scholarly journals Lipopolysaccharide Stimulates p62-Dependent Autophagy-Like Aggregate Clearance in Hepatocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Christine Chen ◽  
Meihong Deng ◽  
Qian Sun ◽  
Patricia Loughran ◽  
Timothy R. Billiar ◽  
...  

Impairment of autophagy has been associated with liver injury. TLR4-stimulation by LPS upregulates autophagy in hepatocytes, although the signaling pathways involved remain elusive. The objective of this study was to determine the signaling pathway leading to LPS-stimulated autophagy in hepatocytes. Cell lysates from livers of wild type (WT; C57BL/6) mice given LPS (5 mg/kg-IP) and hepatocytes from WT, TLR4ko, and MyD88ko mice treated with LPS (100 ng/mL) up to 24 h were collected. LC3II, p62/SQSTM1, Nrf2, and beclin1 levels were determined by immunoblot, immunofluorescence, and qPCR. Autophagy-like activation was measured by GFP-LC3-puncta formation and LC3II-expression. Beclin1, Nrf2, p62, MyD88, and TIRAP were knocked-down using siRNA. LC3II-expression increased in both liver and hepatocytes after LPS and was dependent on TLR4. Beclin1 expression did not increase after LPS in hepatocytes and beclin1-knockdown did not affect LC3II levels. In hepatocytes given LPS, expression of p62 increased and p62 colocalized with LC3. p62-knockdown prevented LC3II puncta formation. LPS-induced LC3II/p62-puncta also required MyD88/TIRAP signaling and localization of both Nrf2 and NFκB transcription factors to the nucleus to upregulate p62-expression. Therefore, TLR4-activation by LPS in hepatocytes induces a p62-mediated, not beclin1-mediated, autophagy-like clearance pathway that is hepatoprotective by clearing aggregate-prone or misfolded proteins from the cytosol and preserving energy homeostasis under stress.

2020 ◽  
Author(s):  
Haiwei Wang ◽  
Xinrui Wang ◽  
Liangpu Xu ◽  
Hua Cao

Abstract Background: Heart failure is one of leading cause of death worldwide. However, the transcriptional profiling of heart failure is unclear. Moreover, the signaling pathways and transcription factors involving the heart failure development also are largely unknown. Using published Gene Expression Omnibus (GEO) datasets, in the present study, we aim to comprehensively analyze the differentially expressed genes in failing heart tissues, and identified the critical signaling pathways and transcription factors involving heart failure development. Methods: The transcriptional profiling of heart failure was identified from previously published gene expression datasets deposited in GSE5406, GSE16499 and GSE68316. The enriched signaling pathways and transcription factors were analyzed using DAVID website and gene set enrichment analysis (GSEA) assay. The transcriptional networks were created by Cytoscape. Results: Compared with the normal heart tissues, 90 genes were particularly differentially expressed in failing heart tissues, and those genes were associated with multiple metabolism signaling pathways and insulin signaling pathway. Metabolism and insulin signaling pathway were both inactivated in failing heart tissues. Transcription factors MYC and C/EBPβ were both negatively associated with the expression profiling of failing heart tissues in GSEA assay. Moreover, compared with normal heart tissues, MYC and C/EBPβ were down regulated in failing heart tissues. Furthermore, MYC and C/EBPβ mediated downstream target genes were also decreased in failing heart tissues. MYC and C/EBPβ were positively correlated with each other. At last, we constructed MYC and C/EBPβ mediated regulatory networks in failing heart tissues, and identified the MYC and C/EBPβ target genes which had been reported involving the heart failure developmental progress. Conclusions: Our results suggested that metabolism pathways and insulin signaling pathway, transcription factors MYC and C/EBPβ played critical roles in heart failure developmental progress.


2020 ◽  
Vol 21 (4) ◽  
pp. 1446 ◽  
Author(s):  
Jia Wang ◽  
Li Song ◽  
Xue Gong ◽  
Jinfan Xu ◽  
Minhui Li

Jasmonic acid (JA) is an endogenous growth-regulating substance, initially identified as a stress-related hormone in higher plants. Similarly, the exogenous application of JA also has a regulatory effect on plants. Abiotic stress often causes large-scale plant damage. In this review, we focus on the JA signaling pathways in response to abiotic stresses, including cold, drought, salinity, heavy metals, and light. On the other hand, JA does not play an independent regulatory role, but works in a complex signal network with other phytohormone signaling pathways. In this review, we will discuss transcription factors and genes involved in the regulation of the JA signaling pathway in response to abiotic stress. In this process, the JAZ-MYC module plays a central role in the JA signaling pathway through integration of regulatory transcription factors and related genes. Simultaneously, JA has synergistic and antagonistic effects with abscisic acid (ABA), ethylene (ET), salicylic acid (SA), and other plant hormones in the process of resisting environmental stress.


2020 ◽  
Vol 11 (9) ◽  
pp. 8297-8308
Author(s):  
Yuanyuan Li ◽  
Jialin Xu ◽  
Dongli Li ◽  
Hang Ma ◽  
Yu Mu ◽  
...  

GUB, a main phenolic compound present in guava fruits, could alleviate APAP-induced liver injury in vitro and in vivo by activating the Nrf2 signaling pathway and inhibiting the JNK signaling pathway.


2005 ◽  
Vol 289 (1) ◽  
pp. G129-G137 ◽  
Author(s):  
Jun Sun ◽  
Michael E. Hobert ◽  
Yingli Duan ◽  
Anjali S. Rao ◽  
Tong-Chuan He ◽  
...  

Salmonella-epithelial cell interactions are known to activate the proinflammatory NF-κB signaling pathway and have recently been found to also influence the β-catenin signaling pathway, an important regulator of epithelial cell proliferation and differentiation. Here, using polarized epithelial cell models, we demonstrate that these same bacteria-mediated effects also direct the molecular crosstalk between the NF-κB and β-catenin signaling pathways. Convergence of these two pathways is a result of the direct interaction between the NF-κB p50 subunit and β-catenin. We show that PhoPc, the avirulent derivative of a wild-type Salmonella strain, attenuates NF-κB activity by stabilizing the association of β-catenin with NF-κB. In cell lines expressing constitutively active β-catenin, IκBα protein was indirectly stabilized and NF-κB activity was repressed after wild-type Salmonella colonization. Accordingly, constitutively active β-catenin was found to inhibit the secretion of IL-8. Thus our findings strongly suggest that the crosstalk between the β-catenin and NF-κB signaling pathways is an important regulator of intestinal inflammation.


2021 ◽  
Author(s):  
Yongjing Li ◽  
Huiru Fu ◽  
Fuqiang Zhang ◽  
Liting Ren ◽  
Jing Tian ◽  
...  

AbstractThe involvement of insulin/insulin-like growth factor (IIS) signaling pathway in growth regulation of marine invertebrates remains largely unexplored. In this study, we used a fast-growing Pacific oyster (Crassostrea gigas) variety “Haida No.1” as material to unravel the role of IIS system in growth regulation in oysters. Systematic bioinformatics analyses allowed to identify major components of IIS signaling pathway and insulin-like peptide receptor (ILPR) mediated signaling pathways, including PI3K-AKT, RAS-MAPK, and TOR, in C. gigas. Expression levels of the major genes in IIS and its downstream signaling pathways were significantly higher in “Haida No.1” than wild oysters, suggesting their involvement in growth regulation of C. gigas. Expression profiles of IIS and its downstream signaling pathway genes were significantly altered by nutrient abundance and culture temperature. These results suggested that IIS signaling pathway coupled with the ILPR mediated signaling pathways orchestrated energy homeostasis to regulate growth in the Pacific oyster.Research HighlightsILPR, IRS, IGFBPRP, and IGFALS genes were characterized in the C. gigas.Major genes of IIS signaling pathway were highly expressed in fast-growing C. gigas.IIS and downstream pathways participates in energy homeostasis of oysters.ILPR mediated signaling pathways orchestrate growth regulation in oysters.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 58 ◽  
Author(s):  
Daniel P. Gil ◽  
Jeffrey N. Law ◽  
T. M. Murali

PathLinker is a graph-theoretic algorithm for reconstructing the interactions in a signaling pathway of interest. It efficiently computes multiple short paths within a background protein interaction network from the receptors to transcription factors (TFs) in a pathway. We originally developed PathLinker to complement manual curation of signaling pathways, which is slow and painstaking. The method can be used in general to connect any set of sources to any set of targets in an interaction network. The app presented here makes the PathLinker functionality available to Cytoscape users. We present an example where we used PathLinker to compute and analyze the network of interactions connecting proteins that are perturbed by the drug lovastatin.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3406-3406
Author(s):  
Takayuki Tabayashi ◽  
Sigal Gery ◽  
Maya Koren-Michowitz ◽  
H.Phillip Koeffler

Abstract Abstract 3406 Adaptor protein Lnk negatively regulates not only several hematopoietic cytokine receptors including MPL, EpoR and c-Kit, but also non-receptor tyrosine kinases such as JAK2 and Src. Our previous studies demonstrated that Lnk, when expressed in hematopoietic cell lines, binds and regulates the mutant proteins, JAK2V617F and MPLW515L. Recent in vivo studies have shown that Lnk has an important role in the development of myeloproliferative neoplasms. These data suggest that Lnk may have the ability to inhibit constitutively activated signaling pathways in hematopoietic malignancies. However, how Lnk can attenuate the activity of Bcr-Abl is unclear. In the present study, we tested the hypothesis that Lnk might play a role in regulating Bcr-Abl function. In order to assess if Lnk can inhibit the proliferation of Bcr-Abl-positive hematopoietic cells, Bcr-Abl-expressing BaF3 cells were stably transfected with either Lnk (BaF3/Bcr-Abl/Lnk) or vector only (BaF3/ Bcr-Abl). Colony-formation assays revealed that Lnk significantly inhibited the proliferation of Bcr-Abl-expressing BaF3 cells. Similarly, overexpression of Lnk inhibited growth in the human CML cell line, K562. To determine the cause of growth inhibition by Lnk, assays for apoptosis were performed. Annexin V staining demonstrated that Lnk overexpression induced apoptosis in Bcr-Abl-expressing BaF3 cells. Western blotting analysis of protein lysates from BaF3/ Bcr-Abl /Lnk cells and BaF3/ Bcr-Abl cells found that Lnk-mediated growth inhibition was associated with downregulation of the Stat5 signaling pathway, but not associated with MAPK and PI3K signaling pathways. In addition, experiments in 293T cells expressing Bcr-Abl and Stat5 with either wild-type Lnk or SH2 mutant Lnk revealed that wild-type Lnk, but not SH2 mutant Lnk, inhibited phosphorylation of Stat5. Interestingly, Lnk inhibited Bcr-Abl-induced Stat5 phosphorylation in a dose-dependent manner. These data suggest that the SH2 domain of Lnk is essential for Lnk–mediated downregulation of the Stat5 signaling pathway in Bcr-Abl-positive cells. Taken together, our data suggest that Lnk inhibits Bcr-Abl-induced cell proliferation by attenuating the Stat5 signal transduction and may become a therapeutic target for Bcr-Abl-positive leukemias such as chronic myeloid leukemia and Philadelphia chromosome positive acute lymphoblastic leukemia. Disclosures: No relevant conflicts of interest to declare.


2020 ◽  
Author(s):  
Haiwei Wang ◽  
Xinrui Wang ◽  
Liangpu Xu ◽  
Hua Cao

Abstract Background: Heart failure is one of leading cause of death worldwide. However, the transcriptional profiling of heart failure is unclear. Moreover, the signaling pathways and transcription factors involving the heart failure development also are largely unknown. Using published Gene Expression Omnibus (GEO) datasets, in the present study, we aim to comprehensively analyze the differentially expressed genes in failing heart tissues, and identified the critical signaling pathways and transcription factors involving heart failure development. Methods: The transcriptional profiling of heart failure was identified from previously published gene expression datasets deposited in GSE5406, GSE16499 and GSE68316. The enriched signaling pathways and transcription factors were analyzed using Database for Annotation, Visualization and Integrated Discovery (DAVID) website and gene set enrichment analysis (GSEA) assay. The transcriptional networks were created by Cytoscape. Results: Compared with the normal heart tissues, 90 genes were particularly differentially expressed in failing heart tissues, and those genes were associated with multiple metabolism signaling pathways and insulin signaling pathway. Metabolism and insulin signaling pathway were both inactivated in failing heart tissues. Transcription factors MYC and C/EBPβ were both negatively associated with the expression profiling of failing heart tissues in GSEA assay. Moreover, compared with normal heart tissues, MYC and C/EBPβ were down regulated in failing heart tissues. Furthermore, MYC and C/EBPβ mediated downstream target genes were also decreased in failing heart tissues. MYC and C/EBPβ were positively correlated with each other. At last, we constructed MYC and C/EBPβ mediated regulatory networks in failing heart tissues, and identified the MYC and C/EBPβ target genes which had been reported involving the heart failure developmental progress. Conclusions: Our results suggested that metabolism pathways and insulin signaling pathway, transcription factors MYC and C/EBPβ played critical roles in heart failure developmental progress.


2020 ◽  
Author(s):  
Haiwei Wang ◽  
Xinrui Wang ◽  
Liangpu Xu ◽  
Hua Cao

Abstract Background: Heart failure is one of leading cause of death worldwide. However, the transcriptional profiling of heart failure is unclear. Moreover, the signaling pathways and transcription factors involving the heart failure development also are largely unknown. Using published Gene Expression Omnibus (GEO) datasets, in the present study, we aim to comprehensively analyze the differentially expressed genes in failing heart tissues, and identified the critical signaling pathways and transcription factors involving heart failure development.Methods: The transcriptional profiling of heart failure was identified from previously published gene expression datasets deposited in GSE5406, GSE16499 and GSE68316. The enriched signaling pathways and transcription factors were analyzed using Database for Annotation, Visualization and Integrated Discovery (DAVID) website and gene set enrichment analysis (GSEA) assay. The transcriptional networks were created by Cytoscape.Results: Compared with the normal heart tissues, 90 genes were particularly differentially expressed in failing heart tissues, and those genes were associated with multiple metabolism signaling pathways and insulin signaling pathway. Metabolism and insulin signaling pathway were both inactivated in failing heart tissues. Transcription factors MYC and C/EBPβ were both negatively associated with the expression profiling of failing heart tissues in GSEA assay. Moreover, compared with normal heart tissues, MYC and C/EBPβ were down regulated in failing heart tissues. Furthermore, MYC and C/EBPβ mediated downstream target genes were also decreased in failing heart tissues. MYC and C/EBPβ were positively correlated with each other. At last, we constructed MYC and C/EBPβ mediated regulatory networks in failing heart tissues, and identified the MYC and C/EBPβ target genes which had been reported involving the heart failure developmental progress.Conclusions: Our results suggested that metabolism pathways and insulin signaling pathway, transcription factors MYC and C/EBPβ played critical roles in heart failure developmental progress.


2020 ◽  
Vol 27 ◽  
Author(s):  
Mohammad Kashif Iqubal ◽  
Aiswarya Chaudhuri ◽  
Ashif Iqubal ◽  
Sadaf Saleem ◽  
Madan Mohan Gupta ◽  
...  

: At present, skin cancer is a widespread malignancy in human beings. Among diverse population types, Caucasian populations are much more prone in comparison to darker skin populations due to the comparative lack of skin pigmentation. Skin cancer is divided into malignant and non-melanoma skin cancer, which is additionally categorized as basal and squamous cell carcinoma. The exposure to ultraviolet radiation, chemical carcinogen (polycyclic aromatic hydrocarbons, arsenic, tar, etc.), and viruses (herpes virus, human papillomavirus, and human T-cell leukemia virus type-1) are major contributing factors of skin cancer. There are distinct pathways available through which skin cancer develops, such as the JAKSTAT pathway, Akt pathway, MAPKs signaling pathway, Wnt signaling pathway, to name a few. Currently, several targeted treatments are available, such as monoclonal antibodies, which have dramatically changed the line of treatment of this disease but possess major therapeutic limitations. Thus, recently many phytochemicals have been evaluated either alone or in combination with the existing synthetic drugs to overcome their limitations and have found to play a promising role in the prevention and treatment. In this review, complete tracery of skin cancer, starting from the signaling pathways involved, newer developed drugs with their targets and limitations along with the emerging role of natural products alone or in combination as potent anticancer agents and their molecular mechanism involved has been discussed. Apart from this, various nanocargos have also been mentioned here, which can play a significant role in the management and treatment of different types of skin cancer.


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