Release activity-dependent control of vesicle endocytosis by the synaptic adhesion molecule N-cadherin

Abstract

At synapses in the mammalian brain, continuous information transfer requires the long-term maintenance of homeostatic coupling between exo- and endocytosis of synaptic vesicles. Because classical endocytosis is orders of magnitude slower than the millisecond-range exocytosis of vesicles, high frequency vesicle fusion could potentially compromise structural stability of synapses. However, the molecular mechanisms mediating the tight coupling of exo- and endocytosis are largely unknown. Here, we investigated the role of the transsynaptic adhesion molecules N-cadherin and Neuroligin1 in regulating vesicle exo- and endocytosis by using activity-induced FM4–64 staining and by using synaptophysin-pHluorin fluorescence imaging. The synaptic adhesion molecules N-cadherin and Neuroligin1 had distinct impacts on exo- and endocytosis at mature cortical synapses. Expression of Neuroligin1 enhanced vesicle release in a N-cadherin-dependent way. Most intriguingly, expression of N-cadherin enhanced both vesicle exo- and endocytosis. Further detailed analysis of N-cadherin knockout neurons revealed that the boosting of endocytosis by N-cadherin was largely dependent on preceding high levels of vesicle release activity. In summary, regulation of vesicle endocytosis was mediated at the molecular level by N-cadherin in a release activity-dependent manner. Because of its endocytosis enhancing function, N-cadherin might play an important role in the coupling of vesicle exo- and endocytosis.

Idelalisib for optimized CD19‐specific chimeric antigen receptor T cells in chronic lymphocytic leukemia patients

“…First CAR vectors contained only a CD3ζ‐chain domain, whereas the second generation (2G) and 3G have been developed using or combining co‐stimulatory domains such as CD28, 4‐1BB (CD137) and/or OX40 (CD134) . It is known that CD28 supports stronger T cell expansion and enhanced tumor eradication whereas activity of 4‐1BB is linked to longer persistence and reduced risk of relapse . Combining two co‐stimulatory domains in a 3G CAR vector has the potential to combine both benefits.…”

“…43,44 It is known that CD28 supports stronger T cell expansion and enhanced tumor eradication whereas activity of 4-1BB is linked to longer persistence and reduced risk of relapse. 45 Combining two co-stimulatory domains in a 3G CAR vector has the potential to combine both benefits. Ramos et al examined the simultaneous infusion of 2G (CD28) and 3G (CD28/4-1BB) CD19-specific CART cells into patients and demonstrated that 3G CART cells had superior expansion and persistence properties.…”

Astrocyte lineage cells are essential for functional neuronal differentiation and synapse maturation in human iPSC‐derived neural networks

“…Secondary antibodies were: Alexa488 goat anti‐chicken; Alexa555 goat anti‐rabbit, Alexa 555 goat anti‐mouse, Alexa647 goat anti‐mouse (all from Invitrogen, Carlsbad, CA). Transfection with EGFP plasmid was performed as described previously (van Stegen, Dagar, & Gottmann, ). Fluorescence imaging was done as described previously (Nieweg et al, ; van Stegen et al, ).…”

“…Transfection with EGFP plasmid was performed as described previously (van Stegen, Dagar, & Gottmann, ). Fluorescence imaging was done as described previously (Nieweg et al, ; van Stegen et al, ). To estimate the density of MAP2 immunostained dendrites, a line‐scan analysis was performed (using ImageJ), in which the number of dendrites crossing randomly chosen lines of defined length was counted.…”

“…Transfection with EGFP plasmid was performed as described previously (van Stegen, Dagar, & Gottmann, 2017). Fluorescence imaging was done as described previously (Nieweg et al, 2015;van Stegen et al, 2017).…”