The luciferase reporter system of the MMP12 endogenous promoter for investigating transcriptional regulation of the human MMP12 gene

Background: Matrix metalloproteinase 12 (MMP12), a member of MMPs, can take lots of roles including extracellular matrix component degradation, viral infection, inflammation, tissue remodeling and tumorigenesis. To explore the transcriptional regulation of MMP12 gene, a sensitive luciferase reporter HEK293 cell line for endogenous MMP12 promoter was generated by CRISPR/Cas9 technology. Results: The HEK293-MMP12-T2A-luciferase-KI cell line was successfully established by CRISPR/Cas9 technology. The sequencing results indicated that one allele of the genome was proven to have a site-directed insertion of luciferase gene and another allele of the genome was confirmed to have additional 48 bp insertion in this cell line. The cell line was further demonstrated to be a sensitive reporter of the endogenous MMP12 promoter by applying transcription factors STAT3, AP-1 and SP-1 to the cell line. The reporter cell line was then screened with bioactive small molecule library, and a small molecule Tanshinone I was found to significantly inhibit the transcriptional activity of MMP12 gene in HEK293-MMP12-T2A-luciferase-KI cell line by luciferase activity assay, which was further confirmed to inhibit the expression of MMP12 mRNA in wild-type HEK293 cells. Conclusions: This novel luciferase knock-in reporter system will be helpful for investigating the transcriptional regulation of MMP12 gene and screening the drugs targeting MMP12 gene.

Pressure therapy upregulates matrix metalloproteinase expression and downregulates collagen expression in hypertrophic scar tissue / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Pressure therapy improves hypertrophic scar healing, but the mechanisms for this process are not well understood. We sought to investigate the differential expression of matrix metalloproteinases (Mmps) and collagen in posttraumatic hypertrophic scar tissue with mechanical pressure and delineate the molecular mechanisms of pressure therapy for hypertrophic scars.</p><p><b>METHODS</b>Fibroblast lines of normal skin and scar tissue were established and a mechanical pressure system was devised to simulate pressure therapy. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting assays were used to compare differences in the mRNA and protein expression of Mmps and collagen in scar fibroblasts before and after pressure therapy.</p><p><b>RESULTS</b>The expression differed between the hypertrophic scar cell line and the normal cell line. RT-PCR assays showed that Collagen I, highly expressed in the hypertrophic scar cell line, decreased significantly after pressure therapy. Mmp2, Mmp9, and Mmp12 expression in the hypertrophic scar tissue increased significantly after pressure therapy (P < 0.05). Western blotting assays further revealed that Mmp9 and Mmp12 expression increased significantly in the hypertrophic scar tissue after pressure therapy (P < 0.05) but not Mmp2 expression (P > 0.05).</p><p><b>CONCLUSION</b>Mechanical pressure induces degradation of Collagen I in hypertrophic scar tissue by affecting the expression of Mmp9 and Mmp12.</p>

Prognostic significance of gelsolin and MMP12 in Langerhans cell histiocytosis / 대한혈액학회지

BACKGROUND: Gelsolin and matrix metalloproteinase 12 (MMP12) expression has been reported in Langerhans cell histiocytosis (LCH), but the clinical significance of this expression is unknown. We investigated the associations of these proteins with clinical manifestations in patients diagnosed with LCH. METHODS: We performed a retrospective analysis of clinical data from patients diagnosed with LCH and followed up between 1998 and 2008. Available formalin-fixed, paraffin-embedded specimens were used for gelsolin and MMP12 immunohistochemical staining. We analyzed the expression levels of these proteins and their associations with LCH clinical features. RESULTS: Specimens from 36 patients (20 males, 16 females) with a diagnosis of LCH based on CD1a positivity with clinical manifestations were available for immunohistochemical staining. Median patient age was 62 months (range, 5 to 207). The expression of gelsolin varied; it was high in 17 patients (47.2%), low in 11 patients (30.6%), and absent in 8 patients (22.2%). The high gelsolin expression group had a higher tendency for multi-organ and risk organ involvement, although the trend was not statistically significant. MMP12 was detected only in 7 patients (19.4%) who showed multi-system involvement (P=0.018) and lower event-free survival (P=0.002) in comparison to patients with negative MMP12 staining. CONCLUSION: Gelsolin and MMP12 expression may be associated with the clinical course of LCH, and MMP12 expression may be particularly associated with severe LCH. Further studies of larger populations are needed to define the precise role and significance of gelsolin and MMP12 in the pathogenesis of LCH.

Screen and validation of differentially expressing genes related to silicotic pulmonary fibrosis in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To screen the differentially expressing genes between silicotic lung tissue and normal lung tissue, to identify the differentially expressing genes of matrix metalloproteinase-12 (MMP-12) and Cathepsin E and to explore the roles of those genes in silicosis development.</p><p><b>METHODS</b>Thirty male SD rats were divided randomly into two groups: control group (6 rats) and exposure group (24 rats) which was exposed to SiO2 by intra-tracheal perfusion. On the 30 th, 60 th and 90 th days after exposure, 8 rats in model group and 2 rats in control group were executed and the lung tissues were obtained. The morphologic changes of lung tissues were observed with HE staining and VG staining under a light microscope. The gene microarrays were used to identify differentially expressing genes of lung tissues in rats exposed to SiO2 for 60 days. Two significantly up-regulated genes, MMP-12 and Cathepsin E, were validated using RT-PCR, immunohistochemistry and Western Blot assay.</p><p><b>RESULTS</b>A total of 338 differentially expressing genes were identified from the 26 962 genes between silicotic rats and normal rats, including 267 up-regulated genes and 71 down-regulated genes. The results of RT-PCR showed that in the lung tissues of exposure group on the 30 th, 60 th and 90 th days, the mRNA expression levels of MMP-12 were 4.306, 5.338, 6.713 times higher than those in the control group, the mRNA expression levels of Cathepsin E were 1.434, 2.974, 3.889 times higher than those in the control group, respectively. The results of immunohistochemical showed that in the lung tissues of exposure group on the 30th, 60th and 90th days, the mRNA expression levels of MMP-12 were 1.435, 1.746, 2.069 times higher than those in the control group, the mRNA expression levels of Cathepsin E were 1.372, 1.663, 2.103 times higher than those in the control group, respectively. The results of immunohistochemical showed that in the lung tissues of exposure group on the 30th, 60th and 90th days, the expression levels of MMP-12 protein were 1.214, 1.531, 1.959 times higher than those in the control group, the expression levels of Cathepsin E protein were 1.262, 1.828, 1.907 times higher than those in the control group, respectively. Compared with the control group, the mRNA and protein expression levels of MMP-12 and Cathepsin E in lung tissues of exposure group were significantly up-regulated (P < 0.05).</p><p><b>CONCLUSION</b>The differentially expressing genes in rat lung tissues screened by gene chip were validated, which suggested that a complex gene regulatory network may be contributed to occurrence of silicosis. MMP-12 and Cathepsin E genes may be involved in the development of silicotic pulmonary fibrosis by degrading the basement membrane of alveolar wall and participating in the immune response.</p>

Association of functional polymorphisms on MMP-12 and MMP-13 gene promoter region with epithelial ovarian carcinoma / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate whether the functional polymorphisms in the promoter region of MMP-12 (-82A/G) and MMP-13(-77A/G) are associated with epithelial ovarian carcinoma (EOC).</p><p><b>METHODS</b>The MMP-12 -82A/G and MMP-13 -77A/G were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 300 epithelial ovarian carcinoma patients and 300 control women.</p><p><b>RESULTS</b>The A/G genotype frequency of the MMP-12 gene was significantly higher in the patients than in the controls (P= 0.003); similarly, the frequency of MMP-12 -82G allele was higher in the patient group (P= 0.004). Compared with the A/A genotype, the A/G genotype carriers significantly increased the risk of EOC development (OR= 2.81, 95%CI: 1.38-5.74). No overall association between the MMP-13 -77A/G polymorphism and EOC(P= 0.15) was observed. However, the A/A genotype carriers in the MMP-13 -77A/G locus had significantly higher risk of developing serous-papillary and mucinous ovarian cancer (OR= 1.93, 95% CI: 1.05-3.53; OR= 5.16, 95% CI: 1.62-16.44, respectively), comparing with the G/G genotype carriers. Combining the two SNPs, the haplotype distributions in patients were not significantly different from that in control women (P= 0.06).</p><p><b>CONCLUSION</b>These results suggested that individuals with MMP-12 -82A/G and MMP-13 -77A/A might have higher risk of overall or special histological type of EOC development.</p>

Tanshinone IIA down-regulates the expression of MMP-12 and TF in RAW 264.7 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of tanshinone IIA (TanIIA) on the expression of tissue factor (TF) and matrix metalloproteinase-12 (MMP-12) in RAW264.7 cells and explore the possible mechanism.</p><p><b>METHODS</b>RAW 264.7 cells were incubated with ox-LDL in the presence or absence of different concentrations of tanshinone IIA. At the end of the incubation, the cell proliferation was assessed by MTT assay, and superoxide dismutase (SOD) activity and malondialdehyde (MDA) and TF concentrations in the supernatant were detected by xanthine oxidase method, thiobarbituric acid method and ELISA, respectively. Western blotting was employed to determine MMP-12 expression in the cells.</p><p><b>RESULTS</b>The cell proliferation was dose-dependently inhibited by TanIIA. SOD activity in the supernatant was increased significantly, while the MDA and TF concentration and MMP-12 expression in cells decreased after treatment of the cells with different concentrations of TanIIA.</p><p><b>CONCLUSION</b>TanIIA inhibits the cell proliferation and TF and MMP-12 expressions in RAW264.7 cells stimulated by ox-LDL, and these effects may be related with the anti-oxidation property of TanIIA.</p>

Establishment and characteristics of acute lung injury model induced by cigarette smoke in ICR mice / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a mouse model of acute lung injury induced by cigarette smoke (CS) and to investigate inflammatory changes with the model.</p><p><b>METHODS</b>ICR mice exposed to CS for 20-min, 3/d. Bronchoalveolar lavage fluid (BALF) and lung tissue were harvested at d 0, d 1, d 3 and d 7 after CS exposure. Neutrophil count in BAFL, TNF-alpha and MMP-12 levels, the activity of MPO in lung tissue were determined.</p><p><b>RESULT</b>Neutrophil count in BALF, MMP-12 and MPO levels in lung tissue were increased after CS exposure in a time-dependent manner with a peak at d3. TNF-alpha level sharply increased at d1, and remained high level until d7.</p><p><b>CONCLUSION</b>ICR mice are tolerant and sensitive to CS exposure, which may be used as an appropriate animal model for acute lung injury induced by cigarette smoke.</p>

The expression of human macrophage metalloelastase mRNA in gastric cancer cell lines and tissues and its clinical significance / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To make measurement of the expression of HME mRNA in both gastric cancer cell lines and tissues and evaluate its role in development of gastric cancer.</p><p><b>METHODS</b>The HME mRNA expression in 3 gastric cancer cell lines and tissues was detected by real-time fluorescent quantitative PCR.</p><p><b>RESULTS</b>All three gastric cancer cell lines expressed HME mRNA, and the HME mRNA expression level in gastric cancer tissues was higher than that in normal tissues (P <0.05). The rate of lymph node metastasis of HME mRNA positive cases was lower than that of HME mRNA negative ones (P < 0.05). Expression of drug resistance gene GST of HME mRNA positive cases was lower than that of HME mRNA negative ones (P <0.05). The two-year survival rate of HME mRNA positive cases was higher than that of HME mRNA negative ones (P < 0.05). There was no correlation between the expression of HME gene and the tumor location, size, depth of invasion, degree of malignancy, expression of drug resistance gene top II and PG.</p><p><b>CONCLUSION</b>The expression of HME gene in gastric cancers may be related with lower possibility of metastasis and predict a better prognosis.</p>

Study on matrix metalloproteinase 1, 9, 12 polymorphisms and susceptibility to chronic obstructive pulmonary disease among Han nationality in northern China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the association between the functional polymorphism of matrix metalloproteinases (MMPs) and the development of chronic obstructive pulmonary disease (COPD).</p><p><b>METHODS</b>147 COPD patients and 120 healthy smoking controls were selected. Spirometry and chest X-rays had been taken. Questionnaires including sex, age, smoking history, occupational exposure were completed. MMP-9 (-1562 C/T), MMP-1(-1607 1G/2G), MMP-12 (-82 A/G), MMP-12(-357 Asn/ Ser) alleles were determined using PCR-RFLP method. Independent samples T test analysis was carried out to compare patients' age, smoking index, FEV1 /FVC, FEV1 % pred with that of healthy controlled group. The frequencies of genotypes and alleles between groups were analyzed by chi-square tests and multilogistic regression.</p><p><b>RESULTS</b>MMP12 Asn/Asn, CT/AsnAsn were risk factors for smoking-induced COPD. The ORs were 2.361 (95% CI: 1.369-4.017) and 2.433(95% CI: 1.159-5.342) respectively while CC/1G1G/ SerSer seemed to be a protective factor for smoking-induced COPD, with OR as 0.457 and 95% CI as 0.231-0.911.</p><p><b>CONCLUSION</b>Asn/Asn, CT/AsnAsn might be susceptible genotypes while CC/GG/SerSer might serve as protective genotype.</p>

Changes of gene expression profiles in CCl4 injured liver of mice / 药学学报

<p><b>AIM</b>To study the gene expression profiles between the CCl4 injured liver and normal liver in mice, and to screen the differentially expressed genes that relate to liver injury by CCl4 on a large scale using cDNA microarrays.</p><p><b>METHODS</b>Male Kunming strain mice were divided into two groups: one was control group and another was CCl4 injured liver group that was given 0.1% CCI4 oil solution ip at dose of 10 mL x kg(-1) every three days, totally for ten times. Then mRNA in livers of the two groups of mice was extracted, separately, and reversely transcribed to cDNA with the incorporation of different fluorescent-labeled dUTP as the hybridization probes. The mixed probes were hybridized to the cDNA microarrays. The fluorescent signal values were acquired by scanner and analyzed with statistical software.</p><p><b>RESULTS</b>Among the 14 100 target genes, 379 genes were differentially expressed, in which 163 genes were up-regulated and the other 216 genes were down-regulated. They are closely related to a range of biological functions.</p><p><b>CONCLUSION</b>Using the cDNA microarray and experimental animal modeling technique, the differentially expressed genes of CCl4 injured liver in mice on a large scale could be studied. It is useful for further investigation of the injury mechanism of CCl4.</p>

Pathogenesis of cigarette smoke-induced chronic obstructive pulmonary disease and therapeutic effects of glucocorticoids and N-acetylcysteine in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>T lymphocytes and matrix metalloproteinase (MMP) play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the details of the mechanisms involved are unclear. The aims of this study were to investigate the changes in interferon-gamma (IFN-gamma), interleukin-4 (IL-4), MMP-9, MMP-12 and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in a smoke-induced COPD rat model and the therapeutic effects of glucocorticoids and N-acetylcysteine.</p><p><b>METHODS</b>Male Wistar rats were exposed to cigarette smoke for 3.5 months. Budesonide or N-acetylcysteine was given in the last month. Lung function was measured at the end of the study. IL-4 and IFN-gamma levels were then determined in bronchoalveolar lavage fluid and lung tissue samples by enzyme-linked immunosorbent assay. The expression of MMP-9, MMP-12 and TIMP-1 mRNA in lung tissue was determined by RT-PCR.</p><p><b>RESULTS</b>In comparison with the control group, rats exposed to smoke had a significant increase in IL-4 and MMP-12 levels and a significant decrease in IFN-gamma levels. In addition, the IL-4/IFN-gamma ratio and MMP-12/TIMP-1 ratio were both higher. At the same time, the ratio of forced expiratory volume in 0.3 second to forced vital capacity (FEV(0.3)/FVC) and dynamic compliance (C(dyn)) decreased and expiratory resistance (Re) increased. By measuring pulmonary mean linear intercept and mean alveolar numbers, obvious emphysematous changes were observed in the smoke exposed group. After treatment with budesonide, IL-4 and MMP-12 decreased and IFN-gamma increased. The IL-4/IFN-gamma ratio returned to normal, though the MMP-12/TIMP-1 ratio remained unchanged. FEV(0.3)/FVC was significantly higher and Re was significantly lower than that in untreated smoke exposed rats. No significant differences were found in pulmonary mean linear intercept and mean alveolar numbers. After treatment with N-acetylcysteine, IFN-gamma increased and the IL-4/IFN-gamma ratio decreased. The MMP-12/TIMP-1 ratio remained unchanged. Re and C(dyn) both improved obviously. No significant differences were found in pulmonary mean linear intercept and mean alveolar numbers. Correlation analysis indicated that IL-4 levels in lung tissue correlated negatively with FEV(0.3)/FVC (r = -0.53, P = 0.001), IFN-gamma levels in lung tissue correlated negatively with Re (r = -0.63, P = 0.000) and positively with C(dyn) (r = 0.44, P = 0.009), and that the IL-4/IFN-gamma ratio correlated negatively with FEV(0.3)/FVC (r = -0.44, P = 0.010) and C(dyn) (r = -0.42, P = 0.015) and positively with Re (r = 0.58, P = 0.000). Finally, MMP-12 correlated negatively with FEV(0.3)/FVC (r = -0.36, P = 0.026).</p><p><b>CONCLUSIONS</b>Cigarette smoke exposure increases IL-4 levels and decreases IFN-gamma levels. This may be the result of smoke-induced changes in lung function. Budesonide can mitigate the changes in IL-4 and IFN-gamma levels induced by smoke exposure. N-acetylcysteine has no effect on IL-4, but increases IFN-gamma levels and brings the IL-4/IFN-gamma ratio back to normal. Cigarette smoke can also promote MMP-12 gene expression and elevate the MMP-12/TIMP-1 ratio. This effect may play a role in smoke-induced emphysema. Budesonide and N-acetylcysteine do not alter the MMP-12/TIMP-1 ratio in this study when given in the late phase of smoke exposure.</p>