Background:Cancer cells selectively promote the translation of oncogenic tran-scripts to stimulate cancer progression.Although growing evidence has revealed that tRNA modifications and related genes participate in thi...Background:Cancer cells selectively promote the translation of oncogenic tran-scripts to stimulate cancer progression.Although growing evidence has revealed that tRNA modifications and related genes participate in this process,their roles in head and neck squamous cell carcinoma(HNSCC)remain largely unchar-acterized.Here,we sought to investigate the function and mechanisms of the transfer RNA(tRNA)N7-methylguanosine(m'G)modification in regulating the occurrence and development of HNSCC.Methods:Cell lost of-function and gain-of function assays,xenograft models,conditional knockout and knockin mouse models were used to study the physi-ological functions of tRNA m'G modification in HNSCC tumorigenesis.tRNA modification and expression profiling,mRNA translation profiling and res-cue assays were performed to uncover the underlying molecular mechanisms.Single-cell RNA sequencing(scRNA seq)was conducted to explore the tumor microenvironment changes.Results:The tRNA.m7G methyltransferase complex components Methyltransferase-like 1(METTL1)/WD repeat domain 4(WDR4)were upregulated in HNSCC and associated with a poor prognosis.Functionally,METTL1/WDR4 promoted HNSCC progression and metastasis in cell-based and transgenic mouse models.Mechanistically,ablation of METTL1 reduced the m'G levels of 16 tRNAS,inhibiting the translation of a subset of oncogenic transcripts,including genes related to the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR)signaling pathway.In addition,chemical modulators of the PI3K/Akt/mTOR signaling pathway reversed the effects of Mettll in mouse HNSCC.Furthermore,scRNA-seq results revealed that Mettll knockout in mouse tumor cells altered the immune landscape and cell-cell interaction between the tumor and stromal compartment.Conclusions:The tRNA m?G methyltransferase METTLI was found to promote the development and malignancy of HNSCC through regulating global mRNA translation,including the PI3K/AKT/mTOR signaling pathway,and found to alter immune landscape.METTLI could be a promising treatment target for HNSCC patients.展开更多
Microglia are involved in the inflammatory response and retinal ganglion cell damage in glaucoma.Here,we investigated how microglia proliferate and migrate in a mouse model of chronic ocular hypertension(COH).In COH r...Microglia are involved in the inflammatory response and retinal ganglion cell damage in glaucoma.Here,we investigated how microglia proliferate and migrate in a mouse model of chronic ocular hypertension(COH).In COH retinas,the microglial proliferation that occurred was inhibited by the P2X7 receptor(P2X7R)blocker BBG or P2X7R knockout,but not by the P2X4R blocker 5-BDBD.Treatment of primary cultured microglia with BzATP,a P2X7R agonist,mimicked the effects of cell proliferation and migration in COH retinas through the intracellular MEK/ERK signaling pathway.Transwell migration assays showed that the P2X4R agonist CTP induced microglial migration,which was completely blocked by 5-BDBD.In vivo and in vitro experiments demonstrated that ATP,released from activated Müller cells through connexin43 hemichannels,acted on P2X7R to induce microglial proliferation,and acted on P2X4R/P2X7R(mainly P2X4R)to induce microglial migration.Our results suggest that inhibiting the interaction of Müller cells and microglia may attenuate microglial proliferation and migration in glaucoma.展开更多
Flares of joint inflammation and resistance to currently available biologic therapeutics in rheumatoid arthritis(RA)patients could reflect activation of innate immune mechanisms.Herein,we show that a TLR7 GU-rich endo...Flares of joint inflammation and resistance to currently available biologic therapeutics in rheumatoid arthritis(RA)patients could reflect activation of innate immune mechanisms.Herein,we show that a TLR7 GU-rich endogenous ligand,miR-Let7b,potentiates synovitis by amplifying RA monocyte and fibroblast(FLS)trafficking.miR-Let7b ligation to TLR7 in macrophages(MΦs)and FLSs expanded the synovial inflammatory response.Moreover,secretion of M1 monokines triggered by miR-Let7b enhanced Th1/Th17 cell differentiation.We showed that IRAK4 inhibitor(i)therapy attenuated RA disease activity by blocking TLR7-induced M1 MΦor FLS activation,as well as monokine-modulated Th1/Th17 cell polarization.IRAK4i therapy also disrupted RA osteoclastogenesis,which was amplified by miR-Let7b ligation to joint myeloid TLR7.Hence,the effectiveness of IRAK4i was compared with that of a TNF inhibitor(i)or anti-IL-6R treatment in collagen-induced arthritis(CIA)and miR-Let7b-mediated arthritis.We found that TNF or IL-6R blocking therapies mitigated CIA by reducing the infiltration of joint F480+iNOS+MΦs,the expression of certain monokines,and Th1 cell differentiation.Unexpectedly,these biologic therapies were unable to alleviate miR-Let7b-induced arthritis.The superior efficacy of IRAK4i over anti-TNF or anti-IL-6R therapy in miR-Let7b-induced arthritis or CIA was due to the ability of IRAK4i therapy to restrain the migration of joint F480+iNOS+MΦs,vimentin+fibroblasts,and CD3+T cells,in addition to negating the expression of a wide range of monokines,including IL-12,MIP2,and IRF5 and Th1/Th17 lymphokines.In conclusion,IRAK4i therapy may provide a promising strategy for RA therapy by disconnecting critical links between inflammatory joint cells.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:81872409,82173362Natural Science Foundation of Guangdong Province,Grant/Award Numbers:2018A030313610,2019A1515110110,2020A1515010291+1 种基金The Open Funding of the State Key Laboratory of Oral Diseases,Grant/Award Number:SKLOD2021OF02and the use was approved by the Institutional Review Board of the First Affiliated Hospital of Sun Yat-Sen University(2016074).The nude mouse experi-ments performed were approved by the Laboratory Ani-mal Center of Sun Yat-SenUniversity(SYSU-IACUC-2021-000092).The transgenic mouse experiments performed were approved by the Laboratory Animal Center of Sun Yat-Sen University(SYSU-IACUC-2020-000569).
文摘Background:Cancer cells selectively promote the translation of oncogenic tran-scripts to stimulate cancer progression.Although growing evidence has revealed that tRNA modifications and related genes participate in this process,their roles in head and neck squamous cell carcinoma(HNSCC)remain largely unchar-acterized.Here,we sought to investigate the function and mechanisms of the transfer RNA(tRNA)N7-methylguanosine(m'G)modification in regulating the occurrence and development of HNSCC.Methods:Cell lost of-function and gain-of function assays,xenograft models,conditional knockout and knockin mouse models were used to study the physi-ological functions of tRNA m'G modification in HNSCC tumorigenesis.tRNA modification and expression profiling,mRNA translation profiling and res-cue assays were performed to uncover the underlying molecular mechanisms.Single-cell RNA sequencing(scRNA seq)was conducted to explore the tumor microenvironment changes.Results:The tRNA.m7G methyltransferase complex components Methyltransferase-like 1(METTL1)/WD repeat domain 4(WDR4)were upregulated in HNSCC and associated with a poor prognosis.Functionally,METTL1/WDR4 promoted HNSCC progression and metastasis in cell-based and transgenic mouse models.Mechanistically,ablation of METTL1 reduced the m'G levels of 16 tRNAS,inhibiting the translation of a subset of oncogenic transcripts,including genes related to the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR)signaling pathway.In addition,chemical modulators of the PI3K/Akt/mTOR signaling pathway reversed the effects of Mettll in mouse HNSCC.Furthermore,scRNA-seq results revealed that Mettll knockout in mouse tumor cells altered the immune landscape and cell-cell interaction between the tumor and stromal compartment.Conclusions:The tRNA m?G methyltransferase METTLI was found to promote the development and malignancy of HNSCC through regulating global mRNA translation,including the PI3K/AKT/mTOR signaling pathway,and found to alter immune landscape.METTLI could be a promising treatment target for HNSCC patients.
基金This work was supported by grants from the National Natural Science Foundation of China(81790642 and 31872765)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)ZJ Lab,and the Shanghai Center for Brain Science and Brain-Inspired Technology.
文摘Microglia are involved in the inflammatory response and retinal ganglion cell damage in glaucoma.Here,we investigated how microglia proliferate and migrate in a mouse model of chronic ocular hypertension(COH).In COH retinas,the microglial proliferation that occurred was inhibited by the P2X7 receptor(P2X7R)blocker BBG or P2X7R knockout,but not by the P2X4R blocker 5-BDBD.Treatment of primary cultured microglia with BzATP,a P2X7R agonist,mimicked the effects of cell proliferation and migration in COH retinas through the intracellular MEK/ERK signaling pathway.Transwell migration assays showed that the P2X4R agonist CTP induced microglial migration,which was completely blocked by 5-BDBD.In vivo and in vitro experiments demonstrated that ATP,released from activated Müller cells through connexin43 hemichannels,acted on P2X7R to induce microglial proliferation,and acted on P2X4R/P2X7R(mainly P2X4R)to induce microglial migration.Our results suggest that inhibiting the interaction of Müller cells and microglia may attenuate microglial proliferation and migration in glaucoma.
基金This work was supported in part by awards from the Department of Veteran’s Affairs MERIT Award(1I01BX002286)the National Institutes of Health(AR056099 and AR065778)+2 种基金the National Psoriasis Foundation(NPF)the Pfizer Investigator Initiated Research(IIR)Programthe Chicago Biomedical Consortium(CBC)Accelerator Award.
文摘Flares of joint inflammation and resistance to currently available biologic therapeutics in rheumatoid arthritis(RA)patients could reflect activation of innate immune mechanisms.Herein,we show that a TLR7 GU-rich endogenous ligand,miR-Let7b,potentiates synovitis by amplifying RA monocyte and fibroblast(FLS)trafficking.miR-Let7b ligation to TLR7 in macrophages(MΦs)and FLSs expanded the synovial inflammatory response.Moreover,secretion of M1 monokines triggered by miR-Let7b enhanced Th1/Th17 cell differentiation.We showed that IRAK4 inhibitor(i)therapy attenuated RA disease activity by blocking TLR7-induced M1 MΦor FLS activation,as well as monokine-modulated Th1/Th17 cell polarization.IRAK4i therapy also disrupted RA osteoclastogenesis,which was amplified by miR-Let7b ligation to joint myeloid TLR7.Hence,the effectiveness of IRAK4i was compared with that of a TNF inhibitor(i)or anti-IL-6R treatment in collagen-induced arthritis(CIA)and miR-Let7b-mediated arthritis.We found that TNF or IL-6R blocking therapies mitigated CIA by reducing the infiltration of joint F480+iNOS+MΦs,the expression of certain monokines,and Th1 cell differentiation.Unexpectedly,these biologic therapies were unable to alleviate miR-Let7b-induced arthritis.The superior efficacy of IRAK4i over anti-TNF or anti-IL-6R therapy in miR-Let7b-induced arthritis or CIA was due to the ability of IRAK4i therapy to restrain the migration of joint F480+iNOS+MΦs,vimentin+fibroblasts,and CD3+T cells,in addition to negating the expression of a wide range of monokines,including IL-12,MIP2,and IRF5 and Th1/Th17 lymphokines.In conclusion,IRAK4i therapy may provide a promising strategy for RA therapy by disconnecting critical links between inflammatory joint cells.
