Circulating myeloid-derived MMP8 in stress susceptibility and depression.

Psychosocial stress has profound effects on the body, including the immune system and the brain1,2. Although a large number of pre-clinical and clinical studies have linked peripheral immune system alterations to stress-related disorders such as major depressive disorder (MDD)3, the underlying mechanisms are not well understood. Here we show that expression of a circulating myeloid cell-specific proteinase, matrix metalloproteinase 8 (MMP8), is increased in the serum of humans with MDD as well as in stress-susceptible mice following chronic social defeat stress (CSDS). In mice, we show that this increase leads to alterations in extracellular space and neurophysiological changes in the nucleus accumbens (NAc), as well as altered social behaviour. Using a combination of mass cytometry and single-cell RNA sequencing, we performed high-dimensional phenotyping of immune cells in circulation and in the brain and demonstrate that peripheral monocytes are strongly affected by stress. In stress-susceptible mice, both circulating monocytes and monocytes that traffic to the brain showed increased Mmp8 expression following chronic social defeat stress. We further demonstrate that circulating MMP8 directly infiltrates the NAc parenchyma and controls the ultrastructure of the extracellular space. Depleting MMP8 prevented stress-induced social avoidance behaviour and alterations in NAc neurophysiology and extracellular space. Collectively, these data establish a mechanism by which peripheral immune factors can affect central nervous system function and behaviour in the context of stress. Targeting specific peripheral immune cell-derived matrix metalloproteinases could constitute novel therapeutic targets for stress-related neuropsychiatric disorders.

Association study for the role of MMP8 gene polymorphisms in Colorectal cancer susceptibility.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignant tumors, influenced by several genetic loci in its clinical phenotypes. The aim of this study was to determine the relationship between the MMP8 gene polymorphism and CRC risk in the Chinese Han population. METHOD: This study recruited 688 CRC patients and 690 healthy controls. The relationship between MMP8 polymorphism and CRC susceptibility was assessed by calculating the odds ratio (OR) and 95% confidence interval (CI) after stratifying by age, gender, body mass index (BMI), smoking, and alcohol consumption under a multi-genetic model. RESULTS: MMP8 rs3740938 was associated with increased CRC predisposition (p = 0.016, OR = 1.24, 95% CI: 1.04-1.48), and this association was detected particularly in subjects aged > 60 years, females, people with BMI > 24 kg/m2, smokers, and drinkers. Moreover, rs3740938 was found to be associated with the pathological type of rectal cancer. CONCLUSIONS: Our results first displayed that rs3740938 in MMP8 was a risk factor for CRC predisposition. This finding may provide a new biological perspective for understanding the role of the MMP8 gene in CRC pathogenesis.

Chromatin insulation orchestrates matrix metalloproteinase gene cluster expression reprogramming in aggressive breast cancer tumors.

BACKGROUND: Triple-negative breast cancer (TNBC) is an aggressive subtype that exhibits a high incidence of distant metastases and lacks targeted therapeutic options. Here we explored how the epigenome contributes to matrix metalloprotease (MMP) dysregulation impacting tumor invasion, which is the first step of the metastatic process. METHODS: We combined RNA expression and chromatin interaction data to identify insulator elements potentially associated with MMP gene expression and invasion. We employed CRISPR/Cas9 to disrupt the CCCTC-Binding Factor (CTCF) binding site on an insulator element downstream of the MMP8 gene (IE8) in two TNBC cellular models. We characterized these models by combining Hi-C, ATAC-seq, and RNA-seq with functional experiments to determine invasive ability. The potential of our findings to predict the progression of ductal carcinoma in situ (DCIS), was tested in data from clinical specimens. RESULTS: We explored the clinical relevance of an insulator element located within the Chr11q22.2 locus, downstream of the MMP8 gene (IE8). This regulatory element resulted in a topologically associating domain (TAD) boundary that isolated nine MMP genes into two anti-correlated expression clusters. This expression pattern was associated with worse relapse-free (HR = 1.57 [1.06 - 2.33]; p = 0.023) and overall (HR = 2.65 [1.31 - 5.37], p = 0.005) survival of TNBC patients. After CRISPR/Cas9-mediated disruption of IE8, cancer cells showed a switch in the MMP expression signature, specifically downregulating the pro-invasive MMP1 gene and upregulating the antitumorigenic MMP8 gene, resulting in reduced invasive ability and collagen degradation. We observed that the MMP expression pattern predicts DCIS that eventually progresses into invasive ductal carcinomas (AUC = 0.77, p < 0.01). CONCLUSION: Our study demonstrates how the activation of an IE near the MMP8 gene determines the regional transcriptional regulation of MMP genes with opposing functional activity, ultimately influencing the invasive properties of aggressive forms of breast cancer.

Altered Peripheral Blood Gene Expression in Childhood Cancer Survivors With Anthracycline-Induced Cardiomyopathy - A COG-ALTE03N1 Report.

Background Anthracycline-induced cardiomyopathy is a leading cause of premature death in childhood cancer survivors, presenting a need to understand the underlying pathogenesis. We sought to examine differential blood-based mRNA expression profiles in anthracycline-exposed childhood cancer survivors with and without cardiomyopathy. Methods and Results We designed a matched case-control study (Children's Oncology Group-ALTE03N1) with mRNA sequencing on total RNA from peripheral blood in 40 anthracycline-exposed survivors with cardiomyopathy (cases) and 64 matched survivors without (controls). DESeq2 identified differentially expressed genes. Ingenuity Pathway Analyses (IPA) and Gene Set Enrichment Analyses determined the potential roles of altered genes in biological pathways. Functional validation was performed by gene knockout in human-induced pluripotent stem cell-derived cardiomyocytes using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) technology. Median age at primary cancer diagnosis for cases and controls was 8.2 and 9.7 years, respectively. Thirty-six differentially expressed genes with fold change ≥±2 were identified; 35 were upregulated. IPA identified "hepatic fibrosis" and "iron homeostasis" pathways to be significantly modulated by differentially expressed genes, including toxicology functions of myocardial infarction, cardiac damage, and cardiac dilation. Leading edge analysis from Gene Set Enrichment Analyses identified lactate dehydrogenase A (LDHA) and cluster of differentiation 36 (CD36) genes to be significantly upregulated in cases. Interleukin 1 receptor type 1, 2 (IL1R1, IL1R2), and matrix metalloproteinase 8, 9 (MMP8, MMP9) appeared in multiple canonical pathways. LDHA-knockout human-induced pluripotent stem cell-derived cardiomyocytes showed increased sensitivity to doxorubicin. Conclusions We identified differential mRNA expression profiles in peripheral blood of anthracycline-exposed childhood cancer survivors with and without cardiomyopathy. Upregulation of LDHA and CD36 genes suggests metabolic perturbations in a failing heart. Dysregulation of proinflammatory cytokine receptors IL1R1 and IL1R2 and matrix metalloproteinases, MMP8 and MMP9 indicates structural remodeling that accompanies the clinical manifestation of symptomatic cardiotoxicity.

Impact of Matrix Metalloproteinase-8 Genotypes on Colorectal Cancer Risk in Taiwan.

BACKGROUND/AIM: This study aimed to investigate the involvement of matrix metalloproteinase-8 (MMP-8) genotypes in the development of colorectal cancer (CRC). MATERIALS AND METHODS: The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to analyze the genotypes of MMP-8 C-799T (rs11225395), Val436Ala (rs34009635), and Lys460Thr (rs35866072) in 362 patients with CRC and 362 controls. Additionally, the potential associations between these genotypes and factors such as age, sex, smoking, alcohol consumption, and body mass index (BMI) status in relation to CRC risk were also assessed. RESULTS: No significant differences in the distribution of MMP-8 rs11225395 genotypes were found between the control and case groups (p for trend=0.3836). Logistic regression analysis demonstrated that individuals with the MMP-8 rs11225395 variant CT and TT genotypes had a 0.83 and 0.77-fold risk of CRC, respectively. Moreover, carriers of the rs11225395 CT+TT genotypes were not associated with CRC risk either (p=0.2063). Furthermore, individuals with the MMP-8 rs11225395 TT genotype exhibited significantly lower odds of CRC risk compared to those with the CC genotype among non-smokers (p=0.0379). No significant associations were observed with respect to MMP-8 rs34009635 or rs35866072. CONCLUSION: The analyzed genotypes of MMP-8 play a minor role in determining individual susceptibility to CRC risk.

Solar radiation leads to increased collagenase gene expression (MMP1) in HERDA (Hereditary equine regional dermal asthenia) affected horses and may explain the typical dorsal distribution of their lesions.

BACKGROUND: Hereditary equine regional dermal asthenia (HERDA) is a genetic disease that alters collagen biosynthesis. Affected horses exhibit fragile, hyperextensible skin, especially over the dorsal region. Although ultraviolet (UV) radiation seems to contribute to the regional distribution of lesions and worsening of clinical signs, the molecular mechanisms involved are largely unknown. OBJECTIVES: To evaluate the effect of solar radiation on matrix metalloproteinase MMP1, MMP8 and MMP13 gene expression in the dorsal and ventral skin of HERDA-affected and HERDA-unaffected horses [wild-type (WT) horses]. ANIMALS: Six HERDA-affected and six unaffected Quarter horses (WT) were paired according to age, sex and coat colour. MATERIALS AND METHODS: Horses were submitted to 30 day sunlight restriction, followed by 15 day sunlight exposure. Dorsal and ventral skin biopsies were obtained at six sampling times over 45 days. The expression of MMP1, MMP8 and MMP13 genes was measured by quantitative PCR. RESULTS: Although solar radiation modulated MMP1, MMP8 and MMP13 expression, the effects were more pronounced on MMP1. Sun exposure for three days significantly upregulated MMP1 in the dorsal region when compared to the ventral skin in both unaffected and HERDA-affected horses. CONCLUSIONS AND CLINICAL RELEVANCE: This study shows that solar irradiation leads to upregulation of skin collagenase genes particularly MMP1 in the dorsal, sun-exposed skin of horses. Furthermore, this was more marked in HERDA-affected horses. The increased activity of collagenases on the disorganised collagen present in HERDA affected horses would explain why UV radiation leads to deterioration of clinical signs in affected individuals.

Mesenchymal Stem Cells Promote Wound Healing and Effects on Expression of Matrix Metalloproteinases-8 and 9 in the Wound Tissue of Diabetic Rats.

Diabetic foot ulcer (DFU) is a multifactorial complication of diabetes, mainly manifested as infection, ulcer, or destruction of deep tissue, and there is currently no effective treatment. Several preclinical and clinical studies have proved that the transplantation of mesenchymal stem cells (MSCs) improved wound healing. In this study, we evaluated the therapeutic efficacy of human umbilical cord (hUC-MSCs) in DFU rat model. One dose of hUC-MSCs (1 × 106 cells) was subcutaneously injected around wounds in male Sprague-Dawley rats. Wound healing was evaluated macroscopically (wound closure) every 3 days. In addition, we measured growth factors and specific proteins [matrix metalloproteinases (MMPs)-9 and MMP-8] on Day 14 post hUC-MSC transplantation. Results showed significant differences in the wound healing kinetics of lesions that received hUC-MSCs compared to lesions that received vehicle (phosphate buffered saline; P < 0.05). Enzyme-linked immunosorbent assay analyses indicated that MMP-9 protein contents were significantly upregulated in DFU animals, while MMP-8 was downregulated compared to the diabetic rats (P < 0.05). After MSC treatment, the level of MMP-9 and MMP-8 decreased and increased compared to the vehicle group, respectively. These findings suggest that hUC-MSC transplantation can ameliorate the healing process of DFU rats and a potential mechanism through which MSCs enhance DFU wound healing by decreasing MMP-9 expression and increasing MMP-8 expression. This study represents a promising opportunity to gain insight into how MSCs mediate wound healing.

Distinct Expression Patterns of Genes Coding for Biological Response Modifiers Involved in Inflammatory Responses and Development of Fibrosis in Chronic Hepatitis C: Upregulation of SMAD-6 and MMP-8 and Downregulation of CAV-1, CTGF, CEBPB, PLG, TIMP-3, MMP-1, ITGA-1, ITGA-2 and LOX.

Background and Objectives: The aim of this study was to analyze the expression of genes on transcriptomic levels involved in inflammatory immune responses and the development of fibrosis in patients with chronic hepatitis C. Materials and Methods: Expression patterns of 84 selected genes were analyzed with real-time quantitative RT PCR arrays in the peripheral blood of treatment-naive patients with chronic hepatitis C and healthy controls. The panel included pro- and anti-fibrotic genes, genes coding for extracellular matrix (EMC) structural constituents and remodeling enzymes, cell adhesion molecules, inflammatory cytokines, chemokines and growth factors, signal transduction members of the transforming growth factor- beta (TGF-ß) superfamily, transcription factors, and genes involved in epithelial to mesenchymal transition. Results: The expression of SMAD-6 coding for a signal transduction TGF-beta superfamily member as well as MMP-8 coding for an ECM protein were significantly increased in CHC patients compared with controls. Conclusions: Chronic hepatitis C was also characterized by a significant downregulation of a set of genes including CAV-1, CTGF, TIMP-3, MMP-1, ITGA-1, LOX, ITGA-2, PLG and CEBPB encoding various biological response modifiers and transcription factors. Our results suggest that chronic hepatitis C is associated with distinct patterns of gene expression modulation in pathways associated with the regulation of immune responses and development of fibrosis.

Targeted Inhibition of Matrix Metalloproteinase-8 Prevents Aortic Dissection in a Murine Model.

Aortic dissection (AD) is a lethal aortic pathology without effective medical treatments since the underlying pathological mechanisms responsible for AD remain elusive. Matrix metalloproteinase-8 (MMP8) has been previously identified as a key player in atherosclerosis and arterial remodeling. However, the functional role of MMP8 in AD remains largely unknown. Here, we report that an increased level of MMP8 was observed in 3-aminopropionitrile fumarate (BAPN)-induced murine AD. AD incidence and aortic elastin fragmentation were markedly reduced in MMP8-knockout mice. Importantly, pharmacologic inhibition of MMP8 significantly reduced the AD incidence and aortic elastin fragmentation. We observed less inflammatory cell accumulation, a lower level of aortic inflammation, and decreased smooth muscle cell (SMC) apoptosis in MMP8-knockout mice. In line with our previous observation that MMP8 cleaves Ang I to generate Ang II, BAPN-treated MMP8-knockout mice had increased levels of Ang I, but decreased levels of Ang II and lower blood pressure. Additionally, we observed a decreased expression level of vascular cell adhesion molecule-1 (VCAM1) and a reduced level of reactive oxygen species (ROS) in MMP8-knockout aortas. Mechanistically, our data show that the Ang II/VCAM1 signal axis is responsible for MMP8-mediated inflammatory cell invasion and transendothelial migration, while MMP8-mediated SMC inflammation and apoptosis are attributed to Ang II/ROS signaling. Finally, we observed higher levels of aortic and serum MMP8 in patients with AD. We therefore provide new insights into the molecular mechanisms underlying AD and identify MMP8 as a potential therapeutic target for this life-threatening aortic disease.

The roles of MMP8/MMP10 polymorphisms in ischemic stroke susceptibility.

BACKGROUND: Ischemic stroke (IS), a multifactorial and polygenic disease, is the most common cause of death. This study aimed to determine the roles of MMP8/MMP10 polymorphisms in IS susceptibility in the Chinese Han population. METHODS: MMP8 rs1940475 and rs3765620, and MMP10 rs17860949 from 700 IS patients and 700 controls were genotyped by the MassARRAY iPLEX platform. The impact of polymorphisms on IS risk was evaluated by logistic regression analysis. RESULTS: Our study indicated that rs17860949 in MMP10 was significantly associated with a reduced risk of IS (OR = 0.632, p = .002). Precisely, stratification analysis showed that rs17860949 was relate to a decreased susceptibility to IS in patients aged > 55 years (OR = 0.472, p < .001), males (OR = 0.632, p = .012), nonsmokers (OR = 0.610, p = .017), and nondrinkers (OR = 0.559, p = .006). All these significant findings were verified by false-positive report probability test. Furthermore, GG genotype and AG genotype in MMP8 rs3765620 polymorphism were related to a reduced triglycerides concentration (p = .018). CONCLUSION: Our study suggests that rs17860949 in MMP10 may play a protective role in IS in the Chinese Han population.

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.

Atorvastatin attenuates NS1 (Non-structural protein-1) of dengue type-2 serotype-induced expressions of matrix metalloproteinases in HL-60 cells, differentiated to neutrophils: Implications for the immunopathogenesis of dengue viral disease.

BACKGROUND: The dengue is a vector borne viral infection in humans. Bite of mosquito infected with a dengue virus transmits the disease. The neutrophils support more to the innate immune response by switching to infected tissues and triggering immunomodulatory mechanisms including the release of proteases and host defence peptides. METHODS: Cell viability by MTT and trypan blue dye exclusion assay, bright field microscopy for assessment of cell morphology, cytokines measurements by ELISA, estimation of protein by Bradford assay were done. Assessments of matrix metalloproteinase genes mRNA expressions were done using real-time PCR. RESULTS: In the present study, we have for the first time unveiled that, NS1 antigen of dengue type-2 serotype, induce and stimulate the neutrophils cells to express high levels of matrix metalloproteases. NS1 exposure of HL-60 cells differentiated to neutrophils affected cell morphology and in 24 h of exposure. We have demonstrated that, the NS1 antigen has induced MMP-2, MMP-14 and MMP-9 expressions in neutrophils in a 24hrs exposure time. NS1 exposure has also further upregulated MMP-1, MMP-13, and MMP-8 expressions in neutrophils in a 24hrs exposure time. Notably, treatment with atorvastatin concentrations downregulated the expression profile of the all matrix metalloprotease significantly. Importantly, NS1 antigen has significantly increased the IL-6, IL-13 release by the HL,60 cells which was reversed by atorvastatin. On the other hand, NS1 exposure enhanced the mRNA expressions of VEGF-A and VEGF-D which was reversed by atorvastatin. However, we found that, NS1 exposure reduced the mRNA expressions profile of VEGF-C, which was reversed by atorvastatin. CONCLUSION: In conclusion, we report that, neutrophils associated matrix metalloprotease are involved in the pathogenesis of dengue viral disease. VEGF growth factors may also be released by the neutrophils which may subsequently participate in the endothelial dysfunctions leading to dengue shock syndrome.

MicroRNA-320-3p promotes the progression of acute pancreatitis by blocking DNMT3a-mediated MMP8 methylation in a targeted manner.

In this research, we screened out two genes upregulated in mice with acute pancreatitis (AP) by gene sequencing: microRNA (miR)-320-3p and matrix metalloprotease 8 (MMP8). This study was designed to determine whether miR-320-3p and MMP8 participate in AP development and explore the mechanisms, with a new idea for clinical diagnosis and treatment of AP. Expression of miR-320-3p, DNA methyltransferase 3a (DNMT3a), and MMP8 in mouse pancreatic tissues and AR42J cells was tested by RT-qPCR and western blot assays. Pancreatic pathological changes, serum amylase and lipase, and inflammatory factors in mouse serum and cell supernatant were measured by hematoxylin-eosin staining, automation analyzer, and enzyme-linked immunosorbent assay, respectively. Cell proliferation and apoptosis were determined by CCK-8 assay and flow cytometry. The interaction between miR-320-3p, DNMT3a, and MMP8 was verified by luciferase activity assay, ChIP-qPCR, and MSP assay. High expression of miR-320-3p and MMP8, and low expression of DNMT3a were observed in pancreatic tissues of AP mice and caerulein-induced AP cellular model. Downregulation of miR-320-3p alleviated injury of mouse pancreas, reduced the levels of serum amylase and lipase, and blocked inflammatory factor levels in AP mice. In caerulein-induced AP cellular models, inhibiting miR-320-3p facilitated proliferation and inhibited apoptosis. Upregulation of MMP8 resulted in the opposite results, which could be reversed by simultaneous inhibition of miR-320-3p. miR-320-3p targeted DNMT3a, and downregulating miR-320-3p promoted DNMT3a expression. Moreover, DNMT3a promoted DNA methylation in MMP8 promoter region, thereby inhibiting MMP8 expression in AP mouse and cellular models. This research suggests that miR-320-3p inhibits DNMT3a to reduce MMP8 methylation and increase MMP8 expression, thereby promoting AP progression.

A common Matrix metalloproteinase 8 promoter haplotype enhances the risk for hypertension via diminished interactions with nuclear factor kappa B.

OBJECTIVES: Matrix metalloproteinase 8 (MMP8) has a prominent role in collagen turnover in blood vessels and vascular remodeling. The contribution of regulatory single nucleotide polymorphisms in MMP8 to cardiovascular diseases is unclear. We aimed to delineate the influence of MMP8 promoter variations on hypertension. METHODS: A case-control study in unrelated individuals ( n  = 2565) was carried out. Resequencing of the MMP8 proximal promoter, linkage disequilibrium analysis, genotyping of variants and regression analyses were performed. MMP8 promoter-reporter constructs were generated and expressed in human vascular endothelial cells under various conditions. RESULTS: We identified four single nucleotide polymorphisms (SNPs) in the promoter region of MMP8 : -1089A/G (rs17099452), -815G/T (rs17099451), -795C/T (rs11225395), -763A/T (rs35308160); these SNPs form three major haplotypes. Hap3 (viz., GTTT haplotype) carriers showed significant associations with hypertension in two geographically distinct human populations (e.g., Chennai: odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.16-1.86, P  = 2 × 10 -3 ; Chandigarh: OR = 1.85, 95% CI = 1.21-2.81, P  = 4 × 10 -3 ). Hap3 carriers also displayed elevated systolic blood pressure, diastolic blood pressure and mean arterial pressure levels. Hap3 promoter-reporter construct showed lower promoter activity than the wild-type (Hap1) construct. In silico analysis and molecular dynamics studies predicted diminished binding of the transcription factor nuclear factor kappa B (NF-κB) to the functional -815T allele of Hap3 compared to the -815G wild-type allele; this prediction was validated by in-vitro experiments. Hap3 displayed impaired response to tumor necrosis factor-alpha treatment, possibly due to weaker binding of NF-κB. Notably, MMP8 promoter haplotypes were identified as independent predictors of plasma MMP8 and endothelial dysfunction markers (von Willebrand factor and endothelin-1) levels. CONCLUSION: MMP8 promoter GTTT haplotype has a functional role in reducing MMP8 expression during inflammation via diminished interaction with NF-κB and in enhancing the risk of hypertension.

Lab-Attenuated Rabies Virus Facilitates Opening of the Blood-Brain Barrier by Inducing Matrix Metallopeptidase 8.

Infection with laboratory-attenuated rabies virus (RABV), but not wild-type (wt) RABV, can enhance the permeability of the blood-brain barrier (BBB), which is considered a key determinant for RABV pathogenicity. A previous study showed that the enhancement of BBB permeability is directly due not to RABV infection but to virus-induced inflammatory molecules. In this study, the effect of the matrix metallopeptidase (MMP) family on the permeability of the BBB during RABV infection was evaluated. We found that the expression level of MMP8 was upregulated in mice infected with lab-attenuated RABV but not with wt RABV. Lab-attenuated RABV rather than wt RABV activates inflammatory signaling pathways mediated by the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Activated NF-κB (p65) and AP-1 (c-Fos) bind to the MMP8 promoter, resulting in upregulation of its transcription. Analysis of mouse brains infected with the recombinant RABV expressing MMP8 indicated that MMP8 enhanced BBB permeability, leading to infiltration of inflammatory cells into the central nervous system (CNS). In brain-derived endothelial cells, treatment with MMP8 recombinant protein caused the degradation of tight junction (TJ) proteins, and the application of an MMP8 inhibitor inhibited the degradation of TJ proteins after RABV infection. Furthermore, an in vivo experiment using an MMP8 inhibitor during RABV infection demonstrated that BBB opening was diminished. In summary, our data suggest that the infection of lab-attenuated RABV enhances the BBB opening by upregulating MMP8. IMPORTANCE The ability to change BBB permeability was associated with the pathogenicity of RABV. BBB permeability was enhanced by infection with lab-attenuated RABV instead of wt RABV, allowing immune cells to infiltrate into the CNS. We found that MMP8 plays an important role in enhancing BBB permeability by degradation of TJ proteins during RABV infection. Using an MMP8 selective inhibitor restores the reduction of TJ proteins. We reveal that MMP8 is upregulated via the MAPK and NF-κB inflammatory pathways, activated by lab-attenuated RABV infection but not wt RABV. Our findings suggest that MMP8 has a critical role in modulating the opening of the BBB during RABV infection, which provides fresh insight into developing effective therapeutics for rabies and infection with other neurotropic viruses.

The Role of Functional Polymorphisms in the Extracellular Matrix Modulation-Related Genes on Dupuytren's Contracture.

(1) Background: genetic variations, localized in the functional regions of the extracellular matrix (ECM) modulation-related genes, may alter the transcription process and impact the Dupuytren's contracture (DC). The present study investigated the association of single nucleotide polymorphisms (SNPs), localized in the functional regions of the MMP8, MMP14, and CHST6 genes, with DC risk. (2) Methods: we enrolled 219 genomic DNA samples, which were extracted from 116 patients with DC and 103 healthy controls. Genotyping of selected SNPs was performed using TaqMan single nucleotide polymorphisms genotyping assay. Three polymorphisms (MMP8 rs11225395, MMP14 rs1042704, and CHST6 rs977987) were analyzed. All studied SNPs were in Hardy-Weinberg equilibrium. (3) Results: significant associations of the studied SNPs with the previous onset of the disease were observed between the CHST6 rs977987 minor T allele (p = 0.036) and the MMP14 rs1042704 mutant AA genotype (p = 0.024). Significant associations with the previous onset of the disease were also observed with a positive family history of the DC (p = 0.035). Moreover, risk factor analysis revealed that a combination of major disease risk factors (smoking and manual labor) and the MMP14 minor A allele increases the risk of DC development by fourteen times (p = 0.010). (4) Conclusions: our findings suggest that CHST6 rs977987, MMP14 rs1042704, and positive family history are associated with the previous onset of Dupuytren's contracture. In addition, the combination of the MMP14 minor A allele and additional risk factors increase the likelihood of the manifestation of the DC.

Peri-Implant Surgical Treatment Downregulates the Expression of sTREM-1 and MMP-8 in Patients with Peri-Implantitis: A Prospective Study.

sTREM-1 and its ligand PGLYRP1 play an essential role in the inflammatory process around teeth and implants. In this study, we aimed to evaluate the impact of peri-implant treatment on the salivary levels of the sTREM-1/PGLYRP-1/MMP-8 axis after 3 months. A total of 42 participants (with a mean age of 61 years old ± 7.3) were enrolled in this longitudinal study, 24 having peri-implant mucositis (MU) and 18 having peri-implantitis (PI). Clinical peri-implant parameters, such as probing pocket depth (PPD), % of plaque, and bleeding on probing (BOP), and the whole unstimulated saliva samples were evaluated at baseline and 3 months after treatment. The MU group received nonsurgical peri-implant treatment, while the PI group received open-flap procedures. The levels of sTREM-1, PGLYRP-1, MMP-8, and TIMP-1 were analyzed using enzyme-linked immunosorbent assays. BOP, plaque levels, and PPD significantly reduced after treatment in both groups. A significant decrease in the salivary levels of sTREM-1, MMP-8, and TIMP-1 in the PI group and PGLYRP1 and TIMP-1 in the MU group were observed. Salivary levels of sTREM-1 were significantly reduced in patients with PI but not with MU. Additionally, peri-implant treatment had a significantly higher impact on MMP-8 reduction in patients with PI than in those with MU.

Analysis of Sepsis Markers and Pathogenesis Based on Gene Differential Expression and Protein Interaction Network.

OBJECTIVE: The purpose of the present study is to screen the hub genes associated with sepsis, comprehensively understand the occurrence and progress mechanism of sepsis, and provide new targets for clinical diagnosis and treatment of sepsis. METHODS: The microarray data of GSE9692 and GSE95233 were downloaded from the Gene Expression Omnibus (GEO) database. The dataset GSE9692 contained 29 children with sepsis and 16 healthy children, while the dataset GSE95233 included 102 septic subjects and 22 healthy volunteers. Differentially expressed genes (DEGs) were screened by GEO2R online analysis. The DAVID database was applied to conduct functional enrichment analysis of the DEGs. The STRING database was adopted to acquire protein-protein interaction (PPI) networks. RESULTS: We identified 286 DEGs (217 upregulated DEGs and 69 downregulated DEGs) in the dataset GSE9692 and 357 DEGs (236 upregulated DEGs and 121 downregulated DEGs) in the dataset GSE95233. After the intersection of DEGs of the two datasets, a total of 98 co-DEGs were obtained. DEGs associated with sepsis were involved in inflammatory responses such as T cell activation, leukocyte cell-cell adhesion, leukocyte-mediated immunity, cytokine production, immune effector process, lymphocyte-mediated immunity, defense response to fungus, and lymphocyte-mediated immunity. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis suggested that sepsis was connected to bacterial and viral infections. Through PPI network analysis, we screened the most important hub genes, including ITK, CD247, MMP9, CD3D, MMP8, KLRK1, and GZMK. CONCLUSIONS: In conclusion, the present study revealed an unbalanced immune response at the transcriptome level of sepsis and identified genes for potential biomarkers of sepsis, such as ITK, CD247, MMP9, CD3D, MMP8, KLRK1, and GZMK.

Loss of mutual protection between human osteoclasts and chondrocytes in damaged joints initiates osteoclast-mediated cartilage degradation by MMPs.

Osteoclasts are multinucleated, bone-resorbing cells. However, they also digest cartilage during skeletal maintenance, development and in degradative conditions including osteoarthritis, rheumatoid arthritis and primary bone sarcoma. This study explores the mechanisms behind the osteoclast-cartilage interaction. Human osteoclasts differentiated on acellular human cartilage expressed osteoclast marker genes (e.g. CTSK, MMP9) and proteins (TRAP, VNR), visibly damaged the cartilage surface and released glycosaminoglycan in a contact-dependent manner. Direct co-culture with chondrocytes during differentiation increased large osteoclast formation (p < 0.0001) except when co-cultured on dentine, when osteoclast formation was inhibited (p = 0.0002). Osteoclasts cultured on dentine inhibited basal cartilage degradation (p = 0.012). RNA-seq identified MMP8 overexpression in osteoclasts differentiated on cartilage versus dentine (8.89-fold, p = 0.0133), while MMP9 was the most highly expressed MMP. Both MMP8 and MMP9 were produced by osteoclasts in osteosarcoma tissue. This study suggests that bone-resident osteoclasts and chondrocytes exert mutually protective effects on their 'native' tissue. However, when osteoclasts contact non-native cartilage they cause degradation via MMPs. Understanding the role of osteoclasts in cartilage maintenance and degradation might identify new therapeutic approaches for pathologies characterized by cartilage degeneration.