Adenylate kinase phosphate energy shuttle underlies energetic communication in flagellar axonemes

The complexities of energy transfer mechanisms in the flagella of mammalian sperm flagella have been intensively investigated and demonstrate significant diversity across species.Enzymatic shuttles,particularly adenylate kinase(AK)and creatine kinase(CK),are pivotal in the efficient transfer of intracellular ATP,showing distinct tissue-and species-specificity.Here,the expression profiles of AK and CK were investigated in mice and found to fall into four subgroups,of which Subgroup III AKs were observed to be unique to the male reproductive system and conserved across chordates.Both AK8 and AK9 were found to be indispensable to male reproduction after analysis of an infertile male cohort.Knockout mouse models showed that AK8 and AK9 were central to promoting sperm motility.Immunoprecipitation combined with mass spectrometry revealed that AK8 and AK9 interact with the radial spoke(RS)of the axoneme.Examination of various human and mouse sperm samples with substructural damage,including the presence of multiple RS subunits,showed that the head of radial spoke 3 acts as an adapter for AK9 in the flagellar axoneme.Using an ATP probe together with metabolomic analysis,it was found that AK8 and AK9 cooperatively regulated ATP transfer in the axoneme,and were concentrated at sites associated with energy consumption in the flagellum.These findings indicate a novel function for RS beyond its structural role,namely,the regulation of ATP transfer.In conclusion,the results expand the functional spectrum of AK proteins and suggest a fresh model regarding ATP transfer within mammalian flagella.

NIR-triggered on-site NO/ROS/RNS nanoreactor:Cascade-amplified photodynamic/photothermal therapy with local and systemic immune responses activation

Photothermal and photodynamic therapies(PTT/PDT)hold promise for localized tumor treatment,yet their full potential is hampered by limitations such as the hypoxic tumor microenvironment and inadequate systemic immune activation.Addressing these challenges,we present a novel near-infrared(NIR)-triggered RNS nanoreactor(PBNO-Ce6)to amplify the photodynamic and photothermal therapy efficacy against triple-negative breast cancer(TNBC).The designed PBNOCe6 combines sodium nitroprusside-doped Prussian Blue nanoparticles with Chlorin e6 to enable on-site RNS production through NIR-induced concurrent NO release and ROS generation.This not only enhances tumor cell eradication but also potentiates local and systemic antitumor immune responses,protecting mice from tumor rechallenge.Our in vivo evaluations revealed that treatment with PBNO-Ce6 leads to a remarkable 2.7-fold increase in cytotoxic T lymphocytes and a 62%decrease in regulatory T cells in comparison to the control PB-Ce6(Prussian Blue nanoparticles loaded with Chlorin e6),marking a substantial improvement over traditional PTT/PDT.As such,the PBNO-Ce6 nanoreactor represents a transformative approach for improving outcomes in TNBC and potentially other malignancies affected by similar barriers.