Ashiqueali, Sarah A.

Summary Human spaceflight has historically been led by government agencies, but the emergence of commercial organizations is enabling broader participation and new research opportunities. In this study, we present a comprehensive molecular characterization of early human responses to spaceflight, leveraging multi-omics data across the first three weeks of two commercial missions. Biospecimens from six individuals, four from the Axiom 2 mission (10 days) and two from Axiom 3 (21 days), were analyzed using single-cell and bulk RNA sequencing, alongside proteomic profiling. Individual and integrative analyses of these datasets reveal systemic changes in cell types, transcripts, and proteins related to immune regulation, osteoclast differentiation, NF-κB signaling, and blood homeostasis pathways. Importantly, several of the detected pathways align with physiological patterns observed in longer-duration missions. This work establishes a foundational resource for understanding early adaptation to spaceflight at the cellular and molecular levels, providing insights to reduce future space-travel health risks. Highlights First integrated multi-omics analysis using single-cell, bulk RNA sequencing and proteomic profiling of early human spaceflight responses across two commercial missions (Ax-2 and Ax-3). Distinct PBMC clustering was observed across Ax-2 and Ax-3, and post-flight samples. It showed fewer monocytes, dendritic cells, and megakaryocytes with increased naïve CD4⁺ and cytotoxic T cells. Multi-omics integration identifies shared biological signatures, including osteoclast differentiation, metabolic stress, and coagulation changes. These findings lay the foundation for developing countermeasures to protect immune, skeletal, and vascular health during spaceflight.

Cellular senescence is defined as a state of permanent cell cycle arrest, providing a natural barrier against cancer. However, senescent cells are very metabolically active and secrete a complex mixture of bioactive molecules collectively known as the senescence-associated secretory phenotype (SASP), which play a dual role in cancer biology. While the SASP can suppress tumors by facilitating immunosurveillance, it can also promote tumor progression by fostering a pro-inflammatory milieu, stimulating angiogenesis, enhancing invasiveness, and enabling immune evasion. In Head and Neck Cancers (HNCs), a highly heterogeneous group of malignancies, SASP has emerged as a critical player in disease progression and treatment resistance. Persistent DNA damage response (DDR) signaling drives SASP and thereby contributes to the progression of head and neck cancer by modulating the tumour microenvironment. It influences the tumor microenvironment (TME) by facilitating epithelial-to-mesenchymal transition (EMT), promoting cancer stem cell-like properties, and impairing the efficacy of radiotherapy, chemotherapy, and immune checkpoint inhibitors. These effects underscore the need for targeted interventions to regulate SASP activity. This review presents a comprehensive overview of the molecular mechanisms underlying SASP generation and its effects on HNCs. We discuss the dual roles of SASP in tumor suppression and progression, its contribution to therapy resistance, and emerging therapeutic strategies, including novel senolytic and senomorphic drugs. Finally, we highlight key challenges and future directions for translating SASP-targeted therapies into clinical practice, emphasizing the need for biomarker discovery, and a deeper understanding of SASP heterogeneity. By targeting the SASP, there is potential to enhance therapeutic outcomes and improve the management of HNCs.

Abstract The aging process is universal, and it is characterized by a progressive deterioration and decrease in physiological function leading to decline on the organismal level. Nevertheless, a number of genetic and nongenetic interventions have been described, which successfully extend healthspan and lifespan in different species. Furthermore, a number of clinical trials have been evaluating the feasibility of different interventions to promote human health. The goal of the annual Biological Sciences Section of the Gerontological Society of America meeting was to share current knowledge of different topics in aging research and provide a vision of the future of aging research. The meeting gathered international experts in diverse areas of aging research including basic biology, demography, and clinical and translational studies. Specific topics included metabolism, inflammaging, epigenetic clocks, frailty, senescence, neuroscience, stem cells, reproductive aging, inter-organelle crosstalk, comparative transcriptomics of longevity, circadian clock, metabolomics, and biodemography.