			Home About us Contact

Extracellular Matrix Components (extracellular + matrix_component)

Distribution by Scientific Domains

Medical Sciences	57%
Life Sciences	30%
Chemistry	12%

Distribution within Medical Sciences

Dermatology	15%
Hepatology	10%

Selected Abstracts

Behavior of Cardiomyocytes and Skeletal Muscle Cells on Different Extracellular Matrix Components,Relevance for Cardiac Tissue Engineering

ARTIFICIAL ORGANS, Issue 1 2007
Karin Macfelda
Abstract:, Myocardial cell transplantation in patients with heart failure is emerging as a potential therapeutic option to augment the function of remaining myocytes. Nevertheless, further investigations on basic issues such as ideal cell type continue to be evaluated. Therefore, the aim of our studies was to compare the performance of skeletal muscle cells and cardiomyocytes with respect to their proliferation rate and viability on different extracellular matrix components (EMCs). Rat cardiomyocytes (RCM) and rat skeletal muscle cells (RSMC) were cultured on EMCs such as collagen type I, type IV, laminin, and fibronectin. The components were used as "single coating" as well as "double coating." Proliferation rates were determined by proliferation assays on days 1, 2, 4, and 8 after inoculation of the cells. The most essential result is that collagen type I enhances the proliferation rate of RSMC but decreases the proliferation of RCM significantly. This effect is independent of the second EMC used for the double-coating studies. Other EMCs also influence cellular behavior, whereas the sequence of the EMCs is essential. Results obtained in our studies reveal the significant different proliferation behavior of RCM and RSMC under identical conditions. As skeletal muscle cells are also used in heart tissue engineering models, these results are essential and should be investigated in further studies to prove the applicability of skeletal muscle cells for heart tissue engineering purposes. [source]

Hyaluronan and its receptors in mucoepidermoid carcinoma

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 2 2006
Richard O. Wein MD
Abstract Background. Hyaluronan (HA) is a prominent extracellular matrix component undergoing continuous production and degradation. Increased HA levels have been described in a variety of tumors. The objective of this study was to examine the staining patterns of HA and two of its associated receptors (CD44 and HARE) in relation to the metastatic potential of mucoepidermoid carcinoma (MC). Immunohistochemical staining of preserved surgical specimens was used. Methods. Tissues from 12 patients with a histologic diagnosis of salivary MC (10 parotid, one submandibular gland, one minor salivary gland) were studied. Half (six of 12) of the patients had regional metastases. Tumor, normal salivary tissue, and regional lymph nodes were stained for HA, CD44, and HARE expression. Specimens were graded for staining intensity and a percent of the specimen stained. Results. Normal salivary tissue did not demonstrate epithelial cell surface HA expression, whereas HA was expressed on tumor cells and in regional lymph nodes containing metastases. These differences were both significant using Student's t test (p < .00002, and p < .0022, respectively). Tumors with positive nodes tended to have greater cell surface HA. Decreased expression or downregulation of HARE was also noted in involved lymph nodes. No differences in CD44 expression were seen between primary specimens and lymph nodes. The observed staining patterns for CD44 and HARE were not reflective of the metastatic potential of the primary MC. Conclusions. Increased HA expression was seen on mucoepidermoid carcinoma cells compared with adjacent normal salivary gland epithelium. This observation may assist in explaining the development of regional metastasis in these tumors. We did not identify specific HA, CD44, or HARE staining patterns in primary lesions that were predictive of regional metastases. © 2005 Wiley Periodicals, Inc. Head Neck27: XXX,XXX, 2005 [source]

PI3K/AKT regulates aggrecan gene expression by modulating Sox9 expression and activity in nucleus pulposus cells of the intervertebral disc

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2009
Chin-Chang Cheng
The goal of the investigation was to test the hypothesis that the phosphoinositide-3 kinase (PI3K)/AKT signaling pathway regulates the expression of the major extracellular matrix component of the intervertebral disc, aggrecan, in nucleus pulposus cells. Primary rat nucleus pulposus cells were treated with PI3K inhibitor to measure changes in gene and protein expression. In addition, cells were transfected with various luciferase reporter plasmids to investigate mechanisms of regulation of aggrecan gene expression. We found that treatment of nucleus pulposus cells with a PI3K inhibitor, LY294002 resulted in decreased expression of aggrecan and a reduction in deposition of sulfated glycosaminoglycans. Moreover, pharmacological suppression or co-expression of dominant negative (DN)-PI3K or DN-AKT resulted in downregulation of aggrecan promoter activity. Expression of constitutively active (CA)-PI3K significantly induced aggrecan promoter activity. We observed that PI3K maintained Sox9 gene expression and activity: inhibition of PI3K/AKT resulted in decreased Sox9 expression, lowered promoter activity, and mediated a reduction in Sox9 transcriptional activity. PI3K effects were independent of phosphorylation status of C-terminus transactivation domain (TAD) of Sox9. Finally, we noted that in nucleus pulposus cells, PI3K signaling controlled transactivation of p300 (p300-TAD activity), an important transcriptional co-activator of Sox9. Results of these studies demonstrate for the first time that PI3K/AKT signaling controls aggrecan gene expression, in part by modulating Sox9 expression and activity in cells of the nucleus pulposus. J. Cell. Physiol. 221: 668,676, 2009. © 2009 Wiley-Liss, Inc. [source]

Matrix metalloproteinase 11 (MMP-11; stromelysin-3) and synthetic inhibitors

MEDICINAL RESEARCH REVIEWS, Issue 4 2007
Magdalini Matziari
Abstract Matrix metalloproteinase (MMP)-11, or Stromelysin 3, is a particular member of MMP family, a group of zinc-dependent endopeptidases involved in matrix degradation and tissue remodeling. Despite intense efforts since its first characterization 15 years ago, its role and target substrates in different diseases remain largely unknown. While mice with MMP-11 deficiency display no particular phenotype, analysis of different tumorigenesis models with these mice lead to the conclusion that MMP-11 promotes tumor development. In contrast with other MMPs, MMP-11 is unable to degrade any major extracellular matrix component and unlike most of other MMPs that are secreted as inactive proenzymes and activated extracellularly, MMP-11 is secreted under active form. MMP-11 may thus play a unique role in tissue remodeling processes, including those associated with tumor progression. Although MMP-11 and other MMPs have been considered as promising targets to combat cancer, a first series of clinical trials using broad-spectrum MMP inhibitors have not led to significant therapeutic benefits. These disappointing results highlight the need for better understanding of the exact role played by each MMP during the different stages of tumor progression. Among the different strategies to fill this gap, highly specific MMP inhibitors would be of great value. This review provides an update on the selectivity profile of phosphinic MMP-11 synthetic inhibitors developed and discusses the opportunities and limitations to identify inhibitors able to fully discriminate MMP-11 from the other MMPs. © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 4, 528,552, 2007 [source]

4411: Immunohistochemical methods to evaluate vitreoretinal scaring

ACTA OPHTHALMOLOGICA, Issue 2010
ML BOCHATON-PIALLAT
Purpose Formation of scarlike epiretinal membranes (ERMs) constitutes potentially the end stage of evolution of proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR) and idiopathic vitreoretinopathy. Among various cellular populations, ERMs contain cells with contractile features typical of myofibroblasts. Myofibroblasts have been described in granulation tissue during wound healing and in practically all fibrocontractive diseases, in which they participate in the generation of isometric tension and in the synthesis of extracellular matrix components; these phenomena are in turn responsible for granulation tissue remodeling and retraction. The main marker of the myofibroblastic phenotype is the expression of alpha-SMA. The transforming growth factor-beta1 and the ED-A splice variant of cellular fibronectin, an extracellular matrix component, are key players of the complex process of myofibroblast differentiation. Methods Proteins were detected by means of immunohistochemical staining on paraffin sections from formol fixed tissues and double immunofluorescence staining on whole tissues. Samples were observed by using classical light and confocal microscopes. Results The presence of alpha-SM actin-positive myofibroblasts was associated with the expression of TGF-beta1, TGF-beta receptor II, and ED-A FN in all types of ERMs studied. Conclusion The results furnish new data on the mechanism of alpha-SM actin stimulation in fibroblasts in a human pathologic setting. [source]

Connective tissue growth factor and cardiac fibrosis

ACTA PHYSIOLOGICA, Issue 3 2009
A. Daniels
Abstract Cardiac fibrosis is a major pathogenic factor in a variety of cardiovascular diseases and refers to an excessive deposition of extracellular matrix components in the heart, which leads to cardiac dysfunction and eventually overt heart failure. Evidence is accumulating for a crucial role of connective tissue growth factor (CTGF) in fibrotic processes in several tissues including the heart. CTGF orchestrates the actions of important local factors evoking cardiac fibrosis. The central role of CTGF as a matricellular protein modulating the fibrotic process in cardiac remodelling makes it a possible biomarker for cardiac fibrosis and a potential candidate for therapeutic intervention to mitigate fibrosis in the heart. [source]

New insights into the pathophysiology of diabetic nephropathy: from haemodynamics to molecular pathology

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2004
G. Wolf
Abstract Although debated for many years whether haemodynamic or structural changes are more important in the development of diabetic nephropathy, it is now clear that these processes are interwoven and present two sides of one coin. On a molecular level, hyperglycaemia and proteins altered by high blood glucose such as Amadori products and advanced glycation end-products (AGEs) are key players in the development of diabetic nephropathy. Recent evidence suggests that an increase in reactive oxygen species (ROS) formation induced by high glucose-mediated activation of the mitochondrial electron-transport chain is an early event in the development of diabetic complications. A variety of growth factors and cytokines are then induced through complex signal transduction pathways involving protein kinase C, mitogen-activated protein kinases, and the transcription factor NF-,B. High glucose, AGEs, and ROS act in concert to induce growth factors and cytokines. Particularly, TGF-, is important in the development of renal hypertrophy and accumulation of extracellular matrix components. Activation of the renin-angiotensin system by high glucose, mechanical stress, and proteinuria with an increase in local formation of angiotensin II (ANG II) causes many of the pathophysiological changes associated with diabetic nephropathy. In fact, it has been shown that angiotensin II is involved in almost every pathophysiological process implicated in the development of diabetic nephropathy (haemodynamic changes, hypertrophy, extracellular matrix accumulation, growth factor/cytokine induction, ROS formation, podocyte damage, proteinuria, interstitial inflammation). Consequently, blocking these deleterious effects of ANG II is an essential part of every therapeutic regiment to prevent and treat diabetic nephropathy. Recent evidence suggests that regression of diabetic nephropathy could be achieved under certain circumstances. [source]

Extracts from Glycine max (soybean) induce elastin synthesis and inhibit elastase activity

EXPERIMENTAL DERMATOLOGY, Issue 10 2009
Renbin Zhao
Abstract:, Elastic fibres are essential extracellular matrix components of the skin, contributing to its resilience and elasticity. In the course of skin ageing, elastin synthesis is reduced, and elastase activity is accelerated, resulting in skin sagging and reduced skin elasticity. Our studies show that non-denatured Glycine max (soybean) extracts induced elastin promoter activity, inhibited elastase activity and protected elastic fibres from degradation by exogenous elastases in vitro. Mouse and swine skins topically treated with soybean extracts showed enhanced elastic fibre network and increased desmosine content. Elastin expression was also augmented in human skin transplanted onto SCID mice in response to soy treatment. These data suggest that non-denatured soybean extracts may be used as skin care agents to reduce the signs of skin ageing. [source]

Serum-free cultured keratinocytes fail to organize fibronectin matrix and possess different distribution of beta-1 integrins

EXPERIMENTAL DERMATOLOGY, Issue 2 2001
G. Altankov
Abstract: The development of serum free medium formulation for culturing keratinocytes was a breakthrough in achieving a high number of epidermal cells for experimental and therapeutic studies, in particular to support the wound healing process. It is not clear, however, if switching the cells to highly proliferative phenotype may reflect change in other cellular functions important for the wound repair as their adhesive interactions with the extracellular matrix components. Remodelling of the extracellular matrix, particularly of fibronectin plays an essential role for guiding the cells during wound healing. The molecular mechanisms for organization of this provisional fibronectin matrix, however, are still not clear. We found that keratinocytes in serum containing medium, although in fewer numbers than fibroblasts, were able to remove adsorbed fluorescent labelled fibronectin from the substratum and reorganize it in a fibrilar pattern along the cell periphery. After 3 days the secreted fibronectin had also been organized as matrix-like fibers and as clusters deposited on the substratum after migrating cells. In contrast, serum free cultured keratinocytes fail to organize pre-adsorbed fluorescent labelled fibronectin, as well as the secreted fibronectin, although they grow very well under these conditions. Switching the cells to serum containing medium initiates the removal of fluorescent labelled fibronectin from the substratum, however without reorganization in fibrillar pattern. Most likely, these keratinocytes remove fluorescent labelled fibronectin by the expression of proteolytic activity, rather than with the mechanical function of ,1 integrins. The latter were diffusely dispersed in serum containing conditions and tend to organize in focal adhesions in serum free cultured cells. We assumed their transient expression and different affinity state might be important for the keratinocyte migration and matrix assembly mechanism. [source]

Characterization of chitinase-like proteins (Cg -Clp1 and Cg -Clp2) involved in immune defence of the mollusc Crassostrea gigas

FEBS JOURNAL, Issue 14 2007
Fabien Badariotti
Chitinase-like proteins have been identified in insects and mammals as nonenzymatic members of the glycoside hydrolase family 18. Recently, the first molluscan chitinase-like protein, named Crassostrea gigas (Cg)-Clp1, was shown to control the proliferation and synthesis of extracellular matrix components of mammalian chondrocytes. However, the precise physiological roles of Cg -Clp1 in oysters remain unknown. Here, we report the cloning and the characterization of a new chitinase-like protein (Cg -Clp2) from the oyster Crassostrea gigas. Gene expression profiles monitored by quantitative RT-PCR in adult tissues and through development support its involvement in tissue growth and remodelling. Both Cg -Clp1- and Cg -Clp2-encoding genes were transcriptionally stimulated in haemocytes in response to bacterial lipopolysaccharide challenge, strongly suggesting that these two close paralogous genes play a role in oyster immunity. [source]

Matrix metalloproteinase-2 is involved in myelination of dorsal root ganglia neurons

GLIA, Issue 5 2009
Helmar C. Lehmann
Abstract Matrix metalloproteinases (MMPs) comprise a large family of endopeptidases that are capable of degrading all extracellular matrix components. There is increasing evidence that MMPs are not only involved in tissue destruction but may also exert beneficial effects during axonal regeneration and nerve remyelination. Here, we provide evidence that MMP-2 (gelatinase A) is associated with the physiological process of myelination in the peripheral nervous system (PNS). In a myelinating co-culture model of Schwann cells and dorsal root ganglia neurons, MMP-2 expression correlated with the degree of myelination as determined by immunocytochemistry, zymography, and immunosorbent assay. Modulation of MMP-2 activity by chemical inhibitors led to incomplete and aberrant myelin formation. In vivo MMP-2 expression was detected in the cerebrospinal fluid (CSF) of patients with Guillain-Barré syndrome as well as in CSF and sural nerve biopsies of patients with chronic inflammatory demyelinating polyneuropathy. Our findings suggest an important, previously unrecognized role for MMP-2 during myelination in the PNS. Endogenous or exogenous modulation of MMP-2 activity may be a relevant target to enhance regeneration in demyelinating diseases of the PNS. © 2008 Wiley-Liss, Inc. [source]

Role of metalloproteins in the clinical management of head and neck squamous cell carcinoma

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 12 2007
W. Cooper Scurry Jr. MD
Abstract Metalloproteins are a group of catalytic proteins, which play significant roles in cell cycle and death. Matrix metalloproteinases (MMPs) are a family of endopeptidases that are capable of digesting extracellular matrix components. They have been implicated in carcinogenesis and recent developments have been made to use MMPs clinically to predict outcomes. In the future, selective inhibition of these proteins and their regulatory pathways may prove useful in anticancer therapeutics. We present a review article on the clinical applications of metalloproteins in head and neck squamous cell carcinoma (HNSCC). Metalopanstimulin is highlighted as a putative metalloprotein of interest for those treating HNSCC. Expression of particular metalloproteins has correlation with lymph node metastasis, tumor invasiveness, and overall prognosis in HNSCC. © 2007 Wiley Periodicals, Inc. Head Neck 2007 [source]

Protection of estrogens against the progression of chronic liver disease

HEPATOLOGY RESEARCH, Issue 4 2007
Ichiro Shimizu
Hepatitis C virus infections are recognized as a major causative factor of chronic liver disease. A characteristic feature of chronic hepatitis C, alcoholic liver disease and non-alcoholic fatty liver disease is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which, in turn, activates hepatic stellate cells (HSCs). HSCs are also thought to be the primary target cells for inflammatory and oxidative stimuli, and to produce extracellular matrix components. Based on available clinical information, chronic hepatitis C appears to progress more rapidly in men than in women, and cirrhosis is predominately a disease of men and postmenopausal women. Estradiol is a potent endogenous antioxidant. Hepatic steatosis was reported to become evident in an aromatase-deficient mouse and was diminished in animals after treatment with estradiol. Our previous studies showed that estradiol suppressed hepatic fibrosis in animal models, and attenuated HSC activation by suppressing the generation of reactive oxygen species in primary cultures. Variant estrogen receptors were found to be expressed to a greater extent in male patients with chronic liver disease than in female subjects. A better understanding of the basic mechanisms underlying the gender-associated differences observed in the progression of chronic liver disease would provide valuable information relative to the search for effective antifibrogenic therapies. [source]

Finasteride treatment alters MMP-2 and -9 gene expression and activity in the rat ventral prostate

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2010
Flávia K. Delella
Summary The safety of using finasteride as a prevention of prostate cancer is still under debate. In this study, we investigated the effects of finasteride on the location, gene expression and activities of matrix metalloproteinases -2 and -9, which are involved in the degradation of extracellular matrix components during tissue remodelling and prostate cancer progression, invasion and metastasis. Ventral prostates (VP) from Wistar rats treated with finasteride (25 mg/kg/day) for 7 and 30 days and age-matched controls were evaluated using histology, immunohistochemistry, semi-quantitative RT-PCR and gelatin zymography. Finasteride treatment reduced the epithelial immunostaining of MMP-2 but increased MMP-9 immunostaining in the epithelial cells and in the stroma. The mRNA expression of both MMP-2 and MMP-9 were significantly increased on day 7 of finasteride treatment, mainly for MMP-9 and returned to the control levels by day 30. However, gelatin zymography showed that MMP-9 activity was significantly increased on day 7 of finasteride treatment and remained elevated on day 30 (p < 0.05), while MMP-2 activity was reduced after 30 days of treatment. Finasteride increases MMP-9 and reduces MMP-2 activities in the prostate, which may affect negatively and positively both normal and tumoural prostatic cell behaviour during the treatment. Studies on expression of MMPs in the prostate during different androgen manipulation or cancer chemoprevention strategies can contribute to understand the tissue's overall response and clinical data. [source]

Mesenchymal stem cell interaction with a non-woven hyaluronan-based scaffold suitable for tissue repair

JOURNAL OF ANATOMY, Issue 5 2008
G. Pasquinelli
Summary The fabrication of biodegradable 3-D scaffolds enriched with multipotent stem cells seems to be a promising strategy for the repair of irreversibly injured tissues. The fine mechanisms of the interaction of rat mesenchymal stem cells (rMSCs) with a hyaluronan-based scaffold, i.e. HYAFF®11, were investigated to evaluate the potential clinical application of this kind of engineered construct. rMSCs were seeded (2 × 106 cells cm,2) on the scaffold, cultured up to 21 days and analysed using appropriate techniques. Light (LM), scanning (SEM) and transmission (TEM) electron microscopy of untreated scaffold samples showed that scaffolds have a highly porous structure and are composed of 15-µm-thick microfibres having a rough surface. As detected by trypan blue stain, cell adhesion was high at day 1. rMSCs were viable up to 14 days as shown by CFDA assay and proliferated steadily on the scaffold as revealed by MTT assay. LM showed rMSCs in the innermost portions of the scaffold at day 3. SEM revealed a subconfluent cell monolayer covering 40 ± 10% of the scaffold surface at day 21. TEM of early culture showed rMSCs wrapping individual fibres with regularly spaced focal contacts, whereas confocal microscopy showed polarized expression of CD44 hyaluronan receptor; TEM of 14-day cultures evidenced fibronexus formation. Immunohistochemistry of 21-day cultures showed that fibronectin was the main matrix protein secreted in the extracellular space; decorin and versican were seen in the cell cytoplasm only and type IV collagen was minimally expressed. The expression of CD90, a marker of mesenchymal stemness, was found unaffected at the end of cell culture. Our results show that HYAFF®11 scaffolds support the adhesion, migration and proliferation of rMSCs, as well as the synthesis and delivery of extracellular matrix components under static culture conditions without any chemical induction. The high retention rate and viability of the seeded cells as well as their fine modality of interaction with the substrate suggest that such scaffolds could be potentially useful when wide tissue defects are to be repaired as in the case of cartilage repair, wound healing and large vessel replacement. [source]

Stromelysin-3 suppresses tumor cell apoptosis in a murine model,

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2001
Erxi Wu
Abstract Stromelysin-3 (STR-3) is a matrix metalloproteinase with a unique pattern of expression and substrate specificity. During embryogenesis and remodeling of normal adult tissues, STR-3 is produced by stromal cells in direct contact with epithelial cells undergoing regional apoptosis and selective cell survival. STR-3 is also overexpressed by interdigitating stromal cells in primary epithelial malignancies. Although STR-3 does not degrade classic extracellular matrix components, the enzyme promotes the establishment of local tumors in nude mice by as yet undefined mechanisms. STR-3 is induced when malignant epithelial cells come into contact with surrounding stromal elements; the active stromal cell-derived 45 kDa enzyme is subsequently processed to a 35 kDa protein without enzymatic activity. We have generated MCF-7 transfectants expressing wild type or catalytically inactive 45 kDa STR-3 (STR-3wt and STR-3cat- ) or secreted 35 kDa STR-3 (35 kDa STR-3sec) and evaluated their implantation and survival in nude mice. Tumors developed significantly more rapidly in animals receiving STR-3wt, rather than vector-only, STR-3cat- or 35 kDa STR-3sec transfectants. Most importantly, STR-3wt tumors had a significantly lower percentage of apoptotic cells than tumors derived from vector-only, STR-3cat- or 35 kDa STR-3sec transfectants. Taken together, these studies suggest that the active STR-3 enzyme may increase tumor take by suppressing tumor cell apoptosis and that 45 kDa to 35 kDa STR-3 processing limits STR-3 activity at the tumor/stromal interface. Because STR-3 is secreted as an active enzyme rather than a proform, subsequent 45 kDa to 35 kDa STR-3 processing may represent a novel mechanism for regulating enzymatic activity. J. Cell. Biochem. 82: 549,555, 2001. © 2001 Wiley-Liss, Inc. [source]

Posthatching development of Alligator mississippiensis ovary and testis

JOURNAL OF MORPHOLOGY, Issue 5 2010
Brandon C. Moore
Abstract We investigated ovary and testis development of Alligator mississippiensis during the first 5 months posthatch. To better describe follicle assembly and seminiferous cord development, we used histochemical techniques to detect carbohydrate-rich extracellular matrix components in 1-week, 1-month, 3-month, and 5-month-old gonads. We found profound morphological changes in both ovary and testis. During this time, oogenesis progressed up to diplotene arrest and meiotic germ cells increasingly interacted with follicular cells. Concomitant with follicles becoming invested with full complements of granulosa cells, a periodic acid Schiff's (PAS)-positive basement membrane formed. As follicles enlarged and thecal layers were observed, basement membranes and thecal compartments gained periodic acid-methionine silver (PAMS)-reactive fibers. The ovarian medulla increased first PAS- and then PAMS reactivity as it fragmented into wide lacunae lined with low cuboidal to squamous epithelia. During this same period, testicular germ cells found along the tubule margins were observed progressing from spermatogonia to round spermatids located within the center of tubules. Accompanying this meiotic development, interstitial Leydig cell clusters become more visible and testicular capsules thickened. During the observed testis development, the thickening tunica albuginea and widening interstitial tissues showed increasing PAS- and PAMS reactivity. We observed putative intersex structures in both ovary and testis. On the coelomic aspect of testes were cell clusters with germ cell morphology and at the posterior end of ovaries, we observed "medullary rests" resembling immature testis cords. We hypothesize laboratory conditions accelerated gonad maturation due to optimum conditions, including nutrients and temperature. Laboratory alligators grew more rapidly and with increased body conditions compared with previous measured, field-caught animals. Additionally, we predict the morphological maturation observed in these gonads is concomitant with increased endocrine activities. J. Morphol. 2010. © 2009 Wiley-Liss, Inc. [source]

Intervertebral disc cell response to dynamic compression is age and frequency dependent,

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2009
Casey L. Korecki
Abstract The maintenance of the intervertebral disc extracellular matrix is regulated by mechanical loading, nutrition, and the accumulation of matrix proteins and cytokines that are affected by both aging and degeneration. Evidence suggests that cellular aging may lead to alterations in the quantity and quality of extracellular matrix produced. The aims of this study were to examine the role of loading and maturation (a subset of aging), and the interaction between these two factors in intervertebral disc cell gene expression and biosynthesis in a controlled 3D culture environment. Cells were isolated from young (4,6 months) and mature (18,24 months) bovine caudal annulus fibrosus and nucleus pulposus tissue. Isolated cells were seeded into alginate and dynamically compressed for 7 days at either 0.1, 1, or 3 Hz or maintained as a free-swelling control. After 7 days, DNA and sulfated glycosaminoglycan contents were analyzed along with real time, quantitative reverse transcription-polymerase chain reaction analysis for collagen types I and II, aggrecan, and matrix metalloproteinase-3 gene expression. Results suggest that maturation plays an important role in intervertebral disc homeostasis and influences the cell response to mechanical loading. While isolated intervertebral disc cells responded to mechanical compression in 3D culture, the effect of loading frequency was minimal. Altered cellular phenotype and biosynthesis rates appear to be an attribute of the cell maturation process, potentially independent of changes in cellular microenvironment associated with lost nutrition and disc degeneration. Mature cells may have a decreased capacity to create or retain extracellular matrix components in response to mechanical loading compared to young cells. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 800,806, 2009 [source]

Melatonin reduces dimethylnitrosamine-induced liver fibrosis in rats

JOURNAL OF PINEAL RESEARCH, Issue 2 2004
Veysel Tahan
Abstract:, Increased deposition of the extracellular matrix components, particularly collagen, is a central phenomenon in liver fibrosis. Stellate cells, the central mediators in the pathogenesis of fibrosis are activated by free radicals, and synthesize collagen. Melatonin is a potent physiological scavenger of hydroxyl radicals. Melatonin has also been shown to be involved in the inhibitory regulation of collagen content in tissues. At present, no effective treatment of liver fibrosis is available for clinical use. We aimed to test the effects of melatonin on dimethylnitrosamine (DMN)-induced liver damage in rats. Wistar albino rats were injected with DMN intraperitoneally. Following a single dose of 40 mg/kg DMN, either saline (DMN) or 100 mg/kg daily melatonin was administered for 14 days. In other rats, physiologic saline or melatonin were injected for 14 days, following a single injection of saline as control. Hepatic fibrotic changes were evaluated biochemically by measuring tissue hydroxyproline levels and histopathogical examination. Malondialdehyde (MDA), an end product of lipid peroxidation, and glutathione (GSH) and superoxide dismutase (SOD) levels were evaluated in blood and tissue homogenates. DMN caused hepatic fibrotic changes, whereas melatonin suppressed these changes in five of 14 rats (P < 0.05). DMN administration resulted in increased hydroxyproline and MDA levels, and decreased GSH and SOD levels, whereas melatonin reversed these effects. When melatonin was administered alone, no significant changes in biochemical parameters were noted. In conclusion, the present study suggests that melatonin functions as a potent fibrosuppressant and antioxidant, and may be a therapeutic choice. [source]

Signalling molecules and growth factors for tissue engineering of cartilage,what can we learn from the growth plate?,

JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 6 2009
Christoph Brochhausen
Abstract Modern tissue engineering concepts integrate cells, scaffolds, signalling molecules and growth factors. For the purposes of regenerative medicine, fetal development is of great interest because it is widely accepted that regeneration recapitulates in part developmental processes. In tissue engineering of cartilage the growth plate of the long bone represents an interesting, well-organized developmental structure with a spatial distribution of chondrocytes in different proliferation and differentiation stages, embedded in a scaffold of extracellular matrix components. The proliferation and differentiation of these chondrocytes is regulated by various hormonal and paracrine factors. Thus, members of the TGF, superfamily, the parathyroid hormone-related peptide,Indian hedgehog loop and a number of transcription factors, such as Sox and Runx, are involved in the regulation of chondrocyte proliferation and differentiation. Furthermore, adhesion molecules, homeobox genes, metalloproteinases and prostaglandins play a role in the complex regulation mechanisms. The present paper summarizes the morphological organization of the growth plate and provides a short but not exhaustive overview of the regulation of growth plate development, giving interesting insights for tissue engineering of cartilage. Copyright © 2009 John Wiley & Sons, Ltd. [source]

EDTA enhances high-throughput two-dimensional bioprinting by inhibiting salt scaling and cell aggregation at the nozzle surface

JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 4 2009
Cheryl A. Parzel
Abstract Tissue-engineering strategies may be employed in the development of in vitro breast tissue models for use in testing regimens of drug therapies and vaccines. The physical and chemical interactions that occur among cells and extracellular matrix components can also be elucidated with these models to gain an understanding of the progression of transformed epithelial cells into tumours and the ultimate metastases of tumour cells. The modified inkjet printer may be a useful tool for creating three-dimensional (3D) in vitro models, because it offers an inexpensive and high-throughput solution to microfabrication, and because the printer can be easily manipulated to produce varying tissue attributes. We hypothesized, however, that when ink is replaced with a biologically based fluid (i.e. a ,bio-ink'), specifically a serum-free cell culture medium, printer nozzle failure can result from salt scale build-up as fluid evaporates on the printhead surface. In this study, ethylene diamine tetra-acetic acid (EDTA) was used as a culture medium additive to prevent salt scaling and cell aggregation during the bioprinting process. The results showed that EDTA, at a concentration typically found in commercially available trypsin solutions (0.53 mM), prevented nozzle failure when a serum-free culture medium was printed from a nozzle at 1000 drops/s. Furthermore, increasing concentrations of EDTA appeared to mildly decrease aggregation of 4T07 cells. Cell viability studies were performed to demonstrate that addition of EDTA did not result in significant cell death. In conclusion, it is recommended that EDTA be incorporated into bio-ink solutions containing salts that could lead to nozzle failure. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Insights into Serotonin Signaling Mechanisms Associated with Canine Degenerative Mitral Valve Disease

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
M.A. Oyama
Little is known about the molecular abnormalities associated with canine degenerative mitral valve disease (DMVD). The pathology of DMVD involves the differentiation and activation of the normally quiescent mitral valvular interstitial cell (VIC) into a more active myofibroblast phenotype, which mediates many of the histological and molecular changes in affected the valve tissue. In both humans and experimental animal models, increased serotonin (5-hydroxytryptamine, 5HT) signaling can induce VIC differentiation and myxomatous valve damage. In canine DMVD, numerous lines of evidence suggest that 5HT and related molecules such as transforming growth factor-, play a critical role in the pathogenesis of this disease. A variety of investigative techniques, including gene expression, immunohistochemistry, protein blotting, and cell culture, shed light on the potential role of 5HT in the differentiation of VIC, elaboration of myxomatous extracellular matrix components, and activation of mitogen-activated protein kinase pathways. These studies help support a hypothesis that 5HT and its related pathways serve as an important stimulus in canine DMVD. This review describes the pathological characteristics of canine DMVD, the organization and role of the 5HT pathway in valve tissue, involvement of 5HT in human and experimental models of valve disease, avenues of evidence that suggest a role for 5HT in naturally occurring DMVD, and finally, a overarching hypothesis describing a potential role for 5HT in canine DMVD. [source]

Allicin, the active component of garlic, prevents immune-mediated, concanavalin A-induced hepatic injury in mice

LIVER INTERNATIONAL, Issue 3 2005
Rafael Bruck
Abstract: Background/Aim: Allicin, the immunologically active component of garlic, has been found to affect oxidative stress and immune response in several experimental systems. In the present study, we examined the ability of allicin to prevent immune-mediated, concanavalin A (Con A)-induced liver damage in mice. Methods: Mice were pretreated with allicin for 7 days before their inoculation with Con A (15 mg/kg). The serum levels of liver enzymes and liver histology were examined 24 h after Con A administration. The effect of Con A and allicin on serum levels of tumor necrosis factor-, (TNF-,) and nuclear factor-,B (NF-,B) activation in the liver were examined 2 h after Con A administration, in a separate group of rats, and the effect of allicin on Con A-induced expression of inducible nitric oxide synthase (iNOS) was determined by western blot analysis 24 h after Con A injection. Results: The histopathologic damage in the mouse livers, and the Con A-induced increase of aminotransferases and TNF-, were markedly inhibited in the mice pretreated with allicin before Con A injection (P<0.01). NF-,B binding activity to the nucleus, which increased 2 h after Con A administration, was attenuated by allicin. The expression of iNOS protein which was induced following Con A administration was significantly attenuated by allicin. In vitro studies showed that allicin inhibited TNF-,-mediated T cell adhesion to extracellular matrix components and to endothelial cells. Allicin also inhibited TNF-,-mediated intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression on human vascular endothelial cells. Conclusions: This study demonstrates that immune-mediated liver damage in mice can be prevented by allicin, probably because of its immunomodulatory effects on T cells and adhesion molecules and inhibition of NF-,B activation. [source]

Ergocalciferol promotes in vivo differentiation of keratinocytes and reduces photodamage caused by ultraviolet irradiation in hairless mice

PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 5 2004
Hiroaki Mitani
Background: Ergocalciferol (VD2) is usually administered orally and it is metabolized to produce its biologically active metabolites in the liver and kidney. Active vitamin D is a well-known potent regulator of cell growth and differentiation. Purpose: Active vitamin D such as 1,25-dihydroxyvitamin D3 (1,,25(OH)2D3) prevents photodamage, including wrinkles and morphologic alterations. However, its clinical and cosmetic use is limited because of its potent, associated effect on calcium metabolism. We examined the efficacy of vitamin D analogues with few adverse effects for preventing skin photodamage. Method: Topical application of VD2 to hairless mouse dorsal skin, and exposure to solar-simulating ultraviolet (UV) radiation at a dose of 10.8 J/cm2 (UVA) were performed for 15 weeks, five times a week on weekdays. At the end of the final irradiation, histological and analytical studies were performed. Results: Topical application of VD2 significantly prevented wrinkle formation and abnormal accumulation of extracellular matrix components. In addition, VD2 suppressed excessive secretion of IL-6 induced by UV irradiation in cultured human normal keratinocytes, in a dose-dependent manner. Conclusion: VD2 promoted keratinocytes differentiation in the epidermis and showed diverse physiological effects, the same as the active form of VD3. The results suggested that the suppression of skin photodamage involved the promotion of keratinocytes differentiation and suppression of IL-6 secretion induced by exposure to UV. Topical application of VD2 may become an effective means to suppress solar UV-induced human skin damage. [source]

Proteomic analysis of membrane proteins expressed specifically in pluripotent murine embryonic stem cells

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 1 2009
Atsushi Intoh
Abstract Embryonic stem cells (ESCs) are established from the inner cell mass of preimplantation embryos, are capable of self-renewal, and exhibit pluripotency. Given these unique properties, ESCs are expected to have therapeutic potential in regenerative medicine and as a powerful tool for in vitro differentiation studies of stem cells. Various growth factors and extracellular matrix components regulate the pluripotency and differentiation of ESC progenies. Thus, the cell surface receptors that bind these regulatory factors are crucial for the precise regulation of stem cells. To identify membrane proteins that are involved in the regulation of pluripotent stem cells, the membrane proteins of murine ESCs cultured with or without leukemia inhibitory factor (LIF) were purified and analyzed by quantitative proteomics. 2-D PAGE-based analysis using fluorescently labeled proteins and shotgun-based analysis with isotope-labeled peptides identified 338 proteins, including transmembrane, membrane-binding, and extracellular proteins, which were expressed specifically in pluripotent or differentiated murine ESCs. Functions of the identified proteins revealed cell adhesion molecules, channels, and receptors, which are expected to play important roles in the maintenance of murine ESC pluripotency. Membrane proteins that are expressed in pluripotent ESCs but not in differentiated cells such as Slc16a1 and Bsg could be useful for the selection of the stem cells in vitro. [source]

Interaction between myostatin and extracellular matrix components

ANIMAL SCIENCE JOURNAL, Issue 1 2010
Takayuki MIURA
ABSTRACT Myostatin, a member of the TGF-, superfamily, is a negative regulator of skeletal muscle mass. We have recently demonstrated that decorin binds to myostatin in vitro, and that immobilized decorin within the collagen matrix prevents myostatin-mediated inhibition of myoblast proliferation. However, little is known about other ECM molecules that bind to myostatin and modulate its activity. Thus, in the present study, we investigated the interaction of several other ECM molecules with myostatin. We here show that fibromodulin, fibronectin and laminin bind to myostatin in the presence of Zn2+ with a dissociation constant (KD) of 10,10,10,8 mol/L. Fibromodulin shows the highest affinity for myostatin among them. These results suggest that these ECM molecules may modulate myostatin activity like decorin does. [source]

The melanocortin system in articular chondrocytes: Melanocortin receptors, pro-opiomelanocortin, precursor proteases, and a regulatory effect of ,-melanocyte,stimulating hormone on proinflammatory cytokines and extracellular matrix components

ARTHRITIS & RHEUMATISM, Issue 10 2009
Susanne Grässel
Objective The pro-opiomelanocortin (POMC),derived neuropeptide ,-melanocyte,stimulating hormone (,-MSH) mediates its effects via melanocortin (MC) receptors. This study was carried out to investigate the expression patterns of the MC system and the effects of ,-MSH in human articular chondrocytes. Methods Articular chondrocytes established from human osteoarthritic joint cartilage were analyzed by reverse transcription,polymerase chain reaction (RT-PCR) and Western blotting for the expression of MC receptors, POMC, and prohormone convertases (PCs). MC-1 receptor (MC-1R) expression in articular cartilage was further studied by immunohistochemistry. Ca2+ and cAMP assays were used to monitor ,-MSH signaling, while studies of ,-MSH function were performed in cultures with chondrocyte micromass pellets stimulated with ,-MSH. Expression of cytokines and extracellular matrix (ECM) components was determined by real-time RT-PCR, Western immunoblotting, and enzyme-linked immunosorbent assays. Results MC-1R expression was detected in articular chondrocytes in vitro and in articular cartilage in situ. In addition, expression of transcripts for MC-2R, MC-5R, POMC, and PCs was detected in articular chondrocytes. Stimulation with ,-MSH increased the levels of intracellular cAMP, but not Ca2+, in chondrocytes. Both messenger RNA and protein expression of various proinflammatory cytokines, collagens, matrix metalloproteinases (MMPs), and SOX9 was modulated by ,-MSH. Conclusion Human articular chondrocytes are target cells for ,-MSH. The effects of ,-MSH on expression of cytokines and MMPs suggest that this neuropeptide plays a role in inflammatory and degenerative processes in cartilage. It is conceivable that inflammatory reactions can be mitigated by the induction of endogenous MCs or administration of ,-MSH to the affected joints. The induction pattern of regulatory and structural ECM components such as collagens as well as SOX9 and anabolic and catabolic cytokines points to a function of ,-MSH as a trophic factor in skeletal development during endochondral ossification rather than as a factor in homeostasis of permanent cartilage. [source]

Behavior of Cardiomyocytes and Skeletal Muscle Cells on Different Extracellular Matrix Components,Relevance for Cardiac Tissue Engineering

Glycosaminoglycan in cerebrum, cerebellum and brainstem of young sheep brain with particular reference to compositional and structural variations of chondroitin,dermatan sulfate and hyaluronan

BIOMEDICAL CHROMATOGRAPHY, Issue 9 2008
Virginia Kilia
Abstract Recent advances in the structural biology of chondroitin sulfate chains have suggested important biological functions in the development of the brain. Several studies have demonstrated that the composition of chondroitin sulfate chains changes with aging and normal brain maturation. In this study, we determined the concentration of all glycosaminoglycan types, i.e. chondroitin sulfate, dermatan sulfate, keratan sulfate, heparan sulfate, hyaluronan and chondroitin in cerebrum, cerebellum and brainstem of young sheep brain. In all cases, chondroitin sulfate was the predominant glycosaminoglycan type, comprising about 54,58% of total glycosaminoglycans, with hyaluronan being present also in significant amounts of about 19,28%. Of particular interest was the increased presence of the disulfated disaccharides and dermatan sulfate in cerebellum and brainstem, respectively, as well as the detectable and measurable occurrence of chondroitin in young sheep brain. Among the three brain areas, cerebrum was found to be significantly richer in chondroitin sulfate and hyaluronan, two major extracellular matrix components. These findings imply that the extracellular matrix of the cerebrum is different from those of cerebellum and brainstem, and probably this fact is related to the particular histological and functional characteristics of each anatomic area of the brain. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Trichloroethylene effects on gene expression during cardiac development

BIRTH DEFECTS RESEARCH, Issue 7 2003
J. Michael Collier
Abstract BACKGROUND Halogenated hydrocarbon exposure is associated with changes in gene expression in adult and embryonic tissue. Our study was undertaken to identify differentially expressed mRNA transcripts in embryonic hearts from Sprague-Dawley rats exposed to trichloroethylene (TCE) or potential bio-transformation products dichloroethylene (DCE) and trichloroacetic acid (TCAA). METHODS cDNA subtractive hybridization was used to selectively amplify expressed mRNA obtained from control or halogenated hydrocarbon exposed rat embryos. The doses used were 1100 and 110 ppm (8300 and 830 ,M) TCE, 110 and 11 ppm (1100 and 110 ,M) DCE, and 27.3 and 2.75 mg/ml (100 and 10 mM) TCAA. Control animals were given distilled drinking water throughout the period of experiments. RESULTS Sequencing of over 100 clones derived from halogenated hydrocarbon exposed groups resulted in identification of numerous differentially regulated gene sequences. Up-regulated transcripts identified include genes associated with stress response (Hsp 70) and homeostasis (several ribosomal proteins). Down-regulated transcripts include extracellular matrix components (GPI-p137 and vimentin) and Ca2+ responsive proteins (Serca-2 Ca2+ -ATPase and ,-catenin). Two possible markers for fetal TCE exposure were identified: Serca-2 Ca2+ -ATPase and GPI-p137, a GPI-linked protein of unknown function. Differential regulation of expression of both markers by TCE was confirmed by dot blot analysis and semi-quantitative RT-PCR with levels of TCE exposure between 100 and 250 ppb (0.76 and 1.9 ,M) sufficient to decrease expression. CONCLUSIONS Sequences down-regulated with TCE exposure appear to be those associated with cellular housekeeping, cell adhesion, and developmental processes, while TCE exposure up-regulates expression of numerous stress response and homeostatic genes. Birth Defects Research (Part A) 67488,495, 2003. © 2003 Wiley-Liss, Inc. [source]