Exploratory transcriptomic analysis of mouse articular cartilage in response to tissue inhibitor of metalloproteinase 3 identifies inflammation-associated gene expression changes.

A transient COS-7 cell expression system was used to investigate the functional domain arrangement of tissue inhibitor of metalloproteinases-3 (TIMP-3), specifically to assess the contribution of the amino- and carboxyl-terminal domains of the molecule to its matrix metalloproteinase (MMP) inhibitory and extracellular matrix (ECM) binding properties. Wild type TIMP-3 was entirely localized to the ECM in both its glycosylated (27 kDa) and unglycosylated (24 kDa) forms. A COOH-terminally truncated TIMP-3 molecule was found to be a non-ECM bound MMP inhibitor, whereas a chimeric TIMP molecule, consisting of the NH2-terminal domain of TIMP-2 fused to the COOH-terminal domain of TIMP-3, displayed ECM binding, albeit with a lower affinity than the wild type TIMP-3 molecule. Thus the functional domain arrangement of TIMP-3 is analogous to that seen in TIMP-1 and -2, namely that the NH2-terminal domain is responsible for MMP inhibition whereas the COOH-terminal domain is most important in mediating the specific functions of the molecule. A mutant TIMP-3 in which serine 181 was changed to a cysteine, found in Sorsby's fundus dystrophy, a hereditary macular degenerative disease, was also expressed in COS-7 cells. This gave rise to an additional 48-kDa species (possibly a TIMP-3 dimer) that retained its ability to inhibit MMPs and localize to the ECM. These data favor the hypothesis that the TIMP-3 mutations seen in Sorsby's fundus dystrophy contribute to disease progression by accumulation of mutant protein rather than by the loss of functional TIMP-3.

One well documented family of enzymes responsible for the proteolytic processes that occur in the extracellular matrix is the soluble and membrane-associated matrix metalloproteinases. Here we present the first theoretical model of the biochemical network describing the proteolysis of collagen I by matrix metalloproteinases 2 (MMP2) and membrane type 1 matrix metalloproteinases (MT1-MMP) in the presence of the tissue inhibitor of metalloproteinases 2 (TIMP2) in a bulk, cell-free, well stirred environment. The model can serve as a tool for describing quantitatively the activation of the MMP2 proenzyme (pro-MMP2), the ectodomain shedding of MT1-MMP, and the collagenolysis arising from both of the enzymes. We show that pro-MMP2 activation, a process that involves a trimer formation of the proenzyme with TIMP2 and MT1-MMP, is suppressed at high inhibitor levels and paradoxically attains maximum only at intermediate TIMP2 concentrations. We also calculate the conditions for which pro-MMP2 activation is maximal. Furthermore we demonstrate that the ectodomain shedding of MT1-MMP can serve as a mechanism controlling the MT1-MMP availability and therefore the pro-MMP2 activation. Finally the proteolytic synergism of MMP2 and MT1-MMP is introduced and described quantitatively. The model provides us a tool to determine the conditions under which the synergism is optimized. Our approach is the first step toward a more complete description of the proteolytic processes that occur in the extracellular matrix and include a wider spectrum of enzymes and substrates as well as naturally occurring or artificial inhibitors.

Dissecting the interaction between tissue inhibitor of metalloproteinases-3 (TIMP-3) and low density lipoprotein receptor-related protein-1 (LRP-1): Development of a “TRAP” to increase levels of TIMP-3 in the tissue

Tissue inhibitors of matrix metalloproteinases (TIMPs) comprise a family of four members, of which TIMP4 is characterized by being primarily restricted to cardiovascular structures. We demonstrate with immunohistochemical analysis of healthy human tissue that TIMP4 is present in medial smooth muscle cells and adventitial capillaries of arteries as well as in cardiomyocytes. Animal studies have suggested a role for TIMP4 in several inflammatory diseases and cardiovascular pathologies. We therefore examined whether TIMP4 is involved in human inflammatory cardiovascular disorders, specifically atherosclerosis, giant cell arteritis and chronic rejection of heart allografts. TIMP4 was most clearly visible in cardiovascular tissue areas populated by abundant inflammatory cells, mainly macrophages and CD3+ T cells. Using western blotting and immunocytochemistry, human blood derived lymphocytes, monocytes/macrophages and mast cells were shown to produce TIMP4. In advanced atherosclerotic lesions, TIMP4 was detected around necrotic lipid cores, whereas TIMP3 and caspase 3 resided within and around the core regions, indicating different roles for TIMP3 and TIMP4 in inflammation-induced apoptosis and in matrix turnover. In conclusion, the data demonstrate upregulation of TIMP4 in human cardiovascular disorders exhibiting inflammation, suggesting its future use as a novel systemic marker for vascular inflammation.

Sorsby's fundus dystrophy (SFD) is a dominantly inherited degenerative disease of the retina that leads to loss of vision in middle age. It has been shown to be caused by mutations in the gene for tissue inhibitor of metalloproteinases-3 (TIMP-3). Five different mutations have previously been identified, all introducing an extra cysteine residue into exon 5 (which forms part of the C-terminal domain) of the TIMP-3 molecule; however, the significance of these mutations to the disease phenotype was unknown. In this report, we describe the expression of several of these mutated genes, together with a previously unreported novel TIMP-3 mutation from a family with SFD that results in truncation of most of the C-terminal domain of the molecule. Despite these differences, all of these molecules are expressed and exhibit characteristics of the normal protein, including inhibition of metalloproteinases and binding to the extracellular matrix. However, unlike wild-type TIMP-3, they all form dimers. These observations, together with the recent finding that expression of TIMP-3 is increased, rather than decreased, in eyes from patients with SFD, provides compelling evidence that dimerized TIMP-3 plays an active role in the disease process by accumulating in the eye. Increased expression of TIMP-3 is also observed in other degenerative retinal diseases, including the more severe forms of age-related macular degeneration, the most common cause of blindness in the elderly in developed countries. We hypothesize that overexpression of TIMP-3 may prove to be a critical step in the progression of a variety of degenerative retinopathies.

Tissue inhibitor of metalloproteinases 4 (TIMP4) is expressed highly in heart and found dysregulated in human cardiovascular diseases. It controls extracellular matrix remodeling by inhibiting matrix metalloproteinases (MMPs) and is implicated in processes including cell proliferation, apoptosis, and angiogenesis. Timp4-deficient mice (Timp4(-/-)) were generated to assess TIMP4 function in normal development and in models of heart disease. We deleted exons 1-3 of the Timp4 gene by homologous recombination. Timp4(-/-) mice are born healthy, develop normally, and produce litters of normal size and gender distribution. These mice show no compensation by overexpression of Timp1, Timp2, or Timp3 in the heart. Following cardiac pressure overload by aortic banding, Timp4(-/-) mice have comparable survival rate, cardiac histology, and cardiac function to controls. In this case, Timp4 deficiency is compensated by increased cardiac Timp2 expression. Strikingly, the induction of myocardial infarction (MI) leads to significantly increased mortality in Timp4(-/-) mice primarily due to left ventricular rupture. The post-MI mortality of Timp4(-/-) mice is reduced by administration of a synthetic MMP inhibitor. Furthermore, combining the genetic deletion of Mmp2 also rescues the higher post-MI mortality of Timp4(-/-) mice. Finally, Timp4(-/-) mice suffer reduced cardiac function at 20 months of age. Timp4 is not essential for murine development, although its loss moderately compromises cardiac function with aging. Timp4(-/-) mice are more susceptible to MI but not to pressure overload, and TIMP4 functions in its capacity as a metalloproteinase inhibitor after myocardial infarction.

The destruction of extracellular matrix by matrix metalloproteinases is a key event in cancer progression. The tissue inhibitors of metalloproteinases can restrain tumor growth by inhibiting these enzymes. We sought to determine whether overexpression of tissue inhibitor of metalloproteinase-3 (TIMP-3) could suppress the malignant phenotype of human prostate cancer cell line PC-3M. Stable overexpression of TIMP-3 inhibited cell proliferation significantly by MTT assay. Both early and late apoptosis were observed in TIMP-3 overexpressing cells, and flow cytometry analysis showed S-phase blocking of the cell cycle. Monolayer invasion assay and transwell invasion assay showed significantly decreased invasive potential in TIMP-3 overexpressing cells compared with control cells. Cell adhesion and motility were also lower after TIMP-3 was overexpressed. In vivo, cells stably overexpressing TIMP-3 completely lost the ability to form tumors after injection into nude mice. Transfection of TIMP-3 into established tumors by electroporation also had a significant antitumor effect. TIMP-3-treated tumor tissues had significant apoptosis by TUNEL assay. These results showed that overexpression of TIMP-3 inhibits invasion and proliferation of prostate cancer cells in vitro and inhibits tumor growth in vivo. The experiments suggest a potential use for TIMP-3 in the gene therapy of prostate cancer.

The objective of the study was the assessment of serum levels and tissue expression of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of matrix metalloproteinases 2 (TIMP-2) in patients with colorectal cancer (CRC). The study included 72 CRC patients and 68 healthy subjects. The serum levels of MMP-2 and TIMP-2 were measured using enzyme-linked immunosorbent assay (ELISA) method, whereas tissue expression of MMP-2 and TIMP-2 in cancer cells, interstitial inflammatory cells, and adjacent normal colorectal mucosa were examined by immunohistochemical staining of tumor samples. The serum levels of MMP-2 and TIMP-2 in cancer patients were significantly lower than those in control group, but the percentage of positive immunoreactivity of these proteins were higher in malignant and inflammatory cells as compared to normal tissue. There was a significant correlation between MMP-2 immunoreactivity in inflammatory cells and the presence of distant metastases and between TIMP-2 expression in inflammatory cells and tumor size, nodal involvement, and distant metastases. Area under receiver operating characteristic (ROC) curve (AUC) for serum MMP-2 was higher than for serum TIMP-2. Moreover, positive tissue expression of MMP-2 was a significant prognostic factor for CRC patients’ survival. Our findings suggest that MMP-2 and TIMP-2 might play a role in the process of colorectal cancer invasion and metastasis, but the significance of their interactions with tumor stroma and interstitial inflammatory infiltration in colorectal neoplasia require further elucidation.

Tissue Inhibitor of Metalloproteinases 3 Regulates Resolution of Inflammation following Acute Lung Injury

149 Tissue Inhibitor of Metalloproteinases 3 (TIMP3) Regulation in Cholangiocarcinoma By MicroRNA-21 and Promoter Hypermethylation

Tissue inhibitor of metalloproteinase 3 (TIMP3) is unique among the four TIMPs due to its extracellular matrix (ECM)-binding property and broad range of inhibitory substrates that includes matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs), and ADAM with thrombospondin motifs (ADAMTSs). In addition to its metalloproteinase-inhibitory function, TIMP3 can interact with proteins in the extracellular space resulting in its multifarious functions. TIMP3 mRNA has a long 3’ untranslated region (UTR) which is a target for numerous microRNAs. TIMP3 levels are reduced in various cardiovascular diseases, and studies have shown that TIMP3 replenishment ameliorates the disease, suggesting a therapeutic potential for TIMP3 in cardiovascular diseases. While significant efforts have been made in identifying the effector targets of TIMP3, the regulatory mechanism for the expression of this multi-functional TIMP has been less explored. Here, we provide an overview of TIMP3 gene structure, transcriptional and post-transcriptional regulators (transcription factors and microRNAs), protein structure and partners, its role in cardiovascular pathology and its application as therapy, while also drawing reference from TIMP3 function in other diseases.

Tissue inhibitor of metalloproteinase 3 (TIMP3) serves as a prominent endogenous inhibitor of matrix metalloproteinases (MMPs), playing a crucial role in inhibiting metastasis, and angiogenesis. However, its exact contributions to colorectal cancer (CRC) remain largely unidentified. We aimed to ascertain the prognostic significance of TIMP3 in CRC patients through a bioinformatic approach. GEPIA, UALCAN, Kaplan–Meier plotter, LinkedOmics, cBioPortal, GeneMANIA, TIMER, TISIDB, the ScTIME database, TISMO, TIDE, CAMOIP, and TISCH2 were employed to comprehensively analyze the differential expression, prognostic value, genetic alterations, signaling pathways, immune cell infiltration, tumor microenvironment (TME) and associated genes of TIMP3 in CRC patients. Compared to adjacent normal tissues, we observed a significant downregulation of TIMP3 expression in CRC samples. Gene interaction networks elucidated that TIMP3 and its associated genes play a pivotal role in cancer progression, particularly in processes critical to colorectal cancer, such as extracellular matrix organization and angiogenesis. Analysis of the TME further indicates that TIMP3 expression was intricately associated with diverse immune cell types infiltration levels, chemokines, and immunomodulators. Most importantly, those with elevated TIMP3 expression had improved immunological scores. Moreover, TIMP3 exhibited strong correlations with major infiltration-related immune cells, including B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, dendritic cells, and fibroblasts. Furthermore, improved immunotherapeutic responses against PD-1/PD-L1 were linked to elevated TIMP3 levels. In TIMP3-high groups, there was a considerable increase in IL10, PDCD1, CD80, CXCL9, and CXCR3. This highlights the extensive influence of TIMP3 downregulation on the immune milieu within CRC. Our findings emphasize the multifaceted involvement of TIMP3 in CRC, not only influencing the molecular pathways associated with cancer progression, but also intricately shaping the immune microenvironment. As a result, TIMP3 appears promising as a potential CRC therapeutic target.

Objective:Tissue inhibitor of metalloproteinases 2 (TIMP2) is produced peripherally, crosses the blood-brain barrier, and improves synaptic plasticity and hippocampal-dependent cognition in aged mice; however, the role of TIMP2 in human cognitive aging is unclear. We examined associations of circulating TIMP2 levels in blood with a known plasticity-inducing behavior, physical activity, and cognitive functioning among older adults along the Alzheimer’s disease continuum.Participants and Methods:Participants included 84 community-dwelling older adults (meanage = 78.8; 57% female; 82% cognitively normal; 14% MCI; 4% mild dementia; 35% PET Aß+) enrolled in the UC San Francisco Memory and Aging Center. All participants completed 30 days of observational FitbitTM monitoring to quantify physical activity (average daily steps), as well as a comprehensive in-person visit including blood draw (proteins assayed on SOMAscan platform), [18F]AV-45 positron emission tomography (PET) to quantify brain beta-amyloid (centiloids), and neuropsychological assessment. Composite cognitive z-scores were calculated for memory (California Verbal Learning Test-II [CVLT-II] and Benson Figure Recall), semantic processing (animal fluency and Boston Naming Test), and executive functioning (digits backwards span, Stroop inhibition, modified trail making test, lexical fluency, and design fluency). Multiple linear regression examined TIMP2 as a function of physical activity, covarying for age and PET centiloids. Additional regression models separately examined cognitive z-scores as a function of TIMP2, covarying for age, sex, education, PET centiloids, and body mass index (BMI).Results:TIMP2 was not significantly correlated with age, sex, education, or PET centiloids (ps > 0.05); however, TIMP2 was negatively correlated with BMI (r = -0.23, p = 0.036). Greater average daily steps related to higher levels of TIMP2 (b = 0.30, 95%CI = 0.04-0.55, p = 0.022). TIMP2 also related to better semantic processing (b = 0.28, 95%CI = 0.04-0.51, p = 0.021) and executive functioning (b = 0.26, 95%CI = 0.03-0.49, p = 0.028). TIMP2 did not significantly relate to memory (p > 0.05).Conclusions:Greater physical activity was associated with higher concentrations of blood factor TIMP2, which in turn related to better cognitive functioning independent of Alzheimer’s disease pathology burden. These results support previous mouse models by broadly replicating relationships between TIMP2 and cognition in humans, while also uniquely demonstrating an association between TIMP2 and physical activity, a modifiable protective factor in both typical and diseased cognitive aging. Our domain-specific results, however, suggest that benefits of TIMP2 in humans may involve a broader neuroanatomical network than the hippocampal-specific effects previously shown in mice. Although exact mechanisms of TIMP2 need further examination, TIMP2 is known to be enriched in human umbilical cord plasma, has been shown to be involved in cell-growth promoting activities, and may relate to increased neural plasticity in older age. Further examination of TIMP2 and other novel blood-based proteins as potential therapeutic targets for improved cognitive aging, including in the presence of Alzheimer’s disease, is warranted.

The family of tissue inhibitors of metalloproteinases (TIMPs) presently numbers four distinct gene products that are specific inhibitors of the matrix metalloproteinases (MMPs). The local balance between MMPs and TIMPs is believed to play a major role in extracellular matrix (ECM) remodeling during development and in diseases such as cancer and arthritis. Unlike the other TIMPs, which are soluble. TIMP-3 is unique in being a component of ECM. Mutations in the human TIMP-3 gene cause a dominantly inherited, adult-onset blindness (Sorsby's fundus dystrophy or SFD). In this article, we summarize what is currently known about TIMP-3, discuss possible mechanisms leading up to SFD, and investigate the effect of TIMP-3 on tumor growth. Breast carcinoma and malignant melanoma cell lines were transfected with TIMP-3 expression plasmids and injected subcutaneously into nude mice. Growth curves of the resulting tumors over a period of 6 to 8 weeks demonstrated that increased expression of TIMP-3 resulted in a statistically significant suppression of tumor growth. Deposition of TIMP-3 in the surrounding ECM by tumor cells may inhibit tumor growth by preventing local expansion of tumor, retarding the release of growth factors sequestered in ECM, or inhibiting angiogenesis. TIMP-3 over-expression had no effect on the growth of the two tumor cell lines in vitro. Because recombinant TIMP-3 inhibits endothelial cell migration and tube formation in response to angiogenic factors, we believe that the effect of TIMP-3 on tumor growth seen in this study may be a consequence of its angiostatic action.

Background:Tissue inhibitor of metalloproteinases 2 (TIMP2) has been shown to revitalize aspects of synaptic plasticity and hippocampus-dependent cognition in aged mice. We examined TIMP2’s relevance in human brain aging and tested whether TIMP2 may be modifiable via known pro-plasticity behaviors in humans and mice.Methods:Plasma TIMP2 levels were quantified via SomaScan in three independent human cohorts, including two cross-sectional (UCSF: n=83; Stanford: n=31) and one with longitudinal measurement (ROSMAP: n=213). We examined associations of plasma TIMP2 with cognitive performance, brain volumes, and engagement in neuroprotective lifestyle behaviors, including objectively measured physical activity (UCSF) and a multi-domain lifestyle composite (ROSMAP). We used mouse models to directly test effects of environmental enrichment on (1) plasma TIMP2 levels and (2) hippocampal neurogenesis in wildtype versus TIMP2 knockout mice.Results:Higher plasma TIMP2 associated with better global cognition and larger brain volumes across human cohorts. Longitudinal decreases in plasma TIMP2 associated with steeper cognitive decline. Physical activity positively associated with plasma TIMP2 cross-sectionally, and longitudinal changes in multi-domain lifestyle factors positively associated with change in TIMP2 levels over time in humans. Mice exposed to an enriched environment for 3 weeks exhibited elevated plasma TIMP2 levels. While wildtype mice exposed to enrichment exhibited elevated adult hippocampal neurogenesis, this effect was lost in mice in which TIMP2 had been deleted.Conclusions:TIMP2 demonstrates clinical relevance for brain aging in humans and may represent a mechanism through which lifestyle behaviors confer neuroprotection. Further examination of TIMP2 as a potential therapeutic target for prevention of cognitive decline is warranted.