Collagen ; biosynthesis ; Liver Cirrhosis ; metabolism ; pathology

Recombinant collagen, as an alternative to natural collagen, has the potential to be widely used in biomaterials, biomedicine, etc. Diverse recombinant collagens and their variants can be industrially produced in a variety of expression systems, which lays a foundation for exploring and expanding the clinical application of recombinant collagens. We reviewed different expression systems for recombinant collagens, such as prokaryotic expression systems, yeast expression systems, as well as plant, insect, mammal, and human cell expression systems, and introduced the advantages, potential applications, and limitations of recombinant collagen. In particularly, we focused on the current progress in the recombinant collagen production, including recombinant expression system construction and hydroxylation strategies of recombinant collagen, and summarized the current biomedical applications of recombinant collagen.
Animals ; Biocompatible Materials ; Collagen/biosynthesis* ; Humans ; Hydroxylation ; Recombinant Proteins/biosynthesis*

OBJECTIVEThe aim of this study was to investigate the expression of collagen in the process of masseter muscle reattachment to the cortical and cancellous bones of mandible.

METHODSA total of nine adult goats were used in the study. One was the control. The other eight were treated with bilateral detachment of the masseter muscles. The biopsies of bone and muscle were taken at 2, 4, 8 and 12 weeks after the operation. The characteristics of the healing muscle-bone interfaces were examined using immunohistochemical techniques.

RESULTSImmunohistochemical analysis illustrated that the locations of collagen type I, II and III were different during the healing process, but similar in the cortical and cancellous bones.

CONCLUSIONThis study demonstrates that the distribution of the three types of collagens at the muscle-bone interfaces is associated with time, but not related with their locations.

Animals ; Collagen ; biosynthesis ; genetics ; Collagen Type I ; biosynthesis ; genetics ; Collagen Type II ; biosynthesis ; genetics ; Collagen Type III ; biosynthesis ; genetics ; Female ; Goats ; Male ; Mandible ; metabolism ; pathology ; surgery ; Masseter Muscle ; metabolism ; pathology ; surgery ; Wound Healing ; physiology

OBJECTIVETo investigate the role of recombinant human transforming growth factor beta3 (rhTGFbeta3) on fibroblast and its possible mechanism.

METHODSNormal skin fibroblast (NSFb) and hypertrophic scar fibroblast (HSFb) were cultured in vitro, and were processed by different concentrations of rhTGFbeta3. NSFb and HSFb in DMEM solution without rhTGFbeta3 were employed as control. The changes in the protein and mRNA expression of type I and III collagen in NSFb and HSFb were observed.

RESULTS(1) The expression of type I and III procollagen in NSFb was evidently different from that of HSFb (2) The synthesis of type I and III procollagen in all test groups was increased obviously after rhTGFbeta3 process (P < 0.001) while the ratio of type I to III procollagen was decreased when compared with that in control group. (3) The effects of rhTGFbeta3 on the biological behavior exhibited an obvious dose- effects relationship. The contents of type I to III procollagen in HSFb were higher than those in NSFb when the dose of rhTGFbeta3 was same.

CONCLUSIONrhTGFbeta3 could effectively promote the synthesis of type I and III procollagen, especially type III procollagen in fibroblasts. This might be beneficial to the accelerate of wound healing and to inhibit or prevent scar formation.

Cicatrix, Hypertrophic ; metabolism ; Collagen Type I ; biosynthesis ; Collagen Type III ; biosynthesis ; Fibroblasts ; drug effects ; metabolism ; Humans ; In Vitro Techniques ; Recombinant Proteins ; pharmacology ; Transforming Growth Factor beta3 ; pharmacology

OBJECTIVETo evaluate the effects of taurine in diet on the expression of type I and III collagen and collagen ratio at different time points in rats lung by image process technology.

METHODSWistar rats were randomly divided into three groups: the saline instilled with a control diet (the saline treated group); silica instilled with a control diet (the silica treated group); and silica instilled with a diet containing 2.5% taurine (the taurine treated group). Animal models were established by the direct tracheal instillation of silica into rat lungs exposed surgically. The taurine concentration of serum was analyzed by means of HPLC. Paraffin embedded lung sections were stained with Sirius red. Polarization microscopy and Image Pro Plus Version 4.5 for windows were used for detecting type I and III collagen.

RESULTSThe concentration of taurine in serum of the taurine treated group was significantly elevated compared to the saline treated and silica treated group (P < 0.05 or P < 0.01). Sirius red polarization microscopy showed that type I and III collagen positive area percentage were elevated in the silica treated rats compared with the saline treated group. On the 7th, 14th, 21st, 28th day after silica instillation type I collagen positive area percentage was increased by 3.84, 3.77, 3.73, 9.83 respectively (P < 0.01), and type III collagen positive area percentage were elevated by a little in the silica treated rats compared with saline treated group. The taurine treatment significantly decreased elevation of silica type I collagen positive area percentage of lung by 2.39, 1.62, 7.13 at the 7th, 21st, 28th day respectively (P < 0.05 or P < 0.01), and type III collagen positive area percentage of lung by 2.62 at the 28th day (P < 0.05) compared with the silica treated group. The ratio of type I to III collagen was increased from the 7th day to 28th day after silica instillation, and reached 1.87 at the 28th day with the maximal ratio in the silica-treated group.

CONCLUSIONTreatment with taurine can effectively attenuate type I and III collagen expression in the rat lung induced by silica particles at different time points in our study.

Animals ; Collagen Type I ; biosynthesis ; Collagen Type III ; biosynthesis ; Female ; Lung ; drug effects ; metabolism ; Male ; Random Allocation ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Taurine ; pharmacology

OBJECTIVETo observe the in vitro effects of gamma-interferon (IFNgamma) on gene expression of collagen I (Col I), III (Col III) and tissue inhibitor of metalloprotenase 1 (TIMP1) of HSC-T6 cells.

METHODSCultured HSC-T6 cells were exposed to IFNgamma at concentrations of 0.1, 1, 10, 10(2), 10(3), 10(4), 2.5 x 10(5), 5 x10(5) U/ml for 48 hours. 4,5-simethylthiazaoly colormetric assay was used to evaluate the effect of IFNgamma on HSC-T6 cell proliferation. After incubating with IFNgamma (1 U/ml, 10(2) U/ml and 10(4) U/ml) for 48 hours, HSC-T6 cells were harvested to detect Col I, Col III and TIMP1 steady state mRNA levels by quantitative reverse-transcription polymerase chain reaction (RT-PCR).

RESULTSThe Col I, Col III and TIMP1 mRNA levels of the control group were 2.86+/-0.21, 2.00+/-0.23 and 3.90+/-0.81, respectively. Col I and Col III mRNA levels in HSC-T6 cells treated by different concentrations of IFNgamma were lower than that of the controls (P < 0.01). There was no significant difference in TIMP1 mRNA levels between IFNgamma groups and controls.

CONCLUSIONIFNgamma suppresses expression of Col I and Col III whereas it has no effect on TIMP1 mRNA expression. The antifibrotic mechanism of IFNgamma may be partly due to its down-regulation of Col I and Col III mRNA levels in HSC-T6 cells.

Animals ; Cell Line ; Collagen Type I ; biosynthesis ; genetics ; Collagen Type III ; biosynthesis ; genetics ; Hepatocytes ; cytology ; metabolism ; Interferon-gamma ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Tissue Inhibitor of Metalloproteinase-1 ; biosynthesis ; genetics

This study was aimed to further investigate the function of platelet collagen receptor-glycoprotein VI and to screen its specific inhibitor. The extracellular domain of platelet glycoprotein VI (GPVI) in E. coli was expressed by recombinant technology, the extracellular domain cDNA of GPVI was amplified from pBluescript KS(-)-GPVI plasmid by PCR. Proved by sequencing, the expression vector pET-20b(+)-GPVI was constructed, which was then transformed into E. coli (BL21(DE3)pLysS) and induced by IPTG. The recombinant GPVI was purified on Ni-NTA resin column and renatured in PBS containing GSH and GSSG. The anti-penta His McAb and anti-GPVI polyclonal antibody were used to identify the recombinant GPVI in Western blotting. Collagen binding test was conducted to investigate the biological activity of recombinant GPVI. The results showed that the recombinant GPVI was expressed in E. coli and successfully purified, which was confirmed to be similar to the native GPVI in Western blotting. The recombinant GPVI can bind the type I collagen in dose-dependent manner. In conclusion, the recombinant GPVI can be achieved in E. coli and restore its native characteristics after renaturation.
Blood Platelets ; metabolism ; Blotting, Western ; Escherichia coli ; genetics ; Humans ; Integrin alpha2beta1 ; Platelet Membrane Glycoproteins ; biosynthesis ; genetics ; Protein Binding ; Receptors, Collagen ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; isolation & purification

Collagen Type I ; biosynthesis ; Hepatocyte Growth Factor ; biosynthesis ; Hepatocytes ; cytology ; metabolism ; physiology ; Liver Cirrhosis ; metabolism ; pathology ; physiopathology ; Liver Regeneration ; Receptors, Vitronectin ; biosynthesis

BACKGROUNDOsteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma.

METHODSOsteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type I collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed.

RESULTSObservation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type I collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicle of osteochondroma or outside osteochondroma were endothelial-lined.

CONCLUSIONThese observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry.

Bone Neoplasms ; pathology ; ultrastructure ; Cell Line, Tumor ; Collagen ; biosynthesis ; Humans ; Immunohistochemistry ; Neovascularization, Pathologic ; pathology ; Osteosarcoma ; pathology

The present study was undertaken to determine the effect of tensile force on DNA and protein biosynthesis in bone cells, and to identify the cell type(s) which primarily respond to external physical force among the heterogenous bone cell populations. As a prerequisite for this study, two bone cell populations which retain fibroblastic and osteoblastic feature were isolated from fetal rat calvaria with sequential enzyme digestion scheme. Tensile force was delivered to each bone cell population by two acrylic resin plates connected with a orthodontic expansion screw during culture period. Rate of DNA and protein synthesis in each bone cell population were assessed by the incorporated radioactivity of [3H]-thymidine into DNA and [3H]-proline into fraction of collagenase-digestible protein and noncollagenous protein, respectively. DNA synthesis of osteoblast-like calvarial cell populations was increased significantly by the application of tensile force for 24 hours. In contrast, no alteration in DNA synthesis of fibroblast-like populations could be observed in response to applied force. Tensile force induced the change in protein synthesis of bone cell populations with the same pattern. Total protein and collagen synthesis were increased within 24 hours in osteoblast-like populations, but not in fibroblast-like populations by tensile force application. These findings indicate that physical force can affect cellullar activity of the particular cell population, not all cell populations residing in bone and osteoblasts respond more sensitively than fibroblasts. So osteoblasts can modulate the behavior of other bone cells including osteoclasts by producing several local regulating factors of bone metabolism. In this context, preferential responsiveness of osteoblasts to applied tensile force observed in this study suggests that osteoblasts may play an important role in regulation of physical force-induced remodeling process.
Animals ; Collagen ; Digestion ; DNA* ; Fibroblasts ; Metabolism ; Osteoblasts ; Osteoclasts ; Protein Biosynthesis ; Radioactivity ; Rats ; Skull