Chang Mei-Chi, Wu Ju-Hui, Chen Shyuan-Yow, Hsu Yung-Ting, Yeung Sin-Yuet, Pan Yu-Hwa, Jeng Jiiang-Huei
Biomedical Science Team, Chang Gung University of Science and Technology, Kwei-Shan, Taoyuan City, Taiwan.
Department of Dentistry, Chang Gung Memorial Hospital, Taipei, Taiwan.
J Dent Sci. 2024 Apr;19(2):1190-1199. doi: 10.1016/j.jds.2023.11.009. Epub 2023 Nov 25.
BACKGROUND/PURPOSE: Bacterial infection was the major etiology for pulpal/root canal infection. This study aimed to investigate the activation of toll-like receptor-3 (TLR) on cyclooxygenase-2 (COX-2) expression and prostaglandin E (PGE) and PGF production of human dental pulp cells (HDPCs) and associated signaling.
HDPCs were exposed to different concentrations of Poly (I:C) (a TLR3 activator). Cell viability was determined by 3- (4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and alkaline phosphatase (ALP) activity was evaluated by ALP staining. Activation of extracellular signal-regulated kinase (ERK) and p38 by Poly (I:C) was determined by immunofluorescent staining. The COX-2 protein expression was analyzed by Western blot. PGE and PGF production was measured by enzyme-linked immunosorbent assay. The mRNA expression was studied by real-time polymerase-chain reaction. Moreover, HDPCs were exposed to Poly(I:C) with/without U0126 or SB203580 treatment and analysis of COX-2 expression and prostanoid production were conducted.
Poly (I:C) showed little effect on ALP activity, but decreased viability of HDPCs. It stimulated COX-2 mRNA and protein expression. Poly (I:C) induced PGE and PGF production of HDPCs. Poly (I:C) activated -ERK, and p-p38 protein expression. Treatment by U0126 (a mitogen-activated protein kinase kinase (MEK)/ERK inhibitor) and SB203580 (a p38 inhibitor) attenuated Poly (I:C)-induced COX-2 mRNA and protein expression as well as PGE and PGF production.
TLR3 activation is involved in the infection and inflammatory responses of pulp tissues, via MEK/ERK, and p38 signaling to mediate COX-2 expression as well as PGE and PGF production, contributing to the pathogenesis and progression of pulpal/periapical diseases.
背景/目的：细菌感染是牙髓/根管感染的主要病因。本研究旨在探讨Toll样受体3（TLR）激活对人牙髓细胞（HDPCs）环氧合酶-2（COX-2）表达、前列腺素E（PGE）和前列腺素F（PGF）产生及相关信号传导的影响。
将HDPCs暴露于不同浓度的聚肌苷酸胞苷酸（Poly（I:C），一种TLR3激活剂）。通过3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐（MTT）法测定细胞活力，通过碱性磷酸酶（ALP）染色评估ALP活性。通过免疫荧光染色测定Poly（I:C）对细胞外信号调节激酶（ERK）和p38的激活作用。通过蛋白质免疫印迹法分析COX-2蛋白表达。通过酶联免疫吸附测定法测量PGE和PGF的产生。通过实时聚合酶链反应研究mRNA表达。此外，将HDPCs暴露于有/无U0126或SB203580处理的Poly（I:C）中，并进行COX-2表达和前列腺素产生的分析。
Poly（I:C）对ALP活性影响较小，但降低了HDPCs的活力。它刺激了COX-2 mRNA和蛋白表达。Poly（I:C）诱导了HDPCs的PGE和PGF产生。Poly（I:C）激活了ERK和p-p38蛋白表达。用U0126（一种丝裂原活化蛋白激酶激酶（MEK）/ERK抑制剂）和SB203580（一种p38抑制剂）处理减弱了Poly（I:C）诱导的COX-2 mRNA和蛋白表达以及PGE和PGF产生。
TLR3激活通过MEK/ERK和p38信号传导参与牙髓组织的感染和炎症反应，介导COX-2表达以及PGE和PGF产生，促进牙髓/根尖周疾病的发病机制和进展。
