Dysregulated circadian rhythm pathway in human osteoarthritis: NR1D1 and BMAL1 suppression alters TGF-β signaling in chondrocytes

Autor: R. Akagi, Oscar Alvarez-Garcia, Kathleen M. Fisch, Andrew I. Su, Y. Muramatsu, Martin Lotz, Yorikazu Akatsu, Takahisa Sasho, Masahiko Saito, Takeshi Teramura
Rok vydání: 2016
Předmět:
0301 basic medicine
Adult
Cartilage
Articular
Male
endocrine system
medicine.medical_specialty
Small interfering RNA
Adolescent
Biomedical Engineering
Chondrocyte
Article
03 medical and health sciences
Young Adult
0302 clinical medicine
Chondrocytes
Rheumatology
Transforming Growth Factor beta
Internal medicine
medicine
Humans
Orthopedics and Sports Medicine
RNA
Messenger
Regulation of gene expression
Messenger RNA
biology
Cartilage homeostasis
Cartilage
RNA
ARNTL Transcription Factors
Transforming growth factor beta
Middle Aged
Osteoarthritis
Knee
Cell biology
Circadian Rhythm
030104 developmental biology
Endocrinology
medicine.anatomical_structure
Gene Expression Regulation
Gene Knockdown Techniques
Nuclear Receptor Subfamily 1
Group D
Member 1
biology.protein
Female
030217 neurology & neurosurgery
Signal Transduction
Zdroj: Osteoarthritis and cartilage. 25(6)
ISSN: 1522-9653
Popis: Summary Objectives Circadian rhythm (CR) was identified by RNA sequencing as the most dysregulated pathway in human osteoarthritis (OA) in articular cartilage. This study examined circadian rhythmicity in cultured chondrocytes and the role of the CR genes NR1D1 and BMAL1 in regulating chondrocyte functions. Methods RNA was extracted from normal and OA-affected human knee cartilage ( n = 14 each). Expression levels of NR1D1 and BMAL1 mRNA and protein were assessed by quantitative PCR and immunohistochemistry. Human chondrocytes were synchronized and harvested at regular intervals to examine circadian rhythmicity in RNA and protein expression. Chondrocytes were treated with small interfering RNA (siRNA) for NR1D1 or BMAL1, followed by RNA sequencing and analysis of the effects on the transforming growth factor beta (TGF-β) pathway. Results NR1D1 and BMAL1 mRNA and protein levels were significantly reduced in OA compared to normal cartilage. In cultured human chondrocytes, a clear circadian rhythmicity was observed for NR1D1 and BMAL1. Increased BMAL1 expression was observed after knocking down NR1D1, and decreased NR1D1 levels were observed after knocking down BMAL1. Sequencing of RNA from chondrocytes treated with NR1D1 or BMAL1 siRNA identified 330 and 68 significantly different genes, respectively, and this predominantly affected the TGF-β signaling pathway. Conclusions The CR pathway is dysregulated in OA cartilage. Interference with circadian rhythmicity in cultured chondrocytes affects TGF-β signaling, which is a central pathway in cartilage homeostasis.
Databáze: OpenAIRE
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