Abnormal TNF activity in Timp3-/- mice leads to chronic hepatic inflammation and failure of liver regeneration

PANoptosis and Autophagy-Related Molecular Signature and Immune Landscape in Ulcerative Colitis: Integrated Analysis and Experimental Validation

Background

Ulcerative colitis (UC) is an autoimmune inflammatory disorder of the gastrointestinal tract. Programmed cell death (PCD), including PANoptosis and autophagy, plays roles in inflammation and immunity. This study aimed to investigate the molecular signature and immune landscape of the PANoptosis- and autophagy-related differentially expressed genes (DEGs) in UC.

Methods

Analyzing UC dataset GSE206285 yielded DEGs. Differentially expressed PANoptosis- and autophagy-related genes were identified using DEGs and relevant gene collections. Functional and pathway enrichment analyses were conducted. A protein-protein interaction (PPI) network was established to identify hub genes. TRRUST database predicted transcription factors (TFs), pivotal miRNAs, and drugs interacting with hub genes. Immune infiltration analysis, UC-associated single-cell sequencing data analysis, and construction of a competing endogenous RNA (ceRNA) network for hub genes were conducted. Machine learning identified key candidate genes, evaluated for diagnostic value via receiver operating characteristic (ROC) curves. A UC mice model verified expression of key candidate genes.

Results

Identifying ten PANoptosis-related hub DEGs and four autophagy-related hub DEGs associated them with cell chemotaxis, wound healing and positive MAPK cascade regulation. Immune infiltration analysis revealed increased immunocyte infiltration in UC patients, with hub genes closely linked to various immune cell infiltrations. Machine learning identified five key candidate genes, TIMP1, TIMP2, TIMP3, IL6, and CCL2, with strong diagnostic performance. At the single-cell level, these genes exhibited high expression in inflammatory fibroblasts (IAFs). They showed significant expression differences in the colon mucosa of both UC patients and UC mice model.

Conclusion

This study identified and validated novel molecular signatures associated with PANoptosis and autophagy in UC, potentially influencing immune dysregulation and wound healing, thus opening avenues for future research and therapeutic interventions.

Promoter DNA methylation patterns in oral, laryngeal and oropharyngeal anatomical regions are associated with tumor differentiation, nodal involvement and survival

Differentially methylated regions (DMRs) can be used as head and neck squamous cell carcinoma (HNSCC) diagnostic, prognostic and therapeutic targets in precision medicine workflows. DNA from 21 HNSCC and 10 healthy oral tissue samples was hybridized to a genome-wide tiling array to identify DMRs in a discovery cohort. Downstream analyses identified differences in promoter DNA methylation patterns in oral, laryngeal and oropharyngeal anatomical regions associated with tumor differentiation, nodal involvement and survival. Genome-wide DMR analysis showed 2,565 DMRs common to the three subsites. A total of 738 DMRs were unique to laryngeal cancer (n=7), 889 DMRs were unique to oral cavity cancer (n=10) and 363 DMRs were unique to pharyngeal cancer (n=6). Based on the genome-wide analysis and a Gene Ontology analysis, 10 candidate genes were selected to test for prognostic value and association with clinicopathological features. TIMP3 was associated with tumor differentiation in oral cavity cancer (P=0.039), DAPK1 was associated with nodal involvement in pharyngeal cancer (P=0.017) and PAX1 was associated with tumor differentiation in laryngeal cancer (P=0.040). A total of five candidate genes were selected, DAPK1, CDH1, PAX1, CALCA and TIMP3, for a prevalence study in a larger validation cohort: Oral cavity cancer samples (n=42), pharyngeal cancer tissues (n=25) and laryngeal cancer samples (n=52). PAX1 hypermethylation differed across HNSCC anatomic subsites (P=0.029), and was predominantly detected in laryngeal cancer. Kaplan-Meier survival analysis (P=0.043) and Cox regression analysis of overall survival (P=0.001) showed that DAPK1 methylation is associated with better prognosis in HNSCC. The findings of the present study showed that the HNSCC subsites oral cavity, pharynx and larynx display substantial differences in aberrant DNA methylation patterns, which may serve as prognostic biomarkers and therapeutic targets.

Expression Profiles of Matrix Metalloproteinases and Their Inhibitors in Nasal Polyps

Purpose

Nasal polyp (NP) is characterized by inflammation of the sinonasal mucosa with predominant inflammatory cell infiltration. Matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) are recognized to play an important role in leukocyte migration in airway inflammation. Herein, efforts were made to confirm the expression levels of MMPs/TIMPs and study the relationship between the infiltration of inflammatory cells and local expression levels of MMPs/TIMPs in NPs.

Patients and Methods

NP tissues were obtained from 42 Chinese patients with bilateral nasal polyps during the endoscopic sinus surgery. Inferior turbinate (IT) tissues from 19 patients with septal deviation were taken during the rhinoplasty surgery as controls. mRNA and protein levels of MMP1, MMP9, MMP10, MMP12, TIMP1 and TIMP3 were assessed by quantitative PCR and immunohistochemistry.

Results

Eosinophilia (72%, 23/32 samples), neutrophilia (41%, 13/32 samples), and increase in macrophages (38%, 12/32 samples) were found in NP tissues. mRNA expression of MMP1 (10.9-fold), MMP9 (4.1-fold), MMP10 (6.7-fold) and MMP12 (3.5-fold) were significantly up-regulated, while TIMP1 (1.5-fold) and TIMP3 (6.0-fold) were significantly down-regulated in NPs (n=42) as compared to the controls (n=19). The immunostaining levels of all 4 MMPs and two TIMPs were higher in NPs than those in controls. The co-localization of MMP1/MMP10/MMP12 and macrophages were identified in NPs. MMP9 was mainly expressed in neutrophils, while TIMP1 or TIMP3 were mostly found in eosinophils in NPs.

Conclusion

The results of our study indicate that tissue remodeling is significant in NPs, where MMPs/TIMPs play important roles in both tissue remodeling and inflammatory cells infiltration.

The protease ADAM17 at the crossroads of disease: revisiting its significance in inflammation, cancer, and beyond

The protease A Disintegrin And Metalloproteinase 17 (ADAM17) plays a central role in the pathophysiology of several diseases. ADAM17 is involved in the cleavage and shedding of at least 80 known membrane-tethered proteins, which subsequently modulate several intracellular signaling pathways, and therefore alter cell behavior. Dysregulated expression and/or activation of ADAM17 has been linked to a wide range of autoimmune and inflammatory diseases, cancer, and cardiovascular disease. In this review, we provide an overview of the current state of knowledge from preclinical models and clinical data on the diverse pathophysiological roles of ADAM17, and discuss the mechanisms underlying ADAM17-mediated protein shedding and the potential therapeutic implications of targeting ADAM17 in these diseases.

Using siRNA Silencing to Analyze ADAM17 in Macrophages

Silencing expression with short interfering RNA (siRNA) is a rapid and cost-effective way to analyze the involvement of target genes in a range of biological processes. Here we describe isolation of primary human monocytes from peripheral blood and their in vitro differentiation to macrophages, followed by electroporation with siRNA to silence expression of a disintegrin and metalloproteinase 17 (ADAM17). This enables evaluation of ADAM17's role in cleaving transmembrane proteins, such as its prototypic substrate tumor necrosis factor (TNF), by enzyme-linked immunosorbent assay (ELISA), flow cytometry, or immunoblotting.

Unveiling the power of microenvironment in liver regeneration: an in-depth overview

The liver serves as a vital regulatory hub for various physiological processes, including sugar, protein, and fat metabolism, coagulation regulation, immune system maintenance, hormone inactivation, urea metabolism, and water-electrolyte acid-base balance control. These functions rely on coordinated communication among different liver cell types, particularly within the liver's fundamental hepatic lobular structure. In the early stages of liver development, diverse liver cells differentiate from stem cells in a carefully orchestrated manner. Despite its susceptibility to damage, the liver possesses a remarkable regenerative capacity, with the hepatic lobule serving as a secure environment for cell division and proliferation during liver regeneration. This regenerative process depends on a complex microenvironment, involving liver resident cells, circulating cells, secreted cytokines, extracellular matrix, and biological forces. While hepatocytes proliferate under varying injury conditions, their sources may vary. It is well-established that hepatocytes with regenerative potential are distributed throughout the hepatic lobules. However, a comprehensive spatiotemporal model of liver regeneration remains elusive, despite recent advancements in genomics, lineage tracing, and microscopic imaging. This review summarizes the spatial distribution of cell gene expression within the regenerative microenvironment and its impact on liver regeneration patterns. It offers valuable insights into understanding the complex process of liver regeneration.

Construction of an Exudative Age-Related Macular Degeneration Diagnostic and Therapeutic Molecular Network Using Multi-Layer Network Analysis, a Fuzzy Logic Model, and Deep Learning Techniques: Are Retinal and Brain Neurodegenerative Disorders Related?

Neovascular age-related macular degeneration (nAMD) is a leading cause of irreversible visual impairment in the elderly. The current management of nAMD is limited and involves regular intravitreal administration of anti-vascular endothelial growth factor (anti-VEGF). However, the effectiveness of these treatments is limited by overlapping and compensatory pathways leading to unresponsiveness to anti-VEGF treatments in a significant portion of nAMD patients. Therefore, a system view of pathways involved in pathophysiology of nAMD will have significant clinical value. The aim of this study was to identify proteins, miRNAs, long non-coding RNAs (lncRNAs), various metabolites, and single-nucleotide polymorphisms (SNPs) with a significant role in the pathogenesis of nAMD. To accomplish this goal, we conducted a multi-layer network analysis, which identified 30 key genes, six miRNAs, and four lncRNAs. We also found three key metabolites that are common with AMD, Alzheimer's disease (AD) and schizophrenia. Moreover, we identified nine key SNPs and their related genes that are common among AMD, AD, schizophrenia, multiple sclerosis (MS), and Parkinson's disease (PD). Thus, our findings suggest that there exists a connection between nAMD and the aforementioned neurodegenerative disorders. In addition, our study also demonstrates the effectiveness of using artificial intelligence, specifically the LSTM network, a fuzzy logic model, and genetic algorithms, to identify important metabolites in complex metabolic pathways to open new avenues for the design and/or repurposing of drugs for nAMD treatment.

Single-cell analysis of dorsal root ganglia reveals metalloproteinase signaling in satellite glial cells and pain

Satellite glial cells (SGCs) are among the most abundant non-neuronal cells in dorsal root ganglia (DRGs) and closely envelop sensory neurons that detect painful stimuli. However, little is still known about their homeostatic activities and their contribution to pain. Using single-cell RNA sequencing (scRNA-seq), we were able to obtain a unique transcriptional profile for SGCs. We found enriched expression of the tissue inhibitor metalloproteinase 3 (TIMP3) and other metalloproteinases in SGCs. Small interfering RNA and neutralizing antibody experiments revealed that TIMP3 modulates somatosensory stimuli. TIMP3 expression decreased after paclitaxel treatment, and its rescue by delivery of a recombinant TIMP3 protein reversed and prevented paclitaxel-induced pain. We also established that paclitaxel directly impacts metalloproteinase signaling in cultured SGCs, which may be used to identify potential new treatments for pain. Therefore, our results reveal a metalloproteinase signaling pathway in SGCs for proper processing of somatosensory stimuli and potential discovery of novel pain treatments.

Impact of Gut Recolonization on Liver Regeneration: Hepatic Matrisome Gene Expression after Partial Hepatectomy in Mice

The hepatic matrisome is involved in the remodeling phase of liver regeneration. As the gut microbiota has been implicated in liver regeneration, we investigated its role in liver regeneration focusing on gene expression of the hepatic matrisome after partial hepatectomy (PHx) in germ-free (GF) mice, and in GF mice reconstituted with normal gut microbiota (XGF). Liver mass restoration, hepatocyte proliferation, and immune response were assessed following 70% PHx. Hepatic matrisome and collagen gene expression were also analyzed. Reduced liver weight/body weight ratio, mitotic count, and hepatocyte proliferative index at 72 h post PHx in GF mice were preceded by reduced expression of cytokine receptor genes Tnfrsf1a and Il6ra, and Hgf gene at 3 h post PHx. In XGF mice, these indices were significantly higher than in GF mice, and similar to that of control mice, indicating normal liver regeneration. Differentially expressed genes (DEGs) of the matrisome were lower in GF compared to XGF mice at both 3 h and 72 h post PHx. GF mice also demonstrated lower collagen expression, with significantly lower expression of Col1a1, Col1a2, Col5a1, and Col6a2 compared to WT mice at 72 h post PHx. In conclusion, enhanced liver regeneration and matrisome expression in XGF mice suggests that interaction of the gut microbiota and matrisome may play a significant role in the regulation of hepatic remodeling during the regenerative process.

Role of the extracellular matrix in COVID-19

An outbreak of coronavirus disease 2019 (COVID-19) has spread globally, with over 500 million cases and 6 million deaths to date. COVID-19 is associated with a systemic inflammatory response and abnormalities of the extracellular matrix (ECM), which is also involved in inflammatory storms. Upon viral infection, ECM proteins are involved in the recruitment of inflammatory cells and interference with target organ metabolism, including in the lungs. Additionally, serum biomarkers of ECM turnover are associated with the severity of COVID-19 and may serve as potential targets. Consequently, understanding the expression and function of ECM, particularly of the lung, during severe acute respiratory syndrome of the coronavirus 2 infection would provide valuable insights into the mechanisms of COVID-19 progression. In this review, we summarize the current findings on ECM, such as hyaluronic acid, matrix metalloproteinases, and collagen, which are linked to the severity and inflammation of COVID-19. Some drugs targeting the extracellular surface have been effective. In the future, these ECM findings could provide novel perspectives on the pathogenesis and treatment of COVID-19.

The extracellular microenvironment in immune dysregulation and inflammation in retinal disorders

Inherited retinal dystrophies (IRDs) as well as genetically complex retinal phenotypes represent a heterogenous group of ocular diseases, both on account of their phenotypic and genotypic characteristics. Therefore, overlaps in clinical features often complicate or even impede their correct clinical diagnosis. Deciphering the molecular basis of retinal diseases has not only aided in their disease classification but also helped in our understanding of how different molecular pathologies may share common pathomechanisms. In particular, these relate to dysregulation of two key processes that contribute to cellular integrity, namely extracellular matrix (ECM) homeostasis and inflammation. Pathological changes in the ECM of Bruch's membrane have been described in both monogenic IRDs, such as Sorsby fundus dystrophy (SFD) and Doyne honeycomb retinal dystrophy (DHRD), as well as in the genetically complex age-related macular degeneration (AMD) or diabetic retinopathy (DR). Additionally, complement system dysfunction and distorted immune regulation may also represent a common connection between some IRDs and complex retinal degenerations. Through highlighting such overlaps in molecular pathology, this review aims to illuminate how inflammatory processes and ECM homeostasis are linked in the healthy retina and how their interplay may be disturbed in aging as well as in disease.

Transcriptomic landscape of TIMP3 oncosuppressor activity in thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid tumor. The tissue inhibitor of metalloproteinase-3 (TIMP3) gene encodes a matrix metalloproteinases inhibitor that exerts a tumor suppressor role in several tumor types. TIMP3 is frequently downregulated in PTC by promoter methylation. We have previously functionally demonstrated that TIMP3 exerts an oncosuppressor role in PTC: TIMP3 restoration in the PTC-derived NIM1 cell line affects in vitro migration, invasion and adhesive capability, while reduces tumor growth, angiogenesis and macrophage recruitment in vivo. To get a deeper insight on the mediators of TIMP3 oncosuppressor activity in thyroid tumors, here we focused on the TIMP3 related transcriptome.

METHODS

TCGA database was used for investigating the genes differentially expressed in PTC samples with low and high TIMP3 expression. Genome wide expression analysis of clones NIM1-T23 (expressing a high level of TIMP3 protein) and NIM1-EV (control empty vector) was performed. Gene sets and functional enrichment analysis with clusterProfiler were applied to identify the modulated biological processes and pathways. CIBERSORT was used to evaluate the distribution of different immunological cell types in TCGA-PTC tumor samples with different TIMP3 expression levels. Real time PCR was performed for the validation of selected genes.

RESULTS

Thyroid tumors with TIMP3-high expression showed a down-modulation of inflammation-related gene sets, along with a reduced protumoral hematopoietic cells fraction; an enrichment of cell adhesion functions was also identified. Similar results were obtained in the TIMP3-overexpessing NIM1 cells in vitro model, where a down-regulation of immune-related function gene sets, some of which also identified in tumor samples, was observed. Interestingly, through enrichment analysis, were also recognized terms related to cell adhesion, extracellular matrix organization, blood vessel maintenance and vascular process functions that have been found modulated in our previous in vitro and in vivo functional studies.

CONCLUSIONS

Our results highlight the correlation of TIMP3 expression levels with the regulation of inflammatory functions and the immune infiltration composition associated with different PTC prognosis, thus providing a broader view on the oncosuppressor role of TIMP3 in PTC.

Potential CRISPR Base Editing Therapeutic Options in a Sorsby Fundus Dystrophy Patient

TIMP3 mutations are associated with early-onset macular choroidal neovascularisation for which no treatment currently exists. CRISPR base editing, with its ability to irreversibly correct point mutations by chemical modification of nucleobases at DNA level, may be a therapeutic option. We report a bioinformatic analysis of potential therapeutic options in a patient presenting with Sorsby fundus dystrophy. Genetic testing in a 35-year-old gentleman with bilateral macular choroidal neovascularisation revealed the patient to be heterozygous for a TIMP3 variant c.610A>T, p.(Ser204Cys). Using a glycosylase base editor (GBE), another DNA-edit could be introduced that would revert the variant back to wild-type on amino acid level. Alternatively, the mutated residue could be changed to another amino acid that would be better tolerated, and for that, an available 'NG'-PAM site was found to be available for the SpCas9-based adenine base editor (ABE) that would introduce p.(Ser204Arg). In silico analyses predicted this variant to be non-pathogenic; however, a bystander edit, p.Ile205Thr, would be introduced. This case report highlights the importance of considering genetic testing in young patients with choroidal neovascularisation, particularly within the context of a strong family history of presumed wet age-related macular degeneration, and describes potential therapeutic options.

Treatment of Sorsby fundus dystrophy with anti-tumor necrosis factor-alpha medication

PURPOSE

Tissue inhibitor of matrix metalloproteinase (TIMP)-3 has many functions, including preventing the constituent formation of tumor necrosis factor-alpha (TNFα) in tissue. Sorsby macular dystrophy is caused by a mutation in the gene responsible for TIMP-3, suggesting a potential treatment.

METHODS

Comprehensive ophthalmologic examination with multimodal imaging to include optical coherence tomography (OCT) and OCT angiography were used to evaluate a patient with Sorsby fundus dystrophy treated first with intravitreal triamcinolone, then with adalimumab.

RESULTS

A 35-year-old woman presented in 2003 with aggressive macular neovascularization in both eyes related to Sorsby macular dystrophy c.610A>T (p.Ser204Cys). Her visual acuity was 20/25 in the right and 20/400 in the left eye. She was treated with periodic intravitreal injections of 4 mg triamcinolone, which caused the neovascularization to become inactive. When switched to intravitreal bevacizumab, she showed disease activity. She was switched back to intravitreal triamcinolone with minimal signs of exudation and hemorrhage. Because of the high lifetime risk of complication, she was switched to subcutaneous adalimumab and in follow-up over 18 months had no signs of disease activity. The visual acuity in the right eye was 20/20.

CONCLUSIONS

TIMP3 has numerous effects including controlling local TNFα production. It is possible with the mutation in the gene for TIMP-3, abnormally high tissue levels of TNFα are produced in the eye. Direct inhibition of TNFα action by adalimumab offers a molecularly targeted approach to the disease pathophysiology and merits increased study.

Tumor necrosis factor-α and matrix metalloproteinase-9 cooperatively exacerbate neurovascular degeneration in the neonatal rat retina

Matrix metalloproteinases (MMPs) and tumor necrosis factor (TNF)-α contribute to the pathogenesis of several ocular diseases. Previous studies have shown that MMP-9 activation plays an important role in capillary degeneration in injured retinas. In this study, we aimed to determine the roles of TNF-α in capillary degeneration and MMP-9 activation in the injured retina. In rats, retinal injury was induced by intravitreal injection of N-methyl-D-aspartic acid (NMDA, 200 nmol) at postnatal day 7. We examined (1) the effects of blocking MMP-9 and TNF-α signaling pathway on capillary degeneration, (2) changes in protein levels and distribution of MMP-9 and TNF-α, and (3) the interaction between MMP-9 and TNF-α in regulating the expression level of each protein in retinas of NMDA-injected eyes. Intravitreal injection of GM6001, an MMP inhibitor, or TNF-α neutralizing antibody (anti-TNF-α Ab) attenuated capillary degeneration in retinas of NMDA-injected eyes. Protein levels of TNF-α increased 2 h after NMDA injection, whereas those of MMP-9 increased 4 h after the injection. Anti-TNF-α Ab suppressed activation of MMP-9 in retinas of NMDA-injected eyes, whereas GM6001 diminished the TNF-α protein expression. Incubation of recombinant TNF-α with supernatants of homogenized retina increased protein levels and activity of MMP-9. These results suggest that TNF-α and MMP-9 collaboratively increase their expression levels in the retina following neurodegeneration, thus leading to retinal capillary degeneration. The cooperative interaction between MMP-9 and TNF-α could be involved in the exacerbation of retinal neurovascular degeneration.

Dysregulation of Liver Regeneration by Hepatitis B Virus Infection: Impact on Development of Hepatocellular Carcinoma

The liver is unique in its ability to regenerate in response to damage. The complex process of liver regeneration consists of multiple interactive pathways. About 2 billion people worldwide have been infected with hepatitis B virus (HBV), and HBV causes 686,000 deaths each year due to its complications. Long-term infection with HBV, which causes chronic inflammation, leads to serious liver-related diseases, including cirrhosis and hepatocellular carcinoma. HBV infection has been reported to interfere with the critical mechanisms required for liver regeneration. In this review, the studies on liver tissue characteristics and liver regeneration mechanisms are summarized. Moreover, the inhibitory mechanisms of HBV infection in liver regeneration are investigated. Finally, the association between interrupted liver regeneration and hepatocarcinogenesis, which are both triggered by HBV infection, is outlined. Understanding the fundamental and complex liver regeneration process is expected to provide significant therapeutic advantages for HBV-associated hepatocellular carcinoma.

ADAM Metalloproteinase Domain 17 Regulates Cholestasis-Associated Liver Injury and Sickness Behavior Development in Mice

Disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) is a ubiquitously expressed membrane-bound enzyme that mediates shedding of a wide variety of important regulators in inflammation including cytokines and adhesion molecules. Hepatic expression of numerous cytokines and adhesion molecules are increased in cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), however, the pathophysiological role of ADAM17 in regulating these conditions remains unknown. Therefore, we evaluated the role of ADAM17 in a mouse model of cholestatic liver injury due to bile duct ligation (BDL). We found that BDL enhanced hepatic ADAM17 protein expression, paralleled by increased ADAM17 bioactivity. Moreover, inhibition of ADAM17 bioactivity with the specific inhibitor DPC 333 significantly improved both biochemical and histological evidence of liver damage in BDL mice. Patients with cholestatic liver disease commonly experience adverse behavioral symptoms, termed sickness behaviors. Similarly, BDL in mice induces reproducible sickness behavior development, driven by the upregulated expression of cytokines and adhesion molecules that are in turn regulated by ADAM17 activity. Indeed, inhibition of ADAM17 activity significantly ameliorated BDL-associated sickness behavior development. In translational studies, we evaluated changes in ADAM17 protein expression in liver biopsies obtained from patients with PBC and PSC, compared to normal control livers. PSC and PBC patients demonstrated increased hepatic ADAM17 expression in hepatocytes, cholangiocytes and in association with liver-infiltrating immune cells compared to normal controls. In summary, cholestatic liver injury in mice and humans is associated with increased hepatic ADAM17 expression. Furthermore, inhibition of ADAM17 activity improves both cholestatic liver injury and associated sickness behavior development, suggesting that ADAM17 inhibition may represent a novel therapeutic approach for treating patients with PBC/PSC.

Dichotomous Role of Tumor Necrosis Factor in Pulmonary Barrier Function and Alveolar Fluid Clearance

Alveolar-capillary leak is a hallmark of the acute respiratory distress syndrome (ARDS), a potentially lethal complication of severe sepsis, trauma and pneumonia, including COVID-19. Apart from barrier dysfunction, ARDS is characterized by hyper-inflammation and impaired alveolar fluid clearance (AFC), which foster the development of pulmonary permeability edema and hamper gas exchange. Tumor Necrosis Factor (TNF) is an evolutionarily conserved pleiotropic cytokine, involved in host immune defense against pathogens and cancer. TNF exists in both membrane-bound and soluble form and its mainly -but not exclusively- pro-inflammatory and cytolytic actions are mediated by partially overlapping TNFR1 and TNFR2 binding sites situated at the interface between neighboring subunits in the homo-trimer. Whereas TNFR1 signaling can mediate hyper-inflammation and impaired barrier function and AFC in the lungs, ligand stimulation of TNFR2 can protect from ventilation-induced lung injury. Spatially distinct from the TNFR binding sites, TNF harbors within its structure a lectin-like domain that rather protects lung function in ARDS. The lectin-like domain of TNF -mimicked by the 17 residue TIP peptide- represents a physiological mediator of alveolar-capillary barrier protection. and increases AFC in both hydrostatic and permeability pulmonary edema animal models. The TIP peptide directly activates the epithelial sodium channel (ENaC) -a key mediator of fluid and blood pressure control- upon binding to its α subunit, which is also a part of the non-selective cation channel (NSC). Activity of the lectin-like domain of TNF is preserved in complexes between TNF and its soluble TNFRs and can be physiologically relevant in pneumonia. Antibody- and soluble TNFR-based therapeutic strategies show considerable success in diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, but their chronic use can increase susceptibility to infection. Since the lectin-like domain of TNF does not interfere with TNF's anti-bacterial actions, while exerting protective actions in the alveolar-capillary compartments, it is currently evaluated in clinical trials in ARDS and COVID-19. A more comprehensive knowledge of the precise role of the TNFR binding sites versus the lectin-like domain of TNF in lung injury, tissue hypoxia, repair and remodeling may foster the development of novel therapeutics for ARDS.

Liver regeneration biology: Implications for liver tumour therapies

The liver has remarkable regenerative potential, with the capacity to regenerate after 75% hepatectomy in humans and up to 90% hepatectomy in some rodent models, enabling it to meet the challenge of diverse injury types, including physical trauma, infection, inflammatory processes, direct toxicity, and immunological insults. Current understanding of liver regeneration is based largely on animal research, historically in large animals, and more recently in rodents and zebrafish, which provide powerful genetic manipulation experimental tools. Whilst immensely valuable, these models have limitations in extrapolation to the human situation. In vitro models have evolved from 2-dimensional culture to complex 3 dimensional organoids, but also have shortcomings in replicating the complex hepatic micro-anatomical and physiological milieu. The process of liver regeneration is only partially understood and characterized by layers of complexity. Liver regeneration is triggered and controlled by a multitude of mitogens acting in autocrine, paracrine, and endocrine ways, with much redundancy and cross-talk between biochemical pathways. The regenerative response is variable, involving both hypertrophy and true proliferative hyperplasia, which is itself variable, including both cellular phenotypic fidelity and cellular trans-differentiation, according to the type of injury. Complex interactions occur between parenchymal and non-parenchymal cells, and regeneration is affected by the status of the liver parenchyma, with differences between healthy and diseased liver. Finally, the process of termination of liver regeneration is even less well understood than its triggers. The complexity of liver regeneration biology combined with limited understanding has restricted specific clinical interventions to enhance liver regeneration. Moreover, manipulating the fundamental biochemical pathways involved would require cautious assessment, for fear of unintended consequences. Nevertheless, current knowledge provides guiding principles for strategies to optimise liver regeneration potential.

Transcriptome-Wide Analysis of Human Liver Reveals Age-Related Differences in the Expression of Select Functional Gene Clusters and Evidence for a PPP1R10-Governed 'Aging Cascade'

A transcriptome-wide analysis of human liver for demonstrating differences between young and old humans has not yet been performed. However, identifying major age-related alterations in hepatic gene expression may pinpoint ontogenetic shifts with important hepatic and systemic consequences, provide novel pharmacogenetic information, offer clues to efficiently counteract symptoms of old age, and improve the overarching understanding of individual decline. Next-generation sequencing (NGS) data analyzed by the Mann-Whitney nonparametric test and Ensemble Feature Selection (EFS) bioinformatics identified 44 transcripts among 60,617 total and 19,986 protein-encoding transcripts that significantly (p = 0.0003 to 0.0464) and strikingly (EFS score > 0.3:16 transcripts; EFS score > 0.2:28 transcripts) differ between young and old livers. Most of these age-related transcripts were assigned to the categories 'regulome', 'inflammaging', 'regeneration', and 'pharmacogenes'. NGS results were confirmed by quantitative real-time polymerase chain reaction. Our results have important implications for the areas of ontogeny/aging and the age-dependent increase in major liver diseases. Finally, we present a broadly substantiated and testable hypothesis on a genetically governed 'aging cascade', wherein PPP1R10 acts as a putative ontogenetic master regulator, prominently flanked by IGFALS and DUSP1. This transcriptome-wide analysis of human liver offers potential clues towards developing safer and improved therapeutic interventions against major liver diseases and increased insights into key mechanisms underlying aging.

Structure-based molecular insights into matrix metalloproteinase inhibitors in cancer treatments

Protease inhibitors are of considerable interest as anticancer agents. Matrix metalloproteinases (MMPs) were the earliest type of proteases considered as anticancer targets. The developments of MMP inhibitors (MMPIs) by pharmaceutical companies can be dated from the early 1980s. Thus far, none of the over 50 MMPIs entering clinical trials have been approved. This work summarizes the reported studies on the structure of MMPs and complexes with ligands and inhibitors, based on which, the authors analyzed the clinical failures of MMPIs in a structural biological manner. Furthermore, MMPs were systematically compared with urokinase, a protease-generating plasmin, which plays similar pathological roles in cancer development; the reasons for the clinical successes of urokinase inhibitors and the clinical failures of MMPIs are discussed.

SARS-CoV-2 and pathological matrix remodeling mediators

BACKGROUND

Recognizing only sharp elevation in a short period of time, the COVID-19 SARS-CoV-2 propagation is more and more marked in the whole world. Induced inflammation afterwards infection engenders a high infiltration of immune cells and cytokines that triggers matrix metalloproteinases (MMPs) activation. These endopeptidases are mediators of the lung extracellular matrix (ECM), a basic element for alveoli structure and gas exchange.

METHODS

When immune cells, MMPs, secreted cytokines and several other mediators are gathered a pathological matrix remodeling occurs. This phenomenon tends to tissue destruction in the first place and a pulmonary hypertrophy and fibrosis in the second place.

FINDINGS

After pathological matrix remodeling establishment, pathological diseases take place even after infection state. Since post COVID-19 pulmonary fibrosis is an emerging complication of the disease, there is an urge to better understand and characterize the implication of ECM remodeling during SARS-CoV-2 infection.

CONCLUSION

Targeting MMPs and their inhibitors could be a probable solution for occurred events since there are many cured patients that remain with severe sequels even after the end of infection.

Quantitative Proteomics Reveals Changes Induced by TIMP-3 on Cell Membrane Composition and Novel Metalloprotease Substrates

Ectodomain shedding is a key mechanism of several biological processes, including cell-communication. Disintegrin and metalloproteinases (ADAMs), together with the membrane-type matrix metalloproteinases, play a pivotal role in shedding transmembrane proteins. Aberrant shedding is associated to several pathological conditions, including arthritis. Tissue inhibitor of metalloproteases 3 (TIMP-3), an endogenous inhibitor of ADAMs and matrix metalloproteases (MMPs), has been proven to be beneficial in such diseases. Thus, strategies to increase TIMP-3 bioavailability in the tissue have been sought for development of therapeutics. Nevertheless, high levels of TIMP-3 may lead to mechanism-based side-effects, as its overall effects on cell behavior are still unknown. In this study, we used a high-resolution mass-spectrometry-based workflow to analyze alterations induced by sustained expression of TIMP-3 in the cell surfaceome. In agreement with its multifunctional properties, TIMP-3 induced changes on the protein composition of the cell surface. We found that TIMP-3 had differential effects on metalloproteinase substrates, with several that accumulated in TIMP-3-overexpressing cells. In addition, our study identified potentially novel ADAM substrates, including ADAM15, whose levels at the cell surface are regulated by the inhibitor. In conclusion, our study reveals that high levels of TIMP-3 induce modifications in the cell surfaceome and identifies molecular pathways that can be deregulated via TIMP-3-based therapies.

Strategies to Target ADAM17 in Disease: From its Discovery to the iRhom Revolution

For decades, disintegrin and metalloproteinase 17 (ADAM17) has been the object of deep investigation. Since its discovery as the tumor necrosis factor convertase, it has been considered a major drug target, especially in the context of inflammatory diseases and cancer. Nevertheless, the development of drugs targeting ADAM17 has been harder than expected. This has generally been due to its multifunctionality, with over 80 different transmembrane proteins other than tumor necrosis factor α (TNF) being released by ADAM17, and its structural similarity to other metalloproteinases. This review provides an overview of the different roles of ADAM17 in disease and the effects of its ablation in a number of in vivo models of pathological conditions. Furthermore, here, we comprehensively encompass the approaches that have been developed to accomplish ADAM17 selective inhibition, from the newest non-zinc-binding ADAM17 synthetic inhibitors to the exploitation of iRhom2 to specifically target ADAM17 in immune cells.

Classical and novel GH receptor signaling pathways

In this review, I summarize historical and recent features of the classical pathways activated by growth hormone (GH) through the cell surface GH receptor (GHR). GHR is a cytokine receptor superfamily member that signals by activating the non-receptor tyrosine kinase, JAK2, and members of the Src family kinases. Activation of the GHR engages STATs, PI3K, and ERK pathways, among others, and details of these now-classical pathways are presented. Modulating elements, including the SOCS proteins, phosphatases, and regulated GHR metalloproteolysis, are discussed. In addition, a novel physical and functional interaction of GHR with IGF-1R is summarized and discussed in terms of its mechanisms, consequences, and physiological and therapeutic implications.

Myeloid tumor necrosis factor and heme oxygenase-1 regulate the progression of colorectal liver metastases during hepatic ischemia-reperfusion

The liver ischemia-reperfusion (IR) injury that occurs consequently to hepatic resection performed in patients with metastases can lead to tumor relapse for not fully understood reasons. We assessed the effects of liver IR on tumor growth and the innate immune response in a mouse model of colorectal (CR) liver metastasis. Mice subjected to liver ischemia 2 days after intrasplenic injection of CR carcinoma cells displayed a higher metastatic load in the liver, correlating with Kupffer cells (KC) death through the activation of receptor-interating protein 3 kinase (RIPK3) and caspase-1 and a recruitment of monocytes. Interestingly, the immunoregulatory mediators, tumor necrosis factor-α (TNF-α) and heme oxygenase-1 (HO-1) were strongly upregulated in recruited monocytes and were also expressed in the surviving KC following IR. Using TNF^flox/flox LysM^cre/wt mice, we showed that TNF deficiency in macrophages and monocytes favors tumor progression after IR. The antitumor effect of myeloid cell-derived TNF involved direct tumor cell apoptosis and a reduced expression of immunosuppressive molecules such as transforming growth factor-β, interleukin (IL)-10, inducible nitric oxyde synthase (iNOS), IL-33 and HO-1. Conversely, a monocyte/macrophage-specific deficiency in HO-1 (HO-1^flox/flox LysM^cre/wt ) or the blockade of HO-1 function led to the control of tumor progression post-liver IR. Importantly, host cell RIPK3 deficiency maintains the KC number upon IR, inhibits the IR-induced innate cell recruitment, increases the TNF level, decreases the HO-1 level and suppresses the tumor outgrowth. In conclusion, tumor recurrence in host undergoing liver IR is associated with the death of antitumoral KC and the recruitment of monocytes endowed with immunosuppressive properties. In both of which HO-1 inhibition would reinforce their antitumoral activity.

Noninvasive Assessment of Liver Fibrosis: Current and Future Clinical and Molecular Perspectives

Liver fibrosis is one of the risk factors for hepatocellular carcinoma (HCC) development. The staging of liver fibrosis can be evaluated only via a liver biopsy, which is an invasive procedure. Noninvasive methods for the diagnosis of liver fibrosis can be divided into morphological tests such as elastography and serum biochemical tests. Transient elastography is reported to have excellent performance in the diagnosis of liver fibrosis and has been accepted as a useful tool for the prediction of HCC development and other clinical outcomes. Two-dimensional shear wave elastography is a new technique and provides a real-time stiffness image. Serum fibrosis markers have been studied based on the mechanism of fibrogenesis and fibrolysis. In the healthy liver, homeostasis of the extracellular matrix is maintained directly by enzymes called matrix metalloproteinases (MMPs) and their specific inhibitors, tissue inhibitors of metalloproteinases (TIMPs). MMPs and TIMPs could be useful serum biomarkers for liver fibrosis and promising candidates for the treatment of liver fibrosis. Further studies are required to establish liver fibrosis-specific markers based on further clinical and molecular research. In this review, we summarize noninvasive fibrosis tests and molecular mechanism of liver fibrosis in current daily clinical practice.

Poncirin attenuates CCL4-induced liver injury through inhibition of oxidative stress and inflammatory cytokines in mice

Background

In the present study, the poncirin which is flavonoid-7-o-glycosides (isolated from the Poncirus trifoliata) in nature was evaluated against the Carbon tetra chloride (CCL4)-induced liver injury. The poncirin have been reported for various anti-inflammatory, analgesic activity etc. Based on the previous studies it was anticipated that the poncirin will ameliorate CCL4-induced liver injury.

Methods

The CCL4-induced acute and chronic liver injury model (albino BALB/c mice) was used. Following the induction of the liver injury various parameters such as food and water intake, body weight and weight to dry ratio changes were assessed. Furthermore, various hematological, biochemical parameters and histological studies such as hemotoxylin and eosin (H and E) staining were performed. The poncirin treatment was also evaluated against the pro-inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) using enzyme link immunosorbant assay (ELISA). The Swiss Target prediction software was used to investigate interaction of the poncirin on the various hepatic enzymes.

Results

The poncirin treatment markedly improved the behavioral parameters such as food and water intake. The liver weight variation was attenuated and total body was improved markedly. The hematological and biochemical parameters were significantly improved compared to the CCL4 treated groups. The anti-oxidants were induced, while oxidative stress markers were reduced promisingly. The H and E staining showed that poncirin treatment significantly improved the histology of liver compared to the CCL4 treated group. Furthermore, the poncirin treatment also evidently decreased the inflammatory mediators.

Conclusions

The poncirin treatment showed marked improvement in behavioral, biochemical and histological parameters following CCL4-induced liver injury. Additionally, the poncirin treatment also markedly improved the antioxidant enzymes, attenuated the oxidative stress markers and inflammatory cytokines.

Loss of TIMP3 expression induces inflammation, matrix degradation, and vascular ingrowth in nucleus pulposus: A new mechanism of intervertebral disc degeneration

Low back pain (LBP) is one of the most common complains in orthopedic outpatient department and intervertebral disc degeneration (IDD) is one of the most important reasons of LBP. The mechanisms of IDD contain a complex biochemical cascade which includes inflammation, vascular ingrowth, and results in degradation of matrix. In our study, we used both in vitro and in vivo models to investigate the relation between tissue inhibitor of metalloproteinase-3 (TIMP3) expression and IDD. Loss of TIMP3 expression was found in degenerative intervertebral disc (IVD), this change of expression was closely related with the dephosphorylation of smad2/3. Overexpression of TIMP3 significantly inhibited the release of TNF-α and matrix degradation induced by Lipopolysaccharide. Vascular ingrowth was also suppressed by TIMP3 in the in vitro and in vivo models. Further, animal experiments confirmed that the degeneration of IVD was reduced after overexpression of TIMP3 in nucleus pulposus. Taken together, our results indicated TIMP-3 might play an important role in the pathogenesis of IDD and therefore be a potential therapeutic target in the future.

Overexpression of TIMP3 inhibits discogenic pain by suppressing angiogenesis and the expression of substance P in nucleus pulposus

Approximately 50% of the cases of low back pain (LBP) are attributed to discogenic origin. The causes of discogenic pain are complicated and consist of a complex biochemical cascade. Neovascularization of intervertebral discs (IVDs) is believed to be associated with discogenic pain. The anti‑angiogenesis ability of tissue inhibitor of metalloproteinase‑3 (TIMP3) has been reported in many tumors, yet whether TIMP3 is associated with neovascularization of IVDs remains unknown. In the present study, both in vitro and in vivo models were used to investigate the association between discogenic pain and TIMP3 expression in nucleus pulposus (NP). PCR results demonstrated that inflammation induced downregulation of TIMP3 expression in NP cells. By using an adenovirus system to upregulate TIMP3 expression, the effect of TIMP3 on angiogenesis was measured by endothelial cell migration and tube formation assays. The results demonstrated that overexpression of TIMP3 suppressed angiogenesis in NP without the regulation of vascular endothelial growth factor (VEGF) expression. TNF‑α converting enzyme (TACE) expression was downregulated by TIMP3, thus inhibiting the TACE‑induced activation of TNF‑α in NP cells. Immunohistochemical staining of IVDs also confirmed that TIMP3 inhibited the expression of substance P in NP. Taken together, the present results indicated the expression of TIMP3 in NP may have a key role in the development of discogenic pain.

Tissue Inhibitor of Metalloproteinase 3 Deficiency Disrupts the Hepatocyte E-Cadherin/β-Catenin Complex and Induces Cell Death in Liver Ischemia/Reperfusion Injury

Tissue inhibitor of metalloproteinase (TIMP) 3 is a naturally occurring inhibitor of a broad range of proteases, with key roles in extracellular matrix turnover and in the pathogenesis of various diseases. In this study, we investigated the response of mice lacking TIMP3 (TIMP3-/-) to hepatic ischemia/reperfusion injury (IRI). We report here that TIMP3-/- mice showed an enhanced inflammatory response, exacerbated organ damage, and further impaired liver function after IRI when compared with their wild-type littermates. Loss of TIMP3 led to the cleavage and shedding of E-cadherin during hepatic IRI; the full-length 120-kDa E-cadherin and the ratio of 38-kDa C-terminal fragment/120-kDa E-cadherin were decreased and increased, respectively, in TIMP3-/- livers after IRI. Moreover, GI254023X, a potent inhibitor of a disintegrin and metalloprotease (ADAM) 10, was capable of partially rescuing the expression of E-cadherin in the TIMP3-null hepatocytes. The proteolysis of E-cadherin in the TIMP3-/- livers was also linked to the loss of β-catenin from the hepatocyte membranes and to an increased susceptibility to apoptosis after liver IRI. In a similar fashion, depression of the E-cadherin/β-catenin complex mediated by TIMP3 deletion and knockdown of β-catenin by small interfering RNA were both capable of inducing caspase activation in isolated hepatocytes subjected to H₂ O₂ oxidative stress. Hence, these results support a protective role for TIMP3 expression in sheltering the hepatocyte E-cadherin/β-catenin complex from proteolytic processing and inhibiting apoptosis after hepatic IRI.

Silver Decorated Mesoporous Carbons for the Treatment of Acute and Chronic Wounds, in a Tissue Regeneration Context

INTRODUCTION

Silver decorated mesoporous carbons are interesting systems that may offer effective solutions for advanced wound care products by combining the well-known anti-microbial activity of silver nanoparticles with the versatile properties of ordered mesoporous carbons. Silver is being used as a topical antimicrobial agent, especially in wound repair. However, while silver shows bactericidal properties, it is also cytotoxic at high concentrations. Therefore, the incorporation of silver into ordered mesoporous carbons allows to exploit both silver's biological effects and mesoporous carbons' biocompatibility and versatility with the purpose of conceiving silver-doped materials in light of the growing health concern in wound care.

METHODS

The wound healing potential of an ordered mesoporous carbon also doped with two different loadings of silver nanoparticles (2 wt% and 10 wt%), was investigated through a biological assessment study based on different assays (cell viability, inflammation, antibacterial tests, macrophage-conditioned fibroblast and human keratinocyte cell cultures).

RESULTS

The results show silver-doped ordered mesoporous carbons to positively condition cell viability, with a cell viability percentage >70% even for 10 wt% Ag, to modulate the expression of inflammatory cytokines and of genes involved in tissue repair (KRT6a, VEGFA, IVN) and remodeling (MMP9, TIMP3) in different cell systems. Furthermore, along with the biocompatibility and the bioactivity, the silver-doped ordered mesoporous carbons still retain an antibacterial effect, as shown by a maximum of 13.1% of inhibited area in the Halo test. The obtained results clearly showed that the silver-doped ordered mesoporous carbons exhibit both good biocompatibility and antibacterial effect with enhanced re-epithelialization, angiogenesis promotion and tissue regeneration.

DISCUSSION

These findings suggest that the exceptional properties of silver-doped ordered mesoporous carbons could be exploited in the treatment of acute and chronic wounds and that such carbon materials could be potential candidates for use in medical devices for wound healing purposes, in particular, the 10 wt% loading, as the results showed to be the most effective.

The Diverse Roles of TIMP-3: Insights into Degenerative Diseases of the Senescent Retina and Brain

Tissue inhibitor of metalloproteinase-3 (TIMP-3) is a component of the extracellular environment, where it mediates diverse processes including matrix regulation/turnover, inflammation and angiogenesis. Rare TIMP-3 risk alleles and mutations are directly linked with retinopathies such as age-related macular degeneration (AMD) and Sorsby fundus dystrophy, and potentially, through indirect mechanisms, with Alzheimer's disease. Insights into TIMP-3 activities may be gleaned from studying Sorsby-linked mutations. However, recent findings do not fully support the prevailing hypothesis that a gain of function through the dimerisation of mutated TIMP-3 is responsible for retinopathy. Findings from Alzheimer's patients suggest a hitherto poorly studied relationship between TIMP-3 and the Alzheimer's-linked amyloid-beta (A) proteins that warrant further scrutiny. This may also have implications for understanding AMD as aged/diseased retinae contain high levels of A. Findings from TIMP-3 knockout and mutant knock-in mice have not led to new treatments, particularly as the latter does not satisfactorily recapitulate the Sorsby phenotype. However, recent advances in stem cell and in vitro approaches offer novel insights into understanding TIMP-3 pathology in the retina-brain axis, which has so far not been collectively examined. We propose that TIMP-3 activities could extend beyond its hitherto supposed functions to cause age-related changes and disease in these organs.

ADAM17: An Emerging Therapeutic Target for Lung Cancer

Lung cancer is the leading cause of cancer-related mortality, which histologically is classified into small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). NSCLC accounts for approximately 85% of all lung cancer diagnoses, with the majority of patients presenting with lung adenocarcinoma (LAC). KRAS mutations are a major driver of LAC, and are closely related to cigarette smoking, unlike mutations in the epidermal growth factor receptor (EGFR) which arise in never-smokers. Although the past two decades have seen fundamental progress in the treatment and diagnosis of NSCLC, NSCLC still is predominantly diagnosed at an advanced stage when therapeutic interventions are mostly palliative. A disintegrin and metalloproteinase 17 (ADAM17), also known as tumour necrosis factor-α (TNFα)-converting enzyme (TACE), is responsible for the protease-driven shedding of more than 70 membrane-tethered cytokines, growth factors and cell surface receptors. Among these, the soluble interleukin-6 receptor (sIL-6R), which drives pro-inflammatory and pro-tumourigenic IL-6 trans-signaling, along with several EGFR family ligands, are the best characterised. This large repertoire of substrates processed by ADAM17 places it as a pivotal orchestrator of a myriad of physiological and pathological processes associated with the initiation and/or progression of cancer, such as cell proliferation, survival, regeneration, differentiation and inflammation. In this review, we discuss recent research implicating ADAM17 as a key player in the development of LAC, and highlight the potential of ADAM17 inhibition as a promising therapeutic strategy to tackle this deadly malignancy.

Post-stroke inflammation-target or tool for therapy?

Inflammation is currently considered a prime target for the development of new stroke therapies. In the acute phase of ischemic stroke, microglia are activated and then circulating immune cells invade the peri-infarct and infarct core. Resident and infiltrating cells together orchestrate the post-stroke inflammatory response, communicating with each other and the ischemic neurons, through soluble and membrane-bound signaling molecules, including cytokines. Inflammation can be both detrimental and beneficial at particular stages after a stroke. While it can contribute to expansion of the infarct, it is also responsible for infarct resolution, and influences remodeling and repair. Several pre-clinical and clinical proof-of-concept studies have suggested the effectiveness of pharmacological interventions that target inflammation post-stroke. Experimental evidence shows that targeting certain inflammatory cytokines, such as tumor necrosis factor, interleukin (IL)-1, IL-6, and IL-10, holds promise. However, as these cytokines possess non-redundant protective and immunoregulatory functions, their neutralization or augmentation carries a risk of unwanted side effects, and clinical translation is, therefore, challenging. This review summarizes the cell biology of the post-stroke inflammatory response and discusses pharmacological interventions targeting inflammation in the acute phase after a stroke that may be used alone or in combination with recanalization therapies. Development of next-generation immune therapies should ideally aim at selectively neutralizing pathogenic immune signaling, enhancing tissue preservation, promoting neurological recovery and leaving normal function intact.

Integrated network analysis of transcriptomic and protein-protein interaction data in taurine-treated hepatic stellate cells

BACKGROUND

Studies show that the antifibrotic mechanism of taurine may involve its inhibition of the activation and proliferation of hepatic stellate cells (HSCs). Since the molecular mechanism of taurine-mediated antifibrotic activity has not been fully unveiled and is little studied, it is imperative to use “omics” methods to systematically investigate the molecular mechanism by which taurine inhibits liver fibrosis.

AIM

To establish a network including transcriptomic and protein-protein interaction data to elucidate the molecular mechanism of taurine-induced HSC apoptosis.

METHODS

We used microarrays, bioinformatics, protein-protein interaction (PPI) network, and sub-modules to investigate taurine-induced changes in gene expression in human HSCs (LX-2). Subsequently, all of the differentially expressed genes (DEGs) were subjected to gene ontology function and Kyoto encyclopedia of genes and genomes pathway enrichment analysis. Furthermore, the interactions of DEGs were explored in a human PPI network, and sub-modules of the DEGs interaction network were analyzed using Cytoscape software.

RESULTS

A total of 635 DEGs were identified in taurine-treated HSCs when compared with the controls. Of these, 304 genes were statistically significantly up-regulated, and 331 down-regulated. Most of these DEGs were mainly located on the membrane and extracellular region, and are involved in the biological processes of signal transduction, cell proliferation, positive regulation of extracellular regulated protein kinases 1 (ERK1) and ERK2 cascade, extrinsic apoptotic signaling pathway and so on. Fifteen significantly enriched pathways with DEGs were identified, including mitogen-activated protein kinase (MAPK) signaling pathway, peroxisome proliferators-activated receptor signaling pathway, estrogen signaling pathway, Th1 and Th2 cell differentiation, cyclic adenosine monophosphate signaling pathway and so on. By integrating the transcriptomics and human PPI data, nine critical genes, including MMP2, MMP9, MMP21, TIMP3, KLF10, CX3CR1, TGFB1, VEGFB, and EGF, were identified in the PPI network analysis.

CONCLUSION

Taurine promotes the apoptosis of HSCs via up-regulating TGFB1 and then activating the p38 MAPK-JNK-Caspase9/8/3 pathway. These findings enhance the understanding of the molecular mechanism of taurine-induced HSC apoptosis and provide references for liver disorder therapy.

LRP1 Controls TNF Release via the TIMP-3/ADAM17 Axis in Endotoxin-Activated Macrophages

The metalloproteinase ADAM17 plays a pivotal role in initiating inflammation by releasing TNF from its precursor. Prolonged TNF release causes many chronic inflammatory diseases, indicating that tight regulation of ADAM17 activity is essential for resolution of inflammation. In this study, we report that the endogenous ADAM17 inhibitor TIMP-3 inhibits ADAM17 activity only when it is bound to the cell surface and that cell surface levels of TIMP-3 in endotoxin-activated human macrophages are dynamically controlled by the endocytic receptor LRP1. Pharmacological blockade of LRP1 inhibited endocytic clearance of TIMP-3, leading to an increase in cell surface levels of the inhibitor that blocked TNF release. Following LPS stimulation, TIMP-3 levels on the surface of macrophages increased 4-fold within 4 h and continued to accumulate at 6 h, before a return to baseline levels at 8 h. This dynamic regulation of cell surface TIMP-3 levels was independent of changes in TIMP-3 mRNA levels, but correlated with shedding of LRP1. These results shed light on the basic mechanisms that maintain a regulated inflammatory response and ensure its timely resolution.

TIMP Loss Activates Metalloproteinase-TNFα-DKK1 Axis To Compromise Wnt Signaling and Bone Mass

Deregulated proteolysis invariably underlies most human diseases including bone pathologies. Metalloproteinases constitute the largest of the five protease families, and the metzincin metalloproteinases are inhibited by the four tissue inhibitors of metalloproteinase called TIMPs. We hypothesized that Timp genes are essential for skeletal homeostasis. We bred individual Timp knockout mice to generate unique mouse models, the quadruple Timp null strain (QT) as well as mice harboring only a single Timp3 allele (QT3^+/- ). QT mice are grossly smaller and exhibit a dramatic reduction of trabeculae in long bones by μCT imaging with a corresponding increase in metalloproteinase activity. At the cellular level, Timp deficiency compromised differentiation markers, matrix deposition and mineralization in neonatal osteoblasts from calvariae, as well as the fibroblastic colony-forming unit (CFU-F) capacity of bone marrow-derived stromal cells. In contrast, we observed that osteoclasts were overactive in the Timp null state, consistent with the noted excessive bone resorption of QT bones. Immunohistochemistry (IHC) and immunofluorescence (IF) analyses of bone sections revealed higher Cathepsin K and RANKL signals upon Timp loss. Seeking the molecular mechanism, we identified abnormal TNFα bioactivity to be a central event in Timp-deficient mice. Specifically, TNFα triggered induction of the Wnt signaling inhibitor Dkk1 in the osteoblasts at the mRNA and protein levels, with a simultaneous increase in RANKL. Neutralizing TNFα antibody was capable of rescuing the induction of Dkk1 as well as RANKL. Therefore, the generation of novel Timp-deficient systems allowed us to uncover the essential and collective function of TIMP proteins in mammalian long-bone homeostasis. Moreover, our study discovers a functional TIMP/metalloproteinase-TNFα-Dkk1/RANKL nexus for optimal control of the bone microenvironment, which dictates coexistence of the osteoblast and osteoclast lineages. © 2018 American Society for Bone and Mineral Research.

Tissue inhibitor of the metalloproteinases-3 gene polymorphisms and carotid plaque susceptibility in the Han Chinese population

Tissue inhibitor of metalloproteinases (TIMPs) are endogenous inhibitors of matrix metalloproteinases that are involved in normal cellular processes and in the development and progression of atherosclerosis. Our purpose was to evaluate the polymorphisms of the TIMP-3 genes for their associations with carotid plaques or with serum protein levels in the Han Chinese population. Two promoter variants, -915A/G (rs2234921) and -1296T/C (rs9619311), were genotyped in 548 subjects with no plaques, 462 subjects with echogenic plaques, and 427 subjects with mixture plaques. The serum TIMP-3 levels were measured using an enzyme-linked immunosorbent assay (ELISA). There was a strong linkage disequilibrium between -1296T/C and -915A/G (D' = 1.0, r² = 0.991). The individuals with the genotype (TC+CC) were 1.8 times more likely to have mixture plaques than the individuals with the TT genotype (P = 0.001, OR: 1.836, 95%CI: 1.269-2.665). The frequency of the C allele in the mixture plaque group was significantly higher than in the no plaque group (P = 0.009, CI: 1.119-2.187). We observed a significant elevation of the TIMP-3 levels in the serum of patients affected with mixture plaques compared to those with no plaques (P = 0.013). The current data suggest that genetic variation in the TIMP-3 genes may contribute to individual differences in mixture plaque susceptibility in the Han Chinese population.

Multipotent Adult Progenitor Cells, but Not Tissue Inhibitor of Matrix Metalloproteinase-3, Increase Tissue Sparing and Reduce Urological Complications following Spinal Cord Injury

Following spinal cord injury (SCI), inflammation amplifies damage beyond the initial insult, providing an opportunity for targeted treatments. An ideal protective therapy would reduce both edema within the lesion area and the activation/infiltration of detrimental immune cells. Previous investigations demonstrated the efficacy of intravenous injection of multipotent adult progenitor cells (MAPC^®) to modulate immune response following SCI, leading to significant improvements in tissue sparing, locomotor and urological functions. Separate studies have demonstrated that tissue inhibitor of matrix metalloproteinase-3 (TIMP3) reduces blood-brain barrier permeability following traumatic brain injury in a mouse model, leading to improved functional recovery. This study examined whether TIMP3, delivered alone or in concert with MAPC cells, improves functional recovery from a contusion SCI in a rat model. The results suggest that intravenous delivery of MAPC cell therapy 1 day following acute SCI significantly improves tissue sparing and impacts functional recovery. TIMP3 treatment provided no significant benefit, and further, when co-administered with MAPC cells, it abrogated the therapeutic effects of MAPC cell therapy. Importantly, this study demonstrated for the first time that acute treatment of SCI with MAPC cells can significantly reduce the incidence of urinary tract infection (UTI) and the use of antibiotics for UTI treatment.

Sphingosine 1-phosphate stimulates eyelid closure in the developing rat by stimulating EGFR signaling

In many mammals, the eyelids migrate over the eye and fuse during embryogenesis to protect the cornea from damage during birth and early life. Loss-of-function mutations affecting the epidermal growth factor receptor (EGFR) signaling pathway cause an eyes-open-at-birth (EOB) phenotype in rodents. We identified an insertional mutation in Spinster homolog 2 (Spns2) in a strain of transgenic rats exhibiting the EOB phenotype. Spns2, a sphingosine 1-phosphate (S1P) transporter that releases S1P from cells, was enriched at the tip of developing eyelids in wild-type rat embryos. Spns2 expression or treatment with S1P or any one of several EGFR ligands rescued the EOB Spns2 mutant phenotype in vivo and in tissue explants in vitro and rescued the formation of stress fibers in primary keratinocytes from mutants. S1P signaled through the receptors S1PR1, S1PR2, and S1PR3 to activate extracellular signal–regulated kinase (ERK) and EGFR-dependent mitogen-activated protein kinase kinase kinase 1 (MEKK1)–c-Jun signaling. S1P also induced the nuclear translocation of the transcription factor MAL in a manner dependent on EGFR signaling. MAL and c-Jun stimulated the expression of the microRNAs miR-21 and miR-222, both of which target the metalloprotease inhibitor TIMP3, thus promoting metalloprotease activity. The metalloproteases ADAM10 and ADAM17 stimulated EGFR signaling by cleaving a membrane-anchored form of EGF to release the ligand. Our results outline a network by which S1P transactivates EGFR signaling through a complex mechanism involving feedback between several intra- and extracellular molecules to promote eyelid fusion in the developing rat.

Targeting hepatic miR-221/222 for therapeutic intervention of nonalcoholic steatohepatitis in mice

Background

Effective targeting therapies for common chronic liver disease nonalcoholic steatohepatitis (NASH) are in urgent need. MicroRNA-targeted therapeutics would be potentially an effective treatment strategy of hepatic diseases. Here we investigated the functional role of miR-221/222 and the therapeutic effects of antimiRs-221/222 in NASH mouse models.

Methods

We generated the miR-221/222^flox/flox mice on a C57BL/6 J background and the hepatic miR-221/222 knockout (miR-221/222-LKO) mice. The mice were challenged with the methionine and choline deficient diet (MCDD) or chronic carbon tetrachloride (CCl₄) treatment to generate experimental steatohepatitis models. Adenovirus-mediated re-expression of miR-221/222 was performed on the MCDD-fed miR-221/222-LKO mice. The MCDD and control diet-fed mice were treated with locked nucleic acid (LNA)-based antimiRs of miR-221/222 to evaluate the therapeutic effects. Histological analysis, RNA-seq, quantitative PCR and Western blot of liver tissues were carried out to study the hepatic lipid accumulation, inflammation and collagen deposition in mouse models.

Findings

Hepatic deletion of miR-221/222 resulted in significant reduction of liver fibrosis, lipid deposition and inflammatory infiltration in the MCDD-fed and CCl4-treated mouse models. The hepatic steatosis and fibrosis were dramatically aggravated by miR-221/222 re-expression in MCDD-fed miR-221/222-LKO mice. AntimiRs of miR-221/222 could effectively reduce the MCDD-mediated hepatic steatosis and fibrosis. Systematically mechanistic study revealed that hepatic miR-221/222 controlled the expression of target gene Timp3 and promoted the progression of NASH.

Interpretation

Our findings demonstrate that miR-221/222 are crucial for the regulation of lipid metabolism, inflammation and fibrosis in the liver. LNA-antimiRs targeted miR-221/222 could reduce steatohepatitis with prominent antifibrotic effect in NASH mice.

Fund

This work is supported by the Natural Science Foundation of China (81530020, 81390352 to Dr. Ning and 81522032 to Dr. Cao and 81670793 to Dr. Jiang); National Key Research and Development Program (No. 2016YFC0905001 and 2017YFC0909703 to Dr. Cao); the Shanghai Rising-Star Program (15QA1402900 to Dr. Cao); Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant (20171905 to Dr. Jiang).

Increased TIMP-3 expression alters the cellular secretome through dual inhibition of the metalloprotease ADAM10 and ligand-binding of the LRP-1 receptor

The tissue inhibitor of metalloproteinases-3 (TIMP-3) is a major regulator of extracellular matrix turnover and protein shedding by inhibiting different classes of metalloproteinases, including disintegrin metalloproteinases (ADAMs). Tissue bioavailability of TIMP-3 is regulated by the endocytic receptor low-density-lipoprotein receptor-related protein-1 (LRP-1). TIMP-3 plays protective roles in disease. Thus, different approaches have been developed aiming to increase TIMP-3 bioavailability, yet overall effects of increased TIMP-3 in vivo have not been investigated. Herein, by using unbiased mass-spectrometry we demonstrate that TIMP-3-overexpression in HEK293 cells has a dual effect on shedding of transmembrane proteins and turnover of soluble proteins. Several membrane proteins showing reduced shedding are known as ADAM10 substrates, suggesting that exogenous TIMP-3 preferentially inhibits ADAM10 in HEK293 cells. Additionally identified shed membrane proteins may be novel ADAM10 substrate candidates. TIMP-3-overexpression also increased extracellular levels of several soluble proteins, including TIMP-1, MIF and SPARC. Levels of these proteins similarly increased upon LRP-1 inactivation, suggesting that TIMP-3 increases soluble protein levels by competing for their binding to LRP-1 and their subsequent internalization. In conclusion, our study reveals that increased levels of TIMP-3 induce substantial modifications in the cellular secretome and that TIMP-3-based therapies may potentially provoke undesired, dysregulated functions of ADAM10 and LRP-1.

TIMP3 Overexpression Improves the Sensitivity of Osteosarcoma to Cisplatin by Reducing IL-6 Production

Osteosarcoma is the most common bone cancer in children and adolescents. Tissue inhibitors of metalloproteinases (TIMPs)-3 inhibit matrix metalloproteinases to limit extracellular matrix degradation. Cisplatin is a widely used chemotherapeutic drug used to cure osteosarcoma. Interleukin (IL)-6 and TIMP3 play important roles in the drug resistance of osteosarcoma; however, their relationship in this process remains unclear. This study aimed to explore the role of TIMP3 in the cisplatin sensitivity of osteosarcoma and its underlying molecular mechanisms in vitro and in vivo. We compared TIMP3 expression levels between patients with cisplatin-sensitive and -insensitive osteosarcoma. TIMP3 was overexpressed or knocked down in the Saos2-lung cell line, which is a Saos2 subtype isolated from pulmonary metastases that has higher cisplatin chemoresistance than Saos2 cells. IL-6 expression, cell proliferation, sensitivity to cisplatin, migration, and invasion after TIMP3 overexpression or knockdown were determined. The same experiments were performed using MG63 and U2OS cells. Subsequently, luciferase-labeled Saos2-lung cells overexpressing TIMP3 were injected into the tibiae of nude mice treated with cisplatin. The results showed that IL-6 inhibited TIMP3 expression in Saos2 and Saos2-lung cells via signal transducer and activator of transcription 3 (STAT3) activation. STAT3 knockdown reversed the effect of IL-6. The expression of TIMP3 was higher in patients with cisplatin-sensitive osteosarcoma than in those with insensitive osteosarcoma. IL-6 expression was downregulated upon TIMP3 overexpression, and upregulated by TIMP3 knockdown. TIMP3 overexpression suppressed cell proliferation and enhanced cisplatin sensitivity by activating apoptosis-related signal pathways and inhibiting IL-6 expression in vitro and in vivo. In conclusion, cisplatin sensitivity correlated positively with TIMP3 expression, which is regulated by the IL-6/TIMP3/caspase pathway. The TIMP3 pathway could represent a target for new therapies to treat osteosarcoma.

IL-32 gamma reduces lung tumor development through upregulation of TIMP-3 overexpression and hypomethylation

The low expression of tissue inhibitor of metalloproteinase 3 (TIMP-3) is important in inflammatory responses. Therefore, inhibition of TIMP-3 may promote tumor development. Our study showed that expression of TIMP-3 was elevated in lL-32γ mice lung tissues. In this study, we investigated whether IL-32γ mice inhibited lung tumor development through overexpression of TIMP-3 and its methylation. To explore the possible underlying mechanism, lung cancer cells were transfected with IL-32γ cDNA plasmid. A marked increase in TIMP-3 expression was caused by promoter methylation. Mechanistic studies indicated that TIMP-3 overexpression reduced NF-κB activity, which led to cell growth inhibition in IL-32γ transfected lung cancer cells. We also showed that IL-32γ inhibits expression of DNA (cytosine-5-)-methyltransferase 1 (DNMT1). Moreover, IL-32γ inhibits the binding of DNMT1 to TIMP-3 promoter, but this effect was reversed by the treatment of DNA methyltransferase inhibitor (5-Aza-CdR) and NF-κB inhibitor (PS1145), suggesting that a marked increase in TIMP-3 expression was caused by inhibition of promoter hypermethylation via decreased DNMT1 expression through the NF-κB pathway. In an in vivo carcinogen induced lung tumor model, tumor growth was inhibited in IL-32γ overexpressed mice with elevated TIMP-3 expression and hypomethylation accompanied with reduced NF-κB activity. Moreover, in the lung cancer patient tissue, the expression of IL-32 and TIMP-3 was dramatically decreased at a grade-dependent manner compared to normal lung tissue. In summary, IL-32γ may increase TIMP-3 expression via hypomethylation through inactivation of NF-κB activity, and thereby reduce lung tumor growth.

Pericyte ALK5/TIMP3 Axis Contributes to Endothelial Morphogenesis in the Developing Brain

The murine embryonic blood-brain barrier (BBB) consists of endothelial cells (ECs), pericytes (PCs), and basement membrane. Although PCs are critical for inducing vascular stability, signaling pathways in PCs that regulate EC morphogenesis during BBB development remain unexplored. Herein, we find that murine embryos lacking the transforming growth factor β (TGF-β) receptor activin receptor-like kinase 5 (Alk5) in brain PCs (mutants) develop gross germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH). The germinal matrix (GM) is a highly vascularized structure rich in neuronal and glial precursors. We show that GM microvessels of mutants display abnormal dilation, reduced PC coverage, EC hyperproliferation, reduced basement membrane collagen, and enhanced perivascular matrix metalloproteinase activity. Furthermore, ALK5-depleted PCs downregulate tissue inhibitor of matrix metalloproteinase 3 (TIMP3), and TIMP3 administration to mutants improves endothelial morphogenesis and attenuates GMH-IVH. Overall, our findings reveal a key role for PC ALK5 in regulating brain endothelial morphogenesis and a substantial therapeutic potential for TIMP3 during GMH-IVH.

TIMP3 deficiency exacerbates iron overload-mediated cardiomyopathy and liver disease

Chronic iron overload results in heart and liver diseases and is a common cause of morbidity and mortality in patients with genetic hemochromatosis and secondary iron overload. We investigated the role of tissue inhibitor of metalloproteinase 3 (TIMP3) in iron overload-mediated tissue injury by subjecting male mice lacking Timp3 ( Timp3^-/-) and wild-type (WT) mice to 12 wk of chronic iron overload. Whereas WT mice with iron overload developed diastolic dysfunction, iron-overloaded Timp3^-/- mice showed worsened cardiac dysfunction coupled with systolic dysfunction. In the heart, loss of Timp3 was associated with increased myocardial fibrosis, greater Timp1, matrix metalloproteinase ( Mmp) 2, and Mmp9 expression, increased active MMP-2 levels, and gelatinase activity. Iron overload in Timp3^-/- mice showed twofold higher iron accumulation in the liver compared with WT mice because of constituently lower levels of ferroportin. Loss of Timp3 enhanced the hepatic inflammatory response to iron overload, leading to greater neutrophil and macrophage infiltration and increased hepatic fibrosis. Expression of inflammation-related MMPs (MMP-12 and MMP-13) and inflammatory cytokines (IL-1β and monocyte chemoattractant protein-1) was elevated to a greater extent in iron-overloaded Timp3^-/- livers. Gelatin zymography demonstrated equivalent increases in MMP-2 and MMP-9 levels in WT and Timp3^-/- iron-overloaded livers. Loss of Timp3 enhanced the susceptibility to iron overload-mediated heart and liver injury, suggesting that Timp3 is a key protective molecule against iron-mediated pathology. NEW & NOTEWORTHY In mice, loss of tissue inhibitor of metalloproteinase 3 ( Timp3) was associated with systolic and diastolic dysfunctions, twofold higher hepatic iron accumulation (attributable to constituently lower levels of ferroportin), and increased hepatic inflammation. Loss of Timp3 enhanced the susceptibility to iron overload-mediated injury, suggesting that Timp3 plays a key protective role against iron-mediated pathology.

Induction of liver proliferation using a polymeric platform in mice

AIMS

Currently, animal models of liver regeneration are based on extensive lesions of the native organ and on cellular approaches using biomaterials to host growth factors and extracellular components to create artificial liver systems. We report a polymeric biological platform, minimally invasive, that induced sequential proliferation of liver parenchyma inside the scaffold in mice.

MAIN METHODS

Porous discs of polyether-polyurethane were surgically placed under the left liver lobe and removed at days 4, 8, 12 and 25 after implantation. No exogenous growth factors or extracellular matrix components were added to the scaffold. Histological analysis of the implants was performed to identify hepatocytes, liver vascular structures and bile ducts in the newly formed tissue. In addition, systemic markers for hepatic function were determined.

KEY FINDINGS

This biohybrid device provided a scaffold that was gradually filled with parenchymal and non-parenchymal liver tissue as detected by histological analysis. At day 4, the pores of the scaffold were filled with inflammatory cells and spindled-shaped like fibroblasts, and extracellular matrix components. At day 8, hepatocytes clusters, central lobular hepatic veins, portal space containing arteries, veins and biliary ducts were detected. By days 12 and 25 a liver-like structure filled 2/3 of the scaffold. Its organization resembled that of a mature liver. Serum concentration of ALT increased three-fold initially after implantation, returning gradually to control levels.

SIGNIFICANCE

The plain synthetic scaffold (without addition of exogenous molecules) placed under the intact left liver lobe exhibits the potential to investigate physiological mechanisms that regulate liver parenchyma proliferation.