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1. chinaXiv:201605.01376 [pdf]

The Endoplasmic Reticulum Adaptor Protein ERAdP Initiates NK Cell Activation via the Ubc13-Mediated NF-kappa B Pathway

Chen, Jun; Hao, Lu; Li, Chong; Ye, Buqing; Du, Ying; Zhang, Honglian; Zhu, Pingping; Liu, Benyu; Yang, Liuliu; Fan, Zusen; Chen, Jun; Hao, Lu; Long, Bo; Long, Bo; Li, Peifeng; Tian, Yong
Subjects: Biology >> Biophysics >> Immunology

NK cells play a pivotal role in innate immune responses against pathogenic infections. However, the underlying mechanisms driving defined NK functions remain largely elusive. In this study, we identified a novel endoplasmic reticulum (ER) membrane protein, ER adaptor protein (ERAdP), which is constitutively expressed in human and mouse NK cells. ERAdP is expressed at low levels in peripheral NK cells of hepatitis B virus-associated hepatocellular carcinoma patients. We show that ERAdP initiates NK cell activation through the NF-kappa B pathway. Notably, ERAdP interacts with ubiquitin-conjugating enzyme 13 (Ubc13) to potentiate its charging activity. Thus, ERAdP augments Ubc13-mediated NF-kappa B essential modulator ubiquitination to trigger the Ubc13-mediated NF-kappa B pathway, leading to NK cell activation. Finally, ERAdP transgenic mice display hyperactivated NK cells that are more resistant to pathogenic infections. Therefore, understanding the mechanism of ERAdP-mediated NK cell activation will provide strategies for treatment of infectious diseases.

submitted time 2016-05-12 Hits2222Downloads1221 Comment 0

2. chinaXiv:201605.01374 [pdf]

Sox2 functions as a sequence-specific DNA sensor in neutrophils to initiate innate immunity against microbial infection

Xia, Pengyan; Wang, Shuo; Ye, Buqing; Du, Ying; Huang, Guanling; Zhu, Pingping; Fan, Zusen
Subjects: Biology >> Biophysics >> Immunology

Neutrophils express Toll-like receptors (TLRs) for the recognition of conserved bacterial elements to initiate antimicrobial responses. However, whether other cytosolic DNA sensors are expressed by neutrophils remains elusive. Here we found constitutive expression of the transcription factor Sox2 in the cytoplasm of mouse and human neutrophils. Neutrophil-specific Sox2 deficiency exacerbated bacterial infection. Sox2 directly recognized microbial DNA through its high-mobility-group (HMG) domain. Upon challenge with bacterial DNA, Sox2 dimerization was needed to activate a complex of the kinase TAK1 and its binding partner TAB2, which led to activation of the transcription factors NE-kappa B and AP-1 in neutrophils. Deficiency in TAK1 or TAB2 impaired Sox2-mediated antibacterial immunity. Overall, we reveal a previously unrecognized role for Sox2 as a cytosolic sequence-specific DNA sensor in neutrophils, which might provide potential therapeutic strategies for the treatment of infectious diseases.

submitted time 2016-05-12 Hits2129Downloads1190 Comment 0

3. chinaXiv:201605.01338 [pdf]

ZIC2-dependent OCT4 activation drives self-renewal of human liver cancer stem cells

Zhu, Pingping; Wang, Yanying; Huang, Guanling; Du, Ying; Zhang, Geng; Yan, Xinlong; Xia, Pengyan; Ye, Buqing; Wang, Shuo; Hao, Lu; Wu, Jiayi; Fan, Zusen; He, Lei; Huang, Guanling; Hao, Lu; Wu, Jiayi; Fan, Zusen
Subjects: Biology >> Biophysics

Liver cancer stem cells (CSCs) have been identified and shown to have self-renewal and differentiation properties; however, the biology of these hepatic CSCs remains largely unknown. Here, we analyzed transcriptome gene expression profiles of liver CSCs and non-CSCs from hepatocellular carcinoma (HCC) cells lines and found that the transcription factor (TF) ZIC2 is highly expressed in liver CSCs. ZIC2 was required for the self-renewal maintenance of liver CSCs, as ZIC2 depletion reduced sphere formation and xenograft tumor growth in mice. We determined that ZIC2 acts upstream of the TF OCT4 and that ZIC2 recruits the nuclear remodeling factor (NURF) complex to the OCT4 promoter, thereby initiating OCT4 activation. In HCC patients, expression levels of the NURF complex were consistent with clinical severity and prognosis. Moreover, ZIC2 and OCT4 levels positively correlated to the clinicopathological stages of HCC patients. Altogether, our results indicate that levels of ZIC2, OCT4, and the NURF complex can be detected and used for diagnosis and prognosis prediction of HCC patients. Moreover, these factors may be potential therapeutic targets for eradicating liver CSCs.

submitted time 2016-05-11 Hits2168Downloads1153 Comment 0

4. chinaXiv:201605.01337 [pdf]

C8orf4 negatively regulates self-renewal of liver cancer stem cells via suppression of NOTCH2 signalling

Zhu, Pingping; Zhu, Pingping; Wang, Yanying; Du, Ying; Huang, Guanling; Zhang, Geng; Yan, Xinlong; Fan, Zusen; He, Lei
Subjects: Biology >> Biophysics

Liver cancer stem cells (CSCs) harbour self-renewal and differentiation properties, accounting for chemotherapy resistance and recurrence. However, the molecular mechanisms to sustain liver CSCs remain largely unknown. In this study, based on analysis of several hepatocellular carcinoma (HCC) transcriptome datasets and our experimental data, we find that C8orf4 is weakly expressed in HCC tumours and liver CSCs. C8orf4 attenuates the self-renewal capacity of liver CSCs and tumour propagation. We show that NOTCH2 is activated in liver CSCs. C8orf4 is located in the cytoplasm of HCC tumour cells and associates with the NOTCH2 intracellular domain, which impedes the nuclear translocation of N2ICD. C8orf4 deletion causes the nuclear translocation of N2ICD that triggers the NOTCH2 signalling, which sustains the stemness of liver CSCs. Finally, NOTCH2 activation levels are consistent with clinical severity and prognosis of HCC patients. Altogether, C8orf4 negatively regulates the self-renewal of liver CSCs via suppression of NOTCH2 signalling.

submitted time 2016-05-11 Hits1558Downloads796 Comment 0

5. chinaXiv:201605.01301 [pdf]

The Long Noncoding RNA IncTCF7 Promotes Self-Renewal of Human Liver Cancer Stem Cells through Activation of Wnt Signaling

Wang, Yanying; Du, Ying; Zhu, Pingping; Huang, Guanling; Yan, Xinlong; Ye, Buqing; Li, Chong; Xia, Pengyan; Zhang, Geng; Fan, Zusen; He, Lei; Huang, Guanling; Fan, Zusen; Luo, Jianjun; Tian, Yong; Chen, Runsheng
Subjects: Biology >> Biophysics

Hepatocellular carcinoma (HCC) is the most prevalent subtype of liver cancer, and it is characterized by a high rate of recurrence and heterogeneity. Liver cancer stem cells (CSCs) may well contribute to both of these pathological properties, but the mechanisms underlying their self-renewal and maintenance are poorly understood. Here, using transcriptome microarray analysis, we identified a long noncoding RNA (IncRNA) termed IncTCF7 that is highly expressed in HCC tumors and liver CSCs. LncTCF7 is required for liver CSC self-renewal and tumor propagation. Mechanistically, IncTCF7 recruits the SWI/SNF complex to the promoter of TCF7 to regulate its expression, leading to activation of Wnt signaling. Our data suggest that IncTCF7-mediated Wnt signaling primes liver CSC self-renewal and tumor propagation. In sum, therefore, we have identified an IncRNA-based Wnt signaling regulatory circuit that promotes tumorigenic activity in liver cancer stem cells, highlighting the role that IncRNAs can play in tumor growth and propagation.

submitted time 2016-05-11 Hits1714Downloads1089 Comment 0

6. chinaXiv:201605.00745 [pdf]

FoxO1-mediated autophagy is required for NK cell development and innate immunity

Wang, Shuo; Xia, Pengyan; Huang, Guanling; Zhu, Pingping; Liu, Jing; Ye, Buqing; Du, Ying; Fan, Zusen;
Subjects: Biology >> Biophysics

Natural killer (NK) cells exert a crucial role in early immune responses as a major innate effector component. However, the underlying mechanisms of NK cell development remain largely elusive. Here we show that robust autophagy appears in the stage of immature NK cells (iNKs), which is required for NK cell development. Autophagy defects result in damaged mitochondria and accumulation of reactive oxygen species (ROS) that leads to apoptosis of NK cells. Autophagy protects NK cell viability during development through removal of damaged mitochondria and intracellular ROS. Phosphorylated Forkhead box O (FoxO)1 is located to the cytoplasm of iNKs and interacts with Atg7, leading to induction of autophagy. FoxO1 deficiency or an inactive FoxO1(AAA) mutant abrogates autophagy initiation in iNKs and impairs NK cell development and viral clearance. Therefore we conclude that FoxO1-mediated autophagy is required for NK cell development and NK cell-induced innate immunity.

submitted time 2016-05-05 Hits1537Downloads844 Comment 0

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