Effect of hypercholesterolemia on circulating and cardiomyocyte-derived extracellular vesicles.

Hypercholesterolemia (HC) induces, propagates and exacerbates cardiovascular diseases via various mechanisms that are yet not properly understood. Extracellular vesicles (EVs) are involved in the pathomechanism of these diseases. To understand how circulating or cardiac-derived EVs could affect myocardial functions, we analyzed the metabolomic profile of circulating EVs, and we performed an in-depth analysis of cardiomyocyte (CM)-derived EVs in HC. Circulating EVs were isolated with Vezics technology from male Wistar rats fed with high-cholesterol or control chow. AC16 human CMs were treated with Remembrane HC supplement and EVs were isolated from cell culture supernatant. The biophysical properties and the protein composition of CM EVs were analyzed. THP1-ASC-GFP cells were treated with CM EVs, and monocyte activation was measured. HC diet reduced the amount of certain phosphatidylcholines in circulating EVs, independently of their plasma level. HC treatment significantly increased EV secretion of CMs and greatly modified CM EV proteome, enriching several proteins involved in tissue remodeling. Regardless of the treatment, CM EVs did not induce the activation of THP1 monocytes. In conclusion, HC strongly affects the metabolome of circulating EVs and dysregulates CM EVs, which might contribute to HC-induced cardiac derangements.

Identification of disease- and headache-specific mediators and pathways in migraine using blood transcriptomic and metabolomic analysis.

BACKGROUND: Recent data suggest that gene expression profiles of peripheral white blood cells can reflect changes in the brain. We aimed to analyze the transcriptome of peripheral blood mononuclear cells (PBMC) and changes of plasma metabolite levels of migraineurs in a self-controlled manner during and between attacks. METHODS: Twenty-four patients with migraine were recruited and blood samples were collected in a headache-free (interictal) period and during headache (ictal) to investigate disease- and headache-specific alterations. Control samples were collected from 13 age- and sex-matched healthy volunteers. RNA was isolated from PBMCs and single-end 75 bp RNA sequencing was performed using Illumina NextSeq 550 instrument followed by gene-level differential expression analysis. Functional analysis was carried out on information related to the role of genes, such as signaling pathways and biological processes. Plasma metabolomic measurement was performed with the Biocrates MxP Quant 500 Kit. RESULTS: We identified 144 differentially-expressed genes in PBMCs between headache and headache-free samples and 163 between symptom-free patients and controls. Network analysis revealed that enriched pathways included inflammation, cytokine activity and mitochondrial dysfunction in both headache and headache-free samples compared to controls. Plasma lactate, succinate and methionine sulfoxide levels were higher in migraineurs while spermine, spermidine and aconitate were decreased during attacks. CONCLUSIONS: It is concluded that enhanced inflammatory and immune cell activity, and oxidative stress can play a role in migraine susceptibility and headache generation.

[Skin and occupational artificial UV-radiation]. / Haut und berufliche UV-Strahlung künstlicher Quellen.

In various areas of professional activity, exposure of skin to ultraviolet radiation coming from artificial sources may occur. These UV rays differ from the solar UV radiation due to their intensity and spectrum. We review current developments with the introduction of statutory exposure limit values for jobs with UV radiation from artificial sources, a selection of relevant activities with artificial UV exposure and an overview of the occurrence of skin disorders and dermatologically relevant skin diseases caused by these specific occupational exposures. The latter is relevant for medical advice in occupational dermatology and occupational medicine. On the basis of existing studies on welders and studies regarding occupations with "open flames" (using the example of the glassblower) it is evident that so far no reliable data exist regarding the chronic photodamage or the occurrence of UV-typical skin cancers, but instead clear evidence exists regarding the regular occurrence of acute light damage in these occupations.

Does IL-4 play a role in the expansion of V beta 8a T cell receptor-bearing cells?

BACKGROUND: Peripheral blood mononuclear cells (PBMC) of subjects allergic to the insect-derived allergen Chi t 1--9 are characterized by an allergen-induced pronounced proliferation and increased expression of activation markers (CD25, HLA-DR, CD23). T cell lines showed an elevated percentage of V beta 8a-positive cells following stimulation by Chi t 1--9. OBJECTIVE: The aim of the present study was to investigate whether V beta 8a dominance plays an important role in PBMC short-term cultures (24 h) as well. The role of exogenous added cytokines, especially IL-4, has been determined. METHODS: The T cell receptor repertoire was measured with 16 monoclonal antibodies to epitopes on the variable region of the beta chain by flow cytometry. Patients allergic to Chi t 1--9 were compared to nonallergic subjects as well as to subjects with other occupational allergies. In addition, cytokines were determined intracellulary by flow cytometry. Studies were performed with PBMC cultured for 24 h. RESULTS: After cultivation for 24 h without or with different stimuli (cytokines, allergen, phytohaemagglutinin), changes in the T cell receptor profile and the cytokine profile were measurable compared to the baseline value (without cultivation). Stimulation with IL-4 revealed increased percentages of V beta 8a-expressing cells in Chi t 1--9-sensitized patients. This IL-4-induced V beta 8a increase did not occur in PBMC from the two control subject groups (non-allergic and allergic to other allergens than Chi t 1--9). CONCLUSION In conclusion, the dominance of certain T cell receptor types seems to arise due to the exposure to specific allergens and cytokine production. Some T cell receptors are often affected, for example V beta 8a, whereas others only show minor variations. V beta 8a expression obviously plays an important role in Chi t 1-9 allergy.

T-cell receptor repertoire expression in workers with occupational asthma due to platinum salt.

There is a high incidence of asthma, rhinitis, conjunctivitis and contact urticaria in workers of precious metal refineries. Symptoms are closely associated with sensitization to halogenated platinum compounds, as assessed by skin-prick test. The aim of the present study was to examine the molecular mechanisms involved by describing the T-cell receptor (TCR) repertoire distribution of peripheral blood mononuclear cells (PBMCs) without and after in vitro stimulation with sodium hexachloroplatinate. PBMCs of 17 sensitized subjects with work-related asthma and a positive skin-prick test result to sodium hexachloroplatinate and of 15 nonexposed subjects were isolated and TCR expression determined by flow cytometry. Furthermore, the sodium hexachloroplatinate-mediated in vitro effects on the frequency of Vbeta-expressing T-cells, the proliferation response and the expression of cell surface molecules like CD71, CD25, CD95 and HLA-DR were studied. CD3-positive lymphocytes of platinum salt-sensitized workers had a significantly higher frequency of Valpha2a+, Vbeta11+ and Vbeta21.3+ T-cells than controls (p<0.01, p<0.01 and p<0.001 respectively). In vitro stimulation of PBMCs from platinum salt-sensitized as well as control subjects with sodium hexachloroplatinate increased the percentage of CD3-positive cells bearing specific TCRs, especially Vbeta5.3, Vbeta6.7, Vbeta8a, Vbeta20 and Vbeta21.3. This effect was time- and dose-dependent. The present results indicate that the frequencies of Valpha2a-, V11 and Vbeta21.3-bearing blood T-cells and platinum salt-induced lymphocyte proliferation are strongly enhanced in subjects who suffer from asthma due to platinum salt. In addition, in vitro stimulation with sodium hexachloroplatinate modulates the frequencies of certain T-cell receptor-bearing T-cells.