Inductive effect of SORT1 on odontoblastic differentiation of human dental pulp-derived stem cells

Daisuke Omagari; Taku Toriumi; Hiromasa Tsuda; Manabu Hayatsu; Keisuke Watanabe; Yusuke Mizutami; Masaki Honda; Yoshikazu Mikami

doi:10.1016/j.diff.2023.08.001

Inductive effect of SORT1 on odontoblastic differentiation of human dental pulp-derived stem cells

Differentiation. 2023 Sep-Oct:133:88-97. doi: 10.1016/j.diff.2023.08.001. Epub 2023 Aug 9.

Authors

Daisuke Omagari¹, Taku Toriumi², Hiromasa Tsuda³, Manabu Hayatsu⁴, Keisuke Watanabe⁵, Yusuke Mizutami⁶, Masaki Honda⁷, Yoshikazu Mikami⁸

Affiliations

¹ Department of Pathology, Tsurumi University School of Dental Medicine, Kanagawa, Japan.
² Department of Physical Therapy, Faculty of Rehabilitation, Kyushu Nutrition Welfare University, Fukuoka, Japan; Department of Anatomy, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan.
³ Department of Biochemistry, Nihon University School of Dentistry, Tokyo, Japan.
⁴ Division of Microscopic Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
⁵ Division of Gross Anatomy and Morphogenesis, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
⁶ Office of Institutional Research, Hokkaido University, Hokkaido, Japan.
⁷ Department of Oral Anatomy, Aichi Gakuin University School of Dentistry, Aichi, Japan.
⁸ Division of Microscopic Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan. Electronic address: mikami-yoshikazu@med.niigata-u.ac.jp.

PMID: 37579565
DOI: 10.1016/j.diff.2023.08.001

Abstract

This study investigated the expression of sortilin 1 (SORT1) in cultured human dental pulp-derived stem cells (hDPSCs) and its role in their odontoblastic differentiation. Permanent teeth were extracted from five patients, and the dental pulp was harvested for explant culture. Fluorescence-activated cell sorting was used to analyze the outgrowth of adherent cells and cells that had migrated from the tissue margin. SORT1 expression was detected in hDPSCs simultaneously expressing the mesenchymal stem cell markers CD44 and CD90. The odontoblastic differentiation potential of SORT1-positive hDPSCs was examined via staining for alkaline phosphatase (ALP), an early odontoblastic differentiation marker. ALP staining was more intense in SORT1-positive than in SORT1-negative hDPSCs. Consistently, the expression of mRNA encoding SORT1 and p75^NTR, a binding partner of SORT1, increased in SORT1-positive hDPSCs during odontoblastic differentiation. In addition, pro-nerve growth factor (NGF), a ligand for SORT1-p75^NTR co-receptor, promoted ALP expression in SORT1-positive hDPSCs, and the interaction between SORT1 and p75^NTR was detected using a coimmunoprecipitation assay. The function of SORT1 in odontoblastic differentiation was examined via RNA interference using shRNA targeting SORT1. ALP staining intensity in SORT1/shRNA-transfected cells was markedly lower than in control/shRNA-transfected cells. SORT1 knockdown decreased JUN phosphorylation and recruitment of phosphorylated JUN to the ALP promoter. Collectively, these results indicate that SORT1 is involved in the odontoblastic differentiation of hDPSCs through the JUN N-terminal kinases (JNK)/JUN signaling pathway and that the binding of SORT1 and p75^NTR plays an important role in this process.

Keywords: Dental pulp; Odontoblasts; Osteoblasts; P75(NTR); SORT1; Stem cells.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Differentiation / genetics
Cells, Cultured
Dental Pulp*
Humans
Odontoblasts* / metabolism
RNA, Small Interfering / pharmacology
Stem Cells

Substances

sortilin
RNA, Small Interfering