Histochemical examinations on cortical bone regeneration induced by thermoplastic bioresorbable plates applied to bone defects of rat calvariae

Immunohistochemical analysis of periostin in the hearts of Lewis rats with experimental autoimmune myocarditis

Periostin plays a critical role in tissue regeneration and homeostasis. The aim of this study was to evaluate the changes in periostin levels in the hearts of rats with experimental autoimmune myocarditis (EAM). Western blot analysis revealed that the expression levels of periostin and alpha-smooth muscle actin were significantly increased at day 14 post-immunization. Immunohistochemical analysis indicated that periostin was expressed in macrophages and fibroblasts in the hearts of EAM-induced rats. In conclusion, these results suggest that increased periostin expression in macrophages and fibroblasts promotes cardiac fibrosis in EAM-induced rats, potentially by enhancing immune cell infiltration. Therefore, periostin should be further investigated as a candidate therapeutic target for myocarditis.

Upregulation of periostin in MOG-induced experimental autoimmune encephalomyelitis in mice

Periostin has dual roles as a multifunctional cytokine and an extracellular matrix protein that binds to several integrins on a variety of cells. This study evaluated whether the expression and cellular localization of periostin changes in the spinal cord of mice with experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis. Western blot analysis revealed that periostin was significantly upregulated in the spinal cord of EAE-induced mice in the effector stage, and did not significantly decrease in the recovery stage of EAE, compared with normal control. Periostin was constitutively detected in the neurons, ependymal cells, vascular endothelial cells, and astrocytes of normal mice. In the paralytic stage of EAE, periostin immunoreactivity was detected in some macrophages in the subarachnoid space (SAS), as well as in some microglial cells; in addition, periostin immunoreactivity was enhanced in astrocytes and vascular endothelial cells in EAE lesions. Collectively, these results suggest that periostin, either from monocyte-derived macrophages in SAS or glial cells in the parenchyma, partly facilitates the migration of inflammatory cells in the effector stage of EAE; moreover, periostin in the recovery stage of EAE appears to be involved in the plasticity of damaged central nervous system tissues.

Evaluation of gingival crevicular fluid and peri-implant sulcus fluid levels of periostin: A preliminary report

BACKGROUND

Periostin is a protein present in alveolar bone and periodontal ligament whose function is related to response to external forces. The aims of this study are to detect levels of periostin in peri-implant sulcular fluid (PISF) and gingival crevicular fluid (GCF) and to evaluate the relationship between periostin, pyridinoline cross-linked carboxyterminal telopeptide of Type I collagen (ICTP), and C-terminal cross-linked telopeptide of Type I collagen (CTX) levels and clinical inflammatory symptoms and duration of functional loading.

METHODS

The study population comprised nine women and four men with mean age 43.23 ± 12.48. Twenty "bone-level designed" dental implants (DIs) placed in molar or premolar sites, without any signs of peri-implant bone loss and with a restoration in function for at least 12 months, were included in the study with 20 contralateral natural teeth (NT) as controls. Clinical parameters and restoration dates of the implants were recorded. PISF, GCF, ICTP, CTX, and periostin levels were evaluated using enzyme-linked immunosorbent assay.

RESULTS

ICTP, CTX, and periostin levels were similar between DI and NT groups. There were no statistically significant differences between PISF and GCF values. When implants were grouped as healthy (gingival index [GI] = 0) and inflamed (GI ≥0), ICTP levels and PISF volume were lower in healthy implants compared with the inflamed group. Both periostin and CTX levels were negatively correlated with functioning time, suggesting less bone remodeling around DIs at later stages of functioning.

CONCLUSION

Findings of this study suggest collagen breakdown products may be used as markers to evaluate peri-implant metabolism.

Inhibitory effect of bisphosphonate on osteoclast function contributes to improved skeletal pain in ovariectomized mice

The aim of this study was to evaluate skeletal pain associated with osteoporosis and to examine the inhibitory effect of bisphosphonate (BP) on pain in an ovariectomized (OVX) mouse model. We evaluated skeletal pain in OVX mice through an examination of pain-like behavior as well as immunohistochemical findings. In addition, we assessed the effects of alendronate (ALN), a potent osteoclast inhibitor, on those parameters. The OVX mice showed a decrease in the pain threshold value, and an increase in the number of c-Fos immunoreactive neurons in laminae I-II of the dorsal horn of the spinal cord. Alendronate caused an increase in the pain threshold value and inhibited c-Fos expression. The serum level of tartrate-resistant acid phosphatase 5b, a marker of osteoclast activity, was significantly negatively correlated with the pain threshold value. Furthermore, we found that an antagonist of the transient receptor potential channel vanilloid subfamily member 1, which is an acid-sensing nociceptor, improved pain-like behavior in OVX mice. These results indicated that the inhibitory effect of BP on osteoclast function might contribute to an improvement in skeletal pain in osteoporosis patients.

Functional role of periostin in development and wound repair: implications for connective tissue disease

Integrity of the extracellular matrix (ECM) is essential for maintaining the normal structure and function of connective tissues. ECM is secreted locally by cells and organized into a complex meshwork providing physical support to cells, tissues, and organs. Initially thought to act only as a scaffold, the ECM is now known to provide a myriad of signals to cells regulating all aspects of their phenotype from morphology to differentiation. Matricellular proteins are a class of ECM related molecules defined through their ability to modulate cell-matrix interactions. Matricellular proteins are expressed at high levels during development, but typically only appear in postnatal tissue in wound repair or disease, where their levels increase substantially. Members of the CCN family, tenascin-C, osteopontin, secreted protein acidic rich in cysteine (SPARC), bone sialoprotein, thrombospondins, and galectins have all been classed as matricellular proteins. Periostin, a 90 kDa secreted homophilic cell adhesion protein, was recently added to matricellular class of proteins based on its expression pattern and function during development as well as in wound repair. Periostin is expressed in connective tissues including the periodontal ligament, tendons, skin and bone, and is also prominent in neoplastic tissues, cardiovascular disease, as well as in connective tissue wound repair. This review will focus on the functional role of periostin in tissue physiology. Fundamentally, it appears that periostin influences cell behaviour as well as collagen fibrillogenesis, and therefore exerts control over the structural and functional properties of connective tissues in both health and disease. Periostin is a novel matricellular protein with close homology to Drosophila fasciclin 1. In this review, the functional role of periostin is discussed in the context of connective tissue physiology, in development, disease, and wound repair.