Impact of TRP Channels in Oral Pathology and Therapeutic Targeting Options: A Narrative Review

BACKGROUND

Transient Receptor Potential (TRP) channels are non-selective Ca2+ permeable channels with a wide and dynamic involvement in the perception of environmental stimuli in the oral cavity and a pivotal role in oral tissues' pathology and oral diseases. Several factors secreted during pulpitis and periodontitis, such as pro-inflammatory cytokines, prostaglandins, glutamate, extracellular ATP, and bradykinin, can trigger TRPs, either directly or indirectly, lowering the threshold of sensory neurons and regulate immune cell function.

OBJECTIVE

To investigate the diverse functions and molecular mechanisms of TRP channels in oral pathology and critically discuss their clinical significance and therapeutic targeting potential.

METHODS

Relevant keywords were used for research in scientific databases (Pumped, Scopus, and Science Direct). Only articles in English were included, screened, and critically analyzed. The key findings of these studies were included, along with their clinical importance.

RESULTS

Certain TRP channels were detected as key mediators of oral pathology. TRPV1 was revealed to play an important role in pain transduction in pulpits, induce inflammation, and be involved in bone resorption during periodontitis. TRPM2 activation may reduce saliva secretion in acinar salivary cells and xerostomia after head and neck radiation, while TRPV1 and TRPA1 channels mediate trigeminal nerve pain. Several TRP agonists and antagonists have been demonstrated to block pathological pathways in oral diseases along with certain compounds such as capsaicin, capsazepine, nifedipine, eugenol, thapsigargin and specific targeting techniques such as UHF-USP and Er: YAG lasers. Current TRP targeting approaches have been shown to exert beneficial effects in osteoblasts and fibroblasts proliferation, carcinoma cells' apoptosis, saliva secretion, and nociception.

CONCLUSION

TRPs play a central role in pain transduction, inflammatory responses in oral tissues, and pathological conditions of the oral mucosa, including oral squamous cell carcinoma and ulcerative mucositis.

Pivotal role of Transient Receptor Potential Channels in oral physiology

BACKGROUND

Transient Receptor Potential (TRP) Channels constitute a large family of non-selective permeable ion channels involved in the perception of environmental stimuli with a central and continuously expanding role in oral tissue homeostasis. Recent studies indicate the regulatory role of TRPs in pulp physiology, oral mucosa sensation, dental pain nociception and salivary gland secretion. This review provides an update on the diverse functions of TRP channels in the physiology of oral cavity, with emphasis on their cellular location, the underlying molecular mechanisms and clinical significance.

METHODS

A structured search of bibliographic databases (PubMed and MEDLINE) was performed for peer reviewed studies on TRP channels function on oral cavity physiology the last ten years. A qualitative content analysis was performed in screened papers and a critical discussion of main findings is provided.

RESULTS

TRPs expression has been detected in major cell types of the oral cavity, including odontoblasts, periodontal ligament, oral epithelial, salivary gland cells, and chondrocytes of temporomandibular joints, where they mediate signal perception and transduction of mechanical, thermal, and osmotic stimuli. They contribute to pulp physiology through dentin formation, mineralization, and periodontal ligament formation along with alveolar bone remodeling in dental pulp and periodontal ligament cells. TRPs are also involved in oral mucosa sensation, dental pain nociception, saliva secretion, swallowing reflex and temporomandibular joints' development.

CONCLUSION

Various TRP channels regulate oral cavity homeostasis, playing an important role in the transduction of external stimuli to intracellular signals in a cell type-specific manner and presenting promising drug targets for the development of pharmacological strategies to manage oral diseases.

Central Regulatory Role of Cytokines in Periodontitis and Targeting Options

BACKGROUND

Periodontitis is an immune-inflammatory disease that leads to the progressive destruction of bone and connective tissue in the periodontal area. The cytokine network plays a primary role in tissue homeostasis, the recruitment of immune cells to control the pathogenic impact and the regulation of osteoclastic function, thus modulating the intensity and duration of the immune response. This review provides an update on the main cytokines implicated in the pathogenesis and progression of periodontitis and their targeting potential in order to enrich current treatment options.

METHODS

A structured search of bibliographic databases (PubMed, MEDLINE, Scopus) was performed for peer-reviewed cytokine studies focused on periodontitis the last ten years. A qualitative content analysis was performed in screened papers and a critical discussion of main findings is provided.

RESULTS

An altered cytokine profile has been detected in periodontitis patients and the interplay of pro-inflammatory and/or anti-inflammatory cytokines has been associated with disease pathogenesis. Among the most prominent pro-inflammatory cytokines, TNF-α, IL-1β, IL-17, IL-6 and the chemokines CXCL-6, CXCL-8 are overexpressed in periodontitis patients and correlate with disease progression. On the other hand, the anti-inflammatory IL-4 and IL- 11 levels are reduced while IL-12 and IFN-γ expression play a dual role in periodontal disease. Current periodontitis treatment strategies include selective antibiotics, antimicrobial photodynamic therapy and probiotics, which can modulate the cytokine network and when applied in combination with specific anti-cytokine agents can exert additional beneficial effects.

CONCLUSION

It is evident that cytokines play a central regulatory role in the inflammatory process and immune cell response that underlies bone destruction in periodontitis. Specific cytokine targeting should be considered as a complementary therapeutic scheme to current periodontal management.