brief notes - doxycycline, TGF-beta, microgravity
The topic of low dose doxycycline (DOX) for Parkinson's came up on a forum. Rationale for its use in PD is typically based inhibition of a-syn aggregation , however DOX is a matrix metalloproteinase inhibitor (2 and 9). Matrix metalloproteinases are a group of enzymes that break down collagen and some other extracellular matrix proteins. White tea is supposed to be good for preventing skin aging since it contains a substance that inhibits one or two matrix metalloproteinases (can't remember which ones). The extracellular matrix is the stuff in between cells and it is mostly collagen. A lot of TGF-beta, a signalling molecule involved in the immune system, is localized in the ECM and engages in 'solid state' signalling - it is not dissolved in fluid, it stays put and interacts with cells as they come in contact when the tissue is deformed by mechanical pressure or cells migrate . People with connective tissue disorders often have immune system problems because