Circadian Regulation of the Biology of Allergic Disease: Clock Disruption Can Promote Allergy

The Beneficial Roles of Sargassum spp. in Skin Disorders

As the body's largest organ, the skin is located at the internal and external environment interface, serving as a line of defense against various harmful stressors. Recently, marine-derived physiologically active ingredients have attracted considerable attention in the cosmeceutical industry due to their beneficial effects on skin health. Sargassum, a genus of brown macroalgae, has traditionally been consumed as food and medicine in several countries and is rich in bioactive compounds such as meroterpenoids, sulfated polysaccharides, fucoidan, fucoxanthin, flavonoids, and terpenoids. Sargassum spp. have various beneficial effects on skin disorders. They help with atopic dermatitis by improving skin barrier protection and reducing inflammation. Several species show potential in treating acne by inhibiting bacterial growth and reducing inflammation. Some species, such as Sargassum horneri, demonstrate antiallergic effects by modulating mast cell activity. Certain Sargassum species exhibit anticancer activity by inhibiting tumor growth and promoting apoptosis, and some species help with wound healing by promoting angiogenesis and reducing oxidative stress. Overall, Sargassum spp. demonstrate potential for treating and managing various skin conditions. Therefore, the bioactive compounds of Sargassum spp. may be natural ingredients with a wide range of functional properties for preventing and treating skin disorders. The present review focused on the various biological effects of Sargassum extracts and derived compounds on skin disorders.

Melatonin regulates circadian clock proteins expression in allergic airway inflammation

Asthma demonstrates a strong circadian rhythm with disrupted molecular clock. Melatonin which can directly regulate circadian rhythm has been reported to alleviate asthma, but whether this effect is related to its regulation on circadian clock has not yet been known. Here, female C57BL/6 mice were challenged with ovalbumin (OVA) to establish allergic airway inflammation, and were treated with melatonin or Luzindole to investigate whether the expressions of circadian clock proteins were changed in response to OVA and were affected by exogenous/endogenous melatonin. Airway inflammation, mucus secretion, protein expressions of circadian proteins (Bmal1, Per1, Clock, Timeless, Cry1 and Cry2), melatonin biosynthetase (ASMT, AANAT) and melatonin receptor (Mel-1A/B-R) were analyzed accordingly. The results showed that in the successfully established allergic airway inflammation model, inflammatory cells infiltration, expressions of circadian clock proteins in the lung tissues of OVA-challenged mice were all notably up-regulated as compared to that of the vehicle mice. Meanwhile, the protein expression of ASMT and the level of melatonin in the lung tissues were reduced in allergic mice, while the expression of melatonin receptor Mel-1A/B-R was markedly increased. After addition of exogenous melatonin, the OVA-induced airway inflammation was pronouncedly ameliorated, while simultaneously the OVA-induced expressions of Per1 and Clock were further increased. However, a melatonin receptor antagonist Luzindole further augmented the OVA-induced airway inflammation, accompanied with remarkably decreased expressions of Per1, Bmal1, Cry1 and Cry2 but notably increased expression of Timeless. Collectively, our results demonstrated that the expression of circadian clock proteins was increased in the lungs during allergic airway inflammation, and Per1 was a clock protein that can be regulated by both exogenous and endogenous melatonin, suggesting Per1 may be an important potential circadian clock target for melatonin as a negative regulatory factor against Th2-type airway inflammation.

The role of circadian clock in regulating cell functions: implications for diseases

The circadian clock system orchestrates daily behavioral and physiological rhythms, facilitating adaptation to environmental and internal oscillations. Disruptions in circadian rhythms have been linked to increased susceptibility to various diseases and can exacerbate existing conditions. This review delves into the intricate regulation of diurnal gene expression and cell function by circadian clocks across diverse tissues. . Specifically, we explore the rhythmicity of gene expressions, behaviors, and functions in both immune and non-immune cells, elucidating the regulatory effects and mechanisms imposed by circadian clocks. A detailed discussion is centered on elucidating the complex functions of circadian clocks in regulating key cellular signaling pathways. We further review the circadian regulation in diverse diseases, with a focus on inflammatory diseases, cancers, and systemic diseases. By highlighting the intimate interplay between circadian clocks and diseases, especially through clock-controlled cell function, this review contributes to the development of novel disease intervention strategies. This enhanced understanding holds significant promise for the design of targeted therapies that can exploit the circadian regulation mechanisms for improved treatment efficacy.

Influence of light at night on allergic diseases: a systematic review and meta-analysis

BACKGROUND

Allergic diseases impose a significant global disease burden, however, the influence of light at night exposure on these diseases in humans has not been comprehensively assessed. We aimed to summarize available evidence considering the association between light at night exposure and major allergic diseases through a systematic review and meta-analysis.

METHODS

We completed a search of six databases, two registries, and Google Scholar from inception until December 15, 2023, and included studies that investigated the influence of artificial light at night (ALAN, high vs. low exposure), chronotype (evening vs. morning chronotype), or shift work (night vs. day shift work) on allergic disease outcomes (asthma, allergic rhinitis, and skin allergies). We performed inverse-variance random-effects meta-analyses to examine the association between the exposures (ALAN exposure, chronotype, or shiftwork) and these allergic outcomes. Stratification analyses were conducted by exposure type, disease type, participant age, and geographical location along with sensitivity analyses to assess publication bias.

RESULTS

We included 12 publications in our review. We found that exposure to light at night was associated with higher odds of allergic diseases, with the strongest association observed for ALAN exposure (OR: 1.88; 95% CI: 1.04 to 3.39), followed by evening chronotype (OR: 1.35; 95% CI: 0.98 to 1.87) and exposure to night shift work (OR: 1.33; 95% CI: 1.06 to 1.67). When analyses were stratified by disease types, light at night exposure was significantly associated with asthma (OR: 1.62; 95% CI: 1.19 to 2.20), allergic rhinitis (OR: 1.89; 95% CI: 1.60 to 2.24), and skin allergies (OR: 1.11; 95% CI: 1.09 to 1.91). We also found that the association between light at night exposure and allergic diseases was more profound in youth (OR: 1.63; 95% CI: 1.07 to 2.48) than adults (OR: 1.30; 95% CI: 1.03 to 1.63). Additionally, we observed significant geographical variations in the association between light at night exposure and allergic diseases.

CONCLUSIONS

Light at night exposure was associated with a higher prevalence of allergic diseases, both in youth and adults. More long-term epidemiological and mechanistic research is required to understand the possible interactions between light at night and allergic diseases.

Sleep and allergic diseases among young Chinese adults from the Singapore/Malaysia Cross-Sectional Genetic Epidemiology Study (SMCGES) cohort

BACKGROUND AND OBJECTIVE

Sleep disruption has been shown to affect immune function and thus influence allergic disease manifestation. The specific effects of sleep on allergic diseases, however, are less well-established; hence, in a unique population of young Chinese adults, we investigated the association between sleep and allergic disease.

METHODS

Young Chinese adults recruited from Singapore in the Singapore/Malaysia Cross-Sectional Genetic Epidemiology Study (SMCGES) were analyzed. We used the International Study of Asthma and Allergies in Childhood (ISAAC) protocol and a skin prick test to determine atopic dermatitis (AD), allergic rhinitis (AR), and asthma status. Information regarding total sleep time (TST) and sleep quality (SQ) was also obtained.

RESULTS

Of 1558 participants with a mean age of 25.0 years (SD = 7.6), 61.4% were female, and the mean total sleep time (TST) was 6.8 h (SD = 1.1). The proportions of AD, AR, and asthma were 24.5% (393/1542), 36.4% (987/1551), and 14.7% (227/1547), respectively. 59.8% (235/393) of AD cases suffered from AD-related sleep disturbances, 37.1% (209/564) of AR cases suffered from AR-related sleep disturbances, and 25.1% (57/227) of asthma cases suffered from asthma-related sleep disturbances. Only asthma cases showed a significantly lower mean TST than those without asthma (p = 0.015). Longer TST was significantly associated with lower odds of AR (OR = 0.905, 95% CI = 0.820-0.999) and asthma (OR = 0.852, 95% CI = 0.746-0.972). Linear regression analyses showed that lower TST was significantly associated with asthma (β =  - 0.18, SE = 0.076, p-value = 0.017), and AR when adjusted for AR-related sleep disturbances (β =  - 0.157, SE = 0.065, p-value = 0.016). Only sleep disturbances due to AR were significantly associated with a poorer SQ (OR = 1.962, 95% CI = 1.245-3.089).

CONCLUSIONS

We found that sleep quality, but not sleep duration was significantly poorer among AD cases, although the exact direction of influence could not be determined. In consideration of the literature coupled with our findings, we posit that TST influences allergic rhinitis rather than vice versa. Finally, the association between TST and asthma is likely mediated by asthma-related sleep disturbances, since mean TST was significantly lower among those with nighttime asthma symptoms. Future studies could consider using objective sleep measurements coupled with differential expression analysis to investigate the pathophysiology of sleep and allergic diseases.

House dust mite and Th2 cytokine-mediated epithelial barrier dysfunction attenuation by KL001 in 16-HBE cells

House dust mite (HDM) is a common aeroallergen that can disrupt the airway epithelial barrier leading to dysregulated immune response, resulting in allergic lung diseases such as asthma. Cryptochrome (CRY), a circadian clock gene, plays an important role in the regulation of metabolism, and immune response. It remains unclear whether stabilizing CRY using KL001 can attenuate HDM/Th2 cytokine-induced epithelial barrier dysfunction in 16-HBE cells. We evaluate the effect of KL001 (20 µM) pre-treatment (4 hrs) in HDM/Th2 cytokine (IL-4 or IL-13)-mediated change in epithelial barrier function. HDM and Th2 cytokine-induced changes in transepithelial electrical resistance (TEER) were determined by an xCELLigence real-time cell analyzer and delocalization of adherens junction complex (AJC: E-cadherin and β-catenin) and tight junction proteins (TJP: Occludin and Zonula occludens-1) by immunostaining and confocal microscopy. Finally, quantitative real-time PCR (qRT-PCR) and Western blotting were used to measure altered gene expression and protein abundance of the epithelial barrier function and core clock genes, respectively. HDM and Th2 cytokine treatment significantly decreased TEER associated with altered gene expression and protein abundance of the selected epithelial barrier function and circadian clock genes. However, pre-treatment with KL001 attenuated HDM and Th2 cytokine-induced epithelial barrier dysfunction as early as 12-24 hrs. KL001 pre-treatment showed attenuation of HDM and Th2 cytokine-induced alteration in the localization and gene expression of AJP and TJP (Cdh1, Ocln, and Zo1) and core clock genes (Clock, Arntl/Bmal1, Cry1/2, Per1/2, Nr1d1/Rev-erbα, and Nfil3). We demonstrate, for the first time, the protective role of KL001 in HDM and Th2 cytokine-mediated epithelial barrier dysfunction.

Circadian clock disruption in autoimmune thyroiditis

Objective

A vicious cycle between circadian disruption and escalating immune responses has been described in diverse inflammatory disease. The current study aimed to explore the role of circadian clock disruption in autoimmune thyroiditis (AIT).

Methods

Thirty AIT patients and 30 controls were enrolled and biopsied for thyroid tissues. Alterations of core clock genes expression in AIT thyroid tissues, and its association with serum and tissue inflammatory biomarkers were assessed. For animal studies, C57BL/6J mice administered with porcine thyroglobulin or PBS (as control) combined with adjuvants were sacrificed at four time points to investigate the circadian characteristic of experimental autoimmune thyroiditis (EAT). Light shift (LS) conditions were used to explore the influence of external circadian disturbance on EAT.

Results

The expression of clock genes BMAL1 and PER2 was significantly reduced in thyroid tissues from AIT patients and was negatively correlated to levels of thyroid peroxidase antibodies. In mouse models, diurnal fluctuations of proinflammatory cytokines were demonstrated, and further exposing mice to LS led to overproduction of TNF-α, IFN-γ, and anti-thyroglobulin antibodies. Circadian analysis revealed significant oscillations of Bmal1, Clock, Per2, Cry1, Ror, and Rev-erb, which was broadly disturbed in EAT, LS, and EAT + LS groups.

Conclusions

This study demonstrates that expression pattern of clock genes was disrupted in AIT thyroid, and chronic circadian disruption may aggravate the inflammatory responses in AIT. Whether maintaining a regular circadian rhythm can alleviate autoimmune thyroid diseases warrants further research.

PPARG stimulation restored lung mRNA expression of core clock, inflammation- and metabolism-related genes disrupted by reversed feeding in male mice

The circadian rhythm system regulates lung function as well as local and systemic inflammations. The alteration of this rhythm might be induced by a change in the eating rhythm. Peroxisome proliferator-activated receptor gamma (PPARG) is a key molecule involved in circadian rhythm regulation, lung functions, and metabolic processes. We described the effect of the PPARG agonist pioglitazone (PZ) on the diurnal mRNA expression profile of core circadian clock genes (Arntl, Clock, Nr1d1, Cry1, Cry2, Per1, and Per2) and metabolism- and inflammation-related genes (Nfe2l2, Pparg, Rela, and Cxcl5) in the male murine lung disrupted by reversed feeding (RF). In mice, RF disrupted the diurnal expression pattern of core clock genes. It decreased Nfe2l2 and Pparg and increased Rela and Cxcl5 expression in lung tissue. There were elevated levels of IL-6, TNF-alpha, total cells, macrophages, and lymphocyte counts in bronchoalveolar lavage (BAL) with a significant increase in vascular congestion and cellular infiltrates in male mouse lung tissue. Administration of PZ regained the diurnal clock gene expression, increased Nfe2l2 and Pparg expression, and reduced Rela, Cxcl5 expression and IL-6, TNF-alpha, and cellularity in BAL. PZ administration at 7 p.m. was more efficient than at 7 a.m.

Pathogenesis of allergic diseases and implications for therapeutic interventions

Allergic diseases such as allergic rhinitis (AR), allergic asthma (AAS), atopic dermatitis (AD), food allergy (FA), and eczema are systemic diseases caused by an impaired immune system. Accompanied by high recurrence rates, the steadily rising incidence rates of these diseases are attracting increasing attention. The pathogenesis of allergic diseases is complex and involves many factors, including maternal-fetal environment, living environment, genetics, epigenetics, and the body's immune status. The pathogenesis of allergic diseases exhibits a marked heterogeneity, with phenotype and endotype defining visible features and associated molecular mechanisms, respectively. With the rapid development of immunology, molecular biology, and biotechnology, many new biological drugs have been designed for the treatment of allergic diseases, including anti-immunoglobulin E (IgE), anti-interleukin (IL)-5, and anti-thymic stromal lymphopoietin (TSLP)/IL-4, to control symptoms. For doctors and scientists, it is becoming more and more important to understand the influencing factors, pathogenesis, and treatment progress of allergic diseases. This review aimed to assess the epidemiology, pathogenesis, and therapeutic interventions of allergic diseases, including AR, AAS, AD, and FA. We hope to help doctors and scientists understand allergic diseases systematically.

Allergic rhinitis and sleep disorders in children - coexistence and reciprocal interactions

OBJECTIVE

To review, critically analyze and synthesize knowledge from the international literature regarding the association between allergic rhinitis (AR) and sleep disorders, the impact of AR treatment on children's sleep, and lay the foundation for future research on this topic.

SOURCE OF DATA

A literature search using PubMed database including original and review articles, systematic reviews and meta-analyses using keywords related to AR, sleep disorders and sleep-disordered breathing.

SYNTHESIS OF DATA

Sleep is fundamental to health, and its assessment and control of conditions that trigger or aggravate disturbances are of the uttermost importance. Allergic rhinitis (AR) is common in children and may interfere with both their quality of life and quality of sleep. It has emerged as one of the most important risk factors for habitual snoring in children and appeared to increase the risk of Obstructive Sleep Apnea (OSA), with AR severity exhibiting a significant and independent association with pediatric OSA severity. However, in some studies, those associations between AR and OSA in children are not very consistent.

CONCLUSIONS

A substantial level of controversy exists regarding the interactions between AR and OSA in children. Notwithstanding, identifying and treating AR in clinical settings is probably an important step toward improving symptoms and preventing deterioration of sleep quality in children and may improve the severity of underlying OSA. Considering the high prevalence, morbidity, economic and social implications of both AR and sleep problems, it is crucial that healthcare providers improve their understanding of the relationships between those conditions among children.

Time will tell about mast cells: Circadian control of mast cell activation

Mast cell activation is crucial to the development of allergic disease. New studies have shown that both IgE-dependent and -independent mast cell activation is temporally regulated by the circadian clock, a time-of-day-keeping system that consists of transcriptional-translational feedback loops of several clock genes. For instance, the core clock gene Clock controls the expression of the high-affinity IgE receptor (FcεRI) and interleukin-33 (IL-33) receptor ST2 on mast cells in a time-dependent manner. As a result, the threshold of IgE-dependent or IL-33-dependent mast cell activation differs between daytime and nighttime. This mechanism may underlie the observation that allergic disease shows a marked day-night change in symptom occurrence and severity. Consistent with this novel concept, environmental and lifestyle factors that disturb the normal rhythmicity of the circadian clock, such as irregular eating habits, can lead to the loss of circadian control of mast cell activation. Consequently, the degree of mast cell activation becomes equally strong at all times of day, which might clinically result in worsening allergic symptoms. Therefore, further understanding of the association between mast cell activation and the circadian clock is important to better manage patients with allergic disease in the real world, characterized by a "24/7 society" filled with environmental and lifestyle factors that disturb the circadian clock rhythmicity.

Tight Junctions, the Epithelial Barrier, and Toll-like Receptor-4 During Lung Injury

Lung epithelium is constantly exposed to the environment and is critically important for the orchestration of initial responses to infectious organisms, toxins, and allergic stimuli, and maintenance of normal gaseous exchange and pulmonary function. The integrity of lung epithelium, fluid balance, and transport of molecules is dictated by the tight junctions (TJs). The TJs are formed between adjacent cells. We have focused on the topic of the TJ structure and function in lung epithelial cells. This review includes a summary of the last twenty years of literature reports published on the disrupted TJs and epithelial barrier in various lung conditions and expression and regulation of specific TJ proteins against pathogenic stimuli. We discuss the molecular signaling and crosstalk among signaling pathways that control the TJ structure and function. The Toll-like receptor-4 (TLR4) recognizes the pathogen- and damage-associated molecular patterns released during lung injury and inflammation and coordinates cellular responses. The molecular aspects of TLR4 signaling in the context of TJs or the epithelial barrier are not fully known. We describe the current knowledge and possible networking of the TLR4-signaling with cellular and molecular mechanisms of TJs, lung epithelial barrier function, and resistance to treatment strategies.

The Natural Janus Kinase Inhibitor Agerarin Downregulates Interleukin-4-Induced PER2 Expression in HaCaT Keratinocytes

The circadian clock system is closely associated with inflammatory responses. Dysregulation of the circadian clock genes in the skin impairs the skin barrier function and affects the pathophysiology of atopic dermatitis. Interleukin 4 (IL-4) is a proinflammatory cytokine derived from T-helper type 2 cells; it plays a critical role in the pathogenesis of atopic dermatitis. Agerarin (6,7-dimethoxy-2,2-dimethyl-2H-chromene) is a natural JAK1/2/3 inhibitor isolated from Ageratum houstonianum that has a protective effect on the epidermal skin barrier. However, it remains unclear whether agerarin affects the circadian clock system. The aim of this study is to investigate the effect of agerarin on IL-4-induced PER2 gene expression in human keratinocytes through reverse transcription (RT)-PCR, quantitative real-time PCR (qPCR), immunoblotting, immunofluorescence microscopic analysis, and real-time bioluminescence analysis. We found that agerarin reduced IL-4-induced PER2 mRNA expression by suppressing the JAK-STAT3 pathway. In addition, real-time bioluminescence analysis in PER2:luc2p promoter-reporter cells revealed that agerarin restored the oscillatory rhythmicity of PER2 promoter activity altered by IL-4. These findings suggest that agerarin may be useful as a cosmeceutical agent against inflammatory skin conditions associated with disrupted circadian rhythms, such as atopic dermatitis.

Circadian rhythm disruption exacerbates Th2-like immune response in murine allergic airway inflammation

BACKGROUND

Chronic jet lag (CJL)-induced circadian rhythm disruption (CRD) is positively correlated with an increased risk of allergic diseases. However, little is known about the mechanism involved in allergic rhinitis (AR).

METHODS

Aberrant light/dark cycles-induced CRD mice were randomly divided into negative control (NC) group, AR group, CRD+NC group, and CRD+AR group (n = 8/group). After ovalbumin (OVA) challenge, nasal symptom scores were recorded. The expression of Occludin and ZO-1 in both nasal mucosa and lung tissues was detected by reverse transcription-quantitative polymerase chain reaction (RT-PCR) and immunohistochemical staining. The level of OVA-specific immunoglobulin E (sIgE) and T-helper (Th)-related cytokines in the plasma was measured by enzyme-linked immunosorbent assay (ELISA), and the proportion of Th1, Th2, Th17, and regulatory T cell (Treg) in splenocytes was evaluated by flow cytometry.

RESULTS

The nasal symptom score in the CRD+AR group was significantly higher than those in the AR group with respect to eosinophil infiltration, mast cell degranulation, and goblet cell hyperplasia. The expression of ZO-1 and Occludin in the nasal mucosa and lung tissues in the CRD+AR group were significantly lower than those in the AR group. Furthermore, Th2 and Th17 cell counts from splenocytes and OVA-sIgE, interleukin 4 (IL-4), IL-6, IL-13, and IL-17A levels in plasma were significantly increased in the CRD+AR group than in the AR group, whereas Th1 and Treg cell count and interferon γ (IFN-γ) level were significantly decreased in the CRD+AR group.

CONCLUSION

CRD experimentally mimicked CJL in human activities, could exacerbate local and systemic allergic reactions in AR mice, partially through decreasing Occludin and ZO-1 level in the respiratory mucosa and increasing Th2-like immune response in splenocytes.

Association of delayed chronotype with allergic diseases in primary school children

To investigate the associations of sleep midpoint for both weekdays and weekends, and chronotype, with allergic diseases, specifically asthma, allergic rhinitis, and eczema in primary school children. In this cross-sectional study, we evaluated 10409 children between 7 and 12 years of age (mean 9.21 ± 1.51 years; male 52.2%). Each allergic disease was defined as children with both diagnosed disease and current symptoms, and the reference group was described as children without any allergic symptoms. Sleep durations and mid-sleep times were calculated by reported sleep timing. Chronotype was determined by mid-sleep time on free days corrected for oversleeping. Children with allergies have shorter sleep duration and later sleep preferences. Late weekly sleep midpoints were associated with higher odds of allergies, and the odds were even higher for later weekday midpoints than their weekend counterparts. Regarding chronotype, the more evening chronotype, the higher the odds of allergic rhinitis and eczema. Additionally, effect of weekday late sleep midpoint on allergies was stronger as the participants who slept less (asthma: aOR,1.62, 95 CI%,1.25-2.10, p < .001; allergic rhinitis: aOR,2.12, 95 CI%,1.68-2.67, p < .001; eczema: aOR, 1.94, 95 CI%,1.52-2.48, p < .001). Further, the associations of chronotype with allergic rhinitis were confounded by second-hand smoking exposure. Our study, which finds an association between chronotype and the odds of three allergic diseases, hopes to improve sleep health awareness, especially in the particular population with allergic diseases, and describes the importance of evaluating modifiable behavioral factors, such as sleep habits, as a plausible factor for the prevention and treatment of allergic diseases.

Temporal Modulation of Drug Desensitization Procedures

Drug hypersensitivity reactions are an unavoidable clinical consequence of the presence of new therapeutic agents. These adverse reactions concern patients afflicted with infectious diseases (e.g., hypersensitivity to antibiotics), and with non-infectious chronic diseases, such as in cancers, diabetes or cystic fibrosis treatments, and may occur at the first drug administration or after repeated exposures. Here we revise recent key studies on the mechanisms underlying the desensitization protocols, and propose an additional temporal regulation layer that is based on the circadian control of the signaling pathway involved and on the modulation of the memory effects established by the desensitization procedures.

Using Microbiome-Based Approaches to Deprogram Chronic Disorders and Extend the Healthspan following Adverse Childhood Experiences

Adverse childhood experiences (ACEs), which can include child trafficking, are known to program children for disrupted biological cycles, premature aging, microbiome dysbiosis, immune-inflammatory misregulation, and chronic disease multimorbidity. To date, the microbiome has not been a major focus of deprogramming efforts despite its emerging role in every aspect of ACE-related dysbiosis and dysfunction. This article examines: (1) the utility of incorporating microorganism-based, anti-aging approaches to combat ACE-programmed chronic diseases (also known as noncommunicable diseases and conditions, NCDs) and (2) microbiome regulation of core systems biology cycles that affect NCD comorbid risk. In this review, microbiota influence over three key cyclic rhythms (circadian cycles, the sleep cycle, and the lifespan/longevity cycle) as well as tissue inflammation and oxidative stress are discussed as an opportunity to deprogram ACE-driven chronic disorders. Microbiota, particularly those in the gut, have been shown to affect host–microbe interactions regulating the circadian clock, sleep quality, as well as immune function/senescence, and regulation of tissue inflammation. The microimmunosome is one of several systems biology targets of gut microbiota regulation. Furthermore, correcting misregulated inflammation and increased oxidative stress is key to protecting telomere length and lifespan/longevity and extending what has become known as the healthspan. This review article concludes that to reverse the tragedy of ACE-programmed NCDs and premature aging, managing the human holobiont microbiome should become a routine part of healthcare and preventative medicine across the life course.

Potential effects of shift work on skin autoimmune diseases

Shift work is associated with systemic chronic inflammation, impaired host and tumor defense and dysregulated immune responses to harmless antigens such as allergens or auto-antigens. Thus, shift workers are at higher risk to develop a systemic autoimmune disease and circadian disruption with sleep impairment seem to be the key underlying mechanisms. Presumably, disturbances of the sleep-wake cycle also drive skin-specific autoimmune diseases, but epidemiological and experimental evidence so far is scarce. This review summarizes the effects of shift work, circadian misalignment, poor sleep, and the effect of potential hormonal mediators such as stress mediators or melatonin on skin barrier functions and on innate and adaptive skin immunity. Human studies as well as animal models were considered. We will also address advantages and potential pitfalls in animal models of shift work, and possible confounders that could drive skin autoimmune diseases in shift workers such as adverse lifestyle habits and psychosocial influences. Finally, we will outline feasible countermeasures that may reduce the risk of systemic and skin autoimmunity in shift workers, as well as treatment options and highlight outstanding questions that should be addressed in future studies.

Transcriptome analysis reveals intrinsic pro-inflammatory signaling in healthy African American skin

Differences in morphology and physiology of darkly pigmented compared to lightly pigmented skin are well recognized. There are also disparities in prevalence and clinical features for many inflammatory skin diseases including atopic dermatitis and psoriasis; however, the underlying mechanisms are largely unknown. We compared the baseline gene expression in full thickness skin biopsies from healthy individuals self-reporting as African American (AA) or White Non-Hispanic (WNH). Extensively validated RNA-Seq analysis identified 570 differentially expressed genes (DEG) in AA skin including immunoglobulins and their receptors such as FCER1G; pro-inflammatory genes such as TNFα, IL-32; EDC (epidermal differentiation cluster) and keratin genes. DEGs were functionally enriched for inflammatory responses, keratinization, cornified envelope formation. RNA-seq analysis of 3D human skin equivalents (HSE) made from AA and WNH primary keratinocytes revealed 360 DEGs (some shared with skin) which were enriched by similar functions. AA HSE appeared more responsive to TNFα pro-inflammatory effects. Finally, AA-specific DEGs in skin and HSE significantly overlapped with molecular signatures of skin in AD and psoriasis patients. Overall, these findings suggest the existence of intrinsic pro-inflammatory circuits in AA keratinocytes/skin that may account for disease disparities and will help to build a foundation for the development of targeted skin disease prevention.

Circadian disruption and human health

Circadian disruption is pervasive and can occur at multiple organizational levels, contributing to poor health outcomes at individual and population levels. Evidence points to a bidirectional relationship, in that circadian disruption increases disease severity and many diseases can disrupt circadian rhythms. Importantly, circadian disruption can increase the risk for the expression and development of neurologic, psychiatric, cardiometabolic, and immune disorders. Thus, harnessing the rich findings from preclinical and translational research in circadian biology to enhance health via circadian-based approaches represents a unique opportunity for personalized/precision medicine and overall societal well-being. In this Review, we discuss the implications of circadian disruption for human health using a bench-to-bedside approach. Evidence from preclinical and translational science is applied to a clinical and population-based approach. Given the broad implications of circadian regulation for human health, this Review focuses its discussion on selected examples in neurologic, psychiatric, metabolic, cardiovascular, allergic, and immunologic disorders that highlight the interrelatedness between circadian disruption and human disease and the potential of circadian-based interventions, such as bright light therapy and exogenous melatonin, as well as chronotherapy to improve and/or modify disease outcomes.

Disrupted Expression of Circadian Clock Genes in Patients with Bronchial Asthma

Purpose

Circadian clock is synchronized to the 24-hour day by the daily light–dark cycle and proper function of circadian rhythm is essential for many physiological processes. Disruption of circadian rhythm can affect disease processes and influence disease severity, treatment responses, and even survivorship. In this retrospective case-controlled study, we tried to explore whether expression of circadian clock genes was disturbed in patients with bronchial asthma.

Patients and Methods

We performed real-time quantitative reverse transcriptase-polymerase chain reactions to examine the expression of the nine core circadian clock genes (BMAL1, CK1ε, CLOCK, CRY1, CRY2, PER1, PER2, PER3, and TIM) in total leukocytes of peripheral blood collected at chest clinics from 120 patients with asthma and 60 health individuals.

Results

Expression levels of the nine circadian clock genes were significantly different between patients and healthy individuals, but not associated with the asthma control status. We also noted the difference of PER3 expression in asthmatic patients with and without nocturnal symptoms. In well-controlled asthmatics, expression of BMAL1, CK1ε, CLOCK, CRY1, CRY2, and PER1 was significantly lower in patients with nocturnal symptoms than those without nocturnal symptoms. However, in not well-controlled asthmatics, expression of only BMAL1, CK1ε, PER1, and PER2 was significantly different between patients with and without nocturnal symptoms. Binary logistic regression analysis selected BMAL1, CKIε, PER3, and TIM as independent factors for bronchial asthma and ROC curves showed the combined expression of these four genes enhanced the capability of predicting asthma (AUC=0.924; 95% CI=0.875–0.958; P<0.001).

Conclusion

Our results showed altered expression of circadian clock genes in patients with bronchial asthma and down-regulated PER3 in patients with nocturnal symptoms. Altered expression of circadian clock genes was also observed in asthmatics with or without nocturnal symptoms in well- or not well-controlled subgroups. Combined expression of BMAL1, CKIε, PER3, and TIM could be a potential predictor for bronchial asthma.