Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 724
Filtrar
3.
Cureus ; 16(6): e62545, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39022523

RESUMEN

Progressive multifocal leukoencephalopathy (PML) is a rare, demyelinating infectious disease of the central nervous system, primarily affecting immunosuppressed individuals, such as those with acquired immunodeficiency syndrome (AIDS) or undergoing immunosuppressive therapy. The causative agent is the dormant John Cunningham (JC) polyomavirus, which reactivates in immunocompromised patients. PML is diagnosed through clinical observations, imaging, and polymerase chain reaction (PCR) analysis, detecting JC virus deoxyribonucleic acid (DNA) in the cerebrospinal fluid (CSF). Here, we report a case of a 42-year-old male, recently diagnosed with human immunodeficiency virus (HIV), who presented with slurred speech, difficulty articulating, tingling in both feet, difficulty walking, and significant weight loss. Examination revealed absent reflexes, coordination impairment, and diminished vibration sense. Blood tests showed anemia, elevated D-dimer, and HIV-1 positivity with a low CD4 count. CSF analysis indicated a lymphocytic profile with elevated protein and marginally increased adenosine deaminase (ADA). Autoantibody testing was positive for antinuclear antibodies (ANA), but CSF culture and India ink staining were negative. Magnetic resonance imaging (MRI) of the brain revealed hyperintense lesions on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images in the left peritrigonal and parietal white matter, suggesting demyelination. The diagnosis of PML was confirmed by a positive JC virus PCR result from the CSF. The patient was started on combination antiretroviral therapy (cART) and supportive measures to improve immune status. This case underscores the importance of considering PML in patients with new-onset neurological symptoms and immunosuppression.

4.
Microbiol Spectr ; : e0062824, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38874395

RESUMEN

The human polyomavirus, JCPyV, establishes a lifelong persistent infection in the peripheral organs of a majority of the human population worldwide. Patients who are immunocompromised due to underlying infections, cancer, or to immunomodulatory treatments for autoimmune disease are at risk for developing progressive multifocal leukoencephalopathy (PML) when the virus invades the CNS and infects macroglial cells in the brain parenchyma. It is not yet known how the virus enters the CNS to cause disease. The blood-choroid plexus barrier is a potential site of virus invasion as the cells that make up this barrier are known to be infected with virus both in vivo and in vitro. To understand the effects of virus infection on these cells we challenged primary human choroid plexus epithelial cells with JCPyV and profiled changes in host gene expression. We found that viral infection induced the expression of proinflammatory chemokines and downregulated junctional proteins essential for maintaining blood-CSF and blood-brain barrier function. These data contribute to our understanding of how JCPyV infection of the choroid plexus can modulate the host cell response to neuroinvasive pathogens. IMPORTANCE: The human polyomavirus, JCPyV, causes a rapidly progressing demyelinating disease in the CNS of patients whose immune systems are compromised. JCPyV infection has been demonstrated in the choroid plexus both in vivo and in vitro and this highly vascularized organ may be important in viral invasion of brain parenchyma. Our data show that infection of primary choroid plexus epithelial cells results in increased expression of pro-inflammatory chemokines and downregulation of critical junctional proteins that maintain the blood-CSF barrier. These data have direct implications for mechanisms used by JCPyV to invade the CNS and cause neurological disease.

5.
Neuroimaging Clin N Am ; 34(3): 439-452, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38942526

RESUMEN

Magnetic resonance imaging is the most sensitive method for detecting inflammatory activity in multiple sclerosis, particularly in the brain where it reveals subclinical inflammation. Established MRI markers include contrast-enhancing lesions and active T2 lesions. Recent promising markers like slowly expanding lesions and phase rim lesions are being explored for monitoring chronic inflammation, but require further validation for clinical use. Volumetric and quantitative MRI techniques are currently limited to clinical trials and are not yet recommended for routine clinical use. Additionally, MRI is crucial for detecting complications from disease-modifying treatments and for implementing MRI-based pharmacovigilance strategies, such as in patients treated with natalizumab.


Asunto(s)
Imagen por Resonancia Magnética , Esclerosis Múltiple , Humanos , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/tratamiento farmacológico , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Resultado del Tratamiento , Neuroimagen/métodos
6.
Cell Signal ; 121: 111278, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38944257

RESUMEN

Promyelocytic leukemia protein (PML), a tumor suppressor protein, plays a key role in cell cycle regulation, apoptosis, senescence and cellular metabolism. Here, we report that PML promotes apoptosis and ferroptosis. Our data showed that PML over-expression inhibited cell proliferation and migration. PML over-expression increased apoptotic cells, nuclear condensation and the loss of mitochondrial membrane potential, accompanied by regulation of Bcl-2 family proteins and reactive oxygen species (ROS) level, suggesting that PML enhanced apoptosis. Meanwhile, PML over-expression not only increased lipid ROS accumulation and Malondialdehyde (MDA) content but also downregulated solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) expression, indicating that PML enhanced ferroptosis. Additionally, knockdown of p53 attenuated the effect of PML on SLC7A11 and GPX4, and inhibited the increase of lipid ROS and ROS by PML over-expression. Moreover, translocation of PML from nucleus to cytoplasm not only promoted apoptosis and ferroptosis, but also inhibited cell proliferation. Taken together, PML promotes apoptosis and ferroptosis, in which the mediation of p53 and the nuclear export of PML play important roles.

7.
Diseases ; 12(5)2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38785755

RESUMEN

Progressive Multifocal Leukoencephalopathy (PML) is a possibly fatal demyelinating disease and John Cunningham Polyomavirus (JCPyV) is believed to cause this condition. The so-called JCPyV was initially reported in lymphoma and Human Immunodeficiency Virus (HIV) cases, whereas nowadays, its incidence is increasing in Multiple Sclerosis (MS) cases treated with natalizumab (Tysabri). However, there are conflicting literature data on its pathology and diagnosis, whereas some misdiagnosed reports exist, giving rise to further questions towards the topic. In reality, the so-called PML and the supposed JCPyV are not what they seem to be. In addition, novel and more frequent PML-like conditions may be reported, especially after the Coronavirus Disease 2019 (COVID-19) pandemic.

8.
Am J Transplant ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38734417

RESUMEN

The strategy for progressive multifocal leukoencephalopathy (PML) in solid organ transplant recipients primarily focuses on reducing immunosuppressive therapy. However, this approach offers limited efficacy and carries a high risk of graft loss. Here, we present the case of a 64-year-old male kidney transplant recipient with a high degree of immunosuppression who developed PML in October 2022. Despite the standard reduction of immunosuppressive therapy, the patient's condition continued to deteriorate, as evidenced by worsening neurological symptoms and increasing JC virus (JCV) DNA levels in cerebrospinal fluid. This prompted the innovative use of BKPyV-virus-specific T cell (BKPyV-VST) therapy, given the genetic similarities between BK and JCVs. Infusion of third-party donor BKPyV-VST resulted in clinical stabilization, a significant reduction in JCV-DNA levels, and the emergence of a JCV-specific T cell response, as observed in enzyme-linked immunospot assays and TCRß sequencing. This represents the first case report of successful third-party BKPyV-VST therapy in a kidney recipient presenting PML, without graft-versus-host disease or graft dysfunction.

9.
Mult Scler Relat Disord ; 87: 105664, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38735204

RESUMEN

BACKGROUND: Natalizumab is an effective treatment for relapsing multiple sclerosis (MS). During therapy, individuals are at increased risk of developing progressive multifocal leukoencephalopathy (PML). So far, the relevant reservoir for PML-type JC polyomavirus (JCV) remains elusive. We here tested if the detection of JCV-DNA in stool of persons with MS treated with natalizumab could be a future tool for PML risk assessment. METHODS: The presence of JCV-DNA in stool, urine, and whole blood of MS patients treated with natalizumab and known serum anti-JCV antibodies index values (IV) was studied. Different DNA extraction methods, real-time (RT) and droplet digital (dd) PCR techniques were compared. JCV isolates were screened for PML-associated variants by sequencing. RESULTS: Thirty MS patients treated with natalizumab were screened. For 21 patients, blood, stool, and urine samples were available. These patients were stratified according to their serum anti-JCV antibody IV (high (>1.5, n = 12); medium (1.5-0.9, n = 2); low (<0.9, n = 1); negative (n = 6)). JCV-DNA could not be detected in the whole blood or stool samples. Four urine samples had measurable JCV-DNA, ranging from 1.71×104-1.07×108 international units (IU)/mL detected by RT-PCR, corresponding to 4.62×104-9.85×106 copies/mL measured by ddPCR. All JCV variants were wild-type and derived from patients with high antibody IV. CONCLUSION: Stool-specific DNA extraction methods provided the highest quality of DNA, while the sensitivity of ddPCR and RT- PCR was comparable. Our findings do not support assessing stool samples for PML risk stratification in persons with MS. Further studies are needed to explore where PML-associated viral variants arise.


Asunto(s)
Anticuerpos Antivirales , ADN Viral , Heces , Factores Inmunológicos , Virus JC , Natalizumab , Humanos , Virus JC/aislamiento & purificación , Virus JC/inmunología , Natalizumab/uso terapéutico , Heces/virología , Adulto , Masculino , Femenino , Anticuerpos Antivirales/sangre , ADN Viral/sangre , ADN Viral/análisis , Persona de Mediana Edad , Leucoencefalopatía Multifocal Progresiva/sangre , Leucoencefalopatía Multifocal Progresiva/virología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/sangre , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/virología , Esclerosis Múltiple/sangre
10.
J Neurol Sci ; 461: 123046, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38761670

RESUMEN

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is a potentially life-threatening complication among Multiple Sclerosis (MS) patients under natalizumab treatment, with serum anti-JCV antibody titers being used for stratification risk. Given the critical role of interferon (IFN)/B-cell activating factor (BAFF) axis in humoral immune responses against viruses, we explored whether it is involved in the generation of serum anti-JCV antibodies among these patients. METHODS: 162 consecutive patients with relapsing-remitting MS under natalizumab treatment were included. Serum anti-JCV antibodies were measured at baseline, as well as 12 and 24 months after treatment initiation. Type I and II IFN-inducible genes and BAFF expression were quantitated in peripheral blood by qRT-PCR. Moreover, BAFF rs9514828, rs1041569, and rs9514827 gene variants were assessed by RFLP-PCR. RESULTS: While type I and II IFN inducible gene expression were not associated with anti-JCV serum titers, the latter were significantly correlated with BAFF gene expression. Of interest, the TTT haplotype of the studied BAFF variants was more frequently detected in male, but not female anti-JCV (+) MS patients compared to anti-JCV (-) counterparts at baseline, as well as at 12 months and 24 months of natalizumab treatment. Measures of clinical validity/utility for the BAFF TTT haplotype showed 88% specificity, 45%, positive predictive value, and sensitivity of 70% for the discrimination of anti-JCV (+) male MS patients after 24 months of treatment. CONCLUSIONS: Our study suggests an implication of the BAFF axis in the production of serum anti-JCV antibodies. Additionally, the BAFF TTT haplotype derived from the rs9514828, rs1041569, and rs9514827 variants may represent a novel risk factor for anti-JCV seropositivity and indirectly for PML development among male MS patients treated with natalizumab.


Asunto(s)
Factor Activador de Células B , Factores Inmunológicos , Virus JC , Leucoencefalopatía Multifocal Progresiva , Natalizumab , Humanos , Natalizumab/uso terapéutico , Factor Activador de Células B/sangre , Factor Activador de Células B/genética , Masculino , Leucoencefalopatía Multifocal Progresiva/sangre , Leucoencefalopatía Multifocal Progresiva/genética , Adulto , Femenino , Factores Inmunológicos/uso terapéutico , Virus JC/inmunología , Virus JC/genética , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/sangre , Esclerosis Múltiple Recurrente-Remitente/genética , Esclerosis Múltiple Recurrente-Remitente/inmunología , Persona de Mediana Edad , Anticuerpos Antivirales/sangre , Polimorfismo de Nucleótido Simple
11.
EMBO Mol Med ; 16(6): 1324-1351, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38730056

RESUMEN

Clear-cell renal cell carcinoma (ccRCC), the major subtype of RCC, is frequently diagnosed at late/metastatic stage with 13% 5-year disease-free survival. Functional inactivation of the wild-type p53 protein is implicated in ccRCC therapy resistance, but the detailed mechanisms of p53 malfunction are still poorly characterized. Thus, a better understanding of the mechanisms of disease progression and therapy resistance is required. Here, we report a novel ccRCC dependence on the promyelocytic leukemia (PML) protein. We show that PML is overexpressed in ccRCC and that PML depletion inhibits cell proliferation and relieves pathologic features of anaplastic disease in vivo. Mechanistically, PML loss unleashed p53-dependent cellular senescence thus depicting a novel regulatory axis to limit p53 activity and senescence in ccRCC. Treatment with the FDA-approved PML inhibitor arsenic trioxide induced PML degradation and p53 accumulation and inhibited ccRCC expansion in vitro and in vivo. Therefore, by defining non-oncogene addiction to the PML gene, our work uncovers a novel ccRCC vulnerability and lays the foundation for repurposing an available pharmacological intervention to restore p53 function and chemosensitivity.


Asunto(s)
Carcinoma de Células Renales , Senescencia Celular , Neoplasias Renales , Proteína de la Leucemia Promielocítica , Proteína p53 Supresora de Tumor , Proteína de la Leucemia Promielocítica/metabolismo , Proteína de la Leucemia Promielocítica/genética , Carcinoma de Células Renales/metabolismo , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/tratamiento farmacológico , Humanos , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , Senescencia Celular/efectos de los fármacos , Animales , Neoplasias Renales/metabolismo , Neoplasias Renales/patología , Neoplasias Renales/genética , Neoplasias Renales/tratamiento farmacológico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Trióxido de Arsénico/farmacología , Ratones
12.
BMC Neurol ; 24(1): 151, 2024 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-38704555

RESUMEN

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a rare and fatal opportunistic viral demyelinating infectious disease of the central nervous system (CNS). There are various clinical presenting symptoms for the disease. CASE PRESENTATION: This paper presents a clinical case of PML in a patient with B-Chronic lymphocytic leukemia (B-CLL), previously treated with Chlorambucil, later complicated later with COVID-19 and mucormycosis. CONCLUSION: PML can develop in the setting of cellular immune dysfunction. Late diagnosis of this disease based on nonspecific symptoms is common, therefore when we face a neurological complication in a CLL or immunocompromised patient, we should consider PML infection. A remarkable feature of this case is the possible triggering effect of COVID-19 vaccination for emergence of PML as the disease can be asymptomatic or sub-clinical before diagnosis.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Leucemia Linfocítica Crónica de Células B , Leucoencefalopatía Multifocal Progresiva , Mucormicosis , Anciano , Humanos , Masculino , COVID-19/complicaciones , Vacunas contra la COVID-19/efectos adversos , Huésped Inmunocomprometido , Leucemia Linfocítica Crónica de Células B/complicaciones , Leucoencefalopatía Multifocal Progresiva/etiología , Leucoencefalopatía Multifocal Progresiva/diagnóstico , Mucormicosis/complicaciones
13.
J Neurovirol ; 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38778006

RESUMEN

Progressive multifocal leukoencephalopathy (PML) is an opportunistic infectious demyelinating disease of the central nervous system caused by JC polyomavirus predominantly affecting immunocompromised individuals. Nowadays, HIV, hematological malignancies and iatrogenic immune suppression account for most PML cases. For unknown reasons, spinal cord is classically protected from PML lesions. Here, we report the course of a patient harboring spinal cord lesions in the context of PML with immune reconstitution inflammatory syndrome and review the eight other cases reported in the literature so far. Then, we discuss the evolving spectrum of PML over recent years, potentially making its diagnosis more challenging.

14.
Mult Scler Relat Disord ; 86: 105605, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38640586

RESUMEN

BACKGROUND: Use of natalizumab (NTZ) is precluded in many Multiple Sclerosis (MS) patients by the risk of progressive multifocal leukoencephalopathy (PML). Regardless, some patients may commence natalizumab for short term disease control in spite of being seropositive, and others may seroconvert whilst on treatment. In these circumstances, discontinuation of NTZ should not occur until a clear exit strategy is established to prevent post-NTZ disease reactivation, which often exceeds the severity of disease activity prior to NTZ treatment. The objective of this systematic review was to summarise the available evidence for CD20-monoclonal antibodies (CD20mAb) as a suitable NTZ exit strategy, and to identify whether a superior switch protocol can be established. METHODS: In accordance with PRISMA guidelines, a total of 2393 references were extracted from a search of three online databases (PubMed, Scopus, MEDLINE). Following the application of inclusion/exclusion criteria, a total of 5 studies representing 331 patients were included. RESULTS: The overall incidence of clinical relapse during washout periods ranging from 4.4-10.7 weeks was 0 %. The incidence of clinical relapse during two-year follow-up ranged from 1.8 % to 10 % for switches to all types of CD20 monoclonal antibody. The weighted mean for clinical relapse at 12 months was 8.8 %. Three studies reported an annualised relapse rate (ARR) ranging from 0.02-0.12 with a weighted mean ARR of 0.07. The overall incidence of PML during washout was 0 % and the overall incidence of PML within 6 months follow-up was 0.6 %. CONCLUSIONS: This systematic review provides the first attempt at identifying a superior switch protocol in patients at risk of PML transitioning from NTZ to a CD20mAb. Our results indicate that CD20mAb's are a suitable transitional option for patients who discontinue NTZ, with our cohort demonstrating very low rates of carryover PML and low rates of clinical relapse. The most appropriate washout period is unclear due to confounding factors but is likely between 4 and 12 weeks.


Asunto(s)
Factores Inmunológicos , Esclerosis Múltiple Recurrente-Remitente , Natalizumab , Humanos , Antígenos CD20/inmunología , Sustitución de Medicamentos , Factores Inmunológicos/efectos adversos , Factores Inmunológicos/farmacología , Factores Inmunológicos/administración & dosificación , Leucoencefalopatía Multifocal Progresiva/inducido químicamente , Leucoencefalopatía Multifocal Progresiva/inmunología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/inmunología , Natalizumab/efectos adversos , Natalizumab/uso terapéutico
15.
Cell Signal ; 119: 111156, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38574938

RESUMEN

In the seemingly well-researched field of vascular research, there are still many underestimated factors and molecular mechanisms. In recent years, SUMOylation has become increasingly important. SUMOylation is a post-translational modification in which small ubiquitin-related modifiers (SUMO) are covalently attached to target proteins. Sites where these SUMO modification processes take place in the cell nucleus are PML nuclear bodies (PML-NBs) - multiprotein complexes with their essential main component and organizer, the PML protein. PML and SUMO, either alone or as partners, influence a variety of cellular processes, including regulation of transcription, senescence, DNA damage response and defence against microorganisms, and are involved in innate immunity and inflammatory responses. They also play an important role in maintaining homeostasis in the vascular system and in pathological processes leading to the development and progression of cardiovascular diseases. This review summarizes information about the function of SUMO(ylation) and PML(-NBs) in the human vasculature from angiogenesis to disease and highlights their clinical potential as drug targets.


Asunto(s)
Proteínas Nucleares , Proteína de la Leucemia Promielocítica , Sumoilación , Factores de Transcripción , Humanos , Proteína de la Leucemia Promielocítica/metabolismo , Proteínas Nucleares/metabolismo , Factores de Transcripción/metabolismo , Animales , Proteínas Supresoras de Tumor/metabolismo , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/metabolismo , Enfermedades Cardiovasculares/metabolismo , Enfermedades Cardiovasculares/patología
16.
Epigenetics ; 19(1): 2337142, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38583183

RESUMEN

Deregulation of ten-eleven Translocation protein 1 (TET1) is commonly reported to induce imbalances in gene expression and subsequently to colorectal cancer development (CRC). On the other hand, vitamin C (VitC) improves the prognosis of colorectal cancer by reprogramming the cancer epigenome and limiting chemotherapeutic drug resistance events. In this study, we aimed to characterize TET1-specific subcellular compartments and evaluate the effect of VitC on TET1 compartmentalization in colonic tumour cells. We demonstrated that TET1 is concentrated in coarse nuclear bodies (NB) and 5-hydroxymethylcytosine (5hmC) in foci in colorectal cancer cells (HCT116, Caco-2, and HT-29). To our knowledge, this is the first report of a novel intracellular localization profile of TET1 and its demethylation marker, 5hmC, in CRC cells. Interestingly, we found that TET1-NBs frequently interacted with Cajal bodies, but not with promyelocytic leukaemia (PML) bodies. In addition, we report that VitC treatment of HCT116 cells induces 5hmC foci biogenesis and triggers 5hmC marks to form active complexes with nuclear body components, including both Cajal and PML proteins. Our data highlight novel NB-concentrating TET1 in CRC cells and demonstrate that VitC modulates TET1-NBs' interactions with other nuclear structures. These findings reveal novel TET1-dependent cellular functions and potentially provide new insights for CRC management.


Asunto(s)
Ácido Ascórbico , Neoplasias Colorrectales , Humanos , Células CACO-2 , Ácido Ascórbico/farmacología , Cuerpos Nucleares de la Leucemia Promielocítica , Metilación de ADN , Cuerpos Nucleares , Vitaminas , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Oxigenasas de Función Mixta/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo
17.
Cancers (Basel) ; 16(7)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38611029

RESUMEN

The story of acute promyelocytic leukemia (APL) discovery, physiopathology, and treatment is a unique journey, transforming the most aggressive form of leukemia to the most curable. It followed an empirical route fueled by clinical breakthroughs driving major advances in biochemistry and cell biology, including the discovery of PML nuclear bodies (PML NBs) and their central role in APL physiopathology. Beyond APL, PML NBs have emerged as key players in a wide variety of biological functions, including tumor-suppression and SUMO-initiated protein degradation, underscoring their broad importance. The APL story is an example of how clinical observations led to the incremental development of the first targeted leukemia therapy. The understanding of APL pathogenesis and the basis for cure now opens new insights in the treatment of other diseases, especially other acute myeloid leukemias.

18.
Molecules ; 29(8)2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38675671

RESUMEN

Atmospheric water harvesting (AWH) is considered a promising strategy for sustainable freshwater production in landlocked and arid regions. Hygroscopic salt-based composite sorbents have attracted widespread attention for their water harvesting performance, but suffer from aggregation and leakage issues due to the salting-out effect. In this study, we synthesized a PML hydrogel composite by incorporating zwitterionic hydrogel (PDMAPS) and MIL-101(Cr) as a host for LiCl. The PML hydrogel was characterized using various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The swelling properties and water vapor adsorption-desorption properties of the PML hydrogel were also assessed. The results demonstrate that the MIL-101(Cr) was uniformly embedded into PDMAP hydrogel, and the PML hydrogel exhibits a swelling ratio of 2.29 due to the salting-in behavior. The PML hydrogel exhibited exceptional water vapor sorption capacity of 0.614 g/g at 298 K, RH = 40% and 1.827 g/g at 298 K, RH = 90%. It reached 80% of its saturated adsorption capacity within 117 and 149 min at 298 K, RH = 30% and 90%, respectively. Additionally, the PML hydrogel showed excellent reversibility in terms of water vapor adsorption after ten consecutive cycles of adsorption-desorption. The remarkable adsorption capacity, favorable adsorption-desorption rate, and regeneration stability make the PML hydrogel a potential candidate for AWH. This polymer-MOF synergistic strategy for immobilization of LiCl in this work offers new insights into designing advanced materials for AWH.

19.
Microbiol Spectr ; 12(5): e0378823, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38567974

RESUMEN

The key to a curative treatment of hepatitis B virus (HBV) infection is the eradication of the intranuclear episomal covalently closed circular DNA (cccDNA), the stable persistence reservoir of HBV. Currently, established therapies can only limit HBV replication but fail to tackle the cccDNA. Thus, novel therapeutic approaches toward curative treatment are urgently needed. Recent publications indicated a strong association between the HBV core protein SUMOylation and the association with promyelocytic leukemia nuclear bodies (PML-NBs) on relaxed circular DNA to cccDNA conversion. We propose that interference with the cellular SUMOylation system and PML-NB integrity using arsenic trioxide provides a useful tool in the treatment of HBV infection. Our study showed a significant reduction in HBV-infected cells, core protein levels, HBV mRNA, and total DNA. Additionally, a reduction, albeit to a limited extent, of HBV cccDNA could be observed. Furthermore, this interference was also applied for the treatment of an established HBV infection, characterized by a stably present nuclear pool of cccDNA. Arsenic trioxide (ATO) treatment not only changed the amount of expressed HBV core protein but also induced a distinct relocalization to an extranuclear phenotype during infection. Moreover, ATO treatment resulted in the redistribution of transfected HBV core protein away from PML-NBs, a phenotype similar to that previously observed with SUMOylation-deficient HBV core. Taken together, these findings revealed the inhibition of HBV replication by ATO treatment during several steps of the viral replication cycle, including viral entry into the nucleus as well as cccDNA formation and maintenance. We propose ATO as a novel prospective treatment option for further pre-clinical and clinical studies against HBV infection. IMPORTANCE: The main challenge for the achievement of a functional cure for hepatitis B virus (HBV) is the covalently closed circular DNA (cccDNA), the highly stable persistence reservoir of HBV, which is maintained by further rounds of infection with newly generated progeny viruses or by intracellular recycling of mature nucleocapsids. Eradication of the cccDNA is considered to be the holy grail for HBV curative treatment; however, current therapeutic approaches fail to directly tackle this HBV persistence reservoir. The molecular effect of arsenic trioxide (ATO) on HBV infection, protein expression, and cccDNA formation and maintenance, however, has not been characterized and understood until now. In this study, we reveal ATO treatment as a novel and innovative therapeutic approach against HBV infections, repressing viral gene expression and replication as well as the stable cccDNA pool at low micromolar concentrations by affecting the cellular function of promyelocytic leukemia nuclear bodies.


Asunto(s)
Trióxido de Arsénico , Núcleo Celular , ADN Circular , ADN Viral , Virus de la Hepatitis B , Hepatitis B , Sumoilación , Replicación Viral , Trióxido de Arsénico/farmacología , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/fisiología , Humanos , Replicación Viral/efectos de los fármacos , Hepatitis B/virología , Hepatitis B/tratamiento farmacológico , Hepatitis B/metabolismo , Sumoilación/efectos de los fármacos , ADN Circular/genética , ADN Circular/metabolismo , Núcleo Celular/metabolismo , ADN Viral/genética , ADN Viral/metabolismo , Antivirales/farmacología , Proteínas del Núcleo Viral/metabolismo , Proteínas del Núcleo Viral/genética , Células Hep G2
20.
Proc Natl Acad Sci U S A ; 121(18): e2317690121, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38648485

RESUMEN

The underlying mechanism(s) by which the PML::RARA fusion protein initiates acute promyelocytic leukemia is not yet clear. We defined the genomic binding sites of PML::RARA in primary mouse and human hematopoietic progenitor cells with V5-tagged PML::RARA, using anti-V5-PML::RARA chromatin immunoprecipitation sequencing and CUT&RUN approaches. Most genomic PML::RARA binding sites were found in regions that were already chromatin-accessible (defined by ATAC-seq) in unmanipulated, wild-type promyelocytes, suggesting that these regions are "open" prior to PML::RARA expression. We found that GATA binding motifs, and the direct binding of the chromatin "pioneering factor" GATA2, were significantly enriched near PML::RARA binding sites. Proximity labeling studies revealed that PML::RARA interacts with ~250 proteins in primary mouse hematopoietic cells; GATA2 and 33 others require PML::RARA binding to DNA for the interaction to occur, suggesting that binding to their cognate DNA target motifs may stabilize their interactions. In the absence of PML::RARA, Gata2 overexpression induces many of the same epigenetic and transcriptional changes as PML::RARA. These findings suggested that PML::RARA may indirectly initiate its transcriptional program by activating Gata2 expression: Indeed, we demonstrated that inactivation of Gata2 prior to PML::RARA expression prevented its ability to induce self-renewal. These data suggested that GATA2 binding creates accessible chromatin regions enriched for both GATA and Retinoic Acid Receptor Element motifs, where GATA2 and PML::RARA can potentially bind and interact with each other. In turn, PML::RARA binding to DNA promotes a feed-forward transcriptional program by positively regulating Gata2 expression. Gata2 may therefore be required for PML::RARA to establish its transcriptional program.


Asunto(s)
Factor de Transcripción GATA2 , Células Madre Hematopoyéticas , Proteínas de Fusión Oncogénica , Animales , Humanos , Ratones , Sitios de Unión , Autorrenovación de las Células , Cromatina/metabolismo , ADN/metabolismo , Factor de Transcripción GATA2/metabolismo , Factor de Transcripción GATA2/genética , Células Madre Hematopoyéticas/metabolismo , Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patología , Proteínas de Fusión Oncogénica/metabolismo , Proteínas de Fusión Oncogénica/genética , Proteína de la Leucemia Promielocítica/metabolismo , Proteína de la Leucemia Promielocítica/genética , Unión Proteica , Receptor alfa de Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...