1.
Cell division in tissues enables macrophage infiltration.
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Akhmanova, M
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Emtenani, S
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Krueger, D
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Gyoergy, A
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Guarda, M
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Vlasov, M
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Vlasov, F
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Akopian, A
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Ratheesh, A
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De Renzis, S
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Siekhaus, DE
Abstract:
Cells migrate through crowded microenvironments within tissues during normal development, immune response, and cancer metastasis. Although migration through pores and tracks in the extracellular matrix (ECM) has been well studied, little is known about cellular traversal into confining cell-dense tissues. We find that embryonic tissue invasion by Drosophila macrophages requires division of an epithelial ectodermal cell at the site of entry. Dividing ectodermal cells disassemble ECM attachment formed by integrin-mediated focal adhesions next to mesodermal cells, allowing macrophages to move their nuclei ahead and invade between two immediately adjacent tissues. Invasion efficiency depends on division frequency, but reduction of adhesion strength allows macrophage entry independently of division. This work demonstrates that tissue dynamics can regulate cellular infiltration.
2.
Optogenetic delivery of trophic signals in a genetic model of Parkinson's disease.
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Ingles-Prieto, A
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Furthmann, N
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Crossman, SH
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Tichy, AM
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Hoyer, N
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Petersen, M
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Zheden, V
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Biebl, J
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Reichhart, E
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Gyoergy, A
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Siekhaus, DE
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Soba, P
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Winklhofer, KF
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Janovjak, H
Abstract:
Optogenetics has been harnessed to shed new mechanistic light on current and future therapeutic strategies. This has been to date achieved by the regulation of ion flow and electrical signals in neuronal cells and neural circuits that are known to be affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and are implicated in degenerative disorders, has never been demonstrated in an animal model of disease. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson's disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to inspire novel strategies towards a spatio-temporal regulation of tissue repair.