STING-dependent peripheral inflammaging drives neurodegeneration via extracellular vesicles.

Age-associated decline of Lamtor5 drives immunosenescence and systemic aging via cGAS-mediated paracrine inflammation.

LRRK2 G2019S reprograms innate and adaptive immunity to drive context-dependent host defense outcomes

Introduction Parkinson’s disease (PD) is increasingly recognized as a neurological disorder characterized not only by neurodegeneration but also by chronic immune dysregulation across the lifespan. Although the initiating events underlying PD remain unclear, accumulating evidence suggests that inflammatory processes may contribute to disease susceptibility and progression. Mutations in leucine-rich repeat kinase 2 (LRRK2), particularly the gain-of-function G2019S variant, represent the common genetic cause of familial PD and have been implicated in immune regulation and infection susceptibility. To date, most research has focused on the effect of LRRK2 mutation in neurons and the contributions of G2019S-mediated kinase activity to neuronal toxicity, leaving the role of G2019S-mediated kinase activity in immune cell homeostasis and its contribution to PD pathogenesis largely unresolved. Methods Here, we used murine overexpression models of wildtype and G2019S variant of mouse Lrrk2 to examine how Lrrk2 G2019S shapes host defense across viral and bacterial infection models. We tested systemic sepsis and Escherichia coli infection to examine bacterial clearance. We followed up by testing macrophage responses to intracellular (Listeria monocytogenes) or primarily extracellular (Pseudomonas aeruginosa) bacteria. Finally, tested antibody-mediated immunity using influenza and cytotoxic T cell-mediated immunity using lymphocytic choriomeningitis virus (LCMV) infection. Results We found that Lrrk2 G2019S overexpression enhanced survival and bacterial clearance during P. aeruginosa lung infection, whereas the same genotype worsened outcomes in polymicrobial sepsis, with increased mortality, pulmonary myeloid infiltration and a hematopoietic cell-intrinsic phenotype. During L. monocytogenes infection, Lrrk2 G2019S selectively reduced non-classical monocytes without altering disease progression. In influenza and LCMV infection, G2019S altered antigen-specific CD8+ T cell distribution without major changes in cell memory responses clinical severity. Discussion Together, these data show that Lrrk2 G2019S selectively reprograms innate and adaptive immunity in a pathogen- and tissue-dependent manner, uncoupling inflammatory magnitude from effective host defense. These results and previous work support a model in which the G2019S LRRK2 variant contributes to maladaptive inflammatory responses to specific infection challenges, providing insight into how lifetime immune perturbations may intersect with genetic susceptibility to influence lifetime infection risk.

Complosome as a key modulator of cellular senescence, aging and age-related diseases.

Aging is characterized by progressive physiological decline and accumulation of senescent cells that drive chronic "inflammaging" through the senescence-associated secretory phenotype (SASP). The complement system, traditionally viewed as a systemic extracellular defense mechanism, is now recognized as an essential intracellular network (the complosome). This review synthesizes current research on how intracellular C3 (intC3), and intracellular C5 (intC5) in certain contexts engage in extensive crosstalk with the mTOR, NF-κB, and AMPK pathways to modulate core cellular processes. We detail how intC3 intersects with multiple canonical hallmarks of aging-including cellular senescence, mitochondrial dysfunction, proteostasis loss, genomic instability, epigenetic alterations, altered intercellular communication, stem cell exhaustion, and deregulated nutrient sensing. Furthermore, we examine organ-specific consequences of intC3 dysregulation across the aging brain, liver, eye, kidney, vasculature, lung, and immune system, as well as cancer. Finally, we discuss therapeutic strategies-including complement inhibitors, senolytics, senomorphics, RNA interference, proteolysis targeting chimeras (PROTACs), and nanotechnology-enabled delivery-and outline critical gaps in compartment-specific tools, conditional knockouts, and longitudinal models. Precision strategies that preserve systemic complement function while selectively modulating intracellular pools will be essential to translate complosome biology into durable interventions for age-related diseases.

The role and mechanisms of the cGAS-STING signaling pathway in age-related pathophysiological processes: challenges and therapeutic strategies.

Agingis characterized by chronic low-grade inflammation ("inflammaging"), a key driver of functional decline and age-related diseases. The cGAS-STING pathway, which senses cytosolic DNA, has emerged as a central mediator of this sterile inflammation. Here, we systematically review the mechanisms of cGAS-STING activation in aging-including mitochondrial DNA leakage, nuclear envelope disruption, and retrotransposon activation-and its role in driving cellular senescence and the senescence-associated secretory phenotype (SASP). We examine the pathway's pathological contributions across multiple systems, including the nervous, cardiovascular, musculoskeletal, metabolic, reproductive, and sensory systems. We also discuss therapeutic strategies targeting cGAS-STING, encompassing small-molecule inhibitors, natural products, nanomedicine, and gene therapy. Furthermore, we integrate AlphaFold3-based structural modeling and CB-DOCK2 molecular docking analyses to characterize the binding modes and affinities of key inhibitors (e.g., H-151, RU.521, VBIT-4, Mdivi-1) to cGAS, STING, VDAC1, and DRP1, providing a structural rationale for their therapeutic potential. Finally, we address current challenges, including tissue-specific effects and pathway complexity, and highlight future directions for translating these insights into clinical interventions for aging and age-associated disorders.

Mitochondrial homeostasis and aging: the mtDNA-cGAS-STING axis

Aging and its associated diseases have become an increasingly severe global health challenge, not only significantly exacerbating the global disease burden but also posing a continuous threat to public health systems worldwide. During the aging process, the aberrant release of endogenous mitochondrial DNA (mtDNA) is a key trigger for the activation of the cGAS–STING innate immune pathway. Existing research has confirmed that the overactivation of the cGAS–STING pathway is the core molecular mechanism driving the senescence-associated secretory phenotype (SASP), chronic inflammation, and organ functional decline. Notably, the mechanisms of mtDNA release and the activation characteristics of the cGAS–STING pathway exhibit significant organ-specificity. Different tissues mediate mtDNA leakage through specific pathways, such as mitochondrial permeability transition, oxidative damage, and defective mitophagy, thereby differentially regulating downstream inflammatory signals. Given the central driving role of the aberrantly activated mtDNA-cGAS-STING axis in age-related organ damage, targeting this pathway has emerged as a promising therapeutic strategy for the systemic mitigation of aging-associated chronic inflammation. This review systematically elucidates the molecular basis of the mtDNA-cGAS-STING pathway, delves into its organ-specific activation mechanisms, and critically evaluates current intervention frameworks and clinical prospects, aiming to provide a theoretical basis and innovative perspectives for the precision prevention and clinical management of age-related diseases.

cGAS-STING signaling in aging and age-related diseases: therapeutic promise and precaution.