title: The macroscopic structure of RADA16 peptide hydrogel stimulates monocyte/macrophage differentiation in HL60 cells via cholesterol synthesis.
abstract: Cells can sense physical properties of surrounding 3-dimensional (3D) culture substrata; however, the physiological influences of such sensing are not fully understood. Here, we studied the physiological characteristics and activities of the macroscopic structure of a routinely used 3D culture substrata, the RADA16 self-assembling peptide scaffold. We found that RADA16 exhibited three distinct assembly patterns depending on its concentration, and one of these assemblies, formed with 0.01% (w/v) RADA16, was capable of inducing differentiation of human myelocytic leukemia HL-60 cells into monocytes/macrophages. This activity was largely reduced by destroying the 3D structure of the assembly, suggesting that the assembly intrinsically retained the ability to induce HL-60 differentiation. When cultured in the RADA16 scaffold, HL-60 cells accumulated intracellular cholesterol about 10 times more than normally cultured cells. Both the RADA16 culture and cholesterol loading brought about similar gene expression profiles. These results showed that HL-60 cells can sense the physical properties of the RADA16 scaffold through a mechanism that may involve intracellular pathways of cholesterol synthesis and/or transport.
authors.affiliation: Science & Education Center, Ochanomizu University, Ohtsuka, Tokyo, Japan. kakiuchi.yasutaka@ocha.ac.jp
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kakiuchi
authors.forename: Noritaka
authors.initials: N
authors.lastname: Hirohashi
authors.forename: Kimiko
authors.initials: K
authors.lastname: Murakami-Murofushi
mesh_terms: D000595:Amino Acid Sequence; D001692:Biological Transport; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002784:Cholesterol / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D020100:Hydrogels / Q000737:chemistry / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: D015415:Biomarkers; D020100:Hydrogels; D010455:Peptides; C546681:RADA16-I; D002784:Cholesterol