1. BMP7 increases protein synthesis in SW1353 cells and determines rRNA levels in a NKX3-2-dependent manner.
- Author
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Ripmeester EGJ, Welting TJM, van den Akker GGH, Surtel DAM, Steijns JSJ, Cremers A, van Rhijn LW, and Caron MMJ
- Subjects
- Bone Morphogenetic Protein 7 pharmacology, Cell Proliferation drug effects, Cell Proliferation genetics, Cells, Cultured, Chondrocytes drug effects, Chondrocytes physiology, Chondrogenesis drug effects, Chondrogenesis genetics, Core Binding Factor Alpha 1 Subunit genetics, Core Binding Factor Alpha 1 Subunit metabolism, Humans, Promoter Regions, Genetic drug effects, Protein Biosynthesis drug effects, RNA, Ribosomal genetics, Transcription, Genetic drug effects, Transcription, Genetic genetics, Up-Regulation drug effects, Up-Regulation genetics, Bone Morphogenetic Protein 7 physiology, Chondrocytes metabolism, Homeodomain Proteins physiology, Protein Biosynthesis genetics, RNA, Ribosomal metabolism, Transcription Factors physiology
- Abstract
BMP7 is a morphogen capable of counteracting the OA chondrocyte hypertrophic phenotype via NKX3-2. NKX3-2 represses expression of RUNX2, an important transcription factor for chondrocyte hypertrophy. Since RUNX2 has previously been described as an inhibitor for 47S pre-rRNA transcription, we hypothesized that BMP7 positively influences 47S pre-rRNA transcription through NKX3-2, resulting in increased protein translational capacity. Therefor SW1353 cells and human primary chondrocytes were exposed to BMP7 and rRNA (18S, 5.8S, 28S) expression was determined by RT-qPCR. NKX3-2 knockdown was achieved via transfection of a NKX3-2-specific siRNA duplex. Translational capacity was assessed by the SUNsET assay, and 47S pre-rRNA transcription was determined by transfection of a 47S gene promoter-reporter plasmid. BMP7 treatment increased protein translational capacity. This was associated by increased 18S and 5.8S rRNA and NKX3-2 mRNA expression, as well as increased 47S gene promotor activity. Knockdown of NKX3-2 led to increased expression of RUNX2, accompanied by decreased 47S gene promotor activity and rRNA expression, an effect BMP7 was unable to restore. Our data demonstrate that BMP7 positively influences protein translation capacity of SW1353 cells and chondrocytes. This is likely caused by an NKX3-2-dependent activation of 47S gene promotor activity. This finding connects morphogen-mediated changes in cellular differentiation to an aspect of ribosome biogenesis via key transcription factors central to determining the chondrocyte phenotype., Competing Interests: MMJ Caron and TJM Welting are inventors on patents WO2017178251 and WO2017178253 (Owned by Chondropeptix). LW van Rhijn and TJM Welting are shareholder in Chondropeptix and are CDO, and CSO of Chondropeptix, respectively. All other authors have no competing interests to declare. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
- Published
- 2022
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