Distinct Effects of Carrageenan and High-Fat Consumption on the Mechanisms of Insulin Resistance in Nonobese and Obese Models of Type 2 Diabetes
Serum galectin-3 increased following carrageenan or HFD. (a) Serum galectin-3 increased following carrageenan or HFD or their combination (, ). (b) Galectin-3 binding with the insulin receptor increased in the liver and muscle membrane preparations of the treated mice, with the greatest effect following the combined exposure (, ). (c) In HepG2 cells, the insulin-induced increase in phospho(Tyr)-IRS1 was significantly inhibited by administration of exogenous recombinant human galectin-3 (, ). (d) The insulin-induced glucose uptake in the HepG2 cells was blocked by administration of exogenous recombinant human galectin-3 (, ). (e) The Pearson correlation between the glucose uptake and the phospho(Tyr)-IRS-1 in the HepG2 cells was 0.985. (f) Activity of the enzyme arylsulfatase B (ARSB; N-acetylgalactosamine-4-sulfatase), which removes 4-sulfate groups from the nonreducing end of chondroitin 4-sulfate and dermatan sulfate, was inhibited by exposure to carrageenan, but not by the HFD, in the liver and pancreas of the treated mice (, ). ARSB = arylsulfatase B; CGN = carrageenan; IRS = insulin receptor substrate.