RESUMO
Fate mapping and genetic manipulation of renin cells have relied on either noninducible Cre lines that can introduce the developmental effects of gene deletion or bacterial artificial chromosome transgene-based inducible models that may be prone to spurious and/or ectopic gene expression. To circumvent these problems, we generated an inducible mouse model in which CreERT2 is under the control of the endogenous Akr1b7 gene, an independent marker of renin cells that is expressed in a few extrarenal tissues. We confirmed the proper expression of Cre using Akr1b7CreERT2/+;R26RmTmG/+ mice in which Akr1b7+/renin+ cells become green fluorescent protein (GFP)+ upon tamoxifen administration. In embryos and neonates, GFP was found in juxtaglomerular cells, along the arterioles, and in the mesangium, and in adults, GFP was present mainly in juxtaglomerular cells. In mice treated with captopril and a low-salt diet to induce recruitment of renin cells, GFP extended along the afferent arterioles and in the mesangium. We generated Akr1b7CreERT2/+;Ren1cFl/-;R26RmTmG/+ mice to conditionally delete renin in adult mice and found a marked reduction in kidney renin mRNA and protein and mean arterial pressure in mutant animals. When subjected to a homeostatic threat, mutant mice were unable to recruit renin+ cells. Most importantly, these mice developed concentric vascular hypertrophy ruling out potential developmental effects on the vasculature due to the lack of renin. We conclude that Akr1b7CreERT2 mice constitute an excellent model for the fate mapping of renin cells and for the spatial and temporal control of gene expression in renin cells.NEW & NOTEWORTHY Fate mapping and genetic manipulation are important tools to study the identity of renin cells. Here, we report on a novel Cre mouse model, Akr1b7CreERT2, for the spatial and temporal regulation of gene expression in renin cells. Cre is properly expressed in renin cells during development and in the adult under basal conditions and under physiological stress. Moreover, renin can be efficiently deleted in the adult, leading to the development of concentric vascular hypertrophy.
Assuntos
Camundongos Transgênicos , Renina , Animais , Renina/metabolismo , Renina/genética , Camundongos , Sistema Justaglomerular/metabolismo , Aldeído Redutase/genética , Aldeído Redutase/metabolismo , Captopril/farmacologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Regulação da Expressão Gênica , Integrases/genética , Integrases/metabolismoRESUMO
Acute myeloid leukemia (AML) is a hematologic malignancy that frequently relapses, even if remission can be achieved with intensive chemotherapy. One known relapse mechanism is the escape of leukemic cells from immune surveillance. Currently, there is no effective immunotherapy for AML because of the lack of specific antigens. Here, we aimed to elucidate the association between CD155 and CD112 in AML cell lines and primary AML samples and determine the therapeutic response. Briefly, we generated NK-92 cell lines (NK-92) with modified DNAX-associated molecule 1 (DNAM-1) and T-cell immunoglobulin and ITIM domain (TIGIT), which are receptors of CD155 and CD112, respectively. Analysis of 200 cases of AML indicated that the survival of patients with high expression of CD112 was shorter than that of patients with low expression. NK-92 DNAM-1 exhibited enhanced cytotoxic activity against AML cell lines and primary cells derived from patients with AML. DNAM-1 induction in NK-92 cells enhanced the expression of cytotoxicity-related genes, thus overcoming the inhibitory activity of TIGIT. Between CD155 and CD112, CD112 is an especially important target for natural killer (NK)-cell therapy of AML. Using a xenograft model, we confirmed the enhanced antitumor effect of NK-92 DNAM-1 compared with that of NK-92 alone. We also discovered that CD112 (Nectin-2), an immune checkpoint molecule belonging to the Nectin/Nectin-like family, functions as a novel target of immunotherapy. In conclusion, modification of the DNAM-1/CD112 axis in NK cells may be an effective novel immunotherapy for AML. Furthermore, our findings suggest that the levels of expression of these molecules are potential prognostic markers in AML.
Assuntos
Proteínas de Checkpoint Imunológico , Leucemia Mieloide Aguda , Humanos , Nectinas , Proteínas de Checkpoint Imunológico/metabolismo , Células Matadoras Naturais , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/metabolismo , Receptores Imunológicos , Terapia Baseada em Transplante de Células e Tecidos , Antígenos de Diferenciação de Linfócitos T/genética , Antígenos de Diferenciação de Linfócitos T/metabolismoRESUMO
The impact of absolute neutrophil count (ANC) before allogenic hematopoietic stem cell transplantation (HSCT) on the outcomes for patients with aplastic anemia (AA) remains unclear. We retrospectively evaluated the relationship between ANC before transplantation and patient outcomes, involving 883 adult Japanese patients with AA who underwent allogeneic HSCT as their first transplantation between 2008 and 2020. Patients were divided into three groups based on ANC: 0/µL (n = 116); 1-199 (n = 210); and ≥ 200 (n = 557). In the low ANC groups (ANC < 200), patient age was higher, previous anti-thymocyte globulin (ATG) treatments were infrequent, duration from diagnosis to transplantation was shorter, hematopoietic cell transplantation-comorbidity index (HCT-CI) was higher, ATG-based conditioning was used infrequently, and peripheral blood stem cell from related donor and cord blood were used frequently. In multivariate analysis, patient age, previous ATG treatment, HCT-CI, stem cell source, and ANC before transplantation were significantly associated with 5-year overall survival (OS) ("ANC ≥ 200": 80.3% vs. "ANC 1-199": 71.7% vs. "ANC 0": 64.4%). The cumulative incidence of bacterial infection, invasive fungal disease, and early death before engraftment were significantly higher in the low ANC groups. Among patients with ANC of zero before transplantation, younger patient age, shorter duration from diagnosis to transplantation, HCT-CI of 0, and bone marrow from related donor as stem cell source were significantly associated with better OS. Consequently, ANC before allogeneic HSCT was found to be a significant prognostic factor in adult patients with AA. Physicians should pay attention to ANC before transplantation.
Assuntos
Anemia Aplástica , Transplante de Células-Tronco Hematopoéticas , Neutrófilos , Humanos , Anemia Aplástica/terapia , Anemia Aplástica/mortalidade , Anemia Aplástica/sangue , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adolescente , Adulto Jovem , Idoso , Contagem de Leucócitos , Soro Antilinfocitário/uso terapêutico , Taxa de Sobrevida , Transplante Homólogo , Condicionamento Pré-Transplante , AloenxertosRESUMO
This study investigated the immunotoxic effects of the mycotoxin nivalenol (NIV) using antigen-presenting cells and a mouse model of atopic dermatitis (AD). In vitro experiments were conducted using a mouse macrophage cell line (RAW 264.7) and mouse dendritic cell line (DC 2.4). After cells were exposed to NIV (0.19-5 µmol) for 24 h, the production of pro-inflammatory cytokines (IL-1ß, IL-6, and TNFα) was quantified. To further investigate the inflammatory cytokine production pathway, the possible involvement of mitogen-activated protein kinase (MAPK) pathways, such as ERK1/2, p-38, and JNK, in NIV exposure was analyzed using MAPK inhibitors and phosphorylation analyses. In addition, the pro-inflammatory effects of oral exposure to NIV at low concentrations (1 or 5 ppm) were evaluated in an NC/Nga mouse model of hapten-induced AD. In vitro experiments demonstrated that exposure to NIV significantly enhanced the production of TNFα. In addition, it also directly induced the phosphorylation of MAPK, indicated by the inhibition of TNFα production following pretreatment with MAPK inhibitors. Oral exposure to NIV significantly exacerbated the symptoms of AD, including a significant increase in helper T cells and IgE-produced B cells in auricular lymph nodes and secretion of pro-inflammatory cytokines, such as IL-4, IL-5, and IL-13, compared with the vehicle control group. Our findings indicate that exposure to NIV directly enhanced the phosphorylation of ERK1/2, p-38, and JNK, resulting in a significant increase in TNFα production in antigen-presenting cells, which is closely related to the development of atopic dermatitis.
Assuntos
Citocinas , Dermatite Atópica , Tricotecenos , Animais , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/imunologia , Tricotecenos/toxicidade , Tricotecenos/administração & dosagem , Camundongos , Administração Oral , Citocinas/metabolismo , Células RAW 264.7 , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/imunologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Modelos Animais de Doenças , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Células Dendríticas/imunologia , Fosforilação , Masculino , Fator de Necrose Tumoral alfa/metabolismo , FemininoRESUMO
Both alopecia areata (AA) and vitiligo are distinct, heterogenous, and complex disease entities, characterized by nonscarring scalp terminal hair loss and skin pigment loss, respectively. In AA, inflammatory cell infiltrates are in the deep reticular dermis close to the hair bulb (swarm of bees), whereas in vitiligo the inflammatory infiltrates are in the epidermis and papillary dermis. Immune privilege collapse has been extensively investigated in AA pathogenesis, including the suppression of immunomodulatory factors (e.g., transforming growth factor-ß (TGF-ß), programmed death-ligand 1 (PDL1), interleukin-10 (IL-10), α-melanocyte-stimulating hormone (α-MSH), and macrophage migration inhibitory factor (MIF)) and enhanced expression of the major histocompatibility complex (MHC) throughout hair follicles. However, immune privilege collapse in vitiligo remains less explored. Both AA and vitiligo are autoimmune diseases that share commonalities in pathogenesis, including the involvement of plasmacytoid dendritic cells (and interferon-α (IFN- α) signaling pathways) and cytotoxic CD8+ T lymphocytes (and activated IFN-γ signaling pathways). Blood chemokine C-X-C motif ligand 9 (CXCL9) and CXCL10 are elevated in both diseases. Common factors that contribute to AA and vitiligo include oxidative stress, autophagy, type 2 cytokines, and the Wnt/ß-catenin pathway (e.g., dickkopf 1 (DKK1)). Here, we summarize the commonalities and differences between AA and vitiligo, focusing on their pathogenesis.
Assuntos
Alopecia em Áreas , Vitiligo , Alopecia em Áreas/imunologia , Alopecia em Áreas/patologia , Alopecia em Áreas/etiologia , Alopecia em Áreas/metabolismo , Humanos , Vitiligo/imunologia , Vitiligo/patologia , Vitiligo/metabolismo , Vitiligo/etiologia , Animais , Privilégio Imunológico , Citocinas/metabolismoRESUMO
This study aimed to determine whether oral fumonisin exposure contributes to the development of psoriasis. Oral administration of fumonisin B1 (FB1, 0.1 mg/kg) or fumonisin B2 (FB2, 0.1 mg/kg) was conducted for 10 days, in addition to the induction of psoriatic symptoms through topical application of 5% imiquimod cream from day 6 to day 10 (5 days) in female BALB/c mice. The results demonstrated that oral administration of FB2 significantly exacerbated psoriatic symptoms, including skin thickness, itching behavior, transepidermal water loss, immune cell infiltration in the dermis, and proinflammatory cytokine production. However, no changes were observed following exposure to FB1. Our results confirm that oral exposure to FB2 adversely affects the pathogenesis of psoriasis by increasing skin thickness and impairing barrier function.
Assuntos
Fumonisinas , Imiquimode , Camundongos Endogâmicos BALB C , Psoríase , Animais , Psoríase/induzido quimicamente , Psoríase/patologia , Psoríase/metabolismo , Imiquimode/efeitos adversos , Fumonisinas/toxicidade , Camundongos , Feminino , Administração Oral , Pele/efeitos dos fármacos , Pele/metabolismo , Pele/patologia , Citocinas/metabolismo , Modelos Animais de DoençasRESUMO
An 84-year-old woman was diagnosed as having acute promyelocytic leukemia(APL)in July Year X-3. The test for promyelocytic leukemia- retinoic acid receptor alpha(PML-RARA)mRNA was positive, while that for CD56 was negative. Since her white blood cell( WBC) count was <3,000/µL, with a count of APL cells of <1,000/µL, she was started on monotherapy with all-trans retinoic acid(ATRA). In September Year X-3, complete hematological remission(CHR)was confirmed. she refused to provide consent for receiving consolidation therapy. In February Year X-2, hematological relapse occurred. She was started on re-induction therapy with arsenite(ATO), and in June Year X-2, complete molecular remission(CMR)was achieved. She was started on post-remission therapy with ATO. In August Year X-1, she developed molecular relapse and was started on tamibarotene(Am80). In October Year X-1, hematological relapse was detected, and the test for CD56 was positive. She was started on combined venetoclax(VEN)+azacitidine(AZA)(VEN+AZA). After completion of 1 course of treatment, CMR was achieved, but she developed hematological relapse after 5 courses of treatment. She died of gastrointestinal hemorrhage. This is considered a valuable case for accumulating information on the treatment of CD56-positive APL resistant to ATRA and ATO.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Leucemia Promielocítica Aguda , Sulfonamidas , Humanos , Feminino , Idoso de 80 Anos ou mais , Leucemia Promielocítica Aguda/tratamento farmacológico , Trióxido de Arsênio/uso terapêutico , Azacitidina/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Tretinoína/uso terapêutico , RecidivaRESUMO
Nucleophosmin1 (NPM1) mutations are the most frequently detected gene mutations in acute myeloid leukemia (AML) and are considered a favorable prognostic factor. We retrospectively analyzed the prognosis of 605 Japanese patients with de novo AML, including 174 patients with NPM1-mutated AML. Although patients with NPM1-mutated AML showed a high remission rate, this was not a favorable prognostic factor for overall survival (OS); this is contrary to generally accepted guidelines. Comprehensive gene mutation analysis showed that mutations in codon R882 of DNA methyltransferase 3A (DNMT3AR882 mutations) were a strong predicative factor indicating poor prognosis in all AML (p < 0.0001) and NPM1-mutated AML cases (p = 0.0020). Furthermore, multivariate analysis of all AML cases showed that DNMT3AR882 mutations and the co-occurrence of internal tandem duplication in FMS-like tyrosine kinase 3 (FLT3-ITD), NPM1 mutations, and DNMT3AR882 mutations (triple mutations) were independent factors predicting a poor prognosis related to OS, with NPM1 mutations being an independent factor for a favorable prognosis (hazard ratios: DNMT3AR882 mutations, 1.946; triple mutations, 1.992, NPM1 mutations, 0.548). Considering the effects of DNMT3AR882 mutations and triple mutations on prognosis and according to the classification of NPM1-mutated AML into three risk groups based on DNMT3AR882 /FLT3-ITD genotypes, we achieved the improved stratification of prognosis (p < 0.0001). We showed that DNMT3AR882 mutations are an independent factor for poor prognosis; moreover, when confounding factors that include DNMT3AR882 mutations were excluded, NPM1 mutations were a favorable prognostic factor. This revealed that ethnological prognostic discrepancies in NPM1 mutations might be corrected through prognostic stratification based on the DNMT3A status.
Assuntos
DNA (Citosina-5-)-Metiltransferases , Leucemia Mieloide Aguda , Humanos , DNA (Citosina-5-)-Metiltransferases/genética , Análise Mutacional de DNA , Leucemia Mieloide Aguda/genética , Mutação , Nucleofosmina/genética , Prognóstico , Estudos RetrospectivosRESUMO
Contamination with fumonisins produced by Fusarium spp. is rapidly growing in both developing and developed countries. The purpose of this study was to determine whether oral exposure to fumonisin contributed to the development of allergic diseases. We initially examined the immunotoxic potential of short-term, oral administration of fumonisin B1 (FB1, 1 mg/kg) and fumonisin B2 (FB2, 1 mg/kg), both naturally occurring fumonisins, using a BALB/c mouse model of allergic contact dermatitis and Dermatophagoides farina-induced asthma. Using an NC/nga mouse model of atopic dermatitis (AD), we evaluated the adverse effects of subchronic oral exposure to low concentrations of FB2 (2 or 200 µg/kg). Finally, we explored the influence of FB2 on regulatory T cell proliferation and function in mesenteric lymph nodes after 1-week oral exposure to FB2 in BALB/c mice. Oral exposure to FB2 markedly exacerbated the symptoms of allergy, including skin thickness, histological evaluation, immunocyte proliferation, and proinflammatory cytokine production, although no change was observed following exposure to FB1. Furthermore, oral exposure to low concentrations of FB2 considerably exacerbated the AD scores, skin thickness, transepidermal water loss, histological features, and proinflammatory cytokine production. The aggravated allergic symptoms induced by oral exposure to FB2 could be attributed to the direct inhibition of IL-10 production by regulatory T cells in mesenteric lymph nodes. Our findings indicate that the recommended maximum fumonisin level should be reconsidered based on the potential for allergy development.
Assuntos
Dermatite Alérgica de Contato , Fumonisinas , Animais , Camundongos , Fumonisinas/toxicidade , Interleucina-10 , Linfócitos T Reguladores , LinfonodosRESUMO
Citrinin, a mycotoxin produced by Penicillium citrinum and Penicillium verrucosum, mainly contaminates cereals. The aim of study was to investigate the novel immunoreactive effect of citrinin using a mouse model of psoriasis. A mouse model of psoriasis was generated by topical application of 5% imiquimod in female BALB/c mice. Standard rodent diet and rice samples with 3 ppm of citrinin were mixed to obtain a final citrinin concentration of 0.3 ppm, and a citrinin-contaminated diet was fed to mice daily. Skin thickness, scratching behavior, and trans epidermal water loss (TEWL) were monitored continuously during the imiquimod application. Immediately after the final imiquimod application, ear skin and auricular lymph node (LN) were sampled for further analysis. Only a slight increase was observed in skin thickness in the citrinin exposure group; however, citrinin exposure significantly exacerbated hyperkeratinization and inflammatory cell infiltration in histological evaluation. TEWL, which is representative of cutaneous barrier function, was significantly increased by citrinin exposure. In terms of immune function, the number of immune cells in LN (T cells and dendritic cells) and gene expression of interleukin (IL)-17 in skin tissue were significantly increased by citrinin exposure. Direct interaction of dendritic cells (DCs) in citrinin-induced psoriasis development was further examined by proinflammatory cytokine determination in THP-1 cells and murine bone marrow derived DCs. IL-6 and/or tumor necrosis factor α were significantly increased by citrinin exposure. Taken together, our results imply that oral exposure to citrinin exacerbates the symptoms of a mouse model of psoriasis via direct activation of DCs.
Assuntos
Citrinina , Psoríase , Feminino , Animais , Camundongos , Imiquimode/toxicidade , Citrinina/toxicidade , Citrinina/metabolismo , Aminoquinolinas/toxicidade , Aminoquinolinas/metabolismo , Células Dendríticas , Psoríase/induzido quimicamente , Pele , Modelos Animais de Doenças , Camundongos Endogâmicos BALB CRESUMO
Our understanding of allergic contact dermatitis mechanisms has progressed over the past decade. Innate immune cells that are involved in the pathogenesis of allergic contact dermatitis include Langerhans cells, dermal dendritic cells, macrophages, mast cells, innate lymphoid cells (ILCs), neutrophils, eosinophils, and basophils. ILCs can be subcategorized as group 1 (natural killer cells; ILC1) in association with Th1, group 2 (ILC2) in association with Th2, and group 3 (lymphoid tissue-inducer cells; ILC3) in association with Th17. Pattern recognition receptors (PRRs) including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) in innate immune cells recognize damage-associated molecular patterns (DAMPs) and cascade the signal to produce several cytokines and chemokines including tumor necrosis factor (TNF)-α, interferon (IFN)-α, IFN-γ, interleukin (IL)-1ß, IL-4, IL-6, IL-12, IL-13, IL-17, IL-18, and IL-23. Here we discuss the recent findings showing the roles of the innate immune system in allergic contact dermatitis during the sensitization and elicitation phases.
Assuntos
Dermatite Alérgica de Contato , Imunidade Inata , Humanos , Linfócitos , Citocinas , Interferon-alfaRESUMO
Myelofibrosis (MF) is a chronic myeloproliferative tumor with a poor prognosis that not only impairs the quality of life because of splenomegaly and debilitating systemic symptoms but also has a high acute myeloid leukemia progression rate. Ruxolitinib, a JAK inhibitor, enhances systemic symptoms in MF and prolongs survival; however, it is not effective in suppressing bone marrow fibrosis and leukemia progression, and allogeneic hematopoietic stem cell transplantation remains needed for treatment. As a result, many new drugs for MF are presently being developed. Many similar drugs have been demonstrated to enhance therapeutic effectiveness if combined with ruxolitinib, particularly BCL-2/BCL-XL inhibitors, bromodomain and extra-terminal domain inhibitors, and human double-minute homolog 2 inhibitors, to improve bone marrow fibrosis. This study provides an overview of drugs currently employed in clinical trials being performed in Japan.
Assuntos
Antineoplásicos , Mielofibrose Primária , Humanos , Mielofibrose Primária/tratamento farmacológico , Mielofibrose Primária/complicações , Qualidade de Vida , Esplenomegalia , Pirazóis/uso terapêutico , Antineoplásicos/uso terapêutico , Janus Quinase 2RESUMO
In bifidobacteria, phosphoketolase (PKT) plays a key role in the central hexose fermentation pathway called "bifid shunt." The three-dimensional structure of PKT from Bifidobacterium longum with co-enzyme thiamine diphosphate (ThDpp) was determined at 2.1 Å resolution by cryo-EM single-particle analysis using 196,147 particles to build up the structural model of a PKT octamer related by D4 symmetry. Although the cryo-EM structure of PKT was almost identical to the X-ray crystal structure previously determined at 2.2 Å resolution, several interesting structural features were observed in the cryo-EM structure. Because this structure was solved at relatively high resolution, it was observed that several amino acid residues adopt multiple conformations. Among them, Q546-D547-H548-N549 (the QN-loop) demonstrate the largest structural change, which seems to be related to the enzymatic function of PKT. The QN-loop is at the entrance to the substrate binding pocket. The minor conformer of the QN-loop is similar to the conformation of the QN-loop in the crystal structure. The major conformer is located further from ThDpp than the minor conformer. Interestingly, the major conformer in the cryo-EM structure of PKT resembles the corresponding loop structure of substrate-bound Escherichia coli transketolase. That is, the minor and major conformers may correspond to "closed" and "open" states for substrate access, respectively. Moreover, because of the high-resolution analysis, many water molecules were observed in the cryo-EM structure of PKT. Structural features of the water molecules in the cryo-EM structure are discussed and compared with water molecules observed in the crystal structure.
Assuntos
Aldeído Liases/química , Bifidobacterium longum/enzimologia , Microscopia Crioeletrônica/métodos , Escherichia coli , Modelos Moleculares , Tiamina Pirofosfato , ÁguaRESUMO
Caenorhabditis elegans contains two pathways for propionate metabolism, the vitamin B12-dependent and shunt pathways, which are similar to those in humans. In this study, we monitored the changes in propionate metabolism in the whole body of C. elegans using novel 13CO2 gas analysis. We measured the increase in 13CO2 excreted in the air after administering [1-13C]-labeled propionate ([13C]propionate) to the worms. The 13CO2 generated from [13C]propionate in C. elegans increased in a dose-dependent manner, reaching a maximum at 48 h. Enhanced expression of propionate metabolism-related genes was observed after administration of propionate. Knockdown of mmcm-1, which encodes the rate-limiting enzyme of the propionate metabolism, using RNAi reduced 13CO2 excretion. Thus, 13CO2 gas analysis could be confirmed 13CO2 excretion associated with changes in the metabolism of [13C]propionate in nematodes. This analysis can contribute to further understanding of the physiological effects of short-chain fatty acids.
Assuntos
Caenorhabditis elegans , Propionatos , Animais , Testes Respiratórios , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Dióxido de Carbono/metabolismo , Isótopos de Carbono , Propionatos/metabolismo , Vitamina B 12RESUMO
Thermostability is a key factor in the industrial and clinical application of enzymes, and understanding mechanisms of thermostability is valuable for molecular biology and enzyme engineering. In this chapter, we focus on the thermostability of leucine dehydrogenase (LDH, EC 1.4.1.9), an amino acid-metabolizing enzyme that is an NAD+-dependent oxidoreductase which catalyzes the deamination of branched-chain l-amino acids (BCAAs). LDH from Geobacillus stearothermophilus (GstLDH) is a highly thermostable enzyme that has already been applied to quantify the concentration of BCAAs in biological specimens. However, the molecular mechanism of its thermostability had been unknown because no high-resolution structure was available. Here, we discuss the thermostability of GstLDH on the basis of its structure determined by cryo-electron microscopy. Sequence comparison with other structurally characterized LDHs (from Lysinibacillus sphaericus and Sporosarcina psychrophila) indicated that non-conserved residues in GstLDH, including Ala94, Tyr127, and the C-terminal region, are crucial for oligomeric stability through intermolecular interactions between protomers. Furthermore, NAD+ binding to GstLDH increased the thermostability of the enzyme as additional intermolecular interactions formed on cofactor binding. This knowledge is important for further applications and development of amino acid metabolizing enzymes in industrial and clinical fields.
Assuntos
Leucina Desidrogenase/química , Leucina Desidrogenase/metabolismo , Bacillaceae/enzimologia , Microscopia Crioeletrônica , Estabilidade Enzimática , Geobacillus stearothermophilus/enzimologia , Leucina Desidrogenase/ultraestrutura , Sporosarcina/enzimologiaRESUMO
Essential thrombocythemia (ET) and polycythemia vera (PV), are common Philadelphia-negative myeloproliferative neoplasms (MPN). Patients with MPN have a high rate of cardiovascular complications and often have acquired JAK2V617F and CALR genetic mutations. In this study, we aimed to analyze vascular endothelial function in patients with MPN.We evaluated 27 outpatients, including 10 patients diagnosed with MPN, flow-mediated dilatation (FMD), and nitroglycerin-mediated dilation (NMD), between September 2014 and August 2016. We measured serum adiponectin, which protects vascular endothelial function, and serum asymmetric dimethyl arginine (ADMA), which inhibits the production of adiponectin. The presence or absence of JAK2V617F and CALR mutations was evaluated in patients with MPN.Venous thrombosis was observed more frequently in patients with MPN than in those without. Seven MPN patients were diagnosed with PV, and 3 MPN patients were diagnosed with ET. JAK2V617F and CALR mutations were found in 5 and 3 MPN patients, respectively. FMD was significantly lower in JAK2V617F-positive MPN patients than in JAK2V617F-negative MPN patients, although NMD, adiponectin, and ADMA were similar in both groups. Adiponectin levels were higher and ADMA levels were lower in CALR-positive MPN patients than in CALR-negative MPN patients. There was no difference in FMD and NMD prevalence between the 2 groups. Furthermore, we had 3 representative MPN patients who were complicated with coronary spasm, possibly caused by MPN-related endothelial dysfunction.We found that patients with MPN presented with endothelial dysfunction, which was related to the presence of genetic mutations and was sometimes associated with cardiovascular disease.
Assuntos
Transtornos Mieloproliferativos , Policitemia Vera , Trombocitemia Essencial , Doenças Vasculares , Adiponectina , Calreticulina/genética , Humanos , Janus Quinase 2/genética , Mutação , Transtornos Mieloproliferativos/complicações , Transtornos Mieloproliferativos/genética , Policitemia Vera/genética , Trombocitemia Essencial/genéticaRESUMO
The impact of calcineurin inhibitor types and anti-thymocyte globulin (ATG) in conditioning on overall survival (OS) and GVHD-free, relapse-free survival (GRFS) has not yet been analyzed in detail for aplastic anemia. We herein examined 517 adult patients with aplastic anemia who underwent BMT from HLA-matched sibling donors (MSD, n = 255) and unrelated donors (UD, n = 262) and were treated with cyclosporine A (CSA) + methotrexate (MTX) (n = 258) and tacrolimus (TAC) + MTX (n = 259). In total, 330 patients received ATG in conditioning. CSA + MTX versus TAC + MTX did not have a significant impact on acute and chronic GVHD, OS, or GRFS in each donor type. The use of ATG in conditioning reduced the risk of grade II-IV acute GVHD in the MSD and UD cohorts (HR 0.42, P = 0.014, and HR 0.3, P < 0.001, respectively); however, a differential impact on GRFS was identified, namely, better GRFS in MSD recipients (HR 0.56, P = 0.016), but not in UD recipients (HR 1.1, P = 0.657). In conclusion, CSA + MTX and TAC + MTX were similar as GVHD prophylaxis regardless of the donor type, and ATG in conditioning increased GRFS in MSD transplants, but not in UD transplants.
Assuntos
Anemia Aplástica/tratamento farmacológico , Soro Antilinfocitário/administração & dosagem , Ciclosporina/administração & dosagem , Doença Enxerto-Hospedeiro/prevenção & controle , Metotrexato/administração & dosagem , Tacrolimo/administração & dosagem , Adolescente , Adulto , Idoso , Anemia Aplástica/diagnóstico , Anemia Aplástica/mortalidade , Estudos de Coortes , Quimioterapia Combinada , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/mortalidade , Humanos , Imunossupressores/administração & dosagem , Masculino , Pessoa de Meia-Idade , Profilaxia Pré-Exposição/métodos , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Condicionamento Pré-Transplante/métodos , Condicionamento Pré-Transplante/mortalidade , Adulto JovemRESUMO
BACKGROUND: Immunoglobulin A nephropathy (IgAN) is the most common glomerulonephritis worldwide, characterized by mesangial polymeric IgA1 deposition. IgAN is believed to develop owing to aberrant mucosal immunoreaction against commensals in the tonsils. However, the exact interrelation between pathogenic IgA and mucosal microbiota in IgAN patients is unclear. METHODS: Biopsy-proven IgAN or recurrent tonsillitis (RT) patients who had undergone tonsillectomy were enrolled. We used 16S ribosomal RNA gene amplicon sequencing with a flow cytometry-based bacterial cell sorting technique) and immunoglobulin repertoire sequencing of the IgA heavy chain to characterize IgA-coated bacteria of the tonsillar microbiota (IgA-SEQ) and their corresponding IgA repertoire. Furthermore, we fractionated patient serum using gel-filtration chromatography and performed flow cytometry-based analysis of IgA binding to bacteria cultured from incised tonsils. RESULTS: Tonsillar proliferation-inducing ligand and B-cell activating factor levels were significantly higher in IgAN than in RT patients. IgA-SEQ for tonsillar microbiota revealed the preferential binding ability of IgA to Bacteroidetes in IgAN tonsils compared with those from RT patients. Expression of immunoglobulin heavy (IGH) constant alpha 1 with IGH variable 3-30 was significantly higher in IgAN than that in RT, and positively correlated with the IgA-coated enrichment score of Bacteroidetes. Serum polymeric IgA, comprising high levels of GdIgA1, exhibited considerable binding to Bacteroidetes strains cultured from the tonsils of IgAN patients. CONCLUSIONS: These findings provide evidence that aberrant mucosal immune responses to tonsillar anaerobic microbiota, primarily consisting of members of the phylum Bacteroidetes, are involved in IgAN pathophysiology.
Assuntos
Glomerulonefrite por IGA/complicações , Imunidade nas Mucosas/imunologia , Microbiota , Tonsila Palatina/microbiologia , Tonsilite/complicações , Adulto , Feminino , Citometria de Fluxo , Glomerulonefrite por IGA/microbiologia , Glomerulonefrite por IGA/patologia , Humanos , Masculino , Transdução de Sinais , Tonsilectomia , Tonsilite/imunologia , Tonsilite/microbiologiaRESUMO
A simple method for the cross ß-alkylation of linear alcohols with benzyl alcohols in the presence of DMF-stabilized iridium nanoparticles was developed. The nanoparticles were prepared in one-step and thoroughly characterized. Furthermore, the optimum reaction conditions have a wide substrate scope and excellent product selectivity.
RESUMO
INTRODUCTION: We conducted a post-marketing surveillance of laninamivir octanoate hydrate for Inhalation Suspension Set in patients under the age of 5 infected with the influenza virus to evaluate safety and efficacy of the drug. METHODS: Subjects enrolled by the centralized enrollment system were administered laninamivir once using a nebulizer based on the package insert. RESULTS: Safety was evaluated in 1104 patients. The incidence of ADRs was 1.00% (11/1104). Compared to the incidence of ADRs of 2.04% (9/441) in the clinical trials for development, no increase in the frequency of ADRs was noted. Serious ADRs were noted in 3 patients (5 cases): 2 cases of convulsive attack, each 1 case of muscular weakness, a depressed level of consciousness, and pain in extremities. Excluding 2 patients with unknown outcomes, all of the patients recovered or their symptoms were alleviated. To detect risk factors for the occurrence of ADRs, 16 attributes were examined, and none of them were found to be significant. Efficacy was evaluated in 881 patients. The median time (95% CI) to fever resolution was 37.0 (33.0-39.0) h in type A virus (785 patients), 45.0 (34.0-56.0) h in type B virus (95 patients), and 22.0 h (1 patient) in the mixed type. This was similar to the time to fever resolution in the clinical trials. CONCLUSION: The results of this surveillance verified that there are no noticeable problems with the safety or efficacy of laninamivir for children under the age of 5 infected with the influenza A and B viruses.