Neuronal-immune axis alters pain and sensory afferent damage during dental pulp injury.

ABSTRACT: Dental pulp tissue is densely innervated by afferent fibers of the trigeminal ganglion. When bacteria cause dental decay near the pulpal tissue, a strong neuronal and immune response occurs, creating pulpitis, which is associated with severe pain and pulp tissue damage. Neuroimmune interactions have the potential to modulate both the pain and pathological outcome of pulpitis. We first investigated the role of the neuropeptide calcitonin gene-related peptide (CGRP), released from peptidergic sensory afferents, in dental pain and immune responses by using Calca knockout (Calca -/- ) and wild-type (Calca +/+ ) mice, in a model of pulpitis by creating a mechanical exposure of the dental pulp horn. We found that the neuropeptide CGRP, facilitated the recruitment of myeloid cells into the pulp while also increasing spontaneous pain-like behavior 20% to 25% at an early time point. Moreover, when we depleted neutrophils and monocytes, we found that there was 20% to 30% more sensory afferent loss and increased presence of bacteria in deeper parts of the tissue, whereas there was a significant reduction in mechanical pain response scores compared with the control group at a later time point. Overall, we showed that there is a crosstalk between peptidergic neurons and neutrophils in the pulp, modulating the pain and inflammatory outcomes of the disease.

Characterization of initial/early histologic features of proliferative leukoplakia and correlation with malignant transformation: a multicenter study.

The aim of this multicenter retrospective study is to characterize the histopathologic features of initial/early biopsies of proliferative leukoplakia (PL; also known as proliferative verrucous leukoplakia), and to analyze the correlation between histopathologic features and malignant transformation (MT). Patients with a clinical diagnosis of PL who have at least one biopsy and one follow-up visit were included in this study. Initial/early biopsy specimens were reviewed. The biopsies were evaluated for the presence of squamous cell carcinoma (SCCa), oral epithelial dysplasia (OED), and atypical verrucous hyperplasia (AVH). Cases that lacked unequivocal features of dysplasia were termed "hyperkeratosis/parakeratosis not reactive (HkNR)". Pearson chi-square test and Wilcoxon test were used for statistical analysis. There were 86 early/initial biopsies from 59 patients; 74.6% were females. Most of the cases had a smooth/homogenous (34.8%) or fissured appearance (32.6%), and only 13.0% had a verrucous appearance. The most common biopsy site was the gingiva/alveolar mucosa (40.8%) and buccal mucosa (25.0%). The most common histologic diagnosis was OED (53.5%) followed by HkNR (31.4%). Of note, two-thirds of HkNR cases showed only hyperkeratosis and epithelial atrophy. A lymphocytic band was seen in 34.8% of OED cases and 29.6% of HkNR cases, mostly associated with epithelial atrophy. Twenty-eight patients (47.5%) developed carcinoma and 28.9% of early/initial biopsy sites underwent MT. The mortality rate was 11.9%. Our findings show that one-third of cases of PL do not show OED with most exhibiting hyperkeratosis and epithelial atrophy, but MT nevertheless occurred at such sites in 3.7% of cases.

Insulin-like growth factor binding protein 2 null mice (Igfbp2-/-) are protected against trabecular bone loss after vertical sleeve gastrectomy.

BACKGROUND: Bariatric surgery has been shown to result in weight loss, improved hemoglobin A1C, and decreased mortality but can also lead to bone loss and increased fracture rates. Serum IGFBP-2 is elevated in patients after bariatric surgery and although it may lead to improved blood glucose, may also drive bone resorption, and inhibit IGF-I action. This study tested the hypothesis that Igfbp2-/- mice were acutely protected from bone loss after vertical sleeve gastrectomy (VSG). METHODS: Thirty-four mice, 17 Igfbp2-/- and 17 + / + underwent a hand-sewn VSG or sham surgery, at 16 weeks of age. Mice were harvested at 20 weeks of age. DXA was measured for body composition, areal bone mineral density (aBMD), areal bone mineral content (aBMC), femoral bone mineral density (fBMD), and femoral bone mineral content (fBMC) at 15, 18, and 20 weeks of age. Micro-computed tomography and serum ELISA assays were measured and analyzed at 20 weeks of age. RESULTS: Both Igfbp2-/- and + / + mice lost significant weight (P = 0.0251, P = 0.0003, respectively) and total fat mass (P = 0.0082, P = 0.0004, respectively) at 4 weeks after VSG. Igfbp2+/+ mice lost significant aBMD, fBMD, fBMC, trabecular BMD, trabecular BV/TV and cortical tissue mineral density (P = 0.0150, P = 0.0313, P = 0.0190, P = 0.0072, and 0.0320 respectively). The Igfbp2-/- mice did not show significant bone loss in these parameters nor in trabecular BV/TV. Both Igfbp2-/- and + / + mice had less cortical bone area (P = 0.0181, P = < .00001), cortical area over total area (P = 0.0085, P = 0.0007), and cortical thickness (P = 0.0050, P = < 0.0001), respectively. Igfbp2+/+ mice demonstrated significantly lower polar, minimum, and maximum moments of inertia (P = 0.0031, P = 0.0239, and P = 0.0037, respectively). Igfbp2+/+ had significantly higher levels of IGFBP-2 at 2 weeks postoperatively after VSG (P = 0.035), and elevated levels of CTx and P1NP (P = 0.0127, P = 0.0058, respectively). CONCLUSIONS: Igfbp2-/- mice were protected against trabecular bone loss and had attenuated cortical bone loss 4 weeks after VSG.

Gingival Leukoplakia: Hyperkeratosis with Epithelial Atrophy Is A Frequent Histopathologic Finding.

White lesions on the gingiva and palatal mucosa may represent reactive keratoses, including specific diseases such as benign alveolar ridge keratosis, or nonreactive keratoses, such as true leukoplakia, the latter being associated with a high recurrence rate at this site. The aim of this study is to determine the histopathologic features of gingival keratoses. Hyperkeratotic lesions from the gingiva, palatal mucosa, and alveolar ridge mucosa were available for evaluation after excluding specific keratotic lesions such as candidiasis. There were 321 biopsies from 296 patients and approximately half of the cases (159/321, 49.5%) were reactive keratoses. The rest of the 162 biopsies from 149 patients (76 females; 51.0%) represented true leukoaplakias. The most common location was the gingiva (73.2%) followed by the palatal mucosa (17.0%). Hyperkeratosis/parakeratosis not reactive (HkNR) represented 43.8% of cases; 45.7% were dysplasia or carcinoma, and the rest were not readily classifiable as reactive or non-reactive keratoses. Histopathologic features commonly noted in the HkNR lesions include sharp demarcation (72.7%), corrugated surface (53.5%), and epithelial atrophy (48.1%). A lymphocytic band was noted in 8.5% of the cases, mostly associated with epithelial atrophy (5/6 cases). Seven patients with 17 biopsies from noncontiguous sites likely had proliferative leukoplakia; the most common location was the gingiva (88.2%) and the most common diagnosis was HkNR (52.9%). HkNR is a common histopathologic diagnosis for leukoplakias on the gingiva, and these lesions frequently exhibit thick hyperkeratosis, epithelial atrophy and a lymphocytic band at the interface.

Oral hairy leukoplakia: a series of 45 cases in immunocompetent patients.

OBJECTIVE: Oral hairy leukoplakia (OHL) is a benign Epstein-Barr virus infection typically presenting as a white lesion on the lateral border of the tongue. Historically, OHL was described in patients who are severely immunocompromised, such as those with HIV/AIDS and organ transplant patients. OHL is increasingly seen in patients who are not severely immunocompromised. This study reviews 45 cases of OHL in a single institution and characterizes the clinical features of these relatively immunocompetent patients. STUDY DESIGN: Retrospective study. RESULTS: There were 45 cases with 23 male patients (51.1%) and a median age of 64 (range, 24-100 years). The lateral/ventral tongue was the affected site in 41 cases (91.1%), and 5 cases presented bilaterally. A review of the medical history and medications showed the most common conditions were hypertension (53.3%), hyperlipidemia (42.2%), and chronic respiratory conditions (33.3%); 8 patients (17.8%) had diabetes mellitus, and 1 had rheumatoid arthritis. Eleven cases (24.4%) reported no underlying medical conditions or history of medications. The most frequently reported medications included antihypertensive drugs (21.0%), steroid inhalers (14.6%), and cholesterol-lowering drugs (11.0%). CONCLUSIONS: OHL is not exclusively seen in profoundly immunocompromised patients. Localized immunosuppression (from steroid inhalers) and immunosenescence (aging) are possible contributing factors.

Inhibition of longevity regulator PAPP-A modulates tissue homeostasis via restraint of mesenchymal stromal cells.

Pregnancy-associated plasma protein-A (PAPP-A) is a secreted metalloprotease that increases insulin-like growth factor (IGF) availability by cleaving IGF-binding proteins. Reduced IGF signaling extends longevity in multiple species, and consistent with this, PAPP-A deletion extends lifespan and healthspan; however, the mechanism remains unclear. To clarify PAPP-A's role, we developed a PAPP-A neutralizing antibody and treated adult mice with it. Transcriptomic profiling across tissues showed that anti-PAPP-A reduced IGF signaling and extracellular matrix (ECM) gene expression system wide. The greatest reduction in IGF signaling occurred in the bone marrow, where we found reduced bone, marrow adiposity, and myelopoiesis. These diverse effects led us to search for unifying mechanisms. We identified mesenchymal stromal cells (MSCs) as the source of PAPP-A in bone marrow and primary responders to PAPP-A inhibition. Mice treated with anti-PAPP-A had reduced IGF signaling in MSCs and dramatically decreased MSC number. As MSCs are (1) a major source of ECM and the progenitors of ECM-producing fibroblasts, (2) the originating source of adult bone, (3) regulators of marrow adiposity, and (4) an essential component of the hematopoietic niche, our data suggest that PAPP-A modulates bone marrow homeostasis by potentiating the number and activity of MSCs. We found that MSC-like cells are the major source of PAPP-A in other tissues also, suggesting that reduced MSC-like cell activity drives the system-wide reduction in ECM gene expression due to PAPP-A inhibition. Dysregulated ECM production is associated with aging and drives age-related diseases, and thus, this may be a mechanism by which PAPP-A deficiency enhances longevity.

Calcifying synovial sarcoma of the tongue with SS18 rearrangement: a rare variant in a rare location.

Synovial sarcoma is a soft tissue malignancy harboring t(X;18) resulting in fusion of two genes SS8 (at 18q11) and SSX (1, 2 or 4 at Xp11) forming the gene fusion product SS18-SSX. It affects adults in their 3rd-4th decades, most frequently in the para-articular regions of the extremities. Less than 10% of the cases occur within the head and neck region and of these, 60% occur in the neck and only 10% occur in the oral cavity. We report a synovial sarcoma of the tongue in a 14-year-old female patient with unusual histology. The patient presented with a mass occupying most of the tongue with extension into the floor of mouth and the lingual gingiva of the anterior mandibular teeth. The tumor was composed of a highly cellular proliferation of spindle cells in a herringbone pattern with many small vessels but without glandular structures, and with extensive calcifications throughout the tumor. Tumor cells were positive for epithelial membrane antigen and transducin-like enhancer of split-1, and fluorescence in situ hybridization studies identified SS18 gene rearrangement. The patient was managed with two debulking procedures followed by chemoradiation and is currently alive with disease.

The role of Zfp467 in mediating the pro-osteogenic and anti-adipogenic effects on bone and bone marrow niche.

Conditional deletion of the PTH receptor (Pth1r) in mesenchymal progenitors reduces osteoblast differentiation and bone mass while enhancing adipogenesis and bone marrow adipose tissue. Mechanistically, PTH suppresses the expression of Zfp467, a pro-adipogenic zinc finger transcription factor. Consequently, Pth1r deficiency in mesenchymal progenitors leads to increased Zfp467 expression. Based on these observations, we hypothesized that genetic loss of Zfp467 would lead to a shift in marrow progenitor cell fate towards osteogenesis and increased bone mass. To test this hypothesis, we generated Zfp467-/- mice. Zfp467-/- mice (-/-) were significantly smaller than Zfp467+/+ mice (+/+). µCT showed significantly higher trabecular bone and cortical bone area in -/- vs. +/+, and histomorphometry showed higher structural and dynamic formation parameters in -/- mice vs. +/+. Femoral gene expression including Alpl, Sp7, and Acp5 were increased in -/-mice, whereas Adiponectin, Cebpa, Lepr, and Ppraγ mRNA were lower in -/- mice. Similarly, Fabp4 and Lep in the inguinal depot were also decreased in -/- mice. Moreover, marrow adipocyte numbers were reduced in -/- vs +/+ mice (p<0.007). In vitro, COBs and BMSCs-/- showed more positive ALP and Alizarin Red staining and a decrease in ORO droplets. Pth1r mRNA and protein levels were increased in COBs and BMSCs from -/- mice vs +/+ (p<0.02 for each parameter, -/- vs. +/+). -/- cells also exhibited enhanced endogenous levels of cAMP vs. control cells. Moreover, in an ovariectomy (OVX) mouse model, Zfp467-/- mice had significantly lower fat mass but similar bone mass compared to OVX +/+ mice. In contrast, in a high fat diet (HFD) mouse model, in addition to reduced adipocyte volume and adipogenesis related gene expression in both peripheral and bone marrow fat tissue, greater osteoblast number and higher osteogenesis related gene expression were also observed in -/- HFD mice vs. +/+ HFD mice. Taken together, these results demonstrate that ZFP467 negatively influences skeletal homeostasis and favors adipogenesis. Global deletion of Zfp467 increases PTHR1, cAMP and bone turnover, hence its repression is a component of PTH signaling and its regulation. These data support a critical role for Zfp467 in early lineage allocation and provide a novel potential mechanism by which PTH acts in an anabolic manner on the bone remodeling unit.

Comparative analysis of prevalence of apical periodontitis in smokers and non-smokers using cone-beam computed tomography.

OBJECTIVE: The aim of this study was to compare the prevalence and size of periapical lesions among smokers and non-smokers using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Retrievable CBCT datasets for 46 male patients ≥18 years during a consecutive period from 2008 to 2016 were examined. The medical, smoking history and other clinical findings (signs of previous dental trauma; Decayed Missing Filled Teeth (DMFT) scores; the percentage of root filled teeth; and oral hygiene status) were obtained. Periapical status of all included teeth was assessed by CBCT images. Statistical analysis was conducted using t-test, Pearson correlation and multiple regression. RESULTS: The prevalence of apical periodontitis was 13.93% in smokers and 14.26% in non-smokers with no significant difference (p = 0.936). The mean of the average size of lesions between the two groups were almost comparable, 3.50 mm in smokers and 2.89 mm in non-smokers (p = 0.567). Pearson correlation and multiple regression analysis showed that the percentage of lesion present and the average lesion size were not correlated to any independent variable. CONCLUSIONS: While smoking is considered a risk factor for marginal periodontitis, there was no difference between smokers and non-smokers in terms of apical periodontitis.

Oral Kaposi Sarcoma in HIV-seronegative Saudi patient: Literature review and case report.

Kaposi Sarcoma (KS) is an intermediate neoplasm affecting the endothelial cells of mucous membranes and skin. It arises most commonly among HIV-infected individuals. We present an intra-oral KS in an 80-year-old Saudi male patient, who is HIV-seronegative, non-immunosuppressed, and with no history of organ transplantation. The patient was treated with fractionated radiation therapy, and had no recurrence in the 48 months of follow-up. The clinical disease, histologic features, and treatment modality used, as well as the relative literature are presented in this paper.