Expression of the Metalloproteinase ADAM8 Is Upregulated in Liver Inflammation Models and Enhances Cytokine Release In Vitro

Transcriptome alterations in sf3b4-depleted zebrafish: Insights into cataract formation in retinitis pigmentosa model

Posterior subcapsular cataract (PSC) frequently develops as a complication in patients with retinitis pigmentosa (RP). Despite numerous scientific investigations, the intricate pathomechanisms underlying cataract formation in individuals affected by RP remain elusive. Therefore, our study aims to elucidate the potential pathogenesis of cataracts in an RP model using splicing factor subunit 3b (sf3b4) mutant zebrafish. By analyzing our previously published transcriptome dataset, we identified that, in addition to RP, cataract was listed as the second condition in our transcriptomic analysis. Furthermore, we confirmed the presence of nucleus retention in the lens fiber cells, along with abnormal cytoskeleton expression in both the lens fiber cells and lens epithelial cells in sf3b4-depleted fish. Upon closer examination, we identified 20 differentially expressed genes (DEGs) that played a role in cataract formation, with 95 % of them related to the downregulation of structural lens proteins. Additionally, we also identified that among all the DEGs, 13 % were associated with fibrotic processes. It seems that the significant upregulation of inflammatory mediators, in conjunction with TGF-β signaling, plays a central role in the cellular biology of PSC and posterior capsular opacification (PCO) in sf3b4 mutant fish. In summary, our study provides valuable insights into cataract formation in the RP model of sf3b4 mutants, highlighting its complexity driven by changes in structural lens proteins and increased cytokines/growth factors.

ADAM8 silencing suppresses the migration and invasion of fibroblast-like synoviocytes via FSCN1/MAPK cascade in osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is a degenerative joint disease that affects elderly populations worldwide, causing pain and disability. Alteration of the fibroblast-like synoviocytes (FLSs) phenotype leads to an imbalance in the synovial inflammatory microenvironment, which accelerates the progression of OA. Despite this knowledge, the specific molecular mechanisms of the synovium that affect OA are still unclear.

METHODS

Both in vitro and in vivo experiments were undertaken to explore the role of ADAM8 playing in the synovial inflammatory of OA. A small interfering RNA (siRNA) was targeting ADAM8 to intervene. High-throughput sequencing was also used.

RESULTS

Our sequencing analysis revealed significant upregulation of the MAPK signaling cascade and ADAM8 gene expression in IL-1β-induced FLSs. The in vitro results demonstrated that ADAM8 blockade inhibited the invasion and migration of IL-1β-induced FLSs, while also suppressing the expression of related matrix metallomatrix proteinases (MMPs). Furthermore, our study revealed that inhibiting ADAM8 weakened the inflammatory protein secretion and MAPK signaling networks in FLSs. Mechanically, it revealed that inhibiting ADAM8 had a significant effect on the expression of migration-related signaling proteins, specifically FSCN1. When siADAM8 was combined with BDP-13176, a FSCN1 inhibitor, the migration and invasion of FLSs was further inhibited. These results suggest that FSCN1 is a crucial downstream factor of ADAM8 in regulating the biological phenotypes of FLSs. The in vivo experiments demonstrated that ADAM8 inhibition effectively reduced synoviocytes inflammation and alleviated the progression of OA in rats.

CONCLUSIONS

ADAM8 could be a promising therapeutic target for treating OA by targeting synovial inflammation.

A jack of all trades - ADAM8 as a signaling hub in inflammation and cancer

As a member of the family of A Disintegrin And Metalloproteinases (ADAM) ADAM8 is preferentially expressed in lymphatic organs, immune cells, and tumor cells. The substrate spectrum for ADAM8 proteolytic activity is not exclusive but is related to effectors of inflammation and signaling in the tumor microenvironment. In addition, complexes of ADAM8 with extracellular binding partners such as integrin β-1 cause an extensive intracellular signaling in tumor cells, thereby activating kinase pathways with STAT3, ERK1/2, and Akt signaling, which causes increased cell survival and enhanced motility. The cytoplasmic domain of ADAM8 harbors five SRC homology-3 (SH3) domains that can potentially interact with several proteins involved in actin dynamics and cell motility, including Myosin 1F (MYO1F), which is essential for neutrophil motility. The concept of ADAM8 thus involves immune cell recruitment, in most cases leading to an enhancement of inflammatory (asthma, COPD) and tumor (including pancreatic and breast cancers) pathologies. In this review, we report on available studies that qualify ADAM8 as a therapeutic target in different pathologies. As a signaling hub, ADAM8 controls extracellular, intracellular, and intercellular communication, the latter one mainly mediated by the release of extracellular vesicles with ADAM8 as cargo. Here, we will dissect the contribution of different domains to these distinct ways of communication in several pathologies. We conclude that therapeutic targeting attempts for ADAM8 should consider blocking more than a single domain and that this requires a thorough evaluation of potent molecules targeting ADAM8 in an in vivo setting.

In vitro assessment of inflammatory skin potential of poly(methyl methacrylate) at non-cytotoxic concentrations

Poly(methyl methacrylate) (PMMA) is considered an attractive substrate material for fabricating wearable skin sensors such as fitness bands and microfluidic devices. Despite its widespread use, inflammatory and allergic responses have been attributed to the use of this material. Therefore, the main objective of this study was to obtain a comprehensive understanding of potential biological effects triggered by PMMA at non-cytotoxic concentrations using in vitro models of NIH3T3 fibroblasts and reconstructed human epidermis (RhE). It was hypothesized that concentrations that do not reduce cell viability are sufficient to activate pathways of inflammatory processes in the skin. The study included cytotoxicity, cell metabolism, cytokine quantification, histopathological, and gene expression analyses. The NIH3T3 cell line was used as a testbed for screening cell toxicity levels associated with the concentration of PMMA with different molecular weights (MWs) (i.e., MW ~5,000 and ~15,000 g/mol). The lower MW of PMMA had a half-maximal inhibitory concentration (IC50 ) value of 5.7 mg/cm2 , indicating greater detrimental effects than the higher MW (IC50  = 14.0 mg/cm2 ). Non-cytotoxic concentrations of 3.0 mg/cm2 for MW ~15,000 g/mol and 0.9 mg/cm2 for MW ~5,000 g/mol) induced negative metabolic changes in NIH3T3 cells. Cell viability was severely reduced to 7% after the exposure to degradation by-products generated after thermal and photodegradation degradation of PMMA. PMMA at non-cytotoxic concentrations still induced overexpression of pro-inflammatory cytokines, chemokines, and growth factors (IL1B, CXCL10, CCL5, IL1R1, IL7, IL17A, VEGFA, FGF2, IFNG, IL15) on the RhE model. The inflammatory response was also supported by histopathological and gene expression analyses of PMMA-treated RhE, indicating tissue damage and gene overexpression. Results suggested that non-cytotoxic concentrations of PMMA (3.0 to 5.6 mg/cm2 for MW ~15,000 g/mol and 0.9 to 2.1 mg/cm2 for MW ~5,000 g/mol) were sufficient to negatively alter NIH3T3 cells metabolism and activate inflammatory events in the RhE skin.

An integrated multi-omics analysis of identifies distinct molecular characteristics in pulmonary infections of Pseudomonas aeruginosa

Pseudomonas aeruginosa (P. aeruginosa) can cause severe acute infections, including pneumonia and sepsis, and cause chronic infections, commonly in patients with structural respiratory diseases. However, the molecular and pathophysiological mechanisms of P. aeruginosa respiratory infection are largely unknown. Here, we performed assays for transposase-accessible chromatin using sequencing (ATAC-seq), transcriptomics, and quantitative mass spectrometry-based proteomics and ubiquitin-proteomics in P. aeruginosa-infected lung tissues for multi-omics analysis, while ATAC-seq and transcriptomics were also examined in P. aeruginosa-infected mouse macrophages. To identify the pivotal factors that are involved in host immune defense, we integrated chromatin accessibility and gene expression to investigate molecular changes in P. aeruginosa-infected lung tissues combined with proteomics and ubiquitin-proteomics. Our multi-omics investigation discovered a significant concordance for innate immunological and inflammatory responses following P. aeruginosa infection between hosts and alveolar macrophages. Furthermore, we discovered that multi-omics changes in pioneer factors Stat1 and Stat3 play a crucial role in the immunological regulation of P. aeruginosa infection and that their downstream molecules (e.g., Fas) may be implicated in both immunosuppressive and inflammation-promoting processes. Taken together, these findings indicate that transcription factors and their downstream signaling molecules play a critical role in the mobilization and rebalancing of the host immune response against P. aeruginosa infection and may serve as potential targets for bacterial infections and inflammatory diseases, providing insights and resources for omics analyses.