Analysis of the association between an insertion/deletion polymorphism within the 3' untranslated region of COL1A2 and chronic venous insufficiency

Network Pharmacology Approaches Used to Identify Therapeutic Molecules for Chronic Venous Disease Based on Potential miRNA Biomarkers

Chronic venous disease (CVD) is a prevalent condition in adults, significantly affecting the global elderly population, with a higher incidence in women than in men. The modulation of gene expression through microRNA (miRNA) partly regulated the development of cardiovascular disease (CVD). Previous research identified a functional analysis of seven genes (CDS2, HDAC5, PPP6R2, PRRC2B, TBC1D22A, WNK1, and PABPC3) as targets of miRNAs related to CVD. In this context, miRNAs emerge as essential candidates for CVD diagnosis, representing novel molecular and biological knowledge. This work aims to identify, by network analysis, the miRNAs involved in CVD as potential biomarkers, either by interacting with small molecules such as toxins and pollutants or by searching for new drugs. Our study shows an updated landscape of the signaling pathways involving miRNAs in CVD pathology. This latest research includes data found through experimental tests and uses predictions to propose both miRNAs and genes as potential biomarkers to develop diagnostic and therapeutic methods for the early detection of CVD in the clinical setting. In addition, our pharmacological network analysis has, for the first time, shown how to use these potential biomarkers to find small molecules that may regulate them. Between the small molecules in this research, toxins, pollutants, and drugs showed outstanding interactions with these miRNAs. One of them, hesperidin, a widely prescribed drug for treating CVD and modulating the gene expression associated with CVD, was used as a reference for searching for new molecules that may interact with miRNAs involved in CVD. Among the drugs that exhibit the same miRNA expression profile as hesperidin, potential candidates include desoximetasone, curcumin, flurandrenolide, trifluridine, fludrocortisone, diflorasone, gemcitabine, floxuridine, and reversine. Further investigation of these drugs is essential to improve the treatment of cardiovascular disease. Additionally, supporting the clinical use of miRNAs as biomarkers for diagnosing and predicting CVD is crucial.

Vicious Circle With Venous Hypertension, Irregular Flow, Pathological Venous Wall Remodeling, and Valve Destruction in Chronic Venous Disease: A Review

Substantial advances occurred in phlebological practice in the last two decades. With the use of modern diagnostic equipment, the patients' venous hemodynamics can be examined in detail in everyday practice. Application of venous segments for arterial bypasses motivated studies on the effect of hemodynamic load on the venous wall. New animal models have been developed to study hemodynamic effects on the venous system. In vivo and in vitro studies revealed cellular phase transitions of venous endothelial, smooth muscle, and fibroblastic cells and changes in connective tissue composition, under hemodynamic load and at different locations of the chronically diseased venous system. This review is an attempt to integrate our knowledge from epidemiology, paleoanthropology and anthropology, clinical and experimental hemodynamic studies, histology, cell physiology, cell pathology, and molecular biology on the complex pathomechanism of this frequent disease. Our conclusion is that the disease is initiated by limited genetic adaptation of mankind not to bipedalism but to bipedalism in the unmoving standing or sitting position. In the course of the disease several pathologic vicious circles emerge, sustained venous hypertension inducing cellular phase transitions, chronic wall inflammation, apoptosis of cells, pathologic dilation, and valvular damage which, in turn, further aggravate the venous hypertension.

MicroRNA expression biomarkers of chronic venous disease

Chronic venous disease (CVD) is a common disease caused by hemodynamic disorders of the venous circulation in the lower extremities. The clinical image of this disease is complex and includes such signs as telangiectases, varicose veins, leg edema and skin changes, usually accompanied with ache, pain, tightness, heaviness, swelling and muscle cramps of legs. Venous ulcers develop in the advanced stages of the disease and lead to significant impairment of patient abilities and reduction of the quality of life. CVD is diagnosed based on physical and image examinations, and main treatment options include compression therapy, invasive treatments like endovenous ablation and foam sclerotherapy, as well as pharmacotherapy. Currently, there is no biochemical and molecular biomarkers utilized in diagnosis or treatment of CVD. With regard to this situation, one of the most investigated fields for identification of disease biomarkers is microRNA (miRNA). These constitute a pool of small, non-coding RNAs that play crucial roles in maintaining cellular homeostasis through posttranscriptional regulation of genes expression. Dysregulations of miRNA expression profiles have been found in patients with various diseases, and this situation provides information about potential miRNA signatures involved in pathophysiology. In this review, the studies focused on investigations of miRNA expression patterns in patients with CVD were collected. The performed literature analysis provides contemporary knowledge in the field of miRNA-dependent mechanisms involved in the etiopathogenesis of CVD and shows gaps that need to be filled in further studies.

Understanding Chronic Venous Disease: A Critical Overview of Its Pathophysiology and Medical Management

Chronic venous disease (CVD) is a multifactorial condition affecting an important percentage of the global population. It ranges from mild clinical signs, such as telangiectasias or reticular veins, to severe manifestations, such as venous ulcerations. However, varicose veins (VVs) are the most common manifestation of CVD. The explicit mechanisms of the disease are not well-understood. It seems that genetics and a plethora of environmental agents play an important role in the development and progression of CVD. The exposure to these factors leads to altered hemodynamics of the venous system, described as ambulatory venous hypertension, therefore promoting microcirculatory changes, inflammatory responses, hypoxia, venous wall remodeling, and epigenetic variations, even with important systemic implications. Thus, a proper clinical management of patients with CVD is essential to prevent potential harms of the disease, which also entails a significant loss of the quality of life in these individuals. Hence, the aim of the present review is to collect the current knowledge of CVD, including its epidemiology, etiology, and risk factors, but emphasizing the pathophysiology and medical care of these patients, including clinical manifestations, diagnosis, and treatments. Furthermore, future directions will also be covered in this work in order to provide potential fields to explore in the context of CVD.

Dysregulations of MicroRNA and Gene Expression in Chronic Venous Disease

Chronic venous disease (CVD) is a vascular disease of lower limbs with high prevalence worldwide. Pathologic features include varicose veins, venous valves dysfunction and skin ulceration resulting from dysfunction of cell proliferation, apoptosis and angiogenesis. These processes are partly regulated by microRNA (miRNA)-dependent modulation of gene expression, pointing to miRNA as a potentially important target in diagnosis and therapy of CVD progression. The aim of the study was to analyze alterations of miRNA and gene expression in CVD, as well as to identify miRNA-mediated changes in gene expression and their potential link to CVD development. Using next generation sequencing, miRNA and gene expression profiles in peripheral blood mononuclear cells of subjects with CVD in relation to healthy controls were studied. Thirty-one miRNAs and 62 genes were recognized as potential biomarkers of CVD using DESeq2, Uninformative Variable Elimination by Partial Least Squares (UVE-PLS) and ROC (Receiver Operating Characteristics) methods. Regulatory interactions between potential biomarker miRNAs and genes were projected. Functional analysis of microRNA-regulated genes revealed terms closely related to cardiovascular diseases and risk factors. The study shed new light on miRNA-dependent regulatory mechanisms involved in the pathology of CVD. MicroRNAs and genes proposed as CVD biomarkers may be used to develop new diagnostic and therapeutic methods.

Collagens and elastin genetic variations and their potential role in aging-related diseases and longevity in humans

Collagens and elastin are 'building blocks' of tissues and extracellular matrix. Mutations in these proteins cause severe congenital syndromes. Adverse genetic variations may accelerate the aging process in adults contributing to premature morbidity, disability and/or mortality. Favorable variants may contribute to longevity and/or healthy aging, but this is much less studied. We reviewed the association between variation in the genes of collagens and elastin and premature aging, accelerated aging, age-related diseases and/or frailty; and the association between genetic variation in those and longevity and/or healthy aging in humans. A systematic search was conducted in MEDLINE and other online databases (OMIM, Genetics Home Reference, Orphanet, ClinVar). Results suggest that genetic variants lead to aging phenotypes of known congenital disease, but also to association with common age-related diseases in adults without known congenital disease. This may be due to the variable penetrance and expressivity of many variants. Some collagen variants have been associated with longevity or healthy aging. A limitation is that most studies had <1000 participants and their criterion for statistical significance was p < 0.05. Results highlight the importance of adopting a lifecourse approach to the study of the genomics of aging. Gerontology can help with new methodologies that operationalize biological aging.

Insertion/deletion polymorphism in the 3' untranslated region of COL1A2 disrupts its interaction with microRNA-382 and leads to decreased susceptibility to osteoporotic fracture

A growing body of evidence has proved that the expression of COL1A2 is associated with a reduced risk of osteoporotic fracture. One single-nucleotide polymorphism (rs3917) located within the 3'-untranslated region of COL1A2 may "alter" binding site of miR-382 and thereby associated with the risk of osteoporotic fracture. Bioinformatic analysis, luciferase reporter assay, site-directed mutagenesis, Western blot and real-time PCR were performed in this study. In this study, we validated COL1A2 as a target of miR-382 in osteoblast. In addition, bone tissue samples were genotyped as wild-type rs3917, heterozygous rs3917, and homozygous rs3917. The expression of miR-382 was comparable between the genotype groups, whereas the expression of COL1A2 mRNA and protein was much higher in heterozygous rs3917 and homozygous rs3917 than the wild-type rs3917 group. Furthermore, we transfected the wild-type rs3917 and heterozygous rs3917 cells with miR-382 mimics or inhibitors and found that the transfection with miR-382 mimics significantly increased the level of the miR-382 in the cells of both genotypes, and the introduction of miR-382 inhibitors substantially suppressed the level of miR-382 in both cells. In wild-type rs3917 cells, transfection of miR-382 mimics and COL1A2 small interfering RNA (siRNA) similarly and substantially downregulated the expression of COL1A2, while in heterozygous rs3917 cells, only COL1A2 siRNA notably reduced the expression of COL1A2, whereas introduction of miR-382 mimics left expression of COL1A2 intact. The findings showed rs3917 polymorphism interfered with the interaction between COL1A2 mRNA and miR-382, and minor allele is associated with a reduced risk of osteoporotic fracture.

Global Expression Profiling Identifies a Novel Hyaluronan Synthases 2 Gene in the Pathogenesis of Lower Extremity Varicose Veins

Lower extremities varicose veins (VV) are among the most easily recognized venous abnormalities. The genetic mechanism of VV is largely unknown. In this study, we sought to explore the global expressional change of VV and identify novel genes that might play a role in VV. We used next-generation ribonucleic acid (RNA) sequence (RNA seq) technology to study the global messenger RNA expressional change in the venous samples of five diseased and five control patients. We identified several differentially expressed genes, which were further confirmed by conventional reverse transcription polymerase chain reaction (RT-PCR). Using these significant genes we performed in silico pathway analyses and found distinct transcriptional networks, such as angiogenesis, cell adhesion, vascular injury, and carbohydrate metabolisms that might be involved in the mechanism of VV. Among these significant genes, we also found hyaluronan synthases 2 gene (HAS2) played a pivotal role and governed all these pathways. We further confirmed that HAS2 expression was decreased in the venous samples of patients with VV. Finally, we used a zebrafish model with fluorescence emitting vasculature and red blood cells to see the morphological changes of the venous system and blood flow. We found that HAS2 knockdown in zebrafish resulted in dilated venous structural with static venous flow. HAS2 may modulate the transcriptional networks of angiogenesis, cell adhesion, vascular injury, and carbohydrate metabolisms in venous tissues and downregulation of HAS2 may underlie the mechanism of VV.

Allele rs2010963 C of the VEGFA gene is associated with the decreased risk of primary varicose veins in ethnic Russians

Objective To study the association of polymorphisms rs699947, rs2010963, rs3025039 in the VEGFA gene region and rs1870377, rs2305949, rs2071559 in the VEGFR2 gene region with the risk of primary varicose veins in ethnic Russians. Methods Genotypes were determined by real-time PCR allelic discrimination. The case group consisted of 448 patients with primary varicose veins and the control group comprised 609 individuals without a history of chronic venous disease. Association was studied by logistic regression analysis. Results Allele rs2010963 C was associated with the decreased risk of varicose veins (additive model of inheritance: odds ratio = 0.73, 95% confidence interval = 0.59-0.91, P = 0.004). Conclusions Our results provide evidence that polymorphism rs2010963 located in the 5' untranslated region of the VEGFA gene can influence genetic susceptibility to primary varicose veins in Russians. Otherwise, it can be in linkage disequilibrium with another functional single nucleotide polymorphism that can alter the level of vascular endothelial growth factor A protein.

The Discovery of Novel Genomic, Transcriptomic, and Proteomic Biomarkers in Cardiovascular and Peripheral Vascular Disease: The State of the Art

Cardiovascular disease (CD) and peripheral vascular disease (PVD) are leading causes of mortality and morbidity in western countries and also responsible of a huge burden in terms of disability, functional decline, and healthcare costs. Biomarkers are measurable biological elements that reflect particular physiological or pathological states or predisposition towards diseases and they are currently widely studied in medicine and especially in CD. In this context, biomarkers can also be used to assess the severity or the evolution of several diseases, as well as the effectiveness of particular therapies. Genomics, transcriptomics, and proteomics have opened new windows on disease phenomena and may permit in the next future an effective development of novel diagnostic and prognostic medicine in order to better prevent or treat CD. This review will consider the current evidence of novel biomarkers with clear implications in the improvement of risk assessment, prevention strategies, and medical decision making in the field of CD.

Primary venous insufficiency increases risk of deep vein thrombosis

BACKGROUND

Varicose veins have been recognized as a risk factor for deep vein thrombosis (DVT). However, venous reflux has not carried the same correlation. This study evaluated the association between primary valvular reflux and DVT.

METHODS

We performed a nested case-control study with enrollment of outpatients presenting to the vascular laboratory with signs and symptoms of DVT. All patients had a complete bilateral venous duplex examination evaluating for DVT and superficial and deep venous valvular reflux. Eighty-seven patients with confirmed DVT on venous duplex were selected for the study group. The control group was randomly selected from the same cohort in a 4:1 ratio matched by age and gender (n = 348). Groups were compared for the prevalence of deep and superficial reflux.

RESULTS

DVT outpatients were 4.7-times more likely to have primary valvular reflux than symptomatic controls (65.5% vs 29.0%; 95% confidence interval [CI], 2.8-7.7; P < .000001). Deep reflux was 2.1-times more prevalent (36.8% vs 21.6%; odds ratio, 2.12; 95% CI, 1.28-3.51; P = .005) and superficial reflux was 4.6-times more prevalent (43.7% vs 14.4%; odds ratio, 4.62; 95% CI, 2.75-7.77; P < .0000001) in DVT patients than in controls. DVT patients were also 2.1-times more likely to have combined deep and superficial reflux than non-DVT patients (13.8% vs 6.6%, 95% CI, 1.08-4.75; P = .044).

CONCLUSIONS

The prevalence of primary valvular reflux in patients with DVT is significantly higher than expected. Reflux may be considered as a novel risk factor for DVT. Two-thirds of patients with DVT have pre-existent primary chronic venous disease, which is likely to contribute to post-thrombotic morbidity.

HFE p.C282Y gene variant is associated with varicose veins in Russian population

Recently, the association of polymorphism rs1800562 (p.C282Y) in the hemochromatosis (HFE) gene with the increased risk of venous ulceration was shown. We hypothesized that HFE gene polymorphism might be involved not only in ulceration process, but also in susceptibility to primary varicose veins. We genotyped HFE p.C282Y (rs1800562) and p.H63D (rs1799945) variants in patients with primary varicose veins (n = 463) and in the control group (n = 754). In our study, p.282Y variant (rs1800562 A allele) was significantly associated with the risk of varicose veins (OR 1.79, 95 % CI = 1.11-2.89, P = 0.02). A borderline significant reverse association of p.63D variant (rs1799945 G allele) with venous leg ulcer development was revealed in Russians (OR 0.25, 95 % CI = 0.06-1.00, P = 0.05), but not in the meta-analysis (P = 0.56). We conclude that the HFE gene polymorphism can affect the risk of developing primary varicose veins.

Genetic polymorphisms of vein wall remodeling in chronic venous disease: a narrative and systematic review

Chronic venous disease encompasses a spectrum of disorders caused by an abnormal venous system. They include chronic venous insufficiency, varicose veins, lipodermatosclerosis, postthrombotic syndrome, and venous ulceration. Some evidence suggests a genetic predisposition to chronic venous disease from gene polymorphisms associated mainly with vein wall remodeling. The literature exploring these polymorphisms has not been reviewed and compiled thus far. In this narrative and systematic review, we present the current evidence available on the role of polymorphisms in genes involved in vein wall remodeling and other pathways as contributors to chronic venous disease. We searched the EMBASE, Medline, and PubMed databases from inception to 2013 for basic science or clinical studies relating to genetic associations in chronic venous disease and obtained 38 relevant studies for this review. Important candidate genes/proteins include the matrix metalloproteinases (extracellular matrix degradation), vascular endothelial growth factors (angiogenesis and vessel wall integrity), FOXC2 (vascular development), hemochromatosis (involved in venous ulceration and iron absorption), and various types of collagen (contributors to vein wall strength). The data on associations between these genes/proteins and the postthrombotic syndrome are limited and additional studies are required. These associations might have future prognostic and therapeutic implications.