Connective Tissue Matrix Components Research Articles

Pathophysiological and Therapeutic Roles of Fascial Hyaluronan in Obesity-Related Myofascial Disease.

Myofascial disease is an important complication associated with obesity and one of the leading causes of physical disability globally. In the face of limited treatment options, the burden of myofascial disorders is predicted to increase along with the escalating prevalence of obesity. Several pathological processes in obesity contribute to modifications in fascial extracellular matrix mechanical and biological properties and functions. Changes in adipose tissue metabolism, chronic inflammatory phenotype, oxidative stress, and other mechanisms in obesity may alter the physiochemical and biomechanical properties of fascial hyaluronan. Understanding the pathophysiological importance of hyaluronan and other components of the fascial connective tissue matrix in obesity may shed light on the etiology of associated myofascial disorders and inform treatment strategies. Given its unique and favorable pharmacological properties, hyaluronan has found a broad range of clinical applications, notably in orthopedic conditions such as osteoarthritis and tendinopathies, which share important pathophysiological mechanisms implicated in myofascial diseases. However, while existing clinical studies uniformly affirm the therapeutic value of hyaluronan in myofascial disorders, more extensive studies in broader pharmacological and clinical contexts are needed to firmly validate its therapeutic adaptation.

Connective Tissue and Age-Related Diseases.

We begin this chapter by describing normal characteristics of several pertinent connective tissue components, and some of the basic changes they undergo with ageing. These alterations are not necessarily tied to any specific disease or disorders, but rather an essential part of the normal ageing process. The general features of age-induced changes, such as skin wrinkles, in selected organs with high content of connective or soft tissues are discussed in the next part of the chapter. This is followed by a section dealing with age-related changes in specific diseases that fall into at least two categories. The first category encompasses common diseases with high prevalence among mostly ageing populations where both genetic and environmental factors play roles. They include but may not be limited to atherosclerosis and coronary heart disease, type II diabetes, osteopenia and osteoporosis, osteoarthritis, tendon dysfunction and injury, age-related disorders of spine and joints. Disorders where genetics plays the primary role in pathogenesis and progression include certain types of progeria, such as Werner syndrome and Hutchinson-Gilford progeria belong to the second category discussed in this chapter. These disorders are characterized by accelerated signs and symptoms of ageing. Other hereditary diseases or syndromes that arise from mutations of genes encoding for components of connective tissue and are less common than diseases included in the first group will be discussed briefly as well, though they may not be directly associated with ageing, but their connective tissue undergoes some changes compatible with ageing. Marfan and Ehlers-Danlos syndromes are primary examples of such disorders. We will probe the role of specific components of connective tissue and extracellular matrix if not in each of the diseases, then at least in the main representatives of these disorders.

Basic Components of Vascular Connective Tissue and Extracellular Matrix.

Though the composition of the three layers constituting the blood vessel wall varies among the different types of blood vessels, and some layers may even be missing in capillaries, certain basic components, and properties are shared by all blood vessels, though each histologically distinct layer contains a unique complement of extracellular components, growth factors and cytokines, and cell types as well. The structure and composition of vessel layers informs and is informed by the function of the particular blood vessel. The adaptation of the composition and the resulting function of the extracellular matrix (ECM) to changes in circulation/blood flow and a variety of other extravascular stimuli can be characterized as remodeling spearheaded by vascular cells. There is a surprising amount of cell traffic among the three layers. It starts with endothelial cell mediated transmigration of inflammatory cells from the bloodstream into the subendothelium, and then into tissue adjoining the blood vessel. Smooth muscle cells and a variety of adventitial cells reside in tunica media and tunica externa, respectively. The latter cells are a mixture of progenitor/stem cells, fibroblasts, myofibroblasts, pericytes, macrophages, and dendritic cells and respond to endothelial injury by transdifferentiation as they travel into the two inner layers, intima and media for corrective mission in the ECM composition. This chapter addresses the role of various vascular cell types and ECM components synthesized by them in maintenance of normal structure and in their contribution to major pathological processes, such as atherosclerosis, organ fibrosis, and diabetic retinopathy.

Perlecan and vascular endothelial growth factor-encoding DNA-loaded chitosan scaffolds promote angiogenesis and wound healing

The repair of dermal wounds, particularly in the diabetic population, poses a significant healthcare burden. The impaired wound healing of diabetic wounds is attributed to low levels of endogenous growth factors, including vascular endothelial growth factor (VEGF), that normally stimulate multiple phases of wound healing. In this study, chitosan scaffolds were prepared via freeze drying and loaded with plasmid DNA encoding perlecan domain I and VEGF189 and analyzed in vivo for their ability to promote dermal wound healing. The plasmid DNA encoding perlecan domain I and VEGF189 loaded scaffolds promoted dermal wound healing in normal and diabetic rats. This treatment resulted in an increase in the number of blood vessels and sub-epithelial connective tissue matrix components within the wound beds compared to wounds treated with chitosan scaffolds containing control DNA or wounded controls. These results suggest that chitosan scaffolds containing plasmid DNA encoding VEGF189 and perlecan domain I have the potential to induce angiogenesis and wound healing.

Cinquantenaire de la Société Française des Tissus Conjonctifs

The Society was founded in 1962, at an international meeting organized at the Biomedical Institute rue des Saints-Pères, in Paris in the Department of Biochemistry headed at that time by Pr. Max F. Jayle, and published in the "Exposés Annuels de Biochimie Médicale" in 1963. At its beginnings a "Club", with a limited number of participants, it expanded rapidly into a Society, renamed recently "French Society of the Biology of Extracellular Matrix", with approximately 200 members working on a variety of subjects. Only six of these teams could present an oral report at the meeting of the Biological Society on January18, 2012, celebrating this anniversary at the Curie Institute. A few more could send written contributions for this special issue of "Biologie Aujourd'hui". In this short introduction we shall recall some important stages of the developing connective tissue science. Besides such classical subjects, as the macromolecular components of connective tissue matrix, this discipline incorporated progressively receptors, integrins and other molecules, that mediate cell-matrix interactions.

Presence of Activated Mobile Fibroblasts in Bronchial Alveolar Lavage from Mild Asthmatic Patients

The remodeling process in the lung of asthmatic patients results in a deposition of connective tissue and extracellular matrix components (ECM), which has been described as a subepithelial fibrosis. Fibroblasts, with the phenotypic appearance of myofibroblasts, are considered as the key source of the ECM in the fibrotic tissue. Furthermore, has the ECM molecule biglycan shown to correlate to the hyperactivity of the lung of asthmatic patients. In this study, we report the novel finding of a stretched fibroblast phenotype from bronchoalveolar lavage fluid (BALF) in 30% of the asthmatic subjects (n = 13). No fibroblasts were obtained in BALF from any of the nonasthmatic control subjects (n = 17). These BALF fibroblasts with several characteristics of a myofibroblast displayed increased migratory capacity, accompanied by an induced expression of the small GTPases RhoA and Rac1, when compared to myofibroblasts from corresponding lung biopsies. Data also shows that patients with BALF myofibroblast also have more cells in their lung tissue near to the basement membrane that stain for markers for mesechymal progenitor cells. Moreover, the BALF‐myofibroblasts showed an increase in production of several types of proteoglycans like biglycan. By adding biglycan to normal fibrobalsts it is further possible to mimic the migratory type of myofibroblast found in BALF. To study differences in protein expression pattern between the two phenotypes, we used a gel‐based proteomic technique in combination with MALDI‐TOF mass spectrometry. BALF‐myofibroblast displayed an increase in heat shock protein 20 (HSP20) and myofibroblasts from biopsies displayed an increase in chloride intracellular channel protein (CLIC) and cofilin. These proteins are all known to regulate cell migration by interacting with the actin cytoskeleton. In summery, data demonstrates that biglycan and mesenchymal progenitor cells might have an important role in the early ‐remodeling process in asthmatic patients and are potential future biomarkers for sub‐epithelial fibrosis formation.

Ultrastructural Aspects of Long-term Cat Placental Explant Culture

Changes in tissue architecture and ultrastructure in the cat placenta during long-term explant culture have been examined over an 11-day period. Pieces of cat placenta, dissected from the lamellar region, were cultured in CMRL-1066 medium and tissue was fixed for electron microscopy at 2, 5, 7, and 11 days' culture, as well as before culture was initiated (day 0). Four samples were examined at each time point. After two days, the trophoblast basal lamina and attached cytotrophoblast cells had begun to separate from the syncytium and the cytotrophoblasts were spreading over the surface of the exposed fetal stromal compartment, and by five days were showing signs of growth. At seven days' culture, cytotrophoblast multilayering was common, and vascular and stromal components were also well preserved with collagen biosynthesis evident. By 11 days, the centre of the culture was compacted and degenerate with loss of tissue architecture, but on the outside polyp-like growths could be seen, with a well-developed covering of trophoblast containing fat and secretory droplets, lining a connective tissue matrix and stromal components. The cat placenta, therefore, like the human, has the capacity for regrowth in explant culture, including both trophoblast and stromal components.

Alpha 1-antiproteinase deficiency

The dysbalance between proteolytic neutrophil elastase and its endogeneous inhibitor seems to be a pathogenetic key mechanism in the origin of pulmonary emphysema (elastase-antielastase hypothesis). This hypothesis is supported by the observation, that low serum levels of alpha 1-antitrypsin can be observed in smokers with premature pulmonary emphysema. alpha 1-proteinase inhibitor is an acute phase protein with known structural and moleculargenetic aspects, which is synthesized by the liver and reaches the lung by the circulation. Its role is the inactivation of excessive neutrophil elastase in the pulmonary parenchyma, which is liberated during inflammation and destroys elastin and other components of extra-cellular connective tissue matrix. This is an overview on epidemiology, clinical aspects, genetics and molecular biology of this particular disease which was described in 1963.

Pathogenesis of diabetic nephropathy, advanced glcation and new therapy

It is well understood that persistent hyperglycemia contributes to diabetic tissue and end-organ damage [1], by promoting the formation of advanced glycosylation endproducts (AGEs) [2, 3]. AGEs form principally from the rearrangement of early glycation products, i.e. Amadori products, which produce a class o f stable moieties that possess distinctive chemical cross-linking and biological properties [2, 31 . It has been generally believed that proteins with half-lives of greater than a few weeks are most susceptible to advanced glycosylation and the highest levels o f AGEs occur on proteins that comprise the long-lived structural components of connective tissue matrix and basement membrane. Of particular interest, however, has been the recent observation that AGEs can also occur on short-lived proteins, on lipid constituents and on nucleic acids. This is most apparent under conditions o£ high AGE accumulation such as diabetes and renal failure, and results from the fact that AGE formation proceeds through a succession of reactive intermediates which can bind indiscriminantly to amino groups present on diverse "bystander" proteins. 1keactive intermediates can also be released from naturally degraded tissue AGE, only to bind again on other substances, if not cleared via the kidney, forming "second" generation AGEs. Cell surface receptors that are specific for the recognition, and degradation of AGE-modified proteins also have been identified on circulating monocytes, lymphocytes, endothelial, renal mesangial cells and other cellular systems to partake in both normal tissue remodeling and tissue damage. In this synoptic review, selected recent studies are highlighted which

Pericranial flaps and free calvarial grafts in skull base defects reconstructions: Complications and consequences

To pursue the events around hydroxyapatite (HA) discs (diameter 9 mm), implanted in calvarial defects in rabbits (diameter 11 mm), immunohistochemical changes of fibronectin and type I, II and III collagen were quantitatively determined in the connective tissue-HA (CTHA) and host bone-HA (BHA) interface at 8, 12 and 16 wk postimplantation. A marked enhancement of type I collagen staining in the BHA interface was noted at the 12th and the 16th wk in comparison to the CTHA interface and connective tissue in the untreated control defect. However, one of the characteristics of the staining in the CTHA interface was the finding of exceptionally high fibronectin and type III collagen at the 8th and the 12th wk in contrast to the BHA interface and the untreated control defect. The change in these immunohistochemically determined compositions was probably due to an active proliferation of vascular components in the CTHA interface. Bone regeneration in the CTHA interface was parallel to an increase in type I collagen and a decrease in fibronectin and type III collagen from 8 to 16 wk. This study indicated that variances in composition or characteristics of connective tissue in CTHA interface have taken place ahead of bone morphogenesis. The time-related derivation of connective tissue matrix components in the BHA and CTHA interface was confined to the interaction of implanted HA with host tissues in contact with the implant.

Recent progress in advanced glycation and diabetic vascular disease: role of advanced glycation end product receptors.

Advanced glycosylation end products (AGEs) form principally from the rearrangement of early glycation products, i.e., Amadori products, which produce a class of stable moieties that possess distinctive chemical crosslinking and biological properties. It has been generally believed that proteins with half-lives of longer than a few weeks are most susceptible to advanced glycosylation and that the highest levels of AGEs occur on proteins that comprise the long-lived structural components of connective tissue matrix and basement membrane.

Atherogenesis and immune inflammation

A universal approach to atherosclerosis pathogenesis is discussed according to which humoral factors, first of all modified lipoproteins and cells of the vascular wall, are considered as an entity. Although the arterial wall is estimated as a target organ realizing leading pathogenetic factors, the process in the arterial wall is a trigger of cell reactions resulting in the formation of an atherosclerotic plaque. Immune inflammation developing in the vascular wall as a response to deposition or formation of the autoimmune complex that includes a modified lipoprotein as an antigen, is regarded as an integral part of atherogenesis. Cytokines produced by the activated macrophages and lymphocytes purposefully affect parietal cells promoting the formation of foam cells and phenotypic modification of GMK with their production of the components of the connective tissue matrix.

Time-related deviations of fibronectin and type I, II and III collagen on the interface between a hydroxyapatite disc and the rim of a calvarial trephine defect in rabbits

To pursue the events around hydroxyapatite (HA) discs (diameter 9 mm), implanted in calvarial defects in rabbits (diameter 11 mm), immunohistochemical changes of fibronectin and type I, II and III collagen were quantitatively determined in the connective tissue-HA (CTHA) and host bone-HA (BHA) interface at 8, 12 and 16 wk postimplantation. A marked enhancement of type I collagen staining in the BHA interface was noted at the 12th and the 16th wk in comparison to the CTHA interface and connective tissue in the untreated control defect. However, one of the characteristics of the staining in the CTHA interface was the finding of exceptionally high fibronectin and type III collagen at the 8th and the 12th wk in contrast to the BHA interface and the untreated control defect. The change in these immunohistochemically determined compositions was probably due to an active proliferation of vascular components in the CTHA interface. Bone regeneration in the CTHA interface was parallel to an increase in type I collagen and a decrease in fibronectin and type III collagen from 8 to 16 wk. This study indicated that variances in composition or characteristics of connective tissue in CTHA interface have taken place ahead of bone morphogenesis. The time-related derivation of connective tissue matrix components in the BHA and CTHA interface was confined to the interaction of implanted HA with host tissues in contact with the implant.

Extracellular matrix interactions during the in vivo degradation of collagen membranes in the rat skin: Immunohistochemical distribution of collagen types IV, V, and VI

The role of collagen implant material (CIM) in periodontology is of considerable interest to the clinical dentist because of the capacity of connective tissue (CT) regeneration and partial prevention of epithelial cell migration onto the root surface. The aim of this study was to demonstrate alterations of the CT matrix after the use of CIM in subcutaneous pockets in the rat skin. We used 15 rats in this study. After sedation, two subcutaneous pockets (2 cm in length) were surgically made in the animals' backs. Collagen membranes were implanted in one of the two pockets (test site). The other pocket served as control. Then, 4, 7, 14, 21, and 28 days after implantation, the animals were sacrificed and biopsies preserved for histologic and immunohistochemical examination. Incubation with antibodies against CT matrix components (collagen type IV, V, and VI) were used for immunostaining. Histologically, the CIM was migrated by inflammatory cells in the first 7 days. Newly formed fibroblasts and blood vessels (BV) were present 14 days postimplantation. Collagen type IV was localized in the basement membranes of the epithelium, BV, and nerves. An increase in the BV amount was demonstrated around (and later in) the implant material. Collagen type V was found in a filament pattern of distribution and was inserted into the implant after 4 weeks of healing. Collagen type VI showed a microfibrillar pattern of distribution with a delayed formation in the graft mass. The data showed the alterations of the matrix after implantation of collagen type I membranes in the rat skin.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of reactive oxygen species on the biosynthesis of collagen and glycosaminoglycans in cultured human dermal fibroblasts.

The purpose of this study was to evaluate the possibility that the biological changes observed in connective tissue matrix components of photoaging skin may be induced by an alteration of biosynthesis in fibroblasts damaged by reactive oxygen species (ROS). We investigated the effect of ROS induced by xanthine and the xanthine oxidase system on the biosynthesis of connective tissue matrix components, collagen and glucosaminoglycans (GAGs) in cultured human dermal fibroblasts. ROS decreased collagen production and increased GAGs synthesis. Interestingly, these changes were consistent with the biological alterations of connective tissue matrix components observed in photoaging skin. Moreover, catalase and alpha-tocopherol completely prevented the ROS-induced alterations of collagen and GAGs biosynthesis, whereas superoxide dismutase had no effect on the ROS-induced changes. These results suggest that ROS may be one of the factors which cause the biological changes of connective tissue matrix components observed in photoaging skin.

Tumor necrosis factor-alpha stimulates the biosynthesis of matrix metalloproteinases and plasminogen activator in cultured human chorionic cells.

To investigate the role of tumor necrosis factor-alpha (TNF alpha) in advanced collagenolysis and degradation of connective tissue components in preterm parturition, the effects of human recombinant TNF alpha (hrTNF alpha) on the production of matrix metalloproteinase 1 (MMP-1)/tissue collagenase, MMP-3/stromelysin, tissue inhibitor of metalloproteinases (TIMP), urokinase type-plasminogen activator (uPa) and prostaglandin (PG) E2 in human chorionic cells were examined in vitro. Human chorionic cells, but not amniotic cells, were found to respond to macrophage-conditioned medium (contains mainly interleukin 1) to produce MMP-1 and MMP-3. This indicated that the chorionic cell is one of the MMP-producing cells of fetal membranes. When confluent chorionic cells were treated with hrTNF alpha, the production of MMP-1 and MMP-3 as well as of uPa and PGE2 was greatly increased in a dose-dependent manner. In contrast, the production of TIMP was suppressed by hrTNF alpha. These results suggested that TNF alpha may participate in destruction of collagen and other connective tissue matrix components of fetal membranes and in promotion of uterine contractility in preterm parturition with intraamniotic infection.

Connective Tissue Metabolism in Bone and Cartilage of Adjuvant Arthritic Rat

The metabolism of connective tissue matrix components such as glycosaminoglycans and glycoproteins was investigated in normal as well as pathological tissues of bone and cartilage associated with adjuvant arthritis using rat as animal model of the disease. The inflammatory process of adjuvant arthritis was induced in rats with the inoculation of Freund's adjuvant containing heat killed Mycobacterium tuberculosis suspended in paraffin oil. The changes in the metabolism of matrix components in bone and cartilage were examined using radioactive isotopic labeling measurements during the acute as well as chronic phases of arthritic disease. The glycosaminoglycans were fractionated into sulfated and non-sulfated glycosaminoglycans by chemical and enzymic modifications. The biosynthesis of sulfated glycosaminoglycans was evaluated using radioactive labeled (35S)-sulfate. Alterations were demonstrated in the metabolism of connective tissue in the bone and cartilage tissues of arthritic rat. The results obtained showed an increased incorporation of radioactive sulfate in specimens of bone and cartilage during the process of adjuvant arthritis. The contents of sulfated as well as non-sulfated glycosaminoglycans were found to be increased in both the tissues of arthritic rat. Similarly, the amount of total glycosaminoglycans was also found to be increased significantly in the diseased tissues. In addition, various components of tissue glycoproteins such as fucose, sialic acid and total hexose were found to be elevated in insoluble fractions of bone and cartilage during the diseased state. The effects of experimentally induced adjuvant arthritis on the connective tissue were discussed in the light of changes taking place in the metabolism of glycosaminoglycans and glycoproteins in bone and cartilage of arthritic rat.

Collagen, proteoglycan and hyaluronidase activity in cultures from normal and scoliotic chicken fibroblasts

Connective tissue matrix components were investigated using skin fibroblasts from normal or inbred scoliotic lines of chickens. Specifically, the fibroblasts were obtained from either an isogenic line or a backcross, derived by crossing the isogenic line with a pure line of scoliotic birds. From the backcross, both affected (35–45%) and non-affected (55–65%) progeny were produced. The affected birds had spinal curves greater than 20°. Several abnormalities of connective tissue were observed when cells from scoliotic chicks were grown in culture: increased collagen extractability, decreased aggregatability of proteoglycans under associative conditions and lower than normal levels of hyaluronic acid. There was also less colagen deposited in the cell layer with proportionately increased amounts of collagen secreted into the culture media by cells from scoliotic versus normal chick fibroblasts. Values for collagen matrix stability, as estimated by extractability and net deposition, were intermediate for cells from the backcrossed, but non-affected, birds. Moreover, hyaluronidase, an enzyme that degrades hyaluronic acid, was abnormally elevated in the fibroblast cultures from scoliotic chicks. It is proposed that the increase in hyaluronidase contributes to the abnormalities observed in extracellular matrix components and may be a factor in the expression of scoliosis in susceptible birds.

Incomplete normalization of dog gracilis muscle grafts with neurovascular repair despite long-term recovery

Skeletal muscle grafts performed with neurovascular repair are used extensively in clinical situations. However, most controlled experimental studies on the efficacy of such grafts have been conducted on muscles with a relatively small mass and over a limited recovery period. Therefore, selected cellular and matrix component properties of the comparatively large dog gracilis muscle (75 g) were studied 9-12 mo after orthotopic neurovascular grafting. The grafted muscle wet weights were 71% of the contralateral control (sham-operated) muscles. In addition, the concentrations of noncollagenous protein (13%), DNA (28%), and RNA (34%) were significantly reduced in the grafts. However, the concentration of collagen was significantly higher (41%) in the grafts. In this regard, the type III collagen phenotype showed the greatest relative increase. There was no difference between the grafted and control proteoglycan concentration. The metabolic profiles of the grafted muscles were significantly different from control. The activities of myofibrillar adenosinetriphosphatase (34%) and alpha-glycerophosphate dehydrogenase (25%) were reduced, whereas citrate synthase remained unchanged. These data suggest that recovery of up to 1 yr was insufficient for the normalization of several connective tissue matrix components and biochemical properties of the grafts.

Short-term keloid treatment in vivo with human interferon alfa-2b results in a selective and persistent normalization of keloidal fibroblast collagen, glycosaminoglycan, and collagenase production in vitro

Two intralesional injections of interferon alfa-2b (1.5 million U per injection) into a progressively enlarging keloid resulted in a 41% reduction in its area. Fibroblasts cultured from the keloid before and 9 days after the initial injection were compared with fibroblasts cultured from the patient's normal skin with respect to proliferation and production of connective tissue matrix components and collagenase. There were no significant differences in the in vitro doubling times of keloidal fibroblasts before (p greater than 0.2) and after (p greater than 0.5) treatment with interferon alfa-2b, as well as of normal fibroblasts, in subconfluent cultures. Multiple passages of keloidal fibroblasts before interferon alfa-2b therapy assayed as confluent cultures produced more collagen (171%, 187%, and 204%), more glycosaminoglycans (153% and 141%), and less collagenase (26% and 31%) than the patient's own normal fibroblasts. In contrast, keloidal fibroblasts after interferon alfa-2b therapy persistently produced normal or subnormal amounts of collagen (107%, 73%, and 64%) and glycosaminoglycans (97% and 96%) and normalized levels of collagenase activity (96% and 86%). Normal amounts of fibronectin were produced by keloidal fibroblasts before and after treatment with interferon alfa-2b.