Collagen, which widely exists in skin, bone, muscle and other tissues, is a major structural protein in mammalian extracellular matrix. It participates in cell proliferation, differentiation, migration and signal transmission, plays an important role in tissue support and repair and exerts a protective effect. Collagen is widely used in tissue engineering, clinical medicine, food industry, packaging materials, cosmetics and medical beauty due to its good biological characteristics. This paper reviews the biological characteristics of collagen and its application in bioengineering research and development in recent years. Finally, we prospect the future application of collagen as a biomimetic material.
Animals ; Collagen/analysis* ; Tissue Engineering/methods* ; Extracellular Matrix/metabolism* ; Biomimetic Materials/chemistry* ; Bone and Bones ; Tissue Scaffolds ; Mammals/metabolism*

Contributing to organ formation and tissue regeneration, extracellular matrix (ECM) constituents provide tissue with three-dimensional (3D) structural integrity and cellular-function regulation. Containing the crucial traits of the cellular microenvironment, ECM substitutes mediate cell-matrix interactions to prompt stem-cell proliferation and differentiation for 3D organoid construction in vitro or tissue regeneration in vivo. However, these ECMs are often applied generically and have yet to be extensively developed for specific cell types in 3D cultures. Cultured cells also produce rich ECM, particularly stromal cells. Cellular ECM improves 3D culture development in vitro and tissue remodeling during wound healing after implantation into the host as well. Gaining better insight into ECM derived from either tissue or cells that regulate 3D tissue reconstruction or organ regeneration helps us to select, produce, and implant the most suitable ECM and thus promote 3D organoid culture and tissue remodeling for in vivo regeneration. Overall, the decellularization methodologies and tissue/cell-derived ECM as scaffolds or cellular-growth supplements used in cell propagation and differentiation for 3D tissue culture in vitro are discussed. Moreover, current preclinical applications by which ECM components modulate the wound-healing process are reviewed.
Cell Differentiation ; Cell Proliferation ; Decellularized Extracellular Matrix ; Extracellular Matrix/metabolism* ; Humans ; Mesenchymal Stem Cells ; Tissue Engineering/methods* ; Tissue Scaffolds/chemistry*

OBJECTIVE: To construct a novel non-viral vector loaded with growth and differentiation factor-5 (GDF-5) plasmid using chitosan, hyaluronic acid, and chondroitin sulfate for osteoarthritis (OA) gene therapy. METHODS: Nano-microspheres (NMPs) were prepared by mixing chitosan, hyaluronic acid, and chondroitin sulfate. GDF-5 plasmid was encapsulated in the NMPs through electrostatic adsorption. The basic characteristics of the NMPs were observed, and then they were co-cultured with chondrocytes to observe their effects on extracellular matrix (ECM) protein expression. Finally, NMPs loaded with GDF-5 were injected into the articular cavities of rabbits to observe their therapeutic effects on OA in vivo. RESULTS: NMPs exhibited good physicochemical properties and low cytotoxicity. Their average diameter was (0.61±0.20) μm, and encapsulation efficiency was (38.19±0.36)%. According to Cell Counting Kit-8 (CCK-8) assay, relative cell viability was 75%-99% when the total weight of NMPs was less than 560 μg. Transfection efficiency was (62.0±2.1)% in a liposome group, and (60.0±1.8)% in the NMP group. There was no significant difference between the two groups (P>0.05). Immunohistochemical staining results suggested that NMPs can successfully transfect chondrocytes and stimulate ECM protein expression in vitro. Compared with the control groups, the NMP group significantly promoted the expression of chondrocyte ECM in vivo (P<0.05), as shown by analysis of the biochemical composition of chondrocyte ECM. When NMPs were injected into OA model rabbits, the expression of ECM proteins in chondrocytes was significantly promoted and the progression of OA was slowed down. CONCLUSIONS Based on these data, we think that these NMPs with excellent physicochemical and biological properties could be promising non-viral vectors for OA gene therapy.
Animals ; Cell Differentiation ; Cell Survival/drug effects* ; Chitosan/chemistry* ; Chondrocytes/cytology* ; Chondroitin Sulfates/chemistry* ; Drug Carriers ; Extracellular Matrix/metabolism* ; Genetic Therapy/methods* ; Growth Differentiation Factor 5/genetics* ; Hyaluronic Acid/chemistry* ; Microspheres ; Nanomedicine ; Osteoarthritis/therapy* ; Plasmids/metabolism* ; Rabbits

Articular cartilage is a connective tissue consisting of a specialized extracellular matrix (ECM) that dominates the bulk of its wet and dry weight. Type II collagen and aggrecan are the main ECM proteins in cartilage. However, little attention has been paid to less abundant molecular components, especially minor collagens, including type IV, VI, IX, X, XI, XII, XIII, and XIV, etc. Although accounting for only a small fraction of the mature matrix, these minor collagens not only play essential structural roles in the mechanical properties, organization, and shape of articular cartilage, but also fulfil specific biological functions. Genetic studies of these minor collagens have revealed that they are associated with multiple connective tissue diseases, especially degenerative joint disease. The progressive destruction of cartilage involves the degradation of matrix constituents including these minor collagens. The generation and release of fragmented molecules could generate novel biochemical markers with the capacity to monitor disease progression, facilitate drug development and add to the existing toolbox for in vitro studies, preclinical research and clinical trials.
Aggrecans ; chemistry ; genetics ; metabolism ; Animals ; Biomarkers ; metabolism ; Cartilage, Articular ; chemistry ; metabolism ; pathology ; Collagen ; chemistry ; classification ; genetics ; metabolism ; Extracellular Matrix Proteins ; chemistry ; genetics ; metabolism ; Gene Expression ; Humans ; Osteoarthritis ; diagnosis ; genetics ; metabolism ; pathology ; Protein Isoforms ; chemistry ; classification ; genetics ; metabolism

OBJECTIVETo explore effects of exendin-4 on the metabolism of extracellular matrix (ECM) in human mesangial cells (HMC) cultured in the presence of high glucose and explore the possible mechanism.

METHODSHuman mesangial cells (HMC) were treated with exendin-4 under high glucose conditions. The cell proliferation was observed using CCK8 assay, and the expressions of collagen type I, fibronectin, transforming growth factor-β1 (TGFβ1) expression and extracellular signal- regulated kinase (ERK) signaling pathway activity were assessed using Western blotting.

RESULTSExendin-4 inhibited cell proliferation and the expressions of collagen type I, fibronectin and TGFβ1 and reversed ERK phosphorylation in high glucose-induced HMC.

CONCLUSIONExendin-4 can regulate ECM metabolism in HMC cultured in high glucose by inhibiting TGFβ1/ERK pathway, suggesting the beneficial effects of exendin-4 in preventing and treating diabetic nephropathy.

Cell Proliferation ; Cells, Cultured ; Collagen Type I ; metabolism ; Culture Media ; chemistry ; Diabetic Nephropathies ; Extracellular Matrix ; metabolism ; Fibronectins ; metabolism ; Glucose ; chemistry ; Humans ; MAP Kinase Signaling System ; Mesangial Cells ; drug effects ; Peptides ; pharmacology ; Phosphorylation ; Signal Transduction ; Transforming Growth Factor beta1 ; metabolism ; Venoms ; pharmacology

Pericellular matrix (PCM) is a narrow tissue region surrounding chondrocytes, which "chondron" with its enclosed cells. A number of studies suggested that PCM is rich in proteoglycans, collagen and fibronectin, and plays an important role in regulating microenvironment of chondrocytes. Direct measures of PCM properties through micropipette aspiration technique showed that PCM was different from mechanical property of chondrocytes and nature extracellular matrix. However, the function of PCM is not clear, and need further study.
Animals ; Biomechanical Phenomena ; Chondrocytes ; chemistry ; cytology ; metabolism ; Extracellular Matrix ; chemistry ; metabolism ; Humans

OBJECTIVETo screen potential mutation of the CRELD1 gene in congenital atrioventricular septal defect (AVSD) and explore its functional implications.

METHODSFragments encompassing the 11 coding exons of CRELD1 gene, including at least 50 bp of flanking intronic regions, were amplified with PCR and subjected to DNA sequencing. Results of sequencing were compared with predicted sequence from the GenBank database. Eukaryotic expression vector pcDNA3.1CRELD1 containing the mutational sequence was constructed. Western blotting and real-time fluorescent quantitative reverse transcription polymerase chain reaction (FQ RT-PCR) was applied to examine the expression of CRELD1, Tenascin C and Aggrecan.

RESULTSC857G was identified in a girl with an isolated partial AVSD. The mutation has resulted in a substitution of Alanine for Proline at amino acid 286 in the first cbEGF domain. Western blotting and FQ RT-PCR confirmed that the P286R missense mutation has been a gain-of-function mutation. Compared with the unloaded control, the Aggrecan mRNA expression was downregulated for both wild-type and mutant type samples (t=140.27 vs. 26.36, P < 0.01). The downregulation was more significant in mutant type (t=25.69, P=0.002). There was no significant difference of the Tenascin C expression between wild-type and the unload control (t=1.167, P> 0.05), whilst the Tenascin C expression was up-regulated in mutant type (t=6.66, P=0.022).

CONCLUSIONMutation of the CRELD1 gene may increase the risk for AVSD rather than being directly causative. The P286R mutation of CRELD1 can downregulate the expression of Aggrecan and upregulates the expression of Tenascin C protein, both of which are crucial to extracellular matrix in the formation of the atrioventricular septum. The P286R mutation of CRELD1 may be correlated to the occurrence of AVSD.

Adolescent ; Amino Acid Sequence ; Animals ; Base Sequence ; Cell Adhesion Molecules ; chemistry ; genetics ; metabolism ; Child ; Child, Preschool ; Extracellular Matrix Proteins ; chemistry ; genetics ; metabolism ; Female ; Heart Septal Defects ; genetics ; metabolism ; pathology ; Humans ; Infant ; Male ; Molecular Sequence Data ; Mutation, Missense ; Sequence Alignment

This study was purposed to establish a new inducing system for differentiation of human embryonic stem cells into hematopoietic progenitor cells and to explore the effect of different extracellular matrices (DEM) on production of hematopoietic cells. The 3 kinds of extracellular matrices-matrigel, fibronectin and IV type collagen (collagen IV) were chosen to package cultured plates, the direct adherent culture on extracellular matrix was used, and the hematopoietic growth factors were added into cultured plates to induce the differentiation of human embryonic stem cells into hematopoietic progenitor cells. The hematopoietic colony forming unit assay was used to determine the yielded colony forming cells, the flow cytometry and real-time quantitative PCR were used to detect the expression of markers specific to hematopoiesis and the effect of 3 extracellular matrices on production of hematopoietic progenitor cells was compared. The results showed that after being induced for 14 days, the total yield of colony forming cells, the ratio of CD34(+) cells and the expression level of SCL and CD34 on collagen IV were significantly higher than those on matrigel and fibronectin groups (P < 0.05). It is concluded that human embryonic stem cells can efficiently differentiate into hematopoietic progenitor cells by direct adherent culture on extracellular matrices, and the collagen IV can improve the hematopoietic differentiation of human embryonic stem cells.
Antigens, CD34 ; metabolism ; Cell Differentiation ; Collagen ; chemistry ; Collagen Type IV ; chemistry ; Drug Combinations ; Embryonic Stem Cells ; cytology ; Extracellular Matrix ; chemistry ; Fibronectins ; chemistry ; Flow Cytometry ; Hematopoietic Stem Cells ; cytology ; Humans ; Laminin ; chemistry ; Proteoglycans ; chemistry

BACKGROUND: Estrogens act on estrogen receptors distributed in articular cartilages, synovial membrane, and ligaments, which are thought to be related with degenerative changes. Meanwhile, progesterone is known to have a weak anabolic action on bone formation This study evaluates the effects of estrogen and progesterone hormone on bone/cartilage turnover in ovariectomized (OVX) rats. METHODS: Thirty-five 7-month-old female Sprague-Dawley rats were randomly divided into 5 groups and then ovariectomized bilaterally except the sham control group. The first and the second group acting as controls did not receive hormonal therapy, the third group received estrogen, the fourth group received progesterone, and the fifth group received combination of both hormones 10 weeks after surgery. Evaluations were done using the serum levels of cartilage oligomeric matrix protein (COMP) for cartilage turnover, collagen type I C-telopeptide (CTX-1) and osteocalcin (OC) for bone turnover at 11, 15, 19 weeks after OVX and histology using the Osteoarthritis Research Society International (OARSI) osteoarthritis (OA) cartilage histopathology assessment system. RESULTS: Significantly less cartilage degradation (decreased levels of COMP) was found in the combined hormone treated group in comparison with OVX group. Similarly, both hormonal treatment resulted in increased bone formation and decreased bone resorption i.e., a low overall bone turnover status (decrease in the serum OC and CTX-1 levels). CONCLUSIONS: Combined estrogen and progesterone therapy was found to be convincing in terms of reducing the severity of OA in this experimental model.
Animals ; Biological Markers/blood/metabolism ; Bone Remodeling/*drug effects ; Bone and Bones/chemistry/drug effects ; Cartilage/chemistry/*drug effects ; Collagen Type I/blood/metabolism ; Disease Models, Animal ; Estrogens/*pharmacology ; Extracellular Matrix Proteins/blood/metabolism ; Female ; Glycoproteins/blood/metabolism ; Histocytochemistry ; Hormone Replacement Therapy/*methods ; Osteoarthritis/blood/*drug therapy ; Osteocalcin/blood/metabolism ; Ovariectomy ; Progesterone/*pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVEThe imbalance between extracellular matrix (ECM) synthesis and degradation induces the excessive ECM deposition and thus renal fibrosis. The decoction (A&A) which is a combination of two Chinese herbs, Astragalus membranaceus var. mongholicus and Angelica sinensis, has been shown to alleviate ECM production in animal models of chronic kidney diseases. In this paper, the effect of A&A on ECM degradation was investigated with interstitial fibrosis in rats.

METHODMale Wistar rats were randomly divided into sham, unilateral ureteral obstruction (UUO) and UAA (UUO plus A&A administration) groups. After administration of A&A (14 g x kg(-1) x d(-1)) by gavage for 3, 7 and 10 days, morphological changes were evaluated by HE, PAS and Sirius red staining technique. The expression of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA), the activity of PAI-1 and t-PA were determined by ELISA. The activity of matrix metalloproteinases (MMP-9, MMP-2), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were evaluated by gelatin zymography or reverse gelatin zymography, respectively.

RESULTMorphological analysis showed severe interstitial mononuclear cells infiltration, tubular atrophy, renal fibrosis and collagen expression in kidneys of UUO group, which was reduced by A&A administration (P < 0.05, UAA vs UUO group). Compared with the sham group, the expression of PAI-1 was significantly increased in UUO group by 63%, 91% and 112% at day 3, 7 and 10 respectively; and there were a remarkable decrease in UAA group by 44%, 43% and 52% at day 3, 7 and 10. The expression of active PAI-1 was strikingly increased in UUO group at day 3 [(30.5 +/- 23.8) ng x g(-1) vs. (0.0 +/- 0.0) ng x g(-1), P < 0.05)], day 7 [(36.5 +/- 11.2) ng x g(-1) vs. (0.0 +/- 0.0) ng x g(-1), P < 0.05)], and day 10 [(54.5 +/- 14.2) ng x g(-1) vs. (0.5 +/- 0.5) ng x g(-1), P < 0.05)]. The active PAI-1 was decreased in UAA group at day 7 [(14.9 +/- 0.5) ng x g(-1) vs. (36.5 +/- 11.2) ng x g(-1), P < 0.05] and day 10 [(15.4 +/- 4.8) ng x g(-1) vs. (54.5 +/- 14.2) ng x g(-1), P < 0.05]. The expression of t-PA was increased in UUO group only at day 3 [(58.1 +/- 16.5) microg x g(-1) vs. (30.1 +/- 17.3) microg x g(-1)], P < 0.05), meanwhile decreased in UAA group [(26.3 +/- 8.7) microg x g(-1) vs. (58.1 +/- 16.5) microg x g(-1), P < 0.05)]. But the expression of active t-PA was shown no significantly difference among the three groups. For MMP-2 and MMP-9 activity, they were significantly higher compared with the sham group in UUO group, but no significantly change after A&A treatment. The TIMP-1 activity was significantly increased in UUO group by 28% and 63% at day 7 and 10 respectively, significantly decreased in UAA group by 40% and 39% at the same time point.

CONCLUSIONThe anti-fibrosis effects of A&A might be associated with modulating the imbalance of PAs/PAIs system as well as MMPs/TIMPs system, thereby alleviate ECM accumulation and interstitial fibrosis.

Angelica sinensis ; chemistry ; Animals ; Astragalus Plant ; chemistry ; Drugs, Chinese Herbal ; administration & dosage ; Extracellular Matrix ; metabolism ; Fibrosis ; Humans ; Kidney ; enzymology ; metabolism ; pathology ; Kidney Diseases ; drug therapy ; enzymology ; metabolism ; pathology ; Male ; Matrix Metalloproteinase 1 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Plasminogen Activator Inhibitor 1 ; metabolism ; Rats ; Rats, Wistar ; Tissue Plasminogen Activator ; metabolism