Proteomic analysis of lipopolysaccharide-treated submandibular gland in rat

We investigated changes in the protein profile of submandibular gland (SMG) with inflammation induced by exposure to lipopolysaccharide (LPS) with the aim of identifying potential molecular markers of injured gland. Lipopolysaccharide (2.5μg) was directly administered into rat SMG unilaterally by retrograde ductal injection. At 12hr after treatment, the gland was excised and the proteins identified by two-dimensional difference gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Many proteins in the LPS-treated gland showed a marked change compared to those in the contralateral gland. Of particular note were increases in ubiquitin, a highly-conserved small regulatory protein and in calgranulin B, which has an immunological function in inflammation. Proteins related to apoptosis and stress also showed change in the inflamed gland. The results of this study suggest that the ubiquitin system of protein modification is involved in LPS-induced inflammation in salivary gland, and that a number of specific proteins might be applicable as molecular markers in the monitoring of inflamed or injured gland.     

Immunohistochemical study of interleukin-1beta and interleukin-1 receptor antagonist in an antigen-induced arthritis of the rabbit temporomandibular joint.

BACKGROUND: In temporomandibular joint (TMJ) arthritis, there is limited knowledge of the relationship between interleukin-1beta (IL-1beta) and interleukin-1 receptor antagonist (IL-1ra), as well as the source of these cytokines. We investigated the development of an antigen-induced arthritis in the rabbit TMJ immunohistochemically. METHODS: Unilateral TMJ arthritis was induced in 32 adult New Zealand White rabbits. From 6 h to 12 weeks after induction of arthritis, topology of IL-1beta and IL-1ra were observed. RESULT: The acute stage of induced arthritis lasted for one week after induction, thereafter it became chronic. In the early phase of the acute stage, infiltrating inflammatory cells, as well as synovial cells, produced IL-1beta and IL-1ra. In the late phase of the acute stage, the main source of these cytokines was subsynovial fibroblasts. In this phase of arthritis, IL-1beta and IL-1ra did not appear to be produced by synovial cells. From the early to intermediate phase of the chronic stage, proliferating synovial cells produced IL-1beta and IL-1ra. In this phase of the arthritis, these cytokines were also observed in a cluster formation in chondrocytes. CONCLUSION: This arthritis model shows a staging of the joint inflammation process with time. IL-1beta and IL-1ra are produced by a certain kind of cells depending on the stage of inflammation.     

Orthodontic tooth movement under extracorporeal shock wave therapy: the characteristics of the inflammatory reaction--a preliminary study

Extracorporeal generated shock waves were introduced in medical therapy approximately 20 years ago in order to disintegrate kidney stones. Over the last 10 years, extracorporeal generated shock waves have been used to stimulate healing processes. No report to date has examined its influence on different inflammation mediators and growth factors in the periodontium. Orthodontic tooth movement is a model including the induction of an aseptic inflammation and its resolution. We conducted a preliminary study to investigate the periodontium cytokine concentration fluctuations after induction of orthodontic force with and without extracorporeal shock wave therapy (ESWT) in a rat model. An orthodontic appliance was fabricated and applied between the molars and the incisors of rats. The rats were treated by a single episode of 1000 shock waves and gingival crevicular fluid was collected for 3 days. The concentration of typical acute phase cytokines was evaluated by ELISA assay. Of the three tested cytokines, IL-1beta was the only detected cytokine along the study timeframe. IL-1beta concentration rose in both the treated and non treated shockwave groups on the first day, however it was statistically significantly higher in the treated group on day 2. On day 3, IL-1beta concentrations in both groups decreased and reached a lower level in the treated group, revealing a statistically significant difference than its level on the previous day. The application of ESWT during orthodontic force induction enhances IL-1beta production as part of mechanical forces transduction triggering a biologic response, which may contribute to accelerated periodontal remodeling and therefore foreshortening the orthodontic tooth movement period.     

Differential coupling of the P2Y1 receptor to Galpha14 and Galphaq/11 proteins during the development of the rat salivary gland

In rat submandibular gland (SMG), the P2Y1 receptor (P2Y1R) mediates increases in the intracellular calcium concentration, [Ca2+]i that diminish as the animal ages from 1 to 4-6 weeks. However, P2Y1R mRNA levels do not change with age, suggesting that the age-dependent decrease in the [Ca2+]i response to P2Y1R agonists may be due to alterations in the activity of a component of the P2Y1R signalling pathway. OBJECTIVES: To assess whether the decrease in P2Y1R-mediated intracellular calcium signalling in SMG cells as rats age is due to a decrease in P2Y1R coupling to G proteins or to a decrease in the expression of a cognate G protein. DESIGN: SMG cells were isolated from Sprague-Dawley rats. P2Y1R function was assessed by measuring 2-MeSADP-induced increases in [Ca2+]i and ERK1/2 activation. P2Y(1)R-mediated activation of G proteins was determined by the [35S]GTPgammaS binding assay. Gq protein expression was determined by RT-PCR, Northern, and Western analysis. RESULTS: In SMG cells from 1-week-old rats, two bands (52 and 42kDa) were detected using anti-Galpha14 antibody, whereas in SMG cells from 4- to 6-week-old rats only the 42 kDa band was detected. Furthermore, 2-MeSADP-induced GTPgamma35S binding to Galpha14 and Galphaq/11 decreases in SMG cells from 4- to 6-week-old rats as compared to 1-week-old rats. CONCLUSIONS: These findings suggest that the age-dependent decrease in P2Y1R-mediated intracellular calcium signalling in rat SMG cells is due to a loss of 52 kDa Galpha14 and indicate the differential coupling of the P2Y1R to Galpha14 and Galphaq/11 as the gland develops.     

Induction of secretory and serum antibody responses following oral administration of antigen with bioadhesive degradable starch microparticles

Bioadhesive degradable starch microparticles were used to deliver antigen and immunoglobulin A (IgA)-enhancing cytokines to the oral mucosa. Degradable starch microparticle immunization groups consisted of rats dosed topically at the sublingual epithelium of the oral cavity, by subcutaneous injection in the vicinity of the major salivary glands or by oral intubation with degradable starch microparticles containing dinitrophenyl-bovine serum albumin +/- IL-5/IL-6 +/- penetration enhancer (alpha-lysophosphatidylcholine). Dinitrophenyl-bovine serum albumin was also adsorbed onto alum for salivary gland vicinity injection and administered to the oral cavity in soluble form. Animals were subjected to 3 immunization cycles, and sequential samples were assayed by radioimmunoassay for salivary IgA, tear IgA and serum IgG anti-dinitrophenyl antibodies after secondary and tertiary immunization. Salivary IgA responses were highest in degradable starch microparticle groups receiving penetration enhancer at 71 days post-secondary immunization and continued in one degradable starch microparticle((oral cavity) and two injected (salivary gland vicinity) groups for up to 88 days post-tertiary immunization. Long-term tear responses were also observed in degradable starch microparticle groups receiving penetration enhancer, but they dissipated before the salivary gland-alum responses following tertiary immunization. Serum IgG responses were most pronounced in salivary gland groups, but long-term low level responses were detectable in oral cavity groups receiving degradable starch microparticle formulations with penetration enhancer. Inclusion of IL-5 and IL-6 in oral cavity-delivered degradable starch microparticle formulations consistently enhanced tear IgA while only upregulating salivary IgA antibody responses at early time points post immunization. IL-5 and IL-6 did not enhance serum IgG antibodies in any group. These data indicate that bioadhesive degradable starch microparticles can be used as a vehicle to deliver antigen and cytokine signals to the oral cavity and, when delivered in combination with a penetration enhancer, can potentiate long-term salivary IgA responses.     

Differential regulation of immune responses by odontoblasts

Odontoblasts (OBs) are cells lining the inner surface of the tooth. Their potential role in host defenses within the tooth is suggested by their production of antimicrobial beta-defensins, but their role needs confirmation. The present study sought to define the roles of human OBs in microbial recognition and innate host responses. Toll-like receptor 2 (TLR2) and TLR4, as well as CCR6, were immunolocalized in human OBs and their dentinal processes in situ. To examine OB function we used organotypic tooth crown cultures to maintain human OBs within their dentin scaffold. Cells in the OB layer of cultured and non-cultured crown preparations expressed mRNA for several markers of innate immunity including chemokine CCL20, chemokine receptor CCR6, TLR2, TLR4 and the OB marker dentin sialophosphoprotein (DSPP). Expression of human beta-defensin 1 (hBD1), hBD2, hBD3, interleukin-8 (IL-8), and CCL20 increased with time in culture. Tooth crown odontoblast (TcOB) cultures were stimulated with agonist that was specific for TLR2 (Pam3CSK4) or TLR4 [Escherichia coli lipopolysaccharide (LPS)]. Nuclear factor-kappaB assays confirmed the TLR2 activity of Pam3CSK4 and the TLR4 activity of LPS. LPS up-regulated IL-1beta, tumor necrosis factor-alpha (TNF-alpha), CCL20, hBD2, IL-8, TLR2 and TLR4; however, Pam3CSK4 down-regulated these mRNAs. IL-1beta, TNF-alpha, CCL20 were also up-regulated from six-fold to 30-fold in TcOB preparations from decayed teeth. Our results show for the first time that OBs express microbial pattern recognition receptors in situ, thus allowing differential responses to gram-positive and gram-negative bacteria, and suggest that pro-inflammatory cytokines and innate immune responses in decayed teeth may result from TLR4 signaling.     

Endodontic Infection–induced Inflammation Resembling Osteomyelitis of the Jaws in Toll-like Receptor 2/Interleukin 10 Double-knockout Mice

Introduction

In general, mice develop chronic and nonhealing periapical lesions after endodontic infection. Surprisingly, we recently found that toll-like receptor 2 (TLR2)/interleukin 10 (IL-10) double-knockout (dKO) mice exhibited acute but resolving osteomyelitislike inflammation. In this study, we examined the kinetics of endodontic infection–induced inflammation in TLR2/IL-10 dKO mice and explored a potential mechanism of periapical wound healing mediated by the hypoxia-inducible factor 1 alpha (HIF-1α) subunit and arginase 1.

Involvement of tumor necrosis factor-α and interleukin-8 in antigen-induced arthritis of the rabbit temporomandibular joint

BACKGROUND: In temporomandibular joint (TMJ) arthritis, knowledge is limited about the source of the inflammatory mediators. The aim of this study was to investigate the immunohistochemical role of tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) in the development of the antigen-induced arthritis of the rabbit TMJ. METHODS: Unilateral TMJ arthritis was induced in 28 adult rabbits. From 6 h to 6 weeks after induction of arthritis, the topology of TNF-alpha and IL-8 was observed. RESULTS: Positive reaction for TNF-alpha of synovial cells was observed within 3 days after induction and at 3 weeks after induction. TNF-alpha positive vascular endothelial cells and chondrocytes were identified throughout the observation period. IL-8 was detected only during the acute stage. CONCLUSIONS: The cytokines TNF-alpha and IL-8 were observed in specific cells depending on the stage. TNF-alpha was particularly related with angiogenesis and cartilage destruction and IL-8 was involved in the acute stage of inflammation.     

Toll样受体4在慢性牙周炎诱发大鼠肝脏炎症中的作用

目的:初步探究Toll样受体4(Toll like receptor 4,TLR4)在慢性牙周炎诱发大鼠肝脏炎症中的作用。方法:将24只雄性Wistar大鼠随机分成两组,对照组和牙周炎组每组各12只,2%戊巴比妥钠麻醉下检测牙龈出血指数、牙周探诊深度及松动度;将20μL牙龈卟啉单胞菌脂多糖(Porphyromonas gingivalis lipopolysaccharide,Pg-LPS)(1 g/L)注射到大鼠双侧上颌第一磨牙龈沟及第一二磨牙龈间隙内,隔1 d注射1次,每周3次,连续6周。对照组不做处理。最后一次注射Pg-LPS 12 h后,2%戊巴比妥钠麻醉下检测牙周探诊深度、牙龈出血指数及松动度等3项牙周指标后将大鼠处死,取其上颌骨及肝脏,采用组织学方法、实时荧光定量聚合酶链反应(quantitative real-time polymerase chain reaction,qRT-PCR)、Western blot分别检测肝组织炎症反应情况及TLR4、肿瘤坏死因子-α(tumor necrosis factor,TNF-α)和白细胞介素-6(interleukin-6,IL-6)的基因和蛋白表达水平。结果:牙周炎组大鼠牙周探诊深度、牙龈出血指数及松动度均重于对照组;苏木精-伊红(hematoxylin-eosin,HE)染色结果显示慢性牙周炎大鼠肝组织内肝索结构紊乱,汇管区可见大量淋巴细胞浸润,大量肝细胞呈空泡样改变;qRT-PCR结果显示慢性牙周炎组大鼠肝组织TLR4、TNF-α和IL-6的mRNA表达水平较对照组升高;Western blot结果显示TLR4蛋白表达与基因表达一致。结论:TLR4在慢性牙周炎诱发大鼠肝脏炎症性改变的过程中发挥着重要的作用。     

Suppression of lipopolysaccharide-induced cytokine production of gingival fibroblasts by a soybean, Kunitz trypsin inhibitor

BACKGROUND: Human bikunin, a Kunitz-type trypsin inhibitor, inhibits inflammation by down-regulating the expression of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) in tumor cells and inflammatory cells. OBJECTIVES: We analyzed the effect of a soybean-derived Kunitz trypsin inhibitor (KTI) on TNF-alpha production in human gingival fibroblasts stimulated by lipopolysaccharide (LPS), an inflammatory inducer. MATERIAL AND METHODS: Mitogen-activated protein kinase (MAPK) activation and cytokine levels were monitored using western blot and a specific enzyme-linked immunosorbent assay (ELISA). RESULTS: Here, we show (i) a soybean KTI abrogates LPS-induced up-regulation of TNF-alpha mRNA and protein expression in a dose-dependent manner in gingival fibroblasts, (ii) KTI also blocks the induction of TNF-alpha target molecules interleukin-1beta (IL-1beta) and IL-6 proteins, (iii) inhibition by KTI of TNF-alpha induction correlates with the suppressive capacity of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 signaling pathways, implicating repressed ERK1/2 and p38 signalings in the inhibition, and (iv) pretreatment of cells with KTI blocked LPS-induced nuclear factor kappaB (NFkappaB) activation. CONCLUSION: Our results indicate that KTI inhibits LPS-induced up-regulation of cytokine expression possibly through suppression of ERK1/2 and p38 kinase-mediated NFkappaB activation. These findings may identify anti-inflammatory properties of KTI at the level of gingival fibroblasts and may be relevant to the use of KTI in modulating inflammation, including periodontal disease.     

Botulinum toxin A treatment of epiphora secondary to autologous submandibular gland transplantation

The aim of this study was to explore whether botulinum toxin A (BTXA) injection treats epiphora secondary to submandibular gland (SMG) transplantation for severe keratoconjunctivitis sicca.Fifteen patients with epiphora after SMG transplantation were separated to three groups, and received 15 U, 20 U and 25 U BTXA injection in the transplanted SMG, respectively. Secretion of transplanted SMG was assessed subjectively by visual analogue scale (VAS) regarding epiphora, and objectively by Schirmer test.There were no significant differences in the 15-U BTXA group regarding the values of the VAS on epihora before and 1 month after BTXA injection. While in 20-U group and 25-U group, the values of VAS on epihora decreased significantly after BTXA injection, and lasted for 6 months. Under resting conditions, the secretion of transplanted SMG decreased 64.4%, 73.0% and 78.0% in 15-U, 20-U and 25-U groups, respectively (P < 0.01), in 1 month after BTXA injection; significant secretion decreasing lasted 3 months only in the 25-U BTXA group.BTXA injection can decrease the secretion of transplanted SMG significantly, relieving the symptoms of epiphora; 25 U BTXA is a suitable dose to treat ‘opportunistic epiphora’ after SMG transplantation.     

Activation of innate immune responses through Toll-like receptor 3 causes a rapid loss of salivary gland function

Background:  Recent studies have demonstrated the expression of Toll-like receptor 3 (TLR3) in salivary glands and epithelial cell lines derived from Sjögren's syndrome (SS) patients. As viral infections are considered to be a trigger for SS, in this study we investigated whether in vivo engagement of TLR3 affects salivary gland function.
Methods:  Female New Zealand Black/WF1 mice were repeatedly injected with polyinosinic:polycytidylic acid [poly(I:C)]. TLR3 expression within submandibular glands was studied using immunohistochemistry. RNA levels of inflammatory cytokines in the submandibular glands were determined by real time polymerase chain reaction. Pilocarpine induced saliva volume was used as an index of glandular function.
Results:  Immunohistochemical analysis of submandibular glands showed TLR3 expression in epithelium of serous and mucous acini, granular convoluted tubules, and ducts. Poly(I:C) treatment rapidly up-regulated the mRNA levels of type I interferon (IFN) and inflammatory cytokines in the submandibular glands. One week after treatment, the saliva volumes in poly(I:C) treated mice were significantly reduced in comparison with the phosphate-buffered saline (PBS) treated mice. Hematoxylin and eosin staining showed that salivary gland histology was normal and lymphocytic foci were not detected. Glandular function recovered after poly(I:C) treatment was stopped.
Conclusions:  Our results demonstrate that engagement of TLR3 within the salivary glands results in a rapid loss of glandular function. This phenomenon is associated with the production of type I IFN and inflammatory cytokines in the salivary glands. Restoration of glandular function suggests that for viral etiology of SS, a chronic infection of salivary glands might be necessary.     

中间普氏菌致蜕膜炎症诱导孕鼠死胎模型研究

目的研究牙周病常见的条件致病菌中间普氏菌（Pi）致蜕膜炎症引发C57BL/6孕鼠死胎的动物模型的建立方法,初步分析蜕膜炎症部位炎症相关基因表达水平。 方法经尾静脉注射5 × 10⁶ CFU Pi（ATCC25561）至孕15~ 16日雌鼠体内,分别在12、24和48 h后处死小鼠后解剖,剥离胎鼠胎盘组织,其中部分胎盘组织分离为蜕膜组织和非蜕膜胎盘组织,用于后续实时荧光定量聚合酶链反应（PCR）检测10种细胞因子和7种信号通路关键分子的mRNA表达水平。另外,两种对照组分别是尾静脉注射大肠埃希氏菌（E.coli）JM109（E.coli组）和磷酸盐缓冲液（PBS组）,尾静脉注射Pi为实验组（Pi组）,注射后48 h后处死孕鼠,计数胎鼠数量和死亡胎鼠数量,比较胎鼠死亡率。采用独立样本t检验分析细胞因子、信号分子的mRNA表达水平差异。卡方检验分析Pi组和E.coli组、PBS组之间孕鼠体内胎鼠死亡率的差异。 结果静脉注射Pi（5 × 10⁶ CFU）、E.coli（5 × 10⁶ CFU）和PBS 48 h后导致孕鼠的胎鼠死亡率分别为39.2%、3.0%和0%,实验组死亡率均显著高于对照组死亡率（Pi组vs. E.coli组：χ²= 17.54,P<0.001;Pi组vs. PBS组：χ²= 21.49,P<0.001）。实时荧光定量PCR检测结果显示,与PBS组相比,Pi组胎盘组织内细胞因子白细胞介素（IL）-1α、IL-1β、肿瘤坏死因子α（TNF-α）、IL-6、粒细胞集落刺激因子（GCSF）、人IL-8同系物（KC）和信号分子环氧化酶2（COX2）、核因子κB （NF-κB）、髓样细胞分化因子88（MyD88）、Toll样受体4（TLR4）至少在注射24 h后mRNA表达水平显著升高（均P<0.05）。而干扰素γ（IFN-γ）、IL-12、IL-18、IL-10、前列腺素E合成酶（PGES）、COX1、诱导白细胞介素B的TIR相关区域接受蛋白（Trif）差异无统计学意义。进一步比较胎盘内蜕膜和非蜕膜组织IL-1α、IL-1β、TNF-α、COX2的表达水平证实炎症发生主要位于胎盘内蜕膜组织。 结论牙周病常见的条件致病菌Pi静脉注射可导致孕鼠出现死胎,潜在机制与蜕膜部分的急性炎症关系密切。     

mRNAs for PRPs, statherin, and histatins in von Ebner's gland tissues

A search was made for expression of genes for proline-rich proteins (PRPs) and other salivary-type proteins, including statherin and histatins, in taste-bud tissues of mice and primates because of previous genetic findings in mice (Azen et al., 1986) that Prp and taste genes for certain bitter substances are either the same or closely linked. Taste-bud tissues and other tissues were tested for specific mRNAs with labeled DNA probes by Northern blotting and in situ hybridization. It was found that PRP mRNAs were present in von Ebner's glands of mice and macaques, and that there was a much greater degree of PRP mRNA induction in mouse parotid (16-fold) than in von Ebner's gland (two-fold) after in vivo isoproterenol stimulation. This difference may be due, in part, to differences in autonomic nerve innervation. Statherin and histatin mRNAs were found in macaque taste-bud tissues containing von Ebner's gland, and statherin protein was found in human von Ebner's gland by immunohistochemistry. The finding of PRP gene expression in von Ebner's gland, whose secretions have been suggested to play a role in taste stimulation, adds further support to a possible function of PRPs in bitter tasting. The possible functions of statherin and histatins in von Ebner's gland secretions may be related to statherin's regulation of salivary calcium and histatins' antibacterial and antifungal properties.