Effect of Matrix Metallopeptidase 13 on the Function of Mouse Bone Marrow-derived Dendritic Cells

Background： Dendritic 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. Methods： Bone marrow-derived dendritic cells were obtained fiom 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. Results： Compared to the control DCs, MMP- 13-silenced DCs increased expression of anti-apoptosis-related genes, BAGl （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, CASPI （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. Conclusion： These results indicate that MMP-13 inhibition dampens DC maturation, apoptosis, and phagocytosis.

Identification of key genes and biological pathways in lung adenocarcinoma by integrated bioinformatics analysis

BACKGROUND The objectives of this study were to identify hub genes and biological pathways involved in lung adenocarcinoma(LUAD)via bioinformatics analysis,and investigate potential therapeutic targets.AIM To determine reliable prognostic biomarkers for early diagnosis and treatment of LUAD.METHODS To identify potential therapeutic targets for LUAD,two microarray datasets derived from the Gene Expression Omnibus(GEO)database were analyzed,GSE3116959 and GSE118370.Differentially expressed genes(DEGs)in LUAD and normal tissues were identified using the GEO2R tool.The Hiplot database was then used to generate a volcanic map of the DEGs.Weighted gene co-expression network analysis was conducted to cluster the genes in GSE116959 and GSE-118370 into different modules,and identify immune genes shared between them.A protein-protein interaction network was established using the Search Tool for the Retrieval of Interacting Genes database,then the CytoNCA and CytoHubba components of Cytoscape software were used to visualize the genes.Hub genes with high scores and co-expression were identified,and the Database for Annotation,Visualization and Integrated Discovery was used to perform enrichment analysis of these genes.The diagnostic and prognostic values of the hub genes were calculated using receiver operating characteristic curves and Kaplan-Meier survival analysis,and gene-set enrichment analysis was conducted.The University of Alabama at Birmingham Cancer data analysis portal was used to analyze relationships between the hub genes and normal specimens,as well as their expression during tumor progression.Lastly,validation of protein expression was conducted on the identified hub genes via the Human Protein Atlas database.RESULTS Three hub genes with high connectivity were identified;cellular retinoic acid binding protein 2(CRABP2),matrix metallopeptidase 12(MMP12),and DNA topoisomerase II alpha(TOP2A).High expression of these genes was associated with a poor LUAD prognosis,and the genes exhibited high diagnostic value.CONCLUSION Expression levels of CRABP2,MMP12,and TOP2A in LUAD were higher than those in normal lung tissue.This observation has diagnostic value,and is linked to poor LUAD prognosis.These genes may be biomarkers and therapeutic targets in LUAD,but further research is warranted to investigate their usefulness in these respects.

Pretreatment with Danhong injection protects the brain against ischemia-reperfusion injury

Danhong injection （DHI）, a Chinese Materia Medica standardized product extracted from Radix Salviae miltiorrhizae and Flos Carthami tinctorii, is widely used in China for treating acute isch-emic stroke. In the present study, we explored the neuroprotective efficacy of DHI in a rat model of temporary middle cerebral artery ocdusion, and evaluated the potential mechanisms under-lying its effects. Pretreatment with DHI （0.9 and 1.8 mL/kg） resulted in a significantly smaller infarct volume and better neurological scores than pretreatment with saline. Furthermore, DHI significantly reduced the permeability of the blood-brain barrier, increased occludin protein expression and decreased neutrophil infiltration, as well as profoundly suppressing the upreg-ulation of matrix metallopeptidase-9 expression seen in rats that had received vehicle. Matrix metallopeptidase-2 expression was not affected by ischemia or DHI. Moreover, DHI （1.8 mL/kg） administered 3 hours after the onset of ischemia also improved neurological scores and reduced infarct size. Our results indicate that the neuroprotective efficacy of DHI in a rat model of cerebral ischemia-reperfusion injury is mediated by a protective effect on the blood-brain barrier and the reversal of neutrophil infiltration.

Human platelets inhibit liver fibrosis in severe combined immunodeficiency mice

AIM:To investigate the role of human platelets in liver fibrosis.METHODS:Severe combined immunodeficiency(SCID)mice were administered CCl4and either phosphate-buffered saline(PBS group)or human platelet transfusions(hPLT group).Concentrations of hepatocyte growth factor(HGF),matrix metallopeptidases(MMP)-9,and transforming growth factor-β(TGF-β)in the liver tissue were compared between the PBS and the hPLT groups by enzyme-linked immunosorbent assay(ELISA)and Western blotting.The effects of a human platelet transfusion on liver fibrosis included the fibrotic area,hydroxyproline content,and-smooth muscle actin(α-SMA)expression,which were evaluated by picrosirius red staining,ELISA,and immunohistochemical staining using an anti-mouse-SMA antibody,respectively.Phosphorylations of mesenchymal-epithelial transition factor(Met)and SMAD3,downstream signals of HGF and TGF-β,were compared between the two groups by Western blotting and were quantified using densitometry.Hepatocyte apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling.Furthermore,the accumulation of human platelets in the liver 2 h after platelet transfusion was compared between normal and fibrotic livers by immunohistochemical staining using an anti-human CD41 antibody.RESULTS:The fibrotic area and hydroxyproline content in the liver were both significantly lower in the hPLT group when compared to the PBS group(fibrotic area,1.7%±0.6%vs 2.5%±0.6%,P=0.03;hydroxyproline content,121±26 ng/g liver vs 156±47 ng/g liver,P=0.04).There was less α-smooth muscle actin staining in the hPLT group than in the PBS group(0.5%±0.1%vs 0.8%±0.3%,P=0.02).Hepatic expression levels of mouse HGF and MMP-9were significantly higher in the hPLT group than in the PBS group(HGF,109±13 ng/g liver vs 88±22 ng/g liver,P=0.03;MMP-9,113%±7%/GAPDH vs 92%±11%/GAPDH,P=0.04).In contrast,the concentration of mouse TGF-β in the liver tissue was significantly lower in the hPLT group than in the PBS group(22±5ng/g liver vs 39±6 ng/g liver,P=0.02).Phosphorylation of Met was more prevalent in the hPLT group than in the PBS group(37%±4%/GAPDH vs 20%±8%/GAPDH,P=0.03).Phosphorylation of SMAD3was weaker in the hPLT group than in the PBS group(60%±12%/GAPDH vs 84%±12%/GAPDH,P=0.1),although this difference was not significant.Furthermore,a lower rate of hepatocyte apoptosis was observed in the hPLT group than in the PBS group(5.9%±1.7%vs 2.9%±2.1%,P=0.02).Significant human platelet accumulation was observed in the fibrotic liver tissues,whereas few platelets accumulated in the normal liver.CONCLUSION:Human platelets inhibit liver fibrosis in SCID mice.Increased concentration of HGF in the liver suppresses hepatic stellate cell activation,induces MMPs,and inhibits hepatocyte apoptosis.

Effect of exercise training on left ventricular remodeling in patients with myocardial infarction and possible mechanisms

BACKGROUND A growing amount of evidence provides support for the hypothesis that acute myocardial infarction(AMI)patients should go through cardiopulmonary exercise testing(CPET)about 3-5 d after AMI is diagnosed,make reasonable exercising prescription,and conduct exercise training under guidance.AIM To investigate the effect of exercise training(ET)on left ventricular systolic function and left ventricular remodeling(LVRM)and to study the possible mechanisms of LVRM by the changes of matrix metallopeptidase 9(MMP-9)and tissue inhibitor of metalloproteinases 1(TIMP-1)in patients with acute STsegment elevation myocardial infarction(STEMI).METHODS Sixty patients with first STEMI undergoing direct percutaneous coronary intervention from February 2008 to October 2008 were randomly assigned to an exercise group(n=30)and a control group(n=30).The levels of MMP-9 and TIMP-1 were measured in all patients at 1 d,10-14 d,30 d,and 6 mo after admission.Two-dimensional echocardiography and cardiopulmonary exercise testing were done in patients at 10-14 d and 6 mo after admission.RESULTS There was no significant difference in CPET at baseline between the exercise group and the control group.At 6 mo,the time of exercise,peak and anaerobic threshold values of O2 uptake,and metabolic equivalents increased in both groups,but markedly increased in the exercise group.At baseline,there were no significant differences in left ventricular ejection fraction(LVEF)between the two groups.At 6 mo,LVEF increased in the exercise group,but not in the control group.At 6 mo,the percentage of patients with positive result of LVRM was 26.6%in the exercise group and 52.6%in the control group(P<0.05).The levels of plasma MMP-9 and TIMP-1 and the ratio of MMP-9 to TIMP-1 in both groups had no significant difference at 1 d and 10-14 d after AMI,but at 30 d and 6 mo,the levels of plasma MMP-9 and TIMP-1 in the exercise group were significantly lower than those in the control group;the ratio of MMP-9 to TIMP-1 in the exercise group was significantly higher than that in the control group.CONCLUSION ET under supervision based on home condition in early and recovery stage of AMI can improve exercise cardiopulmonary function and prevent the LVRM.Therefore,it may reduce unfavorable remodeling response by decreasing the levels of plasma MMP-9 and TIMP-1 and adjusting the ratio of MMP-9 to TIMP-1 hereafter.

Serum amyloid A and pairing formyl peptide receptor 2 are expressed in corneas and involved in inflammation-mediated neovascularization

AIM:To solidify the involvement of Saa-related pathway in corneal neovascularization(CorNV).The pathogenesis of inflammatory CorNV is not fully understood yet,and our previous study implicated that serum amyloid A(Saa)1(Saa1)and Saa3 were among the genes up-regulated upon CorNV induction in mice.METHODS:Microarray data obtained during our profiling project on CorNV were analyzed for the genes encoding the four SAA family members(Saa1-4),six reported SAA receptors(formyl peptide receptor 2,Tlr2,Tlr4,Cd36,Scarb1,P2rx7)and seven matrix metallopeptidases(Mmp)1a,1b,2,3,9,10,13reportedly to be expressed upon SAA pathway activation.The baseline expression or changes of interested genes were further confirmed in animals with CorNV using molecular or histological methods.CorNV was induced in Balb/c and C57BL/6 mice by placing either three interrupted 10-0 sutures or a 2 mm filter paper soaked with sodium hydroxide in the central area of the cornea.At desired time points,the corneas were harvested for histology examination or for extraction of mRNA and protein.The mRNA levels of Saa1,Saa3,Fpr2,Mmp2and Mmp3 in corneas were detected using quantitative reverse transcription-PCR,and SAA3 protein in tissues detected using immunohistochemistry or western blotting.RESULTS:Microarray data analysis revealed that Saa1,Saa3,Fpr2,Mmp2,Mmp3 messengers were readily detected in normal corneas and significantly upregulated upon CorNV induction.The changes of these five genes were confirmed with real-time PCR assay.Onthe contrary,other SAA members(Saa2,Saa4),other SAA receptors(Tlr2,Tlr4,Cd36,P2rx7,etc),or other Mmps(Mmp1a,Mmp1b,Mmp9,Mmp10,Mmp13)did not show consistent changes.Immunohistochemistry study and western blotting further confirmed the expression of SAA3 products in normal corneas as well as their upregulation in corneas with CorNV.CONCLUSION:SAA-FPR2 pathway composing genes were expressed in normal murine corneas and,upon inflammatory stimuli challenge to the corneas,their expressions were up-regulated,suggesting their roles in pathogenesis of CorNV.The potential usefulness of SAA-FPR2 targets in future management of CorNVrelated diseases deserves investigation.

Protective Effect of Simvastatin on Impaired Intestine Tight Junction Protein ZO-1 in a Mouse Model of Parkinson's Disease

Summary： Recently, several studies showed that gastrointestinal tract may be associated with patho- physiology of Parkinson＇s disease （PD）. Intestine tight junction protein zonula occluden-1 （ZO-1） is an important component of intestinal barrier which can be degraded by matrix metallopeptidase 9 （MMP-9）. In our previous study, a significant decline in ZO-1 was observed along with enhanced MMP-9 activity in the duodenum and distal colon of 1-methyl-4-phenyl-l,2,3,6-tetrahydropyridine （MPTP）-intoxicated mice. In this study, the protective effect of simvastatin on ZO-1 was investigated using an MPTP mouse model of PD. Seven days after the end of MPTP application, the expression level of ZO-1 was evaluated by immunohistochemistry. The protein expression levels of ZO-1 and MMP9 were detected by Western blotting. Meanwhile, MMP-9 activity was analyzed by gelatin zymography. MPTP treatment led to a decrease in the expression of ZO-1, which was accompanied by elevated MMP-9 activity. Treatment with simvastatin could partly reverse the MPTP-induced changes in ZO-I expression and reduce MMP-9 protein and activity. Taken together, these findings suggest that simvas- tatin administration may partially reverse the impairment of ZO-1 induced by MPTP via inhibiting the activity of MMP9, fortify the impaired intestinal barrier and limit gut-derived toxins that＇pass across the intestinal barrier.

Molecular Characterization and Expression Analysis of Matrix Metalloproteinase 3 in the Asian Yellow Pond Turtle Mauremys mutica

Matrix metallopeptidase 3 is a zinc-containing proteinase that participates in tissue remodeling and immune responses. In this study, a cDNA encoding matrix metallopeptidase 3 was isolated and characterized from the Asian yellow pond turtle Mauremys mutica（designated as MaMMP3）. The MaMMP3 cDNA is 1805 bp and consists of a 5＇-untranslated region（UTR） of 56 bp, a 3＇-UTR of 243 bp, and an open reading frame（ORF） of 1506 bp encoding 481 amino acids. Homology analysis of MaMMP3 revealed that the MaMMP3 shared 25%–63% similarity to other known MMP3 sequences. The genomic sequence covers 6007 bp. Comparative analysis of the cDNA sequence revealed that the Asian yellow pond turtle MMP3 has eight exons and seven introns. The phylogenetic tree showed that the MaMMP3 is closely related to Gallus gallus MMP3 and Taeniopygia guttata MMP3. The mRNA expression of the MaMMP3 in normal group without any bacterial challenge could be detected in all studied tissues including kidney, heart, live and spleen, with the highest level in the spleen. The results of immune challenge showed that the expression level of MaMMP3 was up-regulated in the spleen and liver. These results provided an important information for studying the roles of Asian yellow pond turtle MMP3 in immunity further.

Cloning, Expression, Purification, and Crystallization of <i>P. aeruginosa </i>ICMP

Pseudomonas aeruginosa (P. aeruginosa) is a common opportunistic human pathogen that can lead to severe diseases in immunocompromised patients. The insulin-cleaving membrane protease (ICMP) of P. aeruginosa plays a vital role in the pathogenesis of the bacterium and is therefore characterized as an important bacterial virulence factor. In addition, ICMP also serves as a founding member of the M75 peptidase family and represents a prototype of the imelysin/imelysin-like proteins. Despite of its functional importance in the pathogenesis of P. aeruginosa and of a root position as the prototypic imelysin/imelysin-like member, the structural features of the protein remain uninvestigated. Since preparation of homogeneous and crystallizable protein species is the prerequisite for structural studies by crystallography, we reported the successful expression, purification, and crystallization of P. aeruginosa ICMP in this study. The protein was over-expressed in Escherichia coli as a GST-fusion protein, cleaved to remove the fusion tag, and then purified to homogeneity. Diffractable crystals were obtained using the sitting-drop vapour-diffusion method. The crystals diffracted to 2.5 &#197;?resolution and belonged to space group P212121, with unit-cell parameters a = 54.47, b = 158.98, c = 162.84 &#197;, α = β = γ = 90°. Preliminary analysis of the diffraction data revealed high-quality crystallographic statistics with a Matthews coefficient of about 2.61 &#197;3.Da-1 and a solvent content of about 52.58%, indicating the presence of three ICMP molecules in the asymmetric unit. The current work therefore paved the way for future studies aiming to delineate the characteristics of ICMP at the atomic level.

A Genome‑Wide Association Study for Susceptibility to Axial Length in Highly Myopic Eyes

High myopia has long been highly prevalent worldwide with a largely yet unexplained genetic contribution.To identify novel susceptibility genes for axial length(AL)in highly myopic eyes,a genome-wide association study(GWAS)was performed using the genomic dataset of 350 deep whole-genome sequencing data from highly myopic patients.Top single nucleotide polymorphisms(SNPs)were functionally annotated.Immunofluorescence staining,quantitative polymerase chain reaction,and western blot were performed using neural retina of form-deprived myopic mice.Enrichment analyses were further performed.We identified the four top SNPs and found that ADAM Metallopeptidase With Thrombospondin Type 1 Motif 16(ADAMTS16)and Phosphatidylinositol Glycan Anchor Biosynthesis Class Z(PIGZ)had the potential of clinical signifi-cance.Animal experiments confirmed that PIGZ expression could be observed and showed higher expression level in form-deprived mice,especially in the ganglion cell layer.The messenger RNA(mRNA)levels of both ADAMTS16 and PIGZ were significantly higher in the neural retina of form-deprived eyes(p=0.005 and 0.007 respectively),and both proteins showed significantly upregulated expression in the neural retina of deprived eyes(p=0.004 and 0.042,respectively).Enrichment analysis revealed a significant role of cellular adhesion and signal transduction in AL,and also several AL-related pathways including circadian entrainment and inflammatory mediator regulation of transient receptor potential channels were proposed.In conclusion,the current study identified four novel SNPs associated with AL in highly myopic eyes and confirmed that the expression of ADAMTS16 and PIGZ was significantly upregulated in neural retina of deprived eyes.Enrichment analyses provided novel insight into the etiology of high myopia and opened avenues for future research interest.

Salvianolic acid B promotes the invasion and migration of H_(2)O_(2)-induced HTR-8/Svneo trophoblast cells by upregulating matrix metalloproteinase-9 via the phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B pathway

OBJECTIVE:To elucidate the regulatory effects of salvianolic acid B(Sal B)on trophoblast cells in preeclampsia(PE).METHODS:3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide(MTT)assays were used to detect the viability of human extravillous trophoblast HTR-8/Svneo cells induced by H_(2)O_(2)following treatment with different concentrations of Sal B.The levels of oxidative stressrelated molecules,including superoxide dismutase,glutathione-Px and malondialdehyde were detected using corresponding kits.Cell apoptosis was detected using a Terminal deoxynucleotidyl transferase(Td T)d UTP NickEnd Labeling(TUNEL)assay,and the expression of apoptosis-related proteins was detected using western blot analysis.In the present study,wound healing and Transwell assays were performed to measure the levels of cell invasion and migration.Western blot analysis was also used to detect the expression levels of epithelialmesenchymal transition-related proteins.The mechanisms underlying Sal B were further investigated using reverse transcription-quantitative real-time polymerase chain reaction(RT-q PCR)and western blot analysis,to determine the expression levels of matrix metallopeptidase 9(MMP-9)and phosphatidylinositol-4,5-bisphosphate 3-kinase(PI3K)/protein kinase B(Akt).RESULTS:Sal B increased the activity of HTR-8/Svneo cells,inhibited oxidative damage and promoted the invasion and migration of trophoblast cells induced by H_(2)O_(2).Furthermore,the expression levels of MMP-9 and members of the PI3K/Akt signaling pathway were significantly decreased.The pathway agonist,LY294002,and MMP-9 inhibitor,GM6001,reversed the effects of Sal B on H_(2)O_(2)-induced cells.CONCLUSIONS:Sal B promoted the invasion and migration of H_(2)O_(2)-induced HTR-8/Svneo trophoblast cells by upregulating MMP-9 via the PI3K/Akt signaling pathway.