Multi-Omics Pan-Cancer Analysis of Procollagen N-Propeptidase Gene Family of ADAMTS as Novel Biomarkers to Associate with Prognosis, Tumor Immune Microenvironment, Signaling Pathways, and Drug Sensitivities.

BACKGROUND: The extracellular matrix (ECM) modeling induced by the metalloproteinases is a vital characteristic for tumor progression. Previous studies mainly focus on the functions of two subgroups of metalloproteinases: matrix metalloproteinases (MMPs) and a disintegrin and metalloproteases (ADAMs) in tumors. The roles of another important group: the ADAMs with thrombospondin motifs (ADAMTS) remain unclear. This study aimed to perform a pan-cancer analysis of procollagen N-propeptidase subgroup of ADAMTS (PNPSA). METHODS: We systematically analyzed expression landscape, genomic variations, prognostic value, and cell expression clusters of PNPSA in pan-cancer based on the multiple integrated open databases. Besides, we also analyzed the impacts of expressions and genomic variations of PNPSA members on tumor immune microenvironment (TIME) and immune-related molecules in pan-cancer based on the immune-related open databases. The Gene Set Variation Analysis (GSVA) was performed to evaluate the associations of the whole PNPSA with prognosis, tumor indicators, TIME, and drug sensitivities. Meanwhile, the Kyoto Encyclopedia of Genes and Genomes (KEGG) was performed to reveal related signaling pathways. Finally, immunohistochemical staining was used to validate the differential analysis results. RESULTS: We found a dual prognostic role of PNPSA members in pan-cancer and they were significantly correlated with TIME and immune-related molecules. Interestingly, the copy number variations (CNVs) of all PNPSA members were revealed to be negatively correlated with NK cell infiltration in most cancers. Single-cell sequencing analysis reveals expressions of PNPSA gene family members on some specific tumor and immune cells in addition to the fibroblasts. The GSVA score was found to have some predictive value for survival status in Brain Lower Grade Glioma (LGG), Mesothelioma (MESO), and Uveal Melanoma (UVM) and to be significantly correlated with tumorigenesis-related pathways such as PI3K-Akt, AGE-RAGE, etc. The GSVA score also shows some predictive value for chemotherapy and immunotherapy efficacy in some tumors. CONCLUSIONS: PNPSA was correlated with tumor development and might be potential tumor biomarker and therapeutic target.

Current knowledge on autoantigens and autoantibodies in psoriasis.

In the past decades, clinical and experimental evidence has demonstrated that psoriasis is an immune-mediated inflammatory disease of the skin that occurs in genetically susceptible individuals. Psoriasis also shows clear autoimmune pathomechanisms, but specific cellular targets for the onset and maintenance of psoriatic lesions were not established until 2014. Since then, four psoriasis autoantigens were discovered, namely cathelicidin LL-37, melanocytic ADAMTSL5, lipid antigen PLA2G4D and keratin 17. Autoreactive T cells against these autoantigens were found in a number of patients with moderate-to-severe plaque psoriasis. Moreover, the discovery of autoantibodies against LL-37 and ADAMTSL5 and their strong association with psoriatic arthritis (PsA) suggest a potential role of these autoantibodies in the pathogenesis of PsA. This review discusses the current studies on psoriatic autoantigens and the associated circulating autoantibodies and their mechanisms involved in the development and maintenance of psoriatic plaques. Recent autoimmune evidence fuelled the discussion on psoriasis as an autoimmune skin disorder and has the potential to develop new treatment strategies with protective and therapeutic antigen-targeted methods.

Identification of Novel Autoantibodies Associated With Psoriatic Arthritis.

OBJECTIVE: The autoimmune etiology in psoriasis remains to be clarified. We therefore undertook this study to identify novel pathogenic autoantigens and autoantibodies in patients with psoriasis, with the aim of shedding light on the molecular and cellular basis of the pathogenesis of psoriasis and psoriatic arthritis (PsA). METHODS: In this study, we developed an autoantigen array system that harbors a variety of antigens, including typical autoantigens in rheumatic diseases as well as skin antigens, inflammatory mediators, and putative autoantigens in psoriasis. Serum samples from patients with psoriasis (n = 73) were used to interrogate the antigens on the array. In addition, enzyme-linked immunosorbent assays of individual autoantibodies were used in validation studies. RESULTS: Levels of several autoantibodies were found to be elevated in the serum of patients with psoriasis compared to healthy controls; in particular, IgG autoantibodies against 2 novel antigens, LL-37 and ADAMTS-L5, were significantly increased in patients with psoriasis. Importantly, serum levels of IgG autoantibodies against LL-37 and ADAMTS-L5 were correlated with the Psoriasis Area and Severity Index, and reflected disease progression in longitudinally collected serum samples from patients with psoriasis. Importantly, both anti-ADAMTS-L5 and anti-LL-37 autoantibody levels were also significantly elevated in psoriasis patients with PsA compared to those without PsA, suggesting that these molecules may be involved in the pathogenesis of PsA. CONCLUSION: Our findings indicate that these identified autoantibodies may be useful biomarkers and may serve as therapeutic targets in psoriasis and PsA.

Role of ADAMTS-12 in Protecting Against Inflammatory Arthritis in Mice By Interacting With and Inactivating Proinflammatory Connective Tissue Growth Factor.

OBJECTIVE: It has been reported that ADAMTS-12 is a susceptibility gene for rheumatoid arthritis (RA) development, and its level is significantly increased in RA patients. In addition, ADAMTS-12 is reported to be required for inflammation in otherwise healthy subjects. This study was undertaken to determine the role of ADAMTS-12 and the underlying mechanisms in the pathogenesis of inflammatory arthritis. METHODS: The collagen-induced arthritis (CIA) model was established in ADAMTS-12-deficient mice and their control littermates to determine the role of ADAMTS-12 in vivo. Micro-computed tomography scanning was used to demonstrate the destruction of the ankle joint; histologic analysis illustrated synovitis, pannus formation, and bone and cartilage destruction; enzyme-linked immunosorbent assay was performed to measure serum levels of inflammatory cytokines; and protein-protein interaction assays were performed to detect the interactions of ADAMTS-12 and its various deletion mutants with connective tissue growth factor (CTGF). RESULTS: Deficiency of ADAMTS-12 led to accelerated inflammatory arthritis in the CIA mouse model. Loss of ADAMTS-12 caused enhanced osteoclastogenesis. In vitro and in vivo protein-protein interaction assays demonstrated that ADAMTS-12 bound and processed CTGF, a previously unrecognized substrate of ADAMTS-12. In addition, deletion of ADAMTS-12 enhanced, while overexpression of ADMATS-12 reduced, CTGF-mediated inflammation. Furthermore, ADAMTS-12 regulation of inflammation was largely lost in CTGF-deficient macrophages. Importantly, blocking of CTGF attenuated elevated inflammatory arthritis seen in the ADAMTS-12-deficient CIA mouse model. CONCLUSION: This study provides evidence that ADAMTS-12 is a critical regulator of inflammatory arthritis and that this is mediated, at least in part, through control of CTGF turnover.

Spontaneous atopic dermatitis due to immune dysregulation in mice lacking Adamts2 and 14.

Since its first description, ADAMTS14 has been considered as an aminoprocollagen peptidase based on its high similarity with ADAMTS3 and ADAMTS2. As its importance for procollagen processing was never experimentally demonstrated in vivo, we generated Adamts14-deficient mice. They are healthy, fertile and display normal aminoprocollagen processing. They were further crossed with Adamts2-deficient mice to evaluate potential functional redundancies between these two highly related enzymes. Initial characterizations made on young Adamts2-Adamts14-deficient animals showed the same phenotype as that of Adamts2-deficient mice, with no further reduction of procollagen processing and no significant aggravation of the structural alterations of collagen fibrils. However, when evaluated at older age, Adamts2-Adamts14-deficient mice surprisingly displayed epidermal lesions, appearing in 2 month-old males and later in some females, and then worsening rapidly. Immunohistological evaluations of skin sections around the lesions revealed thickening of the epidermis, hypercellularity in the dermis and extensive infiltration by immune cells. Additional investigations, performed on young mice before the formation of the initial lesions, revealed that the primary cause of the phenotype was not related to alterations of the epidermal barrier but was rather the result of an abnormal activation and differentiation of T lymphocytes towards a Th1 profile. However, the primary molecular defect probably does not reside in the immune system itself since irradiated Adamts2-Adamts14-deficient mice grafted with WT immune cells still developed lesions. While originally created to better characterize the common and specific functions of ADAMTS2 and ADAMTS14 in extracellular matrix and connective tissues homeostasis, the Adamts2-Adamts14-deficient mice revealed an unexpected but significant role of ADAMTS in the regulation of immune system, possibly through a cross-talk involving mesenchymal cells and the TGFß pathways.

Human Properdin Opsonizes Nanoparticles and Triggers a Potent Pro-inflammatory Response by Macrophages without Involving Complement Activation.

Development of nanoparticles as tissue-specific drug delivery platforms can be considerably influenced by the complement system because of their inherent pro-inflammatory and tumorigenic consequences. The complement activation pathways, and its recognition subcomponents, can modulate clearance of the nanoparticles and subsequent inflammatory response and thus alter the intended translational applications. Here, we report, for the first time, that human properdin, an upregulator of the complement alternative pathway, can opsonize functionalized carbon nanotubes (CNTs) via its thrombospondin type I repeat (TSR) 4 and 5. Binding of properdin and TSR4+5 is likely to involve charge pattern/polarity recognition of the CNT surface since both carboxymethyl cellulose-coated carbon nanotubes (CMC-CNT) and oxidized (Ox-CNT) bound these proteins well. Properdin enhanced the uptake of CMC-CNTs by a macrophage cell line, THP-1, mounting a robust pro-inflammatory immune response, as revealed by qRT-PCR, multiplex cytokine array, and NF-κB nuclear translocation analyses. Properdin can be locally synthesized by immune cells in an inflammatory microenvironment, and thus, its interaction with nanoparticles is of considerable importance. In addition, recombinant TSR4+5 coated on the CMC-CNTs inhibited complement consumption by CMC-CNTs, suggesting that nanoparticle decoration with TSR4+5, can be potentially used as a complement inhibitor in a number of pathological contexts arising due to exaggerated complement activation.

The molecular basis for peptide repertoire selection in the human leucocyte antigen (HLA) C*06:02 molecule.

Human leukocyte antigen (HLA)-C*06:02 is identified as the allele associated with the highest risk for the development of the autoimmune skin disease psoriasis. However, the diversity and mode of peptide presentation by the HLA-C*06:02 molecule remains unclear. Here, we describe the endogenous peptide repertoire of ∼3,000 sequences for HLA-C*06:02 that defines the peptide-binding motif for this HLA allomorph. We found that HLA-C*06:02 predominantly presents nonamer peptides with dominant arginine anchors at the P2 and P7 positions and a preference for small hydrophobic residues at the C terminus (PΩ). To determine the structural basis of this selectivity, we determined crystal structures of HLA-C*06:02 in complex with two self-peptides (ARTELYRSL and ARFNDLRFV) and an analogue of a melanocyte autoantigen (ADAMTSL5, VRSRR-abu-LRL) implicated in psoriasis. These structures revealed that HLA-C*06:02 possesses a deep peptide-binding groove comprising two electronegative B- and E-pockets that coincide with the preference for P2 and P7 arginine anchors. The ADAMTSL5 autoantigen possessed a P7-Leu instead of the P7-Arg residue, but nevertheless was accommodated within the HLA-C*06:02 antigen-binding cleft. Collectively, our results provide the structural basis for understanding peptide repertoire selection in HLA-C*06:02.

The development of monoclonal anti-ADAMTS18 antibodies with precise validation of ADAMTS18 post-translational modification status in living organisms.

ADAMTS18 is a member of a secreted Zn-metalloproteinase ADAMTS family, and has been implicated in development, hemostasis, and various malignancies. It has thus far proven difficult to resolve its post-translational modification status, cleaved forms, and splice variants in living organisms due to the lack of specific antibodies available to characterize this enzyme. In this study, we develop six murine monoclonal antibodies (mAbs) against different functional regions of ADAMTS18 using hybridoma technology. These mAbs exhibit cross-recognition between ADAMTS18 and the homology domain of its family members. Using the tissues from Adamts18 knockout (KO) mice, we find that two of these mAbs (N-3 and C-5) precisely identify five significantly attenuated bands located at 180, 135, 95, 72, and 45 kDa. These bands represent the forms of ADAMTS18 that potentially exist in the tissues. These mAbs will provide a useful tool to investigate the ADAMTS18's biologic significance in the tissues.