Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitro

Summary: Objective: The actin cytoskeleton regulates cell shape and plays a role in regulating chondrocyte phenotype. Most studies investigating regulation of the chondrocyte phenotype by the actin cytoskeleton use chondrocytes isolated from full-thickness (FT) cartilage, which has a heterogeneous...

Full description

Bibliographic Details
Main Authors: Elizabeth Delve, Vivian Co, Rita A. Kandel
Format: Article
Language:English
Published: Elsevier 2020-09-01
Series:Osteoarthritis and Cartilage Open
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2665913120300601
_version_ 1818364095849562112
author Elizabeth Delve
Vivian Co
Rita A. Kandel
author_facet Elizabeth Delve
Vivian Co
Rita A. Kandel
author_sort Elizabeth Delve
collection DOAJ
description Summary: Objective: The actin cytoskeleton regulates cell shape and plays a role in regulating chondrocyte phenotype. Most studies investigating regulation of the chondrocyte phenotype by the actin cytoskeleton use chondrocytes isolated from full-thickness (FT) cartilage, which has a heterogeneous cell population. Superficial zone chondrocytes (SZC) have an elongated morphology and account for 10–20% of chondrocytes, while the remaining chondrocytes in the deeper zones appear more rounded. This study characterizes the actin cytoskeleton and expression of actin-associated molecules in SZC and deep zone (DZ) chondrocytes (DZC) in vitro in order to identify molecules differentially expressed by SZC and DZC that may contribute to the observed differences in zonal chondrocyte shapes. Design: SZ, DZ, and FT chondrocytes isolated from bovine metacarpal-phalangeal joints were cultured in monolayer for 48 h. Macroscopic morphology, actin polymerization status, and expression of select actin-associated molecules (adseverin, cofilin, transgelin, vinculin, MRTF-A, and YAP/TAZ) were determined. Results: SZC appeared more elongated and have more filamentous actin compared to DZC, as determined by quantifying cell circularity and G-/F-actin ratio. MRTF-A gene and protein levels were significantly higher in SZC compared to DZC while DZC more highly expressed transgelin and TAZ. Although there was differential gene expression, no significant differences in adseverin, cofilin, vinculin, or YAP protein levels were observed between the two cell populations. Conclusions: This study identifies differences in actin polymerization status and expression of actin-associated molecules in primary SZC and DZC in vitro. These findings further our understanding of candidate actin-related pathways that may be regulating zonal chondrocyte phenotype.
first_indexed 2024-12-13T21:58:56Z
format Article
id doaj.art-984bfc6c7676424fbdbfbbb4664b6f6d
institution Directory Open Access Journal
issn 2665-9131
language English
last_indexed 2024-12-13T21:58:56Z
publishDate 2020-09-01
publisher Elsevier
record_format Article
series Osteoarthritis and Cartilage Open
spelling doaj.art-984bfc6c7676424fbdbfbbb4664b6f6d2022-12-21T23:30:04ZengElsevierOsteoarthritis and Cartilage Open2665-91312020-09-0123100071Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitroElizabeth Delve0Vivian Co1Rita A. Kandel2Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, CanadaUniversity of Ontario Institute of Technology, Oshawa, ON, CanadaLunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada; Corresponding author. Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, 600 University Avenue, Suite 6-500, Toronto, Ontario, M5G 1X5, Canada.Summary: Objective: The actin cytoskeleton regulates cell shape and plays a role in regulating chondrocyte phenotype. Most studies investigating regulation of the chondrocyte phenotype by the actin cytoskeleton use chondrocytes isolated from full-thickness (FT) cartilage, which has a heterogeneous cell population. Superficial zone chondrocytes (SZC) have an elongated morphology and account for 10–20% of chondrocytes, while the remaining chondrocytes in the deeper zones appear more rounded. This study characterizes the actin cytoskeleton and expression of actin-associated molecules in SZC and deep zone (DZ) chondrocytes (DZC) in vitro in order to identify molecules differentially expressed by SZC and DZC that may contribute to the observed differences in zonal chondrocyte shapes. Design: SZ, DZ, and FT chondrocytes isolated from bovine metacarpal-phalangeal joints were cultured in monolayer for 48 h. Macroscopic morphology, actin polymerization status, and expression of select actin-associated molecules (adseverin, cofilin, transgelin, vinculin, MRTF-A, and YAP/TAZ) were determined. Results: SZC appeared more elongated and have more filamentous actin compared to DZC, as determined by quantifying cell circularity and G-/F-actin ratio. MRTF-A gene and protein levels were significantly higher in SZC compared to DZC while DZC more highly expressed transgelin and TAZ. Although there was differential gene expression, no significant differences in adseverin, cofilin, vinculin, or YAP protein levels were observed between the two cell populations. Conclusions: This study identifies differences in actin polymerization status and expression of actin-associated molecules in primary SZC and DZC in vitro. These findings further our understanding of candidate actin-related pathways that may be regulating zonal chondrocyte phenotype.http://www.sciencedirect.com/science/article/pii/S2665913120300601Superficial zone chondrocyteDeep zone chondrocyteActin cytoskeletonMRTF-AYAP/TAZ
spellingShingle Elizabeth Delve
Vivian Co
Rita A. Kandel
Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitro
Osteoarthritis and Cartilage Open
Superficial zone chondrocyte
Deep zone chondrocyte
Actin cytoskeleton
MRTF-A
YAP/TAZ
title Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitro
title_full Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitro
title_fullStr Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitro
title_full_unstemmed Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitro
title_short Superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin-associated molecules in vitro
title_sort superficial and deep zone articular chondrocytes exhibit differences in actin polymerization status and actin associated molecules in vitro
topic Superficial zone chondrocyte
Deep zone chondrocyte
Actin cytoskeleton
MRTF-A
YAP/TAZ
url http://www.sciencedirect.com/science/article/pii/S2665913120300601
work_keys_str_mv AT elizabethdelve superficialanddeepzonearticularchondrocytesexhibitdifferencesinactinpolymerizationstatusandactinassociatedmoleculesinvitro
AT vivianco superficialanddeepzonearticularchondrocytesexhibitdifferencesinactinpolymerizationstatusandactinassociatedmoleculesinvitro
AT ritaakandel superficialanddeepzonearticularchondrocytesexhibitdifferencesinactinpolymerizationstatusandactinassociatedmoleculesinvitro