含雙色胺酸功能區氧化還原酶(WWOX)過去被認為是能引起癌細胞死亡的腫瘤抑制因子。WWOX缺乏的小鼠會有離乳前死亡、骨發育異常、發育遲緩、神經性異常以及胸腺和脾臟萎縮的現象。一則全基因分析研究指出，WWOX基因的單核甘酸多態性與克隆氏症(Crohn’s disease)的發炎嚴重程度有相關性。另外，透過氣管投予抑制WWOX的小分子干擾核糖核酸，會使脂多醣lipopolysaccharide (LPS)引起的小鼠肺臟發炎更為嚴重。為了探討WWOX調控免疫系統的分子機制，我們建立了Wwox基因缺陷的小鼠模式，並且發現缺乏WWOX的小鼠胸腺細胞大量死亡並且有發育的缺陷。NOTCH1訊息對於胸腺細胞的存活和發育是不可或缺的，我們發現Notch1蛋白質的表現於缺乏Wwox的小鼠胸腺細胞中大量地減少。原因為胸腺細胞缺乏WWOX後，無法抑制泛素化酶ITCH的表現、和其結合至NOTCH1的能力，進而造成NOTCH1大量地被ITCH泛素化並降解。我們更進一步證明WWOX會結合NOTCH1，讓它不被會ITCH結合並泛素化，因而維持胸腺細胞的發育。除此之外，我們也利用LPS引起小鼠敗血性休克的模式，來探討WWOX調節發炎的分子機制。相較於控制組，Wwox缺陷的小鼠對於LPS引起的敗血性休克更為敏感。在LPS給予細胞後，細胞的TLR4會接收訊號並活化Myddosome來傳遞訊息。在LPS刺激之下，缺乏WWOX的巨噬細胞製造的促發炎細胞激素較多，透過NF-κB傳遞的訊息也較強。當WWOX缺乏的巨噬細胞受到LPS的刺激後，Myddosome活化的程度較強。另外，WWOX能與 IRAK1和MyD88結合，進而加速其降解。這些結果指出WWOX可以透過調控IRAK1和MyD88來抑制TLR4的訊息傳遞。以上的研究結果指出WWOX不只能調控細胞死亡，它也透過影響NOTCH1而維持胸腺細胞發育，並且能抑制TLR4的訊息來控制發炎。

WW domain-containing oxidoreductase (designated WWOX, FOR or murine WOX1) has been shown to promote stress-induced cancer cell death and function as a tumor suppressor. Previous studies have reported that Wwox-/- mice exhibited preweaning lethality, abnormal bone formation, growth retardation, neural disorders, and thymic and splenic atrophy. A genome-wide analysis indicated that an SNP in WWOX is associated with the inflammatory severity in Crohn’s disease. Moreover, intratracheal introduction of Wwox siRNA resulted in elevated neutrophilic inflammation upon lipopolysaccharide (LPS) treatment. However, how WWOX regulates the immune system remains unclear. We have generated Wwox-/- mice by gene targeting to study the regulatory roles of WWOX in the immune system. We found significantly increased levels of thymocyte apoptosis due to an intrinsic developmental defect in Wwox-/- mice. The protein expression of NOTCH1, a critical receptor for transmitting the developmental and survival signal in thymocytes, was downregulated in Wwox-/- thymocytes. We demonstrated that WWOX competed with ITCH, a HECT domain-type E3 ligase, for binding to NOTCH1, and this competition stabilized NOTCH1 protein and maintained NOTCH1 signaling in thymocytes. Additionally, WWOX also interacted with ITCH and promoted Lys48-linked polyubiquitination and degradation of ITCH. To further study the regulatory role of WWOX in the inflammatory response, we also established an LPS-induced septic shock animal model with the use of our generated Wwox-/- mice. We found that Wwox-/- mice were more susceptible to LPS-induced septic shock as compared with their control littermates. Increased NF-κB activation and pro-inflammatory cytokine production upon LPS stimulation of Toll-like receptor 4 (TLR4) were observed in Wwox-knockdown Raw 264.7 cells and Wwox-/- bone marrow-derived macrophages. After LPS treatment, TLR4 triggers the assembly of Myddosome, which is composed of the adaptor MyD88 and the IRAK family kinases, to transduce downstream signaling. Increased Myddosome formation and activation were found in Wwox-knockdown Raw 264.7 macrophages after LPS treatment. Moreover, our data showed that WWOX interacted with both IRAK1 and MyD88 and promoted their degradation, suggesting that WWOX suppresses TLR4 signaling via downregulating Myddosome formation. Together, our in vivo and in vitro findings run against the role of WWOX as a pro-apoptotic protein and unravel novel functions of WWOX in both thymocyte development and inflammation.

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