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1.
J Intern Med ; 294(1): 58-68, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37038359

RESUMO

BACKGROUND: Although a few case reports have shown that immune checkpoint inhibitors (ICIs) are potential inducers of capillary leak syndrome (CLS), an incidental finding cannot be ruled out. The aim of this study was to describe the clinical characteristics of ICI-induced CLS through a systematic review and to assess a potential safety signal. METHODS: Medline/PubMed, Embase, and Reactions Weekly were screened, and a global disproportionality study was performed using the World Health Organization pharmacovigilance database through January 15, 2023. A signal of disproportionate reporting was defined as a Bayesian information component (IC) with a 95% credibility interval (CrI) lower boundary that exceeds 0. RESULTS: A total of 47 cases of ICI-associated CLS were included, 14 from the systematic review (of 61 screened articles) and 33 from VigiBase (of 34,058,481 reports of adverse drug reactions). The median time to CLS onset from the start of ICI was 12 weeks (interquartile range 8-49, n = 24). A total of 57% (8/14) of patients experienced an immune-related adverse event (irAE) before CLS. A fatal outcome was reported in 23% (7/31) of patients. A significant overreporting of CLS was found with ICIs compared with all other drugs (IC 2.4, 95% CrI from 1.8 to 2.8). CONCLUSION: This study showed a significant signal of disproportionality reporting for ICI-induced CLS, characterized by a long time to onset, and compared with the idiopathic form of the disease with a less abrupt onset and a less consistent hemoconcentration pattern.


Assuntos
Antineoplásicos Imunológicos , Síndrome de Vazamento Capilar , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Inibidores de Checkpoint Imunológico , Farmacovigilância , Teorema de Bayes , Antineoplásicos Imunológicos/efeitos adversos , Estudos Retrospectivos
2.
J Lipid Res ; 61(3): 376-386, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31919051

RESUMO

Angiopoietin-like protein 3 (ANGPTL3) inhibits lipid clearance and is a promising target for managing cardiovascular disease. Here we investigated the effects of a high-sugar (high-fructose) diet on circulating ANGPTL3 concentrations in rhesus macaques. Plasma ANGPTL3 concentrations increased ∼30% to 40% after 1 and 3 months of a high-fructose diet (both P < 0.001 vs. baseline). During fructose-induced metabolic dysregulation, plasma ANGPTL3 concentrations were positively correlated with circulating indices of insulin resistance [assessed with fasting insulin and the homeostatic model assessment of insulin resistance (HOMA-IR)], hypertriglyceridemia, adiposity (assessed as leptin), and systemic inflammation [C-reactive peptide (CRP)] and negatively correlated with plasma levels of the insulin-sensitizing hormone adropin. Multiple regression analyses identified a strong association between circulating APOC3 and ANGPTL3 concentrations. Higher baseline plasma levels of both ANGPTL3 and APOC3 were associated with an increased risk for fructose-induced insulin resistance. Fish oil previously shown to prevent insulin resistance and hypertriglyceridemia in this model prevented increases of ANGPTL3 without affecting systemic inflammation (increased plasma CRP and interleukin-6 concentrations). ANGPTL3 RNAi lowered plasma concentrations of ANGPTL3, triglycerides (TGs), VLDL-C, APOC3, and APOE. These decreases were consistent with a reduced risk of atherosclerosis. In summary, dietary sugar-induced increases of circulating ANGPTL3 concentrations after metabolic dysregulation correlated positively with leptin levels, HOMA-IR, and dyslipidemia. Targeting ANGPTL3 expression with RNAi inhibited dyslipidemia by lowering plasma TGs, VLDL-C, APOC3, and APOE levels in rhesus macaques.


Assuntos
Proteínas Semelhantes a Angiopoietina/antagonistas & inibidores , Dislipidemias/tratamento farmacológico , Óleos de Peixe/farmacologia , Frutose/antagonistas & inibidores , Interferência de RNA , Proteínas Semelhantes a Angiopoietina/sangue , Proteínas Semelhantes a Angiopoietina/metabolismo , Animais , Suplementos Nutricionais , Dislipidemias/sangue , Dislipidemias/induzido quimicamente , Óleos de Peixe/administração & dosagem , Inflamação/metabolismo , Lipoproteínas/metabolismo , Macaca mulatta , Masculino
3.
J Lipid Res ; 60(4): 805-818, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30723097

RESUMO

Dyslipidemia and insulin resistance are significant adverse outcomes of consuming high-sugar diets. Conversely, dietary fish oil (FO) reduces plasma lipids. Diet-induced dyslipidemia in a rhesus model better approximates the pathophysiology of human metabolic syndrome (MetS) than rodent models. Here, we investigated relationships between metabolic parameters and hypertriglyceridemia in rhesus macaques consuming a high-fructose diet (n = 59) and determined the effects of FO supplementation or RNA interference (RNAi) on plasma ApoC3 and triglyceride (TG) concentrations. Fructose supplementation increased body weight, fasting insulin, leptin, TGs, and large VLDL particles and reduced adiponectin concentrations (all P < 0.001). In multiple regression analyses, increased plasma ApoC3 was the most consistent and significant variable related to diet-induced hypertriglyceridemia. FO supplementation, which attenuated increases of plasma TG and ApoC3 concentrations, reversed fructose-induced shifts of lipoprotein particle size toward IDL and VLDL, a likely mechanism contributing to beneficial metabolic effects, and reduced hepatic expression of genes regulated by the SREBP pathway, particularly acetyl-CoA carboxylase. Furthermore, RNAi-mediated ApoC3 inhibition lowered plasma TG concentrations in animals with diet-induced hypertriglyceridemia. In summary, ApoC3 is an important independent correlate of TG-rich lipoprotein concentrations in rhesus macaques consuming a high-fructose diet. ApoC3 is a promising therapeutic target for hypertriglyceridemia in patients with MetS and diabetes.


Assuntos
Apolipoproteína C-III/metabolismo , Óleos de Peixe/farmacologia , Hipertrigliceridemia/tratamento farmacológico , Hipertrigliceridemia/metabolismo , Interferência de RNA , Animais , Suplementos Nutricionais , Óleos de Peixe/administração & dosagem , Frutose , Hipertrigliceridemia/induzido quimicamente , Macaca mulatta , Masculino
4.
J Nurs Scholarsh ; 49(5): 548-556, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28715603

RESUMO

PURPOSE: To examine the exemplary practice of nurse consultants (NCs) and derive a model to illustrate the highest level of advanced nursing practice. DESIGN: A descriptive study was conducted to examine the practice and outcomes of seven NC roles in varied clinical specialties in Hong Kong. Exemplary practice was examined in relation to competencies for advanced practice nursing in Hong Kong and the United Kingdom. METHODS: Data about NC characteristics and their practices were collected using a structured questionnaire and analyzed using descriptive statistics. Health service documents and clinical notes were analyzed using the framework approach. FINDINGS: All NCs demonstrated the competence expected of an advanced practice nurse with impacts on patients, nursing profession, and the organization as identified in the advanced nursing practice framework in Hong Kong. NCs also performed at the highest level of practice delineated by Skills for Health in the United Kingdom. They were involved in diagnostic and therapeutic practice, and identified patient satisfaction and symptom management as key outcomes. CONCLUSIONS: This study provides new insight into levels of advanced practice and illustrates the exemplary work of NCs to demonstrate how they have developed and shaped services to bring about positive patient and organizational outcomes. Career laddering that places NCs at the highest level of advanced practice is important for making the best use of nursing expertise to achieve optimal patient and organizational outcomes. CLINICAL RELEVANCE: This study addresses a knowledge gap to enrich our current understanding of the impact of advanced practice nursing roles by linking NC role practices and competencies to key outcomes.


Assuntos
Prática Avançada de Enfermagem/normas , Consultores , Padrões de Prática em Enfermagem/normas , Competência Clínica , Pesquisas sobre Atenção à Saúde , Hong Kong , Humanos , Modelos de Enfermagem , Papel do Profissional de Enfermagem , Pesquisa em Avaliação de Enfermagem , Satisfação do Paciente , Resultado do Tratamento , Reino Unido
5.
Clin Cancer Res ; 30(11): 2402-2411, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38652038

RESUMO

PURPOSE: ARO-HIF2 is an siRNA drug designed to selectively target hypoxia-inducible factor-2α (HIF2α) interrupting downstream pro-oncogenic signaling in clear cell renal cell carcinoma (ccRCC). The aims of this Phase 1 study (AROHIF21001) were to evaluate safety, tolerability, pharmacokinetics, and establish a recommended Phase 2 dose. PATIENTS AND METHODS: Subjects with ccRCC and progressive disease after at least 2 prior therapies that included VEGF and immune checkpoint inhibitors were progressively enrolled into dose-escalation cohorts of ARO-HIF2 administered intravenously at 225, 525, or 1,050 mg weekly. RESULTS: Twenty-six subjects received ARO-HIF2. The most common treatment emergent adverse events (AE) irrespective of causality were fatigue (50.0%), dizziness (26.9%), dyspnea (23.1%), and nausea (23.1%). Four subjects (15.4%) had treatment-related serious AEs. AEs of special interest included neuropathy, hypoxia, and dyspnea. ARO-HIF2 was almost completely cleared from plasma circulation within 48 hours with minimal renal clearance. Reductions in HIF2α were observed between pre- and post-dosing tumor biopsies, but the magnitude was quite variable. The objective response rate was 7.7% and the disease control rate was 38.5%. Responses were accompanied by ARO-HIF2 uptake in tumor cells, HIF2α downregulation, as well as rapid suppression of tumor produced erythropoietin (EPO) in a patient with paraneoplastic polycythemia. CONCLUSIONS: ARO-HIF2 downregulated HIF2α in advanced ccRCC-inhibiting tumor growth in a subset of subjects. Further development was hampered by off-target neurotoxicity and low response rate. This study provides proof of concept that siRNA can target tumors in a specific manner.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , Neoplasias Renais/patologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/administração & dosagem , Adulto , Interferência de RNA , Antineoplásicos/efeitos adversos , Antineoplásicos/administração & dosagem , Idoso de 80 Anos ou mais
6.
Clin Cancer Res ; 28(24): 5405-5418, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36190432

RESUMO

PURPOSE: HIF2α is a key driver of kidney cancer. Using a belzutifan analogue (PT2399), we previously showed in tumorgrafts (TG) that ∼50% of clear cell renal cell carcinomas (ccRCC) are HIF2α dependent. However, prolonged treatment induced resistance mutations, which we also identified in humans. Here, we evaluated a tumor-directed, systemically delivered, siRNA drug (siHIF2) active against wild-type and resistant-mutant HIF2α. EXPERIMENTAL DESIGN: Using our credentialed TG platform, we performed pharmacokinetic and pharmacodynamic analyses evaluating uptake, HIF2α silencing, target gene inactivation, and antitumor activity. Orthogonal RNA-sequencing studies of siHIF2 and PT2399 were pursued to define the HIF2 transcriptome. Analyses were extended to a TG line generated from a study biopsy of a siHIF2 phase I clinical trial (NCT04169711) participant and the corresponding patient, an extensively pretreated individual with rapidly progressive ccRCC and paraneoplastic polycythemia likely evidencing a HIF2 dependency. RESULTS: siHIF2 was taken up by ccRCC TGs, effectively depleted HIF2α, deactivated orthogonally defined effector pathways (including Myc and novel E2F pathways), downregulated cell cycle genes, and inhibited tumor growth. Effects on the study subject TG mimicked those in the patient, where HIF2α was silenced in tumor biopsies, circulating erythropoietin was downregulated, polycythemia was suppressed, and a partial response was induced. CONCLUSIONS: To our knowledge, this is the first example of functional inactivation of an oncoprotein and tumor suppression with a systemic, tumor-directed, RNA-silencing drug. These studies provide a proof-of-principle of HIF2α inhibition by RNA-targeting drugs in ccRCC and establish a paradigm for tumor-directed RNA-based therapeutics in cancer.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Policitemia , Animais , Humanos , Camundongos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , Neoplasias Renais/patologia , RNA Interferente Pequeno/genética , Ensaios Clínicos Fase I como Assunto
7.
Chem Commun (Camb) ; 55(51): 7319-7322, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31165814

RESUMO

Waste PLA can be upcycled to metal organic frameworks of potential high value in a one-pot synthesis scheme, where PLA depolymerisation occurs in situ. Three homochiral lactate based frameworks were successfully synthesised and characterised from PLA as a feed source, including ZnBLD. The chiral separation ability of ZnBLD was maintained.

10.
J Ren Care ; 2018 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-29664189

RESUMO

BACKGROUND: Over-hydration (OH) and malnutrition are prevalent among patients on dialysis therapy. The prevalence of OH and malnutrition as well as the risk factors associated with OH and malnutrition in our patients on home peritoneal dialysis (PD) and home haemodialysis (HD) are examined. DESIGN AND METHODS: This was a cross-sectional study. The hydration and nutritional status of the study groups were assessed by a Body Composition Monitor. Patients who were stable on home dialysis therapy for over one year were invited to participate. Univariate and multivariate analyses were performed to identify associated factors and determine the predictors of OH and malnutrition, respectively. RESULTS: Eighty-eight patients (41 PD and 47 home HD) were recruited. A 32.95% of our patients on home dialysis therapy were in OH status. There was a significance difference in the prevalence of hydration status between patients on PD and home HD (p = 0.014), as overhydration was more common in patients on PD than home HD (46.34 vs. 21.28%). Dehydration was more common in patients on home HD than PD (29.79 vs. 9.76%). Male gender, decreasing haemoglobin level and presence of diabetes mellitus (DM) were risk factors of OH on multivariable analysis. There was no significance difference in the prevalence of malnutrition between patients on PD and home HD (p = 0.27). Increasing Fat Tissue Index (FTI), height and patients on PD therapy were at higher risk of malnutrition. CONCLUSION: OH and malnutrition were prevalent patients on home dialysis therapy.

11.
Mol Cancer Ther ; 17(1): 140-149, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29079709

RESUMO

Targeted therapy against VEGF and mTOR pathways has been established as the standard-of-care for metastatic clear cell renal cell carcinoma (ccRCC); however, these treatments frequently fail and most patients become refractory requiring subsequent alternative therapeutic options. Therefore, development of innovative and effective treatments is imperative. About 80%-90% of ccRCC tumors express an inactive mutant form of the von Hippel-Lindau protein (pVHL), an E3 ubiquitin ligase that promotes target protein degradation. Strong genetic and experimental evidence supports the correlate that pVHL functional loss leads to the accumulation of the transcription factor hypoxia-inducible factor 2α (HIF2α) and that an overabundance of HIF2α functions as a tumorigenic driver of ccRCC. In this report, we describe an RNAi therapeutic for HIF2α that utilizes a targeting ligand that selectively binds to integrins αvß3 and αvß5 frequently overexpressed in ccRCC. We demonstrate that functional delivery of a HIF2α-specific RNAi trigger resulted in HIF2α gene silencing and subsequent tumor growth inhibition and degeneration in an established orthotopic ccRCC xenograft model. Mol Cancer Ther; 17(1); 140-9. ©2017 AACR.


Assuntos
Carcinoma de Células Renais/terapia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , RNA Interferente Pequeno/administração & dosagem , Animais , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Feminino , Inativação Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Integrina alfaVbeta3/metabolismo , Camundongos , Camundongos Nus , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores de Vitronectina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Drug Deliv ; 14(6): 357-69, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17701525

RESUMO

In vivo phage display is a powerful source of new peptide ligands for specific organ targeting by drugs and gene therapy vectors. Since the introduction of this methodology a decade ago, a number of peptides that preferentially react with organ-specific endothelium and parenchymal markers have been selected. One organ that has been conspicuously missing from these selection studies is the liver, which possesses a multitude of acquired and hereditary disorders and represents a highly important therapeutic target. Herein, we set out to fill this gap by introducing a novel peptide display system containing cloned sequences in the tail fiber protein (p17) of phage T7. The p17 display effectively avoids the innate immune system and is well suited both for selection of new liver-specific ligands and for validation of protein sequences that have been implicated in liver targeting by the use of conventional biochemical methods.


Assuntos
Bacteriófago T7/genética , Fígado/metabolismo , Biblioteca de Peptídeos , Peptídeos/metabolismo , Animais , Apolipoproteínas B/genética , Apolipoproteínas B/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Vetores Genéticos , Imunidade Inata , Imuno-Histoquímica , Ligantes , Masculino , Camundongos , Camundongos Endogâmicos ICR , Mutação , Especificidade de Órgãos , Peptídeos/genética , Proteínas Virais/genética
13.
J Nucl Med ; 46(2): 283-91, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15695788

RESUMO

UNLABELLED: The current perception of using contrast-enhanced CT (CECT) for attenuation correction (AC) is that of caution, as it might lead to erroneously elevated (18)F-FDG uptake on the PET scan. This study evaluates in vivo whether an intravenous iodinated contrast agent produces a significant AC artifact in the level of standardized uptake value (SUV) changes in PET/CT. METHODS: Fifty-four patients referred for whole-body (WB) PET/CT scans were enrolled and subdivided into 2 groups. In part I, 26 patients had a single WB PET scan that was corrected for attenuation using noncontrast and intravenous CECT obtained before and after the emission data, respectively. The final PET images were compared for any visual and SUV maximum (SUV(max)) measurement difference. This allowed analysis of the compatibility of the scaling processes between the 2 different CTs and the PET. The SUV(max) values were obtained from ascending aorta, upper lung, femoral head, iliopsoas muscle, spleen, liver, and the site of pathology (total, 193 regions). Part II addressed whether intravenous contrast also influenced the PET emission data. For that purpose, the remaining 28 patients underwent a limited plain CT scan from lung base to lower liver edge, followed by a 1-bed PET scan of the same region and then a WB intravenous contrast CT scan in tandem with a WB PET scan. SUV(max) values were obtained at the lung base, liver, spleen, T11 or T12 vertebra, and paraspinal muscle (total, 135 regions). The data obtained from pre- and post-intravenous contrast PET scans were analyzed as in part I. RESULTS: There was no statistically significant elevation of the SUV level in the measured anatomic sites as a whole (part I: mean SUV(max) difference = 0.06, P > 0.05; Part II: mean SUV(max) difference = -0.02, P > 0.05). However, statistically significant results as a group (mean SUV(max) difference = 0.26, P < 0.05)--albeit considered to be clinically insignificant--were observed for areas of pathology in the part I study. No abnormal focal increased (18)F-FDG activity was detected as a result of the intravenous contrast in both parts of this examination. CONCLUSION: No statistically or clinically significant spuriously elevated SUV level that might potentially interfere with the diagnostic value of PET/CT was identified as a result of the application of intravenous iodinated contrast.


Assuntos
Artefatos , Meios de Contraste , Fluordesoxiglucose F18 , Aumento da Imagem/métodos , Iopamidol , Neoplasias/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Erros de Diagnóstico/prevenção & controle , Feminino , Humanos , Injeções Intravenosas , Iopamidol/administração & dosagem , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Técnica de Subtração , Tomografia Computadorizada por Raios X/métodos
14.
Methods Mol Biol ; 1218: 163-86, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25319651

RESUMO

The discoveries of RNA interference (RNAi) and short interfering RNAs (siRNAs) have provided the opportunity to treat diseases in a fundamentally new way: by co-opting a natural process to inhibit gene expression at the mRNA level. Given that siRNAs must interact with the cells' natural RNAi machinery in order to exert their silencing effect, one of the most fundamental requirements for their use is efficient delivery to the desired cell type and, specifically, into the cytoplasm of those cells. Numerous research efforts involving the testing of a large number of delivery approaches using various carrier molecules and inventing several distinct formulation technologies during the past decade illustrate the difficulty and complexity of this task. We have developed synthetic polymer formulations for in vivo siRNA delivery named Dynamic PolyConjugates™ (DPCs) that are designed to mimic the features viruses possess for efficient delivery of their nucleic acids. These include small size, long half-life in circulation, capability of displaying distinct host cell tropism, efficient receptor binding and cell entry, disassembly in the endosome and subsequent release of the nucleic acid cargo to the cytoplasm. Here we present an example of this delivery platform composed of a hepatocyte-targeted endosome-releasing agent and a cholesterol-conjugated siRNA (chol-siRNA). This delivery platform forms the basis of ARC-520, an siRNA-based therapeutic for the treatment of chronic hepatitis B virus (HBV) infection. In this chapter, we provide a general overview of the steps in developing ARC-520 and detailed protocols for two critical stages of the discovery process: (1) verifying targeted in vivo delivery to hepatocytes and (2) evaluating in vivo drug efficacy using a mouse model of chronic HBV infection.


Assuntos
Endossomos/metabolismo , Genoma Viral , Hepatite B Crônica/terapia , Interferência de RNA , RNA Mensageiro/antagonistas & inibidores , RNA Interferente Pequeno/genética , Proteínas Virais/antagonistas & inibidores , Animais , Colesterol/química , Colesterol/metabolismo , Modelos Animais de Doenças , Portadores de Fármacos , Meia-Vida , Vírus da Hepatite B/genética , Vírus da Hepatite B/crescimento & desenvolvimento , Hepatite B Crônica/genética , Hepatite B Crônica/patologia , Hepatite B Crônica/virologia , Hepatócitos/metabolismo , Hepatócitos/patologia , Hepatócitos/virologia , Humanos , Cinética , Camundongos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo
16.
J Control Release ; 209: 57-66, 2015 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-25886706

RESUMO

The safe and efficacious delivery of membrane impermeable therapeutics requires cytoplasmic access without the toxicity of nonspecific cytoplasmic membrane lysis. We have developed a mechanism for control of cytoplasmic release which utilizes endogenous proteases as a trigger and results in functional delivery of small interfering RNA (siRNA). The delivery approach is based on reversible inhibition of membrane disruptive polymers with protease-sensitive substrates. Proteolytic hydrolysis upon endocytosis restores the membrane destabilizing activity of the polymers thereby allowing cytoplasmic access of the co-delivered siRNA. Protease-sensitive polymer masking reagents derived from polyethylene glycol (PEG), which inhibit membrane interactions, and N-acetylgalactosamine, which targets asialoglycoprotein receptors on hepatocytes, were synthesized and used to formulate masked polymer-siRNA delivery vehicles. The size, charge and stability of the vehicles enable functional delivery of siRNA after subcutaneous administration and, with modification of the targeting ligand, have the potential for extrahepatic targeting.


Assuntos
Fator VII/genética , Técnicas de Transferência de Genes , Peptídeo Hidrolases/metabolismo , RNA Interferente Pequeno/administração & dosagem , Animais , Eritrócitos/efeitos dos fármacos , Feminino , Hemólise/efeitos dos fármacos , Macaca fascicularis , Masculino , Camundongos Endogâmicos ICR , Polímeros/química , RNA Interferente Pequeno/química , Ratos
17.
Nucleic Acid Ther ; 22(6): 380-90, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23181701

RESUMO

Effective in vivo delivery of small interfering (siRNA) has been a major obstacle in the development of RNA interference therapeutics. One of the first attempts to overcome this obstacle utilized intravenous injection of cholesterol-conjugated siRNA (chol-siRNA). Although studies in mice revealed target gene knockdown in the liver, delivery was relatively inefficient, requiring 3 daily injections of 50 mg/kg of chol-siRNA to obtain measurable reduction in gene expression. Here we present a new delivery approach that increases the efficacy of the chol-siRNA over 500-fold and allows over 90% reduction in target gene expression in mice and, for the first time, high levels of gene knockdown in non-human primates. This improved efficacy is achieved by the co-injection of a hepatocyte-targeted and reversibly masked endosomolytic polymer. We show that knockdown is absolutely dependent on the presence of hepatocyte-targeting ligand on the polymer, the cognate hepatocyte receptor, and the cholesterol moiety of the siRNA. Importantly, we provide evidence that this increase in efficacy is not dependent on interactions between the chol-siRNA with the polymer prior to injection or in the bloodstream. The simplicity of the formulation and efficacy of this mode of siRNA delivery should prove beneficial in the use of siRNA as a therapeutic.


Assuntos
Acetilgalactosamina/análogos & derivados , Colesterol/administração & dosagem , Endossomos/efeitos dos fármacos , Polivinil/administração & dosagem , RNA Interferente Pequeno/administração & dosagem , Acetilgalactosamina/administração & dosagem , Acetilgalactosamina/farmacocinética , Animais , Apolipoproteínas B/sangue , Apolipoproteínas B/genética , Receptor de Asialoglicoproteína/genética , Receptor de Asialoglicoproteína/metabolismo , Colesterol/farmacocinética , Fator VII/genética , Fator VII/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Técnicas de Transferência de Genes , Hepatócitos/metabolismo , Lipídeos/sangue , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Macaca mulatta , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Polivinil/farmacocinética , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacocinética , Receptores de LDL/genética , Receptores de LDL/metabolismo
18.
Drug Deliv ; 16(5): 268-73, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19538008

RESUMO

It has previously been reported that a peptide sequence of T7 phage protein p17 mediates uptake of its cargo by liver parenchymal cells. The aim of this study was to identify the phage-binding receptor. The involvement of LRP was confirmed by the observations that phage binding to Hepa 1c1c7 cells was inhibited by the LRP-binding receptor-associated protein, LRP-deficient mouse embryonic fibroblasts bound phage with lower efficiency than their wild-type counterparts, and using mouse models with ablated LRP liver expression. The identification of LRP as a cognate receptor for this sequence offers a new ligand-receptor combination for hepatocyte delivery of therapeutic agents.


Assuntos
Bacteriófago T7/química , Hepatócitos/metabolismo , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Peptídeos/farmacologia , Sequência de Aminoácidos , Peptídeos beta-Amiloides , Animais , Bacteriófago T7/metabolismo , Sítios de Ligação , Proteínas de Transporte/metabolismo , Células Cultivadas , Endocitose/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/deficiência , Camundongos , Ligação Proteica
19.
Proc Natl Acad Sci U S A ; 104(32): 12982-7, 2007 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-17652171

RESUMO

Achieving efficient in vivo delivery of siRNA to the appropriate target cell would be a major advance in the use of RNAi in gene function studies and as a therapeutic modality. Hepatocytes, the key parenchymal cells of the liver, are a particularly attractive target cell type for siRNA delivery given their central role in several infectious and metabolic disorders. We have developed a vehicle for the delivery of siRNA to hepatocytes both in vitro and in vivo, which we have named siRNA Dynamic PolyConjugates. Key features of the Dynamic PolyConjugate technology include a membrane-active polymer, the ability to reversibly mask the activity of this polymer until it reaches the acidic environment of endosomes, and the ability to target this modified polymer and its siRNA cargo specifically to hepatocytes in vivo after simple, low-pressure i.v. injection. Using this delivery technology, we demonstrate effective knockdown of two endogenous genes in mouse liver: apolipoprotein B (apoB) and peroxisome proliferator-activated receptor alpha (ppara). Knockdown of apoB resulted in clear phenotypic changes that included a significant reduction in serum cholesterol and increased fat accumulation in the liver, consistent with the known functions of apoB. Knockdown of ppara also resulted in a phenotype consistent with its known function, although with less penetrance than observed in apoB knockdown mice. Analyses of serum liver enzyme and cytokine levels in treated mice indicated that the siRNA Dynamic PolyConjugate was nontoxic and well tolerated.


Assuntos
Apolipoproteínas B/antagonistas & inibidores , Sistemas de Liberação de Medicamentos , Hepatócitos/metabolismo , Polímeros/administração & dosagem , RNA Interferente Pequeno/administração & dosagem , Animais , Apolipoproteínas B/genética , Química Farmacêutica , Relação Dose-Resposta a Droga , Endossomos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , RNA Mensageiro/análise , RNA Interferente Pequeno/metabolismo
20.
Mol Pharm ; 3(4): 386-97, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16889432

RESUMO

A critical step for liver-directed gene therapy is the selective targeting of nucleic acids to hepatocytes. We have previously discovered that the proximal half of the T7 phage tail fiber protein (p17) targeted intact T7 phage and recombinant proteins to hepatocytes in vivo. In the present study, we have localized the targeting activities to a 33 amino acid sequence within the p17 coiled-coil rod domain. Given that the tail fiber domain from which the peptide was derived may form alpha and triple helical structures, biophysical studies (CD spectra and analytical ultracentrifugation) were conducted to determine the secondary and tertiary structures of the peptide. This peptide is able to target proteins, polymers, and siRNA and also particles such as DNA polyplexes and liposomes to hepatocytes. A variety of coupling strategies and chemistries were employed, thus demonstrating that this peptide is a versatile system for delivering cargo. The ability of this hepatocyte-targeting peptide to target DNA-containing particles suggests that it should be useful in the development of both nonviral and viral vectors. However, biological function of delivered cargo has not been demonstrated. This was primarily due to failure of delivered cargo to escape the endosomes. Further studies are in progress to provide functional activity of delivered nucleic acids by enabling their endosomal escape.


Assuntos
Bacteriófago T7/genética , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Ácidos Nucleicos/administração & dosagem , Ácidos Nucleicos/genética , Proteínas Virais/administração & dosagem , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Carbocianinas , Corantes Fluorescentes , Marcação de Genes , Terapia Genética/métodos , Vetores Genéticos , Lipossomos , Camundongos , Camundongos Endogâmicos ICR , Dados de Sequência Molecular , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Proteínas Virais/química
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