Knockout of NOS2 Promotes Adipogenic Differentiation of Rat MSCs by Enhancing Activation of JAK/STAT3 Signaling

Aiping Qin; Sheng Chen; Ping Wang; Xiaotao Huang; Yu Zhang; Lu Liang; Ling-Ran Du; De-Hua Lai; Li Ding; Xiyong Yu; Andy Peng Xiang

doi:10.3389/fcell.2021.638518

Knockout of NOS2 Promotes Adipogenic Differentiation of Rat MSCs by Enhancing Activation of JAK/STAT3 Signaling

Front Cell Dev Biol. 2021 Mar 19:9:638518. doi: 10.3389/fcell.2021.638518. eCollection 2021.

Authors

Aiping Qin^{1

2}, Sheng Chen¹, Ping Wang¹, Xiaotao Huang¹, Yu Zhang¹, Lu Liang¹, Ling-Ran Du¹, De-Hua Lai³, Li Ding⁴, Xiyong Yu¹, Andy Peng Xiang²

Affiliations

¹ Key Laboratory of Molecular Target and Clinical Pharmacology, State Key Laboratory of Respiratory Disease, The Fifth Affiliated Hospital, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China.
² Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, China.
³ Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
⁴ Department of Pathology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

Abstract

Mesenchymal stromal cells (MSCs) are a heterogeneous population of cells that possess multilineage differentiation potential and extensive immunomodulatory properties. In mice and rats, MSCs produce nitric oxide (NO), as immunomodulatory effector molecule that exerts an antiproliferative effect on T cells, while the role of NO in differentiation was less clear. Here, we investigated the role of NO synthase 2 (NOS2) on adipogenic and osteogenic differentiation of rat MSCs. MSCs isolated from NOS2-null (NOS2^-/-) and wild type (WT) Sprague-Dawley (SD) rats exhibited homogenous fibroblast-like morphology and characteristic phenotypes. However, after induction, adipogenic differentiation was found significantly promoted in NOS2^-/- MSCs compared to WT MSCs, but not in osteogenic differentiation. Accordingly, qRT-PCR revealed that the adipogenesis-related genes PPAR-γ, C/EBP-α, LPL and FABP4 were markedly upregulated in NOS2^-/- MSCs, but not for osteogenic transcription factors or marker genes. Further investigations revealed that the significant enhancement of adipogenic differentiation in NOS2^-/- MSCs was due to overactivation of the STAT3 signaling pathway. Both AG490 and S3I-201, small molecule inhibitors that selectively inhibit STAT3 activation, reversed this adipogenic effect. Furthermore, after high-fat diet (HFD) feeding, knockout of NOS2 in rat MSCs resulted in significant obesity. In summary, NOS2 is involved in the regulation of rat MSC adipogenic differentiation via the STAT3 signaling pathway.

Keywords: JAK/STAT3 signaling; NOS2; adipogenesis; differentiation; rat mesenchymal stromal cells.