Effects of cyclosporin A on the production of experimental anti-erythrocyte autoantibodies in mice

Ca2+ -Calmodulin-Calcineurin Signaling Modulates α-Synuclein Transmission

BACKGROUND

The intercellular transmission of pathogenic proteins plays a crucial role in the progression of neurodegenerative diseases. Previous research has shown that the neuronal uptake of such proteins is activity-dependent; however, the detailed mechanisms underlying activity-dependent α-synuclein transmission in Parkinson's disease remain unclear.

OBJECTIVE

To examine whether α-synuclein transmission is affected by Ca2+ -calmodulin-calcineurin signaling in cultured cells and mouse models of Parkinson's disease.

METHODS

Mouse primary hippocampal neurons were used to examine the effects of the modulation of Ca2+ -calmodulin-calcineurin signaling on the neuronal uptake of α-synuclein preformed fibrils. The effects of modulating Ca2+ -calmodulin-calcineurin signaling on the development of α-synuclein pathology were examined using a mouse model injected with α-synuclein preformed fibrils.

RESULTS

Modulation of Ca2+ -calmodulin-calcineurin signaling by inhibiting voltage-gated Ca2+ channels, calmodulin, and calcineurin blocked the neuronal uptake of α-synuclein preformed fibrils via macropinocytosis. Different subtypes of voltage-gated Ca2+ channel differentially contributed to the neuronal uptake of α-synuclein preformed fibrils. In wild-type mice inoculated with α-synuclein preformed fibrils, we found that inhibiting calcineurin ameliorated the development of α-synuclein pathology.

CONCLUSION

Our data suggest that Ca2+ -calmodulin-calcineurin signaling modulates α-synuclein transmission and has potential as a therapeutic target for Parkinson's disease. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Cyclosporin A--a chemoprotectant against microcystin-LR toxicity

Microcystin-LR (MCLR) is a potent hepatotoxin that rapidly produces death in experimental animals. We have shown that cyclosporin A (CsA) can prevent the toxic and lethal effects of MCLR in mice. The LD50 of MCLR in mice is approximately 61 micrograms/kg, and 100 micrograms/kg produces death in 100% of treated mice. The minimum dose of CsA which prevented lethality in mice given 100 micrograms MCLR/kg i.p. was 10 mg/kg. This dose of CsA did not protect mice against higher doses of MCLR. Survival of all mice given 100 micrograms MCLR/kg was achieved if 10 mg CsA/kg was given 0.5-3 h prior to the MCLR but not if the CsA was co-administered or given after the MCLR. The results indicate that CsA effectively protects mice against a lethal dose of MCLR, but that the time of administration and the dose of CsA are critical determinants of the chemoprotective effects.