Humoral immune response to heat shock protein 60 of Aggregatibacter actinomycetemcomitans and cross-reactivity with malondialdehyde acetaldehyde-modified LDL

Association between periodontal disease and coronary heart disease: A bibliometric analysis

Background

Periodontal disease and coronary heart disease are both prevalent diseases worldwide and cause patients physical and mental suffering and a global burden. Recent studies have suggested a link between periodontal disease and coronary heart disease, but there is less research in this field from the perspective of bibliometrics.

Objective

This study aimed to quantitatively analyze the literature on periodontal disease and coronary heart disease to summarize intellectual bases, research hotspots, and emerging trends and pave the way for future research.

Methods

The Science Citation Index Expanded database was used to retrieve study records on periodontal disease and coronary heart disease from 1993 to 2022. After manual screening, the data were used for cooperative network analysis (including countries/regions, institutions and authors), keyword analysis, and reference co-citation analysis by CiteSpace software. Microsoft Excel 2019 was applied for curve fitting of annual trend in publications and citations.

Results

A total of 580 studies were included in the analysis. The number of publications and citations in this field has shown an upward trend over the past 30 years. There was less direct collaboration among authors and institutions in this field but closer collaboration between countries. The United States was the country with the most published articles in this field (169/580, 29.14%). Based on the results of keyword analysis and literature co-citation analysis, C-reactive protein, oral flora, atherosclerosis, infection, and inflammation were previous research hotspots, while global burden and cardiovascular outcomes were considered emerging trends in this field.

Conclusion

Studies on periodontal disease and coronary heart disease, which have attracted the attention of an increasing number of researchers, have been successfully analyzed using bibliometrics and visualization techniques. This paper will help scholars better understand the dynamic evolution of periodontal disease and coronary heart disease and point out the direction for future research.

Clinical significance

This paper presents an overview between periodontal disease and coronary heart disease. Further exploration of the two diseases themselves and the potential causal relationship between the two is necessary and relevant, which may impact basic research, diagnosis, and treatment related to both diseases. This will aid the work of researchers and specialist doctors, and ultimately benefit patients with both diseases.

Mining Autoimmune-Disorder-Linked Molecular-Mimicry Candidates in Clostridioides difficile and Prospects of Mimic-Based Vaccine Design: An In Silico Approach

Molecular mimicry, a phenomenon in which microbial or environmental antigens resemble host antigens, has been proposed as a potential trigger for autoimmune responses. In this study, we employed a bioinformatics approach to investigate the role of molecular mimicry in Clostridioides difficile-caused infections and the induction of autoimmune disorders due to this phenomenon. Comparing proteomes of host and pathogen, we identified 23 proteins that exhibited significant sequence homology and were linked to autoimmune disorders. The disorders included rheumatoid arthritis, psoriasis, Alzheimer's disease, etc., while infections included viral and bacterial infections like HIV, HCV, and tuberculosis. The structure of the homologous proteins was superposed, and RMSD was calculated to find the maximum deviation, while accounting for rigid and flexible regions. Two sequence mimics (antigenic, non-allergenic, and immunogenic) of ≥10 amino acids from these proteins were used to design a vaccine construct to explore the possibility of eliciting an immune response. Docking analysis of the top vaccine construct C2 showed favorable interactions with HLA and TLR-4 receptor, indicating potential efficacy. The B-cell and T-helper cell activity was also simulated, showing promising results for effective immunization against C. difficile infections. This study highlights the potential of C. difficile to trigger autoimmunity through molecular mimicry and vaccine design based on sequence mimics that trigger a defensive response.

Atheroprotective Aspects of Heat Shock Proteins

Atherosclerosis is a major global health problem. Being a harbinger of a large number of cardiovascular diseases, it ultimately leads to morbidity and mortality. At the same time, effective measures for the prevention and treatment of atherosclerosis have not been developed, to date. All available therapeutic options have a number of limitations. To understand the mechanisms behind the triggering and development of atherosclerosis, a deeper understanding of molecular interactions is needed. Heat shock proteins are important for the normal functioning of cells, actively helping cells adapt to gradual changes in the environment and survive in deadly conditions. Moreover, multiple HSP families play various roles in the progression of cardiovascular disorders. Some heat shock proteins have been shown to have antiatherosclerotic effects, while the role of others remains unclear. In this review, we considered certain aspects of the antiatherosclerotic activity of a number of heat shock proteins.

Total fecal IgA levels increase and natural IgM antibodies decrease after gastric bypass surgery

Obesity is associated with low-grade inflammation and increased systemic oxidative stress. Roux-en-Y gastric bypass (RYGB) surgery is known to ameliorate the obesity-induced metabolic dysfunctions. We aimed to study the levels of natural antibodies in feces, before and 6 months after RYGB surgery in obese individuals with and without type 2 diabetes (T2D). Sixteen individuals with T2D and 14 non-diabetic (ND) individuals were operated. Total IgA, IgG and IgM antibody levels and specific antibodies to oxidized low-density lipoprotein (oxLDL), malondialdehyde-acetaldehyde adducts (MAA adducts), Porphyromonas gingivalis gingipain A hemagglutinin domain (Rgp44) and phosphocholine (PCho) were measured using chemiluminescence immunoassay. Total fecal IgA was elevated, while total IgM and IgG were not affected by the surgery. Fecal natural IgM specific to oxLDL decreased significantly in both T2D and ND individuals, while fecal IgM to Rgp44 and PCho decreased significantly in T2D individuals. A decrease in IgG to MAA-LDL, Rgp44 and PCho was detected. RYGB surgery increases the levels of total fecal IgA and decreases fecal natural IgG and IgM antibodies specific to oxLDL. Natural antibodies and IgA are important in maintaining the normal gut homeostasis and first-line defense against microbes, and their production is markedly altered with RYGB surgery.

Anti-inflammatory and Immunomodulatory Therapies in Atherosclerosis

Hypercholesterolemia is a major risk factor in atherosclerosis development and lipid-lowering drugs (i.e., statins) remain the treatment of choice. Despite effective reduction of LDL cholesterol in patients, a residual cardiovascular risk persists in some individuals, highlighting the need for further therapeutic intervention. Recently, the CANTOS trial paved the way toward the development of specific therapies targeting inflammation, a key feature in atherosclerosis progression. The pre-existence of multiple drugs modulating both innate and adaptive immune responses has significantly accelerated the number of translational studies applying these drugs to atherosclerosis. Additional preclinical research has led to the discovery of new therapeutic targets, offering promising perspectives for the treatment and prevention of atherosclerosis. Currently, both drugs with selective targeting and broad unspecific anti-inflammatory effects have been tested. In this chapter, we aim to give an overview of current advances in immunomodulatory treatment approaches for atherosclerotic cardiovascular diseases.

Salivary IgA antibody to malondialdehyde-acetaldehyde associates with mild periodontal pocket depth

OBJECTIVE

Oxidized epitopes such as malondialdehyde-acetaldehyde (MAA) play a crucial role in the progression of atherosclerosis through activation of the humoral immune response. The exact mechanism of the association between atherosclerosis and periodontal diseases is not fully understood. The aim of the current study is to evaluate the association of oral humoral immune response to oxidized epitopes with parameters of periodontal disease.

MATERIALS AND METHODS

The Parogene cohort consist of patients who have undergone coronary angiography due to cardiac symptoms. In this study, 423 patients were randomly selected for an extensive oral examination. Salivary Immunoglobulin A to oxidized epitopes and bacterial antigens was determined by chemiluminescence immunoassay.

RESULTS

In a binary logistic regression model adjusted with periodontal disease confounders, periodontal pocket depth (PPD) 4-5 mm associated with salivary IgA antibodies to MAA-LDL (p = 0.034), heat shock protein 60 of Aggregatibacter actinomycetemcomitans (p = 0.045), Porphyromonas gingivalis (p = 0.045), A. actinomycetemcomitans (p = 0.005), P. intermedia (p = 0.020), and total IgA (p = 0.003).

CONCLUSIONS

The current study shows the association of salivary IgA to MAA-LDL with PPD 4-5 mm in a cohort of patients with chronic coronary artery disease. Humoral immune cross-reactivation to oxidized epitopes such MAA-LDL could partly explain the link of periodontitis with systemic diseases.

Circulating antibodies against leukotoxin A as marker of periodontitis grades B and C and oral infection with Aggregatibacter actinomycetemcomitans

BACKGROUND

The facultative bacterium Aggregatibacter actinomycetemcomitans (Aa) is strongly associated with periodontitis and is occasionally found in periodontally healthy subjects. We aimed to determine the prevalence of salivary Aa among patients with either periodontitis grade B (periodontitis-B) or grade C (periodontitis-C), periodontally healthy controls (HCs), and to determine if systemic antibodies against Aa or its virulence factor leukotoxin A (LtxA) may serve as biomarkers that reveal the oral presence of the bacterium and discriminate subjects with periodontitis-C, periodontitis-B, or no periodontitis from each other.

METHODS

Serum and unstimulated saliva samples were collected from patients with periodontitis-C (n = 27), patients with periodontitis-B (n = 34), and HCs (n = 28). Serum level of immunoglobulin G antibodies to fragmented whole Aa and to LtxA were quantified using a bead-based assay. Aa was identified in saliva using quantitative polymerase chain reaction (qPCR). All analyses were adjusted for age, sex, and current smoking status.

RESULTS

Aa was present in saliva from 11% of HCs, in 32% of patients with periodontitis-B (P = 0.04 versus HCs), and in 37% of patients with periodontitis-C (P = 0.02 versus HCs). Serum antibodies to fragments of Aa associated significantly with periodontitis-C (P = 0.03), while serum anti-LtxA antibodies associated with both periodontitis-B and periodontitis-C (P = 0.002 and P = 9×10^-4 , respectively). Moreover, a significant association between serum anti-LtxA antibodies and Aa count in saliva was observed (P = 0.001). On the basis of serum anti-LtxA antibody levels, patients with periodontitis could be discriminated from HCs (AUC = 0.74 in ROC curve-analysis, P = 0.0003), and carriers of Aa could be discriminated from non-carriers (AUC = 0.78, P <0.0001).

CONCLUSIONS

Aa is highly prevalent in saliva of patients with periodontitis-B or periodontitis-C. Systemic immunoglobulin G antibodies against LtxA distinguish patients with periodontitis, regardless of grade, from HCs, while their quantity reflects the concurrent bacterial burden in the oral cavity.