Single-cell RNA sequencing identifies a migratory keratinocyte subpopulation expressing THBS1 in epidermal wound healing

Ratklao Siriwach; Anh Quynh Ngo; Makio Higuchi; Kentaro Arima; Satoko Sakamoto; Akira Watanabe; Shuh Narumiya; Dean Thumkeo

doi:10.1016/j.isci.2022.104130

Single-cell RNA sequencing identifies a migratory keratinocyte subpopulation expressing THBS1 in epidermal wound healing

iScience. 2022 Mar 21;25(4):104130. doi: 10.1016/j.isci.2022.104130. eCollection 2022 Apr 15.

Authors

Ratklao Siriwach¹, Anh Quynh Ngo¹, Makio Higuchi¹, Kentaro Arima¹, Satoko Sakamoto², Akira Watanabe², Shuh Narumiya¹, Dean Thumkeo¹

Affiliations

¹ Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
² Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.

Abstract

Keratinocyte differentiation is an intricate process that is regulated by multiple mediators. Using cultured human keratinocytes, we found that lysophosphatidic acid (LPA) induced the differentiation of a previously unsuspected keratinocyte subpopulation expressing the extracellular matrix protein, thrombospondin-1 (THBS1). This action of LPA was mediated by the RHO/ROCK-SRF signaling downstream of LPA₁ and LPA₅ receptors and required ERK activity. Suppression of THBS1 in vitro suggested a migratory role of THBS1⁺ keratinocytes. Moreover, we analyzed publicly deposited single-cell RNA sequencing dataset and identified Thbs1-expressing keratinocytes in the mouse wound skin. Immunohistochemistry analysis revealed that Thbs1⁺ keratinocytes were apparently differentiated from basal keratinocytes upon wounding, subsequently polarized and migrated suprabasally toward the wound front, and eventually underwent terminal differentiation in the neo-epidermis. Importantly, inhibition of Erk activity suppressed Thbs1⁺ keratinocyte differentiation in wound healing. Based on these findings, we suggest that THBS1⁺ keratinocyte is a migratory keratinocyte subpopulation that facilitates epidermal wound healing.

Keywords: Biological sciences; Cell biology; Stem cells research.