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Despite effective antiretroviral therapy (ART), mild forms of HIV-associated neurocognitive disorders (HAND) continue to afflict approximately half of all people living with HIV (PLWH). As PLWH age, HIV-associated inflammation perturbs the balance between brain matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs), likely contributing to neuropathogenesis. The MMP/TIMP balance is associated with cognition, learning, and memory, with TIMPs eliciting neuroprotective effects. Dysregulation of the MMP/TIMP balance was evident in the brains of PLWH where levels of TIMP-1, the inducible family member, were significantly lower than non-infected controls, and MMPs were elevated. Here, we evaluated the MMP/TIMP levels in the doxycycline (DOX)-induced glial fibrillary acidic protein promoter-driven HIV-1 transactivator of transcription (Tat) transgenic mouse model. The HIV-1 protein Tat is constitutively expressed by most infected cells, even during ART suppression of viral replication. Many studies have demonstrated indirect and direct mechanisms of short-term Tat-associated neurodegeneration, including gliosis, blood-brain barrier disruption, elevated inflammatory mediators and neurotoxicity. However, the effects of acute vs. prolonged exposure on Tat-induced dysregulation remain to be seen. This is especially relevant for TIMP-1 as expression was previously shown to be differentially regulated in human astrocytes during acute vs. chronic inflammation. In this context, acute Tat expression was induced with DOX intraperitoneal injections over 3 weeks, while DOX-containing diet was used to achieve long-term Tat expression over 6 months. First, a series of behavior tests evaluating arousal, ambulation, anxiety, and cognition was performed to examine impairments analogous to those observed in HAND. Next, gene expression of components of the MMP/TIMP axis and known HAND-relevant inflammatory mediators were assessed. Altered anxiety-like, motor and/or cognitive behaviors were observed in Tat-induced (iTat) mice. Gene expression of MMPs and TIMPs was altered depending on the duration of Tat expression, which was independent of the HIV-associated neuroinflammation typically implicated in MMP/TIMP regulation. Collectively, we infer that HIV-1 Tat-mediated dysregulation of MMP/TIMP axis and behavioral changes are dependent on duration of exposure. Further, prolonged Tat expression demonstrates a phenotype comparable to asymptomatic to mild HAND manifestation in patients. [ABSTRACT FROM AUTHOR]

There is increasing awareness that in addition to the metabolic crisis of diabetic ketoacidosis (DKA) caused by severe insulin deficiency, the immune inflammatory response is likely an active multicomponent participant in both the acute and chronic insults of this medical crisis, with strong evidence of activation for both the cytokine and complement system. Recent studies report that the matrix metalloproteinase enzymes and their inhibitors are systemically activated in young Type 1 diabetes mellitus (T1D) patients during DKA and speculate on their involvement in blood-brain barrier (BBB) disruption. Based on our previous studies, we address the question if matrix metalloproteinase 9 (MMP9) is expressed in the brain in the fatal brain edema (BE) of DKA. Our data show significant expression of MMP9 on the cells present in brain intravascular areas. The presence of MMP9 in intravascular cells and that of MMP+ cells seen passing the BBB indicates a possible role in tight junction protein disruption of the BBB, possibly leading to neurological complications including BE. We have also shown that MMP9 is expressed on neurons in the hippocampal areas of both BE/DKA cases investigated, while expression of tissue inhibitor of metalloproteinases 1 (TIMP1) was reduced in the same areas. We can speculate that intraneuronal MMP9 can be a sign of neurodegeneration. Further studies are necessary to determine the role of MMP9 in the pathogenesis of the neurologic catastrophe of the brain edema of DKA. Inhibition of MMP9 expression might be helpful in preserving neuronal function and BBB integrity during DKA. Unlabelled Image • MMP9 is extensively expressed in intravascular cells from DKA brains. • MMP9 is expressed in hippocampal neurons in DKA brains. • TIMP1 is expressed at lower levels in intravascular cells and hippocampal neurons. • Hippocampal neurons from DKA brains express high levels of RGC-32 and C5b-9. • Further studies are needed to establish MMP9 role in DKA brains. [ABSTRACT FROM AUTHOR]

Abstract The matrix metallopeptidase 13 (MMP13) is a central regulator of chondrocyte senescence that contributes to the development and progression of osteoarthritis (OA). In the present study, the native inhibitory structure of MMP13 in complex with its natural cognate inhibitor, the tissue inhibitor of metalloproteinases 1 (TIMP1), was modeled at atomic level using a grafting-based structural bioinformatics method with existing crystal structures. The modeled complex structure was then examined in detail, from which a TIMP1 inhibitory site that directly inserts into the active site of MMP13 enzyme was identified. The inhibitory site contains a coiled inhibitory loop (ILP) and a stretched N-terminal tail (NTT); they are highly structured in the intact MMP13–TIMP1 complex interface, but exhibit a large flexibility and intrinsic disorder when split from the interface context. In vitro binding assays demonstrated that the isolated ILP and NTT peptides cannot effectively rebind at the MMP13 active site (K d > ~100 μM or = n.d.), although they have all key interacting residues in the enzyme inhibition. In silico simulations revealed that splitting of the peptide segments from TIMP1 inhibitory site does not influence the direct intermolecular interaction between MMP13 and the peptides substantially; instead, the large conformational flexibility of these isolated peptides in absence of interface context is primarily responsible for the affinity impairment, which would incur a considerable entropy penalty upon the peptide binding to MMP13. An extended version of ILP peptide, namely eILP (63TPAMESVCGY72), was redesigned with a rational strategy to derive a number of its cyclized counterparts by introducing a disulfide bridge across the peptide two-termini; the redesign reduces the peptide flexibility in free state and constrains the peptide pre-folding to a native-like conformation, which would help the peptide binding with minimized entropy penalty. Binding assays substantiated that the affinity K d values of four designed cyclic peptides (Image 5 , Image 6 , Image 7 and Image 8) were improved to 23, 67, 42 and 18 μM, respectively, from the 96 μM of linear eILP peptide. [ABSTRACT FROM AUTHOR]

Summary: Asthma is a chronic inflammatory respiratory disease characterized by airway inflammation, airway hyperresponsiveness and reversible airway obstruction. Understanding the mechanisms that underlie the various endotypes of asthma could lead to novel and more personalized therapies for individuals with asthma. Using a tissue inhibitor of metalloproteinases 1 (TIMP‐1) knockout murine allergic asthma model, we previously showed that TIMP‐1 deficiency results in an asthma phenotype, exhibiting airway hyperreactivity, enhanced eosinophilic inflammation and T helper type 2 cytokine gene and protein expression following sensitization with ovalbumin. In the current study, we compared the expression of Galectins and other key cytokines in a murine allergic asthma model using wild‐type and TIMP‐1 knockout mice. We also examined the effects of Galectin‐3 (Gal‐3) inhibition on a non‐T helper type 2 cytokine interleukin‐17 (IL‐17) to evaluate the relationship between Gal‐3 and the IL‐17 axis in allergic asthma. Our results showed a significant increase in Gal‐3, IL‐17 and transforming growth factor‐β1 gene expression in lung tissue isolated from an allergic asthma murine model using TIMP‐1 knockout. Gal‐3 gene and protein expression levels were also significantly higher in lung tissue from an allergic asthma murine model using TIMP‐1 knockout. Our data show that Gal‐3 may regulate the IL‐17 axis and play a pivotal role in the modulation of inflammation during experimental allergic asthma. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is an important infectious disease of humans and other animals. Conventional diagnostic methods, including the tuberculin skin test, chest X-rays and bacterial culture, have certain innate disadvantages for the early, rapid and specific diagnosis of tuberculosis. The present study aimed to identify a novel diagnostic biomarker to overcome these disadvantages. The potential target identified in the present study was tissue inhibitor of metalloproteinases 1 (TIMP-1), which has previously been demonstrated to be critical in the immune response to TB. The concentration of TIMP-1 in the blood was determined using a commercial ELISA kit, and the relative mRNA expression levels following bacterial infection were detected by reverse transcription-quantitative polymerase chain reaction. Based on a clinical and microbiological diagnosis, the ELISA for plasma TIMP-1 had a sensitivity of 91.80% [95% confidence interval (CI): 85.44, 96.00] and a specificity of 91.41% (95% CI: 85.14, 95.63). In a THP-1 cell model, Bacillus Calmette-Guérin and Mycobacterium bovis significantly upregulated the mRNA expression levels of TIMP-1 post infection in a time-dependent manner (P=0.006 for BCG 24 h PI, P=3.2×10-7 for M. bovis 24 PI). The results of the present study indicate that plasma TIMP-1 may be a potential biomarker for the diagnosis of TB. [ABSTRACT FROM AUTHOR]

Introduction: Proteinases and proteinase inhibitors have been described to play a role in autoimmune skin blistering diseases. We studied skin lesional biopsies from patients affected by several autoimmune skin blistering diseases for proteinases and proteinase inhibitors. Methods: We utilized immunohistochemistry to evaluate biopsies for alpha-1-antitrypsin, human matrix metalloproteinase 9 (MMP9), human tissue inhibitor of metalloproteinases 1 (TIMP-1), metallothionein and urokinase type plasminogen activator receptor (uPAR). We tested 30 patients affected by endemic pemphigus, 30 controls from the endemic area, and 15 normal controls. We also tested 30 biopsies from patients with bullous pemphigoid (BP), 20 with pemphigus vulgaris (PV), 8 with pemphigus foliaceus, and 14 with dermatitis herpetiformis (DH). Results: Contrary to findings in the current literature, most autoimmune skin blistering disease biopsies were negative for uPAR and MMP9. Only some chronic patients with El Bagre-EPF were positive to MMP9 in the dermis, in proximity to telocytes. TIMP-1 and metallothionein were positive in half of the biopsies from BP patients at the basement membrane of the skin, within several skin appendices, in areas of dermal blood vessel inflammation and within dermal mesenchymal-epithelial cell junctions.

Proteinases and proteinase inhibitors have been described to play a role in autoimmune skin blistering diseases. We studied skin lesional biopsies from patients affected by several autoimmune skin blistering diseases for proteinases and proteinase inhibitors. Methods: We utilized immunohistochemistry to evaluate biopsies for a-1-antitrypsin, human matrix metalloproteinase 9 (MMP9), human tissue inhibitor of metalloproteinases 1 (TIMP-1), metallothionein and urokinase type plasminogen activator receptor (uPAR). We tested 30 patients affected by endemic pemphigus, 30 controls from the endemic area, and 15 normal controls. We also tested 30 biopsies from patients with bullous pemphigoid (BP), 20 with pemphigus vulgaris (PV), 8 with pemphigus foliaceus, and 14 with dermatitis herpetiformis (DH). Results: Contrary to findings in the current literature, most autoimmune skin blistering disease biopsies were negative for uPAR and MMP9. Only some chronic patients with El Bagre-EPF were positive to MMP9 in the dermis, in proximity to telocytes. TIMP-1 and metallothionein were positive in half of the biopsies from BP patients at the basement membrane of the skin, within several skin appendices, in areas of dermal blood vessel inflammation and within dermal mesenchymal-epithelial cell junctions. [ABSTRACT FROM AUTHOR]

Objective: To investigate the potential correlation of transforming growth factor-β (TGF-β), matrix metalloprotein 9 (MMP-9), tissue inhibitor of metalloproteinases 1 (TIMP-1), Interleukin 1 (IL-1), IL-4, IL-6, IL-17, and tumor necrosis factor alpha (TNF-α) in refractory chronic rhinosinusitis., Methods: A total of 150 participants were retrospectively included in this study from August 2018 to February 2020. The people enrolled were equally allocated into refractory group (patients with refractory chronic rhinosinusitis), chronic group (patients with chronic rhinosinusitis), and control group (normal people). The level of TGF-β1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α were recorded. The unconditional multivariate binary logistic regression was used to analyze the factors affecting refractory chronic rhinosinusitis., Results: The Davos score, T&T olfactometer threshold test, and Lund-Mackay CT scores in refractory group were significantly higher than the chronic group (P<0.05). The level of TGF-β1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α in the refractory group were significantly higher than the chronic group and the control group (all P<0.05). Similarly, the level of the above mentioned indexes in the chronic group were significantly higher than the control group (P<0.05). The Davos score, T&T olfactometer threshold test score, Lund-Mackay CT score, and the level of TGF-β1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α positively correlated with refractory chronic rhinosinusitis. Moreover, the unconditional multivariate binary logistic regression showed that the influencing factors of refractory chronic rhinosinusitis included TGF-β1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α., Conclusion: The findings of the present study provide evidence for TGF-β1, MMP-9, TIMP-1, IL-4, IL-6, IL-17, and TNF-α as the influencing factors of refractory chronic rhinosinusitis.

Aim: To investigate the effects of exercise on atherosclerotic plaque composition, the concentration of matrix metalloproteinases (MMPs) in the atherosclerotic plaque and the systemic circulation. Methods: Ninety apolipoprotein E-deficient (apoE–/–) mice (45 male) were randomized to the following groups (n = 15 each): control male/female; sedentary male/female; exercise male/female. Mice were kept on a 16-week high-fat diet. Subsequently, the control groups were sacrificed, while the rest of the animals were placed on a normal diet for 6 more weeks. During the latter period, the exercise groups were trained daily on treadmill. At the end of the study, mice were euthanized, and blood samples as well as aortic root specimens were obtained. Results: Compared to control and sedentary animals, exercise training reduced atherosclerotic plaques (–30%; p < 0.01) and increased elastin and collagen content in both genders (p < 0.05). Body weight or lipid profile did not change significantly. Decreased macrophages and MMP-9 as well as increased tissue inhibitor of metalloproteinases 1 (TIMP-1) levels were observed in the atherosclerotic plaques of the exercise-treated groups (p < 0.05). Plasma concentrations of MMP-9 decreased, while plasma TIMP-1 levels increased in the exercise compared to control and sedentary groups (p < 0.05). Conclusions: Exercise training had a favorable effect on the size and composition of the atherosclerotic plaque in apoE–/– mice, associated with suppressed MMP activity. [ABSTRACT FROM AUTHOR]

Aim: To elucidate cellular features accountable for colorectal cancers’ (CRC) capability to invade normal tissue and to metastasize, we investigated the level of the collagenase matrix metalloproteinase 9 (MMP-9) and its physiological inhibitor tissue inhibitor of metalloproteinases 1 (TIMP-1) in cancer cells and supporting stroma cells of CRC. Methods: Immunoreactivity of MMP-9 and TIMP-1 by carcinoma cells, lymphocytes and fibroblasts in archival specimens of paraffin-embedded primary tumours were retrospectively associated with outcome in 340 consecutive patients completely resected for CRC stages II–IV and subsequently treated with adjuvant 5-fluorouracil. Results: Expression of MMP-9 by carcinoma cells was demonstrated in 9% of specimens without association to recurrence free survival (RFS) (HR=1.0; 95% CI: 0.6–1.8; P =0.9) or overall survival (OS) (HR=0.9; 95% CI: 0.5–1.6; P =0.6). TIMP-1 expression by carcinoma cells, which appeared in 64% of the specimens, was inversely related with RFS (HR=1.3; 95% CI: 0.9–1.8; P =0.08) and OS (HR=1.5; 95% CI: 1.1–2.1; P =0.02). Expression of TIMP-1 by fibroblasts at the invasive border was directly related to RFS (HR=0.7; 95% CI: 0.6–0.9; P =0.02) and OS (HR=0.7; 95% CI: 0.6–1.0; P =0.05). Expression of MMP-9 by lymphocytes correlated significantly with the degree of peritumoural inflammation (P =0.02) but not with RFS (HR=0.9; 95% CI: 0.7–1.1; P =0.2) or OS (HR=0.8; 95% CI: 0.7–1.0; P =0.07). Conclusion: TIMP-1 in cancer cells is associated with poor prognosis independent of its function as inhibitor of MMP-9. MMP-9 and TIMP-1 are important mediators of the host–cancer cell interaction in the tumour microenvironment with significant influence on the histopathology and on prognosis of CRC. [Copyright &y& Elsevier]

Problem Assessment of concentration of the metalloproteinase 9 (MMP9), tissue inhibitor of metalloproteinases 1 (TIMP1), urokinase plasminogen activator (uPA) and its receptor (uPAR) and leukaemia inhibitory factor (LIF) in the uterine fluid in women with idiopathic infertility and unknown cause for recurrent miscarriage. Method of study Uterine fluid obtained from patients with idiopathic infertility ( n = 13), patients with unknown cause of recurrent miscarriages ( n = 16) and healthy fertile women ( n = 14). The assessment of MMP9, TIMP1, uPA, uPAR and LIF were performed with enzyme-linked immunosorbent assay. Results Statistically lower expression of MMP9 and TIMP1 in uterine fluid during implantation window in women with infertility and recurrent miscarriage of unknown cause. Conclusion Changed turnover of the extracellular matrix might be a cause of improper endometrial transition and in effect cause faulty implantation. [ABSTRACT FROM AUTHOR]

Traditionally, studies to address the characterization of mechanisms promoting tumor aggressiveness and progression have been focused only on primary tumor analyses, which could provide relevant information but have limitations to really characterize the more aggressive tumor population. To overcome these limitations, circulating tumor cells (CTCs) represent a noninvasive and valuable tool for real-time profiling of disseminated tumor cells. Therefore, the aim of the present study was to explore the value of CTC enumeration and characterization to identify markers associated with the outcome and the aggressiveness of triple-negative breast cancer (TNBC). For that aim, the CTC population from 32 patients diagnosed with TNBC was isolated and characterized. This population showed important cell plasticity in terms of expression of epithelia/mesenchymal and stemness markers, suggesting the relevance of epithelial to mesenchymal transition (EMT) intermediate phenotypes for efficient tumor dissemination. Importantly, the CTC signature demonstrated prognostic value to predict the patients' outcome and pointed to a relevant role of tissue inhibitor of metalloproteinases 1 (TIMP1) and androgen receptor (AR) for TNBC biology. Furthermore, we also analyzed the usefulness of the AR and TIMP1 blockade to target TNBC proliferation and dissemination using in vitro and in vivo zebra fish and mouse models. Overall, the molecular characterization of CTCs from advanced TNBC patients identifies highly specific biomarkers with potential applicability as noninvasive prognostic markers and reinforced the value of TIMP1 and AR as potential therapeutic targets to tackle the most aggressive breast cancer. [ABSTRACT FROM AUTHOR]

Objective: This study aims to investigate the effects of co-transfection of the genes for connective tissue growth factor (CTGF) and tissue inhibitor of metalloproteinase-1 (TIMP1) mediated by adeno-associated virus 2 (AAV2) on degenerative lumbar intervertebral discs in a primate model., Methods: Twelve 4-7 year-old rhesus monkeys weighing 4.5-7.0 kg were utilized. CTGF and TIMP1 genes carried by AAV2 were injected into the degenerative lumbar intervertebral discs. Cytokine expression and biological effects were determined using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and 35 S-sulfate incorporation assays. A rhesus monkey model of intervertebral disc degeneration was successfully established., Results: At post-transfection, CTGF mRNA expression was higher in the transfection group than in the control group ( P < 0.05). Furthermore, TIMP1 mRNA expression in the transfection group was several times the levels observed in the control group ( P < 0.05). Moreover, type-II collagen mRNA expression was higher in the transfection group than in the control group ( P < 0.05). In addition, higher aggrecan mRNA expression and synthesis were observed in the transfection group, compared to that in the control group ( P < 0.05)., Conclusion: The stable expression of CTGF and TIMP1 genes in vivo promoted the synthesis of aggrecan and type II collagen in the nucleus pulposus in the rhesus monkey model of intervertebral disc degeneration, which has a potential for intervertebral disc regeneration., Competing Interests: None.

Background & Aims: Progressive fibrosis is a major cause of morbidity and mortality in chronic liver disease. To replace liver biopsy for disease staging, multiple serum markers are under evaluation with multiparametric panels yielding the most promising results. The Enhanced Liver Fibrosis (ELF) score is an ECM marker set consisting of tissue inhibitor of metalloproteinases 1 (TIMP-1), amino-terminal propeptide of type III procollagen (PIIINP) and hyaluronic acid (HA) showing good correlations with fibrosis stages in chronic liver disease., Methods: The ELF score was measured in 400 healthy controls and 79 chronic hepatitis C patients using an ADVIA Centaur automated system. The ELF score was calculated using the published algorithm combining TIMP-1, PIIINP and HA values. Patients' fibrosis stage was defined histologically. ROC analyses were performed to study marker validity. Reference values and influence factors for the ELF score were validated., Results: ELF score reference values ranged from 6.7 to 9.8 and were significantly higher for men vs. women (7.0-9.9 vs. 6.6-9.3, respectively). Afternoon values were slightly higher than morning values (6.7-9.9 vs. 6.6-9.5, respectively). Age was a notable influence factor. We identified three cut-off values: 7.7 for a high sensitivity exclusion of fibrosis, 9.8 for a high specificity identification of fibrosis (sensitivity 69%, specificity 98% for moderate fibrosis), and 11.3 to discriminate cirrhosis (sensitivity 83%, specificity 97%). ELF score validity was superior to the results of the single tests., Conclusions: The ELF score can predict moderate fibrosis and cirrhosis. However, influence factors such as gender and age need to be taken into account., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Regulatory CD4(+) T cells (Tregs) are considered to affect outcomes of HCV infection, because they increase in number during chronic hepatitis C and can suppress T-cell functions., Methods: Using microarray analysis, in situ immunofluorescence, ELISA, and flowcytometry, we characterised functional differentiation and localisation of adaptive Tregs in patients with chronic hepatitis C., Results: We found substantial upregulation of IL-8 in Foxp3(+)CD4(+) Tregs from chronic hepatitis C. Activated GARP-positive IL-8(+) Tregs were particularly enriched in livers of patients with chronic hepatitis C in close proximity to areas of fibrosis and their numbers were correlated with the stage of fibrosis. Moreover, Tregs induced upregulation of profibrogenic markers TIMP1, MMP2, TGF-beta1, alpha-SMA, collagen, and CCL2 in primary human hepatic stellate cells (HSC). HSC activation, but not Treg suppressor function, was blocked by adding a neutralizing IL-8 antibody., Conclusions: Our studies identified Foxp3(+)CD4(+) Tregs as an additional intrahepatic source of IL-8 in chronic hepatitis C acting on HSC. Thus, Foxp3(+)CD4(+) Tregs in chronic hepatitis C have acquired differentiation as regulators of fibrogenesis in addition to suppressing local immune responses., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)