PLT Test Blog

    A microglial cell, labelled in green, contacts and attacks a myelinated axon (in red). In the presence of the pHERV-W envelope protein, this interaction leads to axonal injury. The blue structures are cell nuclei. Credit: HHU / Joel Gruchot / Patrick Küry     It is surprising that only about 2% of human DNA encodes the 20,000 or so genes we all have.   The other 98% used to be called junk DNA. About 8% of your DNA is made up of Endogenous retroviruses (ERVs) that have been picked up during evolution and most of which have been inactivated and can indeed be regarded as junk. Some of these old viruses that became part of human DNA remain fully functional, can be activated; they are implicated in disease ranging from Multiple Sclerosis (MS), to cancer, to schizophrenia and ALS (motor neuron disease). The best documented ERV is the one that affects some people with MS, it is called HERV-W  (the H is for Human).   Only in the presence of a protein ...

Acid sensing ion channels (ASICs) are another emerging area of science where much remains known.   It would seem that ASICs have evolved for a good reason, when pH levels fall they trigger a reaction to compensate.   (The lower the pH the higher is the acidity)   In some cases, like seizures, this seems to work, but in other cases the reaction produced actually makes a bad situation worse. Research is ongoing to find inhibitors of ASICs to treat specific conditions raging from MS (Multiple Sclerosis), Parkinson’s and Huntington’s to depression and anxiety. Perhaps autism should be added to the list. NSAIDs like ibuprofen are inhibitors of ASICs. The complicated-looking chart below explains the mechanism.   The ASIC is on the left, also present is a voltage-gated calcium channel (VGCC) and an NMDA receptor. We already know that VGCCs can play a key role in autism and mast cell degranulation. Similarly we know that in autism there is very often either too much or too l...