AIM： To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 a...AIM： To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 and its downstream targets which been found significant expression in our previous study.METHODS： Quantitative real-time polymerase chain reaction （qRT-PCR） was used to detect microRNA-21 expression in normal uveal tissue and uveal melanoma cell lines. Lenti-virus expression system was used to construct OCM-1, MuM-2B and M619 cell line with stable overexpression and inhibition of microRNA-21. In vitro cell function tests such as cell proliferation, cell apoptosis, cell circle and abilities of migration and invasion were examined by MTT, BrdU assay, flow cytometry, transwell assay and Matrigel invasion assay respectively. The target gene was predicted by bioinformatics and confirmed by using a dual luciferase reporter assay. The expression of p53 and its suspected downstream targets LIM and SH3 protein 1 （LASP1） and Glutathione S Transferase pi （GST-Pi） were determined by qRT-PCR in mRNA level and western blotting analysis in protein level. Finally, the effect of microRNA-21 in a xenograft tumor model was assessed in four-week-old BALB/c nude mice. RESULTS： Compared to normal uveal melanoma, expressions of microRNA-21 were significantly higher in uveal melanoma cell lines. Overexpression of microRNA-21 promoted proliferation, migration, and invasion of OCM-1, M619 and MuM-2B cells, while inhibition of microRNA-21 reveal opposite effects. Wild type p53 was identified as a target gene of microRNA-21-3p, and proved by dual luciferase reporter assay. Up-regulated microRNA-21 inhibited the expression of wild type p53 gene, and the increased expression of LASP1 in mRNA level and protein level, while down-regulated microRNA-21 presented opposite way. However, GST-pi showed the potential pattern as expected, but relative mRNA level showed no statistically significant difference in OCM-1 cells. Furthermore, the mRNA expression of GST-pi was decreased in microRNA-21 overexpressing MuM-2B, and increased in M619 cells with inhibition of microRNA-21. In vivo, inhibition of microRNA-21 reduced tumor growth with statistically significant difference.CONCLUSION： These findings provide novel insight into molecular etiology of microRNA-21 in uveal melanoma cell lines, and suggest that microRNA-21 might be a potential candidate for the diagnosis and prognostic factor of human uveal melanoma in future.展开更多
Background:Papillary thyroid cancer(PTC)is the most prevalent histological type of differentiated thyroid malignancy.Circular RNAs(circRNAs)have been implicated in the pathogenesis and progression of various cancers.c...Background:Papillary thyroid cancer(PTC)is the most prevalent histological type of differentiated thyroid malignancy.Circular RNAs(circRNAs)have been implicated in the pathogenesis and progression of various cancers.circTIAM1(hsa_circ_0061406)is a novel circRNA with aberrant expression in PTC.However,its functional roles in PTC progression remain to be investigated.Methods:The expression levels of circTIAM1 in the PTC and the matched para-cancerous tissues were detected by quantitative real-time reverse-transcription PCR(qRT-PCR).The subcellular localization of circTIAM1 was examined by fluorescence in-situ hybridization(FISH).Kaplan-Meier plot was used to analyze the association of clinicopathological features with circTIAM1 expression.Bioinformatics databases were utilized to predict the target miRNAs of circTIAM1 and the downstream target mRNAs.RNA pulldown,RIP assay,and dual-luciferase reporter assay were used to confirm the interactions.Functional experiments,such as CCK-8,EDU staining,and apoptosis assays,as well as in vivo xenograft model were employed to explore the impacts of circTIAM1,miR-338-3p,and LIM/SH3 protein 1(LASP1)on the malignant phenotype of the PTC cells.Results:CircTIAM1 was highly expressed in PTC cells.Moreover,circTIAM1 silencing suppressed the proliferation and invasion of PTC cells in vitro and impaired tumorigenesis in vivo.Furthermore,miR-338-3p was verified as a miRNA target of circTIAM1.LASP1 was also identified as a downstream target of miR-338-3p.The anti-tumorigenic effect of miR-338-3p overexpression and the pro-tumorigenic effect of LASP1 was further explored by functional assays,which demonstrated that circTIAM1 modulated the PTC progression through targeting miR-338-3p/LASP1 axis.Conclusion:The overexpression of circTIAM1 is associated with the malignant progression of PTC.A high level of circTIAM1 promotes the malignancy of PTC cells via the miR-338-3p/LASP1 axis.展开更多
BACKGROUND Immune checkpoint inhibitors(ICIs)targeting programmed cell death protein 1(PD-1)and T cell immunoglobulin and mucin domain-containing protein 3(TIM-3)are beneficial to the resumption of anti-tumor immunity...BACKGROUND Immune checkpoint inhibitors(ICIs)targeting programmed cell death protein 1(PD-1)and T cell immunoglobulin and mucin domain-containing protein 3(TIM-3)are beneficial to the resumption of anti-tumor immunity response and hold extreme potential as efficient therapies for certain malignancies.However,ICIs with a single target exhibit poor overall response rate in hepatocellular carcinoma(HCC)patients due to the complex pathological mechanisms of HCC.AIM To investigate the effects of combined TIM-3 and PD-1 blockade on tumor development in an HCC mouse model,aiming to identify more effective immunotherapies and provide more treatment options for HCC patients.METHODS The levels of PD-1 and TIM-3 on CD4+and CD8+T cells from tumor tissues,ascites,and matched adjacent tissues from HCC patients were determined with flow cytometry.An HCC xenograft mouse model was established and treated with anti-TIM-3 monoclonal antibody(mAb)and/or anti-PD-1 mAb.Tumor growth in each group was measured.Hematoxylin and eosin staining and immunohistochemical staining were used to evaluate T cell infiltration in tumors.The percentage of CD4+and CD8+T cells in tissue samples from mice was tested with flow cytometry.The percentages of PD-1+CD8+,TIM-3+CD8+,and PD-1+TIM-3+CD8+T cells was accessed by flow cytometry.The levels of the cytokines including tumor necrosis factor alpha(TNF-α),interferon-γ(IFN-γ),interleukin(IL)-6,and IL-10 in tumor tissues were gauged with enzyme-linked immunosorbent assay kits.RESULTS We confirmed that PD-1 and TIM-3 expression was substantially upregulated in CD4+and CD8+T cells isolated from tumor tissues and ascites of HCC patients.TIM-3 mAb and PD-1 mAb treatment both reduced tumor volume and weight,while combined blockade had more substantial anti-tumor effects than individual treatment.Then we showed that combined therapy increased T cell infiltration into tumor tissues,and downregulated PD-1 and TIM-3 expression on CD8+T cells in tumor tissues.Moreover,combined treatment facilitated the production of T cell effector cytokines TNF-α and IFN-γ,and reduced the production of immunosuppressive cytokines IL-10 and IL-6 in tumor tissues.Thus,we implicated that combined blockade could ameliorate T cell exhaustion in HCC mouse model.CONCLUSION Combined TIM-3 and PD-1 blockade restrains HCC development by facilitating CD4+ and CD8+T cell-mediated antitumor immune responses.展开更多
Plants usually keep resistance(R)proteins in a static state under normal conditions to avoid autoimmunity and save energy for growth,but R proteins can be rapidly activated upon perceiving pathogen invasion.Pib,the fi...Plants usually keep resistance(R)proteins in a static state under normal conditions to avoid autoimmunity and save energy for growth,but R proteins can be rapidly activated upon perceiving pathogen invasion.Pib,the first cloned blast disease R gene in rice,encoding a nucleotide-binding leucine-rich repeat(NLR)protein,mediates resistance to the blast fungal(Magnaporthe oryzae)isolates carrying the avirulence gene AvrPib.However,the molecular mechanisms about how Pib recognizes AvrPib and how it is inactivated and activated remain largely unclear.In this study,through map-based cloning and CRISPR-Cas9 gene editing,we proved that Pib contributes to the blast disease resistance of rice cultivar Yunyin(YY).Furthermore,an SH3 domain-containing protein,SH3P2,was found to associate with Pib mainly at clathrin-coated vesicles in rice cells,via direct binding with the coiled-coil(CC)domain of Pib.Interestingly,overexpression of SH3P2 in YY compromised Pib-mediated resistance to M.oryzae isolates carrying AvrPib and Pib-AvrPib recognition-induced cell death.SH3P2 competitively inhibits the self-association of the Pib CC domain in vitro,suggesting that binding of SH3P2 with Pib undermines its homodimerization.Moreover,SH3P2 can also interact with AvrPib and displays higher affinity to AvrPib than to Pib,which leads to dissociation of SH3P2 from Pib in the presence of AvrPib.Taken together,our results suggest that SH3P2 functions as a“protector”to keep Pib in a static state by direct interaction during normal growth but could be triggered off by the invasion of AvrPib-carrying M.oryzae isolates.Our study reveals a new mechanism about how an NLR protein is inactivated under normal conditions but is activated upon pathogen infection.展开更多
Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun1...Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun14 domain-containing protein 1 （FUNDC1） was reported to be a new receptor for hypoxia-induced mitophagy in mammalian cells and interact with micro-tubule-associated protein light chain 3 beta （LC3B） through its LC3 interaction region （LIR）. Moreover, the phosphorylation modification of FUNDC1 affects its binding affinity for LC3B and regulates selective mitophagy. However, the structural basis of this regulation mechanism remains unclear. Here, we present the crystal structure of LC3B in complex with a FUNDCI LIR peptide phosphorylated at Ser17 （pS17）, demonstrating the key residues of LC3B for the specific recognition of the phosphorylated or dephosphorylated FUNDC1. Intriguingly, the side chain of LC3B Lys49 shifts remarkably and forms a hydrogen bond and electrostatic interaction with the phosphate group of FUNDC1 pS17. Alternatively, phosphorylated Tyr18 （PY18） and Ser13 （PS13） in FUNDC1 significantly obstruct their interaction with the hydrophobic pocket and Arg10 of LC3B, respectively. Structural observations are further validated by mutation and isothermal titration calorimetry （ITC） assays. Therefore, our structural and biochemical results reveal a working model for thespecific recognition of FUNDCI by LC3B and imply that the reversible phosphorylation modification of mitophagy receptors may be a switch for selective mitophagy.展开更多
OBJECTIVE:To investigate synergistic effect of Reduning(RDN)injection plus ribavirin against severe pneumonia induced by H1 N1 influenza A virus in mice.METHODS:We established a mouse model of severe pneumonia induced...OBJECTIVE:To investigate synergistic effect of Reduning(RDN)injection plus ribavirin against severe pneumonia induced by H1 N1 influenza A virus in mice.METHODS:We established a mouse model of severe pneumonia induced by influenza A virus by infecting Balb/c mice with CA07 virus.We randomly assigned the infected mice into four groups,and treated them with normal saline(NS group),RDN(injection,86.6 mg/kg),ribavirin(injection,66.6 mg/kg)or double Ribavirin plus RDN group,the same dosage as used in the single treatments)for 5 d.Lung index and lung pathology were recorded or calculated in terms of the curative effective.Cytokines,NOD-like receptor family pyrin domain containing 3(NLRP3)inflammasome related protein including caspase-associated recruitment domain(CARD)domain Apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),caspase-1 and NOD-like receptor family,pyrin domain containing 3(NLRP3),and reactive oxygen species were simultaneously investigated.RESULTS:RDN plus ribavirin treatment,not RDN or ribavirin alone,provided a significant survival benefit to the influenza A virus-infected mice.The combination treatment protected the mice against severe influenza infection by attenuating the severe lung injury.The combined treatment also reduced the viral titers in mouse lungs and lung index,downregulated their immunocytokine levels,including IL-1βand IL-18,and down regulated the NLRP3,especially the transcription and translation of caspase-1.Meanwhile NS group had significantly higher reactive oxygen species(ROS)expression which could was dramatically reduced by the treatment of RDN plus ribavirin.CONCLUSION:Our study showed that RDN combined with ribavirin could protect the mice,and reduce the lung immunopathologic damage caused by severe influenza pneumonia.The mechanism could be that it reduced ROS produce and inhibited NLRP3 inflammasome activation so that mainly lower the downstream inflammatory cytokines IL-1βand IL-18.展开更多
Cystathionine-γ-lyase(CSE),an enzyme associated with hydrogen sulfide(H2S)production,is an important endogenous regulator of inflammation.Jumonji domain-containing protein 3(JMJD3)is implicated in the immune response...Cystathionine-γ-lyase(CSE),an enzyme associated with hydrogen sulfide(H2S)production,is an important endogenous regulator of inflammation.Jumonji domain-containing protein 3(JMJD3)is implicated in the immune response and inflammation.Here,we investigated the potential contribution of JMJD3 to endogenous CSE-mediated inflammation in rheumatoid arthritis(RA).Upregulated CSE and JMJD3 were identified in synovial fibroblasts(SFs)from RA patients as well as in the joints of arthritic mice.Knocking down CSE augmented inflammation in IL-1β-induced SFs by increasing JMJD3 expression.In addition,CSE−/−mice with collagen-induced arthritis(CIA)developed severe joint inflammation and bone erosion.Conversely,overexpressing CSE inhibited JMJD3 expression by the transcription factor Sp-1 and was accompanied by reduced inflammation in IL-1β-treated SFs.Furthermore,JMJD3 silencing or the administration of the JMJD3 inhibitor GSK-J4 significantly decreased the inflammatory response in IL-1β-treated SFs,mainly by controlling the methylation status of H3K27me3 at the promoter of its target genes.GSK-J4 markedly attenuated the severity of arthritis in CIA mice.In conclusion,suppressing JMJD3 expression by the transcription factor Sp-1 is likely responsible for the ability of CSE to negatively modulate the inflammatory response and reduce the progression of RA.展开更多
Cerebral ischemia is a neurological disorder associated with complex pathological mechanisms,including autophagic degradation of neuronal mitochondria,or termed mitophagy,following ischemic events.Despite being well-d...Cerebral ischemia is a neurological disorder associated with complex pathological mechanisms,including autophagic degradation of neuronal mitochondria,or termed mitophagy,following ischemic events.Despite being well-documented,the cellular and molecular mechanisms under-lying the regulation of neuronal mitophagy remain unknown.So far,the evidence suggests neuronal autophagy and mitophagy are separately regulated in ischemic neurons,the latter being more likely activated by reperfusional injury.Specifically,given the polarized morphology of neurons,mitophagy is regulated by different neuronal compartments,with axonal mitochondria being degraded by autophagy in the cell body following ischemia-reperfusion insult.A variety of molecules have been associated with neuronal adaptation to ischemia,including PTEN-induced kinase 1,Parkin,BCL2 and adenovirus E1B 19-kDa-interacting protein 3(Bnip3),Bnip3-like(Bnip3l)and FUN14 domain-containing 1.Moreover,it is still controversial whether mitophagy protects against or instead aggravates ischemic brain injury.Here,we review recent studies on this topic and provide an updated overview of the role and regulation of mitophagy during ischemic events.展开更多
基金Supported by the National Natural Science Foundation of China (No.81570891 No.81272981)+3 种基金Beijing Natural Science Foundation (No.7151003)Advanced Health Care Professionals Development Project of Beijing Municipal Health Bureau (No.2014-2-003)the Capital Health Research and Development of Special (No.2016-1-2051)Hospitals’ Ascent Plan (No.DFL20150201)
文摘AIM： To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 and its downstream targets which been found significant expression in our previous study.METHODS： Quantitative real-time polymerase chain reaction （qRT-PCR） was used to detect microRNA-21 expression in normal uveal tissue and uveal melanoma cell lines. Lenti-virus expression system was used to construct OCM-1, MuM-2B and M619 cell line with stable overexpression and inhibition of microRNA-21. In vitro cell function tests such as cell proliferation, cell apoptosis, cell circle and abilities of migration and invasion were examined by MTT, BrdU assay, flow cytometry, transwell assay and Matrigel invasion assay respectively. The target gene was predicted by bioinformatics and confirmed by using a dual luciferase reporter assay. The expression of p53 and its suspected downstream targets LIM and SH3 protein 1 （LASP1） and Glutathione S Transferase pi （GST-Pi） were determined by qRT-PCR in mRNA level and western blotting analysis in protein level. Finally, the effect of microRNA-21 in a xenograft tumor model was assessed in four-week-old BALB/c nude mice. RESULTS： Compared to normal uveal melanoma, expressions of microRNA-21 were significantly higher in uveal melanoma cell lines. Overexpression of microRNA-21 promoted proliferation, migration, and invasion of OCM-1, M619 and MuM-2B cells, while inhibition of microRNA-21 reveal opposite effects. Wild type p53 was identified as a target gene of microRNA-21-3p, and proved by dual luciferase reporter assay. Up-regulated microRNA-21 inhibited the expression of wild type p53 gene, and the increased expression of LASP1 in mRNA level and protein level, while down-regulated microRNA-21 presented opposite way. However, GST-pi showed the potential pattern as expected, but relative mRNA level showed no statistically significant difference in OCM-1 cells. Furthermore, the mRNA expression of GST-pi was decreased in microRNA-21 overexpressing MuM-2B, and increased in M619 cells with inhibition of microRNA-21. In vivo, inhibition of microRNA-21 reduced tumor growth with statistically significant difference.CONCLUSION： These findings provide novel insight into molecular etiology of microRNA-21 in uveal melanoma cell lines, and suggest that microRNA-21 might be a potential candidate for the diagnosis and prognostic factor of human uveal melanoma in future.
基金the Ethics Committee of University-Town Hospital of Chongqing Medical University(LL-201682)the Laboratory Animal Ethics Committee of of University-Town Hospital of Chongqing Medical University(2022-053).
文摘Background:Papillary thyroid cancer(PTC)is the most prevalent histological type of differentiated thyroid malignancy.Circular RNAs(circRNAs)have been implicated in the pathogenesis and progression of various cancers.circTIAM1(hsa_circ_0061406)is a novel circRNA with aberrant expression in PTC.However,its functional roles in PTC progression remain to be investigated.Methods:The expression levels of circTIAM1 in the PTC and the matched para-cancerous tissues were detected by quantitative real-time reverse-transcription PCR(qRT-PCR).The subcellular localization of circTIAM1 was examined by fluorescence in-situ hybridization(FISH).Kaplan-Meier plot was used to analyze the association of clinicopathological features with circTIAM1 expression.Bioinformatics databases were utilized to predict the target miRNAs of circTIAM1 and the downstream target mRNAs.RNA pulldown,RIP assay,and dual-luciferase reporter assay were used to confirm the interactions.Functional experiments,such as CCK-8,EDU staining,and apoptosis assays,as well as in vivo xenograft model were employed to explore the impacts of circTIAM1,miR-338-3p,and LIM/SH3 protein 1(LASP1)on the malignant phenotype of the PTC cells.Results:CircTIAM1 was highly expressed in PTC cells.Moreover,circTIAM1 silencing suppressed the proliferation and invasion of PTC cells in vitro and impaired tumorigenesis in vivo.Furthermore,miR-338-3p was verified as a miRNA target of circTIAM1.LASP1 was also identified as a downstream target of miR-338-3p.The anti-tumorigenic effect of miR-338-3p overexpression and the pro-tumorigenic effect of LASP1 was further explored by functional assays,which demonstrated that circTIAM1 modulated the PTC progression through targeting miR-338-3p/LASP1 axis.Conclusion:The overexpression of circTIAM1 is associated with the malignant progression of PTC.A high level of circTIAM1 promotes the malignancy of PTC cells via the miR-338-3p/LASP1 axis.
基金Supported by the First-Class Discipline Construction Founded Project of Ningxia Medical University and the School of Clinical Medicine,No.2020008.
文摘BACKGROUND Immune checkpoint inhibitors(ICIs)targeting programmed cell death protein 1(PD-1)and T cell immunoglobulin and mucin domain-containing protein 3(TIM-3)are beneficial to the resumption of anti-tumor immunity response and hold extreme potential as efficient therapies for certain malignancies.However,ICIs with a single target exhibit poor overall response rate in hepatocellular carcinoma(HCC)patients due to the complex pathological mechanisms of HCC.AIM To investigate the effects of combined TIM-3 and PD-1 blockade on tumor development in an HCC mouse model,aiming to identify more effective immunotherapies and provide more treatment options for HCC patients.METHODS The levels of PD-1 and TIM-3 on CD4+and CD8+T cells from tumor tissues,ascites,and matched adjacent tissues from HCC patients were determined with flow cytometry.An HCC xenograft mouse model was established and treated with anti-TIM-3 monoclonal antibody(mAb)and/or anti-PD-1 mAb.Tumor growth in each group was measured.Hematoxylin and eosin staining and immunohistochemical staining were used to evaluate T cell infiltration in tumors.The percentage of CD4+and CD8+T cells in tissue samples from mice was tested with flow cytometry.The percentages of PD-1+CD8+,TIM-3+CD8+,and PD-1+TIM-3+CD8+T cells was accessed by flow cytometry.The levels of the cytokines including tumor necrosis factor alpha(TNF-α),interferon-γ(IFN-γ),interleukin(IL)-6,and IL-10 in tumor tissues were gauged with enzyme-linked immunosorbent assay kits.RESULTS We confirmed that PD-1 and TIM-3 expression was substantially upregulated in CD4+and CD8+T cells isolated from tumor tissues and ascites of HCC patients.TIM-3 mAb and PD-1 mAb treatment both reduced tumor volume and weight,while combined blockade had more substantial anti-tumor effects than individual treatment.Then we showed that combined therapy increased T cell infiltration into tumor tissues,and downregulated PD-1 and TIM-3 expression on CD8+T cells in tumor tissues.Moreover,combined treatment facilitated the production of T cell effector cytokines TNF-α and IFN-γ,and reduced the production of immunosuppressive cytokines IL-10 and IL-6 in tumor tissues.Thus,we implicated that combined blockade could ameliorate T cell exhaustion in HCC mouse model.CONCLUSION Combined TIM-3 and PD-1 blockade restrains HCC development by facilitating CD4+ and CD8+T cell-mediated antitumor immune responses.
基金This work was supported by the National Key R&D Program Foundation of China(grant no.2016YFD0300508)the National Rice Industry Technology System of Modern Agriculture for China(grant no.CARS-01-20)+2 种基金the“5511”Collaborative Innovation Project for High-Quality Development and Surpasses of Agriculture between Government of Fujian and Chinese Academy of Agricultural Sciences(grant no.XTCXGC2021001)Key Program of Science and Technology in Fujian province,China(no.2020NZ08016)the Special Foundation of Non-Profit Research Institutes of Fujian Province(grant no.2018R1021-5).
文摘Plants usually keep resistance(R)proteins in a static state under normal conditions to avoid autoimmunity and save energy for growth,but R proteins can be rapidly activated upon perceiving pathogen invasion.Pib,the first cloned blast disease R gene in rice,encoding a nucleotide-binding leucine-rich repeat(NLR)protein,mediates resistance to the blast fungal(Magnaporthe oryzae)isolates carrying the avirulence gene AvrPib.However,the molecular mechanisms about how Pib recognizes AvrPib and how it is inactivated and activated remain largely unclear.In this study,through map-based cloning and CRISPR-Cas9 gene editing,we proved that Pib contributes to the blast disease resistance of rice cultivar Yunyin(YY).Furthermore,an SH3 domain-containing protein,SH3P2,was found to associate with Pib mainly at clathrin-coated vesicles in rice cells,via direct binding with the coiled-coil(CC)domain of Pib.Interestingly,overexpression of SH3P2 in YY compromised Pib-mediated resistance to M.oryzae isolates carrying AvrPib and Pib-AvrPib recognition-induced cell death.SH3P2 competitively inhibits the self-association of the Pib CC domain in vitro,suggesting that binding of SH3P2 with Pib undermines its homodimerization.Moreover,SH3P2 can also interact with AvrPib and displays higher affinity to AvrPib than to Pib,which leads to dissociation of SH3P2 from Pib in the presence of AvrPib.Taken together,our results suggest that SH3P2 functions as a“protector”to keep Pib in a static state by direct interaction during normal growth but could be triggered off by the invasion of AvrPib-carrying M.oryzae isolates.Our study reveals a new mechanism about how an NLR protein is inactivated under normal conditions but is activated upon pathogen infection.
基金This work was supported by National Natural Science Founda- tion （Grant No. 31400629） the Strategic Priority Research Program of the Chinese Academy of Science （No. XDB08010101）+1 种基金 Ministry Of Science And Technology of China （No. 2016YFA0500700） China Postdoctoral Science Foundation （No. 2015M582009 and 2016T90579） and National Natural Science Foundation （Grant No. 31330018）.
文摘Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun14 domain-containing protein 1 （FUNDC1） was reported to be a new receptor for hypoxia-induced mitophagy in mammalian cells and interact with micro-tubule-associated protein light chain 3 beta （LC3B） through its LC3 interaction region （LIR）. Moreover, the phosphorylation modification of FUNDC1 affects its binding affinity for LC3B and regulates selective mitophagy. However, the structural basis of this regulation mechanism remains unclear. Here, we present the crystal structure of LC3B in complex with a FUNDCI LIR peptide phosphorylated at Ser17 （pS17）, demonstrating the key residues of LC3B for the specific recognition of the phosphorylated or dephosphorylated FUNDC1. Intriguingly, the side chain of LC3B Lys49 shifts remarkably and forms a hydrogen bond and electrostatic interaction with the phosphate group of FUNDC1 pS17. Alternatively, phosphorylated Tyr18 （PY18） and Ser13 （PS13） in FUNDC1 significantly obstruct their interaction with the hydrophobic pocket and Arg10 of LC3B, respectively. Structural observations are further validated by mutation and isothermal titration calorimetry （ITC） assays. Therefore, our structural and biochemical results reveal a working model for thespecific recognition of FUNDCI by LC3B and imply that the reversible phosphorylation modification of mitophagy receptors may be a switch for selective mitophagy.
基金Supported by The Beijing Natural Science Foundation the research on the mechanisms of Reduning Injection which protects mice from severe pneumonia in terms of the activation level of NLRP3 inflammatomes(No.7172099)
文摘OBJECTIVE:To investigate synergistic effect of Reduning(RDN)injection plus ribavirin against severe pneumonia induced by H1 N1 influenza A virus in mice.METHODS:We established a mouse model of severe pneumonia induced by influenza A virus by infecting Balb/c mice with CA07 virus.We randomly assigned the infected mice into four groups,and treated them with normal saline(NS group),RDN(injection,86.6 mg/kg),ribavirin(injection,66.6 mg/kg)or double Ribavirin plus RDN group,the same dosage as used in the single treatments)for 5 d.Lung index and lung pathology were recorded or calculated in terms of the curative effective.Cytokines,NOD-like receptor family pyrin domain containing 3(NLRP3)inflammasome related protein including caspase-associated recruitment domain(CARD)domain Apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),caspase-1 and NOD-like receptor family,pyrin domain containing 3(NLRP3),and reactive oxygen species were simultaneously investigated.RESULTS:RDN plus ribavirin treatment,not RDN or ribavirin alone,provided a significant survival benefit to the influenza A virus-infected mice.The combination treatment protected the mice against severe influenza infection by attenuating the severe lung injury.The combined treatment also reduced the viral titers in mouse lungs and lung index,downregulated their immunocytokine levels,including IL-1βand IL-18,and down regulated the NLRP3,especially the transcription and translation of caspase-1.Meanwhile NS group had significantly higher reactive oxygen species(ROS)expression which could was dramatically reduced by the treatment of RDN plus ribavirin.CONCLUSION:Our study showed that RDN combined with ribavirin could protect the mice,and reduce the lung immunopathologic damage caused by severe influenza pneumonia.The mechanism could be that it reduced ROS produce and inhibited NLRP3 inflammasome activation so that mainly lower the downstream inflammatory cytokines IL-1βand IL-18.
基金supported by grants from National Natural Science Foundation of China(No.8167342881330080)a key laboratory program of the Education Commission of Shanghai Municipality(No.ZDSYS14005).
文摘Cystathionine-γ-lyase(CSE),an enzyme associated with hydrogen sulfide(H2S)production,is an important endogenous regulator of inflammation.Jumonji domain-containing protein 3(JMJD3)is implicated in the immune response and inflammation.Here,we investigated the potential contribution of JMJD3 to endogenous CSE-mediated inflammation in rheumatoid arthritis(RA).Upregulated CSE and JMJD3 were identified in synovial fibroblasts(SFs)from RA patients as well as in the joints of arthritic mice.Knocking down CSE augmented inflammation in IL-1β-induced SFs by increasing JMJD3 expression.In addition,CSE−/−mice with collagen-induced arthritis(CIA)developed severe joint inflammation and bone erosion.Conversely,overexpressing CSE inhibited JMJD3 expression by the transcription factor Sp-1 and was accompanied by reduced inflammation in IL-1β-treated SFs.Furthermore,JMJD3 silencing or the administration of the JMJD3 inhibitor GSK-J4 significantly decreased the inflammatory response in IL-1β-treated SFs,mainly by controlling the methylation status of H3K27me3 at the promoter of its target genes.GSK-J4 markedly attenuated the severity of arthritis in CIA mice.In conclusion,suppressing JMJD3 expression by the transcription factor Sp-1 is likely responsible for the ability of CSE to negatively modulate the inflammatory response and reduce the progression of RA.
基金funded by National Natural Science Foundation of China(81973402)Natural Science Foundation of Zhejiang Province(LYY22H310009)+1 种基金Hospital Pharmacy Scientific Research Funding Project of Zhejiang Pharmaceutical Association(2020ZYY10)Clinical research fund project of Zhejiang Medical Association(2020ZYC-A07).
文摘Cerebral ischemia is a neurological disorder associated with complex pathological mechanisms,including autophagic degradation of neuronal mitochondria,or termed mitophagy,following ischemic events.Despite being well-documented,the cellular and molecular mechanisms under-lying the regulation of neuronal mitophagy remain unknown.So far,the evidence suggests neuronal autophagy and mitophagy are separately regulated in ischemic neurons,the latter being more likely activated by reperfusional injury.Specifically,given the polarized morphology of neurons,mitophagy is regulated by different neuronal compartments,with axonal mitochondria being degraded by autophagy in the cell body following ischemia-reperfusion insult.A variety of molecules have been associated with neuronal adaptation to ischemia,including PTEN-induced kinase 1,Parkin,BCL2 and adenovirus E1B 19-kDa-interacting protein 3(Bnip3),Bnip3-like(Bnip3l)and FUN14 domain-containing 1.Moreover,it is still controversial whether mitophagy protects against or instead aggravates ischemic brain injury.Here,we review recent studies on this topic and provide an updated overview of the role and regulation of mitophagy during ischemic events.
