Delphinidin: A Novel Agent For Treatment Of Psoriasis

描述（由申请人提供）：银屑病的特征是角质形成细胞过度增殖、颗粒层丢失和角化不全分化。Caspase-14是一种非凋亡的caspase家族成员，其在表皮中的表达仅限于基底层上，并且与终末分化相关。在正常皮肤中，caspase-14在整个基底上层的细胞质和细胞核中检测到。然而，在银屑病皮肤的角化不全区域，其特征在于缺乏核破坏，caspase-14表达下调。上调caspase-14表达的策略可能对包括银屑病在内的角化不全疾病构成新的治疗贡献。导致表皮角质形成细胞分化的试剂可具有针对银屑病的治疗效果，并且还可用于伤口愈合和其它过度增殖性皮肤病症。因此，鉴定具有诱导表皮角质形成细胞分化而不诱导细胞凋亡的试剂的天然存在的补充和替代医学方法是高度期望的目标。飞燕草色素是色素水果和蔬菜中的主要花青素，具有很强的抗氧化活性。最近，我们已经表明，局部应用飞燕草素抑制紫外线B介导的DNA损伤和TUNEL阳性细胞在SKH-1无毛小鼠皮肤的形成。然而，还没有研究检测飞燕草素处理对正常人角质形成细胞功能的影响。我们的初步未发表的研究是值得注意的，我们已经证明，飞燕草素诱导procaspase-14蛋白和mRNA在正常人表皮角质形成细胞的表达。我们还发现了外皮蛋白和转氨酶-1的蛋白质和mRNA表达的显着增加。值得注意的是，在相同的处理条件下，飞燕草素没有导致诱导细胞凋亡。这种显著的区别形成了本申请的基础，该申请被设计为在体外人重建皮肤模型系统和临床前体内环境中研究飞燕草素对角质形成细胞分化的作用。在本申请中待检验的中心假设是“飞燕草素将通过诱导半胱天冬酶-14和早期和晚期分化的其它标志物的表达以及通过抑制细胞增殖而不诱导细胞凋亡来减少银屑病样病变的病理标志物”。为了检验我们的假设，提出了以下具体目标：（1）为了研究飞燕草素处理是否增加了体外三维人重建皮肤中角化细胞分化标志物的分布和表达水平，该皮肤作为允许完全表皮分化的实验模型系统，（2）采用活体皮肤（fsn/fsn）检测局部应用飞燕草素对银屑病样病变病理标志物的影响小鼠和脱髓鞘（FSN/FSN）胱天蛋白酶14-/-小鼠。将进行研究以确定半胱天冬酶-14表达是否与表皮病理学症状减轻相关。 公共卫生相关性：本申请旨在定义一种存在于有色水果和蔬菜中的用于治疗银屑病的新试剂飞燕草素，并且还可用于伤口愈合和其它过度增殖性皮肤病。

DESCRIPTION (provided by applicant): Psoriasis is characterized by keratinocyte hyperproliferation, loss of granular layer and parakeratotic differentiation. Caspase-14 is a nonapoptotic caspase family member whose expression in the epidermis is confined to the suprabasal layers, and is associated with terminal differentiation. In normal skin, caspase-14 is detected in the cytoplasm and nuclei throughout the suprabasal layers. However, in the parakeratotic regions of psoriatic skin, which are characterized by the lack of nuclear destruction, caspase-14 expression is down-regulated. Strategies to upregulate caspase-14 expression may constitute a novel therapeutic contribution to diseases involving parakeratosis, including psoriasis. Agents that lead to differentiation of epidermal keratinocytes may have therapeutic effects against psoriasis and could also be useful in wound healing and other hyperproliferative skin disorders. Thus, identifying a naturally occurring Complimentary and Alternative Medicine approach with a agent that induces differentiation of epidermal keratinocytes without inducing apoptosis is a highly desirable goal. Delphinidin, a major anthocyanidin in pigmented fruits and vegetables, possesses potent antioxidant activity. Recently, we have shown that topical application of delphinidin inhibited ultraviolet B-mediated formation of DNA damage and TUNEL-positive cells in SKH-1 hairless mouse skin. However, no studies have examined the impact ofdelphinidin treatment on the function of normal human keratinocytes. Our preliminary unpublished studies are noteworthy where we have demonstrated that delphinidin induces procaspase-14 protein and mRNA expression in normal human epidermal keratinocytes. We also found a significant increase in the protein and mRNA expression of involucrin and transglutaminase-1. It is noteworthy that delphinidin under identical treatment conditions did not result in induction of apoptosis. This remarkable distinction forms the basis of this application which is designed to investigate the effect of delphinidin on keratinocyte differentiation both in in vitro human reconstituted skin model system and in preclinical in vivo settings. The central hypothesis to be tested in this application is that "delphinidin will reduce the pathological markers of psoriasiform lesions by inducing the expression of caspase-14, and other markers of early and late differentiation and by suppressing cell proliferation without inducing apoptosis". To test our hypothesis, the following specific aims are proposed: (1) To investigate whether delphinidin treatment increases the distribution and expression level of keratinocyte differentiation markers in in vitro three- dimensional human reconstituted skin as an experimental model system that allow complete epidermal differentiation, and (2) To examine the effect of topical application of delphinidin on pathological markers of psoriasiform lesions under in vivo situation employing flaky skin (fsn/fsn) mice and flaky skin (fsn/fsn) caspase 14-/- mice. Studies will be conducted to determine whether caspase- 14 expression is associated with reduced symptoms of epidermal pathology. PUBLIC HEALTH RELEVANCE: This application intends to define a novel agent delphinidin present in pigmented fruits and vegetables for the treatment of psoriasis and could also be useful in wound healing and other hyperproliferative skin disorders.