Genome-wide transcriptome induced by Porphyromonas gingivalis LPS supports the notion of host-derived periodontal destruction and its association with systemic diseases

Prediction of Interactomic HUB Genes in Periodontitis With Acute Myocardial Infarction

BACKGROUND

Acute myocardial infarction (AMI) risk correlates with C-reactive protein (CRP) levels, suggesting systemic inflammation is present well before AMI. Studying different types of periodontal disease (PD), extremely common in individuals at risk for AMI, has been one important research topic. According to recent research, AMI and PD interact via the systemic production of certain proinflammatory and anti-inflammatory cytokines, small signal molecules, and enzymes that control the onset and development of both disorders' chronic inflammatory reactions. This study uses machine learning to identify the interactome hub biomarker genes in acute myocardial infarction and periodontitis.

METHODS

GSE208194 and GSE222883 were chosen for our research after a thorough search using keywords related to the study's goal from the gene expression omnibus (GEO) datasets. DEGs were identified from the GEOR tool, and the hub gene was identified using Cytoscape-cytohubba. Using expression values, Random Forest, Adaptive Boosting, and Naive Bayes, widgets-generated transcriptomics data, were labelled, and divided into 80/20 training and testing data with cross-validation. ROC curve, confusion matrix, and AUC were determined. In addition, Functional Enrichment Analysis of Differentially Expressed Gene analysis was performed.

RESULTS

Random Forest, AdaBoost, and Naive Bayes models with 99%, 100%, and 75% AUC, respectively. Compared to RF, AdaBoost, and NB classification models, AdaBoost had the highest AUC. Categorization algorithms may be better predictors than important biomarkers.

CONCLUSIONS

Machine learning model predicts hub and non-hub genes from genomic datasets with periodontitis and acute myocardial infarction.

Contribution of -Omics Technologies in the Study of Porphyromonas gingivalis during Periodontitis Pathogenesis: A Minireview

Periodontitis is a non-communicable chronic inflammatory disease characterized by the progressive and irreversible breakdown of the soft periodontal tissues and resorption of teeth-supporting alveolar bone. The etiology of periodontitis involves dysbiotic shifts in the diversity of microbial communities inhabiting the subgingival crevice, which is dominated by anaerobic Gram-negative bacteria, including Porphyromonas gingivalis. Indeed, P. gingivalis is a keystone pathogen with a repertoire of attributes that allow it to colonize periodontal tissues and influence the metabolism, growth rate, and virulence of other periodontal bacteria. The pathogenic potential of P. gingivalis has been traditionally analyzed using classical biochemical and molecular approaches. However, the arrival of new techniques, such as whole-genome sequencing, metagenomics, metatranscriptomics, proteomics, and metabolomics, allowed the generation of high-throughput data, offering a suitable option for bacterial analysis, allowing a deeper understanding of the pathogenic properties of P. gingivalis and its interaction with the host. In the present review, we revise the use of the different -omics technologies and techniques used to analyze bacteria and discuss their potential in studying the pathogenic potential of P. gingivalis.

Examining the role of nickel and NiTi nanoparticles promoting inflammation and angiogenesis

Nickel titanium (NiTi, or Nitinol) alloy is used in several biomedical applications, including cardiac, peripheral vascular, and fallopian tube stents. There are significant biocompatibility issues of metallic implants to nickel ions and nano-/micro-sized alloy particles. Our laboratories have recently shown that microscale CoCr wear particles from metal-on-metal hips crosslink with the innate immune signaling Toll-like receptor 4 (TLR4), prompting downstream signaling that results in interleukin (IL)-1β and IL-8 gene expression. In vivo, NiTi alloy can also generate wear particles on the nanoscale (NP) that have thus far not been studied for their potential to induce inflammation and angiogenesis that can, in turn, contribute to implant (e.g. stent) failure. Earlier studies by others demonstrated that nickel could induce contact hypersensitivity by crosslinking the human, but not the mouse, TLR4. In the present work, it is demonstrated that NiCl₂ ions and NiTi nanoparticles induce pro-inflammatory and pro-angiogenic cytokine/chemokine expression in human endothelial and monocyte cell lines in vitro. These observations prompt concerns about potential mechanisms for stent failure. The data here showed a direct correlation between intracellular uptake of Ni²⁺ and generation of reactive oxygen species. To determine a role for nickel and NiTi nanoparticles in inducing angiogenesis in vivo, 1-cm silicone angioreactors were implanted subcutaneously into athymic (T-cell-deficient) nude mice. The angioreactors contained Matrigel (a gelatinous protein mixture that resembles extracellular matrix) in addition to one of the following: PBS (negative control), VEGF/FGF-2 (positive control), NiCl_2, or NiTi NP. The implantation of angioreactors represents a potential tool for quantification of angiogenic potentials of medical device-derived particles and ions in vivo. By this approach, NiTi NP were found to be markedly angiogenic, while Ni²⁺ was less-so. The angioreactors may provide a powerful tool to examine if debris shed from medical devices may promote untoward biological effects.

Periodontitis is associated to increased systemic inflammation in postmyocardial infarction patients

Objective

Periodontitis has been independently associated to cardiovascular disease. However, the biological mechanisms underlying such association are still partially unknown. Thus, this study aimed to discover immunological clues accounting for the increased risk of myocardial infarction (MI) in patients having periodontitis.

Methods

We included 100 patients with a first MI, 50 with and 50 without severe periodontitis, and 100 age-matched, sex-matched and area-matched controls from the Periodontitis and Its Relation to Coronary Artery Disease Study. Participants underwent comprehensive clinical and laboratory examinations 6–10 weeks after the MI and plasma expression of 92 inflammation-related markers was assessed through proximity extension assay.

Results

Patients who had an MI displayed altered expression of CCL19, TNFRSF9 and LAP TGF-β1 in comparison with controls. TNFRSF9 correlated significantly with the amount of alveolar bone loss. MI patients with deep periodontal pockets showed increased white cell count and higher expression of FGF-21, HGF, OSM, CCL20 and IL-18R1 than patients without. White cell count correlated significantly with four of these proteins.

Conclusions

Collectively, our results indicate molecular markers that could be responsible for the increased systemic inflammatory activity in patients with MI with periodontitis.

Crosstalk between RNA-Binding Proteins and Immune Microenvironment Revealed Two RBP Regulatory Patterns with Distinct Immunophenotypes in Periodontitis

Periodontitis is an inflammatory disease whose pathogenesis is closely related with immunology. RNA-binding proteins (RBPs) were found to play crucial roles in immunity. Therefore, we aimed to investigate the potential impact of RBPs in the immune microenvironment in periodontitis. The differential expressions of RBPs in periodontitis and healthy samples were determined and were used to construct an RBP-based classifier for periodontitis using logistic regression. The correlations between RBPs and immune characteristics were investigated by the Spearman correlation. Unsupervised clustering was conducted to identify the RBP regulatory patterns. RBP-related genes were identified by WGCNA, while biological distinctions were revealed by GSVA and GO. 24 dysregulated RBPs were identified, from which a 12-RBP classifier was established to distinguish periodontitis with AUC of 0.942. Close protein-protein interactions and expression correlations were observed especially between SPATS2 and ISG20. ISG20 and ESRP1 were found to be highly correlated with immunocyte infiltration, immune signaling activation, and HLA expressions in periodontitis. Two distinct RBP regulatory patterns were identified with different immune and other biological characteristics in periodontitis. Our findings indicate a significant impact of RBPs in shaping the immune microenvironment in periodontitis, which might bring new insights into the understanding of immune mechanisms in the pathogenesis of periodontitis.

High expression of ISG20 predicts a poor prognosis in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is one of the most malignant hematopoietic system diseases. Interferon stimulated exonuclease gene 20 (ISG20) is a protein induced by interferons or double-stranded RNA, which is associated with poor prognosis in several malignant tumors. However its expression in AML is unknown.

OBJECTIVE

To explore the expression of ISG20 in AML and its prognostic significance.

METHODS

The expression of ISG20 in AML patients was analyzed by GEPIA database, detected by qRT-PCR and their prognosis was followed-up. Chi-square test was used to identify the association between ISG20 expression and clinical characteristics of the patients. Kaplan-Meier analysis was performed to draw survival curves and Cox regression analysis to confirm the independent prognostic factors of AML patients.

RESULTS

Kaplan-Meier analysis revealed that whether to receive treatment, karyotype, and ISG20 expression were related to overall survival time of AML patients (P< 0.05). Cox regression analysis showed that whether to receive treatment (HR = 0.248, 95% CI = 0.076-0.808, P= 0.021) and high expression of ISG20 (HR = 4.266, 95% CI = 1.118-16.285, P= 0.034) were independent unfavorable prognostic factors for AML patients.

CONCLUSION

The high expression of ISG20 acts as a poor prognosis indicator in AML patients.

The MIR155 host gene/microRNA-627/HMGB1/NF-κB loop modulates fibroblast proliferation and extracellular matrix deposition

Pulmonary fibrosis (PF), which is characterized by excessive matrix formation, may ultimately lead to irreversible lung damage and thus death. Fibroblast activation has been regarded as a central event during PF pathogenesis. In our previous study, we confirmed that the miR-627/high-mobility group box protein 1 (HMGB1)/Nuclear factor kappa beta (NF-κB) axis modulates transforming growth factor beta 1 (TGFβ1)-induced pulmonary fibrosis. In the present study, we investigated the upstream factors leading to miR-627 dysregulation in the process of pulmonary fibroblast activation and PF. The lncRNA MIR155 host gene (MIR155HG) was found to be abnormally upregulated in pulmonary fibrosis tissues and TGFβ1-stimulated normal human primary lung fibroblasts (NHLFs). By directly binding to miR-627, MIR155HG inhibited miR-627 expression. MIR155HG overexpression enhanced TGFβ1-induced increases in HMGB1 protein expression and p65 phosphorylation, NHLF proliferation, and extracellular matrix (ECM) deposition. In contrast, miR-627 overexpression attenuated the TGFβ1-induced changes in NHLFs and significantly reversed the effects of MIR155HG overexpression. Under TGFβ1 stimulation, miR-627 inhibition promoted, whereas JSH-23 treatment inhibited NF-κB activation; in NHLFs, NF-κB overexpression upregulated, whereas JSH-23 treatment downregulated MIR155HG expression. In tissue samples, HMGB1 protein levels and p65 phosphorylation were increased; MIR155HG was negatively correlated with miR-627 and positively correlated with HMGB1. In conclusion, we validated that the MIR155HG/miR-627/HMGB1/NF-κB axis formed a regulatory loop that modulates TGFβ1-induced NHLF activation. Considering the critical role of NHLF activation in PF pathogenesis, the NF-κB/MIR155HG/miR-627/HMGB1 regulatory loop could exert a vital effect on PF pathogenesis. Further in vivo and clinical investigations are required to confirm this model.

Effects of 1,25-dihydroxyvitamin D3 on experimental periodontitis and AhR/NF-κB/NLRP3 inflammasome pathway in a mouse model

Vitamin D has been known to have important regulatory functions in inflammation and immune response and shows inhibitory effects on experimental periodontitis in animal models. However, the potential mechanism has yet to be clarified. Recent studies have highlighted Aryl hydrocarbon receptor (AhR) and its downstream signaling as a crucial regulator of immune homeostasis and inflammatory regulation.

OBJECTIVE

This study aimed to clarify the effect of 1,25-dihydroxyvitamin D3 (VD3) on experimental periodontitis and AhR/nuclear factor-κB (NF-κB)/NLR pyrin domain-containing 3 (NLRP3) inflammasome pathway in the gingival epithelium in a murine model.

METHODOLOGY

We induced periodontitis in male C57BL/6 wild-type mice by oral inoculation of Porphyromonas gingivalis (P. gingivalis), and subsequently gave intraperitoneal VD3 injection to the mice every other day for 8 weeks. Afterwards, we examined the alveolar bone using scanning electron microscopy (SEM) and detected the gingival epithelial protein using western blot analysis and immunohistochemical staining.

RESULTS

SEM images demonstrated that alveolar bone loss was reduced in the periodontitis mouse model after VD3 supplementation. Western blot analyses and immunohistochemical staining of the gingival epithelium showed that the expression of vitamin D receptor, AhR and its downstream cytochrome P450 1A1 were enhanced upon VD3 application. Additionally, VD3 decreased NF-κB p65 phosphorylation, and NLRP3, apoptosis-associated speck-like protein, caspase-1, interleukin-1β (IL-1β) and IL-6 protein expression.

CONCLUSIONS

These results implicate the alleviation of periodontitis and the alteration of AhR/NF-κB/NLRP3 inflammasome pathway by VD3 in the mouse model. The attenuation of this periodontal disease may correlate with the regulation of AhR/NF-κB/NLRP3 inflammasome pathway by VD3.

Transcriptome-wide analysis of filarial extract-primed human monocytes reveal changes in LPS-induced PTX3 expression levels

Filarial nematodes modulate immune responses in their host to enable their survival and mediate protective effects against autoimmunity and allergies. In this study, we examined the immunomodulatory capacity of extracts from the human pathogenic filaria Brugia malayi (BmA) on human monocyte responses in a transcriptome-wide manner to identify associated pathways and diseases. As previous transcriptome studies often observed quiescent responses of innate cells to filariae, the potential of BmA to alter LPS driven responses was investigated by analyzing >47.000 transcripts of monocytes from healthy male volunteers stimulated with BmA, Escherichia coli LPS or a sequential stimulation of both. In comparison to ~2200 differentially expressed genes in LPS-only stimulated monocytes, only a limited number of differentially expressed genes were identified upon BmA priming before LPS re-stimulation with only PTX3↓ reaching statistical significance after correcting for multiple testing. Nominal significant differences were reached for metallothioneins↑, MMP9↑, CXCL5/ENA-78↑, CXCL6/GCP-2↑, TNFRSF21↓, and CCL20/MIP3α↓ and were confirmed by qPCR or ELISA. Flow cytometric analysis of activation markers revealed a reduced LPS-induced expression of HLA-DR and CD86 on BmA-primed monocytes as well as a reduced apoptosis of BmA-stimulated monocytes. While our experimental design does not allow a stringent extrapolation of our results to the development of filarial pathology, several genes that were identified in BmA-primed monocytes had previously been associated with filarial pathology, supporting the need for further research.

ISG20 promotes local tumor immunity and contributes to poor survival in human glioma

Recent evidence has confirmed that a mutation of the isocitrate dehydrogenase (IDH) gene occurs early in gliomagenesis and contributes to suppressed immunity. The present study aimed to determine the candidate genes associated with IDH mutation status that could serve as biomarkers of immune suppression for improved prognosis prediction. Clinical information and RNA-seq gene expression data were collected for 932 glioma samples from the CGGA and TCGA databases, and differentially expressed genes in both lower-grade glioma (LGG) and glioblastoma (GBM) samples were identified according to IDH mutation status. Only one gene, interferon-stimulated exonuclease gene 20 (ISG20), with reduced expression in IDH mutant tumors, demonstrated significant prognostic value. ISG20 expression level significantly increased with increasing tumor grade, and its high expression was associated with a poor clinical outcome. Moreover, increased ISG20 expression was associated with increased infiltration of monocyte-derived macrophages and neutrophils, and suppressed adaptive immune response. ISG20 expression was also positively correlated with PD-1, PD-L1, and CTLA4 expression, along with the levels of several chemokines. We conclude that ISG20 is a useful biomarker to identify IDH-mediated immune processes in glioma and may serve as a potential therapeutic target.

Strontium ion attenuates lipopolysaccharide-stimulated proinflammatory cytokine expression and lipopolysaccharide-inhibited early osteogenic differentiation of human periodontal ligament cells

BACKGROUND AND OBJECTIVE

Periodontitis is a chronic inflammatory disease characterized by the destruction of the periodontium. The strontium ion (Sr²⁺ ) can prevent the bone loss associated with periodontitis and promote the regeneration of the bone. The mechanisms by which the Sr²⁺ works remain poorly understood. We aim to investigate the effects of the Sr²⁺ ion on cell proliferation, inflammatory regulation and osteogenic differentiation of human periodontal ligament cells (hPDLCs) in pathological conditions.

MATERIAL AND METHODS

hPDLCs were obtained from premolars that came from the orthodontic extraction. The hPDLCs were treated with Sr²⁺ and/or lipopolysaccharide (LPS), which was applied as the pathological condition of periodontitis. The effect of the dose of Sr²⁺ on cell proliferation was analyzed using a Cell Counting Kit-8 assay. The gene and protein expression of proinflammatory cytokines were detected by the real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The osteogenic differentiation and mineralization were assessed by the real-time polymerase chain reaction, alkaline phosphatase activity assay and alizarin red staining.

RESULTS

Results demonstrated that Sr²⁺ in a range of concentrations from 0.02 to 2.5 mmol/L significantly improved the proliferation of hPDLCs. Sr²⁺ reversed LPS-stimulated proinflammatory cytokine expressions such as tumor necrosis factor alpha, interleukin (IL)-1β, IL-6 and IL-8. Moreover, Sr²⁺ rescued the LPS-inhibited gene expression of osteogenic differentiation. Although it appeared to suppress the late mineralization, Sr²⁺ can reverse the LPS-inhibited early osteogenic differentiation of hPDLCs.

CONCLUSION

These results indicated that Sr²⁺ could attenuate the LPS-stimulated proinflammatory molecule expression and inhibit early osteogenic differentiation of hPDLCs.

Periodontitis prevalence in adults ≥ 65 years of age, in the USA

The older adult population is growing rapidly in the USA and it is expected that by 2040 the number of adults ≥ 65 years of age will have increased by about 50%. With the growth of this subpopulation, oral health status, and periodontal status in particular, becomes important in the quest to maintain an adequate quality of life. Poor oral health can have a major impact, leading to tooth loss, pain and discomfort, and may prevent older adults from chewing food properly, often leading to poor nutrition. Periodontitis is monitored in the USA at the national level as part of the Healthy People 2020 initiative. In this report, we provide estimates of the overall burden of periodontitis among adults ≥ 65 years of age and after stratification according to sociodemographic factors, modifiable risk factors (such as smoking status), the presence of other systemic conditions (such as diabetes) and access to dental care. We also estimated the burden of periodontitis within this age group at the state and local levels. Data from the National Health and Nutrition Examination Survey 2009/2010 and 2011/2012 cycles were analyzed. Periodontal measures from both survey cycles were based on a full-mouth periodontal examination. Nineteen per cent of adults in this subpopulation were edentulous. The mean age was 73 years, 7% were current smokers, 8% lived below the 100% Federal Poverty Level and < 40% had seen a dentist in the past year. Almost two-thirds (62.3%) had one or more sites with ≥ 5 mm of clinical attachment loss and almost half had at least one site with probing pocket depth of ≥ 4 mm. We estimated the lowest prevalence of periodontitis in Utah (62.3%) and New Hampshire (62.6%) and the highest in New Mexico, Hawaii, and the District of Columbia each with a prevalence of higher than 70%. Overall, periodontitis is highly prevalent in this subpopulation, with two-thirds of dentate older adults affected at any geographic level. These findings provide an opportunity to determine how the overall health-care management of older adults should consider the improvement of their oral health conditions. Many older adults do not have dental insurance and are also likely to have some chronic conditions, which can adversely affect their oral health.

Primary Asthenic Gout by Augustin-Jacob Landre-Beauvais in 1800: Is this the first description of Rheumatoid Arthritis?

Although Alfred Baring Garrod was the physician who introduced the term Rheumatoid Arthritis, it was the French medical student Augustin-Jacob Landre-Beauvais who firstly described the newly appeared type of arthritis. In his opinion, “Goutte Asthénique Primitive”, as he named it, affected mostly the poor, with bigger prevalence among women, presenting characteristic capsular swelling, limitation of motion of the joints in the hands and fingers, and development of bony ankylosis with disorganisation of many joints. Landre-Beauvais was known for his empathy towards his patients, an acquired feeling due to his internship under Pinel. His greatest treatise “Séméiotique, ou Traité des signes des maladies” was greatly influenced in its structure by the concept of Corpus Hippocraticum.

Genome-wide transcriptome induced by nickel in human monocytes

Nickel-containing alloys are frequently used in the biomedical field, although, owing to corrosive processes metal ion leaching is inevitable. Due to nickel ion (Ni(2+)) leaching several adverse effects are described in the literature. However, only a few studies evaluated the genetic profile of Ni(2+) in human cells which is of great importance since nickel-induced effects differ between humans and mice as a result of species-specific receptor variability. Thus, we investigated gene expression induced by Ni(2+)in human monocytes using a transcriptome-wide approach determining new target genes implicated in nickel-induced pathologies. Monocytes were isolated from healthy volunteers of Central European origin using stringent inclusion criteria. Cells were challenged with different Ni(2+) concentrations. Array-based gene expression analysis was performed comprising more than 47,000 transcripts followed by pathway analyses. Transcriptional data were validated by protein and cell surface markers. Ni(2+) significantly influenced the expression of 1385 transcripts in a dose-dependent manner. Apart from known targets (CCL20↑, PTGS2↑, MTs↑, SLCs↑), we identified new candidates implicated in Ni(2+)-elicited processes (various microRNAs↑, INSIG1↑, NAMPT↑, MS4A6A↓, DHRS9↓). Several of these transcripts correspond to immunity, inflammation and were shown to be involved in cellular reactions related to hypersensitivity, cancer, colitis, and encephalitis. Moreover, 459 canonical pathways/signaling, 500 pathologies and 2687 upstream regulators were detected. Protein results validated our findings. To our knowledge, the present systematic transcriptome-wide expression study is the first which explored Ni(2+)-elicited cell responses in human primary monocytes identifying new target genes, pathways and upstream regulators of relevance to diagnostic and therapeutic strategies.

STATEMENT OF SIGNIFICANCE

Nickel is widely applied in the biomedical field, although several adverse effects are documented in the literature due to nickel ion (Ni(2+)) leaching. In humans, allergic reactions like contact dermatitis are the most common adverse effect to Ni(2+), whereas serious concerns relate to possible systemic and carcinogenic activities. Using a systematic genome-wide transcriptional approach in human primary monocytes unveil new target genes, pathways and upstream regulators implicated in nickel-elicited immune response which are of significance to diagnostic and therapeutic strategies. This approach provides new information of how host-derived immune response contributes to the interaction with antigens and supports the interplay between metal ions and systemic diseases.