Long-term spaceflight is known to induce disruptions in circadian rhythms, which are driven by a central pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus, but the underlying molecular mechanisms remain unclear. Here, we developed a rat model that simulated microgravity and isolation environments through tail suspension and isolation (TSI). We found that the TSI environment imposed circadian disruptions to the core body temperature, heart rate, and locomotor-activity rhythms of rats, especially in the amplitude of these rhythms. In TSI model rats’ SCNs, the core circadian gene NR1D1 showed higher protein but not mRNA levels along with decreased BMAL1 levels, which indicated that NR1D1 could be regulated through post-translational regulation. The autophagosome marker LC3 could directly bind to NR1D1 via the LC3-interacting region (LIR) motifs and induce the degradation of NR1D1 in a mitophagy-dependent manner. Defects in mitophagy led to the reversal of NR1D1 degradation, thereby suppressing the expression of BMAL1. Mitophagy deficiency and subsequent mitochondrial dysfunction were observed in the SCN of TSI models. Urolithin A (UA), a mitophagy activator, demonstrated an ability to enhance the amplitude of core body temperature, heart rate, and locomotor-activity rhythms by prompting mitophagy induction to degrade NR1D1. Cumulatively, our results demonstrate that mitophagy exerts circadian control by regulating NR1D1 degradation, revealing mitophagy as a potential target for long-term spaceflight as well as diseases with SCN circadian disruption.

The glioma tumor microenvironment (TME) exhibits profound heterogeneity that drives tumor progression and therapy resistance. By integrating single-cell RNA sequencing (eleven samples) and spatial transcriptomics (two samples), the cellular components of the glioma microenvironment were deconvoluted, revealing tumor-associated foam cells (TAFCs) as the most abundant and centrally connected subtype. The high expression of two prognostic candidate genes, growth differentiation factor 8 (GDF-8, also known as myostatin, MSTN) and transcription factor 12 (TCF12), in TAFCs was found to be correlated with poor overall survival. These two genes were associated with M2 macrophage infiltration, altered cholesterol homeostasis, and immunosuppressive signaling. Regulatory network and pathway analyses, based on computational motif enrichment and co-expression analysis, linked them to ribosome, Notch signaling, DNA repair, and cell-cycle pathways. Pseudotime trajectories revealed dynamic expression during differentiation. Additionally, drug sensitivity prediction analysis demonstrated that MSTN expression was significantly associated with sensitivity to paclitaxel and VE-822, while TCF12 expression showed potential associations with sensitivity to cytarabine, olaparib, Wee1 inhibitor, paclitaxel, and VE-822. Logistic regression analysis combining clinical parameters with MSTN and TCF12 expression effectively achieved risk stratification for glioma, with higher composite scores predicting worse 2- and 3-year survival outcomes. Calibration curves demonstrated high consistency between nomogram-predicted overall survival probabilities and actual observed outcomes. Immunofluorescence confirmed upregulated expression of MSTN and TCF12 in glioma tissues and their co-localization with macrophages. In conclusion, this study identified TAFCs as the central cells in the glioma microenvironment, with their signature genes MSTN and TCF12 representing candidate immunometabolic signatures associated with macrophage-mediated immunosuppression and metabolic reprogramming in glioma, suggesting their potential as biomarkers for patient stratification and as targets for immunometabolic therapies.

Age-related decline in learning and memory functions poses significant challenges in an aging society, with epigenetic dysregulation emerging as a key contributor to cognitive deterioration. As the most prevalent internal RNA modification, N6-methyladenosine (m6A) dynamically orchestrates neural transcriptome plasticity through its “writers,” “erasers,” and “readers,” yet its role in aging-associated cognitive impairment remains underexplored. This study employs an integrated epitranscriptomic approach to investigate m6A-mediated regulation in hippocampal aging processes. Through comparative m6A-mRNA epitranscriptomic microarray analysis of senescence-accelerated mouse prone 8 (SAMP8) and senescence-resistant SAMR1 hippocampi, we identified neural cell adhesion molecule 1 (NCAM1) as a key m6A-regulated effector whose decreased expression correlates with accelerated cognitive deterioration. Mechanistically, we revealed that Methyltransferase-like 3 (METTL3)-mediated m6A modification governs Ncam1 mRNA stability through insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) reader protein-dependent mechanisms, forming a regulatory axis that modulates cyclic AMP response element-binding protein (CREB) signaling pathway activity. Remarkably, targeting of this METTL3/IGF2BP1/NCAM1 axis significantly attenuated cognitive deficits in aged SAMP8 mice. Our findings establish an m6A methylation-dependent paradigm for NCAM1-mediated cognitive preservation during aging, uncovering a novel epitranscriptomic layer in age-related neurodegeneration.