An in vivo experimental study on osteopenia in diabetic rats.
ABSTRACT Osteopenia is a significant problem associated with Diabetes mellitus. Osteopenia may result in an increased delay in healing of bone fractures and subsequently affect the quality of life. We evaluated the immunohistochemical localization of TRAIL and its receptor DR5 in the femoral bone of 10-week-old Sprague-Dawley male rats treated with sesame oil (control, group 1), streptozotocin (STZ), a diabetes inducer (group 2), L-NAME, a general inhibitor of NOS activity (group 3), L-arginine (group 4), (arginine acts as a NO substrate) and iNOS immunostaining in group 1 and group 4. Histological and histochemical findings showed decreased growth of metaphyseal cartilage (which was thinner), decreased osteoid surface, and reduced mineral apposition rate in STZ- and L-NAME-treated rats. These findings confirm that bone formation is impaired in diabetic osteopenia. L-arginine supplementation seems to prevent diabetes-induced bone alterations and preserve the calcification process, allowing synthesis of new bone matrix. The immunohistochemical study revealed increased immunostaining of TRAIL and DR5 in osteoblastic cells of the diaphysis (pre-metaphysis) and epiphysis treated with STZ and L-NAME, related to activation of osteoblastic apoptotic death, while the group receiving L-arginine was comparable to the control group and the higher indications of iNOS activity that may reflect its induction by L-arginine administration. The action of L-arginine suggests that increased NO synthesis and availability is potentially useful for effective prevention and treatment of diabetic osteopenia.
- SourceAvailable from: Karin Pichler[Show abstract] [Hide abstract]
ABSTRACT: Abstract The growth plate at the end of long bones is the cartilaginous organ responsible for longitudinal bone growth in children. Trauma to the growth plate, i.e. fractures, can severely impair longitudinal bone growth, leading to growth disorders due to destruction of the epiphyseal circulation and formation of a bone bridge. From the clinical experience it is known that in some patients this bone bridge eventually disappears during the growth process. However the molecular mechanisms involved in bone bridge formation and dissolution have not been clarified yet. The aim of this study was to investigate the spatial and temporal protein level of molecules potentially involved in these processes, i.e. RANKL, OPG, DKK-1, Coll 10, BMP-2 and IL-6, in an experimental rat model using an immunohistochemical approach. The results from our study suggest that bone bridge formation might be an early event starting immediately after growth plate injury and involving several pro-osteoblastic molecules, i.e. IL-6, BMP-2 as well as OPG and Coll X. In the late studied time points 3 and 9 month post injury expression of anti-osteoblastic proteins, i.e. DKK1 and RANKL, was increased. This indicates that bone bridge dissolution might be late event and potentially linked to WNT signaling inhibition and RANK/RANKL signaling activation.Connective tissue research 08/2013; · 1.55 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Mediterranean diet includes a relatively high fat consumption mostly from monounsaturated fatty acids mainly provided by olive oil, the principal source of culinary and dressing fat. The beneficial effects of olive oil have been widely studied and could be due to its phytochemicals, which have been shown to possess anti-inflammatory properties. Lubricin is a chondroprotective glycoprotein and it serves as a critical boundary lubricant between opposing cartilage surfaces. A joint injury causes an initial flare of cytokines, which decreases lubricin expression and predisposes to cartilage degeneration such as osteoarthritis. The aim of this study was to evaluate the role of extra-virgin olive oil diet and physical activity on inflammation and expression of lubricin in articular cartilage of rats after injury. In this study we used histomorphometric, histological, immunocytochemical, immunohistochemical, western blot and biochemical analysis for lubricin and interleukin-1 evaluations in the cartilage and in the synovial fluid. We report the beneficial effect of physical activity (treadmill training) and extra-virgin olive oil supplementation, on the articular cartilage. The effects of anterior cruciate ligament transection decrease drastically the expression of lubricin and increase the expression of interleukin-1 in rats, while after physical activity and extra-virgin olive oil supplemented diet, the values return to a normal level compared to the control group. With our results we can confirm the importance of the physical activity in conjunction with extra-virgin olive oil diet in medical therapy to prevent osteoarthritis disease in order to preserve the articular cartilage and then the entire joint.The Journal of nutritional biochemistry 12/2013; 24(12):2064–2075. · 4.29 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The aim of this study was to investigate for the first time lubricin expression in intact menisci and in menisci from patients with recent knee joint injury using histology, immunohistochemistry, Western blotting and gene expression analysis, to provide insights into pathological processes affecting meniscal tissue. Lubricin expression was studied in vivo in 20 patients (14 males and 6 females) with recent joint injury subjected to arthroscopic partial meniscectomy and in vitro in fibroblast-like cells from meniscus tissue to establish whether it is down-regulated following acute traumatic knee injury. The control group consisted of cadaver donors with normal menisci. Histology demonstrated a normal tissue without structural changes in control samples and structural alterations and clefts in injured menisci. Very strong lubricin immunohistochemical staining was observed in intact menisci; in contrast weak staining was seen in injured menisci. Western blot and mRNA expression analysis also demonstrated strong lubricin expression in control cells and a negligible amount of lubricin in injured fibroblast-like cells. Our data provide information concerning the immediate in vivo response to injury of human knee menisci by documenting early changes in the boundary-lubricating ability of synovial fluid and articular cartilage integrity. These findings may provide the biological basis for developing novel medical therapies to be applied before surgical treatment to preserve tissue function and prevent cartilage damage.Annals of anatomy = Anatomischer Anzeiger: official organ of the Anatomische Gesellschaft 09/2012; · 1.96 Impact Factor