ABSTRACT
OBJECTIVE: Major vault protein (MVP) is vital in various macrophage-related inflammatory diseases. However, the effects of MVP on macrophage polarization during fracture repair are still unknown. METHODS: We used Mvpflox/floxLyz2-Cre mice (myeloid-specific MVP gene knockout, abbreviated as MacKO) and Mvpflox/flox (abbreviated as MacWT) mice to compare their fracture healing phenotype. Next, we traced the changes in macrophage immune status in vivo and in vitro. We further explored the effects of MVP on osteogenesis and osteoclastogenesis. Finally, we re-expressed MVP in MacKO mice to confirm the role of MVP in fracture healing. RESULTS: The lack of MVP in macrophages impaired their transition from a pro-inflammatory to an anti-inflammatory phenotype during fracture repair. The increased secretion of pro-inflammatory cytokines by macrophages promoted their osteoclastic differentiation and impaired BMSC osteogenic differentiation, ultimately leading to impaired fracture repair in MacKO mice. Last, adeno-associated virus (AAV)-Mvp tibial injection significantly promoted fracture repair in MacKO mice. CONCLUSIONS: Our findings showed MVP has a previously unknown immunomodulatory role in macrophages during fracture repair. Targeting macrophage MVP may represent a novel therapeutic method for fracture treatment.
Subject(s)
Macrophages , Osteogenesis , Mice , Animals , Vault Ribonucleoprotein Particles/metabolism , Vault Ribonucleoprotein Particles/pharmacology , Cytokines/metabolismABSTRACT
Vault nanoparticles represent promising vehicles for drug and probe delivery. Innately found within human cells, vaults are stable, biocompatible nanocapsules possessing an internal volume that can encapsulate hundreds to thousands of molecules. They can also be targeted. Unlike most nanoparticles, vaults are nonimmunogenic and monodispersed and can be rapidly produced in insect cells. Efforts to create vaults with modified properties have been, to date, almost entirely limited to recombinant bioengineering approaches. Here we report a systematic chemical study of covalent vault modifications, directed at tuning vault properties for research and clinical applications, such as imaging, targeted delivery, and enhanced cellular uptake. As supra-macromolecular structures, vaults contain thousands of derivatizable amino acid side chains. This study is focused on establishing the comparative selectivity and efficiency of chemically modifying vault lysine and cysteine residues, using Michael additions, nucleophilic substitutions, and disulfide exchange reactions. We also report a strategy that converts the more abundant vault lysine residues to readily functionalizable thiol terminated side chains through treatment with 2-iminothiolane (Traut's reagent). These studies provide a method to doubly modify vaults with cell penetrating peptides and imaging agents, allowing for in vitro studies on their enhanced uptake into cells.
Subject(s)
Drug Delivery Systems , Fluorescent Dyes/chemistry , Nanoparticles/chemistry , Optical Imaging , Vault Ribonucleoprotein Particles/chemistry , Animals , CHO Cells , Cell Survival/drug effects , Cells, Cultured , Cricetulus , Dose-Response Relationship, Drug , Flow Cytometry , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/pharmacology , HeLa Cells , Humans , Mice , Microscopy, Confocal , Molecular Structure , RAW 264.7 Cells , Structure-Activity Relationship , Vault Ribonucleoprotein Particles/chemical synthesis , Vault Ribonucleoprotein Particles/pharmacologyABSTRACT
Los autores hacen una descripción, adentrándose en la fisiología articular, del movimiento de las articulaciones del pie en general y del tobillo en particular. Analizan la acción de los dos músculos retromaleolares, peroneo lateral largo (PLL) y peroneo lateral corto (PLC) cuando el pie está apoyado en el suelo durante el movimiento lineal, marcha y carrera. Describen las ventajas mecánicas que propicia la ubicación, trayecto e inserción de ambos músculos para facilitar el movimiento, tanto en la fase de apoyo unipodal, como en la fase de impulso. Para concluir afirman que es la acción en carga del pie la que ha solicitado de todas las modificaciones mecánicas necesarias, en el complejo articular del tobillo, para economizar al máximo el gasto energético, utilizando como ejemplo la acción de los músculos PLL y PLC (AU)
The authors carry out a description of foot joints movement and more particularly of the ankle joint one, taking into account the joint physiology. They analyse the action of retromalleolar muscles, peroneus longus (PLL) and peroneus brevis (PLC), during the unipodal phase of linear movement (running and walking). The mechanical advantage in the movement as result of location, trajectory and insertion of muscles are described for both the unipodal support and impulse phases. In order to conclude, the writers argue that mechanical modifications of ankle joint during the human evolution process have been conditioned by the foot load force and energy consumption reduction principle. They use as example PLL and PLC muscles (AU)
