Glucose Regulation of Thrombospondin and Its Role in the Modulation of Smooth Muscle Cell Proliferation
Figure 2
The IAP binding domain of TSP-1 increases IGF-I signaling in normal glucose. (a) SMCs were grown to confluency in DMEM containing 5 mM glucose and then incubated overnight in SFM with 5 mM glucose. The following day the incubation was continued for 6 hours with (+) 4N1K or 4NG1G (1 g/mL). Equal amounts of lysate were then subjected to immunoprecipitation (IP) with and anti-SHPS-1 antibody prior to immunoblotting (IB) with an anti-IAP antibody or immunoblotted directly with an anti-SHPS-1 antibody. The graph shows the results from three similar experiments expressed as arbitrary scanning units ( when the amount of IAP associated with SHPS-1 is compared with the value for SMC incubated in 5 mM glucose containing medium). (b) SMCs were grown to confluency in DMEM containing 5 mM glucose and then incubated overnight in SFM with 5 mM glucose. The following day the incubation was continued for 6 hours with (+) 4N1K or 4NG1G (1 g/mL) followed by IGF-I (50 ng/mL) for 5 minutes. Equal amounts of lysate were then subjected to immunoprecipitation (IP) with and anti-SHPS-1 antibody prior to immunoblotting (IB) with either an antiphosphotyrosine (p-Tyr) or Shc antibody or immunoblotted directly with an anti-SHPS-1 antibody. The graph shows the results from three similar experiments expressed as fold increase in response to IGF-I compared with no addition of peptide (). (c) SMCs were grown to confluency in DMEM containing 5 mM glucose and then incubated overnight in SFM with 5 mM glucose. The following day the incubation was continued for 6 hours with (+) 4N1K or 4NG1G (1 g/mL) followed by IGF-I (50 ng/mL) for 5 minutes. Equal amounts of lysate were then subjected to immunoblotting (IB) with either an anti-phosphoERK or total-ERK antibody. The graph shows the results from three similar experiments expressed as fold increase in response to IGF-I compared with no addition of peptide ().
