Circadian rhythms in psoriasis and the potential of chronotherapy in psoriasis management

Melatonin Attenuates Imiquimod-Induced Psoriasis-Like Inflammation and Restores the Th17/Treg Immune Balance

Psoriasis is a common immune-mediated skin disease characterized by abnormally reactive inflammation and epidermal hyperplasia. Previous studies have shown melatonin (MLT) has powerful anti-inflammatory effects. The mechanisms that MLT regulates psoriasis-associated skin inflammation remain unclear. Here, in imiquimod-induced psoriasis-like mice, MLT supplementation reduced skin inflammation and corrected the Th17/Treg cell imbalance. Network pharmacology and proteome sequencing analyses revealed that MLT attenuates the inflammatory response in the skin of psoriatic mice by inhibiting the PI3K/Akt signaling pathway. Overall, the data suggest that MLT has a protective effect against psoriasis-like inflammation.

The skin circadian clock gene F3 as a potential marker for psoriasis severity and its bidirectional relationship with IL-17 signaling in keratinocytes

OBJECTIVE

Psoriasis is an immune-mediated skin disease where the IL-17 signaling pathway plays a crucial role in its development. Chronic circadian rhythm disorder in psoriasis pathogenesis is gaining more attention. The relationship between IL and 17 signaling pathway and skin clock genes remains poorly understood.

METHODS

GSE121212 with psoriatic lesion and healthy controls was used as the exploration cohort for searching analysis. Datasets GSE54456, GSE13355, GSE14905, GSE117239, GSE51440, and GSE137218 were applied to validation analysis. Single-cell RNA sequencing (scRNA-seq) dataset GSE173706 was used to explore the F3 expression and related pathway activities in single-cell levels. Through intersecting with high-expression DEGs, F3 was selected as the signature skin circadian gene in psoriasis for further investigation. Functional analyses, including correlation analyses, prediction of transcription factors, protein-protein interaction, and single gene GSEA to explore the potential roles of F3. ssGSEA algorithm was performed to uncover the immune-related characteristics of psoriasis. We further explored F3 expression in the specific cell population in scRNA-seq dataset, besides this, AUCell analysis was performed to explore the pathway activities and the results were further compared between the specific cell cluster. Immunohistochemistry experiment, RT-qPCR was used to validate the location and expression of F3, small interfering RNA (siRNA) transfection experiment in HaCaT, and transcriptome sequencing analysis were applied to explore the potential function of F3.

RESULTS

F3 was significantly down-regulated in psoriasis and interacted with IL-17 signaling pathway. Low expression of F3 could upregulate the receptor of JAK-STAT signaling, thereby promoting keratinocyte inflammation.

CONCLUSION

Our research revealed a bidirectional link between the skin circadian gene F3 and the IL-17 signaling pathway in psoriasis, suggesting that F3 may interact with the IL-17 pathway by activating JAK-STAT within keratinocytes and inducing abnormal intracellular inflammation.

Circadian clock gene disruption in white blood cells of patients with celiac disease

Clock gene disruption has been reported in inflammatory and autoimmune diseases. Specifically, it has been shown that clock gene expression is down-regulated in intestinal tissue and peripheral blood mononuclear cells of patients with inflammatory bowel disease (IBD). We aimed to determine the systemic expression of the circadian clock genes in newly diagnosed untreated, young patients with celiac disease (CeD). We prospectively enrolled patients younger than 20 years old who underwent diagnostic endoscopic procedures either for CeD diagnosis or due to other gastrointestinal complaints, at the pediatric and adult gastroenterology units, the Tel Aviv Sourasky Medical Center from 8/2016-8/2022. Demographic data, anthropometric parameters, and endoscopic macroscopic and microscopic findings were obtained. Blood samples were obtained to determine tissue transglutaminase (tTG) and core clock gene (CLOCK, BMAL1, PER1, PER2, CRY1, CRY2) expression in white blood cells (WBC). Thirty individuals were analyzed (18 with newly diagnosed CeD and 12 controls). Expression of the clock genes CLOCK, BMAL1, CRY2, PER1 and PER2 was significantly reduced in CeD patients compared to controls, while CRY1 did not differ between the groups. In conclusion, newly diagnosed, untreated, young patients with CeD have reduced clock gene expression in WBC compared to controls. These results suggest that, in CeD, the inflammatory response is associated with systemic disruption of clock gene expression, as is manifested in other inflammatory and autoimmune diseases. CLINICALTRIALS.GOV IDENTIFIER: NCT03662646.

Differential Photosensitivity of Fibroblasts Obtained from Normal Skin and Hypertrophic Scar Tissues

It is unclear whether normal human skin tissue or abnormal scarring are photoreceptive. Therefore, this study investigated photosensitivity in normal skin tissue and hypertrophic scars. The expression of opsins, which are photoreceptor proteins, in normal dermal fibroblasts (NDFs) and hypertrophic scar fibroblasts (HSFs) was examined. After exposure to blue light (BL), changes in the expression levels of αSMA and clock-related genes, specifically PER2 and BMAL1, were examined in both fibroblast types. Opsins were expressed in both fibroblast types, with OPN3 exhibiting the highest expression levels. After peripheral circadian rhythm disruption, BL induced rhythm formation in NDFs. In contrast, although HSFs showed changes in clock-related gene expression levels, no distinct rhythm formation was observed. The expression level of αSMA was significantly higher in HSFs and decreased to the same level as that in NDFs upon BL exposure. When OPN3 knocked-down HSFs were exposed to BL, the reduction in αSMA expression was inhibited. This study showed that BL exposure directly triggers peripheral circadian synchronization in NDFs but not in HSFs. OPN3-mediated BL exposure inhibited HSFs. Although the current results did not elucidate the relationship between peripheral circadian rhythms and hypertrophic scars, they show that BL can be applied for the prevention and treatment of hypertrophic scars and keloids.

Liangxue Jiedu formula improves imiquimod-induced psoriasiform dermatitis with circadian desynchrony by regulating Th17 cell differentiation based on network pharmacological analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Liangxue Jiedu formula (LXJDF) is an effective traditional Chinese medicine (TCM) formula for treating psoriasis of blood-heat syndrome and has been used in clinics for decades.

AIM OF THE STUDY

This study aimed to discover the mechanism of LXJDF in psoriasis and the circadian clock by network pharmacology and experimental studies.

MATERIALS AND METHODS

The compounds of LXJDF were obtained from the TCMSP and BATMAN-TCM databases. The genes related to psoriasis and circadian rhythm/clock were identified by the OMIM and GeneCards databases. Then, target genes were integrated by Venn and analyzed by the String, CytoNCA, DAVID (GO and KEGG) databases, and the network was constructed using Cytoscape. Mice were raised under light disturbance for fourteen days. On the eighth day, mouse dorsal skin was shaved and smeared with 62.5 mg 5% imiquimod at 8:00 (ZT0) for six successive days. Mice were randomly divided into the model, LXJDF-H (49.2 g/kg·bw), LXJDF-L (24.6 g/kg·bw), and positive drug (dexamethasone) groups. Other mice were smeared with Vaseline under the normal light cycle as the control. The drug of each group was administered at 10:00 (ZT2) and 22:00 (ZT14). The skin lesions were observed, and PASI was scored daily. HE and immunofluorescence were used to measure pathological morphology. Th17 cytokines in serum and skin were measured by flow cytometry and qPCR. Circadian clock gene and protein expression levels were determined by qPCR and Western blotting.

RESULTS

We found 34 potential targets of LXJDF in the treatment of psoriasis and circadian rhythm and confirmed their importance by topology analysis. KEGG pathway analysis revealed that the two major pathways were Th17 cell differentiation and the HIF-1 signaling pathway. At ZT2 and ZT14, LXJDF improved IMQ-induced light disturbance mouse skin lesions, including alleviating scales, erythema, and infiltration, reducing PASI, and inhibiting keratinocyte hyperproliferation and parakeratosis. LXJDF reduced IL-17A, IL-17F, TNF-α, and IL-6 in serum at ZT2 and increased IL-10 at ZT2 and ZT14. LXJDF downregulated the expression of IL-17A and IL-17F in skin. At ZT2, LXJDF significantly upregulated CLOCK and REV-ERBα expression and downregulated HIF-1α expression. At ZT14, LXJDF decreased HIF-1α and RORγt expression and significantly increased REV-ERBα expression.

CONCLUSION

LXJDF improves psoriasis dermatitis with circadian rhythm disorders by regulating Th17 cell differentiation.

Investigating Chronotype and Sleep Quality in Psoriatic Patients: Results from an Observational, Web-Based Survey

BACKGROUND

Psoriasis is an inflammatory disease for which the implications and repercussions go far beyond the skin. Psoriasis patients suffer not only due to its skin manifestations and related symptoms but also because of comorbidities and a huge emotional impact.

OBJECTIVE

The objective of this study was to investigate chronotype and sleep quality in a group of Italian psoriatic patients.

MATERIALS AND METHODS

An observational, cross-sectional, web-based study was set up by the Dermatology and Clinical Medicine Sections of the Department of Medical Sciences, University of Ferrara, Italy. The web questionnaire was sent to an email list of an Italian association of psoriatic patients with the aim of recording their main demographic, social, historical, and clinical data. The survey included two questionnaires: the Morningness-Eveningness Questionnaire (MEQ) and the Pittsburg Sleep Quality Index (PSQI).

RESULTS

Two hundred and forty-three psoriatic patients (mean age 52.9 ± 12.8 yrs., 32.5% males and 67.5% females) filled out the questionnaire. A good 63.8% of them were affected with psoriasis for more than 10 years, 25.9% reported having a diffuse psoriasis, and 66.7% were on treatment at the time they completed the questionnaire. With reference to chronotype, the mean MEQ score was 55.2 ± 10.7; furthermore, 44% of the patients were "morning-oriented types", M-types, or "larks", 44.5% were "intermediate-types" or I-types, and 11.5% were "evening-oriented types", E-types, or "owls". No correlations were found between chronotype and psoriasis extension. Based on the PSQI results, 72.8% of the study population was judged to have a low sleep quality. Sleep disturbance was significantly related to female sex, living alone, and the presence of comorbidities.

CONCLUSIONS

Sleep disturbance is very common in psoriatic patients, especially in those with comorbidities, in females, and in patients who live alone. The chronotype in psoriatic patients does not appear different when compared to the general population, nor does it seem to have any link with psoriasis severity.

Unleashing the pathological imprinting of cancer in autoimmunity: Is ZEB1 the answer?

The intriguing scientific relationship between autoimmunity and cancer immunology have been traditionally indulged to throw spotlight on novel pathological targets. Understandably, these "slowly killing" diseases are on the opposite ends of the immune spectrum. However, the immune regulatory mechanisms between autoimmunity and cancer are not always contradictory and sometimes mirror each other based on disease stage, location, and timepoint. Moreover, the blockade of immune checkpoint molecules or signalling pathways that unleashes the immune response against cancer is being leveraged to preserve self-tolerance and treat many autoimmune disorders. Therefore, understanding the common crucial factors involved in cancer is of paramount importance to paint the autoimmune disease spectrum and validate novel drug candidates. In the current review, we will broadly describe how ZEB1, or Zinc-finger E-box Binding Homeobox 1, reinforces immune exhaustion in cancer or contributes to loss of self-tolerance in auto-immune conditions. We made an effort to exchange information about the molecular pathways and pathological responses (immune regulation, cell proliferation, senescence, autophagy, hypoxia, and circadian rhythm) that can be regulated by ZEB1 in the context of autoimmunity. This will help untwine the intricate and closely postured pathogenesis of ZEB1, that is less explored from the perspective of autoimmunity than its counterpart, cancer. This review will further consider several approaches for targeting ZEB1 in autoimmunity.

Transcriptomic profiling of TLR-7-mediated immune-challenge in zebrafish embryos in the presence and absence of glucocorticoid-induced immunosuppression

Although numerous studies imply a correlation between chemical contamination and an impaired immunocompetence of wildlife populations, the assessment of immunomodulatory modes of action is currently not covered in the regulatory requirements for the approval of new substances. This is not least due to the complexity of the immune system and a lack of standardised methods and validated biomarkers. To tackle this issue, in this study, the transcriptomic profiles of zebrafish embryos were analysed in response to the immunosuppressive compound clobetasol propionate, a synthetic glucocorticoid, and/or the immunostimulatory compound imiquimod (IMQ), a TLR-7 agonist. Using IMQ, known for its potential to induce psoriasis-like effects in mice and human, this study additionally aimed at evaluating the usability of the zebrafish embryo model as an alternative and 3R conform system for the IMQ-induced psoriasis mouse model. Our study substantiates the suitability of previously proposed genes as possible biomarkers for immunotoxicity, such as socs3, nfkbia, anxa1c, fkbp5 and irg1l. Likewise, however, our findings indicate that these genes may be less suitable to distinguish a suppressive from stimulating fashion of action. In contrast, based on a differential regulation in opposite direction in response to both compounds, krt17, rtn4a, and1, smhyc1 and gmpr were identified as potential novel biomarkers with said power to differentiate. Observed IMQ-induced alterations in the expression of genes previously associated with the pathogenesis of psoriasis such as krt17, nfkbia, parp1, pparg, nfil3-6, per2, stat4, klf2, rtn4a, anxa1c and nr1d2 indicate the inducibility of psoriatic effects in the zebrafish embryo. Our work contributes to the establishment of an approach for a 3R-compliant investigation of immunotoxic mechanisms of action in aquatic vertebrates. The validated and newly identified biomarker candidates of specific immunotoxic effects can be used in future studies in the context of environmental hazard assessment of substances or also for human-relevant immunotoxicological questions.

The Associations of Chronotype and Shift Work With Rheumatoid Arthritis

The circadian clock regulates multiple aspects of human physiology including immunity. People have a circadian preference termed chronotype. Those with an evening preference may be better suited to shift work, but also carry higher risk of adverse health. Shift work leads to misalignment of circadian rhythms and is associated with increased risk of inflammatory disease such as asthma and cancer. Here, we investigate the association between chronotype, shift work, and rheumatoid arthritis (RA). The associations between exposures of shift work and chronotype on risk of RA were studied in up to 444,210 U.K. Biobank participants. Multivariable logistic regression models were adjusted for covariates: age, sex, ethnicity, alcohol intake, smoking history, Townsend Deprivation Index (TDI), sleep duration, length of working week, and body mass index (BMI). After adjusting for covariates, individuals with a morning chronotype had lower odds of having rheumatoid arthritis (RA; odds ratio [OR]: 0.93, 95% confidence interval [CI]: 0.88-0.99) when compared to intermediate chronotypes. The association between morning chronotype and RA persisted with a more stringent RA case definition (covariate-adjusted OR: 0.89, 95% CI: 0.81-0.97). When adjusted for age, sex, ethnicity, and TDI, shift workers had higher odds of RA (OR: 1.22, 95% CI: 1.1-1.36) compared to day workers that attenuated to the null after further covariate adjustment (OR: 1.1, 95% CI: 0.98-1.22). Morning chronotypes working permanent night shifts had significantly higher odds of RA compared to day workers (OR: 1.89, 95% CI: 1.19-2.99). These data point to a role for circadian rhythms in RA pathogenesis. Further studies are required to determine the mechanisms underlying this association and understand the potential impact of shift work on chronic inflammatory disease and its mediating factors.

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.

The Yin and Yang dualistic features of autophagy in thermal burn wound healing

Burn healing should be regarded as a dynamic process consisting of two main, interrelated phases: (a) the inflammatory phase when neutrophils and monocytes infiltrate the injury site, through localized vasodilation and fluid extravasation, and (b) the proliferative-remodeling phase, which represents a key event in wound healing. In the skin, both canonical autophagy (induced by starvation, oxidative stress, and environmental aggressions) and non-canonical or selective autophagy have evolved to play a discrete, but, essential, “housekeeping” role, for homeostasis, immune tolerance, and survival. Experimental data supporting the pro-survival roles of autophagy, highlighting its Yang, luminous and positive feature of this complex but insufficient explored molecular pathway, have been reported. Autophagic cell death describes an “excessive” degradation of important cellular components that are necessary for normal cell function. This deadly molecular mechanism brings to light the darker, concealed, Yin feature of autophagy. Autophagy seems to perform dual, conflicting roles in the angiogenesis context, revealing once again, its Yin–Yang features. Autophagy with its Yin–Yang features remains the shadow player, able to decide quietly whether the cell survives or dies.