Pub Date : 2024-09-10Epub Date: 2024-09-04DOI: 10.1073/pnas.2405560121
Chaoyu Fu, Florian Dilasser, Shao-Zhen Lin, Marc Karnat, Aditya Arora, Harini Rajendiran, Hui Ting Ong, Nai Mui Hoon Brenda, Sound Wai Phow, Tsuyoshi Hirashima, Michael Sheetz, Jean-François Rupprecht, Sham Tlili, Virgile Viasnoff
Collective cell migration is crucial in various physiological processes, including wound healing, morphogenesis, and cancer metastasis. Adherens Junctions (AJs) play a pivotal role in regulating cell cohesion and migration dynamics during tissue remodeling. While the role and origin of the junctional mechanical tension at AJs have been extensively studied, the influence of the actin cortex structure and dynamics on junction plasticity remains incompletely understood. Moreover, the mechanisms underlying stress dissipation at junctions are not well elucidated. Here, we found that the ligand-independent phosphorylation of epithelial growth factor receptor (EGFR) downstream of de novo E-cadherin adhesion orchestrates a feedback loop, governing intercellular viscosity via the Rac pathway regulating actin dynamics. Our findings highlight how the E-cadherin-dependent EGFR activity controls the migration mode of collective cell movements independently of intercellular tension. This modulation of effective viscosity coordinates cellular movements within the expanding monolayer, inducing a transition from swirling to laminar flow patterns while maintaining a constant migration front speed. Additionally, we propose a vertex model with adjustable junctional viscosity, capable of replicating all observed cellular flow phenotypes experimentally.
细胞集体迁移在伤口愈合、形态发生和癌症转移等各种生理过程中至关重要。粘连接头(AJ)在组织重塑过程中调节细胞内聚力和迁移动力学方面发挥着关键作用。虽然对 AJ 连接处机械张力的作用和起源进行了广泛研究,但对肌动蛋白皮层结构和动态对连接处可塑性的影响仍不甚了解。此外,交界处的应力消散机制也没有得到很好的阐明。在这里,我们发现上皮生长因子受体(EGFR)在新生 E-cadherin 粘附下游的配体非依赖性磷酸化协调了一个反馈回路,通过调节肌动蛋白动力学的 Rac 通路控制细胞间粘度。我们的研究结果突显了依赖于 E-粘连蛋白的表皮生长因子受体活性如何控制细胞集体运动的迁移模式,而不受细胞间张力的影响。这种对有效粘度的调节协调了细胞在扩张单层中的运动,诱导了从漩涡到层流模式的转变,同时保持了恒定的迁移前沿速度。此外,我们还提出了一种具有可调交界粘度的顶点模型,能够复制实验观察到的所有细胞流动表型。
{"title":"Regulation of intercellular viscosity by E-cadherin-dependent phosphorylation of EGFR in collective cell migration.","authors":"Chaoyu Fu, Florian Dilasser, Shao-Zhen Lin, Marc Karnat, Aditya Arora, Harini Rajendiran, Hui Ting Ong, Nai Mui Hoon Brenda, Sound Wai Phow, Tsuyoshi Hirashima, Michael Sheetz, Jean-François Rupprecht, Sham Tlili, Virgile Viasnoff","doi":"10.1073/pnas.2405560121","DOIUrl":"https://doi.org/10.1073/pnas.2405560121","url":null,"abstract":"<p><p>Collective cell migration is crucial in various physiological processes, including wound healing, morphogenesis, and cancer metastasis. Adherens Junctions (AJs) play a pivotal role in regulating cell cohesion and migration dynamics during tissue remodeling. While the role and origin of the junctional mechanical tension at AJs have been extensively studied, the influence of the actin cortex structure and dynamics on junction plasticity remains incompletely understood. Moreover, the mechanisms underlying stress dissipation at junctions are not well elucidated. Here, we found that the ligand-independent phosphorylation of epithelial growth factor receptor (EGFR) downstream of de novo E-cadherin adhesion orchestrates a feedback loop, governing intercellular viscosity via the Rac pathway regulating actin dynamics. Our findings highlight how the E-cadherin-dependent EGFR activity controls the migration mode of collective cell movements independently of intercellular tension. This modulation of effective viscosity coordinates cellular movements within the expanding monolayer, inducing a transition from swirling to laminar flow patterns while maintaining a constant migration front speed. Additionally, we propose a vertex model with adjustable junctional viscosity, capable of replicating all observed cellular flow phenotypes experimentally.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Higher-order topological phases in non-Hermitian photonics revolutionize the understanding of wave propagation and modulation, which lead to hierarchical states in open systems. However, intrinsic insulating properties endorsed by the lattice symmetry of photonic crystals fundamentally confine the robust transport only at explicit system boundaries, letting alone the flexible reconfiguration in hierarchical states at arbitrary positions. Here, we report a dynamic topological platform for creating the reconfigurable hierarchical bound states in heat transport systems and observe the robust and nonlocalized higher-order states in both the real- and imaginary-valued bands. Our experiments showcase that the hierarchical features of zero-dimension corner and nontrivial edge modes occur at tailored positions within the system bulk states instead of the explicit system boundaries. Our findings uncover the mechanism of non-localized hierarchical non-trivial topological states and offer distinct paradigms for diffusive transport field management.
{"title":"Hierarchical bound states in heat transport.","authors":"Shuihua Yang,Guoqiang Xu,Xue Zhou,Jiaxin Li,Xianghong Kong,Chenglong Zhou,Haiyan Fan,Jianfeng Chen,Cheng-Wei Qiu","doi":"10.1073/pnas.2412031121","DOIUrl":"https://doi.org/10.1073/pnas.2412031121","url":null,"abstract":"Higher-order topological phases in non-Hermitian photonics revolutionize the understanding of wave propagation and modulation, which lead to hierarchical states in open systems. However, intrinsic insulating properties endorsed by the lattice symmetry of photonic crystals fundamentally confine the robust transport only at explicit system boundaries, letting alone the flexible reconfiguration in hierarchical states at arbitrary positions. Here, we report a dynamic topological platform for creating the reconfigurable hierarchical bound states in heat transport systems and observe the robust and nonlocalized higher-order states in both the real- and imaginary-valued bands. Our experiments showcase that the hierarchical features of zero-dimension corner and nontrivial edge modes occur at tailored positions within the system bulk states instead of the explicit system boundaries. Our findings uncover the mechanism of non-localized hierarchical non-trivial topological states and offer distinct paradigms for diffusive transport field management.","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142165857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proteostasis and genomic integrity are respectively regulated by the endoplasmic reticulum-associated protein degradation (ERAD) and DNA damage repair signaling pathways, with both pathways essential for carcinogenesis and drug resistance. How these signaling pathways coordinate with each other remains unexplored. We found that ER stress specifically induces the DNA-PKcs-regulated nonhomologous end joining (NHEJ) pathway to amend DNA damage and impede cell death. Intriguingly, sustained ER stress rapidly decreased the activity of DNA-PKcs and DNA damage accumulated, facilitating a switch from adaptation to cell death. This DNA-PKcs inactivation was caused by increased KU70/KU80 protein degradation. Unexpectedly, the ERAD ligase HRD1 was found to efficiently destabilize the classic nuclear protein HDAC1 in the cytoplasm, by catalyzing HDAC1's polyubiquitination at lysine 74, at a late stage of ER stress. By abolishing HDAC1-mediated KU70/KU80 deacetylation, HRD1 transmits ER signals to the nucleus. The resulting enhanced KU70/KU80 acetylation provides binding sites for the nuclear E3 ligase TRIM25, resulting in the promotion of polyubiquitination and the degradation of KU70/KU80 proteins. Both in vitro and in vivo cancer models showed that genetic or pharmacological inhibition of HADC1 or DNA-PKcs sensitizes colon cancer cells to ER stress inducers, including the Food and Drug Administration-approved drug celecoxib. The antitumor effects of the combined approach were also observed in patient-derived xenograft models. These findings identify a mechanistic link between ER stress (ERAD) in the cytoplasm and DNA damage (NHEJ) pathways in the nucleus, indicating that combined anticancer strategies may be developed that induce severe ER stress while simultaneously inhibiting KU70/KU80/DNA-PKcs-mediated NHEJ signaling.
{"title":"ER-associated degradation ligase HRD1 links ER stress to DNA damage repair by modulating the activity of DNA-PKcs.","authors":"Zhiyuan Xiang, Guixue Hou, Shanliang Zheng, Minqiao Lu, Tianyu Li, Qingyu Lin, Hao Liu, Xingwen Wang, Tianqi Guan, Yuhan Wei, Wenxin Zhang, Yi Zhang, Chaoran Liu, Li Li, Qun-Ying Lei, Ying Hu","doi":"10.1073/pnas.2403038121","DOIUrl":"https://doi.org/10.1073/pnas.2403038121","url":null,"abstract":"<p><p>Proteostasis and genomic integrity are respectively regulated by the endoplasmic reticulum-associated protein degradation (ERAD) and DNA damage repair signaling pathways, with both pathways essential for carcinogenesis and drug resistance. How these signaling pathways coordinate with each other remains unexplored. We found that ER stress specifically induces the DNA-PKcs-regulated nonhomologous end joining (NHEJ) pathway to amend DNA damage and impede cell death. Intriguingly, sustained ER stress rapidly decreased the activity of DNA-PKcs and DNA damage accumulated, facilitating a switch from adaptation to cell death. This DNA-PKcs inactivation was caused by increased KU70/KU80 protein degradation. Unexpectedly, the ERAD ligase HRD1 was found to efficiently destabilize the classic nuclear protein HDAC1 in the cytoplasm, by catalyzing HDAC1's polyubiquitination at lysine 74, at a late stage of ER stress. By abolishing HDAC1-mediated KU70/KU80 deacetylation, HRD1 transmits ER signals to the nucleus. The resulting enhanced KU70/KU80 acetylation provides binding sites for the nuclear E3 ligase TRIM25, resulting in the promotion of polyubiquitination and the degradation of KU70/KU80 proteins. Both in vitro and in vivo cancer models showed that genetic or pharmacological inhibition of HADC1 or DNA-PKcs sensitizes colon cancer cells to ER stress inducers, including the Food and Drug Administration-approved drug celecoxib. The antitumor effects of the combined approach were also observed in patient-derived xenograft models. These findings identify a mechanistic link between ER stress (ERAD) in the cytoplasm and DNA damage (NHEJ) pathways in the nucleus, indicating that combined anticancer strategies may be developed that induce severe ER stress while simultaneously inhibiting KU70/KU80/DNA-PKcs-mediated NHEJ signaling.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10Epub Date: 2024-09-06DOI: 10.1073/pnas.2409201121
Kang Xiao, Bo-Hao Xiao, Jian-Xi Li, Shunsheng Cao, Zhao-Qing Liu
Transition metal oxides ion diffusion channels have been developed for ammonium-ion batteries (AIBs). However, the influence of microstructural features of diffusion channels on the storage and diffusion behavior of NH4+ is not fully unveiled. In this study, by using MnCo2O4 spinel as a model electrode, the asymmetric ion diffusion channels of MnCo2O4 have been regulated through bond length optimization strategy and investigate the effect of channel size on the diffusion process of NH4+. In addition, the reducing channel size significantly decreases NH4+ adsorption energy, thereby accelerating hydrogen bond formation/fracture kinetics and NH4+ reversible diffusion within 3D asymmetric channels. The optimized MnCo2O4 with oxygen vacancies/carbon nanotubes composite exhibits impressive specific capacity (219.2 mAh g-1 at 0.1 A g-1) and long-cycle stability. The full cell with 3,4,9,10-perylenetetracarboxylic diimide anode demonstrates a remarkable energy density of 52.3 Wh kg-1 and maintains 91.9% capacity after 500 cycles. This finding provides a unique approach for the development of cathode materials in AIBs.
{"title":"Efficient asymmetric diffusion channel in MnCo<sub>2</sub>O<sub>4</sub> spinel for ammonium-ion batteries.","authors":"Kang Xiao, Bo-Hao Xiao, Jian-Xi Li, Shunsheng Cao, Zhao-Qing Liu","doi":"10.1073/pnas.2409201121","DOIUrl":"https://doi.org/10.1073/pnas.2409201121","url":null,"abstract":"<p><p>Transition metal oxides ion diffusion channels have been developed for ammonium-ion batteries (AIBs). However, the influence of microstructural features of diffusion channels on the storage and diffusion behavior of NH<sub>4</sub><sup>+</sup> is not fully unveiled. In this study, by using MnCo<sub>2</sub>O<sub>4</sub> spinel as a model electrode, the asymmetric ion diffusion channels of MnCo<sub>2</sub>O<sub>4</sub> have been regulated through bond length optimization strategy and investigate the effect of channel size on the diffusion process of NH<sub>4</sub><sup>+</sup>. In addition, the reducing channel size significantly decreases NH<sub>4</sub><sup>+</sup> adsorption energy, thereby accelerating hydrogen bond formation/fracture kinetics and NH<sub>4</sub><sup>+</sup> reversible diffusion within 3D asymmetric channels. The optimized MnCo<sub>2</sub>O<sub>4</sub> with oxygen vacancies/carbon nanotubes composite exhibits impressive specific capacity (219.2 mAh g<sup>-1</sup> at 0.1 A g<sup>-1</sup>) and long-cycle stability. The full cell with 3,4,9,10-perylenetetracarboxylic diimide anode demonstrates a remarkable energy density of 52.3 Wh kg<sup>-1</sup> and maintains 91.9% capacity after 500 cycles. This finding provides a unique approach for the development of cathode materials in AIBs.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10Epub Date: 2024-09-03DOI: 10.1073/pnas.2408654121
Scott Chimileski, Gary G Borisy, Floyd E Dewhirst, Jessica L Mark Welch
Organisms display an immense variety of shapes, sizes, and reproductive strategies. At microscopic scales, bacterial cell morphology and growth dynamics are adaptive traits that influence the spatial organization of microbial communities. In one such community-the human dental plaque biofilm-a network of filamentous Corynebacterium matruchotii cells forms the core of bacterial consortia known as hedgehogs, but the processes that generate these structures are unclear. Here, using live-cell time-lapse microscopy and fluorescent D-amino acids to track peptidoglycan biosynthesis, we report an extraordinary example of simultaneous multiple division within the domain Bacteria. We show that C. matruchotii cells elongate at one pole through tip extension, similar to the growth strategy of soil-dwelling Streptomyces bacteria. Filaments elongate rapidly, at rates more than five times greater than other closely related bacterial species. Following elongation, many septa form simultaneously, and each cell divides into 3 to 14 daughter cells, depending on the length of the mother filament. The daughter cells then nucleate outgrowth of new thinner vegetative filaments, generating the classic "whip handle" morphology of this taxon. Our results expand the known diversity of bacterial cell cycles and help explain how this filamentous bacterium can compete for space, access nutrients, and form important interspecies interactions within dental plaque.
{"title":"Tip extension and simultaneous multiple fission in a filamentous bacterium.","authors":"Scott Chimileski, Gary G Borisy, Floyd E Dewhirst, Jessica L Mark Welch","doi":"10.1073/pnas.2408654121","DOIUrl":"https://doi.org/10.1073/pnas.2408654121","url":null,"abstract":"<p><p>Organisms display an immense variety of shapes, sizes, and reproductive strategies. At microscopic scales, bacterial cell morphology and growth dynamics are adaptive traits that influence the spatial organization of microbial communities. In one such community-the human dental plaque biofilm-a network of filamentous <i>Corynebacterium matruchotii</i> cells forms the core of bacterial consortia known as hedgehogs, but the processes that generate these structures are unclear. Here, using live-cell time-lapse microscopy and fluorescent D-amino acids to track peptidoglycan biosynthesis, we report an extraordinary example of simultaneous multiple division within the domain <i>Bacteria</i>. We show that <i>C. matruchotii</i> cells elongate at one pole through tip extension, similar to the growth strategy of soil-dwelling <i>Streptomyces</i> bacteria. Filaments elongate rapidly, at rates more than five times greater than other closely related bacterial species. Following elongation, many septa form simultaneously, and each cell divides into 3 to 14 daughter cells, depending on the length of the mother filament. The daughter cells then nucleate outgrowth of new thinner vegetative filaments, generating the classic \"whip handle\" morphology of this taxon. Our results expand the known diversity of bacterial cell cycles and help explain how this filamentous bacterium can compete for space, access nutrients, and form important interspecies interactions within dental plaque.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electrochemical ammonia (NH3) synthesis from nitrate reduction (NITRR) offers an appealing solution for addressing environmental concerns and the energy crisis. However, most of the developed electrocatalysts reduce NO3- to NH3 via a hydrogen (H*)-mediated reduction mechanism, which suffers from undesired H*-H* dimerization to H2, resulting in unsatisfactory NH3 yields. Herein, we demonstrate that reversed I1Cu4 single-atom sites, prepared by anchoring iodine single atoms on the Cu surface, realized superior NITRR with a superior ammonia yield rate of 4.36 mg h-1 cm-2 and a Faradaic efficiency of 98.5% under neutral conditions via a proton-coupled electron transfer (PCET) mechanism, far beyond those of traditional Cu sites (NH3 yield rate of 0.082 mg h-1 cm-2 and Faradaic efficiency of 36.5%) and most of H*-mediated NITRR electrocatalysts. Theoretical calculations revealed that I single atoms can regulate the local electronic structures of adjacent Cu sites in favor of stronger O-end-bidentate NO3- adsorption with dual electron transfer channels and suppress the H* formation from the H2O dissociation, thus switching the NITRR mechanism from H*-mediated reduction to PCET. By integrating the monolithic I1Cu4 single-atom electrode into a flow-through device for continuous NITRR and in situ ammonia recovery, an industrial-level current density of 1 A cm-2 was achieved along with a NH3 yield rate of 69.4 mg h-1 cm-2. This study offers reversed single-atom sites for electrochemical ammonia synthesis with nitrate wastewater and sheds light on the importance of switching catalytic mechanisms in improving the performance of electrochemical reactions.
{"title":"Reversed I<sub>1</sub>Cu<sub>4</sub> single-atom sites for superior neutral ammonia electrosynthesis with nitrate.","authors":"Bing Zhou, Yawen Tong, Yancai Yao, Weixing Zhang, Guangming Zhan, Qian Zheng, Wei Hou, Xiang-Kui Gu, Lizhi Zhang","doi":"10.1073/pnas.2405236121","DOIUrl":"https://doi.org/10.1073/pnas.2405236121","url":null,"abstract":"<p><p>Electrochemical ammonia (NH<sub>3</sub>) synthesis from nitrate reduction (NITRR) offers an appealing solution for addressing environmental concerns and the energy crisis. However, most of the developed electrocatalysts reduce NO<sub>3</sub><sup>-</sup> to NH<sub>3</sub> via a hydrogen (H*)-mediated reduction mechanism, which suffers from undesired H*-H* dimerization to H<sub>2</sub>, resulting in unsatisfactory NH<sub>3</sub> yields. Herein, we demonstrate that reversed I<sub>1</sub>Cu<sub>4</sub> single-atom sites, prepared by anchoring iodine single atoms on the Cu surface, realized superior NITRR with a superior ammonia yield rate of 4.36 mg h<sup>-1</sup> cm<sup>-2</sup> and a Faradaic efficiency of 98.5% under neutral conditions via a proton-coupled electron transfer (PCET) mechanism, far beyond those of traditional Cu sites (NH<sub>3</sub> yield rate of 0.082 mg h<sup>-1</sup> cm<sup>-2</sup> and Faradaic efficiency of 36.5%) and most of H*-mediated NITRR electrocatalysts. Theoretical calculations revealed that I single atoms can regulate the local electronic structures of adjacent Cu sites in favor of stronger O-end-bidentate NO<sub>3</sub><sup>-</sup> adsorption with dual electron transfer channels and suppress the H* formation from the H<sub>2</sub>O dissociation, thus switching the NITRR mechanism from H*-mediated reduction to PCET. By integrating the monolithic I<sub>1</sub>Cu<sub>4</sub> single-atom electrode into a flow-through device for continuous NITRR and in situ ammonia recovery, an industrial-level current density of 1 A cm<sup>-2</sup> was achieved along with a NH<sub>3</sub> yield rate of 69.4 mg h<sup>-1</sup> cm<sup>-2</sup>. This study offers reversed single-atom sites for electrochemical ammonia synthesis with nitrate wastewater and sheds light on the importance of switching catalytic mechanisms in improving the performance of electrochemical reactions.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10Epub Date: 2024-09-03DOI: 10.1073/pnas.2319804121
Robert Cahill, Yu Wang, R Patrick Xian, Alex J Lee, Hongkui Zeng, Bin Yu, Bosiljka Tasic, Reza Abbasi-Asl
The rapid growth of large-scale spatial gene expression data demands efficient and reliable computational tools to extract major trends of gene expression in their native spatial context. Here, we used stability-driven unsupervised learning (i.e., staNMF) to identify principal patterns (PPs) of 3D gene expression profiles and understand spatial gene distribution and anatomical localization at the whole mouse brain level. Our subsequent spatial correlation analysis systematically compared the PPs to known anatomical regions and ontology from the Allen Mouse Brain Atlas using spatial neighborhoods. We demonstrate that our stable and spatially coherent PPs, whose linear combinations accurately approximate the spatial gene data, are highly correlated with combinations of expert-annotated brain regions. These PPs yield a brain ontology based purely on spatial gene expression. Our PP identification approach outperforms principal component analysis and typical clustering algorithms on the same task. Moreover, we show that the stable PPs reveal marked regional imbalance of brainwide genetic architecture, leading to region-specific marker genes and gene coexpression networks. Our findings highlight the advantages of stability-driven machine learning for plausible biological discovery from dense spatial gene expression data, streamlining tasks that are infeasible by conventional manual approaches.
{"title":"Unsupervised pattern identification in spatial gene expression atlas reveals mouse brain regions beyond established ontology.","authors":"Robert Cahill, Yu Wang, R Patrick Xian, Alex J Lee, Hongkui Zeng, Bin Yu, Bosiljka Tasic, Reza Abbasi-Asl","doi":"10.1073/pnas.2319804121","DOIUrl":"https://doi.org/10.1073/pnas.2319804121","url":null,"abstract":"<p><p>The rapid growth of large-scale spatial gene expression data demands efficient and reliable computational tools to extract major trends of gene expression in their native spatial context. Here, we used stability-driven unsupervised learning (i.e., staNMF) to identify principal patterns (PPs) of 3D gene expression profiles and understand spatial gene distribution and anatomical localization at the whole mouse brain level. Our subsequent spatial correlation analysis systematically compared the PPs to known anatomical regions and ontology from the Allen Mouse Brain Atlas using spatial neighborhoods. We demonstrate that our stable and spatially coherent PPs, whose linear combinations accurately approximate the spatial gene data, are highly correlated with combinations of expert-annotated brain regions. These PPs yield a brain ontology based purely on spatial gene expression. Our PP identification approach outperforms principal component analysis and typical clustering algorithms on the same task. Moreover, we show that the stable PPs reveal marked regional imbalance of brainwide genetic architecture, leading to region-specific marker genes and gene coexpression networks. Our findings highlight the advantages of stability-driven machine learning for plausible biological discovery from dense spatial gene expression data, streamlining tasks that are infeasible by conventional manual approaches.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10Epub Date: 2024-09-05DOI: 10.1073/pnas.2411583121
Paolo Armanetti, Irene Locatelli, Chiara Venegoni, Elisa Alchera, Beatrice Campanella, Filippo Pederzoli, Mirko Maturi, Erica Locatelli, Silvia Tortorella, Flavio Curnis, Angelo Corti, Roberta Lucianò, Massimo Onor, Andrea Salonia, Francesco Montorsi, Marco Moschini, Viktor Popov, Jithin Jose, Mauro Comes Franchini, Ean Hin Ooi, Luca Menichetti, Massimo Alfano
Residual nonvisible bladder cancer after proper treatment caused by technological and therapeutic limitations is responsible for tumor relapse and progression. This study aimed to demonstrate the feasibility of a solution for simultaneous detection and treatment of bladder cancer lesions smaller than one millimeter. The α5β1 integrin was identified as a specific marker in 81% of human high-grade nonmuscle invasive bladder cancers and used as a target for the delivery of targeted gold nanorods (GNRs). In a preclinical model of orthotopic bladder cancer expressing the α5β1 integrin, the photoacoustic imaging of targeted GNRs visualized lesions smaller than one millimeter, and their irradiation with continuous laser was used to induce GNR-assisted hyperthermia. Necrosis of the tumor mass, improved survival, and computational modeling were applied to demonstrate the efficacy and safety of this solution. Our study highlights the potential of the GNR-assisted theranostic strategy as a complementary solution in clinical practice to reduce the risk of nonvisible residual bladder cancer after current treatment. Further validation through clinical studies will support the findings of the present study.
{"title":"Gold nanorod-assisted theranostic solution for nonvisible residual disease in bladder cancer.","authors":"Paolo Armanetti, Irene Locatelli, Chiara Venegoni, Elisa Alchera, Beatrice Campanella, Filippo Pederzoli, Mirko Maturi, Erica Locatelli, Silvia Tortorella, Flavio Curnis, Angelo Corti, Roberta Lucianò, Massimo Onor, Andrea Salonia, Francesco Montorsi, Marco Moschini, Viktor Popov, Jithin Jose, Mauro Comes Franchini, Ean Hin Ooi, Luca Menichetti, Massimo Alfano","doi":"10.1073/pnas.2411583121","DOIUrl":"https://doi.org/10.1073/pnas.2411583121","url":null,"abstract":"<p><p>Residual nonvisible bladder cancer after proper treatment caused by technological and therapeutic limitations is responsible for tumor relapse and progression. This study aimed to demonstrate the feasibility of a solution for simultaneous detection and treatment of bladder cancer lesions smaller than one millimeter. The α5β1 integrin was identified as a specific marker in 81% of human high-grade nonmuscle invasive bladder cancers and used as a target for the delivery of targeted gold nanorods (GNRs). In a preclinical model of orthotopic bladder cancer expressing the α5β1 integrin, the photoacoustic imaging of targeted GNRs visualized lesions smaller than one millimeter, and their irradiation with continuous laser was used to induce GNR-assisted hyperthermia. Necrosis of the tumor mass, improved survival, and computational modeling were applied to demonstrate the efficacy and safety of this solution. Our study highlights the potential of the GNR-assisted theranostic strategy as a complementary solution in clinical practice to reduce the risk of nonvisible residual bladder cancer after current treatment. Further validation through clinical studies will support the findings of the present study.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142140870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10Epub Date: 2024-09-04DOI: 10.1073/pnas.2404250121
Madeline R Sponholtz, Patrick O Byrne, Alison G Lee, Ajit R Ramamohan, Jory A Goldsmith, Ryan S McCool, Ling Zhou, Nicole V Johnson, Ching-Lin Hsieh, Megan Connors, Krithika P Karthigeyan, Chelsea M Crooks, Adelaide S Fuller, John D Campbell, Sallie R Permar, Jennifer A Maynard, Dong Yu, Matthew J Bottomley, Jason S McLellan
Human cytomegalovirus (HCMV) glycoprotein B (gB) is a class III membrane fusion protein required for viral entry. HCMV vaccine candidates containing gB have demonstrated moderate clinical efficacy, but no HCMV vaccine has been approved. Here, we used structure-based design to identify and characterize amino acid substitutions that stabilize gB in its metastable prefusion conformation. One variant containing two engineered interprotomer disulfide bonds and two cavity-filling substitutions (gB-C7), displayed increased expression and thermostability. A 2.8 Å resolution cryoelectron microscopy structure shows that gB-C7 adopts a prefusion-like conformation, revealing additional structural elements at the membrane-distal apex. Unlike previous observations for several class I viral fusion proteins, mice immunized with postfusion or prefusion-stabilized forms of soluble gB protein displayed similar neutralizing antibody titers, here specifically against an HCMV laboratory strain on fibroblasts. Collectively, these results identify initial strategies to stabilize class III viral fusion proteins and provide tools to probe gB-directed antibody responses.
人巨细胞病毒(HCMV)糖蛋白 B(gB)是病毒进入人体所需的第三类膜融合蛋白。含有 gB 的 HCMV 候选疫苗已显示出适度的临床疗效,但目前还没有 HCMV 疫苗获得批准。在这里,我们利用基于结构的设计来确定和描述能使 gB 稳定在其可转移的预融合构象中的氨基酸取代。其中一个变体包含两个原体间二硫键和两个空腔填充取代(gB-C7),其表达和热稳定性均有所提高。2.8 Å 分辨率的冷冻电镜结构显示,gB-C7 采用了类似预融合的构象,揭示了膜远端顶点的附加结构元素。与之前对几种 I 类病毒融合蛋白的观察结果不同的是,用融合后或融合前稳定形式的可溶性 gB 蛋白免疫小鼠,显示出相似的中和抗体滴度,在此特别针对成纤维细胞上的 HCMV 实验室株。总之,这些结果确定了稳定 III 类病毒融合蛋白的初步策略,并为探究 gB 引导的抗体反应提供了工具。
{"title":"Structure-based design of a soluble human cytomegalovirus glycoprotein B antigen stabilized in a prefusion-like conformation.","authors":"Madeline R Sponholtz, Patrick O Byrne, Alison G Lee, Ajit R Ramamohan, Jory A Goldsmith, Ryan S McCool, Ling Zhou, Nicole V Johnson, Ching-Lin Hsieh, Megan Connors, Krithika P Karthigeyan, Chelsea M Crooks, Adelaide S Fuller, John D Campbell, Sallie R Permar, Jennifer A Maynard, Dong Yu, Matthew J Bottomley, Jason S McLellan","doi":"10.1073/pnas.2404250121","DOIUrl":"https://doi.org/10.1073/pnas.2404250121","url":null,"abstract":"<p><p>Human cytomegalovirus (HCMV) glycoprotein B (gB) is a class III membrane fusion protein required for viral entry. HCMV vaccine candidates containing gB have demonstrated moderate clinical efficacy, but no HCMV vaccine has been approved. Here, we used structure-based design to identify and characterize amino acid substitutions that stabilize gB in its metastable prefusion conformation. One variant containing two engineered interprotomer disulfide bonds and two cavity-filling substitutions (gB-C7), displayed increased expression and thermostability. A 2.8 Å resolution cryoelectron microscopy structure shows that gB-C7 adopts a prefusion-like conformation, revealing additional structural elements at the membrane-distal apex. Unlike previous observations for several class I viral fusion proteins, mice immunized with postfusion or prefusion-stabilized forms of soluble gB protein displayed similar neutralizing antibody titers, here specifically against an HCMV laboratory strain on fibroblasts. Collectively, these results identify initial strategies to stabilize class III viral fusion proteins and provide tools to probe gB-directed antibody responses.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10Epub Date: 2024-09-06DOI: 10.1073/pnas.2408699121
Filipa L Lopes, Pau Formosa-Jordan, Alice Malivert, Leonor Margalha, Ana Confraria, Regina Feil, John E Lunn, Henrik Jönsson, Benoît Landrein, Elena Baena-González
In plants, development of all above-ground tissues relies on the shoot apical meristem (SAM) which balances cell proliferation and differentiation to allow life-long growth. To maximize fitness and survival, meristem activity is adjusted to the prevailing conditions through a poorly understood integration of developmental signals with environmental and nutritional information. Here, we show that sugar signals influence SAM function by altering the protein levels of SHOOT MERISTEMLESS (STM), a key regulator of meristem maintenance. STM is less abundant in inflorescence meristems with lower sugar content, resulting from plants being grown or treated under limiting light conditions. Additionally, sucrose but not light is sufficient to sustain STM accumulation in excised inflorescences. Plants overexpressing the α1-subunit of SUCROSE-NON-FERMENTING1-RELATED KINASE 1 (SnRK1) accumulate less STM protein under optimal light conditions, despite higher sugar accumulation in the meristem. Furthermore, SnRK1α1 interacts physically with STM and inhibits its activity in reporter assays, suggesting that SnRK1 represses STM protein function. Contrasting the absence of growth defects in SnRK1α1 overexpressors, silencing SnRK1α in the SAM leads to meristem dysfunction and severe developmental phenotypes. This is accompanied by reduced STM transcript levels, suggesting indirect effects on STM. Altogether, we demonstrate that sugars promote STM accumulation and that the SnRK1 sugar sensor plays a dual role in the SAM, limiting STM function under unfavorable conditions but being required for overall meristem organization and integrity under favorable conditions. This highlights the importance of sugars and SnRK1 signaling for the proper coordination of meristem activities.
{"title":"Sugar signaling modulates SHOOT MERISTEMLESS expression and meristem function in <i>Arabidopsis</i>.","authors":"Filipa L Lopes, Pau Formosa-Jordan, Alice Malivert, Leonor Margalha, Ana Confraria, Regina Feil, John E Lunn, Henrik Jönsson, Benoît Landrein, Elena Baena-González","doi":"10.1073/pnas.2408699121","DOIUrl":"https://doi.org/10.1073/pnas.2408699121","url":null,"abstract":"<p><p>In plants, development of all above-ground tissues relies on the shoot apical meristem (SAM) which balances cell proliferation and differentiation to allow life-long growth. To maximize fitness and survival, meristem activity is adjusted to the prevailing conditions through a poorly understood integration of developmental signals with environmental and nutritional information. Here, we show that sugar signals influence SAM function by altering the protein levels of SHOOT MERISTEMLESS (STM), a key regulator of meristem maintenance. STM is less abundant in inflorescence meristems with lower sugar content, resulting from plants being grown or treated under limiting light conditions. Additionally, sucrose but not light is sufficient to sustain STM accumulation in excised inflorescences. Plants overexpressing the α1-subunit of SUCROSE-NON-FERMENTING1-RELATED KINASE 1 (SnRK1) accumulate less STM protein under optimal light conditions, despite higher sugar accumulation in the meristem. Furthermore, SnRK1α1 interacts physically with STM and inhibits its activity in reporter assays, suggesting that SnRK1 represses STM protein function. Contrasting the absence of growth defects in SnRK1α1 overexpressors, silencing <i>SnRK1α</i> in the SAM leads to meristem dysfunction and severe developmental phenotypes. This is accompanied by reduced <i>STM</i> transcript levels, suggesting indirect effects on STM. Altogether, we demonstrate that sugars promote STM accumulation and that the SnRK1 sugar sensor plays a dual role in the SAM, limiting STM function under unfavorable conditions but being required for overall meristem organization and integrity under favorable conditions. This highlights the importance of sugars and SnRK1 signaling for the proper coordination of meristem activities.</p>","PeriodicalId":20548,"journal":{"name":"Proceedings of the National Academy of Sciences of the United States of America","volume":null,"pages":null},"PeriodicalIF":9.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}