Research progress on AMPARs involved in regulating orofacial pain / 口腔疾病防治

@#The incidence of orofacial pain is high, and its pathological mechanism is complex. Currently, there is a lack of long-lasting and effective clinical treatment drugs, resulting in a major economic burden to patients and society. Therefore, it is important to develop more durable and effective drugs for treatment. In recent years, substantial evidence has shown that α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) play a vital role in somatic and orofacial pain. Among them, subunit phosphorylation regulated by protein kinases and interactions with partner proteins promote the activation and trafficking of AMPARs and signal transduction to regulate the expression of AMPARs. The increase of GluA1-containing AMPARs promotes calcium ion influx, further activating protein kinases and auxiliary proteins, which forms a self-feedback loop. This is an important mechanism that promotes chronic pain. The expression of AMPARs in the trigeminal nervous system and the spinal cord nervous system overlaps, and the above mechanism may also participate in regulating orofacial pain. However, research on AMPARs in orofacial neuropathic pain or cancer-related pain is relatively insufficient, and more in-depth research is needed in the future. Furthermore, there is a lack of clinical evidence for AMPAR antagonists to treat pain. Understanding the regulatory mechanisms of the activation and trafficking of AMPARs and precisely intervening in the activation and trafficking of AMPARs may provide effective strategies for the development of new analgesics and offer new insights for treating orofacial pain.

Research progress on the roles and mechanisms of γδT cells in periodontitis / 口腔疾病防治

@#Periodontitis is a chronic infectious disease that occurs in periodontal support tissues. Plaque microorganisms are its initiating factor, while local inflammation and alveolar bone loss resulting from periodontitis are the most common causes of tooth loss. Interleukin-17 (IL-17), which plays an important role in the immune response to periodontitis, mostly originates from T helper cell 17 (Th17) and γδT cells. In periodontitis, the role of Th17 cells has been demonstrated broadly, but the role of γδT cells was not revealed until recent years. As a highly heterogeneous group of T lymphocytes, γδT cells are considered a link between innate immunity and adaptive immunity. Studies have found that γδT cells are mostly distributed in the oral epithelium near the biofilm, where they can interact with microorganisms to produce IL-17, recruit neutrophils, macrophages, etc., and participate in the host immune response to periodontitis. They also play a role in the association between periodontitis and relevant systemic diseases. In addition, γδT cells have been proven to produce tissue repair-related factors with a protective effect against periodontitis. The possible mechanism of γδT cells in periodontitis is discussed in this review.

The p38 MAPK and NF-κB Pathways are Involved in Cyclic Compressive Force-induced IL-6 Secretion in MLO-Y4 Cells

ABSTRACT We previously revealed the involvement of extracellular regulated protein kinases 1/2 (ERK1/2) in interleukin-6 (IL-6) secretion induced by cyclic compressive force (CCF) in MLO-Y4 cells. In this study, we investigated the contributions of the p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways to IL-6 secretion by stimulating MLO-Y4 cells with CCF. At 80% confluence, different magnitudes (1000μstrain, 2000 μstrain and 4000 μstrain), frequencies (0.5 Hz, 1.0 Hz and 2.0 Hz) and durations (10 min, 30 min, 1 h, 3 h and 6 h) of CCF were loaded onto cells using a four-point bending system. Flow Cytometry (FCM) analysis was used to analyze cell mortality rates after CCF loading. p38 and p65 phosphorylation as well as IκBα degradation in MLO-Y4 cells were detected by Western blotting (WB). Changes in IL-6 secretion after inhibitor treatment were assessed by enzyme-linked immunosorbent assays (ELISAs). Cellular viability was over 90 percent after CCF. p38 and p65 phosphorylation increased under all conditions, whereas IκBα protein levels decreased. However, phosphorylation and degradation were not completely dependent on the loading magnitude, frequency or duration. Furthermore, p38 inhibition using the specific inhibitor SB203580 reduced both p38 phosphorylation and IL-6 secretion. Similarly, NF-κB inhibition using BAY 11-7082 decreased p65 phosphorylation and IL-6 secretion but increased the concentration of IκBα. These findings reveal significant roles for the p38 and NF-κB signaling pathways in IL-6 secretion induced by CCF in MLO-Y4 cells.

The pharmacological properties of salvia essential oils.

Salvia essential oils isolated by hydrodistillation from the plant’s commercial dried aerial parts(Fig.1)，have powerful biological activity and pharmacological properties. The oils contain more than 100 different bioactive compounds, which mainly include Monoterpene hydrocarbons, Oxygenated monoterpenes, Sesquiterpene hydrocarbons, Diterpenes, Not iso-prenoid compounds and Oxygenated sesquiterpenes. It has a number of pharmacological effects including antimicrobial, antioxidant, anti-cholinesterase, improvement of cognitive performance and mood, reducing work-related stress, anti-mutagenic, anticancer, anti-inflammatory, choleretic activities and so on. The present review focuses on the pharmacological activities of Salvia essential oils.