Objective: Mechanical signals are key determinants in tissue morphogenesis, maintenance, and restoration strategies in regenerative medicine, although molecular mechanisms of mechanotransduction remain to be elucidated. This study was undertaken to investigate the mechanotransduction process of expression of superficial zone protein (SZP), a critical joint lubricant.
Methods: Regional expression of SZP was first quantified in cartilage obtained from the femoral condyles of immature bovines, using immunoblotting, and visualized by immunohistochemistry. Contact pressure mapping in whole joints was accomplished using pressure-sensitive film and a load application system for joint testing. Friction measurements on cartilage plugs were acquired under boundary lubrication conditions using a pin-on-disk tribometer modified for reciprocating sliding. Direct mechanical stimulation by shear loading of articular cartilage explants was performed with and without inhibition of transforming growth factor beta (TGFbeta) signaling, and SZP content in media was quantified by enzyme-linked immunosorbent assay.
Results: An unexpected pattern of SZP localization in knee cartilage was initially identified, with anterior regions exhibiting high levels of SZP expression. Regional SZP patterns were regulated by mechanical signals and correlated with tribological behavior. Direct relationships were demonstrated between high levels of SZP expression, maximum contact pressures, and low friction coefficients. Levels of SZP expression and accumulation were increased by applying shear stress, depending on location within the knee, and were decreased to control levels with the use of a specific inhibitor of TGFbeta receptor type I kinase and subsequent phospho-Smad2/3 activity.
Conclusion: These findings indicate a new role for TGFbeta signaling in the mechanism of cellular mechanotransduction that is especially significant for joint lubrication.
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http://dx.doi.org/10.1002/art.23024 | DOI Listing |
Heliyon
October 2024
Advanced Polymer Materials Group, National University of Science and Technology Politehnica Bucharest, 1-7 Gh. Polizu Street, 011061, Bucharest, Romania.
Gene therapy is one of the most potential therapeutic approaches in direct and specific regulation of biological functions of macrophages at the gene level for efficient cell therapy. However, the delivery of genetic material to macrophages is extremely challenging, because of low stability, specificity and inability of therapeutic genes to efficiently enter the cells. Here, we present a method that uses the hybrid electrospun architectures based on gelatin-alginate decorated with carboxylated graphene oxide (HAG/G) as efficient substrate for loading and local and controlled delivery of plasmid DNA (pDNA) to macrophages as an alternative to systemic gene delivery carriers.
View Article and Find Full Text PDFBrain Sci
July 2023
Department of Psychology, University Innsbruck, 6020 Innsbruck, Austria.
Background: Attachment theory offers an important framework for understanding interpersonal interaction experiences. In the present study, we examined the neural correlates of attachment patterns and oxytocin in schizophrenic patients (SZP) compared to healthy controls (HC) using fMRI. We assumed that male SZP shows a higher proportion of insecure attachment and an altered level of oxytocin compared to HC.
View Article and Find Full Text PDFJ Pain Symptom Manage
August 2023
Division of Palliative Medicine, Department of Medicine (S.S.N., E.L.C, M.W.R., S.Z.P, K.E.B.), University of California San Francisco, San Francisco, California, USA. Electronic address:
Context: Little is known about equity in utilization of outpatient palliative care (PC).
Objectives: To explore whether patient-level factors are associated with completing initial and follow-up visits among patients referred to outpatient PC.
Methods: Using electronic health record data, we generated a cohort of all adults referred to outpatient PC at University of California, San Francisco October 2017-October 2021.
Pharm Biol
December 2023
Nuclear Medicine Department, Guangdong Provincial Peoples Hospital, Guangzhou, China.
J Mol Graph Model
May 2023
Department of Chemistry, Faculty of Basic Sciences, Hakim Sabzevari University, 96179-76487, Sabzevar, Iran.
Here, the electronic transport characteristics of the 1,3,3-trimethylindolino-6'-nitrobenzopyrylospiran were studied by using NEGF and DFT methods. By being exposed to UV or visible light, this molecule can change from its MC to SP states. The titled structure was optimized at B3LYP/6-311++G(d,p) level of theory.
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