Immunohistochemical localization of periostin in human gingiva

Immunohistochemical Characterization of Gingival Fibromas

PURPOSE

Gingival fibromas (GFs) are fibrous lesions of the gingiva that are not well defined in the literature. They are histologically similar to peripheral ossifying fibromas (POFs), both being characterized as cellular proliferations of dense fibrous tissue, with POFs differing in that they demonstrate foci of calcification. This study aims to expand upon the immunohistochemical characterization of GFs, and to confirm their osteoblastic phenotype.

METHODS

Formalin fixed, paraffin embedded GFs, POFs and fibroepithelial polyps (FEPs) of the gingiva were examined. Immunohistochemical staining was performed for special AT-rich sequence binding protein 2 (SATB2), runt-related transcription factor 2 (RUNX2), osteocalcin and alpha-smooth muscle actin (αSMA). Sections were evaluated by light microscopy and the immunohistochemical staining patterns were assigned immunoreactive scores (IRS) based on percentage of stained cells and intensity of staining.

RESULTS

GFs, POFs, and FEPs of the gingiva expressed osteoblastic markers SATB2, RUNX2 and osteocalcin. GFs and POFs expressed αSMA while FEPs of the gingiva did not. GFs and POFs had similar staining patterns of SATB2, RUNX2 and αSMA.

DISCUSSION

These findings demonstrate that GFs and POFs exhibit a similar immunohistochemical profile, and supports a theory that GFs are osteoblastic lesions possibly related to POFs.

Periostin: Immunomodulatory Effects on Oral Diseases

Periostin is a microcellular adapter protein. It plays a wide range of essential roles during the development and in immunomodulation. Periostin is a prominent contributor during the process of angiogenesis, tumorigenesis, and cardiac repair. It is expressed in periodontal ligaments, tendons, skin, adipose tissues, muscle, and bone. This is a protein-based biomolecule that has the diagnostic and monitoring capability and can potentially be used as a biomarker to detect physiological and pathological conditions. The aim of the present review was to explore the periostin morphology and associated structural features. Additionally, periostin’s immunomodulatory effects and associated biomarkers in context of oral diseases have been discussed.

Periostin and Human Teeth

Periostin is a secreted matricellular protein that primarily interacts with type I collagen and fibronectin extracellular matrix proteins, and is widely distributed in tissues rich in collagen-rich connective tissues, including the periodontal ligament. Its expression in these tissues is especially regulated by mechanical load. While the expression and regulation of periostin in the teeth of murine models and cell lines is well known, its presence in human teeth is poorly documented. Here we update and summarize the available data on the distribution of periostin in the human periodontal ligament, gingiva and dental pulp.

[Progress relationship between periostin and periodontitis]

Periostin, a kind of matricellular protein highly expressed in periodontal ligament and periosteum, is an important regulator of the integrity of periodontal ligament and periodontitis processes. Periostin has been shown to play a positive role in the recovery of periodontitis. This paper reviews relevant literature about the role of periostin in periodontal tissue and periodontitis.

Is there still room for novelty, in histochemical papers?

Histochemistry continues to be widely applied in biomedical research, being nowadays mostly addressed to detect and locate single molecules or molecular complexes inside cells and tissues, and to relate structural organization and function at the high resolution of the more advanced microscopical techniques. In the attempt to see whether histochemical novelties may be found in the recent literature, the articles published in the European Journal of Histochemistry in the period 2014-2016 have been reviewed. In the majority of the published papers, standardized methods have been preferred by scientists to make their results reliably comparable with the data in the literature, but several papers (approximately one fourth of the published articles) described novel histochemical methods and procedures. It is worth noting that there is a growing interest for minimally-invasive in vivo techniques (magnetic resonance imaging, autofluorescence spectroscopy), which may parallel conventional histochemical analyses to acquire evidence not only on the morphological features of living organs and tissues, but also on their functional, biophysical and molecular characteristics. Thanks to this unceasing methodological refinement, histochemistry will continue to provide innovative applications in the biomedical field.

Histochemistry in biology and medicine: a message from the citing journals

Especially in recent years, biomedical research has taken advantage of the progress in several disciplines, among which microscopy and histochemistry. To assess the influence of histochemistry in the biomedical field, the articles published during the period 2011-2015 have been selected from different databases and grouped by subject categories: as expected, biological and biomedical studies where histochemistry has been used as a major experimental approach include a wide of basic and applied researches on both humans and other animal or plant organisms. To better understand the impact of histochemical publications onto the different biological and medical disciplines, it was useful to look at the journals where the articles published in a multidisciplinary journal of histochemistry have been cited: it was observed that, in the five-years period considered, 20% only of the citations were in histochemical periodicals, the remaining ones being in journals of Cell & Tissue biology,  general and experimental Medicine, Oncology, Biochemistry & Molecular biology, Neurobiology, Anatomy & Morphology, Pharmacology & Toxicology, Reproductive biology, Veterinary sciences, Physiology, Endocrinology, Tissue engineering & Biomaterials,  as well as in multidisciplinary journals.It is easy to foresee that also in the future the histochemical journals will be an attended forum for basic and applied scientists in the biomedical field. It will be crucial that these journals be open to an audience as varied as possible, publishing articles on the application of refined techniques to very different experimental models: this will stimulate non-histochemist scientists to approach histochemistry whose application horizon could expand to novel and possibly exclusive subjects.