TIMP metallopeptidase inhibitor 3 (TIMP-3) may contribute to the pathogenesis of venous thromboembolism (VTE). However, few studies have investigated the effect of TIMP-3 on VTE. Therefore, a two-sample Mendelian randomization (MR) analysis was conducted to investigate the association between TIMP-3 levels and VTE. Seven independent single-nucleotide polymorphisms (SNPs) for TIMP-3 levels were obtained from a published genome-wide association study (the KORA Consortium, including 997 Europeans). We obtained outcome datasets for VTE, pulmonary embolism (PE), and deep vein thrombosis (DVT) from the FinnGen Consortium. The primary analytical method used in the MR analysis was the inverse variance weighted (IVW) method. To enhance the robustness of the MR results, some other MR methods including weighted median, MR-Egger, and MR-PRESSO were conducted. Moreover, several sensitivity analyses were performed to identify potential horizontal pleiotropy and heterogeneity. In primary IVW MR analyses, per log increase in genetically predicted TIMP-3 levels were positively associated with the incidence of VTE (odds ratio [OR], 1.03; 95 % confidence interval (CI), 1.01, 1.06; P = 0.010), PE (OR, 1.04; 95 % CI, 1.01, 1.08; P = 0.009), and DVT (OR, 1.06; 95 % CI, 1.02, 1.10; P= 0.003). The results of the weighted median, MR-Egger, and MR-PRESSO were similar to the main findings. No unbalanced pleiotropy or heterogeneity was observed. The study suggests that genetically predicted high levels of TIMP-3 may be associated with an increased risk of VTE. These findings indicate that strategies targeting TIMP-3 may provide a basis for the prevention and treatment of VTE. Further investigation is required to clarify this potential mechanism.

BACKGROUND: Promoting the balance between bone formation and bone resorption is the main therapeutic goal for postmenopausal osteoporosis (PMOP), and bone marrow mesenchymal stem cells (BMSCs) osteogenic differentiation plays an important regulatory role in this process. Recently, several long non-coding RNAs (lncRNAs) have been reported to play an important regulatory role in the occurrence and development of OP and participates in a variety of physiological and pathological processes. However, the role of lncRNA tissue inhibitor of metalloproteinases 3 (lncTIMP3) remains to be investigated.
METHODS: The characteristics of BMSCs isolated from the PMOP rat model were verified by flow cytometry assay, alkaline phosphatase (ALP), alizarin red and Oil Red O staining assays. Micro-CT and HE staining assays were performed to examine histological changes of the vertebral trabeculae of the rats. RT-qPCR and western blotting assays were carried out to measure the RNA and protein expression levels. The subcellular location of lncTIMP3 was analyzed by FISH assay. The targeting relationships were verified by luciferase reporter assay and RNA pull-down assay.
RESULTS: The trabecular spacing was increased in the PMOP rats, while ALP activity and the expression levels of Runx2, Col1a1 and Ocn were all markedly decreased. Among the RNA sequencing results of the clinical samples, lncTIMP3 was the most downregulated differentially expressed lncRNA, also its level was significantly reduced in the OVX rats. Knockdown of lncTIMP3 inhibited osteogenesis of BMSCs, whereas overexpression of lncTIMP3 exhibited the reverse results. Subsequently, lncTIMP3 was confirmed to be located in the cytoplasm of BMSCs, implying its potential as a competing endogenous RNA for miRNAs. Finally, the negative targeting correlations of miR-214 between lncTIMP3 and Smad4 were elucidated in vitro.
CONCLUSIONS: lncTIMP3 may delay the progress of PMOP by promoting the activity of BMSC, the level of osteogenic differentiation marker gene and the formation of calcium nodules by acting on the miR-214/Smad4 axis. This finding may offer valuable insights into the possible management of PMOP.

OBJECTIVE: This study aims to evaluate the effects of intermittent compressive force (ICF) on the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) by human periodontal ligament cells (hPDLCs).
METHODS: hPDLCs were subjected to ICF with a magnitude of 1.5 g/cm2 and loaded for 24 h. mRNA and protein expression of several MMPs and TIMPs were assessed using RT-PCR and ELISA analyses. An inhibitor of TGF-β (SB431542) was used to assess a possible role of TGF-β in the expression of MMPs and TIMPs under ICF.
RESULTS: mRNA and protein analyses showed that ICF significantly induced expression of TIMP1 and TIMP3, but decreased expression of MMP1. Incubation with the TGF-β inhibitor and applied to ICF showed a downregulation of TIMP3, but expression of MMP1 was not affected.
CONCLUSIONS: ICF is likely to affect ECM homeostasis by hPDLCs by regulating the expression of MMP1 and TIMPs. Moreover, TGF-β1 regulated expression of TIMP3. These findings suggest ICF may decrease the degradation of ECM and may thus be essential for maintaining PDL homeostasis.

OBJECTIVE: Tissue inhibitors of matrix metalloproteinases (TIMPs) are prognostic markers in cancers. However, the role of TIMPs in DNA methylation during invasive pituitary adenoma (PA) remains unclear. The purpose of this study was to assess the effects of TIMP2 and TIMP3 promoter demethylation on the proliferation, migration, and invasion of invasive PA cells.
METHODS: Methylation-specific polymerase chain reaction (PCR), quantitative PCR, and western blots were used to analyze the promoter methylation and expression of TIMP1-3. Cell counting kit-8 (CCK-8), wound healing, and transwell assays were carried out to determine the effects of TIMP2 and TIMP3 demethylation.
RESULTS: TIMP1-3 showed downregulated expression in invasive PA tissues and cell lines (p < 0.05). The low expression of TIMP1-3 was due to promoter methylation of these genes (p < 0.05). The results showed that downregulation of TIMP2 and TIMP3 can promote cell proliferation, migration, and invasion (p < 0.05), whereas overexpression of TIMP2 and TIMP3 can inhibit cell proliferation, migration, and invasion (p < 0.05). After treatment with 5-azacytidine (5-AzaC), the cell activity decreased, the proliferation rate decreased, and the invasion ability weakened (p < 0.05). Treatment with 5-AzaC increased TIMP2 and TIMP3 expression and decreased DNA (cytosine-5-)-methyltransferase 1 (DNMT1), DNMT3a, and DNMT3b expression (p < 0.05).
CONCLUSIONS: We showed that DNA methylation causes the silencing of TIMP2 and TIMP3 in invasive PA, it can also lead to malignant cell proliferation and cause pathological changes, whereas the use of 5-AzaC can inhibit the methylation process and can inhibit cell proliferation. Our results provide a novel method for clinical diagnosis and prevention of invasive PA.

BACKGROUND Acute kidney injury (AKI) is a common and serious complication after massive burn injury. One of the postulated etiologies is destruction of the extracellular matrix of nephrons, caused by a local imbalance between matrix metalloproteinases (MMPs) and specific inhibitors. The aim of this study was to analyze the dynamics of tissue inhibitors of metalloproteinases (TIMPs) during the first 5 days after massive thermal injury and the relationship with the risk of AKI. MATERIAL AND METHODS Thirty-three adults (22 men, 11 women) with severe burns were enrolled in the study. The values of TIMPs 1 to 4 were measured in blood serum and urine using the multiplex Luminex system. The associations between TIMPs and the risk of AKI were analyzed by using the generalized linear mixed models for repeated measurements. RESULTS Significant changes in serum and urine activities of TIMPs were confirmed, especially during the first 2 days after burn injury. Almost half of patients presented renal problems during the study. Significant differences between values of TIMPs in AKI and non-AKI status were also observed. However, a significant relationship between concentration of TIMPs and risk of AKI was confirmed only for urine TIMP-1 and serum TIMP-3. CONCLUSIONS The evaluation of TIMPs in the early stage after burn injury has potential benefits. The important roles of urine TIMP-1 and serum TIMP-3, as novel markers of the risk of AKI development, were confirmed. Other parameters require further analysis.

UNASSIGNED: We sought to explore whether sex imbalances are discernible in several autosomally inherited macular dystrophies.
UNASSIGNED: We searched the electronic patient records of our large inherited retinal disease cohort, quantifying numbers of males and females with the more common (non-ABCA4) inherited macular dystrophies (associated with BEST1, EFEMP1, PROM1, PRPH2, RP1L1, and TIMP3). BEST1 cases were subdivided into typical autosomal dominant and recessive disease. For PRPH2, only patients with variants at codons 172 or 142 were included. Recessive PROM1 and recessive RP1L1 cases were excluded because these variants give a more widespread or peripheral degeneration. The proportion of females was calculated for each condition; two-tailed binomial testing was performed. Where a significant imbalance was found, previously published cohorts were also explored.
UNASSIGNED: Of 325 patients included, numbers for BEST1, EFEMP1, PROM1, PRPH2, RP1L1, and TIMP3 were 152, 35, 30, 50, 14, and 44, respectively. For autosomal dominant Best disease (n = 115), there were fewer females (38%; 95% confidence interval [CI], 29-48%; P = 0.015). For EFEMP1-associated disease (n = 35), there were significantly more females (77%; 95% CI, 60%-90%; P = 0.0019). No significant imbalances were seen for the other genes. When pooling our cohort with previous large dominant Best disease cohorts, the proportion of females was 37% (95% CI, 31%-43%; P = 1.2 × 10-5). Pooling previously published EFEMP1-cases with ours yielded an overall female proportion of 62% (95% CI, 54%-69%; P = 0.0023).
UNASSIGNED: This exploratory study found significant sex imbalances in two autosomal macular dystrophies, suggesting that sex could be a modifier. Our findings invite replication in further cohorts and the investigation of potential mechanisms.

Sorsby fundus dystrophy (SFD) is a rare autosomal dominant disorder with macular dystrophy and severe visual loss. Mutations in TIMP3 gene has been related to SFD with mechanisms unclear. We have successfully reprogrammed the peripheral blood mononuclear cells (PBMCs) from an SFD patient carrying c.484G>A mutation in TIMP3 gene to induced pluripotent stem cells (iPSCs) and characterized their pluripotency and genetic stability. This line may serve as a useful tool to explore the role of TIMP3 in SFD pathogenesis.

Subarachnoid hemorrhage (SAH) is associated with high mortality and disability rates, and secondary white matter injury is an important cause of poor prognosis. However, whether brain capillary pericytes can directly affect the differentiation and maturation of oligodendrocyte precursor cells (OPCs) and subsequently affect white matter injury repair has still been revealed. This study was designed to investigate the effect of tissue inhibitor of metalloproteinase-3 (TIMP-3) for OPC differentiation and maturation. PDGFRβret/ret and wild-type C57B6J male mice were used to construct a mouse model of SAH via endovascular perforation in this study. Mice were also treated with vehicle, TIMP-3 RNAi or TIMP-3 RNAi + TIMP-3 after SAH. The effect of TIMP-3 on the differentiation and maturation of OPCs was determined using behavioral score, ELISA, transmission electron microscopy, immunofluorescence staining and cell culture. We found that TIMP-3 was secreted mainly by pericytes and that SAH and TIMP-3 RNAi caused a significant decrease in the TIMP-3 content, reaching a nadir at 24 h, followed by gradual recovery. In vitro, the myelin basic protein content of oligodendrocytes after oxyhemoglobin treatment was increased by TIMP-3 overexpression. The data indicates TIMP-3 could promote the differentiation and maturation of OPCs and subsequently improve neurological outcomes after SAH. Therefore, TIMP-3 could be beneficial for repair after white matter injury and could be a potential therapeutic target in SAH.

We aim to report the ocular phenotype and molecular genetic findings in two Czech families with Sorsby fundus dystrophy and to review all the reported TIMP3 pathogenic variants. Two probands with Sorsby fundus dystrophy and three first-degree relatives underwent ocular examination and retinal imaging, including optical coherence tomography angiography. The DNA of the first proband was screened using a targeted ocular gene panel, while, in the second proband, direct sequencing of the TIMP3 coding region was performed. Sanger sequencing was also used for segregation analysis within the families. All the previously reported TIMP3 variants were reviewed using the American College of Medical Genetics and the Association for Molecular Pathology interpretation framework. A novel heterozygous variant, c.455A>G p.(Tyr152Cys), in TIMP3 was identified in both families and potentially de novo in one. Optical coherence tomography angiography documented in one patient the development of a choroidal neovascular membrane at 54 years. Including this study, 23 heterozygous variants in TIMP3 have been reported as disease-causing. Application of gene-specific criteria denoted eleven variants as pathogenic, eleven as likely pathogenic, and one as a variant of unknown significance. Our study expands the spectrum of TIMP3 pathogenic variants and highlights the importance of optical coherence tomography angiography for early detection of choroidal neovascular membranes.

Sorsby fundus dystrophy (SFD) is a rare, inherited form of macular degeneration caused by mutations in the gene encoding tissue inhibitor of metalloproteinases 3 (TIMP-3). There are 21 mutations currently associated with SFD, with some variants (e.g., Ser179Cys, Tyr191Cys, and Ser204Cys) having been studied much more than others. We review what is currently known about the identified SFD variants in terms of their dimerization, metalloproteinase inhibition, and impact on angiogenesis, with a focus on disparities between reports and areas requiring further study. We also explore the potential molecular mechanisms leading to the accumulation of extracellular TIMP-3 in SFD and consider how accumulated TIMP-3 causes macular damage. Recent reports have identified extraocular pathologies in a small number of SFD patients. We discuss these intriguing findings and consider the apparent discrepancy between the widespread expression of TIMP-3 and the primarily retinal manifestations of SFD. The potential benefits of novel experimental approaches (e.g., metabolomics and stem cell models) in terms of investigating SFD pathology are presented. The review thus highlights gaps in our current molecular understanding of SFD and suggests ways to support the development of novel therapies.