Downregulation of CXCR-2 but not CXCR-1 expression by human keratinocytes by UVB

Chronic Inflammation as the Underlying Mechanism of the Development of Lung Diseases in Psoriasis: A Systematic Review

Psoriasis is a systemic inflammatory disease caused by dysfunctional interactions between the innate and adaptive immune responses. The systemic inflammation in psoriasis may be associated with the development of comorbidities, including lung diseases. In this review, we aimed to provide a summary of the evidence regarding the prevalence of lung diseases in patients with psoriasis and the potential underlying mechanisms. Twenty-three articles published between March 2010 and June 2021 were selected from 195 initially identified records. The findings are discussed in terms of the prevalence of asthma, chronic obstructive pulmonary disease, interstitial lung disease, obstructive sleep apnea, pulmonary hypertension, and sarcoidosis in psoriasis. A higher prevalence of lung diseases in psoriasis has been confirmed in asthma, chronic obstructive pulmonary disease, obstructive sleep apnea, and pulmonary hypertension. These conditions are important as they are previously unrecognized causes of morbidity and mortality in psoriasis. The development of lung diseases in patients with psoriasis can be explained by several mechanisms, including common risk factors, shared immune and molecular characteristics associated with chronic inflammation, as well as other mechanisms. Understanding the prevalence of lung diseases in psoriasis and their underlying mechanisms can help implement appropriate preventative and therapeutic strategies to address respiratory diseases in patients with psoriasis.

Interleukin-8 in Melanoma Pathogenesis, Prognosis and Therapy-An Integrated View into Other Neoplasms and Chemokine Networks

Cutaneous melanoma accounts for only about 7% of skin cancers but is causing almost 90% of deaths. Melanoma cells have a distinct repertoire of mutations from other cancers, a high plasticity and degree of mimicry toward vascular phenotype, stemness markers, versatility in evading and suppress host immune control. They exert a significant influence on immune, endothelial and various stromal cells which form tumor microenvironment. The metastatic stage, the leading cause of mortality in this neoplasm, is the outcome of a complex, still poorly understood, cross-talk between tumor and other cell phenotypes. There is accumulating evidence that Interleukin-8 (IL-8) is emblematic for advanced melanomas. This work aimed to present an updated status of IL-8 in melanoma tumor cellular complexity, through a comprehensive analysis including data from other chemokines and neoplasms. The multiple processes and mechanisms surveyed here demonstrate that IL-8 operates following orchestrated programs within signaling webs in melanoma, stromal and vascular cells. Importantly, the yet unknown molecularity regulating IL-8 impact on cells of the immune system could be exploited to overturn tumor fate. The molecular and cellular targets of IL-8 should be brought into the attention of even more intense scientific exploration and valorization in the therapeutical management of melanoma.

Genome-wide association studies detects candidate genes for wool traits by re-sequencing in Chinese fine-wool sheep

BACKGROUND

The quality and yield of wool determine the economic value of the fine-wool sheep. Therefore, discovering markers or genes relevant to wool traits is the cornerstone for the breeding of fine-wool sheep. In this study, we used the Illumina HiSeq X Ten platform to re-sequence 460 sheep belonging to four different fine-wool sheep breeds, namely, Alpine Merino sheep (AMS), Chinese Merino sheep (CMS), Aohan fine-wool sheep (AHS) and Qinghai fine-wool sheep (QHS). Eight wool traits, including fiber diameter (FD), fiber diameter coefficient of variance (FDCV), fiber diameter standard deviation (FDSD), staple length (SL), greasy fleece weight (GFW), clean wool rate (CWR), staple strength (SS) and staple elongation (SE) were examined. A genome-wide association study (GWAS) was performed to detect the candidate genes for the eight wool traits.

RESULTS

A total of 8.222 Tb of raw data was generated, with an average of approximately 8.59X sequencing depth. After quality control, 12,561,225 SNPs were available for analysis. And a total of 57 genome-wide significant SNPs and 30 candidate genes were detected for the desired wool traits. Among them, 7 SNPs and 6 genes are related to wool fineness indicators (FD, FDCV and FDSD), 10 SNPs and 7 genes are related to staple length, 13 SNPs and 7 genes are related to wool production indicators (GFW and CWR), 27 SNPs and 10 genes associated with staple elongation. Among these candidate genes, UBE2E3 and RHPN2 associated with fiber diameter, were found to play an important role in keratinocyte differentiation and cell proliferation. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results, revealed that multitude significant pathways are related to keratin and cell proliferation and differentiation, such as positive regulation of canonical Wnt signaling pathway (GO:0090263).

CONCLUSION

This is the first GWAS on the wool traits by using re-sequencing data in Chinese fine-wool sheep. The newly detected significant SNPs in this study can be used in genome-selective breeding for the fine-wool sheep. And the new candidate genes would provide a good theoretical basis for the fine-wool sheep breeding.

Identification of candidate biomarkers and pathways associated with psoriasis using bioinformatics analysis

Background

The aim of this study was to identify the candidate biomarkers and pathways associated with psoriasis. GSE13355 and GSE14905 were extracted from the Gene Expression Omnibus (GEO) database. Then the differentially expressed genes (DEGs) with |logFC| > 2 and adjusted P < 0.05 were chosen. In addition, the Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for DEGs were performed. Then, the GO terms with P < 0.05 and overlap coefficient greater than 0.5 were integrated by EnrichmentMap. Additionally, risk subpathways analysis for DEGs was also conducted by using the iSubpathwayMiner package to obtain more psoriasis-related DEGs and pathways. Finally, protein-protein interaction (PPI) network analysis was performed to identify the hub genes, and the DGIdb database was utilized to search for the candidate drugs for psoriasis.

Results

A total of 127 DEGs which were mostly associated with keratinization, keratinocyte differentiation, and epidermal cell differentiation biological processes were identified. Based on these GO terms, 3 modules (human skin, epidermis and cuticle differentiation, and enzyme activity) were constructed. Moreover, 9 risk subpathways such as steroid hormone biosynthesis, folate biosynthesis, and pyrimidine metabolism were screened. Finally, PPI network analysis demonstrated that CXCL10 was the hub gene with the highest degree, and CXCR2, CXCL10, IVL, OASL, and ISG15 were the potential gene targets of the drugs for treating psoriasis.

Conclusion

Psoriasis may be mostly caused by keratinization, keratinocyte differentiation, and epidermal cell differentiation; the pathogeneses were more related with pathways such as steroid hormone biosynthesis, folate biosynthesis, and pyrimidine metabolism. Besides, some psoriasis-related genes such as SPRR genes, HSD11B1, GGH, CXCR2, IVL, OASL, ISG15, and CXCL10 may be important targets in psoriatic therapy.

Association between Psoriasis and Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-analysis

Psoriasis is considered a systemic inflammatory disorder. Previous studies have reported conflicting positive or negative correlations between psoriasis and chronic obstructive pulmonary disease. We performed a meta-analysis to determine whether there is an associated risk between psoriasis and chronic obstructive pulmonary disease. We performed a complete 30-year literature search of MEDLINE, Embase, and Cochrane Central Register databases on this topic. Four observational studies with a total of 13,418 subjects were identified. The odds ratios of chronic obstructive pulmonary disease in subjects with psoriasis/mild-to-moderate psoriasis were analyzed using the random-effects model, while the odds ratios of chronic obstructive pulmonary disease in subjects with severe psoriasis and current smoking in subjects with psoriasis were analyzed using the fixed-effect model. We found that psoriasis patients were at a greater risk of developing chronic obstructive pulmonary disease than the general population (odds ratio, 1.90; 95% confidence interval, 1.36–2.65) and that the association between of psoriasis and with chronic obstructive pulmonary disease was stronger among patients with severe psoriasis (odds ratio, 2.15; 95% confidence interval, 1.26–3.67). Psoriasis patients should be advised to cease smoking to reduce their risk of COPD. Moreover, identification of this potential risk may enable earlier implementation of preventive measures for reduction comorbidity and mortality rates.

ELR+-CXC chemokines and their receptors in early metanephric development

Although originally identified as mediators of inflammation, it is now apparent that chemokines play a fundamental role in tissue development. In this study, ELR(+)-CXC chemokine family members CXCL2 and CXCL7, along with their preferred receptor CXCR2, were expressed at the earliest stages of metanephric development in the rat, and signaling through this receptor was required for the survival and maintenance of the undifferentiated metanephric mesenchyme (MM). A specific antagonist of the CXCR2 receptor SB225002 induced apoptosis in this population but did not affect more mature structures or cells in the ureteric bud. CXCL7 treatment of isolated MM elicited an angiogenic response by upregulation of matrix metalloprotease 9 and endothelial and mesangial markers (platelet-endothelial cell adhesion molecule, Megsin, Thy-1, PDGF receptor alpha, and vascular alpha-actin) and induced SB225002-sensitive cell invasion through a matrix. Because Wilms' tumor cells may similarly depend on CXCR2 signaling for survival, primary tumor samples were analyzed, and 15 of 16 Wilms' tumors were found to be CXCR2 positive, whereas grossly normal kidney tissues from tumor patients or renal cell carcinomas were CXCR2 negative. Furthermore, cell lines derived from Wilms' tumors but not those from renal cell carcinomas were sensitive to SB225002-induced apoptosis. These data provide evidence for a prosurvival and proangiogenic role of ELR(+)-CXC chemokines and their receptor CXCR2 during metanephric development and suggest a novel mechanism for chemotherapeutic intervention in Wilms' tumor.

Repeated doses of UVR cause minor alteration in cytokine serum levels in humans

The aim of our study was to compare serum concentration of IL-1β, IL-6, IL-8, IL-10, and TNF-α in 105 healthy volunteers before and after exposure to UVR: 25 subjects (10 days of UVB), 55 (10 days of UVB or solar-simulated radiation, followed by acute UVB dose), and 25 (local high dose of UVB). In all the individuals blood samples were analyzed before and after final irradiation by chemiluminescence assay. After 10 days of UVB irradiation a statistically significant increase in serum concentration only in IL-8 (P < .05) and strong tendency in TNF-α (P = .05) were observed. The applied schedules of irradiation have minor impact on serum cytokine level and still a threshold dose of UVR causing systemic immune impairment is unknown.

Expression of CXC receptor 1 and 2 in esophageal mucosa of patients with reflux esophagitis

AIM: Interleukin 8 (IL-8) mediates neutrophil trafficking via its receptors. Recent studies have shown that IL-8 is likely involved in the development and progression of erosive reflux esophagitis (RE), yet little is known about the two distinct receptors, CXC receptor (CXCR)-1 and -2. The purpose of this study was to determine CXCR-1 and -2 messenger RNA expression levels in RE.

METHODS: We studied 26 patients with RE and 15 asymptomatic controls. Paired biopsy samples were taken from the esophagus 3 cm above the gastroesophageal junction; one biopsy was snap frozen for measurement of CXCR-1 and -2 mRNA levels by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and another was formalin-fixed for histopathological evaluation. We also examined the association of the expression levels of CXCR-1 and -2 mRNA with histopathological hallmarks of RE.

RESULTS: The relative CXCR-1 and -2 mRNA expression levels were rather decreased in esophageal mucosa of patients with RE, compared to those in normal esophagus of controls. There were no significant difference in the relative mRNA expression levels of CXCR-1 and -2 among endoscopic grades of RE based on the Los Angeles classification. Each histopathological hallmark of GERD was not associated with the expression levels of CXCR-1 and -2 mRNA.

CONCLUSION: Apart from overexpression of IL-8, the relative expression levels of CXCR-1 and -2 mRNA were rather lower than expected in the affected esophageal mucosa of patients with RE.

TARC augments TNF-alpha-induced CTACK production in keratinocytes

Thymus- and activation-regulated chemokine (TARC)/CCL17 and cutaneous T cell-attracting chemokine (CTACK)/CCL27 are both pivotal mediators of the inflammatory reaction of atopic dermatitis (AD). TARC attracts CCR4 positive T cells known to be mainly of Th2 subtype whereas CTACK attracts skin-homing T cells of both Th1 and Th2 subtype that express CCR10. We found that CTACK can be induced in cultured human keratinocytes by tumor necrosis factor-alpha (TNF-alpha), but not by TARC alone. However, if the keratinocytes were preincubated with TNF-a for 6 h, TARC was able to augment the CTACK-inducing effect of TNF-a. Performing immunohistochemical stainings, reverse-transcription polymerase chain reaction (RT-PCR), and Western blotting, we found that TNF-a-induced CCR4 mRNA production, but that stimulated as well as non-stimulated keratinocytes expressed CCR4. In order to see if these results had any clinical relevance, we investigated the plasma concentrations of TARC and CTACK from 48 patients suffering from AD. This revealed that TARC and CTACK concentrations in plasma correlate with each other. Surprisingly, p-CTACK correlated inversely with SCORAD scores of the patients, which most likely is due to the treatment the patients received. Our results suggest that the primary Th2-dominated inflammatory reaction in AD induced by TARC leads to an augmented skin-specific inflammatory reaction through CTACK.

Whole-body UVB (TL-01) or UVA-1 irradiation does not alter the levels of immunomodulatory cytokines in the serum of human volunteers

BACKGROUND/PURPOSE

Ultraviolet (UV) exposure of mammalian skin induces local and systemic immunosuppression. In mice it has been proposed that systemic immunosuppression is mediated by an UV-induced cytokine cascade involving systemic interleukin (IL)-4 and IL-10 and a reduction in IL-12 activity. To investigate whether there was a parallel mechanism in humans we examined the effect of whole-body narrowband ultraviolet B (UVB) (311-313 nm; TL-01) and ultraviolet A (UVA)-1 (340-400 nm) on serum cytokine levels.

METHODS/RESULTS

In a first study, five male psoriatic subjects were whole-body irradiated with three sessions of a standard UVB (TL-01) phototherapy regimen previously shown to cause downregulation of natural killer cell activity and T helper 1 (Th1) and Th2 cytokine production by peripheral blood mononuclear cells. Enzyme-linked immunoabsorbent assay (ELISA) of sera taken before and after the third session showed no effect of phototherapy on IL-10 and tumour necrosis factor-alpha (TNF-alpha). In a second study, five healthy subjects received three whole-body exposures of UVB (TL-01) and five other healthy subjects received three exposures of UVA-1 on alternate days (total 22 J/cm(2)). Blood samples were taken before the first irradiation and at 0, 4, 8, 12, 14, 24 and 48 h after the third irradiation. The sera were subsequently analysed for IL-10, IL-12, IL-8, IL-1beta and TNF-alpha, by ELISA. The levels of IL-1beta and TNF-alpha were below detection limits (<5 pg/ml), while no significant change in the levels of IL-10, IL-12 or IL-8 was detected as a result of either TL-01 or UVA-1.

CONCLUSIONS

It seems unlikely that a modulation in these circulating cytokines assessed in this study accounts for systemic UV-induced immunosuppression in human subjects.

Enhanced expression of interleukin-8 and activation of nuclear factor kappa-B in endoscopy-negative gastroesophageal reflux disease

OBJECTIVE

Interleukin-8 (IL-8) mediates neutrophil trafficking via its receptors. Recent studies have shown that IL-8 is likely involved in the development and progression of erosive reflux esophagitis (RE), yet little is known about its implication in endoscopy-negative gastroesophageal reflux disease (GERD). The purpose of this study was to determine IL-8 messenger ribonucleic acid (mRNA) expression levels in endoscopy-negative GERD, along with assessment of nuclear factor kappaB (NF-kappaB) activation, which upregulates IL-8 expression.

METHODS

We studied 31 patients with endoscopy-negative GERD, 15 patients with erosive RE, and 15 asymptomatic controls. Paired biopsy samples were taken from the esophagus 3 cm above the gastroesophageal junction; one biopsy was snap-frozen for measurement of IL-8 mRNA levels by real-time quantitative polymerase chain reaction, and another was formalin-fixed for histopathological evaluation. In nine endoscopy-negative GERD patients, the IL-8 mRNA expression levels were measured before and 8 wk after treatment with lansoprazole. We also sampled additional specimens for NF-kappaB-DNA binding assay and immunohistochemical analyses of NF-kappaB p65 and p50 subunits, IL-8 and specific IL-8 receptor, CXCR-1.

RESULTS

The relative IL-8 mRNA expression levels were significantly higher in esophageal mucosa of patients with endoscopy-negative GERD than those of the controls. The presence of basal zone hyperplasia and intraepithelial neutrophils, histopathological hallmarks of GERD, were associated with higher levels of IL-8 mRNA. Lansoprazole treatment significantly reduced the IL-8 mRNA expression levels. The esophageal epithelium of patients with GERD showed intense immunoreactivity for IL-8, and expressed CXCR-1 antigen. We found NF-kappaB activation in esophageal mucosa in GERD patients and the NF-kappaB subunits were localized predominantly in the nuclei of IL-8-expressing cells.

CONCLUSIONS

Our results demonstrate enhanced mucosal expression of IL-8 in incipient GERD even without mucosal breaks. NF-kappaB activation may be implicated in the pathogenesis in GERD.

Solar ultraviolet radiation as a trigger of cell signal transduction

Ultraviolet light radiation in sunlight is known to cause major alterations in growth and differentiation patterns of exposed human tissues. The specific effects depend on the wavelengths and doses of the light, and the nature of the exposed tissue. Both growth inhibition and proliferation are observed, as well as inflammation and immune suppression. Whereas in the clinical setting, these responses may be beneficial, for example, in the treatment of psoriasis and atopic dermatitis, as an environmental toxicant, ultraviolet light can induce significant tissue damage. Thus, in the eye, ultraviolet light causes cataracts, while in the skin, it induces premature aging and the development of cancer. Although ultraviolet light can damage many tissue components including membrane phospholipids, proteins, and nucleic acids, it is now recognized that many of its cellular effects are due to alterations in growth factor- and cytokine-mediated signal transduction pathways leading to aberrant gene expression. It is generally thought that reactive oxygen intermediates are mediators of some of the damage induced by ultraviolet light. Generated when ultraviolet light is absorbed by endogenous photosensitizers in the presence of molecular oxygen, reactive oxygen intermediates and their metabolites induce damage by reacting with cellular electrophiles, some of which can directly initiate cell signaling processes. In an additional layer of complexity, ultraviolet light-damaged nucleic acids initiate signaling during the activation of repair processes. Thus, mechanisms by which solar ultraviolet radiation triggers cell signal transduction are multifactorial. The present review summarizes some of the mechanisms by which ultraviolet light alters signaling pathways as well as the genes important in the beneficial and toxic effects of ultraviolet light.

Impact of endoscopically minimal involvement on IL-8 mRNA expression in esophageal mucosa of patients with non-erosive reflux disease

AIM: Little has been known about the pathogenesis of non-erosive reflux disease (NERD). Recent studies have implicated interleukin 8 (IL-8) in the development and progression of gastroesophgeal reflux disease (GERD). The purpose of this study was to determine IL-8 RNA expression levels in NERD patients with or without subtle mucosal changes.

METHODS: We studied 26 patients with NERD and 13 asymptomatic controls. Biopsy sample was taken from the esophagus 3 cm above the gastroesophageal junction and snap frozen for measurement of IL-8 mRNA levels by real-time quantitative polymerase chain reaction (PCR). We also examined mRNA expression of IL-8 receptors, CXCR-1 and -2 by reverse transcriptase PCR. The patients were endoscopically classified into grade M (mucosal color changes without visible mucosal break) and N (neither minimal involvement nor mucosal break) of the modified Los Angeles classification.

RESULTS: The relative IL-8 mRNA expression levels were significantly higher in esophageal mucosa of NERD patients than those of the controls. There was a significant difference in IL-8 mRNA levels between grade M and N. The CXCR-1 and -2 mRNAs were constitutively expressed in esophageal mucosa.

CONCLUSION: Our results suggest that high IL-8 levels in esophageal mucosa may be involved in the pathogenesis of NERD through interaction with its receptors. NERD seems to be composed of a heterogeneous population in terms of not only endoscopically minimal involvement but also immune and inflammatory processes.

UVB light suppresses nitric oxide production by murine keratinocytes and macrophages

Nitric oxide is an important mediator of excessive cell growth and inflammation associated with many epidermal proliferative disorders. It is a highly reactive oxidant generated in keratinocytes and macrophages via the inducible form of the enzyme nitric oxide synthase (NOS2). In the present studies, we examined the effects of ultraviolet light (UVB, 2.5-25mJ/cm(2)) on interferon-gamma (IFN-gamma)-induced expression of NOS2 in these cells. Transient transfection assays using wild-type and mutant NOS2 promoter/luciferase reporter constructs showed that DNA binding of the transcription factors Stat1 and NF-kappaB was essential for optimal expression of the NOS2 gene. Whereas NF-kappaB was constitutively expressed in both cell types, Stat1 phosphorylation and nuclear binding activity were dependent upon IFN-gamma. UVB light, which is used therapeutically to treat inflammatory dermatosis, was found to suppress IFN-gamma-induced expression of NOS2 mRNA and protein, and nitric oxide production in both keratinocytes and macrophages. In macrophages, this was associated with complete inhibition of NF-kappaB nuclear binding activity and partial (approximately 20-25%) reduction of Stat1 activity. In keratinocytes, both responses were partially reduced at the highest doses of UVB light (15-25mJ/cm(2)). Whereas in macrophages UVB light suppressed NOS2 wild-type promoter-luciferase reporter activity, this activity was stimulated in keratinocytes. These data suggest that UVB light functions to suppress NOS2 gene expression in macrophages by inhibiting the activity of key regulatory transcription factors. In contrast, in keratinocytes, inhibition occurs downstream of NOS2 promoter activity.

Molecular machinations: chemokine signals in host-pathogen interactions

Chemokines and their G-protein-coupled receptors represent an ancient and complex system of cellular communication participating in growth, development, homeostasis and immunity. Chemokine production has been detected in virtually every microbial infection examined; however, the precise role of chemokines is still far from clear. In most cases they appear to promote host resistance by mobilizing leukocytes and activating immune functions that kill, expel, or sequester pathogens. In other cases, the chemokine system has been pirated by pathogens, especially protozoa and viruses, which have exploited host chemokine receptors as modes of cellular invasion or developed chemokine mimics and binding proteins that act as antagonists or inappropriate agonists. Understanding microbial mechanisms of chemokine evasion will potentially lead to novel antimicrobial and anti-inflammatory therapeutic agents.