1-磷酸鞘氨醇诱导上皮重塑在鼻息肉激素抵抗中的作用和机制研究

Systemic/local corticosteroid is the main treatment of chronic sinusitis with nasal polyps at present. However, nearly 20 ~ 40% of these patients is insensitive or resistant to corticosteroid. Therefore, it is urgent to explore an effective treatment on steroid-resistant nasal polyps. Our team found that Sphingosine-1-phosphate (S1P) increased in tissues of steroid-resistant nasal polyps significantly. It can stimulate the proliferation of the epithelium cells in nasal polyps and the oral corticosteroid can not suppress expression of S1P. Under the context of the state-of-the-art research at home and abroad, also based on the preliminary work, this research work proposed that, S1P can mediate steroid resistance by inducing epithelium remodelling of nasal polyps. Due to this proposal, our new experiment will be carried out in the following sections. Experiment in vitro: First, to explore the characteristics of S1P expression pattern in human nasal polyps by detecting nasal polyps through Western Blot、real time-PCR、Elisa, etc. Second, S1P is used to stimulate the epithelial cells of nasal polyps cultivated in vitro to explore the effect of S1P on epithelium remodelling and the role of corticosteroid in the effect above. After that, to research the mechanism furtherly of S1P on inducing epithelial cells proliferation and abnormal differentiation of human nasal polyps using technologies including PCR chip, siRNA interference strategies, etc. Experiment in vivo: To set up nasal polyp model in mice. Similar experimental technique with experiment in vitro could be adopted to reveal the role of S1P in promoting epithelium remodelling and inducing steroid resistance of mice nasal polys. In conclusion, the research work has significantly meanings in clarifying the mechanism of steroid resistance in nasal polyps, and providing an innovative evidence and therapeutic target in improving and reversing steroid-resistant nasal polyps.

目前慢性鼻窦炎鼻息肉的治疗方法主要以全身/局部糖皮质激素药物为主，然而临床上仍约有20~40%的患者对糖皮质激素的治疗不敏感或抵抗。因此，治疗激素抵抗型的鼻息肉是当前亟待解决的问题。我们研究发现激素抵抗型的鼻息肉组织中1-磷酸鞘氨醇（S1P）显著升高，S1P能刺激鼻息肉上皮细胞增殖，且口服糖皮质激素不能抑制其表达。本课题组综合国内外研究和前期基础提出假设：S1P 可能通过诱导鼻息肉上皮重塑介导对糖皮质激素的抵抗效应。我们拟采用Western Blot、real time-PCR、Elisa、PCR芯片、siRNA干扰策略等技术结合实验动物模型，研究S1P 在人鼻息肉组织中的表达特征，探讨其对上皮重塑的作用及糖皮质激素对该作用的影响及其诱导人鼻息肉上皮细胞增殖和异常分化的机制。本研究将有助于进一步揭示鼻息肉产生糖皮质激素抵抗的机制，为改善或逆转鼻息肉激素抵抗提供新的治疗靶点和实验依据。

慢性鼻窦炎伴鼻息肉激素抵抗的机制尚未明确，其发生发展可能与多种因素有关，例如Mucin4的高表达等，近期研究发现1-磷酸鞘氨醇在激素抵抗型鼻息肉中表达升高并与p63呈正相关，S1P能刺激鼻息肉上皮细胞增殖，且口服糖皮质激素不能抑制其表达。本课题组综合国内外研究和前期研究基础提出假设：S1P 可能通过诱导鼻息肉上皮重塑介导对糖皮质激素的抵抗效应。本研究纳入术前口服甲泼尼龙20天的鼻息肉患者对其用药前后进行内镜评分、snot-22、及主观症状评分，收集其鼻息肉标本进行免疫组化及免疫荧光，western blot及Qpcr检测，同时建立小鼠鼻息肉动物模型。对收集到的临床资料进行秩合检验及sperman相关性分析。研究发现组织内 1-磷酸鞘氨醇 蛋白表达量与组织内嗜酸性粒细胞计数没有相关性，无论患者对激素敏感与否，其预后情况与血清嗜酸性粒细胞及组织内嗜酸性粒细胞没有相关性。在激素抵抗型鼻息肉中 Jnk1+2,MAPk14 及 TNF-A 表达增高，在 SPhK1(1-磷酸鞘氨醇激酶）表达增高的同时，上皮重塑相关因子MMP-7 及 ADMM33 蛋白表达量增高。