脂合成代谢的增强会引起甘油三酯在肝脏内异常堆积,导致胰岛素耐受或者非酒精性脂肪肝性病变。SREBP1(sterol regulatory element-binding protein 1)是调控脂合成代谢的重要转录调控因子,SREBP1合成后以非活性前体的形式存在于内质网...脂合成代谢的增强会引起甘油三酯在肝脏内异常堆积,导致胰岛素耐受或者非酒精性脂肪肝性病变。SREBP1(sterol regulatory element-binding protein 1)是调控脂合成代谢的重要转录调控因子,SREBP1合成后以非活性前体的形式存在于内质网。在胰岛素信号通路激活或在体内低固醇水平诱导下,SREBP1以依赖于COPII(coat protein complex II)的方式从内质网转运到高尔基体,并在高尔基体受蛋白酶加工剪切,成熟后的SREBP1进入细胞核诱导脂合成相关基因的表达。尽管研究人员对SREBP1调控脂代谢的功能有了相当多的认识和理解,但对代谢性疾病中SREBP1活性增强的分子机制一直不清楚。我们的研究结果表明,CRTC2(CREB regulated transcription coactivator 2)介导了m TOR(mechanistic target of rapamycin)调控的且依赖于COPII复合物的SREBP1的成熟,揭示了CRTC2介导的信号通路在调控肝脏脂代谢中的重要作用。展开更多
BACKGROUND Pulmonary mucoepidermoid carcinoma(PMEC)is a rare malignancy that arises from minor salivary glands within the tracheobronchial tree.The clear cell variant of PMEC is exceptionally uncommon and presents not...BACKGROUND Pulmonary mucoepidermoid carcinoma(PMEC)is a rare malignancy that arises from minor salivary glands within the tracheobronchial tree.The clear cell variant of PMEC is exceptionally uncommon and presents notable diagnostic challenges,primarily attributable to its morphological similarity to other tumors containing clear cells.CASE SUMMARY A 22-year-old male,formerly in good health,came in with a two-month duration of persistent cough and production of sputum.Subsequent imaging and bronchoscopy examinations revealed a 2 cm tumor in the distal left main bronchus,which resulted in complete atelectasis of the left lung.Further assessment via positron emission tomography/computed tomography scans and endoscopic biopsy confirmed the primary malignant nature of the tumor,charac-terized by clear cell morphology in most of the tumor cells.The patient underwent a left lower lobe sleeve resection accompanied by systematic mediastinal lymph node dissection.Molecular pathology analysis subsequently revealed a CRTC3-MAML2 gene fusion,leading to a definitive pathological diagnosis of the clear cell variant of PMEC,staged as T2N0M0.After surgery,the patient experienced a smooth recovery and exhibited no signs of recurrence during the one-and-a-half-year follow-up period.CONCLUSION This article describes an unusual case of a clear cell variant of PMEC characterized by the presence of a CRTC3-MAML2 gene fusion in a 22-year-old male.The patient underwent successful left lower lobe sleeve resection.This case underscores the distinctive challenges associated with diagnosing and treating this uncommon malignancy,underscoring the importance of precise diagnosis and personalized treatment strategies.展开更多
The CREB-regulated transcriptional co-activators(CRTCs),including CRTC1,CRTC2 and CRTC3,enhance transcription of CREB-targeted genes.In addition to regulating host gene expression in response to cAMP,CRTCs also increa...The CREB-regulated transcriptional co-activators(CRTCs),including CRTC1,CRTC2 and CRTC3,enhance transcription of CREB-targeted genes.In addition to regulating host gene expression in response to cAMP,CRTCs also increase the infection of several viruses.While human immunodeficiency virus type 1(HIV-1)long terminal repeat(LTR)promoter harbors a cAMP response element and activation of the cAMP pathway promotes HIV-1 transcription,it remains unknown whether CRTCs have any effect on HIV-1 transcription and HIV-1 infection.Here,we reported that CRTC2 expression was induced by HIV-1 infection,but CRTC2 suppressed HIV-1 infection and diminished viral RNA expression.Mechanistic studies revealed that CRTC2 inhibited transcription from HIV-1 LTR and diminished RNA PolⅡoccupancy at the LTR independent of its association with CREB.Importantly,CRTC2 inhibits the activation of latent HIV-1.Together,these data suggest that in response to HIV-1 infection,cells increase the expression of CRTC2 which inhibits HIV-1 gene expression and may play a role in driving HIV-1 into latency.展开更多
基金Hunan Provincial Natural Science Foundation of China,No.2022JJ40246The Hunan Cancer Hospital Climb Plan,No.2021NSFC-B005.
文摘BACKGROUND Pulmonary mucoepidermoid carcinoma(PMEC)is a rare malignancy that arises from minor salivary glands within the tracheobronchial tree.The clear cell variant of PMEC is exceptionally uncommon and presents notable diagnostic challenges,primarily attributable to its morphological similarity to other tumors containing clear cells.CASE SUMMARY A 22-year-old male,formerly in good health,came in with a two-month duration of persistent cough and production of sputum.Subsequent imaging and bronchoscopy examinations revealed a 2 cm tumor in the distal left main bronchus,which resulted in complete atelectasis of the left lung.Further assessment via positron emission tomography/computed tomography scans and endoscopic biopsy confirmed the primary malignant nature of the tumor,charac-terized by clear cell morphology in most of the tumor cells.The patient underwent a left lower lobe sleeve resection accompanied by systematic mediastinal lymph node dissection.Molecular pathology analysis subsequently revealed a CRTC3-MAML2 gene fusion,leading to a definitive pathological diagnosis of the clear cell variant of PMEC,staged as T2N0M0.After surgery,the patient experienced a smooth recovery and exhibited no signs of recurrence during the one-and-a-half-year follow-up period.CONCLUSION This article describes an unusual case of a clear cell variant of PMEC characterized by the presence of a CRTC3-MAML2 gene fusion in a 22-year-old male.The patient underwent successful left lower lobe sleeve resection.This case underscores the distinctive challenges associated with diagnosing and treating this uncommon malignancy,underscoring the importance of precise diagnosis and personalized treatment strategies.
基金We thank National Infrastructure of Microbial Resources(NIMR-2014-3)for providing valuable reagentsThis work was supported by the National Mega-Project for Infectious Disease(2018ZX10301408 SC)+4 种基金the National Key Research and Development program of China(2018YFE0107600 SC)the National Natural Science Foundation of China(81903679 LM)the National Natural Science Foundation of China(81772205 SC)Peking Union Medical College Youth Fund(332017075 LM)CAMS innovation fund for Medical Sciences(2018-I2M-3-004 SC).
文摘The CREB-regulated transcriptional co-activators(CRTCs),including CRTC1,CRTC2 and CRTC3,enhance transcription of CREB-targeted genes.In addition to regulating host gene expression in response to cAMP,CRTCs also increase the infection of several viruses.While human immunodeficiency virus type 1(HIV-1)long terminal repeat(LTR)promoter harbors a cAMP response element and activation of the cAMP pathway promotes HIV-1 transcription,it remains unknown whether CRTCs have any effect on HIV-1 transcription and HIV-1 infection.Here,we reported that CRTC2 expression was induced by HIV-1 infection,but CRTC2 suppressed HIV-1 infection and diminished viral RNA expression.Mechanistic studies revealed that CRTC2 inhibited transcription from HIV-1 LTR and diminished RNA PolⅡoccupancy at the LTR independent of its association with CREB.Importantly,CRTC2 inhibits the activation of latent HIV-1.Together,these data suggest that in response to HIV-1 infection,cells increase the expression of CRTC2 which inhibits HIV-1 gene expression and may play a role in driving HIV-1 into latency.
