Elastin Fibers Research Articles

Cyclo-VEGI inhibits bronchial artery remodeling in a murine model of chronic asthma

Purpose/Aim: In the context of asthma, airway bronchial remodeling and angiogenesis in the bronchial mucosa are well established. Cyclopeptidic-vascular endothelial growth inhibitor (cyclo-VEGI) is an inhibitor of the vascular endothelial growth factor (VEGF) receptor that increases the proliferation of endothelial cells and the formation of new vessels. However, changes in the bronchial arteries of patients with asthma have not been clearly elucidated. We investigated whether structural changes occurred in bronchial arteries, as well as the effects of cyclo-VEGI in a mouse model of chronic asthma (in vivo) and human fibroblasts (in vitro). Materials and Methods: A validated mouse model of allergic airway inflammation with ovalbumin (OVA) as the causative allergen was used for the study. Mice were treated with cyclo-VEGI or fluticasone during OVA challenge. In vitro experiments were conducted to determine whether fibroblasts proliferated following elastin exposure and the effects of cyclo-VEGI on them. Results: OVA sensitization and challenge led to greater perivascular smooth muscle area, more elastic fibers, and elevated expression of vascular cell adhesion molecule (VCAM)-1 antigen. These phenomena indicated changes to bronchial arteries. Cyclo-VEGI and fluticasone treatment both inhibited airway hyper-responsiveness and inflammation. Cyclo-VEGI-treated mice exhibited decreased perivascular smooth muscle area, elastin fibers, and VCAM-1 expression. Fluticasone-treated mice exhibited reductions in perivascular smooth muscle but not in perivascular elastin or VCAM-1 expression. In vitro, fibroblast proliferation was enhanced by elastin treatment, which was inhibited by cyclo-VEGI treatment. Eotaxin expression was elevated in elastin-treated fibroblasts and decreased with cyclo-VEGI treatment. Conclusions: Vascular remodeling occurred in our mouse model of chronic asthma. Cyclo-VEGI could reduce airway inflammation and hyper-responsiveness by inhibiting VCAM-1 expression and elastin deposition around the bronchial arteries.

Matrix Gla Protein Levels Are Associated With Arterial Stiffness and Incident Heart Failure With Preserved Ejection Fraction.

Arterial stiffness is a risk factor for cardiovascular disease, including heart failure with preserved ejection fraction (HFpEF). MGP (matrix Gla protein) is implicated in vascular calcification in animal models, and circulating levels of the uncarboxylated, inactive form of MGP (ucMGP) are associated with cardiovascular disease-related and all-cause mortality in human studies. However, the role of MGP in arterial stiffness is uncertain. Approach and Results: We examined the association of ucMGP levels with vascular calcification, arterial stiffness including carotid-femoral pulse wave velocity (PWV), and incident heart failure in community-dwelling adults from the Framingham Heart Study. To further investigate the link between MGP and arterial stiffness, we compared aortic PWV in age- and sex-matched young (4-month-old) and aged (10-month-old) wild-type and Mgp+/- mice. Among 7066 adults, we observed significant associations between higher levels of ucMGP and measures of arterial stiffness, including higher PWV and pulse pressure. Longitudinal analyses demonstrated an association between higher ucMGP levels and future increases in systolic blood pressure and incident HFpEF. Aortic PWV was increased in older, but not young, female Mgp+/- mice compared with wild-type mice, and this augmentation in PWV was associated with increased aortic elastin fiber fragmentation and collagen accumulation. This translational study demonstrates an association between ucMGP levels and arterial stiffness and future HFpEF in a large observational study, findings that are substantiated by experimental studies showing that mice with Mgp heterozygosity develop arterial stiffness. Taken together, these complementary study designs suggest a potential role of therapeutically targeting MGP in HFpEF.

Visualization and Quantification of the Extracellular Matrix in Prostate Cancer Using an Elastin Specific Molecular Probe.

Simple SummaryOne of the most commonly diagnosed cancers in men is prostate cancer (PCa). Understanding tumor progression can help diagnose and treat the disease at an early stage. Components of the extracellular matrix (ECM) play a key role in the development and progression of PCa. Elastin is an essential component of the ECM and constantly changes during tumor development. This article visualizes and quantifies elastin in magnetic resonance imaging (MRI) using a small molecule probe. Results were correlated with histological examinations. Using an elastin-specific molecular probe, we were able to make predictions about the cellular structure in relation to elastin and thus draw conclusions about the size of the tumor, with smaller tumors having a higher elastin content than larger tumors.Human prostate cancer (PCa) is a type of malignancy and one of the most frequently diagnosed cancers in men. Elastin is an important component of the extracellular matrix and is involved in the structure and organization of prostate tissue. The present study examined prostate cancer in a xenograft mouse model using an elastin-specific molecular probe for magnetic resonance molecular imaging. Two different tumor sizes (500 mm3 and 1000 mm3) were compared and analyzed by MRI in vivo and histologically and analytically ex vivo. The T1-weighted sequence was used in a clinical 3-T scanner to calculate the relative contrast enhancement before and after probe administration. Our results show that the use of an elastin-specific probe enables better discrimination between tumors and surrounding healthy tissue. Furthermore, specific binding of the probe to elastin fibers was confirmed by histological examination and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS). Smaller tumors showed significantly higher signal intensity (p > 0.001), which correlates with the higher proportion of elastin fibers in the histological evaluation than in larger tumors. A strong correlation was seen between relative enhancement (RE) and Elastica–van Gieson staining (R2 = 0.88). RE was related to inductively coupled plasma–mass spectrometry data for Gd and showed a correlation (R2 = 0.78). Thus, molecular MRI could become a novel quantitative tool for the early evaluation and detection of PCa.

Fundamentals of vaping-associated pulmonary injury leading to severe respiratory distress.

Vaping of flavored liquids has been touted as safe alternative to traditional cigarette smoking with decreased health risks. The popularity of vaping has dramatically increased over the last decade, particularly among teenagers who incorporate vaping into their daily life as a social activity. Despite widespread and increasing adoption of vaping among young adults, there is little information on long-term consequences of vaping and potential health risks. This study demonstrates vaping-induced pulmonary injury using commercial JUUL pens with flavored vape juice using an inhalation exposure murine model. Profound pathological changes to upper airway, lung tissue architecture, and cellular structure are evident within 9 wk of exposure. Marked histologic changes include increased parenchyma tissue density, cellular infiltrates proximal to airway passages, alveolar rarefaction, increased collagen deposition, and bronchial thickening with elastin fiber disruption. Transcriptional reprogramming includes significant changes to gene families coding for xenobiotic response, glycerolipid metabolic processes, and oxidative stress. Cardiac systemic output is moderately but significantly impaired with pulmonary side ventricular chamber enlargement. This vaping-induced pulmonary injury model demonstrates mechanistic underpinnings of vaping-related pathologic injury.

Natural Compound Resveratrol Attenuates TNF-Alpha-Induced Vascular Dysfunction in Mice and Human Endothelial Cells: The Involvement of the NF-κB Signaling Pathway.

Resveratrol, a natural compound in grapes and red wine, has drawn attention due to potential cardiovascular-related health benefits. However, its effect on vascular inflammation at physiologically achievable concentrations is largely unknown. In this study, resveratrol in concentrations as low as 1 μm suppressed TNF-α-induced monocyte adhesion to human EA.hy926 endothelial cells (ECs), a key event in the initiation and development of atherosclerosis. Low concentrations of resveratrol (0.25–2 μm) also significantly attenuated TNF-α-stimulated mRNA expressions of MCP-1/CCL2 and ICAM-1, which are vital mediators of EC-monocyte adhesion molecules and cytokines for cardiovascular plaque formation. Additionally, resveratrol diminished TNF-α-induced IκB-α degradation and subsequent nuclear translocation of NF-κB p65 in ECs. In the animal study, resveratrol supplementation in diet significantly diminished TNF-α-induced increases in circulating levels of adhesion molecules and cytokines, monocyte adhesion to mouse aortic ECs, F4/80-positive macrophages and VCAM-1 expression in mice aortas and restored the disruption in aortic elastin fiber caused by TNF-α treatment. The animal study also confirmed that resveratrol blocks the activation of NF-κB In Vivo. In conclusion, resveratrol at physiologically achievable concentrations displayed protective effects against TNF-α-induced vascular endothelial inflammation in vitro and In Vivo. The ability of resveratrol in reducing inflammation may be associated with its role as a down-regulator of the NF-κB pathway.

Is It Good to Have a Stiff Aorta with Aging? Causes and Consequences.

Aortic stiffness increases with advancing age, more than doubling during the human life span, and is a robust predictor of cardiovascular disease (CVD) clinical events independent of traditional risk factors. The aorta increases in diameter and length to accommodate growing body size and cardiac output in youth, but in middle and older age the aorta continues to remodel to a larger diameter, thinning the pool of permanent elastin fibers, increasing intramural wall stress and resulting in the transfer of load bearing onto stiffer collagen fibers. Whereas aortic stiffening in early middle age may be a compensatory mechanism to normalize intramural wall stress and therefore theoretically "good" early in the life span, the negative clinical consequences of accelerated aortic stiffening beyond middle age far outweigh any earlier physiological benefit. Indeed, aortic stiffness and the loss of the "windkessel effect" with advancing age result in elevated pulsatile pressure and flow in downstream microvasculature that is associated with subclinical damage to high-flow, low-resistance organs such as brain, kidney, retina, and heart. The mechanisms of aortic stiffness include alterations in extracellular matrix proteins (collagen deposition, elastin fragmentation), increased arterial tone (oxidative stress and inflammation-related reduced vasodilators and augmented vasoconstrictors; enhanced sympathetic activity), arterial calcification, vascular smooth muscle cell stiffness, and extracellular matrix glycosaminoglycans. Given the rapidly aging population of the United States, aortic stiffening will likely contribute to substantial CVD burden over the next 2-3 decades unless new therapeutic targets and interventions are identified to prevent the potential avalanche of clinical sequelae related to age-related aortic stiffness.

Histologic Analysis of Urethral Stricture in 9 Patients Following Dorsal Vaginal Graft Urethroplasty.

To present the pathologic analysis of female urethral strictures obtained during reconstructive urethroplasty. Nine separate female urethral tissue specimens were obtained during dorsal vaginal graft urethroplasty by a single surgeon (S.P.P.). Samples were serially sectioned and fixed in 10% formalin 6 to 12 hours before routine processing in paraffin blocks. Serial 5-µm sections were subjected to H&E, Masson trichrome, and elastin staining. End point analysis included evaluation for epithelial hyperplasia and cell type, mucosal edema, degree of fibroblast/inflammatory cell infiltrate, and elastin fiber density and distribution. Nine specimens were examined. Six specimens had epithelial linings of stratified squamous epithelium overlying fibrosis (67%), 1 had mixed squamous and urothelial epithelium, and 2 had only urothelial epithelium. Two specimens (29%) showed acute injury with prominent squamous papillary hyperplasia, focal erosion, and patchy mucosal hemorrhage. Areas of urethral stricture were variably thickened, with increased, densely packed collagen fibers and associated mucosal lymphocytic inflammation ranging from mild and patchy to focally dense with lymphoid aggregates. The highest elastin fiber density appeared to be associated with vessels and overlying muscle bundles in the submucosa. Further elucidation of histopathologic characteristics may illuminate more appropriate therapeutic pathways for female urethral stricture disease management.

Evaluation of Anti-Photoaging Effects of a Novel Cosmeceutical Containing a Retinoids Mixture Using In Vitro Cell Models

Physiological ageing due to the passing of time and prolonged exposure to harmful sun rays generate wrinkles and reduce skin elasticity. These visible and clinical signs can be prevented or reversed by known strategies, such as the daily use of cosmetic products with antioxidant combinations or retinoids. A new dermocosmetic formulation enriched with a complex of retinoids, called RETINOIDS SERUM, was investigated through in vitro assays using human skin cells. The experiments were carried out to assess the anti-ageing activity in normal human dermal fibroblasts (NHDF) and epidermal keratinocytes (HaCaT). After the preliminary MTT assay, the proliferation together with the synthesis of collagen and elastin fibers was performed on NHDF cells after 24 h treatment with the two non-cytotoxic concentrations. Using UVB-irradiated HaCaT cells, the measurement of matrix metalloproteinase-1 (MMP-1) levels was also investigated. In vitro studies show that the dermocosmetic product improves collagen and elastin synthesis and the renewal of dermal fibroblasts. Moreover, a reduction in the MMP-1 secretion was also highlighted in UVB-irradiated HaCaT cells. These results suggest that the cosmetic formulation containing functional compounds such as retinoids can be useful to prevent the natural sign of ageing.

Angiotensin II receptor blockers in modulation of transforming growth factor-beta effects on mitral valve myxomatous degeneration

Abstract Growing evidence supports role transforming growth factor-β (TGF-β) as a mediator of the myxomatous changes in the mitral valve prolapse. Recently, angiotensin II receptor blockers (ARB) emerged as a potentially effective inhibitor of TGF-β signaling. Treatment of valvular interstitial cells (VICs) with ARB resulted in effective inhibition of TGF-β-induced ECM expression. Our aim was to evaluate the effect of preoperative ARB therapy in modulation of transforming growth factor-β effects on mitral valve myxomatous degeneration. Methods A total of 233 asymptomatic patients (mean age: 53.8±12.9) undergoing mitral valve surgery for severe mitral regurgitation due to mitral valve prolapse were enrolled in our retrospective, non-randomized, single-center study. Resected abnormal segments of the mitral leaflets (segment of the posterior leaflet or the entire valve) were obtained during mitral valve repair/replacement surgery and examined by experienced pathologists. Immunohistochemical characterization of mitral valve sections was performed with the primary antibodies. Quantification was performed by counting TGF-β1 and TGF-β2 positive cells within 10 random high-power fields divided by the total number of cells in specimens. Quantification of immunohistochemical staining for collagen III was performed by measurement of staining area divided by the total area of the specimens. Results Two hundred thirty-three consecutive patients (66% males, mean age 53.8±12.9 years, range 19–80) with severe MR were enrolled in the study. According to the case reports, 43 patients (18.5%) received losartan or telmisartan before surgery and were included in study group. 190 patients (81.5%) did not receive any ARB and were enrolled in the control group. Histological examination showed disorganized collagen and elastin fibers, expansion of the spongiosa layer in both groups. However, MV specimens' immunohistochemistry revealed a lower expression of type III collagen in ARB group as compared to controls (31.3% ± 10.8% vs. 43.8% ± 15.3%; p<0.001). MV leaflets in control group showed the increased VICs density (95.3±39.9 vs. 70.0±21.7/high-power field, p=0.0001). TGF-β1 and TGF-β2 positive cells were significantly rare in the ARB than in control MV specimens (18% vs. 33%, p=0.012 and 16% vs. 38%, p<0.ehab724.15541, respectively). Expression of type III collagen and TGF-β2 positive cells count showed a weak, but significant correlation (r=0.28; p=0.ehab724.155414). The multivariate Cox analysis showed a decrease in the relative risk of valvular thickening (myxomatous degeneration) with ARB therapy (0.85; 95% CI: 0.61 – 1.17; p=0.01). Conclusions We indicate a beneficial effect of ARB treatment through the inhibition of TGF-β pathway on valvular myxomatous degeneration in patients with MVP. Modulation of the progression of MVP with such therapeutic agents may have great clinical significance. Funding Acknowledgement Type of funding sources: None.

Vascular Stiffening Mediated by Rho-Associated Coiled-Coil Containing Kinase Isoforms.

BackgroundThe pathogenesis of vascular stiffening and hypertension is marked by non‐compliance of vessel wall because of deposition of collagen fibers, loss of elastin fibers, and increased vascular thickening. Rho/Rho‐associated coiled‐coil containing kinases 1 and 2 (ROCK1 and ROCK2) have been shown to regulate cellular contraction and vascular remodeling. However, the role of ROCK isoforms in mediating pathogenesis of vascular stiffening and hypertension is not known.Methods and ResultsHemizygous Rock mice (Rock1 +/− and Rock2 +/−) were used to determine the role of ROCK1 and ROCK2 in age‐related vascular dysfunction. Both ROCK activity and aortic stiffness increased to a greater extent with age in wild‐type mice compared with that of Rock1 +/− and Rock2 +/− mice. As a model for age‐related vascular stiffening, we administered angiotensin II (500 ng/kg per minute) combined with nitric oxide synthase inhibitor, L‐Nω‐nitroarginine methyl ester (0.5 g/L) for 4 weeks to 12‐week‐old male Rock1 +/− and Rock2 +/− mice. Similar to advancing age, angiotensin II/L‐Nω‐nitroarginine methyl ester caused increased blood pressure, aortic stiffening, and vascular remodeling, which were attenuated in Rock2 +/−, and to a lesser extent, Rock1 +/− mice. The reduction of aortic stiffening in Rock2 +/− mice was accompanied by decreased collagen deposition, relatively preserved elastin content, and less aortic wall hypertrophy. Indeed, the upregulation of collagen I by transforming growth factor‐β1 or angiotensin II was greatly attenuated in Rock2 −/− mouse embryonic fibroblasts.ConclusionsThese findings indicate that ROCK1 and ROCK2 mediate both age‐related and pharmacologically induced aortic stiffening, and suggest that inhibition of ROCK2, and to a lesser extent ROCK1, may have therapeutic benefits in preventing age‐related vascular stiffening.

Brillouin confocal microscopy to determine biomechanical properties of SULEEI-treated bovine pericardium for application in cardiac surgery.

Heart valves are exposed to a highly dynamic environment and underlie high tensile and shear forces during opening and closing. Therefore, analysis of mechanical performance of novel heart valve bioprostheses materials, like SULEEI-treated bovine pericardium, is essential and usually carried out by uniaxial tensile tests. Nevertheless, major drawbacks are the unidirectional strain, which does not reflect the in vivo condition and the deformation of the sample material. An alternative approach for measurement of biomechanical properties is offered by Brillouin confocal microscopy (BCM), a novel, non-invasive and three-dimensional method based on the interaction of light with acoustic waves. BCM is a powerful tool to determine viscoelastic tissue properties and is, for the first time, applied to characterize novel biological graft materials, such as SULEEI-treated bovine pericardium. Therefore, the method has to be validated as a non-invasive alternative to conventional uniaxial tensile tests. Vibratome sections of SULEEI-treated bovine pericardium (decellularized, riboflavin/UV-cross-linked and low-energy electron irradiated) as well as native and GA-fixed controls (n = 3) were analyzed by BCM. In addition, uniaxial tensile tests were performed on equivalent tissue samples and Young's modulus as well as length of toe region were analyzed from stress-strain diagrams. The structure of the extracellular matrix (ECM), especially collagen and elastin, was investigated by multiphoton microscopy (MPM). SULEEI-treated pericardium exhibited a significantly higher Brillouin shift and hence higher tissue stiffness in comparison to native and GA-fixed controls (native: 5.6±0.2 GHz; GA: 5.5±0.1 GHz; SULEEI: 6.3±0.1 GHz; n = 3, p < 0.0001). Similarly, a significantly higher Young's modulus was detected in SULEEI-treated pericardia in comparison to native tissue (native: 30.0±10.4 MPa; GA: 31.8±10.7 MPa; SULEEI: 42.1±7.0 MPa; n = 3, p = 0.027). Native pericardia showed wavy and non-directional collagen fibers as well as thin, linear elastin fibers generating a loose matrix. The fibers of GA-fixed and SULEEI-treated pericardium were aligned in one direction, whereat the SULEEI-sample exhibited a much denser matrix. BCM is an innovative and non-invasive method to analyze elastic properties of novel pericardial graft materials with special mechanical requirements, like heart valve bioprostheses.

167 Contribution of miRNAs as epigenetic regulators of Retinol efficacy in the skin dermis

Vitamin A and its derivatives, particularly retinol, slow both chronological and photo-induced aging processes. Retinol reduces the appearance of wrinkles and the decrease of the skin firmness and elasticity by protecting against collagen and elastin fiber changes. In addition to retinol’s rejuvenating skin benefits through direct transcriptional activation, recent studies also suggest an epigenetic regulation through micro-RNAs (miRNAs) modulation. We investigated how retinol supports the stimulation of type I collagen and elastin through proteomic, transcriptomic and epigenetic miRNA- expression changes in human skin fibroblasts.

130 Skin ageing: an explorative study based on mechanical properties investigated by Atomic Force Microscopy

Skin constitutes a barrier against external injuries and contributes to the maintenance of homeostasis. Dermis with collagen and elastin fibres has a role of support with the extracellular matrix (ECM). During ageing numerous mechanisms induce skin degradation by loss of elasticity, skin thickness and collagen network disorganization. Atomic Force Microscopy (AFM) has been described as a reliable tool to study mechanical properties of various samples. The purpose here is to develop an AFM-based method to quantify nanoscale changes in the biomechanical properties of the different skin layers. Firstly, the global skin explant mechanical properties were measured by AFM Stiffness Tomography (ST), secondly the impact of skin ageing at cellular level was explored (structure and tension between cells, tension between cell and matrix). Three groups from 10 different ages donors were studied (below 30 years old (yo), from 30 to 50 yo and above 50 yo). At the tissue level, a controlled AFM indentation with a spherical tip was applied on fresh tissue sample. Skin explant was maintained by a special device designed to induce an isotropic tension. Mechanical properties were extracted gradually by ST along the skin depth. A global skin elastic modulus evaluation was provided according to the different ages. Then, cryosectionned skin samples were characterized with a sharper AFM tip. The elastic modulus of cell-cell junctions was measured in epidermis and ECM mechanical properties were assessed in the dermis (papillary and reticular). Data showed a general increase of dermis and epidermis elastic modulus across ageing. At the cellular level, epidermic elastic modulus heterogeneity has been showed with an increase of the basal layer skin stiffness. We also observed a bell-curve distribution of the elastic modulus for the papillary dermis and an increase of the reticular dermis rigidity.

Epi-O-07 - Granulomatous slack skin: clinical retrospective study of 8 cases of the Cutaneous Lymphoma French Study Group

Granulomatous slack skin (GSS) is a rare variant of mycosis fungoides (MF) presenting clinically as pendulous and lax plaques or tumours and histologically as a dermal infiltrate of neoplastic T-cells with multinucleated giant cells, loss of dermal elastin fibres and sometimes elastophagocytosis and lymphophagocytosis. Because of its scarcity, GSS is poorly known. The aim of this study was to describe the clinical and evolutive features and the response to treatment of a GSS cohort. In this retrospective multicenter study, we have identified the cases of GSS in the Cutaneous Lymphoma French Study Group database and member centers.

Biomimetic Elastin Fiber Patch in Rat Aorta Angioplasty.

Introduction: Vascular grafts significantly contribute to advances in vascular surgery, but none of the currently available prosthetic grafts have elastin fibers similar to native arteries. We hypothesized that a novel elastin patch could be produced after a rat decellularized thoracic aorta elastin fiber scaffold is implanted subcutaneously in rats; we tested this novel elastin patch in a rat aortic arterioplasty model. Methods: Sprague–Dawley rats (200 g) were used. Rat thoracic aortae were decellularized and sectioned at a thickness of 30 μm. A single elastin fiber scaffold was fabricated as a net (5 × 5 mm2), and then a three-layer scaffold was constructed to make a new patch. The hyaluronic acid–sodium alginate (HA/SA) hydrogel was fabricated by reacting sodium SA, HA, and CaCO3, and then the hydrogel was added to the patch to secure the elastin fibers. The patches were implanted subcutaneously in rats and harvested at day 14. The elastin patches were then implanted into the same rat’s aorta and harvested at day 14; a decellularized rat thoracic aorta (TA) patch was used as a control. Sections of the retrieved patches were stained by immunohistochemistry and immunofluorescence. Results: The elastin fibers could be secured by the hydrogel. After 14 days, the subcutaneously implanted elastin patch was incorporated into the rat tissue, and H&E staining showed that new tissue had formed around the elastin patch with almost no hydrogel left. After implantation into the rat aorta and then retrieval on day 14, H&E staining showed that there was neointima and adventitia formation in both the TA and elastin patch groups. Both patches showed a similar histological structure after implantation, and immunofluorescence showed that there were CD34- and nestin-positive cells in the neointima. In both groups, the endothelial cells expressed the arterial identity markers Ephrin-B2 and dll-4; almost one-third of the cells in the neointima were PCNA-positive with rare cleaved caspase-3-positive cells. Conclusion: We demonstrated a novel approach to making elastin fiber scaffold hydrogel patches (elastin patches) and tested them in a rat aorta arterioplasty model. This patch showed a similar healing process as the decellularized TA patch; it also showed potential applications in large animals and may be a substitute for prosthetic grafts in vascular surgery.

Ultrastructural pathology of bioprosthetic heart valves with infectious endocarditis

Aim. To study the ultrastructure of mitral bioprosthetic heart valves (BHVs) which failed due to infective endocarditis.Materials and Methods. Here we examined 7 ethylene glycol diglycidyl ether-treated xenopericardial BHVs excised during repeated BHV replacement because of prosthetic endocarditis. After being fixed in formalin and postfixed in osmium tetroxide, BHVs were dehydrated and stained in uranyl acetate with the subsequent embedding into epoxy resin, grinding, polishing, and lead citrate counterstaining. Upon the sputter coating with carbon, we visualised the BHV microanatomy by means of backscattered scanning electron microscopy at 15 kV voltage.Results. The extracellular matrix underwent degradation and disintegration resulting in loosening, fragmentation, and reduction in the electron density of collagen and elastin fibers. We observed a number of recipient cells (macrophages, multinucleated giant cells, neutrophils, endothelial cells and smooth muscle cells) within the BHVs. The highest number of cells was localized on the valve surfaces. The localization of the recipient cells on the ventricular and atrial surfaces was different. The central part of the valves was abundantly populated by macrophages.Conclusion. Prosthetic endocarditis is accompanied by the migration of recipient cells into the BHV structure, which is the consequence of surface and extracellular matrix disintegration.

Pilot Gene Expression and Histopathologic Analysis of Tracheal Resections in Tracheobronchomalacia

BackgroundThe airway structures and messenger RNA expression of genes that regulate airway inflammation and remodeling may be altered in the trachea of patients with tracheobronchomalacia (TBM). MethodsFourteen tracheal specimens obtained from 2005 to 2018 were used in this study. Surgical resection specimens from patients with TBM and tracheal stenosis (TS) were compared with control tracheal specimens obtained from autopsy cases. We investigated the messenger RNA expression of genes encoding fibroblast growth factor (FGF) binding protein 2 (FGFBP2), FGF receptor R3 (FGFR3), interleukin-1β (IL1β), tumor growth factor-β1 (TGFβ1), tissue inhibitor of metalloproteinases 1 (TIMP1), and intercellular adhesion molecule 1 (ICAM1) as well as established markers of airway inflammation including interferon-γ (IFNγ) and tumor necrosis factor (TNF). The relative expression of target transcripts was assessed by quantitative real-time polymerase chain reaction. A histologic examination of the same resected airway specimens was performed on formalin-fixed paraffin-embedded tissue sections. ResultsFGFBP2 and FGFR3 showed higher expression in TBM compared with TS and control groups (P < .05 and P < .01, respectively). Furthermore, both TGFβ1 and TIMP1 were elevated in TBM patients compared with control subjects (P < .05). Conversely ICAM1 was downregulated in TBM versus TS and control subjects (P < .05). IL1β, IFNγ, and TNF were increased in TBM, although it did not achieve statistical significance. Histologically compared with control airways both TBM and TS demonstrated submucosal fibrotic changes, with TBM additionally demonstrating alterations in elastin fiber quality and density in the posterior membrane. ConclusionsSignificant changes in gene expression are observed in the tracheal walls of patients with TBM and TS compared with control subjects.

Hyaluronic Acid/Collagen Nanofiber Tubular Scaffolds Support Endothelial Cell Proliferation, Phenotypic Shape and Endothelialization.

In this study, we designed and synthetized artificial vascular scaffolds based on nanofibers of collagen functionalized with hyaluronic acid (HA) in order to direct the phenotypic shape, proliferation, and complete endothelization of mouse primary aortic endothelial cells (PAECs). Layered tubular HA/collagen nanofibers were prepared using electrospinning and crosslinking process. The obtained scaffold is composed of a thin inner layer and a thick outer layer that structurally mimic the layer the intima and media layers of the native blood vessels, respectively. Compared with the pure tubular collagen nanofibers, the surface of HA functionalized collagen nanofibers has higher anisotropic wettability and mechanical flexibility. HA/collagen nanofibers can significantly promote the elongation, proliferation and phenotypic shape expression of PAECs. In vitro co-culture of mouse PAECs and their corresponding smooth muscle cells (SMCs) showed that the luminal endothelialization governs the biophysical integrity of the newly formed extracellular matrix (e.g., collagen and elastin fibers) and structural remodeling of SMCs. Furthermore, in vitro hemocompatibility assays indicated that HA/collagen nanofibers have no detectable degree of hemolysis and coagulation, suggesting their promise as engineered vascular implants.

Percolation of collagen stress in a random network model of the alveolar wall

Fibrotic diseases are characterized by progressive and often irreversible scarring of connective tissue in various organs, leading to substantial changes in tissue mechanics largely as a result of alterations in collagen structure. This is particularly important in the lung because its bulk modulus is so critical to the volume changes that take place during breathing. Nevertheless, it remains unclear how fibrotic abnormalities in the mechanical properties of pulmonary connective tissue can be linked to the stiffening of its individual collagen fibers. To address this question, we developed a network model of randomly oriented collagen and elastin fibers to represent pulmonary alveolar wall tissue. We show that the stress–strain behavior of this model arises via the interactions of collagen and elastin fiber networks and is critically dependent on the relative fiber stiffnesses of the individual collagen and elastin fibers themselves. We also show that the progression from linear to nonlinear stress–strain behavior of the model is associated with the percolation of stress across the collagen fiber network, but that the location of the percolation threshold is influenced by the waviness of collagen fibers.

Coenzyme Q10. Structure, role, sources and application in cosmetology

Cell division, the synthesis of amino acids, glycosaminoglycans and enzymes as well as the maturation of collagen and elastin fibers are the basic processes that take place in healthy skin. These reactions are possible due to participation of cellular energy of ATP (adenosine triphosphate), which is produced inside the mitochondria. Within one eukaryotic cell there are from several to several thousand mitochondria. The process of producing energy in the mitochondria is called cellular respiration, known also as the citric acid cycle or the Krebs cycle. Coenzyme Q10 is a key carrier of electrons in the respiratory chain. At the same time, it is responsible for the neutralization of free radicals formed in the Krebs cycle, leading to reduction oxidative stress and minimalization the aging processes of tissues. The article presents the collected information on coenzyme Q10, its structure, role, sources and application in cosmetology. Supplementation in case of coenzyme Q10 deficiency in the skin is possible through the use of appropriate cosmetic preparations, cosmetology treatments and dietary supplements.