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Huang H, Zhao J, Guo H, Weng B, Zhang H, Saha RA, Zhang M, Lai F, Zhou Y, Juan RZ, Chen PC, Wang S, Steele JA, Zhong F, Liu T, Hofkens J, Zheng YM, Long J, Roeffaers MBJ. Noble-Metal-Free High-Entropy Alloy Nanoparticles for Efficient Solar-Driven Photocatalytic CO 2 Reduction. Adv Mater 2024:e2313209. [PMID: 38591644 DOI: 10.1002/adma.202313209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/18/2024] [Indexed: 04/10/2024]
Abstract
Metal nanoparticle (NP) cocatalysts are widely investigated for their ability to enhance the performance of photocatalytic materials; however, their practical application is often limited by the inherent instability under light irradiation. This challenge has catalyzed interest in exploring high-entropy alloys (HEAs), which, with their increased entropy and lower Gibbs free energy, provide superior stability. In this study, 3.5 nm-sized noble-metal-free NPs composed of a FeCoNiCuMn HEA are successfully synthesized. With theoretic calculation and experiments, the electronic structure of HEA in augmenting the catalytic CO2 reduction has been uncovered, including the individual roles of each element and the collective synergistic effects. Then, their photocatalytic CO2 reduction capabilities are investigated when immobilized on TiO2. HEA NPs significantly enhance the CO2 photoreduction, achieving a 23-fold increase over pristine TiO2, with CO and CH4 production rates of 235.2 and 19.9 µmol g-1 h-1, respectively. Meanwhile, HEA NPs show excellent stability under simulated solar irradiation, as well high-energy X-ray irradiation. This research emphasizes the promising role of HEA NPs, composed of earth-abundant elements, in revolutionizing the field of photocatalysis.
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Affiliation(s)
- Haowei Huang
- cMACS, Department of Microbial, and Molecular Systems, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Jiwu Zhao
- State Key Lab of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350116, China
| | - Hele Guo
- Department of Chemistry, Faculty of Sciences, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Bo Weng
- cMACS, Department of Microbial, and Molecular Systems, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
| | - Hongwen Zhang
- cMACS, Department of Microbial, and Molecular Systems, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Rafikul Ali Saha
- cMACS, Department of Microbial, and Molecular Systems, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Menglong Zhang
- College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Feili Lai
- Department of Chemistry, Faculty of Sciences, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Yufan Zhou
- Department of Materials Science, Fudan University, Shanghai, 200438, China
| | - Rubio-Zuazo Juan
- BM25-SpLine Beamline at the ESRF, 71 Avenue des Martyrs, Grenoble, 38043, France
- Instituto de Ciencia de Materiales de Madrid-CSIC, Sor Juana Inés de la Cruz, 3, Cantoblanco, Madrid, 28049, Spain
| | - Peng-Cheng Chen
- Department of Materials Science, Fudan University, Shanghai, 200438, China
| | - Sibo Wang
- State Key Lab of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350116, China
| | - Julian A Steele
- Australian Institute for Bioengineering and Nanotechnology and School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Fulan Zhong
- National Engineering Research Center of Chemical Fertilizer Catalyst (NERC-CFC), College of Chemical Engineering, Fuzhou University, Fuzhou, 350002, P. R. China
| | - Tianxi Liu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China
| | - Johan Hofkens
- Department of Chemistry, Faculty of Sciences, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Yu-Ming Zheng
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
| | - Jinlin Long
- State Key Lab of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350116, China
| | - Maarten B J Roeffaers
- cMACS, Department of Microbial, and Molecular Systems, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
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Vanheer L, Fantuzzi F, To SK, Schiavo A, Van Haele M, Ostyn T, Haesen T, Yi X, Janiszewski A, Chappell J, Rihoux A, Sawatani T, Roskams T, Pattou F, Kerr-Conte J, Cnop M, Pasque V. Inferring regulators of cell identity in the human adult pancreas. NAR Genom Bioinform 2023; 5:lqad068. [PMID: 37435358 PMCID: PMC10331937 DOI: 10.1093/nargab/lqad068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 06/17/2023] [Accepted: 06/28/2023] [Indexed: 07/13/2023] Open
Abstract
Cellular identity during development is under the control of transcription factors that form gene regulatory networks. However, the transcription factors and gene regulatory networks underlying cellular identity in the human adult pancreas remain largely unexplored. Here, we integrate multiple single-cell RNA-sequencing datasets of the human adult pancreas, totaling 7393 cells, and comprehensively reconstruct gene regulatory networks. We show that a network of 142 transcription factors forms distinct regulatory modules that characterize pancreatic cell types. We present evidence that our approach identifies regulators of cell identity and cell states in the human adult pancreas. We predict that HEYL, BHLHE41 and JUND are active in acinar, beta and alpha cells, respectively, and show that these proteins are present in the human adult pancreas as well as in human induced pluripotent stem cell (hiPSC)-derived islet cells. Using single-cell transcriptomics, we found that JUND represses beta cell genes in hiPSC-alpha cells. BHLHE41 depletion induced apoptosis in primary pancreatic islets. The comprehensive gene regulatory network atlas can be explored interactively online. We anticipate our analysis to be the starting point for a more sophisticated dissection of how transcription factors regulate cell identity and cell states in the human adult pancreas.
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Affiliation(s)
| | | | - San Kit To
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Andrea Schiavo
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - Matthias Van Haele
- Department of Imaging and Pathology; Translational Cell and Tissue Research, KU Leuven and University Hospitals Leuven; Herestraat 49, B-3000 Leuven, Belgium
| | - Tessa Ostyn
- Department of Imaging and Pathology; Translational Cell and Tissue Research, KU Leuven and University Hospitals Leuven; Herestraat 49, B-3000 Leuven, Belgium
| | - Tine Haesen
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Xiaoyan Yi
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - Adrian Janiszewski
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Joel Chappell
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Adrien Rihoux
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Toshiaki Sawatani
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - Tania Roskams
- Department of Imaging and Pathology; Translational Cell and Tissue Research, KU Leuven and University Hospitals Leuven; Herestraat 49, B-3000 Leuven, Belgium
| | - Francois Pattou
- University of Lille, Inserm, CHU Lille, Institute Pasteur Lille, U1190-EGID, F-59000 Lille, France
- European Genomic Institute for Diabetes, F-59000 Lille, France
- University of Lille, F-59000 Lille, France
| | - Julie Kerr-Conte
- University of Lille, Inserm, CHU Lille, Institute Pasteur Lille, U1190-EGID, F-59000 Lille, France
- European Genomic Institute for Diabetes, F-59000 Lille, France
- University of Lille, F-59000 Lille, France
| | - Miriam Cnop
- Correspondence may also be addressed to Miriam Cnop. Tel: +32 2 555 6305; Fax: +32 2 555 6239;
| | - Vincent Pasque
- To whom correspondence should be addressed. Tel: +32 16 376283; Fax: +32 16 330827;
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3
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Zhang H, Debroye E, Fu S, González MCR, du Fossé I, Geuchies JJ, Gao L, Yu X, Houtepen AJ, De Feyter S, Hofkens J, Bonn M, Wang HI. Optical Switching of Hole Transfer in Double-Perovskite/Graphene Heterostructure. Adv Mater 2023:e2211198. [PMID: 37060330 DOI: 10.1002/adma.202211198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 04/08/2023] [Indexed: 06/07/2023]
Abstract
Synergically combining their respective ultrahigh charge mobility and strong light absorption, graphene (Gr)/semiconductor heterostructures are promising building blocks for efficient optoelectronics, particularly photodetectors. Charge transfer (CT) across the heterostructure interface crucially determines device efficiency and functionality. Here, it is reported that hole-transfer processes dominate the ultrafast CT across strongly coupled double-perovskite Cs2 AgBiBr6 /graphene (DP/Gr) heterostructures following optical excitation. While holes are the primary charges flowing across interfaces, their transfer direction, as well as efficiency, show a remarkable dependence on the excitation wavelength. For excitation with photon energies below the bandgap of DPs, the photoexcited hot holes in Gr can compete with the thermalization process and inject into in-gap defect states in DPs. In contrast, above-bandgap excitation of DP reverses the hole-transfer direction, leading to hole transfer from the valence band of DPs to Gr. Experimental evidence that increasing the excitation photon energy enhances CT efficiency for both below- and above-bandgap photoexcitation regimes is further provided, unveiling the positive role of excess energy in enhancing interfacial CT. The possibility of switching the hole-transfer direction and thus the interfacial photogating field by tuning the excitation wavelength, provides a novel way to control the interfacial charge flow across a DP/Gr heterojunction.
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Affiliation(s)
- Heng Zhang
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Elke Debroye
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Shuai Fu
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | | | - Indy du Fossé
- Optoelectronic Materials Section, Faculty of Applied Sciences, Delft University of Technology, Delft, 2629HZ, The Netherlands
| | - Jaco J Geuchies
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Lei Gao
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- School of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing, 211189, China
| | - Xiaoqing Yu
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Arjan J Houtepen
- Optoelectronic Materials Section, Faculty of Applied Sciences, Delft University of Technology, Delft, 2629HZ, The Netherlands
| | - Steven De Feyter
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Johan Hofkens
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven, 3001, Belgium
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Hai I Wang
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
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Podnar E, Erega A, Danevčič T, Kovačec E, Lories B, Steenackers H, Mandic-Mulec I. Nutrient Availability and Biofilm Polysaccharide Shape the Bacillaene-Dependent Antagonism of Bacillus subtilis against Salmonella Typhimurium. Microbiol Spectr 2022; 10:e0183622. [PMID: 36342318 PMCID: PMC9769773 DOI: 10.1128/spectrum.01836-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
Salmonella enterica is one of the most common foodborne pathogens and, due to the spread of antibiotic resistance, new antimicrobial strategies are urgently needed to control it. In this study, we explored the probiotic potential of Bacillus subtilis PS-216 and elucidated the mechanisms that underlie the interactions between this soil isolate and the model pathogenic strain S. Typhimurium SL1344. The results reveal that B. subtilis PS-216 inhibits the growth and biofilm formation of S. Typhimurium through the production of the pks cluster-dependent polyketide bacillaene. The presence of S. Typhimurium enhanced the activity of the PpksC promoter that controls bacillaene production, suggesting that B. subtilis senses and responds to Salmonella. The level of Salmonella inhibition, overall PpksC activity, and PpksC induction by Salmonella were all higher in nutrient-rich conditions than in nutrient-depleted conditions. Although eliminating the extracellular polysaccharide production of B. subtilis via deletion of the epsA-O operon had no significant effect on inhibitory activity against Salmonella in nutrient-rich conditions, this deletion mutant showed an enhanced antagonism against Salmonella in nutrient-depleted conditions, revealing an intricate relationship between exopolysaccharide production, nutrient availability, and bacillaene synthesis. Overall, this work provides evidence on the regulatory role of nutrient availability, sensing of the competitor, and EpsA-O polysaccharide in the social outcome of bacillaene-dependent competition between B. subtilis and S. Typhimurium. IMPORTANCE Probiotic bacteria represent an alternative for controlling foodborne disease caused by Salmonella enterica, which constitutes a serious concern during food production due to its antibiotic resistance and resilience to environmental stress. Bacillus subtilis is gaining popularity as a probiotic, but its behavior in biofilms with pathogens such as Salmonella remains to be elucidated. Here, we show that the antagonism of B. subtilis is mediated by the polyketide bacillaene and that the production of bacillaene is a highly dynamic trait which depends on environmental factors such as nutrient availability and the presence of competitors. Moreover, the production of extracellular polysaccharides by B. subtilis further alters the influence of these factors. Hence, this work highlights the inhibitory effect of B. subtilis, which is condition-dependent, and the importance of evaluating probiotic strains under conditions relevant to the intended use.
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Affiliation(s)
- Eli Podnar
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Andi Erega
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Tjaša Danevčič
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Eva Kovačec
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Bram Lories
- Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Hans Steenackers
- Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Ines Mandic-Mulec
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- Chair of Microprocess Engineering and Technology (COMPETE), University of Ljubljana, Ljubljana, Slovenia
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Sobota M, Rodilla Ramirez PN, Cambré A, Rocker A, Mortier J, Gervais T, Haas T, Cornillet D, Chauvin D, Hug I, Julou T, Aertsen A, Diard M. The expression of virulence genes increases membrane permeability and sensitivity to envelope stress in Salmonella Typhimurium. PLoS Biol 2022; 20:e3001608. [PMID: 35389980 PMCID: PMC9017878 DOI: 10.1371/journal.pbio.3001608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 04/19/2022] [Accepted: 03/17/2022] [Indexed: 11/19/2022] Open
Abstract
Virulence gene expression can represent a substantial fitness cost to pathogenic bacteria. In the model entero-pathogen Salmonella Typhimurium (S.Tm), such cost favors emergence of attenuated variants during infections that harbor mutations in transcriptional activators of virulence genes (e.g., hilD and hilC). Therefore, understanding the cost of virulence and how it relates to virulence regulation could allow the identification and modulation of ecological factors to drive the evolution of S.Tm toward attenuation. In this study, investigations of membrane status and stress resistance demonstrate that the wild-type (WT) expression level of virulence factors embedded in the envelope increases membrane permeability and sensitizes S.Tm to membrane stress. This is independent from a previously described growth defect associated with virulence gene expression in S.Tm. Pretreating the bacteria with sublethal stress inhibited virulence expression and increased stress resistance. This trade-off between virulence and stress resistance could explain the repression of virulence expression in response to harsh environments in S.Tm. Moreover, we show that virulence-associated stress sensitivity is a burden during infection in mice, contributing to the inherent instability of S.Tm virulence. As most bacterial pathogens critically rely on deploying virulence factors in their membrane, our findings could have a broad impact toward the development of antivirulence strategies.
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Affiliation(s)
| | | | - Alexander Cambré
- Department of Microbial and Molecular Systems, KU Leuven, Leuven, Belgium
| | | | - Julien Mortier
- Department of Microbial and Molecular Systems, KU Leuven, Leuven, Belgium
| | - Théo Gervais
- Biozentrum, University of Basel, Basel, Switzerland
- Swiss Institute of Bioinformatics, Basel, Switzerland
| | | | | | - Dany Chauvin
- Biozentrum, University of Basel, Basel, Switzerland
- Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Isabelle Hug
- Biozentrum, University of Basel, Basel, Switzerland
| | - Thomas Julou
- Biozentrum, University of Basel, Basel, Switzerland
- Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Abram Aertsen
- Department of Microbial and Molecular Systems, KU Leuven, Leuven, Belgium
- * E-mail: (AA); (MD)
| | - Médéric Diard
- Biozentrum, University of Basel, Basel, Switzerland
- * E-mail: (AA); (MD)
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Wegge M, Dok R, Nuyts S. Hypoxia and Its Influence on Radiotherapy Response of HPV-Positive and HPV-Negative Head and Neck Cancer. Cancers (Basel) 2021; 13:5959. [PMID: 34885069 PMCID: PMC8656584 DOI: 10.3390/cancers13235959] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/15/2021] [Accepted: 11/19/2021] [Indexed: 12/24/2022] Open
Abstract
Head and neck squamous cancers are a heterogeneous group of cancers that arise from the upper aerodigestive tract. Etiologically, these tumors are linked to alcohol/tobacco abuse and infections with high-risk human papillomavirus (HPV). HPV-positive HNSCCs are characterized by a different biology and also demonstrate better therapy response and survival compared to alcohol/tobacco-related HNSCCs. Despite this advantageous therapy response and the clear biological differences, all locally advanced HNSCCs are treated with the same chemo-radiotherapy schedules. Although we have a better understanding of the biology of both groups of HNSCC, the biological factors associated with the increased radiotherapy response are still unclear. Hypoxia, i.e., low oxygen levels because of an imbalance between oxygen demand and supply, is an important biological factor associated with radiotherapy response and has been linked with HPV infections. In this review, we discuss the effects of hypoxia on radiotherapy response, on the tumor biology, and the tumor microenvironment of HPV-positive and HPV-negative HNSCCs by pointing out the differences between these two tumor types. In addition, we provide an overview of the current strategies to detect and target hypoxia.
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Affiliation(s)
- Marilyn Wegge
- Laboratory of Experimental Radiotherapy, Department of Oncology, University of Leuven, 3000 Leuven, Belgium; (M.W.); (R.D.)
| | - Rüveyda Dok
- Laboratory of Experimental Radiotherapy, Department of Oncology, University of Leuven, 3000 Leuven, Belgium; (M.W.); (R.D.)
| | - Sandra Nuyts
- Laboratory of Experimental Radiotherapy, Department of Oncology, University of Leuven, 3000 Leuven, Belgium; (M.W.); (R.D.)
- Department of Radiation Oncology, Leuven Cancer Institute, UZ Leuven, 3000 Leuven, Belgium
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Geldhof B, Pattyn J, Eyland D, Carpentier S, Van de Poel B. A digital sensor to measure real-time leaf movements and detect abiotic stress in plants. Plant Physiol 2021; 187:1131-1148. [PMID: 34618089 PMCID: PMC8566216 DOI: 10.1093/plphys/kiab407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/02/2021] [Indexed: 05/31/2023]
Abstract
Plant and plant organ movements are the result of a complex integration of endogenous growth and developmental responses, partially controlled by the circadian clock, and external environmental cues. Monitoring of plant motion is typically done by image-based phenotyping techniques with the aid of computer vision algorithms. Here we present a method to measure leaf movements using a digital inertial measurement unit (IMU) sensor. The lightweight sensor is easily attachable to a leaf or plant organ and records angular traits in real-time for two dimensions (pitch and roll) with high resolution (measured sensor oscillations of 0.36 ± 0.53° for pitch and 0.50 ± 0.65° for roll). We were able to record simple movements such as petiole bending, as well as complex lamina motions, in several crops, ranging from tomato to banana. We also assessed growth responses in terms of lettuce rosette expansion and maize seedling stem movements. The IMU sensors are capable of detecting small changes of nutations (i.e. bending movements) in leaves of different ages and in different plant species. In addition, the sensor system can also monitor stress-induced leaf movements. We observed that unfavorable environmental conditions evoke certain leaf movements, such as drastic epinastic responses, as well as subtle fading of the amplitude of nutations. In summary, the presented digital sensor system enables continuous detection of a variety of leaf motions with high precision, and is a low-cost tool in the field of plant phenotyping, with potential applications in early stress detection.
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Affiliation(s)
- Batist Geldhof
- Department of Biosystems, Division of Crop Biotechnics, Molecular Plant Hormone Physiology Lab, University of Leuven, Leuven 3001, Belgium
| | - Jolien Pattyn
- Department of Biosystems, Division of Crop Biotechnics, Molecular Plant Hormone Physiology Lab, University of Leuven, Leuven 3001, Belgium
| | - David Eyland
- Department of Biosystems, Division of Crop Biotechnics, Tropical Crop Improvement Laboratory, University of Leuven, Leuven 3001, Belgium
| | - Sebastien Carpentier
- Department of Biosystems, Division of Crop Biotechnics, Tropical Crop Improvement Laboratory, University of Leuven, Leuven 3001, Belgium
- Bioversity International, Leuven, 3001, Belgium
| | - Bram Van de Poel
- Department of Biosystems, Division of Crop Biotechnics, Molecular Plant Hormone Physiology Lab, University of Leuven, Leuven 3001, Belgium
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Pang L, Weeks SD, Van Aerschot A. Aminoacyl-tRNA Synthetases as Valuable Targets for Antimicrobial Drug Discovery. Int J Mol Sci 2021; 22:1750. [PMID: 33578647 PMCID: PMC7916415 DOI: 10.3390/ijms22041750] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/04/2021] [Accepted: 02/06/2021] [Indexed: 12/20/2022] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) catalyze the esterification of tRNA with a cognate amino acid and are essential enzymes in all three kingdoms of life. Due to their important role in the translation of the genetic code, aaRSs have been recognized as suitable targets for the development of small molecule anti-infectives. In this review, following a concise discussion of aaRS catalytic and proof-reading activities, the various inhibitory mechanisms of reported natural and synthetic aaRS inhibitors are discussed. Using the expanding repository of ligand-bound X-ray crystal structures, we classified these compounds based on their binding sites, focusing on their ability to compete with the association of one, or more of the canonical aaRS substrates. In parallel, we examined the determinants of species-selectivity and discuss potential resistance mechanisms of some of the inhibitor classes. Combined, this structural perspective highlights the opportunities for further exploration of the aaRS enzyme family as antimicrobial targets.
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Affiliation(s)
- Luping Pang
- KU Leuven, Rega Institute for Medical Research, Medicinal Chemistry, Herestraat 49–box 1041, 3000 Leuven, Belgium;
- KU Leuven, Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49–box 822, 3000 Leuven, Belgium
| | | | - Arthur Van Aerschot
- KU Leuven, Rega Institute for Medical Research, Medicinal Chemistry, Herestraat 49–box 1041, 3000 Leuven, Belgium;
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Rombouts J, Gelens L. Dynamic bistable switches enhance robustness and accuracy of cell cycle transitions. PLoS Comput Biol 2021; 17:e1008231. [PMID: 33411761 PMCID: PMC7817062 DOI: 10.1371/journal.pcbi.1008231] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/20/2021] [Accepted: 11/18/2020] [Indexed: 02/06/2023] Open
Abstract
Bistability is a common mechanism to ensure robust and irreversible cell cycle transitions. Whenever biological parameters or external conditions change such that a threshold is crossed, the system abruptly switches between different cell cycle states. Experimental studies have uncovered mechanisms that can make the shape of the bistable response curve change dynamically in time. Here, we show how such a dynamically changing bistable switch can provide a cell with better control over the timing of cell cycle transitions. Moreover, cell cycle oscillations built on bistable switches are more robust when the bistability is modulated in time. Our results are not specific to cell cycle models and may apply to other bistable systems in which the bistable response curve is time-dependent. Many systems in nature show bistability, which means they can evolve to one of two stable steady states under exactly the same conditions. Which state they evolve to depends on where the system comes from. Such bistability underlies the switching behavior that is essential for cells to progress in the cell division cycle. A quick switch happens when the cell jumps from one steady state to another steady state. Typical of this switching behavior is its robustness and irreversibility. In this paper, we expand this viewpoint of the dynamics of the cell cycle by considering bistable switches which themselves are changing in time. This gives the cell an extra layer of control over transitions both in time and in space, and can make those transitions more robust. Such dynamically changing bistability can appear very naturally. We show this in a model of mitotic entry, in which we include a nuclear and cytoplasmic compartment. The activity of a crucial cell cycle protein follows a bistable switch in each compartment, but the shape of its response is changing in time as proteins are imported into and exported from the nucleus.
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Affiliation(s)
- Jan Rombouts
- Laboratory of Dynamics in Biological Systems, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), B-3000 Leuven, Belgium
- * E-mail: (J.R.); (L.G.)
| | - Lendert Gelens
- Laboratory of Dynamics in Biological Systems, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), B-3000 Leuven, Belgium
- * E-mail: (J.R.); (L.G.)
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10
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Verheyen D, Xu XM, Govaert M, Baka M, Skåra T, Van Impe JF. Food Microstructure and Fat Content Affect Growth Morphology, Growth Kinetics, and Preferred Phase for Cell Growth of Listeria monocytogenes in Fish-Based Model Systems. Appl Environ Microbiol 2019; 85:e00707-19. [PMID: 31175191 PMCID: PMC6677851 DOI: 10.1128/aem.00707-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/30/2019] [Indexed: 11/20/2022] Open
Abstract
Food microstructure significantly affects microbial growth dynamics, but knowledge concerning the exact influencing mechanisms at a microscopic scale is limited. The food microstructural influence on Listeria monocytogenes (green fluorescent protein strain) growth at 10°C in fish-based food model systems was investigated by confocal laser scanning microscopy. The model systems had different microstructures, i.e., liquid, xanthan (high-viscosity liquid), aqueous gel, and emulsion and gelled emulsion systems varying in fat content. Bacteria grew as single cells, small aggregates, and microcolonies of different sizes (based on colony radii [size I, 1.5 to 5.0 μm; size II, 5.0 to 10.0 μm; size III, 10.0 to 15.0 μm; and size IV, ≥15 μm]). In the liquid, small aggregates and size I microcolonies were predominantly present, while size II and III microcolonies were predominant in the xanthan and aqueous gel. Cells in the emulsions and gelled emulsions grew in the aqueous phase and on the fat-water interface. A microbial adhesion to solvent assay demonstrated limited bacterial nonpolar solvent affinities, implying that this behavior was probably not caused by cell surface hydrophobicity. In systems containing 1 and 5% fat, the largest cell volume was mainly represented by size I and II microcolonies, while at 10 and 20% fat a few size IV microcolonies comprised nearly the total cell volume. Microscopic results (concerning, e.g., growth morphology, microcolony size, intercolony distances, and the preferred phase for growth) were related to previously obtained macroscopic growth dynamics in the model systems for an L. monocytogenes strain cocktail, leading to more substantiated explanations for the influence of food microstructural aspects on lag phase duration and growth rate.IMPORTANCEListeria monocytogenes is one of the most hazardous foodborne pathogens due to the high fatality rate of the disease (i.e., listeriosis). In this study, the growth behavior of L. monocytogenes was investigated at a microscopic scale in food model systems that mimic processed fish products (e.g., fish paté and fish soup), and the results were related to macroscopic growth parameters. Many studies have previously focused on the food microstructural influence on microbial growth. The novelty of this work lies in (i) the microscopic investigation of products with a complex composition and/or structure using confocal laser scanning microscopy and (ii) the direct link to the macroscopic level. Growth behavior (i.e., concerning bacterial growth morphology and preferred phase for growth) was more complex than assumed in common macroscopic studies. Consequently, the effectiveness of industrial antimicrobial food preservation technologies (e.g., thermal processing) might be overestimated for certain products, which may have critical food safety implications.
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Affiliation(s)
- Davy Verheyen
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
| | - Xiang Ming Xu
- Centre for Organelle Research, University of Stavanger, Stavanger, Norway
| | - Marlies Govaert
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
| | - Maria Baka
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
| | | | - Jan F Van Impe
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
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11
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Corporaal SHA, Bruijn SM, Hoogkamer W, Chalavi S, Boisgontier MP, Duysens J, Swinnen SP, Gooijers J. Different neural substrates for precision stepping and fast online step adjustments in youth. Brain Struct Funct 2018; 223:2039-2053. [PMID: 29368052 PMCID: PMC5884917 DOI: 10.1007/s00429-017-1586-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/30/2017] [Indexed: 12/27/2022]
Abstract
Humans can navigate through challenging environments (e.g., cluttered or uneven terrains) by modifying their preferred gait pattern (e.g., step length, step width, or speed). Growing behavioral and neuroimaging evidence suggests that the ability to modify preferred step patterns requires the recruitment of cognitive resources. In children, it is argued that prolonged development of complex gait is related to the ongoing development of involved brain regions, but this has not been directly investigated yet. Here, we aimed to elucidate the relationship between structural brain properties and complex gait in youth aged 9–18 years. We used volumetric analyses of cortical grey matter (GM) and whole-brain voxelwise statistical analyses of white matter (WM), and utilized a treadmill-based precision stepping task to investigate complex gait. Moreover, precision stepping was performed on step targets which were either unperturbed or perturbed (i.e., unexpectedly shifting to a new location). Our main findings revealed that larger unperturbed precision step error was associated with decreased WM microstructural organization of tracts that are particularly associated with attentional and visual processing functions. These results strengthen the hypothesis that precision stepping on unperturbed step targets is driven by cortical processes. In contrast, no significant correlations were found between perturbed precision stepping and cortical structures, indicating that other (neural) mechanisms may be more important for this type of stepping.
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Affiliation(s)
- Sharissa H A Corporaal
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium
| | - Sjoerd M Bruijn
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium
- Department of Human Movement Sciences, MOVE Research Institute Amsterdam, VU University Amsterdam, Amsterdam, The Netherlands
| | - Wouter Hoogkamer
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium
- Department of Integrative Physiology, University of Colorado, Boulder, USA
| | - Sima Chalavi
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium
| | - Matthieu P Boisgontier
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium
| | - Jacques Duysens
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium
| | - Stephan P Swinnen
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium
- Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium
| | - Jolien Gooijers
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Tervuursevest 101, box 1501, 3001, Leuven, Belgium.
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