title: Thyroid organoid formation in simulated microgravity: influence of keratinocyte growth factor.
abstract: The generation of artificial human thyroid tissues in suspension (low-shear environment, present in simulated microgravity [MG] and generated by a rotary cell culture system [RCCS]), was enhanced by increasing medium kinematic viscosity with a (3% v/v) suspension of extracellular matrix (basement membrane extract [BME]) in serum-free medium to generate artificial human thyroid organoids. Recombinant human keratinocyte growth factor (KGF, 7 ng/mL) facilitated human thyrocyte aggregation and three-dimensional (3-D) differentiation. There was an MG-associated decrease in extractable DNA that was reversed after addition of keratinocyte growth factor (KGF). In simulated MG, the increase in extractable DNA after KGF addition was up to 170% over non-KGF control cultures. In contrast, monolayer cultures in unit gravity showed a maximum DNA increase of 39% after KGF addition. Morphologically, differentiated thyroid neofollicles displayed polarization and were located in close proximity after 2 weeks of culture. Immunogold labeling with antibody to human thyroglobulin (Tg) revealed staining of follicular lumina and secretory vesicles, and a time-dependent increase in human Tg was detected in the culture media. Culture under simulated MG thus allowed direct visualization of KGF-facilitated thyrocyte/extracellular matrix interaction. Such artificial human thyroid organoids-generated in MG and in the presence of KGF-structurally resembled natural thyroid tissue. The above findings may have implications for autoimmune thyroid disease where KGF (if, for example, secreted locally by intraepithelial gammadelta T cells among other cells) may contribute to thyroid cell growth.
authors.affiliation: Department of Medicine, Mount Sinai School of Medicine, New York, New York, USA. andreas.martin@mssm.edu
authors.forename: A
authors.initials: A
authors.lastname: Martin
authors.forename: A
authors.initials: A
authors.lastname: Zhou
authors.forename: R E
authors.initials: RE
authors.lastname: Gordon
authors.forename: S C
authors.initials: SC
authors.lastname: Henderson
authors.forename: A E
authors.initials: AE
authors.lastname: Schwartz
authors.forename: A E
authors.initials: AE
authors.lastname: Schwartz
authors.forename: E W
authors.initials: EW
authors.lastname: Friedman
authors.forename: T F
authors.initials: TF
authors.lastname: Davies
mesh_terms: D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000235:genetics; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D051526:Fibroblast Growth Factor 10; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D009940:Organoids / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013954:Thyroglobulin / Q000378:metabolism; D013961:Thyroid Gland / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D014783:Viscosity; D018474:Weightlessness Simulation
chemical_list: D015815:Cell Adhesion Molecules; C496453:FGF7 protein, human; D051526:Fibroblast Growth Factor 10; D006133:Growth Substances; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D004247:DNA; D013954:Thyroglobulin