Characterization of macrophages infiltrating periâ implantitis lesions

ObjectivesThe mechanisms involved in the initiation and progression of periâ implantitis lesions are poorly understood. It was the aim to determine the content and activation status of macrophages present in human periâ implantitis lesions and compare the current findings with the macrophage polarization associated with periodontitis lesions.Material and MethodsA total of 14 patients were studied in this investigation. Seven were soft tissue biopsies from dental implants affected by periâ implantitis that required explantation. Seven biopsies were from chronic periodontal disease. Immunofluorescence stains were performed using biomarkers to identify macrophages (CD68+) undergoing M1 polarization (iNOS+) and M2 polarization (CD206+), along with Hoechst 33,342 to identify DNA content. All samples were stained and photographed, and doubleâ positive cells for CD68 and iNOS or CD68 and CD206 were quantified.ResultsAll periâ implantitis biopsies examined revealed a mixed population of macrophages undergoing M1 polarization and M2 polarization. Further analysis demonstrated the coâ expression of iNOS and CD206, which indicates the presence of a heterogenic immune response on periâ implantitis lesions. Macrophage polarization in periâ implantitis lesions presents a distinct pattern than in periodontitis. We observed a significant increase in the population of M1 macrophages on periâ implantitis samples compared to periodontal disease samples.ConclusionOur results demonstrate that periâ implantitis has higher numbers of macrophages displaying a distinct macrophage M1 polarization signature compared to periodontitis lesions. This pattern may explain, in part, the distinct nature of periâ implantitis progression vs. periodontitis in humans.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154542/1/clr13568_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154542/2/clr13568.pd

Characterization of macrophage polarization in periodontal disease

AimTo explore the M1/M2 status of macrophage polarization from healthy, gingivitis, and periodontitis patient samples.Materials and methodsGingival biopsies were collected from 42 individuals (14 gingivitis, 18 periodontitis, and 10 healthy samples) receiving periodontal therapy. Histomorphology analysis was performed with haematoxylin and eosin staining. Immunofluorescence was performed using a combination of CD68 (macrophages), iNOS (M1), and CD206 (M2) in order to acquire changes in macrophage polarization at a singleâ cell resolution. Macrophages were quantified under microscopy using narrow wavelength filters to detect Alexa 488, Alexa 568, Alexa 633 fluorophores, and Hoechst 33342 to identify cellular DNA content.ResultsGingivitis and periodontitis samples showed higher levels of macrophages compared with healthy samples. Unexpectedly, periodontitis samples displayed lower levels of macrophages dispersed in the stromal tissues compared with gingivitis samples; however, it remained higher than healthy tissues. The polarization of macrophages appears to be reduced in periodontitis and showed similar levels to those observed in healthy tissues.ConclusionsOur study found that gingivitis and periodontitis differ from each other by the levels of macrophage infiltrate, but not by changes in macrophage polarization.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150506/1/jcpe13156_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150506/2/jcpe13156.pd

Entinostat is a novel therapeutic agent to treat oral squamous cell carcinoma

IntroductionAlterations of the epigenome may influence cancer initiation and progression. At the cellular level, histones are key regulators of chromatin accessibility and gene transcription; thus, the inhibition of histone deacetylase enzymes (HDACs) constitutes an attractive target for therapy. In this study, we investigated the effects of the HDAC inhibitor entinostat on oral squamous cell carcinoma (OSCC).Materials and MethodsWe tested the effects of entinostat on OSCC cell lines. Cell viability and growth were analyzed using MTT assay. Cell cycle analysis, cell apoptosis, cancer stem cell (CSC) content, and the concentration of reactive oxygen species (ROS) in OSCC tumor cells were assessed using flow cytometry. The expression of histones and cell cycle regulatory proteins was examined by Western blot.ResultsThe administration of entinostat resulted in reduced proliferation of OSCC cells, followed by cell cycle arrest at the G0/G1 phase, as well as substantial tumor apoptosis. We found an increase in ROS production and significant reductions in CSCs. We also found that entinostat caused increased acetylation histone H3 and histone H4, and changes in the expression of cell cycle‐associated proteins such as p21.ConclusionThis study indicates that entinostat is a potential novel therapeutic agent for OSCC by halting tumor proliferation, inducing cytotoxicity and intracellular ROS, and attacking the CSCs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162762/2/jop13039.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162762/1/jop13039_am.pd

Asparaginase induces selective dose- and time- dependent cytotoxicity, apoptosis, and reduction of NFκB expression in oral cancer cells

Asparaginase is fundamental to the treatment of haematological malignancies. However, little has been studied on the effects that asparaginase could exert on solid tumours. Thus, this study aimed to evaluate the effects of asparaginase on an oral carcinoma cell line. The cytotoxicity of asparaginase in SCC- 9 (tongue squamous cell carcinoma) and HaCaT (human keratinocyte) cell lines was evaluated with MTT cell viability assay. The cells were treated with asparaginase at 0.04, 0.16, 0.63, 1.0, 1.5, 2.5, and 5.0 IU/mL. Dose- response curves and IC50 values were obtained and the Tumour Selectivity Index (TSI) was calculated. The effect of asparaginase on procaspase- 3 and nuclear factor κB (NFκB) expression was evaluated with western blot because it was reported that the overexpression of NFκB has been shown to contribute to tumour cell survival, proliferation, and migration. Caspase 3/7 staining was performed to identify cell death using flow cytometry. Effective asparaginase concentrations were lower for SCC- 9 cells when compared to HaCaT cells. The cytotoxicity results at 48 and 72 hours were significantly different for SCC- 9 cells. The TSI indicated that asparaginase was selective for the tumour cells. A decrease in procaspase- 3 and NFκB protein levels was observed in SCC- 9 cells. Furthermore, asparaginase resulted in significant apoptosis after 48 and 72 hours. Based on these results, asparaginase was cytotoxic in a dose- and time- dependent manner, induces apoptosis, and reduces NFκB expression in oral cancer cells. These results encourage further studies on the effectiveness of this enzyme as a treatment for solid tumours, especially head and neck cancer.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154950/1/cep13256.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154950/2/cep13256_am.pd

Periostin Responds to Mechanical Stress and Tension by Activating the MTOR Signaling Pathway

Current knowledge about Periostin biology has expanded from its recognized functions in embryogenesis and bone metabolism to its roles in tissue repair and remodeling and its clinical implications in cancer. Emerging evidence suggests that Periostin plays a critical role in the mechanism of wound healing; however, the paracrine effect of Periostin in epithelial cell biology is still poorly understood. We found that epithelial cells are capable of producing endogenous Periostin that, unlike mesenchymal cell, cannot be secreted. Epithelial cells responded to Periostin paracrine stimuli by enhancing cellular migration and proliferation and by activating the mTOR signaling pathway. Interestingly, biomechanical stimulation of epithelial cells, which simulates tension forces that occur during initial steps of tissue healing, induced Periostin production and mTOR activation. The molecular association of Periostin and mTOR signaling was further dissected by administering rapamycin, a selective pharmacological inhibitor of mTOR, and by disruption of Raptor and Rictor scaffold proteins implicated in the regulation of mTORC1 and mTORC2 complex assembly. Both strategies resulted in ablation of Periostin-induced mitogenic and migratory activity. These results indicate that Periostin-induced epithelial migration and proliferation requires mTOR signaling. Collectively, our findings identify Periostin as a mechanical stress responsive molecule that is primarily secreted by fibroblasts during wound healing and expressed endogenously in epithelial cells resulting in the control of cellular physiology through a mechanism mediated by the mTOR signaling cascade.This work was funded by the National Institutes of Health (NIH/NCI) P50-CA97248 (University of Michigan Head and Neck SPORE)

Oral health care professionals recommending and administering the HPV vaccine: Understanding the strengths and assessing the barriers.

IntroductionHead and neck cancer is a deadly cancer that ranks among the six most common cancers worldwide. The HPV vaccine has been used to prevent head and neck cancer of the oropharynx, and changes in health policies and state law are impacting the role of dental professionals in HPV vaccination. However, relatively little is known about dental professionals' attitudes regarding the vaccine.ObjectivesOur study assesses dental professionals' willingness to administer the HPV vaccine, their confidence discussing HPV with patients, beliefs about the vaccine's efficacy, perceived barriers to administering it, and sites of referral.MethodsWe surveyed 623 dental professionals, including dentists, hygienists, dental students, and hygiene students across Michigan. Attitudes toward the vaccine and predictive characteristics were evaluated by logistic regression, ANOVAs, and t-tests.ResultsThe majority of the respondents (51% of dentists, 63% of hygienists, 82% of dental students, and 71% of hygiene students) were willing to administer the HPV vaccine if allowed by law. The role of dental and dental hygiene students would be one of advocacy, educating and recommending the vaccine, and the dental students administering it once licensed. Dental professionals were variably confident discussing HPV with patients and generally believed it enhanced patients' health. Stronger confidence and beliefs were associated with greater willingness to administer the vaccine. Barriers among professionals opposing the HPV vaccine included lack of knowledge on the subject, liability concerns, and personal beliefs.ConclusionDental professionals can become leaders in preventing HPV-related cancers. Training and continuing education courses could enhance their confidence and willingness to recommend and administer the HPV vaccine.Policy implicationsLegislation that permits dental professionals to administer the vaccine could increase the vaccine's accessibility to patients, improve vaccination rates, and population health

Histone Modification on Parathyroid Tumors: A Review of Epigenetics

Parathyroid tumors are very prevalent conditions among endocrine tumors, being the second most common behind thyroid tumors. Secondary hyperplasia can occur beyond benign and malignant neoplasia in parathyroid glands. Adenomas are the leading cause of hyperparathyroidism, while carcinomas represent less than 1% of the cases. Tumor suppressor gene mutations such as MEN1 and CDC73 were demonstrated to be involved in tumor development in both familiar and sporadic types; however, the epigenetic features of the parathyroid tumors are still a little-explored subject. We present a review of epigenetic mechanisms related to parathyroid tumors, emphasizing advances in histone modification and its perspective of becoming a promising area in parathyroid tumor research

Accelerated wound healing by mTOR activation in genetically defined mouse models

Background: The management of slow or non-healing ulcerations constitutes an increasing clinical challenge in the developed world because of the ageing of the population and the pandemic rise in type II diabetes. Recent studies suggest that molecular circuitries deployed by tumor cells to promote cancerous growth may also contribute to tissue regeneration. Here, we exploited this emerging information to search for novel molecular targets to accelerate wound healing. Methodology/Principal Findings: We found that the activation of the PI3K-Akt-mTOR pathway, whose aberrant function is a frequent event in human neoplasia, represents an integral component of the normal wound healing process. By the use of genetically defined approaches, including the epithelial-specific ablation of Pten and Tsc1, we show that mTOR activation can dramatically increase epithelial cell proliferation, migration, and cutaneous wound healing, while pharmacological inhibition of mTOR with rapamycin delays wound closure. Conclusions/Significance: Overall, our findings indicate that the transient pharmacologic activation of the PI3K-Akt-mTOR signaling axis may represent a novel clinical intervention strategy to accelerate the healing of debilitating and lifethreatening wounds

Empowering the youth to choose non-traditional careers in research and academia

BackgroudThe United States is facing a dramatic shortage of clinician-scientists within the domains of medicine and dentistry.Point of viewIn this perspective article, we stressed the problem involving the continuous shortage of specialized professionals capable of addressing complex basic sciences questions, while maintaining clinical relevance. Here we present a different perspective regarding the early engagement of young students to clinical sciences by teaming up with high schools across the United States, and to energize the debate on our current shortage of clinician-scientists.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/176329/1/jop13407.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/176329/2/jop13407_am.pd