Hotamisligil & Erbay, 2008.
Confused? Yeah, sorry. It looks confusing but really this figure is very interesting because we are taking a snap shot of the inside of a cell, and looking at all the signalling pathways involved. Notice the top, there is glucose (gold ball), amino acids, cholesterol (green balls) and off to the left are fatty acids (blue balls). These are nutrients you obtain from you diet and each one has an important role on your cells. In our case we are looking at the inside of the cell at what is called the endoplasmic reticulum (ER). This little guy responds to nutrient-associated signals—from insulin, fatty acids, glucose, and free cholesterol (as I just listed). What actually happens is another protein—called the unfolded-protein response (UPR)—is induced in response to an ER that is “stressed” leading to a hold cohort of inflammatory responses. A stressed ER can result in response to high glucose levels—or hyperglycemia. Prolonged levels of hyperglycemia (elevated glucose) lead to the pathway shown above. Your cell’s UPR protein reacts to a “stressed ER.” The now stressed ER from excess glucose turns on a whole bunch of pathways that lead to altered metabolic responses, a term used to describe the dysfunction of metabolism and in our case this metabolism occurs that the cellular level.
I don’t expect you to understand the figure, I am showing you this because you can see the complicated mechanism involved and the result is metabolic dysfunction and inflammation—two processes associated with dyslipidemia and obesity. This just goes to show the impact nutrients have at the cellular level, and the degree as to which that can stimulate harmful pathways. I must note that metabolic dysfunction and inflammation as seen above usually only occurs after chronic ill nutrition, that is a diet lacking in essential nutrients but one that contains high levels of glucose, and fat.
The take away message: the foods you eat every day have a direct effect on your cells, and your cells can respond in a positive or negative manner—I hope its the former.
Hotamisligil GS & Erbay E. Nutrient sensing and inflammation in metabolic diseases. Nat Rev Immunol. 2008 December; 8(12): 923.