👤 Kiryu Asakura

Transferrin receptor 1 (TfR1), an intracellular iron receptor, has multiple biological functions. We have previously reported that aortic TfR1 expression increases in human and murine abdominal aortic aneurysm, but its role in the development of atherosclerosis remains unclear. In the present study, we generated apolipoprotein-E (ApoE) and TfR1 deficient mice and examined the impact of its deletion on the development of atherosclerosis. Homozygous ApoE deficient ( These results indicate that TfR1 deletion attenuates the development of atherosclerotic lesion formation in Show less

Proteoglycans (PGs), a family of glycosaminoglycan (GAG)-protein glycoconjugates, contribute to animal physiology through interactions between their glycan chains and growth factors, chemokines and adhesion molecules. However, it remains unclear how GAG structures are changed during the aging process. Here, we found that polyamine levels are correlated with the expression level of heparan sulfate (HS) in human skin. In cultured cell lines, the EXT1 and EXT2 enzymes, initiating HS biosynthesis, were stimulated at the translational level by polyamines. Interestingly, the initiation codon recognition by 43S preinitiation complex during EXT2 translation is suppressed by let-7b, a member of the let-7 microRNA family, through binding at the N-terminal amino acid coding sequence in EXT2 mRNA. Let-7b-mediated suppression of initiation codon depends on the length of 5'-UTR of EXT2 mRNA and its suppression is inhibited in the presence of polyamines. These findings provide new insights into the HS biosynthesis related to miRNA and polyamines. Show less