Wow, really interesting paper on immune system activation and evolution of our disease fighting systems:
In the symposium entitled “Transcriptional controls of energy sensing,” the authors presented recent advances on 1) AMP kinase, an intracellular energy sensor; 2) PGC-1? (peroxisome proliferator-activated receptor ? co-activator 1?), a transcriptional co-activator that has powerful effects on mitochondria; 3) methylation and demethylation in response to metabolic fluctuations; and 4) FGF21 (fibroblast growth factor 21) as an emerging hormone-like intercellular metabolic coordinator. This introduction places these advances within a broad overview of energy sensing and energy balance, with a focus on human evolution and disease. Four key elements of human biology are analyzed: 1) elevated body temperature; 2) complex prolonged reproductive pathways; 3) emergence of 4 large, well-defined fat depots, each with its own functional role; and 4) an immune system that is often up-regulated by nutrition-related signals, independent of the actual presence of a pathogen. We propose that an overactive immune system, including the “metabolic syndrome,” was adopted evolutionarily in the distant past to help hold out against unconquerable infections such as tuberculosis, malaria, and trypanosomiasis. This immune activation is advantageous in the absence of other disease management methods, especially under conditions in which life expectancy is short. The inflammation has become a major agent of pathology in wealthy populations in whom the pathogens are a minor threat and life expectancy is long.
Paper
here.
Awesome article based on new gene research...I thought we were years away from making these kinds of conclusions.
A genetic variation that may increase a woman’s risk of gestational diabetes is widespread today because it was actually beneficial to early agricultural populations, a new study suggests.
Pregnant women who carry two copies of a low-activity form of the gene GIP have higher blood-glucose levels — a marker of gestational diabetes risk — Sheau Yu Teddy Hsu of Stanford University and colleagues report online February 7 in Diabetes. But when the gene’s low-activity version arose somewhere in Eurasia an estimated 8,100 years ago, that same glucose-boosting quality may have helped women maintain their pregnancies during lean times.
The new work takes an important step toward characterizing how one particular form of a gene shapes physiology and how evolution may act on that gene, says Joshua Akey, an evolutionary biologist and population geneticist at the University of Washington in Seattle.
Hsu and his colleagues recently reported evidence that the low-activity version of the GIP gene first appeared about 8,100 years ago and rapidly became part of the genetic makeup of Eurasians. Today about half of Europeans carry the new form of GIP, while 70 percent or more of Asians do. Only about 5 to 10 percent of Africans have the new form of the gene.
“It arose very fast, so it must have some dramatic effect on human viability,” Hsu says.
Full article here.
From a Canadian Surgeon; his conclusions are not as interesting in my opinion, but the excerpt below is great:
RECENTLY I WORKED as an internist-intensivist at the Canadian Combat Surgical Hospital in Kandahar. Most of our casualties were Afghans: National Army soldiers, National Police and civilians caught in crossfire. They were diminutive men, almost always less than a hundred and forty pounds. I cannot comment on the body masses of the Taliban—they were never brought to us. But they are not likely larger than those of the soldiers and the police. And because, in war, soldiers are fed first—prospering right up to the moment they are pierced—the civilians were even thinner.
For someone used to the life and the pathologies of the rich and settled, much about practicing medicine in Afghanistan felt unfamiliar. One of the striking differences was the way gunshot victims’ abdomens looked in CT scans. Back home, I was used to seeing organs stand out with some prominence from the abdominal fat. In fact, in Canadians, the state of the kidneys can be partly assessed by the degree of inflammation in the perinephric fat that envelops them. It’s the same with the pancreas, and the liver often looks like it belonged to a French goose fattened for foie gras. Indeed, the idea of “normal” in a Canadian body proceeds from the assumption that it might be normal to spend one’s days tied to a grain spout, beak pried open, being filled with cracked corn.
