RESUMEN
This phase 1 study evaluated the addition of vorinostat to pembrolizumab in patients with relapsed/refractory (RR) classical Hodgkin lymphoma (cHL), diffuse large B-cell lymphoma, and follicular lymphoma. We report the results in cases of cHL. Adult patients with RR cHL who had received ≥1 prior lines of therapy and were ineligible for transplantation were treated in a dose-escalation cohort with 2 dose levels (DLs) and then on an expansion cohort at the recommended phase 2 dose (RP2D) in 21-day cycles. Vorinostat 100 mg twice a day (DL1) and 200 mg twice a day (DL2) was administered orally from days 1 to 5 and 8 to 12; all patients received pembrolizumab 200 mg IV every 3 weeks. The primary end point was safety and determination of RP2D. In total, 32 patients with cHL were enrolled, including 30 at DL2 (RP2D); 78% had received prior anti-programmed cell death 1 (anti-PD-1) therapy, and 56% were PD-1 refractory. Grade ≥3 adverse events (AEs) included hypertension (9%), neutropenia (9%), hypophosphatemia (9%), thrombocytopenia (6%), and lymphopenia (6%). Immune-related AEs included grade 1 or 2 thyroiditis (13%), grade 1 rash (6%), and grade 3 esophagitis/duodenitis (3%). The overall response rate (ORR) was 72% and complete response (CR) rate was 34%. Patients refractory to prior PD-1 blockade (n = 18) had ORR and CR rates of 56% and 11%, respectively. Pembrolizumab and vorinostat was well tolerated with a high ORR rate in RR cHL including in anti-PD-1-refractory disease. This trial was registered at www.clinicaltrials.gov as #NCT03150329.
Asunto(s)
Anticuerpos Monoclonales Humanizados , Enfermedad de Hodgkin , Adulto , Humanos , Enfermedad de Hodgkin/tratamiento farmacológico , Vorinostat , Receptor de Muerte Celular Programada 1/uso terapéutico , Recurrencia Local de NeoplasiaRESUMEN
Outcomes after programmed death-1 (PD-1) blockade in B-cell lymphomas are disappointing with few durable responses. Histone deacetylase inhibitors exhibit favorable immunomodulatory effects and demonstrate synergistic anti-tumor immune responses with anti-PD-1 therapy in preclinical models. We, therefore, developed a phase I study to evaluate the safety and preliminary efficacy of pembrolizumab with vorinostat in relapsed/refractory B-cell lymphomas. Patients were treated in a dose-escalation cohort using a Rolling 6 design followed by an expansion cohort at the recommended phase II dose (R2PD). Fifty-two patients were enrolled (32 Hodgkin and 20 non-Hodgkin lymphoma [NHL]). Here, we report safety data from the dose escalation cohort, and the toxicity and efficacy within NHL patients. Vorinostat was administered twice daily on days 1-5 and 8-12 (dose-level [DL]1: 100 mg; DL2: 200 mg) and pembrolizumab (200 mg) was administered on day 1 of each 3-week cycle. Of six patients treated at DL1, one had a dose-limiting toxicity (DLT) (Stevens-Johnson syndrome [SJS]), and one of six had a DLT at DL2 (thromboembolism); therefore, DL2 was the RP2D. The patient developing SJS was treated with corticosteroids, infliximab, and cyclosporine but ultimately died of invasive fungal infection from the extensive immunosuppression used to treat the SJS. The most common adverse events were hypertension, diarrhea, and cytopenias. Of 20 NHL patients, nine had follicular lymphoma (FL) and 11 had diffuse large B-cell lymphoma (DLBCL). Five DLBCL patients had primary mediastinal B-cell lymphoma (PMBL). The complete and overall response rates (CR and ORR) were 11% and 22% for FL and 45% and 55% for all DLBCL. Amongst DLBCL, the CR and ORR was 80% and 80% for PMBL and 17% and 33% for non-PMBL. In conclusion, pembrolizumab with vorinostat was tolerable and produced responses in relapsed/refractory B-cell NHL, with particularly notable efficacy in PMBL (clinicaltrials gov. Identifier: NCT03150329).
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Anticuerpos Monoclonales Humanizados , Linfoma Folicular , Linfoma de Células B Grandes Difuso , Linfoma no Hodgkin , Humanos , Vorinostat , Recurrencia Local de Neoplasia/patología , Linfoma no Hodgkin/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/patologíaRESUMEN
RanBPM is a recently identified scaffold protein that links and modulates interactions between cell surface receptors and their intracellular signaling pathways. RanBPM has been shown to interact with a variety of functionally unrelated proteins; however, its function remains unclear. Here, we show that RanBPM is essential for normal gonad development as both male and female RanBPM(-/-) mice are sterile. In the mutant testis there was a marked decrease in spermatogonia proliferation during postnatal development. Strikingly, the first wave of spermatogenesis was totally compromised, as seminiferous tubules of homozygous mutant animals were devoid of post-meiotic germ cells. We determined that spermatogenesis was arrested around the late pachytene-diplotene stages of prophase I; surprisingly, without any obvious defect in chromosome synapsis. Interestingly, RanBPM deletion led to a remarkably quick disappearance of all germ cell types at around one month of age, suggesting that spermatogonia stem cells are also affected by the mutation. Moreover, in chimeric mice generated with RanBPM(-/-) embryonic stem cells all mutant germ cells disappeared by 3 weeks of age suggesting that RanBPM is acting in a cell-autonomous way in germ cells. RanBPM homozygous mutant females displayed a premature ovarian failure due to a depletion of the germ cell pool at the end of prophase I, as in males. Taken together, our results highlight a crucial role for RanBPM in mammalian gametogenesis in both genders.
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Proteínas Adaptadoras Transductoras de Señales/fisiología , Proteínas del Citoesqueleto/fisiología , Proteínas Nucleares/fisiología , Oogénesis , Espermatogénesis , Animales , Femenino , Gónadas/crecimiento & desarrollo , Masculino , Profase Meiótica I , Ratones , Insuficiencia Ovárica Primaria/etiologíaRESUMEN
INTRODUCTION: BV is an antibody-drug conjugate directed against CD30 and is safe and effective in relapsed/refractory (R/R) Hodgkin lymphoma (HL). Most patients with r/r cHL respond well to BV monotherapy; however, the large of majority of them eventually progress on this drug, and BV-resistant HL remains an unmet need. Preclinical data suggest that BV resistance is mediated at least in part by increased drug efflux associated with increased expression of multidrug resistance pump 1 (MDR1) while CD30 expression appears to be preserved in BV resistant cell lines and patient samples. We conducted a phase 1 study evaluating BV + cyclosporine (CsA) in BV-refractory HL and previous reported results in the dose finding cohort. Here we report the final results from the phase 1 study. METHODS: This was a phase I trial of BV + CsA in patients with r/r HL with dose-finding and dose escalation cohorts. Eligibility criteria included age ≥ 18 years with r/r HL after at least 1 prior line of therapy. Treatment consisted of 1.8 mg/kg BV intravenously on day 1 and CsA 5 to 7.5 mg/kg PO twice daily on days 1 to 5; cycles were 21 days long. Patients in the expansion cohort had to have cHL refractory to BV. The primary objectives were to evaluate safety and tolerability and to determine MTD of BV + CsA; the secondary objective was to determine efficacy of this combination. RESULTS: 29 patients were enrolled onto the study, 14 in the dose finding cohort and 15 in the dose expansion BV refractory cohort. Study accrual was terminated before target accrual due to unacceptable toxicity. 62% of patients were male, and the median age was 36 years (range: 20-69). The median number of prior therapies was 5 (range: 3-12); all patients had prior BV, and 93% had PD-1 directed therapy, and 93% were BV-refractory. Of 22 evaluable patients, CR rate was 27% and ORR 64%; median DOR 4.9 months. Treatment-related deaths occurred in 3 patients, and another patient died during cycle 1 due to cardiac arrest deemed unlikely related to be protocol therapy. All grade GI toxicity was seen in 90% of patients (G3+ in 24%); other common adverse events were nausea (90%), hypertension (90%), nausea (90%), hypertension (90%), anemia (86%), fatigue (76%), neutropenia (76%), leukopenia (76%), hypomagnesemia (76%), anorexia (66%), and hyponatremia (66%). DISCUSSION: BV + CsA demonstrated modest activity in BV-refractory r/r HL; however, toxicity is substantial.
RESUMEN
BACKGROUND: CD30 expression is universal in anaplastic large-cell lymphoma and is expressed in some other peripheral T-cell lymphoma subtypes. Incorporation of brentuximab vedotin into initial therapy for people with CD30-positive peripheral T-cell lymphomas prolonged progression-free survival, but there is room for improvement, especially for people with non-anaplastic large-cell lymphoma subtypes. METHODS: We conducted a multicentre, international, single-arm, phase 2 trial to evaluate the safety and activity of CHEP-BV (cyclophosphamide, doxorubicin, prednisone, brentuximab vedotin, and etoposide) followed by brentuximab vedotin consolidation in patients with CD30-expressing peripheral T-cell lymphomas across five academic centres in the USA and Canada. Adults aged 18 years or older with newly diagnosed, untreated CD30-positive peripheral T-cell lymphomas, Eastern Cooperative Oncology Group score of 0-2, and adequate organ function were eligible to receive six planned cycles of CHEP-BV (ie, 1·8 mg/kg brentuximab vedotin intravenously on day 1, cyclophosphamide 750 mg/m2 intravenously on day 1, doxorubicin 50 mg/m2 intravenously on day 1, etoposide 100 mg/m2 daily intravenously on days 1-3, and prednisone 100 mg daily orally on days 1-5) with prophylactic G-CSF. Patients who responded to the treatment could receive brentuximab vedotin consolidation for up to ten additional cycles either after autologous haematopoietic stem-cell transplantation (HSCT) or directly after CHEP-BV. The primary endpoints were unacceptable toxicity during a 3-plus-3 safety lead-in in participants who received study treatment and completed the safety evaluation period (to confirm the recommended phase 2 dose of brentuximab vedotin in CHEP-BV) and the complete response rate after CHEP-BV induction therapy in participants who received study treatment and had response evaluation. The study was registered at ClinicalTrials.gov (NCT03113500), and this cohort completed the trial. The trial is ongoing with the enrolment of a new cohort. FINDINGS: 54 patients were screened for eligibility and 48 were eligible for the study. The participants (18 [38%] women and 30 [63%] men; 34 [71%] White, four [8%] Black, five [10%] Asian, ten [21%] Hispanic, and 37 [77%] non-Hispanic people) were recruited and enrolled between Dec 4, 2017, and June 14, 2021, and followed up until Aug 25, 2023, when the database was locked for analysis. 48 participants were evaluable for toxicity, and 47 were evaluable for response (one participant died from COVID-19 before response assessment). During the safety lead-in, one of six participants had an unacceptable toxicity (ie, platelet count <10 000 per mm3 in a participant with extensive bone marrow involvement), and the proposed phase 2 dose of 1·8 mg/kg brentuximab vedotin in CHEP-BV was confirmed. At completion of CHEP-BV, 37 of 47 participants had complete response, yielding a complete response rate of 79% (95% CI 64-89). The most common CHEP-BV-related toxicities of grade 3 or higher were neutropenia (14 [29%] of 48), leukopenia (11 [23%]), anaemia (ten [21%]), febrile neutropenia (ten [21%]), lymphopenia (nine [19%]), and thrombocytopenia (nine [19%]). There were no treatment-related deaths. INTERPRETATION: In patients with mostly CD30-expressing peripheral T-cell lymphomas other than non-anaplastic large-cell lymphoma, CHEP-BV (with or without autologous HSCT) followed by brentuximab vedotin consolidation was safe and active. FUNDING: SeaGen, Leukemia and Lymphoma Society, Lymphoma Research Foundation, and the National Cancer Institute of the National Institutes of Health.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Brentuximab Vedotina , Ciclofosfamida , Doxorrubicina , Etopósido , Antígeno Ki-1 , Linfoma de Células T Periférico , Prednisona , Humanos , Brentuximab Vedotina/uso terapéutico , Femenino , Masculino , Persona de Mediana Edad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Ciclofosfamida/uso terapéutico , Ciclofosfamida/administración & dosificación , Doxorrubicina/uso terapéutico , Doxorrubicina/administración & dosificación , Linfoma de Células T Periférico/tratamiento farmacológico , Etopósido/uso terapéutico , Etopósido/administración & dosificación , Antígeno Ki-1/metabolismo , Adulto , Prednisona/uso terapéutico , Prednisona/administración & dosificación , Prednisona/efectos adversos , Anciano , Quimioterapia de ConsolidaciónRESUMEN
BACKGROUND: After autologous haematopoietic stem-cell transplantation (HSCT), consolidation with brentuximab vedotin in patients with high-risk relapsed or refractory classic Hodgkin lymphoma has been shown to improve progression-free survival compared with placebo. Brentuximab vedotin plus nivolumab is a safe and effective treatment for relapsed or refractory classic Hodgkin lymphoma; therefore, we aimed to evaluate the safety and activity of this drug combination post-autologous HSCT consolidation in patients with high-risk relapsed or refractory classic Hodgkin lymphoma. METHODS: We did a multicentre phase 2 trial at five centres in the USA. Eligible patients were aged 18 years or older with high-risk relapsed or refractory classic Hodgkin lymphoma, had an ECOG performance status of 0-2, and had adequate organ and bone marrow function. Enrolled patients received brentuximab vedotin (1·8 mg/kg) and nivolumab (3 mg/kg) intravenously starting 30-60 days after autologous HSCT on day 1 of each 21-day cycle for up to 8 cycles. Nivolumab dose reduction was not allowed. Brentuximab vedotin dose reduction to 1·2 mg/kg was permitted. If one drug was discontinued because of a toxic effect, the other could be continued. The primary endpoint was 18-month progression-free survival in all treated patients. This study is registered with ClinicalTrials.gov, number NCT03057795. FINDINGS: Between May 3, 2017, and July 13, 2019, 59 patients were enrolled and received the study therapy. Patients initiated brentuximab vedotin plus nivolumab for a median of 54 days (IQR 46-58) after autologous HSCT and received a median of 8 cycles (8-8). 34 (58%) of 59 patients were male, 29 (49%) completed 8 cycles of brentuximab vedotin plus nivolumab, and 45 (76%) completed 8 cycles of at least one drug. The median follow-up time was 29·9 months (IQR 24·6-34·8). The 18-month progression-free survival in all 59 patients was 94% (95% CI 84-98). The most common adverse events were sensory peripheral neuropathy (31 [53%] of 59) and neutropenia (25 [42%]), and immune-related adverse events requiring corticosteroids occurred in 17 (29%) of 59 patients. No treatment-related deaths were observed. INTERPRETATION: Brentuximab vedotin plus nivolumab was highly active post-autologous HSCT consolidation for patients with high-risk relapsed or refractory classic Hodgkin lymphoma, most of whom had previous exposure to either brentuximab vedotin or PD-1 blockade. Combination immunotherapy in this setting should be further studied in patients with classic Hodgkin lymphoma with further refinement of the regimen to mitigate toxic effects, particularly in high-risk patients in whom more intensive therapy to prevent relapse is warranted. FUNDING: Bristol Myers Squibb, Leukemia and Lymphoma Society, Lymphoma Research Foundation, and National Cancer Institute of the National Institutes of Health.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Enfermedad de Hodgkin , Inmunoconjugados , Humanos , Adulto , Masculino , Femenino , Brentuximab Vedotina/uso terapéutico , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/patología , Nivolumab/efectos adversos , Inmunoconjugados/efectos adversos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante AutólogoRESUMEN
Alisertib, an Aurora kinase A inhibitor, was evaluated in a Phase 1 study in combination with the histone deacetylase inhibitor vorinostat, in patients with relapsed/refractory lymphoid malignancies (N = 34; NCT01567709). Patients received alisertib plus vorinostat in 21-day treatment cycles with escalating doses of alisertib following a continuous or an intermittent schedule. All dose-limiting toxicities (DLTs) were hematologic and there were no study-related deaths. The recommended phase 2 dose (RP2D) of the combination was 20 mg bid of alisertib and 200 mg bid of vorinostat on the intermittent schedule. A 13-patient expansion cohort was treated for a total of 18 patients at the RP2D. There were no DLTs at the RP2D, and toxicities were mainly hematologic. Two patients with DLBCL achieved a durable complete response, and two patients with HL achieved partial response. Alisertib plus vorinostat showed encouraging clinical activity with a manageable safety profile in heavily pretreated patients with advanced disease.
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Aurora Quinasa A , Inhibidores de Histona Desacetilasas/uso terapéutico , Trastornos Linfoproliferativos/tratamiento farmacológico , Vorinostat/uso terapéutico , Azepinas , Humanos , Recurrencia Local de Neoplasia , PirimidinasRESUMEN
PURPOSE: In classical Hodgkin lymphoma, the malignant Reed-Sternberg cells express the cell surface marker CD30. Brentuximab vedotin is an antibody-drug conjugate (ADC) that selectively delivers a potent cytotoxic agent, monomethyl auristatin E (MMAE), to CD30-positive cells. Although brentuximab vedotin elicits a high response rate (75%) in relapsed/refractory Hodgkin lymphoma, most patients who respond to brentuximab vedotin eventually develop resistance. PATIENTS AND METHODS: We developed two brentuximab vedotin-resistant Hodgkin lymphoma cell line models using a pulsatile approach and observed that resistance to brentuximab vedotin is associated with an upregulation of multidrug resistance-1 (MDR1). We then conducted a phase I trial combining brentuximab vedotin and cyclosporine A (CsA) in patients with relapsed/refractory Hodgkin lymphoma. RESULTS: Here, we show that competitive inhibition of MDR1 restored sensitivity to brentuximab vedotin in our brentuximab vedotin-resistant cell lines by increasing intracellular MMAE levels, and potentiated brentuximab vedotin activity in brentuximab vedotin-resistant Hodgkin lymphoma tumors in a human xenograft mouse model. In our phase I trial, the combination of brentuximab vedotin and CsA was tolerable and produced an overall and complete response rate of 75% and 42% in a population of patients who were nearly all refractory to brentuximab vedotin. CONCLUSIONS: This study may provide a new therapeutic strategy to combat brentuximab vedotin resistance in Hodgkin lymphoma. This is the first study reporting an effect of multidrug resistance modulation on the therapeutic activity of an ADC in humans. The expansion phase of the trial is ongoing and enrolling patients who are refractory to brentuximab vedotin to confirm clinical activity in this population with unmet need.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Resistencia a Antineoplásicos/efectos de los fármacos , Enfermedad de Hodgkin/tratamiento farmacológico , Células de Reed-Sternberg/patología , Subfamilia B de Transportador de Casetes de Unión a ATP/antagonistas & inhibidores , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , Adulto , Anciano , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Brentuximab Vedotina/administración & dosificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ciclosporina/administración & dosificación , Femenino , Enfermedad de Hodgkin/metabolismo , Enfermedad de Hodgkin/patología , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Persona de Mediana Edad , Estudios Prospectivos , Células de Reed-Sternberg/efectos de los fármacos , Células de Reed-Sternberg/metabolismo , Resultado del Tratamiento , Ensayos Antitumor por Modelo de Xenoinjerto , Adulto JovenRESUMEN
c-Kit is a tyrosine kinase receptor important for gametogenesis, hematopoiesis, melanogenesis and mast cell biology. Dysregulation of c-Kit function is oncogenic and its expression in the stem cell niche of a number of tissues has underlined its relevance for regenerative medicine and hematopoietic stem cell biology. Yet, very little is known about the mechanisms that control c-Kit protein levels. Here we show that the RanBPM/RanBP9 scaffold protein binds to c-Kit and is necessary for normal c-Kit protein expression in the mouse testis and subset lineages of the hematopoietic system. RanBPM deletion causes a reduction in c-Kit protein but not its mRNA suggesting a posttranslational mechanism. This regulation is specific to the c-Kit receptor since RanBPM reduction does not affect other membrane proteins examined. Importantly, in both mouse hematopoietic system and testis, RanBPM deficiency causes defects consistent with c-Kit loss of expression suggesting that RanBPM is an important regulator of c-Kit function. The finding that this regulatory mechanism is also present in human cells expressing endogenous RanBPM and c-Kit suggests a potential new strategy to target oncogenic c-Kit in malignancies.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Células de la Médula Ósea/metabolismo , Proteínas del Citoesqueleto/metabolismo , Células Germinativas/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo , Células Madre/metabolismo , Testículo/patología , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Células de la Médula Ósea/patología , Diferenciación Celular , Proteínas del Citoesqueleto/genética , Regulación de la Expresión Génica , Células Germinativas/patología , Células HEK293 , Humanos , Masculino , Ratones , Ratones Noqueados , Proteínas Nucleares/genética , Unión Proteica , Proteínas Proto-Oncogénicas c-kit/genética , ARN Interferente Pequeño/genética , Células Madre/patologíaRESUMEN
Plasma-membrane calcium pumps (PMCAs) are responsible for the expulsion of Ca(2+) from the cytosol of all eukaryotic cells and are one of the major transport systems involved in long-term regulation of resting intracellular Ca(2+) concentration. An important feature of stony corals, one of the major groups of calcifying animals, is the continuous export of large quantities of Ca(2+) for skeletogenesis. Here, we report the cloning and functional expression of the stpPMCA gene from the coral Stylophora pistillata, and whose features resemble those of the plasma-membrane Ca(2+)-ATPase family of mammalian cells. This is the first known example of a Ca(2+)-ATPase from the phylum Cnidaria, and thus, the most phylogenetically distant PMCA sequence in the animal kingdom described to date. We demonstrate that the localization of stpPMCA within calicoblastic cells is fully coherent with its role in calcification. We also show that the coral Ca(2+) pump is more closely related to vertebrate PMCAs than to Caenorhabditis elegans PMCAs. The cloning of evolutionarily conserved genes from cnidarian species repeatedly shows that these genes encode similar functional domains. Moreover, this high level of gene conservation further validates the use of cnidarian model systems for studying processes shared by Eumetazoans.
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Antozoos/enzimología , ATPasas Transportadoras de Calcio/genética , ATPasas Transportadoras de Calcio/metabolismo , Secuencia de Aminoácidos , Animales , Antozoos/genética , Calmodulina/metabolismo , Bovinos , Línea Celular , Membrana Celular/enzimología , Clonación Molecular , Expresión Génica , Humanos , Hibridación in Situ , Datos de Secuencia Molecular , Filogenia , Unión Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Distribución TisularRESUMEN
Brain-derived neurotrophic factor (BDNF) is critical for mammalian development and plasticity of neuronal circuitries affecting memory, mood, anxiety, pain sensitivity, and energy homeostasis. Here we report a novel unexpected role of BDNF in regulating the cardiac contraction force independent of the nervous system innervation. This function is mediated by the truncated TrkB.T1 receptor expressed in cardiomyocytes. Loss of TrkB.T1 in these cells impairs calcium signaling and causes cardiomyopathy. TrkB.T1 is activated by BDNF produced by cardiomyocytes, suggesting an autocrine/paracrine loop. These findings unveil a novel signaling mechanism in the heart that is activated by BDNF and provide evidence for a global role of this neurotrophin in the homeostasis of the organism by signaling through different TrkB receptor isoforms.
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Factor Neurotrófico Derivado del Encéfalo/metabolismo , Cardiomiopatías/enzimología , Glicoproteínas de Membrana/metabolismo , Fuerza Muscular , Contracción Miocárdica , Miocitos Cardíacos/enzimología , Proteínas Tirosina Quinasas/metabolismo , Animales , Comunicación Autocrina , Factor Neurotrófico Derivado del Encéfalo/genética , Factor Neurotrófico Derivado del Encéfalo/farmacología , Señalización del Calcio , Cardiomiopatías/genética , Cardiomiopatías/patología , Cardiomiopatías/fisiopatología , Activación Enzimática , Genotipo , Preparación de Corazón Aislado , Masculino , Glicoproteínas de Membrana/deficiencia , Glicoproteínas de Membrana/genética , Ratones Noqueados , Ratones Transgénicos , Fuerza Muscular/efectos de los fármacos , Contracción Miocárdica/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Comunicación Paracrina , Fenotipo , Proteínas Tirosina Quinasas/deficiencia , Proteínas Tirosina Quinasas/genética , Transducción de Señal , Factores de TiempoRESUMEN
RanBPM is a multimodular scaffold protein that interacts with a great variety of molecules including nuclear, cytoplasmic, and membrane proteins. By building multiprotein complexes, RanBPM is thought to regulate various signaling pathways, especially in the immune and nervous system. However, the diversity of these interactions does not facilitate the identification of its precise mechanism of action, and therefore the physiological role of RanBPM still remains unclear. Recently, RanBPM has been shown to be critical for the fertility of both genders in mouse. Although mechanistically it is still unclear how RanBPM affects gametogenesis, the data collected so far suggest that it is a key player in this process. Here, we examine the RanBPM sterility phenotype in the context of other genetic mutations affecting mouse gametogenesis to investigate whether this scaffold protein affects the function of other known proteins whose deficiency results in similar sterility phenotypes.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas del Citoesqueleto/metabolismo , Gametogénesis , Proteínas Nucleares/metabolismo , Proteínas Adaptadoras Transductoras de Señales/química , Proteínas Adaptadoras Transductoras de Señales/deficiencia , Animales , Proteínas del Citoesqueleto/química , Proteínas del Citoesqueleto/deficiencia , Células Germinativas/citología , Células Germinativas/metabolismo , Humanos , Meiosis , Proteínas Nucleares/química , Proteínas Nucleares/deficiencia , Fenotipo , ReproducciónRESUMEN
The adult subventricular zone (SVZ) contains progenitors cells, which continually give rise to new neurons that migrate along the rostral migratory stream (RMS) to the olfactory bulbs (OB). Prokineticin receptor 2 (ProKR2) is a G-protein-coupled receptor that plays an essential role in this migration process. However, the identity of the prokr2-expressing cells has not yet been clearly established. Here, we have characterized in detail the identity of the prokr2-expressing cells in the SVZ/RMS/OB pathway in adult mice. In the SVZ, accumulation of prokr2 transcripts was detected in almost all migrating neuroblasts or type A cells as well as in a large population of their precursors, the rapidly dividing type C cells. Moreover, we observed that, in dissociated SVZ cells from Mash1::GFP postnatal mice, ProKR2 protein is also present in type C and type A cells. We found that, along the RMS and in the OB, prokr2 expression was restricted to migrating type A cells and was absent in astrocytes. Finally, we observed a highly marked decrease of prokr2 expression in Mash1-/- mutant mice, suggesting that this transcription factor directly or indirectly regulates prokr2 expression. Although the expression of ProKR2 in migrating type A cells is in good agreement with the essential role played by this receptor during this migration process, its expression in a large population of their progenitors suggests an additional function for ProKR2, providing novel insights into the role of ProKR2/ProK2 signalling in adult neurogenesis.
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Encéfalo/citología , Movimiento Celular , Neuronas/fisiología , Receptores Acoplados a Proteínas G/metabolismo , Células Madre/fisiología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Encéfalo/fisiología , Ratones , Ratones Noqueados , Ratones Transgénicos , Vías Nerviosas , Neuronas/citología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Células Madre/citologíaRESUMEN
PopA is released by type III secretion from the bacterial plant pathogen Ralstonia solanacearum and triggers the hypersensitive response (HR) in tobacco. The function of PopA remains obscure, mainly because mutants lacking this protein are not altered in their ability to interact with plants. In an attempt to identify the site of PopA activity in plant cells, we generated transgenic tobacco plants expressing the popA gene under the control of an inducible promoter. Immunocytologic analysis revealed that the HR phenotype of these plants correlated with the presence of PopA at the plant plasma membrane. Membrane localization was observed irrespective of whether the protein was designed to accumulate in the cytoplasm or to be secreted by the plant cell, suggesting a general lipid-binding ability. We found that the protein had a high affinity for sterols and sphingolipids in vitro and that it required Ca2+ for both lipid binding and oligomerization. In addition, the protein was integrated into liposomes and membranes from Xenopus laevis oocytes where it formed ion-conducting pores. These characteristics suggest that PopA is part of a system that aims to attach the host cell plasma membrane and to allow molecules cross this barrier.