Endothelial cell-derived MMP19 promotes pulmonary fibrosis by inducing E(nd)MT and monocyte infiltration.

BACKGROUND: Matrix metalloproteinases (MMPs) play important roles in remodeling the extracellular matrix and in the pathogenesis of idiopathic pulmonary fibrosis (IPF). MMP19, which is an MMP, was significantly upregulated in hyperplastic alveolar epithelial cells in IPF lung tissues and promoted epithelial-mesenchymal transition (EMT). Recent studies have demonstrated that endothelial-to-mesenchymal transition (E(nd)MT) contributes to pulmonary fibrosis. However, the role of MMP19 in pulmonary vascular injury and repair and E(nd)MT remains unclear. METHODS: To determine the role of MMP19 in E(nd)MT and pulmonary fibrosis. MMP19 expressions were determined in the lung endothelial cells of IPF patients and bleomycin (BLM)-induced mice. The roles of MMP19 in E(nd)MT and endothelial barrier permeability were studied in the MMP19 cDNA-transfected primary human pulmonary microvascular endothelial cells (HPMECs) and MMP19 adenoassociated virus (MMP19-AAV)-infected mice. The regulatory mechanism of MMP19 in pulmonary fibrosis was elucidated by blocking its interacting proteins SDF1 and ET1 with AMD3100 and Bosentan, respectively. RESULTS: In this study, we found that MMP19 expression was significantly increased in the lung endothelial cells of IPF patients and BLM-induced mice compared to the control groups. MMP19 promoted E(nd)MT and the migration and permeability of HPMECs in vitro, stimulated monocyte infiltration into the alveolus, and aggravated BLM-induced pulmonary fibrosis in vivo. SDF1 and Endothelin-1 (ET1) were physically associated with MMP19 in HPMECs and colocalized with MMP19 in endothelial cells in IPF patient lung tissues. AMD3100 and bosentan alleviated the fibrosis induced by MMP19 in the BLM mouse model. CONCLUSION: MMP19 promoted E(nd)MT by interacting with ET1 and stimulated monocyte infiltration into lung tissues via the SDF1/CXCR4 axis, thus aggravating BLM-induced pulmonary fibrosis. Vascular integrity regulated by MMP19 could be a promising therapeutic target for suppressing pulmonary fibrosis. Video abstract.

Long noncoding RNA ZEB1-AS1 affects paclitaxel and cisplatin resistance by regulating MMP19 in epithelial ovarian cancer cells.

PURPOSE: The long noncoding RNA (lncRNA) ZEB1-AS1 is reported overexpressed in sensitive ovarian cancer cells A2780 compared with paclitaxel (PTX)-and cisplatin (DDP)- resistant. However, the function and mechanism of ZEB1-AS1 in EOC cells still unknown. METHODS: We used quantitative real-time PCR (qPCR) to detect ZEB1-AS1 expression in A2780 and A2780/R cells. A combination of siRNA, plasmids, CCK8 and flow cytometry was used to detect the effect of ZEB1-AS1 on ovarian cancer cell A2780 PTX and DDP resistance. Transcriptome sequencing, qPCR, and western blot were used for further mechanistic studies. RESULTS: ZEB1-AS1 depletion using siRNA in chemosensitive A2780 cells significantly increased PTX and DDP resistance. In contrast, ZEB1-AS1 overexpression in PTX- and DDP-resistant A2780/resistant (A2780/R) cells reversed the observed drug resistance. Thus, ZEB1-AS1 plays an important role in PTX and DDP resistance in EOC cells. However, quantitative real-time PCR (qPCR) and western blot results suggested that ZEB1-AS1 did not regulate chemoresistance through regulation of ZEB1 protein. We used sequencing to detect mRNA expression changes in A2780 cells after ZEB1-AS1 silencing. The results indicated that MMP19 was the likely downstream factor of ZEB1-AS1. We further examined whether ZEB1-AS1 played an important role in chemoresistance by silencing MMP19 in ZEB1-AS1-overexpressing cells. CCK8 assay results suggested that MMP19 knockdown promoted ZEB1-AS1-induced chemoresistance to PTX and DDP in A2780 cells. CONCLUSION: This study is the first to reveal that ZEB1-AS1 plays a pivotal role in cancer chemoresistance.

Upregulation of circular RNA circ-ERBB2 predicts unfavorable prognosis and facilitates the progression of gastric cancer via miR-503/CACUL1 and miR-637/MMP-19 signaling.

Gastric cancer (GC) is one of the most common malignancies of digestive system with aggressive phenotypes. Circular RNAs (circRNAs) play a pivotal function in cancer initiation and development. Nevertheless, the function and mechanism of circRNAs in gastric cancer (GC) is not fully understood. We found circ-ERBB2 was strikingly increased in GC tissues and cells. Noticeably, circ-ERBB2 upregulation in tumorous tissues was linked to patients' tumor size, depth of invasion, and overall survival. A series of gain and loss-of-function assays indicated its oncogenic role in GC cells, including cell proliferation, apoptosis, migration and invasion. We further predicted and identified circ-ERBB2 sponged miR-503 and miR-637 by bioinformatics analysis and luciferase reporter system. CACUL1 and MMP-19 were then predicted and confirmed as the target of miR-503 and miR-637, respectively. Furthermore, rescue assays indicated that circ-ERBB2 promoted tumor growth and invasion via miR-503/CACUL1 and miR-637/MMP-19 pathways, respectively. In summary, these findings demonstrated that circ-ERBB2 functions as an oncogene in GC and might be useful in developing promising therapies for this fatal malignancy.

High expression of MMP19 is associated with poor prognosis in patients with colorectal cancer.

BACKGROUND: Matrix metalloproteinase 19 (MMP19) is a member of zinc-dependent endopeptidases, which have been involved in various physiological and pathological processes. Its expression has been demonstrated in some types of cancers, but the clinical significance of MMP19 in colorectal cancer (CRC) has not been reported. Thus, we aimed to analyze the clinical significance of MMP19 in CRC in present study. METHODS: The expression of MMP19 was first explored in The Cancer Genome Atlas (TCGA) cohort, and then validated in the GSE39582 cohort and our own database. Clinicopathological features and survival rate were also investigated. RESULTS: MMP19 was found to be a predictor for overall survival (OS) in both univariate (hazard ratio [HR]: 1.449, 95% confidence interval [CI]: 1.108-1.893, P = 0.007) and multivariate survival analyses (HR: 1.401, 95% CI: 1.036-1.894, P = 0.028) in the TCGA database. MMP19 was further validated as an independent factor for recurrence free survival in the GSE39582 database by both univariate analysis (HR: 2.061, 95%CI: 1.454-2.921, P < 0.001) and multivariate analysis (HR = 1.470, 95% CI: 1.025-2.215, P = 0.032). In an in-house cohort, MMP19 was significantly upregulated in CRC tissues when compared with their adjacent normal controls (P < 0.001). Ectopic MMP19 expression was positively associated with lymph node metastases (P = 0.029), intramural vascular invasion (P = 0.015) and serum carcinoembryonic antigen levels (P = 0.045). High MMP19 expression correlated with a shorter OS (HR = 5.595; 95% CI: 2.573-12.164; P < 0.001) and disease free survival (HR = 4.699; 95% CI: 2.461-8.974; P < 0.001) in multivariate cox regression analysis. CONCLUSIONS: Expression of MMP19 was upregulated in CRC. High expression of MMP19 was determined to be an independent and poor prognostic factor in CRC. These results suggest that MMP19 may be a good biomarker for CRC.

MicroRNA-193b-3p regulates matrix metalloproteinase 19 expression in interleukin-1ß-induced human chondrocytes.

Micro(mi)RNAs are small, non-coding RNA molecules known to play a significant role in osteoarthritis (OA) initiation and development, and similar to matrix metalloproteinases (MMPs), they participate in cartilage degeneration and cleave multiple extracellular matrices. The aim of this study was to determine whether the expression of MMP-19 in interleukin (IL)-1ß-induced human chondrocytes is directly regulated by miR-193b-3p. Expression levels of miR-193b-3p and MMP-19 in normal and osteoarthritis (OA) human cartilage, and interleukin-1 ß (IL-1ß)-induced human chondrocytes were determined by real-time polymerase chain reaction. Additionally, expression level of MMP-19 in IL-1ß-induced human chondrocytes was estimated by Western blotting and immunohistochemistry analyses. The effect of miR-193b-3p on MMP-19 expression was evaluated using transient transfection of normal human chondrocytes with miR-193b-3p mimic or its antisense inhibitor (miR-193b-3p inhibitor), and siMMP-19. The putative binding site of miR-193b-3p in the 3'-untranslated region (UTR) of MMP-19 mRNA was validated by luciferase reporter assay. miR-193b-3p expression was reduced in OA cartilage compared to that in normal chondrocytes, while the opposite was observed for MMP-19. Upregulation of MMP-19 expression was correlated with downregulation of miR-193b-3p in IL-1ß-stimulated normal chondrocytes. Increase in miR-193b-3p levels was associated with silencing of MMP-19. Overexpression of miR-193b-3p suppressed the activity of the reporter construct containing the 3'-UTR of human MMP-19 mRNA and inhibited the IL-1ß-induced expression of MMP-19 and iNOS in chondrocytes, while treatment with miR-193b-3p inhibitor enhanced MMP-19 expression. MiR-193b-3p is an important regulator of MMP-19 in human chondrocytes and may relieve the inflammatory response in OA.

Heterozygous triplication of upstream regulatory sequences leads to dysregulation of matrix metalloproteinase 19 in patients with cavitary optic disc anomaly.

Patients with a congenital optic nerve disease, cavitary optic disc anomaly (CODA), are born with profound excavation of the optic nerve resembling glaucoma. We previously mapped the gene that causes autosomal-dominant CODA in a large pedigree to a chromosome 12q locus. Using comparative genomic hybridization and quantitative PCR analysis of this pedigree, we report identifying a 6-Kbp heterozygous triplication upstream of the matrix metalloproteinase 19 (MMP19) gene, present in all 17 affected family members and no normal members. Moreover, the triplication was not detected in 78 control subjects or in the Database of Genomic Variants. We further detected the same 6-Kbp triplication in one of 24 unrelated CODA patients and in none of 172 glaucoma patients. Analysis with a Luciferase assay showed that the 6-Kbp sequence has transcription enhancer activity. A 773-bp fragment of the 6-Kbp DNA segment increased downstream gene expression eightfold, suggesting that triplication of this sequence may lead to dysregulation of the downstream gene, MMP19, in CODA patients. Lastly, immunohistochemical analysis of human donor eyes revealed strong expression of MMP19 in optic nerve head. These data strongly suggest that triplication of an enhancer may lead to overexpression of MMP19 in the optic nerve that causes CODA.

Loss of NDRG2 promotes epithelial-mesenchymal transition of gallbladder carcinoma cells through MMP-19-mediated Slug expression.

BACKGROUND & AIMS: Gallbladder carcinoma (GBC) is the most common malignancy of the biliary tract and one of the most lethal forms of human cancer. However, there is limited information about the molecular pathogenesis of GBC. Here, we examined the functional role of the tumor suppressor N-myc downstream-regulated gene 2 (NDRG2) and the underlying molecular mechanisms of disease progression in GBC. METHODS: Clinical correlations between NDRG2 expression and clinicopathological factors were determined by immunohistochemical analysis of tumor tissues from 86 GBC patients. Biological functions of NDRG2 and NDRG2-mediated signaling pathways were determined in GBC cell lines with NDRG2 knockdown or overexpression. RESULTS: Loss of NDRG2 expression was an independent predictor of decreased survival and was significantly associated with a more advanced T stage, higher cellular grade, and lymphatic invasion in patients with GBC. GBC cells with loss of NDRG2 expression showed significantly enhanced proliferation, migration, and invasiveness in vitro, and tumor growth and metastasis in vivo. Loss of NDRG2 induced the expression of matrix metalloproteinase-19 (MMP-19), which regulated the expression of Slug at the transcriptional level. In addition, MMP-19-induced Slug, increased the expression of a receptor tyrosine kinase, Axl, which maintained Slug expression through a positive feedback loop, and stabilized epithelial-mesenchymal transition of GBC cells. CONCLUSIONS: The results of our study help to explain why the loss of NDRG2 expression is closely correlated with malignancy of GBC. These results strongly suggest that NDRG2 could be a favorable prognostic indicator and promising target for therapeutic agents against GBC.

Matrix metalloproteinase-19 promotes metastatic behavior in vitro and is associated with increased mortality in non-small cell lung cancer.

RATIONALE: Lung cancer is the leading cause of cancer death in both men and women in the United States and worldwide. Matrix metalloproteinases (MMPs) have been implicated in the development and progression of lung cancer, but their role in the molecular pathogenesis of lung cancer remains unclear. We have found that MMP19, a relatively novel member of the MMP family, is overexpressed in lung tumors when compared with control subjects. OBJECTIVES: To test the hypothesis that MMP19 plays a significant role in the development and progression of non-small cell lung cancer (NSCLC). METHODS: We have analyzed lung cancer gene expression data, immunostained lung tumors for MMP19, and performed in vitro assays to test the effects of MMP19 in NSCLC cells. MEASUREMENTS AND MAIN RESULTS: We found that MMP19 gene and protein expression is increased in lung cancer tumors compared with adjacent and histologically normal lung tissues. In three independent datasets, increased MMP19 gene expression conferred a poorer prognosis in NSCLC. In vitro, we found that overexpression of MMP19 promotes epithelial-mesenchymal transition, migration, and invasiveness in multiple NSCLC cell lines. Overexpression of MMP19 with a mutation at the catalytic site did not impair epithelial-mesenchymal transition or expression of prometastasis genes. We also found that miR-30 isoforms, a microRNA family predicted to target MMP19, is markedly down-regulated in human lung cancer and regulates MMP19 expression. CONCLUSIONS: Taken together, these findings suggest that MMP19 is associated with the development and progression of NSCLC and may be a potential biomarker of disease severity and outcome.

IL-17 induces NSCLC cell migration and invasion by elevating MMP19 gene transcription and expression through the interaction of p300-dependent STAT3-K631 acetylation and its Y705-phosphorylation.

The cancer cell metastasis is a major death reason for patients with non-small cell lung cancer (NSCLC). Although researchers have disclosed that interleukin 17 (IL-17) can increase matrix metalloproteinases (MMPs) induction causing NSCLC cell metastasis, the underlying mechanism remains unclear. In the study, we found that IL-17 receptor A (IL-17RA), p300, p-STAT3, Ack-STAT3, and MMP19 were up-regulated both in NSCLC tissues and NSCLC cells stimulated with IL-17. p300, STAT3 and MMP19 overexpression or knockdown could raise or reduce IL-17-induced p-STAT3, Ack-STAT3 and MMP19 level as well as the cell migration and invasion. Mechanism investigation revealed that STAT3 and p300 bound to the same region (-544 to -389 nt) of MMP19 promoter, and p300 could acetylate STAT3-K631 elevating STAT3 transcriptional activity, p-STAT3 or MMP19 expression and the cell mobility exposed to IL-17. Meanwhile, p300-mediated STAT3-K631 acetylation and its Y705-phosphorylation could interact, synergistically facilitating MMP19 gene transcription and enhancing cell migration and invasion. Besides, the animal experiments exhibited that the nude mice inoculated with NSCLC cells by silencing p300, STAT3 or MMP19 gene plus IL-17 treatment, the nodule number, and MMP19, Ack-STAT3, or p-STAT3 production in the lung metastatic nodules were all alleviated. Collectively, these outcomes uncover that IL-17-triggered NSCLC metastasis involves up-regulating MMP19 expression via the interaction of STAT3-K631 acetylation by p300 and its Y705-phosphorylation, which provides a new mechanistic insight and potential strategy for NSCLC metastasis and therapy.

Potential therapeutic targets for pelvic organ prolapse: insights from key genes related to blood vessel development.

Objective: Pelvic organ prolapse (POP) is a disease in which pelvic floor support structures are dysfunctional due to disruption of the extracellular matrix (ECM). The vascular system is essential for maintaining ECM homeostasis. Therefore, this study explored the potential mechanism of blood vessel development-related genes (BVDRGs) in POP. Methods: POP-related datasets and BVDRGs were included in this study. Differentially expressed genes (DEGs) between the POP and control groups were first identified in the GSE12852 and GSE208271 datasets, and DE-BVDRGs were identified by determining the intersection of these DEGs and BVDRGs. Subsequently, the feature genes were evaluated by machine learning. Feature genes with consistent expression trends in the GSE12852 and GSE208271 datasets were considered key genes. Afterward, the overall diagnostic efficacy of key genes in POP was evaluated through receiver operating characteristic (ROC) curve analysis. Based on the key genes, enrichment analysis, immune infiltration analysis and regulatory network construction were performed to elucidate the molecular mechanisms underlying the functions of the key genes in POP. Results: A total of 888 DEGs1 and 643 DEGs2 were identified in the GSE12852 and GSE208271 datasets, and 26 candidate genes and 4 DE-BVDRGs were identified. Furthermore, Hyaluronan synthase 2 (HAS2), Matrix metalloproteinase 19 (MMP19) and Plexin Domain Containing 1 (PLXDC1) were identified as key genes in POP and had promising value for diagnosing POP (AUC > 0.8). Additional research revealed that the key genes were predominantly implicated in immune cell activation, chemotaxis, and cytokine release via the chemokine signaling pathway, the Nod-like receptor signaling pathway, and the Toll-like receptor signaling pathway. Analysis of immune cell infiltration confirmed a decrease in the proportion of plasma cells in POP, and MMP19 expression showed a significant negative correlation with plasma cell numbers. In addition, regulatory network analysis revealed that MALAT1 (a lncRNA) targeted hsa-miR-503-5p, hsa-miR-23a-3p and hsa-miR-129-5p to simultaneously regulate three key genes. Conclusion: We identified three key BVDRGs (HAS2, MMP19 and PLXDC1) related to the ECM in POP, providing markers for diagnostic studies and investigations of the molecular mechanism of POP.

Identification of macrophage correlated biomarkers to predict the prognosis in patients with intrahepatic cholangiocarcinoma.

Background: It has been shown that tumor-associated immune cells, particularly macrophages, play a fundamental role in the development and treatment response of intrahepatic cholangiocarcinoma (ICC). However, little is known about macrophages at the single cellular level of ICC patients. Methods: ScRNA-seq from Zhang et al. was used in the present study to identify the genes differentially expressed in ICCs. Furthermore, transcriptomic data from TCGA datasets, IHC and flowcytometry from our cohort were used to confirm the findings. Kaplan-Meier and TIDE scores were also used for prognostic analysis and ICB responses. Results: A significant number of macrophages were found in ICCs as compared to adjacent tissues. We then extracted, processed, and classified the macrophages from the ICCs and adjacent tissues into 12 clusters. Significantly, the macrophages from the ICC exhibited an immunosuppressed state in terms of both signature gene expression and functional enrichment. Furthermore, our results indicate that, of the 10 selective tumor-promoting genes of macrophages, only MMP19 and SIRPα can predict ICB responses in ICCs. Although a higher expression of MMP19 and SIRPα predict a poor prognosis for ICCs without immunotherapy after surgery, patients with high SIRPα expression were more sensitive to immunotherapy, whereas those with high MMP19 expression were not sensitive to immunotherapy. To define the mechanisms, we found that SIRPαhi ICCs exhibited an increased enrichment KEGG pathway of leukocyte transendothelial migration and neutrophil extracellular trap formation. The increased immune cell infiltration will increase sensitivity to immunotherapy. Conclusion: Collectively, macrophages are critical to the immune status of ICCs, and MMP19 and SIRPα can predict prognosis and ICB responses for ICCs.

Circular RNA hsa_circ_0005556 Accelerates Gastric Cancer Progression by Sponging miR-4270 to Increase MMP19 Expression.

PURPOSE: Circular RNAs (circRNAs) are a new class of RNA molecules whose function is largely unknown. There is a growing evidence that circRNAs play an important regulatory role in the progression of a variety of human cancers. However, the exact roles and the mechanisms of circRNAs in gastric cancer are not clear. In this study, we aimed to elucidate the mechanism of hsa_circ_0005556. MATERIALS AND METHODS: Real-time quantitative polymerase chain reaction was used to detect the expression of hsa_circ_0005556, miR-4270, and matrix metalloproteinase-19 (MMP19) in gastric cancer tissues and cell lines. The expression of hsa_circ_0005556 in gastric cancer cells was silenced by lentivirus, and cell proliferation, invasion, migration, and tumorigenesis in nude mice were assessed to evaluate the function of hsa_circ_0005556 in gastric cancer. RESULTS: The expression of hsa_circ_0005556 in gastric cancer tissues and gastric cancer cell lines was higher compared to normal controls. In vitro, the downregulation of hsa_circ_0005556 significantly inhibited proliferation, migration, and invasion of gastric cancer cells. In vivo, the downregulation of hsa_circ_0005556 suppressed tumor growth in nude mice. CONCLUSIONS: Our study shows that the hsa_circ_0005556/miR-4270/MMP19 axis is involved in proliferation, migration, and invasion of gastric cancer cells through the competing endogenous RNA (ceRNA) mechanism.

The expression of MMP19 and its clinical significance in glioma.

AIMS: The expression of phosphoglycerate kinase 1 (MMP19) is elevated in some cancers. However, the clinical features and prognostic value of glioma patients with MMP19 expression are unclear. In this study, the expression level of MMP19 and the correlation between the level of MMP19 expression and the clinicopathologic data in glioma patients including survival were examined. METHODS AND RESULTS: Using real-time PCR, the mRNA expression of MMP19 was examined in 61 fresh glioma tissues and 32 brain samples. The result indicated that MMP19 mRNA was obviously elevated in glioma tissues compared to brain tissues. Further, we observed that MMP19 mRNA was much higher in stage III patients than it was in stage I-II patients. The expression of the MMP19 protein was determined by immunohistochemical analysis in 156 paraffin-embedded glioma samples and 35 normal paraffin-embedded brain samples. The MMP19 protein level was significantly increased in glioma tissues compared to brain tissues (P = 0.008). Furthermore, we observed that a high expression of MMP19 protein was positively associated with clinical stage (P = 0.008) but did not correlate with age, gender, or histological type. An increased MMP19 protein expression was associated with poor overall survival rates (P = 0.001). A stratified analysis showed that patients with high MMP19 protein expression indicated a worse prognosis occurring in WHO III-IV stages (P = 0.001). A Multivariate analysis indicated that a high expression of the MMP19 protein was an independent prognostic indicator of patient survival (P = 0.009). CONCLUSIONS: MMP19 is overexpressed and plays a significant role in disease progression and poor outcome in glioma patients.

Integrated mRNA and microRNA transcriptome sequencing characterizes sequence variants and mRNA-microRNA regulatory network in nasopharyngeal carcinoma model systems.

Nasopharyngeal carcinoma (NPC) is a prevalent malignancy in Southeast Asia among the Chinese population. Aberrant regulation of transcripts has been implicated in many types of cancers including NPC. Herein, we characterized mRNA and miRNA transcriptomes by RNA sequencing (RNASeq) of NPC model systems. Matched total mRNA and small RNA of undifferentiated Epstein-Barr virus (EBV)-positive NPC xenograft X666 and its derived cell line C666, well-differentiated NPC cell line HK1, and the immortalized nasopharyngeal epithelial cell line NP460 were sequenced by Solexa technology. We found 2812 genes and 149 miRNAs (human and EBV) to be differentially expressed in NP460, HK1, C666 and X666 with RNASeq; 533 miRNA-mRNA target pairs were inversely regulated in the three NPC cell lines compared to NP460. Integrated mRNA/miRNA expression profiling and pathway analysis show extracellular matrix organization, Beta-1 integrin cell surface interactions, and the PI3K/AKT, EGFR, ErbB, and Wnt pathways were potentially deregulated in NPC. Real-time quantitative PCR was performed on selected mRNA/miRNAs in order to validate their expression. Transcript sequence variants such as short insertions and deletions (INDEL), single nucleotide variant (SNV), and isomiRs were characterized in the NPC model systems. A novel TP53 transcript variant was identified in NP460, HK1, and C666. Detection of three previously reported novel EBV-encoded BART miRNAs and their isomiRs were also observed. Meta-analysis of a model system to a clinical system aids the choice of different cell lines in NPC studies. This comprehensive characterization of mRNA and miRNA transcriptomes in NPC cell lines and the xenograft provides insights on miRNA regulation of mRNA and valuable resources on transcript variation and regulation in NPC, which are potentially useful for mechanistic and preclinical studies.

Molecular characterization of porcine MMP19 and MMP23B genes and its association with immune traits.

MMP19 and MMP23B belong to the Matrix metalloproteases (MMPs) family, which are zinc-binding endopeptidases that are capable of degrading various components of the extracellular matrix. They are thought to play important roles in embryonic development, reproduction and tissue remodeling, as well as in cell proliferation, differentiation, migration, angiogenesis, apoptosis and host defense. However, they are poorly understood in pigs. Here, we obtained the full length coding region sequence and genomic sequence of the porcine MMP19 and MMP23B genes and analyzed their genomic structures. The deduced amino acid sequence shares similar precursor protein domains with human and mouse MMP19 and MMP23B protein, respectively. Using IMpRH panel, MMP19 was mapped to SSC5p12-q11 (closely linked to microsatellite DK) and MMP23B was mapped to SSC8q11-q12 (linked to microsatellite Sw2521). Quantitative real-time PCR showed that MMP19 was abundantly expressed in the liver, while MMP23B was strongly expressed in the ovarian and heart. Furthermore, both genes were all expressed increasingly in prenatal skeletal muscle during development. Three SNPs were detected by sequencing and PCR-RFLP methods, and association analysis indicated that C203T at exon 5 of MMP19 has a significant association with the blood parameters WBC (G/L) and IgG2 (mg/mL) (P<0.05), SNP C131T at exon 3 of MMP23B is significantly associated with the blood parameters HGB (g/L) and MCH (P<0.05), and A150G in exon 4 has no significant association with the economic traits in pigs.