ADAM17: a molecular switch to control inflammation and tissue regeneration

Longitudinal proteomic analysis of pathophysiology in plasma and bronchoalveolar lavage fluid of patients with ARDS

BACKGROUND

Acute respiratory distress syndrome (ARDS) remains a significant clinical challenge, and its pathogenesis is not fully understood. Proteomic analyses of plasma and bronchoalveolar lavage fluid (BALF) in patients with ARDS have been performed to uncover diagnostic and prognostic markers, although previous studies have not adequately focused on longitudinal comparison of biomarkers. This study aimed to elucidate the proteomic profiles of patients with ARDS in the acute and subacute phases to better understand the pathophysiological progression of ARDS.

METHODS

This was a single-center, prospective, observational study of adult patients with ARDS in whom plasma and BALF samples were collected in the acute and subacute phases of ARDS and comprehensive proteins were identified and analyzed by mass spectrometry.

RESULTS

Plasma and BALF were collected from 21 ARDS patients and plasma from 24 healthy donors, from which 694 plasma proteins and 2017 BALF proteins were analyzed. Processes related to coagulation and complement commonly activated in plasma and BALF were more pronounced in the acute phase than in the subacute phase. In BALF in the acute phase, pathways related to humoral and immune responses were activated, whereas processes related to chaperones and protein folding were suppressed. IPA analysis showed that B cell receptor signaling was most activated, whereas heat shock protein 90 (HSP90) chaperone cycle, protein folding, and other pathways associated with cellular stress responses and proper protein processing were suppressed. The most activated upstream regulator was interferon gamma (IFN-γ) and the most suppressed was notch receptor 1 (NOTCH1).

CONCLUSIONS

The proteomics of plasma and BALF from patients with ARDS were compared in both the acute and subacute phases. In BALF in the acute phase, humoral immunity, mainly B-cell receptor signaling, was activated, whereas the HSP90 cycle and protein folding mechanisms were inactivated.

Controversies and insights into cytokine regulation of neurogenesis and behavior in adult rodents

Adult learning, memory, and social interaction partially depend on neurogenesis in two regions: the hippocampus and the subventricular zone. There is evidence that the immune system is important for these processes in pathological situations, but there is no review of its role in non-pathological or near-physiological conditions. Although further research is warranted in this area, some conclusions can be drawn. Intrusive LyC6hi monocytes and autoreactive CD4+ T cells have a positive impact on neurogenesis and behavior, but the latter are deleterious if specific to external antigens. Mildly activated microglia play a crucial role in promoting these processes, by eliminating apoptotic neuronal progenitors and producing low levels of interleukins, which increase if the cells are activated, leading to inhibition of neurogenesis. Chemokines are poorly studied, but progenitor cells and neurons express their receptors, which appear important for migration and maturation. The few works that jointly analyzed neurogenesis and behavior showed congruent effects of immune cells and cytokines. In conclusion, the immune system components -mostly local- seem of utmost importance for the control of behavior under non-pathological conditions.

IL-6 Signalling to Responding T Cells Is Key to Calcitonin Gene-Related Peptide-Exposed Endothelial Cell Enhancement of Th17 Immunity During Langerhans Cell Antigen Presentation

Calcitonin gene-related peptide (CGRP) biases Langerhans cell (LC) Ag presentation to CD4+ T cells towards Th17-type immunity through actions on endothelial cells (ECs). We now report further evidence that IL-6 signalling at responding T cells mediates this effect. This CGRP effect was absent with ECs from IL-6 KO mice. Exposure of LCs, but not T cells, to IL-6 enhanced IL-6 and IL-17A production and reduced IFN-γ in the T-cell response. Pretreatment of LCs with IL-6 receptor α-chain (IL-6Rα) antibodies prior to IL-6 exposure significantly inhibited these responses. However, T-cell pretreatment with an IL-6/IL-6Rα chimera mimicked the effect of IL-6 pretreatment of LCs on T-cell responses. When this experiment was performed in the presence of the ADAM17 and ADAM10 inhibitor TAPI-1 during LC pretreatment of LCs and during the Ag presentation culture, release of soluble IL-6Rα chains into the medium was very significantly reduced, but this did not affect levels of T-cell cytokine release. Interestingly, LC exposure to IL-6 significantly increased LC IL-6 expression. Furthermore, pretreatment of T cells with antibodies against the IL-6 receptor β-chain significantly inhibited the IL-6 effect. CGRP may stimulate ECs in lymphatics and/or lymph nodes to produce IL-6 which likely results in migrating LCs nonclassically presenting IL-6. Furthermore, we found that IL-6 induces IL-6 production by LCs, suggesting an autocrine amplification pathway for this effect.

Sustained release of cytokines from migrasomes

Cytokines are released by cells in response to infections and tissue damage. A recent paper by Jiao et al. demonstrates that circulating monocytes release the cytokines tumor necrosis factor and Interleukin-6 encapsulated in large extracellular vesicles called migrasomes, from which the cytokines are secreted locally in a sustained fashion.

Therapeutic Potential of Qilianxiaopi Formula: Targeting ADAM17-Mediated Chronic Inflammation in Atrophic Gastritis

Background: Gastric cancer (GC) is a leading cause of mortality worldwide, particularly in China. Chronic atrophic gastritis (CAG) and intestinal metaplasia (IM) are recognized as precancerous conditions contributing to GC development. Qilianxiaopi formula (QLXP), a traditional Chinese medicine (TCM), has demonstrated significant therapeutic effects on CAG and IM; however, its underlying mechanisms remain poorly understood. Methods: This study utilized chromatography-mass spectrometry to identify the major compounds in QLXP. Network pharmacology was used to predict the associated targets of these components. Thermal proteome profiling (TPP) pinpointed the potential binding proteins of QLXP, which were validated by bioinformatic analyses. Bio-layer interferometry (BLI) was used to analyze the interactions between QLXP and its key target proteins, thereby determining their binding components. Molecular docking predicted the binding modes between the components and proteins. Results: ADAM17 was identified as a key binding protein for QLXP. Further investigation revealed that QLXP inhibits the enzymatic activity of ADAM17, thereby reducing the secretion of the pro-inflammatory cytokine TNF-α, contributing to the anti-inflammatory properties of QLXP. BLI confirmed direct and reversible binding interactions between QLXP and ADAM17. Narirutin, isolated from the ADAM17 binding fraction, displayed the highest affinity for QLXP. Conclusions: This study highlights ADAM17 as a key molecular target of QLXP and narirutin as its principal binding component. The integrated approach combining chromatography-mass spectrometry, network pharmacology, TPP, BLI, and molecular docking provides a robust framework for elucidating the mechanisms of action of TCM.

L-Arginine Activates the Neuregulin-1/ErbB Receptor Signaling Pathway and Increases Utrophin mRNA Levels in C2C12 Cells

L-arginine induces the expression of utrophin in skeletal muscle cells, so it has been proposed as a pharmacological treatment to attenuate the symptoms of Duchenne muscular dystrophy (DMD). On the other hand, it has been described that one of the pathways that participates in the expression of utrophin in muscle is the Neuregulin-1 (NRG-1)/ErbB receptors pathway. Several studies have postulated that disintegrin and metalloprotease-17 (ADAM17) causes the proteolytic processing of NRG of transmembrane, allowing the release of NRG to the medium, which when joining its ErbB receptor activates the signaling pathway that triggers utrophin transcription. The aim of this study was to evaluate the effect of L-arginine in the activation of NRG-1/ErbB pathway and utrophin mRNA levels in C2C12 cells, and the participation of ADAM17 in this process. Our results indicate that L-arginine induces phosphorylation of ErbB2 and increases utrophin mRNA levels in C2C12 myotubes, with a maximum increase of 2-fold at 4 h post-stimulation. This effect is not observed when the myotubes are stimulated in the presence of GM6001 (general metalloprotease inhibitor) or PD-158780 (specific inhibitor of ErbB receptor phosphorylation). Experiments performed by flow cytometry suggest that L-arginine stimulates ADAM17 activation in our study model. Furthermore, immunofluorescence analysis supports our findings that L-arginine stimulates ADAM17 increase in treated myotubes. However, our results using pharmacological inhibitors suggest that ADAM17 does not participate in utrophin expression in C2C12 cells treated with L-arginine. The results obtained help to clarify the mechanism of action of L-arginine in the expression of utrophin in muscle cells, which will contribute to the design of new therapeutic strategies in pathologies such as DMD.

ADAM17/PTGS2 Facilitates Pulmonary Fibrosis by Regulating Ferroptosis

Pulmonary fibrosis (PF) is a chronic and progressive interstitial lung disease characterised by excessive deposition of extracellular matrix (ECM), resulting in high mortality rates. In this study, we provide evidence that ADAM17/PTGS2 plays a crucial role in inducing ferroptosis in fibroblasts, promoting PF. Initially, an assessment was made of ADAM17 protein levels in patients diagnosed with connective tissue diseases-interstitial lung diseases (CTD-ILD), using ELISA assays. Confirmation of the relationship between ADAM17 and fibrosis was achieved by stimulating cells with PMA or TAPI-1 (the ADAM17 inhibitor), in conjunction with the fibrosis-inducing factor, TGFβ1. To further explore the major downstream proteins of ADAM17 contributing to altered PF, we employed mRNA transcriptomics. To further investigate the role of ADAM17/PTGS2 in promoting ferroptosis and fibrosis, we employed western blot assays, immunofluorescence and transmission electron microscopy (TEM). Furthermore, the effects of the ADAM17/PTGS2/ferroptosis pathway in PF were verified using Adeno-associated virus (AAV)-mediated ADAM17 gene knockdown in mice. In CTD-ILD patients, ADAM17 expression was significantly elevated. Upon PMA stimulation, lung fibroblasts exhibited increased fibrosis-related proteins, and the combined stimulation of PMA and TGFβ1 synergistically promoted cellular fibrosis. Conversely, TAPI-1 alleviated fibrotic stimulation induced by TGFβ1. Transcriptomic analysis of lung fibroblast specimens overexpressing ADAM17 revealed significantly elevated PTGS2 expression levels. Knockdown and ferroptosis inhibition assays demonstrated that ADAM17 regulates ferroptosis in lung fibroblasts via PTGS2, ultimately inducing fibrosis. Furthermore, the deficiency of ADAM17 alleviated bleomycin-induced PF and inflammation in mice. These findings first verified that ADAM17/PTGS2/ferroptosis is a novel mechanism for regulating PF; it provides a new theoretical basis for further exploring the treatment of PF.

Comparative proteomic analysis of the telogen-to-anagen transition in cashmere goat secondary hair follicles

Secondary hair follicles (SHFs) in cashmere goats produce high-value cashmere fibers, which cyclic regulation is critical for optimizing cashmere yield and quality. This study explores the phenotypic changes and differential protein expression profiles involved in the telogen-to-anagen transition of SHFs. Through histological observations, proteomic analyses, and immunohistochemical validation, we identified key molecular features and regulatory pathways underlying SHF cyclic renewal. Histological analysis showed that telogen-phase SHFs exhibit a reduced volume, decreased dermal papilla cell (DPC) and hair matrix cell (HMC) activity, compact structure, and superficial localization in the dermis. Anagen-phase SHFs exhibit significantly increased volume, deeper dermal penetration, and active cell proliferation. Proteomic analysis identified 3,654 proteins in skin samples, with 458 differentially expressed proteins (DEPs) significantly associated with biological processes such as cell adhesion, signal transduction, protein synthesis, and metabolism. These DEPs were enriched in key regulatory pathways, including Notch, Wnt, Jak-STAT, PI3K-Akt, and ECM-receptor interaction. Protein-protein interaction analysis identified A Disintegrin and Metalloproteinase Domain 17 (ADAM17), Secreted Frizzled-Related Protein 1 (SFRP1), and Protein Phosphatase 1 Catalytic Subunit Alpha (PPP1CA) as core regulators of SHF cyclic transitions. Validation by RT-qPCR, Western blot, and immunohistochemical analyses confirmed that ADAM17, SFRP1, and PPP1CA were predominantly localized in functional regions, including the outer root sheath (ORS), dermal papilla (DP), and hair matrix (HM). Their expression levels were significantly enhanced during anagen. ADAM17 is suggested to promote the growth of SHFs by regulating ORS cells proliferation and mediating signal transduction in DPCs, while SFRP1, as a modulator of the Wnt signaling pathway, likely supports SHFs growth and regeneration by modulating the activity of Secondary hair follicle stem cells (SHFSCs) and promoting the differentiation of HMCs. PPP1CA may enhance cell proliferation and metabolic activity by modulating phosphorylation states. In conclusion, this study identifies key molecular factors and pathways driving the telogen-to-anagen transition in cashmere goat SHFs. It emphasizes the roles of ADAM17, SFRP1, and PPP1CA in SHF renewal and offers insights into SHF development mechanisms and cashmere fiber improvement.

Novel insights into the central protective role of ACE2 in diabetic cardiomyopathy: from underlying signaling pathways to therapeutic perspectives

Diabetic cardiomyopathy (DCM) is a cardiac complication specific to individuals with diabetes. It is defined as abnormalities of myocardial structure and function in diabetic patients who do not exhibit any obvious coronary artery disease, hypertensive heart disease, valvular heart disease, or inherited cardiomyopathy. A significant cardiovascular protective factor identified recently is angiotensin-converting enzyme 2 (ACE2), which is a rising star in the renin angiotensin system (RAS) and is responsible for the onset and progression of DCM. Nonetheless, there is not a comprehensive review outlining ACE2's effect on DCM. From the perspective of the pathogenesis of DCM, this review summarizes the myocardial protective role of ACE2 in the aspects of alleviating myocardial structure and dysfunction, correcting energy metabolism disorders, and restoring vascular function. Concurrently, we propose the connections between ACE2 and underlying signaling pathways, including ADAM17, Apelin/APJ, and Nrf2. Additionally, we highlight ACE2-related pharmaceutical treatment options and clinical application prospects for preventing and managing DCM. Further and underlying research is extensively required to completely comprehend the principal pathophysiological mechanism of DCM and the distinctive function of ACE2, switching experimental findings into clinical practice and identifying efficient therapeutic approaches.

A Disintegrin and Metalloproteinase 17 Disrupts Bovine Macrophage MER Proto-Oncogene Tyrosine Kinase Integrity to Impede Apoptotic Cell Clearance and Promote Inflammation in Clinical Mastitis

In clinical mastitis of dairy cows, the abnormal accumulation of apoptotic cells (ACs) and subsequent secondary necrosis and inflammation pose significant concerns, with macrophage-mediated efferocytosis, crucial for ACs clearance, remaining unexplored in this context. In nonruminants, MER proto-oncogene tyrosine kinase (MERTK) receptors are essential for efferocytosis and A Disintegrin and Metalloproteinase 17 (ADAM17) is thought to play a role in regulating MERTK integrity. This study aimed to delineate the in situ role of efferocytosis in clinical mastitis, with a particular focus on the interaction between MERTK and ADAM17 in bovine macrophages. In mastitic mammary tissue, a significant accumulation of ACs was observed, along with active macrophage efferocytosis. Western blotting analysis revealed elevated expressions of MERTK and ADAM17, and immunofluorescence confirmed that MERTK is predominantly localized within CD163+ macrophages. Additionally, elevated levels of soluble MERTK (sol-MER) in serum indicated impaired integrity and functionality of MERTK. In vitro experiments with the bovine macrophage cell line Bo-mac cells selectively phagocytosed apoptotic MAC-T cells, a process associated with increased MERTK phosphorylation and an anti-inflammatory phenotype. The activation of ADAM17 by Phorbol 12-myristate 13-acetate (PMA) induced sol-Mer release and impaired efferocytosis, with these effects reversed by the ADAM17 inhibitor TAPI-1. Bo-mac efferocytosis was influenced by the presence and activation of MERTK. Silencing MERTK interrupted efferocytosis, a phenomenon also observed with the inhibition of MERTK phosphorylation by UNC2025, which concurrently suppressed anti-inflammatory cytokine production. These findings suggest that targeting the MERTK-ADAM17 axis could enhance inflammatory resolution, providing a novel therapeutic strategy for dairy cattle health management.

High temperature aggravated hypoxia-induced intestine toxicity on juvenile Chinese mitten crab (Eriocheir sinensis)

High temperature and hypoxia in water due to global warming threaten the growth and development of aquatic animals. In natural or cultured environments, stress usually does not occur independently, whereas the synergistic effect of high temperature and hypoxia on Chinese mitten crab (Eriocheir sinensis) are rarely reported. In this study, 450 juvenile crabs were equally divided into control group (24 °C ± 0.5 °C, DO 6.8 ± 0.1 mg/L), hypoxia stress group (24 °C ± 0.5 °C, DO 1 ± 0.1 mg/L) and combined stress group (30 °C ± 0.5 °C, DO 1 ± 0.1 mg/L), and the intestinal health status, microbial diversity and metabolite profiles were evaluated for 24 h treatment. The results showed that hypoxia stress induced the expression level of pro-inflammatory related genes were significantly up-regulated in intestine of juvenile E. sinensis, and intestinal peritrophic membrane factor related genes were significantly down-regulated. High temperature further amplified the effects of hypoxia on pro-inflammatory and peritrophic membrane factor-related genes. Interesting, hypoxia stress induced a significant up-regulated of intestinal antioxidant-related genes, whereas high temperature reversed this trend. In addition, single stress or/and combined stress led to changes in intestinal microbiota diversity and abundance, and intestinal metabolite profiles. Compared with hypoxia stress, the synergistic effect of high temperature and hypoxia led to an increase in the abundance of pathogenic bacteria and a decrease in the abundance of probiotic bacteria. Moreover, intestinal metabolic pathways were significantly changed, especially amino acid metabolism and glycerophospholipid metabolism. Therefore, the results indicated that hypoxia stress could induce intestinal inflammatory response and oxidative stress, and lead to abnormal changes in intestinal microbiota and metabolic profiles, whereas high temperature further aggravate the toxic effects of hypoxia on the intestine. This study preliminarily revealed the synergistic toxic effects of high temperature and hypoxia on the intestine of juvenile E. sinensis.

Role of MMP-2 and MMP-9 in the Relationship between Inflammation, Fibrosis, and Apoptosis during Progression of Non-Alcoholic Fatty Liver Disease and Diagnostic Significance of Plasma Levels of Their Active Forms

MMP-2 and MMP-9 play an important role in pathogenesis of chronic liver diseases, participating in the processes of inflammation and fibrosis. Their role in progression of non-alcoholic fatty liver disease (NAFLD) is poorly understood. Analysis of MMP-2, -9 levels in the blood plasma of patients with different forms of NAFLD [liver steatosis (LS) and non-alcoholic steatohepatitis (NASH) of weak (-WA), moderate (MA), high (-HA) activity without pronounced fibrosis] was performed. Correlations between the levels of MMP-2, -9 and mRNA of the genes MMP2, MMP9, ADAM17, NLRP3, caspase 3 activity in peripheral blood leukocytes (PBL), TNFα, IL-6, sIL-6R, cytokeratin-18 fragments in plasma were assessed. In steatosis, the levels of MMP2 gene mRNA in PBL and MMP-2 in plasma are lower than in the control, and expression of the NLRP3 gene in PBL is increased relative to other groups. In the NASH-WA, the level of MMP-9 is higher than in the control, in LS, and in NASH-MA, which could be associated with activation of inflammation during transformation of LS into NASH. The plasma level of MMP-9 over 389.50 pg/ml has been shown to be diagnostically significant for identification of NASH-WA among the patients with steatosis (AUC ROC = 0.818, 95% CI = 0.689-0.948, p < 0.001). In NAFLD, the level of MMP-9 could be associated not only with inflammation, but also with apoptosis. ADAM17 probably plays a certain role in this regard. In the advanced NASH, hepatocyte apoptosis is increased, the level of caspase 3 activity in PBL is increased, the level of MMP-9 in the blood is reduced to the level of the control and LS. In the NASH-HA, the level of mRNA of the ADAM17 gene in PBL is increased compared to the control, NASH-WA, and NASH-MA. Thus, MMP-2 and MMP-9 are involved in pathogenesis of NAFLD already at the early stages and their level in blood could be associated with the presence and severity of inflammation in the liver parenchyma.

Downregulation of PIK3IP1/TrIP on T cells is controlled by TCR signal strength, PKC, and metalloprotease-mediated cleavage

The protein known as PI3K-interacting protein (PIK3IP1), or transmembrane inhibitor of PI3K (TrIP), is highly expressed by T cells and can modulate PI3K activity in these cells. Several studies have also revealed that TrIP is rapidly downregulated following T cell activation. However, it is unclear how this downregulation is controlled. Using a novel monoclonal antibody that robustly stains cell-surface TrIP, we demonstrate that TrIP is lost from the surface of activated T cells in a manner dependent on the strength of signaling through the T cell receptor and specific downstream signaling pathways, in particular classical PKC isoforms. TrIP expression returns by 24 h after stimulation, suggesting that it may play a role in resetting T cell receptor signaling at later time points. We also provide evidence that ADAM family proteases are required for both constitutive and stimulation-induced downregulation of TrIP in T cells. Finally, by expressing truncated forms of TrIP in cells, we identify the region in the extracellular stalk domain of TrIP that is targeted for proteolytic cleavage.

Downregulation of PIK3IP1/TrIP on T cells is controlled by TCR signal strength, PKC and metalloprotease-mediated cleavage

The protein known as PI3K-interacting protein (PIK3IP1), or transmembrane inhibitor of PI3K (TrIP), is highly expressed by T cells and can modulate PI3K activity in these cells. Several studies have also revealed that TrIP is rapidly downregulated following T cell activation. However, it is unclear as to how this downregulation is controlled. Using a novel monoclonal antibody that robustly stains cell-surface TrIP, we demonstrate that TrIP is lost from the surface of activated T cells in a manner dependent on the strength of signaling through the T cell receptor (TCR) and specific downstream signaling pathways, in particular classical PKC isoforms. TrIP expression returns by 24 hours after stimulation, suggesting that it may play a role in resetting TCR signaling at later time points. We also provide evidence that ADAM family proteases are required for both constitutive and stimulation-induced downregulation of TrIP in T cells. Finally, by expressing truncated forms of TrIP in cells, we identify the region in the extracellular stalk domain of TrIP that is targeted for proteolytic cleavage.

Cardiomyocyte-specific knockout of ADAM17 alleviates doxorubicin-induced cardiomyopathy via inhibiting TNFα-TRAF3-TAK1-MAPK axis

The pathogenesis of doxorubicin-induced cardiomyopathy remains unclear. This study was carried out to test our hypothesis that ADAM17 aggravates cardiomyocyte apoptosis induced by doxorubicin and inhibition of ADAM17 may ameliorate doxorubicin-induced cardiomyopathy. C57BL/6J mice were intraperitoneally injected with a cumulative dose of doxorubicin to induce cardiomyopathy. Cardiomyocyte-specific ADAM17-knockout (A17α-MHCKO) and ADAM17-overexpressing (AAV9-oeA17) mice were generated. In addition, RNA sequencing of the heart tissues in different mouse groups and in vitro experiments in neonatal rat cardiomyocytes (NRCMs) receiving different treatment were performed. Mouse tumor models were constructed in A17fl/fl and A17α-MHCKO mice. In addition, cardiomyocyte-specific TRAF3-knockdown and TRAF3-overexpressing mice were generated. ADAM17 expression and activity were markedly upregulated in doxorubicin-treated mouse hearts and NRCMs. A17α-MHCKO mice showed less cardiomyocyte apoptosis induced by doxorubicin than A17fl/fl mice, and cardiomyocyte ADAM17 deficiency did not affect the anti-tumor effect of doxorubicin. In contrast, AAV9-oeA17 mice exhibited markedly aggravated cardiomyocyte apoptosis relative to AAV9-oeNC mice after doxorubicin treatment. Mechanistically, doxorubicin enhanced the expression of transcription factor C/EBPβ, leading to increased expression and activity of ADAM17 in cardiomyocyte, which enhanced TNF-α shedding and upregulated the expression of TRAF3. Increased TRAF3 promoted TAK1 autophosphorylation, resulting in activated MAPKs pathway and cardiomyocyte apoptosis. ADAM17 acted as a positive regulator of cardiomyocyte apoptosis and cardiac remodeling and dysfunction induced by doxorubicin by upregulating TRAF3/TAK1/MAPKs signaling. Thus, targeting ADAM17/TRAF3/TAK1/MAPKs signaling holds a promising potential for treating doxorubicin-induced cardiotoxicity.

Photoreceptors inhibit pathological retinal angiogenesis through transcriptional regulation of Adam17 via c-Fos

Pathological retinal angiogenesis profoundly impacts visual function in vascular eye diseases, such as retinopathy of prematurity (ROP) in preterm infants and age-related macular degeneration in the elderly. While the involvement of photoreceptors in these diseases is recognized, the underlying mechanisms remain unclear. This study delved into the pivotal role of photoreceptors in regulating abnormal retinal blood vessel growth using an oxygen-induced retinopathy (OIR) mouse model through the c-Fos/A disintegrin and metalloprotease 17 (Adam17) axis. Our findings revealed a significant induction of c-Fos expression in rod photoreceptors, and c-Fos depletion in these cells inhibited pathological neovascularization and reduced blood vessel leakage in the OIR mouse model. Mechanistically, c-Fos directly regulated the transcription of Adam17 a shedding protease responsible for the production of bioactive molecules involved in inflammation, angiogenesis, and cell adhesion and migration. Furthermore, we demonstrated the therapeutic potential by using an adeno-associated virus carrying a rod photoreceptor-specific short hairpin RNA against c-fos which effectively mitigated abnormal retinal blood vessel overgrowth, restored retinal thickness, and improved electroretinographic (ERG) responses. In conclusion, this study highlights the significance of photoreceptor c-Fos in ROP pathology, offering a novel perspective for the treatment of this disease.

Angiotensin-Converting Enzyme 2 Posttranslational Modifications and Implications for Hypertension and SARS-CoV-2: 2023 Lewis K. Dahl Memorial Lecture

ACE2 (angiotensin-converting enzyme 2), a multifunctional transmembrane protein, is well recognized as an important member of the (RAS) renin-angiotensin system with important roles in the regulation of cardiovascular function by opposing the harmful effects of Ang-II (angiotensin II) and AT1R (Ang-II type 1 receptor) activation. More recently, ACE2 was found to be the entry point for the SARS-CoV-2 virus into cells, causing COVID-19. This finding has led to an exponential rise in the number of publications focused on ACE2, albeit these studies often have opposite objectives to the preservation of ACE2 in cardiovascular regulation. However, notwithstanding accumulating data of the role of ACE2 in the generation of angiotensin-(1-7) and SARS-CoV-2 internalization, numerous other putative roles of this enzyme remain less investigated and not yet characterized. Currently, no drug modulating ACE2 function or expression is available in the clinic, and the development of new pharmacological tools should attempt targeting each step of the lifespan of the protein from synthesis to degradation. The present review expands on our presentation during the 2023 Lewis K. Dahl Memorial Lecture Sponsored by the American Heart Association Council on Hypertension. We provide a critical summary of the current knowledge of the mechanisms controlling ACE2 internalization and intracellular trafficking, the mutual regulation with GPCRs (G-protein-coupled receptors) and other proteins, and posttranslational modifications. A major focus is on ubiquitination which has become a critical step in the modulation of ACE2 cellular levels.

Targeting a disintegrin and metalloprotease (ADAM) 17-CD122 axis enhances CD8+ T cell effector differentiation and anti-tumor immunity

CD8+ T cell immune responses are regulated by multi-layer networks, while the post-translational regulation remains largely unknown. Transmembrane ectodomain shedding is an important post-translational process orchestrating receptor expression and signal transduction through proteolytic cleavage of membrane proteins. Here, by targeting the sheddase A Disintegrin and Metalloprotease (ADAM)17, we defined a post-translational regulatory mechanism mediated by the ectodomain shedding in CD8+ T cells. Transcriptomic and proteomic analysis revealed the involvement of post-translational regulation in CD8+ T cells. T cell-specific deletion of ADAM17 led to a dramatic increase in effector CD8+ T cell differentiation and enhanced cytolytic effects to eliminate pathogens and tumors. Mechanistically, ADAM17 regulated CD8+ T cells through cleavage of membrane CD122. ADAM17 inhibition led to elevated CD122 expression and enhanced response to IL-2 and IL-15 stimulation in both mouse and human CD8+ T cells. Intriguingly, inhibition of ADAM17 in CD8+ T cells improved the efficacy of chimeric antigen receptor (CAR) T cells in solid tumors. Our findings reveal a critical post-translational regulation in CD8+ T cells, providing a potential therapeutic strategy of targeting ADAM17 for effective anti-tumor immunity.

The TGFβ Induced MicroRNAome of the Trabecular Meshwork

Primary open-angle glaucoma (POAG) is a progressive optic neuropathy with a complex, multifactorial aetiology. Raised intraocular pressure (IOP) is the most important clinically modifiable risk factor for POAG. All current pharmacological agents target aqueous humour dynamics to lower IOP. Newer therapeutic agents are required as some patients with POAG show a limited therapeutic response or develop ocular and systemic side effects to topical medication. Elevated IOP in POAG results from cellular and molecular changes in the trabecular meshwork driven by increased levels of transforming growth factor β (TGFβ) in the anterior segment of the eye. Understanding how TGFβ affects both the structural and functional changes in the outflow pathway and IOP is required to develop new glaucoma therapies that target the molecular pathology in the trabecular meshwork. In this study, we evaluated the effects of TGF-β1 and -β2 treatment on miRNA expression in cultured human primary trabecular meshwork cells. Our findings are presented in terms of specific miRNAs (miRNA-centric), but given miRNAs work in networks to control cellular pathways and processes, a pathway-centric view of miRNA action is also reported. Evaluating TGFβ-responsive miRNA expression in trabecular meshwork cells will further our understanding of the important pathways and changes involved in the pathogenesis of glaucoma and could lead to the development of miRNAs as new therapeutic modalities in glaucoma.

ADAM17 variant causes hair loss via ubiquitin ligase TRIM47-mediated degradation

Hypotrichosis is a genetic disorder characterized by a diffuse and progressive loss of scalp and/or body hair. Nonetheless, the causative genes for several affected individuals remain elusive, and the underlying mechanisms have yet to be fully elucidated. Here, we discovered a dominant variant in a disintegrin and a metalloproteinase domain 17 (ADAM17) gene caused hypotrichosis with woolly hair. Adam17 (p.D647N) knockin mice mimicked the hair abnormality in patients. ADAM17 (p.D647N) mutation led to hair follicle stem cell (HFSC) exhaustion and caused abnormal hair follicles, ultimately resulting in alopecia. Mechanistic studies revealed that ADAM17 binds directly to E3 ubiquitin ligase tripartite motif-containing protein 47 (TRIM47). ADAM17 variant enhanced the association between ADAM17 and TRIM47, leading to an increase in ubiquitination and subsequent degradation of ADAM17 protein. Furthermore, reduced ADAM17 protein expression affected the Notch signaling pathway, impairing the activation, proliferation, and differentiation of HFSCs during hair follicle regeneration. Overexpression of Notch intracellular domain rescued the reduced proliferation ability caused by Adam17 variant in primary fibroblast cells.

Combination of ADAM17 knockdown with eplerenone is more effective than single therapy in ameliorating diabetic cardiomyopathy

Background

The renin-angiotensin-aldosterone system (RAAS) members, especially Ang II and aldosterone, play key roles in the pathogenesis of diabetic cardiomyopathy (DCM). Angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers combined with aldosterone receptor antagonists (mineralocorticoid receptor antagonists) have substantially improved clinical outcomes in patients with DCM. However, the use of the combination has been limited due to its high risk of inducing hyperkalemia.

Methods

Type 1 diabetes was induced in 8-week-old male C57BL/6J mice by intraperitoneal injection of streptozotocin at a dose of 55 mg/kg for 5 consecutive days. Adeno-associated virus 9-mediated short-hairpin RNA (shRNA) was used to knock down the expression of ADAM17 in mice hearts. Eplerenone was administered via gavage at 200 mg/kg daily for 4 weeks. Primary cardiac fibroblasts were exposed to high glucose (HG) in vitro for 24 h to examine the cardiac fibroblasts to myofibroblasts transformation (CMT).

Results

Cardiac collagen deposition and CMT increased in diabetic mice, leading to cardiac fibrosis and dysfunction. In addition, ADAM17 expression and activity increased in the hearts of diabetic mice. ADAM17 inhibition and eplerenone treatment both improved diabetes-induced cardiac fibrosis, cardiac hypertrophy and cardiac dysfunction, ADAM17 deficiency combined with eplerenone further reduced the effects of cardiac fibrosis, cardiac hypertrophy and cardiac dysfunction compared with single therapy in vivo. High-glucose stimulation promotes CMT in vitro and leads to increased ADAM17 expression and activity. ADAM17 knockdown and eplerenone pretreatment can reduce the CMT of fibroblasts that is induced by high glucose levels by inhibiting TGFβ1/Smad3 activation; the combination of the two can further reduce CMT compared with single therapy in vitro.

Conclusion

Our findings indicated that ADAM17 knockout could improve diabetes-induced cardiac dysfunction and remodeling through the inhibition of RAAS overactivation when combined with eplerenone treatment, which reduced TGF-β1/Smad3 pathway activation-mediated CMT. The combined intervention of ADAM17 deficiency and eplerenone therapy provided additional cardiac protection compared with a single therapy alone without disturbing potassium level. Therefore, the combination of ADAM17 inhibition and eplerenone is a potential therapeutic strategy for human DCM.

Exploring the landscape of synthetic IL-6-type cytokines

Interleukin-6 (IL-6)-type cytokines not only have key immunomodulatory functions that affect the pathogenesis of diseases such as autoimmune diseases, chronic inflammatory conditions, and cancer, but also fulfill important homeostatic tasks. Even though the pro-inflammatory arm has hindered the development of therapeutics based on natural-like IL-6-type cytokines to date, current synthetic trends might pave the way to overcome these limitations and eventually lead to immune-inert designer cytokines to aid type 2 diabetes and brain injuries. Those synthetic biology approaches include mutations, fusion proteins, and inter-cytokine swapping, and resulted in IL-6-type cytokines with altered receptor affinities, extended target cell profiles, and targeting of non-natural cytokine receptor complexes. Here, we survey synthetic cytokine developments within the IL-6-type cytokine family and discuss potential clinical applications.

Sesquiterpene Lactones Containing an α-Methylene-γ-Lactone Moiety Selectively Down-Regulate the Expression of Tumor Necrosis Factor Receptor 1 by Promoting Its Ectodomain Shedding in Human Lung Adenocarcinoma A549 Cells

Alantolactone is a eudesmane-type sesquiterpene lactone containing an α-methylene-γ-lactone moiety. Previous studies showed that alantolactone inhibits the nuclear factor κB (NF-κB) signaling pathway by targeting the inhibitor of NF-κB (IκB) kinase. However, in the present study, we demonstrated that alantolactone selectively down-regulated the expression of tumor necrosis factor (TNF) receptor 1 (TNF-R1) in human lung adenocarcinoma A549 cells. Alantolactone did not affect the expression of three adaptor proteins recruited to TNF-R1. The down-regulation of TNF-R1 expression by alantolactone was suppressed by an inhibitor of TNF-α-converting enzyme. Alantolactone increased the soluble forms of TNF-R1 that were released into the culture medium as an ectodomain. The structure-activity relationship of eight eudesmane derivatives revealed that an α-methylene-γ-lactone moiety was needed to promote TNF-R1 ectodomain shedding. In addition, parthenolide and costunolide, two sesquiterpene lactones with an α-methylene-γ-lactone moiety, increased the amount of soluble TNF-R1. Therefore, the present results demonstrate that sesquiterpene lactones with an α-methylene-γ-lactone moiety can down-regulate the expression of TNF-R1 by promoting its ectodomain shedding in A549 cells.

The Association of Cytokines IL-2, IL-6, TNF-α, IFN-γ, and IL-10 With the Disease Severity of COVID-19: A Study From Bangladesh

Introduction Clinically, the early prediction of the severity of COVID-19 is often challenging, as a dramatic change in severity can occur without warning. The severity of COVID-19 disease is associated with an increased level of inflammatory mediators, including cytokines. This study aimed to evaluate the association of the levels of cytokines interleukin (IL)-2, IL-6, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and IL-10 with the severity of COVID-19 in Bangladesh. Materials and methods This cross-sectional study included a total of 60 confirmed cases of COVID-19, comprising 30 severe cases (Group A) and 30 non-severe cases (Group B), and 10 healthy individuals (Group C) attending Bangabandhu Sheikh Mujib Medical University (BSMMU) from March 2021 to February 2022. The cytokine assay was performed using the human Th1/Th2/Th17 cytokine kit BD cytometric bead array (CBA) on the BD Accuri C6 Plus flow cytometer. Statistical analysis was conducted using IBM SPSS Statistics for Windows, Version 23 (Released 2015; IBM Corp., Armonk, New York). Results The mean ages of the patients in Groups A, B, and C were 60.73±5.97, 57.13±7.68, and 48.10±9.13 years, respectively, with a male predominance in all groups. The mean IL-2, IL-6, IL-10, and TNF-α levels had a positive correlation with the increased age group and male gender, although it was not statistically significant. The mean IL-6 and IFN-γ levels were significantly higher among severe cases (216.95±147.78 and 0.98±0.95 pg/mL, respectively) compared to non-severe cases (94.29±128.79 and 0.41±0.61 pg/mL, respectively) and healthy individuals (1.08±1.97 and 0.15±0.28 pg/mL, respectively). Furthermore, the anti-inflammatory cytokine IL-10 was also significantly higher among severe cases (17.92±21.87 pg/mL) compared to non-severe cases (5.38±6.73 pg/mL) and healthy individuals (1.62±1.65 pg/mL). Conclusion IL-6, IFN-γ, and IL-10 have a significant association with the severity of COVID-19 disease. Clinicians treating patients with COVID-19 can consider the level of these cytokines as biomarkers of severity.

The soluble IL-2 receptor α/CD25 as a modulator of IL-2 function

The pleiotropic cytokine interleukin-2 (IL-2) is an integral regulator of healthy and pathological immune responses, with the most important role in regulating the homeostasis of regulatory T cells. IL-2 signalling involves three distinct receptors: The IL-2 receptor α (IL-2Rα/CD25), IL-2Rβ, and IL-2Rγ/γc . While IL-2Rβ and γc are essential for signal transduction, IL-2Rα regulates the affinity of the receptor complex towards IL-2. A soluble form of the IL-2Rα (sIL-2Rα) is present in the blood of healthy individuals and increased under various pathological conditions. Although it is known that the sIL-2Rα retains its ability to bind IL-2, it is not fully understood how this molecule affects IL-2 function and thus immune responses. Here, we summarize the current knowledge on the generation and function of the sIL-2Rα. We describe the molecular mechanisms leading to sIL-2Rα generation and discuss the different IL-2 modulating functions that have been attributed to the sIL-2Rα. Finally, we describe attempts to utilize the sIL-2Rα as a therapeutic tool.

Discovery of galectin-8 as an LILRB4 ligand driving M-MDSCs defines a class of antibodies to fight solid tumors

LILRB4 is an immunosuppressive receptor, and its targeting drugs are undergoing multiple preclinical and clinical trials. Currently, the absence of a functional LILRB4 ligand in solid tumors not only limits the strategy of early antibody screening but also leads to the lack of companion diagnostic (CDx) criteria, which is critical to the objective response rate in early-stage clinical trials. Here, we show that galectin-8 (Gal-8) is a high-affinity functional ligand of LILRB4, and its ligation induces M-MDSC by activating STAT3 and inhibiting NF-κB. Significantly, Gal-8, but not APOE, can induce MDSC, and both ligands bind LILRB4 noncompetitively. Gal-8 expression promotes in vivo tumor growth in mice, and the knockout of LILRB4 attenuates tumor growth in this context. Antibodies capable of functionally blocking Gal-8 are able to suppress tumor growth in vivo. These results identify Gal-8 as an MDSC-driving ligand of LILRB4, and they redefine a class of antibodies for solid tumors.

Organoids in COVID-19: can we break the glass ceiling?

COVID-19 emerged in September 2020 as a disease caused by the virus SARS-CoV-2. The disease presented as pneumonia at first but later was shown to cause multisystem infections and long-term complications. Many efforts have been put into discovering the exact pathogenesis of the disease. In this review, we aim to discuss an emerging tool in disease modeling, organoids, in the investigation of COVID-19. This review will introduce some methods and breakthroughs achieved by organoids and the limitations of this system.

FXR agonists INT-787 and OCA increase RECK and inhibit liver steatosis and inflammation in diet-induced ob/ob mouse model of NASH

BACKGROUND AND AIMS

We have previously shown in a model of hepatic ischaemia/reperfusion injury that the farnesoid X receptor (FXR) agonist obeticholic acid (OCA) restores reversion-inducing-cysteine-rich protein with Kazal motifs (RECK), an inverse modulator of metalloproteases (MMPs) and inhibitor of the sheddases ADAM10 and ADAM17 involved in inflammation and fibrogenesis. Here, the effects of FXR agonists OCA and INT-787 on hepatic levels of RECK, MMPs, ADAM10 and ADAM17 were compared in a diet-induced ob/ob mouse model of non-alcoholic steatohepatitis (NASH).

METHODS

Lep ob/ob NASH mice fed a high-fat diet (HFD) or control diet (CD) for 9 weeks (wks) were treated with OCA or INT-787 0.05% dosed via HFD admixture (30 mg/kg/day) or HFD for further 12 wks. Serum alanine transaminase (ALT) and inflammatory cytokines, liver RECK, MMP-2 and MMP-9 activity as well as ADAM10, ADAM17, collagen deposition (Sirius red), hepatic stellate cell activation (α-SMA) and pCK+ reactive biliary cells were quantified.

RESULTS

Only INT-787 significantly reduced serum ALT, IL-1β and TGF-β. A downregulation of RECK expression and protein levels observed in HFD groups (at 9 and 21 wks) was counteracted by both OCA and INT-787. HFD induced a significant increase in liver MMP-2 and MMP-9; OCA administration reduced both MMP-2 and MMP-9 while INT-787 markedly reduced MMP-2 expression. OCA and INT-787 reduced both ADAM10 and ADAM17 expression and number of pCK+ cells. INT-787 was superior to OCA in decreasing collagen deposition and α-SMA levels.

CONCLUSION

INT-787 is superior to OCA in controlling specific cell types and clinically relevant anti-inflammatory and antifibrotic molecular mechanisms in NASH.

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.

Role of Metalloproteinases in Diabetes-associated Mild Cognitive Impairment

Diabetes has been linked to an increased risk of mild cognitive impairment (MCI), a condition characterized by a subtle cognitive decline that may precede the development of dementia. The underlying mechanisms connecting diabetes and MCI involve complex interactions between metabolic dysregulation, inflammation, and neurodegeneration. A critical mechanism implicated in diabetes and MCI is the activation of inflammatory pathways. Chronic low-grade inflammation, as observed in diabetes, can lead to the production of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), and interferon-gamma (IFNγ), each of which can exacerbate neuroinflammation and contribute to cognitive decline. A crucial enzyme involved in regulating inflammation is ADAM17, a disintegrin, and metalloproteinase, which can cleave and release TNF-α from its membrane-bound precursor and cause it to become activated. These processes, in turn, activate additional inflammation-related pathways, such as AKT, NF-κB, NLP3, MAPK, and JAK-STAT pathways. Recent research has provided novel insights into the role of ADAM17 in diabetes and neurodegenerative diseases. ADAM17 is upregulated in both diabetes and Alzheimer's disease, suggesting a shared mechanism and implicating inflammation as a possible contributor to much broader forms of pathology and pointing to a possible link between inflammation and the emergence of MCI. This review provides an overview of the different roles of ADAM17 in diabetes-associated mild cognitive impairment diseases. It identifies mechanistic connections through which ADAM17 and associated pathways may influence the emergence of mild cognitive impairment.

Development of artificial bone graft via in vitro endochondral ossification (ECO) strategy for bone repair

Endochondral ossification (ECO) is a form of bone formation whereby the newly deposited bone replaces the cartilage template. A decellularized artificial cartilage graft (dLhCG), which is composed of hyaline cartilage matrixes, has been developed in our previous study. Herein, the osteogenesis of bone marrow-derived MSCs in the dLhCG through chondrogenic differentiation, chondrocyte hypertrophy, and subsequent transdifferentiation induction has been investigated by simulating the physiological processes of ECO for repairing critical-sized bone defects. The MSCs were recellularized into dLhCGs and subsequently allowed to undergo a 14-day proliferation period (mrLhCG). Following this, the mrLhCG constructs were subjected to two distinct differentiation induction protocols to achieve osteogenic differentiation: chondrogenic medium followed by chondrocytes culture medium with a high concentration of fetal bovine serum (CGCC group) and canonical osteogenesis inducing medium (OI group). The formation of a newly developed artificial bone graft, ossified dLhCG (OsLhCG), as well as its capability of aiding bone defect reconstruction were characterized by in vitro and in vivo trials, such as mRNA sequencing, quantitative real-time PCR (qPCR), immunohistochemistry, the greater omentum implantation in nude mice, and repair for the critical-sized femoral defects in rats. The results reveal that the differentiation induction of MSCs in the CGCC group can realize in vitro ECO through chondrogenic differentiation, hypertrophy, and transdifferentiation, while the MSCs in the OI group, as expected, realize ossification through direct osteogenic differentiation. The angiogenesis and osteogenesis of OsLhCG were proved by being implanted into the greater omentum of nude mice. Besides, the OsLhCG exhibits the capability to achieve the repair of critical-size femoral defects.

Dietary fish intake increased the concentration of soluble ACE2 in rats: can fish consumption reduce the risk of COVID-19 infection through interception of SARS-CoV-2 by soluble ACE2?

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the cells after binding to the membrane-bound receptor angiotensin-converting enzyme 2 (ACE2), but this may be prevented through interception by soluble ACE2 (sACE2) or by inhibition of the ACE2 receptor, thus obstructing cell entry and replication. The main objective of this study was to investigate if fish intake affected the concentration of sACE2 in rats. The secondary aim was to evaluate the in vitro ACE2-inhibiting activity of fish proteins. Rats were fed cod muscle as 25 % of dietary protein, and blood was collected after 4 weeks of intervention. Muscle, backbone, skin, head, stomach, stomach content, intestine and swim bladder from haddock, saithe, cod and redfish were hydrolysed with trypsin before ACE2-inhibiting activity was measured in vitro. In vivo data were compared using unpaired Student's t test, and in vitro data were compared using one-way ANOVA followed by the Tukey HSD post hoc test. The mean sACE2 concentration was 47 % higher in rats fed cod when compared with control rats (P 0·034), whereas serum concentrations of angiotensin II and TNF-α were similar between the two experimental groups. Muscle, backbone, skin and head from all four fish species inhibited ACE2 activity in vitro, whereas the remaining fractions had no effect. To conclude, our novel data demonstrate that fish intake increased the sACE2 concentration in rats and that the hydrolysed fish proteins inhibited ACE2 activity in vitro.

Optimization of fluorescent substrates for ADAM17 and their utility in the detection of diabetes

ADAM17 (a disintegrin and metalloproteinase 17) is a sheddase that releases various types of membrane-associated proteins, including adhesive molecules, cytokines and their receptors, and inflammatory mediators. Evidence suggests that the enzyme is involved in the proteolytic cleavage of antiaging transmembrane protein Klotho (KL). What is more, reduced serum and urinary KL levels are observed in the early stages of chronic kidney disease. This study aimed to optimise the ADAM17 specific and selective fluorescent substrates. Then, the obtained substrate was used to detect the enzyme in urine samples of patients diagnosed with diabetes. It turned out that in all cases we were able to detect proteolytic activity, which was the opposite of the healthy samples.

Discovery of dual-target natural inhibitors of meprins α and β metalloproteases for inflammation regulation: pharmacophore modelling, molecular docking, ADME prediction, and molecular dynamics studies

Meprins, zinc-dependent metalloproteinases belonging to the metzincin family, have been associated with various inflammatory diseases due to their abnormal expression and activity. In this study, we utilized pharmacophore modelling to identify crucial features for discovering potential dual inhibitors targeting meprins α and β. We screened four pharmacophoric features against a library of 270,540 natural compounds from the Zinc database, resulting in 84,092 matching compounds. Molecular docking was then performed on these compounds, targeting the active sites of meprins α and β. Docking results revealed six compounds capable of interacting with both isoforms, with binding affinities ranging from -10.0 to -10.5 kcal/mol and -6.9 to -9.9 kcal/mol for meprin α and β, respectively. Among these compounds, ZINC000008790788 and ZINC000095099469 displayed superior docking scores and MM-GBSA binding free energy compared to reference ligands. Furthermore, these two compounds exhibited acceptable predicted pharmacokinetic properties and stable interactions with meprins α and β during molecular dynamics simulations. This study presents a comprehensive approach for identifying potential dual inhibitors of meprin α and β, offering insights into the development of therapeutic interventions for inflammatory diseases associated with meprin dysregulation.

Biomolecular interactions between the antibacterial ceftolozane and the human inflammatory disease target ADAM17: a drug repurposing study

Inhibition of a disintegrin and metalloproteinase-17 (ADAM17), a metzincin, is proposed as a novel therapeutic strategy to suppress overproduction of the proinflammatory cytokine TNF-α in rheumatoid arthritis and inflammatory bowel disease. Existing ADAM17 inhibitors generate toxic metabolites in-vivo or haven't progressed in clinical trials. Previous studies suggest that ligands which bind to ADAM17 active site by interacting with the Zn ion and L-shaped hydrophobic S1'- and S3'-pockets and forming favorable hydrogen bonds could act as potential ADAM17 inhibitors. Here, we investigated whether the FDA-approved anti-bacterial drug ceftolozane, a cephalosporin containing aromatic groups and carboxyl groups as probable zinc binding groups (ZBGs), forms non-covalent interactions resulting in its binding in the active site of ADAM17. In this study, the density functional theory (DFT), molecular docking and molecular dynamics calculations with the catalytic chain of ADAM17 show that carboxyl group of ceftolozane acts as moderate ZBG, and its extended geometry forms hydrogen bonds and hydrophobic interactions resulting in a binding affinity comparable to the co-crystallized known ADAM17 inhibitor. The favorable binding interactions identified here suggest the potential of ceftolozane to modulate ADAM17 activity in inflammatory diseases. ADAM17 cleaves and releases epidermal growth factor (EGF) ligands from the cell surface. The shed EGF ligands then bind to the EGF receptors to drive embryonic development. Therefore, our findings also suggest that use of ceftolozane during pregnancy may inhibit ADAM17-mediated shedding of EGF and thus increase the risk of birth defects in humans.Communicated by Ramaswamy H. Sarma.

Identification of host receptors for viral entry and beyond: a perspective from the spike of SARS-CoV-2

Identification of the interaction between the host membrane receptor and viral receptor-binding domain (RBD) represents a crucial step for understanding viral pathophysiology and for developing drugs against pathogenic viruses. While all membrane receptors and carbohydrate chains could potentially be used as receptors for viruses, prioritized searches focus typically on membrane receptors that are known to have been used by the relatives of the pathogenic virus, e.g., ACE2 used as a receptor for SARS-CoV is a prioritized candidate receptor for SARS-CoV-2. An ideal receptor protein from a viral perspective is one that is highly expressed in epithelial cell surface of mammalian respiratory or digestive tracts, strongly conserved in evolution so many mammalian species can serve as potential hosts, and functionally important so that its expression cannot be readily downregulated by the host in response to the infection. Experimental confirmation of host receptors includes (1) infection studies with cell cultures/tissues/organs with or without candidate receptor expression, (2) experimental determination of protein structure of the complex between the putative viral RDB and the candidate host receptor, and (3) experiments with mutant candidate receptor or homologues of the candidate receptor in other species. Successful identification of the host receptor opens the door for mechanism-based development of candidate drugs and vaccines and facilitates the inference of what other animal species are vulnerable to the viral pathogen. I illustrate these approaches with research on identification of the receptor and co-factors for SARS-CoV-2.

Investigation of CD56, ADAM17 and FGF21 Expressions in the Placentas of Preeclampsia Cases

Objective: In the present study, we investigated the expression of CD56, ADAM17 and FGF21 antibodies (Ab), which we think have an effect on the pathophysiology of preeclampsia (PE), in pregnant patients with healthy placentas and placentas with PE. The expression of these antibodies has been investigated in a limited amount of former research, but their role in PE has not yet been clarified. With this study, we aimed to contribute to the elucidation of the pathophysiology of PE and the detection of new target molecules for treatment. Materials and Methods: Parturients with singleton pregnancy at 32 weeks or above without any maternal or fetal pathology who were admitted to the Department of Obstetrics and Gynecology, Zonguldak Bülent Ecevit University Practice and Research Hospital between 11 January 2020 and 7 January 2022 were included in the present study. Pregnant women with coexisting disease or a pathology related to the placenta (ablation placenta, vasa previa, hemangioma, etc.) were excluded. CD56, ADAM17 and FGF21 antibodies were histopathologically and immunohistochemically detected in 60 placentas with PE (study group) and 43 healthy placentas (control group). Results: CD56, ADAM17 and FGF21 proteins were all more intensely expressed in preeclamptic placentas and a statistically significant difference was found between the two groups for all three antibodies (p < 0.001). Deciduitis, perivillous fibrin deposition, intervillous fibrin, intervillous hemorrhage, infarct, calcification, laminar necrosis and syncytial node were found to be significantly more common in the study group (p < 0.001). Conclusions: We observed that CD56, ADAM17 and FGF21 expressions increased in preeclamptic placentas. These Ab may be responsible for the pathogenesis of PE, which can be illuminated with further studies.

Transcriptomic analysis of World Trade Center particulate Matter-induced pulmonary inflammation and drug treatments

Over 400,000 people are estimated to have been exposed to World Trade Center particulate matter (WTC_PM) since the attack on the Twin Towers in Lower Manhattan on September 11, 2001. Epidemiological studies have found that exposure to dust may cause respiratory ailments and cardiovascular diseases. However, limited studies have performed a systematic analysis of transcriptomic data to elucidate the biological responses to WTC_PM exposure and the therapeutic options. Here, we developed an in vivo mouse exposure model of WTC_PM and administered two drugs (i.e., rosoxacin and dexamethasone) to generate transcriptomic data from lung samples. WTC_PM exposure increased the inflammation index, and this index was significantly reduced by both drugs. We analyzed the transcriptomics derived omics data using a hierarchical systems biology model (HiSBiM) with four levels, including system, subsystem, pathway, and gene analyses. Based on the selected differentially expressed genes (DEGs) from each group, WTC_PM and the two drugs commonly affected the inflammatory responses, consistent with the inflammation index. Among these DEGs, the expression of 31 genes was affected by WTC_PM exposure and consistently reversed by the two drugs, and these genes included Psme2, Cldn18, and Prkcd, which are involved in immune- and endocrine-related subsystems and pathways such as thyroid hormone synthesis, antigen processing and presentation, and leukocyte transendothelial migration. Furthermore, the two drugs reduced the inflammatory effects of WTC_PM through distinct pathways, e.g., vascular-associated signaling by rosoxacin, whereas mTOR-dependent inflammatory signaling was found to be regulated by dexamethasone. To the best of our knowledge, this study constitutes the first investigation of transcriptomics data of WTC_PM and an exploration of potential therapies. We believe that these findings provide strategies for the development of promising optional interventions and therapies for airborne particle exposure.

The Hepatotoxicity of Nigella sativa Oil Linked to the Route of Administration

Background:

Even Nigella sativa oil (NSO) has several pharmacological effects; the route of administration is critical to obtain the desired activity in which intraperitoneal injection (IP) of oil recruits macrophages and induces inflammation.

Objective:

The current study aimed to determine the best administration route of NSO in rats either oral or IP.

Methods:

The components of NSO, routine blood analyses, hepatic oxidative stress and proinflammatory parameters, and liver histopathological study were evaluated.

Results:

NSO contained 32.14% E,E,Z- 1, 3 , 12- nonadecatriene- 5, 14 diol, 25% thymoquinone (TQ) and 3.74% dimethyl sulfoxide (DMSO). In addition, the rats who received IP injection of NSO showed an increase in hepatic enzymes, lipid profiles, oxidative stress, and inflammatory markers. This was associated with hepatic up-regulation of the A disintegrin and metalloproteinase 17 (ADAM- 17) genes, which are corroborated by a reduction in hepatic tissue inhibitor of metalloproteinase 3 (TIMP-3) concentration. These indications were seen in rats given a small amount of DMSO (NSO vehicle), indicating that NSO-oral delivery was safer than IP.

Conclusion:

NSO-IP administration promotes the hepatic oxidative stress-inflammation axis; thus, NSO is a generally safe chemical, especially when administered orally to experimental animals.

A structural model of the iRhom-ADAM17 sheddase complex reveals functional insights into its trafficking and activity

Several membrane-anchored signal mediators such as cytokines (e.g. TNFα) and growth factors are proteolytically shed from the cell surface by the metalloproteinase ADAM17, which, thus, has an essential role in inflammatory and developmental processes. The membrane proteins iRhom1 and iRhom2 are instrumental for the transport of ADAM17 to the cell surface and its regulation. However, the structure-function determinants of the iRhom-ADAM17 complex are poorly understood. We used AI-based modelling to gain insights into the structure-function relationship of this complex. We identified different regions in the iRhom homology domain (IRHD) that are differentially responsible for iRhom functions. We have supported the validity of the predicted structure-function determinants with several in vitro, ex vivo and in vivo approaches and demonstrated the regulatory role of the IRHD for iRhom-ADAM17 complex cohesion and forward trafficking. Overall, we provide mechanistic insights into the iRhom-ADAM17-mediated shedding event, which is at the centre of several important cytokine and growth factor pathways.

Phylogeny and expression of ADAM10 and ADAM17 homologs in lamprey

The ADAMs (a disintegrin and metalloproteinase) play regulatory roles in cell adhesion, migration and proteolysis. To explore the origin and evolution of ADAMs, this study identified the homologs of adam10 and adam17 in Lampetra morii and Lampetra japonica. Sequence analysis revealed that they share the same genomic structures with their counterparts in jawed vertebrates. The putative proteins possess conserved motifs, including a furin cut site (RXXR) for precursor processing, an enzyme catalytic motif (HEXGEHXXGXXH) for hydrolysis, and a Ca²⁺-binding motif (CGNXXXEXGEXCD) for stabilizing protein structure. In addition, a substrate recognition domain is present at the membrane-proximal region of lamprey ADAM17. The cytoplasmic region of lamprey ADAM10 contains a potential threonine phosphorylation site which has been shown to be activated by protein kinase C (PKC) in mammals. Both the adam10 and adam17 genes were constitutively expressed in the brain, kidney, and gills and were differentially regulated in the primary blood leukocytes by lipopolysaccharide (LPS) and pokeweed mitogen (PWM). Adam10 was induced by LPS but not PWM; conversely, adam17 was induced by PWM but not LPS. Taken together, our results suggest that the activation pathways and functions of ADAM10 and ADAM17 are conserved in agnathans.

Functions and cellular signaling by ribosomal extracellular RNA (rexRNA): Facts and hypotheses on a non-typical DAMP

Upon microbial infections with the subsequent host response of innate immunity, a variety of fragmented RNA- and DNA-based "Pathogen-associated molecular patterns" (PAMPs) are recognized mainly by endosomal or cytoplasmic host cell "Pattern recognition receptors" (PRRs), particularly "Toll-like receptors" (TLRs). Concomitantly, various self-extracellular RNA species (exRNAs) are present in extracellular body fluids where they contribute to diverse physiological and homeostatic processes. In principle, such exRNAs, including the most abundant one, ribosomal exRNA (rexRNA), are designated as "Danger-associated molecular patterns" (DAMPs) and are prevented by e.g. natural modifications from uncontrolled signaling via TLRs to avoid hyper-inflammatory responses or autoimmunity. Upon cellular stress or tissue damage/necrosis, the levels and composition of released self-exRNA species, either in free form, in complex with proteins or in association with extracellular vesicles (EVs), can change considerably. Among the self-exRNAs, rexRNA is considered as a non-typical DAMP, since it may induce inflammatory responses by cell membrane receptors, both in the absence or presence of PAMPs. Yet, its mode of receptor activation to mount inflammatory responses remains obscure. RexRNA also serves as a universal damaging factor in cardiovascular and other diseases independent of PRRs. In general, RNase1 provides a profound antagonist in these pathologies and in rexRNA-mediated inflammatory cell responses. Based on the extrapolation of the here described aspects of rexRNA-biology, further activities of this molecular entity are hypothesized that may stimulate additional research in this area.

S Protein, ACE2 and Host Cell Proteases in SARS-CoV-2 Cell Entry and Infectivity; Is Soluble ACE2 a Two Blade Sword? A Narrative Review

Since the spread of the deadly virus SARS-CoV-2 in late 2019, researchers have restlessly sought to unravel how the virus enters the host cells. Some proteins on each side of the interaction between the virus and the host cells are involved as the major contributors to this process: (1) the nano-machine spike protein on behalf of the virus, (2) angiotensin converting enzyme II, the mono-carboxypeptidase and the key component of renin angiotensin system on behalf of the host cell, (3) some host proteases and proteins exploited by SARS-CoV-2. In this review, the complex process of SARS-CoV-2 entrance into the host cells with the contribution of the involved host proteins as well as the sequential conformational changes in the spike protein tending to increase the probability of complexification of the latter with angiotensin converting enzyme II, the receptor of the virus on the host cells, are discussed. Moreover, the release of the catalytic ectodomain of angiotensin converting enzyme II as its soluble form in the extracellular space and its positive or negative impact on the infectivity of the virus are considered.

Immune complex-induced haptokinesis in human non-classical monocytes

Formation and deposition of immune complexes (ICs) are hallmarks of various autoimmune diseases. Detection of ICs by IC receptors on leukocytes induces downstream signaling and shapes the local immune response. In many cases the pathological relevance of ICs is not well understood. We here show that ICs induce a distinct migratory response, i.e. haptokinesis in 6-sulfo LacNAc⁺ monocytes (slanMo) and in non-classical monocytes (ncMo) but not in intermediate (imMo) and classical monocytes (cMo). Using live imaging combined with automated cell tracking, we show that the main features of IC-dependent haptokinesis are elongation of the cell body, actin polarization at the leading edge, and highly directional migration. We find that CD16-dependent signaling mediates haptokinesis as blocking of CD16 or blocking SYK-signaling inhibited the migratory response. The activity of the metalloproteinase ADAM17 also modifies IC-dependent haptokinesis, likely at least partially via cleavage of CD16. Furthermore, using matrices with defined ligand spacing, we show that ligand density impacts the magnitude of the migratory response. Taken together, we have demonstrated that ICs induce a specific migratory response in ncMo but not in other monocyte subsets. Therefore, our work lays the groundwork for the investigation of IC-dependent haptokinesis in ncMo as a potential pathomechanism in IC-mediated autoimmune diseases.

Dissecting Interleukin-6 Classic and Trans-signaling in Inflammation and Cancer

Interleukin-6 (IL-6) is a cytokine synthesized by many cells in the human body. IL-6 binds to a membrane-bound receptor (IL-6R), which is only present on hepatocytes, some epithelial cells, and some leukocytes. The complex of IL-6 and IL-6R binds to the ubiquitously expressed receptor subunit gp130, which forms a homodimer and thereby initiates intracellular signaling, e.g., the JAK/STAT and MAPK pathways. Proteases can cleave the membrane-bound IL-6R from the cell surface and generate a soluble IL-6R (sIL-6R), which retains its ability to bind IL-6. The IL-6/sIL-6R complex associates with gp130 and induces signaling even on cells which do not express the IL-6R. This paradigm has been called IL-6 trans-signaling, whereas signaling via the membrane-bound IL-6R is referred to as classic signaling. We have generated several molecular tools to differentiate between both pathways and to analyze the consequences of cellular IL-6 signaling in vivo. One of these tools is soluble gp130Fc, which selectively inhibits IL-6 trans-signaling. This protein under the WHO name Olamkicept has successfully undergone phase II clinical trials in patients with autoimmune diseases. Here, in this chapter, we describe several molecular tools to differentiate between IL-6 classic and trans-signaling and to analyze the consequences of cellular IL-6 signaling in vivo.

Acute thiamethoxam exposure induces hepatotoxicity and neurotoxicity in juvenile Chinese mitten crab (Eriocheir sinensis)

The similar nervous system structure between crustaceans and insects and the high-water solubility of thiamethoxam can lead to the more severe toxicity of thiamethoxam to crustaceans. However, the effects of thiamethoxam on crustaceans are unclear. Therefore, a 96-h acute toxicity test was performed to explore the hepatotoxicity and neurotoxicity effects of thiamethoxam on Chinese mitten crab (Eriocheir sinensis) at concentrations 0 µg/L, 150 µg/L and 300 µg/L. The antioxidant and detoxification systems (including phases I and II) were significantly activated after exposure of juvenile crabs to thiamethoxam for 24 h in 300 µg/L group, whereas the toxic activation effect in 150 μg/L group was delayed. Moreover, a similar pattern was observed for the transcription levels of immune-related genes. Further analysis of inflammatory signaling pathway-related genes showed that thiamethoxam exposure with 300 µg/L for 24 h may induce a pro-inflammatory response through the NF-κB pathway. In contrast, the gene expression levels in 150 µg/L group were significantly upregulated compared with 0 µg/L group after 96 h. In addition, although the acute exposure of 150 μg/L thiamethoxam did not seem to induce significant neurotoxicity, the acetylcholinesterase activity was significantly decreased in 300 μg/L group after thiamethoxam exposure for 96 h. Correspondingly, thiamethoxam exposure with 300 µg/L for 24 h resulted in significantly downregulated transcriptional levels of synaptic transmission-related genes (e.g. dopamine-, gamma-aminobutyric acid- and serotonin-related receptors). Therefore, thiamethoxam may be harmful and cause potential toxic threats such as neurotoxicity and metabolic damage to crustaceans.

SARS-CoV-2-mediated liver injury: pathophysiology and mechanisms of disease

BACKGROUND

SARS-CoV-2-induced severe inflammatory response can be associated with severe medical consequences leading to multi-organ failure, including the liver. The main mechanism behind this assault is the aggressive cytokine storm that induces cytotoxicity in various organs. Of interest, hepatic stellate cells (HSC) respond acutely to liver injury through several molecular mechanisms, hence furthering the perpetuation of the cytokine storm and its resultant tissue damage. In addition, hepatocytes undergo apoptosis or necrosis resulting in the release of pro-inflammatory and pro-fibrogenic mediators that lead to chronic liver inflammation.

AIMS

The aim of this review is to summarize available data on SARS-CoV-2-induced liver inflammation in addition to evaluate the potential effect of anti-inflammatory drugs in attenuating SARS-CoV-2-induced liver inflammation.

METHODS

Thorough PubMed search was done to gather and summarize published data on SARS-CoV-2-induced liver inflammation. Additionally, various anti-inflammatory potential treatments were also documented.

RESULTS

Published data documented SARS-CoV-2 infection of liver tissues and is prominent in most liver cells. Also, histological analysis showed various features of tissues damage, e.g., hepatocellular necrosis, mitosis, cellular infiltration, and fatty degeneration in addition to microvesicular steatosis and inflammation. Finally, the efficacy of the different drugs used to treat SARS-CoV-2-induced liver injury, in particular the anti-inflammatory remedies, are likely to have some beneficial effect to treat liver injury in COVID-19.

CONCLUSION

SARS-CoV-2-induced liver inflammation is a serious condition, and drugs with potent anti-inflammatory effect can play a major role in preventing irreversible liver damage in COVID-19.

Immunomodulatory role of metalloproteases in cancers: Current progress and future trends

Metalloproteinases (MPs) is a large family of proteinases with metal ions in their active centers. According to the different domains metalloproteinases can be divided into a variety of subtypes mainly including Matrix Metalloproteinases (MMPs), A Disintegrin and Metalloproteases (ADAMs) and ADAMs with Thrombospondin Motifs (ADAMTS). They have various functions such as protein hydrolysis, cell adhesion and remodeling of extracellular matrix. Metalloproteinases expressed in multiple types of cancers and participate in many pathological processes involving tumor genesis and development, invasion and metastasis by regulating signal transduction and tumor microenvironment. In this review, based on the current research progress, we summarized the structure of MPs, their expression and especially immunomodulatory role and mechanisms in cancers. Additionally, a relevant and timely update of recent advances and future directions were provided for the diagnosis and immunotherapy targeting MPs in cancers.

The key role of Calpain in COVID-19 as a therapeutic strategy

COVID-19 is one of the viral diseases that has caused many deaths and financial losses to humans. Using the available information, this virus appears to activate the host cell-death mechanism through Calpain activation. Calpain inhibition can stop its downstream cascade reactions that cause cell death. Given the main roles of Calpain in the entry and pathogenicity of the SARS-CoV-2, its inhibition can be effective in controlling the COVID-19. This review describes how the virus activates Calpain by altering calcium flow. When Calpain was activated, the virus can enter the target cell. Subsequently, many complications of the disease, such as inflammation, cytokine storm and pulmonary fibrosis, are caused by virus-activated Calpain function. Calpain inhibitors appear to be a potential drug to control the disease and prevent death from COVID-19.