Review
Neurosciences
Bo P. Lear, Darcie L. Moore
Summary: Axon regeneration is limited in the adult mammalian central nervous system due to intrinsic and extrinsic factors. The developmental age can influence the axon growth ability, with embryonic rodents showing longer axons compared to postnatal and adult neurons. This review discusses the advantages and disadvantages of human neuronal model systems and highlights the importance of studying axon growth in human neurons to uncover novel drivers of axon growth in the field of CNS regeneration.
FRONTIERS IN NEUROSCIENCE
(2023)
Article
Neurosciences
Yoshiki Sakai, Mayuka Tsunekawa, Kohei Ohta, Tatsuhiro Shimizu, Strahil Iv. Pastuhov, Hiroshi Hanafusa, Naoki Hisamoto, Kunihiro Matsumoto
Summary: In Caenorhabditis elegans hermaphrodites, axon injury activates TLN-1/talin through the cAMP-Epac-Rap GTPase cascade, leading to integrin inside-out activation and subsequent activation of the RhoA-ROCK signaling pathway. The C. elegans integrin signaling network regulates axon regeneration through the Src-RhoGEF-RhoA axis.
JOURNAL OF NEUROSCIENCE
(2021)
Article
Cell Biology
Tobias Heib, Heike M. Hermanns, Georgi Manukjan, Maximilian Englert, Charly Kusch, Isabelle Carlotta Becker, Annika Gerber, Lou Martha Wackerbarth, Philipp Burkard, Thomas Dandekar, Johannes Balkenhol, Daniel Jahn, Sarah Beck, Mara Meub, Sebastian Dutting, Christian Stigloher, Markus Sauer, Deya Cherpokova, Harald Schulze, Cord Brakebusch, Bernhard Nieswandt, Zoltan Nagy, Irina Pleines
Summary: The study demonstrates that RhoA/Cdc42 signaling is crucial for platelet precursor formation, and that the polyploidization and cytoplasmic maturation of MKs are separately regulated processes.
Article
Neurosciences
Yuichi Sekine, Ramakrishnan Kannan, Xingxing Wang, Stephen M. Strittmatter
Summary: Neural repair after traumatic spinal cord injury relies on axonal sprouting and regeneration. Rab GTPases were found to inhibit successful sprouting and regeneration. This study identified Rabphilin3A as an effector within regenerating axons, and its loss enhanced axon extension by increasing integrin action in the growth cone.
EXPERIMENTAL NEUROLOGY
(2022)
Article
Neurosciences
Menghon Cheah, Yuyan Cheng, Veselina Petrova, Anda Cimpean, Pavla Jendelova, Vivek Swarup, Clifford J. Woolf, Daniel H. Geschwind, James W. Fawcett
Summary: Sensory dorsal root ganglion (DRG) neurons in the peripheral branch regenerate readily after injury, but not in the central branch. However, expression of a9 integrin and its activator kindlin-1 (a9k1) enables axons to interact with tenascin-C, promoting extensive regeneration and reconnection of sensory axons in the spinal cord. Transcriptomic analyses of adult male rat DRG neurons revealed that a9k1 expression upregulates a known peripheral nerve regeneration program. Coupling a9k1 treatment with dorsal root axotomy leads to extensive central axonal regeneration, accompanied by the expression of a distinctive CNS regeneration program involving genes associated with ubiquitination, autophagy, ER, trafficking, and signaling. Pharmacological inhibition of these processes blocks axon regeneration, validating their causal contributions to sensory regeneration.
JOURNAL OF NEUROSCIENCE
(2023)
Article
Cell Biology
Mengya Zhao, Kenichi Toma, Benyam Kinde, Liang Li, Amit K. Patel, Kong-Yan Wu, Matthew R. Lum, Chengxi Tan, Jody E. Hooper, Arnold R. Kriegstein, Anna La Torre, Yaping Joyce Liao, Derek S. Welsbie, Yang Hu, Ying Han, Xin Duan
Summary: Chronic neurodegeneration and acute injuries lead to neuron losses via diverse processes. We compared retinal ganglion cell (RGC) responses between chronic glaucomatous conditions and the acute injury model. Among major RGC subclasses, aRGCs and intrinsically photosensitive RGCs (ipRGCs) preferentially survive glaucomatous conditions, similar to findings in the retina subject to axotomy. This study reveals the role of Spp1 in mediating neuronal resiliency in glaucoma, as Spp1 overexpression can protect susceptible RGC subclasses.
Article
Chemistry, Multidisciplinary
Pascal Achenbach, Laura Hillerbrand, Joseï L. Gerardo-Nava, Axel Dievernich, Dorothee Hodde, Antonio S. Sechi, Paul D. Dalton, Andrij Pich, Joachim Weis, Haktan Altinova, Gary A. Brook
Summary: Schwann cell transplantation is hindered by barrier formation between grafted cells and reactive astrocytes, limiting axonal regeneration. A cell confrontation assay revealed that oriented poly(& epsilon;-caprolactone) nanofibers reduced astrocyte reactivity and facilitated intermingling between Schwann cells and astrocytes, promoting neurite outgrowth. These findings have important implications for the design of biomaterial-based scaffolds for nervous tissue repair.
Review
Biochemistry & Molecular Biology
Hiroko Ikeshima-Kataoka, Chikatoshi Sugimoto, Tatsuya Tsubokawa
Summary: The integrin family plays important roles in various biological functions and disease pathogenesis. They are multifunctional receptors composed of alpha and beta subunits, binding to various ligands including extracellular matrix proteins. Integrins are found in both vertebrates and invertebrates, and are widely used in genetic and disease research. This paper discusses the phylogenetic analysis of the integrin family among different species, summarizes integrin signaling in teleost fish, and highlights the potential of drug development targeting integrins for the treatment of neurodegenerative diseases and brain injury in mammals.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Neurosciences
Seth Blackshaw
Summary: This article discusses various hypotheses proposed to explain the evolutionary loss of regenerative competence in vertebrates. The molecular mechanisms and supporting evidence are examined. The most compelling explanation is the selection for greater resistance to intra-CNS infections, which has led to a loss of regenerative ability.
FRONTIERS IN NEUROSCIENCE
(2022)
Article
Cell Biology
Sharif Alhajlah, Adam M. Thompson, Zubair Ahmed
Summary: The study shows that RTN3 may play a critical role in promoting axon regeneration in the central nervous system, especially after spinal cord and optic nerve injuries. Overexpression of RTN3 can enhance neurite outgrowth in cell culture and promote survival and axon regeneration in vivo.
Article
Multidisciplinary Sciences
Yuyan Cheng, Yuqin Yin, Alice Zhang, Alexander M. Bernstein, Riki Kawaguchi, Kun Gao, Kyra Potter, Hui-Ya Gilbert, Yan Ao, Jing Ou, Catherine J. Fricano-Kugler, Jeffrey L. Goldberg, Zhigang He, Clifford J. Woolf, Michael V. Sofroniew, Larry I. Benowitz, Daniel H. Geschwind
Summary: In this study, the authors used integrative genomic analysis and experimental validation to identify REST as a novel suppressor of a pro-regenerative gene program and CNS axon regeneration in mice. They demonstrated the inhibitory role of REST and highlighted the importance of a systems biology approach in CNS repair.
NATURE COMMUNICATIONS
(2022)
Article
Genetics & Heredity
Sucheta S. Kulkarni, Vidur Sabharwal, Seema Sheoran, Atrayee Basu, Kunihiro Matsumoto, Naoki Hisamoto, Anindya Ghosh-Roy, Sandhya P. Koushika
Summary: The study demonstrates that UNC-16 inhibits axonal regeneration by limiting the availability of the long isoform of DLK-1 at the injury site and regulating cytoskeletal dynamics. Additionally, UNC-16's inhibitory role in regeneration occurs through a tight temporal and spatial control of DLK-1 and cytoskeletal dynamics, ultimately affecting the functional recovery in unc-16 mutants.
Article
Cell Biology
Xinwang Ying, Xiaolan Yu, Jintao Zhu, Xuqing Li, Yujun Zheng, Qingfeng Xie, Qiaoyun Wu, Shengcun Li, Jingjing Yue, Ye Zhou, Kecheng Zhou, Wenzhan Tu, Songhe Jiang
Summary: The study found that rehabilitative training plays a positive role in recovery from spinal cord injury (SCI). It reduces tissue damage, promotes neuronal regeneration, and reduces apoptosis caused by SCI. In addition, rehabilitative training inhibits the increase of inflammatory factors and astrocyte and microglia activation, and reduces the level of chondroitin sulfate proteoglycan.
OXIDATIVE MEDICINE AND CELLULAR LONGEVITY
(2022)
Review
Cell Biology
Debasish Roy, Andrea Tedeschi
Summary: Lipids, particularly phospholipids, play a crucial role in axonal and dendritic growth, regeneration, and neuronal function. Dysregulation of lipid metabolism can impede axon regeneration and contribute to neurological complications post-CNS trauma. Modulating lipid metabolism presents a promising therapeutic strategy for improving neurological recovery after injury or disease.
Article
Biochemistry & Molecular Biology
Yannick Lichterfeld, Laura Kalinski, Sarah Schunk, Theresa Schmakeit, Sebastian Feles, Timo Frett, Harald Herrmann, Ruth Hemmersbach, Christian Liemersdorf
Summary: Neuronal activity plays a crucial role in behavior, and disturbances in synaptic signals can lead to neurological disorders. This study investigates the impact of hypergravity on astrocyte reactivity and reveals that hypergravity reduces the spreading rates, migration velocities, and stellation of astrocytes. Additionally, cytoskeletal remodeling and altered cell structure are observed under hypergravity conditions. The findings could contribute to the development of pharmacological interventions for enhancing neuronal regeneration.
Article
Genetics & Heredity
Lin Xu, Tingjian Zu, Tao Li, Min Li, Jun Mi, Fuxiang Bai, Guanyi Liu, Jie Wen, Hui Li, Cord Brakebusch, Xuxia Wang, Xunwei Wu
Summary: ATF3 plays an anti-tumor role in tongue squamous cell carcinoma (TSCC) cells by negatively regulating its downstream targets IFI6 and IFI27, which suppress cell growth and migration. Understanding ATF3 functions and downstream signaling pathways may lead to the development of new therapeutics for treating tumors like TSCCs.
Editorial Material
Developmental Biology
Frank Bradke, Antonina Roll-Mecak
DEVELOPMENTAL NEUROBIOLOGY
(2021)
Article
Neurosciences
Brett J. Hilton, Andreas Husch, Barbara Schaffran, Tien-chen Lin, Emily R. Burnside, Sebastian Dupraz, Max Schelski, Jisoo Kim, Johannes Alexander Mueller, Susanne Schoch, Cordelia Imig, Nils Brose, Frank Bradke
Summary: Axons in the adult mammalian central nervous system fail to regenerate after spinal cord injury due to the inhibitory effects of critical components of the presynaptic active zone. The acquisition of axon regeneration ability leads to downregulation of molecular constituents of the synapse in adult sensory neurons. Specific presynaptic active zone proteins inhibit axon regeneration, while Baclofen promotes regeneration by reducing calcium influx.
Article
Gastroenterology & Hepatology
Luz del Carmen Martinez-Sanchez, Phuong Anh Ngo, Rashmita Pradhan, Lukas-Sebastian Becker, David Boehringer, Despina Soteriou, Marketa Kubankova, Christine Schweitzer, Tatyana Koch, Veronika Thonn, Lena Erkert, Iris Stolzer, Claudia Guenther, Christoph Becker, Benno Weigmann, Monika Klewer, Christoph Daniel, Kerstin Amann, Stefan Tenzer, Raja Atreya, Martin Bergo, Cord Brakebusch, Alastair J. M. Watson, Jochen Guck, Ben Fabry, Imke Atreya, Markus F. Neurath, Rocio Lopez-Posadas
Summary: Abnormal cell shedding is associated with intestinal barrier dysfunction and inflammatory bowel diseases. Deletion of PGGTase and RAC1 in intestinal epithelial cells leads to cell overcrowding and epithelial leakage, resulting in chronic intestinal inflammation. RAC1 plays a crucial role in regulating cytoskeletal dynamics, cell mechanics, and intestinal cell shedding.
Article
Microbiology
Lara Petersen, Svenja Stroh, Dennis Schoettelndreier, Guntram A. Grassl, Klemens Rottner, Cord Brakebusch, Joerg Fahrer, Harald Genth
Summary: Clostridioides difficile infection causes pseudomembranous colitis, characterized by a loss of epithelial barrier function and colonic inflammation. The toxins TcdA and TcdB inhibit colonic stem cell proliferation and regeneration, leading to the development of PMC.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Immunology
Anila Vadakumchery, Hemin Faraidun, Omar El Ayoubi, Issame Outaleb, Vera Schmid, Hend Abdelrasoul, Timm Amendt, Ahmad Khadour, Corinna Setz, Katharina Goehring, Karoline Lodd, Christoffer Hitzing, Alabbas Alkhatib, Mayas Bilal, Julian Benckendorff, Abdul Kader Al Shugri, Cord Herbert Brakebusch, Niklas Engels, Moumita Datta, Elias Hobeika, Ameera Alsadeq, Hassan Jumaa
Summary: The adaptor protein SLP65 controls the down-regulation of PI3K signaling in B cells by inducing the activity of small GTPase RHOA, which activates the negative regulator PTEN. RHOA plays a unique role in B cell generation and selection, and blocking its function offers potential for treating B cell malignancies.
FRONTIERS IN IMMUNOLOGY
(2022)
Review
Cell Biology
Eissa Alfadil, Frank Bradke
Summary: Understanding axon growth is crucial for reactivating it under pathological conditions. Previous studies mainly focused on cultured neurons on flat surfaces, while recent 3D studies revealed more complex aspects of axon development. This article reviews current views on axon growth, highlights gaps in our knowledge, and proposes the need for studying axon growth in a more physiological setting to uncover relevant mechanisms and promote axon regeneration.
SEMINARS IN CELL & DEVELOPMENTAL BIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Zilu Ye, Gulcan Kilic, Sally Dabelsteen, Irina N. Marinova, Jens F. B. Thofner, Ming Song, Asha M. Rudjord-Levann, Ieva Bagdonaite, Sergey Y. Vakhrushev, Cord H. Brakebusch, Jesper v Olsen, Hans H. Wandall
Summary: This study investigates the importance of TGF-beta signaling pathway in human epithelial tissue homeostasis and transformation. Using genetic engineering, 3D tissue models, and quantitative proteomics, the study reveals that the loss of TGF-beta signaling promotes cell proliferation, delays differentiation, and induces invasive growth. The loss of TGF-beta receptor II (TGF-beta RII) has a stronger impact on cell proliferation and differentiation, and it also affects cell-matrix interactions and activates proinflammatory mediators.
Article
Multidisciplinary Sciences
Max Schelski, Frank Bradke
Summary: In developing vertebrate neurons, microtubules flow retrogradely within the neurites to the soma, inhibiting neurite growth. However, shortly after axon formation, microtubule retrograde flow slows down, enabling axon extension.
Article
Neurosciences
Ana I. Seixas, Miguel R. G. Morais, Cord Brakebusch, Joao B. Relvas
Summary: Myelin plays a vital role in improving axonal conduction velocity and is essential for nerve development and regeneration. The process of myelin sheath formation in peripheral nerves is not yet fully understood, but it has been found that RhoA is involved in promoting the initiation of myelination and regulating myelin growth at different stages of peripheral myelination. RhoA acts on actin filament turnover, actomyosin contractility, and cortical actin-membrane attachments in Schwann cells, which in turn regulate axon-Schwann cell interaction/adhesion and myelin growth. This study highlights the importance of RhoA in controlling Schwann cell state transitions for proper myelination of peripheral nerves.
PROGRESS IN NEUROBIOLOGY
(2023)
Article
Cell Biology
Renato Socodato, Tiago O. Almeida, Camila C. Portugal, Evelyn C. S. Santos, Joana Tedim-Moreira, Joao Galvao-Ferreira, Teresa Canedo, Filipa I. Baptista, Ana Magalhaes, Antonio F. Ambrosio, Cord Brakebusch, Boris Rubinstein, Irina S. Moreira, Teresa Summavielle, Ines Mendes Pinto, Joao B. Relvas
Summary: This study demonstrates that Rac1 in microglia is crucial for sensing and interpreting the brain microenvironment, as well as for the communication between microglia and synapses that drives experience-dependent plasticity and cognitive performance.
Article
Cell Biology
Marco Kirchenwitz, Jessica Halfen, Kristin von Peinen, Silvia Prettin, Jana Kollasser, Susanne zur Lage, Wulf Blankenfeldt, Cord Brakebusch, Klemens Rottner, Anika Steffen, Theresia E. B. Stradal
Summary: The study found that RhoB is upregulated after Salmonella infection, and it binds to SopB and localizes on early phagosomes of intracellular Salmonella. RhoB is specifically required for Salmonella-induced upregulation of autophagy, promoting the intracellular survival of the bacterium.
EUROPEAN JOURNAL OF CELL BIOLOGY
(2023)
Article
Biochemical Research Methods
Erna A. van Niekerk, Riki Kawaguchi, Camila Marques de Freria, Kimberly Groeniger, Maria C. Marchetto, Sebastian Dupraz, Frank Bradke, Daniel H. Geschwind, Fred H. Gage, Mark H. Tuszynski
Summary: This study reports a method for culturing adult central nervous system neurons in large quantities and for extended periods of time across multiple brain regions. These cultured neurons develop polarity, maintain resting membrane potentials, and exhibit characteristics reflective of their regions of origin. Additionally, the study identifies a conditioning effect in the central nervous system after spinal cord injury using adult motor cortex cultures.
CELL REPORTS METHODS
(2022)
Article
Clinical Neurology
Christof Kugler, Nelli Blank, Hana Matuskova, Christian Thielscher, Nicole Reichenbach, Tien-Chen Lin, Frank Bradke, Gabor C. Petzold
Summary: Ischaemic stroke is a major cause of death and disability globally. Surviving neurons in the peri-infarct area can establish new connections, but this is hindered by a growth-inhibitory environment induced by cells like reactive astrocytes. This study found that the anticonvulsant drug pregabalin can promote axon elongation in the glial scar, leading to improved recovery after stroke.
BRAIN COMMUNICATIONS
(2022)