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1.
J Vet Med Sci ; 86(4): 354-357, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38355119

ABSTRACT

A mixed-breed, 8-year-old male dog developed neutropenia, thrombocytopenia, and hyperglobulinemia. Bone marrow hyperplasia and splenic plasmacytosis were cytologically observed. The dog had never been outside of Tokyo or Shizuoka Prefecture. Splenectomy was performed to confirm and remove the cause of splenic plasmacytosis. A histopathological diagnosis of splenic plasmacytoma was made; however, serum protein electrophoresis showed polyclonal gammopathy. Further screening was performed, and Ehrlichia canis infection was confirmed. The dog was treated with doxycycline for 5 weeks. After the antibiotic therapy, no relapse of neutropenia, thrombocytopenia, hyperglobulinemia, or positive polymerase chain reaction result of E. canis infection was observed for 3 years. Careful attention should be given to ehrlichiosis when exploring the cause of pancytopenia or hyperglobulinemia, regardless of the travel history.


Subject(s)
Dog Diseases , Ehrlichiosis , Neutropenia , Thrombocytopenia , Male , Dogs , Animals , Ehrlichia canis , Japan/epidemiology , Ehrlichiosis/epidemiology , Ehrlichiosis/veterinary , Thrombocytopenia/veterinary , Neutropenia/veterinary , Dog Diseases/pathology , Ehrlichia
2.
BMC Cancer ; 23(1): 219, 2023 Mar 08.
Article in English | MEDLINE | ID: mdl-36890471

ABSTRACT

BACKGROUND: Soft tissue sarcomas (STS) are a rare type of malignancy comprising a variety of histological diagnoses. Chemotherapy constitutes the standard treatment for advanced STS. Doxorubicin-based regimens, which include the administration of doxorubicin alone or in combination with ifosfamide or dacarbazine, are widely accepted as first-line chemotherapy for advanced STS. Trabectedin, eribulin, pazopanib, and gemcitabine plus docetaxel (GD), which is the empirical standard therapy in Japan, are major candidates for second-line chemotherapy for advanced STS, although clear evidence of the superiority of any one regimen is lacking. The Bone and Soft Tissue Tumor Study Group of the Japan Clinical Oncology Group (JCOG) conducts this trial to select the most promising regimen among trabectedin, eribulin, and pazopanib for comparison with GD as the test arm regimen in a future phase III trial of second-line treatment for patients with advanced STS. METHODS: The JCOG1802 study is a multicenter, selection design, randomized phase II trial comparing trabectedin (1.2 mg/m2 intravenously, every 3 weeks), eribulin (1.4 mg/m2 intravenously, days 1 and 8, every 3 weeks), and pazopanib (800 mg orally, every day) in patients with unresectable or metastatic STS refractory to doxorubicin-based first-line chemotherapy. The principal eligibility criteria are patients aged 16 years or above; unresectable and/or metastatic STS; exacerbation within 6 months prior to registration; histopathological diagnosis of STS other than Ewing sarcoma, embryonal/alveolar rhabdomyosarcoma, well-differentiated liposarcoma and myxoid liposarcoma; prior doxorubicin-based chemotherapy for STS, and Eastern Cooperative Oncology Group performance status 0 to 2. The primary endpoint is progression-free survival, and the secondary endpoints include overall survival, disease-control rate, response rate, and adverse events. The total planned sample size to correctly select the most promising regimen with a probability of > 80% is 120. Thirty-seven institutions in Japan will participate at the start of this trial. DISCUSSION: This is the first randomized trial to evaluate trabectedin, eribulin, and pazopanib as second-line therapies for advanced STS. We endeavor to perform a subsequent phase III trial comparing the best regimen selected by this study (JCOG1802) with GD. TRIAL REGISTRATION: This study was registered with the Japan Registry of Clinical Trials ( jRCTs031190152 ) on December 5, 2019.


Subject(s)
Liposarcoma, Myxoid , Sarcoma , Soft Tissue Neoplasms , Humans , Adult , Trabectedin/therapeutic use , Japan , Sarcoma/pathology , Soft Tissue Neoplasms/pathology , Doxorubicin/therapeutic use , Gemcitabine , Docetaxel/therapeutic use , Medical Oncology , Randomized Controlled Trials as Topic , Multicenter Studies as Topic , Clinical Trials, Phase II as Topic
3.
Genes Cells ; 28(2): 111-128, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36504347

ABSTRACT

STATa is a pivotal transcription factor for Dictyostelium development. dutA is the most abundant RNA transcribed by RNA polymerase II in Dictyostelium, and its functional interplay with STATa has been suggested. This study demonstrates that dutA RNA molecules are distributed as spot-like structures in the cytoplasm, and that its cell type-specific expression changes dramatically during development. dutA RNA was exclusively detectable in the prespore region of slugs and then predominantly localized in prestalk cells, including the organizer region, at the Mexican hat stage before most dutA transcripts, excluding those in prestalk O cells, disappeared as culmination proceeded. dutA RNA was not translated into small peptides from any potential open reading frame, which confirmed that it is a cytoplasmic lncRNA. Ectopic expression of dutA RNA in the organizer region of slugs caused a prolonged slug migration period. In addition, buffered suspension-cultured cells of the strain displayed reduced STATa nuclear translocation and phosphorylation on Tyr702. Analysis of gene expression in various dutA mutants revealed changes in the levels of several STATa-regulated genes, such as the transcription factors mybC and gtaG, which might affect the phenotype. dutA RNA may regulate several mRNA species, thereby playing an indirect role in STATa activation.


Subject(s)
Dictyostelium , RNA, Long Noncoding , Dictyostelium/genetics , Dictyostelium/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Gene Expression Regulation , Transcription Factors/metabolism , Phosphorylation , Protozoan Proteins/metabolism
4.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 78(11): 1333-1340, 2022 Nov 20.
Article in Japanese | MEDLINE | ID: mdl-36104224

ABSTRACT

PURPOSE: We aimed to clarify the error of displayed value against the measured value of the average glandular dose (AGD) in two-dimensional (2D) mammography and digital breast tomosynthesis (DBT) and evaluate the accuracy of the displayed AGD as an index to estimate AGD. METHODS: Polymethyl methacrylate (PMMA) phantoms with thicknesses varying from 20 to 80 mm were imaged, and the values displayed on the mammography system were used as the displayed AGD. The incident air kerma and the half-valued layer were measured, and the measured AGD in 2D mammography was calculated using the equation by Dance et al. On the other hand, the measured AGD in DBT was calculated by correcting for different projection angles. The relative error to the PMMA thickness was evaluated by assessing the relative error of the displayed AGD against the measured AGD. RESULTS: The maximum relative error of the displayed AGD against the measured AGD was 17.3% in 2D mammography, 19.1% in the standard (ST) mode, and 19.8% in the high-resolution (HR) mode. CONCLUSION: The relative error of the displayed AGD against the measured AGD tended to increase with increase in PMMA thickness. This tendency was especially noticeable for PMMA with thicknesses of 70 and 80 mm in DBT.


Subject(s)
Polymethyl Methacrylate , Radiographic Image Enhancement , Radiographic Image Enhancement/methods , Radiation Dosage , Mammography/methods , Phantoms, Imaging
5.
Front Vet Sci ; 9: 936623, 2022.
Article in English | MEDLINE | ID: mdl-36172613

ABSTRACT

Haematopoietic stem and progenitor cells (HSPCs) are used for transplantation to reconstruct the haematopoietic pathways in humans receiving severe chemotherapy. However, the characteristics of canine HSPCs, such as specific surface antigens and gene expression profiles, are still unclear. This study aimed to characterise the haematopoietic ability and gene expression profiles of canine bone marrow HSPCs in healthy dogs. In this study, the CD34 positive (CD34+) cells were defined as classical HSPCs, CD34+/CD45 diminished (CD45dim) cells as more enriched HSPCs, and whole viable cells as controls. Haematopoietic abilities and gene expression profiles were evaluated using a colony-forming unit assay and RNA-sequencing analysis. Canine CD34+/CD45dim cells exhibited a significantly higher haematopoietic colony formation ability and expressed more similarity in the gene expression profiles to human and mouse HSPCs than those of the other cell fractions. Furthermore, the canine CD34+/CD45dim cells expressed candidate cell surface antigens necessary to define the canine haematopoietic hierarchy roadmap. These results indicate that the canine CD34+/CD45dim cells express the HSPC characteristics more than the other cell fractions, thereby suggesting that these cells have the potential to be used for studying haematopoietic stem cells in dogs.

6.
Regen Ther ; 19: 1-8, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35024388

ABSTRACT

INTRODUCTION: Differentiation of hepatocytes and culture methods have been investigated in dogs as a tool to establish liver transplant and drug metabolism examination systems. However, mass culture techniques for canine hepatocytes (cHep) have not been investigated, and it is necessary to construct a suitable culture system. Recently, a protocol called Bud production has attracted attention, and a mixed culture of human and mouse hepatocytes, stem cells, and artificial blood vessels significantly improved the size and formation ratio of spheroids. The purpose of this study was to investigate and improve the in vitro culture of cHep by mixing canine adipose-derived mesenchymal stem cells (cASCs) and human umbilical vein endothelial cells (HUVECs). METHODS: Spheroid formation ratio and histological examination were evaluated among four culture methods, including cHep alone, two-mix (cHep + cASCs and cHep + HUVEC), and three-mix (cHep + HUVEC + cASCs), on days 0, 4, and 7. Expression levels of liver-related genes (ALB, AFP, α1-AT, CDH1, CYP2E1, CYP3A12, and TAT) were evaluated by quantitative real-time polymerase chain reaction (RT-PCR). Protein expression of albumin, vimentin, and von Willebrand Factor (vWF) was investigated to confirm the location of the hepatocytes. RESULTS: The ratio of spheroid formation was 60.2% in the three-mix culture and was significantly improved compared with cHep alone (5.9%) and two-mix; cHep + cASCs (36.2%) and cHep + HUVEC (26.4%) (P < 0.001). Histological evaluation revealed that the three-mix spheroids formed large canine hepatocyte spheroids (LcHS), and hepatocytes were distributed in the center of the spheroids. Quantitative gene expression analysis of LcHS showed that liver-related genes expression were maintained the same levels with that of a culture of cHep alone from days 4-7. CONCLUSION: These results revealed that the three-mix culture method using cHep, HUVECs, and cASCs was capable of promoting LcHS without impairing liver function in cHep, suggesting that LcHS could be used for the application of high-volume culture techniques in dogs.

7.
Front Cell Dev Biol ; 9: 692473, 2021.
Article in English | MEDLINE | ID: mdl-34490246

ABSTRACT

The 1-phosphatidylinositol-3-phosphate 5-kinase PIKfyve generates PtdIns3,5P2 on late phagolysosomes, which by recruiting the scission protein Atg18, results in their fragmentation in the normal course of endosome processing. Loss of PIKfyve function causes cellular hypervacuolization in eukaryotes and organ failure in humans. We identified pikfyve as the defective gene in a Dictyostelium mutant that failed to form spores. The amoebas normally differentiated into prespore cells and initiated spore coat protein synthesis in Golgi-derived prespore vesicles. However, instead of exocytosing, the prespore vesicles fused into the single vacuole that typifies the stalk and basal disc cells that support the spores. This process was accompanied by stalk wall biosynthesis, loss of spore gene expression and overexpression of ecmB, a basal disc and stalk-specific gene, but not of the stalk-specific genes DDB_G0278745 and DDB_G0277757. Transdifferentiation of prespore into stalk-like cells was previously observed in mutants that lack early autophagy genes, like atg5, atg7, and atg9. However, while autophagy mutants specifically lacked cAMP induction of prespore gene expression, pikfyve - showed normal early autophagy and prespore induction, but increased in vitro induction of ecmB. Combined, the data suggest that the Dictyostelium endosomal system influences cell fate by acting on cell type specific gene expression.

8.
Case Rep Obstet Gynecol ; 2021: 9980015, 2021.
Article in English | MEDLINE | ID: mdl-34211792

ABSTRACT

Streptococcal toxic shock syndrome (STSS) is a life-threatening illness mainly caused by invasive group A Streptococcus (GAS) infection. Herein, we report a case of a postmenopausal woman who developed STSS from an ascending vaginal GAS infection after cytocervical sampling. The patient complained of vaginal discharge, for which she underwent gynecological examination with vaginal sampling. The following day, there was onset of diarrhea and vomiting. After 7 days, she was admitted to our hospital with septic shock. Necrotizing enterocolitis was suspected and surgical intervention was performed; however, the patient was diagnosed with primary peritonitis and antibiotics were initiated. On day 2, GAS was suspected by blood cultures, and antibiotics were changed in consideration of STSS. On day 4, GAS was confirmed in blood, ascitic fluid, and vaginal swab specimens, and STSS caused by an ascending vaginal GAS infection was diagnosed. This case report indicates that STSS could occur following cytocervical sampling for vaginal discharge. If a woman has unexplained septic shock, especially with gastroenteritis symptoms, STSS should be considered as a differential diagnosis.

9.
Arch Gerontol Geriatr ; 96: 104434, 2021.
Article in English | MEDLINE | ID: mdl-34030044

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) in patients aged ≥75 is one of the major risk factors for stroke, and prescription of oral anticoagulants (OACs) should be considered in these patients. We investigated the use of OAC' for patients certificated for long-term care (LTC) insurance, who have a high risk of bleeding among older patients. METHODS AND RESULTS: From 1169 consecutive inpatients aged 75 or older who were admitted to the geriatric ward of The University of Tokyo Hospital between 2012 and 2017, we identified 175 patients (men 48%, mean age 85.5 years) who had AF during admission. The patients' background, prescription of OACs on discharge, and the level of LTC insurance were checked. Patients were followed up for 1 to 5 years. Major bleeding, stroke, and all-cause mortality were investigated as outcomes. Among patients with AF, 63.4% were taking OACs. In multivariate analysis, older age, low BMI and no history of stroke were significant factors for not prescribing OACs. Care level patients with OACs had a higher incidence of stroke than others. There was no difference, irrespective of OAC prescription and disability level, in incidence of major bleeding. Care level patients without OACs had higher mortality than others. CONCLUSIONS: These results suggest that older care level patients with AF may benefit less from OACs.


Subject(s)
Atrial Fibrillation , Stroke , Administration, Oral , Aged , Aged, 80 and over , Anticoagulants/therapeutic use , Atrial Fibrillation/complications , Atrial Fibrillation/drug therapy , Atrial Fibrillation/epidemiology , Humans , Insurance, Long-Term Care , Male , Risk Factors , Stroke/epidemiology , Stroke/prevention & control
10.
Autophagy ; 17(3): 640-655, 2021 03.
Article in English | MEDLINE | ID: mdl-32116088

ABSTRACT

To resolve the signaling mechanisms that mediate the starvation-induced processes of Dictyostelium sporulation and encystation, we performed insertional mutagenesis on cells harboring an mRFP-tagged spore gene. We isolated a mutant in kinkyA (knkA), a gene without known function, which formed fruiting bodies with a kinked stalk and lacking viable spores. Immunoprecipitation of lysates of KnkA-YFP-transformed knkA- cells yielded a mammalian BCAS3 homolog as a KnkA interactor. bcas3- phenocopied knkA- and Bcas3 colocalized with KnkA to puncta. Bcas3 shares sequence similarity with proppins (beta-propellors that bind phosphoinositides). Mutation of 2 Bcas3 residues that are essential for PtdIns3P binding in proppins prevented Bcas3 binding to PtdIns3P as well as punctate Bcas3 and KnkA localization. KnkA puncta also colocalized with small but not large vesicles that contain the autophagy protein Atg8 and were contiguous with the endoplasmic reticulum. knkA- and bcas3- cells showed a pronounced decrease of RFP-GFP-Atg8 in neutral early autophagosomes, indicating that KnkA and Bcas3 are required for macroautophagy/autophagy. Knockouts in atg7, atg5 or atg9 substantiated this finding by showing similar sporulation defects as knkA- and bcas3-. Defective Dictyostelium sporulation is evidently a useful diagnostic tool for the discovery of novel autophagy genes.Abbreviations: Atg: Autophagy-related; BCAS3: BCAS3 microtubule associated cell migration factor; cAMP: 3',5'-cyclic adenosine monophosphate; ER: endoplasmic reticulum; GFP: green fluorescent protein; PAS: phagophore assembly site; PRKA/PKA: protein kinase cAMP-dependent; Proppin: beta-propellers that bind phosphoinositides; PtdIns3P: phosphatidylinositol 3-phosphate; REMI: restriction enzyme-mediated insertional mutagenesis; RFP: red fluorescent protein; RT-qPCR: reverse transcriptase - quantitative polymerase chain reaction; WIPI: WD repeat domain, phosphoinositide interacting; YFP: yellow fluorescent protein.


Subject(s)
Autophagosomes/genetics , Autophagy/genetics , Dictyostelium/genetics , Endoplasmic Reticulum/metabolism , Animals , Autophagosomes/metabolism , Autophagy/physiology , Autophagy-Related Proteins/metabolism , Dictyostelium/metabolism , Green Fluorescent Proteins/metabolism , Membrane Proteins/metabolism , Phagosomes/metabolism
11.
Regen Ther ; 14: 165-176, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32123700

ABSTRACT

INTRODUCTION: Hepatocytes, which account for the majority of liver tissue, are derived from the endoderm and become hepatocytes via differentiation of hepatic progenitor cells. Induced hepatocyte-like (iHep) cells and artificial liver tissues are expected to become useful, efficient therapies for severe and refractory liver diseases and to contribute to drug discovery research. The establishment of iHep cell lines are needed to carry out liver transplants and assess liver toxicity in the rising number of dogs affected by liver disease. Recently, direct conversion of non-hepatocyte cells into iHep cells was achieved by transfecting mouse adult fibroblasts with the Forkhead box protein A1 (Foxa1) and hepatocyte nuclear factor 4 homeobox alpha (Hnf4α) genes. Here, we applied this conversion process for the differentiation of canine bone marrow stem cells (cBMSCs) into hepatocyte-like cells. METHODS: Bone marrow specimens were collected from four healthy Beagle dogs and used to culture cBMSCs in Dulbecco's Modified Eagle's Medium (DMEM). The cBMSCs displayed the following characteristic features: plastic adherence; differentiation into adipocytes, osteoblasts and chondrocytes; and a cell surface antigen profile of CD29 (+), CD44 (+), CD90 (+), CD45 (-), CD34 (-) and CD14 (-), or CD11b (-) and CD79a (-), or CD19 (-) and HLA class II(-). The cBMSCs were seeded in a collagen I-coated plate and cultured in DMEM with 10% fetal bovine serum and transfected with retroviruses expressing Foxa1 and Hnf4α the following day. Canine iHep cells were differentiated from cBMSCs in culture on day 10, and were analyzed for morphology, RNA expression, immunocytochemistry, urea production, and low-density lipoprotein (LDL) metabolism. RESULTS: The cBMSCs expressed CD29 (98.06 ± 1.14%), CD44 (99.59 ± 0.27%) and CD90 (92.78 ± 4.89%), but did not express CD14 (0.47 ± 0.29%), CD19 (0.44 ± 0.39%), CD34 (0.33 ± 0.25%), CD45 (0.46 ± 0.34%) or MHC class II (0.54 ± 0.40%). The iHep cells exhibited morphology that included circular to equilateral circular shapes, and the formation of colonies that adhered to each other 10 days after Foxa1 and Hnf4α transfection. Quantitative RT-PCR analysis showed that the expression levels of the genes encoding albumin (ALB) and cadherin (CDH) in iHep cells on day 10 were increased approximately 100- and 10,000-fold, respectively, compared with cBMSCs. Corresponding protein expression of ALB and epithelial-CDH was confirmed by immunocytochemistry. Important hepatic functions, including LDL metabolic ability and urea production, were increased in iHep cells on day 10. CONCLUSION: We successfully induced cBMSCs to differentiate into functional iHep cells. To our knowledge, this is the first report of canine liver tissue differentiation using Foxa1 and Hnf4α gene transfection. Canine iHep cells are expected to provide insights for the construction of liver models for drug discovery research and may serve as potential therapeutics for canine liver disease.

12.
Regen Ther ; 15: 210-215, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33426221

ABSTRACT

INTRODUCTION: Primary cultured hepatocytes are an important model for early safety evaluations of newly developed drugs. Many factors, however, hinder the wider applications of this technology, especially the difficulty to maintain these cells in long-term culture. To date, creating a stable supply of human or animal hepatocytes with proper hepatic function in vitro has not been achieved. Furthermore, frequently harvesting hepatocytes from living donors for use in culture is highly invasive and simply not feasible. We have previously reported that canine bone marrow-derived mesenchymal stem cells (cBMSCs) can be effectively converted into induced hepatocyte-like cells (iHep cells); however, these cells had reduced function in comparison to mature hepatocytes. In recent studies, spheroid formation-based three-dimensional (3D) culture has been noted to greatly increase hepatocyte function; nevertheless, no reports have described the use of this technology for culturing canine hepatocytes. Therefore, in this study, we aimed to establish a 3D spheroid culture using converted canine iHep cells to investigate their function as hepatocytes. METHODS: The iHep cells were prepared by introducing two genes, namely, the Forkhead box A1 (Foxa1) and hepatocyte nuclear factor 4 homeobox alpha (Hnf4α), into cBMSCs seeded onto an ultra-low attachment microplate to induce spheroid formation. Thereafter, the hepatic functions of these spheroids were evaluated using immunocytochemistry, as well as qualitative and quantitative PCR. RESULTS: Notably, albumin was observed in the iHep spheroids and the expression of hepatic genes, such as albumin and drug metabolism CYP genes, could also be detected. Another interesting finding was evident upon further comparing the quantified albumin gene and CYP2E1 gene expressions in the two-dimensional and three-dimensional culture systems; notably, a 100- to 200-fold increase in gene expression levels was observed in the three-dimensional spheroids when compared to those in conventional monolayers. CONCLUSIONS: Upon incorporating three-dimensional technology, we managed to achieve iHep spheroids that are closer in gene expression to living liver tissue compared to conventional monolayer cultures. Thus, we are one step closer to creating a sustainable in vitro hepatocyte model. Furthermore, we believe that this system is capable of maintaining the stable drug metabolizing capacity of canine hepatocytes in vitro, which might be useful in improving current drug assessment studies.

13.
BMC Genomics ; 20(1): 890, 2019 Nov 21.
Article in English | MEDLINE | ID: mdl-31752673

ABSTRACT

BACKGROUND: Dictyostelid social amoebas self-organize into fruiting bodies, consisting of spores and up to four supporting cell types in the phenotypically most complex taxon group 4. High quality genomes and stage- and cell-type specific transcriptomes are available for representative species of each of the four taxon groups. To understand how evolution of gene regulation in Dictyostelia contributed to evolution of phenotypic complexity, we analysed conservation and change in abundance, functional domain architecture and developmental regulation of their transcription factors (TFs). RESULTS: We detected 440 sequence-specific TFs across 33 families, of which 68% were upregulated in multicellular development and about half conserved throughout Dictyostelia. Prespore cells expressed two times more TFs than prestalk cells, but stalk cells expressed more TFs than spores, suggesting that gene expression events that define spores occur earlier than those that define stalk cells. Changes in TF developmental expression, but not in TF abundance or functional domains occurred more frequently between group 4 and groups 1-3, than between the more distant branches formed by groups 1 + 2 and 3 + 4. CONCLUSIONS: Phenotypic innovation is correlated with changes in TF regulation, rather than functional domain- or TF acquisition. The function of only 34 TFs is known. Of 12 TFs essential for cell differentiation, 9 are expressed in the cell type for which they are required. The information acquired here on conserved cell type specifity of 120 additional TFs can effectively guide further functional analysis, while observed evolutionary change in TF developmental expression may highlight how genotypic change caused phenotypic innovation.


Subject(s)
Amoebozoa/genetics , Evolution, Molecular , Transcription Factors/genetics , Amoebozoa/classification , Amoebozoa/growth & development , Amoebozoa/metabolism , Dictyostelium/genetics , Gene Expression Regulation, Developmental , Phenotype , Phylogeny , Protein Domains , Transcription Factors/chemistry , Transcription Factors/metabolism , Transcriptome
14.
Dev Biol ; 452(2): 114-126, 2019 08 15.
Article in English | MEDLINE | ID: mdl-31051160

ABSTRACT

Dictyostelium discoideum amoebas display colonial multicellularity where starving amoebas aggregate to form migrating slugs and fruiting bodies consisting of spores and three supporting cell types. To resolve the cell signalling mechanism that control sporulation, we use insertional mutagenesis of amoebas transformed with fusion constructs of spore genes and red fluorescent protein. We identified the defective gene in a mutant lacking spore gene expression as the autophagy gene Atg7. Directed knock-out of atg7 and of autophagy genes like atg5 and atg9 yielded a similar phenotype, with lack of viable spores and excessive differentiation of stalk cells. The atg7-, atg5- and atg9- cells were specifically defective in cAMP induction of prespore genes, but showed enhanced cAMP stimulation of prestalk genes at the same developmental stage. The lack of prespore gene induction in the autophagy mutants was not due to deleterious effects of loss of autophagy on known components of the cAMP pathway, such as cAMP receptors and their cAMP-induced phosphorylation and internalization, PKA and the transcription factors SpaA and GbfA, or to lack of NH3 production by proteolysis, which was previously suggested to stimulate the spore pathway. Our continued mutagenesis approach is the most likely to yield the intriguing link between autophagy and prespore gene induction.


Subject(s)
Autophagy/genetics , Cyclic AMP/metabolism , Dictyostelium/cytology , Dictyostelium/genetics , Gene Expression Regulation, Developmental , Spores/genetics , Ammonia/pharmacology , Autophagy-Related Protein 7/genetics , Autophagy-Related Protein 7/metabolism , Biomarkers/metabolism , Cell Differentiation/genetics , Cyclic AMP-Dependent Protein Kinases/metabolism , Endocytosis , Genes, Protozoan , Mutagenesis/genetics , Mutation/genetics , Phenotype , Phosphorylation , Spores/cytology , Transcription Factors/metabolism
15.
Genes Environ ; 41: 11, 2019.
Article in English | MEDLINE | ID: mdl-30988834

ABSTRACT

BACKGROUND: Chloroethylnitrosourea (CENU) derivatives, such as nimustine (ACNU) and carmustine (BCNU), are employed in brain tumor chemotherapy due to their ability to cross the blood-brain barrier. They are thought to suppress tumor development through DNA chloroethylation, followed by the formation of interstrand cross-links (ICLs) that efficiently block replication and transcription. However, the alkylation of DNA and ICLs may trigger genotoxicity, leading to tumor formation as a side effect of the chemotherapeutic treatment. Although the involvement of O 6-alkylguanine-DNA alkyltransferase (AGT) in repairing chloroethylated guanine (O 6-chloroethylguanine) has been reported, the exact lesion responsible for the genotoxicity and the pathway responsible for repairing it remains unclear. RESULTS: We examined the mutations induced by ACNU and BCNU using a series of Escherichia coli strains, CC101 to CC111, in which reverse mutations due to each episome from F'101 to F'106 and frameshift mutations due to each episome from F'107 to F'111 could be detected. The mutant frequency increased in E. coli CC102, which can detect a GC to AT mutation. To determine the pathway responsible for repairing the CENU-induced lesions, we compared the frequency of mutations induced by CENU in the wild-type strain to those in the ada, ogt (AGT-deficient) strain, uvrA (nucleotide excision repair (NER)-deficient) strain, mismatch repair (MMR)-deficient strains, and recA (recombination deficient) strain of E. coli CC102. The frequencies of mutations induced by ACNU and BCNU increased in the ada, ogt strain, demonstrating that O 6-chloroethylguanines were formed, and that a portion was repaired by AGT.Mutation induced by ACNU in NER-deficient strain showed a similar profile to that in AGT-deficient strain, suggesting that an NER and AGT play at the similar efficacy to protect E. coli from mutation induced by ACNU. O 6-Chloroethylguanine is reported to form ICLs if it is not repaired. We examined the survival rates and the frequencies of mutations induced by ACNU and BCNU in the uvrA strain, the recA strain, as well as a double-deficient strain of CC102. The mutation profile of the double-deficient strain was similar to that of the NER-deficient strain, suggesting that an NER protects E. coli from mutations but not recombination. In addition, cell death was more pronounced in the uvrA, recA double-deficient strain than in the single-deficient strains. CONCLUSION: These results suggest that the toxic lesions induced by CENU were repaired additively or synergistically by NER and recombination. In other words, lesions, such as ICLs, appear to be repaired by NER and recombination independently.

16.
BMC Cardiovasc Disord ; 19(1): 41, 2019 02 19.
Article in English | MEDLINE | ID: mdl-30782136

ABSTRACT

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease characterized by fibrofatty replacement and ventricular arrhythmias. ARVC is believed to be a disease of the young, with most cases being diagnosed before the age of 40 years. We report here a case of newly diagnosed ARVC in an octogenarian associated with a pathogenic variant in the plakophilin 2 gene (PKP2). CASE PRESENTATION: An 80-year-old Japanese man was referred for sustained ventricular tachycardia. His baseline electrocardiogram showed negative T waves in V1-V4. Right ventriculography showed right ventricular aneurysm. Because this case met three major criteria, ARVC was diagnosed. He was successfully treated with radiofrequency ablation and oral amiodarone. Genetic analysis identified an insertion mutation in exon 8 of PKP2 (1725_1728dupGATG), which caused a frameshift and premature termination of translation (R577DfsX5). CONCLUSIONS: To the best of our knowledge, this is the first report of newly diagnosed ARVC in an octogenarian associated with a loss-of-function PKP2 pathogenic variant. Although the late clinical presentation of ARVC is rare, it should be included in the differential diagnosis when treating older patients with ventricular tachyarrhythmias.


Subject(s)
Arrhythmogenic Right Ventricular Dysplasia/genetics , Loss of Function Mutation , Plakophilins/genetics , Aged, 80 and over , Amiodarone/administration & dosage , Anti-Arrhythmia Agents/administration & dosage , Arrhythmogenic Right Ventricular Dysplasia/diagnosis , Arrhythmogenic Right Ventricular Dysplasia/physiopathology , Arrhythmogenic Right Ventricular Dysplasia/therapy , Catheter Ablation , Genetic Predisposition to Disease , Humans , Male , Phenotype , Risk Factors , Treatment Outcome
19.
Sci Rep ; 8(1): 6643, 2018 04 27.
Article in English | MEDLINE | ID: mdl-29704004

ABSTRACT

Sporulation in Dictyostelium fruiting bodies evolved from amoebozoan encystation with both being induced by cAMP acting on PKA, but with downstream components still being unknown. Using tagged mutagenesis to find missing pathway components, we identified a sporeless mutant defective in a nuclear protein, SpaA. Expression of prespore genes was strongly reduced in spaA- cells, while expression of many spore stage genes was absent. Chromatin immunoprecipitation (ChIP) of a SpaA-YFP gene fusion showed that (pre)spore gene promoters bind directly to SpaA, identifying SpaA as a transcriptional regulator. SpaA dependent spore gene expression required PKA in vivo and was stimulated in vitro by the membrane-permeant PKA agonist 8Br-cAMP. The PKA agonist also promoted SpaA binding to (pre)spore promoters, placing SpaA downstream of PKA. Sequencing of SpaA-YFP ChIPed DNA fragments revealed that SpaA binds at least 117 (pre)spore promoters, including those of other transcription factors that activate some spore genes. These factors are not in turn required for spaA expression, identifying SpaA as the major trancriptional inducer of sporulation.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/metabolism , Dictyostelium/growth & development , Spores, Protozoan/growth & development , Transcription Factors/metabolism , Chromatin Immunoprecipitation , DNA Mutational Analysis , DNA, Protozoan/metabolism , Dictyostelium/enzymology , Dictyostelium/genetics , Dictyostelium/metabolism , Gene Deletion , Gene Expression Profiling , Promoter Regions, Genetic , Protein Binding , Spores, Protozoan/enzymology , Spores, Protozoan/genetics , Spores, Protozoan/metabolism , Transcription Factors/genetics
20.
Heart Vessels ; 33(8): 866-876, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29450689

ABSTRACT

Home telemonitoring is becoming more important to home medical care for patients with heart failure. Since there are no data on home telemonitoring for Japanese patients with heart failure, we investigated its effect on cardiovascular outcomes. The HOMES-HF study was the first multicenter, open-label, randomized, controlled trial (RCT) to elucidate the effectiveness of home telemonitoring of physiological data, such as body weight, blood pressure, and pulse rate, for Japanese patients with heart failure (UMIN Clinical Trials Registry 000006839). The primary end-point was a composite of all-cause death or rehospitalization due to worsening heart failure. We analyzed 181 recently hospitalized patients with heart failure who were randomly assigned to a telemonitoring group (n = 90) or a usual care group (n = 91). The mean follow-up period was 15 (range 0-31) months. There was no statistically significant difference in the primary end-point between groups [hazard ratio (HR), 0.95; 95% confidence interval (CI), 0.548-1.648; p = 0.572]. Home telemonitoring for Japanese patients with heart failure was feasible; however, beneficial effects in addition to those of usual care were not demonstrated. Further investigation of more patients with severe heart failure, participation of home medical care providers, and use of a more integrated home telemonitoring system emphasizing communication as well as monitoring of symptoms and physiological data are required.


Subject(s)
Disease Management , Heart Failure/physiopathology , Hemodynamics/physiology , Home Care Services , Monitoring, Physiologic/methods , Telemedicine/methods , Aged , Female , Follow-Up Studies , Heart Failure/epidemiology , Humans , Japan/epidemiology , Male , Morbidity/trends , Prospective Studies
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