Circadian Misalignment and Inflammasome Dynamics: A Molecular Bridge Between Sleep and Inflammation

Molecular clock components: CLOCK, BMAL1, PER, CRY

Circadian biology is an endogenous timekeeping system that regulates nearly all physiological functions, i.e., metabolism, endocrine, and most notably, immune function, by coordinating the expression of genes in time and the activity of cellular pathways over a 24-h period (light–dark cycle) [10]. This mechanism is under the control of molecular circadian pacemakers, the two transcription factors, CLOCK and BMAL1, and their target genes, PER (Period) and CRY (Cryptochrome), forming coupled transcriptional-translational feedback loops that control the cyclic expression of these genes. CLOCK and BMAL1 heterodimerize and activate the transcription of their target genes, including PER and CRY, which in turn, through a negative feedback loop, repress the activity of CLOCK-BMAL1, resulting in a self-sustained oscillation. As well as traditionally regulating circadian rhythm, these core clock proteins have a widespread role in the control of the immune response via modulation of cytokines, chemokines, and the innate immune pathway, as exemplified by inflammasomes.

NLRP3 inflammasome, a tertiary protein complex responsible for initiating inflammatory responses by maturing IL-1β and IL-18 and a key sensor of danger signals, is targeted by the circadian clock, presenting circadian rhythmicity on its priming and activation, which involves clock genes acting on its transcriptional and post-translational regulation [11]. BMAL1 restrains the activation of inflammasomes in myeloid cells from becoming too excessive, while PER and CRY proteins temporally gate the NF-κB signaling output, coupling the inflammatory response to environmental and metabolic stimuli (Table 1). Diurnal expression of these core clock genes is desynchronized with the activity of the inflammasome and production of inflammatory cytokines due to misalignment, such as that caused by shift work, chronic sleep deprivation, disruption of light color, or jet lag, leading to systemic inflammation. Such maladaptation not only prepares for acute inflammatory responses but might also play a role in chronic low-grade inflammatory states common to metabolic disorders, cardiovascular disease, neurodegeneration, and autoimmune pathologies. A twoway crosstalk between the clock machinery and the immune signals serves as a mechanistic link between sleep–wake cycles and immune balance: the timing device enables inflammasome activation to be initiated and resolved in a timely manner, and, in parallel, damaged circadian oscillations boost and interfere with the sustenance of inflammation and immune tolerance.

Table 1.

Studies on molecular clock components and inflammation

Table 1 summarizes studies [12-31] on molecular clock components and inflammation, illustrating how these relationships affect circadian regulation and inflammatory gene expression. Mechanistic insights highlight BMAL1 modulation via PAS-B domain, CRY-mediated phosphorylation control, and CLOCKSIRT1 axis linking metabolism to transcriptional timing.

Figure 1 shows transcriptional–translational feedback loops controlling circadian rhythm in mammalian cells. The timing of perpetual peripheral clocks is dictated by a central pacemaker, the SCN. In the nucleus, BMAL1/CLOCK proteins heterodimerize and bind to E-box elements to activate transcription of Per and Cry as well as Rev-erb and Rorα genes. Initially, PER and CRY proteins are cytoplasmic, they are phosphorylated by CK1ε/δ, and they later translocate into the nucleus, where they inhibit BMAL1/CLOCK activity, performing a negative feedback loop. REV-ERBs and RORα contribute an additional layer to Bmal1 transcriptional regulation. Such crosstalk produces approximately 24-h oscillations of gene expression that are critical for homeostatic regulation of physiology.

Figure 1.

Molecular mechanism of mammalian circadian clock. SCN, suprachiasmatic nucleus.

Circadian control of immune cell trafficking and cytokine release

Circadian biology operates as a major gatekeeper of immune regulation by coordinating the trafficking, activation, and effector functions of immune cells in time, enabling effective host defense with reduced tissue injury due to out-of-control inflammation. Circadian misalignment—driven, for example, by shift work, chronic sleep restriction, or exposure to artificial light at night—uncouples this coordinated spatiotemporal control, resulting in dysregulated trafficking of immune cells, perturbed distribution of specific leukocyte subsets, and loss of appropriate rhythmicity of cytokine release, all of which contribute to enhanced inflammation and increased susceptibility to infection. From a biological perspective, the loss of circadian BMAL1 expression in myeloid cells leads to increased NLRP3 inflammasome activation and IL-1β production. In contrast, the deletion of PER–CRY disrupts NF-κB-mediated transcriptional regulation in these innate immune cells, thereby improving their inflammatory responsiveness. In addition to impairing innate immunity, circadian disruption also affects adaptive immunity by regulating the generation and mobilization of T cells and B cells to various tissues, as well as the arrangement of activated lymphocytes or antigen-presentation activity [32]. This connection subsequently associates chronic insomnia with a loss of immune memory and an increased susceptibility to chronic inflammatory diseases. This evidence underscores a fragile molecular equilibrium among circadian biology and immunity: the precise regulation of immune cell movement and cytokine secretion is essential for robust immune defense and tissue homeostasis, and for mitigating inflammasome-mediated inflammatory responses. Conversely, circadian dysregulation renders individuals susceptible to spontaneous inflammatory events that exacerbate numerous metabolic, cardiovascular, neuroinflammatory, and autoimmune disorders prevalent in modern society.

Temporal gating of inflammatory responses

Circadian disruption, resulting from circadian rhythm, shift work, irregular light exposure, or social jet lag, disrupts this timed orchestration by causing uncoupled clock gene expression and improper priming of the inflammasome and cytokine release timing. This ultimately promotes systemic low-grade inflammation or exacerbates the process, increasing vulnerability to metabolic conditions, cardiac disorders, neurodegeneration, and autoimmunity. According to experimental models, myeloid cellspecific deletion or knockdown of BMAL1 at the gene level increases NLRP3-induced IL-1β production, and PER and CRY deficiency increases NF-κB–mediated expression of proinflammatory mediators, thus providing a mechanistic basis for circadian gating [33]. In addition, the temporal gating is not confined to the innate immunity but also encompasses adaptive responses, including T and B cell activation, antigen presentation, and development of immunological memory, dependent on the time of day. These findings shed light on the molecular link connecting sleep, circadian control, and immune homeostasis. By gating inflammatory signals during specific times of the day, the circadian clock can balance effective pathogen eradication with self-restraint from hyperinflammation, whereas its disruption by lifestyle, environmental factors, or pathological conditions causes chronic inflammatory conditions.

Overview of NLRP3, AIM2, NLRC4, and other inflammasome complexes

Inflammasomes are multi-protein cytosolic complexes that act as key cellular sensors of stress, PAMPs, and DAMPs, and as critical centers of innate immune function by coordinating the maturation and secretion of important proinflammatory cytokines, including IL-1β and IL-18, and inducing pyroptotic cell death through cleavage of gasdermin D [34]. Compositionally, a canonical inflammasome is generally assembled with a pattern recognition receptor (PRR) such as NLRP3, AIM2, or NLRC4, an adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD), and an effector protease caspase-1. The NLRP3 inflammasome is the most well-characterized and can be triggered by a variety of factors, such as extracellular adenosine triphosphate (ATP), crystalline materials (e.g., uric acid and cholesterol crystals), mitochondrial reactive oxygen species (ROS), and lysosomal rupture, which is consistent with its role as a sensor of several forms of cellular stress. NLRP3 activation is a two-hit process: a priming signal, frequently involving activation of Toll-like receptors and NF-κB, to upregulate NLRP3 and pro-IL-1β expression, and a second activation signal to induce the assembly of the inflammasome and the autoprocessing of pro-caspase-1 to active caspase-1, which in turn processes pro-IL-1β and pro-IL-18, as well as gasdermin D, to induce pyroptosis.

On the other hand, the AIM2 inflammasome is a cytosolic sensor for double-stranded DNA originating from viruses or bacteria [35], and it can interact with ASC to activate caspase-1, playing an important role in the antiviral defense and the response to cytosolic DNA damage [35]. The NLRC4, which is normally triggered by bacterial flagellin or type III secretion system proteins, associates with other inflammasome components (NLR family apoptosis inhibitory proteins) and is important for the immune response against Gram-negative bacteria. Other than these canonical complexes, numerous additional types of inflammasomes, such as NLRP1, pyrin, and the noncanonical caspase-11–dependent inflammasomes, broaden the range of cellular sensors and modulate inflammatory responses to distinct pathogen- or sterile-derived triggers. At a functional level, inflammasomes serve as molecular switches connecting danger detection to inflammation, orchestrating the spatial and temporal release of cytokines, controlling cell death pathways, and shaping adaptive immunity through their effects on dendritic cell maturation and T cell priming. Inflammasome dysregulation and its activity are associated with a variety of diseases, including autoinflammatory disorders, metabolic diseases such as type 2 diabetes and atherosclerosis, neurodegenerative diseases such as Alzheimer’s disease, and chronic inflammatory diseases.

Although multiple inflammasome platforms contribute to innate immune sensing—including the NLRP1, NLRC4, and AIM2 inflammasomes, as well as the Caspase-11 noncanonical inflammasome pathway—research has predominantly focused on select pathways. Others remain comparatively underexplored despite their roles in metabolic stress, mitochondrial dysfunction, circadian disruption, and ROS signaling. AIM2 primarily senses cytosolic double-stranded DNA and contributes to antiviral and autoimmune responses, while NLRC4 detects bacterial flagellin and secretion system components, mediating inflammasome assembly often independent of ASC. NLRP1 is activated by pathogenderived proteases and danger signals, distinguished by its autoproteolytic domain and tissue-specific expression. In parallel, caspase-11–dependent pathways (human caspase-4/5 equivalents) respond to intracellular lipopolysaccharide, driving noncanonical inflammasome activation, pyroptosis, and cytokine release. Despite their distinct mechanisms, these families remain less characterized compared to NLRP3, underscoring the need for deeper mechanistic exploration of their roles in immune regulation and disease. AIM2 is activated by cytosolic double-stranded DNA, NLRC4 responds to bacterial flagellin and type III secretion system proteins, and NLRP1 is triggered by pathogenderived proteases or cellular stress signals. In contrast, NLRP3 integrates diverse upstream signals such as ion flux, mitochondrial ROS, and disrupted cellular energetics, making it the most relevant inflammasome in the context of circadian misalignment. This contextual comparison clarifies the broader inflammasome landscape while explaining why subsequent mechanistic analysis centers on NLRP3.

Triggers and signaling cascades leading to IL-1β and IL-18 release

Inflammasomes act as complex intracellular signaling platforms to sense the wide array of stress and danger signals and to generate a strong response of inflammation, mediating the maturation and release of the main proinflammatory cytokines IL-1β and IL-18 and triggering the pyroptotic cell death to get rid of infected or damaged cells [36]. From a structural point of view, canonical inflammasomes consist of a sensor, including NLRP3, AIM2, NLRC4, NLRP1, or pyrin; an adaptor protein ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain); and the effector cysteine protease caspase-1. Each inflammasome is activated by a different trigger: NLRP3 responds to an array of potent endogenous and exogenous stressors, including ATP, mitochondrial-reacting oxygen species, lysosomal rupture, and crystals such as uric acid and cholesterol; AIM2 recognizes cytosolic dsDNA from bacteria, viruses, or damaged host cells; NLRC4 is mainly activated by the bacterial components flagellin and T3SS (type III secretion system); and pyrin senses alterations in Rho GTPases caused by bacterial toxins. Inflammasomes are typically activated by a two-step activation process, namely a priming step followed by an activation step.

The priming process involves the PRR-dependent recognition of PAMPs or DAMPs followed by NF-κB dependent transcriptional induction of inflammasome components, including NLRP3, ASC, pro-caspase-1, and the pro-forms of IL-1β and IL-18. The downstream activation process only occurs upon recognition of triggers that cause conformational changes in the sensor molecules, leading to their oligomerization and recruitment of ASC with concurrent formation of the filamentous ASC speck, actively promoting proximity-induced autocatalytic self-proteolytic cleavage of pro-caspase-1 into caspase-1 [37]. The generated active caspase-1 enzyme is responsible for the enzymatic processing of pro-IL-1β and pro-IL-18 to their active cytokine forms, which are transported out of cells through unconventional pathways, including gasdermin D–mediated pore formation. Moreover, this also induces pyroptosis, a lytic type of programmed cell death that enhances the local pro-inflammatory signals. Several upstream signaling cascades converge on the activation of inflammasomes: potassium efflux, calcium flux, mitochondrial impairment, lysosomal breakage, generation of ROS, and accumulation of posttranslational modifications (such as ubiquitination, phosphorylation, and SUMOylation) contribute all together as integrative inputs that tailor inflammasome sensitivity.

Role in sterile inflammation and chronic disease

Inflammasomes, as essential intracellular signaling platforms, are involved intimately not only in host defense against pathogens but also in mediating sterile inflammation initiated by endogenous danger signals, instead of infectious organisms, and are emerging as crucial contributors to the pathogenesis of diverse chronic lesions. The aseptic inflammatory stimuli are associated with metabolism-based stress factors, including saturated fatty acids, cholesterol crystals, uric acid, advanced glycation end products, and oxidized low-density lipoproteins, as well as well-defined damage-cost signals that come from the cells, which include mitochondrial damage-functional abnormalities, ROS, lysosomal breakdown, and cytosolic DNA that is a product of necrotic cells [38]. Sensors of the inflammasome, such as NLRP3, are particularly tolerant of these sterile cues and, when activated, form large, multimeric protein complexes with ASC and pro-caspase-1 that cleave pro-IL-1β and pro-IL-18 into mature, secreted forms that further amplify both local and systemic inflammatory cascades.

In cardiovascular disease, NLRP3 activation caused by cholesterol crystals results in atheromatous plaque generation, inflammation of the vascular walls, and plaque destabilization, directly linking the inflammasome to morbidity and mortality [39]. In the context of neurological diseases, sterile inflammasome activation appears to be progressively identified in neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases, wherein amyloid-β or α-synuclein accumulation leads to NLRP3-dependent IL-1β release, inducing microglial activation, neuroinflammation, synaptic dysfunction, and ultimately neuron degeneration. Familial Mediterranean fever and cryopyrin-associated periodic syndromes are prototypical of diseases caused by constitutively active inflammasomes, leading to unregulated IL-1β and IL-18 release and episodic systemic inflammation.

Figure 2 outlines systemic and cellular outcomes of sleep deprivation affecting immune regulation and neurological health. Poor sleep affects signaling in the brain and systemic circulation, which affects lymphoid tissue functioning. The major immune changes associated with aging are as follows: decreased natural killer (NK) cell and CD8+ T cell activity, shift from Th1 to Th2 dominance, reduced T cell antigenic uptake and presentation, and impaired B cell antibody production. Meanwhile, the levels of inflammatory mediators like IL-1, IL-6, CRP, and TNF-α are increased. These alterations lead to a greater risk of cancer, infection, neurodegeneration, and cardiovascular disease. The inset details neuroin-flammatory interactions between cytokines, microglia, astrocytes, neurons, and the blood–brain barrier to demonstrate the relationship between peripheral immune dysregulation and central nervous system (CNS) pathology.

Figure 2.

Effects of sleep loss on immunity and neuroinflammation. The figure illustrates how sleep deprivation disrupts immune function and promotes disease. It shows that lack of sleep alters systemic circulation and lymphoid tissue, leading to reduced natural killer (NK) and CD8 T cell activity, impaired antigen presentation, and decreased antibody production. It skews T cell balance toward Th2 and elevates inflammatory mediators like interleukin (IL)-1, IL-6, tumor necrosis factor alpha (TNF-α), and C-reactive protein (CRP). These changes activate microglia and astrocytes, and compromise the blood–brain barrier (BBB), contributing to increased risks of cancer, infection, neurodegeneration, and cardiovascular disease.

Mechanistic links between clock gene disruption, mitochondrial ROS, and NLRP3 activation

Building upon the foundational concepts outlined earlier, this section presents specific molecular and experimental evidence demonstrating that circadian misalignment or loss of core clock components disrupts mitochondrial homeostasis, increases ROS production, and primes the NLRP3 inflammasome. Experimental studies in macrophages, microglia, and circadian-disrupted animal models consistently show that BMAL1 deficiency alters mitochondrial dynamics, amplifies ROS signaling, and promotes IL-1β and IL-18 maturation. While several inflammasomes are involved in pathogen and danger sensing, NLRP3 remains the most extensively studied and mechanistically linked platform to circadian rhythm disturbances, metabolic dysregulation, and ROS-driven inflammation. Therefore, the mechanistic analysis below focuses on NLRP3-specific pathways.

Shift work, jet lag, and sleep fragmentation as circadian disruptors

Circadian misalignment, such as occurs during night or shift work, social or rapid jet lag, and by sleep deprivation or sleep fragmentation, has a significant mechanism-based impact on inflammasome activation, so far solidly linking sleep physiology with innate immunity. Sleep disruption also primes mitochondrial damage, ROS production, intracellular K⁺ efflux, and lysosomal dysfunction, all of which provoke NLRP3 inflammasome activation (Table 2). The net effect of this is exaggerated but ill-timed release of IL-1β/IL-18 and systemic low-grade inflammation, interrupting metabolic balance, vascular health, and neuroimmune crosstalk [40].

Table 2.

Findings on circadian misalignment and inflammasome dynamics

It has been shown that deletion of BMAL1 in myeloid cells or silencing of PER/CRY in them causes enhanced activation of NLRP3 inflammasome and cytokine secretion in experimental models, showing the molecular grip of circadian rhythms over innate immune pathways. In humans, circulating IL-1β and IL-18 are increased in shift workers and exhibit associations with worse glucose tolerance, higher blood pressure, and the presence of markers of endothelial dysfunction (inflammation-induced leukocyte adhesion), highlighting the translational relevance of clock– inflammasome crosstalk in chronic disease susceptibility [41]. Furthermore, circadian misalignment is an evolving phenomenon that collides with other behavioral and environmental stressors (i.e., changes in light exposure or feeding times) to enhance inflammasome activation and feed-forward of inflammation. Besides its immediate effects, chronic discoordination also results in the evolution of the metabolic syndrome, cardiovascular disease, neuroinflammatory disorders, and autoimmune disorders through persistent labor against inflammasome-driven inflammation.

Table 2 summarizes study findings on circadian misalignment and inflammasome dynamics [42-56], highlighting CLOCK/BMAL1, CRY1, and REV-ERBα as key modulators of NLRP3 dynamics, cytokine release, and metabolic-inflammatory balance.

Improving inflammasome priming through clock gene dysregulation: evidence

The circadian system is involved in innate immune signaling regulation through transcriptional and post-translational control of inflammasome components; a disruption of the clock gene is considered the first step in the enhanced priming of the inflammasome. At a molecular level, BMAL1 deficiency or a decrease in the activity of CLOCK has been amply described to affect the transcriptional silencing in the NF-κB-target genes, leading to reduced repression of NLRP3 gene and pro-IL-1β gene at the basal conditions and, thus, eventually supply “sufficient” priming of immune cells, which can subsequently correspond to the intense amplification upon inflammasome activation with a second hit, represented by the triggering stimuli [57]. Clock-controlled genes, such as the feedback proteins PER and CRY onto transcription of clock-driven genes, including inflammatory mediators, are also under-expressed and/or phase-shifted during circadian disruption, eliminating essential temporal gating and exacerbating the intensity of priming signals.

As well as transcriptional priming, deregulation of clock genes affects post-translational modification of inflammasome components (e.g., phosphorylation and ubiquitination), which sets the threshold of activation via protein stability, complex formation, and sensitization of the inflammasome [58]. This mechanistic model postulates that the circadian misalignment serves as a molecular amplifier of inflammasome priming, bridging disrupted sleep–wake cycle and clock gene disruption to enhanced susceptibility to inflammation.

Autoimmune diseases and circadian dysregulation

Autoimmune disorders show strong circadian signatures, yet the contribution of inflammasome pathways remains underappreciated. In systemic lupus erythematosus, altered expression of BMAL1 and PER2 correlates with heightened type I interferon activity and increased NLRP3 priming in monocytes. Rheumatoid arthritis exhibits pronounced diurnal variation in joint stiffness and IL-1β levels, reflecting rhythmic regulation of synovial macrophages. Circadian misalignment enhances NF-κB-driven priming, promotes mitochondrial ROS, and lowers the activation threshold for caspase-1, thereby facilitating joint inflammation. Similarly, multiple sclerosis models show that circadian disruption aggravates CNS immune infiltration and microglial NLRP3 activation. Together, these findings indicate that autoimmune pathophysiology is tightly linked to clock gene oscillations and that targeting circadian–inflammasome interactions may offer therapeutic value.

Mitochondrial dysfunction, ROS, and metabolic stress as mediators

Circadian misalignment significantly impacts the activation of the innate immune response by disturbing mitochondrial function, increasing ROS production, and exerting metabolic stress, which are essential mechanistic mediators in the association between altered sleep-wake patterns and inflammasome activation. In addition to the well-described electron flow generation, mitochondria play a crucial role in the integration of cellular stress signals and the control of the inflammatory responses, notably by regulating NLRP3 inflammasome activation [59]. Circadian disruption– resulting from shift work, jet lag, chronic sleep disruption, or phase-advanced light exposure–disrupts these clock-regulated processes, leading to mitochondrial dysfunction, with reduced oxidative phosphorylation, lower ATP production, accumulation of defective mitochondria, and increased leakage of mitochondrial DNA (mtDNA) into the cytosol. These mitochondria turn into a powerful source of ROS, particularly superoxide and H2O2, which are direct NLRP3 inflammasome activators through thiol oxidation of NLRP3, mitochondrial membrane depolarization releases of cardiolipin, and mtDNA as DAMPs.

Coincidentally, circadian misalignment drives metabolic stress by dysregulating glucose and lipid metabolism, NAD⁺/NADH ratio changes, and AMPK dysregulation that secondarily promotes inflammasome activation by increasing priming signals and decreasing stimulation thresholds [60]. ROS and metabolic intermediates (i.e., succinate and itaconate) crosstalk with post-translational regulation of inflammasome components (ubiquitination, phosphorylation, and S-nitrosylation of NLRP3 and ASC) to regulate assembly and enzymatic activity of caspase-1. The valuation of these integrated pathways creates possibilities for targeted interventions, such as a circadian-timed sleep schedule that includes antioxidant supplementation, metabolic modulating agents, and mitochondrial protective agents. These interventions aim to restore temporal homeostasis, limit ROS-induced inflammasome activity, and decrease the risk of inflammatory diseases. Consequently, the mitochondria–ROS–metabolism axis arises as a crucial mechanistic link connecting circadian biology with inflammasome dynamics.

Mechanistic links between clock genes, mitochondrial function, and NLRP3 inflammasome activation

Building upon the foundational circadian principles outlined earlier, this section focuses on specific experimental and translational evidence. Disruption of BMAL1, CLOCK, or PER/CRY oscillations leads to impaired mitochondrial quality control, altered fusion–fission dynamics, and excessive ROS accumulation—key signals that prime and activate the NLRP3 inflammasome. Studies in macrophages, microglia, and circadian-misaligned animal models show that clock gene deficiency increases mitochondrial ROS, activates NF-κB signaling, and amplifies IL-1β/IL-18 maturation. By limiting this section exclusively to mechanistic data, we eliminate redundancy from earlier descriptive sections and highlight the direct circadian–mitochondrial–inflammasome axis.

Reproductive immunology and circadian–inflammasome interactions

Emerging evidence indicates that circadian misalignment influences reproductive inflammatory pathways through both endocrine and immune mechanisms. Ovarian and endometrial tissues express core clock genes (BMAL1, CLOCK, PER2), which regulate steroidogenesis, follicular maturation, and immune cell infiltration across the menstrual cycle. Disruption of these rhythms increases mitochondrial stress and promotes NLRP3 activation in granulosa and stromal cells, leading to elevated IL-1β and IL-18 production. Such pathways have been implicated in polycystic ovary syndrome, recurrent implantation failure, and endometriosis, where amplified DAMP signaling, macrophage activation, and oxidative stress contribute to reproductive dysfunction. Recent studies further suggest that circadian rhythm disruption alters progesterone–immune interactions, thereby modifying Th1/Th2 balance and uterine NK cell activity. These findings reveal that reproductive tissues are highly sensitive to circadian–inflammasome crosstalk, warranting deeper investigation.

Cardiometabolic disorders: obesity, diabetes, and atherosclerosis

The disruption of the circadian alignment with inflammatory dynamics has important clinical relevance as it pertains to states of cardiometabolic disease, including obesity, type 2 diabetes, and atherosclerosis, where exposure to altered sleep patterns, altered molecular clocks, and chronic inflammation is a shared disease pathogenic element. In obese subjects, the decrease in the rhythmicity of metabolism also leads to metabolic dysfunction through the desynchronization of feeding schedules, changes in the production of adipokines, and the disruption of energy homeostasis, increasing the activation of NLRP3 inflammasome in macrophages of fat tissue. The resulting IL-1β and IL-18 production trigger local and systemic low-grade inflammatory responses, leading to an increase in insulin resistance and diminished glucose uptake by the skeletal muscle and a change in the function of the pancreatic β-cells [61].

In human clinical trials and laboratory-based paradigms, increased peripherally circulating IL-1β and IL-18 have been observed in subjects subjected to sleep restriction or sleep–wake cycle disorder, which are related to impaired glucose tolerance, higher HbA1c, and increased levels of inflammatory markers at the whole-body level. Epidemiological studies indicate the more frequent occurrence of cardiovascular events, higher carotid intima-media thickness, and higher circulating inflammatory markers as consequences of shift work and chronic sleep deprivation, highlighting the translational relevance of sleep–inflammasome crosstalk. At the molecular level, these mechanisms include circadian disruption prompt to intracellular machinery of the structure and function of mitochondria, rigging concomitant accumulation of ROS, potassium flux, and the metabolic pressure, that generates the increased inflammasome assembly, that is blunted to the clock genes dysregulation, that removes the limit gate, yielding in time to granting the IL-1β and IL-18 peak of secretion to peak phases of the physiological activity, hence chronically developing inflammation and leading to the cardiometabolic effects, from the endothelial dysfunction unto the hypertension and the cardiovascular risk [62].

Clinical relevance without mechanistic repetition

This section highlights how circadian misalignment contributes to inflammatory pathologies in humans—such as metabolic syndrome, neuroinflammation, cardiovascular risk, and sleepdisruption disorders—without reintroducing mechanistic details described earlier. Instead, the focus is placed on translational findings, biomarker associations, and potential therapeutic applications of targeting circadian pathways to modulate inflammasome activity.

Neuroinflammatory conditions: Alzheimer’s disease, depression, and multiple sclerosis

Circadian desynchrony influences deep into neuroinflammatory diseases: Alzheimer’s disease, major depressive disorder, and multiple sclerosis, by disturbing the time of response to inflammasome activation and cytokine release, providing, from a molecular point of view, a connection between disrupted sleep–wake cycles and CNS excitation of innate immunity [63]. Alterations in sleep architecture and circadian gene expression and consequent dysregulation of microglial and peripheral immune signaling pathways—together with inflammasome-driven excessive release of cytokines—indirectly undermine neurotransmitter systems (including serotonin and glutamate activity) and lead to hyperactivation of the HPA axis and neuroendocrine imbalance responsible for mood regulation.

In the same way, in multiple sclerosis, circadian misalignment can exacerbate inflammasome priming in CNS-resident microglia and infiltrating macrophages, leading to the augmentation of IL-1β–driven demyelination, T cell activation, and neuroimmune pathology and, consequently, increased disease severity and relapse frequency [64]. On a mechanistic level, mitochondrial dysfunction, metabolic stress, ROS accrual, potassium efflux, and lysosomal instability converge as inflammatory modulators during inflammasome overactivation under conditions of lost rhythmic control through the clock, while disruption of the clock removes temporal regulation of cytokine output, leading to a sustained inflammatory state.

Autoimmune diseases and circadian disruption

There are significant mechanistic implications of circadian misalignment in autoimmunity, by disrupting the specific timing of activity of immune cells and inflammasome activation, associating altered sleep–wake cycles to dysregulated adaptive and innate immune responses that lead to autoimmune diseases. Perturbations of the circadian rhythm of circadian rhythm disorders in diseases like rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis have been reported to be associated with increases in disease activity, elevation of pro-inflammatory cytokines, and deregulation of regulatory T cells, all of which are consequences of sleep disturbances that have been strongly linked to flares and progression of the diseases [65]. Circadian disruption also influences the timing of glucocorticoid release, melatonin rhythms, and sympathetic nervous system signaling, which in turn influence inflammasome activity and adaptive immune responses. This crosstalk provides a mechanistic rationale for tailoring therapeutics for circadian medicine, including timed sleep, phototherapy (targeting NLRP3 or IL-1β signaling by drugs as well as changing the clock genes expression) for the restoration of circadian and immune homeostasis.

In reproductive health, clock proteins such as BMAL1 and PER2 influence ovarian steroidogenesis, implantation timing, and maternal– fetal immune tolerance. Dysregulation of these pathways has been associated with recurrent pregnancy loss, preeclampsia, and altered cytokine profiles, suggesting that circadian misalignment may compromise reproductive success through aberrant inflammasome priming. Similarly, melatonin’s role in modulating oxidative stress and NLRP3 activity provides a mechanistic link between circadian cues and reproductive immunology.

Autoimmune diseases also demonstrate strong circadian signatures. Rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis exhibit diurnal variation in symptom severity and cytokine release. Aberrant BMAL1 or CRY1 activity alters IL-1β and IL-18 secretion, while REVERBα dysregulation contributes to heightened inflammasome activation.

Hormonal modulation of inflammasome activity in males vs. females

Sex differences and chronotype sensitivity are important modulators of inflammasome dynamics in circadian misalignment, which suggests an intricate interplay of hormonal regulation, sleep– wake timing, and inflammasome activity with consequences for the innate immunity in a sex-specific manner [66]. Estrogen has an inhibitory action on NLRP3 inflammasome activation in females, which results in lower IL-1β and IL-18 secretion, through a reduction in NF-κB signaling by activation of the estrogen receptor, regulation of ROS production in the mitochondria, and promotion of antioxidants. Progesterone is also important in suppression of inflammasome responsiveness, and particularly in the luteal phase, progesterone stabilizes mitochondria and facilitates anti-inflammatory signaling pathways. However, in males, androgens, such as T, can be bidirectional by both dampening inflammasome priming (in the case of NLRP3) and, in certain settings, allowing augmented responsiveness to metabolic or sterile stressors, and thereby experiencing sex-specific differences concerning cytokine release and inflammatory tone. These hormonal influences may converge with chronotype (the inherent preference for engaging in morning or evening activities) to dynamically modulate the timing of inflammasome activation: evening types with delayed sleep–wake patterns may be exposed to longer periods of basal NLRP3 priming, particularly when subjected to schedules that do not match their endogenous circadian activity rhythms, whereas morning types may be more tightly synchronized in immune rhythm. Thus, sex-specific personalized modifications such as sleep timing, light exposure, and modulation of inflammasome activity with drugs could differentially benefit males and females and could be used for optimization of temporal homeostasis and also for potentially minimizing the risks of inflammation-driven diseases.

Chronotype-specific vulnerability to inflammatory dysregulation

Chronotype-based susceptibility to inflammatory dysregulation is a key dimension of circadian misalignment on the dynamics of the inflammasome and accounts for the fact that preferred sleep–wake timing typically affects immune responsiveness, cytokine oscillations, as well as the risk of inflammation-mediated disease [67]. Morning chronotypes, on the other hand, maintain endogenous clock/light-dark cycle coupling more closely, which in turn preserves temporal gating of inflammasome activation, restricts overexposure to cytokines, and preserves metabolic homeostasis, hence providing relative resistance to chronic inflammation. Moreover, sex hormones interact with chronotype to further refine inflammasome activity: in females, estrogen and progesterone can rein in evening chronotype–associated hyperinflammatory priming via more stabilized Mito function, less ROS production, and more repression of NF-κB–mediated NLRP3 transcription, which cannot outweigh the suppressive response, whereas males who have evening chronotype could have additive higher susceptibility, due to less-descent suppression of inflammasome priming under hormonal state. Precise sleep and wake schedules, light exposure treatment, feeding timing guided by chronotype, and drugs that target inflammasome function may all protect against hyperinflammatory risk, restore circadian integrity, and improve immune homeostasis. This is especially true for evening chronotypes, who are affected by sleep disturbance or desynchronized behavioral rhythms.

Sleep timing and reproductive immune balance

Sensor timing and sexual dimorphism, along with interconnected chronotype effects, significantly influence the preservation of reproductive immune equilibrium. This requires an accurate classification of a complex molecular intersection, where the vertex includes the regulation of the circadian clock and inflammasome rhythm, managed by hormonal modulation to sustain reproductive viability [68]. Disruption of the sleep–wake cycle caused by delayed sleep onset, nocturnal awakening, or social jetlag results in the desynchronization of clock gene expression in immune or reproductive tissues. This consequently induces mitochondrial ROS production and NLRP3 inflammasome activation, leading to elevated regional and systemic levels of pro-inflammatory cytokines that adversely affect folliculogenesis, luteal function, and gamete quality. Chronotype differentially influences these effects, where evening chronotype is associated with late sleep/wake phase maintenance results in prolonged periods of basal inflammasome priming and mitochondrial stress, permeating sex-specific inflammatory responses and potentially affecting reproductive outcomes, but morning chronotypes typically maintain closer synchrony of endogenous and reproductive-immune cycles, maintaining circadian gating and cytokine balance.

Chronotherapy and circadian realignment interventions

Chronotherapy and circadian realignment interventions have shown promise as therapeutic and preventative measures against the deleterious impact of circadian misalignment on inflammasome dynamics and systemic inflammation, serving as an evidence-based link between the regulation of sleep and immune homeostasis [69]. Chronotherapy can be conceptualized as aiming to correct the temporal misalignment to the individual’s internally synchronized circadian phase by timing both behavioral, environmental (such as light exposure), and pharmacological treatments to be consistent with internal time, in turn strengthening circadian synchrony and the subsequent gating of the temporal domain of the immune system. Non-pharmacological methods, such as light therapy and timed exposure to natural or artificial light, or behavioral programming to consolidate sleep-wake rhythms according to an individual’s circadian preference, may realign central SCN clock timing with the peripheral immune clock rhythms.

Timing of sleep interventions, such as regular sleep onset and wake-up schedules, prolonged sleep duration during recovery phases, and inhibition of nociception to light, are likely to promote clock gene re-entrainment and are accompanied by the reduction of a basal inflammasome priming. Temporal control of feeding, or time-restricted feeding, acts as an additional circadian cue to modulate metabolic cycles, mitochondrial function and ROS generation in immune cells, and thereby to indirectly regulate inflammasome activation. Both pre-clinical and clinical studies show that these time-of-day targeted therapies decrease circulating levels of IL-1β and IL-18, ameliorate metabolic profiles, attenuate cardiovascular and neuro-inflammation risk, and improve reproductive immunological balance, suggesting that there is a translational power in aligning behavioral and molecular clock cycles [70]. Crucially, personalized chronotherapy considers sex differences, hormonal modulation, and resting phase-specific susceptibility to inflammasome activation, as females and evening chronotypes may be at increased sensitivity of the inflammasome during periods of misaligned chronotype.

Melatonin, light therapy, and sleep hygiene protocols

Melatonin supplementation, bright light therapy, and an organized protocol of sleep hygiene are complementary and efficacious approaches for both therapeutic and preventive management of circadian misalignment to reestablish temporal concordance between central and peripheral clocks, prevent disarrangement of inflammasome activity, and counteract the dynamic association between inflammation and pathophysiology [71]. As the principal pineal hormone conveying circadian timing information, melatonin has powerful chronobiotic and immunomodulatory effects via the enhancement of SCN-driven rhythms and the synchronization of peripheral immune and metabolic tissue clocks. Clinically, treatment with exogenous melatonin, administered at times with appropriate phase, has been demonstrated to facilitate sleep onset, consolidate sleep architecture, and decrease systemic markers of inflammation in shift-workers, jet-lagged individuals, and patients who suffer from metabolic and inflammatory pathologies. Light exposure, especially timed bright light in the morning or during the active period, entrains the central SCN pacemaker, reinforces peripheral clock gene oscillations, and restores diurnal immune cell trafficking and cytokine release profiles.

These protocols—the sleep hygiene recommendations including regular sleep–wake timing, avoidance of light in the middle of the dark period, regulation of temperature, minimal consumption of caffeine and electronics before sleep, and adequate sleep duration—support endogenous circadian timing, preserve mitochondrial and metabolic homeostasis, and limit excessive inflammasome activation [72]. Collectively, these interventions reboot both circadian and immune homeostasis: melatonin mediates hormonal and antioxidant status, light entrains central and peripheral clocks, and sleep hygiene consolidates behavioral and environmental cycles. When applying these strategies, sex and chronotype-specific vulnerabilities should be considered, and females and evening chronotypes might need sex-adjusted timing of melatonin administration, light exposure, and sleep scheduling to achieve the best anti-inflammatory effects and to preserve reproductive and metabolic immune balance.

Figure 3 illustrates the regulatory cascade of melatonin synthesis and its neuroprotective effects. The production of melatonin from the pineal gland occurs in response to darkness, regulated by the SCN and inputs from the retina. When melatonin is released, it immediately attaches to melatonin receptors present on neuronal and glial cells, triggering one of several pathways that protect those cells. These include the inhibition of PI3K/AKT/GSK-3β axis, prevention of amyloid-beta (Aβ) build-up, and neurofibrillary tangles. Moreover, melatonin stimulates SIRT1 and PGC-1α, improving mitochondrial function while decreasing ROS. It also inhibits NLRP3 inflammasome to prevent neuroinflammation. Taken together, these pathways reveal the potential therapeutic value of melatonin in neurodegenerative diseases, such as Alzheimer’s disease.

Figure 3.

Neuroprotective pathways of melatonin in the central nervous system. The figure depicts melatonin’s neuroprotective signaling cascade. Darkness stimulates melatonin release via the suprachiasmatic nucleus (SCN) and pineal gland, activating melatonin receptors. This suppresses PI3K/AKT/GSK-3β signaling, reducing amyloid-β plaques and neurofibrillary tangles. Concurrently, melatonin enhances SIRT1 and PGC-1α activity, mitigating mitochondrial dysfunction and oxidative stress. It also inhibits the NLRP3 inflammasome, collectively contributing to neuroprotection.

Targeting inflammasome pathways pharmacologically

Functionally, small molecule inhibitors that target NLRP3 (e.g., MCC950) inhibit NLRP3 ATPase and inflammasome assembly, and block caspase-1 activation and, consequently, IL-1β and IL-18 maturation, without broad immunosuppression of innate immunity [73]. Additional pharmacological strategies include caspase-1 inhibitors, such as VX-765, which directly block the enzymatic cleavage of pro-inflammatory cytokines and biologics targeting IL-1β (anakinra, canakinumab) or IL-18 to block their systemic effects and limit tissue damage in cardiometabolic, neuroinflammatory, autoimmune, and reproductive disorders.

In addition, sex differences and chronotype-associated effects on pharmacodynamics and inflammasome sensitivity would require determining when and how much compounds to deliver to maximize efficacy and reduce off-target effects [74]. In concert with chronotherapy, light manipulation, melatonin treatment, and attention to sleep hygiene, inflammasome targeting pharmacotherapies may provide a multilayered approach to reconstitute circadian and immune balance, attenuate sterile inflammation, and forestall the progression of sleep and circadian disorders. This integrative strategy promotes inflammasome-targeted pharmacotherapy as both a treatment for existing diseases and a preventive measure for at-risk populations experiencing chronic circadian misalignment, thereby linking molecular mechanisms to clinical outcomes within a precision medicine framework.

Omics-based profiling of circadian-inflammation interactions

The evolution of data-rich omics tools is transforming our understanding of the intricate interactions between circadian desynchronization and inflammasome dynamics, providing unprecedented mechanistic insights into the way altered sleep-wake circuitry influences immune homeostasis, metabolism, and systemic inflammation [75]. High-throughput transcriptomic tech-niques, including bulk and single-cell transcriptome sequencing, can quantitatively elucidate the temporal regulation of clock gene expression and inflammasome components (e.g., NLRP3, ASC, caspase-1, pro-IL-1β, and pro-IL-18) in tissues and immune cells, from which cell-type-specific susceptibility to circadian disruption may be determined, indicating intervals of increased inflammasome priming or activation. Proteomics further complements these studies by quantifying temporal post-translational modifications such as phosphorylation, ubiquitinylation, SUMOylation, and acetylation, which regulate assembly of inflammasomes, activation of caspase-1, and maturation of proinflammatory cytokines, as well as hormone-, metabolite-, and ROS-dependent modulatory effects temporally.

Metabolomics and lipidomics yield important information on the regulation of metabolites by the circadian clock, mitochondrial and lipid-derived danger signals of inflammasome activation, illustrating how disturbed feeding-fasting cues, mitochondrial dysfunction, and ROS accumulation contribute to NLRP3 priming and IL-1β/IL-18 release during circadian misalignment [76]. Epigenomics (ATAC-seq and ChIP-seq for histone modifications and transcription factor occupancy) reveals the clock-controlled regulatory landscapes that shape inflammasome gene transcription to expose how CLOCK:BMAL1, PER, and CRY complexes interact with NF-κB, STAT, and other immune transcription factors to set the temporal gating of inflammatory responses.

Integrative multi-omics assessments of circadian-inflammation networks (including transcriptomic, proteomic, metabolomic, and epigenomic) enable systems-level modeling of the relationships among these data and highlight downstream molecular nodes and signaling pathways sensitive to sleep deprivation, sexspecific differences in microbes or microglia, and adaptations of the chronotype [77]. These strategies also provide for biomarker discovery and the detection of timing windows for optimal chronotherapeutic interventions, predictive signatures of inflammasome hyperactivation, and personalized approaches to restoring circadian and immune homeostasis. Furthermore, the rise of single-cell and spatial omics technologies will allow for the mapping of circadian-inflammasome crosstalk within tissue microenvironments (e.g., the adipose tissue, vasculature, CNS, and reproductive organs), providing a glimpse into the underlying molecular mechanisms by which locally established inflammation niches respond to systemic perturbations of sleep and circadian rhythms.

Wearable devices and real-time circadian monitoring

Wearable devices and bedside/point-of-care circadian monitoring are a transformative frontier in our knowledge of the relationship between circadian misalignment and inflammasome oscillations, allowing for constant, personalized, and high-resolution data that integrates behavioral rhythms with actual molecular immune activity. Current wearable devices include actigraphy-based sleep tracking, heart rate variability monitors, core body temperature sensors, and light exposure counters, which enable exact determination of an individual’s sleep–wake pattern, physical activity– rest rhythm, as well as environmental cues for central or peripheral clock entrainment. Integration of these physiological readouts with circadian phase markers (e.g., DLMO, cortisol rhythms) enables researchers to map the extent of temporal misalignment between behavioral timing and the endogenous molecular circadian system that is a key determinant of basal priming and activation of the inflammasome (e.g., NLRP3, ASC, caspase-1), and downstream IL-1β and IL-18 secretion [78]. Such devices allow for long-term tracking of chronotype-specific vulnerabilities, potentially allowing identification of times of increased vulnerability to inflammation for evening chronotypes, shift workers, or people with social jet lag.

Preliminary clinical applications using wearable-based monitoring could detect associations of disturbed sleep–wake patterns, increased nocturnal heart rate variability, body temperature perturbations, and biomarkers of systemic inflammation, proving the translational potential of these devices for recognition (and potential prevention) of subclinical inflammasome-driven disease [79]. Wearable-enabled circadian monitoring can act as a non-invasive, scalable method that can bridge the gap between lifestyle, circadian biology, and immunity to conjoin behavioral phenotypes and molecular inflammatory signatures in cardiometabolic, neuroinflammatory, autoimmune, and reproductive disorders.

Artificial intelligence–driven modeling of sleep–immune dynamics

Artificial intelligence (AI)-based modeling of sleep–immune dynamics is opening novel frontiers in understanding complex and dynamic circadian misalignment–inflammasome interactions, inferring previously unattainable computational ability to unify multi-layered biological, behavioral, and environmental data into models predicting inflammation and disease risk [80]. Algorithms such as machine learning and AI will be able to integrate these disparate data streams (e.g., wearable-based sleep metrics; hormone rhythms including melatonin, cortisol, sex steroids; transcriptomics, proteomics, metabolomics, epigenomics; and cytokine trajectories) to model the temporal relationship between circadian phase, sleep quality, and inflammasome activation. These models enable accurate identification of individualized susceptibility windows when immune cells are prone to hyperactivation, and they offer a quantitative framework for forecasting innate immune hyperactivation or disease susceptibility in cardiometabolic, neuroinflammatory, autoimmune, or reproductive contexts.

AI-based modeling further makes it possible to find more subtle and nonlinear patterns and indirect effects in sleep–immune associations that are better at dealing with common statistical methods. This could lead to new mechanistic insights into how temporal misalignment might increase basal inflammasome priming or systemic cytokine release [81]. These models can likely be adapted to a personalized medicine structure by forecasting individual responses to behavioral and pharmacological interventions, determining optimal patient-specific treatment timing, and identifying populations at risk for early-stage preventive therapies.

Controversies, knowledge gaps, and methodological limitations

Despite growing evidence linking circadian disruption to enhanced inflammasome activity, several studies report contradictory results. For example, while BMAL1 deficiency consistently increases NLRP3 activation in macrophages and microglia, some reports suggest tissue-specific or context-dependent effects in which BMAL1 loss does not increase IL-1β production or may even exert anti-inflammatory roles under certain metabolic conditions. Similarly, the direction and magnitude of circadian modulation of inflammasomes vary depending on model system, environmental lighting, and metabolic status.

Translational interpretation remains challenging because human and rodent systems exhibit notable differences in circadian gene expression patterns, immune cell timing, and inflammasome sensitivity. Rodents are nocturnal, possess distinct feeding rhythms, and often exhibit exaggerated NLRP3 responses relative to human primary immune cells. These differences complicate direct cross-species extrapolation and highlight the need for human-specific circadian and immunological studies.

Current experimental approaches frequently rely on artificial synchronization techniques (e.g., serum shock, dexamethasone pulses) that do not fully recapitulate physiological circadian entrainment. Many in vitro studies examine inflammasome activation at single timepoints rather than capturing dynamic oscillations across the 24-hour cycle. Environmental factors such as feeding time, temperature, and light contamination—which strongly influence circadian rhythms—vary widely across laboratories and are often insufficiently reported. Additionally, commonly used stimuli such as LPS and ATP trigger inflammasomes through supra-physiological pathways that may not reflect realworld inflammatory factors. It remains unclear whether circadian misalignment directly amplifies inflammasome activity in humans or whether associated metabolic stressors (e.g., altered feeding patterns, sleep loss, endocrine disruption) act as primary mediators. Longitudinal human studies are limited, and mechanistic links between circadian rhythms, mitochondrial dynamics, and inflammasome activation require further validation in clinical cohorts. These uncertainties represent important areas for future research.