Periostin Staining Research Articles

Abstract TMP1: Cerebral Aneurysm Walls Contain Myoglobin That is Possibly Produced by Myofibroblasts and Contributes to Wall Thickening

Background: Cerebral aneurysms rupture at a thin-walled region; however, mechanisms of aneurysmal wall thinning and thickening remain unclear. Myoglobin scavenges nitric oxide and reactive oxygen spices which promote aneurysmal development. Objectives: To investigate the biological role of myoglobin in aneurysmal wall. Methods: Cerebral aneurysmal wall samples were collected between August 2020 and March 2022 for proteomic analysis and immunohistology. We examined the co-localization of myoglobin expression within smooth muscle cells, identified by α-smooth muscle actin (α-SMA) staining, and myofibroblasts, identified by periostin staining. Collagen and myoglobin density in the same sample areas were investigated for its correlation in the aneurysm walls. Results: A total of 35 specimens were obtained from 21 patients who underwent aneurysmal clipping. Proteome analysis was performed using 11 specimens, which firstly detected myoglobin predominantly in the thickened wall. Among 24 formalin-fixed samples, 19 samples were found myoglobin expression. Myoglobin was mostly scattered within the vascular smooth muscle layer and tended to be expressed at sites where iNOS was scarce. Double-label immunofluorescence staining confirmed that the myoglobin-positive rate within α-SMA-positive cells/areas was 33.2±23.8%/31.3±37.8%, respectively, whereas within periostin-positive cells/areas it was 92.2±13.7%/79.8±29.5, respectively. A total of 32 areas were investigated for the correlation between collagen and myoglobin density , which a strong correlation was observed with a Spearman's rank correlation coefficient of 0.635 (p < 0.001). Conclusions: Cerebral aneurysmal walls express myoglobin, which may be produced by myofibroblasts in the wall. Areas with high myoglobin levels retain high levels of collagen fibers, and myoglobin may be involved in wall thickening by suppressing destructive changes in the extracellular collagen fibers.

IL13 and periostin in active fibrogenic areas of the extrahepatic bile ducts in biliary atresia patients.

The leading pathology of biliary atresia (BA) is inflammatory and fibrous obstruction of extrahepatic bile duct, but the pathogenesis remains unclear. IL13 is a cytokine associated with allergies and inflammatory fibrosis, and periostin induces fibrogenesis by stimulation with IL13. We analyzed the involvement of IL13 and periostin in inflammatory fibrosis in the extrahepatic bile duct of BA patients. Surgically resected tissues from the hepatic hilar area of BA patients were immunostained with CD45, α-SMA, IL13 and periostin and statistically analyzed. Fibroblasts from the resected tissue were cultured with recombinant IL13, and periostin production was analyzed by quantitative polymerase chain reaction and Western blotting. IL13 was stained in 93% of large and micro bile ducts, and 92.1% matched with the CD45 location (p = 0.006) around the large bile ducts. Periostin staining correlated with the localization of IL13 and αSMA (p < 0.001) around the large bile ducts. Periostin mRNA and protein were upregulated by IL13 stimulation in cultured fibroblasts. IL13 was associated with induced periostin expression by fibroblasts, playing a vital role in the pathogenesis of fibrogenesis around the extrahepatic bile duct in BA.

Potential of the Stromal Matricellular Protein Periostin as a Biomarker to Improve Risk Assessment in Prostate Cancer.

Prostate cancer (PCa) ranges from indolent to aggressive tumors that may rapidly progress and metastasize. The switch to aggressive PCa is fostered by reactive stroma infiltrating tumor foci. Therefore, reactive stroma-based biomarkers may potentially improve the early detection of aggressive PCa, ameliorating disease classification. Gene expression profiles of PCa reactive fibroblasts highlighted the up-regulation of genes related to stroma deposition, including periostin and sparc. Here, the potential of periostin as a stromal biomarker has been investigated on PCa prostatectomies by immunohistochemistry. Moreover, circulating levels of periostin and sparc have been assessed in a low-risk PCa patient cohort enrolled in active surveillance (AS) by ELISA. We found that periostin is mainly expressed in the peritumoral stroma of prostatectomies, and its stromal expression correlates with PCa grade and aggressive disease features, such as the cribriform growth. Moreover, stromal periostin staining is associated with a shorter biochemical recurrence-free survival of PCa patients. Interestingly, the integration of periostin and sparc circulating levels into a model based on standard clinico-pathological variables improves its performance in predicting disease reclassification of AS patients. In this study, we provide the first evidence that circulating molecular biomarkers of PCa stroma may refine risk assessment and predict the reclassification of AS patients.

Novel In Situ-Cross-Linked Electrospun Gelatin/Hydroxyapatite Nonwoven Scaffolds Prove Suitable for Periodontal Tissue Engineering.

Periodontal diseases affect millions of people worldwide and can result in tooth loss. Regenerative treatment options for clinical use are thus needed. We aimed at developing new nonwoven-based scaffolds for periodontal tissue engineering. Nonwovens of 16% gelatin/5% hydroxyapatite were produced by electrospinning and in situ glyoxal cross-linking. In a subset of scaffolds, additional porosity was incorporated via extractable polyethylene glycol fibers. Cell colonization and penetration by human mesenchymal stem cells (hMSCs), periodontal ligament fibroblasts (PDLFs), or cocultures of both were visualized by scanning electron microscopy and 4′,6-diamidin-2-phenylindole (DAPI) staining. Metabolic activity was assessed via Alamar Blue® staining. Cell type and differentiation were analyzed by immunocytochemical staining of Oct4, osteopontin, and periostin. The electrospun nonwovens were efficiently populated by both hMSCs and PDLFs, while scaffolds with additional porosity harbored significantly more cells. The metabolic activity was higher for cocultures of hMSCs and PDLFs, or for PDLF-seeded scaffolds. Periostin and osteopontin expression was more pronounced in cocultures of hMSCs and PDLFs, whereas Oct4 staining was limited to hMSCs. These novel in situ-cross-linked electrospun nonwoven scaffolds allow for efficient adhesion and survival of hMSCs and PDLFs. Coordinated expression of differentiation markers was observed, which rendered this platform an interesting candidate for periodontal tissue engineering.

Proteomic signature of tubulointerstitial tissue predicts prognosis in IgAN

BackgroundIgA nephropathy (IgAN) is associated with a significant risk of progression to kidney failure. Tubular atrophy is an established important risk factor for progressive disease, but few studies have investigated tubulointerstitial molecular markers and mechanisms of progression in IgAN.MethodsBased on data from the Norwegian Renal Registry, two groups were included: IgAN patients with (n = 9) or without (n = 18) progression to kidney failure during 10 years of follow-up. Tubulointerstitial tissue without discernible interstitial expansion or pronounced tubular alterations was microdissected, proteome was analysed using tandem mass spectrometry and relative protein abundances were compared between groups. ResultsProteome analyses quantified 2562 proteins with at least 2 unique peptides. Of these, 150 proteins had significantly different abundance between progressive and non-progressive IgAN patients, 67 were more abundant and 83 less abundant. Periostin was the protein with the highest fold change between progressive and non-progressive IgAN (fold change 8.75, p < 0.05) and periostin staining was also stronger in patients with progressive vs non-progressive IgAN. Reactome pathway analyses showed that proteins related to inflammation were more abundant and proteins involved in mitochondrial translation were significantly less abundant in progressive vs non-progressive patients.ConclusionsMicrodissection of tubulointerstitial tissue with only mild damage allowed for identification of proteome markers of early progressive IgAN. Periostin abundance showed promise as a novel and important risk marker of progression.

Evaluation of periostin, fibronectin and tenascin-C in patients chronic otitis media with cholesteatoma

BackgroundAlthough many studies have investigated the mechanisms of cholesteatoma formation, its pathogenesis remains unclear. The aim of this study was to evaluate the levels of periostin, fibronectin and tenascin-C, which are involved in many mechanisms, such as cell adhesion, cell differentiation, inflammation, fibrosis, angiogenesis and cell proliferation, in patients with chronic otitis media (COM). A total of 80 participants, 65 COM patients undergoing surgery and 15 healthcare personnel volunteers serving as controls, were included in this study. The participants were divided into four groups: cholesteatoma, granulation, avivation and control group. The serum periostin, fibronectin and tenascin-C levels of all participants were determined biochemically. Histopathological evaluation of tissue samples and 20 skin samples used as controls was performed by immunohistochemistry.ResultsOf the 65 patients, 22 presented with cholesteatoma, 15 with granulation tissue and 28 with the edge of the tympanic membrane perforation freshening tissue. There were no significant differences in serum periostin, fibronectin and tenascin-C levels between the groups. In the immunohistochemical evaluation, fibronectin and periostin staining was significantly more intense in the cholesteatoma group than in the other groups (p = 0.001). Epithelial tenascin-C staining was significantly more intense in the avivation group than in the other groups (p = 0.041).ConclusionThe levels of periostin and fibronectin were higher in cholesteatoma tissue than in other forms of chronic otitis and skin tissue. This suggests that they may be involved in the mechanism of cholesteatoma formation. These proteins could be used as biomarkers in the diagnosis and treatment of cholesteatoma.

Effect of root surface treatment with denusomab after delayed tooth replantation.

To evaluate denosumab, a human monoclonal antibody that mimics the effects of osteoprotegerin in bone metabolism, as a topical treatment of root surface to be used prior to delayed tooth replantation. Thirty-six rats' right incisors were used. Teeth were extracted and divided into: delayed replantation without root surface treatment (control); delayed replantation with root surface treatment with denosumab 60mg/mL and 30mg/mL, respectively, for 10min both experimentals groups. After that, the root canals were filled with calcium hydroxide and replanted. After 15 and 60days, the animals were euthanized, and the samples were collected and processed for microscopic analysis. Histological sections were performed, and stained with HE to describe the dental characteristics, measure ankylosis, replacement resorption, and dental resorption by conventional microscopy. Also, was performed Brown & Brenn staining and immunohistochemistry for RANKL, OPG, and periostin. Denosumab 60mg/mL reducted ankylosis (p < 0.0001), replacement resorption (p < 0.0001), and tooth resorption, 60days after replantation, compared to untreated replanted teeth (p < 0.005). Lower bacterial contamination in root surface in the denosumab treatment groups was found, regardless of the concentration used (p < 0.001). Also, denosumab treatment inhibited the expression of RANKL without modulating OPG. Periostin was observed in periodontal ligament of replanted tooth, although this labelling was absent in the ankylosis areas, in both experimental periods. Treatment of the root surface with denosumab at 60mg/mL of rat teeth before delayed replantation reduced dental root resorption compared with the untreated teeth after 60days. Survival of a replanted tooth has been a challenge in clinical practice. The use of a medication, such as denosumab, to limit dental root resorption represents an important therapeutical approach.

Self-healing and injectable hybrid hydrogel for bone regeneration of femoral head necrosis and defect

BackgroundHA modified by bisphosphonate (BP) (HA-BP) was synthesized by chemical reaction and possessed promising properties such as self-healing, injection ability, and strong adhesion. The main aim of this study was to confirm its role in promoting osteogenic differentiation in vitro and bone regeneration in vivo. MethodsThe cell biocompatibility of this material was determined using the CCK-8 assay. Alkaline phosphatase (ALP), osteocalcin (OT), vascular endothelial growth factor (VEGF), and collagen I were assessed by quantitative real-time polymerase chain reaction (Q-PCR) in the treated group. The number and density of calcium nodules and ALP were evaluated by Alizarin Red staining and ALP staining. We have successfully developed an animal model simulating osteonecrosis of the femoral head (ONFH). Utilizing this animal model, the impact of HA-BP/CaP on bone formation was assessed. The amount of bone regeneration at 1 and 2 months after HA-BP/CaP injection was estimated by micro-computed tomography (micro-CT) analysis and H&E, collagen I, and periostin staining. ResultsThe number of cells gradually increased in the experimental group over time and was close to that of the blank control group. ALP, collagen I, and VEGF expression was significantly higher in the experimental group than in the blank group (VEGF, ALP, both **p < 0.01; collagen I, ***p<0.001). In addition, the number and density of calcium nodules and ALP was clearly greater in the material group than in the control group.The quantification analysis showed that the mineral contents of regenerated bone at 1 and 2 months after HA-BP/CaP injection were significantly greater than those in the control group, according to micro-CT evaluation (**p<0.01). The amount of organic components in the HA-BP/CaP group was greater than that in the control group after decalcification and H&E staining. In addition, collagen I and periostin staining further confirmed the results of H&E staining. ConclusionThis material can boost proliferation and osteogenic differentiation of MC3T3-E1 cells in vitro. It can intensely accelerate bone regeneration in vivo, which is a promising strategy for tissue engineering.

Epithelial periostin expression is correlated with poor survival in patients with invasive breast carcinoma.

Invasion and metastasis are direct causes of mortality in patients with breast cancer and require reciprocal interactions between cancer cells and the extracellular matrix (ECM). Periostin, a fasciclin-containing adhesive ECM glycoprotein, is frequently overexpressed in various types of human cancer, and its overexpression in cancer-associated stroma and/or cancer cells is usually associated with poor clinical outcomes. However, the expression of periostin in the successive steps of breast tumorigenesis and its association with outcome variables have not been well established in breast carcinoma. The present study aimed to assess the role of periostin alteration in breast tumorigenesis and evaluate the putative prognostic value of periostin as a function of its compartmentalization. Immunohistochemical staining with anti-periostin antibody was performed in a total of 300 patients (26 patients with normal breast tissues, 76 patients with ductal carcinoma in situ [DCIS], and 198 patients with invasive breast carcinoma [IBC]) using tissue microarray. Periostin immunoreactivity was assessed in both epithelial tissue and the surrounding stromal compartment. The mRNA and protein expression of periostin were analyzed in 10 paired normal/invasive cancer frozen specimens by quantitative real time-polymerase chain reaction and western blot analysis, respectively. In cancer tissues, periostin mRNA and protein expression were increased compared with adjacent normal tissues. Both epithelial and stromal periostin staining scores significantly increased in a stepwise manner with disease progression from normal breast tissue to DCIS and IBC (P = 0.000 and 0.000, respectively). High epithelial and stromal periostin expression was observed in 109/189 (57.7%) and 158/189 (83.6%) cases of IBC, respectively. High epithelial periostin expression was more frequently observed in the distant metastatic relapse-positive group than in the distant metastatic relapse-negative group (41/51 [80.4%] vs. 68/138 [49.3%] cases [P = 0.000]). Furthermore, high epithelial periostin expression was associated with reduced disease-free survival and overall survival in univariate and multivariate analysis. Periostin may play an important role in the progression of breast tumor, and epithelial periostin expression may serve as a new parameter for prediction of prognosis in patients with IBC. Further studies examining periostin expression and its potential as a target of IBC therapy are warranted.

Phospho-STAT5B Expression Is a Prognostic Marker for Merkel Cell Carcinoma.

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma. Although recent reports suggest that tumor-infiltrating leukocytes (TILs), especially CD8+ T-cells, contribute to the pathogenesis of MCC, it is difficult for a single Institute with a small number of patients with MCC to determine the threshold number of CD8+ cells. Therefore, clearer and easier methods of evaluating prognostic factors of MCC are needed. In order to identify the prognostic factors of 24 cases of MCC, we employed immuno histochemical staining of phospho-signal transducer and activator of transcription 5B (pSTAT5B), which has been reported to be a prognostic marker for several types of cancers. All MCC cases with a good outcome (n=16) expressed pSTAT5B, whereas all MCC cases with a poor outcome (n=8) did not express pSTAT5B. Moreover, we additionally employed immunohistochemical staining of periostin (POSTN) and interleukin-4, as well as sub-populations of TILs (granulysin-bearing cells, regulatory T-cells, CD163+ cells, and CD206+ cells), and the deposition of matrix metalloproteinase 12 in the lesional skin of patients with MCC. The results suggested that there is no significant difference in stromal factors between MCC cases with a good and those with a poor outcome. pSTAT5B expression may be an indicator of positive prognosis in patients with MCC.

Abstract P2-07-06: Periostin is associated with breast tumor progression and epithelial periostin expression is correlated with poor survival in patients with invasive breast carcinoma

Abstract Background: Invasion and metastasis are the direct causes of mortality in patients with breast cancer and require reciprocal interactions between cancer cells and the extracellular matrix (ECM). Periostin, a fasciclin-containing adhesive ECM glycoprotein, is frequently overexpressed in various types of human cancer, and its overexpression in cancer-associated stroma and/or cancer cells is usually associated with poor clinical outcomes. However, the expression of periostin in the successive steps of breast tumorigenesis and its association with outcome variables have not been well established in breast carcinoma. The purposes of the present study were to assess the role of periostin alteration in breast tumorigenesis and evaluate the putative prognostic value of periostin as a function of its compartmentalization. Materials and Methods: Immunohistochemical staining with anti-periostin antibody was performed in a total of 300 patients (26 patients with normal breasts, 76 patients with ductal carcinoma in situ [DCIS], and 198 patients with invasive breast carcinoma [IBC]) using tissue microarray. Periostin immunoreactivity was assessed in both epithelial tissue and the surrounding stromal compartment. In addition, the mRNA and protein expression of periostin was analyzed in 10 paired normal/invasive cancer frozen specimens by quantitative real time-polymerase chain reaction and western blot analysis, respectively. Results: Periostin mRNA and protein expression in cancer tissues was increased compared with that in adjacent normal tissues. Both epithelial and stromal periostin staining scores were significantly increased with disease progression in a stepwise manner to DCIS and IBC compared with those in normal breast tissues (P = 0.000 and 0.000, respectively). High epithelial and stromal periostin expression was observed in 109 of 189 (57.7%) and 158 of 189 (83.6%) cases of IBC, respectively. High epithelial periostin expression was more frequently observed in the distant metastatic relapse-positive group than in the distant metastatic relapse-negative group (41 [80.4%] of 51 cases versus 68 [49.3%] of 138 cases [P = 0.000]). Furthermore, high epithelial periostin expression was associated with reduced disease-free and overall survival on univariate and multivariate analyses. Conclusion: Periostin might play an important role in the progression of breast tumor, and epithelial periostin expression may serve as a new parameter for prognostic prediction in patients with IBC. Further study of periostin expression and its potential as a target of therapy for IBC appears warranted. Citation Format: Lee JS, Kim G-E, Park MH, Yoon JH. Periostin is associated with breast tumor progression and epithelial periostin expression is correlated with poor survival in patients with invasive breast carcinoma. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-07-06.

Identification of novel biomarker candidates for immunohistochemical diagnosis to distinguish low-grade chondrosarcoma from enchondroma.

Chondrosarcoma is the third most common primary bone cancer, requiring surgical resection. However, differentiation of low-grade chondrosarcoma (grade 1) from enchondroma that is benign and only requires regular follow-up is one of the most frequent diagnostic dilemmas facing orthopedic oncologists in clinical management. Although multiple techniques are applied to make the distinction, immunohistochemistry is an important ancillary technique, especially when a histopathological stain of specimen must be obtained in order to guarantee an accurate confirmation. Currently, no adequate immunohistochemical diagnostic protein biomarkers are available to distinguish low-grade chondrosarcoma from enchondroma. To discover novel protein biomarker candidates, an LC-MS/MS approach was applied to directly compare formalin-fixed, paraffin-embedded low-grade chondrosarcoma with enchondroma tissue samples. The proteomics analysis revealed 17 protein biomarker candidates. A principle was developed to prioritize the candidates using category and ranking. An algorithm, prioritization index of biomarker candidates for immunohistochemistry on tissue specimens, was developed to rank the candidates inside each category. Using the proteomics data and bioinformatics results, the prioritization index of biomarker candidates for immunohistochemistry on tissue revealed periostin as a top candidate. Immunohistochemical staining of periostin in 23 low-grade chondrosarcoma and 31 enchondroma tissue specimens disclosed 87% specificity and 70% sensitivity.

Overexpression of periostin in stroma positively associated with aggressive prostate cancer.

BackgroundPeriostin is an important extracellular matrix protein involved in cell development and adhesion. Previously, we identified periostin to be up-regulated in aggressive prostate cancer (CaP) using quantitative glycoproteomics and mass spectrometry. The expression of periostin was further evaluated in primary radical prostatectomy (RP) prostate tumors and adjacent non-tumorous prostate tissues using immunohistochemistry (IHC). Our IHC results revealed a low background periostin levels in the adjacent non-tumorous prostate tissues, but overexpressed periostin levels in the peritumoral stroma of primary CaP tumors.MethodsIn this study, periostin expression in CaP was further examined on multiple tissue microarrays (TMAs), which were conducted in four laboratories. To achieve consistent staining, all TMAs were stained with same protocol and scored by same image computation tool to determine the total periostin staining intensities. The TMAs were further scored by pathologists to characterize the stromal staining and epithelial staining.ResultsThe periostin staining was observed mainly in peritumoral stromal cells and in some cases in tumor epithelial cells though the stronger staining was found in peritumoral stromal cells. Both periostin stromal staining and epithelial staining can differentiate BPH from CaP including low grade CaP (Gleason score ≤6), with significant p-value of 2.2e-16 and 0.001, respectively. Periostin epithelial staining differentiated PIN from low grade CaP (Gleason score ≤6) (p=0.001), while periostin stromal staining differentiated low grade Cap (Gleason score ≤6) from high grade Cap (Gleason score ≤6) (p=1.7e-05). In addition, a positive correlation between total periostin staining and Gleason score was observed (r=0.87, p=0.002).ConclusionsThe results showed that periostin staining was positively correlated with increasing Gleason score and the aggressiveness of prostate disease.

Periostin: a novel tissue biomarker correlates with chronicity index and renal function in lupus nephritis patients.

Lupus nephritis (LN) is one of the most serious complications in patients with systemic lupus erythematosus (SLE). At present, there is no specific biomarker with high sensitivity and renal pathology involvement in use in clinical practice. Periostin is an extracellular matrix protein involved in kidney development and kidney injury. We performed immunohistochemical analysis for periostin and routine staining of 42 kidney tissues from LN patients compared with controlled kidney tissues. Activity index, chronicity index and periostin staining were evaluated and scored by a renal pathologist. Periglomerular staining of periostin was the most predominant finding. Positive periostin staining was also observed in areas with fibrosis such as sclerosed glomeruli, interstitial fibrosis and fibrous vessels. Moreover, the tubules seemed to be the main location for periostin staining. There was a statistically different level of periostin staining score between patient and control tissues. Periostin staining score also correlated with the chronicity index score of renal pathology (r = 0.594, p < 0.001). Periostin was also correlated with worsening renal outcomes including serum creatinine, blood urea nitrogen and estimated glomerular filtration rate (eGFR). Subgroup analysis within patients with low activity index score or low chronicity index score found that there was a statistical difference in serum creatinine and eGFR between groups with low and high periostin staining scores. We concluded that periostin staining score correlated with chronicity index score and renal function in patients with lupus nephritis.

Evaluation of Osteogenic and Cementogenic Potential of Periodontal Ligament Fibroblast Spheroids Using a Three-Dimensional In Vitro Model of Periodontium.

The aim of this study was to develop a three-dimensional in vitro model of periodontium to investigate the osteogenic and cementogenic differentiation potential of the periodontal ligament fibroblast (PDLF) spheroids within a dentin-membrane complex. PDLFs were cultured in both spheroid forms and monolayers and were seeded onto two biological collagen-based and synthetic membranes. Cell-membrane composites were then transferred onto dentin slices with fibroblasts facing the dentin surface and further cultured for 20 days. The composites were then processed for histology and immunohistochemical analyses for osteocalcin, Runx2, periostin, and cementum attachment protein (CAP). Both membranes seeded with PDLF-derived cells adhered to dentin and fibroblasts were present at the dentin interface and spread within both membranes. All membrane-cell-dentine composites showed positive staining for osteocalcin, Runx2, and periostin. However, CAP was not expressed by any of the tissue composites. It can be concluded that PDLFs exhibited some osteogenic potential when cultured in a 3D matrix in the presence of dentin as shown by the expression of osteocalcin. However the interaction of cells and dentin in this study was unable to stimulate cementum formation. The type of membrane did not have a significant effect upon differentiation, but fibroblast seeded-PGA membrane demonstrated better attachment to dentin than the collagen membrane.

Periostin: a novel prognostic predictor for meningiomas.

The expression and role of periostin in meningiomas remains unknown. Tissue specimens of 175 convexity meningiomas were immunohistochemically examined with antibodies against periostin and Ki67. The expression levels of periostin and Ki67 were compared among different WHO groups. The role of periostin and Ki67 in postoperative prognosis of meningiomas was also analyzed. Negative (-) expression of Ki67 was observed in 101 (57.7 %) cases of all the surgical tissue samples. The Ki67 expressions differed significantly among the WHO groups (P < 0.001) and correlated positively with the WHO grade (r = 0.673, P < 0.001). Low/negative staining of periostin was observed in 116 (66.3 %) cases. The periostin expressions differed significantly among the WHO groups (P < 0.001). Periostin expression correlated positively with the WHO grade (r = 0.742, P < 0.001). There was a positive correlation between Ki67 expression and periostin (r = 0.513, P < 0.001). Both Ki67 expression and periostin expression was found statistically different between brain invasion tumor and non-invasion tumor (p < 0.001). The recurrence rate and PFS rate in both varied Ki67 expression groups and periostin expression groups was statistically different (P < 0.001). The survival time and PFS time in both varied Ki67 expression groups and periostin expression groups was also statistically different (P < 0.001). Periostin was expressed in tumor stroma of meningiomas. Both periostin and Ki67 may behave as a maker in predicting the grade and prognosis in meningiomas. Drugs that targets periostin aims at reducing invasion of meningioma patients should be further researched.

Immunohistochemical and Histochemical Analysis of Newly Formed Tissues in Root Canal Space Transplanted with Dental Pulp Stem Cells Plus Platelet-rich Plasma

IntroductionTissue regeneration in root canals after pulpectomy can be achieved by transplantation of autologous dental pulp stem cells and/or platelet-rich plasma. However, the identity of the newly formed tissue in the pulp space has been only examined by histologic analysis. This study aimed to apply immunohistochemistry and histochemistry to detect specific markers in the newly generated tissues after root canal regenerative treatment. MethodsIn our previous study, 32 root canals in 4 mature dogs were treated with a pulp regeneration procedure after pulpectomy using either blood clot, transplantation of dental pulp stem cells, platelet-rich plasma, or a combination of cells and plasma. In the present study, the tissues were examined for the expression of periostin to detect periodontal ligament tissue, nestin and dentin sialoprotein for odontoblasts, and bone sialoprotein and osteocalcin for bone tissues. Samples were also stained for tartrate-resistant acid phosphatase (TRAP) as a marker for osteoclastic lineages. ResultsContinuous periostin-positive tissue was observed extending from the periodontal ligament into the inner canal surface in which the mineral islands were surrounded by weak periostin staining. There was also positive staining for TRAP, bone sialoprotein, and osteocalcin in the canal space, suggesting the presence of bone tissue. A layer of mineralized tissue along the inner surface of the root canal was negative for TRAP, suggesting the tissue likely to be cementum. In all samples, no nestin-positive reaction was observed, whereas dentin sialoprotein was detected in PDL, dentinal tubules, and intracanal fibrous tissues. There was no difference between any of the 4 groups. ConclusionsThe tissues formed in the dog mature root canals after regenerative endodontic procedures are not pulp tissues but mainly periodontal tissues.

Lack of circulating toll-like receptor 2 promotes survival and prevents adverse remodeling after myocardial infarction

Purpose: Adverse cardiac remodeling after myocardial infarction is mediated by excessive inflammation. Toll-like receptors (TLR) are known for their crucial role in inflammatory responses after injury. In the present study, we investigated the role of TLR2 in adverse remodeling after myocardial infarction. Methods: C57Bl6 wild-type (WT), TLR2 -/- and chimeric (WT bone marrow transplanted in TLR2 -/- mice and vice versa) mice underwent permanent ligation of the left coronary artery. Cardiac function and geometry were assessed with 9.4T mouse-MRI at baseline, 7 and 28 days after infarction. Infarct size (IS) as a percentage of the left ventricle (LV) was determined by Evan's blue dye injection and TTC staining at 2 days (IS/LV). Fibroblast differentiation and activation was performed via immunohistochemical staining for αSMA and periostin. Inflammation in the remote and infarct area was assessed by expression of cytokines (multiplex). Results: TLR2 -/- mice showed improved survival compared to WT and were relatively protected against adverse cardiac remodeling during 28 days follow-up, despite similar infarct sizes (39±1.4% vs. 42±1.5%; p=0.256). Furthermore, systolic performance of both infarcted and remote myocardium was better in TLR2-/- mice compared to WT animals (ESV in ul: 112.4±6.2 vs. 207.4±15.7, p<0.001). Chimeric mice experiments demonstrated that bone marrow derived TLR2 expression mediated the expansive remodeling after infarction. Inflammatory cytokine levels (TNFα, IL-1α, GM-CSF and IL-10) and white blood cell count were significantly reduced in TLR2 -/- mice at resp. 3 days and 7 days after infarction. In addition, αSMA- and periostin-positive areas were significantly reduced in TLR2-/- animals at 3 and 7 days after infarction (periostin: 21.50±12.45% vs. 7.30±4.77%, p=0.02). Conclusions: Lack of TLR2 improves survival and cardiac function after myocardial infarction and is determined by leukocytic TLR2 deficiency via reduced inflammation. Current efforts are to clarify the reduced myofibroblast staining, suggesting a pivotal role for TLR2 in fibroblast and leucocyte transdifferentiation and activation. Future interventional studies are required to address the potential of TLR2 as a therapeutic target to prevent adverse remodeling after myocardial infarction.

The expression and immunohistochemical localization of periostin in odontogenic tumors of mixed epithelial/mesenchymal origin

The object of this study was to determine the expression and localization of periostin in the major mixed odontogenic tumors and to correlate any differential staining of the mesenchymal components to the interrelationship of these tumors. Five ameloblastic fibromas, 8 ameloblastic fibro-odontomas and 10 odontomas were assessed immunohistochemically for periostin staining. Because mesenchymal tissues were consistently present in all studied cases, these tissues were selected for statistical analysis of differential periostin staining. Periostin was variably localized to the mesenchymal component of the tumors as well as to preameloblasts and ameloblasts. Analysis of the mesenchymal staining intensity was statistically significantly different between ameloblastic fibro-odontomas and odontomas (P < .001; Dunn multiple comparisons test). Our results document periostin staining in human mixed odontogenic tumors. Statistical analysis of differential stromal staining supports the concept that the ameloblastic fibroma is a histogenetically distinct neoplasm as compared to ameloblastic fibro-odontoma and odontoma.

Increased periostin gene expression in degenerative intervertebral disc cells

Background contextDisc degeneration is a multifactorial disease that may cause clinical symptoms such as chronic back pain or radiculopathy in the extremities. Periostin, an extracellular matrix protein involved in the process of fibrosis, expressed in tissues subjected to mechanical stress such as intervertebral disc. However, the expression of periostin during disc degeneration has not yet been studied. PurposeThe aim of this study is to elucidate the difference in gene expression profiles between degenerative and nondegenerative intervertebral discs for a better understanding of disc degeneration. Study designDegenerative and nondegenerative nucleus pulposus cells were isolated from elderly patients with degenerative disc disease and younger patients with adolescent idiopathic scoliosis, respectively. MethodsAffymetrix GeneChip Human arrays were used to derive gene expression profiles for disc degeneration, and gene expressions of periostin and other degeneration-related markers were confirmed by reverse transcription-polymerase chain reaction (RT-PCR), real-time RT-PCR, and western blot analysis. Immunohistochemical analysis of periostin and Gomori trichrome stain was performed to show the relationship of periostin, fibrosis, and disc degeneration. The mechanical stress experiment was designed to demonstrate the relationship of periostin, stress, and disc degeneration. ResultsFourteen genes were identified to express at significantly different levels between degenerative and nondegenerative groups. An increase of periostin gene expression was observed in human degenerative nucleus pulposus cells for the messenger RNA and protein levels. Histological examination demonstrated an increased positive staining of periostin in degenerative discs from human tissues and rat needle-punctured tails and more fibrosis with architectural disorder and fragmentation in human degenerative disc as compared with nondegenerative discs. The expression of periostin was significantly induced by stress in human degenerative nucleus pulposus cells but not in nondegenerative cells. ConclusionsThis study demonstrates for the first time an upregulation of periostin in addition to the expression levels of Type I collagen and matrix metalloproteinase-2 in human disc degeneration. It suggests that periostin may be a candidate gene that shows promise as a new prognostic marker and a therapeutic target that is worth further study to expand our knowledge of its role in disc degeneration.