32 research outputs found
Ependymoma associated protein Zfta is expressed in immature ependymal cells but is not essential for ependymal development in mice
The fusion protein of uncharacterised zinc finger translocation associated (ZFTA) and effector transcription factor of tumorigenic NFâÎșB signalling, RELA (ZFTAâRELA), is expressed in more than twoâthirds of supratentorial ependymoma (STâEPNâRELA), but ZFTAÂżs expression profile and functional analysis in multiciliated ependymal (E1) cells have not been examined. Here, we showed the mRNA expression of mouse Zfta peaks on embryonic day (E) 17.5 in the wholemount of the lateral walls of the lateral ventricle. Zfta was expressed in the nuclei of FoxJ1âpositive immature E1 (preâE1) cells in E18.5 mouse embryonic brain. Interestingly, the transcription factors promoting ciliogenesis (ciliary TFs) (e.g., multicilin) and ZFTAâRELA upregulated luciferase activity using a 5âČ upstream sequence of ZFTA in cultured cells. Zftatm1/tm1 knockâin mice did not show developmental defects or abnormal fertility. In the Zftatm1/tm1 E1 cells, morphology, gene expression, ciliary beating frequency and ependymal flow were unaffected. These results suggest that Zfta is expressed in preâE1 cells, possibly under the control of ciliary TFs, but is not essential for ependymal development or flow. This study sheds light on the mechanism of the ZFTAâRELA expression in the pathogenesis of STâEPNRELA: Ciliary TFs initiate ZFTAâRELA expression in preâE1 cells, and ZFTAâRELA enhances its own expression using positive feedback
False-negative coagulation factor activity results due to the presence of antiphospholipid antibodies in a case of autoimmune hemolytic anemia
An 88-year-old female was admitted with autoimmune hemolytic anemia (AIHA). Coagulation test revealed severe prolongation of activated partial thromboplastin time (APTT). APTT cross-mixing test with patient plasma and normal plasma demonstrated an inhibitory pattern. Several intrinsic coagulation factor activities, particularly factor IX, showed remarkable decreases, and the inhibitor titers for coagulation factors VIII and IX were elevated. Although AIHA with existing antiphospholipid (aPL) antibodies was diagnosed initially, purpura developed on extremities intermittently during the clinical course. Considering the possibility of coexisting acquired hemophilia, APTT cross-mixing test with patientâs plasma and equal amount of the recombinant factor VIII product instead of normal plasma was performed. The APTT value on equal mixing samples with patient plasma and recombinant factor VIII product was decreased to within the normal range, and coagulation factor IX activity was restored. These results indicate that the recombinant factor VIII product had a neutralizing effect on aPL antibodies. We concluded that recombinant factor VIII product may lead to the repair of incorrect results from the APTT-dependent diagnostic system in the presence of aPL antibodies
Preclinical evaluation of the efficacy of an antibody to human SIRPα for cancer immunotherapy in humanized mouse models
Tumor-associated macrophages (TAMs) are abundant in the tumor microenvironment and are considered potential targets for cancer immunotherapy. To examine the antitumor effects of agents targeting human TAMs in vivo, we here established preclinical tumor xenograft models based on immunodeficient mice that express multiple human cytokines and have been reconstituted with a human immune system by transplantation of human CD34 hematopoietic stem and progenitor cells (HIS-MITRG mice). HIS-MITRG mice supported the growth of both human cell line (Raji)- and patient-derived B cell lymphoma as well as the infiltration of human macrophages into their tumors. We examined the potential antitumor action of an antibody to human SIRPα (SE12C3) that inhibits the interaction of CD47 on tumor cells with SIRPα on human macrophages and thereby promotes Fcγ receptor-mediated phagocytosis of the former cells by the latter. Treatment with the combination of rituximab (antibody to human CD20) and SE12C3 inhibited Raji tumor growth in HIS-MITRG mice to a markedly greater extent than did rituximab monotherapy. This enhanced antitumor effect was dependent on human macrophages and attributable to enhanced rituximab-dependent phagocytosis of lymphoma cells by human macrophages. Treatment with rituximab and SE12C3 also induced reprogramming of human TAMs toward a proinflammatory phenotype. Furthermore, the combination treatment essentially prevented the growth of patient-derived diffuse large B cell lymphoma in HIS-MITRG mice. Our findings thus support the study of HIS-MITRG mice as a model for the preclinical evaluation in vivo of potential therapeutics, such as antibodies to human SIRPα, that target human TAMs
Loss of Dishevelleds Disrupts Planar Polarity in Ependymal Motile Cilia and Results in Hydrocephalus
Defects in ependymal (E) cells, which line the ventricle and generate cerebrospinal fluid flow through ciliary beating, can cause hydrocephalus. Dishevelled genes (Dvls) are essential for Wnt signaling and Dvl2 has been shown to localize to the rootlet of motile cilia. Using the hGFAP-Cre;Dvl1â/â;2flox/flox;3+/â mouse, we show that compound genetic ablation of Dvls causes hydrocephalus. In hGFAP-Cre;Dvl1â/â;2flox/flox;3+/â mutants, E cells differentiated normally, but the intracellular and intercellular rotational alignments of ependymal motile cilia were disrupted. As a consequence, the fluid flow generated by the hGFAP-Cre;Dvl1â/â;2flox/flox;3+/â E cells was significantly slower than that observed in control mice. Dvls were also required for the proper positioning of motile cilia on the apical surface. Tamoxifen-induced conditional removal of Dvls in adult mice also resulted in defects in intracellular rotational alignment and positioning of ependymal motile cilia. These results suggest that Dvls are continuously required for E cell planar polarity and may prevent hydrocephalus
Black carbon and inorganic aerosols in Arctic snowpack
Key Points:
âą First ever measurements with a highâaccuracy singleâparticle soot photometer of black carbon (BC) concentrations in Arctic snowpack
âą Topography and BC emission flux strongly influenced latitudinal variations of mass concentrations and size distributions of BC
âą Measured BC mass concentrations 2â25 times lower than previously reported show the importance of revalidating climate modelsBlack carbon (BC) deposited on snow lowers its albedo, potentially contributing to warming in the Arctic. Atmospheric distributions of BC and inorganic aerosols, which contribute directly and indirectly to radiative forcing, are also greatly influenced by depositions. To quantify these effects, accurate measurement of the spatial distributions of BC and ionic species representative of inorganic aerosols (ionic species hereafter) in snowpack in various regions of the Arctic is needed, but few such measurements are available. We measured mass concentrations of size-resolved BC (CMBC) and ionic species in snowpack by using a single-particle soot photometer and ion chromatography, respectively, over Finland, Alaska, Siberia, Greenland, and Spitsbergen during early spring in 2012â2016. Total BC mass deposited per unit area (DEPMBC) during snow accumulation periods was derived from CMBC and snow water equivalent (SWE). Our analyses showed that the spatial distributions of anthropogenic BC emission flux, total precipitable water, and topography strongly influenced latitudinal variations of CMBC, BC size distributions, SWE, and DEPMBC. The average size distributions of BC in Arctic snowpack shifted to smaller sizes with decreasing CMBC due to an increase in the removal efficiency of larger BC particles during transport from major sources. Our measurements of CMBC were lower by a factor of ~13 than previous measurements made with an Integrating Sphere/Integrating Sandwich spectrophotometer due mainly to interference from coexisting non-BC particles such as mineral dust. The SP2 data presented here will be useful for constraining climate models that estimate the effects of BC on the Arctic climate.Plain Language Summary
Black carbon (BC) particles, commonly known as soot, are emitted from incomplete combustion of fossil fuels and biomass. They efficiently absorb solar radiation and thus heat the atmosphere. BC particles emitted at midlatitudes and in the Arctic are deposited onto snow in the Arctic, accelerating snowmelt in early spring by absorbing solar radiation. These processes contribute to warming in the Arctic. Calculations of this warming effect by using numerical models need to be validated by comparison with observed BC concentrations in snowpack. However, there are very few accurate records of concentrations of BC in snow because of technical difficulties in making these measurements. We developed a new laser-induced incandescence technique to measure BC concentrations in snowpack and applied it for the first time in six Arctic regions (Finland, Alaska, North and South Siberia, Greenland, and Spitsbergen). The BC concentrations we measured were highest in Finland and South Siberia, which are closer to large anthropogenic BC sources than the other regions, where our measured BC concentrations were much lower. On average, our BC concentrations were much lower than those previously measured by different techniques. Therefore, previous comparisons of modeled and observed BC concentrations need to be re-evaluated using the present data
Mechanosensory Genes Pkd1 and Pkd2 Contribute to the Planar Polarization of Brain Ventricular Epithelium.
UNLABELLED: Directional beating of ependymal (E) cells cilia in the walls of the ventricles in the brain is essential for proper CSF flow. E cells display two forms of planar cell polarity (PCP): rotational polarity of individual cilium and translational polarity (asymmetric positioning of cilia in the apical area). The orientation of individual E cells varies according to their location in the ventricular wall (location-specific PCP). It has been hypothesized that hydrodynamic forces on the apical surface of radial glia cells (RGCs), the embryonic precursors of E cells, could guide location-specific PCP in the ventricular epithelium. However, the detection mechanisms for these hydrodynamic forces have not been identified. Here, we show that the mechanosensory proteins polycystic kidney disease 1 (Pkd1) and Pkd2 are present in primary cilia of RGCs. Ablation of Pkd1 or Pkd2 in Nestin-Cre;Pkd1(flox/flox) or Nestin-Cre;Pkd2(flox/flox) mice, affected PCP development in RGCs and E cells. Early shear forces on the ventricular epithelium may activate Pkd1 and Pkd2 in primary cilia of RGCs to properly polarize RGCs and E cells. Consistently, Pkd1, Pkd2, or primary cilia on RGCs were required for the proper asymmetric localization of the PCP protein Vangl2 in E cells apical area. Analyses of single- and double-heterozygous mutants for Pkd1 and/or Vangl2 suggest that these genes function in the same pathway to establish E cells PCP. We conclude that Pkd1 and Pkd2 mechanosensory proteins contribute to the development of brain PCP and prevention of hydrocephalus. SIGNIFICANCE STATEMENT: This study identifies key molecules in the development of planar cell polarity (PCP) in the brain and prevention of hydrocephalus. Multiciliated ependymal (E) cells within the brain ventricular epithelium generate CSF flow through ciliary beating. E cells display location-specific PCP in the orientation and asymmetric positioning of their cilia. Defects in this PCP can result in hydrocephalus. Hydrodynamic forces on radial glial cells (RGCs), the embryonic progenitors of E cells, have been suggested to guide PCP. We show that the mechanosensory proteins Pkd1 and Pkd2 localize to primary cilia in RGCs, and their ablation disrupts the development of PCP in E cells. Early shear forces on RGCs may activate Pkd1 and Pkd2 in RGCs primary cilia to properly orient E cells. This study identifies key molecules in the development of brain PCP and prevention of hydrocephalus
A Case of Acquired Haemophilia A in a Patient with Chronic Myelomonocytic Leukaemia
A 67-year-old male, with a known diagnosis of myelodysplastic syndromes with multilineage dysplasia (MDS-MLD) was admitted to our hospital with a primary complaint of subcutaneous bleeding in his left thigh. Laboratory data showed anaemia and prolongation of activated partial thromboplastin time (85.8âs, normal range 24â39âs) without thrombocytopenia. Coagulation factor VIII (FVIII) activity was less than 1% (normal range 60â150%), and a FVIII inhibitor was identified and quantified at 166âBU/mL to indicate a diagnosis of acquired haemophilia A (AHA). A recent, but sustained circulating monocytosis (>1âĂâ109/L) was observed, which combined with elevated numbers of neutrophil and monocytic cells in the marrow, suggested evolution of MDS-MLD to chronic myelomonocytic leukaemia (CMML), coinciding with AHA. Further analysis revealed a karyotype of 46, XY, i(14) (q10), which was the same abnormality previously identified in the patient. To treat bleeding caused by AHA, steroid and activated prothrombin complex concentrate were administered. Azacitidine (AZA) was used to treat CMML. During the clinical course, bleeding partially improved; however, subsequent acute myocardial infarction occurred on day 87. Worsening bone marrow failure was observed 4âmonths after the original admission, despite administration of AZA therapy, and the patient died due to bleeding from AHA. This case suggests that the evolution of MDS to CMML status can be associated with AHA conferring a bleeding tendency
Expression of mRNA for growth factors and extracellular matrix proteins after injury to cultured peritoneal cells: does the healing process contribute to peritoneal ultrastructural alteration?
Impact of First-Line FOLFIRINOX-Induced Peripheral Neuropathy on the Efficacy of Second-Line GnP in Patients with Unresectable Advanced Pancreatic Cancer
Modified FOLFIRINOX (mFFX) and Gemcitabine plus nab-paclitaxel (GnP) are effective first-line chemotherapies for unresectable advanced pancreatic cancer (APC); however, both lead to peripheral neuropathy (PN). Aims: To evaluate the impact of first-line mFFX-induced PN on the efficacy of second-line GnP in patients with APC. Methods: A database containing patients with APC was retrospectively analyzed to evaluate patients who received second-line GnP after first-line mFFX failure between September 2014 and January 2021. The efficacy and safety of GnP were compared between patients with PN â„ Grade 2 (PN group) and PN †Grade 1 (non-PN group) at the start of second-line GnP. Cox proportional hazards analysis was also performed to examine the effect on overall survival (OS) and time-to-treatment failure (TTF). Results: Fifty-nine patients (PN group, 18 patients; non-PN group, 41 patients) were included. Median OS and TTF in the PN versus non-PN group were 7.7 versus 5.7 months (p = 0.19) and 3.8 versus 2.7 months (p = 0.18), respectively. Multivariate analysis showed that PN (â„Grade 2) was not a significant factor affecting either OS (hazard ratio (HR) 0.66, 95% confidence interval [CI] 0.33â1.31, p = 0.24) or TTF (HR 0.71, 95% CI 0.38â1.33, p = 0.28). No significant difference was observed in the relative dose intensity of GEM or nab-PTX, and incidence of adverse events. Conclusions: mFFX-induced PN has little impact on the efficacy and safety of second-line GnP in patients with APC. Second-line GnP could be a possible treatment option regardless of the presence of PN