Decreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signaling
Abstract Background GEM (GTP-binding protein overexpressed in skeletal muscle) is one of the atypical small GTPase subfamily members recently identified as a regulator of cell differentiation. Abnormal chondrogenesis coupled with an imbalance in the turnover of cartilaginous matrix formation is high...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2023-10-01
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| Series: | Journal of Orthopaedic Surgery and Research |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13018-023-04236-z |
| _version_ | 1797557807258533888 |
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| author | Lu Gan Zhonghao Deng Yiran Wei Hongfang Li Liang Zhao |
| author_facet | Lu Gan Zhonghao Deng Yiran Wei Hongfang Li Liang Zhao |
| author_sort | Lu Gan |
| collection | DOAJ |
| description | Abstract Background GEM (GTP-binding protein overexpressed in skeletal muscle) is one of the atypical small GTPase subfamily members recently identified as a regulator of cell differentiation. Abnormal chondrogenesis coupled with an imbalance in the turnover of cartilaginous matrix formation is highly relevant to the onset and progression of osteoarthritis (OA). However, how GEM regulates chondrogenic differentiation remains unexplored. Methods Cartilage tissues were obtained from OA patients and graded according to the ORASI and ICRS grading systems. The expression alteration of GEM was detected in the Grade 4 cartilage compared to Grade 0 and verified in OA mimic culture systems. Next, to investigate the specific function of GEM during these processes, we generated a Gem knockdown (Gem-Kd) system by transfecting siRNA targeting Gem into ATDC5 cells. Acan, Col2a1, Sox9, and Wnt target genes of Gem-Kd ATDC5 cells were detected during induction. The transcriptomic sequencing analysis was performed to investigate the mechanism of GEM regulation. Wnt signaling pathways were verified by real-time PCR and immunoblot analysis. Finally, a rescue model generated by treating Gem-KD ATDC5 cells with a Wnt signaling agonist was established to validate the mechanism identified by RNA sequencing analysis. Results A decreased expression of GEM in OA patients’ cartilage tissues and OA mimic chondrocytes was observed. While during chondrogenesis differentiation and cartilage matrix formation, the expression of GEM was increased. Gem silencing suppressed chondrogenic differentiation and the expressions of Acan, Col2a1, and Sox9. RNA sequencing analysis revealed that Wnt signaling was downregulated in Gem-Kd cells. Decreased expression of Wnt signaling associated genes and the total β-CATENIN in the nucleus and cytoplasm were observed. The exogenous Wnt activation exhibited reversed effect on Gem loss-of-function cells. Conclusion These findings collectively validated that GEM functions as a novel regulator mediating chondrogenic differentiation and cartilage matrix formation through Wnt/β-catenin signaling. |
| first_indexed | 2024-03-10T17:21:24Z |
| format | Article |
| id | doaj.art-64e52f03658e4d688208449e4aeddb91 |
| institution | Directory Open Access Journal |
| issn | 1749-799X |
| language | English |
| last_indexed | 2024-03-10T17:21:24Z |
| publishDate | 2023-10-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Orthopaedic Surgery and Research |
| spelling | doaj.art-64e52f03658e4d688208449e4aeddb912023-11-20T10:19:59ZengBMCJournal of Orthopaedic Surgery and Research1749-799X2023-10-0118111310.1186/s13018-023-04236-zDecreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signalingLu Gan0Zhonghao Deng1Yiran Wei2Hongfang Li3Liang Zhao4Department of Orthopaedic Surgery, Nanfang Hospital, Southern Medical UniversityDepartment of Orthopaedic Surgery, Nanfang Hospital, Southern Medical UniversityDepartment of Orthopaedic Surgery, Nanfang Hospital, Southern Medical UniversityYijiandian ClinicDepartment of Orthopaedic Surgery, Nanfang Hospital, Southern Medical UniversityAbstract Background GEM (GTP-binding protein overexpressed in skeletal muscle) is one of the atypical small GTPase subfamily members recently identified as a regulator of cell differentiation. Abnormal chondrogenesis coupled with an imbalance in the turnover of cartilaginous matrix formation is highly relevant to the onset and progression of osteoarthritis (OA). However, how GEM regulates chondrogenic differentiation remains unexplored. Methods Cartilage tissues were obtained from OA patients and graded according to the ORASI and ICRS grading systems. The expression alteration of GEM was detected in the Grade 4 cartilage compared to Grade 0 and verified in OA mimic culture systems. Next, to investigate the specific function of GEM during these processes, we generated a Gem knockdown (Gem-Kd) system by transfecting siRNA targeting Gem into ATDC5 cells. Acan, Col2a1, Sox9, and Wnt target genes of Gem-Kd ATDC5 cells were detected during induction. The transcriptomic sequencing analysis was performed to investigate the mechanism of GEM regulation. Wnt signaling pathways were verified by real-time PCR and immunoblot analysis. Finally, a rescue model generated by treating Gem-KD ATDC5 cells with a Wnt signaling agonist was established to validate the mechanism identified by RNA sequencing analysis. Results A decreased expression of GEM in OA patients’ cartilage tissues and OA mimic chondrocytes was observed. While during chondrogenesis differentiation and cartilage matrix formation, the expression of GEM was increased. Gem silencing suppressed chondrogenic differentiation and the expressions of Acan, Col2a1, and Sox9. RNA sequencing analysis revealed that Wnt signaling was downregulated in Gem-Kd cells. Decreased expression of Wnt signaling associated genes and the total β-CATENIN in the nucleus and cytoplasm were observed. The exogenous Wnt activation exhibited reversed effect on Gem loss-of-function cells. Conclusion These findings collectively validated that GEM functions as a novel regulator mediating chondrogenic differentiation and cartilage matrix formation through Wnt/β-catenin signaling.https://doi.org/10.1186/s13018-023-04236-zGEMWnt/β-catenin signalingChondrogenesisOsteoarthritis |
| spellingShingle | Lu Gan Zhonghao Deng Yiran Wei Hongfang Li Liang Zhao Decreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signaling Journal of Orthopaedic Surgery and Research GEM Wnt/β-catenin signaling Chondrogenesis Osteoarthritis |
| title | Decreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signaling |
| title_full | Decreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signaling |
| title_fullStr | Decreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signaling |
| title_full_unstemmed | Decreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signaling |
| title_short | Decreased expression of GEM in osteoarthritis cartilage regulates chondrogenic differentiation via Wnt/β-catenin signaling |
| title_sort | decreased expression of gem in osteoarthritis cartilage regulates chondrogenic differentiation via wnt β catenin signaling |
| topic | GEM Wnt/β-catenin signaling Chondrogenesis Osteoarthritis |
| url | https://doi.org/10.1186/s13018-023-04236-z |
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