Filopodia function as cellular sensors,detecting the microenvironment and directing cell migration.They play a crucial role in cancer metastasis.Quantifying the filopodia characteristics of cancer cells is a prerequis...Filopodia function as cellular sensors,detecting the microenvironment and directing cell migration.They play a crucial role in cancer metastasis.Quantifying the filopodia characteristics of cancer cells is a prerequisite for studying the complex role of filopodia in cancer cell metastasis.Several algorithms have been developed,yet most of these algorithms are typically suited for extracting filopodia from individual cells.This paper aims to develop an independent algorithm(MC-FiloAssay)for quantifying filopodia in multi-cell environments.The filopodia of nasopharyngeal carcinoma cells(CNE2 and 5-8F)and normal nasopharyngeal epithelial cells(NP69)were quantified with MC-FiloAssay.A linear regression analysis comparing filopodia lengths measured by MC-FiloAssay and manual annotation yielded a coefficient of determination(R^(2)=0.99),indicating high accuracy in multi-cell filopodia extraction.Furthermore,MC-FiloAssay outperforms existing algorithms under low signal conditions and in multi-cell fields of view.Analysis of CNE2 cells at different confluences revealed that confluence does not affect filopodia length or width but influences filopodia density.Additionally,significant differences were observed between CNE2 and the other two cell lines(5-8 F and NP69):CNE2 filopodia were longer,thinner,and more densely distributed.These results demonstrate that MCFiloAssay is a robust tool for multi-cell filopodia quantification.展开更多
Cell fusion is a basic biological process that plays critical roles in both physiological and pathological processes.However,how mechanical factors influence the fusion process is not fully understood.In this study,we...Cell fusion is a basic biological process that plays critical roles in both physiological and pathological processes.However,how mechanical factors influence the fusion process is not fully understood.In this study,we reported filopodia-mediated fusion among MCF-7 cells.We showed that the filopodia protrusion force induced significant bending of the cell membrane,which was essential for membrane fusion between neighboring cells,and then eventually induced the formation of multinucleated syncytia.The inhibition of actin polymerization significantly reduced the fusion ratio,whereas increased actin polymerization promoted fusion.We found that several factors influence the fusion process,e.g.,the cell density,substrate pattern,and stiffness.For example,cell density has a significant effect on cell fusion.There was an optimal cell density for cell fusion.The fusion probability increased with increasing cell density within a moderate cell density range but decreased within a high cell density range.Substrate properties also influence the fusion behavior.For example,the fusion ratio was reduced on nanogrooved surfaces and soft substrates because the surface pattern restricted cell alignment and motility,and soft substrates reduced the activity of the actin dynamics of filopodia for cell fusion.This study not only contributes to our under-standing of the basic biology of cell fusion but also has important implications for understanding the mechanisms of cancer progression and potential therapeutic intervention methods.展开更多
Filopodia, a finger-like structure and actin-rich plasma-membrane protrusion at the leading edge of the cell, has important roles in cell motility. However, the mechanisms of filopodia generation are not well-understo...Filopodia, a finger-like structure and actin-rich plasma-membrane protrusion at the leading edge of the cell, has important roles in cell motility. However, the mechanisms of filopodia generation are not well-understood via the actin-related protein 2/3 (ARP2/3) complex in Non-Small Cell Lung Cancer (NSCLC) cells. We previously have demonstrated that PRR11 associates with the ARP2/3 complex to regulate cytoskeleton-nucleoskeleton assembly and chromatin remodeling. In this study, we further demonstrate that PRR11 involves in filopodia formation, focal adhesion turnover and cell motility through ARP2/3 complex. Cell phenotype assays revealed that the silencing of PRR11 increased cellular size and inhibited cell motility in NSCLC cells. Mechanistically, PRR11 recruited and co-localized with Arp2 at the membrane protrusion to promote filopodia formation but not lamellipodia formation. Notably, PRR11 mutant deletion of the proline-rich region 2 (amino acid residues 185–200) abrogated the effect of filopodia formation. In addition, PRR11-depletion inhibited filopodial actin filaments assembly and increased the level of active integrin β1 in the cell surface, whereas reduced the phosphorylation level of focal adhesion kinase (FAKY397) to repress focal adhesion turnover and cell motility in NSCLC cells. Taken together, our findings indicate that PRR11 has critical roles in controlling filopodia formation, focal adhesion turnover and cell motility by recruiting ARP2/3 complex, thus dysregualted expression of PRR11 potentially facilitates tumor metastasis in NSCLC cells.展开更多
The dynamic protrusions of lamellipodia and filopodia have emerged as crucial players in tumor progression and metastasis.These membrane structures,governed by intricate actin cytoskeletal rearrangements,facilitate ca...The dynamic protrusions of lamellipodia and filopodia have emerged as crucial players in tumor progression and metastasis.These membrane structures,governed by intricate actin cytoskeletal rearrangements,facilitate cancer cell migration,invasion,and interaction with the tumor microenvironment.This review provides a comprehensive examination of the structural and functional attributes of lamellipodia and filopodia,shedding light on their pivotal roles in mediating cancer invasion.Navigating through the intricate landscape of cancer biology,the review illuminates the intricate signaling pathways and regulatory mechanisms orchestrating the formation and activity of these protrusions.The discussion extends to the clinical implications of lamellipodia and filopodia,exploring their potential as diagnostic and prognostic markers,and delving into therapeutic strategies that target these structures to impede cancer progression.As we delve into the future,the review outlines emerging technologies and unexplored facets that beckon further research,emphasizing the need for collaborative efforts to unravel the complexities of lamellipodia and filopodia in cancer,ultimately paving the way for innovative therapeutic interventions.展开更多
Hypomyelination leukodystrophies constitute a group of heritable white matter disorders exhibiting defective myelin development.Initially identified as a lysosomal protein,the TMEM106B D252N mutant has recently been a...Hypomyelination leukodystrophies constitute a group of heritable white matter disorders exhibiting defective myelin development.Initially identified as a lysosomal protein,the TMEM106B D252N mutant has recently been associated with hypomyelination.However,how lysosomal TMEM106B facilitates myelination and how the D252N mutation disrupts that process are poorly understood.We used superresolution Hessian structured illumination microscopy(Hessian-SIM)and spinning discconfocal structured illumination microscopy(SD-SIM)to find that the wild-type TMEM106B protein is targeted to the plasma membrane,filopodia,and lysosomes in human oligodendrocytes.The D252N mutation reduces the size of lysosomes in oligodendrocytes and compromises lysosome changes upon starvation stress.Most importantly,we detected reductions in the length and number of filopodia in cells expressing the D252N mutant.PLP1 is the most abundant myelin protein that almost entirely colocalizes with TMEM106B,and coexpressing PLP1 with the D252N mutant readily rescues the lysosome and filopodia phenotypes of cells.Therefore,interactions between TMEM106B and PLP1 on the plasma membrane are essential for filopodia formation and myelination in oligodendrocytes,which may be sustained by the delivery of these proteins from lysosomes via exocytosis.展开更多
Myoclonus dystonia syndrome(MDS)is an inherited movement disorder,and most MDS-related mutations have so far been found in theε-sarcoglycan(SGCE)coding gene.By generating SGCE-knockout(KO)and human 237 C>T mutatio...Myoclonus dystonia syndrome(MDS)is an inherited movement disorder,and most MDS-related mutations have so far been found in theε-sarcoglycan(SGCE)coding gene.By generating SGCE-knockout(KO)and human 237 C>T mutation knock-in(KI)mice,we showed here that both KO and KI mice exerted typical movement defects similar to those of MDS patients.SGCE promoted filopodia development in vitro and inhibited excitatory synapse formation both in vivo and in vitro.Loss of function of SGCE leading to excessive excitatory synapses that may ultimately contribute to MDS pathology.Indeed,using a zebrafish MDS model,we found that among 1700 screened chemical compounds,Vigabatrin was the most potent in readily reversing MDS symptoms of mouse disease models.Our study strengthens the notion that mutations of SGCE lead to MDS and most likely,SGCE functions to brake synaptogenesis in the CNS.展开更多
基金supported by the National Natural Science Foundation of China(No.61975031)Fujian Provincial Health Technology Project(Grant number:2021GGA004)the Natural Science Foundation of Fujian Province(Grant number:2020J011104).
文摘Filopodia function as cellular sensors,detecting the microenvironment and directing cell migration.They play a crucial role in cancer metastasis.Quantifying the filopodia characteristics of cancer cells is a prerequisite for studying the complex role of filopodia in cancer cell metastasis.Several algorithms have been developed,yet most of these algorithms are typically suited for extracting filopodia from individual cells.This paper aims to develop an independent algorithm(MC-FiloAssay)for quantifying filopodia in multi-cell environments.The filopodia of nasopharyngeal carcinoma cells(CNE2 and 5-8F)and normal nasopharyngeal epithelial cells(NP69)were quantified with MC-FiloAssay.A linear regression analysis comparing filopodia lengths measured by MC-FiloAssay and manual annotation yielded a coefficient of determination(R^(2)=0.99),indicating high accuracy in multi-cell filopodia extraction.Furthermore,MC-FiloAssay outperforms existing algorithms under low signal conditions and in multi-cell fields of view.Analysis of CNE2 cells at different confluences revealed that confluence does not affect filopodia length or width but influences filopodia density.Additionally,significant differences were observed between CNE2 and the other two cell lines(5-8 F and NP69):CNE2 filopodia were longer,thinner,and more densely distributed.These results demonstrate that MCFiloAssay is a robust tool for multi-cell filopodia quantification.
基金supported by the National Natural Science Foundation of China(Grant Nos.11932017 and 12122212).
文摘Cell fusion is a basic biological process that plays critical roles in both physiological and pathological processes.However,how mechanical factors influence the fusion process is not fully understood.In this study,we reported filopodia-mediated fusion among MCF-7 cells.We showed that the filopodia protrusion force induced significant bending of the cell membrane,which was essential for membrane fusion between neighboring cells,and then eventually induced the formation of multinucleated syncytia.The inhibition of actin polymerization significantly reduced the fusion ratio,whereas increased actin polymerization promoted fusion.We found that several factors influence the fusion process,e.g.,the cell density,substrate pattern,and stiffness.For example,cell density has a significant effect on cell fusion.There was an optimal cell density for cell fusion.The fusion probability increased with increasing cell density within a moderate cell density range but decreased within a high cell density range.Substrate properties also influence the fusion behavior.For example,the fusion ratio was reduced on nanogrooved surfaces and soft substrates because the surface pattern restricted cell alignment and motility,and soft substrates reduced the activity of the actin dynamics of filopodia for cell fusion.This study not only contributes to our under-standing of the basic biology of cell fusion but also has important implications for understanding the mechanisms of cancer progression and potential therapeutic intervention methods.
文摘Filopodia, a finger-like structure and actin-rich plasma-membrane protrusion at the leading edge of the cell, has important roles in cell motility. However, the mechanisms of filopodia generation are not well-understood via the actin-related protein 2/3 (ARP2/3) complex in Non-Small Cell Lung Cancer (NSCLC) cells. We previously have demonstrated that PRR11 associates with the ARP2/3 complex to regulate cytoskeleton-nucleoskeleton assembly and chromatin remodeling. In this study, we further demonstrate that PRR11 involves in filopodia formation, focal adhesion turnover and cell motility through ARP2/3 complex. Cell phenotype assays revealed that the silencing of PRR11 increased cellular size and inhibited cell motility in NSCLC cells. Mechanistically, PRR11 recruited and co-localized with Arp2 at the membrane protrusion to promote filopodia formation but not lamellipodia formation. Notably, PRR11 mutant deletion of the proline-rich region 2 (amino acid residues 185–200) abrogated the effect of filopodia formation. In addition, PRR11-depletion inhibited filopodial actin filaments assembly and increased the level of active integrin β1 in the cell surface, whereas reduced the phosphorylation level of focal adhesion kinase (FAKY397) to repress focal adhesion turnover and cell motility in NSCLC cells. Taken together, our findings indicate that PRR11 has critical roles in controlling filopodia formation, focal adhesion turnover and cell motility by recruiting ARP2/3 complex, thus dysregualted expression of PRR11 potentially facilitates tumor metastasis in NSCLC cells.
文摘The dynamic protrusions of lamellipodia and filopodia have emerged as crucial players in tumor progression and metastasis.These membrane structures,governed by intricate actin cytoskeletal rearrangements,facilitate cancer cell migration,invasion,and interaction with the tumor microenvironment.This review provides a comprehensive examination of the structural and functional attributes of lamellipodia and filopodia,shedding light on their pivotal roles in mediating cancer invasion.Navigating through the intricate landscape of cancer biology,the review illuminates the intricate signaling pathways and regulatory mechanisms orchestrating the formation and activity of these protrusions.The discussion extends to the clinical implications of lamellipodia and filopodia,exploring their potential as diagnostic and prognostic markers,and delving into therapeutic strategies that target these structures to impede cancer progression.As we delve into the future,the review outlines emerging technologies and unexplored facets that beckon further research,emphasizing the need for collaborative efforts to unravel the complexities of lamellipodia and filopodia in cancer,ultimately paving the way for innovative therapeutic interventions.
基金supported by the National Natural Science Foundation of China(81925022,61827825,32227802,92054301)the Fundamental Research Center Project of the National Natural Science Foundation of China(T2288102)+4 种基金the National Science and Technology Major Project Program(2022YFC3400600)Beijing Natural Science Foundation Key Research Topics(Z20J00059)UMHS-PUHSC Joint Institute for Translational and Clinical Research(BMU2019JI009)Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases(BZ0317)China Postdoctoral Science Foundation(2021M690465)。
文摘Hypomyelination leukodystrophies constitute a group of heritable white matter disorders exhibiting defective myelin development.Initially identified as a lysosomal protein,the TMEM106B D252N mutant has recently been associated with hypomyelination.However,how lysosomal TMEM106B facilitates myelination and how the D252N mutation disrupts that process are poorly understood.We used superresolution Hessian structured illumination microscopy(Hessian-SIM)and spinning discconfocal structured illumination microscopy(SD-SIM)to find that the wild-type TMEM106B protein is targeted to the plasma membrane,filopodia,and lysosomes in human oligodendrocytes.The D252N mutation reduces the size of lysosomes in oligodendrocytes and compromises lysosome changes upon starvation stress.Most importantly,we detected reductions in the length and number of filopodia in cells expressing the D252N mutant.PLP1 is the most abundant myelin protein that almost entirely colocalizes with TMEM106B,and coexpressing PLP1 with the D252N mutant readily rescues the lysosome and filopodia phenotypes of cells.Therefore,interactions between TMEM106B and PLP1 on the plasma membrane are essential for filopodia formation and myelination in oligodendrocytes,which may be sustained by the delivery of these proteins from lysosomes via exocytosis.
基金supported by National Natural Science Foundation of China(31630028,91632305,and 91632303)the Fund for Distinguished Young Scholars of National Natural Science Foundation of China(81425009 and 81425007)+1 种基金the National Basic Science Research Program of China(2012CB933900 and 2015CB755600)the Strategic Priority Research Program(B)of China(XDB02050500)。
文摘Myoclonus dystonia syndrome(MDS)is an inherited movement disorder,and most MDS-related mutations have so far been found in theε-sarcoglycan(SGCE)coding gene.By generating SGCE-knockout(KO)and human 237 C>T mutation knock-in(KI)mice,we showed here that both KO and KI mice exerted typical movement defects similar to those of MDS patients.SGCE promoted filopodia development in vitro and inhibited excitatory synapse formation both in vivo and in vitro.Loss of function of SGCE leading to excessive excitatory synapses that may ultimately contribute to MDS pathology.Indeed,using a zebrafish MDS model,we found that among 1700 screened chemical compounds,Vigabatrin was the most potent in readily reversing MDS symptoms of mouse disease models.Our study strengthens the notion that mutations of SGCE lead to MDS and most likely,SGCE functions to brake synaptogenesis in the CNS.
