1
|
Plaas AHK, Moran MM, Sandy JD, Hascall VC. Aggrecan and Hyaluronan: The Infamous Cartilage Polyelectrolytes - Then and Now. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1402:3-29. [PMID: 37052843 DOI: 10.1007/978-3-031-25588-5_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Cartilages are unique in the family of connective tissues in that they contain a high concentration of the glycosaminoglycans, chondroitin sulfate and keratan sulfate attached to the core protein of the proteoglycan, aggrecan. Multiple aggrecan molecules are organized in the extracellular matrix via a domain-specific molecular interaction with hyaluronan and a link protein, and these high molecular weight aggregates are immobilized within the collagen and glycoprotein network. The high negative charge density of glycosaminoglycans provides hydrophilicity, high osmotic swelling pressure and conformational flexibility, which together function to absorb fluctuations in biomechanical stresses on cartilage during movement of an articular joint. We have summarized information on the history and current knowledge obtained by biochemical and genetic approaches, on cell-mediated regulation of aggrecan metabolism and its role in skeletal development, growth as well as during the development of joint disease. In addition, we describe the pathways for hyaluronan metabolism, with particular focus on the role as a "metabolic rheostat" during chondrocyte responses in cartilage remodeling in growth and disease.Future advances in effective therapeutic targeting of cartilage loss during osteoarthritic diseases of the joint as an organ as well as in cartilage tissue engineering would benefit from 'big data' approaches and bioinformatics, to uncover novel feed-forward and feed-back mechanisms for regulating transcription and translation of genes and their integration into cell-specific pathways.
Collapse
Affiliation(s)
- Anna H K Plaas
- Department of Internal Medicine (Rheumatology), Rush University Medical Center, Chicago, IL, USA
| | - Meghan M Moran
- Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, IL, USA
| | - John D Sandy
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA
| | - Vincent C Hascall
- Department of Biomedical Engineering, The Cleveland Clinic Foundation, Cleveland, OH, USA
| |
Collapse
|
2
|
Ren D, Liu R, Yan X, Zhang Q, Zeng X, Yuan X. Intensive stretch-activated CRT-PMCA1 feedback loop promoted apoptosis of myoblasts through Ca 2+ overloading. Apoptosis 2022; 27:929-945. [PMID: 35976579 DOI: 10.1007/s10495-022-01759-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2022] [Indexed: 11/29/2022]
Abstract
Mechanical stretch exerted pro-apoptotic effect on myoblasts, the mechanism of which is currently unknown. Intracellular Ca2+ accumulation has been implicated in stretch-induced apoptosis. calreticulin (CRT) and plasma membrane Ca2+ transporting ATPase 1 (PMCA1) are two critical components of Ca2+ signaling system participating in intracellular Ca2+ homeostasis. In this study, we explored the contribution of CRT and PMCA1 in mediating stretch-induced Ca2+ accumulation and apoptosis of myoblasts. Stretching stimuli elevated level of CRT while inhibited activity of PMCA1. Moreover, there were bidirectional regulations between CRT and PMCA1, which formed the positive feedback loop leading to continuous increment of CRT level and repression of PMCA1 activity, in stretched myoblasts. Specifically, increased CRT level inhibited PMCA1 activity via suppressing Calmodulin (CaM), while reduced PMCA1 activity promoted CRT expression through activating p38MAPK pathway. Thus, the CRT-CaM-PMCA1 and PMCA1-p38MAPK-CRT pathways constituted a close cycle comprising CRT, PMCA1, CaM and p38MAPK. Inhibition of both CaM and p38MAPK affected the other three factors in stretched myoblasts. Circulation of the vicious cycle resulted in escalated Ca2+ overloading in myoblasts under continuous stretching stimuli. CRT knock-down, PMCA1 overexpression, and p38MAPK inhibition all attenuated the raised intracellular Ca2+ level and ameliorated myoblast apoptosis in the stretching environment. Conversely, CRT overexpression, PMCA1 knock-down, and CaM inhibition all aggravated stretch-induced Ca2+ overloading and myoblast apoptosis. A positive feedback loop between CRT and PMCA1 was activated in stretched myoblasts, which contributed to intracellular Ca2+ accumulation and resultant myoblast apoptosis.
Collapse
Affiliation(s)
- Dapeng Ren
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Ran Liu
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Xiao Yan
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Qiang Zhang
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Xuemin Zeng
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Xiao Yuan
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China. .,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China. .,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China.
| |
Collapse
|