TXNIP Regulates Peripheral Glucose Metabolism in Humans
Figure 5
Genetic Manipulation of TXNIP Expression Affects Both Basal and Insulin-Stimulated Glucose Uptake in Cultured Adipocytes and in Primary Skeletal Muscle Myocytes
(A) Differentiated 3T3-L1 adipocytes cultured in 5.6 mM glucose were transduced with human TXNIP or empty virus particles and allowed to express the genes for 96 h. Cell lysates were immunoblotted using antibodies against TXNIP or actin. The exogenous viral human TXNIP protein is present as the more slowly migrating of the two bands. Glucose uptake with and without insulin was measured as described in Methods. Each data point represents an n = 4. * p < 0.02; ** p < 0.005.
(B) Adipocytes cultured in 25 mM glucose were transfected with siRNA against TXNIP or with negative control siRNA and assayed 48 h posttransfection. Immunoblotting and glucose uptake are as above. n = 4 for each data point. * p < 0.02; ** p < 0.001.
(C) Human skeletal muscle myoblasts obtained from biopsy were differentiated into myotubes in culture and transfected with siRNA against TXNIP or with negative control siRNA. Glucose uptake was measured at 72 h post-transfection with n = 4 for each data point. Each experiment was performed at least three times. * p < 0.01