Objective To review the research progress of C terminal propeptide of collagen type II (CTX-II), a osteoarthritis (OA) biomarker. Methods Domestic and international l iterature about CTX-II was reviewed extensively and summarized. Results CTX-II is investigated broadly and has the best performance of all currently available biomarkers. CTX-II is a truly useful biomarker for early diagnosis, prognosis, and measurement of treatment response in OA. Conclusion Single CTX-II may be not sufficient for early diagnosis and prognosis of OA, so a combination of CTX-II and other biomarkers or diagnosis methods is needed.
Objective To evaluate the effects of the polypeptide growth factors on the periodontal ligament cell(PDLC) based on a comprehensive review onthe literature concerned. Methods The recent literature related to the effects of the polypeptide growth factors on the PDLC were extensivelyand comprehensively reviewed and a corresponding evaluation was made. Results The proliferation and the multidirectional differentiation of thePDLC were found to be the basis for the regeneration of the periodontal tissues. The effects of the polypeptide growth factors on the function of the PDLC became a hot issue of the research on the regeneration of the periodontal tissues. The polypeptide growth factors were found to play an important role in the migration, growth, proliferation, differentiation, and synthesis of protein and matrixof the PDLC. Conclusion The polypeptide growth factors can beused in the periodontal regeneration treatment, but a further research is stillrequired to improve this kind of treatment.
Objective To observe the effect of pilose antler polypeptides(PAP)on the apoptosis of rabbit marrow mesenchymal stem cells (MSCs) differentiated into chondrogenic phenotype by interleukin 1β (IL-1β) so as to optimize the seeding cells in cartilage tissue engineering. Methods The MSCs were separated from the nucleated cells fraction of autologus bone marrow by density gradient centrifuge and cultured in vitro. The MSCs were induced into chondrogenic phenotype by transforming growth factor β1(TGF-β1) and basic fibroblast growth factor(bFGF). According to different medias, the MSCs were randomly divided into four groups: group A as black control group, group B(100 ng IL-1β)，group C(10 μg/ml PAP+100 ng IL-1β) and group D(100 ng/ml TGF-β1 +100 ng IL-1β). The samples were harvested and observed by morphology, flow cytometry analysis, RT-PCR and ELISA at 24, 48 and 72 hours. Results The intranuclear chromatin agglutinated into lump and located under nulear membranes which changed into irregular shapeat 24 hours. The intranuclear chromatin agglutinated intensifily at 48 hours. Then the nucear fragments agglutinated into apoptosic corpuscles at 72 hours in group B. The structure change of cells in groups C and D was later than that in group B, and the number of cells changed shape was fewer than that in group B. The structure change of cells in group A was not significant. The apoptosic rate of cells, the mRNA expression of Caspase-3 and the enzymatic activity of Caspase-3 gradually increased in group B, and there were significant differences compared with groups A,C and D(Plt;0.01). Conclusion Caspase-3 is involved in aoptosis of the MSCs differentiated into chondrogenic phenotype cultured in vitro. PAP could prevent from or reverse apoptosis of these MSCs by decreasing the expression of Caspase-3 and inhibiting the activity of Caspase-3.
ObjectiveTo study the hydrophilicity and the cell biocompatibility of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) coated with a fusion protein polyhydroxyalkanoates granule binding protein (PhaP) fused with Arg-Gly-Asp (RGD) peptide (PhaP-RGD). MethodsPHBV and PHBHHx films were fabricated by solvent evaporation.Scanning electronic microscope (SEM) was used to study the morphology of the films.PhaP-RGD fusion proteins were expressed and purified by the technology of protein engineering; PHBV and PHBHHx films were immersed in the PhaP-RGD with an amount of 3.5 mg/mL protein/per sample respectively.The hydrophilicity of the surface were detected by the contact angle measurements.Septal cartilage cells obtained from human septal cartilage were cultured in vitro.The 2nd passage chondrocytes were incubated on PHBV unmodified with PhaP-RGD in group A1,PHBV modified with PhaP-RGD in group A2,PHBHHx unmodified with PhaP-RGD in group B1,PHBHHx modified with PhaP-RGD in group B2,and on the cell culture plates in group C.After cultured for 3 days,the proliferation of cells was detected by the DAPI staining; the proliferation viability of cells was detected by the MTT assay after cultured for 3 and 7 days; after cultured for 7 days,the adhesion and morphology of the cells on the surface of the biomaterial films were observed by SEM and the matrix of the cells was detected through the toluidine blue staining. ResultsSEM observation showed that PHBV and PHBHHx films had porous structures.The contact angle of the surface of the PHBV and PHBHHx films modified with PhaP-RGD fusion proteins were significantly reduced when compared with the films unmodified with PhaP-RGD fusion proteins (P<0.05).Chondrocytes of human nasal septal cartilage incubated on the films could grow in all groups.After 3 days of cultivation in vitro,the cell proliferation and viability of group B2 were the strongest among all groups (P<0.05); the cell proliferation after cultured for 7 days was significantly stronger than that after cultured for 3 days in groups A1,A2,B1,and B2 (P<0.05); and the cell proliferation was significantly stronger in groups B1 and B2 than groups A1,A2 and C,in group B2 than group B1,and in group A1 than group A2 (P<0.05).The results of toluidine blue staining showed that blue metachromasia matrixes were observed in groups A1,A2,B1,and B2; group A1 and group A2 had similar staining degree,and the staining of group B2 was deeper than that of group B1.The adhesion of cells in all groups was good through SEM observation; and the connection of cells formed and stretched into the pores of the materials. ConclusionThe biomaterial films of PHBHHx modified with PhaP-RGD fusion protein can promote its biocompatibility with chondrocytes.
To investigate the origin and releasing relation of motilin (MTL), vasoactive intestinal peptide (VIP) and somatostatin (SS) in guinea pig bile as well as its effects during gallstone formation. Guinea pig were divided into three groups: control group (50 animals), on normal diet; lithogenic group (70 animals), fed with lowprotein low fat; and recovering group (50 animals), fed with lowprotein low fat and recovering normal food after the experiment of gallstone formation. MTL, VIP and SS in the bile gallbladder tissue and portal vein plasma of the normal control group were measured with radioimmunoassay. Meanwhile the changes of the gut peptides in the bile and the bile components from different groups were also compared. Results: In control group the levels of MTL, VIP and SS in the bile were higher than those in the plasma, but, obviously lower than those in the tissues, the concentration relationship between in the bile and in the tissue was a positive correlation. In contrast to the control group, MTL concentration decreased but VIP and SS increased in the bile of the lithogenic group, the physicochemical nature of the bile also became lithogenic. In the recovering group the bile also became lithogenic, but, the concentration of those peptides and the nature of the bile all got normal. Conclusion: MTL, VIP and SS in guinea pig bile originate mainly form the gallbladder wall tissues. Food components affect the levels of the gut peptides in bile, which promote the bile lithogenic changes and gallstone formation.
Objective To study the feasibil ity of preparation of the poly-D, L-lactide acid (PDLLA) scaffolds treated by ammonia plasma and subsequent conjugation of Gly-Arg-Gly-Asp-Ser (GRGDS) peptides via amide l inkage formation. Methods PDLLA scaffolds (8 mm diameter, 1 mm thickness) were prepared by solvent casting/particulate leaching procedure and then treated by ammonia plasma. The consequent scaffolds were labeled as aminated PDLLA (A/ PDLLA). The pore size, porosity, and surface water contact angle of groups 0 (un-treated control), 5, 10, and 20 minutes A/ PDLLA were measured. A/PDLLA scaffolds in groups above were immersed into the FITC labelled GRGDS aqueous solutionwhich contain 1-[3-(dimethylamino) propyl]-3-ethylcarbodiimide hydrochloride (EDC.HCl) and N-hydroxysuccinimide(NHS), the molar ratio of peptides/EDC.HCL /NHS was 1.5 ∶ 1.5 ∶ 1.0, then brachytely sloshed for 24 hours in roomtemperature. The consequent scaffolds were labelled as peptides conjugated A/PDLLA (PA/PDLLA). The scaffolds in groups 0, 5, 10, and 20 minutes A/PDLLA and groups correspondingly conjugation of peptides were detected using X-ray photoelectron spectroscopy (XPS). The scaffolds in groups of conjugation of peptides were measured by confocal laser scanning microscope and high performance l iquid chromatography (HPLC), un-treated and un-conjugated scaffolds employed as control. Bone marrow mesenchymal stem cells (BMSCs) from SD rats were isolated and cultured by whole bone marrow adherent culture method. BMSCs at the 3rd–6th passages were seeded to the scaffolds as follows: 20 minutes ammonia plasma treatment (group A/PDLLA), 20 minutes ammonia plasma treatment and conjugation of GRGDS (group PA/PDLLA), and untreated PDLLA control (group PDLLA). After 16 hours of culture, the adhesive cells on scaffolds and the adhesive rate were calculated. After 4 and 8 days of culture, the BMSCs/scaffold composites was observed by scanning electron micorscope (SEM). Results No significant difference in pore size and porosity of PDLLA were observed between before and after ammonia plasma treatments (P gt; 0.05). With increased time of ammonia plasma treatment, the water contact angle of A/PDLLA scaffolds surface was decreased, and the hydrophil icity in the treated scaffolds was improved gradually, showing significant differences when these groups were compared with each other (P lt; 0.001). XPS results indicated that element nitrogen appeared on the surface of PDLLA treated by ammonia plasma. With time passing, the peak N1s became more visible, and the ratio of N/C increased more obviously. AfterPDLLA scaffolds treated for 0, 5, 10, and 20 minutes with ammonia plasma and subsequent conjugation of peptides, the ratio of N/C increased and the peak of S2p appeared on the surface. The confocal laser scanning microscope observation showed that the fluorescence intensity of PA/PDLLA scaffolds increased obviously with treatment time. The amount of peptides conjugated for 10 minutes and 20 minutes PA/PDLLA was detected by HPLC successfully, showing significant differences between 10 minutes and 20 minutes groups (P lt; 0.001). However, the amount of peptides conjugated in un-treated control and 0, 5 minutes PA/PDLLA scaffolds was too small to detect. After 16 hours co-culture of BMSCs/scaffolds, the adhesive cells and the adhesive rates of A/PDLLA and PA/PDLLA scaffolds were higher than those of PDLLA scaffolds, showing significant difference between every 2 groups (P lt; 0.01). Also, SEM observation confirmed that BMSCs proliferation in A/PDLLA and PA/PDLLA groups was more detectable than that in PDLLA group, especially in PA/PDLLA group. Conclusion Ammonia plasma treatment will significantly increase the amount of FITC-GRGDS peptides conjugated to surface of PDLLA via amide l inkage formation. This new type of biomimetic bone has stablized bioactivities and has proved to promote the adhesion and proliferation of BMSCs in PDLLA.
ObjectiveTo explore the predictive value of N-terminal-pro-brain natriuretic peptide (NT-ProBNP) for postoperative early outcomes in infants with aortic coarctation (CoA).MethodsA retrospective study was conducted in 344 children with CoA admitted to our hospital from September 2014 to October 2017, including 206 males (59.9%) and 138 females (40.1%), with an average age of 0.2-60.0 (7.1±10.6) months. The levels of NT-proBNP, clinical characteristics, imaging data and early follow-up results were collected and analyzed.ResultsCompared with the normal NT-proBNP group, there were statistical differences in age, the proportion of RACHS-1≥3, the proportion of preoperative pneumonia and dysplastic aortic arch, preoperative cardiac function, left ventricular wall thickness, left ventricular dilatation, hospital stay, ICU duration, ventilator duration, duration of vasoactive drugs use, delayed chest closure, nasal continuous positive airway pressure (nCPAP), postoperative cardiac insufficiency in the abnormal NT-proBNP group (P<0.05). According to multivariate logistic regression analysis, NT-proBNP level (>3 000 pg/mL) was an independent risk factor for prolonged ICU duration [OR=3.17, 95%CI (1.61, 6.23)], prolonged ventilator duration [OR=5.84, 95%CI (2.86, 11.95)], prolonged use of vasoactive drugs [OR=2.22, 95%CI (1.22, 4.02)], postoperative cardiac insufficiency [OR=3.10, 95%CI (1.64, 5.85)]; NT-proBNP level (> 5 000 pg/mL) was an independent risk factor for delayed chest closure [OR=3.55, 95%CI (1.48, 8.50)].ConclusionNT-proBNP level in children with CoA can be affected by many factors, including age, complexity of congenital heart disease, preoperative cardiac insufficiency, et al. The level of NT-proBNP has predictive value for postoperative early outcomes.
Objective To obtain the polypeptides specifically binding to gastric cancer BGC823 cell from a Ph.D-12 TM phage display peptide library (PDPL), to search the markers of gastric cancer for early diagnosis and treatment. Methods The gastric cancer BGC823 cell was used as the antigen and the immortalized gastric epithelial GES cell was used as control for 3 rounds subtraction biopanning from PDPL at room temperature. The positive and specific binding clones were identified by cell enzyme-linked immunosorbent assay (ELISA) and immunochemistry staining. Those DNA sequences of identified clones were sequenced, polypeptides were marked by fluorescein FITC peptide tag, and polypeptides affinity and specificity of gastric cancer cells and tissues were identified. Results After 3 rounds of panning, 20 phage clones were identified by ELISA, one of which （GC-11） was specially binding to the BGC823. Cell and tissue immunofluorescence assay further presented a high affinity of fluorescein-labeled peptide FITC-GC-11 with BGC823 and gastric cancer tissue.Conclusion A peptide GC-11 which is specific binding to gastric cancer BGC823 cell and gastric cancer tissue has been selected from PDPL.
Objective To explore the effect of corn oligopeptide (COP) on dexamethasone-induced muscle atrophy. Methods Forty-nine male Sprague-Dawley rats aged 8 weeks were divided into blank group (n=10) and model group (n=39). The rats in the model group were intraperitoneally injected with dexamethasone (1.0 mg/kg), and the rats in the blank group were injected with normal saline. After 19 days, one rat in the blank group and three rats in the model group were taken to observe whether the model was successfully constructed. After successful modeling, the rats in the model group were randomly divided into model control group, COP low-dose group (COP-L group, 0.5 g/kg), COP medium-dose group (COP-M group, 1.0 g/kg) and COP high-dose group (COP-H group, 2.0 g/kg), with 9 rats in each group. After 33 days, the grip strength of the rats was measured, and then the gastrocnemius, soleus, tibialis anterior and metatarsal muscles were separated and weighed, and muscle fiber diameter, relative expression of Atrogin-1 and MuRF-1 mRNA were measured. Non-targeted metabolomics of gastrocnemius muscle were measured. Results Compared with that in the blank group, the body weight of rats in the model group reduced (P<0.05), and myofibril rupture was observed, indicating that the model was successful. Compared with those in the model control group, the grip strength increased in the COP-L and COP-M groups (P<0.05); the muscle coefficients of gastrocnemius and soleus in the COP-L and COP-H groups increased (P<0.05), and the muscle coefficients of plantaris in the COP-L and COP-M groups increased (P<0.05); the muscle fiber diameter of the tibial anterior muscle increased in the three doses of COP groups (P<0.05), and the muscle fiber diameter of the plantaris muscle increased in the COP-M and COP-H groups (P<0.05); the relative expression of Atrogin-1 mRNA decreased in the three doses of COP groups (P<0.05), while the relative expression of MurF-1 mRNA in the COP-L and COP-H groups decreased (P<0.05). The amino acid synthesis pathway, glycolysis pathway, and acid metabolism pathway were activated in gastrocnemius muscle. Conclusions COP can significantly improve the muscle atrophy induced by dexamethasone. The mechanism may be related to the decrease of Atrogin-1 and MuRF-1 expression in ubiquitin-proteasome pathway and the increase of amino acid biosynthesis.
ObjectiveTo investigate the effect of accessory gene regulator C (agr C) specific binding peptides (named N1) on the biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride (PVC) materials in vitro.MethodsFirstly, the two strains (ATCC35984, ATCC12228) were cultured with N1 at concentrations of 100, 200, 400, 800, and 1 600 μg/mL, respectively. The control group was cultured with agrC specific binding unrelated peptides (named N0) at the same concentrations and the absorbance (A) value was measured after 24 hours to determine the optimal bacteriostatic concentration of N1. The two strains were cultured with N1 and N0 of the optimal concentration, respectively. The A values were measured at 6, 12, 18, 24, 30, and 48 hours to observe the effect of N1 on the biofilm formation ability of Staphylococcus epidermidis. On this basis, the surface structure of the biofilm on the surface of PVC material was observed by scanning electron microscopy after 6, 12, 18, 24, and 30 hours of incubation with PVC material sheet. The thickness of the biofilm was observed by laser confocal microscopy after 6, 12, 18, and 24 hours of incubation with ATCC35984 strain.ResultsThe optimal bacteriostatic concentration of N1 was 800 μg/mL. ATCC 12228 strain did not form obvious biofilm after being cultured with N1 and N0. When ATCC35984 strain was cultured with N1 and N0 for 12 hours, the difference in biofilm formation ability between groups N1 and N0 was statistically significant (P<0.05), but there was no significant difference at 6, 18, 24, 30, and 48 hours (P>0.05). Scanning electron microscopy examination showed that mature biofilm structure was observed in ATCC35984 strain and was not observed in ATCC12228 strain. Laser confocal microscopy observation showed that the number of bacteria in the group N1 was significantly lower than that in the group N0 at 12 hours, and the most of bacteria were dead bacteria. There was no significant difference in the number of bacteria at 6, 18, and 24 hours, and the most of them were live bacteria. The biofilm thickness of group N1 was significantly lower than that of group N0 at 12 and 18 hours (P<0.05).ConclusionThe intensity of N1 inhibiting the formation of Staphylococcus epidermidis biofilm is dose-dependent. During the aggregation period, N1 can inhibit the biofilm formation by hindering the bacterial growth and aggregation. The inhibition effect on mature biofilm is not obvious.