Chemokines gene expression of RAW 264.7 cells by Actinobacillus actinomycetemcomitans lipopolysaccharide using microarray and RT-PCR analysis

CCL5's Role in Periodontal Disease: A Narrative Review

Persistent host inflammatory and immune responses to biofilm play a critical role in the mechanisms that govern soft and hard tissue destruction in periodontal disease. Among the less explored facets of these mechanisms are chemokines, including CCL5 (C-C motif chemokine ligand 5), also known as RANTES (regulated on activation, normal T cell expressed and secreted), a proinflammatory CC subfamily chemokine synthesized by T lymphocytes. Despite its importance, there is currently no comprehensive review of the role of CCL5 in periodontitis in the literature. Therefore, this paper aims to fill this gap by summarizing the existing knowledge on the involvement of CCL5 in the onset and progression of periodontitis. In addition, we aim to stimulate interest in this relatively overlooked factor among periodontitis researchers, potentially accelerating the development of drugs targeting CCL5 or its receptors. The review examines the association of CCL5 with periodontitis risk factors, including aging, cigarette smoking, diabetes, and obesity. It discusses the involvement of CCL5 in pathological processes during periodontitis, such as connective tissue and bone destruction. The data show that CCL5 expression is observed in affected gums and gingival crevicular fluid of periodontitis patients, with bacterial activity contributing significantly to this increase, but the reviewed studies of the association between CCL5 expression and periodontal disease have yielded inconclusive results. Although CCL5 has been implicated in the pathomechanism of periodontitis, a comprehensive understanding of its molecular mechanisms and significance remains elusive, hindering the development of drugs targeting this chemokine or its receptors.

Genotoxicity test of eight natural color additives in the Korean market

BACKGROUND

Various natural color additives are preferred by many consumers over synthetic color additives because they are perceived to be safer. However, most do not have sufficient toxicity data for safety assurance. Color ingredients in particular have some structures suspected of being toxic. Eight natural color additives, gardenia red, blue, and yellow; lac color; cochineal extract; beet red; Curcuma longa Linne extract (Curcuma extract); and Monascus red, currently permitted for use in Korea, were selected and subjected to genotoxicity tests. Acceptable daily intake values have not been allocated to these color additives (except for cochineal extract) due to the lack of toxicity data. We used genotoxicity testing-the bacterial reverse mutation test (Ames test), in vitro mammalian chromosomal aberration test, and in vivo alkaline comet test-for minimum safety assurance.

RESULTS

Gardenia red and blue, cochineal extract, lac color, and beet red did not induce mutagenicity or chromosomal abnormalities. Gardenia yellow was mutagenic in the Ames test, but was not positive in the in vitro chromosomal aberration test or in vivo alkaline comet assay. Curcuma extract and Monascus red induced cytotoxicity in the Ames test at high concentrations in Salmonella typhimurium TA1537 and TA100, without showing mutagenicity. On cytotoxicity testing, Curcuma extract and Monascus red showed cytotoxicity at concentrations higher than 313 μg/ml in Chinese hamster ovary CHO-K1 cells and showed equivocal results in chromosomal aberration assay of the same cells. Curcuma extract and Monascus red produced significant increases in DNA damage at a dose of 2000 mg/kg b.w./day, and induced dose-dependent increases in % DNA in the tail and tail moment on in vivo comet assay.

CONCLUSIONS

Six out of eight food colorants did not cause genotoxicity and cytotoxicity. However, Monascus red and Curcuma extract showed definite cytotoxicity and probable genotoxicity.

The effects of macrophages on cardiomyocyte calcium-handling function using in vitro culture models

Following myocardial infarction (MI), myocardial inflammation plays a crucial role in the pathogenesis of MI injury and macrophages are among the key cells activated during the initial phases of the host response regulating the healing process. While macrophages have emerged as attractive effectors in tissue injury and repair, the contribution of macrophages on cardiac cell function and survival is not fully understood due to complexity of the in vivo inflammatory microenvironment. Understanding the key cells involved and how they communicate with one another is of paramount importance for the development of effective clinical treatments. Here, novel in vitro myocardial inflammation models were developed to examine how both direct and indirect interactions with polarized macrophage subsets present in the post-MI microenvironment affect cardiomyocyte function. The indirect model using conditioned medium from polarized macrophage subsets allowed examination of the effects of macrophage-derived factors on stem cell-derived cardiomyocyte function for up to 3 days. The results from the indirect model demonstrated that pro-inflammatory macrophage-derived factors led to a significant downregulation of cardiac troponin T (cTnT) and sarcoplasmic/endoplasmic reticulum calcium ATPase (Serca2) gene expression. It also demonstrated that inhibition of macrophage-secreted matricellular protein, osteopontin (OPN), led to a significant decrease in cardiomyocyte store-operated calcium entry (SOCE). In the direct model, stem cell-derived cardiomyocytes were co-cultured with polarized macrophage subsets for up to 3 days. It was demonstrated that anti-inflammatory macrophages significantly increased cardiomyocyte Ca²⁺ fractional release while macrophages independent of their subtypes led to significant downregulation of SOCE response in cardiomyocytes. This study describes simplified and controlled in vitro myocardial inflammation models, which allow examination of potential beneficial and deleterious effects of macrophages on cardiomyocytes and vise versa. This can lead to our improved understanding of the inflammatory microenvironment post-MI, otherwise difficult to directly investigate in vivo or by using currently available in vitro models.

Acute and Subchronic Oral Toxicity Study of Gardenia Yellow E500 in Sprague-Dawley Rats

Objective: This study was conducted to evaluate the acute and subchronic toxicity of gardenia yellow, a natural colorant widely used in China and other Asian countries. An acute toxicity test was performed in S-D rats of both genders and the lethal dose (LD₅₀) of per oral gardenia yellow was estimated to be more than 15.0 g/kg·bw. In the subchronic study, gardenia yellow was orally administered to rats by gavage at doses of 0, 0.50, 1.50 and 4.50 g/kg·bw/day for 90 days followed by a recovery period of 28 days. No appreciable toxic-related changes were observed in the 0.50 g/kg·bw/day group. When the animals received gardenia yellow at 1.50 g/kg·bw/day or more, body weight loss was observed, and pigments began to deposit in several vital organs, resulting in significant changes of several hematological and biochemical indicators related to the nutritional status of the body, liver and kidney function, more severe in the high dose group. In the recovery period, the alterations of the clinical symptoms and parameters were relieved a lot. Based on the results of the current study, the no observed adverse effect level (NOAEL) of gardenia yellow E500 in rats was set to be 0.50 g/kg·bw/day.

Modulation of cell proliferation, survival and gene expression by RAGE and TLR signaling in cells of the innate and adaptive immune response: role of p38 MAPK and NF-KB

Objective

The aim of this study was to evaluate a possible synergism between AGE-RAGE and TLR4 signaling and the role of p38 MAPK and NF-kB signaling pathways on the modulation of the expression of inflammatory cytokines and proliferation of cells from the innate and adaptive immune response.

Material and Methods

T lymphocyte (JM) and monocyte (U937) cell lines were stimulated with LPS and AGE-BSA independently and associated, both in the presence and absence of p38 MAPK and NF-kB inhibitors. Proliferation was assessed by direct counting and viability was assessed by a biochemical assay of mitochondrial function. Cytokine gene expression for RAGe, CCL3, CCR5, IL-6 and TNF-α was studied by RT-PCR and RT-qPCR.

Results

RAGE mRNA expression was detected in both cell lines. LPS and AGE-BSA did not influence cell proliferation and viability of either cell line up to 72 hours. LPS and LPS associated with AGE induced expression of IL-6 and TNF-α in monocytes and T cells, respectively.

Conclusions

There is no synergistic effect between RAGE and TLR signaling on the expression of IL-6, TNF-α , RAGE, CCR5 and CCL3 by monocytes and lymphocytes. Activation of RAGE associated or not with TLR signaling also had no effect on cell proliferation and survival of these cell types.

RahU: an inducible and functionally pleiotropic protein in Pseudomonas aeruginosa modulates innate immunity and inflammation in host cells

The aim of this study was to define the functional role of a recently identified RahU protein from Pseudomonas aeruginosa in macrophages and its role in bacterial defense. Recombinant (r)-RahU had no significant effect on cell apoptosis or cell viability in human monocytic THP-1 cells. Gene expression array of murine macrophage cells (RAW 264.7) stimulated with LPS showed modulation of common transcripts (by r-RahU and predisone) involved in inflammation. Functional cellular analysis showed RAW cells incubated with r-RahU at 1.0-10 μg/ml (0.06-0.6 μM) inhibited accumulation of nitric oxide (NO) in the presence of LPS by 10-50%. The IC(50) of r-RahU (0.6 μM) was distinct from the known inhibitors of NO production: prednisone (50 μM) and L-NMMA (100 μM). r-RahU also significantly inhibited chemotactic activity of THP-1 cells toward CCL2 or chemotactic supernatants from apoptotic T-cells. These reports show previously unknown pleiotropic properties of RahU in modulating both microbial physiology and host innate immunity.

Bioinformatics and Data Mining Studies in Oral Genomics and Proteomics: New Trends and Challenges

Genomics and proteomics have promised to change the practice of dentistry and oral pathology, allowing the identification and the characterization of risk factors and therapeutic targets at a molecular level. However, mass-scale molecular genomics and proteomics suffer from some pitfalls: gene/protein expression are significant only if inserted in a detailed network of molecular pathways and gene/gene, gene/protein and protein/protein interactions.

The proper analysis of these complex pictures requires the contribution of theoretical disciplines, like bioinformatics and data mining. In particular, data-mining of existing information could become a strong starting point to formulate new targeted hypotheses and to planad hocexperimentation.

In this review, advantages and disadvantages of the above-mentioned disciplines and their potential in oral pathology are discussed. The leader gene approach is a new data mining algorithm, recently applied to some oral diseases and their correlation with systemic conditions. The preliminary results of the application of the leader gene approach to the correlation between periodontitis and heart ischemia at a molecular level are presented for the first time.

Bioinformatics and data mining studies in oral genomics and proteomics: new trends and challenges

Genomics and proteomics have promised to change the practice of dentistry and oral pathology, allowing the identification and the characterization of risk factors and therapeutic targets at a molecular level. However, mass-scale molecular genomics and proteomics suffer from some pitfalls: gene/protein expression are significant only if inserted in a detailed network of molecular pathways and gene/gene, gene/protein and protein/protein interactions.

The proper analysis of these complex pictures requires the contribution of theoretical disciplines, like bioinformatics and data mining. In particular, data-mining of existing information could become a strong starting point to formulate new targeted hypotheses and to plan ad hoc experimentation.

In this review, advantages and disadvantages of the above-mentioned disciplines and their potential in oral pathology are discussed. The leader gene approach is a new data mining algorithm, recently applied to some oral diseases and their correlation with systemic conditions. The preliminary results of the application of the leader gene approach to the correlation between periodontitis and heart ischemia at a molecular level are presented for the first time.

Mycobacterium tuberculosis-induced expression of Leukotactin-1 is mediated by the PI3-K/PDK1/Akt signaling pathway

Chemokines function in the migration of circulating leukocytes to regions of inflammation, and have been implicated in chronic inflammatory conditions including mycobacterial infection. We investigated whether Leukotactin-1 (Lkn-1), a novel member of the CC-chemokines, is involved in the immune response of macrophages against Mycobacterium tuberculosis (MTB). In PMA-differentiated THP-1 cells, MTB infection increased mRNA expression of Lkn-1 in a dose-dependent manner. Lkn-1 induction peaked 12 h after infection, then declined gradually and returned to its basal level at 72 h. Secretion of Lkn-1 was elevated by MTB infection. The increase in expression and secretion of Lkn-1 caused by MTB was reduced in cells treated with inhibitors of phosphatidylinositol 3-kinase (PI3-K), 3-phosphoinositide-dependent kinase 1 (PDK1) and Akt. MTB-induced Akt phosphorylation was blocked by treatment with a PI3-K inhibitor or a PDK1 inhibitor, implying that PI3-K, PDK1, and Akt are associated with the signaling pathway that up-regulates Lkn-1 in response to MTB. These results suggest that Lkn-1 is novel member of the group of chemokines that is released by macrophages infected with MTB.

X-linked Foxp3 (Scurfy) mutation dominantly inhibits submandibular gland development and inflammation respectively through adaptive and innate immune mechanisms

Scurfy (Foxp3(Sf)/Y), Il2(-/-), and Il2ralpha(-/-) mice are deficient in CD4(+)Foxp3(+) regulatory T cells (Treg), but only the latter two develop inflammation in the submandibular gland (SMG), a critical target of Sjögren's syndrome. In this study, we investigated the reason that SMG of Scurfy (Sf), Sf.Il2(-/-), Sf.Il2ralpha(-/-), and the long-lived Sf.Fas(lpr/lpr) mice remained free of inflammation, even though their lymph node cells induced SMG inflammation in Rag1(-/-) recipients. A strong correlation was observed between the development of the granular convoluted tubules (GCT) of the SMG in these mice and SMG resistance to inflammation. Moreover, GCT development in Sf.Rag1(-/-) mice was not impeded, indicating a role of adaptive immunity. In the Sf.Fas(lpr/lpr) mice, this block was linked to atrophy and inflammation in the accessory reproductive organs. Testosterone treatment restored GCT expression, but did not induce SMG inflammation, indicating GCT is not required for inflammation and additional mechanisms were controlling SMG inflammation. Conversely, oral application of LPS induced SMG inflammation, but not GCT expression. LPS treatment induced up-regulation of several chemokines in SMG with little effect on the chemokine receptors on CD4(+) T cells in Sf mice. Our study demonstrates that Sf mutation affects SMG development through adaptive immunity against accessory reproductive organs, and the manifestation of SMG inflammation in Sf mice is critically controlled through innate immunity.