Psoriasis: it's more than just the skin

Investigation of psoriasis skin tissue by label-free multi-modal imaging: a case study on a phototherapy-treated patient

Background: Psoriasis is a systemic inflammatory disease characterized by epidermal proliferation in the skin. Altered lipid metabolism is considered to be a central factor in the psoriatic etiopathogenesis. Thus, it is necessary to visualize chemical specificity of the samples for better medical diagnosis and treatment. Here, we investigate its role in the development of psoriatic lesions, before and after ultraviolet phototherapy, in a case study.

Methods: The distribution and morphology of different lipids and fibrous proteins in psoriatic (lesional) tissues were visualized by two complementary label-free imaging techniques: 1) non-linear microscopy (NLM), providing images of lipids/proteins throughout the skin layers at submicrometer resolution; and 2) mass spectrometry imaging (MSI), offering high chemical specificity and hence the detection of different lipid species in the epidermal and dermal regions. A conventional method of histological evaluation was performed on the tissues, with no direct comparison with NLM and MSI.

Results: Psoriatic tissues had a higher lipid content, mainly in cholesterol, in both the epidermal and dermal regions, compared to healthy tissues. Moreover, the collagen and elastin fibers in the psoriatic tissues had a tendency to assemble as larger bundles, while healthy tissues showed smaller fibers more homogeneously spread. Although phototherapy significantly reduced the cholesterol content, it also increased the amounts of collagen in both lesional and non-lesional tissues.

Conclusion: This study introduces NLM and MSI as two complementary techniques which are chemical specific and can be used to assess and visualize the distribution of lipids, collagen, and elastin in a non-invasive and label-free manner.

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Triglyceride-to-High-Density Lipoprotein Cholesterol Ratio and Systemic Inflammation in Patients with Idiopathic Pulmonary Arterial Hypertension

Background

Idiopathic pulmonary arterial hypertension (IPAH) patients are characterized by elevated triglyceride (TG)-to-HDL cholesterol (HDL-C) ratio, which has been proposed to be an important prognostic factor in this population. The mechanism of this phenomenon remains unknown. We therefore investigated the potential determinants of increased TG/HDL-C ratio in IPAH patients.

Material/Methods

We prospectively recruited consecutive clinically stable IPAH patients between January 2016 and February 2017. Patients with diabetes or using statins were excluded. Anthropometric measurements included body mass index (BMI) and skinfold thickness; body fat mass was calculated using age and sex-specific equations. We assessed lipid profile, homeostatic model assessment of insulin resistance (HOMA-IR), serum adipokine levels (adiponectin, resistin, leptin, and visfatin), and circulating cytokines (IL-1β, IL-6, MCP-1, and TNF-α).

Results

We assessed 47 IPAH patients: 9 of them had been diagnosed with diabetes and 10 were treated with statins; therefore, were excluded them from further analysis. Age, sex distribution, and BMI were similar irrespectively of TG/HDL-C ratio. Patients with increased TG/HDL-C ratio (>3) as compared to patients with TG/HDL-C ≤3 were characterized by higher levels of IL-1β, MCP-1, and IL-6. TG level was correlated with IL-1β (R=0.76, p<0.001), IL-6 (R=0.52, p=0.005), TNF-α (R=0.62, p<0.001), and MCP-1 (R=0.63, p<0.001). IL-1β was also inversely correlated with HDL-C (R=−0.44, p=0.02). We found no differences in concentration of fasting glucose, insulin, HOMA-IR, body fat content, or adipokine levels between patients with higher and lower TG/HDL-C ratios.

Conclusions

In IPAH patients, elevated TG/HDL-C ratio is a marker of systemic inflammation.

The microbiome in dermatology

The skin supports a delicate ecosystem of microbial elements. Although the skin typically acts as a barrier, these microbes interact with the internal body environment and imbalances from the "healthy" state that have been linked to several dermatologic diseases. Understanding the changes in microbial flora in disease states allows for the potential to treat by restoring equilibrium. With the rising popularity of holistic and natural consumerism, prebiotics, probiotics, symbiotic, and other therapies are under study to find alternative treatments to these skin disorders through manipulation or supplementation of the microbiome.

Roles of microRNAs in psoriasis: Immunological functions and potential biomarkers

MicroRNAs (miRNAs) are small non-coding RNA molecules, which function in RNA silencing and post-transcriptional regulation of gene expression. Psoriasis is an inflammatory skin disease characterized by the dysfunction of keratinocytes, with the immune dysregulation. We reviewed the recent studies on the roles of miRNAs in psoriasis and showed that miRNAs play key roles in psoriasis, including the regulation of hyperproliferation, cytokine and chemokine production in keratinocyte, as well as mediating immune dysfunction in psoriasis. Furthermore, miRNAs, particularly, circulating miRNAs may serve as novel biomarkers for diagnosis, monitoring therapy response and reflecting the disease severity. Thus, targeting specific miRNAs may be used to develop new therapeutic methods for psoriasis.

Psoriasis decreases the anti-oxidation and anti-inflammation properties of high-density lipoprotein

Psoriasis is a chronic inflammatory skin disease, which has been linked to dyslipidemia with potential functional impairment of lipoproteins. This cross-sectional study was designed to characterize the biological activities of plasma lipoproteins in 25 patients with psoriasis and 25 age- and sex-matched healthy controls. In the present study, we found that plasma levels of high-density lipoprotein (HDL) cholesterol were decreased in the psoriasis group compared to healthy controls. The malondialdehyde (MDA) content in plasma, in HDL3 and in low-density lipoprotein (LDL) were increased. However, the activity of plasma paraoxonase-1 (PON-1) decreased in psoriasis and negatively correlated with the psoriasis area and severity index (PASI). Moreover, plasma levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were increased in psoriasis and positively correlated with the PASI. High-sensitivity C-reactive protein (hs-CRP) was increased in psoriasis, but did not reach significance when correlated with PASI. In vitro tests displayed that the functionalities of HDL3 isolated from psoriatic patients significantly decreased, which were assessed in four independent ways, namely (1) protection against LDL oxidation, (2) inhibition of tumor necrosis factor-α (TNF-α) induced monocyte adherence to endothelial cells, (3) prevention of oxidized low density lipoprotein (ox-LDL) induced monocyte migration, and (4) protection of endothelial cells from TNF-α induced apoptosis. Further, pro-oxidative and pro-inflammatory properties of LDL isolated from psoriatic patients were increased. In conclusion, the biological activities of psoriatic lipoproteins are impaired in both HDL and LDL which may provide a link between psoriasis and cardiovas- cular disease.

Antipsoriatic treatment extends beyond the skin: recovering of high-density lipoprotein function

Epidemiological and clinical studies have shown a consistent association of psoriasis with systemic metabolic disorders including an increased prevalence of diabetes, obesity and cardiovascular disease. Psoriasis is accompanied by systemic inflammation and low levels of high-density lipoprotein (HDL) cholesterol. Recent studies provided clear evidence that psoriasis affects HDL composition and function. HDL isolated from patients with psoriasis showed a significantly impaired capability to mobilize cholesterol from macrophages, a crucial step in reverse cholesterol transport and markedly lower paraoxonase activity, a protein that co-transports with HDL in serum with well-known anti-atherogenic properties. Of particular interest, successful antipsoriatic therapy significantly improved HDL composition and function independently of serum HDL cholesterol levels. These novel findings suggest that the conventional approaches of evaluating cardiovascular risk in psoriasis may be in need of refinement. As these data argue for a loss of beneficial activities of HDL in patients with psoriasis, altered HDL functionality should be considered when evaluating the lipid status of patients.