Heat shock protein 27 expression in the epithelium of periapical lesions

Differential Expression of Heat Shock Protein 27 in Oral Epithelial Dysplasias and Squamous Cell Carcinoma

Background:

Oral squamous cell carcinoma (OSCC) is the most devastating neoplasm with dramatic increase in morbidity and mortality. The detection and prognostic evaluation of precancerous lesions could aid in early control of cancer. Heat shock protein (HSP) 27 has found to be a biomarker and therapeutic target in different types of cancer.

Aim:

This study aims to investigate the role of HSP 27 as prognostic molecular indicator of malignant transformation in oral epithelial dysplasias.

Materials and Methods:

Thirty samples of epithelial dysplasia (10 mild dysplasia, 10 moderate dysplasia, and 10 severe dysplasia/carcinoma in situ cases), 10 samples each of well-differentiated OSCC and normal oral mucosa were routinely processed, formalin-fixed, paraffin-embedded, and analyzed for HSP27 expression by immunohistochemistry. Statistical analysis was done by one way-ANOVA and Mann–Whitney test to assess the differences between two individual groups.

Results:

Normal mucosa showed intense, but nonuniform, expression of HSP27. An initial decline was noted in dysplasias. A significant correlation of HSP27 expression was observed with the severity of dysplasia and well-differentiated OSCC (P < 0.05).

Conclusion:

Low HSP 27 expression can be considered as early molecular indicator of initial dysplastic change in normal mucosa. An overexpression of HSP 27 in clinically and histologically confirmed dysplasia could indicate likely transformation to well-differentiated OSCC and could be of prognostic value. However, further studies with a larger sample size are required to confirm the role of HSP 27 as predictive indicator.

Analysis of protein expression in periodontal pocket tissue: a preliminary study

Background

The periodontal disease is caused by a set of inflammatory disorders characterized by periodontal pocket formation that lead to tooth loss if untreated. The proteomic profile and related molecular conditions of pocket tissue in periodontally-affected patients are not reported in literature. To characterize the proteomic profile of periodontally-affected patients, their interproximal periodontal pocket tissue was compared with that of periodontally-healthy patients. Pocket-associated and healthy tissue samples, harvested during surgical therapy, were treated to extract the protein content. Tissues were always collected at sites where no periodontal-pathogenic bacteria were detectable. Proteins were separated using two-dimensional gel electrophoresis and identified by liquid chromatography/mass spectrometry. After identification, four proteins were selected for subsequent Western Blot quantitation both in pathological and healty tissues.

Results

A significant unbalance in protein expression between healthy and pathological sites was recorded. Thirty-two protein spots were overall identified, and four proteins (S100A9, HSPB1, LEG7 and 14-3-3) were selected for Western blot analysis of both periodontally-affected and healthy patients. The four selected proteins resulted over-expressed in periodontal pocket tissue when compared with the corresponding tissue of periodontally-healthy patients. The results of Western blot analysis are congruent with the defensive and the regenerative reaction of injured periodontal tissues.

Conclusions

The proteomic analysis was performed for the first time directly on periodontal pocket tissue. The proteomic network highlighted in this study enhances the understanding of periodontal disease pathogenesis necessary for specific therapeutic strategies setting.

Toll-like receptor 4 expression in the epithelium of inflammatory periapical lesions. An immunohistochemical study

Toll-like receptors (TLR) are essential for the innate immune response against invading pathogens and have been described in immunocompetent cells of areas affected by periapical disease. Besides initiating the inflammatory response, they also directly regulate epithelial cell proliferation and survival in a variety of settings. This study evaluates the in situ expression of TLR4 in periapical granulomas (PG) and radicular cysts, focusing on the epithelial compartment.

Twenty-one periapical cysts (PC) and 10 PG were analyzed; 7 dentigerous non-inflamed follicular cyst (DC) served as control. TLR4 expression was assessed by immunohistochemistry. TLR4 immunoreaction products were detected in the epithelium of all specimens, with a higher percentage of immunostained cells in PG. Although TLR4 overexpression was detected in both PG and PC, there were differences that seemed to be related to the nature of the lesion, since in PG all epithelial cells of strands, islands and trabeculae were strongly immunoreactive for TLR4, whereas in PC only some areas of the basal and suprabasal epithelial layers were immunostained. This staining pattern is consistent with the action of TLR4: in PG it could promote formation of epithelial cell rests of Malassez and in epithelial strands and islands the enhancement of cell survival, proliferation and migration, whereas in PC TLR4 could protect the lining epithelium from extensive apoptosis. These findings go some way towards answering the intriguing question of why many epithelial strands or islands in PG and the lining epithelium of apical cysts regress after non-surgical endodontic therapy, and suggest that TLR4 plays a key role in the pathobiology of the inflammatory process related to periapical disease.

Non-bacterial protein expression in periodontal pockets by proteome analysis

OBJECTIVES

To compare the proteomic profile of inter-proximal pocket tissues with inter-proximal healthy tissues in the same subject to reveal proteins associated with periodontal disease in sites where periodontopathogenic bacteria were not detectable.

METHODS

Twenty-five healthy patients, with moderate-to-advanced chronic periodontitis and presenting with at least one intra-bony defect next to a healthy inter-proximal site were enrolled. The periodontal defects were treated with osseous resective surgery, and the flap design included both the periodontal pockets and the neighbouring inter-proximal healthy sites. Pocket-associated and healthy tissues were harvested for proteomic analyses.

RESULTS

Fifteen proteins were differently expressed between pathological and healthy tissues. In particular, annexin A2, actin cytoplasmic 1, carbonic anhydrase 1 & 2; Ig kappa chain C region (two spots) and flavinreductase were overexpressed, whereas 14-3-3 protein sigma and zeta/delta, heat-shock protein beta -1 (two spots), triosephosphateisomerase, peroxiredoxin-1, fatty acid-binding protein-epidermal, and galectin-7 were underexpressed in pathological tissue.

CONCLUSIONS

The unbalanced functional network of proteins involved could hinder adequate tissue response to pathogenic noxa. The study of periodontal pocket tissue proteomic profile would be crucial to better understand the pathogenesis of and the therapeutic strategies for periodontitis.

Expression of phosphorylated heat shock protein 27 during corneal epithelial wound healing

PURPOSE

The 27-kDa heat shock protein (HSP27) has been implicated in wound healing in multiple tissues. We investigated the expression and localization of phosphorylated HSP27 during epithelial wound healing in the murine cornea.

METHODS

Corneas of 8- to 10-week-old C57BL6 mice were wounded by epithelial debridement (n = 40). Unwounded corneas served as controls (n = 3). After 3, 7, and 14 days, phosphorylated HSP27 localization in wounded corneas was observed by confocal immunohistochemistry and double immunogold labeling transmission immunoelectron microscopy. Western blot analysis was performed to determine expression levels of phosphorylated HSP27 in scraped epithelia. Phosphorylated HSP27 localization was also separately performed with confocal immunohistochemistry 8 hours after epithelial debridement to investigate the early epithelial wound-healing process.

RESULTS

In unwounded corneas, phosphorylated HSP27 was localized only to the superficial epithelium. In contrast, phosphorylated HSP27 was localized in the basal and superficial epithelia 3 days after corneal epithelial wounding. After 7 and 14 days, HSP27 localization was similar to that in unwounded controls. Expression levels of phosphorylated HSP27 were greater in wounded corneal epithelia on day 3 than in unwounded controls and on day 14. After 8 hours, phosphorylated HSP27 expression was prominent in the leading edge of migrating corneal epithelium.

CONCLUSIONS

Constitutive expression of phosphorylated HSP27 is limited to the superficial corneal epithelium in unwounded murine corneas. Changes in HSP27 epithelial distribution and expression levels after corneal epithelial wounding suggest that phosphorylated HSP27 plays a role in early phase of corneal epithelial wound healing.

Expression of selected Ginkgo biloba heat shock protein genes after cold treatment could be induced by other abiotic stress

Heat shock proteins (HSPs) play various stress-protective roles in plants. In this study, three HSP genes were isolated from a suppression subtractive hybridization (SSH) cDNA library of Ginkgo biloba leaves treated with cold stress. Based on the molecular weight, the three genes were designated GbHSP16.8, GbHSP17 and GbHSP70. The full length of the three genes were predicted to encode three polypeptide chains containing 149 amino acids (Aa), 152 Aa, and 657 Aa, and their corresponding molecular weights were predicted as follows: 16.67 kDa, 17.39 kDa, and 71.81 kDa respectively. The three genes exhibited distinctive expression patterns in different organs or development stages. GbHSP16.8 and GbHSP70 showed high expression levels in leaves and a low level in gynoecia, GbHSP17 showed a higher transcription in stamens and lower level in fruit. This result indicates that GbHSP16.8 and GbHSP70 may play important roles in Ginkgo leaf development and photosynthesis, and GbHSP17 may play a positive role in pollen maturation. All three GbHSPs were up-regulated under cold stress, whereas extreme heat stress only caused up-regulation of GbHSP70, UV-B treatment resulted in up-regulation of GbHSP16.8 and GbHSP17, wounding treatment resulted in up-regulation of GbHSP16.8 and GbHSP70, and abscisic acid (ABA) treatment caused up-regulation of GbHSP70 primarily.

Treatment of a periradicular lesion in an alpaca (Vicugna pacos)

This case report describes the diagnosis and surgical treatment of a cyst-like periradicular lesion in an alpaca.

Nitric oxide promotes the progression of periapical lesion via inducing macrophage and osteoblast apoptosis

This study aimed to elucidate the modulation by nitric oxide (NO) of the apoptosis of macrophages and osteoblasts, the essential cellular components in the development of periapical lesions. Lipopolysaccharide (LPS) induced prominent nitrite synthesis in J774 mouse macrophage cell lines. Exposure to LPS induced obvious apoptosis in J774 cells, whereas transient transfection with murine inducible nitric oxide synthase (iNOS), small interfering RNA (siRNA) diminished this effect. Tumor necrosis factor-alpha (TNF-alpha) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) (a NO donor) triggered apoptosis in UMR-106 rat osteoblastic cell lines and a synergistic effect was noted when TNF-alpha and SNAP were added to the medium together. Administration of siRNAs for c-Fos and c-Jun: components of activator protein-1 (AP-1) and transforming growth factor-beta1 attenuated the combined effect markedly. Terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) stain in a rat model of induced periapical lesion showed positive apoptotic signals in macrophages and osteoblasts. Administration of N(G)-monomethyl-l-arginine markedly diminished the extent of bone loss and the amounts of apoptotic macrophages and osteoblasts. In conclusion, NO mediates LPS-stimulated apoptosis of macrophages. It also induces osteoblast apoptosis and augments the pro-apoptotic effect of cytokines. Inhibition of NO synthesis in vivo attenuates apoptosis and the size of periapical lesions. Taken together, these results suggest that NO may promote the progression of periapical lesion by inducing the apoptosis of macrophages and osteoblasts.

Evolution and development of Hertwig's epithelial root sheath

Periodontal regeneration and tissue engineering has re-awakened interest in the role of Hertwig's Epithelial Root Sheath (HERS), an epithelial tissue layer first discovered in amphibians more than a century ago. Using developmental, evolutionary, and cell biological approaches, we have, therefore, performed a careful analysis of the role of HERS in root formation and compared our data with clinical findings. Our developmental studies revealed HERS as a transient structure assembled in the early period of root formation and elongation and, subsequently, fenestrated and reduced to epithelial rests of Malassez (ERM). Our comparative evolutionary studies indicated that HERS fenestration was closely associated with the presence of a periodontal ligament and a gomphosis-type attachment apparatus in crocodilians and mammals. Based on these studies, we are proposing that HERS plays an important role in the regulation and maintenance of periodontal ligament space and function. Additional support for this hypothesis was rendered by our meta-analysis of recent clinical reports related to HERS function.

Genistein-induced proteome changes in the human endometrial carcinoma cell line, ishikawa

Epidemiological studies have shown that Asian populations display a lower incidence of hormone-dependant cancers, cardiovascular disease, osteoporosis, and menopausal ailments compared to Western societies. Available data support the proposal that lower incidence is associated with the high dietary consumption of isoflavones, such as genistein. This study used two-dimensional electrophoresis to characterize the effect of genistein on the proteome of an endometrial tumor cell model, namely the Ishikawa cell line. Proteome maps displaying approx 1800 proteins were obtained from cells treated with vehicle or genistein at physiologically attainable concentrations of 0.5, 5, or 50 μM or supra-physiological concentration, 500 μM. The effects of genistein on protein expression were characterized using image analysis software. A total 65 protein spots displayed a significant decrease in expression and 32 proteins displayed a significant increase in expression. Of these protein spots, 29 were randomly selected for characterization by matrix assisted laser desorption/ionization tandem mass spectrometry, yielding 18 different proteins. This type of analysis enabled the characterization of a wide range of cellular proteins and allowed for the identification of functional and biochemical pathways that may be regulated or affected by genistein, including cellular transcription, cell proliferation, stress response, or modulation of oncogenic pathways.

Influx of macrophages into livers of rats treated with hepatotoxicants (thioacetamide, allyl alcohol, D-galactosamine) induces expression of HSP25

Treatment of rats with a single dose of thioacetamide (TAA) provokes centrilobular inflammation and a significant expression of heat shock protein HSP25 in hepatocytes surrounding the area of inflammation. The HSP25 accumulation in hepatocytes adjacent to inflammatory regions was confirmed by identification of positive hepatocytes concentrated at periportal areas after treatment of rats with allyl alcohol (AA) or distributed diffusely throughout liver lobule after treatment with D-galactosamine (D-gal). In our model of TAA-treated rats the use of the anti-inflammatory drug-indomethacin, and the redox-regulating drug-N-acetylcysteine (NAC), significantly attenuated TAA-induced HSP25 expression and evoked morphological changes of recruited ED1+ macrophages. Treatment of rats with gadolinium chloride (GdCl(3)) decreased considerably the number of Kupffer cells (ED2+ macrophages) without affecting significantly the number and morphology of ED1+ macrophages as well as the expression pattern of TAA-induced HSP25. Our data shows for the first time that ED1+ macrophages recruited into the liver by treatment with TAA play a significant role in HSP25 induction in hepatocytes.

Hsp27 Expression Coincides with Epidermal Stratification during Human Epidermal Morphogenesis

Heat shock protein 27 (Hsp27), apart from its protective function in response to stress, is implicated in the regulation of cell growth, differentiation and apoptosis. Data on the expression of Hsp27 in the developing human epidermis are sparse and partially conflicting. Thus, the purpose of the present study was to investigate Hsp27 expression during the morphogenesis of human epidermis. Skin biopsies and dispase-separated epidermal sheets obtained from 7 human embryos (7 and 8 weeks estimated gestational age, EGA), from 79 human fetuses (9-23 weeks EGA) and from 10 healthy adult volunteers were investigated by immunohistochemistry and Western blotting, respectively. The earliest detection of Hsp27 expression was found by immunohistochemistry at the 12th week EGA (basal and intermediate layer) and by Western blotting at the 9th week EGA. From the 16th to the 23rd week EGA immunoreactivity was not detectable in the basal layer, whereas in the overlying layers it revealed a differentiation-related pattern. The simultaneous onset of epidermal stratification and Hsp27 expression (9th week EGA) and the alterations of the latter in the subsequent stages of development, suggest that this stress protein may be involved in the molecular events underlying human epidermal morphogenesis.

Apoptosis in normal and diseased oral tissues

Apoptotic cell death plays an important role in maintenance of the normal physiological state and in the pathogenesis of diseases in the body. Over the last three decades the molecular mechanisms of apoptosis have been unravelled leading to development of novel therapeutic approaches. This paper aims to present current knowledge of the role of apoptosis in normal oral tissues and in the development of oral diseases.

Apoptosis: an introduction for the endodontist

Apoptosis plays an important role in many aspects of endodontics, yet there is a paucity of information in this regard in the endodontic literature. Apoptosis is a single deletion of scattered cells by fragmentation into membrane-bound particles that are phagocytosed by other cells. It is a key process in the embryological development of the tooth, periodontal ligament and supporting oral tissue in the progression of oral disease, bone resorption, immunological response and inflammation, and in wound healing and certain pharmacological effects. The understanding of the ability of clinical materials to induce or inhibit apoptosis and the investigation of apoptosis as it relates to the pathogenesis of pulpal and periradicular pathology may eventually lead to new treatment approaches for the endodontist. The purpose of this review is to familiarize the clinical endodontist with current knowledge on apoptosis as it relates to the pulp and periradicular tissues.

Detection of vascular endothelial growth factor/ vascular permeability factor in periapical lesions

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), is a multifunctional cytokine. It is overexpressed in several conditions, which are characterized by vascular hyperpermeability and angiogenesis. In this investigation, we have evaluated the possibility that VEGF/VPF could be expressed in periapical lesions. We studied 17 periapical granulomas and 6 periapical cysts by immunohistochemistry. An immunopositive reaction for VEGF/VPF was observed in all 23 periapical lesions; however, the intensity of immunostaining by anti-VEGF antibody varied according to histopathological findings. In periapical granulomas without epithelium, almost all of the inflammatory cells were immunoreactive to anti-VEGF/VIP antibody. In periapical granulomas, which had rests of Malassez in them, some inflammatory cells were stained. On the other hand, epithelial cells always were stained by VEGF/VPF antibody, both in periapical lesions with epithelium and in radicular cysts. This study demonstrated that periapical lesions express VEGF/VPF, although with some differences in cell immunolabeling, which correlated to the lesions' stages of development. Initially, VEGF/VPF would assure angiogenesis and vascular hyperpermeability, resulting in accumulation of inflammatory cells, later it could be involved in cyst fluid accumulation. We hypothesize, therefore, that VEGF/VPF expression plays an important role in the pathogenesis of periapical granulomas and enlargement of radicular cysts by several mechanisms.

Expression of inducible nitric oxide synthase and heat shock proteins in periapical inflammatory lesions

BACKGROUND

The mechanisms responsible for activation and proliferation of lining epithelium involved in inflammatory processes in periapical inflammatory lesions remain unclear. In this study, the expression and distribution of inducible nitric oxide synthase (iNOS) and heat shock proteins (HSPs) were immunohistochemically investigated in periapical inflammatory lesions.

METHODS

Control specimens of periodontal ligaments including Malassez epithelial rests from seven teeth and periapical inflammatory lesions (15 apical granulomas (AGs), 16 radicular cysts (RCs), and 10 residual radicular cysts (RRCs)) were prepared and examined by the standard streptavidin-biotin peroxidase complex method using anti-iNOS rabbit polyclonal antiserum, and anti-HSP27, -HSP60, -HSP70 mouse monoclonal antibodies.

RESULTS

Immunoreactivity for iNOS was detected in macrophages, lymphocytes, and endothelial cells of granulation tissue and in lining epithelium of periapical inflammatory lesions. Malassez epithelial rests showed no or slight staining for iNOS. The epithelial staining intensity of iNOS in RCs was greater than that in Malassez epithelial rests and RRCs. Immunoreactivity for HSP27 was recognized in inflammatory cells, endothelial cells and lining epithelium of periapical inflammatory lesions and in Malassez epithelial rests. HSP60 was detected in some lymphocytes of granulation tissue and in lining epithelium of periapical inflammatory lesions, whereas Malassez epithelial rests showed no staining for HSP60. Epithelial HSP60 reactivity was more intense in RCs than in RRCs. HSP70 was expressed in lymphocytes, endothelial cells and lining epithelium of periapical inflammatory lesions and in Malassez epithelial rests. The staining intensity of HSP70 in Malassez epithelial rests was slightly lower than that in lining epithelium of RCs and RRCs.

CONCLUSIONS

These data demonstrate that the expressions of iNOS, HSP60, and HSP70 are involved in inflammatory processes and might play a role in the activation and proliferation of lining epithelium, leading to progression of periapical inflammatory lesions.