Tofacitinib suppresses mast cell degranulation and attenuates experimental allergic conjunctivitis

BackgroundAllergic conjunctivitis (AC), a common eye inflammation that affects patients’ health and quality of life, is still a therapeutic challenge for ophthalmologists. Tofacitinib, a new Janus kinase (JAK) inhibitor, has been successfully used in the treatment of several disorders. Nonetheless, its effect in AC and the potential anti-allergic mechanisms are still unclear. The objective of the current study was to explore the roles of tofacitinib in preventing AC and elucidate the potential underlying mechanisms.MethodsTofacitinib was used topically in BALB/c mice with experimental allergic conjunctivitis (EAC). Ocular allergic symptoms and biological modifications were examined. To assess the anti-allergic mechanisms of tofacitinib, RBL-2H3 cells and HUVECs were cultured in vitro. The inhibitory effects and mechanisms of tofacitinib were studied and measured by real-time quantitative PCR, ELISA, western blot analysis, and flow cytometry.ResultsTopical administration of tofacitinib reduced the clinical symptoms of OVA-induced EAC, with a substantial mitigation in inflammatory cell infiltration, histamine release, and TNF-α mRNA as well as IL-4 mRNA expression. In vitro, tofacitinib repressed the degranulation and cytokine production in RBL-2H3 cells and reduced histamine-induced vascular hyperpermeability. The underlying mechanism might involve the downregulation of phosphorylation of JAK3/STATs signaling molecules in RBL-2H3 cells and HUVECs.ConclusionsOur findings provide evidence that tofacitinib prevented EAC by targeting the JAK3/STATs pathway. We recommend the use of tofacitinib as an innovative approach for the treatment of AC.     

Olopatadine: a drug for allergic conjunctivitis targeting the mast cell

Importance of the field: Ocular allergic diseases are characterized by specific activation of conjunctival mast cells with subsequent release of preformed and newly formed mediators. Mast cells are thus the first therapeutic target of ocular anti-allergic treatments.

Areas covered in this review: In this review, a Medline literature search was conducted on conjunctival mast cells, their role in ocular allergy and mast cell stabilization by ocular anti-allergic compounds.

What the reader will gain: Olopatadine hydrochloride, a mast cell stabilizer and histamine receptor antagonist, has been shown to inhibit mast cell activation in an in vitro model of human mast cell culture, reducing histamine and TNF-α release and upregulating proinflammatory mediators in conjunctival epithelial cells. In the in vivo conjunctival allergen challenge (CAC) model in allergic subjects, combined with objective evaluations of tear mediators and cytology, olopatadine reduced histamine tear levels and all aspects of allergic inflammation, confirming the positive clinical effects observed in active allergic patients.

Take home message: Mast cells play a central role in the pathogenesis of ocular allergy. The CAC model is ideal for assessing the mast cell stabilizing effects of anti-allergic compounds. This review of clinical studies demonstrates the superiority of olopatadine compared with other topical allergic drugs.     

A chronic model for evaluating the itching associated with allergic conjunctivitis in rats

The present study was performed to develop a new model for evaluating itching associated with allergic conjunctivitis in rats. Repeated topical application of antigen caused an increase in eye scratching behavior in sensitized animals, and a significant difference was observed from days 21 to 42. Almost the same findings were observed in allergic symptoms, hyperemia and edema. Instillation of histamine also resulted in an increase in eye scratching behavior. The sensitivity to histamine in eye scratching behavior was increased by topical antigen application for 42 days after sensitization. In addition, the number of conjunctival eosinophils was significantly increased by repeated topical antigen application from days 21 to 42 in sensitized rats. Some anti-allergic drugs such as olopatadine (H1 antagonist), cetiridine (H1 antagonist) and ramatroban (thromboxane A2 (TXA2) antagonist) caused an inhibition of eye scratching behavior induced by topical sensitization in a dose-related manner. However, zafirlukast (cys-LT antagonist) caused no significant inhibition even at a dose of 30 mg/kg. The findings in present model of itching in allergic conjunctivitis were mainly through histamine H1-activity, and thromboxane A2 receptors were also involved in the response.     

地塞米松预防碘普罗胺过敏反应的调查研究

目的:探讨CT增强扫描前静脉注射地塞米松对碘普罗胺过敏反应的发生率及程度的影响。方法:收集2005年1月至2006年2月使用碘普罗胺进行CT增强扫描的患者4114例。分成2组:实验组2363例,于静脉注射碘普罗胺90～100ml增强扫描前20min静脉注射地塞米松5mg;对照组1751例,只静脉注射相同剂量的碘普罗胺。对2组患者过敏反应的发生率和程度进行了观察和分析。结果:实验组发生过敏反应15例(0.6%),对照组发生过敏反应35例(2.0%),2组过敏反应发生率差异有统计学意义(P>0.05)。过敏反应程度:实验组轻度9例,中度6例,对照组轻度19例,中度16例,2组间轻度和中度过敏反应的构成比无统计学差异(P>0.05)。结论:CT增强造影前静脉注射地塞米松可降低碘普罗胺过敏反应的发生率,而对过敏反应程度无影响。     

The protective effect of Tinospora cordifolia on various mast cell mediated allergic reactions

This study investigated the effect of an aqueous extract of Tinospora cordifolia (Willd.) Miers (Menispermaceae) stem on mast cell mediated allergic reactions in vivo and in vitro and studied its possible mechanism. T. cordifolia (125 to 1000?mg/kg) dose-dependently inhibited compound 48/80 induced lethality in rats, histamine induced paw edema in mice and histamine induced bronchial asthma in guinea pigs. T. cordifolia significantly (p?<?0.001) inhibited the cutaneous anaphylaxis reaction activated by histamine in a rat model and compound 48/80 induced ear swelling response in mice. T. cordifolia (2.5-160?μg/mL) also showed significant (p?<?0.001) inhibition of histamine induced contraction of guinea-pig ileum in vitro implying the H₁ antihistamine activity. T. cordifolia (0.01 to 10?mg/mL) significantly (p?<?0.001) inhibited the histamine release from rat peritoneal mast cells activated by compound 48/80. In addition, T. cordifolia (0.01 to 10?mg/mL) significantly (p?<?0.001) inhibited the secretion of tumor necrosis factor-α (TNF-α) in antidinitrophenyl (DNP) IgE-stimulated rat peritoneal mast cells. The level of cAMP in RPMC transiently and significantly increased compared with that of control cells when T. cordifolia was incubated with mast cells. T. cordifolia (0.01 to 10?mg/mL) showed concentration-dependent inhibition in compound 48/80 induced reactive oxygen species (ROS) generation. In addition, T. cordifolia decreased intracellular calcium levels of activated mast cells. These results show that T. cordifolia may be beneficial in the treatment of acute and chronic allergic disorders.     

Mechanisms of antihistamines and mast cell stabilizers in ocular allergic inflammation

Mast cells play a central role in allergic reactions and inflammation. Successful anti-allergic therapies have typically targeted mast cell mediators, particularly histamine. Antihistaminic compounds interact with the various histamine receptors found on many cells, whereas other compounds such as disodium cromoglycate, are referred to as mast cell stabilizers, as they inhibit degranulation. Some of the most successful compounds developed recently are dual-action, in that they have both anti-histaminic and mast cell stabilizing activities. Recent trends in pharmaceutical intervention, however, have been focused on the secondary effects of mast cell mediators on epithelial cell adhesion molecule expression and mediator release in the process of allergic inflammation. Since, the ocular mucosa is highly exposed to environmental allergens it is commonly involved in allergic reactions and, as such, has been a useful and accessible model in which to test new therapies in vivo. These ocular allergen provocation studies permit analysis of ocular surface cells and evaluation of tear film mediators. Furthermore, techniques to purify conjunctival mast cells have facilitated the study of the effects of mast cell stabilizing compounds on other mast cell mediators, such as cytokines, and the direct effects of mast cell mediators on epithelial cells in vitro. This review will discuss current understanding of how anti-histamines and mast cell stabilizers work, particularly in the context of molecular mechanisms of ocular allergic inflammation.     

色苷酸钠与奥洛他定治疗儿童过敏性结膜炎的临床对比研究

目的探讨色甘酸钠与奥洛他定治疗过敏性结膜炎的临床效果。方法将2010年10月至2012年10月我院诊治的84例过敏性结膜炎患者随机分成2组,对照组42例,采用色甘酸钠滴眼液治疗;实验组42例,采用奥洛他定滴眼液治疗。观察比较两组的近期疗效、眼部综合症状评分、症状体征改善时间。结果实验组的总有效率为92.86%,显著高于对照组的总有效率76.19%,两组比较差异具有统计学意义(P<0.05);实验组治疗3、7、14 d的眼部综合症状评分显著性低于对照组(P<0.05);实验组的眼痒、眼异物感、结膜水肿、结膜充血、眼睑乳头、睑滤泡等症状体征改善时间均显著性短于对照组(P<0.05)。结论奥洛他定治疗过敏性结膜炎的临床药理作用更强,改善眼部症状更快速有效。     

曲安奈德联合氟米龙滴眼液治疗过敏性结膜炎的临床研究

目的 探讨氟米龙联合曲安奈德治疗治疗过敏性结膜炎的临床疗效。方法 选取2021年7月—2022年10月桂林医学院第二附属医院眼科及贵港爱尔眼科收治的70例过敏性结膜炎患者,随机分为对照组（35例）和治疗组（35例）。对照组患者给予氟米龙滴眼液,2滴/次,3次/d。在对照组的基础上,治疗组结膜下注射曲安奈德注射液,10 mg/0.25 mL,1次/d,共2次。两组患者用药7 d。观察两组患者临床疗效,比较治疗前后两组患者症状好转时间,血清炎性因子P物质（SP）、干扰素-γ（IFN-γ）、白细胞介素-17（IL-17）、胸腺基质淋巴细胞生成素（TSLP）水平及不良反应发生情况。结果 治疗后,治疗组患者总有效率（97.14%）明显高于对照组（80.03%,P＜0.05）。治疗后,治疗组眼睛痒、结膜充血、流泪、结膜囊分泌物增多好转时间均短于对照组（P＜0.05）。治疗后,两组血清炎性因子IL-17、SP、TSLP水平低于治疗前,而IFN-γ水平高于治疗前（P＜0.05）,且治疗组这些血清炎性因子水平明显好于对照组（P＜0.05）。结论 氟米龙联合曲安奈德治疗过敏性结膜炎效果确切,能较快好转症状,有效降低炎性因子水平。     

Inhibitory effect of putranjivain A on allergic inflammation through suppression of mast cell activation

A great number of people are suffering from allergic inflammatory disease such as asthma, atopic dermatitis, and sinusitis. Therefore discovery of drugs for the treatment of these diseases is an important subject in human health. Putranjivain A (PJA), member of ellagitannin, is known to possess beneficial effects including anti-cancer and anti-viral activities. The aim of the present study was to elucidate whether PJA modulates the allergic inflammatory reaction and to study its possible mechanisms of action using mast cell-based in vitro and in vivo models. The study was performed in anaphylaxis mouse model and cultured mast cells. PJA inhibited the expression of pro-inflammatory cytokines in immunoglobulin E-stimulated mast cells. PJA reduced this expression by inhibiting nuclear factor (NF)-κB and nuclear factor of activated T cell. The oral administration of PJA reduced systemic and cutaneous anaphylaxis, the release of serum histamine, and the expression of the histamine H₁ receptor. In addition, PJA attenuated the activation of mast cells. PJA inhibited the release of histamine from various types of mast cells by the suppression of intracellular calcium. The inhibitory activity of PJA on the allergic reaction was similar to that of disodium cromoglycate, a known anti-allergic drug. These results suggest that PJA can facilitate the prevention or treatment of allergic inflammatory diseases mediated by mast cells.     

Pharmacological modulation of allergic inflammation in the rat airways and association with mast cell heterogeneity

Administration of ovalbumin by aerosol to sensitised rats produced a rapid (15 min) protein exudation in different airway tissues, as determined by Evans blue staining. This was associated with marked mast cell degranulation determined by histological examination, with there being no difference between mucosal and connective tissue mast cells. A 5-day administration regimen with compound 48/80 selectively depleted connective tissue mast cell (positive to berberine staining) without modifying ovalbumin-induced plasma protein extravasation. Treatment of rats with dexamethasone (1 mg/kg, -12 h) or nor-dihydroguaiaretic acid (30 mg/kg i.p., -30 min) significantly reduced ovalbumin-induced protein extravasation and preserved mucosal mast cell morphology. Indomethacin (4 mg/kg i.v., -30 min) exerted no effect on either parameter. In conclusion, we propose the mucosal mast cell as a target cell responsible at least partly for the inhibitory actions of known anti-inflammatory drugs. We suggest an involvement of endogenous leukotriene(s), but not prostanoid(s), in mucosal mast cell activation/degranulation.     

Inhibitory effects of a cationic liposome on allergic reaction mediated by mast cell activation

Several studies have shown that cationic liposomes exert immunomodulatory effects with low immunogenicity and toxicity, and offer advantages such as easy preparation and targeting. Cationic liposomes not only transport DNA to immune cells but also enhance the function of antigen presenting cells such as dendritic cells and macrophages. Here, we investigated the effect of a particular cationic liposome on mast cell function during allergic reaction. We found that the cationic liposomes bound to the mast cell surface suppressed degranulation induced by cross-linking of high affinity immunoglobulin E receptors in a time- and dose-dependent manner. The suppression of degranulation was mediated by impairment of the sustained level of intracellular Ca²⁺ concentration ([Ca²⁺]_i) derived from the inhibition of store-operated Ca²⁺ entry. The decrease in sustained elevation of [Ca²⁺]_i led to the suppression of phosphorylation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor proteins such as SNAP-23, syntaxin-4, which are necessary for membrane fusion between secretory granules and the plasma membrane during degranulation. Furthermore, the cationic liposomes suppressed vascular permeability elevation induced by mast cell activation in mice. These results showed that cationic liposomes possess the novel property of inhibiting mast cell activation, suggesting the possibility of developing cationic liposomes as anti-allergic effectors.     

Inhibition of scratching behavior associated with allergic dermatitis in mice by tacrolimus, but not by dexamethasone

Itching is the most important problem in many allergic and inflammatory skin diseases especially in atopic dermatitis. However, animal models for allergic dermatitis useful for the study of itching have rarely been established. We established a mouse allergic dermatitis model involving frequent scratching behavior by repeated painting with 2,4-dinitrofluorobenzene (DNFB) acetone solution onto the mouse skin, and comparatively examined the effects of tacrolimus and dexamethasone on the dermatitis and associated scratching behavior. Repeated DNFB painting caused typical dermatitis accompanied by elevated serum immunoglobulin E (IgE) and frequent scratching behavior. An apparent thickening of the epidermis and dermis, and the significant accumulation of inflammatory cells were observed. Increased interferon (IFN)-gamma mRNA expression and the induction of interleukin (IL)-4 and IL-5 mRNA expression were also observed in the skin lesion. The scratching behavior was inhibited by dibucaine and naloxone. Although tacrolimus reduced the increased expression of IFN-gamma and IL-4 mRNA, dexamethasone potently depressed that of IFN-gamma, IL-4 and IL-5 mRNA. Dexamethasone inhibited the accumulation of lymphocytes and eosinophils, although tacrolimus did not. Both drugs failed to inhibit the elevation of serum IgE levels. Tacrolimus significantly inhibited the scratching behavior that was associated with the inhibition of nerve fiber extension into the epidermis, whereas dexamethasone failed to have any effect. The mouse dermatitis model seems to be beneficial for the study of itching associated with allergic dermatitis, such as atopic dermatitis, and tacrolimus seems to exhibit an anti-itch effect through the inhibition of nerve fiber extension at least in part.     

他克莫司联合奥洛他定治疗过敏性结膜炎的疗效观察

目的探讨他克莫司滴眼液联合盐酸奥洛他定滴眼液治疗过敏性结膜炎的临床疗效。方法选取2015年1月—2016年12月四川大学华西医院眼科收治的过敏性结膜炎患者120例为研究对象,按随机数字法将所有患者分为对照组和治疗组,每组各60例。对照组给予盐酸奥洛他定滴眼液,1~2滴/次,3次/d。治疗组在对照组基础上给予他克莫司滴眼液,1滴/次,2次/d。两组患者均连续治疗1周。观察两组的临床疗效,比较两组的Schirmer试验、泪膜破裂时间(BUT)、角膜荧光素染色评分和症状体征改善时间。结果治疗后,对照组和治疗组的总有效率分别为81.67%、96.67%,两组比较差异具有统计学意义(P0.05)。治疗后,两组Schirmer试验、BUT明显升高,角膜荧光素染色评分、症状评分明显降低,同组治疗前后比较差异具有统计学意义(P0.05);且治疗组这些观察指标的改善程度明显优于对照组,两组比较差异具有统计学意义(P0.05)。治疗后,治疗组结膜充血、眼痒、流泪改善时间均明显短于对照组,两组比较差异具有统计学意义(P0.05)。结论他克莫司滴眼液联合盐酸奥洛他定滴眼液治疗过敏性结膜炎具有较好的临床疗效,可改善临床症状,缩短症状体征改善时间,具有一定的临床推广应用价值。     

Progress in allergy signal research on mast cells: signal regulation of multiple mast cell responses through FcepsilonRI

The crosslinking of FcepsilonRI by IgE and antigen (Ag) on mast cells initiates activation cascades that lead to allergic responses. Although it was thought that IgE binding to FcepsilonRI is a passive "sensitization", recent reports suggest that IgE actively promotes mast cell survival in the absence of Ag. However, it is largely unknown how these distinct responses are delivered through the same receptor, FcepsilonRI, depending on the types of stimli. As an underlying molecular mechanism for the generation of diverse responses through FcepsilonRI, we found that the quantity and the duration of the signal through the FcepsilonRI gamma chain (FcRgamma) determine different mast cell responses. Furthermore, FcRgamma-mediated sustained Erk activation is critical for IgE-induced mast cell survival through autocrine production of IL-3. Transmembrane adaptors LAT and NTAL contribute to the maintenance of prolonged Erk activation through membrane retention of the Ras-activating complex, Grb2-Sos. In this review, the signal regulation for the distinct responses of mast cells through FcepsilonRI are discussed.     

Specific IgE for wheat in tear fluid of patients with allergic conjunctivitis

Context: Allergy to hydrolyzed wheat protein in facial soap has become a major social issue in Japan. It has been reported that the most frequent early symptoms of allergy to hydrolyzed wheat protein in soap are allergic conjunctivitis and rhinitis, while wheat-dependent exercise-induced anaphylaxis can be induced by long-term use.

Objective: We evaluated the relation between tear fluid levels of specific IgE for wheat and the features of allergic conjunctivitis.

Methods: A prospective, non-randomized, cross-sectional study was conducted in 103 patients with moderate to severe allergic conjunctivitis (allergic group) and 20 age- and sex-matched healthy control subjects (control group). Specific IgE for wheat was measured in tear fluid with an immunochromatography assay, and a skin prick test (SPT) was also performed. Symptoms (sneezing, rhinorrhea, nasal obstruction, ocular itching, and lacrimation) were assessed in each subject along with the activities of daily living (ADL) score and the total ocular symptom score for allergic conjunctivitis. A severity score (0, 1, 2, or 3) was assigned for various changes of the palpebral and bulbar conjunctiva, as well as for limbal and corneal lesions associated with allergic conjunctivitis.

Results: The IgE positive rate and specific IgE score were both higher in the allergic group than in the control group (71.8% versus 40.0% and 1.9?±?0.7 versus 1.4?±?0.5). A positive SPT for wheat was also more frequent in the allergic group than in the control group (6.8% versus 0.0%). Within the allergic group, patients with a positive SPT had higher specific IgE scores than patients with a negative SPT (3.3?±?0.5 versus 1.8?±?0.6, p?r?=?0.665), tearing (r?=?0.672), and the total ocular symptom score (r?=?0.204). Wheat IgE in tear fluid was also correlated with the severity of rhinitis symptoms, including sneezing (r?=?0.610), nose blowing (r?=?0.640), and nasal obstruction (r?=?0.677). Furthermore, the tear fluid wheat IgE score was correlated with five objective features of allergic conjunctivitis (p?Conclusions: These results suggest that wheat allergy may be involved in the development of allergic conjunctivitis.     

奥洛他定滴眼液治疗变态反应性结膜炎的临床观察

目的观察奥洛他定滴眼液在变态反应性结膜炎中的临床疗效。方法入选变态反应性结膜炎患者56例（88眼）,给予患者0．196盐酸奥洛他定滴眼液,每眼1滴,早晚各1次,共7d。观察治疗前后变态反应性结膜炎各项症状与体征的变化情况。结果奥洛他定滴眼液治疗变态反应性结膜炎的总有效率为94．696．变态反应性结膜炎的各项症状和体征均得到显著的改善。治疗期间未观察到明显的不良反应。结论奥洛他定滴眼液治疗变态反应性结膜炎具有较好的疗效和安全性。     

硫酸皮肤素衍生物对大鼠肥大细胞脱颗粒的影响

目的研究不同来源不同分子量的低分子硫酸皮肤素 (LMWDS)及多硫酸化硫酸皮肤素 (PSDS)对大鼠肥大细胞 (MC)脱颗粒的影响。方法通过大鼠腹腔被动MC脱颗粒实验 ,观察LMWDS及PSDS对卵清蛋白引起MC脱颗粒的影响。结果与Hank液组比较 ,硫酸皮肤素衍生物均能明显抑制MC脱颗粒 ;与色甘酸钠组比较 ,PSDS组、牛肺来源的BLMWDS 3组和猪肠来源的PLMWDS 3组有显著的抑制MC脱颗粒作用。PSDS、BLMWDS、PLMWDS抑制MC脱颗粒作用与剂量呈正相关。结论硫酸皮肤素衍生物具有抑制MC脱颗粒作用 ,该作用与其分子量大小及结构有关     

Effects of MK-801 and amphetamine treatments on allergic lung inflammatory response in mice

Glutamate acts as a neurotransmitter within the Central Nervous System (CNS) and modifies immune cell activity. In lymphocytes, NMDA glutamate receptors regulate intracellular calcium, the production of reactive oxygen species and cytokine synthesis. MK-801, a NMDA receptor open-channel blocker, inhibits calcium entry into mast cells, thereby preventing mast cell degranulation. Several lines of evidence have shown the involvement of NMDA glutamate receptors in amphetamine (AMPH)-induced effects. AMPH treatment has been reported to modify allergic lung inflammation. This study evaluated the effects of MK-801 (0.25 mg/kg) and AMPH (2.0 mg/kg), given alone or in combination, on allergic lung inflammation in mice and the possible involvement of NMDA receptors in this process. In OVA-sensitized and challenged mice, AMPH and MK-801 given alone decreased cellular migration into the lung, reduced IL-13 and IL10 levels in BAL supernatant, reduced ICAM-1 and L-selectin expression in granulocytes in the BAL and decreased mast cell degranulation. AMPH treatment also decreased IL-5 levels. When both drugs were administered, treatment with MK-801 reversed the decrease in the number of eosinophils and neutrophils induced by AMPH in the BAL of OVA-sensitized and challenged mice as well as the effects on the expression of L-selectin and ICAM-1 in granulocytes, the IL-10, IL-5 and IL-13 levels in BAL supernatants and increased mast cell degranulation. At the same time, treatment with MK-801, AMPH or with MK-801 + AMPH increased corticosterone serum levels in allergic mice. These results are discussed in light of possible indirect effects of AMPH and MK-801 via endocrine outflow from the CNS (i.e., HPA-axis activity) to the periphery and/or as a consequence of the direct action of these drugs on immune cell activity, with emphasis given to mast cell participation in the allergic lung response of mice.