Early antitumor activity of oral Langerhans cells is compromised by a carcinogen.

Early diagnosis of oral squamous cell carcinoma (OSCC) remains an unmet clinical need. Therefore, elucidating the initial events of OSCC preceding tumor development could benefit OSCC prognosis. Here, we define the Langerhans cells (LCs) of the tongue and demonstrate that LCs protect the epithelium from carcinogen-induced OSCC by rapidly priming αßT cells capable of eliminating γH2AX+ epithelial cells, whereas γδT and natural killer cells are dispensable. The carcinogen, however, dysregulates the epithelial resident mononuclear phagocytes, reducing LC frequencies, while dendritic cells (DCs), macrophages, and plasmacytoid DCs (pDCs) populate the epithelium. Single-cell RNA-sequencing analysis indicates that these newly differentiated cells display an immunosuppressive phenotype accompanied by an expansion of T regulatory (Treg) cells. Accumulation of the Treg cells was regulated, in part, by pDCs and precedes the formation of visible tumors. This suggests LCs play an early protective role during OSCC, yet the capacity of the carcinogen to dysregulate the differentiation of mononuclear phagocytes facilitates oral carcinogenesis.

Periodontal Disease and Its Association with Metabolic Syndrome-A Comprehensive Review.

Periodontal disease is a complex and progressive chronic inflammatory condition that leads to the loss of alveolar bone and teeth. It has been associated with various systemic diseases, including diabetes mellitus and obesity, among others. Some of these conditions are part of the metabolic syndrome cluster, a group of interconnected systemic diseases that significantly raise the risk of cardiovascular diseases, diabetes mellitus, and stroke. The metabolic syndrome cluster encompasses central obesity, dyslipidemia, insulin resistance, and hypertension. In this review, our objective is to investigate the correlation between periodontal disease and the components and outcomes of the metabolic syndrome cluster. By doing so, we aim to gain insights into the fundamental mechanisms that link each systemic condition with the metabolic syndrome. This deeper understanding of the interplay between these conditions and periodontal disease can pave the way for more effective treatments that take into account the broader impact of managing periodontal disease on the comprehensive treatment of systemic diseases, and vice versa.

Cell-intrinsic regulation of murine epidermal Langerhans cells by protein S.

AXL, a member of the TYRO3, AXL, and MERTK (TAM) receptor tyrosine kinase family, has been shown to play a role in the differentiation and activation of epidermal Langerhans cells (LCs). Here, we demonstrate that growth arrest-specific 6 (GAS6) protein, the predominant ligand of AXL, has no impact on LC differentiation and homeostasis. We thus examined the role of protein S (PROS1), the other TAM ligand acting primarily via TYRO3 and MERTK, in LC function. Genetic ablation of PROS1 in keratinocytes resulted in a typical postnatal differentiation of LCs; however, a significant reduction in LC frequencies was observed in adult mice due to increased apoptosis. This was attributed to altered expression of cytokines involved in LC development and tissue homeostasis within keratinocytes. PROS1 was then excised in LysM+ cells to target LCs at early embryonic developmental stages, as well as in adult monocytes that also give rise to LCs. Differentiation and homeostasis of LCs derived from embryonic precursors was not affected following Pros1 ablation. However, differentiation of LCs from bone marrow (BM) precursors in vitro was accelerated, as was their capability to reconstitute epidermal LCs in vivo. These reveal an inhibitory role for PROS1 on BM-derived LCs. Collectively, this study highlights a cell-specific regulation of LC differentiation and homeostasis by TAM signaling.

The Influence of Shockwave Therapy on Orthodontic Tooth Movement Induced in the Rat.

Shockwave therapy is used in medicine due to its ability to stimulate healing processes. The application of orthodontic force evokes an inflammatory reaction resulting in tooth movement. Shockwave therapy might have an effect on both inflammatory and periodonal ligament cytokine profiles. Our aim was to evaluate the fluctuations of different inflammatory cytokines after orthodontic force induction with and without shockwave therapy. An orthodontic appliance was applied between the rats' molars and incisors. In conjunction with the commencement of orthodontic force, the rats were treated with a single episode of 1000 shock waves and the gingival crevicular fluid was collected for 3 days. The expression and concentration of different cytokines was evaluated by a commercial 4-multiplex fluorescent bead-based immunoassay. The level of all cytokines displayed a similar trend in both shockwave-treated and untreated groups; the concentration peaked on the first day and declined thereafter. In all cases, however, the cytokine levels were smaller in the shockwave-treated than in untreated animals; a significant difference was found for sRANKL and borderline difference for IL-6 on Day 1. We conclude that shockwave therapy during the induction of orthodontic tooth movement influences the expression of inflammatory cytokines.

Cloning, purification and characterization of human dentine matrix protein 1(DMP1).

Introduction: Human teeth are composed mainly of dentin, formed by the odontoblasts. Dentin matrix protein 1 (DMP1) is one of odontoblast differentiation's most important growth factors. Human DMP1 has yet to be completely identified or studied. This study aimed to clone and characterize human DMP1. Materials and methods: The DMP1 gene sequence was prepared and cloned by transfection of human 293 cells. Results: The recombinant DMP1 was purified and characterized. Conclusion: The results suggested its future use in dental tissue regeneration and tissue engineering.

Orthodontic force and extracorporeal shock wave therapy: Assessment of orthodontic tooth movement and bone morphometry in a rat model.

OBJECTIVE: The objective was to investigate the effect of extracorporeal shock wave therapy (ESWT) on the magnitude of orthodontic tooth movement, in a rat model, based on a previously established treatment protocol. DESIGN: In conjunction with orthodontic force commencement, rats underwent ESWT. The amount of tooth movement along with different microarchitectural parameters were measured after three weeks by means of microcomputed tomography. In addition, the percentage of cells expressing vascular endothelial growth factor, the number of tartrate-resistant acid phosphatase (TRAP) positive cells/area and blood vessel density were evaluated both for the pressure and tension sides. RESULTS: The addition of ESWT to the orthodontic force after three weeks more than doubled the average tooth movement. The addition of ESWT on the pressure side induced a significant decrease in volumetric bone mineral density. Blood vessel density and the number of TRAP positive cells were higher after the application of ESWT. CONCLUSION: The induction of ESWT during orthodontic tooth movement in a rat model increases the rate of tooth movement by accelerating bone resorption on the pressure side and possibly enhances bone formation on the tension side.

Acrolein-an α,ß-Unsaturated Aldehyde: A Review of Oral Cavity Exposure and Oral Pathology Effects.

Acrolein is a highly reactive unsaturated aldehyde widely present in the environment, particularly as a product of tobacco smoke. Our previous studies indicated the adverse consequences of even short-term acrolein exposure and proposed a molecular mechanism of its potential harmful effect on oral cavity keratinocytic cells. In this paper we chose to review the broad spectrum of acrolein sources such as pollution, food, and smoking. Consequently, in this paper we consider a high level of oral exposure to acrolein through these sources and discuss the noxious effects it has on the oral cavity including on salivary quality and contents, oral resistance to oxidative stress, and stress mechanism activation in a variety of oral cells.