Lymphangioma of the tongue.
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Administration, Oral↗
Biomedical subjects
S Krisanaprakornkit
Publications and source records attributed to S Krisanaprakornkit.
Oral lesions and dental caries status in perinatally HIV-infected children in Northern Thailand.
UNLABELLED: To describe the prevalence of oral lesions and dental caries status in perinatally HIV-infected children. DESIGN: A cross-sectional study. SETTING: Paediatric HIV outpatient department at the Nakornping Provincial Hospital, Chiang Mai, Thailand. PATIENTS AND METHODS: Forty children with perinatal HIV infection, from early infancy to 12 years of age, were included in the study. These children were examined for oral lesions and dental caries. A number of children receiving antifungal and antiretroviral (ART) therapy were recorded. RESULTS: The mean DMFT and DMFS scores were both 2.1 (SD = 2.3). The dft and dfs scores were 4.1 (SD = 5.0) and 10.9 (SD = 14.8), respectively. A total of 57.5% of the children had one or more oral lesions. Oral candidiasis and hairy leukoplakia were the most common oral lesions. Only 12.5% of children had received ART. A total of 22.5% of the children had a history of receiving antifungal therapy. CONCLUSIONS: Oral lesions and dental caries were relatively high in this study. Consequently, treatment and prevention for oral lesions and dental caries are inevitably required for children with HIV infection in Northern Thailand. Furthermore, ART should be made available for all HIV-infected children to decrease the prevalence of HIV-associated oral lesions.
Anti-HIV Agents↗
Intracellular calcium in signaling human beta-defensin-2 expression in oral epithelial cells.
Expression of human beta-defensins is correlated with differentiation in the oral epithelium, consistent with their function as part of the epithelial antimicrobial barrier. Because calcium is a known regulator of epithelial differentiation, we tested the hypothesis that calcium concentration mediates beta-defensin expression. Gingival epithelial cells were cultured in medium containing low calcium concentration (0.03 mM), then either changed to high extracellular calcium concentrations or stimulated with thapsigargin to release intracellular calcium stores in the presence or absence of BAPTA-AM, a calcium chelator. Human beta-defensin-2 (hBD-2) mRNA expression was rapidly induced by thapsigargin, and more slowly induced by high extracellular calcium. Induction of hBD-2 peptide was confirmed by immunofluorescence. BAPTA-AM inhibited hBD-2 induction by both thapsigargin and calcium in a dose-dependent fashion. In addition, BAPTA-AM inhibited hBD-2 induction by a bacterial stimulant. Collectively, these findings demonstrate that intracellular calcium is a critical mediator of hBD-2 expression. Abbreviations used in this study are: BAPTA-AM, 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetra-acetic acid tetrakis (acetoxymethyl ester); DMSO, dimethylsulfoxide; F. nucleatum, Fusobacterium nucleatum; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; HBDs, human beta-defensins; HGECs, human gingival epithelial cells; MAP, mitogen-activated protein; and RT-PCR, reverse-transcriptase/polymerase chain-reaction.
Adenosine Triphosphatases↗
Detection of beta-defensins secreted by human oral epithelial cells.
Human beta-defensins are antimicrobial peptides that may be critical in the innate immune response to infection. hBD1 and hBD2 are expressed in oral epithelial cells and are detected near the surface of oral tissue, consistent with a role in the epithelial protective barrier function. In this report, we examine secretion of beta-defensins in vitro and in biological fluid using ProteinChip(R) Array, surface enhanced laser desorption/ionization (SELDI) technology combined with time-of-flight mass spectrometry. We show that the 47-amino acid form of hBD1 and the 41-amino acid form of hBD2 are the major secreted forms. These forms are both expressed and secreted under conditions anticipated from previous analysis of beta-defensin mRNAs; specifically, hBD1 is detected in culture supernatant from both unstimulated and stimulated cells, and hBD2 is detected only in stimulated cells. Identity of hBD1 and hBD2 was confirmed by immunocapture on the ProteinChip surface. Both peptides are also present in gingival crevicular fluid that accumulates between the tissue and tooth surface, although hBD1 is also found in several smaller forms suggesting extracellular proteolysis. This methodology offers several technical advantages for detection of defensins in biological fluids, including ease and speed of screening, no need for HPLC preliminary processing, and small sample size.
Cells, Cultured↗
Defensin antimicrobial peptides in the oral cavity.
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Anti-Infective Agents↗
Localized antimicrobial peptide expression in human gingiva.
The stratified epithelia of the oral cavity are continually exposed to bacterial challenge that is initially resisted by innate epithelial factors and by the recruitment of neutrophils. Antimicrobial peptides from phagocytes and epithelia contribute to this antimicrobial barrier. Using antibodies and in situ hybridization, we explored antimicrobial peptide expression in the varied epithelia of the periodontium and in cultured gingival epithelial cells. In gingival tissue, mRNA for the beta-defensins, human beta-defensin 1 (hBD-1) and human beta-defensin 2 (hBD-2) was predominately localized in suprabasal stratified epithelium and the peptides were detected in upper epithelial layers consistent with the formation of the stratified epithelial barrier. In cultured epithelial cells, both hBD-1 and -2 peptides were detected only in differentiating, involucrin-positive epithelial cells, although hBD-2 required stimulation by proinflammatory mediators or bacterial products for expression. Beta-defensins were not detected in junctional epithelium (JE) that serves as the attachment to the tooth surface. In contrast, alpha-defensins and cathelicidin family member LL-37 were detected in polymorphonuclear neutrophils (PMNs) that migrate through the JE, a localization that persists during inflammation, when the JE and surrounding tissue are highly infiltrated with PMNs. Thus, the undifferentiated JE contains exogenously expressed alpha-defensins and LL-37, and the stratified epithelium contains endogenously expressed beta-defensins. These findings show that defensins and other antimicrobial peptides are localized in specific sites in the gingiva, are synthesized in different cell types, and are likely to serve different roles in various regions of the periodontium.
Adult↗
Inducible expression of human beta-defensin 2 by Fusobacterium nucleatum in oral epithelial cells: multiple signaling pathways and role of commensal bacteria in innate immunity and the epithelial barrier.
Human gingival epithelial cells (HGE) express two antimicrobial peptides of the beta-defensin family, human beta-defensin 1 (hBD-1) and hBD-2, as well as cytokines and chemokines that contribute to innate immunity. In the present study, the expression and transcriptional regulation of hBD-2 was examined. HBD-2 mRNA was induced by cell wall extract of Fusobacterium nucleatum, an oral commensal microorganism, but not by that of Porphyromonas gingivalis, a periodontal pathogen. HBD-2 mRNA was also induced by the proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) and phorbol myristate acetate (PMA), an epithelial cell activator. HBD-2 mRNA was also expressed in 14 of 15 noninflamed gingival tissue samples. HBD-2 peptide was detected by immunofluorescence in HGE stimulated with F. nucleatum cell wall, consistent with induction of the mRNA by this stimulant. Kinetic analysis indicates involvement of multiple distinct signaling pathways in the regulation of hBD-2 mRNA; TNF-alpha and F. nucleatum cell wall induced hBD-2 mRNA rapidly (2 to 4 h), while PMA stimulation was slower ( approximately 10 h). In contrast, each stimulant induced interleukin 8 (IL-8) within 1 h. The role of TNF-alpha as an intermediary in F. nucleatum signaling was ruled out by addition of anti-TNF-alpha that did not inhibit hBD-2 induction. However, inhibitor studies show that F. nucleatum stimulation of hBD-2 mRNA requires both new gene transcription and new protein synthesis. Bacterial lipopolysaccharides isolated from Escherichia coli and F. nucleatum were poor stimulants of hBD-2, although they up-regulated IL-8 mRNA. Collectively, our findings show inducible expression of hBD-2 mRNA via multiple pathways in HGE in a pattern that is distinct from that of IL-8 expression. We suggest that different aspects of innate immune responses are differentially regulated and that commensal organisms have a role in stimulating mucosal epithelial cells in maintaining the barrier that contributes to homeostasis and host defense.
Adolescent↗
Expression of the peptide antibiotic human beta-defensin 1 in cultured gingival epithelial cells and gingival tissue.
Human beta-defensin-1 (hBD-1) is a member of the family of small cationic antimicrobial peptides that have been identified in several mucosal epithelia. Because human gingival epithelium is a site that is constantly challenged by oral microorganisms, we examined the expression of hBD-1 in human gingival epithelial and fibroblast cell cultures and tissue samples. Cell cultures were challenged with cell wall extracts of Porphyromonas gingivalis or Fusobacterium nucleatum, Escherichia coli lipopolysaccharide, tumor necrosis factor alpha, or phorbol myristate acetate. hBD-1 mRNA was detected in unstimulated and stimulated cultures by reverse transcription (RT)-PCR using several primer sets specific for hBD-1. Gingival epithelial cells, but not gingival fibroblasts, expressed a product of the predicted size for hBD-1 mRNA. The sequence of the PCR product was identical to that of hBD-1. hBD-1 mRNA expression was not significantly modulated by any of the stimulants tested. Human gingival tissues from noninflamed and inflamed sites were also analyzed by RT-PCR. hBD-1 mRNA was expressed in all tissue samples. The relative expression of hBD-1 mRNA was similar in noninflamed and inflamed tissues obtained from each of four patients undergoing treatment for periodontitis. However, the relative expression of hBD-1 mRNA varied in gingival biopsies obtained from 15 different normal individuals, and the relative hBD-1 expression was unrelated to interleukin-8 expression. Our findings show the constitutive expression of hBD-1 mRNA in cultured epithelial cells and gingival tissues but not gingival fibroblasts. These findings suggest that expression of hBD-1 may play a role as part of the innate host defenses in maintaining normal gingival health.
Adult↗
Epithelial antimicrobial peptides: review and significance for oral applications.
Epithelial tissues provide the first line of defense between an organism and the environment. Disruption of this barrier leads to bacterial invasion and subsequent inflammation. This is precisely the situation existing in the human oral cavity, where tissues are constantly exposed to a variety of microbial challenges that can lead to bacterially induced periodontal diseases, and to infections of the oral mucosa by bacteria, fungi, and viruses. With the recent discoveries of host-derived peptide antibiotics in mammalian mucosal epithelium, a new line of investigation is emerging to test the hypothesis that one class of these peptides, called "beta-defensins", functions to protect the host against microbial pathogenesis at these critical, confrontational sites. In that light, impairment of beta-defensin activity has recently been implicated in chronic bacterial infections in cystic fibrosis patients. The first direct evidence of expression of defensin peptides in the oral mucosa was the identification of a novel epithelial beta-defensin in mammalian tongue. It was shown to be upregulated in inflammation, suggesting that it participates in host defense. It is theorized that epithelial cell-derived antimicrobial peptides function to keep the natural flora of micro-organisms in a steady state in different niches such as the skin, the intestines, the airway, the endocervix, and the mouth. There is now evidence indicating that normal gingival epithelial cells and tissues express two beta-defensins, hBD-1 and the newly described hBD-2. In addition, a cathelin-class antimicrobial peptide, designated LL-37 and found in human neutrophils, is also expressed in skin and gingiva. It is highly likely that these and/or other epithelial antimicrobial peptides play an important role in determining the outcome of the host-pathogen interaction at the oral mucosal barrier, and that they may have important future applications in antibiotic treatment.
Amino Acid Sequence↗