Radosław Kowalewski

Evaluation of Transforming Growth Factor-β Signaling Pathway in the Wall of Normal and Varicose Veins

Objective(s): Extracellular matrix remodeling in the vein wall is involved in varicose vein pathogenesis, with transforming growth factor β1 (TGF-β1) playing a potential role. The aim of the study was to assess the TGF-β signaling pathway including its receptor (TGF-β RII) and phosphorylated receptor-regulated Smads (p-Smad2/3) in varicose veins. Methods: Varicose veins from patients undergoing varicose vein surgery were the studied material, whereas normal greater saphenous veins from patients undergoing infrainguinal arterial bypass surgery were the control material. Expression of TGF-β RII mRNA was assessed with RT-PCR, whereas expression of TGF-β RII and p-Smad2/3 proteins was assessed with Western blot. Results: A significantly increased TGF-β RII mRNA level was found in varicose veins (287 ± 24%), when compared with normal veins (100 ± 26%). The receptor protein expression reflected a changed mRNA level with significantly increased TGF-β RII protein in varicose veins (290 ± 21%), when compared with controls (100 ± 16%). Enhanced TGF-β RII expression was accompanied by increased p-Smad2/3 protein expression in varicose veins (257 ± 19%) in comparison with normal veins (100 ± 9%). Conclusion(s): Increased TGF-β RII expression and activation in the wall of varicose veins may be involved in extracellular matrix remodeling related to TGF-β1 and supports its role in the disease pathogenesis.

Evaluation of enzymes involved in proteoglycan degradation in the wall of abdominal aortic aneurysms

The abdominal aortic aneurysm (AAA) wall represents an extreme example of arterial remodeling with disturbed elastin, collagen and proteoglycan metabolism. The aim of this study was to evaluate enzymes involved in the degradation of glycosaminoglycan chains and core proteins of proteoglycans in the AAA wall. The study material consisted of wall samples from 10 AAA. Fragments of 5 normal abdominal aortas from organ donors were used as a control. The activity of endoglycosidases, exoglycosidases and sulfatases was measured using colorimetric methods. To assess matrix metalloproteinases (MMPs), Western blot and zymography were performed. The activity of endoglycosidase degrading chondroitin-4-sulfate was lower in the AAA wall. Endoglycosidase degrading heparan sulfate and dermatan sulfate, arylosulfatase B, as well as all the exoglycosidases assessed demonstrated higher activities in the AAA wall. Furthermore, increased expression of MMP1, MMP2 and MMP9 was also shown in the AAA wall. Zymography revealed decreased activity of pro-MMP2 and presence of pro-MMP9 in the AAA wall compared to the wall of normal aorta. Extensive changes in the activity of glycosaminoglycan-degrading enzymes and MMPs may influence the organization of the extracellular matrix network and lead to previously demonstrated changes in the proteoglycan and glycosaminoglycan content in the AAA wall.

Evaluation of aFGF/bFGF and FGF Signaling Pathway in the Wall of Varicose Veins

BACKGROUND Extensive extracellular matrix remodeling of the vein wall is involved in varicose veins pathogenesis. The process is controlled by numerous factors, including peptide growth factors. The aim of the study was to evaluate acidic (aFGF) and basic (bFGF) fibroblast growth factors, their receptor (FGFR) and the MAP kinase pathway (ERK 1/2) in the wall of varicose and varicose veins complicated by thrombophlebitis, when compared to normal ones. METHODS Segments of normal, varicose, and varicose veins complicated by thrombophlebitis were collected during varicose veins surgery in 17 patients. Expression and content of aFGF and bFGF were evaluated with Western blot and enzyme-linked immunosorbent assay (ELISA) methods, respectively, whereas RT-PCR was employed to assess mRNA level of growth factors. Expression of FGFR and ERK 1/2 was examined with Western blot method. RESULTS Increased aFGF expression and content were accompanied by increased aFGF mRNA level in the wall of varicose veins. Furthermore, alternatively spliced aFGF mRNA was shown in varicose veins complicated by thrombophlebitis. Expression, content, and mRNA level of bFGF were comparable in the investigated material. FGFR and ERK 1/2 expression was demonstrated in the wall of diseased veins, however, without any significant differences in comparison with the wall of normal veins. CONCLUSIONS Overexpressed aFGF in the wall of varicose veins via FGFR and the MAP kinase pathway may influence expression of enzymes involved in extracellular matrix metabolism and play a role in vein wall remodeling, as well as in the disease pathogenesis.

Glycosaminoglycans of Normal Veins and Their Alterations in Varicose Veins and Varicose Veins Complicated by Thrombophlebitis

The aim of the study was to examine the content and molecular differentiation of glycosaminoglycans (GAGs) in the wall of varicose veins. The studied material consisted of normal, varicose veins and varicose veins complicated by thrombophlebitis collected during operations on 26 patients. In the wall of varicose veins the mean GAGs’ content as well as the content of sulphated GAGs, except heparan sulphate was increased, whereas the amount of hyaluronic acid was decreased. Furthermore, the increased quantitative ratio between sulphated and nonsulphated GAGs was demonstrated. The results indicate an evident extracellular matrix remodelling in the wall of varicose veins particularly those complicated by thrombophlebitis, that is characterised by alterations in the content and molecular differentiation of GAGs.

Assessment of inflammatory infiltration and angiogenesis in the thrombus and the wall of abdominal aortic aneurysms on the basis of histological parameters and computed tomography angiography study

The proliferation of vessels within the aneurysms wall and the intraluminal thrombus of abdominal aortic aneurysm (AAA) may be the main factor responsible for progression and rupture of AAA. The aim of this study was to compare the parameters of the thrombus (size, density, contrast enhancement) measured by com- puted tomography (CT) with histological assessment of thrombi removed during surgery. 29 patients with AAA were examined with angio-CT. Post-surgery histopathological evaluation of AAA was performed. Slides were stained with markers of B- (CD20) and T-lymphocytes (CD3), and markers of endothelial cells (CD34). Throm- bi were enhanced after contrast media administration in angio-CT (p = 0.002). There was a statistically signifi- cant correlation between contrast enhancement and the presence of B lymphocytes. Intensity of endothelial cell marker expression significantly correlated with the presence of inflammatory T- and B-cells. No statistical signif- icant correlation was found between contrast enhancement of the thrombus and markers of endothelial cells. The accumulation of inflammatory cells in the wall of AAA thrombus results in the formation of new vessels which participates to the instability of the thrombus and AAA wall. Assessment of the inflammation and neovas- cularization in the wall and thrombus of the AAA might be an important factor in monitoring the progression and the risk of aneurysms rupture. (Folia Histochemica et Cytobiologica 2012, Vol. 50, No. 4, 547-553)

Influence of thrombophlebitis on TGF-β1 and its signaling pathway in the vein wall.

Extensive extracellular matrix remodeling of the vein wall is involved in varicose veins pathogenesis. This process is controlled by numerous factors, including peptide growth factors. The aim of the study was to evaluate influence of thrombophlebitis on TGF-β1 and its signaling pathway in the vein wall. TGF-β1 mRNAlevels, growth factor content and its expression were evaluated by RT-PCR, ELISA, and western blot methods, respectively, in the walls of normal veins, varicose veins and varicose veins complicated by thrombophlebitis. Western blot analysis was used to assess TGF-β receptor type II (TGF-β RII) and p-Smad2/3 protein expression in the investigated material. Unchanged mRNA levels of TGF-β1, decreased TGF-β1 content, as well as decreased expression of latent and active forms of TGF-β1 were found in varicose veins. Increased expression of TGF-β RII and p-Smad2/3 were found in varicose veins. Thrombophlebitis led to increased protein expression of the TGF-β1 active form and p-Smad2/3 in the vein wall compared to varicose veins. TGF-β1 may play a role in the disease pathogenesis because of increased expression and activation of its receptor in the wall of varicose veins. Thrombophlebitis accelerates activation of TGF-β1 and activity of its receptor in the varicose vein wall.

Evaluation of Vascular Endothelial Growth Factor and Its Receptors in Human Neointima

Objective: The potential contribution of vascular endothelial growth factor (VEGF) in neointima development has been evaluated in numerous animal studies. However, its role remains controversial. Moreover, little is known about neointima formation in humans. In this study we assessed the expression of VEGF-A and its receptors in the human neointima formed within vascular anastomosis. Methods: The studied material comprised neointima samples harvested during secondary vascular operations from patients with chronic limb ischemia after aorto-/iliofemoral bypass grafting who developed vascular graft occlusion at 6-18 months after the initial surgical treatment. The control material consisted of segments of femoral arteries without visible macroscopic lesions collected from organ donors. The expression and content of VEGF-A, VEGFR-1 and VEGFR-2 were analyzed with PCR and ELISA methods, respectively. Results: We observed a significantly increased expression of VEGF-A and VEGFR-2 mRNA in neointima compared to the normal aorta. A significantly higher protein content of VEGF-A and VEGFR-2 in neointima samples compared to the controls was also observed. No significant difference of VEGFR-1 content and VEGFR-1 mRNA expression was found in the studied material. Conclusion: These results indicate a possible involvement of the VEGF-A and VEGFR-2 system in the pathologic process of human neointima formation after vascular interventions.

Ocena skuteczności leczenia endowaskularnego zwężeń i niedrożności tętnicy biodrowej wspólnej oraz zewnętrznej przy użyciu stentu samorozprężalnego Jaguar SM

Summary The goal of this work was to assess the effectiveness of endovascular treatment of common and external iliac artery stenosis/occlusion classified according to TASC using a self-expanding stent Jaguar SM. The study group included 95 patients (61 men and 34 women) who underwent treatment for stenosis or occlusion of lower limb arteries at the Department of Radiology of the University Hospital in Bialystok and the Diagnostic Radiology Department of the Central Clinical Hospital of the Ministry of Interior (MSWiA) in Warsaw between 2005 and 2007. All arterial lesions were of atherosclerotic etiology. The shortest stenotic fragment was 10 mm long and the longest occluded arterial fragment did not exceed 90 mm. Morphological classification of iliac artery lesions in treated patients was performed according to TASC II classification and included 10 patients with type A, 39 cases of type B, 36 with type C and 10 patients with type D lesions. Endovascular procedure failed to restore flow in five patients with TASC type D lesions, who were later referred for surgery. One patient suffered a complication – vessel perforation during predilatation, and had a stentgraft implanted. In 95% of patients stents were expanded using a balloon after implantation. Good results were achieved in practically all patients who underwent stent implantation. Patients were subjected to follow-up clinical and imaging evaluation during next 1–24 months. Success rate of the performed procedures as well as in a 30-day observation period was 100% in case of stenosis and 80% in case of vessel occlusion. A follow-up after 12 and 24 months showed patency of treated vessels in 84% and 76% of patients, respectively.

Hybrid thoracoabdominal procedure for acute aortic dissection Stanford type A using the EVITA OPEN PLUS – case report

Rozwarstwienie aorty typu A wg Stanford to stan zagrożenia życia wymagający pilnej interwencji kardiochirurgicznej. Obecnie obok klasycznych metod operacyjnych możliwe jest zastosowanie technik endowaskularnych. Przedmiotem niniejszego artykułu jest prezentacja przypadku 58-letniej chorej leczonej wieloetapowo z powodu rozwarstwienia aorty typu A wg Stanford, z wykorzystaniem technik hybrydowych, u której zakres leczenia objął całą aortę od zastawki aortalnej, z jej wymianą, do tętnic biodrowych. Słowa kluczowe: rozwarstwienie aorty typu A, operacja hybrydowa. Abstract