Enrolled patients
This study was approved by the IRB committee of the Third Xiangya Hospital, Central South University, China. A total of 30 patients who were diagnosed with psoriasis vulgaris and 30 healthy volunteers were enrolled in this study; we screened 12 psoriatic patients with hyperlipidemia to participate in this trial. All of the participants signed informed consent. Psoriasis disease activity was assessed by psoriasis area and severity index (PASI) score. The inclusion criteria included the following: age of 18 to 60 years old and diagnosed with psoriasis vulgaris by pathologic examinations and with hyperlipidemia [total cholesterol (TC)≧6.2 mmol/L; triglycerides (TG)≧2.3 mmol/L; LDL-C≧4.1 mmol/L; and HDL-C<1.0 mmol/L). The exclusion criteria included the following: allergic to ozone; severe cardiovascular disease; local vessel intolerable treatment; abnormal coagulation; and systemic or local topical corticosteroid, immune inhibitor, or vitamin D3 derivative therapy within the past 2 weeks.
Medical ozone major autohemotherapy
All subjects were treated with OAHT, as follows: 100 to 150 mL of venous blood was mixed with medical pure oxygen and ozone (20 μg/mL) (Humares ozone therapy device, Germany), then transported back into the body, once every other day for 10 times in a course of treatment.
Blood lipid test
All participants needed to undergo blood lipid tests before and after treatment. Venous blood was collected in the morning before treatment after a night of fasting and the next day after treatment, and the serum was used for determination of TC, TG, HDL-C, and LDL-C according to protocols provided by the manufacturer of Hitachi 7060 automatic biochemical analyzer.
Evaluation of clinical photographs and reflectance confocal microscope images of skin lesions
All subjects received free treatment with OAHT only, and received no other drugs or treatments during the trial. Clinical photographs, PASI scores, and reflectance confocal microscope (RCM) images were used by the same professional physicians to evaluate disease severity. The PASI score contains skin lesion area, erythema color, erythema infiltration depth, and scale thickness according to the literature[9]. Each subject was assessed by RCM images from three different skin lesion sites. The scanned total thickness of skin was 51 layers ×3.05 µm vertically for every scan. Under RCM, epidermal thickness and infiltrated inflammatory cells were also evaluated before and after treatment.
Total CD4+ T-cell isolation
Peripheral blood mononuclear cells (PBMCs) were separated from the blood of all patients before and after treatment with density gradient centrifugation (GE Healthcare, Switzerland). CD4+ T cells were isolated by a positive selection using CD4 beads (Miltenyi, Germany) according to the manufacturer's instructions; the purity was generally greater than 95%. Then, the isolated CD4+ T cells were collected for subsequent experiments.
RNA isolation and quantitative PCR (qPCR)
Total RNA was extracted from CD4+ T cells according to the manufacturer's instructions of Trizol reagent (Invitrogen, USA). The mRNA was reverse-transcribed with the PrimeScript®RT reagent kit (TaKaRa Biotech Co., China), and each test consumed 1 μg of total RNA. The reaction mixture in RT-PCR contained 2 μL of cDNA, 10 μL of SYBR Premix Ex Taq™ (TaKaRa Biotech Co., China), and 400 nM sense and antisense primers to a total volume of 20 μL. qPCR was performed on a LightCycler®96 (Roche, Switzerland) thermocycler. The quantity of gene expression was calculated using comparative cycle thres-hold(CT) methods and normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The primers are listed in supplement table 1.
Western blotting
CD4+T cells were lysated and proteins were extracted by Nuclear Extraction Reagent (Boster, China). Proteins were quantified by the Bradford assay (HyClone-Pierce, USA) followed by 10% vertical dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to polyvinylidene difluoride (PVDF) membranes (Millipore, USA). The PVDF membrane was blocked in 5% skim milk for 1 hour at room temperature and then incubated with an antibody against PPAR-γ (Abcam, China) for 12 to 16 hours at 4℃, followed by mouse anti-rabbit immunoglobulin G (IgG) antibody (H&L) (GenScript, USA) for 1 hour at room temperature. Proteins were detected with an ECL western blot detection kit (Thermo Scientific, USA). Band intensity was quantified using an ImageQuantTM LAS 4000 mini (GE-Healthcare). Quantification of PPAR-γ was normalized to GAPDH by densitometry.
Statistical analysis
All of the diagrams and graphs reporting cumulative data were made using GraphPad Prism 6.0. The data are represented as the mean ± standard deviation SD or standard error of the mean (SEM). Distributions of the means were analyzed with non-parametric tests (SPSS 18.0, USA). Differences in individual treatments were analyzed by unpaired or paired t test. Statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001) was assessed using a two-tailed unpaired Student t test for comparisons between two groups and one-way analysis of variance (ANOVA) with relevant post-hoc tests for multiple comparisons.