2017年5月1日, 國際學術權威刊物自然出版集團旗下《Nature》雜誌線上發表了北京生命科學研究所邵峰實驗室題為“Chemotherapy drugs induce pyroptosis through caspase-3 cleavage of a Gasdermin”的研究論文。 論文報導了caspase-3可以通過切割和活化GSDME (DFNA5)蛋白誘導細胞焦亡並進一步發現該焦亡通路是部分化療藥物產生毒副作用的重要原因之一。 邵峰實驗室研究生王玉鵬和高文青為本文共同第一作者, 邵峰博士為本文通訊作者。
細胞焦亡(pyroptosis)傳統是指由caspase蛋白酶家族成員caspase-1介導的、發生在單細胞中的一種促炎性的程式性細胞死亡, 但其性質和機制一直不清楚。 邵峰實驗室此前工作發現caspase-4/5/11, 作為細菌內毒素(LPS)的胞內受體,
邵峰實驗室此前在研究GSDMD時發現, 將GSDMD的caspase-1/4/11切割位點置換成caspase-3切割位點可以將TNFa誘導caspase-3活化引起的HeLa細胞凋亡轉換為焦亡,
進一步的研究發現, 多數常用的(癌)細胞系均不表達GSDME, 研究人員也只找到了人的神經母細胞瘤細胞SH-SY5Y和惡性黑色素瘤細胞MeWo表達高水準的內源GSDME。 在這兩株細胞中, 他們用臨床常用的、導致DNA損傷的化療藥物誘導caspase-3活化後, 發現這兩株細胞均以焦亡的方式死去, 而不表達GSDME的Jurkat細胞, 則和通常認知一樣, 發生經典的凋亡。 後續的一系列細胞實驗也證明了SH-SY5Y細胞在化療藥物作用下發生的焦亡正是由於caspase-3切割GSDME導致的。 值得注意的是, 邵峰團隊在檢測了NCI-60中的57株癌細胞後, 發現其中只有不到1/10的細胞表達較高水準的GSDME, 這和之前文獻報導的GSDME的啟動子在癌細胞中會發生甲基化而表達沉默一致。
和癌細胞不同, 很多正常細胞和組織有很高的GSDME表達。 研究人員在檢測了5株人源的正常原代細胞後, 發現其中3株高表達GSDME。 用化療藥物處理這些原代細胞後, GSDME陽性的細胞發生焦亡, 同時伴隨caspase-3依賴的GSDME切割;而不表達GSDME的細胞則發生凋亡。 在GSDME陽性細胞中用RNAi敲低GSDME表達後, 化療藥物引起的細胞焦亡則轉換為凋亡。 我們知道傳統化療藥物在臨床使用中會產生很大毒副作用,
該研究發現由Gasdermin家族蛋白GSDME介導的細胞焦亡很可能是傳統化療藥物產生毒副作用的重要原因, 為癌症治療提供了新思路,這也是首次展示細胞焦亡在天然免疫之外的生理病理過程中發揮重要功能;同時該研究成果還發現caspase-3也可以(通過活化GSDME)誘導細胞壞死(焦亡),打破了caspase-3啟動必然導致細胞凋亡的經典概念。
原文連結:
原文摘要:
Pyroptosis, activated by the canonical caspase-1 inflammasomes or caspase-4/5/11 by cytosolic LPS, is critical for immunity. The caspases cleave Gasdermin D (GSDMD) in the middle linker to release autoinhibition on its Gasdermin-N domain that executes pyroptosis via the pore-forming activity. GSDMD belongs to a Gasdermin family sharing the pore-forming domain4,6,10. The function and mechanism of activation for other Gasdermins are unknown. Here we show that GSDME, originally identified as DFNA5 (Deafness, Autosomal Dominant 5), could switch TNFα or chemotherapy drugs-induced and caspase-3-mediated apoptosis to pyroptosis. GSDME was specifically cleaved by caspase-3 in the linker, generating a GSDME-N fragment that perforated membranes for pyroptosis induction. Following chemotherapy drugs treatment, caspase-3 cleavage of GSDME determined pyroptosis in certain GSDME-expressing cancer cells. GSDME was silenced in most cancer cells but expressed in many normal tissues. Human primary cells exhibited GSDME-dependent pyroptosis upon caspase-3 activation by chemotherapy drugs. Gsdme-/- mice were protected from chemotherapy drugs-induced various tissue damages and weight loss. These findings bring an unexpected concept that caspase-3 activation can trigger necrosis through cleaving GSDME and offer new insights into cancer chemotherapy.
為癌症治療提供了新思路,這也是首次展示細胞焦亡在天然免疫之外的生理病理過程中發揮重要功能;同時該研究成果還發現caspase-3也可以(通過活化GSDME)誘導細胞壞死(焦亡),打破了caspase-3啟動必然導致細胞凋亡的經典概念。原文連結:
原文摘要:
Pyroptosis, activated by the canonical caspase-1 inflammasomes or caspase-4/5/11 by cytosolic LPS, is critical for immunity. The caspases cleave Gasdermin D (GSDMD) in the middle linker to release autoinhibition on its Gasdermin-N domain that executes pyroptosis via the pore-forming activity. GSDMD belongs to a Gasdermin family sharing the pore-forming domain4,6,10. The function and mechanism of activation for other Gasdermins are unknown. Here we show that GSDME, originally identified as DFNA5 (Deafness, Autosomal Dominant 5), could switch TNFα or chemotherapy drugs-induced and caspase-3-mediated apoptosis to pyroptosis. GSDME was specifically cleaved by caspase-3 in the linker, generating a GSDME-N fragment that perforated membranes for pyroptosis induction. Following chemotherapy drugs treatment, caspase-3 cleavage of GSDME determined pyroptosis in certain GSDME-expressing cancer cells. GSDME was silenced in most cancer cells but expressed in many normal tissues. Human primary cells exhibited GSDME-dependent pyroptosis upon caspase-3 activation by chemotherapy drugs. Gsdme-/- mice were protected from chemotherapy drugs-induced various tissue damages and weight loss. These findings bring an unexpected concept that caspase-3 activation can trigger necrosis through cleaving GSDME and offer new insights into cancer chemotherapy.