HOXB9 promotes laryngeal squamous cell carcinoma progression by upregulating MMP12.

Transcriptional factor HOXB9, a part of the HOX gene family, plays a crucial role in the development of diverse cancer types. This study aimed to elucidate the regulatory mechanism of HOXB9 on the proliferation and invasion of laryngeal squamous cell carcinoma (LSCC) cells to provide guidance for the development and prognosis of LSCC. The CRISPR/Cas9 method was employed in LSCC cell lines to knock out the HOXB9 gene and validate its effects on the proliferation, migration, invasion, and regulation of LSCC cells. CCK-8 and flow cytometry were used to detect cell viability and proliferation; Tunnel was used to detect cell apoptosis, and transwell was used to detect cell migration and invasion. The effect of HOXB9 on tumor growth was tested in nude mice. The downstream target genes regulated by HOXB9 were screened by microarray analysis and verified by Western blotting, immunohistochemistry, chromatin immunoprecipitation, and double-luciferase reporter assays. The current research investigated molecular pathways governed by HOXB9 in the development of LSCC. Additionally, both laboratory- and living-organism-based investigations revealed that disrupting the HOXB9 gene through the CRISPR/CAS9 mechanism restrained cellular growth, movement, and infiltration, while enhancing cellular apoptosis. Detailed analyses of LSCC cell strains and human LSCC samples revealed that HOXB9 promoted LSCC progression by directly elevating the transcriptional activity of MMP12. HOXB9 could influence changes in LSCC cell functions, and the mechanism of action might be exerted through its downstream target gene, MMP12.

RNA Expression of MMP12 Is Strongly Associated with Inflammatory Bowel Disease and Is Regulated by Metabolic Pathways in RAW 264.7 Macrophages.

Macrophage metalloelastase or matrix metalloproteinase-12 (MMP12) is a macrophage-specific proteolytic enzyme involved in the physiopathology of many inflammatory diseases, including inflammatory bowel disease. Although previously published data suggested that the modulation of MMP12 in macrophages could be a determinant for the development of intestinal inflammation, scarce information is available on the mechanisms underlying the regulation of MMP12 expression in those phagocytes. Therefore, in this study, we aimed to delineate the association of MMP12 with inflammatory bowel disease and the molecular events leading to the transcriptional control of this metalloproteinase. For that, we used publicly available transcriptional data. Also, we worked with the RAW 264.7 macrophage cell line for functional experiments. Our results showed a strong association of MMP12 expression with the severity of inflammatory bowel disease and the response to relevant biological therapies. In vitro assays revealed that the inhibition of mechanistic target of rapamycin complex 1 (mTORC1) and the stimulation of the AMP-activated protein kinase (AMPK) signaling pathway potentiated the expression of Mmp12. Additionally, AMPK and mTOR required a functional downstream glycolytic pathway to fully engage with Mmp12 expression. Finally, the pharmacological inhibition of MMP12 abolished the expression of the proinflammatory cytokine Interleukin-6 (Il6) in macrophages. Overall, our findings provide a better understanding of the mechanistic regulation of MMP12 in macrophages and its relationship with inflammation.

Myeloid-Mas Signaling Modulates Pathogenic Crosstalk among MYC+CD63+ Endothelial Cells, MMP12+ Macrophages, and Monocytes in Acetaminophen-Induced Liver Injury.

Acetaminophen overdose is a leading cause of acute liver failure (ALF). Despite the pivotal role of the inflammatory microenvironment in the progression of advanced acetaminophen-induced liver injury (AILI), a comprehensive understanding of the underlying cellular interactions and molecular mechanisms remains elusive. Mas is a G protein-coupled receptor highly expressed by myeloid cells; however, its role in the AILI microenvironment remains to be elucidated. A multidimensional approach, including single-cell RNA sequencing, spatial transcriptomics, and hour-long intravital imaging, is employed to characterize the microenvironment in Mas1 deficient mice at the systemic and cell-specific levels. The characteristic landscape of mouse AILI models involves reciprocal cellular communication among MYC+CD63+ endothelial cells, MMP12+ macrophages, and monocytes, which is maintained by enhanced glycolysis and the NF-κB/TNF-α signaling pathway due to myeloid-Mas deficiency. Importantly, the pathogenic microenvironment is delineated in samples obtained from patients with ALF, demonstrating its clinical relevance. In summary, these findings greatly enhance the understanding of the microenvironment in advanced AILI and offer potential avenues for patient stratification and identification of novel therapeutic targets.

MMP12 is a Potential Predictive and Prognostic Biomarker of Various Cancers Including Lung Adenocarcinoma.

OBJECTIVE: This study sought to explore the clinical value of matrix metalloproteinases 12 (MMP12) in multiple cancers, including lung adenocarcinoma (LUAD). METHODS: Using >10,000 samples, this retrospective study demonstrated the first pan-cancer analysis of MMP12. The expression of MMP12 between cancer groups and their control groups was analyzed using Wilcoxon rank-sum tests. The clinical significance of MMP12 expression in multiple cancers was assessed using receiver operating characteristic curves, Kaplan-Meier curves, and univariate Cox analysis. A further LUAD-related analysis based on 4565 multi-center and in-house samples was performed to verify the findings regarding MMP12 in pan-cancer analysis partly. RESULTS: MMP12 mRNA is highly expressed in 13 cancers compared to their controls, and the MMP12 protein level is elevated in some of these cancers (e.g., colon adenocarcinoma) (P < .05). MMP12 expression makes it feasible to distinguish 21 cancer tissues from normal tissues (AUC = 0.86). A high MMP12 expression is a prognosis risk factor in eight cancers, such as adrenocortical carcinoma (hazard ratio >1, P < .05). The elevated MMP12 expression is also a prognosis protective factor in breast-invasive carcinoma and colon adenocarcinoma (hazard ratio <1, P < .05). Some pan-cancer findings regarding MMP12 are verified in LUAD-MMP12 expression is upregulated in LUAD at both the mRNA and protein levels (P < .05), has the potential to distinguish LUAD with considerable accuracy (AUC = .91), and plays a risk prognosis factor for patients with the disease (P < .05). CONCLUSIONS: MMP12 is highly expressed in most cancers and may serve as a novel biomarker for the prediction and prognosis of numerous cancers.

MTOR Suppresses Cigarette Smoke-Induced Airway Inflammation and MMP12 Expression in Macrophage in Chronic Obstructive Pulmonary Disease.

Background: Macrophage-derived matrix metalloproteinase 12 (MMP12) can cause destruction of lung tissue structure and plays a significant role in the development and progression of chronic obstructive pulmonary disease (COPD). MTOR is a serine/threonine kinase that plays a crucial role in cell growth and metabolism. The activity of MTOR in the lung tissues of COPD patients also shows significant changes. However, it is unclear whether MTOR can regulate the development and progression of COPD by controlling MMP12. This study primarily investigates whether MTOR in macrophages can affect the expression of MMP12 and participate in the progression of COPD. Methods: We tested the changes in MTOR activity in macrophages exposed to cigarette smoke (CS) both in vivo and in vitro. Additionally, we observed the effect of MTOR on the expression of MMP12 in macrophages and on lung tissue inflammation and structural damage in mice, both in vivo and in vitro, using MTOR inhibitors or gene knockout mice. Finally, we combined inhibitor treatment with gene knockout to demonstrate that MTOR primarily mediates the expression of MMP12 through the NF-κB signaling pathway. Results: Exposure to CS can enhance MTOR activity in mouse alveolar macrophages. Inhibiting the activity of MTOR or suppressing its expression leads to increased expression of MMP12. Myeloid-specific knockout of MTOR expression can promote the occurrence of CS-induced pulmonary inflammation and emphysema in mice. Inhibiting the activity of NF-κB can eliminate the effect of MTOR on MMP12. Conclusion: Macrophage MTOR can reduce the expression of MMP12 by inhibiting NF-κB, thereby inhibiting the occurrence of COPD inflammation and destruction of lung tissue structure. Activating the activity of macrophage MTOR may be beneficial for the treatment of COPD.

Mmp12 Is Translationally Regulated in Macrophages during the Course of Inflammation.

Despite the importance of rapid adaptive responses in the course of inflammation and the notion that post-transcriptional regulation plays an important role herein, relevant translational alterations, especially during the resolution phase, remain largely elusive. In the present study, we analyzed translational changes in inflammatory bone marrow-derived macrophages upon resolution-promoting efferocytosis. Total RNA-sequencing confirmed that apoptotic cell phagocytosis induced a pro-resolution signature in LPS/IFNγ-stimulated macrophages (Mϕ). While inflammation-dependent transcriptional changes were relatively small between efferocytic and non-efferocytic Mϕ; considerable differences were observed at the level of de novo synthesized proteins. Interestingly, translationally regulated targets in response to inflammatory stimuli were mostly downregulated, with only minimal impact of efferocytosis. Amongst these targets, pro-resolving matrix metallopeptidase 12 (Mmp12) was identified as a translationally repressed candidate during early inflammation that recovered during the resolution phase. Functionally, reduced MMP12 production enhanced matrix-dependent migration of Mϕ. Conclusively, translational control of MMP12 emerged as an efficient strategy to alter the migratory properties of Mϕ throughout the inflammatory response, enabling Mϕ migration within the early inflammatory phase while restricting migration during the resolution phase.

Genetic Variants in Matrix Metalloproteinases MMP3 (rs3025058) and MMP9 (rs3918242) Associated with Colonic Diverticulosis.

Background and Objectives: Diverticulosis affects a significant portion of the elderly population, with age and lifestyle being established risk factors. Additionally, genetic predisposition is gaining recognition as a contributing factor. This pilot study sought to explore the frequency of genetic variants in matrix metalloproteinases (MMPs) 3, 9, and 12 in a population of colonic diverticulosis patients. Materials and Methods: The study encompassed 134 participants: 59 diagnosed with colon diverticulosis during colonoscopy and 75 healthy controls. The cases and controls were meticulously matched in terms of age and gender. We assessed the distribution of genetic variants MMP3 rs3025058, MMP9 rs3918242, and MMP12 rs2276109 using the polymerase chain reaction-restriction fragments length polymorphism technique. Results: The MMP9 rs3918242 allele T was notably more frequent in individuals with diverticulosis when compared with the control group (p < 0.03). Furthermore, it was associated with dominant (OR = 2.62; 95% CI: 1.24-5.56; p < 0.01) and co-dominant (OR = 2.10; 95% CI: 1.06-4.13; p < 0.03) genetic models. The MMP3 rs3025058 5A/5A genotype was nearly twice as frequent in patients with diverticulosis, while the 6A/6A genotype was only half as common in this group. Conversely, no significant correlation was established between MMP12 rs2276109 and colonic diverticulosis. Conclusions: Our study offers the first insight into a potential connection between genetic variants in MMPs and colon diverticulosis. Specifically, allele T of MMP9 rs3918242 and allele 5A of MMP3 rs3025058 appear to be linked to this condition. These findings indirectly suggest a role for extracellular matrix proteins in the pathogenesis of diverticulosis.

Genetic deletion of MMP12 ameliorates cardiometabolic disease by improving insulin sensitivity, systemic inflammation, and atherosclerotic features in mice.

BACKGROUND: Matrix metalloproteinase 12 (MMP12) is a macrophage-secreted protein that is massively upregulated as a pro-inflammatory factor in metabolic and vascular tissues of mice and humans suffering from cardiometabolic diseases (CMDs). However, the molecular mechanisms explaining the contributions of MMP12 to CMDs are still unclear. METHODS: We investigated the impact of MMP12 deficiency on CMDs in a mouse model that mimics human disease by simultaneously developing adipose tissue inflammation, insulin resistance, and atherosclerosis. To this end, we generated and characterized low-density lipoprotein receptor (Ldlr)/Mmp12-double knockout (DKO) mice fed a high-fat sucrose- and cholesterol-enriched diet for 16-20 weeks. RESULTS: DKO mice showed lower cholesterol and plasma glucose concentrations and improved insulin sensitivity compared with LdlrKO mice. Untargeted proteomic analyses of epididymal white adipose tissue revealed that inflammation- and fibrosis-related pathways were downregulated in DKO mice. In addition, genetic deletion of MMP12 led to alterations in immune cell composition and a reduction in plasma monocyte chemoattractant protein-1 in peripheral blood which indicated decreased low-grade systemic inflammation. Aortic en face analyses and staining of aortic valve sections demonstrated reduced atherosclerotic plaque size and collagen content, which was paralleled by an improved relaxation pattern and endothelial function of the aortic rings and more elastic aortic sections in DKO compared to LdlrKO mice. Shotgun proteomics revealed upregulation of anti-inflammatory and atheroprotective markers in the aortas of DKO mice, further supporting our data. In humans, MMP12 serum concentrations were only weakly associated with clinical and laboratory indicators of CMDs. CONCLUSION: We conclude that the genetic deletion of MMP12 ameliorates obesity-induced low-grade inflammation, white adipose tissue dysfunction, biomechanical properties of the aorta, and the development of atherosclerosis. Therefore, therapeutic strategies targeting MMP12 may represent a promising approach to combat CMDs.

Prognostic and clinicopathological significance of MMP12 in various cancers: a meta-analysis and bioinformatics analysis.

Background: Cancer is one of the top causes of mortality worldwide. The matrix metalloproteinase MMP12 is highly expressed in some cancers, but there is a lack of meta-analyses proving the correlation between MMP12 and cancer. Materials & methods: A literature search was performed using Web of Science, PubMed and other databases. Quantitative meta-analysis of the data was carried out. The Cancer Genome Atlas was further used to validate our results. Results: High MMP12 expression was associated with poorer overall survival and poorer 5-year overall survival. Elevated expression of MMP12 predicted shorter overall survival in six cancers and worse disease-free survival in four malignancies based on validation using the Gene Expression Profiling Interactive Analysis online analysis tool. Conclusion: Elevated MMP12 expression is likely a marker of poor prognosis in various cancers.

What is this summary about? This study looked at how a gene called MMP12 affects the survival time and health of cancer patients. The MMP12 gene makes a protein that helps cancer cells grow. We studied information from 38 research studies involving 9582 patients. We wanted to learn how the gene MMP12 is connected to the prognosis and survival of people who have cancer. What was the result? The study found that patients with less MMP12 tended to live longer. Based on this, we can say that having less of the protein MMP12 may be better for patients. By contrast, high levels of MMP12 were linked to more advanced cancer stages, so this protein may aid cancer growth. What do these results mean? These findings can help doctors diagnose cancer and predict what might happen to patients. If we can control this gene, we might find new treatments to stop cancer from growing and help people live longer. However, we need to do more research to be sure about these findings and to understand this gene better.

MMP12 serves as an immune cell-related marker of disease status and prognosis in lung squamous cell carcinoma.

Background: Worldwide, lung squamous cell carcinoma (LUSC) has wreaked havoc on humanity. Matrix metallopeptidase 12 (MMP12) plays an essential role in a variety of cancers. This study aimed to reveal the expression, clinical significance, and potential molecular mechanisms of MMP12 in LUSC. Methods: There were 2,738 messenger RNA (mRNA) samples from several multicenter databases used to detect MMP12 expression in LUSC, and 125 tissue samples were validated by immunohistochemistry (IHC) experiments. Receiver operator characteristic (ROC) curves, Kaplan-Meier curves, and univariate and multivariate Cox regression analyses were used to assess the clinical value of MMP12 in LUSC. The potential molecular mechanisms of MMP12 were explored by gene enrichment analysis and immune correlation analysis. Furthermore, single-cell sequencing was used to determine the distribution of MMP12 in multiple tumor microenvironment cells. Results: MMP12 was significantly overexpressed at the mRNA level (p < 0.05, SMD = 3.13, 95% CI [2.51-3.75]), which was verified at the protein level (p < 0.001) by internal IHC experiments. MMP12 expression could be used to differentiate LUSC samples from normal samples, and overexpression of MMP12 itself implied a worse clinical prognosis and higher levels of immune cell infiltration in LUSC patients. MMP12 was involved in cancer development and progression through two immune-related signaling pathways. The high expression of MMP12 in LUSC might act as an antigen-presenting cell-associated tumor neoantigen and activate the body's immune response. Conclusions: MMP12 expression is upregulated in LUSC and high expression of MMP12 serves as a risk factor for LUSC patients. MMP12 may be involved in cancer development by participating in immune-related signaling pathways and elevating the level of immune cell infiltration.

Apoptosis inhibitor of macrophage (AIM)/CD5L is involved in the pathogenesis of COPD.

BACKGROUND: Alveolar macrophages (AMs) and AM-produced matrix metalloprotease (MMP)-12 are known to play critical roles in the pathogenesis of chronic obstructive pulmonary disease (COPD). The apoptosis inhibitor of the macrophages (AIM)/CD5 molecule-like (CD5L) is a multifunctional protein secreted by the macrophages that mainly exists in the blood in a combined form with the immunoglobulin (Ig)M pentamer. Although AIM has both facilitative and suppressive roles in various diseases, its role in COPD remains unclear. METHODS: We investigated the role of AIM in COPD pathogenesis using porcine pancreas elastase (PPE)-induced and cigarette smoke-induced emphysema mouse models and an in vitro model using AMs. We also analyzed the differences in the blood AIM/IgM ratio among nonsmokers, healthy smokers, and patients with COPD and investigated the association between the blood AIM/IgM ratio and COPD exacerbations and mortality in patients with COPD. RESULTS: Emphysema formation, inflammation, and cell death in the lungs were attenuated in AIM-/- mice compared with wild-type (WT) mice in both PPE- and cigarette smoke-induced emphysema models. The PPE-induced increase in MMP-12 was attenuated in AIM-/- mice at both the mRNA and protein levels. According to in vitro experiments using AMs stimulated with cigarette smoke extract, the MMP-12 level was decreased in AIM-/- mice compared with WT mice. This decrease was reversed by the addition of recombinant AIM. Furthermore, an analysis of clinical samples showed that patients with COPD had a higher blood AIM/IgM ratio than healthy smokers. Additionally, the blood AIM/IgM ratio was positively associated with disease severity in patients with COPD. A higher AIM/IgM ratio was also associated with a shorter time to the first COPD exacerbation and higher all-cause and respiratory mortality. CONCLUSIONS: AIM facilitates the development of COPD by upregulating MMP-12. Additionally, a higher blood AIM/IgM ratio was associated with poor prognosis in patients with COPD. TRIAL REGISTRATION: This clinical study, which included nonsmokers, healthy smokers, and smokers with COPD, was approved by the Ethics Committee of the Hokkaido University Hospital (012-0075, date of registration: September 5, 2012). The Hokkaido COPD cohort study was approved by the Ethics Committee of the Hokkaido University School of Medicine (med02-001, date of registration: December 25, 2002).

Elevated levels of MMP12 sourced from macrophages are associated with poor prognosis in urothelial bladder cancer.

BACKGROUND: Urothelial bladder cancer is most frequently diagnosed at the non-muscle-invasive stage (NMIBC). However, recurrences and interventions for intermediate and high-risk NMIBC patients impact the quality of life. Biomarkers for patient stratification could help to avoid unnecessary interventions whilst indicating aggressive measures when required. METHODS: In this study, immuno-oncology focused, multiplexed proximity extension assays were utilised to analyse plasma (n = 90) and urine (n = 40) samples from 90 newly-diagnosed and treatment-naïve bladder cancer patients. Public single-cell RNA-sequencing and microarray data from patient tumour tissues and murine OH-BBN-induced urothelial carcinomas were also explored to further corroborate the proteomic findings. RESULTS: Plasma from muscle-invasive, urothelial bladder cancer patients displayed higher levels of MMP7 (p = 0.028) and CCL23 (p = 0.03) compared to NMIBC patients, whereas urine displayed higher levels of CD27 (p = 0.044) and CD40 (p = 0.04) in the NMIBC group by two-sided Wilcoxon rank-sum tests. Random forest survival and multivariable regression analyses identified increased MMP12 plasma levels as an independent marker (p < 0.001) associated with shorter overall survival (HR = 1.8, p < 0.001, 95% CI:1.3-2.5); this finding was validated in an independent patient OLINK cohort, but could not be established using a transcriptomic microarray dataset. Single-cell transcriptomics analyses indicated tumour-infiltrating macrophages as a putative source of MMP12. CONCLUSIONS: The measurable levels of tumour-localised, immune-cell-derived MMP12 in blood suggest MMP12 as an important biomarker that could complement histopathology-based risk stratification. As MMP12 stems from infiltrating immune cells rather than the tumor cells themselves, analyses performed on tissue biopsy material risk a biased selection of biomarkers produced by the tumour, while ignoring the surrounding microenvironment.

Illuminating the potential causality of serum level of matrix metalloproteinases and the occurrence of cardiovascular and cerebrovascular diseases: a Mendelian randomization study.

BACKGROUND: It is still not clear that whether the expression levels of matrix metalloproteinases (MMPs) family are associated with cardiovascular and cerebrovascular diseases (CCDs) in genetic level. We explored the causal role of 12 members of MMPs in CCDs with mendelian randomization (MR) method to facilitate further exploring the underlying mechanisms. METHODS: The relationship between MMPs and CCDs including intracerebral hemorrhage (ICH), hypertension, coronary heart disease (CHD), atrial fibrillation (AF), and outstanding risk factors of type II diabetes were determined with the inverse variance-weighted (IVW) method. The sensitivity analyses including MR-Egger regression, weighted median estimation, and MR pleiotropy residual sum and outlier were utilized to test the robustness of the results generated from the MR method. RESULTS: We found that a higher serum level of MMP-12 was related to a lower risk of ICH (OR = 0.8287, 95% CI: 0.7526-0.9125, p = 0.00013), but not hypertension, CHD, type II diabetes or AF. And our study also revealed that a higher serum level of MMP-8 could result in a lower risk of hypertension (OR = 0.9976, 95% CI: 0.9964-0.9988, p = 0.00012) and AF (OR = 0.9851, 95% CI: 0.9741-0.9963, p = 0.0092), but not ICH, CHD or type II diabetes. All other members of MMPs other than MMP-8 and MMP-12 showed no statistical association with CCDs according to this study. Sensitivity analyses confirmed the reliability of our results. CONCLUSIONS: We provided statistical evidences for a potential causal relationship between MMP-12 and ICH, as well as MMP-8 and hypertension, while other MMPs showed weaker association with CCDs. The underlying mechanisms need to be established in the future.

Homeostatic, Non-Canonical Role of Macrophage Elastase in Vascular Integrity.

BACKGROUND: Matrix metalloproteinase (MMP)-12 is highly expressed in abdominal aortic aneurysms and its elastolytic function has been implicated in the pathogenesis. This concept is challenged, however, by conflicting data. Here, we sought to revisit the role of MMP-12 in abdominal aortic aneurysm. METHODS: Apoe-/- and Mmp12-/-/Apoe-/- mice were infused with Ang II (angiotensin). Expression of neutrophil extracellular traps (NETs) markers and complement component 3 (C3) levels were evaluated by immunostaining in aortas of surviving animals. Plasma complement components were analyzed by immunoassay. The effects of a complement inhibitor, IgG-FH1-5 (factor H-immunoglobulin G), and macrophage-specific MMP-12 deficiency on adverse aortic remodeling and death from rupture in Ang II-infused mice were determined. RESULTS: Unexpectedly, death from aortic rupture was significantly higher in Mmp12-/-/Apoe-/- mice. This associated with more neutrophils, citrullinated histone H3 and neutrophil elastase, markers of NETs, and C3 levels in Mmp12-/- aortas. These findings were recapitulated in additional models of abdominal aortic aneurysm. MMP-12 deficiency also led to more pronounced elastic laminae degradation and reduced collagen integrity. Higher plasma C5a in Mmp12-/- mice pointed to complement overactivation. Treatment with IgG-FH1-5 decreased aortic wall NETosis and reduced adverse aortic remodeling and death from rupture in Ang II-infused Mmp12-/- mice. Finally, macrophage-specific MMP-12 deficiency recapitulated the effects of global MMP-12 deficiency on complement deposition and NETosis, as well as adverse aortic remodeling and death from rupture in Ang II-infused mice. CONCLUSIONS: An MMP-12 deficiency/complement activation/NETosis pathway compromises aortic integrity, which predisposes to adverse vascular remodeling and abdominal aortic aneurysm rupture. Considering these new findings, the role of macrophage MMP-12 in vascular homeostasis demands re-evaluation of MMP-12 function in diverse settings.

MMP-12 knockdown prevents secondary brain damage after ischemic stroke in mice.

We previously reported that increased expression of matrix metalloproteinase-12 (MMP-12) mediates blood-brain barrier disruption via tight junction protein degradation after focal cerebral ischemia in rats. Currently, we evaluated whether MMP-12 knockdown protects the post-stroke mouse brain and promotes better functional recovery. Adult male mice were injected with negative siRNA or MMP-12 siRNA (intravenous) at 5 min of reperfusion following 1 h transient middle cerebral artery occlusion. MMP-12 knockdown significantly reduced the post-ischemic infarct volume and improved motor and cognitive functional recovery. Mechanistically, MMP-12 knockdown ameliorated degradation of tight junction proteins zonula occludens-1, claudin-5, and occludin after focal ischemia. MMP-12 knockdown also decreased the expression of inflammatory mediators, including monocyte chemoattractant protein-1, tumor necrosis factor-α, and interleukin-6, and the expression of apoptosis marker cleaved caspase-3 after ischemia. Overall, the present study indicates that MMP-12 promotes secondary brain damage after stroke and hence is a promising stroke therapeutic target.

Toll-like receptor and matrix metalloproteinase single-nucleotide polymorphisms, haplotypes, and polygenic risk score differentiated between tuberculosis disease and infection.

OBJECTIVES: The association of toll-like receptors (TLRs) and matrix metalloproteinases (MMPs) single-nucleotide polymorphisms (SNPs) among latent tuberculosis (TB) infection and active TB remained less studied. METHODS: We recruited participants with TB disease (active TB) (n = 400) and TB infection (latent TB infection) (n = 203) in this study. We genotyped SNPs in TLR1, TLR2, TLR4, MMP1, MMP8, MMP9, MMP12, and tissue inhibitor of MMP2. Single-variant analysis and haplotype analysis were performed, and a polygenic risk score (PRS) was created. RESULTS: We found that SNPs in TLR1 (rs5743580, rs5743551), TLR2 (rs3804100), and MMP8 (rs2508383) were associated with different TB disease status risks. TLR1 rs5743580 was associated with a higher risk of TB disease status in genotypic, recessive, and additive models. TLR2 rs3804100 polymorphisms demonstrated significant association with TB disease status in genotypic, dominant, and additive models. In the haplotype analysis, the TLR1 haplotype was associated with a higher risk of TB disease, and the MMP12 haplotype was associated with a lower risk of TB disease. A PRS using 3 SNPs was associated with a higher risk of TB disease. CONCLUSION: This study revealed that SNP variants in TLR1, TLR2, and MMP8 differed among TB infection and disease. Haplotypes and PRS could potentially help predict TB disease status.

ADAM-10 Regulates MMP-12 during Lipopolysaccharide-Induced Inflammatory Response in Macrophages.

A disintegrin and metalloprotease 10 (ADAM-10), a member of the ADAM protease family, has biological activities related to TNF-α activation, cell adhesion, and migration, among other functions. Macrophages are important immune cells that are involved in the inflammatory response of the body. ADAM-10 is involved in inflammatory responses, but the specific regulatory mechanisms are not fully understood. In this study, we investigated the regulatory mechanism of ADAM-10 in the lipopolysaccharide-promoted proliferation (LPS) of the macrophage inflammatory response. Differentially expressed or regulated proteins were identified in interfered ADAM-10 (sh ADAM-10) macrophages using tandem mass tag (TMT) proteomics. The changes and regulatory role of ADAM-10 during LPS-induced inflammatory response in normal, interfering, and overexpressing ADAM-10 (EX ADAM-10) cells were determined. Results indicated that ADAM-10 interference affected inflammation-related pathways and reduced matrix metalloproteinase 12 (MMP-12) protein levels, as identified by TMT proteomics. In normal cells, LPS decreased ADAM-10 gene expression, but promoted ADAM-10 secretion, MMP-12 and TNF-α gene expression, and MMP-12, iNOS, IL-10, and cyclinD1 protein expression. Additionally, ADAM-10 knockdown decreased macrophage viability in sh-ADAM-10 cells. Moreover, an MMP-12 inhibitor had no impact on the viability effect of LPS on cells or the expression of ADAM-10. iNOS expression decreased, whereas IL-10 expression increased after ADAM-10 depletion. ADAM-10 knockdown decreased MMP-12, iNOS, TNF-α, IL-1ß, and FKN, while overexpression had an opposite effect. ADAM-10 overexpression further increased MMP-12, iNOS, and TNF-α gene expression in response to LPS. Cell viability was increased in EX ADAM-10 cells, and ADAM-10 secretion was further increased in the EX and LPS groups. Flow cytometry and immunofluorescence staining revealed that EX-ADAM 10 cells had increased iNOS expression, which acted as an IL-6 expression driver. In summary, we found that ADAM-10 is activated by LPS and positively participates in LPS-stimulated macrophage inflammatory responses by positively regulating MMP-12 during the inflammatory process.

Identification of core genes associated with the anti-atherosclerotic effects of Salvianolic acid B and immune cell infiltration characteristics using bioinformatics analysis.

BACKGROUND: Atherosclerosis (AS) is the greatest contributor to pathogenesis of atherosclerotic cardiovascular disease (ASCVD), which is associated with increased mortality and reduced quality of life. Early intervention to mitigate AS is key to prevention of ASCVD. Salvianolic acid B (Sal B) is mainly extracted from root and rhizome of Salvia Miltiorrhiza Bunge, and exerts anti-atherosclerotic effect. The purpose of this study was to screen for anti-AS targets of Sal B and to characterize immune cell infiltration in AS. METHODS: We identified targets of Sal B using SEA ( http://sea.bkslab.org/ ) and SIB ( https://www.sib.swiss/ ) databases. GSE28829 and GSE43292 datasets were obtained from Gene Expression Omnibus database. We identified differentially expressed genes (DEGs) and performed enrichment analysis. Weighted gene co-expression network analysis (WGCNA) was used to determine the most relevant module associated with atherosclerotic plaque stability. Intersecting candidate genes were evaluated by generating receiver operating characteristic (ROC) curves and molecular docking. Then, immune cell types were identified using CIBERSOFT and single-sample gene set enrichment analysis (ssGSEA), the relationship between candidate genes and immune cell infiltration was evaluated. Finally, a network-based approach to explore the candidate genes relationship with microRNAs (miRNAs) and Transcription factors (TFs). RESULTS: MMP9 and MMP12 were been selected as candidate genes from 64 Sal B-related genes, 81 DEGs and turquoise module with 220 genes. ROC curve results showed that MMP9 (AUC = 0.815, P<0.001) and MMP12 (AUC = 0.763, P<0.001) were positively associated with advanced atherosclerotic plaques. The results of immune infiltration showed that B cells naive, B cells memory, Plasma cells, T cells CD8, T cells CD4 memory resting, T cells CD4 memory activated, T cells regulatory (Tregs), T cells gamma delta, NK cells activated, Monocytes, and Macrophages M0 may be involved in development of AS, and the candidate genes MMP9 and MMP12 were associated with these immune cells to different degrees. What' s more, miR-34a-5p and FOXC1, JUN maybe the most important miRNA and TFs. CONCLUSION: The anti-AS effects of Sal B may be related to MMP9 and MMP12 and associated with immune cell infiltration, which is expected to be used in the early intervention of AS.

Deletion of matrix metalloproteinase-12 compromises mechanical homeostasis and leads to an aged aortic phenotype in young mice.

Mechanical homeostasis emerges following normal development of the arterial wall and requires thereafter a slow balanced degradation and deposition of extracellular matrix constituents within an unchanging mechanical state. Recent findings suggest that homeostasis is compromised in arterial aging, which contributes to the structural stiffening that is characteristic of aged central arteries. Matrix metalloproteinases (MMPs) have strong proteolytic activity and play fundamental roles in matrix turnover. Here, we use Mmp12-/- mice to examine effects of a potent metalloelastase, MMP-12, on the biomechanical phenotype of the thoracic and abdominal aorta in young and naturally aged mice. A key finding is that germline deletion of the gene (Mmp12) that encodes MMP-12 alters biomechanical properties from normal more in young adult than in older adult mice. Consequently, percent changes in biomechanical properties during aortic aging are greater in wild-type than in MMP-12 deficient mice, though with similar overall decreases in elastic energy storage and distensibility and increases in calculated pulse wave velocity. Reduced elastic energy storage compromises the ability of the aorta to augment antegrade and retrograde blood flow while an increased pulse wave velocity can adversely affect end organs, both conditions being characteristic of aortic aging in humans. In summary, MMP-12 is fundamental for establishing homeostatic values of biomechanical metrics in the aorta and its absence leads to a pre-aged aortic phenotype in young mice.

Epigenetic aberrations of gene expression in a rat model of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is mostly triggered by environmental and life-style factors and may involve epigenetic aberrations. However, a comprehensive documentation of the link between the dysregulated epigenome, transcriptome, and liver carcinogenesis is lacking. In the present study, Fischer-344 rats were fed a choline-deficient (CDAA, cancer group) or choline-sufficient (CSAA, healthy group) L-amino acid-defined diet. At the end of 52 weeks, transcriptomic alterations in livers of rats with HCC tumours and healthy livers were investigated by RNA sequencing. DNA methylation and gene expression were assessed by pyrosequencing and quantitative reverse-transcription PCR (qRT-PCR), respectively. We discovered 1,848 genes that were significantly differentially expressed in livers of rats with HCC tumours (CDAA) as compared with healthy livers (CSAA). Upregulated genes in the CDAA group were associated with cancer-related functions, whereas macronutrient metabolic processes were enriched by downregulated genes. Changes of highest magnitude were detected in numerous upregulated genes that govern key oncogenic signalling pathways, including Notch, Wnt, Hedgehog, and extracellular matrix degradation. We further detected perturbations in DNA methylating and demethylating enzymes, which was reflected in decreased global DNA methylation and increased global DNA hydroxymethylation. Four selected upregulated candidates, Mmp12, Jag1, Wnt4, and Smo, demonstrated promoter hypomethylation with the most profound decrease in Mmp12. MMP12 was also strongly overexpressed and hypomethylated in human HCC HepG2 cells as compared with primary hepatocytes, which coincided with binding of Ten-eleven translocation 1 (TET1). Our findings provide comprehensive evidence for gene expression changes and dysregulated epigenome in HCC pathogenesis, potentially revealing novel targets for HCC prevention/treatment.