Tag: SPM探针

Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation

The Endosomal Sorting Complex Required for Transport-III (ESCRT-III) is part of a conserved membrane remodeling machine. ESCRT-III employs polymer formation to catalyze inside-out membrane fission processes in a large variety of cellular processes, including budding of endosomal vesicles and enveloped viruses, cytokinesis, nuclear envelope reformation, plasma membrane repair, exosome formation, neuron pruning, dendritic spine maintenance, and preperoxisomal vesicle biogenesis.*

How membrane shape influences ESCRT-III polymerization and how ESCRT-III shapes membranes is yet unclear.*

In the article “Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation” Aurélie Bertin, Nicola de Franceschi, Eugenio de la Mora, Sourav Maity, Maryam Alqabandi, Nolwen Miguet, Aurélie di Cicco, Wouter H. Roos, Stéphanie Mangenot, Winfried Weissenhorn and Patricia Bassereau describe how human core ESCRT-III proteins, CHMP4B, CHMP2A, CHMP2B and CHMP3 are used to address this issue in vitro by combining membrane nanotube pulling experiments, cryo-electron tomography and Atomic Force Microscopy.*

The authors show that CHMP4B filaments preferentially bind to flat membranes or to tubes with positive mean curvature.*

The results presented in the article cited above underline the versatile membrane remodeling activity of ESCRT-III that may be a general feature required for cellular membrane remodeling processes.*

The authors provide novel insight on how mechanics and geometry of the membrane and of ESCRT-III assemblies can generate forces to shape a membrane neck.*

NanoWorld Ultra-Short AFM Cantilevers USC-F1.2-k0.15 were used for the High-speed Atomic Force Microscopy ( HS-AFM ) experiments presented in this article.*

Figure 1 from «Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation” by Aurélie Bertin et al.: CHMP4-ΔC flattens LUVs and binds preferentially to flat membranes or to membranes with a positive mean curvature. 1a CHMP4B-ΔC spirals observed by HS-AFM on a lipid bilayer. Scale bar: 50 nm. Please refer to the full article for the complete figure: https://rdcu.be/b5rOe
Figure 1 from «Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation” by Aurélie Bertin et al.:
CHMP4-ΔC flattens LUVs and binds preferentially to flat membranes or to membranes with a positive mean curvature.
1a CHMP4B-ΔC spirals observed by HS-AFM on a lipid bilayer. Scale bar: 50 nm.
Please refer to the full article for the complete figure: https://rdcu.be/b5rOe

*Aurélie Bertin, Nicola de Franceschi, Eugenio de la Mora, Sourav Maity, Maryam Alqabandi, Nolwen Miguet, Aurélie di Cicco, Wouter H. Roos, Stéphanie Mangenot, Winfried Weissenhorn and Patricia Bassereau
Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation
Nature Communications volume 11, Article number: 2663 (2020)
DOI: https://doi.org/10.1038/s41467-020-16368-5

Please follow this external link to read the full article: https://rdcu.be/b5rOe

Open Access The article “ Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation “ by Aurélie Bertin, Nicola de Franceschi, Eugenio de la Mora, Sourav Maity, Maryam Alqabandi, Nolwen Miguet, Aurélie di Cicco, Wouter H. Roos, Stéphanie Mangenot, Winfried Weissenhorn and Patricia Bassereau is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation

Phonon polaritons (PhPs) have attracted significant interest in the nano-optics communities because of their nanoscale confinement and long lifetimes. Although PhP modification by changing the local dielectric environment has been reported, controlled manipulation of PhPs by direct modification of the polaritonic material itself has remained elusive.*

In the article “Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation” Yingjie Wu, Qingdong Ou, Yuefeng Yin, Yun Li, Weiliang Ma, Wenzhi Yu, Guanyu Liu, Xiaoqiang Cui, Xiaozhi Bao, Jiahua Duan, Gonzalo Álvarez-Pérez, Zhigao Dai, Babar Shabbir, Nikhil Medhekar, Xiangping Li, Chang-Ming Li, Pablo Alonso-González and Qiaoliang Bao demonstrate an effective chemical approach to manipulate PhPs in α-MoO3 by the hydrogen intercalation-induced perturbation of lattice vibrations.*

Their methodology establishes a proof of concept for chemically manipulating polaritons, offering opportunities for the growing nanophotonics community.*

The surface topography and near-field images presented in this article were captured using a commercial s-SNOM setup with a platinum iridium coated NanoWorld Arrow-NCPt AFM probe in tapping mode.*

Fig. 2 a) from “Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation” by Yingjie Wu et al. : Reversible switching of PhPs in the L-RB of α-MoO3 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure. 2 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure. P
Fig. 2 a) from “Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation” by Yingjie Wu et al. :
Reversible switching of PhPs in the L-RB of α-MoO3 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure.
2 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure. Please follow this external link for the full figure: https://www.nature.com/articles/s41467-020-16459-3/figures/2

*Yingjie Wu, Qingdong Ou, Yuefeng Yin, Yun Li, Weiliang Ma, Wenzhi Yu, Guanyu Liu, Xiaoqiang Cui, Xiaozhi Bao, Jiahua Duan, Gonzalo Álvarez-Pérez, Zhigao Dai, Babar Shabbir, Nikhil Medhekar, Xiangping Li, Chang-Ming Li, Pablo Alonso-González & Qiaoliang Bao
Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation
Nature Communications volume 11, Article number: 2646 (2020)
DOI: https://doi.org/10.1038/s41467-020-16459-3

Please follow this external link to read the full article https://rdcu.be/b46eT

Open Access The article “ Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation “ by Yingjie Wu, Qingdong Ou, Yuefeng Yin, Yun Li, Weiliang Ma, Wenzhi Yu, Guanyu Liu, Xiaoqiang Cui, Xiaozhi Bao, Jiahua Duan, Gonzalo Álvarez-Pérez, Zhigao Dai, Babar Shabbir, Nikhil Medhekar, Xiangping Li, Chang-Ming Li, Pablo Alonso-González and Qiaoliang Bao is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Intravascular adhesion and recruitment of neutrophils in response to CXCL1 depends on their TRPC6 channels

Representing a central element of the innate immune system, neutrophils are recruited from the blood stream to a site of inflammation. The recruitment process follows a well-defined sequence of events including adhesion to the blood vessel walls, migration, and chemotaxis to reach the inflammatory focus. A common feature of the underlying signalling pathways is the utilization of Ca2+ ions as intracellular second messengers. However, the required Ca2+ influx channels are not yet fully characterized.*

In the article “Intravascular adhesion and recruitment of neutrophils in response to CXCL1 depends on their TRPC6 channels” Otto Lindemann, Jan Rossaint, Karolina Najder, Sandra Schimmelpfennig, Verena Hofschröer, Mike Wälte, Benedikt Fels, Hans Oberleithner, Alexander Zarbock and Albrecht Schwab report a novel role for TRPC6, a member of the transient receptor potential (TRPC) channel family, in the CXCL1-dependent recruitment of murine neutrophil granulocytes.*

The authors describe how they tested whether TRPC6 channels are central elements of the signalling cascade underlying CXCR2-mediated neutrophil recruitment. They combined intravital microscopy, single-cell force spectroscopy with atomic force microscopy, Ca2+ imaging, and microfluidic flow chamber assays to investigate the role of TRPC6 channels in murine neutrophils for their recruitment in renal ischemia-reperfusion and cremaster models as well as in in vitro assays.*

The study reveals that TRPC6 channels in neutrophils are crucial signalling modules in their recruitment from the blood stream in response to CXCL1.*

The single-cell force spectroscopy experiments were performed by using atomic force microscopy (AFM) with NanoWorld Arrow-TL1 tipless cantilevers which were incubated prior to experiments for 30 min in Cell-Tak to make the AFM cantilever sticky for neutrophils.*


Figure 4a from “Intravascular adhesion and recruitment of neutrophils in response to CXCL1 depends on their TRPC6 channels” by Otto Lindemann et al:
Force-distance curves were obtained by probing bEnd5 cells with the neutrophil-carrying cantilever using 1 nN maximal loading force
NanoWorld Arrow-TL1 Tipless AFM cantilever, single cantilever beam on a silicon support chip
NanoWorld Arrow-TL1
Tipless cantilever,
single cantilever beam on a silicon support chip

*Otto Lindemann, Jan Rossaint, Karolina Najder, Sandra Schimmelpfennig, Verena Hofschröer, Mike Wälte, Benedikt Fels, Hans Oberleithner, Alexander Zarbock and Albrecht Schwab
Intravascular adhesion and recruitment of neutrophils in response to CXCL1 depends on their TRPC6 channels
Journal of Molecular Medicine volume 98, pages349–360(2020)
DOI: https://doi.org/10.1007/s00109-020-01872-4

Please follow this external link to read the full article: https://link.springer.com/article/10.1007/s00109-020-01872-4

Open Access The article “ Intravascular adhesion and recruitment of neutrophils in response to CXCL1 depends on their TRPC6 channels “ by Otto Lindemann, Jan Rossaint, Karolina Najder, Sandra Schimmelpfennig, Verena Hofschröer, Mike Wälte, Benedikt Fels, Hans Oberleithner, Alexander Zarbock and Albrecht Schwab is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.