Cultures of cartilage explants have long been used to study the effects of modulators of extracellular matrix degradation. We present a simple and rapid assay system, based on culture of rabbit cartilage explants, which permits study of the effects of protease inhibitors on proteoglycan degradation (caused by either aggrecanases or matrix metalloproteinases [MMPs]), and on collagen degradation. The assay is based on the ability of interleukin-1 to stimulate both aggrecanase activity and synthesis of inactive MMPs, which are then activated by p-aminophenylmercuric acetate for the study of MMP-mediated proteoglycan degradation or by plasmin for the study of collagen degradation. Proteoglycan degradation is quantified as percent release of radioactivity from cartilage explants previously labeled with (35)SO4(2-). Collagen degradation is calculated as percent release of collagen, measured by colorimetric assay of hydroxyproline.
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http://dx.doi.org/10.1385/1-59259-810-2:219 | DOI Listing |
J Invest Dermatol
January 2025
Dept. of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA; Dept. of Dermatology, Yale School of Medicine, New Haven, Connecticut, USA. Electronic address:
During skin fibrosis, extracellular matrix (ECM) proteins are overproduced, and resident lipid-filled, mature dermal adipocytes are depleted in both human disease and mouse models. However, the mechanisms by which the reduction in lipid-filled adipocytes occurs during fibrosis are not well understood. Here, we identify that adipocyte lipolysis via the rate limiting enzyme, adipocyte triglyceride lipase (Atgl), is required for loss of adipose tissue during skin fibrosis in mice.
View Article and Find Full Text PDFJ Appl Physiol (1985)
January 2025
Department Physical Therapy.
The purpose of this study was to investigate the ability of mechanotherapy to enhance recovery or prevent loss of muscle size with atrophy, in female rats. Female F344/BN rats were assigned to weight bearing (WB), hindlimb suspended (HS) for 14 days with reambulation for 7 days without (RA) or with (RAM) mechanotherapy (study 1), or to WB, HS for 7 days, with (HSM) or without mechanotherapy (study 2) to gastrocnemius. Muscle fiber cross sectional area (CSA) and type, collagen, satellite cell number, and protein synthesis (K) and degradation (K) were assessed.
View Article and Find Full Text PDFJ Med Chem
January 2025
Ma̅tai Ha̅ora - Centre for Redox Biology and Medicine, Department of Biomedical Science and Pathology, University of Otago, Christchurch, Christchurch 8140, New Zealand.
In humans, the 2-oxoglutarate-dependent dioxygenases (2-OGDDs) catalyze hydroxylation reactions involved in cell metabolism, the biosynthesis of small molecules, DNA and RNA demethylation, the hypoxic response and the formation of collagen. The reaction is catalyzed by a highly oxidizing ferryl-oxo species produced when the active site non-heme iron engages molecular oxygen. Enzyme activity is specifically stimulated by l-ascorbic acid (ascorbate, vitamin C), an effect not well mimicked by other reducing agents.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands.
ACS Appl Mater Interfaces
January 2025
Center for Molecular Metabolism, Nanjing University of Science & Technology, Nanjing, Jiangsu 210094, China.
Uncontrolled bleeding and infection following trauma continue to pose significant clinical challenges. This study employs hemoadhican (HD) polysaccharide, known for its superior hemostatic properties, as the foundational material to synthesize antibacterial carbon dots (H-CDs) through a hydrothermal method at various temperatures. The H-CDs exhibiting optimal antimicrobial properties were identified via in vitro antimicrobial characterization.
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