The marine acid polysaccharide fucoidan has attracted attention from both the food and pharmaceutical industries due to its promising therapeutic effects. Fucoidan is a polysaccharide that mainly consists of L-fucose and sulphate groups. Its excellent biological function is attributed to its unique biological structure. Classical activities include antitumor, antioxidant, anticoagulant, antithrombotic, immunoregulatory, antiviral and anti-inflammatory effects. More recently, fucoidan has been shown to alleviate metabolic syndrome, protect the gastrointestinal tract, benefit angiogenesis and bone health. This review focuses on the progress in our understanding of the biological activities of fucoidan, highlighting its benefits for the treatment of human disease. We hope that this review can provide some theoretical basis and inspiration for the product development of fucoidan.

Promoting lysosomal trafficking represents a promising therapeutic approach for lysosome storage diseases. Efficient Ca(2+) mobilization from lysosomes is important for lysosomal trafficking. Ca(2+) release from lysosomes could generate a negative potential in the lumen to disturb subsequent Ca(2+) release in the absence of counter ion flux. Here we report that lysosomes express big-conductance Ca(2+)-activated potassium (BK) channels that form physical and functional coupling with the lysosomal Ca(2+) release channel, TRPML1. Ca(2+) release via TRPML1 causes BK activation, which in turn facilitates further lysosomal Ca(2+) release and membrane trafficking. Importantly, BK overexpression rescues the impaired TRPML1-mediated Ca(2+) release and abnormal lysosomal storage in cells from Niemann-Pick C1 patients. Therefore, we have identified a lysosomal K(+) channel that provides a positive feedback mechanism to facilitate TRPML1-mediated Ca(2+) release and membrane trafficking. Our findings suggest that upregulating BK may be a potential therapeutic strategy for certain lysosomal storage diseases and common neurodegenerative disorders.

P2X4 and calmodulin form a signaling complex in late endosomes and lysosomes that promotes fusion and vacuolation in a Ca2+-dependent fashion.

Background: Ca 2ϩ -permeable P2X4 channels are expressed in lysosomes. Results: Lysosomal P2X4 channels are activated by ATP from the luminal side in a pH-dependent manner. Conclusion: P2X4 forms functional ATP-activated cation channels on lysosomal membranes regulated by luminal pH. Significance: Expanding the research of lysosomal Ca 2ϩ signaling by adding another Ca 2ϩ permeable channel on the lysosomal membranes.

Highlights d Inactivation of T cell autophagy results in enhanced tumor rejection d T cells deficient in autophagy show increased glucose uptake and lactate production d Reduction in SAM transcriptionally reprograms immune cells toward effector memory