Oral manifestations of amyloidosis and the diagnostic applicability of oral tissue biopsy.

BACKGROUND: Amyloidosis exhibits a variable spectrum of systemic signs and oral manifestations that can be difficult to diagnose. This study aimed to characterize the clinical, demographic, and microscopic features of amyloidosis in the oral cavity. METHODS: This collaborative study involved three Brazilian oral pathology centers and described cases with a confirmed diagnosis of amyloidosis on available oral tissue biopsies. Clinical data were obtained from medical records. H&E, Congo-red, and immunohistochemically stained slides were analyzed. RESULTS: Twenty-six oral biopsies from 23 individuals (65.2% males; mean age: 59.6 years) were included. Oral involvement was the first sign of the disease in 67.0% of cases. Two patients had no clinical manifestation in the oral mucosa, although the histological analysis confirmed amyloid deposition. Amyloid deposits were distributed in perivascular (88.0%), periacinar and periductal (80.0%), perineurial (80.0%), endoneurial (33.3%), perimuscular (88.2%), intramuscular (94.1%), and subepithelial (35.3%) sites as well as around fat cells (100.0%). Mild/moderate inflammation was found in 65.4% of cases and 23.1% had giant cells. CONCLUSIONS: Amyloid deposits were consistently found in oral tissues, exhibiting distinct deposition patterns. Oral biopsy is less invasive than internal organ biopsy and enables the reliable identification of amyloid deposits even in the absence of oral manifestations. These findings corroborate the relevance of oral biopsy for the diagnosis of amyloidosis.

Sociodemographic and clinical characterization of cases of 1,103 non-syndromic and 66 syndromic odontogenic keratocyst: a Brazilian multicenter study.

OBJECTIVES: This multicenter study aimed to evaluate cases of non-syndrome and syndromic odontogenic keratocyst, as well as cases of recurrence within these two groups. METHODS: This descriptive, analytical, retrospective cross-sectional study evaluated the sex, age and presence of multiple lesions in 1,169 individuals seen at 10 Brazilian oral and maxillofacial pathology centers. Of these, 1,341 odontogenic keratocysts were analyzed regarding clinical diagnosis, size, site, imaging appearance, signs and symptoms, type of biopsy, treatment, and recurrence. RESULTS: There was a similar distribution by sex. The median age of non-syndromic and syndromic patients was 32 and 17.5 years, respectively. The posterior mandible was the site most affected by small and large lesions in both groups and in recurrent cases. Unilocular lesions were more frequent, also in recurrent cases. Mainly small lesions showed this imaging appearance. Signs and symptoms were absent in most cases. Conservative treatment was the most frequent modality in all age groups, regardless of the patient's condition and recurrence. Recurrences were uncommon. CONCLUSION: This study showed a higher frequency of non-syndromic keratocysts in the population. Clinicopathological features related to the involvement of multiple sites, age, and recurrence may differ between syndromic and non-syndromic cases. Furthermore, we found an association between lesion size and some clinical features and between the time interval to recurrence and the syndromic spectrum. CLINICAL RELEVANCE: To contribute to a better understanding of the distribution and association between clinical, imaging, and sociodemographic characteristics in each spectrum of the lesion.

Interdisciplinary treatment of ankylosed upper central incisors with an anterior vertical ridge defect: A case report.

This case report describes the successful 10-years interdisciplinary treatment of ankylosed upper central incisors with an anterior vertical ridge defect. This treatment was challenging as ankylosis was present before the growth spurt. Orthodontic treatment in association with decoronation, a xenogeneic bone graft, an autogenous sub-epithelial connective tissue graft, and implant placement were performed to correct the vertical ridge defect and to re-establish appropriate function, gingival health, and aesthetics. Decoronation performed during the growth spurt was the key to avoiding alveolar ridge deformity.

Oral and maxillofacial manifestations of IgG4-related disease: A clinicopathological study.

BACKGROUND: IgG4-related disease is a fibroinflammatory and immune-mediated condition, which has extremely variable clinical manifestations. In this study, we aim to investigate the clinicopathological features of IgG4-related disease involving the oral and maxillofacial region. METHODS: Cases of IgG4-related disease manifesting in the oral and maxillofacial region were retrieved from three Brazilian institutions. Clinical and serological data were obtained from the patients' medical charts, while microscopic and immunohistochemical findings were revised by oral pathologists. Diagnosis followed the American College of Rheumatology/European League against Rheumatism criteria. RESULTS: Seven patients diagnosed with IgG4-related disease were included in this study. Women were affected in all analysed cases, with a mean age of 55.4 years. Two patients presented with the clinical involvement of more than one oral and maxillofacial anatomic site. Therefore, our sample comprised nine oral and maxillofacial anatomic sites affected by IgG4-related disease. The submandibular gland was affected in four cases, the tongue and the parotid gland in two cases each, and the palate in one case. In a few cases, exploratory lower lip biopsy was used as a diagnostic approach. A moderate-to-severe lymphoid infiltrate containing plasma cells and lymphocytes, with an increased IgG4/IgG ratio, was common. Treatment varied and steroids were the most frequently used (57.4%). Six patients remained alive, while one died from unknown causes. CONCLUSION: Although major salivary glands are commonly affected by IgG4-related disease, the oral cavity can also be involved, and lower lip biopsy may be an auxiliary diagnostic tool.

Neutrophil extracellular traps mediate joint hyperalgesia induced by immune inflammation.

OBJECTIVE: To evaluate the role of neutrophil extracellular traps (NETs) in the genesis of joint hyperalgesia using an experimental model of arthritis and transpose the findings to clinical investigation. METHODS: C57BL/6 mice were subjected to antigen-induced arthritis (AIA) and treated with Pulmozyme (PLZ) to degrade NETs or Cl-amidine to inhibit NET production. Oedema formation, the histopathological score and mechanical hyperalgesia were evaluated. NETs were injected intra-articularly in wild type (WT), Tlr4-/-, Tlr9-/-, Tnfr1-/- and Il1r-/- mice, and the levels of cytokines and Cox2 expression were quantified. NETs were also quantified from human neutrophils isolated from RA patients and individual controls. RESULTS: AIA mice had increased NET concentration in joints, accompanied by increased Padi4 gene expression in the joint cells. Treatment of AIA mice with a peptidyl arginine deiminase 4 inhibitor or with PLZ inhibited the joint hyperalgesia. Moreover, the injection of NETs into joints of naïve animals generated a dose-dependent reduction of mechanical threshold, an increase of articular oedema, inflammatory cytokine production and cyclooxygenase-2 expression. In mice deficient for Tnfr1, Il1r, Tlr4 and Tlr9, joint hyperalgesia induced by NETs was prevented. Last, we found that neutrophils from RA patients were more likely to release NETs, and the increase in synovial fluid NET concentration correlated with an increase in joint pain. CONCLUSION: The findings indicate that NETs cause hyperalgesia possibly through Toll-like receptor (TLR)-4 and TLR-9. These data support the idea that NETs contribute to articular pain, and this pathway can be an alternative target for the treatment of pain in RA.

Saliva biomonitoring using LPME-GC/MS method to assess dentistry exposure to plasticizers.

Bisphenol A and phthalates are endocrine disruptors widely used as chemical additives mainly in plastic products, including materials for dentistry procedures. Besides, many plasticizers have been associated with important diseases requiring performed methods for their quantification. In the present study, an alternative method for the determination of bisphenol A (BPA) and phthalate metabolites in saliva was developed and validated using hollow fiber liquid phase microextraction (HF-LPME) for sample preparation and gas chromatography coupled to ion trap mass spectrometry (GC/MS) for analysis. A mixture of octanol and ethyl octanoate (1:1 v/v) was used as an acceptor phase in hollow fiber to extract the analytes from saliva samples. A Doehlert design was performed to optimize the variable sample agitation and extraction time. The HF-LPME-GC/MS method developed for saliva analysis showed good selectivity, linearity (R2 > 0.900), and precision (CV = 0.86-18.68%). Limits of detection and quantification ranged from 0.03 to 0.53 µg L-1 and 0.09 to 1.78 µg L-1, respectively. A high concentration of BPA in the oral cavity and oropharyngeal space is a warning of the possible association with the main cancer of the mouth. The method developed and validated was applied to patients with oral squamous cell carcinoma (study group, n = 16) and patients who did not present any oral lesion (control group, n = 16). A principal component analysis was performed and showed a tendency for the association between oral squamous cell carcinoma (OSCC) and plasticizers. Graphical abstract.

Role of atypical chemokine receptor ACKR2 in experimental oral squamous cell carcinogenesis.

BACKGROUND: Chemokines and chemokine receptors are critical in oral tumourigenesis. The atypical chemokine receptor ACKR2 is a scavenger of CC chemokines controlling the availability of these molecules at tumour sites, but the role of ACKR2 in the context of oral carcinogenesis is unexplored. METHODS: In this study, wild-type (WT) and ACKR2 deficient mice (ACKR2-/-) were treated with chemical carcinogen 4-nitroquinoline-1-oxide (4NQO) for induction of oral carcinogenesis. Tongues were collected for macro and microscopic analysis and to evaluate the expression of ACKRs, CC chemokines and its receptors, inflammatory cytokines, angiogenic factors, adhesion molecules and extracellular matrix components. RESULTS: An increased expression of ACKR2 in squamous cell carcinoma (SCC) lesions of 4NQO-treated WT mice was observed. No significant differences were seen in the ACKR1, ACKR3 and ACKR4 mRNA expression comparing SCC lesions from WT and ACKR2-/- treated mice. Significantly higher expression of CCL2, IL-6 and IL-17 was detected in ACKR2-/- treated mice. In contrast, the expression of other CC-chemokines, and receptors, angiogenic factors, adhesion molecules and extracellular matrix components were similarly increased in SCC lesions of both groups. Clinical and histopathological analysis revealed no differences in inflammatory cell recruitment and in the SCC incidence comparing WT and ACKR2-/- treated mice. CONCLUSION: The results suggest that ACKR2 expression regulates inflammation in tumour-microenvironment but the absence of ACKR2 does not impact chemically-induced oral carcinogenesis.

Calcifying epithelial odontogenic tumours: Collaborative study of 32 cases and review of literature.

OBJECTIVES: To analyse the occurrence of calcifying epithelial odontogenic tumours (CEOT) based on biopsy records from different Brazilian geographic regions and to contrast the data with a review of the literature. MATERIALS AND METHODS: A 2-step study was conducted. Step 1 consisted of a collaborative study of biopsies obtained from 1953 to 2017 at six Brazilian oral and maxillofacial pathology centres. Evaluation of 86,268 biopsy records was performed. Demographic and histopathological diagnosis data were assessed. In Step 2, a review of the literature of case reports and cases series of CEOT identified across five electronic databases was conducted. RESULTS: In the collaborative study, 32 cases of CEOT were evaluated. This figure represented 0.03% of the oral and maxillofacial lesions and 1.7% of all odontogenic tumours across the centres. Women in the fourth decade of life were more affected. CEOT occurred more in the mandible than in the maxilla (ratio 1.9:1). The review of the literature showed that Asian individuals were more affected by this neoplasm. CONCLUSIONS: Useful knowledge on the epidemiology, treatment and follow-up of CEOT has been provided. Demographic data and clinical features of the cases presented in this collaborative study were quite similar to those of studies reported worldwide.

Association of oral mucosa hyperpigmentation with imatinib mesylate use: a cross-sectional study and a systematic literature review.

OBJECTIVES: To assess the association between oral mucosa hyperpigmentation in patients with leukemia and imatinib mesylate use. Additionally, we compared our data to those obtained from a systematic review. MATERIALS AND METHODS: A cross-sectional study was conducted with 74 patients undergoing treatment with imatinib mesylate. Sociodemographic characteristics, oral mucosa alterations, and medical history were evaluated. Oral hyperpigmentation was scored. The use of imatinib mesylate and hydroxyurea was evaluated. Association between oral hyperpigmentation and imatinib mesylate was assessed. A systematic review was also conducted to retrieve case reports or case series of patients with oral hyperpigmentation associated with imatinib mesylate. RESULTS: Among the 74 participants, 41 were male (55.4%) and 33 were female (44.6%). Participants' mean age was 49.3 years. Sixty-six (89.2%) patients developed hyperpigmented lesions in the hard palate mucosa. In multivariate analysis, patients who had used imatinib mesylate for > 72 months had a hyperpigmentation score 1.62 times higher than those who had used this medication during a shorter period. Patients who had used hydroxyurea for > 30 days had a hyperpigmentation score 1.43 times higher than those who had used this medication during a shorter period. The systematic review retrieved 20 clinical cases of patients undergoing imatinib mesylate treatment and exhibiting oral hyperpigmentation. CONCLUSIONS: The development of oral hyperpigmentation is associated with imatinib mesylate use. Hydroxyurea seems to increment such an association. CLINICAL RELEVANCE: To assist providers in the differential diagnosis of hyperpigmented lesions associated with imatinib mesylate, as well as in the clinical management of such lesions.

Odontogenic myxoma: A 63-year retrospective multicenter study of 85 cases in a Brazil population and a review of 999 cases from literature.

BACKGROUND: Odontogenic myxoma (OM) is an uncommon neoplasm of the jaws. Considering the importance of defining the relative incidence and demographic profile of these lesions in South America, the aim of this study was to analyze the clinical and imagiological features of OM from three South American oral pathology services and to discuss these findings in light of the literature. METHODS: Data regarding age, gender, anatomic site, and imagiological features from 85 cases of OM were collected. Additionally, we did a review of OM studies published in three electronic databases. RESULTS: Among 63 450 oral biopsies, 1178 (1.85%) were odontogenic tumors (World Health Organization - 2017), of which 85 (7.21%) met the criteria of OM. The mean age was 30.7 years (range: 10-61 years; SD: 12.22). Forty-five (52.9%) cases occurred in females and 40 (47.1%) in males (ratio: 1:1.12). Maxilla was affected in 44 cases (53%) and mandible in 39 (47%). Of the 41 informed cases (48.2%), all of them were radiolucent lesions. The literature review indicated a majority of mean ages in third decade and a predilection for females, mandible, and multilocular radiolucent lesions. CONCLUSIONS: The features of OM samples have strong similarity to that reported in studies from other continents. It is possible to infer that geographic variation does not help to explain some differences observed in the clinical features of OM.

Arthritis-induced alveolar bone loss is associated with changes in the composition of oral microbiota.

Rheumatoid arthritis (RA) and periodontitis (PD) are chronic inflammatory disorders that cause bone loss. PD tends to be more prevalent and severe in RA patients. Previous experimental studies demonstrated that RA triggers alveolar bone loss similarly to PD. The aim of this study was to investigate if arthritis-induced alveolar bone loss is associated with modification in the oral microbiota. Checkerboard DNA-DNA hybridization was employed to analyze forty oral bacterial species in 3 groups of C57BL/6 mice: control (n = 12; without any challenge); Y4 (n = 8; received oral inoculation of Aggregatibacter Actinomycetemcomitans strain FDC Y4) and AIA group (n = 12; chronic antigen-induced arthritis). The results showed that AIA and Y4 group exhibited similar patterns of bone loss. The AIA group exhibited higher counts of most bacterial species analyzed with predominance of Gram-negative species similarly to infection-induced PD. Prevotella nigrescens and Treponema denticola were detected only in the Y4 group whereas Campylobacter showae, Streptococcus mitis and Streptococcus oralis were only found in the AIA group. Counts of Parvimonas micra, Selenomonas Noxia and Veillonella parvula were greater in the AIA group whereas Actinomyces viscosus and Neisseira mucosa were in large proportion in Y4 group. In conclusion, AIA is associated with changes in the composition of the oral microbiota, which might account for the alveolar bone loss observed in AIA mice.

Cytokine measurements in gingival crevicular fluid and periodontal ligament: Are they correlated?

INTRODUCTION: Mechanical stress can induce molecular changes in gingival crevicular fluid (GCF) and the periodontal ligament (PDL). It is still not clear whether changes in the PDL and GCF are linked. In this study, we aimed to analyze the expression of cytokines in GCF and PDL after mechanical stress. METHODS: Twenty-three healthy patients were included. The experimental group consisted of premolars subjected to a force of 0.980 N for 1, 3, 7, 14, 21, or 28 days. The contralateral teeth were the controls. GCF and PDL samples were collected at the same time points for analysis of cytokines using the cytometric bead array. RESULTS: Interleukin (IL)-6 (IL-6) production was significantly elevated in the PDL on day 1 after force application. Significantly strong positive correlations between GCF and PDL in experimental group were seen on days 3 (interferon-gamma), 7 (IL-10), 14 (IL-17A), and 28 (IL-17A, tumor necrosis factor-alpha), and significantly strong negative correlation were seen on days 14 (interferon-gamma) and 21 (IL-2, IL-10). CONCLUSIONS: Different patterns of IL-6 expression were seen in the PDL and GCF after mechanical stress. Despite occasional correlations between GCF and PDL, the molecular contributions of the PDL to the GCF changes could not be clearly defined by our model.

The relation between FoxP3⁺ regulatory T cells and fungal density in oral paracoccidioidomycosis: a preliminary study.

Regulatory T (Treg) cells may play an important role in the pathogenesis of paracoccidioidomycosis (PCM), but data on the role of Treg cells in the context of oral PCM are still scarce. The objectives of this study were to investigate the density of FoxP3(+) T regulatory cells in oral PCM and to correlate the results with the density of Paracoccidioides brasiliensis in the lesions. Cases of chronic oral PCM seen between 2000 and 2008 were included in this study. The diagnosis of all lesions was confirmed with histopathological examination and Grocott-Gomori staining. The quantitative analysis of the viable fungi was conducted in all cases with Grocott-stained slides. Treg cells were identified using antibodies against FoxP3. Pearson correlation coefficient was used to test the correlation between the density of fungi and Treg cells. Results were considered significant when P < 0.05. A total of 11 cases of oral PCM were obtained. There was a positive correlation between fungal density and FoxP3(+) Treg cells density in oral lesions, however, without statistical significance. A positive relation between Treg cells and fungal density was seen in oral PCM. Further studies are required to further elucidate the role of these cells in the pathogenesis of oral PCM, as well the clinical significance of these findings.

Brain-derived neurotrophic factor in chronic periodontitis.

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophic factor family. Outside the nervous system, BDNF has been shown to be expressed in various nonneural tissues, such as periodontal ligament, dental pulp, and odontoblasts. Although a role for BDNF in periodontal regeneration has been suggested, a function for BDNF in periodontal disease has not yet been studied. The aim of this study was to analyze the BDNF levels in periodontal tissues of patients with chronic periodontitis (CP) and periodontally healthy controls (HC). All subjects were genotyped for the rs4923463 and rs6265 BDNF polymorphisms. Periodontal tissues were collected for ELISA, myeloperoxidase (MPO), and microscopic analysis from 28 CP patients and 29 HC subjects. BDNF levels were increased in CP patients compared to HC subjects. A negative correlation was observed when analyzing concentration of BDNF and IL-10 in inflamed periodontium. No differences in frequencies of BDNF genotypes between CP and HC subjects were observed. However, BDNF genotype GG was associated with increased levels of BDNF, TNF-α, and CXCL10 in CP patients. In conclusion, BDNF seems to be associated with periodontal disease process, but the specific role of BDNF still needs to be clarified.

Peripheral blood mono-nuclear cells derived from Alzheimer's disease patients show elevated baseline levels of secreted cytokines but resist stimulation with ß-amyloid peptide.

OBJECTIVES: Among several other factors, the neuro-toxic ß-amyloid peptide (ßAP)-induced inflammatory mechanisms have also been implicated in the pathogenesis of Alzheimer's dementia (AD). Cytokines have recently emerged as prime candidates underlying this immune reaction. The purpose of this study was to evaluate the inflammatory response of peripheral blood mono-nuclear cells (PBMC) in AD. DESIGN: Cross-sectional (observational) study. SETTING: Behavioral and cognitive neurology clinic of the Universidade Federal de Minas Gerais in Belo Horizonte, Brazil. PARTICIPANTS: AD patients (n=19), healthy elderly (n=19) and young (n=14) individuals. MEASUREMENTS: Cytokine levels were assessed by enzyme-linked immuno-sorbent assay (ELISA) after exposing cells to a broad range of ßAP concentrations (10(-4)-10(-10)M) as a stimulus. AD samples were weighed against leukocytes harvested from non-demented young and elderly subjects. RESULTS: Cytokine production of PBMCs in the youth was characterized by low baseline levels when compared to cells from the older generation. In the aging population, AD cells were distinguished from the healthy elderly sub-group by an even higher basal cytokine secretion. The low resting concentration in young individuals was markedly increased after treatment with ßAP, however cells from the elderly, irrespective of their disease status, showed unchanged cytokine release following ßAP administration. Non-specific activation of PBMCs with anti-CD3/CD28 antibodies resulted in elevated interleukin (IL)-1ß concentrations in AD. CONCLUSIONS: These results demonstrate a general over-production of cytokines and resistance to ßAP in the old comparison group, with a more pronounced disruption/boosted pattern in AD. Our findings are in line with the hypothesis of "inflammaging", i.e. an enhanced inflammatory profile with normal aging and a further perturbed environment in AD. The observed cytokine profiles may serve as diagnostic biomarkers in dementia.

Comparative study of the synovial levels of RANKL and OPG in rheumatoid arthritis, spondyloarthritis and osteoarthritis.

INTRODUCTION: In chronic arthropathies, there are several mechanisms of joint destruction. In recent years, studies have reported the implication of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) in the process of activation and differentiation of osteoclasts, a key cell in the development of bone erosion. The RANKL/OPG ratio is increased in the serum of patients with malignant diseases and lytic bone disease, as well as rheumatoid arthritis (RA). The objective of this study was to measure and compare the concentrations of OPG and RANKL in the synovial fluid (SF) of patients with rheumatoid arthritis, spondyloarthritis (SpA) and osteoarthritis (OA). METHODS: This was an observational and cross-sectional study with 83 patients, 33 with RA, 32 with SpA and 18 with OA, followed up regularly in the outpatient clinics of the Rheumatology Department of the Clinics Hospital of the Ribeirão Preto Medical School-USP. All patients were assessed for indications for arthrocentesis by the attending physicians at the time of SF collection and were evaluated for demographic variables and medication use. Disease activity was assessed in individuals with RA and SpA. The quantification of SF OPG and RANKL levels was performed by ELISA, and the correlations of the results with clinical, laboratory and radiological parameters were assessed. RESULTS: We found no statistically significant difference in the RANKL and OPG levels among the groups. Patients with RA showed a positive correlation between the SF cell count and RANKL level (r = 0.59; p < 0.05) and the RANKL/OPG ratio (r = 0.55; p < 0.05). Patients with OA showed a strong correlation between C-reactive protein (CRP) and the RANKL/OPG ratio (r = 0.82; p < 0.05). There was no correlation between the OPG and RANKL levels and markers of inflammatory activity or the disease activity index in patients with RA or SpA. CONCLUSION: Within this patient cohort, the RANKL/OPG ratio was correlated with the SF cell count in patients with RA and with serum CRP in patients with OA, which may suggest a relationship with active inflammation and more destructive joint disease.

Neutrophil Extracellular Traps Aggravate Apical Periodontitis by Stimulating Osteoclast Formation.

INTRODUCTION: Neutrophil extracellular traps (NETs) have been described as structures composed of DNA and proteins, such as elastase and myeloperoxidase, that are able to kill bacteria extracellularly. The aim of the present study was to evaluate the role of NETs in bone resorption observed in pulp infection-induced apical periodontitis in mice. METHODS: Apical periodontitis was experimentally induced by exposing the dental pulp of the mandibular first molar of mice to the oral microenvironment. The expression of NETs was evaluated by immunofluorescence in mice and biopsies of apical periodontitis. Mice were treated with vehicle or DNase I to degrade NETs, and the samples were collected after 7 days. The size of the apical lesion and the osteoclast number were determined in hematoxylin-eosin- and tartrate-resistant acid phosphatase-stained sections, respectively. Osteoclast differentiation and function markers were evaluated by quantitative polymerase chain reaction. The level of NETs in the serum was determined by the myeloperoxidase-DNA PicoGreen assay. RESULTS: We first confirmed the presence of neutrophils and NETs at the site of the lesion in mice and in biopsies of patients with apical periodontitis. The treatment of mice with DNase I reduced the level of NETs in the serum and led to a reduction in apical lesion size and alveolar bone resorption. This effect was associated with a reduction of local inflammatory infiltrate and a reduced number of osteoclasts. We found that the increased expression of Acp5, Ctsk, and Rankl genes associated with osteoclast formation and function were abrogated by the absence of NETs. CONCLUSIONS: Our data highlight NETs as an important player in the pathogenesis of apical periodontitis with regard to the local inflammation and consequent bone resorption after pulp infection.

Bone strength is reduced in a neonatal androgenized rat model.

Background: Whether polycystic ovary syndrome (PCOS) affects bone health during a woman's lifespan remains controversial. An androgenized rodent model replicated many metabolic and reproductive features of women with PCOS, and we aimed to use it to investigate the impact of androgens on microarchitecture (by micro-CT), bone mechanical strength, bone formation and resorption markers in rats with intact ovaries (SHAM) who underwent oophorectomy. Methods: Wistar rats (Rattus norvegicus albinus) were employed for the experiments in this study. The protocol of androgenization consisted of the application of 1.25 mg s.c. testosterone propionate beteween days 2-5 of life, while the controls received the same amount of corn oil s.c. as previously established. Androgenized SHAM rats exhibited chronic anovulation identified by vaginal cytology and a reduction in the proportion of corpus luteum in the ovary in comparison to control SHAM rats. The realization of the ovariectomy or SHAM procedure occurred on Day 100 of life. All groups (n = 8) were followed-up for 180 days to address the study endpoints. Results: Micro-CT from androgenized female rats (SHAM) showed a divergence between the trabecular and cortical bone profiles. Compared to SHAM controls, these rats had an increase in trabecular bone mass with a diminution in bone resorption C-terminal telopeptide of type 1 collagen (CTX) (p < 0.05), a concomitant decrease in cortical area and thickness in the femur, and a reduction in the strength of the femur on the mechanical test (p < 0.01). Conclusions: Our results suggest that a reduction in the cortical thickness and cortical area observed in PCOS model rats was associated with a reduced strength of the femur, despite increased trabecular formation. Ovariectomy in the androgenized OVX group limited the progression rate of cortical bone loss, resulting in bone resistance and cortical thickness comparable to those observed in the control OVX group.

Anti-inflammatory effects of the activation of the angiotensin-(1-7) receptor, MAS, in experimental models of arthritis.

Activation of the renin-angiotensin (Ang) system induces inflammation via interaction between Ang II and type 1 receptor on leukocytes. The relevance of the new arm of the renin-Ang system, namely Ang-converting enzyme-2/Ang-(1-7)/Mas receptor, for inflammatory responses is not known and was investigated in this study. For this purpose, two experimental models were used: Ag-induced arthritis (AIA) in mice and adjuvant-induced arthritis (AdIA) in rats. Male C57BL/6 wild-type or Mas(-/-) mice were subjected to AIA and treated with Ang-(1-7), the Mas agonist AVE 0991, or vehicle. AdIA was performed in female rats that were given AVE 0991 or vehicle. In wild-type mice, Mas protein is expressed in arthritic joints. Administration of AVE 0991 or Ang-(1-7) decreased AIA-induced neutrophil accumulation, hypernociception, and production of TNF-α, IL-1ß, and CXCL1. Histopathological analysis showed significant reduction of inflammation. Mechanistically, AVE 0991 reduced leukocyte rolling and adhesion, even when given after Ag challenge. Mas(-/-) mice subjected to AIA developed slightly more pronounced inflammation, as observed by greater neutrophil accumulation and cytokine release. Administration of AVE 0991 was without effect in Mas(-/-) mice subjected to AIA. In rats, administration of AVE 0991 decreased edema, neutrophil accumulation, histopathological score, and production of IL-1ß and CXCL1 induced by AdIA. Therefore, activation of Mas receptors decreases neutrophil influx and cytokine production and causes significant amelioration of arthritis in experimental models of arthritis in rats and mice. This approach might represent a novel therapeutic opportunity for arthritis.