Correlation between vitamin D levels and apoptosis in geriatric patients infected with hepatitis C virus genotype 4

Circulating microRNAs as potential biomarkers of physical activity in geriatric patients with HCV

BACKGROUND

Circulating microRNAs have been implicated in a diverse array of biological and pathological phenomena. Their potential utility as noninvasive biomarkers for screening and diagnosing various diseases has been proposed.

OBJECTIVE

This study aimed to explore the potential role of the miRNAs miR-122 and miR-486 as molecular biomarkers in the pathogenesis of hepatitis C virus (HCV) infection. Thus, miR-122 and miR-486 were detected in the serum of HCV patients and healthy controls. Moreover, the potential correlations of miR-122 and miR-486 with viral complications, such as physical activity, pain, muscle fatigue, and HCV infection, were identified.

METHODS

A total of 150 subjects aged 30 to 66 years were included in this study. The patients were classified as patients with chronic hepatitis C virus (CHC) (n = 110) or healthy controls (n = 40). Real-time polymerase chain reaction (PCR) analyses were performed to determine miR-122 and miR-486 expression. Physical activity (PA), pain score, HCV genotyping, viral overload, aspartate transaminase (AST), alanine transaminase (ALT), lactic acid dehydrogenase (LDH), creatine kinase (CK), and antioxidant status were also estimated by using prevalidated questionnaires, PCR, and spectrophotometric analyses.

RESULTS

Compared with those in normal controls, significant increases in the serum levels of miR-122 and miR-486 were reported in patients with CHC. In physically active CHC patients, there was a significant correlation between the expression of miRNAs and increased alanine transaminase (ALT), aspartate transaminase (AST), fibrosis scores, and inflammation activity, but no association was reported for hepatitis C virus (HCV) RNA or viral load. Additionally, significant decreases in LDH, CK, GSSG, and pain scores and increases in TAC, GSH, and the GSH/GSSG ratio were reported. Moreover, the expression of miR-122 and miR-486 was positively correlated with changes in body mass index (BMI) and liver fibrosis stage, as well as negatively correlated with sex, PA, TAC, GSH, GSSG, and the GSH/GSSG ratio.

CONCLUSION

MiR-122 and miR-486 expression levels were strongly correlated with physical activity, pain perception, and muscle fatigue biomarkers in HCV-infected patients. These miRNA levels were associated with elevated AST, ALT, fibrosis scores, LDH, CK, and antioxidant status, thus suggesting their potential as biomarkers for disease severity and oxidative stress. However, no correlation was observed with viral load or HCV-RNA expression, thus implying that these miRNAs may impact disease progression and symptoms through host factors, rather than directly affecting viral replication. In summary, the results demonstrated that molecular studies of miR-22 and miR-468 and their associations with PA, pain, adiposity, sex differences, and muscle fatigue, as well as routine biomarkers, could be useful as prognostic nanoninvasive biomarkers, thus providing novel therapeutic targets for CHC infection.

The role of fat-soluble vitamins in efferocytosis

Cell death and the efficient removal of dead cells are two basic mechanisms that maintain homeostasis in multicellular organisms. efferocytosis, which includes four steps recruitment, recognition, binding and signaling, and engulfment. Effectively and quickly removes apoptotic cells from the body. Any alteration in efferocytosis can lead to several diseases, including autoimmune and inflammatory conditions, atherosclerosis, and cancer. A wide range of dietary components affects apoptosis and, subsequently, efferocytosis. Some vitamins, including fat-soluble vitamins, affect different stages of efferocytosis. Among other things, by affecting macrophages, they are effective in the apoptotic cleansing of cells. Also, polyphenols indirectly intervene in efferocytosis through their effect on apoptosis. Considering that there are limited articles on the effect of nutrition on efferocytosis, in this article we will examine the effect of some dietary components on efferocytosis.

Correlations of Serum Vitamin D Level with Markers of Oxidative Stress and Apoptosis in Liver Cirrhosis

In this study we investigated the relationship between vitamin D and markers of oxidative stress and apoptosis in patients with liver cirrhosis stratified according serum GGT activity. Forty-eight patients with liver cirrhosis of various aetiology were selected, among which 58% cases (n=28) diagnosed with alcoholic liver cirrhosis and 42% (n=20) with cirrhosis after hepatitis virus infection. Each group was divided into three quartiles according GGT activity. 25-hydroxyvitamin D [25-(HO) vit D], markers of oxidative stress (catalase, superoxide dismutase) and apoptosis (M30) were compared. Higher levels of GGT were correlated with elevated AST, ALT and ALP values in both groups. A statistically significant difference was observed when comparing 25-(OH) vit D levels of patients suffering from ethanol-induced liver cirrhosis versus control group for all the quartiles as well as for those from the first quartile of viral-induced liver cirrhosis. For SOD, statistically significant differences were noticed between all cirrhosis subgroups and the control group. CAT values in all cirrhosis subgroups were lower than in control, but significant differences were only between Q2.2 and Q1.3 quartiles and Q2.2 and control. Correlation of 25-(OH) vit D versus SOD yields statistically significant results in ethanol-induced cirrhosis patients. M30 activity was increased in patients with alcoholic cirrhosis compared to controls and those with virus-induced cirrhosis, being correlated with the degree of GGT activity. Our results emphasized that vitamin D deficiency is associated with enhanced liver dysfunction regardless of the trigger responsible for disease onset. Furthermore, vitamin D deficiency augments liver injury by promoting oxidative stress which influence the survival mechanisms of parenchymal liver cells.

Decreased circulating vitamin D reflects adverse outcomes of hepatitis C virus infection: A systematic review and meta-analysis

OBJECTIVES

This study aimed to clarify associations of circulating vitamin D and its status with severity of HCV infection.

METHODS

We performed systemic literature search in PubMed, Scopus, and Cochrane library databases from inception until the end of December 2019 with terms related to vitamin D and hepatitis C.

RESULTS

A total of 28 studies consisting of 7736 HCV-infected patients and 14061 control subjects without liver diseases were included. Compared to controls, circulating vitamin D levels were significantly lessened in HCV-infected patients (mean difference, MD=-14.15, 95% CI: -20.51 to -7.80). Remarkably decreased circulating vitamin D was found in the patients with severe fibrosis (MD=-3.38, 95% CI: -4.51 to -2.25), non-achieving SVR (MD=-2.99, 95%CI: -5.55 to -0.42), and advanced inflammation (MD=-4.68, 95% CI: -8.50 to -0.86). Low vitamin D status (<20 ng/mL) was significantly associated with increased odds of HCV infection (pooled OR=2.41, 95% CI: 1.48 to 3.95). Besides, HCV-infected patients with low vitamin D status showed significantly escalated odds of severe fibrosis and non-achieving SVR (pooled OR=1.70, 95% CI: 1.27 to 2.26; pooled OR=2.04, 95% CI: 1.62 to 2.57, respectively).

CONCLUSION

HCV-infected patients with declined circulating vitamin D levels were associated with severe fibrosis, non-achieving SVR, and advanced inflammation.

Controversial Effects of Vitamin D and Related Genes on Viral Infections, Pathogenesis, and Treatment Outcomes

Vitamin D (VD) plays an essential role in mineral homeostasis and bone remodeling. A number of different VD-related genes (VDRG) are required for the metabolic activation of VD and the subsequent induction of its target genes. They include a set of genes that encode for VD-binding protein, metabolic enzymes, and the VD receptor. In addition to its well-characterized skeletal function, the immunoregulatory activities of VD and the related polymorphisms of VDRG have been reported and linked to its therapeutic and preventive actions for the control of several viral diseases. However, in regards to their roles in the progression of viral diseases, inconsistent and, in some cases, contradictory results also exist. To resolve this discrepancy, I conducted an extensive literature search by using relevant keywords on the PubMed website. Based on the volume of hit papers related to a certain viral infection, I summarized and compared the effects of VD and VDRG polymorphism on the infection, pathogenesis, and treatment outcomes of clinically important viral diseases. They include viral hepatitis, respiratory viral infections, acquired immunodeficiency syndrome (AIDS), and other viral diseases, which are caused by herpesviruses, dengue virus, rotavirus, and human papillomavirus. This review will provide the most current information on the nutritional and clinical utilization of VD and VDRG in the management of the key viral diseases. This information should be valuable not only to nutritionists but also to clinicians who wish to provide evidence-based recommendations on the use of VD to virally infected patients.

Evolving Role of Vitamin D in Immune-Mediated Disease and Its Implications in Autoimmune Hepatitis

Vitamin D has immunomodulatory, anti-inflammatory, antioxidant, and anti-fibrotic actions that may impact on the occurrence and outcome of immune-mediated disease. The goals of this review are to describe the nature of these expanded roles, examine the implications of vitamin D deficiency in autoimmune hepatitis, and identify opportunities for future investigation. Abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed. Vitamin D receptors are expressed on the principal cell populations involved in the innate and adaptive immune responses. Macrophages and dendritic cells can produce 1,25-dihydroxyvitamin D within the microenvironment. This active form of vitamin D can inhibit immune cell proliferation, promote an anti-inflammatory cytokine profile, expand regulatory T cells, enhance glucocorticoid actions, increase glutathione production, and inhibit hepatic stellate cells. Vitamin D deficiency has been commonly present in patients with immune-mediated liver and non-liver diseases, and it has been associated with histological severity, advanced hepatic fibrosis, and non-response to conventional glucocorticoid therapy in autoimmune hepatitis. Vitamin D analogues with high potency, low calcemic effects, and independence from hepatic hydroxylation are possible interventions. In conclusion, vitamin D has properties that could ameliorate immune-mediated disease, and vitamin D deficiency has been a common finding in immune-mediated liver and non-liver diseases, including autoimmune hepatitis. Loss of vitamin D-dependent homeostatic mechanisms may promote disease progression. Vitamin D analogues that are independent of hepatic hydroxylation constitute an investigational opportunity to supplement current management of autoimmune hepatitis.

The interplay between vitamin D and viral infections

The pleiotropic role of vitamin D has been explored over the past decades and there is compelling evidence for an epidemiological association between poor vitamin D status and a variety of diseases. While the potential anti-viral effect of vitamin D has recently been described, the underlying mechanisms by which vitamin D deficiency could contribute to viral disease development remain poorly understood. The possible interactions between viral infections and vitamin D appear to be more complex than previously thought. Recent findings indicate a complex interplay between viral infections and vitamin D, including the induction of anti-viral state, functional immunoregulatory features, interaction with cellular and viral factors, induction of autophagy and apoptosis, and genetic and epigenetic alterations. While crosstalk between vitamin D and intracellular signalling pathways may provide an essential modulatory effect on viral gene transcription, the immunomodulatory effect of vitamin D on viral infections appears to be transient. The interplay between viral infections and vitamin D remains an intriguing concept, and the global imprint that vitamin D can have on the immune signature in the context of viral infections is an area of growing interest.

Vitamin D deficiency in hepatitis C virus infection: what is old? what is new?

In the past few years, a growing body of clinical evidence has highlighted the risk of vitamin D deficiency in patients with chronic hepatitis C and that vitamin D levels are associated with the course of hepatitis C virus (HCV) infection, adverse effects, and treatment response to peginterferon/ribavirin. Recently, studies have found that vitamin D status is related to drug resistance and increased risk of infection in patients with liver cirrhosis. Vitamin D-related gene polymorphisms have been found to explain the interactions between vitamin D deficiency and HCV infection, offering a new perspective toward understanding the current problems such as the development of insulin resistance and racial differences in sustained virological response. Studies have been conducted to determine whether vitamin D supplementation as an adjuvant yields a better result compared with traditional HCV treatment. Here, we provide a brief review of the past and present knowledge of vitamin D in HCV infection.

Changes in the human transcriptome upon vitamin D supplementation

Vitamin D is hydroxylated in the liver and kidneys to its active form, which can bind to the vitamin D receptor (VDR). The VDR is present in a wide variety of different cells types and tissues and acts as a transcription factor. Although activation of the VDR is estimated to regulate expression of up to 5% of the human genome, our study is the first analysing gene expression after supplementation in more than 10 subjects. Subjects of a randomized controlled trial (RCT) received either vitamin D₃ (n=47) in a weekly dose of 20,000 IU or placebo (n=47) for a period of three to five years. For this study, blood samples for preparation of RNA were drawn from the subjects and mRNA gene expression in blood was determined using microarray analysis. The two study groups were similar regarding gender, age, BMI and duration of supplementation, whereas the mean serum 25-hydroxyvitamin D (25(OH)D) level as expected was significantly higher in the vitamin D group (119 versus 63nmol/L). When analysing all subjects, nearly no significant differences in gene expression between the two groups were found. However, when analysing men and women separately, significant effects on gene expression were observed for women. Furthermore, when only including subjects with the highest and lowest serum 25(OH)D levels, additional vitamin D regulated genes were disclosed. Thus, a total of 99 genes (p≤0.05, log2 fold change ≥|0.2|) were found to be regulated, of which 72 have not been published before as influenced by vitamin D. These genes were particularly involved in the interleukin signaling pathway, oxidative stress response, apoptosis signaling pathway and gonadotropin releasing hormone receptor pathway. Thus, our results open the possibility for many future studies.

Targeting Hepatic Fibrosis in Autoimmune Hepatitis

Hepatic fibrosis develops or progresses in 25 % of patients with autoimmune hepatitis despite corticosteroid therapy. Current management regimens lack reliable noninvasive methods to assess changes in hepatic fibrosis and interventions that disrupt fibrotic pathways. The goals of this review are to indicate promising noninvasive methods to monitor hepatic fibrosis in autoimmune hepatitis and identify anti-fibrotic interventions that warrant evaluation. Laboratory methods can differentiate cirrhosis from non-cirrhosis, but their accuracy in distinguishing changes in histological stage is uncertain. Radiological methods include transient elastography, acoustic radiation force impulse imaging, and magnetic resonance elastography. Methods based on ultrasonography are comparable in detecting advanced fibrosis and cirrhosis, but their performances may be compromised by hepatic inflammation and obesity. Magnetic resonance elastography has excellent performance parameters for all histological stages in diverse liver diseases, is uninfluenced by inflammatory activity or body habitus, has been superior to other radiological methods in nonalcoholic fatty liver disease, and may emerge as the preferred instrument to evaluate fibrosis in autoimmune hepatitis. Promising anti-fibrotic interventions are site- and organelle-specific agents, especially inhibitors of nicotinamide adenine dinucleotide phosphate oxidases, transforming growth factor beta, inducible nitric oxide synthase, lysyl oxidases, and C-C chemokine receptors types 2 and 5. Autoimmune hepatitis has a pro-fibrotic propensity, and noninvasive radiological methods, especially magnetic resonance elastography, and site- and organelle-specific interventions, especially selective antioxidants and inhibitors of collagen cross-linkage, may emerge to strengthen current management strategies.