Search Results (50)

Objectives: This study aims to explore the histological dimensions of the gingiva and the alveolar mucosa and to evaluate their associations with gingival phenotypic parameters, including gingival thickness (GT), keratinized tissue width (KTW), and gingival transparency. Methods: Histological and clinical assessments were performed on 45 healthy volunteers. Gingival and mucosal tissue samples were collected from the mucogingival junction region of one maxillary central incisor. Histomorphometric analysis included measurements of gingival and mucosal thickness, epithelial thickness, connective tissue thickness, epithelial papilla length and density, and keratinization. Clinical parameters included KTW and probe visibility upon insertion into the gingival sulcus. Correlations were statistically analyzed between clinical and histological parameters. Results: Probe visibility showed no significant correlations with any assessed parameter. Histological gingival thickness strongly correlated with gingival connective tissue thickness, moderately with epithelial thickness and papilla length, and weakly with papilla density. Mucosal thickness was strongly associated with connective tissue thickness and moderately with keratinization, but not with other parameters. KTW exhibited weak correlations with epithelial thickness and papilla length. Conclusions: Variability in gingival and mucosal thickness is primarily determined by connective tissue thickness, with a smaller contribution from the epithelium. Increased thickness is associated with longer, sparser epithelial papillae and with a tendency toward higher keratinization. KTW is significantly associated with epithelial thickness and papilla length, underscoring its relevance in gingival phenotype characterization. Full article

Gingival inflammation compromises the integrity of the gingival epithelium and the underlying tissues, highlighting the need for adjuvant therapies with immunomodulatory and healing properties. Casearia sylvestris, a medicinal plant known as guaçatonga, is traditionally used to treat inflammatory lesions. This study aimed to investigate the effects of C. sylvestris on the synthesis of pro- and anti-inflammatory, proteolytic, and antioxidant molecules and on wound healing in epithelial cells. A human telomerase-immortalized gingival keratinocyte cell line (TIGKs) was used, and cells were exposed to Escherichia coli lipopolysaccharide (LPS) in the presence and absence of C. sylvestris extract, its diterpene-concentrated fraction, and its clerodane diterpene casearin J for 24 h and 48 h. Gene expression and protein synthesis were analyzed by RT-qPCR and ELISA, respectively. Nitric oxide (NO) and NF-κB activation were analyzed by Griess reaction and immunofluorescence, respectively. Additionally, cell viability was evaluated by alamarBlue^® assay, and an automated scratch assay was used for wound healing. LPS significantly increased the expression of cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-10, IL-17), proteases (MMP-1 and MMP-13), iNOS as well as NO synthesis, and triggered NF-κB nuclear translocation. It also reduced IL-4 expression, cell viability, and cellular wound repopulation. Treatment with C. sylvestris derivatives significantly abrogated all aforementioned LPS-induced effects by 80–100%. Furthermore, even at higher concentrations, C. sylvestris did not affect cell viability, thus proving the safety of its derivatives. C. sylvestris exerts anti-inflammatory, antiproteolytic, and antioxidant effects on gingival keratinocytes, highlighting its potential as a valuable adjunct in the prevention and treatment of periodontal diseases. Full article

This scoping review explores the expression patterns and molecular features of sarcoglycans (SGs) in non-muscle organs, challenging the long-standing assumption that their function is confined to skeletal and cardiac muscle. By analyzing evidence from both animal models and human studies, the review highlights the widespread presence of SG subunits in organs, including the nervous system, glands, adipose tissue, oral mucosa, retina, and other structures, with distinct regional and cell-type-specific patterns. Studies on the central nervous system demonstrate a widespread “spot-like” distribution of SG subunits in neurons and glial cells, implicating their involvement in synaptic organization and neurotransmission. Similarly, SGs maintain cellular integrity and homeostasis in glands and adipose tissue. At the same time, the altered expression of SGs is associated with pathological conditions in the gingival epithelium of the oral mucosa. These findings underscore the multifaceted roles of SGs beyond muscle, suggesting that they may contribute to cellular signaling, membrane stability, and neurovascular coupling. However, significant gaps remain regarding SG post-translational modifications and functional implications in non-muscle organs. Future research integrating molecular, cellular, and functional approaches in animal models and human tissues is essential to fully elucidate these roles and explore their potential as therapeutic targets in various diseases. Full article

The junctional epithelium, which lines the inner gingival surface, seals the gingival sulcus to block the infiltration of food debris and pathogens. The junctional epithelium is derived from the reduced enamel epithelium, consisting of late developmental stage ameloblasts and accessory cells. No prior studies have investigated whether defective ameloblast differentiation or enamel matrix formation affects junctional epithelium anatomy or function. Here, we examined the junctional epithelium in mice exhibiting amelogenesis imperfecta due to loss-of-function mutations in the major enamel matrix protein amelogenin (Amelx^−/−) or the critical enamel matrix protease KLK4 (Klk4^−/−). Histological analyses demonstrated altered morphology and cell layer thickness of the junctional epithelium in Amelx^−/− and Klk4^−/− mice as compared to wt. Immunohistochemistry revealed reduced ODAM, laminin 5, and integrin α6, all of which are critical for the adhesion of the junctional epithelium to the enamel in Amelx^−/− and Klk4^−/− mice. Furthermore, we observed altered cell–cell adhesion and increased permeability of Dextran-GFP through the mutants’ junctional epithelium, indicating defective barrier function. Reduced β-catenin and Ki67 at the base of the junctional epithelium in mutants suggest impaired mitotic activity and reduced capacity to replenish continuously desquamated epithelium. These findings highlight the essential role of normal amelogenesis in maintaining junctional epithelium homeostasis. Full article

This study first examines the potential of using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) to extract molecular and organizational markers from human oral mucosa. These indicators are then examined in relation to age and pathophysiological conditions. Oral mucosa biopsies were collected from 38 patients during surgical procedures and analyzed using FTIR and DSC-validated protocols. The patients were divided into two age groups, namely 20–40 and 70–90 years. Vibrational markers of the lamina propria and epithelium, including lipid-to-protein and collagen-to-protein ratios and lipid order, were extracted from the FTIR spectra of both layers. Hydration levels and collagen thermal stability were determined from DSC thermograms of the entire biopsy. The preliminary findings of this study, which will require further validation in a larger patient cohort, indicate a significant decrease in bound water content and collagen denaturation temperature in the older population. This suggests that oral mucosa undergoes structural dehydration and collagen destabilization with age. Further comparisons within the older group revealed links between biophysical markers of the oral mucosa and chronic or local pathologies. Patients with cardiovascular diseases exhibit altered collagen organization, while patients with diabetes display differences in the lipid-to-protein ratio and the order of lipid chains in the epithelium. Gingivitis is associated with variations in the collagen-to-protein ratio, which supports the role of inflammation in extracellular matrix remodeling. Full article

Regenerative processes occur at various levels in all organisms, yet their complexity continues to raise new questions about their mechanisms. It has been demonstrated that small extracellular vesicles (sEVs), secreted by all cells and influencing their function, play a significant role in regeneration. In the context of regenerative processes, oral mucosal tissues consistently receive interest, as they are among the most rapidly healing tissues in the human body. In this study, we utilized spatial transcriptomics to map gene expression to specific spatial locations within the gingiva tissue section, using publicly available transcriptomic data. This analysis revealed new insights into this tissue and the biogenesis of sEVs within it. The identified clusters encompassed two main regions—the epithelium and lamina propria—as well as minor niches within them. Using Gene Ontology (GO) analysis, we identified two clusters most enriched in extracellular vesicle-related GO processes. These included the superficial and deeper layers of the sulcular epithelium, one of the most peripheral regions of the gingiva. Of the 43 genes identified in the literature as having a potential or documented role in sEVs biogenesis, 12 were selected for further analysis. MUC1, SDCBP2, and VPS37B showed clear specificity and the highest expression in the superficial layer of the sulcular epithelium. CHMP4C also exhibited high expression in this layer, though its levels were comparable to the outer layer of the oral epithelium. Other well-established sEVs marker genes, such as ANXA2, CD9, CD63, CD81, FLOT1, RAB22A, RAB27B, and RAB5A, were also expressed in the examined tissue; however, their expression was not specifically exclusive to the sulcular epithelium. Our study is the first to perform a meta-analysis of available gingival transcriptomic data in the specific context of sEVs biogenesis. The presented data and conclusions provide new insights into the role of different structures within healthy human gingiva and shed new light on both known and potential markers of sEVs biogenesis. These findings may contribute to the development of regeneration-targeted research, especially on oral tissues. Full article

Background: Drug-induced gingival enlargement is a commonly documented adverse effect in patients administered with calcium antagonist medications. Nifedipine is the medicine most frequently linked to instances of gingival enlargement; nevertheless, amlodipine, likewise a calcium antagonist, can elicit this adverse effect. This case report aims to detail a case of amlodipine-induced gingival hyperplasia, emphasizing the significance of a multidisciplinary approach and outlining its therapy across various surgical phases. Methods: A 48-year-old hypertensive patient using amlodipine therapy presents with aberrant gingival tissue growth in the upper arch. Intraoral examination reveals localized inflammation and tissue enlargement in the papillae areas of the upper arch gingiva, leading to partial covering of the dental crowns. The patient experienced painful sensations and episodes of spontaneous bleeding in the enlarged gingival tissue. Following an initial professional dental hygiene treatment, which included root planning in the upper quadrants, and in consultation with the referring cardiologist, it was determined to discontinue amlodipine and initiate a replacement therapy with olmesartan medoxomil. Fifteen days following the cessation of amlodipine, surgical excision of the thickened interdental gingival tissues in the anterior region was conducted to obtain biopsies for histological confirmation of the observed pathological condition. Results: Histopathological examination validated the diagnosis of drug-induced gingival enlargement, characterized by chorion fibrosis and significant lymphoplasmacytic infiltration. Specifically, parakeratotic and acanthotic characteristics were seen in the gingival epithelium. Adjacent to the inflammatory regions, fibrosis was noted, along with the presence of cytoid bodies, which are typically linked to pathological diseases driven by inflammatory processes. These histological characteristics were consistent with the diagnosis of drug-induced gingival enlargement. Conclusions: A multidisciplinary approach involving the treating physician, dentist, and hygienist, incorporating drug replacement and targeted oral hygiene sessions, is crucial for the management and resolution of calcium channel blocker-induced gingival enlargement. Full article

Background: Supragingival polishing is a crucial part of nonsurgical periodontal therapy. In recent years, air polishing has been used for this purpose, introducing different polishing powders. The purpose of the following study was to investigate the damage to the gingival margin during air polishing by an inexperienced operator. Methods: Five porcine models were polished by means of three different polishing powders: calcium carbonate, sodium bicarbonate, and erythritol. Their impact on the gingival margin was examined by means of histological and scanning electron microscopical observations and compared to healthy samples and samples polished with a polishing brush and paste. Results: The histological observations revealed superficial to minor lesions limited in the epithelium by all the groups tested. Both examination protocols demonstrated less invasiveness of the erythritol-based polishing powder. Conclusions: Within the limitations of the present study, it could be concluded that air polishing is a safe instrumentation method for periodontal therapy even in inexperienced hands when the exact protocol is followed. The erythritol-based polishing powder seems to provide less of an impact on the gingival margin. Full article

Although cytoplasmic intermediate filaments (cIFs) are essential for cell physiology, the molecular and cell functional consequences of cIF disturbances are poorly understood. Identifying defaults in cell function-controlled tissue homeostasis and understanding the interrelationship between specific cIFs and distinct cell functions remain key challenges. Using an RNAi-based mechanistic approach, we connected the impairment of cell-inherent cIFs with molecular and cell functional consequences, such as proliferation and differentiation. To investigate cIF disruption consequences in the oral epithelium, different cell transformation stages, originating from alcohol-treated oral gingival keratinocytes, were used. We found that impairment of keratin (KRT) KRT5, KRT14 and vimentin (VIM) affects proliferation and differentiation, and modulates the chromatin status. Furthermore, cIF impairment reduces the expression of nuclear integrity participant lamin B1 and the terminal keratinocyte differentiation marker involucrin (IVL). Conversely, impairment of IVL reduces cIF expression levels, functionally suggesting a regulatory interaction between cIFs and IVL. The findings demonstrate that the impairment of cIFs leads to imbalances in proliferation and differentiation, both of which are essential for tissue homeostasis. Thus, targeted impairment of cIFs appears promising to investigate the functional role of cIFs on cell-dependent tissue physiology at the molecular level and identifies putative interactions of cIFs with epithelial differentiation. Full article

The periodontium comprising periodontal ligament (PDL), gingiva, and epithelium play crucial roles in maintaining tooth integrity and function. Understanding tissue cellular composition and gene expression is crucial for illuminating periodontal pathophysiology. This study aimed to identify tissue-specific markers via scRNA-Seq. Primary human PDL, gingiva, and epithelium tissues (n = 7) were subjected to cell hashing and sorting. scRNA-Seq library preparation using 10× Genomics protocol and Illumina sequencing was conducted. The analysis was performed using Cellranger (v3.1.0), with downstream analysis via R packages Seurat (v5.0.1) and SCORPIUS (v1.0.9). Investigations identified eight distinct cellular clusters, revealing the ubiquitous presence of epithelial and gingival cells. PDL cells evolved in two clusters with numerical superiority. The other clusters showed varied predominance regarding gingival and epithelial cells or an equitable distribution of both. The cluster harboring most cells mainly consisted of PDL cells and was present in all donors. Some of the other clusters were also tissue-inherent, while the presence of others was environmentally influenced, revealing variability across donors. Two clusters exhibited genetic profiles associated with tissue development and cellular integrity, respectively, while all other clusters were distinguished by genes characteristic of immune responses. Developmental trajectory analysis uncovered that PDL cells may develop after epithelial and gingival cells, suggesting the inherent PDL cell-dominated cluster as a final developmental stage. This single-cell RNA sequencing study delineates the hierarchical organization of periodontal tissue development, identifies tissue-specific markers, and reveals the influence of environmental factors on cellular composition, advancing our understanding of periodontal biology and offering potential insights for therapeutic interventions. Full article

This study aims to histologically and immunohistochemically evaluate the effect recombinant human bone morphogenetic protein (rh-BMP2) injected in gingival tissue has on the acceleration of the epithelial migration from the wound edges and epithelial cell proliferation after implant surgery. Material and Methods: The study includes 20 patients who underwent bilateral implant surgeries in the premolar-molar region of the mandible, followed by guided bone regeneration. Each patient received an implant in both locations, but rh-BMP2 was only on the right side. At 9 days from the surgery, a gingival biopsy was performed 3 mm distally to the last implant. In total, 20 samples were collected from the left side (control group #1) and 20 from right (test group #1). This was repeated at a 4-month interval during healing abutment placements. Tissues were processed and stained with hematoxylin-eosin and then immunohistochemically for the expression of Ki-67 and further histological examination. Result: Complete closure of the epithelium with new cell formation was observed in the 55% test group and 20% control group after 9 days. At 4 months, although 100% samples of all groups had complete epithelial closure, the test group showed that the epithelial cells were more organized and mature due to the increased number of blood vessels. The average number of new epithelial cells was 17.15 ± 7.545 and 16.12 ± 7.683 cells per mm in test group, respectively, at 9 days and 4 months and 10.99 ± 5.660 and 10.95 ± 5.768 in control groups. Conclusion: Evident from histological observations, rh-BMP-2 can accelerate the closure of gingival wounds, the healing process of epithelial gingival tissue, and the formation of epithelial cells in patients undergoing dental implant treatment. Full article

The oral mucosa represents a defensive barrier between the external environment and the rest of the body. Oral mucosal cells are constantly bathed in hypotonic saliva (normally one-third tonicity compared to plasma) and are repeatedly exposed to environmental stresses of tonicity, temperature, and pH by the drinks we imbibe (e.g., hypotonic: water, tea, and coffee; hypertonic: assorted fruit juices, and red wines). In the mouth, the broad-spectrum antiviral mediator MxA (a dynamin-family large GTPase) is constitutively expressed in healthy periodontal tissues and induced by Type III interferons (e.g., IFN-λ1/IL-29). Endogenously induced human MxA and exogenously expressed human GFP-MxA formed membraneless biomolecular condensates in the cytoplasm of oral carcinoma cells (OECM1 cell line). These condensates likely represent storage granules in equilibrium with antivirally active dispersed MxA. Remarkably, cytoplasmic MxA condensates were exquisitely sensitive sensors of hypotonicity—the condensates in oral epithelium disassembled within 1–2 min of exposure of cells to saliva-like one-third hypotonicity, and spontaneously reassembled in the next 4–7 min. Water, tea, and coffee enhanced this disassembly. Fluorescence changes in OECM1 cells preloaded with calcein-AM (a reporter of cytosolic “macromolecular crowding”) confirmed that this process involved macromolecular uncrowding and subsequent recrowding secondary to changes in cell volume. However, hypertonicity had little effect on MxA condensates. The spontaneous reassembly of GFP-MxA condensates in oral epithelial cells, even under continuous saliva-like hypotonicity, was slowed by the protein-phosphatase-inhibitor cyclosporin A (CsA) and by the K-channel-blocker tetraethylammonium chloride (TEA); this is suggestive of the involvement of the volume-sensitive WNK kinase-protein phosphatase (PTP)-K-Cl cotransporter (KCC) pathway in the regulated volume decrease (RVD) during condensate reassembly in oral cells. The present study identifies a novel subcellular consequence of hypotonic stress in oral epithelial cells, in terms of the rapid and dynamic changes in the structure of one class of phase-separated biomolecular condensates in the cytoplasm—the antiviral MxA condensates. More generally, the data raise the possibility that hypotonicity-driven stresses likely affect other intracellular functions involving liquid–liquid phase separation (LLPS) in cells of the oral mucosa. Full article

Areca nut is a major contributor to the high prevalence of oral cancer in Asia. The precise mechanisms by which areca nut stimulates mucosal cells and contributes to the progression of oral cancer urgently require clarification. The current study aimed to assess the effects of arecoline on the normal human gingival epithelium cell line S-G. Cell viability, levels of reactive oxygen species (ROS), protein expression, cellular morphology, and gene expression were evaluated using the MTT test, flow cytometry, Western blot analysis, optical or confocal microscopy, and RT-qPCR. Keratin (KRT6) analysis involved matched normal and cancer tissues from clinical head and neck specimens. The results demonstrated that 12.5 µg/mL of arecoline induced ROS production, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) mRNA expression in S-G cells. This activation of the MAPK/ERK pathway increased KRT6 expression while limiting cell migration. In head and neck cancer tissues, KRT6B gene expression exceeded that of normal tissues. This study confirms that arecoline induces ROS accumulation in normal cells, leading to the secretion of proinflammatory factors and KRT6 expression. This impedes oral mucosal healing, thereby promoting the progression of oral cancer. Full article

Recently, we reported that oral-epithelial cells (OE) are unique in their response to Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) in that cell cycle arrest (G2/M) occurs without leading to apoptosis. We now demonstrate that Cdt-induced cell cycle arrest in OE has a duration of at least 7 days with no change in viability. Moreover, toxin-treated OE develops a new phenotype consistent with cellular senescence; this includes increased senescence-associated β-galactosidase (SA-β-gal) activity and accumulation of the lipopigment, lipofuscin. Moreover, the cells exhibit a secretory profile associated with cellular senescence known as the senescence-associated secretory phenotype (SASP), which includes IL-6, IL-8 and RANKL. Another unique feature of Cdt-induced OE senescence is disruption of barrier function, as shown by loss of transepithelial electrical resistance and confocal microscopic assessment of primary gingival keratinocyte structure. Finally, we demonstrate that Cdt-induced senescence is dependent upon the host cell protein cellugyrin, a homologue of the synaptic vesicle protein synaptogyrin. Collectively, these observations point to a novel pathogenic outcome in oral epithelium that we propose contributes to both A. actinomycetemcomitans infection and periodontal disease progression. Full article

A number of studies have recently demonstrated the effectiveness of CO₂ laser irradiation for the repair and regeneration of scar tissue from injuries or surgical wounds. However, such studies of the oral mucosa are highly limited. Previous studies using CO₂ laser irradiation have indicated that two factors contribute to esthetic healing, namely, artificial scabs, which are a coagulated and carbonized blood layer formed on the wound surface, and photobiomodulation therapy (PBMT) for suppressing wound scarring and promoting wound healing. This review outlines basic research and clinical studies of esthetic healing with the use of a CO₂ laser for both artificial scab formation by high-intensity laser therapy and PBMT in the treatment of injuries and surgical wounds with small parenchymal defects in oral soft tissues. The results showed that the wound surface was covered by an artificial scab, enabling the accumulation of blood and the perfusion necessary for tissue regeneration and repair. Subsequent PBMT also downregulated the expression of transformation growth factor-b1, which is involved in tissue scarring, and decreased the appearance of myofibroblasts. Taken together, artificial scabs and PBMT using CO₂ lasers contribute to the suppression of scarring in the tissue repair process, leading to favorable esthetic and functional outcomes of wound healing. Full article