The ADAMs family of metalloproteases: multidomain proteins with multiple functions

Deciphering the oncogenic potential of ADAM9 in hepatocellular carcinoma through bioinformatics and experimental approaches

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. This study investigates the role and mechanisms of ADAM9 as a biomarker and potential therapeutic target in HCC. Utilizing RNA-sequencing data and clinicopathological characteristics from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, we conducted survival and meta-analyses, functional enrichment, and immune infiltration studies. Additionally, we evaluated the effects of ADAM9 silencing on HCC cell proliferation, migration, and invasion through in vitro experiments. Our results demonstrate that high ADAM9 expression is associated with poor prognosis and increased immune infiltration in HCC patients. Furthermore, ADAM9 knockdown significantly inhibited tumor cell proliferation and migration. These findings indicate that ADAM9 is a promising prognostic biomarker and potential therapeutic target in HCC. In conclusion, ADAM9 could offer avenues for developing strategies to inhibit tumor progression and improve patient outcomes.

Unveiling potential sex-determining genes and sex-specific markers in autotetraploid Carassius auratus

Autotetraploid Carassius auratus is a stable hereditary autotetraploid fish resulting from the hybridization of Carassius auratus red var. (RCC, ♀) × Megalobrama amblycephala (BSB, ♂), containing four sets of RCC chromosomes. However, the molecular mechanism underlying the determination of sex in this species remains largely unknown. Currently, there lacks a full understanding of the molecular mechanisms governing sex determination and specific molecular markers to differentiate sex in this species. In this study, 25,801,677 SNPs (Single-nucleotide polymorphism) and 6,210,306 Indels (insertion-deletion) were obtained from whole-genome resequencing of 100 individuals (including 50 female and 50 male). Further identification confirmed the candidate chromosomes as Chr46B, with the sex-determining region located at Chr46B: 22,500,000-22,800,000 bp. Based on the male-specific insertion (26 bp) within the candidate sex-determining region, a pair of sex-specific molecular markers has been identified. In addition, based on the screening of candidate sex-determining region genes and RT-qPCR validation analysis, ADAM10, AQP9 and tc1a were identified as candidate sex-determining genes. These findings provide a robust foundation for investigating sex determination mechanisms in fish, the evolution of sex chromosomes, and the development of monosex populations.

ADAM10 isoforms: Optimizing usage of antibodies based on protein regulation, structural features, biological activity and clinical relevance to Alzheimer's disease

A Disintegrin and Metalloproteinase 10 (ADAM10) is a crucial transmembrane protein involved in diverse cellular processes, including cell adhesion, migration, and proteolysis. ADAM10's ability to cleave over 100 substrates underscores its significance in physiological and pathological contexts, particularly in Alzheimer's disease (AD). This review comprehensively examines ADAM10's multifaceted roles, highlighting its critical function in the non-amyloidogenic processing of the amyloid precursor protein (APP), which mitigates amyloid beta (Aβ) production, a critical factor in AD development. We summarize the regulation of ADAM10 at multiple levels: transcriptional, translational, and post-translational, revealing the complexity and responsiveness of its expression to various cellular signals. A standardized nomenclature for ADAM10 isoforms is proposed to improve clarity and consistency in research, facilitating better comparison and replication of findings across studies. We address the challenges in detecting ADAM10 isoforms using antibodies, advocating for standardized detection protocols to resolve discrepancies in results from different biological matrices. By highlighting these issues, this review underscores the potential of ADAM10 as a biomarker for early diagnosis and a therapeutic target in AD. By consolidating current knowledge on ADAM10's regulation and function, we aim to provide insights that will guide future research and therapeutic strategies in the AD context.

Fully human monoclonal antibody targeting the cysteine-rich substrate-interacting region of ADAM17 on cancer cells

ADAM17 sheds EGFR/erbB ligands and triggers oncogenic pathways that lead to the progression of solid tumors. We targeted the ADAM17 disintegrin and cysteine rich domain region (D+C) to generate a panel of single-chain antibody fragments (scFvs) that selectively bind to the D or C domains of ADAM17, but not of ADAM10 or ADAM19. From the panel, we selected one scFv, referred to as C12, based on its high binding affinity towards the target, and re-formatted it to a full IgG for further studies. High-resolution cryo-electron microscopy studies documented that the mAb binds to the ADAM17 C-domain that in ADAM proteases, notably ADAM10 and ADAM17, is known to impart substrate-specificity. The C12 mAb significantly inhibited EGFR phosphorylation in cancer cell lines by hindering the cleavage of EGFR ligands tethered to the cell surface. This inhibition provides a mechanism for potential anti-tumor effects, and indeed C12 diminished the viability of a variety of EGFR-expressing cancer cell lines. Cell-based ELISA studies revealed that C12 preferentially bound to activated ADAM17 present on tumor cells, as compared to the autoinhibited ADAM17 that is the predominant form on HEK293 and other non-tumor cells. C12 also exhibited tumor growth inhibition in an ovarian cancer xenograft mouse model. Consistent with its selective tumor cell binding in vitro, radioimmuno PET (positron emission tomography) imaging with 89Zr-DFO-C12 in mouse xenograft models confirmed tumoral accumulation of the C12 mAb.

Stimulating myelin restoration with BDNF: a promising therapeutic approach for Alzheimer's disease

Alzheimer's Disease (AD) is a chronic neurodegenerative disorder constituting the most common form of dementia (60%-70% of cases). Although AD presents majorly a neurodegenerative pathology, recent clinical evidence highlights myelin impairment as a key factor in disease pathogenesis. The lack of preventive or restorative treatment is emphasizing the need to develop novel therapeutic approaches targeting to the causes of the disease. Recent studies in animals and patients have highlighted the loss of myelination of the neuronal axons as an extremely aggravating factor in AD, in addition to the formation of amyloid plaques and neurofibrillary tangles that are to date the main pathological hallmarks of the disease. Myelin breakdown represents an early stage event in AD. However, it is still unclear whether myelin loss is attributed only to exogenous factors like inflammatory processes of the tissue or to impaired oligodendrogenesis as well. Neurotrophic factors are well established protective molecules under many pathological conditions of the neural tissue, contributing also to proper myelination. Due to their inability to be used as drugs, many research efforts are focused on substituting neurotrophic activity with small molecules. Our research team has recently developed novel micromolecular synthetic neurotrophin mimetics (MNTs), selectively acting on neurotrophin receptors, and thus offering a unique opportunity for innovative therapies against neurodegenerative diseases. These small sized, lipophilic molecules address the underlying biological effect of these diseases (neuroprotective action), but also they exert significant neurogenic actions inducing neuronal replacement of the disease areas. One of the significant neurotrophin molecules in the Central Nervous System is Brain-Derived-Neurotrophin-Factor (BDNF). BDNF is a neurotrophin that not only supports neuroprotection and adult neurogenesis, but also mediates pro-myelinating effects in the CNS. BDNF binds with high-affinity on the TrkB neurotrophin receptor and enhances myelination by increasing the density of oligodendrocyte progenitor cells (OPCs) and playing an important role in CNS myelination. Conclusively, in the present review, we discuss the myelin pathophysiology in Alzheimer's Diseases, as well as the role of neurotrophins, and specifically BDNF, in myelin maintenance and restoration, revealing its valuable therapeutic potential against AD.

Advances in precision gene editing for liver fibrosis: From technology to therapeutic applications

This review presents a comprehensive exploration of gene editing technologies and their potential applications in the treatment of liver fibrosis, a condition often leading to serious complications such as liver cancer. Through an in-depth review of current literature and critical analysis, the study delves into the intricate signaling pathways underlying liver fibrosis development and examines the promising role of gene editing in alleviating this disease burden. Gene editing technologies offer precise, efficient, and reproducible tools for manipulating genetic material, holding significant promise for basic research and clinical practice. The manuscript highlights the challenges and potential risks associated with gene editing technology. By synthesizing existing knowledge and exploring future perspectives, this study aims to provide valuable insights into the potential of precision gene editing to combat liver fibrosis and its associated complications, ultimately contributing to advances in liver fibrosis research and therapy.

Cancer-associated fibroblasts mediate resistance to anti-EGFR therapies in cancer

Over the last decade, epidermal growth factor receptor (EGFR)-targeted therapies have transformed the treatment landscape for patients with advanced solid tumors. Despite these advances, resistance to anti-EGFR therapies is still a significant clinical challenge. While cell-autonomous mechanisms of resistance are well-documented, they do not fully elucidate the complexity of drug resistance. Cancer-associated fibroblasts (CAFs), key mediators within the tumor microenvironment (TME), have emerged as pivotal players in cancer progression and chemoresistance. Recent evidence implicates CAFs in resistance to anti-EGFR therapies, suggesting they may undermine treatment efficacy. This review synthesizes current data, highlighting the critical role of CAFs in resistance pathogenesis and summarizing recent therapeutic strategies targeting CAFs. We underscore the challenges and advocate for the exploration of CAFs as a potential dual-targeted approach.

Inactive metallopeptidase homologs: the secret lives of pseudopeptidases

Inactive enzyme homologs, or pseudoenzymes, are proteins, found within most enzyme families, that are incapable of performing catalysis. Rather than catalysis, they are involved in protein-protein interactions, sometimes regulating the activity of their active enzyme cousins, or scaffolding protein complexes. Pseudoenzymes found within metallopeptidase families likewise perform these functions. Pseudoenzymes within the M14 carboxypeptidase family interact with collagens within the extracellular space, while pseudopeptidase members of the M12 "a disintegrin and metalloprotease" (ADAM) family either discard their pseudopeptidase domains as unnecessary for their roles in sperm maturation or utilize surface loops to enable assembly of key complexes at neuronal synapses. Other metallopeptidase families contain pseudopeptidases involved in protein synthesis at the ribosome and protein import into organelles, sometimes using their pseudo-active sites for these interactions. Although the functions of these pseudopeptidases have been challenging to study, ongoing work is teasing out the secret lives of these proteins.

Causal inference of the effect of blood proteome on the risk of head and neck cancer: two-sample Mendelian randomization

Early diagnosis of head and neck cancer can improve therapeutic outcomes but remains a challenge. The blood proteome can comprise a key source of biomarkers that enable the early diagnosis and precision medicine in head and neck cancer, but blood protein biomarkers of head and neck cancer are not well delineated. Here we applied two-sample Mendelian randomization to a GWAS dataset of 1478 blood proteins and large dataset of head and neck cancer cases and controls to identify blood proteome traits associated with head and neck cancer. Multiple two-sample Mendelian randomization (MR) methods were used to assess causal effects of the exposures, including: Inverse-variance weighted (IVW), Mendelian randomization-Egger method, Weight Median method, simple mode, weight mode. Sensitivity analysis was performed by using heterogeneity test, pleiotropy test and one-by-one exclusion test. Multivariable MR analyses were performed to assess the effects of obesity, diabetes mellitus, and smoking. A significant causal association between A Disintegrin and metalloproteinase domain-containing protein 23 (ADAM23) and head and neck cancer was noted. The sensitivity analysis indicated no significant bias. Multivariate analysis showed that the effect for ADAM23 remained significant after adjusting for the indirect effects of obesity, diabetes mellitus and smoking. In sum, this study showed a significant causal role of genetically dysregulated ADAM23 protein with head and neck cancer risk. The specific mechanisms underlying the role of ADAM23 in mediating head and neck cancer risk, and its role as a potential therapeutic target and biomarker, need further investigation.

Ectodomain shedding of PLA2R1 is mediated by the metalloproteases ADAM10 and ADAM17

Phospholipase A2 receptor 1 (PLA2R1) is a 180-kDa transmembrane protein that plays a role in inflammation and cancer and is the major autoantigen in membranous nephropathy, a rare but severe autoimmune kidney disease. A soluble form of PLA2R1 has been detected in mouse and human serum. It is likely produced by proteolytic shedding of membrane-bound PLA2R1 but the mechanism is unknown. Here, we show that human PLA2R1 is cleaved by A Disintegrin And Metalloprotease 10 (ADAM10) and ADAM17 in HEK293 cells, mouse embryonic fibroblasts, and human podocytes. By combining site-directed mutagenesis and sequencing, we determined the exact cleavage site within the extracellular juxtamembrane stalk of human PLA2R1. Orthologs and paralogs of PLA2R1 are also shed. By using pharmacological inhibitors and genetic approaches with RNA interference and knock-out cellular models, we identified a major role of ADAM10 in the constitutive shedding of PLA2R1 and a dual role of ADAM10 and ADAM17 in the stimulated shedding. We did not observe evidence for cleavage by β- or γ-secretase, suggesting that PLA2R1 may not be a substrate for regulated intramembrane proteolysis. PLA2R1 shedding occurs constitutively and can be triggered by the calcium ionophore ionomycin, the protein kinase C activator PMA, cytokines, and lipopolysaccharides, in vitro and in vivo. Altogether, our results show that PLA2R1 is a novel substrate for ADAM10 and ADAM17, producing a soluble form that is increased in inflammatory conditions and likely exerts various functions in physiological and pathophysiological conditions including inflammation, cancer, and membranous nephropathy.

A Disintegrin and metalloproteinase carves T cell abnormalities and pathogenesis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder impacting various organs, notably prevalent in women of reproductive age. This review explores the involvement of a disintegrin and metalloproteinases (ADAMs) in SLE pathogenesis. Despite advancements in understanding SLE through genome and transcriptome studies, the role of ADAMs in post-translational regulations remains insufficiently explored. ADAMs, transmembrane proteins with diverse functions, impact cell adhesion, migration, and inflammation by shedding cell surface proteins, growth factors, and receptors. Notably, ADAM9 is implicated in Th17 cell differentiation, which is crucial in SLE pathology. ADAM10 and ADAM17 play pivotal roles in T-cell biology, influencing immune cell development and differentiation. Elevated soluble ADAM substrates in SLE patients serve as potential biomarkers correlating with disease activity. Targeting ADAMs or their substrates offers promising therapeutic avenues for SLE management and treatment enhancement.

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.

Transcriptional dynamics and regulatory function of milRNAs in Ascosphaera apis invading Apis mellifera larvae

In the present study, small RNA (sRNA) data from Ascosphaera apis were filtered from sRNA-seq datasets from the gut tissues of A. apis-infected Apis mellifera ligustica worker larvae, which were combined with the previously gained sRNA-seq data from A. apis spores to screen differentially expressed milRNAs (DEmilRNAs), followed by trend analysis and investigation of the DEmilRNAs in relation to significant trends. Additionally, the interactions between the DEmilRNAs and their target mRNAs were verified using a dual-luciferase reporter assay. In total, 974 A. apis milRNAs were identified. The first base of these milRNAs was biased toward U. The expression of six milRNAs was confirmed by stem-loop RT-PCR, and the sequences of milR-3245-y and milR-10285-y were validated using Sanger sequencing. These miRNAs grouped into four significant trends, with the target mRNAs of DEmilRNAs involving 42 GO terms and 120 KEGG pathways, such as the fungal-type cell wall and biosynthesis of secondary metabolites. Further investigation demonstrated that 299 DEmilRNAs (novel-m0011-3p, milR-10048-y, bantam-y, etc.) potentially targeted nine genes encoding secondary metabolite-associated enzymes, while 258 (milR-25-y, milR-14-y, milR-932-x, etc.) and 419 (milR-4561-y, milR-10125-y, let-7-x, etc.) DEmilRNAs putatively targeted virulence factor-encoded genes and nine genes involved in the MAPK signaling pathway, respectively. Additionally, the interaction between ADM-B and milR-6882-x, as well as between PKIA and milR-7009-x were verified. Together, these results not only offer a basis for clarifying the mechanisms underlying DEmilRNA-regulated pathogenesis of A. apis and a novel insight into the interaction between A. apis and honey bee larvae, but also provide candidate DEmilRNA-gene axis for further investigation.

New insight into the role of the ADAM protease family in breast carcinoma progression

Protease and adhesion molecules play a very emphasized role in the occurrence or progression of metastasis in many types of cancers. In this context, a molecule that contains both protease and adhesion functions play a crucial role in metastasis. ADAMs (a disintegrin and metalloprotease) are molecules with this special characteristic. Recently, a lot of attention has been attracted to various ADAM molecules and researchers have tried to elucidate the role of ADAMs in breast cancer occurrence and progression. Disrupting ADAMs protease and adhesion capabilities can lead to the discovery of worthy therapeutic targets in breast cancer treatment. In this review, we intend to discuss the mechanism of action of various ADAM molecules, their relation to pathogenic processes of breast cancer, and their potential as possible targets for breast cancer treatment.

Understanding the complexity of Tityus serrulatus venom: A focus on high molecular weight components

Tityus serrulatus scorpion is responsible for a significant number of envenomings in Brazil, ranging from mild to severe, and in some cases, leading to fatalities. While supportive care is the primary treatment modality, moderate and severe cases require antivenom administration despite potential limitations and adverse effects. The remarkable proliferation of T. serrulatus scorpions, attributed to their biology and asexual reproduction, contributes to a high incidence of envenomation. T. serrulatus scorpion venom predominantly consists of short proteins acting as neurotoxins (α and β), that primarily target ion channels. Nevertheless, high molecular weight compounds, including metalloproteases, serine proteases, phospholipases, and hyaluronidases, are also present in the venom. These compounds play a crucial role in envenomation, influencing the severity of symptoms and the spread of venom. This review endeavors to comprehensively understand the T. serrulatus scorpion venom by elucidating the primary high molecular weight compounds and exploring their potential contributions to envenomation. Understanding these compounds' mechanisms of action can aid in developing more effective treatments and prevention strategies, ultimately mitigating the impact of scorpion envenomation on public health in Brazil.

DNMT3A clonal hematopoiesis-driver mutations induce cardiac fibrosis by paracrine activation of fibroblasts

Hematopoietic mutations in epigenetic regulators like DNA methyltransferase 3 alpha (DNMT3A), play a pivotal role in driving clonal hematopoiesis of indeterminate potential (CHIP), and are associated with unfavorable outcomes in patients suffering from heart failure (HF). However, the precise interactions between CHIP-mutated cells and other cardiac cell types remain unknown. Here, we identify fibroblasts as potential partners in interactions with CHIP-mutated monocytes. We used combined transcriptomic data derived from peripheral blood mononuclear cells of HF patients, both with and without CHIP, and cardiac tissue. We demonstrate that inactivation of DNMT3A in macrophages intensifies interactions with cardiac fibroblasts and increases cardiac fibrosis. DNMT3A inactivation amplifies the release of heparin-binding epidermal growth factor-like growth factor, thereby facilitating activation of cardiac fibroblasts. These findings identify a potential pathway of DNMT3A CHIP-driver mutations to the initiation and progression of HF and may also provide a compelling basis for the development of innovative anti-fibrotic strategies.

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.

Molecular Characteristics and Pathogenicity of Staphylococcus aureus Exotoxins

Staphylococcus aureus stands as one of the most pervasive pathogens given its morbidity and mortality worldwide due to its roles as an infectious agent that causes a wide variety of diseases ranging from moderately severe skin infections to fatal pneumonia and sepsis. S. aureus produces a variety of exotoxins that serve as important virulence factors in S. aureus-related infectious diseases and food poisoning in both humans and animals. For example, staphylococcal enterotoxins (SEs) produced by S. aureus induce staphylococcal foodborne poisoning; toxic shock syndrome toxin-1 (TSST-1), as a typical superantigen, induces toxic shock syndrome; hemolysins induce cell damage in erythrocytes and leukocytes; and exfoliative toxin induces staphylococcal skin scalded syndrome. Recently, Panton-Valentine leucocidin, a cytotoxin produced by community-associated methicillin-resistant S. aureus (CA-MRSA), has been reported, and new types of SEs and staphylococcal enterotoxin-like toxins (SEls) were discovered and reported successively. This review addresses the progress of and novel insights into the molecular structure, biological activities, and pathogenicity of both the classic and the newly identified exotoxins produced by S. aureus.

CRISPR/Cas9-mediated genome editing reveals seven testis-enriched transmembrane glycoproteins dispensable for male fertility in mice

BACKGROUND

Mammalian fertilization is mediated by multiple sperm acrosomal proteins, many of which are testis-enriched transmembrane glycoproteins expressed during spermiogenesis (e.g., Izumo sperm-egg fusion 1, Sperm acrosome associated 6, and Transmembrane protein 95).

METHODS

We hypothesized that proteins with these features might have a role in sperm-egg interaction and thus carried out an in-silico screen based on multiple public databases. We generated knockout mouse lines lacking seven candidate proteins by the CRISPR/Cas9 system and conducted detailed analyses on the fecundity of the knockout males, as well as their testis appearance and weight, testis and epididymis histology, and sperm motility and morphology.

RESULTS

Through the in-silico screen, we identified 4932438H23Rik, A disintegrin and metalloproteinase domain-containing protein 29, SAYSvFN domain-containing protein 1, Sel-1 suppressor of lin-12-like 2 (C. elegans), Testis-expressed protein 2, Transmembrane and immunoglobulin domain-containing 3, and Zinc and ring finger 4. Phenotypic analyses unveiled that the knockout males showed normal testis gross appearance, normal testis and epididymis histology, and normal sperm morphology and motility. Fertility tests further indicated that the knockout male mice could sire pups with normal litter sizes when paired with wild-type females.

DISCUSSION AND CONCLUSION

These findings suggest that these seven proteins are individually dispensable for male reproduction and fertilization. Future studies are warranted to devise advanced in-silico screening approaches that permit effective identification of gamete fusion-required sperm proteins.

Role of ADAM and ADAMTS proteases in pathological tissue remodeling

Pathological tissue remodeling is closely associated with the occurrence and aggravation of various diseases. A Disintegrin And Metalloproteinases (ADAM), as well as A Disintegrin And Metalloproteinase with ThromboSpondin motifs (ADAMTS), belong to zinc-dependent metalloproteinase superfamily, are involved in a range of pathological states, including cancer metastasis, inflammatory disorders, respiratory diseases and cardiovascular diseases. Mounting studies suggest that ADAM and ADAMTS proteases contribute to the development of tissue remodeling in various diseases, mainly through the regulation of cell proliferation, apoptosis, migration and extracellular matrix remodeling. This review focuses on the roles of ADAM and ADAMTS proteinases in diseases with pathological tissue remodeling, with particular emphasis on the molecular mechanisms through which ADAM and ADAMTS proteins mediate tissue remodeling. Some of these reported proteinases have defined protective or contributing roles in indicated diseases, while their underlying regulation is obscure. Future studies are warranted to better understand the catalytic and non-catalytic functions of ADAM and ADAMTS proteins, as well as to evaluate the efficacy of targeting these proteases in pathological tissue remodeling.

Four different gene-related cone-rod dystrophy: clinical and genetic findings in six Chinese families with diverse modes of inheritance

Purpose: To investigate pathogenic variants in six families with cone-rod dystrophy (CORD) presenting various inheritance patterns by using whole-exome sequencing (WES) and analyzing phenotypic features. Methods: A total of six families with CORD were enrolled in Ningxia Eye Hospital for this study. The probands and their family members received comprehensive ophthalmic examinations, and DNA was abstracted from patients and family members. Whole-exome sequencing was performed on probands to screen the causative variants, and all suspected pathogenic variants were determined via Sanger sequencing. Furthermore, co-segregation analysis was performed on available family members. The pathogenicity of novel variants was predicted using in silico analysis and evaluated according to the American College of Medical Genetics and Genomics (ACMG) guidelines. Results: Of the six families, two families were assigned as X-linked recessive (XL), two families were assigned as autosomal recessive (AR), and two families were assigned as autosomal dominant (AD). Pathogenic variants were detected in CACNA1F in two X-linked recessive probands, among which family 1 had a hemizygous frameshift variant c.2201del (p.Val734Glyfs*17) and family 2 had a hemizygous missense variant c.245G>A (p.Arg82Gln). Both probands had high myopia, with fundus tessellation accompanied by abnormalities in the outer structure of the macular area. The homozygous splice variant c.2373 + 5G>T in PROM1 and the homozygous nonsense variant c.604C>T (p.Arg202Ter) in ADAM9 were detected in two autosomal recessive families of the probands. Both probands showed different degrees of atrophy in the macular area, and the lesions showed hypofluorescence changes in autofluorescence. The heterozygous variation in CRX c.682C>T (p.Gln228Ter) was detected in two autosomal dominant families. The onset age of the two probands was late, with better vision and severe macular atrophy. According to ACMG guidelines and the analysis of online in silico tools, all variations were labeled as potentially harmful or pathogenic. Conclusion: Pathogenic variants in CACNA1F, PROM1, ADAM9, and CRX genes were identified in six families affected by the diverse inheritance patterns of CORD. Furthermore, the potential impact of the nonsense-mediated decay (NMD) mechanism on the manifestation of CORD phenotypes was examined and addressed. Simultaneously, the spectrum of pathogenic variants and clinical phenotypes associated with the CORD gene was extended.

Initial study of the detection of ADAM 10 in the urine of type-2 diabetic patients

Diabetes mellitus (DM) is a disease of civilization. If left untreated, it can cause serious complications and significantly shortens the life time. DM is one of the leading causes of end-stage renal disease (uremia) worldwide. Early diagnosis is a prerequisite for successful treatment, preferably before the first symptoms appear. In this paper, we describe the optimization and synthesis of the internally quenched fluorescent substrate disintegrin and metalloproteinase 10 (ADAM10). Using combinatorial chemistry methods with iterative deconvolution, the substrate specificity of the enzyme in non-primed and primed positions was determined. We used the ABZ-Lys-Ile-Ile-Asn-Leu-Lys-Arg-Tyr(3-NO2)-NH2 peptide to study ADAM10 activity in urine samples collected from patients diagnosed with type 2 diabetes, compared to urine samples from healthy volunteers. The proteolytically active enzyme was present in diabetes samples, while in the case of healthy people we did not observe any activity. In conclusion, our study provides a possible basis for further research into the potential role of ADAM10 in the diagnosis of type 2 diabetes.

Fibroblast activation protein drives tumor metastasis via a protease-independent role in invadopodia stabilization

During metastasis, tumor cells invade through the basement membrane and intravasate into blood vessels and then extravasate into distant organs to establish metastases. Here, we report a critical role of a transmembrane serine protease fibroblast activation protein (FAP) in tumor metastasis. Expression of FAP and TWIST1, a metastasis driver, is significantly correlated in several types of human carcinomas, and FAP is required for TWIST1-induced breast cancer metastasis to the lung. Mechanistically, FAP is localized at invadopodia and required for invadopodia-mediated extracellular matrix degradation independent of its proteolytic activity. Live cell imaging shows that association of invadopodia precursors with FAP at the cell membrane promotes the stabilization and growth of invadopodia precursors into mature invadopodia. Together, our study identified FAP as a functional target of TWIST1 in driving tumor metastasis via promoting invadopodia-mediated matrix degradation and uncovered a proteolytic activity-independent role of FAP in stabilizing invadopodia precursors for maturation.

Identification of circulating T-cell immunoglobulin and mucin domain 4 as a potential biomarker for coronary heart disease

Efferocytosis, the process of engulfing and removing apoptotic cells, is attenuated in vulnerable plaques of advanced atherosclerosis. T-cell immunoglobulin and mucin domain 4 (TIMD4) is a recognition receptor protein for efferocytosis that has been implicated in atherosclerosis mouse models. However, the role of serum-soluble TIMD4 (sTIMD4) in coronary heart disease (CHD) remains unknown. In this study, we analyzed serum samples collected from two groups: Group 1 (36 healthy controls and 70 CHD patients) and Group 2 (44 chronic coronary syndrome [CCS]) and 81 acute coronary syndrome [ACS] patients). We found that sTIMD4 levels in patients with CHD were significantly higher than those in healthy controls and were also higher in ACS than in CCS patients. The area under the receiver operating characteristic curve was 0.787. Furthermore, our in vitro results showed that low-density lipoprotein/lipopolysaccharide activated p38 mitogen-activated protein kinase, which in turn enhanced a disintegrin and metalloproteinase 17, resulting in increased secretion of sTIMD4. This impairment of macrophage efferocytosis promoted inflammation. Thus, this study is not only the first identification of a potential novel biomarker of CHD, sTIMD4, but also demonstrated its pathogenesis mechanism, providing a new direction for the diagnosis and treatment of CHD.

Are the integrin binding motifs within SARS CoV-2 spike protein and MHC class II alleles playing the key role in COVID-19?

The previous studies on the RGD motif (aa403-405) within the SARS CoV-2 spike (S) protein receptor binding domain (RBD) suggest that the RGD motif binding integrin(s) may play an important role in infection of the host cells. We also discussed the possible role of two other integrin binding motifs that are present in S protein: LDI (aa585-587) and ECD (661-663), the motifs used by some other viruses in the course of infection. The MultiFOLD models for protein structure analysis have shown that the ECD motif is clearly accessible in the S protein, whereas the RGD and LDI motifs are partially accessible. Furthermore, the amino acids that are present in Epstein-Barr virus protein (EBV) gp42 playing very important role in binding to the HLA-DRB1 molecule and in the subsequent immune response evasion, are also present in the S protein heptad repeat-2. Our MultiFOLD model analyses have shown that these amino acids are clearly accessible on the surface in each S protein chain as monomers and in the homotrimer complex and bind to HLA-DRB1 β chain. Therefore, they may have the identical role in SARS CoV-2 immune evasion as in EBV infection. The prediction analyses of the MHC class II binding peptides within the S protein have shown that the RGD motif is present in the core 9-mer peptide IRGDEVRQI within the two HLA-DRB1*03:01 and HLA-DRB3*01.01 strong binding 15-mer peptides suggesting that RGD motif may be the potential immune epitope. Accordingly, infected HLA-DRB1*03:01 or HLA-DRB3*01.01 positive individuals may develop high affinity anti-RGD motif antibodies that react with the RGD motif in the host proteins, like fibrinogen, thrombin or von Willebrand factor, affecting haemostasis or participating in autoimmune disorders.

Fully human monoclonal antibody targeting activated ADAM10 on colorectal cancer cells

Metastasis and chemoresistance in colorectal cancer are mediated by certain poorly differentiated cancer cells, known as cancer stem cells, that are maintained by Notch downstream signaling initiated upon Notch cleavage by the metalloprotease ADAM10. It has been shown that ADAM10 overexpression correlates with aberrant signaling from Notch, erbBs, and other receptors, as well as a more aggressive metastatic phenotype, in a range of cancers including colon, gastric, prostate, breast, ovarian, uterine, and leukemia. ADAM10 inhibition, therefore, stands out as an important and new approach to deter the progression of advanced CRC. For targeting the ADAM10 substrate-binding region, which is located outside of the catalytic domain of the protease, we generated a human anti-ADAM10 monoclonal antibody named 1H5. Structural and functional characterization of 1H5 reveals that it binds to the substrate-binding cysteine-rich domain and recognizes an activated ADAM10 conformation present on tumor cells. The mAb inhibits Notch cleavage and proliferation of colon cancer cell lines in vitro and in mouse models. Consistent with its binding to activated ADAM10, the mAb augments the catalytic activity of ADAM10 towards small peptide substrates in vitro. Most importantly, in a mouse model of colon cancer, when administered in combination with the therapeutic agent Irinotecan, 1H5 causes highly effective tumor growth inhibition without any discernible toxicity effects. Our singular approach to target the ADAM10 substrate-binding region with therapeutic antibodies could overcome the shortcomings of previous intervention strategies of targeting the protease active site with small molecule inhibitors that exhibit musculoskeletal toxicity.

ADAM17 Confers Temozolomide Resistance in Human Glioblastoma Cells and miR-145 Regulates Its Expression

Glioblastoma (GBM) is a malignant brain tumor, commonly treated with temozolomide (TMZ). Upregulation of A disintegrin and metalloproteinases (ADAMs) is correlated to malignancy; however, whether ADAMs modulate TMZ sensitivity in GBM cells remains unclear. To explore the role of ADAMs in TMZ resistance, we analyzed changes in ADAM expression following TMZ treatment using RNA sequencing and noted that ADAM17 was markedly upregulated. Hence, we established TMZ-resistant cell lines to elucidate the role of ADAM17. Furthermore, we evaluated the impact of ADAM17 knockdown on TMZ sensitivity in vitro and in vivo. Moreover, we predicted microRNAs upstream of ADAM17 and transfected miRNA mimics into cells to verify their effects on TMZ sensitivity. Additionally, the clinical significance of ADAM17 and miRNAs in GBM was analyzed. ADAM17 was upregulated in GBM cells under serum starvation and TMZ treatment and was overexpressed in TMZ-resistant cells. In in vitro and in vivo models, ADAM17 knockdown conferred greater TMZ sensitivity. miR-145 overexpression suppressed ADAM17 and sensitized cells to TMZ. ADAM17 upregulation and miR-145 downregulation in clinical specimens are associated with disease progression and poor prognosis. Thus, miR-145 enhances TMZ sensitivity by inhibiting ADAM17. These findings offer insights into the development of therapeutic approaches to overcome TMZ resistance.

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.

10 years of extracellular matrix proteomics: Accomplishments, challenges, and future perspectives

The extracellular matrix (ECM) is a complex assembly of hundreds of proteins forming the architectural scaffold of multicellular organisms. In addition to its structural role, the ECM conveys signals orchestrating cellular phenotypes. Alterations of ECM composition, abundance, structure, or mechanics, have been linked to diseases and disorders affecting all physiological systems, including fibrosis and cancer. Deciphering the protein composition of the ECM and how it changes in pathophysiological contexts is thus the first step toward understanding the roles of the ECM in health and disease and toward the development of therapeutic strategies to correct disease-causing ECM alterations. Potentially, the ECM also represents a vast, yet untapped reservoir of disease biomarkers. ECM proteins are characterized by unique biochemical properties that have hindered their study: they are large, heavily and uniquely post-translationally modified, and highly insoluble. Overcoming these challenges, we and others have devised mass-spectrometry-based proteomic approaches to define the ECM composition, or "matrisome", of tissues. This review provides a historical overview of ECM proteomics research and presents the latest advances that now allow the profiling of the ECM of healthy and diseased tissues. The second part highlights recent examples illustrating how ECM proteomics has emerged as a powerful discovery pipeline to identify prognostic cancer biomarkers. The third part discusses remaining challenges limiting our ability to translate findings to clinical application and proposes approaches to overcome them. Last, the review introduces readers to resources available to facilitate the interpretation of ECM proteomics datasets. The ECM was once thought to be impenetrable. MS-based proteomics has proven to be a powerful tool to decode the ECM. In light of the progress made over the past decade, there are reasons to believe that the in-depth exploration of the matrisome is within reach and that we may soon witness the first translational application of ECM proteomics.

Treadmill workout activates PPARα in the hippocampus to upregulate ADAM10, decrease plaques and improve cognitive functions in 5XFAD mouse model of Alzheimer's disease

Although liver is rich in peroxisome proliferator-activated receptor α (PPARα), recently we have described the presence of PPARα in hippocampus where it is involved in non-amyloidogenic metabolism of amyloid precursor protein (APP) via ADAM10, decreasing amyloid plaques and improving memory and learning. However, mechanisms to upregulate PPARα in vivo in the hippocampus are poorly understood. Regular exercise has multiple beneficial effects on human health and here, we describe the importance of regular mild treadmill exercise in upregulating PPARα in vivo in the hippocampus of 5XFAD mouse model of Alzheimer's disease. We also demonstrate that treadmill exercise remained unable to stimulate ADAM10, reduce plaque pathology and improve cognitive functions in 5XFADΔPPARα mice (5XFAD mice lacking PPARα). On the other hand, treadmill workout increased ADAM10, decreased plaque pathology and protected memory and learning in 5XFADΔPPARβ mice (5XFAD mice lacking PPARβ). Moreover, the other PPAR (PPARγ) also did not play any role in the transcription of ADAM10 in vivo in the hippocampus of treadmill exercised 5XFAD mice. These results underline an important role of PPARα in which treadmill exercise remains unable to exhibit neuroprotection in the hippocampus in the absence of PPARα.

An overview of Tityus cisandinus scorpion venom: Transcriptome and mass fingerprinting reveal conserved toxin homologs across the Amazon region and novel lipolytic components

Tityus cisandinus, a neglected medically important scorpion in Ecuadorian and Peruvian Amazonia, belongs to a complex of species related to the eastern Amazon endemic Tityus obscurus, spanning a distribution of ca. 4000 km. Despite high morbidity and mortality rates, no effective scorpion antivenom is currently available in the Amazon region. Knowledge of the structural/functional relationships between T. cisandinus venom components and those from related Amazonian species is crucial for designing region-specific therapeutic antivenoms. In this work, we carried out the first venom gland transcriptomic study of an Amazonian scorpion outside Brazil, T. cisandinus. We also fingerprinted its total venom through MALDI-TOF MS, which supported our transcriptomic findings. We identified and calculated the expression level of 94 components: 60 toxins, 25 metalloproteases, five disulfide isomerases, three amidating enzymes, one hyaluronidase, and also uncovered transcripts encoding novel lipolytic beta subunits produced by New World buthid scorpions. This study demonstrates the high similarity between T. cisandinus and T. obscurus venoms, reinforcing the existence of a neglected complex of genetically and toxinologically related Amazonian scorpions of medical importance. Finally, we demonstrated the low recognition of currently available therapeutic sera against T. cisandinus and T. obscurus venoms, and concluded that these should be improved to protect against envenomation by Amazonian Tityus spp.

Affinity-matured DLL4 ligands as broad-spectrum modulators of Notch signaling

The Notch pathway regulates cell fate decisions and is an emerging target for regenerative and cancer therapies. Recombinant Notch ligands are attractive candidates for modulating Notch signaling; however, their intrinsically low receptor-binding affinity restricts their utility in biomedical applications. To overcome this limitation, we evolved variants of the ligand Delta-like 4 with enhanced affinity and cross-reactivity. A consensus variant with maximized binding affinity, DeltaMAX, binds human and murine Notch receptors with 500- to 1,000-fold increased affinity compared with wild-type human Delta-like 4. DeltaMAX also potently activates Notch in plate-bound, bead-bound and cellular formats. When administered as a soluble decoy, DeltaMAX inhibits Notch in reporter and neuronal differentiation assays, highlighting its dual utility as an agonist or antagonist. Finally, we demonstrate that DeltaMAX stimulates increased proliferation and expression of effector mediators in T cells. Taken together, our data define DeltaMAX as a versatile tool for broad-spectrum activation or inhibition of Notch signaling.

The Biochemistry and Physiology of A Disintegrin and Metalloproteinases (ADAMs and ADAM-TSs) in Human Pathologies

Metalloproteinases are a group of proteinases that plays a substantial role in extracellular matrix remodeling and its molecular signaling. Among these metalloproteinases, ADAMs (a disintegrin and metalloproteinases) and ADAM-TSs (ADAMs with thrombospondin domains) have emerged as highly efficient contributors mediating proteolytic processing of various signaling molecules. ADAMs are transmembrane metalloenzymes that facilitate the extracellular domain shedding of membrane-anchored proteins, cytokines, growth factors, ligands, and their receptors and therefore modulate their biological functions. ADAM-TSs are secretory, and soluble extracellular proteinases that mediate the cleavage of non-fibrillar extracellular matrix proteins. ADAMs and ADAM-TSs possess pro-domain, metalloproteinase, disintegrin, and cysteine-rich domains in common, but ADAM-TSs have characteristic thrombospondin motifs instead of the transmembrane domain. Most ADAMs and ADAM-TSs are activated by cleavage of pro-domain via pro-protein convertases at their N-terminus, hence directing them to various signaling pathways. In this article, we are discussing not only the structure and regulation of ADAMs and ADAM-TSs, but also the importance of these metalloproteinases in various human pathophysiological conditions like cardiovascular diseases, colorectal cancer, autoinflammatory diseases (sepsis/rheumatoid arthritis), Alzheimer's disease, proliferative retinopathies, and infectious diseases. Therefore, based on the emerging role of ADAMs and ADAM-TSs in various human pathologies, as summarized in this review, these metalloproteases can be considered as critical therapeutic targets and diagnostic biomarkers.

Metzincin metalloproteases in PGC migration and gonadal sex conversion

Development of a functional gonad includes migration of primordial germ cells (PGCs), differentiations of somatic and germ cells, formation of primary follicles or spermatogenic cysts with somatic gonadal cells, development and maturation of gametes, and subsequent releasing of mature germ cells. These processes require extensive cellular and tissue remodeling, as well as broad alterations of the surrounding extracellular matrix (ECM). Metalloproteases, including MMPs (matrix metalloproteases), ADAMs (a disintegrin and metalloproteinases), and ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs), are suggested to have critical roles in the remodeling of the ECM during gonad development. However, few research articles and reviews are available on the functions and mechanisms of metalloproteases in remodeling gonadal ECM, gonadal development, or gonadal differentiation. Moreover, most studies focused on the roles of transcription and growth factors in early gonad development and primary sex determination, leaving a significant knowledge gap on how differentially expressed metalloproteases exert effects on the ECM, cell migration, development, and survival of germ cells during the development and differentiation of ovaries or testes. We will review gonad development with focus on the evidence of metalloprotease involvements, and with an emphasis on zebrafish as a model for studying gonadal sex differentiation and metalloprotease functions.

Tace/ADAM17 is a bi-directional regulator of axon guidance that coordinates distinct Frazzled and Dcc receptor signaling outputs

Frazzled (Fra) and deleted in colorectal cancer (Dcc) are homologous receptors that promote axon attraction in response to netrin. In Drosophila, Fra also acts independently of netrin by releasing an intracellular domain (ICD) that activates gene transcription. How neurons coordinate these pathways to make accurate guidance decisions is unclear. Here we show that the ADAM metalloprotease Tace cleaves Fra, and this instructs the switch between the two pathways. Genetic manipulations that either increase or decrease Tace levels disrupt midline crossing of commissural axons. These conflicting phenotypes reflect Tace's function as a bi-directional regulator of axon guidance, a function conserved in its vertebrate homolog ADAM17: while Tace induces the formation of the Fra ICD to activate transcription, excessive Tace cleavage of Fra and Dcc suppresses the response to netrin. We propose that Tace and ADAM17 are key regulators of midline axon guidance by establishing the balance between netrin-dependent and netrin-independent signaling.

Divergent regulation of basement membrane trafficking by human macrophages and cancer cells

Macrophages and cancer cells populations are posited to navigate basement membrane barriers by either mobilizing proteolytic enzymes or deploying mechanical forces. Nevertheless, the relative roles, or identity, of the proteinase -dependent or -independent mechanisms used by macrophages versus cancer cells to transmigrate basement membrane barriers harboring physiologically-relevant covalent crosslinks remains ill-defined. Herein, both macrophages and cancer cells are shown to mobilize membrane-anchored matrix metalloproteinases to proteolytically remodel native basement membranes isolated from murine tissues while infiltrating the underlying interstitial matrix ex vivo. In the absence of proteolytic activity, however, only macrophages deploy actomyosin-generated forces to transmigrate basement membrane pores, thereby providing the cells with proteinase-independent access to the interstitial matrix while simultaneously exerting global effects on the macrophage transcriptome. By contrast, cancer cell invasive activity is reliant on metalloproteinase activity and neither mechanical force nor changes in nuclear rigidity rescue basement membrane transmigration. These studies identify membrane-anchored matrix metalloproteinases as key proteolytic effectors of basement membrane remodeling by macrophages and cancer cells while also defining the divergent invasive strategies used by normal and neoplastic cells to traverse native tissue barriers.

Myelin repair in Alzheimer's disease: a review of biological pathways and potential therapeutics

This literature review investigates the significant overlap between myelin-repair signaling pathways and pathways known to contribute to hallmark pathologies of Alzheimer's disease (AD). We discuss previously investigated therapeutic targets of amyloid, tau, and ApoE, as well as other potential therapeutic targets that have been empirically shown to contribute to both remyelination and progression of AD. Current evidence shows that there are multiple AD-relevant pathways which overlap significantly with remyelination and myelin repair through the encouragement of oligodendrocyte proliferation, maturation, and myelin production. There is a present need for a single, cohesive model of myelin homeostasis in AD. While determining a causative pathway is beyond the scope of this review, it may be possible to investigate the pathological overlap of myelin repair and AD through therapeutic approaches.

IL-17A Promotes Epithelial ADAM9 Expression in Cigarette Smoke-Related COPD

Background

It has been reported that a disintegrin and metalloproteinase 9 (ADAM9) is involved in the pathogenesis of cigarette smoke (CS)-associated chronic obstructive pulmonary disease (COPD). But how CS exposure leads to upregulation of ADAM9 remains unknown.

Methods

Patients who underwent lobectomy for a solitary pulmonary nodule were enrolled and divided into three groups: non-smokers with normal lung function, smokers without COPD and smoker patients with COPD. Immunoreactivity of interleukin (IL)-17A and ADAM9 in small airways and alveolar walls was measured by immunohistochemistry. Wild-type and Il17a^−/− C57BL/6 mice were exposed to CS for six months, and ADAM9 expression in the airway epithelia was measured by immunoreactivity. In addition, the protein and mRNA expression levels of IL-17A and ADAM9 were assessed in CS extract (CSE) and/or IL-17A-treated human bronchial epithelial (HBE) cells.

Results

The immunoreactivity of ADAM9 was increased in the airway epithelia and alveolar walls of patients with COPD compared to that of the controls. The expression of IL-17A was also upregulated in airway epithelial cells of patients with COPD and correlated positively with the level of ADAM9. The results from the animal model showed that Il17a^−/− mice were protected from emphysema induced by CS exposure, together with a reduced level of ADAM9 expression in the airway epithelia, suggesting a possible link between ADAM9 and IL-17A. Consistently, our in vitro cell model showed that CSE stimulated the expression of ADAM9 and IL-17A in HBE cells in a dose- and time-dependent manner. Recombinant IL-17A induced ADAM9 upregulation in HBE cells and had a synergistic effect with CSE, whereas blocking IL-17A inhibited CSE-induced ADAM9 expression. Further analysis revealed that IL-17A induced c-Jun N-terminal kinase (JNK) phosphorylation, thereby increasing ADAM9 expression.

Conclusion

Our results revealed a novel role of IL-17A in CS-related COPD, where IL-17A contributes to ADAM9 expression by activating JNK signaling.

Role of ADAM and ADAMTS Disintegrin and Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy (NP) involves intricate processes starting with egg fertilization, proceeding to embryo implantation, placentation and gestation, and culminating in parturition. These pregnancy-related processes require marked uteroplacental and vascular remodeling by proteolytic enzymes and metalloproteinases. A disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS) are members of the zinc-dependent family of proteinases with highly conserved protein structure and sequence homology, which include a pro-domain, and a metalloproteinase, disintegrin and cysteine-rich domain. In NP, ADAMs and ADAMTS regulate sperm-egg fusion, embryo implantation, trophoblast invasion, placental angiogenesis and spiral arteries remodeling through their ectodomain proteolysis of cell surface cytokines, cadherins and growth factors as well as their adhesion with integrins and cell-cell junction proteins. Preeclampsia (PE) is a serious complication of pregnancy characterized by new-onset hypertension (HTN) in pregnancy (HTN-Preg) at or after 20 weeks of gestation, with or without proteinuria. Insufficient trophoblast invasion of the uterine wall, inadequate expansive remodeling of the spiral arteries, reduced uteroplacental perfusion pressure, and placental ischemia/hypoxia are major initiating events in the pathogenesis of PE. Placental ischemia/hypoxia increase the release of reactive oxygen species (ROS), which lead to aberrant expression/activity of certain ADAMs and ADAMTS. In PE, abnormal expression/activity of specific ADAMs and ADAMTS that function as proteolytic sheddases could alter proangiogenic and growth factors, and promote the release of antiangiogenic factors and inflammatory cytokines into the placenta and maternal circulation leading to generalized inflammation, endothelial cell injury and HTN-Preg, renal injury and proteinuria, and further decreases in uteroplacental blood flow, exaggeration of placental ischemia, and consequently fetal growth restriction. Identifying the role of ADAMs and ADAMTS in NP and PE has led to a better understanding of the underlying molecular and vascular pathways, and advanced the potential for novel biomarkers for prediction and early detection, and new approaches for the management of PE.

Melanoma stimulates the proteolytic activity of HaCaT keratinocytes

Background

Keratinocytes constitute a major part of the melanoma microenvironment, considering their protective role towards melanocytes in physiological conditions. However, their interactions with tumor cells following melanomagenesis are still unclear.

Methods

We used two in vitro models (melanoma-conditioned media and indirect co-culture of keratinocytes with melanoma cells on Transwell inserts) to activate immortalized keratinocytes towards cancer-associated ones. Western Blotting and qPCR were used to evaluate keratinocyte markers and mediators of cell invasiveness on protein and mRNA expression level respectively. The levels and activity of proteases and cytokines were analysed using gelatin-FITC staining, gelatin zymography, chemiluminescent enzymatic test, as well as protein arrays. Finally, to further study the functional changes influenced by melanoma we assessed the rate of proliferation of keratinocytes and their invasive abilities by employing wound healing assay and the Transwell filter invasion method.

Results

HaCaT keratinocytes activated through incubation with melanoma-conditioned medium or indirect co-culture exhibit properties of less differentiated cells (downregulation of cytokeratin 10), which also prefer to form connections with cancer cells rather than adjacent keratinocytes (decreased level of E-cadherin). While they express only a small number of cytokines, the variety of secreted proteases is quite prominent especially considering that several of them were never reported as a part of secretome of activated keratinocytes’ (e.g., matrix metalloproteinase 3 (MMP3), ADAM metallopeptidase with thrombospondin type 1 motif 1). Activated keratinocytes also seem to exhibit a high level of proteolytic activity mediated by MMP9 and MMP14, reduced expression of TIMPs (tissue inhibitor of metalloproteinases), upregulation of ERK activity and increased levels of MMP expression regulators-RUNX2 and galectin 3. Moreover, cancer-associated keratinocytes show slightly elevated migratory and invasive abilities, however only following co-culture with melanoma cells on Transwell inserts.

Conclusions

Our study offers a more in-depth view of keratinocytes residing in the melanoma niche, drawing attention to their unique secretome and mediators of invasive abilities, factors which could be used by cancer cells to support their invasion of surrounding tissues.

ADAM-10 Regulates MMP-12 during Lipopolysaccharide-Induced Inflammatory Response in Macrophages

A disintegrin and metalloprotease 10 (ADAM-10), a member of the ADAM protease family, has biological activities related to TNF-α activation, cell adhesion, and migration, among other functions. Macrophages are important immune cells that are involved in the inflammatory response of the body. ADAM-10 is involved in inflammatory responses, but the specific regulatory mechanisms are not fully understood. In this study, we investigated the regulatory mechanism of ADAM-10 in the lipopolysaccharide-promoted proliferation (LPS) of the macrophage inflammatory response. Differentially expressed or regulated proteins were identified in interfered ADAM-10 (sh ADAM-10) macrophages using tandem mass tag (TMT) proteomics. The changes and regulatory role of ADAM-10 during LPS-induced inflammatory response in normal, interfering, and overexpressing ADAM-10 (EX ADAM-10) cells were determined. Results indicated that ADAM-10 interference affected inflammation-related pathways and reduced matrix metalloproteinase 12 (MMP-12) protein levels, as identified by TMT proteomics. In normal cells, LPS decreased ADAM-10 gene expression, but promoted ADAM-10 secretion, MMP-12 and TNF-α gene expression, and MMP-12, iNOS, IL-10, and cyclinD1 protein expression. Additionally, ADAM-10 knockdown decreased macrophage viability in sh-ADAM-10 cells. Moreover, an MMP-12 inhibitor had no impact on the viability effect of LPS on cells or the expression of ADAM-10. iNOS expression decreased, whereas IL-10 expression increased after ADAM-10 depletion. ADAM-10 knockdown decreased MMP-12, iNOS, TNF-α, IL-1β, and FKN, while overexpression had an opposite effect. ADAM-10 overexpression further increased MMP-12, iNOS, and TNF-α gene expression in response to LPS. Cell viability was increased in EX ADAM-10 cells, and ADAM-10 secretion was further increased in the EX and LPS groups. Flow cytometry and immunofluorescence staining revealed that EX-ADAM 10 cells had increased iNOS expression, which acted as an IL-6 expression driver. In summary, we found that ADAM-10 is activated by LPS and positively participates in LPS-stimulated macrophage inflammatory responses by positively regulating MMP-12 during the inflammatory process.

Identification of the extracellular metallo-endopeptidases ADAM and ADAMTS in the yellow fever mosquito Aedes aegypti

The mosquito Aedes aegypti is a major vector for dengue, Zika, yellow fever, and chikungunya (CHIKV) viruses, which cause significant morbidity and mortality among human populations in the tropical regions of the world. Following ingestion of a viremic bloodmeal from a vertebrate host, an arbovirus needs to productively infect the midgut epithelium of the mosquito. De novo synthesized virions then exit the midgut by traversing the surrounding basal lamina (BL) in order to disseminate to secondary tissues and infect those. Once the salivary glands are infected, the virus is transmitted to a vertebrate host along with saliva released during probing of the mosquito. Midgut tissue distention due to bloodmeal ingestion leads to remodeling of the midgut structure and facilitates virus dissemination from the organ. Previously, we described the matrix-metalloproteinases (MMP) of Ae. aegypti as zinc ion dependent endopeptidases (Metzincins) and showed MMP activity during midgut BL rearrangement as a consequence of bloodmeal ingestion and subsequent digestion thereby affecting arbovirus dissemination from the midgut. Here we investigate the ADAM/ADAMTS of Ae. aegypti, which form another major group of multi-domain proteinases within the Metzincin superfamily and are active during extra-cellular matrix (ECM) remodeling. Seven different ADAM and five ADAMTS were identified in Ae. aegypti. The functional protein domain structures of the identified mosquito ADAM resembled those of human ADAM10, ADAM12, and ADAM17, while two of the five mosquito ADAMTS had human orthologs. Expression profiling of Ae. aegypti ADAM/ADAMTS in immature forms, whole body-females, midguts, and ovarian tissues showed transcriptional activity of the proteinases during metamorphosis, bloodmeal ingestion/digestion, and female reproduction. Custom-made antibodies to ADAM10a and ADAM12c showed that both were strongly expressed in midgut and ovarian tissues. Furthermore, transient silencing of ADAM12c significantly reduced the carcass infection rate with CHIKV at 24 h post-infection, while silencing of ADAM12a significantly increased viral titers in secondary tissues at the same time point. Our results indicate a functional specificity for several ADAM/ADAMTS in those selected mosquito tissues.

The emerging role of furin in neurodegenerative and neuropsychiatric diseases

Furin is an important mammalian proprotein convertase that catalyzes the proteolytic maturation of a variety of prohormones and proproteins in the secretory pathway. In the brain, the substrates of furin include the proproteins of growth factors, receptors and enzymes. Emerging evidence, such as reduced FURIN mRNA expression in the brains of Alzheimer's disease patients or schizophrenia patients, has implicated a crucial role of furin in the pathophysiology of neurodegenerative and neuropsychiatric diseases. Currently, compared to cancer and infectious diseases, the aberrant expression of furin and its pharmaceutical potentials in neurological diseases remain poorly understood. In this article, we provide an overview on the physiological roles of furin and its substrates in the brain, summarize the deregulation of furin expression and its effects in neurodegenerative and neuropsychiatric disorders, and discuss the implications and current approaches that target furin for therapeutic interventions. This review may expedite future studies to clarify the molecular mechanisms of furin deregulation and involvement in the pathogenesis of neurodegenerative and neuropsychiatric diseases, and to develop new diagnosis and treatment strategies for these diseases.

Activation and Inhibition of Human Matrix Metalloproteinase-9 (MMP9) by HOCl, Myeloperoxidase and Chloramines

Matrix metalloproteinase-9 (MMP9, gelatinase B) plays a key role in the degradation of extracellular-matrix (ECM) proteins in both normal physiology and multiple pathologies, including those linked with inflammation. MMP9 is excreted as an inactive proform (proMMP9) by multiple cells, and particularly neutrophils. The proenzyme undergoes subsequent processing to active forms, either enzymatically (e.g., via plasmin and stromelysin-1/MMP3), or via the oxidation of a cysteine residue in the prodomain (the “cysteine-switch”). Activated leukocytes, including neutrophils, generate O₂⁻ and H₂O₂ and release myeloperoxidase (MPO), which catalyzes hypochlorous acid (HOCl) formation. Here, we examine the reactivity of HOCl and a range of low-molecular-mass and protein chloramines with the pro- and activated forms of MMP9. HOCl and an enzymatic MPO/H₂O₂/Cl⁻ system were able to generate active MMP9, as determined by fluorescence-activity assays and gel zymography. The inactivation of active MMP9 also occurred at high HOCl concentrations. Low (nM—low μM) concentrations of chloramines formed by the reaction of HOCl with amino acids (taurine, lysine, histidine), serum albumin, ECM proteins (laminin and fibronectin) and basement membrane extracts (but not HEPES chloramines) also activate proMMP9. This activation is diminished by the competitive HOCl-reactive species, methionine. These data indicate that HOCl-mediated oxidation and MMP-mediated ECM degradation are synergistic and interdependent. As previous studies have shown that modified ECM proteins can also stimulate the cellular expression of MMP proteins, these processes may contribute to a vicious cycle of increasing ECM degradation during disease development.

Proteomics and Biochemical Analyses of Secreted Proteins Revealed a Novel Mechanism by Which ADAM12S Regulates the Migration of Gastric Cancer Cells

Gastric cancer is one of the cancers with the highest morbidity and mortality. Although several therapeutic approaches have been developed to treat this disease, the overall survival rate is still very low due to metastasis, drug resistance, and so forth. Therefore, it is necessary to discover new regulatory molecules and signaling pathways that modulate the metastasis of gastric cancer cells. A Disintegrin And Metalloprotease 12 (ADAM12) was highly expressed in gastric cancer tissues and presented in the patient urine. However, it is unclear whether and how ADAM12 regulates the migration of gastric cancer cells. In this work, we used the secretome protein enrichment with click sugars (SPECS) method to purify the secreted glycosylated proteins and performed quantitative proteomics to identify the secreted proteins that were differentially regulated by ADAM12S, the short and secreted form of ADAM12. Our proteomic and biochemical analyses revealed that ADAM12S upregulated the cell surface glycoprotein CD146, a cell adhesion molecule and melanoma marker, which was dependent on the catalytic residue of ADAM12S. Furthermore, we discovered that the ADAM12S-enhanced migration of gastric cancer cells was, at least partially, mediated by CD146. This work may help to evaluate whether ADAM12 could be a potential therapeutic target for the treatment of gastric cancer patients.

The contribution of mouse models to understanding atopic dermatitis

Atopic dermatitis (AD) is a dermatological disease accompanied by dry and cracked skin with severe pruritus. Although various therapeutic strategies have been introduced to alleviate AD, it remains challenging to cure the disorder. To achieve such a goal, understanding the pathophysiological mechanisms of AD is a prerequisite, requiring mouse models that properly reflect the AD phenotypes. Currently, numerous AD mouse models have been established, but each model has its own advantages and weaknesses. In this review, we categorized and summarized mouse models of AD and described their characteristics from a researcher's perspective.

Evaluation of Expression Of ADAM 10 as a Predictor of Lymph Node Metastasis in Oral Squamous Cell Carcinoma-An Immunohistochemical Study

BACKGROUND

Lymph node metastasis (LNM) is a well-known prognostic factor in Oral Squamous Cell Carcinoma(OSCC). A biological marker that predicts the Lymph Node Metastasis (LNM) in OSCC cases is the need of the hour. A Disintegrin And Metalloproteinases (ADAMs), a family of proteins that exhibit a metalloproteinase domain play a pivotal role in the pathogenesis of tumor growth and metastasis. This study aims to evaluate whether ADAM 10 can be used as a predictor of lymph node metastasis in OSCC using immunohistochemistry.

METHOD

A total of 90 samples that were categorized into 3 groups were included in the present study. Group I consisted of 30 samples of the normal oral mucosa, and Group II consisted of 30 samples of OSCC without lymph node metastasis. Group III consisted of 30 samples of OSCC with lymph node metastasis. Esophageal Squamous Cell Carcinoma was used as external positive control. Immunohistochemical expression of ADAM10 in their corresponding stained sections was assessed and staining intensity was calculated.

RESULTS

ADAM10 immunoreactivity was considered positive when located in cytoplasm or membrane or both. This method is similar to that used by Bamane et al. for OSCC cases. The mean value of the Staining Index score "AxB" was highest in Group III (7.90), followed by Group II (3.13) and least in Group I (0.27). These values were statistically significant.

CONCLUSION

Considering the findings of a higher percentage of ADAM10 positive cells, higher staining intensity, and higher staining index, the overexpression of ADAM10 can be used as an independent marker for OSCC patients to predict the lymph node metastasis.

Silencing the ADAM9 Gene through CRISPR/Cas9 Protects Mice from Alcohol-Induced Acute Liver Injury

Alcoholic liver injury is a major global public health concern at present. The ADAM9 gene plays a crucial role in the occurrence and development of various liver diseases, but its role in acute alcoholic liver injury remains ambiguous. In this study, a chimeric single-guide RNA targeting the genomic regions of mouse ADAM9 was designed using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology. Next, the role of ADAM9 in acute alcoholic liver injury in vitro in cultured mouse cells and in vivo in a hydrodynamic injection-based alcoholic liver injury mouse model was documented. The findings of this study suggest that ADAM9 induces by regulating cell proliferation, apoptosis, and stress metabolism in mice. Thus, inhibiting the expression of ADAM9 gene using CRISPR/Cas9 can attenuate alcohol-induced acute liver injury in mice.

An unexpected role for the conserved ADAM-family metalloprotease ADM-2 in Caenorhabditis elegans molting

Molting is a widespread developmental process in which the external extracellular matrix (ECM), the cuticle, is remodeled to allow for organismal growth and environmental adaptation. Studies in the nematode Caenorhabditis elegans have identified a diverse set of molting-associated factors including signaling molecules, intracellular trafficking regulators, ECM components, and ECM-modifying enzymes such as matrix metalloproteases. C. elegans NEKL-2 and NEKL-3, two conserved members of the NEK family of protein kinases, are essential for molting and promote the endocytosis of environmental steroid-hormone precursors by the epidermis. Steroids in turn drive the cyclic induction of many genes required for molting. Here we report a role for the sole C. elegans ADAM–meltrin metalloprotease family member, ADM-2, as a mediator of molting. Loss of adm-2, including mutations that disrupt the metalloprotease domain, led to the strong suppression of molting defects in partial loss-of-function nekl mutants. ADM-2 is expressed in the epidermis, and its trafficking through the endo-lysosomal network was disrupted after NEKL depletion. We identified the epidermally expressed low-density lipoprotein receptor–related protein, LRP-1, as a candidate target of ADM-2 regulation. Whereas loss of ADM-2 activity led to the upregulation of apical epidermal LRP-1, ADM-2 overexpression caused a reduction in LRP-1 levels. Consistent with this, several mammalian ADAMs, including the meltrin ADAM12, have been shown to regulate mammalian LRP1 via proteolysis. In contrast to mammalian homologs, however, the regulation of LRP-1 by ADM-2 does not appear to involve the metalloprotease function of ADM-2, nor is proteolytic processing of LRP-1 strongly affected in adm-2 mutants. Our findings suggest a noncanonical role for an ADAM family member in the regulation of a lipoprotein-like receptor and lead us to propose that endocytic trafficking may be important for both the internalization of factors that promote molting as well as the removal of proteins that can inhibit the process.

The molecular and cellular features of molting in nematodes share many similarities with cellular and developmental processes that occur in mammals. This includes the degradation and reorganization of extracellular matrix materials that surround cells, as well as the intracellular machineries that allow cells to sample and modify their environments. In the current study, we found an unexpected function for a conserved protein that cleaves other proteins on the external surface of cells. Rather than promoting molting through extracellular matrix reorganization, however, the ADM-2 protease appears to function as a negative regulator of molting. This observation can be explained in part by data showing that ADM-2 negatively regulates a cell surface receptor required for molting. Surprisingly, it appears to do so through a mechanism that does not involve proteolysis. Our data provide insights into the mechanisms controlling molting and link several conserved proteins to show how they function together during development.

Disintegrin and Metalloproteinases (ADAMs [A Disintegrin and Metalloproteinase] and ADAMTSs [ADAMs With a Thrombospondin Motif]) in Aortic Aneurysm

Aortic aneurysm is a complex pathology that can be lethal if not detected in time. Although several molecular mechanisms and pathways have been identified to be involved in aortic aneurysm development and growth, the current lack of an effective pharmacological treatment highlights the need for a more thorough understanding of the factors that regulate the remodeling of the aortic wall in response to triggers that lead to aneurysm formation. This task is further complicated by the regional heterogeneity of the aorta and that thoracic and abdominal aortic aneurysm are distinct pathologies with different risk factors and distinct course of progression. ADAMs (a disintegrin and metalloproteinases) and ADAMTS (ADAMs with a thrombospondin motif) are proteinases that share similarities with other proteinases but possess unique and diverse properties that place them in a category of their own. In this review, we discuss what is known on how ADAMs and ADAMTSs are altered in abdominal aortic aneurysm and thoracic aortic aneurysm in patients, in different animal models, and their role in regulating the function of different vascular and inflammatory cell types. A full understanding of the role of ADAMs and ADAMTSs in aortic aneurysm will help reveal a more complete understanding of the underlying mechanism driving aneurysm formation, which will help towards developing an effective treatment in preventing or limiting the growth of aortic aneurysm.