Background: Repeated exposure to ultraviolet (UV) rays damages skin connective tissue, which is thought to be associated with wrinkle formation. We hypothesized that repeated mild inflammation may cause the connective tissue alterations in photoaging.
Objective: To clarify the behavior of neutrophils and neutrophil elastase (NE) activity in the photoaging process and to examine the mechanisms of connective tissue damage resulting from NE in photoaging.
Methods: Mouse dorsal skin was irradiated with a suberythemal dose of UVB three times a week. After 5 or 10 weeks of irradiation, neutrophils were investigated by light microscopy and transmission electron microscopy. NE activity was examined by in situ zymography. Activation of proMMP-2 and proMMP-1 by NE both in the purified enzyme and in human skin fibroblast culture was examined by gelatin zymography or immunoblotting respectively.
Results: Both neutrophil infiltration and NE activity were elevated in photoaging. Furthermore, activated MMP-2 and MMP-1 were increased by NE treatment in a dose-dependent manner.
Conclusions: In the present study, we demonstrated that neutrophil infiltration and NE activity are elevated in the chronic UVB-irradiated skin of hairless mice and we confirmed the involvement of NE in MMP activation. These data suggest that NE indirectly plays a role in skin photoaging through MMP activation.
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http://dx.doi.org/10.1016/j.jdermsci.2010.09.001 | DOI Listing |
Arch Immunol Ther Exp (Warsz)
January 2025
Department of Human Physiology, Medical University of Lublin, Lublin, Poland.
Systemic lupus erythematosus (SLE) is an autoimmune disease whose pathogenesis is not fully understood to date. One of the suggested mechanisms for its development is NETosis, which involves the release of a specific network consisting of chromatin, proteins, and enzymes from neutrophils, stimulating the immune system. One of its markers is citrullinated histone H3 (H3Cit).
View Article and Find Full Text PDFPLoS One
January 2025
Human Anatomy Teaching and Research Section (Digital Medical Center), Inner Mongolia Medical University Basic Medical College, Hohhot, China.
The cervical uncinate process is a unique structure of the cervical spine that undergoes significant changes in its morphological characteristics with age, and these changes may be related to osteoporosis. This study aimed to observe the distribution of cancellous bone in the cervical uncinate process and its morphological features using micro-computed tomography (Micro-CT) to gain a deeper understanding of the morphological characteristics of the uncinate microstructure. We performed Micro-CT scans on 31 sets of C3-C7 vertebrae, a total of 155 intact bone samples, and subsequently used the measurement software with the Micro-CT system to obtain parameters related to the cancellous bone of the uncinate process.
View Article and Find Full Text PDFPLoS One
January 2025
Lawrence Livermore National Laboratory, Physical and Life Science Directorate, Livermore, CA, United States of America.
Post-traumatic osteoarthritis (PTOA) is a painful joint disease characterized by the degradation of bone, cartilage, and other connective tissues in the joint. PTOA is initiated by trauma to joint-stabilizing tissues, such as the anterior cruciate ligament, medial meniscus, or by intra-articular fractures. In humans, ~50% of joint injuries progress to PTOA, while the rest spontaneously resolve.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Orthopedics, Shanghai Pudong New Area People's Hospital, Shanghai, China.
Aim: To explore the role of the hub gene Transforming Growth Factor Beta Induced (TGFBI) in Intervertebral disc degeneration (IDD) pathogenesis and its regulatory relationship with Membrane Associated Ring-CH-Type Finger 8 (MARCHF8).
Background: IDD is a prevalent musculoskeletal disorder leading to spinal pathology. Despite its ubiquity and impact, effective therapeutic strategies remain to be explored.
J Hand Surg Eur Vol
January 2025
Department of Radiology, University Hospital, LMU Munich, Munich, Germany.
Articular malalignment and ulnocarpal impaction can progress to osteoarthritis in the wrist. This may be triggered by tears of the scapholunate ligament (rarely the lunotriquetral ligament) or the foveal lamina of the triangular fibrocartilage complex. In the pre-degenerative stages, radiographic findings are inconclusive, and symptoms may be absent or discrete.
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