title: Astrocytes increase ATP exocytosis mediated calcium signaling in response to microgroove structures.
abstract: Following central nervous system (CNS) injury, activated astrocytes form glial scars, which inhibit axonal regeneration, leading to long-term functional deficits. Engineered nanoscale scaffolds guide cell growth and enhance regeneration within models of spinal cord injury. However, the effects of micro-/nanosize scaffolds on astrocyte function are not well characterized. In this study, a high throughput (HTP) microscale platform was developed to study astrocyte cell behavior on micropatterned surfaces containing 1 μm spacing grooves with a depth of 250 or 500 nm. Significant changes in cell and nuclear elongation and alignment on patterned surfaces were observed, compared to on flat surfaces. The cytoskeleton components (particularly actin filaments and focal adhesions) and nucleus-centrosome axis were aligned along the grooved direction as well. More interestingly, astrocytes on micropatterned surfaces showed enhanced mitochondrial activity with lysosomes localized at the lamellipodia of the cells, accompanied by enhanced adenosine triphosphate (ATP) release and calcium activities. These data indicate that the lysosome-mediated ATP exocytosis and calcium signaling may play an important role in astrocytic responses to substrate topology. These new findings have furthered our understanding of the biomechanical regulation of astrocyte cell-substrate interactions, and may benefit the optimization of scaffold design for CNS healing.
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Ajay V
authors.initials: AV
authors.lastname: Singh
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Michael
authors.initials: M
authors.lastname: Raymond
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Fabiano
authors.initials: F
authors.lastname: Pace
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Anthony
authors.initials: A
authors.lastname: Certo
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Zuidema
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: McKay
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Gilbert
authors.affiliation: Department of Mechanical Engineering, Delaware University, Newark, DE 19716.
authors.forename: X Lucas
authors.initials: XL
authors.lastname: Lu
authors.affiliation: Department of Biomedical Engineering, Center for Biotechnology &Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
authors.forename: Leo Q
authors.initials: LQ
authors.lastname: Wan
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D020013:Calcium Signaling; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000378:metabolism; D005089:Exocytosis; D022001:Focal Adhesions / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D008247:Lysosomes / Q000502:physiology; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D059008:Time-Lapse Imaging
chemical_list: D005904:Glial Fibrillary Acidic Protein; D000255:Adenosine Triphosphate