Localisation of citrullinated and carbamylated proteins in inflamed gingival tissues from rheumatoid arthritis patients.

OBJECTIVES: It has been proposed that citrullination and carbamylation occur in the inflamed periodontium and could be the plausible mechanisms for the generation of antigens involved in the development and progression of RA. The purpose of this study was to determine the presence and location of citrullinated and carbamylated proteins in the gingival tissues and compare their abundance in periodontitis (PD) patients with or without RA. MATERIALS AND METHODS: Gingival tissue samples of healthy (n = 5), PD with RA (n = 5) and PD without RA (n = 5) were collected. Specimens were formalin fixed, paraffin embedded and sectioned at 4 µm. The tissue sections were analysed for the presence of citrullinated and carbamylated proteins by immunohistochemistry. Semi-quantitative analysis was performed to quantify and compare the protein abundance between groups. RESULTS: The number of cells containing citrullinated and carbamylated proteins with higher intensity was markedly increased in gingival tissues from PD with or without RA in comparison with healthy controls. CONCLUSION: Inflamed gingival tissue is a potential source of citrullinated and carbamylated proteins other than synovial tissues. The extent to which the local accumulation of these proteins contributes to the pathogenesis of RA needs further elucidation. CLINICAL RELEVANCE: If PD is a potential source of post-translationally modified proteins, untreated PD should not be taken lightly in the context of RA. Hence, addressing gingival inflammation should be viewed as an important preventive measure in the general population not only for the progression of periodontal disease but also reducing the risk of developing extra-oral comorbidities.

Antibodies against citrullinated proteins in relation to periodontitis with or without rheumatoid arthritis: a cross-sectional study.

BACKGROUND: Previous studies have reported conflicting findings between serum anti-citrullinated protein antibodies (ACPA) levels in rheumatoid arthritis (RA) participants with and without periodontitis (Pd). This study aimed to analyse possible correlations between serum ACPA levels and clinical parameters in Pd and RA participants. METHODS: Full mouth periodontal examination (probing pocket depth, clinical attachment levels, gingival bleeding index, visual plaque index) was conducted and serum samples obtained from 80 participants comprising RA, Pd, both RA and Pd (RAPd) and healthy individuals (HC). Erythrocyte sedimentation rates (ESR) and periodontal inflamed surface area (PISA) were obtained. Serum samples were analysed for ACPA quantification using enzyme-linked immunosorbent assay (ELISA). RESULTS: Median levels (IU/mL) of ACPA (interquartile range, IQR) in RAPd, RA, Pd and HC groups were 118.58(274.51), 102.02(252.89), 78.48(132.6) and 51.67(91.31) respectively. ACPA levels were significantly higher in RAPd and RA as compared to HC group (p < 0.05). However, ACPA levels of any of the groups were not correlated with any clinical periodontal and RA parameters within the respective groups. CONCLUSIONS: At individual level, the amount of serum ACPA seem to have an increasing trend with the diseased condition in the order of RAPd > RA > Pd > HC. However, lack of any significant correlation between the serum ACPA levels with the clinical Pd and RA parameters warrants further studies to investigate the causal link between RA and Pd for such a trend. Further studies involving more inflammatory biomarkers might be useful to establish the causal link between Pd in the development and progression of RA or vice versa.

Impact of non-surgical periodontal therapy on serum Resistin and periodontal pathogen in periodontitis patients with obesity.

BACKGROUND: Non-surgical periodontal therapy (NSPT) known as gold standard treatment in managing periodontitis. The aim of this study was to investigate the response of NSPT in periodontitis subjects who were obese. Clinical parameters of periodontitis, changes in serum resistin and periodontal pathogens in subgingival plaque were compared before and after NSPT in periodontitis subjects who were obese and with normal weight. METHODS: A total of 48 periodontitis subjects (obese, n = 18; normal weight, n = 30) were recruited (hereafter will be referred as participants) to participate into a prospective, before and after clinical trial. Obesity status is defined by body mass index (BMI) criteria (obese: ≥30 kg/ m2; normal weight < 25 kg/m2). Visible Plaque Index (VPI), Gingival Bleeding Index (GBI), Probing Pocket Depth (PPD) and Clinical Attachment Loss (CAL) were recorded; and serum and plaque were collected at baseline and following 12 weeks post-NSPT. Serum resistin level was analyzed using enzyme-linked immune-sorbant assay (ELISA), while detection of periodontal pathogens in dental plaque were carried out using real time PCR (qPCR). RESULTS: Following NSPT, means VPI and GBI showed significant improvement between obese and normal weight groups (p <  0.05), but no difference in means PPD and CAL was observed between groups. Obesity remained as a predictor for VPI and GBI after adjusting for smoking habit. No significant difference was observed in serum resistin level and mean counts for P. gingivalis, T. forsythia, and P. intermedia between obese and normal weight groups following NSPT. CONCLUSIONS: Regardless of obesity status, NSPT has a significant impact on VPI and GBI in periodontitis subjects. However, the impact of NSPT towards serum resistin and periodontal pathogens was non-significant in those with periodontitis. TRIAL REGISTRATION: This study followed the Consolidation Standards of Reporting Trials Statement and retrospectively registered on 26/11/2015 at clinicaltrials.gov (No. NCT02618486).

Carica papaya induces in vitro thrombopoietic cytokines secretion by mesenchymal stem cells and haematopoietic cells.

BACKGROUND: Use of Carica papaya leaf extracts, reported to improve thrombocyte counts in dengue patients, demands further analysis on the underlying mechanism of its thrombopoietic cytokines induction METHODS: In vitro cultures of peripheral blood leukocytes (PBL) and stem cells from human exfoliated deciduous teeth (SHED) were treated with unripe papaya pulp juice (UPJ) to evaluate its potential to induce thrombopoietic cytokines (IL-6 and SCF) RESULTS: In vitro scratch gap closure was significantly faster (p < .05) in SHED culture treated with UPJ. IL-6 concentration was significantly increased (p < .05) in SHED and PBL culture supernatant when treated with UPJ. SCF synthesis in SHED culture was also significantly increased (p < .05) when treated with UPJ CONCLUSION: In vitro upregulated synthesis of IL -6 and SCF both in PBL and SHED reveals the potential mechanism of unripe papaya to induce thrombopoietic cytokines synthesis in cells of hematopoietic and mesenchymal origin.

Inflammatory Responses in Periodontitis with or Without Rheumatoid Arthritis Alter Salivary Metallothionein and Zinc.

Periodontitis (PD) and rheumatoid arthritis (RA) are causally linked by their common inflammatory responses, yet it is largely unknown if these inflammatory responses might have an impact on salivary metallothionein (MT), zinc (Zn), and calcium (Ca) content. In this study, we analysed salivary concentrations of pro-inflammatory (IFN-γ, IL-6, and IL-17) and anti-inflammatory (IL-4 and IL-10) cytokines, as well as MT, Zn, and Ca in four groups of participants, namely control (without PD or RA, n = 21), PD (n = 21), RA (n = 21), or RAPD (n = 19). As expected, an increased amount of salivary pro-inflammatory cytokines were observed in the PD, RA, and RAPD groups. While Ca concentration was not significantly different between the groups, Zn concentration was lower in the PD, RA, and RAPD groups compared to the control group (p < 0.05). These groups also expressed higher MT/Zn ratios compared to the control group (p < 0.05). Unlike the control group, concentrations of inflammatory cytokines, MT, Zn, and Ca correlated with each other in the PD, RA, and RAPD groups (p < 0.05). Additionally, comorbidity of PD and RA appears to have a cumulative immuno-pathological impact that warrants further investigation. This study suggests that, in addition to inflammatory cytokines, salivary MT and Zn could reflect the severity of PD with or without RA, hence providing an important biomarker for diagnosis.

Dysregulation of metallothionein and zinc aggravates periodontal diseases.

BACKGROUND: Periodontitis (PD) is a multifaceted inflammatory disease connected to bacterial infection that results in the destruction of tooth supporting structures and eventually tooth loss. Given their involvement in infection and inflammation, both metallothionein (MT) and zinc (Zn) might play vital roles in the development and progression of PD. More specifically, both MT and Zn are heavily involved in regulating immune functions, controlling bacterial infection, balancing inflammatory responses, and reducing oxidative stress, all of which are associated with the pathogenesis of PD. OBJECTIVE: This review paper will explore the physiological functions of MT and Zn and hypothesise how dysregulation could negatively affect periodontal health, leading to PD. FINDINGS: Bacterial lipopolysaccharide (LPS) derived from periodontal pathogens, namely P. gingivalis initiates the acute phase response, thus upregulating the expression of MT which leads to the subsequent deficiency of Zn, a hallmark of periodontal disease. This deficiency leads to ineffective NETosis, increases the permeability of the gingival epithelium, and disrupts the humoral immune response, collectively contributing to PD. In addition, the presence of LPS in Zn deficient conditions favours M1 macrophage polarisation and maturation of dendritic cells, and also inhibits the anti-inflammatory activity of regulatory T cells. Collectively, these observations could theoretically give rise to the chronic inflammation seen in PD. CONCLUSION: A disrupted MT and Zn homeostasis is expected to exert an adverse impact on periodontal health and contribute to the development and progression of PD.

Zinc and Metallothionein in the Development and Progression of Dental Caries.

Chronic oxidative stress and reactive oxygen species (ROS) in oral cavity as well as acidic pH on dental enamel surface due to the metabolic activities of bacterial plaque are the major contributors in the development and progression of dental caries. Along with other factors, deposition or dissolution Ca and Mg mostly determines the re- or demineralization of dental enamel. Zn plays an important role for both Ca and Mg bioavailability in oral cavity. Metallothionein (MT), a group of small molecular weight, cysteine-rich proteins (~ 7 kDa), is commonly induced by ROS, bacterial infection, and Zn. In the current review, we evaluated MT at the junction between the progression of dental caries and its etiologies that are common in MT biosynthesis.

Dental derived stem cell conditioned media for hair growth stimulation.

Alopecia is a clinical condition caused by excessive hair loss which may result in baldness, the causes of which still remain elusive. Conditioned media (CM) from stem cells shows promise in regenerative medicine. Our aim was to evaluate the potential CM of dental pulp stem cells obtained from human deciduous teeth (SHED-CM) to stimulate hair growth under in vitro and in vivo conditions. SHED and hair follicle stem cells (HFSCs) (n = 3) were cultured in media combinations; i) STK2, ii) DMEM-KO+10% FBS, iii) STK2+2% FBS and profiled for the presence of positive hair growth-regulatory paracrine factors; SDF-1, HGF, VEGF-A, PDGF-BB and negative hair growth-regulatory paracrine factors; IL-1α, IL-1ß, TGF-ß, bFGF, TNF-α, and BDNF. The potential of CM from both cell sources to stimulate hair growth was evaluated based on the paracrine profile and measured dynamics of hair growth under in vitro conditions. The administration of CM media to telogen-staged synchronized 7-week old C3H/HeN female mice was carried out to study the potential of the CM to stimulate hair growth in vivo. SHED and HFSCs cultured in STK2 based media showed a shorter population doubling time, higher viability and better maintenance of MSC characteristics in comparison to cells cultured in DMEM-KO media. STK2 based CM contained only two negative hair growth-regulatory factors; TNF-α, IL-1 while DMEM-KO CM contained all negative hair growth-regulatory factors. The in vitro study confirmed that treatment with STK2 based media CM from passage 3 SHED and HFSCs resulted in a significantly higher number of anagen-staged hair follicles (p<0.05) and a significantly lower number of telogen-staged hair follicles (p<0.05). Administration of SHED-CM to C3H/HeN mice resulted in a significantly faster stimulation of hair growth in comparison to HFSC-CM (p<0.05), while the duration taken for complete hair coverage was similar for both CM sources. Thus, SHED-CM carries the potential to stimulate hair growth which can be used as a treatment tool for alopecia.