Pirouette said...
Psilociraptor said...
...in short lipoproteins carry LBP which binds endotoxins for excretion and both cholesterol synthesis and VLDL are transcriptionally regulated by inflammatory signals.
WOW. I'm really interested in this… although I can't understand it! ;) Can you rephrase in a more pedestrian-friendly version? I would love to share this w/ my Lyme nurse.
-pWell lipoproteins are just packets of fat bound by proteins that circulate in your blood for delivery of fat to tissues. You know these as your HDL and LDL though there are many subfractions of these. But their duel function is not just to deliver fats but to sequester fat-soluble bacterial components using lipopolysaccharide binding protein (and likely other proteins). So they leave from the liver with dietary fats and come back to the liver with bacterial "endotoxins" which get dumped in the bile and pooped out. Transcript
ional regulation just means that these genes are regulated by external signals at the DNA->RNA level. In this case many genes associated with host metabolism and especially those pertaining to lipid "disorders" are modulated in response to inflammatory signals and pathogen recognition systems. So my understanding is as follows...
High fat diets->overgrowth of fat metabolizing gut microbiota->leaky gut->inflammation. Inflammation then triggers insulin resistance/cholesterol and VLDL synthesis/lipoprotein lipase activity and causes all the basic features of metabolic syndrome. As we know with Lyme, many microorganisms do not like to stay in the blood stream because of circulating complement, antibodies, immune cells and so on. So they attempt to break through the blood vessels into deeper tissue. So immune cells chase after them, stimulate local inflammation, recruit more immune cells and lipoproteins and form a plaque which some think may serve to contain the infection and prevent sepsis. I don't think anybody really knows the exact dynamic between HDL/LDL and all the subfractions. But we do know that they pass endotoxins back and forth that are ultimately taken up by the liver. We don't really know why cholesterol is needed either but it could simply have to do with the binding dynamics of lipoproteins. In either case it really has nothing to do with the initiation or propagation of this process (unless of course it also has an adverse effect on gut microbiota). The inflammation comes from the bacterial endotoxins. The plaque comes from the immune cells. And the heart attack risk comes from when plaque ruptures. This is usually attributed to physical stress, but there was one recent study showing the presence of bacterial biofilms inside plaques. And showing that, in vitro, stress signals can cause them to disperse by releasing biofilm degrading enzymes which also rupture the plaque. So that's a possibility too.
But all in all your CVD risk comes from infection, not cholesterol or LDL. Neither is "bad" though they may certainly reflect something bad happening under the surface. It's not really straight forward though. All that stuff changes in a healthy way with diet as well. When i switched to paleo i started eating more meat and my cholesterol levels jumped. But my LDL changed from pattern B to pattern A which is much healthier. So your lipid panels are telling you two things. How your body is handling dietary fat, and your metabolic response to infectious burden. Separating those and getting meaningful information is hard if not impossible right now.