Periodontal infections and atherosclerosis: mere associations?

Porphyromonas gingivalis Lipopolysaccharides Promote Proliferation and Migration of Human Vascular Smooth Muscle Cells through the MAPK/TLR4 Pathway

Atherosclerosis is a major cause of mortality worldwide. The initial change in atherosclerosis is intimal thickening due to muscle cell proliferation and migration. A correlation has been observed between periodontal disease and atherosclerosis. Here, we investigated the proliferation and migration of human aortic smooth muscle cells (HASMCs) using Porphyromonas gingivalis-derived LPS (Pg-LPS). To elucidate intracellular signaling, toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) of HASMCs were knocked down, and the role of these molecules in Pg-LPS-stimulated proliferation and migration was examined. The role of mitogen-activated protein kinase (MAPK) in HASMC proliferation and migration was further elucidated by MAPK inhibition. Pg-LPS stimulation increased the proliferation and migration of HASMCs and activated the TLR4/MyD88 pathway. TLR4 knockdown inhibited Pg-LPS stimulated HASMCs proliferation and migration. Pg-LPS stimulation led to the phosphorylation of P38 MAPK, JNK, and ERK, and MyD88 knockdown inhibited the phosphorylation of P38 MAPK and JNK but not ERK. P38 MAPK and SAPK/JNK inhibition did not suppress the proliferation of HASMCs upon Pg-LPS stimulation, but ERK inhibition significantly inhibited proliferation. SAPK/JNK and ERK inhibition suppressed Pg-LPS-stimulated migration of HASMCs. In conclusion, our findings suggest that Pg-LPS may promote atherosclerosis via the activation of MAPK through TLR4.

The Effects of Porphyromonas gingivalis on Atherosclerosis-Related Cells

Atherosclerosis (AS), one of the most common types of cardiovascular disease, has initially been attributed to the accumulation of fats and fibrous materials. However, more and more researchers regarded it as a chronic inflammatory disease nowadays. Infective disease, such as periodontitis, is related to the risk of atherosclerosis. Porphyromonas gingivalis (P. gingivalis), one of the most common bacteria in stomatology, is usually discovered in atherosclerotic plaque in patients. Furthermore, it was reported that P. gingivalis can promote the progression of atherosclerosis. Elucidating the underlying mechanisms of P. gingivalis in atherosclerosis attracted attention, which is thought to be crucial to the therapy of atherosclerosis. Nevertheless, the pathogenesis of atherosclerosis is much complicated, and many kinds of cells participate in it. By summarizing existing studies, we find that P. gingivalis can influence the function of many cells in atherosclerosis. It can induce the dysfunction of endothelium, promote the formation of foam cells as well as the proliferation and calcification of vascular smooth muscle cells, and lead to the imbalance of regulatory T cells (Tregs) and T helper (Th) cells, ultimately promoting the occurrence and development of atherosclerosis. This article summarizes the specific mechanism of atherosclerosis caused by P. gingivalis. It sorts out the interaction between P. gingivalis and AS-related cells, which provides a new perspective for us to prevent or slow down the occurrence and development of AS by inhibiting periodontal pathogens.

Detection of Periodontal Pathogens in Oral Samples and Cardiac Specimens in Patients Undergoing Aortic Valve Replacement: A Pilot Study

This observational study aimed to: (i) assess the presence of periodontal disease among patients requiring aortic valve replacement; (ii) investigate the presence of oral pathogens in aortic valve specimens and compare them with the microorganisms detected in the oral cavity. Twenty-six patients (15 men and 11 women) were scheduled to be visited the day before the cardiac surgery: periodontal conditions were accurately registered through clinical and radiographic examinations; dental plaque or salivary samples were collected. Valve specimens were collected during surgical aortic valve replacement and analyzed for pathogens detection through microbiological 16SrRna gene sequencing. Bacteria found in plaque samples and valve specimens were assessed according to oral and periodontal conditions. A qualitative comparison between oral and cardiac profiles of the microorganisms detected was performed. The overall number of patients examined for soft tissues conditions was 19, as 7 patients were edentulous. Twelve and three individuals, respectively, presented moderate and severe periodontitis. Nine valves were found to be positive for the presence of oral and periodontopathic bacterial DNA. The microbial species found in valve samples of patients with periodontitis suggest that the presence of these microorganisms in valvular tissue seems to be not coincidental.

Mutual promotions between periodontitis and vascular calcification by rat animal model

OBJECTIVE AND BACKGROUND

To study the relationship between periodontitis and vascular calcification by establishing rat model of chronic periodontitis and vascular calcification.

METHODS

Forty male Wistar rats were divided into four groups randomly: control group, periodontitis group, vascular calcification group, and compound periodontitis and calcification group. Each group rats accepted the corresponding manages to establish the animal model. Clinical examinations and hematoxylin and eosin staining of periodontal tissue were taken to test the periodontal model; calcium assay, alkaline phosphatase activity, expression of mineral-related factors including osteopontin, alkaline phosphatase, core-binding factor-α1 and bone sialoprotein, hematoxylin and eosin staining and von Kossa staining of vascular tissue were taken to test the vascular calcification model; inflammatory factors including C-reactive protein, interleukin-1β, tumor necrosis factor-α, interleukin-6, prostaglandin E2, and serum lipid in serum were also detected at the same time.

RESULTS

The rat model was established. Inflammation of periodontal tissue and alveolar bone resorption in compound group and periodontitis group were more obvious than those in control group and vascular calcification group (P < .05). However, the calcium assay, alkaline phosphatase activity, and mineralized deposition in vascular calcification group and compound group were higher than those in control group and periodontitis group (P < .05), and compound group were the highest (P < .05); as for serum lipid, the level of total cholesterol and low-density lipoprotein-cholesterol in compound group and vascular calcification group were higher than that in control group and periodontitis group (P < .05), and compound group was the highest (P <.05); but the level of high-density lipoprotein cholesterol was higher in control group and periodontitis group. Inflammatory factors expression in serum were higher in compound group and periodontitis group, while mineral-related factors expression were higher in compoundgroup and vascular calcification group.

CONCLUSION

There are some mutual promotions between periodontitis and vascular calcification, which might be related to the increasing inflammatory factors, lipids level, and mineral-related factors.

Mechanisms underlying the association between periodontitis and atherosclerotic disease

Atherosclerosis is central to the pathology of cardiovascular diseases, a group of diseases in which arteries become occluded with atheromas that may rupture, leading to different cardiovascular events, such as myocardial infarction or ischemic stroke. There is a large body of epidemiologic and animal model evidence associating periodontitis with atherosclerotic disease, and many potential mechanisms linking these diseases have been elucidated. This chapter will update knowledge on these mechanisms, which generally fall into 2 categories: microbial invasion and infection of atheromas; and inflammatory and immunologic. With respect to the invasion and infection of atheromas, it is well established that organisms from the subgingival biofilm can enter the circulation and lodge in most distant tissues. Bacteremias resulting from oral interventions, and even oral hygiene activities, are well documented. More recently, indirect routes of entry of oral organisms (via phagocytes or dendritic cells) have been described for many oral organisms, into many tissues. Such organisms include the periodontal pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Tannerella forsythia, and Fusobacterium nucleatum. Intracellular survival of these organisms with dissemination to distant sites (The Trojan Horse approach) has been described. Their relative contribution to atheroma formation and progression has been studied mainly in experimental research, with results demonstrating that these organisms can invade endothelial cells and phagocytic cells within the atheroma, leading to pathogenic changes and progression of the atheroma lesion. The second category of mechanisms potentially linking periodontitis to atherosclerosis includes the dumping of inflammatory mediators originating from periodontal lesions into the systemic circulation. These inflammatory mediators, such as C-reactive protein, matrix metalloproteinases, fibrinogen, and other hemostatic factors, would further accelerate atheroma formation and progression, mainly through oxidative stress and inflammatory dysfunction. Moreover, direct effects on lipid oxidation have also been described. In summary, the evidence supports the concept that periodontitis enhances the levels of systemic mediators of inflammation that are risk factors for atherosclerotic diseases.

CGI-58: Versatile Regulator of Intracellular Lipid Droplet Homeostasis

Comparative gene identification-58 (CGI-58), also known as α/β-hydrolase domain-containing 5 (ABHD5), is a member of a large family of proteins containing an α/β-hydrolase-fold. CGI-58 is well-known as the co-activator of adipose triglyceride lipase (ATGL), which is a key enzyme initiating cytosolic lipid droplet lipolysis. Mutations in either the human CGI-58 or ATGL gene cause an autosomal recessive neutral lipid storage disease, characterized by the excessive accumulation of triglyceride (TAG)-rich lipid droplets in the cytoplasm of almost all cell types. CGI-58, however, has ATGL-independent functions. Distinct phenotypes associated with CGI-58 deficiency commonly include ichthyosis (scaly dry skin), nonalcoholic steatohepatitis, and hepatic fibrosis. Through regulated interactions with multiple protein families, CGI-58 controls many metabolic and signaling pathways, such as lipid and glucose metabolism, energy balance, insulin signaling, inflammatory responses, and thermogenesis. Recent studies have shown that CGI-58 regulates the pathogenesis of common metabolic diseases in a tissue-specific manner. Future studies are needed to molecularly define ATGL-independent functions of CGI-58, including the newly identified serine protease activity of CGI-58. Elucidation of these versatile functions of CGI-58 may uncover fundamental cellular processes governing lipid and energy homeostasis, which may help develop novel approaches that counter against obesity and its associated metabolic sequelae.

[Expression of triggering receptors expressed by myeloid cells-1 in macrophages stimulated by Porphyromonas gingivalis-lipopolysaccharide]

OBJECTIVE

Soluble triggering receptors expressed by myeloid cells-1 (sTREM-1) and inflammatory cytokine tumor necrosis factor-α (TNF-α) in macrophage cells were stimulated by Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS) to investigate the expression of triggering receptors expressed by myeloid cells-1 (TREM-1) and further explore the correlation between TREM-1 and the pathogenesis of periodontitis.

METHODS

THP-1 cells (a human monocytic cell line derived from an acute monocytic leukemia patient) were induced to differentiate THP-1 macrophages by phorbol-12-myristate-13-acetate and were injected with 0 (blank control), 0.5, or 1.0 μg·mL⁻¹ Pg-LPS. The THP-1 cells were then grouped in accordance with incubation time, and each group was incubated for 4, 6, 12, or 24 h. The expression of the TREM-1 mRNA in macrophages was detected by real-time quantitative polymerase chain reaction, while the expression of TREM-1 protein was detected by Western blot; the site where TREM-1 protein expression was observed in macrophages was detected by immunofluorescence staining, and the expression of soluble sTREM-1 and TNF-α in cell culture medium was detected by enzyme-linked immunosorbent assay.

RESULTS

Compared with the blank control group, the expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in Pg-LPS-stimulated macrophages was significantly upregulated (P<0.05). The expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in the supernatant of cell culture was higher in the 1.0 μg·mL⁻¹ Pg-LPS group than in the 0.5 μg·mL⁻¹ group; this expression was statistically significant since the 6, 4, and 4 h time point (P<0.05). Cell immunofluorescence staining showed that TREM-1 protein was positive when the THP-1 macrophages was stimulated by Pg-LPS (1.0 μg·mL⁻¹) for 24 h, and the staining sites of TREM-1 were mainly located in the cell membrane of the macrophages (P<0.05). The expression level of TNF-α increased in groups stimulated by Pg-LPS, and the expression level of TNF-α was significantly higher in 1.0 μg·mL⁻¹ Pg-LPS stimulated groups than in 0.5 μg·mL⁻¹ Pg-LPS-stimulated groups since the 6 h time point (P<0.05). The expressions of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in 0.5 μg·mL⁻¹ Pg-LPS-stimulated macrophages were positively correlated with one another (r=1, P<0.05), but no statistically significant correlation was found in the expression of TNF-α. The positive correlation between sTREM-1 and TNF-α expressions was detected when macrophages were stimulated by 1.0 μg·mL⁻¹ Pg-LPS (r=1, P<0.05).

CONCLUSIONS

The expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in the culture supernatant in Pg-LPS-stimulated macrophages was significantly upregulated on the basis of the concentration of Pg-LPS; moreover, their upregulation was positively correlated with one another. The expression of TNF-α in the supernatant of cell culture was also upregulated and was positively correlated with the expression of sTREM-1 at the group of high Pg-LPS concentration (1.0 μg·mL⁻¹). Results reveal that TREM-1, which has been realized as a proinflammatory receptor protein, can promote the development of periodontitis by regulating the expression of TNF-α in macrophages.

Periodontal Therapy with 0.25%Lemongrass Oil Mouthwash in Reducing Risk of Cardiovascular Diseases: A 3-Arm Prospective Parallel Experimental Study

BACKGROUND

Periodontal disease is associated with cardiovascular diseases because of its role in host immune-inflammatory response. Serum lipids are the commonest risk factors between periodontal disease and cardiovascular diseases.

MATERIALS AND METHOD

A double blinded randomised clinical trial was carried out among 45 subjects with generalised severe periodontitis. They were divided into 3-groups of 15 subjects each. Group A: 0.25% lemongrass oil mouthwash, Group B: 0.12% chlorhexidine mouthwash and Group C: Oral prophylaxis only Group. Oral examinations like assessment of Probing Pocket Depth and Clinical Attachment Loss and Bio-chemical tests like assessment of C-Reactive Protein, Total Cholesterol, High Density Lipid, Low Density Lipid and triglycerides were conducted at baseline followed by oral prophylaxis at the same visit. Reassessment of the above mentioned parameters were done after 3 months of intervention. Data so collected were subjected for statistical analysis using SPSS ver. 20.0.

RESULTS

A statistically significant reduction in C-Reactive Protein, Probing Pocket Depth, Clinical Attachment Loss, Total Cholesterol and Low Density Lipid level in 0.25% lemongrass oil mouthwash group was found. On comparing a statistically significant difference was observed for the post intervention scores of Probing Pocket Depth and Clinical Attachment Loss only; for Group A v/s C and Group B v/s C.

CONCLUSION

0.25% Lemongrass oil mouthwash was found to be a good herbal alternative; both in the treatment of chronic periodontitis and reduction in the level of serum markers of Cardio Vascular Diseasess.

Periodontal Treatment and the Risks of Cardiovascular Disease in Patients with Type 2 Diabetes: A Retrospective Cohort Study

Objective Periodontal disease may predispose individuals to cardiovascular disease (CVD). Diabetes mellitus, especially in patients with severe periodontitis, increases the risk of CVD mortality. However, the outcomes of periodontal therapy vary among the different treatment modalities. We aim to investigate whether periodontal treatment could influence the occurrence of CVD in patients with type 2 diabetes and periodontal problems. Methods A retrospective cohort study was conducted based on a dataset released by Taiwan National Health Insurance (NHI). The dataset was composed of randomly sampled, newly diagnosed diabetic patients who received insurance benefits from 1999 to 2001; patients who were younger than 18 years of age or who already had CVD before 1999 were excluded. The NHI code was used to identify the treatments, including subgingival curettage and flap operations. The patients' demographic variables were matched using a 1:4 propensity score. All of the subjects were followed up until the onset of CVD, or December 31, 2011. A Cox proportional hazards regression analysis was performed to evaluate the effects of periodontal treatment on the rates of myocardial infarction, heart failure and stroke. Results Three thousand thirty-nine and 12,156 diabetic subjects were classified into the advanced periodontal treatment group and the non-advanced periodontal treatment group, respectively. The Cox proportional hazards analysis revealed that although the overall incidence of CVD was not significantly improved (Hazard ratio, HR 0.95; 95% CI 0.90-1.01), advanced periodontal treatment reduced the rates of myocardial infarction (HR 0.92; 95% CI 0.85-0.99) and heart failure (HR 0.60; 95% CI 0.45-0.80). There was no significance difference in the incidence of stroke (HR 0.95; 95% CI 0.85-1.06). Conclusion Advanced periodontal therapy lowers the rate of CVD, especially myocardial infarction and heart failure. Dental management has a beneficial effect on the health of patients with type 2 diabetes.

Porphyromonas gingivalis and related bacteria: from colonial pigmentation to the type IX secretion system and gliding motility

Porphyromonas gingivalis is a gram-negative, non-motile, anaerobic bacterium implicated as a major pathogen in periodontal disease. P. gingivalis grows as black-pigmented colonies on blood agar, and many bacteriologists have shown interest in this property. Studies of colonial pigmentation have revealed a number of important findings, including an association with the highly active extracellular and surface proteinases called gingipains that are found in P. gingivalis. The Por secretion system, a novel type IX secretion system (T9SS), has been implicated in gingipain secretion in studies using non-pigmented mutants. In addition, many potent virulence proteins, including the metallocarboxypeptidase CPG70, 35 kDa hemin-binding protein HBP35, peptidylarginine deiminase PAD and Lys-specific serine endopeptidase PepK, are secreted through the T9SS. These findings have not been limited to P. gingivalis but have been extended to other bacteria belonging to the phylum Bacteroidetes. Many Bacteroidetes species possess the T9SS, which is associated with gliding motility for some of these bacteria.

Association of Serum Cholesterol, Triglyceride, High and Low Density Lipoprotein (HDL and LDL) Levels in Chronic Periodontitis Subjects with Risk for Cardiovascular Disease (CVD): A Cross Sectional Study

PURPOSE

To assess serum cholesterol, triglycerides, high and low density lipoprotein (HDL and LDL) levels (serum lipid profile) in subjects with chronic periodontitis and the possible association for risk of cardiovascular disease (CVD).

MATERIALS AND METHODS

Total of 80 participants (42 males and 38 females) who were in the age range of 30-65 years were divided into test group (group I- 40 subjects with chronic periodontitis) and control group (group II- 40 subjects with healthy periodontium), based on their periodontal disease statuses. Three ml of venous blood samples were taken for measurement of parameters of lipid metabolism [serum cholesterol (chol); triglycerides (Tg); HDL and LDL.

RESULTS

Significant increase in serum cholesterol and LDL (P<0.05) were observed in test group (group I), whereas serum triglycerides and HDL (P>0.66) showed no significant increase in test group (group I) as compared to their values in the control group (group II). A P-value of < 0.05 was considered for statistical significance.

CONCLUSIONS

Subjects with chronic periodontitis showed increased serum cholesterol and LDL levels. This may suggest that these subjects are potentially at a risk of getting CVD.

Porphyromonas gingivalis lipopolysaccharide increases lipid accumulation by affecting CD36 and ATP-binding cassette transporter A1 in macrophages

Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) promotes macrophage-derived foam cell formation, however, the mechanisms are not well established. In macrophages, lipid uptake is mediated by scavenger receptors including SR-A and CD36, while the cholesterol efflux is mediated by ATP-binding cassette transporter G1 (ABCG1), ABCA1 and SR-BI. We further investigated the mechanisms underlying the dysregulation by P. gingivalis LPS of these regulators resulting in the promotion of lipid accumulation in THP-1-derived macrophages. Our results showed that P. gingivalis LPS exacerbated lipid accumulation in oxidized low-density lipoprotein (oxLDL)-treated macrophages. However, cholesterol efflux was inhibited by P. gingivalis LPS in THP-1-derived macrophages. In oxLDL-untreated macrophages, P. gingivalis LPS treatment caused an increase in CD36 mRNA and protein levels, and a decrease in ABCA1 mRNA and protein levels, while having no effect on SR-A, SR-BI or ABCG1 expression. Upregulation of CD36 by P. gingivalis LPS resulted from activation of c-Jun/AP-1, and this was confirmed by the inhibition of increased CD36 expression after AP-1 inhibition using SP600125. However, the decreased protein stability of ABCA1 by P. gingivalis LPS was a result of increased calpain activity. Moreover, small hairpin RNA (shRNA) targeting heme oxygenase-1 (HO-1) augmented the P. gingivalis LPS-induced atherogenic effects on the expression of c-Jun/AP-1, CD36, ABCA1 and calpain activity. Accordingly, P. gingivalis LPS-regulated promotion of lipid accumulation in foam cells was also exacerbated by HO-1 shRNA. These results indicate that P. gingivalis LPS confers a exacerbation effect on the formation of foam cells by a novel HO-1-dependent mediation of cholesterol efflux and lipid accumulation in macrophages.

Very low density lipoproteins derived from periodontitis patients facilitate macrophage activation via lipopolysaccharide function

OBJECTIVE

Periodontitis, a chronic oral infection caused mainly by gram-negative bacteria, induces endotoxemia and associates with the risk for atherosclerosis. We investigated the effect of periodontal treatment on proatherogenic properties of very low density lipoproteins (VLDL).

METHODS

VLDL were isolated from 30 systemically healthy periodontitis patients before (pre-treatment) and 3 months after treatment (post-treatment). The mass compositions were analyzed, and VLDL-induced changes in cellular cholesterol content and expression of selected genes of human THP-1 macrophages were measured.

RESULTS

Periodontal treatment decreased the local inflammation in the periodontium, but did not have a significant effect on C-reactive protein (CRP) levels, VLDL composition, or VLDL potential to induce cholesterol uptake or gene expression by the macrophages. Incubation of macrophages in the presence of VLDL resulted in more than twofold increase in their cellular cholesterol content. Uptake of VLDL with ensuing macrophage cholesterol accumulation correlated positively with VLDL-associated lipopolysaccharide (LPS) activity (r=0.436, P=.016) and apolipoprotein E content (r=0.374, P=.046). Pre-treatment VLDL derived from the patients with high CRP levels displayed higher LPS activity than that of VLDL derived from patients with low CRP (above vs. below median, P=.007). In addition, pre-treatment VLDL isolated from patients with high systemic inflammation induced higher relative mRNA expression of CD14, TNF-α, MCP-1, and IL-6 in the macrophages.

CONCLUSION

Inflammation and endotoxemia induced by severe periodontitis may increase VLDL-dependent macrophage activation and cellular cholesterol accumulation, and thereby atherogenesis.

Circulating microparticles: square the circle

Background

The present review summarizes current knowledge about microparticles (MPs) and provides a systematic overview of last 20 years of research on circulating MPs, with particular focus on their clinical relevance.

Results

MPs are a heterogeneous population of cell-derived vesicles, with sizes ranging between 50 and 1000 nm. MPs are capable of transferring peptides, proteins, lipid components, microRNA, mRNA, and DNA from one cell to another without direct cell-to-cell contact. Growing evidence suggests that MPs present in peripheral blood and body fluids contribute to the development and progression of cancer, and are of pathophysiological relevance for autoimmune, inflammatory, infectious, cardiovascular, hematological, and other diseases. MPs have large diagnostic potential as biomarkers; however, due to current technological limitations in purification of MPs and an absence of standardized methods of MP detection, challenges remain in validating the potential of MPs as a non-invasive and early diagnostic platform.

Conclusions

Improvements in the effective deciphering of MP molecular signatures will be critical not only for diagnostics, but also for the evaluation of treatment regimens and predicting disease outcomes.

Identification of an O-antigen chain length regulator, WzzP, in Porphyromonas gingivalis

The periodontal pathogen Porphyromonas gingivalis has two different lipopolysaccharides (LPSs) designated O-LPS and A-LPS, which are a conventional O-antigen polysaccharide and an anionic polysaccharide that are both linked to lipid A-cores, respectively. However, the precise mechanisms of LPS biosynthesis remain to be determined. In this study, we isolated a pigment-less mutant by transposon mutagenesis and identified that the transposon was inserted into the coding sequence PGN_2005, which encodes a hypothetical protein of P. gingivalis ATCC 33277. We found that (i) LPSs purified from the PGN_2005 mutant were shorter than those of the wild type; (ii) the PGN_2005 protein was located in the inner membrane fraction; and (iii) the PGN_2005 gene conferred Wzz activity upon an Escherichia coli wzz mutant. These results indicate that the PGN_2005 protein, which was designated WzzP, is a functional homolog of the Wzz protein in P. gingivalis. Comparison of amino acid sequences among WzzP and conventional Wzz proteins indicated that WzzP had an additional fragment at the C-terminal region. In addition, we determined that the PGN_1896 and PGN_1233 proteins and the PGN_1033 protein appear to be WbaP homolog proteins and a Wzx homolog protein involved in LPS biosynthesis, respectively.

Mechanisms of triglyceride accumulation in activated macrophages

LPS treatment of macrophages induces TG accumulation, which is accentuated by TG-rich lipoproteins or FFA. We defined pathways altered during macrophage activation that contribute to TG accumulation. Glucose uptake increased with activation, accompanied by increased GLUT1. Oxidation of glucose markedly decreased, whereas incorporation of glucose-derived carbon into FA and sterols increased. Macrophage activation also increased uptake of FFA, associated with an increase in CD36. Oxidation of FA was markedly reduced, whereas the incorporation of FA into TGs increased, associated with increased GPAT3 and DGAT2. Additionally, macrophage activation decreased TG lipolysis; however, expression of ATGL or HSL was not altered. Macrophage activation altered gene expression similarly when incubated with exogenous FA or AcLDL. Whereas activation with ligands of TLR2 (zymosan), TLR3 (poly I:C), or TLR4 (LPS) induced alterations in macrophage gene expression, leading to TG accumulation, treatment of macrophages with cytokines had minimal effects. Thus, activation of TLRs leads to accumulation of TG in macrophages by multiple pathways that may have beneficial effects in host defense but could contribute to the accelerated atherosclerosis in chronic infections and inflammatory diseases.

Periodontal disease and atherosclerotic vascular disease: does the evidence support an independent association?: a scientific statement from the American Heart Association

A link between oral health and cardiovascular disease has been proposed for more than a century. Recently, concern about possible links between periodontal disease (PD) and atherosclerotic vascular disease (ASVD) has intensified and is driving an active field of investigation into possible association and causality. The 2 disorders share several common risk factors, including cigarette smoking, age, and diabetes mellitus. Patients and providers are increasingly presented with claims that PD treatment strategies offer ASVD protection; these claims are often endorsed by professional and industrial stakeholders. The focus of this review is to assess whether available data support an independent association between ASVD and PD and whether PD treatment might modify ASVD risks or outcomes. It also presents mechanistic details of both PD and ASVD relevant to this topic. The correlation of PD with ASVD outcomes and surrogate markers is discussed, as well as the correlation of response to PD therapy with ASVD event rates. Methodological issues that complicate studies of this association are outlined, with an emphasis on the terms and metrics that would be applicable in future studies. Observational studies to date support an association between PD and ASVD independent of known confounders. They do not, however, support a causative relationship. Although periodontal interventions result in a reduction in systemic inflammation and endothelial dysfunction in short-term studies, there is no evidence that they prevent ASVD or modify its outcomes.

Expressions of interleukin-1β and interleukin-6 within aortas and uteri of rats with various severities of ligature-induced periodontitis

To investigate the associations of periodontitis with histological lesions in some other organs, various severities of periodontitis were induced in rats by 3/0 silk ligatures tied around different numbers of their molar necks. Six weeks after the initial placement of ligatures, all rats were sacrificed by an anaesthetic overdose. The distances from the cemento-enamel junction to the alveolar bone crest within the placement zone of the ligature and their contralateral zone in groups L(2) and L(3) were measured. The levels of interleukin (IL)-1β and IL-6 in serum were assayed by enzyme-linked immunosorbent assay techniques, and those within aortas and uteri were measured by real-time polymerase chain reaction and by immunohistochemistry. We divided the ligature-induced periodontitis models into mild, moderate and severe rat periodontitis and observed that although no association between periodontitis and the serum concentrations of IL-1β was detected, the differences in the severity of rat periodontitis led to varying degrees of elevated expressions of IL-1β and IL-6 within aortas and uteri.

Role of extracellular membrane vesicles in the pathogenesis of various diseases, including cancer, renal diseases, atherosclerosis, and arthritis

Extracellular membrane vesicles (MVs) 30-1000 nm in diameter and of varying cellular origins are increasingly recognized for their participation in a range of processes, including the pathogenesis of various diseases, such as: (1) atherosclerosis, (2) thromboembolism, (3) osteoarthritis (OA), (4) chronic renal disease and pulmonary hypertension, (5) tissue invasion and metastasis by cancer cells, (6) gastric ulcers and bacterial infections, and (7) periodontitis. MVs are derived from many different cell types and intracellular mechanisms, and perform different metabolic functions or roles, depending on the cell of origin.The presence of a metabolically active, outer membrane is a distinguishing feature of all MVs, regardless of their cell type of origin and irrespective of terminologies applied to them such as exosomes, microparticles, or matrix vesicles. The MV membrane provides one of the few protected and controlled internal microenvironments outside cells in which specific metabolic objectives of the host cell may be pursued vigorously at a distance from the host cell. MVs are also involved in various forms of normal and abnormal intercellular communication. Evidence is emerging that circulating MVs are good predictors of the severity of several diseases. In addition, recently, the role of MVs in inducing immunity against cancer cells and bacterial infections has become a topic of interest to researchers in the area of therapeutics. The main objective of this review is to list and briefly describe the increasingly well-defined roles of MVs in selected diseases in which they seem to have a significant role in pathogenesis.

The innate immune system and diabetes mellitus: the relevance of periodontitis? A hypothesis

About a decade ago, a hypothesis was proposed suggesting that the innate immune system, including acute-phase reactants, contribute to the development of T2DM [Type 2 DM (diabetes mellitus)] and the metabolic syndrome. In this model, it was hypothesized that the innate immune system modulates the effects of many factors, including genes, fetal programming, nutrition and aging, upon the later development of metabolic problems associated with insulin resistance. In this present article, we expand this hypothesis by looking at the involvement of periodontitis in DM and its complications. Periodontitis is a common inflammatory process involving the innate immune system and is associated with DM. We will also illustrate how dental disease is important in patients with DM and could be implicated in various diabetic complications.

ADRP/ADFP and Mal1 expression are increased in macrophages treated with TLR agonists

Activation of macrophages by TLR agonists enhances foam cell formation, but the underlying mechanisms are not understood. We examined the effects of TLR agonists on ADRP/ADFP, a protein associated with forming lipid droplets, and Mal1 a fatty acid-binding protein, in two mouse macrophage cell lines and human monocytes. Low doses of LPS, a TLR4 agonist increased both mRNA and protein levels of ADRP/ADFP and Mal1 in RAW 264.7 macrophages. Following pretreatment with Intralipid, fatty acids, or acetyl-LDL to increase triglyceride or cholesterol ester storage, LPS treatment still increased ADRP/ADFP and Mal1 mRNA levels. LPS also induced ADRP/ADFP and Mal1 in J774 macrophages and ADRP/ADFP in human monocytes. Zymosan, a fungal product that activates TLR2, poly-I:C, a viral mimetic that activates TLR3, and imiquimod, a TLR7 agonist, also increased ADRP/ADFP. Zymosan, but not poly-I:C or imiquimod, induced Mal1. In contrast, neither gene was induced by TNFalpha, IL-1beta, IL-6, or interferon-gamma. Thus TLR agonists induce ADRP/ADFP and Mal1, which likely contributes to macrophage triglyceride and cholesterol ester storage leading to foam cell formation.

Pro-atherogenic lung and oral pathogens induce an inflammatory response in human and mouse mast cells

A broad variety of microbes are present in atherosclerotic plaques and chronic bacterial infection increases the risk of atherosclerosis by mechanisms that have remained vague. One possible mechanism is that bacteria or bacterial products activate plaque mast cells that are known to participate in the pathogenesis of atherosclerosis. Here, we show by real-time PCR analysis and ELISA that Chlamydia pneumoniae (Cpn) and a periodontal pathogen, Aggregatibacter actinomycetemcomitans (Aa), both induce a time and concentration-dependent expression and secretion of interleukin 8 (IL-8), tumour necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) by cultured human peripheral blood-derived mast cells, but not anti-inflammatory molecules, such as IL-10 or transforming growth factor β1 (TGF-β1). The IL-8 and MCP-1 responses were immediate, whereas the onset of TNF-α secretion was delayed. The Cpn-mediated pro-inflammatory effect was attenuated when the bacteria were inactivated by UV-treatment. Human monocyte-derived macrophages that were pre-infected with Cpn also induced a significant pro-inflammatory response in human mast cells, both in cocultures and when preconditioned media from Cpn-infected macrophages were used. Intranasal and intravenous administration of live Cpn and Aa, respectively induced an accumulation of activated mast cells in the aortic sinus of apolipoprotein E-deficient mice, however, with varying responses in the systemic levels of lipopolysaccharide (LPS) and TNF-α. Pro-atherogenic Cpn and Aa induce a pro-inflammatory response in cultured human connective tissue-type mast cells and activation of mouse aortic mast cells in vivo.

The menopause and oral health

OBJECTIVES

To review the literature about oral symptoms and signs at the menopause with an emphasis on hormone replacement therapy (HRT). To give practical guidelines for women and their physicians in menopause-related oral health problems.

METHODS

The PubMed and Cochrane databases was searched until mid January 2009 with key words such as "menopause", "menopausal complaints", "postmenopausal complaints" and "oral diseases", "oral discomfort", "dental health", "dental diseases", "saliva", "burning mouth syndrome", "dry mouth", "xerostomia". Because of a scarcity of controlled studies no systematic review could be conducted.

RESULTS

Oral discomfort is found in many menopausal women in addition to more general climacteric complaints. The principal peri- and postmenopausal symptoms are dry mouth and burning mouth (glossodynia) which, in turn, may increase the occurrence of oral mucosal and dental diseases, such as candidiasis. The mechanisms of hormone-related oral symptoms and signs are not known although oestrogen receptors, for example, have been detected in the oral mucosa and salivary glands. In principle, the histology of oral and vaginal mucosa is very similar and thus their symptoms might share a common cause. Yet, hormone replacement therapy use does not necessarily prevent or help women with oral symptoms.

CONCLUSION

Properly controlled long-term randomized studies are needed to assess the effect of HRT on oral discomfort. Future gene profiling could identify women who may or may not benefit from HRT with regard to oral symptoms.

Matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 in blood as markers for early atherosclerosis in subjects with chronic periodontitis

BACKGROUND AND OBJECTIVE

An association has been found between periodontal disease and the development of atherosclerosis. We investigated the hypothesis that periodontal disease triggers the expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in blood. Increased levels of these parameters might then indicate early atherosclerosis.

MATERIAL AND METHODS

In this cross-sectional study, the material comprised 80 subjects with chronic periodontitis and 31 subjects with no periodontal disease. Sixteen years after diagnosis of periodontal disease ultrasonography revealed a statistically significant difference (p < 0.001) of carotid intima-media thickness between the subjects with chronic periodontitis and the periodontally healthy subjects. Matrix metalloproteinase-9 and TIMP-1 were analyzed from blood as periodontal and systemic inflammatory markers. The relationship between MMP-9, TIMP-1 and MMP-9/TIMP-1 as dependent variables and several independent variables (age, sex, smoking, education, body mass index, hypertension, periodontal disease and cholesterol) were analyzed in multiple logistic regression models to assess the value of the inflammatory markers in predicting carotid atherosclerosis.

RESULTS

Matrix metalloproteinase-9 and TIMP-1 were significantly higher in plasma from subjects with periodontal disease and atherosclerosis. Periodontal disease was identified as the principal independent predictor both for atherosclerosis (odds ratio 3.89 for increase in bilateral carotid intima-media thickness) and for increased MMP-9, TIMP-1 and MMP-9/TIMP-1 (odds ratio 2.58, 5.53 and 3.41, respectively). Classical atherosclerosis risk factors, such as increased total cholesterol, age and sex (women), were significant predictors in the model.

CONCLUSION

Matrix metalloproteinase-9, TIMP-1 and MMP-9/TIMP-1 in blood from subjects with periodontal disease could be useful laboratory markers for increased carotid artery intima-media thickness.

An ultrastructural study of Porphyromonas gingivalis-induced platelet aggregation

One of the major pathogens of periodontitis, Porphyromonas gingivalis (P. gingivalis), has the ability to aggregate human platelets. To investigate the interaction between P. gingivalis and human platelets in platelet rich plasma (PRP), platelet aggregation was measured by an aggregometer based on laser light scattering (LS) methods, and an ultrastructural study was performed using electron microscopy. A sharp and rapid increase of small-sized platelet aggregates was observed immediately after the addition of P. gingivalis to PRP, followed by the formation of medium- and large-sized aggregates in 2-3 min. In contrast, when Staphylococcus aureus (S. aureus) was used in the control experiment, only a slight increase in small-sized aggregates was detected. By electron microscopy, discoid-shaped platelets were observed prior to adding P. gingivalis. By 5 min after the addition of the bacteria, enormous platelet aggregates were observable. Most of the P. gingivalis were present between the adherent platelets, while some were internalized in platelet engulfment vacuoles. In contrast, when washed platelets were incubated with the bacteria under a non-stirring condition to prevent platelet aggregation, and stained with ruthenium red (RR) as an electron dense tracer of the cell surface including the open canalicular system (OCS), both RR-positive and -negative vacuoles containing P. gingivalis were identified in the activated platelets. Thus, this observation suggests that P. gingivalis residing in the RR-negative vacuoles is incorporated into the platelet cytoplasm by phagocytosis.

Absence of alphavbeta6 integrin is linked to initiation and progression of periodontal disease

Integrin alphavbeta6 is generally not expressed in adult epithelia but is induced in wound healing, cancer, and certain fibrotic disorders. Despite this generalized absence, we observed that alphavbeta6 integrin is constitutively expressed in the healthy junctional epithelium linking the gingiva to tooth enamel. Moreover, expression of alphavbeta6 integrin was down-regulated in human periodontal disease, a common medical condition causing tooth loss and also contributing to the development of cardiovascular diseases by increasing the total systemic inflammatory burden. Remarkably, integrin beta6 knockout mice developed classic signs of spontaneous, chronic periodontal disease with characteristic inflammation, epithelial down-growth, pocket formation, and bone loss around the teeth. Integrin alphavbeta6 acts as a major activator of transforming growth factor-beta1 (TGF-beta1), a key anti-inflammatory regulator in the immune system. Co-expression of TGF-beta1 and alphavbeta6 integrin was observed in the healthy junctional epithelium. Moreover, an antibody that blocks alphavbeta6 integrin-mediated activation of TGF-beta1 initiated inflammatory periodontal disease in a rat model of gingival inflammation. Thus, alphavbeta6 integrin is constitutively expressed in the epithelium sealing the gingiva to the tooth and plays a central role in protection against inflammatory periodontal disease through activation of TGF-beta1.

Prevalence of periodontal pathogens in subgingival lesions, atherosclerotic plaques and healthy blood vessels: a preliminary study

BACKGROUND AND OBJECTIVE

Previous studies have reported different periodontal bacteria in atherosclerotic lesions, but their involvement in plaque formation remains unclear. The aim of the present study was to investigate the presence of 20 periodontal bacteria in atherosclerotic samples and healthy blood vessels (used as controls) and to clarify their relationship in regard to clinical and bacteriological periodontal status.

MATERIAL AND METHODS

The day before vascular surgery the patients had a thorough periodontal examination and bacteriological samples were taken from periodontally diseased sites. Atheromatous plaques, internal mammary arteries and saphenous veins were harvested during surgery. A DNA-DNA hybridization procedure was used to screen periodontal and vascular samples for the 20 selected bacterial species.

RESULTS

Periodontal samples from the severe periodontitis group were found to have a higher prevalence and biomass of bacterial species than the moderate periodontitis group. In vessel samples, the prevalence of the same 20 bacterial species analyzed together was similar in the two groups, except for saphenous veins.

CONCLUSION

The presence of periodontal pathogens in atherosclerotic plaques and in apparently healthy vessels appeared to reflect a higher level of bacteremia rather than infection of endothelial cells.

Atherogenic lipoprotein parameters in patients with aggressive periodontitis

BACKGROUND AND OBJECTIVE

Certain types of chronic infection increase the plasma level of very-low-density lipoprotein, leading to formation of the particularly atherogenic low-density lipoprotein subclass, small dense low-density lipoprotein. In the present study, we examined whether aggressive forms of periodontitis are associated with these atherogenic lipoprotein parameters.

MATERIAL AND METHODS

Twelve healthy control subjects without periodontitis, 12 subjects with localized aggressive periodontitis and 12 subjects with generalized aggressive periodontitis were studied. Lipoprotein subclass levels were determined using nuclear magnetic resonance methodology.

RESULTS

Healthy control subjects, localized aggressive periodontitis subjects and generalized aggressive periodontitis subjects had progressively higher plasma levels of very-low-density lipoprotein and progressively smaller average low-density lipoprotein size (p < 0.05, one-way analysis of variance). In pairwise comparisons, differences were only significant between healthy controls and generalized aggressive periodontitis subjects (p < 0.05, Tukey's post test). After adjustment for body mass index, the mean periodontal pocket depth correlated positively with plasma very-low-density lipoprotein levels (p = 0.047). Very-low-density lipoprotein concentrations correlated positively with small dense low-density lipoprotein levels and negatively with average low-density lipoprotein size. Prevalence of the atherogenic lipoprotein pattern-B in healthy controls, localized aggressive periodontitis subjects and generalized aggressive periodontitis subjects was 8.3%, 33.3% and 66.6%, respectively.

CONCLUSION

These results indicate that periodontal infection is associated with elevated plasma levels of atherogenic lipoprotein species. This association may account for the increased risk of periodontitis patients for cardiovascular disease.

Associations between periodontal diseases and systemic diseases: a review of the inter-relationships and interactions with diabetes, respiratory diseases, cardiovascular diseases and osteoporosis

The aim of this review article is to examine the associations between periodontal diseases and common systemic diseases, namely diabetes, respiratory diseases, cardiovascular diseases and osteoporosis. A substantial number of review articles have been published to elucidate the relationships between these diseases; however, none provide a complete overview on this topic from the aspects of definition, classification, clinical characteristics and manifestations, inter-relationships and interactions, proposed schematic mechanisms, clinical implications and management of periodontal patients with these systemic diseases. The aim of this article is to provide an overall understanding and general concepts of these issues in a concise and inter-related manner.

Periodontitis and premature death: a 16-year longitudinal study in a Swedish urban population

BACKGROUND AND OBJECTIVE

Growing experimental evidence implicates chronic inflammation/infection due to periodontal diseases as a risk factor for death. The objective was to evaluate the role of periodontitis in premature death in a prospective study.

METHODS

The causes of death in 3273 randomly-selected subjects, aged 30-40 years, from 1985 to 2001 were registered. At baseline, 1676 individuals underwent a clinical oral examination (Group A) and 1597 did not (Group B). Mortality and causes of death from 1985 to 2001 were recorded according to ICD-9-10.

RESULTS

In Groups A (clinically examined group) and B, a total of 110 subjects had died: 40 subjects in Group A, and 70 in Group B. In Group A significant differences were present at baseline between survivors and persons who later died, with respect to dental plaque, calculus, gingival inflammation and number of missing molars in subjects with periodontitis (p < 0.001). The multiple logistic regression analysis results of the relationship between being dead (dependent variable) and several independent variables identified periodontitis with any missing molars as a principal independent predictor of death.

CONCLUSIONS

Young individuals with periodontitis and missing molars seem to be at increased risk for premature death by life-threatening diseases, such as neoplasms, and diseases of the circulatory and digestive systems.

Periodontal pathogens in erupting third molars of periodontally healthy subjects

The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Tannerella forsythensis in bacteriologic samples of 5-7-mm deep mandibular third-molar pericoronal pockets was analysed by polymerase chain reaction, to test the hypothesis that these sites would harbour the bacteria. The patients were periodontally healthy 20-year-old Finnish male conscripts. Sixteen had acute pericoronitis, 28 chronic pericoronitis, and 15 were symptom-free controls. A. actinomycetemcomitans was detected in only 7% of the samples from chronic pericoronitis cases, whereas P. gingivalis was positive in 20% of the symptom-free versus 69% (P = 0.018) of the acute and 57% (P = 0.044) of the chronic cases. The percentages for P. intermedia were 93, 94 and 93%, and for T. forsythensis 47, 63 and 57%, respectively. These results confirm that, apart from A. actinomycetemcomitans, periodontopathogens are common in third-molar sites in periodontally healthy individuals.

Atheroprotective role of interleukin-6 in diet- and/or pathogen-associated atherosclerosis using an ApoE heterozygote murine model

BACKGROUND

Pathogens have been implicated in the pathogenesis of inflammatory atherosclerosis. Given the pleiotropic role of interleukin-6 in the regulation of cytokines, lipid homeostasis, vascular remodeling, and apoptosis we hypothesized that IL-6 plays an important role in development and progression to inflammatory atherosclerosis.

METHODS AND RESULTS

To explore the role of IL-6 in inflammation- and infection-associated atherosclerosis, 10-week-old ApoE(+/-)-IL-6(+/-) and ApoE(+/-)-IL-6(-/-) mice fed either high fat diet or regular chow diet were inoculated intravenously, once per week for 14 or 24 consecutive weeks with 50 microl live Porphyromonas gingivalis (P.g.) (10(7)CFU) or vehicle (normal saline). Animals were euthanized at 24 weeks of age (14 weeks injection) or 34 weeks of age (24 weeks injection). Histomorphometric analysis of atheromatous lesions, en face analysis over the aortic tree, immunohistochemistry for macrophages and smooth muscle cell, TUNEL staining for apoptotic cells, serum amyloid A (SAA) levels, serum lipids and glucose level, serum cytokines were obtained. ApoE(+/-)-IL-6(-/-) mice showed a significant increase in atheromatous lesions in proximal aorta and aortic tree compared to ApoE(+/-)-IL-6(+/-) mice for all conditions (chow diet and P.g.-inoculated, high fat diet and P.g.-inoculated, high fat diet and vehicle-inoculated) at 14 weeks and greater at 24 weeks. SAA levels from ApoE(+/-)-IL-6(-/-) mice were significantly higher than ApoE(+/-)-IL-6(+/-) mice. IL-6 deficiency led to profound changes in plaque composition evidenced by increased macrophage infiltration, apoptosis, lipid content and decreased smooth muscle cell mass reflecting an unstable plaque phenotype. Array analysis revealed increased levels of proinflammatory cytokines in ApoE(+/-)-IL-6(-/-) mice compared to ApoE(+/-)-IL-6(+/-) mice, irrespective of diet or inoculation.

CONCLUSION

The genetic deficiency of IL-6 was found to enhance the formation of diet- and/or pathogen-associated atherosclerotic plaques and suggests that IL-6 may play an atheroprotective role.

Correlation between carotid area calcifications and periodontitis: a retrospective study of digital panoramic radiographic findings in pretreatment cancer patients

OBJECTIVES

The objective of this study was to examine the prevalence of carotid area calcifications retrospectively detected on digital panoramic radiographs of pretreatment cancer subjects, and to correlate the finding of such calcifications with radiographic evidence of periodontal bone loss in the same subjects.

STUDY DESIGN

Digital panoramic radiographs of 201 subjects were evaluated for calcifications projected in the carotid artery bifurcation area as well as for alveolar bone loss as a result of periodontal disease. Inclusion criteria were unobscured carotid artery bifurcation regions bilaterally and sufficient index teeth present with a definable cemento-enamel junction and alveolar crest. Radiographs were independently observed for carotid area calcifications and for periodontal status. Image enhancements permitted for detection of calcifications projected in the carotid area included window/level, inverse, and emboss. Periodontal measurements were made on index teeth using proprietary imaging software and a mouse-driven measurement algorithm. A 3-factor analysis of variance was performed with 3 between-subjects comparisons. Percentage of bone loss was the dependent variable. Independent variables were age, subject sex, and the presence or absence of carotid area calcifications.

RESULTS

Differences measured in percentage of bone loss between sexes were not statistically significant. While bone loss did increase with age, comparison of the mean bone loss of each age category revealed no statistical significance. There was a highly significant correlation between carotid artery area calcifications visible on panoramic radiographs and percent alveolar bone loss. Radiographs showing unilateral and bilateral calcifications had a mean percent bone loss of 24.2% +/- 12.6% and 25.7% +/- 13.0% respectively, compared to those with no calcification at 10.4% +/- 9.9%.

CONCLUSIONS

Nearly 1 in 4 subjects in this study evidenced calcifications projected in the carotid bifurcation region. The finding of such calcifications was significantly related to the calculated percentage of alveolar bone loss.

Overexpression of lysosomal acid lipase and other proteins in atherosclerosis

Atherosclerosis is one of the major causes of morbidity and mortality in the western world. The existing data of elevated expression levels of proteins like DNA damage and DNA repair enzymes in human atherosclerotic plaques are reviewed. From the literature, the effect of overexpression of different proteins using adenoviral vectors or the model of transgenic mice on the development of atherosclerosis will be discussed. Special focus is placed on the lysosomal acid lipase (LAL), because LAL connects extra-cellular with intra-cellular lipid metabolism and is the only hydrolase for cleavage of cholesteryl esters delivered to the lysosomes. Patients with a deficiency of LAL show an accumulation of lipids in the cells and develop pre-mature atherosclerosis. To answer the question of the influence of LAL in atherosclerosis if overexpressed, we show for the first time data of transgenic mice overexpressing LAL and the effect on the lipid level.

Is periodontal infection behind the failure of antibiotics to prevent coronary events?

The use of antimicrobial agents to prevent coronary events is under debate. They have reduced cardiovascular events in some studies, but in others, their effect has not been distinguishable from that of placebo. In addition to Chlamydophila (Chlamydia) pneumoniae as a target pathogen, very few other microbes or infections have been targeted, although an association for instance between cardiovascular disease and periodontitis has been established. In our recent pilot study, long-term clarithromycin treatment reduces recurrent cardiovascular events in subjects without periodontitis, but in subjects with periodontitis, fails to show any effect. As a background infection, periodontitis may overpower the beneficial effects of antibiotics. This paper presents the hypothesis that periodontitis is behind the failure of antibiotics to prevent coronary events. We discuss the systemic effects of periodontal infection and consider studies to test our hypothesis, which offers a novel viewpoint for discussion of antibiotics in coronary-disease prevention.

Early Carotid Atherosclerosis in Subjects With Periodontal Diseases

Background and Purpose— There is growing experimental evidence implicating chronic inflammation/infection as an atherosclerotic risk factor. In this study, the involvement of periodontal disease in the development of early atherosclerotic vascular lesions has been evaluated.

Methods— In randomly chosen 82 patients with periodontal disease and 31 periodontally healthy individuals subjected to a clinical oral examination in 1985, atherosclerotic risk factor analysis and carotid ultrasonography was performed during reexamination 16 years later. Common carotid artery intima-media thickness (IMT) and lumen diameter were measured and intima-media area (cIMA) was calculated. The relationship between IMT and cIMA as dependent variables and periodontal disease, age, gender, body mass index, heredity for atherosclerosis, diabetes mellitus, hypertension, plasma cholesterol, smoking, and education as independent variables was evaluated in a multiple logistic regression model.

Results— The mean values of IMT and cIMA were significantly higher in patients with periodontal disease than in controls, both at the right ( P <0.01 and P <0.001, respectively) and left side ( P <0.001 for both variables). When the means of the bilateral measurements of these 2 ultrasonographic variables were tested, multiple logistic regression analysis identified periodontal disease as a principal independent predictor of the common carotid artery cIMA (odds ratio [OR], 5.20; P =0.003) and IMT (OR, 4.64; P =0.004).

Conclusions— The present results indicate that periodontal disease is associated with the development of early atherosclerotic carotid lesions.