76 research outputs found

    A mouse bone marrow stromal cell line, TBR-B, shows inducible expression of smooth muscle-specific genes

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    AbstractWe established an in vitro culture system which mimicked the differentiation pathway of smooth muscle cell, using TBR-B, a bone marrow stromal cell line derived from transgenic mice harboring temperature-sensitive SV40 large T-antigen gene. TBR-B cells have the potential to express smooth muscle-specific genes including h1-calponin, h-caldesmon, SM22α and α-actin, only after cultured in the differentiation medium for 2 weeks. The differentiation state of TBR-B was well controlled by using different culture medium. Using this cell line, we also found that ascorbic acid is a potent factor inducing the expression of h1-calponin and α-actin. TBR-B cells will serve as a useful tool for elucidating the regulatory mechanisms of smooth muscle-specific gene expression, and for identifying compounds that regulate the differentiation state of vascular smooth muscle cells

    Evolutionary Relationships in the Drosophila ananassae Species Cluster Based on Introns of Multiple Nuclear Loci

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    The Drosophila ananassae species cluster includes D. ananassae, D. pallidosa, D. parapallidosa, and the cryptic species “pallidosa-like”, “pallidosa-like Wau” and “papuensis-like” Some of the taxa are sympatric in the South Pacific, Papua New Guinea, and Southeast Asia, and gene flow between different taxa has been suspected for a handful of genes. In the present analysis, we examined DNA sequences of introns in four loci: alpha actinin (Actn) on XL, white (w) on XR, CG7785 on 2L, and zinc ion transmembrane transporter 63C (ZnT63C) on 2R. Phylogenetic trees (neighbor-joining and haplotype network) were inconsistent among these loci. Some haplotypes shared between taxa were found for w, CG7785, and ZnT63C, suggesting recent gene flow. However, no haplotypes were shared, for example, between D. ananassae and D. pallidosa for CG7785, which is close to the proximal breakpoint of In(2L)D. This suggests that taxon-specific inversions prevent gene flow, as predicted by the chromosomal speciation hypothesis

    Signal-transducing adaptor protein-2 delays recovery of B lineage lymphocytes during hematopoietic stress

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    Signal-transducing adaptor protein-2 (STAP-2) was discovered as a C-FMS/M-CSFR interacting protein and subsequently found to function as an adaptor of signaling or transcription factors. These include STAT5, MyD88 and IκB kinase in macrophages, mast cells, and T cells. There is additional information about roles for STAP-2 in several types of malignant diseases including chronic myeloid leukemia, however, none have been reported concerning B lineage lymphocytes. We have now exploited gene targeted and transgenic mice to address this lack of knowledge, and demonstrated that STAP-2 is not required under normal, steady-state conditions. However, recovery of B cells following transplantation was augmented in the absence of STAP-2. This appeared to be restricted to cells of B cell lineage with myeloid rebound noted as unremarkable. Furthermore, all hematological parameters were observed to be normal once recovery from transplantation was complete. Furthermore, overexpression of STAP-2, specifically in lymphoid cells, resulted in reduced numbers of late-stage B cell progenitors within the bone marrow. While numbers of mature peripheral B and T cells were unaffected, recovery from sub-lethal irradiation or transplantation was dramatically reduced. Lipopolysaccharide (LPS) normally suppresses B precursor expansion in response to interleukin 7, however, STAP-2 deficiency made these cells more resistant. Preliminary RNA-Seq analyses indicated multiple signaling pathways in B progenitors as STAP-2-dependent. These findings suggest that STAP-2 modulates formation of B lymphocytes in demand conditions. Further study of this adapter protein could reveal ways to speed recovery of humoral immunity following chemotherapy or transplantation

    Real-world effectiveness and safety analysis of carfilzomib-lenalidomide-dexamethasone and carfilzomib-dexamethasone in relapsed/refractory multiple myeloma: a multicenter retrospective analysis

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    Background: Little is known about the real-world survival benefits and safety profiles of carfilzomib-lenalidomide-dexamethasone (KRd) and carfilzomib-dexamethasone (Kd). Methods: We performed a retrospective analysis to evaluate their efficacy and safety in 157 patients registered in the Kansai Myeloma Forum database. Results: A total of 107 patients received KRd. Before KRd, 99% of patients had received bortezomib (54% were refractory disease), and 82% had received lenalidomide (57% were refractory disease). The overall response rate (ORR) was 68.2%. The median progression-free survival (PFS) and overall survival (OS) were 8.8 and 29.3 months, respectively. Multivariate analysis showed that reduction of the carfilzomib dose and non-IgG M protein were significantly associated with lower PFS and reduction of the carfilzomib dose and refractoriness to prior bortezomib-based regimens were significantly associated with lower OS. A total of 50 patients received Kd. Before Kd, 96% of patients had received bortezomib (54% were refractory disease). The ORR was 62.0%. The median PFS and OS were 7.1 and 20.9 months, respectively. Based on the multivariate analysis, reduction of the carfilzomib dose and International Staging System Stage III (ISS III) were significantly associated with lower PFS. Grade III or higher adverse events were observed in 48% of KRd cases and 54% of Kd cases. Cardiovascular events, cytopenia, and infections were frequent, and 4 KRd patients died due to heart failure, arrhythmia, cerebral hemorrhage, and pneumonia. Conclusion: Our analysis showed that an adequate dose of carfilzomib is important for achieving the best survival benefits in a real-world setting. Adverse effects after KRd and Kd therapy should also be considered

    The Loss of PGAM5 Suppresses the Mitochondrial Degeneration Caused by Inactivation of PINK1 in Drosophila

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    PTEN-induced kinase 1 (PINK1), which is required for mitochondrial homeostasis, is a gene product responsible for early-onset Parkinson's disease (PD). Another early onset PD gene product, Parkin, has been suggested to function downstream of the PINK1 signalling pathway based on genetic studies in Drosophila. PINK1 is a serine/threonine kinase with a predicted mitochondrial target sequence and a probable transmembrane domain at the N-terminus, while Parkin is a RING-finger protein with ubiquitin-ligase (E3) activity. However, how PINK1 and Parkin regulate mitochondrial activity is largely unknown. To explore the molecular mechanism underlying the interaction between PINK1 and Parkin, we biochemically purified PINK1-binding proteins from human cultured cells and screened the genes encoding these binding proteins using Drosophila PINK1 (dPINK1) models to isolate a molecule(s) involved in the PINK1 pathology. Here we report that a PINK1-binding mitochondrial protein, PGAM5, modulates the PINK1 pathway. Loss of Drosophila PGAM5 (dPGAM5) can suppress the muscle degeneration, motor defects, and shorter lifespan that result from dPINK1 inactivation and that can be attributed to mitochondrial degeneration. However, dPGAM5 inactivation fails to modulate the phenotypes of parkin mutant flies. Conversely, ectopic expression of dPGAM5 exacerbated the dPINK1 and Drosophila parkin (dParkin) phenotypes. These results suggest that PGAM5 negatively regulates the PINK1 pathway related to maintenance of the mitochondria and, furthermore, that PGAM5 acts between PINK1 and Parkin, or functions independently of Parkin downstream of PINK1

    Genome evolution in the allotetraploid frog Xenopus laevis

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    To explore the origins and consequences of tetraploidy in the African clawed frog, we sequenced the Xenopus laevis genome and compared it to the related diploid X. tropicalis genome. We characterize the allotetraploid origin of X. laevis by partitioning its genome into two homoeologous subgenomes, marked by distinct families of ???fossil??? transposable elements. On the basis of the activity of these elements and the age of hundreds of unitary pseudogenes, we estimate that the two diploid progenitor species diverged around 34 million years ago (Ma) and combined to form an allotetraploid around 17-18 Ma. More than 56% of all genes were retained in two homoeologous copies. Protein function, gene expression, and the amount of conserved flanking sequence all correlate with retention rates. The subgenomes have evolved asymmetrically, with one chromosome set more often preserving the ancestral state and the other experiencing more gene loss, deletion, rearrangement, and reduced gene expression.ope

    DEXTRAN DEGRADING BACTERIA IN HUMAN ORAL CAVITY AND THEIR ACTIVITY AGAINST INSOLUBLE GLUCAN FROM STREPTOCOCCUS MUTANS

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    The distribution of dextran-degrading microorganisms in the saliva and plaque samples from the human oral cavity was assayed on 9 subjects. Approximately 2/ 3 of the saliva samples degraded Dextran T-150 (Pharmacia, M.W. 150,000) and 1/10 the Blue Dextran (Pharmacia), while 2/5 and 1/8 of the plaque samples degraded Dextran T-150 and Blue Dextran, respectively. Thirty-seven strains of the Blue Dextran degrading bacteria were isolated from the saliva and plaque samples and were classified into 6 groups by their morphology, gram staining and oxygen tolerance. The 24 strains from the 37 isolates, more or less, were shown to degrade the insoluble glucan extracted from Streptococcus mutans FA-1 on the agar plate. The 8 strains, selected from each group, were tested for their activity against the insoluble glucan extracted from Str. mutans (FA-1, HS-6, BHT, CHT, GS-5, LM-7 and PK-1) and Str. salivarius (HHT). The strains belonging to Groups I, II, IV and V showed activity against the insoluble glucan used. Among them, the strains of Group IV (gram negative facultative cocci) and Group V (gram negative strict anaerobic rod) were the most active against the insoluble glucan
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