Elevated expression of interleukin-6 (IL-6) and serum amyloid A (SAA) in the skin and the serum of recessive dystrophic epidermolysis bullosa: Skin as a possible source of IL-6 through Toll-like receptor ligands and SAA

The effect of persistent skin inflammation on extracutaneous organs and blood is not well studied. Patients with recessive dystrophic epidermolysis bullosa (RDEB), a severe form of the inherited blistering skin disorder, have widespread and persistent skin ulcers, and they develop various complications including anaemia, hyperglobulinaemia, hypoalbuminaemia and secondary amyloidosis. These complications are associated with the bioactivities of IL-6, and the development of secondary amyloidosis requires the persistent elevation of serum amyloid A (SAA) level. We found that patients with RDEB had significantly higher serum levels of IL-6 and SAA compared to healthy volunteers and patients with psoriasis or atopic dermatitis. Both IL-6 and SAA were highly expressed in epidermal keratinocytes and dermal fibroblasts of the skin ulcer lesions. Keratinocytes and fibroblasts surrounding the ulcer lesions are continuously exposed to Toll-like receptor (TLR) ligands, pathogen-associated and damage-associated molecular pattern molecules. In vitro, TLR ligands induced IL-6 expression via NF-κB in normal human epidermal keratinocytes (NHEKs) and dermal fibroblasts (NHDFs). SAA further induced the expression of IL-6 via TLR1/2 and NF-κB in NHEKs and NHDFs. The limitation of this study is that NHEKs and NHDFs were not derived from RDEB patients. These observations suggest that TLR-mediated persistent skin inflammation might increase the risk of IL-6-related systemic complications, including RDEB.

"Input/output cytokines" in epidermal keratinocytes and the involvement in inflammatory skin diseases

Considering the role of epidermal keratinocytes, they occupy more than 90% of the epidermis, form a physical barrier, and also function as innate immune barrier. For example, epidermal keratinocytes are capable of recognizing various cytokines and pathogen-associated molecular pattern, and producing a wide variety of inflammatory cytokines, chemokines, and antimicrobial peptides. Previous basic studies have shown that the immune response of epidermal keratinocytes has a significant impact on inflammatory skin diseases. The purpose of this review is to provide foundation of knowledge on the cytokines which are recognized or produced by epidermal keratinocytes. Since a number of biologics for skin diseases have appeared, it is necessary to fully understand the relationship between epidermal keratinocytes and the cytokines. In this review, the cytokines recognized by epidermal keratinocytes are specifically introduced as "input cytokines", and the produced cytokines as "output cytokines". Furthermore, we also refer to the existence of biologics against those input and output cytokines, and the target skin diseases. These use results demonstrate how important targeted cytokines are in real skin diseases, and enhance our understanding of the cytokines.

Co-occurrence of non-alcoholic steatohepatitis exacerbates psoriasis associated with decreased adiponectin expression in a murine model

Introduction

Clinical studies have suggested a bidirectional association between non-alcoholic steatohepatitis (NASH) and psoriasis, affecting each other's development and severity. Here, we explored bidirectional causal linkages between NASH and psoriasis using a murine model.

Methods

NASH was induced in mice by streptozotocin injection at 2 days of age and by high-fat diet feeding (STAM™ model). Psoriasis was induced by topical application of imiquimod (IMQ) on the ear. The severities of liver damage and psoriatic skin changes were determined using histological analysis. Gene expression in the skin tissues was evaluated using quantitative PCR analysis. Serum cytokine levels were determined using enzyme-linked immunosorbent assay. To examine the innate immune responses of normal human epidermal keratinocytes (NHEKs), the cells were treated with interleukin (IL)-17A, tumor necrosis factor (TNF)-α, and AdipoRon, an adiponectin receptor agonist.

Results and Discussion

There were no differences in the degree of liver tissue damage (fat deposition, inflammation, and fibrosis) between NASH mice with and those without psoriasis. Conversely, the co-occurrence of NASH significantly augmented psoriatic skin changes, represented by epidermal hyperplasia, in psoriatic mice. Pro-inflammatory cytokines were expressed in the inflamed skin of psoriatic mice, and the expression of genes, especially Il23a, Il1b, Il36g, and Mip2, was significantly upregulated by the co-occurrence of NASH. The expression of keratinocyte activation marker genes Defb4b and Krt16 was also upregulated by the co-occurrence of NASH. The serum TNF-α and IL-17 levels were increased by the co-occurrence of NASH and psoriasis. The serum adiponectin levels decreased in NASH mice compared with that in non-NASH mice. In NHEK culture, TNF-α and IL-17A synergistically upregulated CXCL1, CXCL8, and IL1B expression. The upregulated pro-inflammatory gene expression was suppressed by AdipoRon treatment, reflecting the anti-inflammatory capacity of adiponectin.

Conclusion

The co-occurrence of NASH exacerbated psoriatic skin changes associated with increased serum inflammatory cytokine levels and decreased serum adiponectin levels. Combined with in vitro findings, increased inflammatory cytokine levels and decreased adiponectin levels likely promote innate immune responses in epidermal keratinocytes in psoriatic skin lesions. Overall, therapeutic intervention for co-occurring NASH is essential to achieve a favorable prognosis of psoriasis in clinical practice.

Coexpression of natural killer cell antigens by T-cell large granular lymphocytes in hydroa vacciniforme lymphoproliferative disorder and the involvement of Vδ1 + epithelial-type γδT cells

Hydroa vacciniforme lymphoproliferative disorder (HV-LPD) is a cutaneous variant of chronic active Epstein-Barr virus disease. We examined the coexpression of T- and natural killer (NK)-cell antigens in five patients with classic HV (cHV) and five with systemic HV (sHV). T-cell receptor (TCR) repertoire analysis was performed with high‑throughput sequencing. All five cHV patients had increased γδT cells (> 5%), whereas five sHV patients showed γδT- and αβT-cell dominance in two patients each, and a mixture of abnormal γδT and αβT cells in one. Circulating CD3 + T cells expressed CD16/CD56 at 7.8-42.3% and 1.1-9.7% in sHV and cHV, respectively. The percentage of CD16/CD56 + T cells was higher in the large granular lymphocyte or atypical T-cell fractions in sHV, but no TCR Vα24 invariant chain characteristic of NKT cells was detected. Considerable numbers of CD3 + cells expressing CD56 were observed in sHV skin infiltrates. Of the circulating γδT cells tested, TCR Vδ1 + cells characteristic of the epithelial type of γδT cells were dominant in two sHV cases. Thus, atypical αβT and γδT cells in HV-LPD can express NK-cell antigens, such as CD16 and CD56, and Vδ1 + epithelial-type γδT cells are a major cell type in some HV-LPD cases.

Revisiting the significance of right bundle branch block

Background/Introduction

The right bundle branch block (RBBB) has been considered a benign finding in asymptomatic individuals. However, this concept based on a few, old, small sample size studies. Recently, the importance of the right ventricular dysfunction was focused on cardiovascular prognosis in clinical cardiology.

Purpose

To determine the prognostic value of RBBB in community-based health checkups cohort with a large sample size in recent years in Japan.

Methods

We assessed 88,089 individuals (mean age, 58.3±10.2 years; 66.1% women) who participated in annual community-based health checkups. Exclusion criteria were current or previous history of heart disease, stroke, and intraventricular block such as left bundle branch block other than RBBB. We followed them from 1993 to 2016. The primary endpoint was cardiovascular death, or all-cause death. The Cox regression model was assessed in each gender. The variables included in the multivariate analyses were age, body mass index, systolic blood pressure, hypertension, total cholesterol level, high-density lipoprotein cholesterol level, treated-hyperlipidemia, hyperglycemia, treated-diabetes, estimated glomerular filtration rate (eGFR), current smoking, and drinking habit.

Results

The prevalence of RBBB was higher in men than women (723/29,863 2.4% in men vs. 581/58,204 1.0% in women, P<0.001). In both genders, subjects with RBBB were significantly older and had higher systolic blood pressure and lower eGFR compared with individuals without RBBB.

In women, RBBB was associated with significantly increased cardiovascular mortality with multivariate-adjusted hazard ratios (HR) of 1.26 [95% confidence interval (CI), 1.03–1.54]. Then, we divided them into younger or elder groups according to the cut-off age of 65-year-old. In women ≤65-year-old, RBBB related to greater cardiovascular mortality with multivariate-adjusted HR of 1.89 [95% CI, 1.27–2.80]. However, in women >65-year-old, RBBB did not show the prognostic significance.

In men, RBBB did not reach the significant results in all participants, however, men >65-year-old with RBBB showed the significant poor prognosis with HR of 1.26 [95% CI, 1.04–1.53].

Conclusions

In this cohort study, contrary to common perception, RBBB was associated with increased cardiovascular mortality in women, especially younger women ≤65-year-old, and elderly men. To the extent we know, the present study is the largest and long-term follow-up study showing that the significance of RBBB differs depending on sex and age. Especially in young women who usually are less prone to show wide QRS, RBBB might represent the pathological abnormality. Although the pathophysiological effect of the RBBB on the cardiovascular outcome needs further investigation in the future, clinicians should alert the RBBB in young women and elder men even if they have no symptoms and evaluate the heart abnormality and follow them up carefully.

Funding Acknowledgement

Type of funding source: None

Above 25 nm emission wavelength shift in blue-violet InGaN quantum wells induced by GaN substrate misorientation profiling: towards broad-band superluminescent diodes

We report a thorough study of InGaN quantum wells spatially modified by varying the local misorientation of the GaN substrate prior to the epitaxial growth of the structure. More than 25 nm shift of emission wavelength was obtained, which is attributed to indium content changes in the quantum wells. Such an active region is promising for broadening of the emission spectrum of (In,Al,Ga)N superluminescent diodes. We observed that the light intensity changes with misorientation, being stable around 0.5° to 2° and decreasing above 2°. This relation can be used as a base for future device designing.

Dermal fillers do not induce upregulation of NLRP3 inflammasomes or expression of inflammatory cytokines in granulomas

BACKGROUND

Filling materials have increasingly been used in aesthetics over the last decades. Understanding the pathophysiology of granuloma formation as a very relevant unwanted side effect of filler application may be essential to help avoid these adverse events.

AIMS

Our aim was to investigate the role of the inflammasome in the formation of filler granuloma, as a central column of the innate immune response.

METHODS

RPMI 1640 medium was used for growth of THP-1 cells and the induction of THP-1 macrophages. Sonication was applied in order to crush the acrylic particles of the filler. ELISA was the method of analysis for the specific cytokines. Biopsy specimens of filler granuloma were analyzed by various immunohistochemical methods. GraphPad Prism 5 software was used for the statistical data analysis.

RESULTS

Neither was the sensor NALP3 overexpressed, nor could an elevated expression of cleaved IL-1β, IL-18, or IFN-γ be detected. Furthermore, no increased expression of IL-8 or IL-1β was detectable in vitro.

CONCLUSION

No increased inflammasome activation could be observed; however, filler granulomas were infiltrated with granulocytes and macrophages. Therefore, we speculate that an unspecific immune response might be the key player in the formation of filler granuloma.

Effects of the time-of-day (morning vs. afternoon) of implementing a combined physical and cognitive exercise program on cognitive functions and mood of older adults: A randomized controlled study

This study examined the effects of the time of conducting a combined physical and cognitive exercise program on cognitive functions and the mood of older adults. We randomly assigned 17 participants (8 men, 9 women, age 73,24±3,75) to the morning group (AM Group), 18 (8 men, 10 women, age 73,11±4,84) to the afternoon group (PM Group), and they completed a 12-week, dual-task exercise program in the morning or the afternoon, respectively. Moreover, the waiting-list control group consisted of 12 participants (6 men, 6 women, age 73,25±5,93). The cognitive functions and the mood of the participants were assessed before and after the program by using the Neurobehavioral Cognitive Status Examination, and the short version of the Profile of Mood States, respectively. As a result, the exercise program conducted in the afternoon had broader effects on cognitive functions (increased Repetition and Memory) than in the morning (increased Repetition), or the waiting-list control group (increased Judgment). Moreover, the program in the afternoon tended to reduce Anger-Hostility, and Fatigue. In conclusion, conducting the exercise program in the afternoon might be more effective for improving cognitive functions and the mood of older adults than in the morning. However, there was heterogeneity between the groups despite the randomization. Therefore, we suggest conducting a more rigorously controlled study using a larger sample to validate these findings.

Knee extensor muscular activity estimation during different walking patterns: flat normal and brisk walking, stair climbing

Preserving mobility, the ability to keep a correct posture and dynamic balance in order to walk properly, is fundamental to maintain autonomy in daily life. Based on the correlation between muscle groups and autonomy, previous research has suggested that maintaining muscular tone in knee extensors is critical. Continuous training of knee extensors during aging is therefore essential to maintain independence. In this work, it is hypothesized that it is possible to estimate knee extensor activity only from IMU data based on a simple lower limbs model. The accuracy of the knee extensor activity estimation algorithm has been tested using sEMG measurements as control data on three different walking patterns: normal walk, fast walk and stair climbing. Estimated knee torque area and measured muscular activity for each step were compared confirming a high estimation accuracy with a correlation efficient R=0.80. Moreover, muscular activity can be divided based on intensity in three groups of statistically significant difference confirmed by the Steel-Dwass method. Future works should test the usability of the algorithm for different walking patterns, and use the collected data and the refined algorithm to implement a smart resistive device to increase knee extensor exertion during each walking pattern to the level necessary for sufficient extensor training.