , invert RNA polymerase , that is used to grow their RNA genome into DNA .
The team then grok a lilliputian deeper and found evidence for one particular HERV - honey oil protein across the cortex region of the genius , and also in sealed neuronal populations of the spinal cord . This retroviral protein , called Env , normally pokes out of the viral membrane like a lollipop and is used to gain entry to target prison cell .
Next , they grew human nerve cell in cup of tea and demonstrated that actuate HERV - K , or more specifically the Env protein grow by the virus , caused them to deteriorate . Taking this one tone further , they added the gene for Env into mice so that the protein was produce throughout their spooky organization . These animals move on to develop amyotrophic lateral sclerosis - similar symptoms , such as problems with travel and balance that aggravate with age . And when they performed post-mortem examination , the squad line up that the only nerves to experience degeneration were those that ascendance movement – motor neurons .
These are an interesting set of upshot , for certain , but in no room can they be used to say that an endogenous retrovirus is a cause of sporadic ALS ; the researchers themselves are even monitory and want others to retroflex their finding . But it should be noted that these ancient viruses have been implicated in anumber of other disease , lay out from schizophrenia to Cancer the Crab , although no studies have definitively proven a causative function . Still , the squad cogitate that they should engage the possibility of using antiretroviral drugs as a form of treatment for those with sporadic ALS , and there ’s already a wide range available , for instance those used to handle HIV .
