The RANK/ RANKL/ OPG interaction in the repair of autogenous bone grafts in female rats with estrogen deficiency

Abstract

The aim of this study was to evaluate the resorption process during the repair of autogenous bone grafts with or without coverage by an expanded polytetrafluoroethylene (e-PTFE) membrane in female rats with estrogen deficiency using the immunohistochemical technique. Eighty female rats were randomly divided into two groups (OVX and SHAM). The 40 female rats in the OVX group were subjected to ovariectomy, and the 40 female rats in the SHAM group were subjected to simulated ovariectomy. The two groups were further divided in subgroup E, which was subjected to surgery for placement of autogenous bone graft (ABG), and subgroup ME, in which the ABG was covered with an e-PTFE membrane. The animals were killed at 0, 7, 21, 45 and 60 days. The specimens were analyzed using immunohistochemistry for the bone resorption markers RANK, RANK-L and Osteoprotegerin (OPG). A higher remodeling rate was observed at 7 and 21 days after the autogenous bone grafts, when the markers were more intensely expressed. At the final time point, the specimens presented similar characteristics to those observed at the initial time point. The expression of immunohistochemical markers was not altered by the estrogen deficiency. The presence of the e-PTFE membrane delayed the bone resorption process, influencing the immunohistochemical expression of markers.

Influence of Cigarette Smoke Inhalation on an Autogenous Onlay Bone Graft Area in Rats with Estrogen Deficiency: A Histomorphometric and Immunohistochemistry Study

“…The literature data have indicated that the use of a collagen membrane prevents graft resorption, thus practically keeping its original size [1,3,4,32,33,34,35] as shown in the present study. Sculean et al (2008) [36] also observed that the use of a collagen membrane associated with bone graft promoted superior tissue repair, rather than grafts without it.…”

Bone Regeneration, Reconstruction and Use of Osteogenic Cells; from Basic Knowledge, Animal Models to Clinical Trials

“…Meanwhile, OPG acts as an antagonist to RANKL activation, with the loss of bone mass being attributed to the increased expression of RANKL [144] and OPG shown, in the study by Jin et al, to overturn this effect. In ageing, it is thought that OPG downregulation, and RANKL upregulation is the cause for increased resorption [145]. In turn, high resorption is linked to the development of osteoporosis.…”

“…In turn, high resorption is linked to the development of osteoporosis. A study by Tera et al proposed that, in ageing, evasive parathyroid extract (PTE) slows down bone resorption and increases the expression of RANK [145]. This need for correctly balancing the levels of expression emphasises the importance of strategically implanting RANKL into bone scaffolds during future applications.…”

Suppressing MicroRNA-30b by Estrogen Promotes Osteogenesis in Bone Marrow Mesenchymal Stem Cells

“…It has been well established by both in vivo and in vitro studies that estrogen inhibits osteoclast formation [2]. Estrogen not only suppresses the formation but also promotes the apoptosis of osteoclasts by regulating the release of cytokines, including interleukin-1, interleukin-6, receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor- α (TNF α ), osteoprotegerin (OPG), and macrophage colony-stimulating factor (MCSF) in the bone microenvironment [3–5]. Recently, several studies suggested that estrogen could also inhibit osteoblast apoptosis and promote osteoblast differentiation, thus protecting against bone loss [6, 7].…”