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*

Objective: To investigate the effects of non-muscle myosin Ⅱ (NMⅡ) gene silenced bone marrow-derived mesenchymal stem cells (BMMSCs) on pulmonary extracellular matrix (ECM) and fibrosis in rats with acute lung injury (ALI) induced by endotoxin/lipopolysaccharide (LPS). Methods: The experimental research methods were adopted. Cells from femur and tibial bone marrow cavity of four one-week-old male Sprague-Dawley rats were identified as BMMSCs by flow cytometry, and the third passage of BMMSCs were used in the following experiments. The cells were divided into NMⅡ silenced group transfected with pHBLV-U6-ZsGreen-Puro plasmid containing small interference RNA sequence of NMⅡ gene, vector group transfected with empty plasmid, and blank control group without any treatment, and the protein expression of NMⅡ at 72 h after intervention was detected by Western blotting (n=3). The morphology of cells was observed by an inverted phase contrast microscope and cells labeled with chloromethylbenzoine (CM-DiⅠ) in vitro were observed by an inverted fluorescence microscope. Twenty 4-week-old male Sprague-Dawley rats were divided into blank control group, ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group according to the random number table, with 5 rats in each group. Rats in blank control group were not treated, and rats in the other 3 groups were given LPS to induce ALI. Immediately after modeling, rats in ALI alone group were injected with 1 mL normal saline via tail vein, rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were injected with 1×10⁷/mL BMMSCs and NMⅡ gene silenced BMMSCs of 1 mL labelled with CM-DiⅠ via tail vein, and rats in blank control group were injected with 1 mL normal saline via tail vein at the same time point, respectively. At 24 h after intervention, the lung tissue was collected to observe intrapulmonary homing of the BMMSCs by an inverted fluorescence microscope. Lung tissue was collected at 24 h, in 1 week, and in 2 weeks after intervention to observe pulmonary inflammation by hematoxylin eosin staining and to observe pulmonary fibrosis by Masson staining, and the pulmonary fibrosis in 2 weeks after intervention was scored by modified Ashcroft score (n=5). The content of α-smooth muscle actin (α-SMA), matrix metalloproteinase 2 (MMP-2), and MMP-9 was detected by immunohistochemistry in 2 weeks after intervention (n=3), the activity of superoxide dismutase (SOD), malondialdehyde, myeloperoxidase (MPO) was detected by enzyme-linked immunosorbent assay at 24 h after intervention (n=3), and the protein expressions of CD11b and epidermal growth factor like module containing mucin like hormone receptor 1 (EMR1) in 1 week after intervention were detected by immunofluorescence staining (n=3). Data were statistically analyzed with one-way analysis of variance, Bonferroni method, and Kruskal-Wallis H test. Results: At 72 h after intervention, the NMⅡprotein expression of cells in NMⅡ silenced group was significantly lower than those in blank control group and vector group (with P values <0.01). BMMSCs were in long spindle shape and grew in cluster shaped like vortexes, which were labelled with CM-DiⅠ successfully in vitro. At 24 h after intervention, cell homing in lung of rats in ALI+NMⅡ silenced BMMSC group was more pronounced than that in ALI+BMMSC group, while no CM-DiⅠ-labelled BMMSCs were observed in lung of rats in blank control group and ALI alone group. There was no obvious inflammatory cell infiltration in lung tissue of rats in blank control group at all time points, while inflammatory cell infiltration in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly less than that in ALI alone group at 24 h after intervention, and alveolar wall turned to be thinner and a small amount of congestion in local lung tissue appeared in rats of the two groups in 1 week and 2 weeks after intervention. In 1 week and 2 weeks after intervention, collagen fiber deposition in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group was significantly aggravated compared with that in blank control group, while collagen fiber deposition in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly improved compared with that in ALI alone group. In 2 weeks after intervention, modified Ashcroft scores for pulmonary fibrosis of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group were 2.36±0.22, 1.62±0.16, 1.06±0.26, respectively, significantly higher than 0.30±0.21 in blank control group (P<0.01). Modified Ashcroft scores for pulmonary fibrosis of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly lower than that in ALI alone group (P<0.01), and modified Ashcroft score for pulmonary fibrosis of rats in ALI+NMⅡ silenced BMMSC group was significantly lower than that in ALI+BMMSC group (P<0.01). In 2 weeks after intervention, the content of α-SMA in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly decreased compared with that in ALI alone group (P<0.05 or P<0.01). The content of MMP-2 in lung tissue of rats in the 4 groups was similar (P>0.05). The content of MMP-9 in lung tissue of rats in ALI alone group was significantly increased compared with that in blank control group (P<0.01), and the content of MMP-9 in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01). At 24 h after intervention, the activity of malondialdehyde, SOD, and MPO in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group were significantly increased compared with that in blank control group (P<0.01), the activity of malondialdehyde in lung tissue of rats in ALI+NMⅡ silenced BMMSC group and the activity of SOD in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly increased compared with that in ALI alone group (P<0.05 or P<0.01), and the activity of SOD in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). The activity of MPO in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01), and the activity of MPO in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). In 1 week after intervention, the protein expression of CD11b in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly increased compared with those in the other three groups (P<0.05 or P<0.01), while the protein expressions of EMR1 in lung tissue of rats in the four groups were similar (P>0.05). Conclusions: Transplantation of NMⅡ gene silenced BMMSCs can significantly improve the activity of ECM components in the lung tissue in LPS-induced ALI rats, remodel its integrity, and enhance its antioxidant capacity, and alleviate lung injury and pulmonary fibrosis.
Acute Lung Injury/therapy* ; Animals ; Bone Marrow ; Collagen/metabolism* ; Endotoxins ; Extracellular Matrix ; Lipopolysaccharides/adverse effects* ; Lung ; Male ; Malondialdehyde/metabolism* ; Matrix Metalloproteinase 2/metabolism* ; Matrix Metalloproteinase 9/metabolism* ; Mesenchymal Stem Cells/metabolism* ; Myosin Type II/metabolism* ; Pulmonary Fibrosis ; Rats ; Rats, Sprague-Dawley ; Saline Solution/metabolism* ; Superoxide Dismutase/metabolism*

Wnt/β-catenin signaling plays a critical role in the achievement of peak bone mass, affecting the commitment of mesenchymal progenitors to the osteoblast lineage and the anabolic capacity of osteoblasts depositing bone matrix. Recent studies suggest that this evolutionarily-conserved, developmental pathway exerts its anabolic effects in part by coordinating osteoblast activity with intermediary metabolism. These findings are compatible with the cloning of the gene encoding the low-density lipoprotein related receptor-5 (LRP5) Wnt co-receptor from a diabetes-susceptibility locus and the now well-established linkage between Wnt signaling and metabolism. In this article, we provide an overview of the role of Wnt signaling in whole-body metabolism and review the literature regarding the impact of Wnt signaling on the osteoblast's utilization of three different energy sources: fatty acids, glucose, and glutamine. Special attention is devoted to the net effect of nutrient utilization and the mode of regulation by Wnt signaling. Mechanistic studies indicate that the utilization of each substrate is governed by a unique mechanism of control with β-catenin-dependent signaling regulating fatty acid β-oxidation, while glucose and glutamine utilization are β-catenin-independent and downstream of mammalian target of rapamycin complex 2 (mTORC2) and mammalian target of rapamycin complex 1 (mTORC1) activation, respectively. The emergence of these data has provided a new context for the mechanisms by which Wnt signaling influences bone development.
Anabolic Agents ; beta Catenin ; Bone Development ; Bone Matrix ; Clone Cells ; Cloning, Organism ; Fatty Acids ; Glucose ; Glutamine ; Lipoproteins ; Metabolism* ; Osteoblasts* ; Sirolimus

OBJECTIVE: To study whether tricalcium phosphate(TCP) wear particles cause injuries of periprosthetic osteocytes in the mouse calvaria, and to explain its molecular mechanism. METHODS: Thirty six-week(ICR)male mice were randomly divided into sham group, model (TCP) group and 3-methyladenine (3-MA) group. A murine calvarial model of osteolysis was established by 30 mg of TCP wear particles implantation over the periosteum around the middle suture of calvaria in mice. On the second postoperative day, the autophagy specific inhibitor 3-MA (1.0 mg/kg) was subcutaneously injected to the calvaria in the 3-MA-treated mice every other day. After 2 weeks, blood and the calvaria were obtained. Micro-CT was used to detect bone mineral density(BMD), bone volume fraction (BVF) and porosity number. HE staining and flow cytometry were performed to analyze the viability and apoptosis of periprosthetic osteocytes. The serum levels of dentin matrix protein 1(DMP-1) and sclerostin (SOST) were determined by ELISA. The proteins expressions of DMP-1, SOST, Beclin-1 and microtuble-associated protein 1 light chain 3 (LC-3) were detected by Western blot in the calvaria osteocytes. RESULTS: Compared with the sham group, the mice in the TCP group showed that a significant decrease in the viability of periprosthetic osteocytes, but obvious increases in number of osteocytes death and osteocytes apoptosis (<0.05), and in serum level and protein expression of SOST; significant decreases in serum level and protein expression of DMP-1 (<0.05), and remarkable up-regulation of autophagy-related factors beclin-1 and the conversion of LC3-Ⅱ from LC3-I in the calvaria osteocytes. Compared with TCP group, the mice in the 3-MA group showed that injuries of calvaria osteocytes were obviously aggravated, and osteocytes apoptosis was significantly increased (<0.05). CONCLUSIONS TCP wear particles can cause injuries of periprosthetic osteocytes via activation of apoptosis and autophagy, which promotes osteolysis around the prosthesis osteolysis and joint aseptic loosening.
Animals ; Apoptosis ; Beclin-1 ; metabolism ; Bone Density ; Calcium Phosphates ; adverse effects ; Extracellular Matrix Proteins ; metabolism ; Glycoproteins ; metabolism ; Male ; Mice ; Mice, Inbred ICR ; Microtubule-Associated Proteins ; metabolism ; Osteocytes ; pathology ; Osteolysis ; Prostheses and Implants ; adverse effects ; Skull

BACKGROUND: Since 1991 many studies evaluated the link between cardiovascular diseases and osteoporosis, two age-related conditions, but the main common pathologic pathway has not been determined yet. The histological similarity between arterial calcified plaque and bone matrix and involvement of similar cells and mediators provide a special field of research. Therefore in the present study, we aimed to evaluate the relationship between coronary artery calcium score (CACS) as a surrogate marker of atherosclerosis and bone mediators and parameters in postmenopausal women. METHODS: Eleven postmenopausal women who had CACS higher than 80 were enrolled into the study and underwent bone densitometry. In addition, their serum and urine samples were taken for measuring osteoprotegerin, osteocalcin, and β cross laps. Patients' 10-year probability of fracture was calculated by the World Health Organization fracture-risk assessment tool (FRAX). RESULTS: The regression analysis of our results showed the association between CACS and OC (std β=0.66, 95% confidence interval [CI] 5.47-72.27, P=0.027), femoral bone density (std β=−0.6, 95% CI -6864.34-14.27, P=0.05) and T-score (std β=−0.6, 95% CI −773.08-1.28, P=0.05) which remained significant after adjustment for age, weight, years since menopause and body mass index. No association was found between CACS and osteoprotegerin, spinal bone density and FRAX score. CONCLUSIONS: In conclusion, this pilot study with small sample size showed the potential association between CACS and osteocalcin, femoral bone density and T-score. However, the relationship between CACS and osteoprotegerin, receptor activator of nuclear factor-kappa B ligand, FRAX score and other bone parameters remain to be clarified in larger sample size studies.
Atherosclerosis ; Biomarkers ; Body Mass Index ; Bone Density ; Bone Matrix ; Calcium* ; Cardiovascular Diseases ; Coronary Artery Disease ; Coronary Vessels* ; Densitometry ; Female ; Humans ; Menopause ; Metabolism* ; Osteocalcin ; Osteoporosis ; Osteoprotegerin ; Pilot Projects* ; RANK Ligand ; Sample Size ; World Health Organization

BACKGROUNDDendritic cells are professional antigen-presenting cells found in an immature state in epithelia and interstitial space, where they capture antigens such as pathogens or damaged tissue. Matrix metallopeptidase 13 (MMP-13), a member of the collagenase subfamily, is involved in many different cellular processes and is expressed in murine bone marrow-derived dendritic cells (DCs). The function of MMP-13 in DCs is not well understood. Here, we investigated the effect of MMP-13 on DC maturation, apoptosis, and phagocytosis.

METHODSBone marrow-derived dendritic cells were obtained from C57BL/6 mice. One short-interfering RNA specific for MMP-13 was used to transfect DCs. MMP-13-silenced DCs and control DCs were prepared, and apoptosis was measured using real-time polymerase chain reaction and Western blotting. MMP-13-silenced DCs and control DCs were analyzed for surface expression of CD80 and CD86 and phagocytosis capability using flow cytometry.

RESULTSCompared to the control DCs, MMP-13-silenced DCs increased expression of anti-apoptosis-related genes, BAG1 (control group vs. MMP-13-silenced group: 4.08 ± 0.60 vs. 6.11 ± 0.87, P = 0.008), BCL-2 (control group vs. MMP-13-silenced group: 7.54 ± 0.76 vs. 9.54 ± 1.29, P = 0.036), and TP73 (control group vs. MMP-13-silenced group: 4.33 ± 0.29 vs. 5.60 ± 0.32, P = 0.001) and decreased apoptosis-related genes, CASP1 (control group vs. MMP-13-silenced group: 3.79 ± 0.67 vs. 2.54 ± 0.39, P = 0.019), LTBR (control group vs. MMP-13-silenced group: 9.23 ± 1.25 vs. 6.24 ± 1.15, P = 0.012), and CASP4 (control group vs. MMP-13-silenced group: 2.07 ± 0.56 vs. 0.35 ± 0.35, P = 0.002). Protein levels confirmed the same expression pattern. MMP-13-silenced groups decreased expression of CD86 on DCs; however, there was no statistical difference in CD80 surface expression. Furthermore, MMP-13-silenced groups exhibited weaker phagocytosis capability.

CONCLUSIONThese results indicate that MMP-13 inhibition dampens DC maturation, apoptosis, and phagocytosis.

Animals ; Apoptosis ; drug effects ; physiology ; Bone Marrow Cells ; cytology ; Dendritic Cells ; cytology ; drug effects ; metabolism ; Female ; Lipopolysaccharides ; pharmacology ; Matrix Metalloproteinase 13 ; metabolism ; physiology ; Mice ; Mice, Inbred C57BL ; RNA, Small Interfering

Canine mesenchymal cells (MSCs) derived from Wharton's jelly were co-cultured, then supplemented or not supplemented with platelet rich plasma (PRP) and demineralized bone matrix (DBM) to verify osteogenic differentiation. Osteoblastic differentiation followed by mineralized bone matrix production was found to be significantly higher (p < 0.05) when MSCs were associated with PRP/DBM in culture after 14-21-days of induction. Osteopontin and osteocalcin gene expression were significantly superior (p < 0.05) under the same culture conditions after 21 days of observation. In conclusion, addition of PRP to DBM co-cultured with MSCs successfully induced osteogenesis in vitro.
Animals ; Bone Demineralization Technique/veterinary ; Bone Matrix/*metabolism ; Cell Differentiation ; Cells, Cultured ; Coculture Techniques/veterinary ; Dogs ; Mesenchymal Stromal Cells/*metabolism ; *Osteogenesis ; Platelet-Rich Plasma/*metabolism ; Umbilical Cord/metabolism

OBJECTIVETo investigate the effect of tumor necrosis factor-α (TNF-α) on the release of matrix metalloproteinase-3 (MMP-3), MMP-9, and interleukin-17 (IL-17) in cultured mouse bone marrow-derived mast cells (BMMCs) in vitro.

METHODSPrimarily cultured mouse BMMCs at 8 weeks were exposed PBS (control) or TNF-α at the concentrations of 2, 10, or 50 ng/mL for 12 or 24 h. Real-time PCR was performed to detect the mRNA expressions of MMP-3, MMP-9, and IL-17 in the exposed cells.

RESULTSA 12-hour exposure of the BMMCs to TNF-α caused significantly increased expressions of MMP-3, MMP-9, and IL-17 in a concentration-dependent manner (P<0.05). Prolonged exposures of the cells to 2 and 10 TNF-α for 24 h further increased MMP-3, MMP-9, and IL-17 mRNA expressions, but exposure to 50 ng/mL TNF-α for 24 h increased only MMP-3 and MMP-9 expressions but not IL-17 mRNA expression.

CONCLUSIONSTNF-α treatment of primarily cultured BMMCs can significantly increase the cellular expressions of MMP-3, MMP-9, and IL-17 mRNA in a time- and dose-dependent manner.

Animals ; Bone Marrow Cells ; metabolism ; Cells, Cultured ; Dose-Response Relationship, Drug ; Interleukin-17 ; metabolism ; Mast Cells ; metabolism ; Matrix Metalloproteinase 3 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Mice ; RNA, Messenger ; Real-Time Polymerase Chain Reaction ; Tumor Necrosis Factor-alpha ; pharmacology

This study was purposed to investigate the expression and clinical significance of MMP-2 and MMP-9 in patients with B-acute lymphoblastic leukemia (B-ALL). The expression of MMP-2 and MMP-9 in bone marrow mononuclear cells of B-ALL patients and normal controls was detected by RT-PCR. The gelatinolytic activity was detected by zymography. The results showed that the expression of MMP-2 in de novo and relapsed B-ALL patients was markedly higher than that in normal controls (P < 0.05). The expression of MMP-9 in de novo and relapsed B-ALL patients was markedly lower than that in normal controls (P < 0.05). The expression of MMP-2 and MMP-9 in patients with extramedullary infiltration was significantly higher than that in patients without extramedullary infiltration. The incidence of extramedullary infiltration in patients with MMP-2/MMP-9 (+) was markedly higher than that in patients with MMP-2/MMP-9 (-). The expression of MMP-9 was markedly higher in high-risk patients than that in standard-risk patients (P < 0.05), but the expression of MMP-2 had no significant difference between the high-risk and standard-risk patients (P > 0.05). It is concluded that MMP-2 and MMP-9 may be secreted by B lymphoblasts and may involve in the extramedullary infiltration. MMP-9 may correlate with poor prognosis.
Adolescent ; Adult ; Aged ; Bone Marrow Cells ; metabolism ; Female ; Humans ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; metabolism ; Prognosis ; RNA, Messenger ; genetics ; Young Adult

Osteoclast, a huge coenocytes,originates from mononuclear macrophages or monocytic series hematopoietic precursor cell, plays an important role in the progree of bone resorption. Formation and abnormal activity of osteoclast may cause osteoprosis, rheumatoid arthritis and aseptic loosening after arthroplasty. Therefore, osteoclast is the target for treating these disease. At present, a lot of study on formation of osteoclast were reported, but the study on how to identify and degradation of bone tissue is not yet reported. Bone mineral are seen as important component of identifing osteoclast, and the research suggested that bone matrix is not the essential ingredients of activiting osteoclast, petri dish covered by vitronectin also can make osteoclast occure certain form of bone resorption, vitronectin plays an significant role in activiting osteoclast. Otherwise, the research found that swallowing and secretion of bone matrix degradation products is benefit for differentiation of osteoclast and maintain of function, and this may be therapeutic target for treatment of musculoskeletal disorders.
Animals ; Bone Matrix ; metabolism ; Bone Resorption ; Humans ; Osteoclasts ; physiology