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1.
JAMA Health Forum ; 5(1): e234731, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38241057

RESUMO

Importance: Despite their widespread adoption across the US, policies imposing one-size-fits-all limits on the duration of prescriptions for opioids have shown modest and mixed implications for prescribing. Objective: To assess whether a prescription duration limit policy tailored to different clinical settings was associated with shorter opioid prescription lengths. Design, Setting, and Participants: This cross-sectional study examined changes in opioid prescribing patterns for opioid-naive Medicaid enrollees aged 12 to 64 years before and after implementation of a statewide prescription duration limit policy in West Virginia in June 2018. Patients with cancer or Medicare coverage were excluded. The policy assigned a 7-day duration limit to opioid prescriptions for adults treated in outpatient hospital- or office-based practices, a 4-day limit for adults treated in emergency departments, and a 3-day limit for pediatric patients younger than 18 years regardless of clinical setting. Data were examined from January 1, 2017, through September 30, 2019, and data were analyzed from June 12 to October 30, 2023. Main Outcomes and Measures: Whether a patient's initial opioid prescription was longer in days than the June 2018 policy limit for a given care setting before and after policy implementation. Interrupted time series models were used to calculate the association between the policy's implementation and outcomes. Results: The analytic sample included 44 703 Medicaid enrollees (27 957 patients [62.5%] before policy implementation and 16 746 patients [37.5%] after policy implementation; mean [SD] age, 33.9 [13.4] years; 27 461 females [61.4%]). Among adults treated in outpatient hospital- or office-based settings, the duration limit policy was associated with a decrease of 8.83 (95% CI, -10.43 to -7.23) percentage points (P < .001), or a 56.8% relative reduction, in the proportion of prescriptions exceeding the 7-day limit. In the emergency department setting, the policy was associated with a decrease of 7.03 (95% CI, -10.38 to -3.68) percentage points (P < .001), a 37.5% relative reduction, in the proportion of prescriptions exceeding the 4-day limit. The proportion of pediatric opioid prescriptions longer than the 3-day limit decreased by 12.80 (95% CI, -17.31 to -8.37) percentage points (P < .001), a 26.5% relative reduction, after the policy's implementation. Conclusions and Relevance: Results of this cross-sectional study suggest that opioid prescription duration limits tailored to different clinical settings are associated with reduced length of prescriptions for opioid-naive patients. Additional research is needed to evaluate whether these limits are associated with reductions in the incidence of opioid use disorder or with unintended consequences, such as shifts to illicit opioids.


Assuntos
Analgésicos Opioides , Medicare , Adulto , Feminino , Humanos , Idoso , Estados Unidos/epidemiologia , Criança , Analgésicos Opioides/uso terapêutico , Estudos Transversais , Padrões de Prática Médica , Prescrições
2.
Cancer Res Commun ; 3(8): 1486-1500, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37559947

RESUMO

While the role of prostaglandin E2 (PGE2) in promoting malignant progression is well established, how to optimally block the activity of PGE2 signaling remains to be demonstrated. Clinical trials with prostaglandin pathway targeted agents have shown activity but without sufficient significance or dose-limiting toxicities that have prevented approval. PGE2 signals through four receptors (EP1-4) to modulate tumor progression. EP2 and EP4 signaling exacerbates tumor pathology and is immunosuppressive through potentiating cAMP production. EP1 and EP3 signaling has the opposite effect through increasing IP3 and decreasing cAMP. Using available small-molecule antagonists of single EP receptors, the cyclooxygenase-2 (COX-2) inhibitor celecoxib, or a novel dual EP2/EP4 antagonist generated in this investigation, we tested which approach to block PGE2 signaling optimally restored immunologic activity in mouse and human immune cells and antitumor activity in syngeneic, spontaneous, and xenograft tumor models. We found that dual antagonism of EP2 and EP4 together significantly enhanced the activation of PGE2-suppressed mouse and human monocytes and CD8+ T cells in vitro as compared with single EP antagonists. CD8+ T-cell activation was dampened by single EP1 and EP3 antagonists. Dual EP2/EP4 PGE2 receptor antagonists increased tumor microenvironment lymphocyte infiltration and significantly reduced disease burden in multiple tumor models, including in the adenomatous polyposis coli (APC)min+/- spontaneous colorectal tumor model, compared with celecoxib. These results support a hypothesis that redundancy of EP2 and EP4 receptor signaling necessitates a therapeutic strategy of dual blockade of EP2 and EP4. Here we describe TPST-1495, a first-in-class orally available small-molecule dual EP2/EP4 antagonist. Significance: Prostaglandin (PGE2) drives tumor progression but the pathway has not been effectively drugged. We demonstrate significantly enhanced immunologic potency and antitumor activity through blockade of EP2 and EP4 PGE2 receptor signaling together with a single molecule.


Assuntos
Neoplasias , Prostaglandinas , Humanos , Animais , Camundongos , Dinoprostona/metabolismo , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Celecoxib/farmacologia , Linfócitos T CD8-Positivos/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Inibidores de Ciclo-Oxigenase 2 , Microambiente Tumoral
3.
Genome Biol ; 24(1): 59, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36991492

RESUMO

BACKGROUND: Genome-wide association studies (GWAS) have identified > 200 loci associated with breast cancer risk. The majority of candidate causal variants are in non-coding regions and likely modulate cancer risk by regulating gene expression. However, pinpointing the exact target of the association, and identifying the phenotype it mediates, is a major challenge in the interpretation and translation of GWAS. RESULTS: Here, we show that pooled CRISPR screens are highly effective at identifying GWAS target genes and defining the cancer phenotypes they mediate. Following CRISPR mediated gene activation or suppression, we measure proliferation in 2D, 3D, and in immune-deficient mice, as well as the effect on DNA repair. We perform 60 CRISPR screens and identify 20 genes predicted with high confidence to be GWAS targets that promote cancer by driving proliferation or modulating the DNA damage response in breast cells. We validate the regulation of a subset of these genes by breast cancer risk variants. CONCLUSIONS: We demonstrate that phenotypic CRISPR screens can accurately pinpoint the gene target of a risk locus. In addition to defining gene targets of risk loci associated with increased breast cancer risk, we provide a platform for identifying gene targets and phenotypes mediated by risk variants.


Assuntos
Estudo de Associação Genômica Ampla , Neoplasias , Animais , Camundongos , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Predisposição Genética para Doença , Fenótipo , Polimorfismo de Nucleotídeo Único
4.
J Neurosci ; 43(10): 1797-1813, 2023 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-36746627

RESUMO

Despite the indispensable role that astrocytes play in the neurovascular unit, few studies have investigated the functional impact of astrocyte signaling in cognitive decline and dementia related to vascular pathology. Diet-mediated induction of hyperhomocysteinemia (HHcy) recapitulates numerous features of vascular contributions to cognitive impairment and dementia (VCID). Here, we used astrocyte targeting approaches to evaluate astrocyte Ca2+ dysregulation and the impact of aberrant astrocyte signaling on cerebrovascular dysfunction and synapse impairment in male and female HHcy diet mice. Two-photon imaging conducted in fully awake mice revealed activity-dependent Ca2+ dysregulation in barrel cortex astrocytes under HHcy. Stimulation of contralateral whiskers elicited larger Ca2+ transients in individual astrocytes of HHcy diet mice compared with control diet mice. However, evoked Ca2+ signaling across astrocyte networks was impaired in HHcy mice. HHcy also was associated with increased activation of the Ca2+/calcineurin-dependent transcription factor NFAT4, which has been linked previously to the reactive astrocyte phenotype and synapse dysfunction in amyloid and brain injury models. Targeting the NFAT inhibitor VIVIT to astrocytes, using adeno-associated virus vectors, led to reduced GFAP promoter activity in HHcy diet mice and improved functional hyperemia in arterioles and capillaries. VIVIT expression in astrocytes also preserved CA1 synaptic function and improved spontaneous alternation performance on the Y maze. Together, the results demonstrate that aberrant astrocyte signaling can impair the major functional properties of the neurovascular unit (i.e., cerebral vessel regulation and synaptic regulation) and may therefore represent a promising drug target for treating VCID and possibly Alzheimer's disease and other related dementias.SIGNIFICANCE STATEMENT The impact of reactive astrocytes in Alzheimer's disease and related dementias is poorly understood. Here, we evaluated Ca2+ responses and signaling in barrel cortex astrocytes of mice fed with a B-vitamin deficient diet that induces hyperhomocysteinemia (HHcy), cerebral vessel disease, and cognitive decline. Multiphoton imaging in awake mice with HHcy revealed augmented Ca2+ responses in individual astrocytes, but impaired signaling across astrocyte networks. Stimulation-evoked arteriole dilation and elevated red blood cell velocity in capillaries were also impaired in cortex of awake HHcy mice. Astrocyte-specific inhibition of the Ca2+-dependent transcription factor, NFAT, normalized cerebrovascular function in HHcy mice, improved synaptic properties in brain slices, and stabilized cognition. Results suggest that astrocytes are a mechanism and possible therapeutic target for vascular-related dementia.


Assuntos
Doença de Alzheimer , Hiper-Homocisteinemia , Camundongos , Masculino , Feminino , Animais , Doença de Alzheimer/metabolismo , Astrócitos/metabolismo , Hiper-Homocisteinemia/metabolismo , Hiper-Homocisteinemia/patologia , Dieta , Fatores de Transcrição/metabolismo
5.
Phys Rev Lett ; 129(17): 174501, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36332239

RESUMO

Acoustic meta-atoms serve as the building blocks of metamaterials, with linear properties designed to achieve functions such as beam steering, cloaking, and focusing. They have also been used to shape the characteristics of incident acoustic fields, which led to the manipulation of acoustic radiation force and torque for development of acoustic tweezers with improved spatial resolution. However, acoustic radiation force and torque also depend on the shape of the object, which strongly affects its scattering properties. We show that by designing linear properties of an object using metamaterial concepts, the nonlinear acoustic effects of radiation force and torque can be controlled. Trapped objects are typically small compared with the wavelength, and are described as particles, inducing monopole and dipole scattering. We extend such models to a polarizability tensor including Willis coupling terms, as a measure of asymmetry, capturing the significance of geometrical features. We apply our model to a three-dimensional, subwavelength meta-atom with maximal Willis coupling, demonstrating that the force and the torque can be reversed relative to an equivalent symmetrical particle. By considering shape asymmetry in the acoustic radiation force and torque, Gorkov's fundamental theory of acoustophoresis is thereby extended. Asymmetrical shapes influence the acoustic fields by shifting the stable trapping location, highlighting a potential for tunable, shape-dependent particle sorting.


Assuntos
Acústica , Torque
6.
Elife ; 112022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36342465

RESUMO

Pathological obesity and its complications are associated with an increased propensity for bone fractures. Humans with certain genetic polymorphisms at the kinase suppressor of ras2 (KSR2) locus develop severe early-onset obesity and type 2 diabetes. Both conditions are phenocopied in mice with Ksr2 deleted, but whether this affects bone health remains unknown. Here we studied the bones of global Ksr2 null mice and found that Ksr2 negatively regulates femoral, but not vertebral, bone mass in two genetic backgrounds, while the paralogous gene, Ksr1, was dispensable for bone homeostasis. Mechanistically, KSR2 regulates bone formation by influencing adipocyte differentiation at the expense of osteoblasts in the bone marrow. Compared with Ksr2's known role as a regulator of feeding by its function in the hypothalamus, pair-feeding and osteoblast-specific conditional deletion of Ksr2 reveals that Ksr2 can regulate bone formation autonomously. Despite the gains in appendicular bone mass observed in the absence of Ksr2, bone strength, as well as fracture healing response, remains compromised in these mice. This study highlights the interrelationship between adiposity and bone health and provides mechanistic insights into how Ksr2, an adiposity and diabetic gene, regulates bone metabolism.


Our bones are living tissues which constantly reshape and renew themselves. This ability relies on stem cells present in the marrow cavity, which can mature into the various types of cells needed to produce new bone material, marrow fat, or other components. Obesity and associated conditions such as type 2 diabetes are often linked to harmful changes in the skeleton. In particular, these metabolic conditions are associated with weight-bearing bones becoming more prone to facture and healing poorly. Mice genetically modified to model obesity and diabetes could help researchers to study exactly how these conditions ­ and the genetic changes that underlie them ­ impact bone health. Gomez et al. aimed to address this question by focusing on KSR2, a gene involved in energy consumption and feeding behavior. Children who carry certain KSR2 mutations are prone to obesity and type 2 diabetes; mice lacking the gene also develop these conditions due to uncontrolled eating. Closely examining mutant mice in which Ksr2 had been deactivated in every cell revealed that the weight-bearing bones of these animals were also more likely to break, and the fractures then healed more slowly. This was the case even though these bones had higher mass and less marrow fat compared to healthy mice. Non-weight bearing bones (such as the spine) did not exhibit these changes. Further experiments revealed that, when expressed normally in the skeleton, Ksr2 skews the stem cell maturation process towards marrow fat cells instead of bone-creating cells. This suggests a new role for Ksr2, which therefore seems to independently regulate both feeding behavior and bone health. In addition, the work by Gomez et al. demonstrate that Ksr2 mutant mice could be a useful model to better understand how obesity and diabetes affect human bones, and to potentially develop new therapies.


Assuntos
Adiposidade , Medula Óssea , Osso Esponjoso , Animais , Humanos , Camundongos , Adiposidade/genética , Medula Óssea/metabolismo , Osso Esponjoso/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Camundongos Knockout , Obesidade/metabolismo , Osteoblastos/metabolismo , Proteínas Serina-Treonina Quinases
7.
Diabetes Care ; 45(9): 2118-2126, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35817022

RESUMO

OBJECTIVE: Inhibiting sodium-glucose cotransporters (SGLTs) improves glycemic and cardiovascular outcomes in patients with type 2 diabetes (T2D). We investigated the differential impact of selective SGLT2 inhibition and dual inhibition of SGLT1 and SGLT2 on multiple parameters. RESEARCH DESIGN AND METHODS: Using a double-blind, parallel-group design, we randomized 40 patients with T2D and hypertension to receive the dual SGLT1 and SGLT2 inhibitor sotagliflozin 400 mg or the selective SGLT2 inhibitor empagliflozin 25 mg, with preexisting antihypertensive treatment, for 8 weeks. In an in-house testing site, mixed-meal tolerance tests (MMTTs) and other laboratory and clinical evaluations were used to study metabolic, intestinal, cardiovascular, and urinary parameters over 24 h. RESULTS: Changes from baseline in glycemic and blood pressure control; intestinal, urine, and metabolic parameters; and cardiovascular biomarkers were generally similar with sotagliflozin and empagliflozin. During the breakfast MMTT, sotagliflozin significantly reduced incremental area under the curve (AUC) values for postprandial glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) and significantly increased incremental AUCs for postprandial glucagon-like peptide 1 (GLP-1) relative to empagliflozin, consistent with sotagliflozin-mediated inhibition of intestinal SGLT1. These changes waned during lunch and dinner MMTTs. Both treatments significantly lowered GIP incremental AUCs relative to baseline over the 14 h MMTT interval; the most vigorous effect was seen with sotagliflozin soon after start of the first meal of the day. No serious or severe adverse events were observed. CONCLUSIONS: Changes from baseline in glycemic and blood pressure control, cardiovascular biomarkers, and other parameters were comparable between sotagliflozin and empagliflozin. However, sotagliflozin but not empagliflozin inhibited intestinal SGLT1 after breakfast as shown by larger changes in postprandial glucose, insulin, GIP, and GLP-1 AUCs, particularly after breakfast. Additional study is warranted to assess the clinical relevance of transient SGLT1 inhibition and differences in incretin responses (NCT03462069).


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Método Duplo-Cego , Polipeptídeo Inibidor Gástrico/metabolismo , Peptídeo 1 Semelhante ao Glucagon , Glicosídeos , Humanos , Hipoglicemiantes/efeitos adversos , Insulina/uso terapêutico , Transportador 2 de Glucose-Sódio/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos
8.
J Neurosci Methods ; 378: 109643, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35691412

RESUMO

BACKGROUND: Limitations have previously existed for the use of brain infusion catheters with extended delivery port designs to achieve larger distribution volumes using convection-enhanced delivery (CED), due to poor transmittance of materials and uncontrolled backflow. The goal of this study was to evaluate a novel brain catheter that has been designed to allow for extended delivery and larger distribution volumes with limited backflow of fluid. It was characterized using a broad range of therapeutic pore sizes both for transmittance across the membranes to address possible occlusion and for distribution in short term infusion studies, both in-vitro in gels and in-vivo in canines. METHODS: Brain catheters with pore sizes of 10, 12, 15, 20 and 30 µm were evaluated using three infusates prepared in 0.9% sterile saline with diameters approximating 2, 5, and 30 nm, respectively. Magnevist™ was chosen as the small molecule infusate to mimic low-molecular weight therapeutics. Galbumin™ served as a surrogate for an assortment of proteins used for brain cancer and Parkinson's disease. Gadoluminate™ was used to assess the distribution of large therapeutics, such as adeno-associated viral particles and synthetic nanoparticles. The transmittance of the medium and large tracer particles through catheters of different pore size (15, 20 and 30 µm) was measured by MRI and compared with the measured concentration of the control. Infusions into 0.2% agarose gels were performed in order to evaluate differences in transmittance and distribution of the small, medium, and large tracer particles through catheters with different pore sizes (10, 12, 15, 20 and 30 µm). In-vivo infusions were performed in the canine in order to evaluate the ability of the catheter to infuse the small, medium, and large tracer particles into brain parenchyma at high flow rates through catheters with different pore sizes (10, 15, and 20 µm). Two catheters were stereotactically inserted into the brain for infusion, one per hemisphere, in each animal (N = 6). RESULTS: The transmittance of Galbumin and Gadoluminate across the catheter membrane surface was 100% to within the accuracy of the measurements. There was no evidence of any blockage or retardation of any of the infusates. Catheter pore size did not appear to significantly affect transmittance or distribution in gels of any of the molecule sizes in the range of catheter pore sizes tested. There were differences in the distributions between the different tracer molecules: Magnevist produced relatively large distributions, followed by Gadoluminate and Galbumin. We observed no instances of uncontrolled backflow in a total of 12 in-vivo infusions. In addition, several of the infusions resulted in substantial amounts remaining in tissue. We expect the in-tissue distributions to be substantially improved in the larger human brain. COMPARISON WITH EXISTING METHODS: The new porous brain catheter performed well in terms of both backflow and intraparenchymal infusion of molecules of varying size in the canine brain under CED flow conditions. CONCLUSIONS: Overall, the data presented in this report support that the novel porous brain catheter can deliver therapeutics of varying sizes at high infusion rates in the brain parenchyma, and resist backflow that can compromise the efficacy of CED therapy. Additional work is needed to further characterize the brain catheter, including animal toxicity studies of chronically implanted brain catheters to lay the foundation for its use in the clinic.


Assuntos
Catéteres , Sistemas de Liberação de Medicamentos , Animais , Encéfalo/diagnóstico por imagem , Convecção , Cães , Sistemas de Liberação de Medicamentos/métodos , Géis , Humanos , Imageamento por Ressonância Magnética , Porosidade
9.
J Bacteriol ; 204(4): e0059221, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35323048

RESUMO

The Gram-negative pathogen Pasteurella multocida is the causative agent of many important animal diseases. While a number of P. multocida virulence factors have been identified, very little is known about how gene expression and protein production is regulated in this organism. One mechanism by which bacteria regulate transcript abundance and protein production is riboregulation, which involves the interaction of a small RNA (sRNA) with a target mRNA to alter transcript stability and/or translational efficiency. This interaction often requires stabilization by an RNA-binding protein such as ProQ or Hfq. In Escherichia coli and a small number of other species, ProQ has been shown to play a critical role in stabilizing sRNA-mRNA interactions and preferentially binds to the 3' stem-loop regions of the mRNA transcripts, characteristic of intrinsic transcriptional terminators. The aim of this study was to determine the role of ProQ in regulating P. multocida transcript abundance and identify the RNA targets to which it binds. We assessed differentially expressed transcripts in a proQ mutant and identified sites of direct ProQ-RNA interaction using in vivo UV-cross-linking and analysis of cDNA (CRAC). These analyses demonstrated that ProQ binds to, and stabilizes, ProQ-dependent sRNAs and transfer RNAs in P. multocida via adenosine-enriched, highly structured sequences. The binding of ProQ to two RNA molecules was characterized, and these analyses showed that ProQ bound within the coding sequence of the transcript PmVP161_1121, encoding an uncharacterized protein, and within the 3' region of the putative sRNA Prrc13. IMPORTANCE Regulation in P. multocida involving the RNA-binding protein Hfq is required for hyaluronic acid capsule production and virulence. This study further expands our understanding of riboregulation by examining the role of a second RNA-binding protein, ProQ, in transcript regulation and abundance in P. multocida.


Assuntos
Proteínas de Escherichia coli , Pasteurella multocida , Pequeno RNA não Traduzido , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Fator Proteico 1 do Hospedeiro/genética , Fator Proteico 1 do Hospedeiro/metabolismo , Pasteurella multocida/genética , Pasteurella multocida/metabolismo , RNA Bacteriano/metabolismo , RNA Mensageiro/genética , Pequeno RNA não Traduzido/genética , Proteínas de Ligação a RNA/metabolismo
10.
J Pediatr Surg ; 57(9): 124-129, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35086680

RESUMO

BACKGROUND: The COVID-19 pandemic forced the cancelation of conventional in-person academic conferences due to the risk of virus transmission and limited ability to travel. Both the American Pediatric Surgical Association (APSA) and International Pediatric Endosurgery Group (IPEG) converted to a virtual format for their 2020 annual meetings. The purpose of this article is to review the successful implementation of the APSA and IPEG virtual meetings and reflect upon lessons learned for future virtual conferences. METHODS: Logistics, structure, and attendance statistics were reviewed. Informal interviews were conducted with key stakeholders and the number of presenters and participants were analyzed. Finally, post-meeting attendee surveys were conducted to elicit feedback after both virtual meetings. RESULTS: The meetings were organized in different ways, with APSA spreading a mix of scientific and clinical educational content over several months and IPEG keeping the meeting compressed, similar to previous in-person versions. Both meetings were free and therefore attracted a high proportion of participants (720 for APSA and 834 for IPEG). The meetings were felt to be educationally appropriate by most, although timing and lack of Continuing Medical Education (CME) opportunities were detractors. Most attendees said they would be willing to pay fees similar to in-person amounts. IPEG compressed presentations into four 2-hour sessions spread over 4 weeks, but also made material available on-line through a proprietary application. There was a broad range of international attendees. IPEG attracted a larger percentage of non-members than did APSA (3:1 nonmember to member ratio). Both societies reported net losses, largely due to lost registration revenue and non-refundable costs from having to switch from an in-person meeting. CONCLUSIONS: The main advantage of the virtual meeting was increased participation while disadvantages included the lack of networking. The key lessons learned from the meetings include methods to increase interactivity, adjustments of technical logistics, and creation of enduring material. In the future, hybrid conferences will likely become more prevalent with advantages of both platforms. LEVEL-OF-EVIDENCE: Level V - Expert Opinion.


Assuntos
COVID-19 , Pandemias , Criança , Educação Médica Continuada , Humanos , Inquéritos e Questionários , Estados Unidos
11.
Nat Commun ; 12(1): 6495, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34764248

RESUMO

Multipotent mesenchymal stromal cells (MSCs) ameliorate a wide range of diseases in preclinical models, but the lack of clarity around their mechanisms of action has impeded their clinical utility. The therapeutic effects of MSCs are often attributed to bioactive molecules secreted by viable MSCs. However, we found that MSCs underwent apoptosis in the lung after intravenous administration, even in the absence of host cytotoxic or alloreactive cells. Deletion of the apoptotic effectors BAK and BAX prevented MSC death and attenuated their immunosuppressive effects in disease models used to define MSC potency. Mechanistically, apoptosis of MSCs and their efferocytosis induced changes in metabolic and inflammatory pathways in alveolar macrophages to effect immunosuppression and reduce disease severity. Our data reveal a mode of action whereby the host response to dying MSCs is key to their therapeutic effects; findings that have broad implications for the effective translation of cell-based therapies.


Assuntos
Apoptose/fisiologia , Morte Celular/fisiologia , Células-Tronco Mesenquimais/metabolismo , Animais , Apoptose/genética , Morte Celular/genética , Células Cultivadas , Feminino , Citometria de Fluxo , Humanos , Immunoblotting , Terapia de Imunossupressão , Macrófagos Alveolares/metabolismo , Transplante de Células-Tronco Mesenquimais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Análise de Componente Principal
12.
Elife ; 102021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34232857

RESUMO

Most eukaryotic mRNAs accommodate alternative sites of poly(A) addition in the 3' untranslated region in order to regulate mRNA function. Here, we present a systematic analysis of 3' end formation factors, which revealed 3'UTR lengthening in response to a loss of the core machinery, whereas a loss of the Sen1 helicase resulted in shorter 3'UTRs. We show that the anti-cancer drug cordycepin, 3' deoxyadenosine, caused nucleotide accumulation and the usage of distal poly(A) sites. Mycophenolic acid, a drug which reduces GTP levels and impairs RNA polymerase II (RNAP II) transcription elongation, promoted the usage of proximal sites and reversed the effects of cordycepin on alternative polyadenylation. Moreover, cordycepin-mediated usage of distal sites was associated with a permissive chromatin template and was suppressed in the presence of an rpb1 mutation, which slows RNAP II elongation rate. We propose that alternative polyadenylation is governed by temporal coordination of RNAP II transcription and 3' end processing and controlled by the availability of 3' end factors, nucleotide levels and chromatin landscape.


Assuntos
Poli A/química , Poliadenilação , Saccharomyces cerevisiae/metabolismo , Regiões 3' não Traduzidas , DNA Helicases , Cinética , RNA Helicases , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae
13.
Int J Mol Sci ; 22(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34070203

RESUMO

Alternative transcript cleavage and polyadenylation is linked to cancer cell transformation, proliferation and outcome. This has led researchers to develop methods to detect and bioinformatically analyse alternative polyadenylation as potential cancer biomarkers. If incorporated into standard prognostic measures such as gene expression and clinical parameters, these could advance cancer prognostic testing and possibly guide therapy. In this review, we focus on the existing methodologies, both experimental and computational, that have been applied to support the use of alternative polyadenylation as cancer biomarkers.


Assuntos
Regiões 3' não Traduzidas , Biomarcadores Tumorais/genética , Processamento Alternativo , Biomarcadores Tumorais/metabolismo , Biologia Computacional , Bases de Dados de Ácidos Nucleicos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Neoplasias/metabolismo , Poliadenilação , Sítios de Splice de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA-Seq , Análise de Célula Única
14.
Eur J Immunol ; 51(8): 2006-2026, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33960413

RESUMO

The NF-κB transcription factor c-Rel is a critical regulator of Treg ontogeny, controlling multiple points of the stepwise developmental pathway. Here, we found that the thymic Treg defect in c-Rel-deficient (cRel-/- ) mice is quantitative, not qualitative, based on analyses of TCR repertoire and TCR signaling strength. However, these parameters are altered in the thymic Treg-precursor population, which is also markedly diminished in cRel-/- mice. Moreover, c-Rel governs the transcriptional programme of both thymic and peripheral Tregs, controlling a core of genes involved with immune signaling, and separately in the periphery, cell cycle progression. Last, the immune suppressive function of peripheral cRel-/- tTregs is diminished in a lymphopenic model of T cell proliferation and is associated with decreased stability of Foxp3 expression. Collectively, we show that c-Rel is a transcriptional regulator that controls multiple aspects of Treg development, differentiation, and function via distinct mechanisms.


Assuntos
Proteínas Proto-Oncogênicas c-rel/imunologia , Proteínas Proto-Oncogênicas c-rel/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Diferenciação Celular/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Timo/imunologia , Timo/metabolismo
16.
J Clin Med ; 10(4)2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33669337

RESUMO

Kidney involvement in systemic lupus erythematosus (SLE)-termed lupus nephritis (LN)-is a severe manifestation of SLE that can lead to end-stage kidney disease (ESKD). LN is characterized by immune complex deposition and inflammation in the glomerulus. We tested the hypothesis that autoantibodies targeting podocyte and glomerular cell proteins contribute to the development of immune complex formation in LN. We used Western blotting with SLE sera from patients with and without LN to identify target antigens in human glomerular and cultured human-derived podocyte membrane proteins. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified the proteins in the gel regions corresponding to reactive bands observed with sera from LN patients. We identified 102 proteins that were present in both the podocyte and glomerular samples. We identified 10 high-probability candidates, including moesin, using bioinformatic analysis. Confirmation of moesin as a target antigen was conducted using immunohistochemical analysis (IHC) of kidney biopsy tissue and enzyme-linked immunosorbent assay (ELISA) to detect circulating antibodies. By IHC, biopsies from patients with proliferative lupus nephritis (PLN, class III/IV) demonstrated significantly increased glomerular expression of moesin (p < 0.01). By ELISA, patients with proliferative LN demonstrated significantly increased antibodies against moesin (p < 0.01). This suggests that moesin is a target glomerular antigen in lupus nephritis.

17.
Mar Drugs ; 19(2)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670308

RESUMO

To tackle the growing problem of antibiotic resistance, it is essential to identify new bioactive compounds that are effective against resistant microbes and safe to use. Natural products and their derivatives are, and will continue to be, an important source of these molecules. Sea sponges harbour a diverse microbiome that co-exists with the sponge, and these bacterial communities produce a rich array of bioactive metabolites for protection and resource competition. For these reasons, the sponge microbiota constitutes a potential source of clinically relevant natural products. To date, efforts in bioprospecting for these compounds have focused predominantly on sponge specimens isolated from shallow water, with much still to be learned about samples from the deep sea. Here we report the isolation of a new Micromonospora strain, designated 28ISP2-46T, recovered from the microbiome of a mid-Atlantic deep-sea sponge. Whole-genome sequencing reveals the capacity of this bacterium to produce a diverse array of natural products, including kosinostatin and isoquinocycline B, which exhibit both antibiotic and antitumour properties. Both compounds were isolated from 28ISP2-46T fermentation broths and were found to be effective against a plethora of multidrug-resistant clinical isolates. This study suggests that the marine production of isoquinocyclines may be more widespread than previously supposed and demonstrates the value of targeting the deep-sea sponge microbiome as a source of novel microbial life with exploitable biosynthetic potential.


Assuntos
Antibacterianos/isolamento & purificação , Microbiota , Micromonospora/isolamento & purificação , Poríferos/microbiologia , Animais , Antibacterianos/farmacologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Oceano Atlântico , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Sequenciamento Completo do Genoma
18.
Genome Biol ; 22(1): 47, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33499898

RESUMO

INTRODUCTION: Genes contain multiple promoters that can drive the expression of various transcript isoforms. Although transcript isoforms from the same gene could have diverse and non-overlapping functions, current loss-of-function methodologies are not able to differentiate between isoform-specific phenotypes. RESULTS: Here, we show that CRISPR interference (CRISPRi) can be adopted for targeting specific promoters within a gene, enabling isoform-specific loss-of-function genetic screens. We use this strategy to test functional dependencies of 820 transcript isoforms that are gained in gastric cancer (GC). We identify a subset of GC-gained transcript isoform dependencies, and of these, we validate CIT kinase as a novel GC dependency. We further show that some genes express isoforms with opposite functions. Specifically, we find that the tumour suppressor ZFHX3 expresses an isoform that has a paradoxical oncogenic role that correlates with poor patient outcome. CONCLUSIONS: Our work finds isoform-specific phenotypes that would not be identified using current loss-of-function approaches that are not designed to target specific transcript isoforms.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Isoformas de Proteínas/genética , Neoplasias Gástricas/genética , Linhagem Celular Tumoral , Proliferação de Células , Ciclina E , Genes Supressores de Tumor , Testes Genéticos , Proteínas de Homeodomínio , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Neoplasias , Proteínas Oncogênicas , Oncogenes , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases
19.
EJHaem ; 2(2): 157-166, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-35845273

RESUMO

Telomere biology disorders (TBDs), including dyskeratosis congenita (DC), are a group of rare inherited diseases characterized by very short telomeres. Mutations in the components of the enzyme telomerase can lead to insufficient telomere maintenance in hematopoietic stem cells, resulting in the bone marrow failure that is characteristic of these disorders. While an increasing number of genes are being linked to TBDs, the causative mutation remains unidentified in 30-40% of patients with DC. There is therefore a need for whole genome sequencing (WGS) in these families to identify novel genes, or mutations in regulatory regions of known disease-causing genes. Here we describe a family in which a partial deletion of the 3' untranslated region (3' UTR) of DKC1, encoding the protein dyskerin, was identified by WGS, despite being missed by whole exome sequencing. The deletion segregated with disease across the family and resulted in reduced levels of DKC1 mRNA in the proband. We demonstrate that the DKC1 3' UTR contains two polyadenylation signals, both of which were removed by this deletion, likely causing mRNA instability. Consistent with the major function of dyskerin in stabilization of the RNA subunit of telomerase, hTR, the level of hTR was also reduced in the proband, providing a molecular basis for his very short telomeres. This study demonstrates that the terminal region of the 3' UTR of the DKC1 gene is essential for gene function and illustrates the importance of analyzing regulatory regions of the genome for molecular diagnosis of inherited disease.

20.
Phys Rev E ; 104(6-2): 065003, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35030931

RESUMO

Acoustophoresis mainly deals with the manipulation of subwavelength scatterers in an incident acoustic field. The geometric details of manipulated particles are often neglected by replacing them with equivalent symmetric geometries such as spheres, spheroids, cylinders, or disks. It has been demonstrated that geometric asymmetry, represented by Willis coupling terms, can strongly affect the scattering of a small object; hence neglecting these terms may miss important force contributions. In this work, we present a generalized formalism of acoustic radiation force and radiation torque based on the polarizability tensor, where Willis coupling terms are included to account for geometric asymmetry. Following Gorkov's approach, the effects of geometric asymmetry are explicitly formulated as additional terms in the radiation force and torque expressions. By breaking the symmetry of a sphere along one axis using intrusion and protrusion, we characterize the changes in the force and torque in terms of partial components, associated with the direct and Willis coupling coefficients of the polarizability tensor. We investigate the cases of standing and traveling plane waves and show how the equilibrium positions and angles are shifted by these additional terms. We show that while the contributions of asymmetry to the force are often negligible for small particles, these terms greatly affect the radiation torque. Our presented theory, providing a way of calculating radiation force and torque directly from polarizability coefficients, shows that it is essential to account for shape of objects undergoing acoustophoretic manipulation, with important implications for applications such as the manipulation of biological cells.

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