熱緊迫誘發雞隻濾泡顆粒細胞死亡其神經鞘磷脂與神經醯胺間轉換之研究

報告時間：2025-6-20
報告地點：407
指導老師：陳洵一
學生：張綺芸

熱緊迫（heat stress, HS）會影響蛋雞卵巢功能與濾泡發育，導致產蛋率下降，而濾泡顆粒細胞（granulosa cells, GC）凋亡係濾泡（small white follicles, SWF）閉鎖的元凶。GC主要分泌性激素，其中大量孕酮（progesterone, P4）的分泌被認為是濾泡發育成熟的指標。研究顯示，細胞內Ceramide（Cer）為誘發GC凋亡之關鍵第二信使，而Cer與Sphingomyelin（SM）皆屬神經鞘脂（sphingolipids）家族，參與細胞凋亡、分化等多項生理機制。SM合成酶（SM synthases, SMS）在Cer/SM轉換扮演重要角色，將神經醯胺和磷脂醯膽鹼（phosphatidylcholine, PC）轉換成SM和二醯甘油（diacylglycerol, DAG）。過去研究顯示，SMS 調節細胞膜上Cer/SM轉換對於細胞存活和增殖非常重要。然而HS對於Cer/SM轉換影響家禽生理功能的研究甚少。本研究目的在於進一步探討HS造成蛋雞濾泡閉鎖之其中機制，聚焦於HS誘發GC凋亡和其Cer/SM轉換之間的關連。本研究以SMS2 overexpression（OE）和knockdown（KD）SMS2方法切入，探討在HS前後共七個時間點Cer/SM 轉換與誘發GC凋亡的關聯。結果顯示，在控制組中，SMS2蛋白表達於HS處理後30分鐘下降，隨後逐漸回升；OE與KD組也呈現相似趨勢，然其於恢復期的變化更為顯著。SM含量於控制組在HS處理後上升，恢復期則下降；而OE與KD組則在HS處理後皆呈SM下降、恢復期上升的趨勢，尤以OE組變化幅度較KD組更劇烈。相反地，Cer含量在各組於HS後皆上升，但OE組上升幅度較小，且於恢復期快速下降；KD組則呈Cer積累現象，顯示SMS2不足可能使Cer無法有效轉化為SM，另外，進一步分析細胞凋亡與其路徑，CCK-8分析結果顯示，與對照組相比，經HS處理後各組細胞活性均明顯下降，尤以Blank與KD組最為顯著，顯示抑制SMS2表達可能加劇HS處理所造成的細胞損傷。caspase 3/7活性分析結果顯示，在HS處理後第180分鐘與恢復期第2小時，各組皆出現活性上升，然而，相較之下，KD組整體活性始終低於OE組。綜上所述，熱緊迫透過SMS2調控Cer/SM轉換影響Cer積累，誘發GC凋亡與後續濾泡閉鎖。

關鍵字: 熱緊迫、顆粒細胞、神經醯胺、神經鞘磷脂、雞
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