Illuminating liver fibrosis with vitamin D

Antagonizing EZH2 combined with vitamin D3 exerts a synergistic role in anti-fibrosis through bidirectional effects on hepatocytes and hepatic stellate cells

BACKGROUND AND AIM

Whether vitamin D3 (VD3) supplementation is associated with improved liver fibrosis is controversial.

METHODS

Liver fibrosis models were treated with VD3, active VD (1,25-OH2 Vitamin D3), or collaboration with GSK126 (Ezh2 inhibitor), respectively. Hepatic stellate cells (HSCs) were co-cultured with hepatocytes and then stimulated with TGF-β. Autophagy of hepatocytes was determined after the intervention of 1,25-OH2 Vitamin D3 and GSK126. Also, the active status of HSCs and the mechanism with 1,25-OH2 Vitamin D3 and GSK126 intervention were detected.

RESULTS

1,25-OH2 Vitamin D3, but not VD3, is involved in anti-fibrosis and partially improves liver function, which might be associated with related enzymes and receptors (especially CYP2R1), leading to decreased of its biotransformation. GSK126 plays a synergistic role in anti-fibrosis. The co-culture system showed increased hepatocyte autophagy after HSCs activation. Supplementation with 1,25-OH2 Vitamin D3 or combined GSK126 reduced these effects. Further studies showed that 1,25-OH2 Vitamin D3 promoted H3K27 methylation of DKK1 promoter through VDR/Ezh2 due to the weakening for HSCs inhibitory signal.

CONCLUSIONS

VD3 bioactive form 1,25-OH2 Vitamin D3 is responsible for the anti-fibrosis, which might have bidirectional effects on HSCs by regulating histone modification. The inhibitor of Ezh2 plays a synergistic role in this process.

Proteomic analysis of serum samples of paracoccidioidomycosis patients with severe pulmonary sequel

Background

Pulmonary sequelae (PS) in patients with chronic paracoccidioidomycosis (PCM) typically include pulmonary fibrosis and emphysema. Knowledge of the molecular pathways involved in PS of PCM is required for treatment and biomarker identification.

Methodology/Principal findings

This non-concurrent cohort study included 29 patients with pulmonary PCM that were followed before and after treatment. From this group, 17 patients evolved to mild/ moderate PS and 12 evolved severe PS. Sera from patients were evaluated before treatment and at clinical cure, serological cure, and apparent cure. A nanoACQUITY UPLC-Xevo QT MS system and PLGS software were used to identify serum differentially expressed proteins, data are available via ProteomeXchange with identifier PXD026906. Serum differentially expressed proteins were then categorized using Cytoscape software and the Reactome pathway database. Seventy-two differentially expressed serum proteins were identified in patients with severe PS compared with patients with mild/moderate PS. Most proteins altered in severe PS were involved in wound healing, inflammatory response, and oxygen transport pathways. Before treatment and at clinical cure, signaling proteins participating in wound healing, complement cascade, cholesterol transport and retinoid metabolism pathways were downregulated in patients with severe PS, whereas signaling proteins in gluconeogenesis and gas exchange pathways were upregulated. At serological cure, the pattern of protein expression reversed. At apparent cure pathways related with tissue repair (fibrosis) became downregulated, and pathway related oxygen transport became upregulated. Additionally, we identified 15 proteins as candidate biomarkers for severe PS.

Conclusions/Significance

Development of severe PS is related to increased expression of proteins involved in glycolytic pathway and oxygen exchange), indicative of the greater cellular activity and replication associated with early dysregulation of wound healing and aberrant tissue repair. Our findings provide new targets to study mechanisms of PS in PCM, as well as potential biomarkers.

Pulmonary fibrosis is the main sequel of paracoccidioidomycosis (PCM), a fungal disease that affects mainly men, rural workers. The development of pulmonary fibrosis is complex and involves several mechanisms that culminate in aberrant collagen production and deposition in the lungs making it became stiff and blocking the air passages. These changes lead to difficulty in breathing and in PCM patients dyspnea in response to high or low levels of exertion is common. Therefore, these patients show incapacity to work and the decreased quality of life. With the possibility of identifying some marker, for example, it could help the indication of respiratory physiotherapy, professional rehabilitation, or therapeutic intervention. This is the first study to examine the pulmonary sequelae (PS) in patients with paracoccidioidomycosis using an approach combining proteomics with bioinformatics. Here, we identify the specific proteome pattern found in PCM patients with severe sequelae that distinguishes these patients from that with mild/moderate sequelae. Our results showed that time points immediately before treatment and at clinical cure are key moments at which PS can progress to severe PS due a dysregulation in wound healing with consequent delayed in the healing processes resulting in an aberrant scar. As such, we suggest that the prognoses for severe PS should be considered as soon as possible and as early as diagnosis of PCM. Furthermore, we used proteomics to identify possible serum biomarkers with which to predict the likely development of severe PS, to be validated in future studies.

Association between serum vitamin D deficiency and age-related macular degeneration in Koreans: Clinical case-control pilot study

The objective of this study was to evaluate the association between serum vitamin D deficiency and age-related macular degeneration (AMD) in Koreans through a clinical case-control pilot study. The study included 96 patients: 30 with late AMD, 32 with early AMD, and 34 normal controls. The patients with late AMD were divided into 2 subgroups based on the presence or absence of subretinal fibrosis on optical coherence tomography (OCT) images. We measured 25-hydroxyvitamin D levels in the serum of all patients during the same season to rule out seasonal variation of serum vitamin D level. Serum vitamin D deficiency was defined as a serum 25-hydroxyvitamin D level below 20 ng/mL. Serum vitamin D deficiency had a tendency to increase the risk of early AMD, although with borderline significance [odds ratio (OR) = 3.59; 95% confidence interval (95% CI) 0.95-13.58; P = .060]. It was significantly associated with a greater risk of late AMD (OR = 3.61; 95%CI 1.04-12.51; P = .043). Among the 2 subgroups of patients with late AMD, those with subretinal fibrosis present on the OCT images showed a greater risk of serum vitamin D deficiency than the normal controls (OR = 7.54; 95% CI 1.34-42.51). However, there was no significant association between serum vitamin D deficiency and late AMD without subretinal fibrosis (OR = 1.89; 95% CI 0.40-8.92). Serum vitamin D deficiency may increase the risk of early and late AMD in Koreans, and may also be associated with subretinal fibrosis in this population.

Relationship between serum 25-hydroxy vitamin D levels and retinopathy of prematurity

Aim To evaluate the relationship between serum 25-hydroxy vitamin D, 25 (OH) D, levels and retinopathy of prematurity. Methods and Results Serum 25 (OH) D levels were measured in 97 very low birth weight infants, prior to vitamin D supplementation. The development of retinopathy of prematurity and its treatment requirement were evaluated. At follow-up, retinopathy of prematurity developed in 71 (73.2%) infants. Serum 25 (OH) D levels were significantly lower in infants with retinopathy of prematurity than ones without retinopathy of prematurity ( P < 0.001). The infants who required treatment had lower 25 (OH) D levels compared with the infants who did not required treatment (7.1 ± 5.2 ng/ml vs. 11.9 ± 6.5 ng/ml; P = 0.003). Multivariate analysis showed that lower serum 25 (OH) D levels may be a risk factor for retinopathy of prematurity development [OR: 1.14, 95% CI (1.02-1.27), P = 0.02]. Conclusion Lower 25 (OH) D levels in the first days of life may be related to retinopathy of prematurity development and treatment requirement in premature infants.

The vitamin D receptor agonist, calcipotriol, modulates fibrogenic pathways mitigating liver fibrosis in-vivo: An experimental study

Vitamin D was found to be involved in liver fibrosis modulation through binding to its receptor (VDR) halting many fibrotic pathways. Targeting vitamin D-VDR axis using vitamin D analogs may represent an efficient strategy for liver fibrosis treatment . The study aims at testing the potential ability of the VDR agonist, calcipotriol, to stop fibrosis progression and/or regeneration of hepatocytes in an experimental model of liver fibrosis. Mice (CD-1) were injected with thioacetamide (TAA, 100mg/kg, i.p., 3 times/week) for 8 weeks to induce fibrosis and were treated with calcipotriol (20, 60 or 80µg/kg, i.p., daily) concurrently with TAA during the last 4 weeks. Liver function and oxidative stress biomarkers were measured by the end of the study and hepatic sections were examined for inflammation, necrosis and fibrosis percentage. Additionally, liver contents of collagen-1-alpha-1 (COL1a1), transforming growth factor (TGF)-β1 and phospho-Smad2 (Ser456/467)/Smad3 (Ser423/425) were measured. Finally, expression of TGF-β1, tissue inhibitor metalloproteinase (TIMP)-1, Smad2/3 and Smad1/5/9 were scored using immunohistochemistry techniques. Mainly, calcipotriol (80µg/kg) significantly (P<0.001) reduced fibrosis percentage and improved TAA effect on transaminases, alkaline phosphatase, COL1a1 level, malondialdehyde, albumin and reduced glutathione (GSH). It also decreased the profibrogenic cytokine TGF-β1, TIMP-1, Smad2/3, Smad1/5/9 and phospoSmad2/3 significantly (P<0.01) when compared to TAA group. Calcipotriol attenuates TAA induced liver fibrosis and can stop its progression through limiting stellate cells activity by decreasing TGF-β1 level and modulating TGF-β1/Smad signaling pathway. It also can help fibrolysis through decreasing TIMP-1 and restoring the balance between metalloproteinases and their inhibitors.

1,25 Dihydroxyvitamin D3 Inhibits TGFβ1-Mediated Primary Human Cardiac Myofibroblast Activation

Aims

Epidemiological and interventional studies have suggested a protective role for vitamin D in cardiovascular disease, and basic research has implicated vitamin D as a potential inhibitor of fibrosis in a number of organ systems; yet little is known regarding direct effects of vitamin D on human cardiac cells. Given the critical role of fibrotic responses in end stage cardiac disease, we examined the effect of active vitamin D treatment on fibrotic responses in primary human adult ventricular cardiac fibroblasts (HCF-av), and investigated the relationship between circulating vitamin D (25(OH)D₃) and cardiac fibrosis in human myocardial samples.

Methods and Results

Interstitial cardiac fibrosis in end stage HF was evaluated by image analysis of picrosirius red stained myocardial sections. Serum 25(OH)D₃ levels were assayed using mass spectrometry. Commercially available HCF-av were treated with transforming growth factor (TGF)β₁ to induce activation, in the presence or absence of active vitamin D (1,25(OH)₂D₃). Functional responses of fibroblasts were analyzed by in vitro collagen gel contraction assay. 1,25(OH)₂D₃ treatment significantly inhibited TGFβ₁-mediated cell contraction, and confocal imaging demonstrated reduced stress fiber formation in the presence of 1,25(OH)₂D₃. Treatment with 1,25(OH)₂D₃ reduced alpha-smooth muscle actin expression to control levels and inhibited SMAD2 phosphorylation.

Conclusions

Our results demonstrate that active vitamin D can prevent TGFβ1-mediated biochemical and functional pro-fibrotic changes in human primary cardiac fibroblasts. An inverse relationship between vitamin D status and cardiac fibrosis in end stage heart failure was observed. Collectively, our data support an inhibitory role for vitamin D in cardiac fibrosis.

Inverse association between high blood 25-hydroxyvitamin D levels and diabetic retinopathy in a representative Korean population

Purpose

To investigate the association between 25-hydroxyvitamin D and diabetic retinopathy (DR).

Methods

A population-based cross-sectional study using a nation-wide, systemically stratified, multistage, clustered sampling method included a total of 18,363 subjects aged ≥40 years who participated in the Korean National Health and Nutrition Examination Survey during 2008–2012. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. Seven standard retinal fundus photographs were obtained from both eyes after pupil dilatation. DR was graded according to the modified Airlie House classification system.

Results

The blood 25-hydroxyvitamin D levels were 19.2 ng/mL in men and 17.9 ng/mL in women. After adjusting for potential confounders, including age, sex, diabetes duration, hemoglobin A1c levels, and hypertension, the odds ratios (OR) for any DR and proliferative DR among men decreased significantly in the highest blood 25-hydroxyvitamin D level quintile relative to the lowest quintile (OR, 0.37; 95% confidence interval [CI], 0.18–0.76; P for trend  = 0.004 and OR, 0.15; 95% CI, 0.03–0.83; P for trend  = 0.043).

Conclusions

This study provides the first epidemiologic findings of the inverse relationships of blood 25-hydroxyvitamin D levels with any DR and proliferative DR only in men. Considering anti-angiogenic and anti-fibrotic action of vitamin D, further studies including longitudinal and interventional analysis are warranted.

Role of vitamin D in liver diseases

Liver diseases, including hepatitis B, hepatitis C, fatty liver diseases, cirrhosis and liver cancer, seriously affect our lives, and patients with liver diseases often have different levels of vitamin D deficiency. The immune-regulatory, anti-infection and anticancer functions of vitamin D make it play a certain role in the occurrence and development of liver diseases. How to use vitamin D to delay the progression of liver diseases will be a valuable topic.