A Disintegrin And Metalloprotease 17 Research Articles

MiR-5586-5p Suppresses Hypoxia-induced Angiogenesis Through Multiple Targeting of HIF-1α, HBEGF and ADAM17 in Breast Cancer.

Hypoxia-inducible factor-1 alpha (HIF-1α) plays a key role in the cellular response to hypoxia, which plays a crucial role in the induction of abnormal angiogenesis and metastasis. Understanding the mechanism for the regulation of angiogenesis by HIF-1α-regulating miRNA will contribute to developing the strategy to prevent metastasis. We conducted a functional screening for HIF-1α-inhibiting miRNAs by evaluating the effects of miRNA mimics on HIF-1α expression and identified miR-5586-5p as an angiogenesis inhibitor through a mechanistic study. Angiogenic activity was assessed by tube formation assays using HUVEC cells exposed to conditioned media from miRNA-transfected breast cancer cells. In vivo activity of miR-5586-5p was examined through intratumoral injection of miRNA in orthotopic xenograft mice established by injecting MDA-MB-231 cells into the mammary fat pads of BALB/c nu/nu mice. The expression of the critical proangiogenic factors vascular endothelial growth factor A (VEGFA) and angiopoietin-like protein 4 (ANGPTL4) was inhibited by miR-5586-5p. Migration and tube formation of human umbilical vein endothelial cells were reduced in the conditioned medium prepared from miR-5586-5p-transfected cells. miR-5586-5p also suppressed the expression of heparin-binding EGF-like growth factor (HBEGF) and a disintegrin and metalloprotease 17 (ADAM17), which play a role in hypoxic signaling to induce the expression of VEGFA and ANGPTL4. HIF-1α, HBEGF, and ADAM17 were verified as the direct targets of miR-5586-5p responsible for the angiogenesis-suppressing function of miR-5586-5p. Expression levels of miR-5586-5p were lower in tumor tissues than in neighboring normal tissues of breast cancer patients. The expression of miR-5586-5p was inversely correlated to those of HIF-1α, HBEGF, ADAM17, VEGFA, and ANGPTL4. Angiogenesis and subsequent tumor growth were suppressed by intratumoral injection of miR-5586-5p in orthotopic MDA-MB-231 xenografts in mice. A potent tumor-suppressive function of miR-5586-5p applicable for the development of a novel cancer treatment strategy is herein described.

Spinal ADAM17 contributes to the pathogenesis of painful diabetic neuropathy in leptin receptor-deficient mice.

The pathogenesis of painful diabetic neuropathy (PDN) is complicated and remains not fully understood. A disintegrin and metalloprotease 17 (ADAM17) is an enzyme that is responsible for the degradation of membrane proteins. ADAM17 is known to be activated under diabetes, but its involvement in PDN is ill defined. Thus, we studied the role of spinal ADAM17 in PDN. Leptin receptor-deficient db/db mice were used as a mouse model of type 2 diabetes. To inhibit ADAM17, we used DNA-modified siRNA against ADAM17 (siADAM17) or TAPI-1, an ADAM17 inhibitor. The number of ADAM17-positive neurons was increased in the spinal dorsal horn (lamina I-V) in db/db mice, while ADAM17-positive microglia were increased only in lamina I-II. Inhibition of spinal ADAM17 by siADAM17 or TAPI-1 significantly attenuated PDN observed in db/db mice. Among several substrates of ADAM17, angiotensin (Ang)-converting enzyme 2 (ACE2) expression was significantly decreased in the spinal plasma membrane of db/db mice. Intrathecal administration of Ang (1-7), a peptide generated by ACE2, to db/db mice produced an anti-hyperalgesic effect, which was abolished by the MAS1 receptor antagonist A779. Our findings reveal a critical role for spinal ADAM17 in the pathogenesis of PDN mediated by the degradation of ACE2, and suggest a novel pain control mechanism acting through the degradation of plasma membrane proteins in the cause of pathological pain.

Acute hyperglycemia induces podocyte apoptosis by monocyte TNF-α release, a process attenuated by vitamin D and GLP-1 receptor agonists.

Targeting optimal glycemic control based on hemoglobin A1c (A1c) values reduces but does not abolish the onset of diabetic kidney disease and its progression to chronic kidney disease (CKD). This suggests that factors other than the average glucose contribute to the residual risk. Vitamin D deficiency and frequent episodes of acute hyperglycemia (AH) are associated with the onset of albuminuria and CKD progression in diabetes. This study aimed to determine if moderate levels of AH harm podocytes directly or promote a pro-inflammatory monocyte/macrophage phenotype that leads to podocyte apoptosis, and whether vitamin D deficiency accelerates these processes. We found that AH (16.7 mM D- glucose) didn't induce podocyte apoptosis directly, but it did promote a pro-inflammatory response in human monocytes and macrophages, resulting in an increased TNF-α secretion causing podocyte apoptosis. The AH-induced monocyte TNF-α secretion was inversely correlated with healthy donors' serum 25(OH)D levels. AH induced monocyte TNF-α release by increasing oxidative and ER stress, which in turn increased ADAM17 (A Disintegrin And Metalloprotease 17) and iRhom2 (inactive Rhomboid protein 2) expression, both essential for TNF-α secretion. Additionally, monocyte activation of glucagon-like peptide-1 receptor (GLP-1R), using a GLP-1R agonist, downregulated ADAM17/iRhom2 expression, decreasing TNF-α release and reducing podocyte apoptosis. These results show that a normal vitamin D status may attenuate a mechanism by which AH contributes to podocyte apoptosis and CKD progression and might enhance a novel anti-inflammatory role of GLP-1 to prevent AH-driven CKD progression in diabetes.

Abstract P159: Conditional deletion of ADAM17 (A disintegrin and metalloprotease 17) in microglia attenuates hypertension and associated inflammation.

Microglia, the resident immune cell in the brain, contributes to neuroinflammation and neurogenic hypertension by secreting various cytokines and chemokines. ADAM17 shedding of these signaling molecules) in microglia modulates synaptic function but the consequences of this process have not been studied in neurogenic hypertension. Accordingly, we hypothesize that deletion of ADAM17 in microglia opposes microglia activation and cytokine secretion thus preventing the development of neuroinflammation in salt-sensitive hypertension. To test our hypothesis, a new mouse model (ADAM17::CX3CR1-CreERT2; A17-Mic-/-) amenable for selective deletion of ADAM17 in microglia was developed. Following the initiation of deoxycorticosterone acetate plus salt (DOCA-salt) hypertension, tamoxifen was injected intracerebroventricularly to delete ADAM17 in microglia and blood pressure (BP) monitored over 3 weeks. In A17-Mic-/- mice, lacking ADAM17 in microglia, the BP increase induced by DOCA-salt treatment was blunted compared to control mice (127.4±5 vs. 143.4±4 mmHg, P<0.05). However, it was not abated in iRhom2-/- mice (149.5±3 mmHg), lacking the rhomboid protein involved in ADAM17 maturation in microglia, suggesting possible compensation by iRhom1. Interestingly, A17-Mic-/- mice showed a reduced level of proinflammatory cytokines and chemokines in the plasma, including TNF-α (A17-Mic-/-: 5.21±0.97, iRhom2-/-: 3.867±1 vs. control: 20.72±4 pg/mL), IL-6 (A17-Mic-/-: 36.53±11.33, iRhom2-/-: 91.41±14 vs. control: 79.65±15.72 pg/mL) and G-CSF (A17-Mic-/-: 508.4±98.7, iRhom2-/-: 3523±897 vs. 838.2±238.2 pg/mL) and MCP-1 (A17-Mic-/-: 38.41±9, iRhom2-/-: 51.87±7 vs. control: 75.52±12 pg/mL), respectively (P<0.05). Together, our data suggests that conditional deletion of ADAM17 opposes the activation of microglia and reduces pro-inflammatory cytokine and chemokine expression in hypertension. Overall, our data highlights the pivotal role of microglial ADAM17 in regulating salt-sensitive hypertension and the associated inflammation.

Correlation between TEX14 and ADAM17 expressions in colorectal cancer tissues of elderly patients and neoplasm staging, invasion, and metastasis

BACKGROUND Colorectal cancer (CRC) is one of the most frequently encountered malignant tumors in clinical settings. Proteins encoded by the testis-expressed gene 14 (TEX14) are imperative for spermatogenesis, necessitating intercellular bridges between germ cells. Anomalous expression of TEX14 has also been associated with the proliferation and differentiation of certain tumor cells. Recombinant A disintegrin and metalloprotease 17 (ADAM17) is known as a membrane-bound protease that regulates cellular activities and signal transduction by hydrolyzing various substrate proteins on the cell membrane. We hypothesize that TEX14 and ADAM17 may serve as potential biomarkers influencing the staging, invasion, and metastasis of CRC. AIM To probe the correlation between TEX17 and ADAM17 profiles in the CRC tissues of elderly patients and their association with CRC staging, invasion, and metastasis. METHODS We gathered data from 86 elderly patients diagnosed pathologically with CRC between April 2020 and December 2023. For each patient, one sample of cancer tissue and one sample of adjacent normal tissue were harvested. Real-time fluorescence quantitative PCR measured the mRNA profiles of TEX14 and ADAM17. Immunohistochemistry ascertained the positivity rates of TEX14 and ADAM17 expressions. Clinical pathological features of neoplasm staging, invasion, and metastasis were collected, and the association between TEX14 and ADAM17 expressions and clinical pathology was evaluated. RESULTS The mRNA and expression profiles of TEX14 and ADAM17 were significantly elevated in CRC tissues. The positivity rates of TEX14 and ADAM17 proteins in CRC tissues were 70.93% and 77.91%, respectively. There were no significant differences in age, sex, pathological type, and tumor diameter between TEX14 and ADAM17-positive and -negative patients. Patients with higher tumor differentiation degree, deeper infiltration and TNM stages ranging from III to IV exhibited higher positivity rates of TEX14 and ADAM17. Patients with lymph node metastasis and distant metastasis showed higher positivity rates of TEX14 and ADAM17 than those without. Positive expressions of TEX14 and ADAM17 were highly correlated with tumor staging, invasion, and metastasis. CONCLUSION TEX14 and ADAM17 profiles were significantly elevated in the CRC tissues of elderly patients, and their high expressions were associated with tumor staging, invasion, and metastasis.

Mesenchymal stem cell-derived extracellular vesicles ameliorate renal interstitial fibrosis via the miR-13474/ADAM17 axis

Renal interstitial fibrosis (RIF) is a prevalent consequence of chronic renal diseases, characterized by excessive extracellular matrix (ECM) deposition. A Disintegrin and Metalloprotease 17 (ADAM17), a transmembrane metalloproteinase, plays a central role in driving renal fibrosis progression by activating Notch 1 protein and the downstream TGF-β signaling pathway. Our study investigated potential therapeutic interventions for renal fibrosis, focusing on human umbilical cord mesenchymal stem cell-derived extracellular vesicles (hucMSC-EVs). We found that hucMSC-EVs inhibit ADAM17, thereby impeding renal fibrosis progression. Analysis of hucMSC-EVs miRNA profiles revealed significant enrichment of miR-13474, which effectively targeted and inhibited ADAM17 mRNA expression, subsequently suppressing Notch1 activation, TGF-β signaling, and collagen deposition. Overexpression of miR-13474 enhanced hucMSC-EVs' inhibitory effect on renal fibrosis, while its downregulation abolished this protective effect. Our findings highlight the efficacy of hucMSC-EVs overexpressing miR-13474 in mitigating renal fibrosis via ADAM17 targeting. These insights offer potential therapeutic strategies for managing renal fibrosis.

The interferon-rich skin environment regulates Langerhans cell ADAM17 to promote photosensitivity in lupus.

The autoimmune disease lupus erythematosus (lupus) is characterized by photosensitivity, where even ambient ultraviolet radiation (UVR) exposure can lead to development of inflammatory skin lesions. We have previously shown that Langerhans cells (LCs) limit keratinocyte apoptosis and photosensitivity via a disintegrin and metalloprotease 17 (ADAM17)-mediated release of epidermal growth factor receptor (EGFR) ligands and that LC ADAM17 sheddase activity is reduced in lupus. Here, we sought to understand how the lupus skin environment contributes to LC ADAM17 dysfunction and, in the process, differentiate between effects on LC ADAM17 sheddase function, LC ADAM17 expression, and LC numbers. We show through transcriptomic analysis a shared IFN-rich environment in non-lesional skin across human lupus and three murine models: MRL/lpr, B6.Sle1yaa, and imiquimod (IMQ) mice. IFN-I inhibits LC ADAM17 sheddase activity in murine and human LCs, and IFNAR blockade in lupus model mice restores LC ADAM17 sheddase activity, all without consistent effects on LC ADAM17 protein expression or LC numbers. Anti-IFNAR-mediated LC ADAM17 sheddase function restoration is associated with reduced photosensitive responses that are dependent on EGFR signaling and LC ADAM17. Reactive oxygen species (ROS) is a known mediator of ADAM17 activity; we show that UVR-induced LC ROS production is reduced in lupus model mice, restored by anti-IFNAR, and is cytoplasmic in origin. Our findings suggest that IFN-I promotes photosensitivity at least in part by inhibiting UVR-induced LC ADAM17 sheddase function and raise the possibility that anifrolumab ameliorates lupus skin disease in part by restoring this function. This work provides insight into IFN-I-mediated disease mechanisms, LC regulation, and a potential mechanism of action for anifrolumab in lupus.

Role of iRhom2 in Olfaction: Implications for Odorant Receptor Regulation and Activity-Dependent Adaptation.

The cell surface metalloprotease ADAM17 (a disintegrin and metalloprotease 17) and its binding partners iRhom2 and iRhom1 (inactive Rhomboid-like proteins 1 and 2) modulate cell-cell interactions by mediating the release of membrane proteins such as TNFα (Tumor necrosis factor α) and EGFR (Epidermal growth factor receptor) ligands from the cell surface. Most cell types express both iRhoms, though myeloid cells exclusively express iRhom2, and iRhom1 is the main iRhom in the mouse brain. Here, we report that iRhom2 is uniquely expressed in olfactory sensory neurons (OSNs), highly specialized cells expressing one olfactory receptor (OR) from a repertoire of more than a thousand OR genes in mice. iRhom2-/- mice had no evident morphological defects in the olfactory epithelium (OE), yet RNAseq analysis revealed differential expression of a small subset of ORs. Notably, while the majority of ORs remain unaffected in iRhom2-/- OE, OSNs expressing ORs that are enriched in iRhom2-/- OE showed fewer gene expression changes upon odor environmental changes than the majority of OSNs. Moreover, we discovered an inverse correlation between the expression of iRhom2 compared to OSN activity genes and that odor exposure negatively regulates iRhom2 expression. Given that ORs are specialized G-protein coupled receptors (GPCRs) and many GPCRs activate iRhom2/ADAM17, we investigated if ORs could activate iRhom2/ADAM17. Activation of an olfactory receptor that is ectopically expressed in keratinocytes (OR2AT4) by its agonist Sandalore leads to ERK1/2 phosphorylation, likely via an iRhom2/ADAM17-dependent pathway. Taken together, these findings point to a mechanism by which odor stimulation of OSNs activates iRhom2/ADAM17 catalytic activity, resulting in downstream transcriptional changes to the OR repertoire and activity genes, and driving a negative feedback loop to downregulate iRhom2 expression.

Serum ADAM -17 and Interleukin-6 Levels as a Predictors in Type 2 Diabetic Patients with Myocardial Infarction Patients

The association of heart diseases with type 2 diabetes, especially myocardial infarction, calls for a search for biomarkers that have a relationship between the two. Which facilitates the process of reducing the development of myocardial infarction in patients with type 2 diabetes. The most prominent of these associations is long-term inflammation and its first and largest factor is interleukin 6, and its close association with A disintegrin and metalloprotease 17 (ADAM-17) and its inverse relationship with type 2 diabetic patients with and without myocardial infarction. This study aims to investigate the role of ADAM-17 in the pathogenesis of diabetic type 2 Iraqi men patients with and without MI by comparing them with a apparantely helthy as control group and to see their association with interleukin-6 levels and other biomarkers. The current study was conducted on 90 Iraqi men between Ja., 2023 and Aug. 2023, 60 samples with T2DM with or without MI and the remaining 30 as apparently healthy control. The patients were selected from the visitors of the coronary care unit (CCU) and Al-Hassan Center for Diabetes and Endocrinology in Kerbala, and they were diagnosed clinically and by laboratory investigations. Various biomarkers such as ADAM-17 and IL-6 have been determined by different biochemical techniques. As a result The highest ADAM-17 and IL-6 level in type 2 diabetes without myocardial infarction was seen as comparison serum levels of IL-6, and ADAM-17 for T2DM (with or without myocardial infarction) with the control group. The correlation between IL-6 and ADAM-17 is strong in type-2 diabetes without MI and between IL-6 and electrocardiogram represented by the two types STEM and NSTEMI in type-2 diabetes with MI. In conclusion, The current study found that ADAM-17 and IL-6 have a negative effect on chronic inflammation as in T2DM without MI is more severe than acute inflammation as T2DM with MI , du to elevation of ADAM-17 and IL-6 levels in type 2 diabetic patients without MI than type 2 diabetic patient with MI.

Cryo-EM reveals that iRhom2 restrains ADAM17 protease activity to control the release of growth factor and inflammatory signals

A disintegrin and metalloprotease 17 (ADAM17) is a membrane-tethered protease that triggers multiple signaling pathways. It releases active forms of the primary inflammatory cytokine tumor necrosis factor (TNF) and cancer-implicated epidermal growth factor (EGF) family growth factors. iRhom2, a rhomboid-like, membrane-embedded pseudoprotease, is an essential cofactor of ADAM17. Here, we present cryoelectron microscopy (cryo-EM) structures of the human ADAM17/iRhom2 complex in both inactive and active states. These reveal three regulatory mechanisms. First, exploiting the rhomboid-like hallmark of TMD recognition, iRhom2 interacts with the ADAM17 TMD to promote ADAM17 trafficking and enzyme maturation. Second, a unique iRhom2 extracellular domain unexpectedly retains the cleaved ADAM17 inhibitory prodomain, safeguarding against premature activation and dysregulated proteolysis. Finally, loss of the prodomain from the complex mobilizes the ADAM17 protease domain, contributing to its ability to engage substrates. Our results reveal how a rhomboid-like pseudoprotease has been repurposed during evolution to regulate a potent membrane-tethered enzyme, ADAM17, ensuring the fidelity of inflammatory and growth factor signaling.

Mammalian target of rapamycin mediates expression and activity of ADAM 17 in diabetic kidney disease

Purpose: Previous data have illustrated a role for the matrix metalloprotease A Disintegrin And Metalloprotease 17 (ADAM17), known to cleave growth factors and cytokines, in renal cell injury in diabetes. The goal of this study was to identify upstream regulators of ADAM17 in the cascade of events contributing to extracellular matrix accumulation in diabetic nephropathy. Rationale: Diabetic kidney disease is a serious complication faced by type 1 and type 2 diabetic patients alike. Albuminuria and extracellular matrix accumulation are prominent features of the disease and this accumulation of extracellular matrix is a contributing factor to renal fibrosis and decline in renal function. The mechanisms involved in the pathogenesis of diabetic kidney disease have not been completely identified. Methodology: Age and weight-matched Sprague Dawley rats were obtained from Harlan Laboratories (Indianapolis, IN). Type 1 diabetes was induced through tail vein injection of streptozotocin. After rats were determined to be diabetic by blood glucose measurement, rapamycin treatments were administered intraperitoneally for two months. Both kidneys were removed and frozen in liquid nitrogen for microscopy and experimental analyses or formalin fixed for morphometric imaging at the experimental endpoint. Kidney cortex homogenates were used for western blot analyses and enzymatic activity assays. Findings: Using the mTOR complex 1 inhibitor rapamycin, it was determined that increased ADAM17 enzymatic activity and ADAM17 protein expression is dependent on mTORC1 in streptozotocin-induced type 1 diabetic rats. Inhibition of mTORC1 with rapamycin abrogated the increase in collagen IV α 2 protein expression observed in diabetic rat cortex. Additionally, this study is the first to provide evidence that mTOR complex 1 activates ADAM17 contributing to extracellular matrix accumulation in diabetic nephropathy. Studies are continuing looking at the molecular mechanisms involved in mTOR activation of ADAM17 resulting in downstream effects in cultured human proximal tubular epithelial cells. Research reported in this poster was supported by the University of the Incarnate Word Offce of Research and Graduate Studies. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Semaphorin 7A promotes endothelial permeability and inflammation via plexin C1 and integrin β1 in Kawasaki disease

BackgroundKawasaki disease (KD) is a pediatric systemic vasculitis characterized by endothelial cell dysfunction. Semaphorin 7A (Sema7A) has been reported to regulate endothelial phenotypes associated with cardiovascular diseases, while its role in KD remains unknown. This study aims to investigate the effect of Sema7A on endothelial permeability and inflammatory response in KD conditions.MethodsBlood samples were collected from 68 KD patients and 25 healthy children (HC). The levels of Sema7A and A Disintegrin and Metalloprotease 17 (ADAM17) in serum were measured by enzyme-linked immunosorbent assay (ELISA), and Sema7A expression in blood cells was analyzed by flow cytometry. Ex vivo monocytes were used for Sema7A shedding assays. In vitro human coronary artery endothelial cells (HCAECs) were cultured in KD sera and stimulated with Sema7A, and TNF-α, IL-1β, IL-6, and IL-18 of HCAECs were measured by ELISA and qRT-PCR. HCAECs monolayer permeability was measured by FITC-dextran.ResultsThe serum level of Sema7A was significantly higher in KD patients than in HC and correlated with disease severity. Monocytes were identified as one of the source of elevated serum Sema7A, which implicates a process of ADAM17-dependent shedding. Sera from KD patients induced upregulation of plexin C1 and integrin β1 in HCAECs compared to sera from HC. Sema7A mediated the proinflammatory cytokine production of HCAECs in an integrin β1-dependent manner, while both plexin C1 and integrin β1 contributed to Sema7A-induced HCAEC hyperpermeability.ConclusionsSema7A is involved in the progression of KD vasculitis by promoting endothelial permeability and inflammation through a plexin C1 and integrin β1-dependent pathway. Sema7A may serve as a potential biomarker and therapeutic target in the prognosis and treatment of KD.

Body Size Effect in Eothenomys miletus of Different Regions from Hengduan Mountain Regions: Roles of Growth Factor Contents

Background: Growth factors are active substances secreted by a variety of cells, acting as messengers to regulate cell migration, proliferation or differentiation, which had important regulatory roles in the growth of individual cells, tissues or organs. Growth factors can regulate the proliferation and differentiation ability of cells, which keep the internal environment stable and affect the body size. Methods: In order to investigate the influence of the changes of growth factors contents on body size in Eothenomys miletus from Hengduan mountain regions, E. miletus in Dali (DL), Jianchuan (JC), Lijiang (LJ), Xianggelila (XGLL) and Deqin (DQ) were collected and their 7 morphological indicators and 9 growth factors, including insulin-like growth factor1 (IGF1), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), growth hormone release inhibitory factor (GRIF), platelet-derived growth factor (PDGF), transcription elongation factor1 (TCEA1), a disintegrin and metalloprotease17 (ADAM7), branched-chain amino acid transaminase1 (BCAT1), high mobility group protein1 (HMG1) were measured. Result: The results showed that body size of E. miletus among five regions had significant differentiated, body mass, body length, forelimb length, hind limb length, tail length, IGF, bFGF, EGF, PDGF, TCEA1 contents in DL, JC and LJ were greater than those of in XGLL and DQ and the contents of GRIF, ADAM7, BCAT1 and HMG1 were also different, decreasing with the increasing of regional latitude. Moreover, the increases in the contents of growth factors lead to the increase of body size in E. miletus, which does not support Bergman's law. Regional differences in body size of E. miletus in different regions may be related to the changes in body mass, morphological indicators and the content of growth factors. Moreover, growth factors may affect the body size of E. miletus by affecting the proliferation of bone, epidermis, muscle and differentiation of cells.

Abstract C039: Disruption of ADAM17-dependent cellular crosstalk inhibits tumor progression of pancreatic ductal adenocarcinoma

Abstract Activation of cellular signaling pathways by crosstalk between tumor cells and their microenvironment is an essential mechanism supporting pancreatic carcinogenesis. In this study, we aim to disrupt cellular signaling pathways by targeting ADAM17 (a disintegrin and metalloprotease 17). ADAM17 is a membrane bound enzyme which cleaves cell surface proteins. Its function is closely linked with autocrine and paracrine signaling of immunomodulation as well as activation of EGFR, which is a central molecule for pancreatic tumorigenesis. To investigate whether EGFR is activated via a paracrine manner from macrophages, the most abundant immune-related stromal cells in pancreas cancers, we generated a pancreatic tumor mouse model with ADAM17 deletion in myeloid cells by using a dual recombinase strategy. We observed that lack of ADAM17 in the myeloid cells resulted in a delay of acinar cell transformation and an associated decrease in EGFR activation. To further examine the tumor supportive role of ADAM17, inhibition of ADAM17 using anti-ADAM17 antibody, MEDI3622, was tested in orthotopic tumor bearing mice. systemic inhibition of ADAM17 led to a reduction in tumor burden and a concomitant decrease in EGFR activation. These effects were observed exclusively in the immunocompetent animals, but not in the immunodeficient animals. It implicates that inhibition of tumor growth by MEDI3622 is highly dependent on the immune response. Furthermore, we found an elevated level of CCL21 in the MEDI3622-treated tumors resulting in increased tumor infiltration by dendritic cells and cytotoxic T cells for tumor killing. Altogether, ADAM17 blockade displays a pronounced anti-tumor effect, suggesting ADAM17 as a therapeutic target of pancreatic cancer. Citation Format: Hui-Ju Wen, Howard Crawford. Disruption of ADAM17-dependent cellular crosstalk inhibits tumor progression of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C039.

Cranial venous-outflow obstruction promotes neuroinflammation via ADAM17/solTNF-α/NF-κB pathway following experimental TBI

Traumatic brain injury (TBI) is a global public health problem. As an important cause of secondary injury, cerebrovascular reaction can cause secondary bleeding, venous sinus thrombosis, and malignant brain swelling. Recent clinical studies have confirmed that intracranial venous return disorder is closely related to the prognosis of patients, yet the specific molecular mechanism involved in this process is still unclear. This study used an acute subdural hematoma (ASDH) model with cranial venous outflow obstruction (CVO) to explore how CVO aggravates the pathological process after TBI, especially for inflammation and tissue damage. The results suggest that intracranial venous return disorder exacerbates neurological deficits and brain edema in rats with ASDH by aggravating the destruction of endothelial cell tight junctions (TJs) proteins and promoting the expression of inflammatory factors, the activation of microglia and expression of recombinant A disintegrin and metalloprotease 17 (ADAM17) as well as the secretion of solTNF-α, a soluble form of tumor necrosis factor-alpha (TNFα), which in turn increase IκB-α ((inhibitor of the transcription factor nuclear factor-κB) and NF-κB p65. Our study revealed a molecular basis of how CVO aggravates inflammation and tissue damage.

Abstract 081: Transactivation Of Brain ADAM17 In Angiotensin II-Induced Hypertension Can Be Prevented By Kinin B1 Receptor Blockade

A disintegrin and metalloprotease 17 (ADAM17) has been implicated in mediating inflammation in several cardiovascular diseases. Targeting brain ADAM17 using siRNA revealed a reduction in blood pressure, confirming its role in hypertension. Previously, we reported that kinin B1 receptor (B1R) activation increases ADAM17 activity in primary hypothalamic neurons, while pretreatment with a B1R antagonist mitigated this effect. However, whether there is a direct interaction between ADAM17 and B1R in hypertension is unknown. In this study, we tested the hypothesis that B1R blockade will prevent the transactivation of ADAM17, thereby, preventing the development of angiotensin II-induced hypertension. Male and female C57BL/6NJ wild-type (WT) and B1R knockout mice (B1RKO) were administered Ang II (600 ng/kg/min; SC, 2 weeks) or saline via osmotic minipumps. Ang II infusion significantly increased mean arterial pressure (radiotelemetry) in WT mice (145 ±13 mmHg vs. 103 ±6, n=6, p<0.01), which was attenuated in B1RKO mice. Both male and female B1RKO mice showed similar attenuation of Ang II-induced hypertension. Ang II-infusion led to a significant upregulation of ADAM17 in the PVN of WT mice and was blunted in B1RKO mice (p<0.05, n=3). Proximity ligation assay (PLA) was used to examine close proximity (<40nm) interactions between two receptors. ADAM17-B1R interactions in the PVN of hypertensive mice were significantly increased (p<0.05, n=3). To further understand this correlation, primary neurons and microglia from the hypothalamus of neonatal WT mice were cultured and treated with Ang II (300 nM) for 24 hours. Ang II increased B1R and ADAM17 protein expression in both cell types and was prevented by a B1R antagonist SSR240612 (10 uM) (p<0.05, n=5). To supplement these findings, PLA was used on primary neurons and microglia and revealed an increase in ADAM17-B1R interactions following Ang II. Furthermore, B1R antagonism attenuated this ADAM17-B1R interaction in both neurons and microglia (p<0.05, n=5). Our data provides novel evidence that B1R blockade can attenuate Ang II-induced hypertension in the brain, possibly through a reduction in B1R-ADAM17 interactions, suggesting that B1R blockade may serve as a potential antihypertensive therapeutic agent.

Blue light exposure collapses the inner blood-retinal barrier by accelerating endothelial CLDN5 degradation through the disturbance of GNAZ and the activation of ADAM17

Blue light is part of the natural light spectrum that emits high energy. Currently, people are frequently exposed to blue light from 3C devices, resulting in a growing incidence of retinopathy. The retinal vasculature is complex, and retinal vessels not only serve the metabolic needs of the retinal sublayers, but also maintain electrolyte homeostasis by forming the inner blood-retinal barrier (iBRB). The iBRB, which is primarily composed of endothelial cells, has well-developed tight junctions. However, with exposure to blue light, the risks of targeting retinal endothelial cells are currently unknown. We found that endothelial claudin-5 (CLDN5) was rapidly degraded under blue light, coinciding with the activation of a disintegrin and metalloprotease 17 (ADAM17), even at non-cytotoxic lighting. An apparently broken tight junction and a permeable paracellular cleft were observed. Mice exposed to blue light displayed iBRB leakage, conferring attenuation of the electroretinogram b-wave and oscillatory potentials. Both pharmacological and genetic inhibition of ADAM17 remarkably alleviated CLDN5 degradation induced by blue light. Under untreated condition, ADAM17 is sequestered by GNAZ (a circadian-responsive, retina-enriched inhibitory G protein), whereas ADAM17 escapes from GNAZ by blue light illuminance. GNAZ knockdown led to ADAM17 hyperactivation, CLDN5 downregulation, and paracellular permeability in vitro, and retinal damage mimicked blue light exposure in vivo. These data demonstrate that blue light exposure might impair the iBRB by accelerating CLDN5 degradation through the disturbance of the GNAZ-ADAM17 axis.

ARPC5 is transcriptionally activated by KLF4, and promotes cell migration and invasion in prostate cancer via up-regulating ADAM17 : ARPC5 serves as an oncogene in prostate cancer.

Prostate cancer (PCa) is one of the most common cancers in men worldwide. Actin-related protein 2/3 complex subunit 5 (ARPC5) has been validated as a critical regulator in several kinds of human tumors. However, whether ARPC5 is implicated in PCa progression remains largely unknown. PCa specimens and PCa cell lines were obtained for detecting gene expressions using western blot and quantitative reverse transcriptase PCR (qRT-PCR). PCa cells transfected with ARPC5 shRNA or a disintegrin and metalloprotease 17 (ADAM17) overexpressed plasmids were harvested for assessing cell proliferation, migration and invasion by using cell counting kit-8 (CCK-8), colony formation and transwell assays, respectively. The interaction relationship between molecules was testified with chromatin immunoprecipitation and luciferase reporter assay. Xenograft mice model was conducted for confirming the role of ARPC5/ADAM17 axis in vivo. Upregulated ARPC5 was observed in PCa tissues and cells, as well as forecasted poor prognosis of PCa patients. Depletion of ARPC5 inhibited PCa cell proliferation, migration and invasion. Krüppel-like factor 4 (KLF4) was identified to be a transcriptional activator of ARPC5 via binding with its promoter region. Furthermore, ADAM17 served as a downstream effector of ARPC5. ADAM17 overexpression overturned ARPC5 knockdown-induced repressive impacts on PCa progression in vitro and in vivo. Collectively, ARPC5 was activated by KLF4 and upregulated ADAM17 to promote PCa progression, which might act as a promising therapeutic target and prognostic biomarker for PCa.

Phosphate, calcium, and vitamin D signaling, transport, and metabolism in the endometria of cyclic ewes

BackgroundRecent evidence suggests important roles for progesterone (P4) and interferon tau in the regulation of calcium, phosphate, and vitamin D signaling in the uteri of pregnant sheep. However, the effects of P4 and estradiol (E2), with respect to the expression of their receptors PGR and ESR1, respectively, in uterine epithelia on mineral signaling during the estrous cycle has not been investigated. Estrous cycles of mature Suffolk ewes were synchronized, prostaglandin F2α was administered, and ewes were observed for estrus (designated as Day 0) in the presence of vasectomized rams. On Days 1, 9, or 14 of the estrous cycle, hysterectomies were performed.Results25-hydroxyvitamin D was more abundant in plasma from ewes on Day 14 than Day 1 (P < 0.05). Expression of fibroblast growth factor receptor 2 (FGFR2), a disintegrin and metalloprotease 17 (ADAM17), and parathyroid hormone-related protein (PTHrP) mRNAs was greater in endometria on Day 9 compared to Days 1 and 14 (P < 0.01). Similarly, expression of transient receptor potential cation channel subfamily V member 6 (TRPV6) mRNA was greater in endometria on Day 9 than Day 1 (P < 0.05). ATPase plasma membrane Ca2+ transporting 4 (ATP2B4) and S100 calcium binding protein G (S100G) mRNA expression was greater in endometria on Day 14 than on Days 1 and 9 (P < 0.01). In contrast, endometrial expression of vitamin D receptor (VDR) mRNA was lower on Days 9 and 14 than Day 1 (P < 0.01). Expression of klotho (KL) (P < 0.05) and cytochrome P450 family 24 subfamily A member 1 (CYP24) (P < 0.01) mRNAs was lower on Day 14 than Days 1 and 9. ADAM17, FGF23, CYP2R1, CYP27B1, KL, and VDR proteins immunolocalized to the uterine myometrium, blood vessels, and uterine luminal (LE), superficial glandular (sGE), and glandular (GE) epithelia. S100A9 protein was weakly expressed in the uterine myometrium, LE, sGE, and GE. Immunoreactivity of CYP2R1 and KL proteins in uterine LE and sGE was less on Day 1 than on Days 9 and 14. In contrast, S100G protein was expressed exclusively by GE, and immunoreactive S100G protein was less on Day 9. S100A12 protein localized to stromal cells of the uterine stratum spongiosum and blood vessels, but not by uterine epithelial cells.ConclusionCollectively, these results implicate E2, P4, and PGR in the regulation of phosphate, calcium, and vitamin D signaling in cyclic ewes.

Repurposing of drugs for combined treatment of COVID-19 cytokine storm using machine learning

Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) induced cytokine storm is the major cause of COVID-19 related deaths. Patients have been treated with drugs that work by inhibiting a specific protein partly responsible for the cytokines production. This approach provided very limited success, since there are multiple proteins involved in the complex cell signaling disease mechanisms. We targeted five proteins: Angiotensin II receptor type 1 (AT1R), A disintegrin and metalloprotease 17 (ADAM17), Nuclear Factor‑Kappa B (NF‑κB), Janus kinase 1 (JAK1) and Signal Transducer and Activator of Transcription 3 (STAT3), which are involved in the SARS‑CoV‑2 induced cytokine storm pathway. We developed machine-learning (ML) models for these five proteins, using known active inhibitors. After developing the model for each of these proteins, FDA-approved drugs were screened to find novel therapeutics for COVID‑19. We identified twenty drugs that are active for four proteins with predicted scores greater than 0.8 and eight drugs active for all five proteins with predicted scores over 0.85. Mitomycin C is the most active drug across all five proteins with an average prediction score of 0.886. For further validation of these results, we used the PyRx software to conduct protein–ligand docking experiments and calculated the binding affinity. The docking results support findings by the ML model. This research study predicted that several drugs can target multiple proteins simultaneously in cytokine storm-related pathway. These may be useful drugs to treat patients because these therapies can fight cytokine storm caused by the virus at multiple points of inhibition, leading to synergistically effective treatments.