Does extracellular matrix of the varicose vein wall change according to clinical stage?

Morphological study of incompetent saphenous veins: apoptosis and ultrastructural changes of smooth muscle cells

BACKGROUND

Varicose veins affect approximately 25% of people in industrialized countries.

METHODS

The study aimed at detecting apoptotic cells and histopathological changes in varicose vein walls. Patients (N.=41) with varicose veins and 30 control group patients were divided into two groups according to their age (younger and older than 50 years). Apoptosis was determined by the TUNEL assay, elastin and collagen IV expression by immunohistochemistry and ultrastructural changes by transmission electron microscopy.

RESULTS

The results show that the number of apoptotic cells in the layers of varicose veins increased, in particular in a group of patients aged over 50 years. In the varicose veins as compared to control veins the elastic fibers were found to be thinner, more fragmented and disorderly arranged. Elastin and collagen IV expression was found to decline in the intima and the media of varicose veins in both age groups. Electron microscopy demonstrated hypertrophy and degeneration of smooth muscle cells. Furthermore, cells with ultrastructural feature of apoptosis were noted. In the disorganized and expanded extracellular matrix membrane-bound vesicles, ghost bodies with different size and electron density were observed. Ghost bodies seem to bud off from smooth muscle cells and are likely to be involved in extracellular matrix remodeling as they are seen in close contact with collagen fibers.

CONCLUSIONS

The study demonstrates increase of apoptotic cells in the wall of varicose veins along with vein wall structural abnormalities including alterations of smooth muscle cells and decline of elastin and collagen IV expression.

A novel view to varicose veins pathogenesis: Proteomic profiling suggests a pivotal role of extracellular matrix degradation

INTRODUCTION

Although morphological and anatomical studies indicate that venous wall weakening and subendothelial fibrosis characterize varicose veins (VV), the pathogenesis of VV remains poorly understood. The aim of this study is to obtain protein expression profiles in patients with VV and thereby get a step closer to understanding the pathogenesis of VV.

METHODS

Specimens were obtained from total of 10 patients, that is, from 5 patients undergoing VV surgical stripping and from 5 non-VV patients undergoing bypass surgery. Specimens were collected from the same layers of venous wall. Proteins were extracted from each specimen and analyzed by ion mobility spectrometry (IMS-MS). In total, 1387 were identified and 486 proteins were identified in all samples. From these, 15 proteins were differentially expressed between VV and non-VV samples (p < .05) and 12 of these showed a fold change >1.5.

RESULTS

Interestingly, among the differentially expressed proteins, only two proteins were significantly increased in the VV tissue, that is, GAPDH (p = .028, fold change 2.74), where several proteins involved in maintaining the homeostasis in the extracellular matrix, that is, the CXXC zinc finger protein 5 (CXXC5) and nucleoporin (SEH1) were prominently downregulated (p = .049, fold change 37.8, and p = .040, fold change 3.46). The downregulation in protein expression of CXXC5 and SEH1 as well as upregulation of GAPDH were validated by Western blotting.

CONCLUSION

The identified differentially expressed proteins suggest an altered profile of the connective tissue proteins as well as an increased proteolytic enzyme activity which both may be central in the pathophysiology of varicose veins.

Flow cytometric characterization of the saphenous veins endothelial cells in patients with chronic venous disease and in patients undergoing bypass surgery: an exploratory study

Recent findings have suggested that the primary factors for development of chronic venous disease (CVD), which commonly manifests as varicose veins (VV), are due to structural and biochemical modifications of the vessel wall. The aim of this exploratory study was to characterize by flow cytometry the endothelial cells (EC) mechanically extracted from the varicose saphenous veins (VSV) segments of patients submitted to VV surgery, and to compare the expression of cell surface molecules in these EC with that observed in the EC from the graft SV (GSV) of patients undergoing bypass surgery. EC were isolated from distal- (varicose trunk) and from proximal- (nearly normal) VSV segments of 30 patients submitted to VV surgery, and from proximal GSV segments of 20 patients submitted to bypass surgery (control group), using a mechanical method, and their immunophenotype was characterized by flow cytometry. EC were identified as being CD45^negCD146^brightCD31^bright, and analyzed for expression of activation-related (CD54, CD62E, CD106), procoagulant (CD142), and cell junction (CD31, CD146) molecules, and for the scavenger receptor, CD36. The EC harvested from the SV segments of CVD patients had lower expression of all the molecules evaluated, in comparison to controls; these differences were more evident for the EC isolated from the distal-VSV. The EC extracted from the proximal- and distal-VSV segments of the CVD patients also differ from each other, the first having lower levels of CD62E, CD106, CD142 and CD36. Groups did not match for gender and controls were heterogeneous concerning the underlying pathologies, which may have a confounding effect. Our study revealed that the EC isolated from varicose (distal) and nearly normal (proximal) VSV segments of the CVD patients differ phenotypically from each other, and from the EC of the control group. The VSV segments more affected by the CVD have the lowest expression of the studied markers. We hypothesize that CVD is associated with a decrease on the EC surface molecules, causing EC dysfunctionality. Further studies with a large number of gender-matched participants are needed, to confirm the results obtained in this exploratory study.

Incidence of the MTHFR polymorphisms in patients with varicose veins

BACKGROUND

Varicose vein disease is one of the most common inherited disorders worldwide that causes mental, cosmetic, medical, and socio-economic problems. Varicose vein formation is thought to be multifactorial and often develops through the interaction of environmental and genetic risk factors. Its incidence displays a trend parallel to the distribution of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism worldwide. The objective of this study was to determine the incidence of MTHFR C677T and A1298C mutations in Turkish patients with varicose veins.

MATERIAL AND METHODS

Our study included 98 patients with varicose veins; twenty-nine (29.6 %) males and 69 (70.4 %) females, with a mean age of 52.9 ± 14.7 (age range: 12-83) years. Polymorphisms were investigated by polymerase chain reaction (PCR) which is an enzymatic reaction of DNA amplification, and allele-specific hybridization.

RESULTS

The homozygous MTHFR C677T polymorphism was detected in 13 (13.3 %), and heterozygous MTHFR C677T polymorphism in 37 (37.7 %) patients. The homozygous and heterozygous MTHFR A1298C polymorphisms were found in nine (9.2 %), and 47 (47.9 %) patients, respectively. The combined double heterozygous genotype MTHFR C677T/MTHFR A1298C was identified in 19 (19.4 %) patients. The rates of factor V Leiden (FVL) and prothrombin gene (PT G20210A) polymorphisms were found as 11.2 %, and 4.1 %, respectively. Additionally, the majority of patients with thrombosed varicose veins were accompanied by FLV polymorphism.

CONCLUSION

Our findings display that the rates of MTHFR C677T and A1298C genotypes are similar between patients with varicose veins and healthy subjects in Turkish society. However, should FLV or PG G20210A polymorphisms accompany these polymorphisms, then there might be a tendency to development of superficial venous thrombosis. Further studies are required to support these findings. HIPPOKRATIA 2017, 21(4): 175-179.