Reduced lysosomal density in neuronal dendrites mediates deficits in synaptic plasticity in Huntington's disease

Structural and functional reorganization of inhibitory synapses by activity-dependent cleavage of neuroligin-2

Recent evidence has demonstrated that the transsynaptic nanoscale organization of synaptic proteins plays a crucial role in regulating synaptic strength in excitatory synapses. However, the molecular mechanism underlying this transsynaptic nanostructure in inhibitory synapses still remains unclear and its impact on synapse function in physiological or pathological contexts has not been demonstrated. In this study, we utilized an engineered proteolysis technique to investigate the effects of acute cleavage of neuroligin-2 (NL2) on synaptic transmission. Our results show that the rapid cleavage of NL2 led to impaired synaptic transmission by reducing both neurotransmitter release probability and quantum size. These changes were attributed to the dispersion of RIM1/2 and GABAA receptors and a weakened spatial alignment between them at the subsynaptic scale, as observed through superresolution imaging and model simulations. Importantly, we found that endogenous NL2 undergoes rapid MMP9-dependent cleavage during epileptic activities, which further exacerbates the decrease in inhibitory transmission. Overall, our study demonstrates the significant impact of nanoscale structural reorganization on inhibitory transmission and unveils ongoing modulation of mature GABAergic synapses through active cleavage of NL2 in response to hyperactivity.

The role of mTORC1/TFEB axis mediated lysosomal biogenesis and autophagy impairment in fluoride neurotoxicity and the intervention effects of resveratrol

Elevated exposures to fluoride have been linked to neurological diseases. Identifying mechanisms of fluoride neurotoxicity and finding ways for prevention and treatment of epidemic fluorosis are important issues of public health. In this study, fluoride inhibited TFEB nuclear translocation by activating p-mTORC1/p-p70S6K, thus inhibiting lysosomal biogenesis, leading to dysfunctional lysosome accumulation, which further negatively affected autophagosome and lysosome fusion, thus impairing autophagy degradation, evidenced by the blocked conversion of LC3II to LC3I, and the increased p62 levels. Interestingly, RSV alleviated rats' cognition by improving fluoride-induced nerve damage and promoted lysosomal biogenesis demonstrated by the increased nucleus translocation of TFEB via inhibiting p-mTORC1 and p-p70S6K, the decreased expression of LC3II and p62. Collectively, we clarified the correlation between fluoride neurotoxicity and mTORC1/TFEB-mediated lysosomal biogenesis and autophagy. Meanwhile, RSV appeared to be a promising drug for the prevention and treatment of epidemic fluorosis.

How autoimmune antibodies kindle a firestorm in the brain

Patient-derived autoantibodies against NMDARs and GABAaRs show a crossover effect on the opposite receptor’s localization and function dependent on neuronal activity.