Collagen In Blood Vessels Research Articles

Transcriptome analysis of skin fibroblasts with dominant negative COL3A1 mutations provides molecular insights into the etiopathology of vascular Ehlers-Danlos syndrome.

Vascular Ehlers-Danlos syndrome (vEDS) is a dominantly inherited connective tissue disorder caused by mutations in the COL3A1 gene that encodes type III collagen (COLLIII), which is the major expressed collagen in blood vessels and hollow organs. The majority of disease-causing variants in COL3A1 are glycine substitutions and in-frame splice mutations in the triple helix domain that through a dominant negative effect are associated with the severe clinical spectrum potentially lethal of vEDS, characterized by fragility of soft connective tissues with arterial and organ ruptures.To shed lights into molecular mechanisms underlying vEDS, we performed gene expression profiling in cultured skin fibroblasts from three patients with different structural COL3A1 mutations. Transcriptome analysis revealed significant changes in the expression levels of several genes involved in maintenance of cell redox and endoplasmic reticulum (ER) homeostasis, COLLs folding and extracellular matrix (ECM) organization, formation of the proteasome complex, and cell cycle regulation. Protein analyses showed that aberrant COLLIII expression is associated with the disassembly of many structural ECM constituents, such as fibrillins, EMILINs, and elastin, as well as with the reduction of the proteoglycans perlecan, decorin, and versican, all playing an important role in the vascular system. Furthermore, the altered distribution of the ER marker protein disulfide isomerase PDI and the strong reduction of the COLLs-modifying enzyme FKBP22 are consistent with the disturbance of ER-related homeostasis and COLLs biosynthesis and post-translational modifications, indicated by microarray analysis. Our findings add new insights into the pathophysiology of this severe vascular disorder, since they provide a picture of the gene expression changes in vEDS skin fibroblasts and highlight that dominant negative mutations in COL3A1 also affect post-translational modifications and deposition into the ECM of several structural proteins crucial to the integrity of soft connective tissues.

Detection and characterization of molecular-level collagen damage in overstretched cerebral arteries.

Arteries play a critical role by carrying oxygen and essential nutrients throughout the body. However, trauma to the head and neck, as well as surgical interventions, can overstretch arteries and alter their mechanics. In order to better understand the cause of these changes, we employ a novel collagen hybridizing peptide (CHP) to study collagen damage in overstretched arteries. Our approach is unique in that we go beyond the fiber- and fibril-level and characterize molecular-level disruption. In addition, we image and quantify fluorescently-labeled CHP to reveal a new structure-property relationship in arterial damage. We anticipate that our approach can be used to better understand arterial damage in clinically relevant settings such as angioplasty and vascular trauma.

Manipulating the structure and mechanical properties of thermoplastic polyurethane/polycaprolactone hybrid small diameter vascular scaffolds fabricated via electrospinning using an assembled rotating collector.

The success of blood vessel transplants with vascular scaffolds (VSs) highly depends on their structure and mechanical properties. The fabrication of small diameter vascular scaffolds (SDVSs) mimicking the properties of native blood vessels has been a challenge. Herein, we propose a facile method to fabricate thermoplastic polyurethane (TPU)/polycaprolactone (PCL) hybrid SDVSs via electrospinning using a modified rotating collector. By varying the ratio between the TPU and the PCL, and changing the electrospinning volume, SDVSs with a wavy configuration and different properties could be obtained. Detailed investigation revealed that certain TPU/PCL hybrid SDVSs closely resembled the mechanical behaviors of blood vessels due to the presence of a wavy region and the combination of flexible TPU and rigid PCL, which mimicked the properties of elastin and collagen in blood vessels. The fabricated TPU/PCL SDVSs achieved lumen diameters of 1-3mm, wall thicknesses of 100-570µm, circumferential moduli of 1-6MPa, ultimate strengths of 2-8MPa, over 250% elongation-at-break values, toe regions of 5.3-9.4%, high recoverability, and compliances close to those of human veins. Moreover, these TPU/PCL SDVSs possessed sufficient suture retention strength and burst pressure to fulfill transplantation requirements and maintain normal blood flow. Human endothelial cell culture revealed good biocompatibility of the scaffolds, and cells were able to grow on the inner surface of the tubular scaffolds, indicating promising prospects for use as tissue-engineered vascular grafts.

Permanent skin replacement using chimeric epithelial cultured sheets comprising xenogeneic and syngeneic keratinocytes.

The present study was undertaken to evaluate the possibility of permanent skin replacement using chimeric xenogeneic-syngeneic graftable sheets previously obtained in vitro. Newborn (<3 days old) BALB/c and human keratinocytes were isolated and cocultured in different ratios as follows: 50% BALB/c to 50% human and 25% BALB/c to 75% human keratinocytes. Four to 5 days after culture and prior to their grafting, all chimeric sheets contained both cell types in ratios similar to those used to seed the initial chimeric cultures. Fourteen and 30 days after chimeric sheet grafting onto BALB/c mice dorsum, the newly generated cutaneous tissue showed a histologically well-organized epidermis presenting basal and suprabasal cell layers. Cutaneous cells in these structures secreted laminin and type IV collagen in blood vessels, and at ground level of the dermoepidermal junction there were signs of physiologically active skin. Cell phenotyping revealed the presence of only syngeneic keratinocytes, whereas xenogeneic cells were passively eliminated without a total rejection of the chimeric implant. This selective and passive elimination of xenogeneic keratinocytes went through cellular and humoral immunity activation. Data suggest that this chimeric culture method can be used for cutaneous therapies such as large congenital nevi, skin ulcers, and extensively burned skin. Indeed, for large third-degree wounded skin treatment, this culture method may shorten the time (4-5 weeks) needed for cell growth and graftable sheet production. Moreover, since the ultimate aim in allogeneic and xenogeneic transplantation is to achieve an immunological acceptance and tolerance to these foreign tissues, the chimeric culture approach may provide ways to lighten tolerance phenomena on cutaneous tissue.

Immunohistochemical differentiation between lymphatic vessels and blood vessels-Use of anti-basement membrane antibodies and anti-Factor VIII-related antigen.

Several immunohistochemical methods using Factor VIII-Related antigen (FVIIIR:Ag), laminin, Type IV collagen and fibronectin antisera were applied for the purpose of differentiating rat lymphatics from blood vessels by light and electron microscopy. Weibel-Palade bodies (WPB) were demonstrated in both types of vessels by conventional electron microscopy. The immunoreactivity to laminin and Type IV collagen in blood vessels showed a strong, continuous, linear subendothelial staining pattern in contrast to lymphatic vessels in which immunoreactivity was absent or weak in paraffin-embedded sections stained with the indirect immunoperoxidase technique. A positive reaction for fibronectin was observed in all extra-vascular tissue spaces as well as in lymphatics and blood vessels. FVIIIR:Ag and WPB were present in both lymphatic and blood endothelial cells. FVIIIR:Ag antiserum labeled with gold particles was observed only in the vacuoles which were assumed to be identical with WPB as demonstrated by our conventional electron microscopy. We conclude that the immunohistochemical method using laminin and Type IV collagen antisera is a reliable and practical way to differentiate lymphatic vessels from blood vessels by light microscopy.

Assembly and processing of procollagen V (AB) in chick blood vessels and other tissues.

The biosynthesis and processing of type V procollagens was investigated in chick embryo blood vessels labeled with radioactive amino acids. Monomeric, pepsin-sensitive pro alpha 1 V and pro alpha 2 V chains are slowly assembled into triple helically folded molecules. A small proportion of these procollagen V molecules contain interchain disulfide bridges, and the disulfide-linked heterodimer and heterotrimer (pro alpha 1 V)2pro alpha 2 V were found. A relatively fast conversion of procollagen V to p-collagen V is followed by slow change to collagen V. This time course is similar to the processing of procollagen III and is much slower than the rate of appearance of type I collagen in blood vessels. A combination of sedimentation and electrophoretic analyses was used to measure the relative size of the type V chains and to demonstrate attachment of noncollagenous peptides (Mr = 33,000) to p alpha 2 V by disulfide linkage. Similar quantitative pulse-chase studies were made with calvaria and crop. As the same unusual features of assembly and processing of type V chains were seen in muscle, bone, and blood vessels, we conclude that these are characteristic of type V collagen biosynthesis.

A case of SLE occurring after splenectomy with ITP as an initial symptom

The patient was a woman, 35 years old, who showed marked thrombocytopenia and decreases of megakaryocytes since 2 years. Hemorrhagic disorders was recovered by blood transfusion and adrenocorticosteroid treatment. As marked thrombocytopenia and hemorrhagic diathesis, which developed thereaffer, were not ameliorated by similar therapy, splenectomy was performed. Although a rise in platelets was observed, she showed increased sedimentation rate of erythrocyte, generalized lymph nodes, erythema and swelling of joint with pain after 4 months. Laboratory examination revealed increases of γ-globulin and IgG in serum protein, positiv CRP and RA test, LE cells and ANF. Finally, she died with evidence of mental and neurologic dysfunction.In the extipated spleen, hyperplastic follicle and angitis (3-4 grades) hyperplasia of media, and interruption of collagen in blood vessels were found, although onion skin lesion was not detected.In the cutaneous tissue, small vessels were surrounded by infiltrated lymphocyte.From clinical course, it is considered that ITP develop, preceeding by several months other obvious manifestation of SLE which occurred after splenectomy.