The vacuolated morphology of chordoma cells is dependent on cytokeratin intermediate filaments

Abstract

Notochordal cells (NCs), characterized by their vacuolated morphology and coexpression of cytokeratin and vimentin intermediate filaments (IFs), form the immature nucleus pulposus (NP) of the intervertebral disc. As humans age, NCs give way to mature NP cells, which do not possess a vacuolated morphology and typically only express vimentin IFs. In light of their concomitant loss, we investigated the relationship between cytosolic vacuoles and cytokeratin IFs, specifically those containing cytokeratin-8 proteins, using a human chordoma cell line as a model for NCs. We demonstrate that the chemical disruption of IFs with acrylamide, F-actin with cytochalasin-D, and microtubules with nocodazole all result in a significant (p < 0.001) decrease in vacuolation. However, vacuole loss was the greatest in acrylamide-treated cells. Examination of the individual roles of vimentin and cytokeratin-8 IFs in the existence of vacuoles was accomplished using small interfering RNA-mediated RNA interference to knock down either vimentin or cytokeratin-8 expression. Reduction of cytokeratin-8 expression was associated with a less-vacuolated cell morphology. These data demonstrate that cytokeratin-8 IFs are involved in stabilizing vacuoles and that their diminished expression could play a role in the loss of vacuolation in NCs during aging. A better understanding of the NCs may assist in preservation of this cell type for NP maintenance and regeneration.

NOTO Transcription Factor Directs Human Induced Pluripotent Stem Cell-Derived Mesendoderm Progenitors to a Notochordal Fate

“…This result indicated that somite-derived sclerotomal cells differentiation is major in untransfected control. Although KRT18 and CDH2 were strongly induced, cytosolic vacuolar structures typically found in human mature juvenile NC were not observed [55][56][57][58]. In addition, the low expression of CA12 and LGALS3 at day 7 indicated that differentiated NLC maintains an immature/embryonic state.…”

In Situ Synthesized Porous Bacterial Cellulose/Poly(vinyl alcohol)‐Based Silk Sericin and Azithromycin Release System for Treating Chronic Wound Biofilm

“…CK14, a cytoskeletal protein that is found in all types of epithelial cells of all different types, was also studied. [ 56 ] As a result, the dark brown color in Figure 9 A underlines the epidermis, while the dermis, comprised of collagen, is completely devoid of CK14. CK14 expression in the BC–PVA@SSga group on day 14 highlighted the complete re‐epithelization, while in the other groups, they did not achieve high expression until day 14 due to the lower wound healing ability of BC–PVA@SSg and Nacl 0.9%.…”

Development of surface functionalization strategies for 3D‐printed polystyrene constructs

“…hMSCs were seeded onto surfaces and grown overnight. Cytochalasin‐D‐treated hMSCs had their media replaced with growth media containing 10 μmol/L cytochalasin‐D for 1 h prior to fixing . Samples were chemically fixed using 4% formaldehyde and 1% sucrose solution and permeabilized with a 300 mmol/L sucrose, 50 mmol/L sodium chloride, 6 mmol/L magnesium chloride, 20 mmol/L HEPES, and 0.5% Triton‐X‐100 solution.…”