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The Journal of Allergy and Clinical... Mar 2019
Topics: Child; Child, Preschool; Hematopoietic Stem Cell Transplantation; Hemorrhage; Humans; Infant; Platelet Count; Splenectomy; Wiskott-Aldrich Syndrome
PubMed: 30048768
DOI: 10.1016/j.jaip.2018.07.009 -
JCI Insight May 2020Several studies have suggested an oncogenic role for the neural Wiskott-Aldrich syndrome protein (N-WASP, encoded by the Wasl gene), but thus far, little is known about...
Several studies have suggested an oncogenic role for the neural Wiskott-Aldrich syndrome protein (N-WASP, encoded by the Wasl gene), but thus far, little is known about its function in pancreatic ductal adenocarcinoma (PDAC). In this study, we performed in silico analysis of WASL expression in PDAC patients and found a correlation between low WASL expression and prolonged survival. To clarify the role of Wasl in pancreatic carcinogenesis, we used 2 oncogenic Kras-based PDAC mouse models with pancreas-specific Wasl deletion. In line with human data, both mouse models had an increased survival benefit due to either impaired tumor development in the presence of the tumor suppressor Trp53 or the delayed tumor progression and senescent phenotype upon genetic ablation of Trp53. Mechanistically, loss of Wasl resulted in cell-autonomous senescence through displacement of the N-WASP binding partners WASP-interacting protein (WIP) and p120ctn; vesicular accumulation of GSK3β, as well as YAP1 and phosphorylated β-catenin, which are components of the destruction complex; and upregulation of Cdkn1a(p21), a master regulator of senescence. Our findings, thus, indicate that Wasl functions in an oncogenic manner in PDAC by promoting the deregulation of the p120-catenin/β-catenin/p21 pathway. Therefore, strategies to reduce N-WASP activity might improve the survival outcomes of PDAC patients.
Topics: Animals; Humans; Mice; Mice, Transgenic; Neoplasms, Experimental; Pancreatic Neoplasms; Tumor Suppressor Protein p53; Wiskott-Aldrich Syndrome Protein, Neuronal
PubMed: 32434991
DOI: 10.1172/jci.insight.127275 -
The Journal of Allergy and Clinical... Nov 2018Wiskott-Aldrich syndrome (WAS) is a rare primary immunodeficiency caused by mutations in Wiskott-Aldrich syndrome protein (WASp), a key regulator of cytoskeletal...
BACKGROUND
Wiskott-Aldrich syndrome (WAS) is a rare primary immunodeficiency caused by mutations in Wiskott-Aldrich syndrome protein (WASp), a key regulator of cytoskeletal dynamics in hematopoietic cells. A high proportion of patients experience autoimmunity caused by a breakdown in T- and B-cell tolerance. Moreover, excessive production of type I interferon (IFN-I) by plasmacytoid dendritic cells (pDCs) contributes to autoimmune signs; however, the factors that trigger excessive innate activation have not been defined.
OBJECTIVE
Neutrophil extracellular traps (NETs) emerged as major initiating factors in patients with diseases such as systemic lupus erythematosus and rheumatoid arthritis. In this study we explored the possible involvement of aberrant neutrophil functions in patients with WAS.
METHODS
We evaluated the expression of a set of granulocyte genes associated with NETs in a cohort of patients with WAS and the presence of NET inducers in sera. Using a mouse model of WAS, we analyzed NET release by WASp-null neutrophils and evaluated the composition and homeostasis of neutrophils in vivo. By using depletion experiments, we assessed the effect of neutrophils in promoting inflammation and reactivity against autoantigens.
RESULTS
Transcripts of genes encoding neutrophil enzymes and antimicrobial peptides were increased in granulocytes of patients with WAS, and serum-soluble factors triggered NET release. WASp-null neutrophils showed increased spontaneous NETosis, induced IFN-I production by pDCs, and activated B cells through B-cell activating factor. Consistently, their depletion abolished constitutive pDC activation, normalized circulating IFN-I levels, and, importantly, abolished production of autoantibodies directed against double-stranded DNA, nucleosomes, and myeloperoxidase.
CONCLUSIONS
These findings reveal that neutrophils are involved in the pathogenic loop that causes excessive activation of innate cells and autoreactive B cells, thus identifying novel mechanisms that contribute to the autoimmunity of WAS.
Topics: Adolescent; Adult; Animals; Autoantibodies; B-Lymphocytes; Child, Preschool; Dendritic Cells; Extracellular Traps; Female; Gene Expression; Humans; Infant; Interferon Type I; Male; Mice, Inbred C57BL; Mice, Knockout; Neutrophils; Wiskott-Aldrich Syndrome; Young Adult
PubMed: 29447842
DOI: 10.1016/j.jaci.2017.11.063 -
Revista Chilena de Pediatria Feb 2020Guillain-Barre Syndrome (GBS) is rarely diagnosed in the first year of life. The association of GBS with Wiskott-Aldrich syndrome (WAS) is even less frequent and has...
INTRODUCTION
Guillain-Barre Syndrome (GBS) is rarely diagnosed in the first year of life. The association of GBS with Wiskott-Aldrich syndrome (WAS) is even less frequent and has been previously reported in only two children to our knowledge. Hydrocephalus is a known but rare complication of GBS.
OBJECTIVE
To describe the case of an infant in which GBS, WAS and hydrocephalus appear clinically associated.
CLINICAL CASE
A nine-months-old male infant with a history of WAS was admitted to our ICU with acute hypotonia and poor general condition. He developed flaccid paralysis, absent deep tendon reflexes, and respiratory failure. A lumbar puncture showed albuminocytologic dissociation. GBS was suspected and an electromyography was performed, showing a demyelinating polyneuropathy. He was successfully treated with intravenous immunoglobulins. During hospitalization, he presented intermittent bradycardia, so a brain CT scan was performed, showing acute hydrocephalus which was managed through an external ventricular drain achieving favorable response. In the long term, the patient underwent bone marrow transplant and had to be reoperated due to valve-related complications. However, his psychomotor development is normal, with no obvious neurological sequelae.
CONCLUSION
We present the third case of GBS in a patient with WAS, which is the first infant younger than one year. Additionally, he presented acute hydrocephalus as a complication of GBS. We suggest considering these three comorbidities since their early diagnosis and prompt management allow bet ter neurological recovery and avoid potentially lethal complications.
Topics: Guillain-Barre Syndrome; Humans; Hydrocephalus; Infant; Male; Wiskott-Aldrich Syndrome
PubMed: 32730420
DOI: 10.32641/rchped.v91i1.1208 -
BMC Cancer Mar 2017Lung cancer is one of the most commonly diagnosed cancers with survival much lower in patients diagnosed with distal metastases. It is therefore imperative to identify...
UNLABELLED
Lung cancer is one of the most commonly diagnosed cancers with survival much lower in patients diagnosed with distal metastases. It is therefore imperative to identify pathways involved in lung cancer invasion and metastasis and to consider the therapeutic potential of agents that can interfere with these molecular pathways. This study examines nWASP expression in human lung cancer tissues and explores the effect of nWASP inhibition and knockdown on lung cancer cell behaviour.
METHODS
QPCR has been used to measure nWASP transcript expression in human lung cancer tissues. The effect of wiskostatin, an nWASP inhibitor, on A-549 and SK-MES-1 lung carcinoma cell growth, adhesion, migration and invasion was also examined using several in vitro functional assays, including ECIS, and immunofluorescence staining. The effect of nWASP knockdown using siRNA on particular behaviours of lung cancer cells was also examined.
RESULTS
Patients with high levels of nWASP expression in tumour tissues have significantly lower survival rates. nWASP transcript levels were found to correlate with lymph node involvement (p = 0.042). nWASP inhibition and knockdown was shown to significantly impair lung cancer cell growth. nWASP inhibition also affected other cell behaviours, in SK-MES-1 invasion and A-549 cell motility, adhesion and migration. Paxillin and FAK activity are reduced in lung cancer cell lines following wiskostatin and nWASP knockdown as shown by immunofluorescence and western blot.
CONCLUSIONS
These findings highlight nWASP as an important potential therapeutic target in lung cancer invasion and demonstrate that inhibiting nWASP activity using the inhibitor wiskostatin can significantly alter cell behaviour in vitro.
Topics: Adenocarcinoma; Apoptosis; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Adhesion; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Neoplasm Invasiveness; Neoplasm Staging; Phosphorylation; Prognosis; RNA, Small Interfering; Signal Transduction; Small Cell Lung Carcinoma; Survival Rate; Tumor Cells, Cultured; Wiskott-Aldrich Syndrome Protein
PubMed: 28351346
DOI: 10.1186/s12885-017-3219-3 -
Scientific Reports Mar 2023Rho family GTPases regulate both linear and branched actin dynamics by activating downstream effectors to facilitate the assembly and function of complex cellular...
Rho family GTPases regulate both linear and branched actin dynamics by activating downstream effectors to facilitate the assembly and function of complex cellular structures such as lamellipodia and contractile actomyosin rings. Wiskott-Aldrich Syndrome (WAS) family proteins are downstream effectors of Rho family GTPases that usually function in a one-to-one correspondence to regulate branched actin nucleation. In particular, the WAS protein Scar/WAVE has been shown to exhibit one-to-one correspondence with Rac GTPase. Here we show that Rac and SCAR are recruited to cell wounds in the Drosophila repair model and are required for the proper formation and maintenance of the dynamic actomyosin ring formed at the wound periphery. Interestingly, we find that SCAR is recruited to wounds earlier than Rac and is still recruited to the wound periphery in the presence of a potent Rac inhibitor. We also show that while Rac is important for actin recruitment to the actomyosin ring, SCAR serves to organize the actomyosin ring and facilitate its anchoring to the overlying plasma membrane. These differing spatiotemporal recruitment patterns and wound repair phenotypes highlight the Rac-independent functions of SCAR and provide an exciting new context in which to investigate these newly uncovered SCAR functions.
Topics: Animals; Actins; Actomyosin; Cytokinesis; Actin Cytoskeleton; Drosophila; rho GTP-Binding Proteins; Cicatrix; Wiskott-Aldrich Syndrome Protein Family; rac GTP-Binding Proteins
PubMed: 36959278
DOI: 10.1038/s41598-023-31973-2 -
The Journal of Cell Biology Sep 2018Primary cilia are polarized organelles that allow detection of extracellular signals such as Hedgehog (Hh). How the cytoskeleton supporting the cilium generates and...
Primary cilia are polarized organelles that allow detection of extracellular signals such as Hedgehog (Hh). How the cytoskeleton supporting the cilium generates and maintains a structure that finely tunes cellular response remains unclear. Here, we find that regulation of actin polymerization controls primary cilia and Hh signaling. Disrupting actin polymerization, or knockdown of N-WASp/Arp3, increases ciliation frequency, axoneme length, and Hh signaling. Cdc42, a potent actin regulator, recruits both atypical protein pinase C iota/lambda (aPKC) and Missing-in-Metastasis (MIM) to the basal body to maintain actin polymerization and restrict axoneme length. Transcriptome analysis implicates the Src pathway as a major aPKC effector. aPKC promotes whereas MIM antagonizes Src activity to maintain proper levels of primary cilia, actin polymerization, and Hh signaling. Hh pathway activation requires Smoothened-, Gli-, and Gli1-specific activation by aPKC. Surprisingly, longer axonemes can amplify Hh signaling, except when aPKC is disrupted, reinforcing the importance of the Cdc42-aPKC-Gli axis in actin-dependent regulation of primary cilia signaling.
Topics: 3T3 Cells; Actin-Related Protein 3; Actins; Animals; Axoneme; Basal Bodies; Cell Line; Cilia; Enzyme Activation; Gene Expression Regulation; Hedgehog Proteins; Mice; Microfilament Proteins; Neoplasm Proteins; Polymerization; Protein Kinase C; Signal Transduction; Wiskott-Aldrich Syndrome Protein, Neuronal; Zinc Finger Protein GLI1; cdc42 GTP-Binding Protein; src-Family Kinases
PubMed: 29945904
DOI: 10.1083/jcb.201703196 -
Molecular Therapy. Methods & Clinical... Mar 2017Wiskott-Aldrich syndrome (WAS) is a life-threatening immunodeficiency caused by mutations within the gene. Viral gene therapy to restore WAS protein (WASp) expression...
Wiskott-Aldrich syndrome (WAS) is a life-threatening immunodeficiency caused by mutations within the gene. Viral gene therapy to restore WAS protein (WASp) expression in hematopoietic cells of patients with WAS has the potential to improve outcomes relative to the current standard of care, allogeneic bone marrow transplantation. However, the development of viral vectors that are both safe and effective has been problematic. While use of viral transcriptional promoters may increase the risk of insertional mutagenesis, cellular promoters may not achieve WASp expression levels necessary for optimal therapeutic effect. Here we evaluate a self-inactivating (SIN) lentiviral vector combining a chromatin insulator upstream of a viral MND (MPSV LTR, NCR deleted, dl587 PBS) promoter driving WASp expression. Used as a gene therapeutic in mice, this vector resulted in stable WASp cells in all hematopoietic lineages and rescue of T and B cell defects with a low number of viral integrations per cell, without evidence of insertional mutagenesis in serial bone marrow transplants. In a gene transfer experiment in non-human primates, the insulated MND promoter (driving GFP expression) demonstrated long-term polyclonal engraftment of GFP cells. These observations demonstrate that the insulated MND promoter safely and efficiently reconstitutes clinically effective WASp expression and should be considered for future WAS therapy.
PubMed: 28344987
DOI: 10.1016/j.omtm.2016.11.001 -
Scandinavian Journal of Immunology Jun 2015The Wiskott-Aldrich syndrome protein (WASp) is an important regulator of the actin cytoskeleton and is required for immune cell function. WASp deficiency causes a marked...
The Wiskott-Aldrich syndrome protein (WASp) is an important regulator of the actin cytoskeleton and is required for immune cell function. WASp deficiency causes a marked reduction in major mature peripheral B cell subsets, particularly marginal zone (MZ) B cells. We hypothesized that WASp deficiency may also lead to a reduction of regulatory B cells (known as B10 cells) belonging to a novel subset of B cells. And in consideration of the key role of B10 cells play in maintaining peripheral tolerance, we conjectured that a deficit of these cells could contribute to the autoimmunity in patients with Wiskott-Aldrich syndrome (WAS). The effects of WASp deficiency on B10 cells have been reported by only one group, which used an antigen-induced arthritis model. To add more information, we measured the percentage of B10 cells, regulatory T cells (Tregs) and Th1 cells in WASp knockout (WASp KO) mice. We also measured the percentage of B10 cells in patients with WAS by flow cytometry. Importantly, we used the non-induced autoimmune WASp KO mouse model to investigate the association between B10 cell frequency and the Treg/Th1 balance. We found that the percentage of B10 cells was reduced in both mice (steady state and inflammatory state) and in humans and that the lower B10 population correlated with an imbalance in the Treg/Th1 ratio in old WASp KO mice with autoimmune colitis. These findings suggest that WASp plays a crucial role in B10 cell development and that WASp-deficient B10 cells may contribute to autoimmunity in WAS.
Topics: Animals; Autoimmune Diseases; B-Lymphocytes, Regulatory; Child; Child, Preschool; Colitis; Flow Cytometry; Humans; Infant; Interleukin-10; Lymphocyte Count; Mice, Inbred C57BL; Mice, Knockout; T-Lymphocytes, Regulatory; Th1 Cells; Wiskott-Aldrich Syndrome; Wiskott-Aldrich Syndrome Protein
PubMed: 25728049
DOI: 10.1111/sji.12282 -
Oncogene Jan 2021Immunodeficiency is associated with cancer risk. Accordingly, hematolymphoid cancers develop in Wiskott-Aldrich syndrome (WAS), an X-linked primary immunodeficiency...
Immunodeficiency is associated with cancer risk. Accordingly, hematolymphoid cancers develop in Wiskott-Aldrich syndrome (WAS), an X-linked primary immunodeficiency disorder (PID) resulting from the deficiency of WAS-protein (WASp) expressed predominantly in the hematolymphoid cell lineages. Despite the correlation between WASp deficiency and hematolymphoid cancers, the molecular mechanism underlying the oncogenic role of WASp is incompletely understood. Employing the WASp-sufficient and WASp-deficient cell-pair model of human T and B lymphocytes, we show that WASp deficiency differentially influences hyperactivation versus inhibition of both CDC42:ERK1/2 and NF-κB:AP-1 pro-oncogenic signaling pathways in nonmalignant versus malignant T and B lymphocytes. Furthermore, WASp deficiency induces a cell-type specific up/down-modulation of the DNA-binding activities of NF-κB, AP-1, and multiple other transcription factors with known roles in oncogenesis. We propose that WASp functions as a putative "tumor-suppressor" protein in normal T and B cells, and "oncoprotein" in a subset of established T and B cell malignancies that are not associated with the NPM-ALK fusion.
Topics: B-Lymphocytes; Cell Proliferation; Cells, Cultured; Humans; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; NF-kappa B; Oncogene Proteins; Signal Transduction; T-Lymphocytes; Transcription Factor AP-1; Tumor Suppressor Proteins; Wiskott-Aldrich Syndrome; Wiskott-Aldrich Syndrome Protein; cdc42 GTP-Binding Protein
PubMed: 33139832
DOI: 10.1038/s41388-020-01533-3