Abstract
The hyperbaric environment, to which many categories of workers are exposed, can provoke injuries that can lead to various types of disorders. A major part of the studies aiming to explore the causes/effects leading to these injuries are conducted in vivo. In the present manuscript, we describe the effects on osteoblast cell cultures stressed in a hyperbaric purpose-built chamber, using an in vitro model to analyze the affected pathways. A hyperbaric chamber for cell cultures was constructed by adapting a pressurized test chamber originally designed for technical use. The MG-63 cell line and human primary osteoblasts were placed into this chamber at different atm and exposure times, at 37 °C. After treatment, the chamber was depressurized by performing controlled decompression stops. Then, the pro-inflammatory cytokines and bone tissue biomarker expression were analyzed. The stress conditions induced the overexpression of pro-inflammatory cytokines, such as IL-6, IL-1β, and TNF-α, along with reactive oxygen species release. Moreover, the alteration of bone tissue marker production was observed. In particular, the increase in Receptor Activator of NF-κB Ligand (RANKL) and the decrease in Osteoprotegerin (OPG) were detected. Further modulation was observed regarding other biomarkers, Alkaline phosphatase, Osteocalcin, Bone Morphogenetic Protein-2, and mainly Collagen type I, all of which were downregulated by treatment. Taken together, these findings account for certain illnesses, such as dysbaric osteonecrosis, diagnosed in workers exposed to a hyperbaric environment. Inflammation induced by this kind of stress affects several factors involved in bone tissue homeostasis, leading to bone injuries, which are among the typical disorders observed in divers.