The Examining Room of Dr. Charles: A Cure for Diabetes?
A very interesting blog entry (on a very interesting blog) about a Cell paper that’s gotten scant media attention. The paper implicates malfunctioning pancreatic neurons in autoimmune (Type I) diabetes. Dr. Charles’ explanation is very accessible, but if you want to go straight to the source, here’s the most relevant paragraph from the paper’s conclusion:
Elimination of TRPV1+ neurons by capsaicin, transient functional normalization by acute local sP injection, or replacement with wild-type trpv1 in Idd4 congenics has the same, islet-specific outcome: normalized insulin sensitivity and abrogation of insulitis, despite unimpeded generation of autoreactive lymphocytes that can transfer disease to untreated NOD hosts. The most parsimonious explanation unifying these observations is a local feedback interaction between β cells and the primary sensory neurons innervating islets (Figure S11), with nerve terminals responding to local insulin with release of neuropeptides that sustain β cell physiology in an optimal range. Normally, this interaction is in balance, but in the NOD mouse, hypofunction of TRPV1 unbalances the feedback, with β cell stress due to hyperinsulinism, insulin resistance, and infiltration by autoreactive T cell pools independently generated in the NOD mouse. Removing TRPV1 neurons leads to elimination of the unbalanced, pathogenic interaction, whereas administering sP exogenously may renormalize the interaction transiently.
Are you still reading this after that quote? Ha! Then you probably want the full text link for the Cell article. All one of you.
I always get a kick out of teaching pancreatic physiology and diabetes. Usually more than half my students have diabetic family members (mostly Type II) so the subject is relevant and personal. They always ask an unusual number of questions, most of which I can’t answer. So, like Dr. Charles, I’m also baffled that this paper didn’t get more media attention.
Still, given the way the media can garble science, perhaps anonymity is a good thing – I can anticipate people wolfing megadoses of hot peppers instead of injecting insulin. Ouch! Just in case, let me be clear: that wouldn’t work. Chili peppers do have promising health benefits, but simply eating them would not produce the effect seen in this Cell study, and eating excessive amounts may be a risk factor for gastric cancer.
Mmm, peppers. Now I want to go to Quizno’s.