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Molecular Biology of the Cell May 2022The spectraplakin family of proteins includes ACF7/MACF1 and BPAG1/dystonin in mammals, VAB-10 in in zebrafish, and Short stop (Shot), the sole member. Spectraplakins...
The spectraplakin family of proteins includes ACF7/MACF1 and BPAG1/dystonin in mammals, VAB-10 in in zebrafish, and Short stop (Shot), the sole member. Spectraplakins are giant cytoskeletal proteins that cross-link actin, microtubules, and intermediate filaments, coordinating the activity of the entire cytoskeleton. We examined the role of Shot during cell migration using two systems: the in vitro migration of tissue culture cells and in vivo through border cell migration. RNA interference (RNAi) depletion of Shot increases the rate of random cell migration in tissue culture cells as well as the rate of wound closure during scratch-wound assays. This increase in cell migration prompted us to analyze focal adhesion dynamics. We found that the rates of focal adhesion assembly and disassembly were faster in Shot-depleted cells, leading to faster adhesion turnover that could underlie the increased migration speeds. This regulation of focal adhesion dynamics may be dependent on Shot being in an open confirmation. Using border cells as an in vivo model for cell migration, we found that RNAi depletion led to precocious border cell migration. Collectively, these results suggest that spectraplakins not only function to cross-link the cytoskeleton but may regulate cell-matrix adhesion.
Topics: Actins; Animals; Cell Movement; Cytoskeletal Proteins; Drosophila; Drosophila Proteins; Focal Adhesions; Mammals; Microfilament Proteins; Microtubules; Zebrafish
PubMed: 35235367
DOI: 10.1091/mbc.E21-09-0434 -
Scientific Reports Jan 2022The adaptation of vertebrates to different environments was associated with changes in the molecular composition and regulation of epithelia. Whales and dolphins,...
The adaptation of vertebrates to different environments was associated with changes in the molecular composition and regulation of epithelia. Whales and dolphins, together forming the clade cetaceans, have lost multiple epithelial keratins during or after their evolutionary transition from life on land to life in water. It is unknown whether the changes in keratins were accompanied by gain or loss of cytoskeletal adapter proteins of the plakin family. Here we investigated whether plakin proteins are conserved in cetaceans and other vertebrates. Comparative analysis of genome sequences showed conservation of dystonin, microtubule actin crosslinking factor 1 (MACF1), plectin, desmoplakin, periplakin and envoplakin in cetaceans. By contrast, EPPK1 (epiplakin) was disrupted by inactivating mutations in all cetaceans investigated. Orthologs of EPPK1 are present in bony and cartilaginous fishes and tetrapods, indicating an evolutionary origin of EPPK1 in a common ancestor of jawed vertebrates (Gnathostomes). In many vertebrates, EPPK1 is flanked by an as-yet uncharacterized gene that encodes protein domains homologous to the carboxy-terminal segment of MACF1. We conclude that epiplakin, unlike other plakins, was lost in cetaceans.
Topics: Animals; Autoantigens; Cetacea; Datasets as Topic; Evolution, Molecular; Genomics; Loss of Function Mutation
PubMed: 35064199
DOI: 10.1038/s41598-022-05087-0 -
The Journal of Investigative Dermatology Mar 2022
Topics: Autoantibodies; Autoantigens; Dystonin; Enzyme-Linked Immunosorbent Assay; Fractures, Bone; Humans; Non-Fibrillar Collagens
PubMed: 34883045
DOI: 10.1016/j.jid.2021.11.028 -
MicroPublication Biology 2021Genetic screens are used to identify genes involved in specific biological processes. An EMS mutagenesis screen in identified growth control phenotypes in the...
Genetic screens are used to identify genes involved in specific biological processes. An EMS mutagenesis screen in identified growth control phenotypes in the developing eye. One mutant line from this screen, , was phenotypically characterized using the FLP/FRT system and genetically mapped by complementation analysis and genomic sequencing by undergraduate students participating in the multi-institution Fly-CURE consortium. was found to have a nonsense mutation in (), anortholog of the mammalian spectraplakin (). and are involved in cytoskeletal organization and play roles during cell growth and proliferation.
PubMed: 34278244
DOI: 10.17912/micropub.biology.000418 -
BMC Pediatrics Jun 2021MYCN amplification and age are two critical prognostic factors of pediatric neuroblastoma. Previously, we had revealed the prognosis of MYCN target genes. However, the...
BACKGROUND
MYCN amplification and age are two critical prognostic factors of pediatric neuroblastoma. Previously, we had revealed the prognosis of MYCN target genes. However, the prognostic effects of age related genes in neuroblastoma are unclear.
METHODS
The prognostic significance of age and MYCN amplification was determined through multivariate cox regression and Kaplan-Meier survival analysis. Genes differentially expressed in MYCN non-amplified younger neuroblastoma patients were identified using Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Gene Expression Omnibus (GEO) datasets. The prognostic effects of age related genes ALCAM, CACNA2D3, DST, EPB41L4A and KIF1B in pediatric neuroblastoma patients were determined by Kaplan-Meier survival.
RESULTS
In a pediatric pan-cancer analysis, age was associated with the overall survival of pediatric B-lineage acute lymphoblastic leukemia, neuroblastoma and wilms tumor in TARGET dataset. Moreover, the prognostic effects of age in neuroblastoma were validated using two independent neuroblastoma cohorts. Furthermore, age and MYCN amplification were independent prognostic factors in pediatric neuroblastoma. Compared with MYCN non-amplified older neuroblastoma patients, MYCN non-amplified younger neuroblastoma patients had better clinical outcomes. ALCAM, CACNA2D3, DST, EPB41L4A and KIF1B were highly expressed in MYCN non-amplified younger neuroblastoma patients. And the higher expression levels of ALCAM, CACNA2D3, DST, EPB41L4A or KIF1B were associated with better prognosis of MYCN non-amplified neuroblastoma patients. DST was an independent prognostic factor in MYCN non-amplified neuroblastoma patients and MYCN non-amplified neuroblastoma younger patients with higher DST expression levels had the best clinical overall survival.
CONCLUSIONS
Age related gene DST was an independent prognostic factor in MYCN non-amplified neuroblastoma. MYCN non-amplified younger neuroblastoma patients with higher DST expression levels had the best clinical overall survival.
Topics: Child; Dystonin; Gene Amplification; Gene Expression; Humans; N-Myc Proto-Oncogene Protein; Neuroblastoma; Prognosis
PubMed: 34116676
DOI: 10.1186/s12887-021-02753-6 -
Frontiers in Immunology 2021Bullous pemphigoid (BP) is a prototypic autoimmune disorder of the elderly, characterized by serum IgG autoantibodies, namely anti-BP180 and anti-BP230, directed against...
Bullous pemphigoid (BP) is a prototypic autoimmune disorder of the elderly, characterized by serum IgG autoantibodies, namely anti-BP180 and anti-BP230, directed against components of the basal membrane zone that lead to sub-epidermal loss of adhesion. Pruritus may be indicative of a pre-clinical stage of BP, since a subset of these patients shows serum IgG autoantibodies against BP230 and/or BP180 while chronic pruritus is increasingly common in the elderly population and is associated with a variety of dermatoses. Clinical and experimental evidence further suggests that pruritus of the elderly may be linked to autoimmunity with loss of self-tolerance against cutaneous autoantigens. Thus, the objective of this study was to determine autoreactive T cell responses against BP180 in elderly patients in comparison to patients with BP. A total of 22 elderly patients with pruritic disorders, 34 patients with bullous or non-bullous BP and 34 age-matched healthy controls were included in this study. The level of anti-BP180 and anti-BP230 IgG serum autoantibodies, Bullous Pemphigoid Disease Area Index (BPDAI), and pruritus severity were assessed for all patients and controls. For characterization of the autoreactive T cell response, peripheral blood mononuclear cells were stimulated with recombinant BP180 proteins (NH- and COOH-terminal domains) and the frequencies of BP180-specific T cells producing interferon-γ, interleukin (IL)-5 or IL-17 were subsequently determined by ELISpot assay. Patients with BP showed a mixed Th1/Th2 response against BP180 while autoreactive Th1 cells were identified in a minor subset of elderly patients with pruritic disorders. Furthermore, our T cell characterization revealed that therapeutic application of topical clobetasol propionate ointment in BP patients significantly reduced peripheral blood BP180-specific T cells, along with clinically improved symptoms, strongly suggesting a systemic immunosuppressive effect of this treatment.
Topics: Aged; Autoantibodies; Autoantigens; Autoimmunity; Clobetasol; Cohort Studies; Cytokines; Dystonin; Enzyme-Linked Immunospot Assay; Glucocorticoids; Humans; Immunoglobulin G; Non-Fibrillar Collagens; Ointments; Pemphigoid, Bullous; Pruritus; T-Lymphocytes, Helper-Inducer; Th17 Cells; Collagen Type XVII
PubMed: 33841390
DOI: 10.3389/fimmu.2021.569287 -
Acta Dermato-venereologica Nov 2020Pruritus is a common symptom of bullous pemphigoid (BP), but has been poorly studied. The aim of this study was to analyse the characteristics of pruritus in patients... (Observational Study)
Observational Study
Pruritus is a common symptom of bullous pemphigoid (BP), but has been poorly studied. The aim of this study was to analyse the characteristics of pruritus in patients with BP and its impact on their quality of life. A multicentre prospective observational study (in 15 French hospitals) was performed. A total of 60 patients were included, with a mean age of 77.4 years. Pruritus occurred daily in 85% of patients, with a mean pruritus intensity of 5.2/10. Tingling sensations were present in 72.4% of patients and burning sensations in 68.9%. Pruritus was exacerbated by stress, fatigue and xerosis. The mean ItchyQol score was 56.2/110 and the mean 5-D Itch Scale score was 16.5/25. The severity of pruritus was not related to age, sex, BP activity score, eosinophilia, or anti-BP230 and anti-BP180 autoantibodies. This study revealed that pruritus in BP is poorly tolerated and is an important cause of impaired quality of life.
Topics: Aged; Autoantibodies; Autoantigens; Dystonin; Humans; Non-Fibrillar Collagens; Pemphigoid, Bullous; Prospective Studies; Pruritus; Quality of Life
PubMed: 33135772
DOI: 10.2340/00015555-3683 -
The Journal of Investigative Dermatology May 2021Bullous pemphigoid (BP) is an autoimmune blistering disease that targets the hemidesmosomal proteins BP180 and BP230/BPAG1e. Whereas the role of anti-BP180 antibodies...
Bullous pemphigoid (BP) is an autoimmune blistering disease that targets the hemidesmosomal proteins BP180 and BP230/BPAG1e. Whereas the role of anti-BP180 antibodies has been extensively characterized, the pathogenicity of anti-BPAG1e antibodies remains unclear. The purpose of this study is to elucidate the role of antibodies to BPAG1e in the experimental bullous pemphigoid models. We generated Bpag1 conditional knockout mice, where the knockout of Bpag1 is restricted to keratin 5-expressing epithelial cells. Bpag1 conditional knockout mice were immunized with the C-terminal portion of BPAG1e, and the splenocytes were injected into Rag2 mice intravenously. The recipient mice presented with erosion on the feet and tails. Microscopic examination showed subepidermal blisters and a linear deposition of IgG at the dermal-epidermal junction. To assess the potential role of trauma on BP development, we inflicted surface wounds on the dorsum of the Rag2 recipient mice after adoptive transfer. The wounded Rag2 mice had increased morbidity and severity of BP-like symptoms. Moreover, the depletion of B cells from splenocytes abolished a subepidermal blistering phenotype in vivo. These findings demonstrate that antibodies to BPAG1e might play a pathogenic role in causing subepidermal blistering, and external factors, including trauma, might be a trigger for BP development.
Topics: Animals; Autoantibodies; DNA-Binding Proteins; Disease Models, Animal; Dystonin; Immunization; Mice; Mice, Inbred C57BL; Pemphigoid, Bullous
PubMed: 33069726
DOI: 10.1016/j.jid.2020.08.031 -
American Journal of Clinical Dermatology Jan 2021The clinical and immunological profile of patients with dipeptidyl peptidase-4 inhibitor (DPP4i)-associated bullous pemphigoid (BP) is inconsistent in the current...
More Severe Erosive Phenotype Despite Lower Circulating Autoantibody Levels in Dipeptidyl Peptidase-4 Inhibitor (DPP4i)-Associated Bullous Pemphigoid: A Retrospective Cohort Study.
BACKGROUND
The clinical and immunological profile of patients with dipeptidyl peptidase-4 inhibitor (DPP4i)-associated bullous pemphigoid (BP) is inconsistent in the current literature.
OBJECTIVES
The aims were to investigate the clinical and immunological features of patients with DPP4i-associated BP and to examine whether there are intraclass differences between different DPP4i agents.
METHODS
A retrospective cohort study was conducted, including all consecutive patients diagnosed with BP throughout the years 2009-2019 in a tertiary referral center.
RESULTS
The study encompassed 273 patients with BP (mean age at diagnosis 79.1 ± 9.9 years), of whom 24 (8.8%) were associated with DPP4i. Sitagliptin was the prescribed agent for 17 patients (70.8%), and vildagliptin was prescribed in seven patients (29.2%). Relative to other patients with BP, patients with DPP4i-associated BP had more prominent truncal involvement (95.8% vs. 73.9%; P = 0.017), greater erosion/blister Bullous Pemphigoid Disease Area Index (BPDAI) subscore (29.8 ± 17.4 vs. 20.6 ± 14.4; P = 0.018), and lower levels of anti-BP180 NC16A (279.2 ± 346.1 vs. 572.2 ± 1352.0 U/ml; P = 0.009) and anti-BP230 (25.5 ± 47.8 vs. 128.6 ± 302.9 U/ml; P = 0.009) antibodies. Relative to patients with sitagliptin-associated BP, those with vildagliptin-associated BP had a lower seropositivity rate (57.1% vs. 94.1%, P = 0.031) and lower levels (96.7 ± 139.0 vs. 354.5 ± 376.5; P = 0.023) of anti-BP180 NC16A antibodies, and tended to present with higher erosion/blister BPDAI subscore (36.3 ± 9.6 vs. 25.8 ± 19.7; P = 0.095).
CONCLUSIONS
DPP4i-associated BP is characterized by a more severe blistering and erosive presentation despite lower levels of typically pathogenic antibodies.
Topics: Aged; Aged, 80 and over; Autoantibodies; Autoantigens; Dipeptidyl-Peptidase IV Inhibitors; Dystonin; Female; Humans; Male; Middle Aged; Non-Fibrillar Collagens; Pemphigoid, Bullous; Retrospective Studies; Severity of Illness Index; Sitagliptin Phosphate; Skin; Vildagliptin; Collagen Type XVII
PubMed: 33026629
DOI: 10.1007/s40257-020-00563-7 -
Neurology. Genetics Oct 2020To determine the genetic cause of axonal Charcot-Marie-Tooth disease in a small family with 2 affected siblings, one of whom had cerebellar features on examination.
OBJECTIVE
To determine the genetic cause of axonal Charcot-Marie-Tooth disease in a small family with 2 affected siblings, one of whom had cerebellar features on examination.
METHODS
Whole-exome sequencing of genomic DNA and analysis for recessively inherited mutations; PCR-based messenger RNA/complementary DNA analysis of transcripts to characterize the effects of variants identified by exome sequencing.
RESULTS
We identified compound heterozygous mutations in dystonin (), which is alternatively spliced to create many plakin family linker proteins (named the bullous pemphigoid antigen 1 [BPAG1] proteins) that function to bridge cytoskeletal filament networks. One mutation (c.250C>T) is predicted to cause a nonsense mutation (p.R84X) that only affects isoform 2 variants, which have an N-terminal transmembrane domain; the other (c.8283+1G>A) mutates a consensus splice donor site and results in a 22 amino acid in-frame deletion in the spectrin repeat domain of all BPAG1a and BPAG1b isoforms.
CONCLUSIONS
These findings introduce a novel human phenotype, axonal Charcot-Marie-Tooth, of recessive mutations, and provide further evidence that BPAG1 plays an essential role in axonal health.
PubMed: 32802955
DOI: 10.1212/NXG.0000000000000496