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1.
Tissue Eng Part A ; 28(5-6): 239-253, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34409851

RESUMO

Elastic fibers do not naturally regenerate in many proteolytic disorders, such as in abdominal aortic aneurysms, and prevent restoration of tissue homeostasis. We have shown drug-based attenuation of the stress-activated protein kinase, JNK-2 to stimulate elastic matrix neoassembly and to attenuate cellular proteolytic activity. We now investigate if JNK2 gene knockdown with small interfering RNA (siRNA) provides greater specificity of action and improved regenerative/antiproteolytic outcomes in a proteolytic injury culture model of rat aneurysmal smooth muscle cells (EaRASMCs). A siRNA dose of 12.5 nM delivered with a transfection reagent significantly enhanced downstream elastic fiber assembly and maturation versus untreated EaRASMC cultures. The optimal siRNA dose was also delivered as a complex with a polymeric transfection vector, polyethyleneimine (PEI) in preparation for future in vivo delivery. Linear 25 kDa PEI-siRNA (5:1 molar ratio of amine to phosphate) and linear 40 kDa PEI-siRNA (2.5:1 ratio) were effective in downregulating the JNK2 gene, and significantly increasing expression of elastic fiber assembly proteins, and decreases in elastolytic matrix metalloprotease-2 versus treatment controls to significantly increase mature elastic fiber assembly. The current work has identified siRNA dosing and siRNA-PEI complexing conditions that are safe and efficient in stimulating processes contributing to improved elastic matrix neoassembly via JNK2 gene knockdown. The results represent a mechanistic basis of a broader therapeutic approach to reverse elastic matrix pathophysiology in tissue disorders involving aberrations of elastic matrix homeostasis, such as in aortic aneurysms. Impact statement The elastic matrix and elastic fibers are key components of the structural extracellular matrix of elastic tissues and are essential to their stretch and recoil and to maintain healthy cell phenotype. Regeneration and repair of elastic matrix is naturally poor and impaired and is an unresolved challenge in tissue engineering. In this work, we investigate a novel gene silencing approach based on inhibiting the JNK2 gene, which provides significant downstream benefits to elastic fiber assembly and maturation. Combined with novel delivery strategies such as nanoparticles, we expect our approach to effect in situ elastic matrix repair in the future.


Assuntos
Matriz Extracelular , Miócitos de Músculo Liso , Animais , Matriz Extracelular/metabolismo , Inativação Gênica , Polietilenoimina/farmacologia , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Regeneração
3.
Acta Biomater ; 112: 225-233, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32504690

RESUMO

Abdominal aortic aneurysms (AAAs), a prototypic proteolytic cardiovascular disorder, are localized expansions of the aortal wall. Chronically upregulated and overexpressed proteases irreversibly degrade and disrupt the elastic matrix, which provides stretch and recoil properties to the aortal wall. Adult vascular smooth muscle cells are inherently unable to produce sufficient elastin to form new elastic fibers to naturally repair the aortal wall and the AAA continues to grow until fatal rupture. Surgical intervention is reserved for AAAs with a high risk of rupture, but there is currently no treatment for small, still growing AAAs. We have previously developed matrix regenerative PEG-PLGA nanoparticles (NPs) with pro-elastogenic and anti-proteolytic properties that act synergistically with a released therapeutic. However, strategies are required to effectively deliver these NPs to the disease site to avail of these benefits. We have identified cathepsin K, a protease overexpressed in AAA tissue, as a potential substrate for antibody based active targeting. We sought to assess the safety and biocompatibility of NPs with anti-cathepsin K antibodies conjugated to the NP surface (cat K Ab-NPs) and then assess their biodistribution and retention in both the targeted aorta and non-target organs in a rat AAA model. In this work, we show that cat K Ab-NPs can selectively target the aneurysmal aorta in a rat AAA model. However, there is unwanted NP uptake and retention in non-target organs that can be addressed in future work. Still, cathepsin K is a viable target for active delivery of NPs in an AAA model. STATEMENT OF SIGNIFICANCE: We have previously developed elastic matrix regenerative polymer nanoparticles (NPs), but require strategies to efficiently target the disease site. Antibodies against cathepsin K, an overexpressed protease in abdominal aortic aneurysms, have been conjugated to the NP surface to act as a targeting moiety. In this work, we assessed NP safety and in vivo biodistribution in an aneurysmal rat model and demonstrated positive targeting and retention for up to 2 weeks within the aortal wall.


Assuntos
Aneurisma da Aorta Abdominal , Nanopartículas , Animais , Aorta Abdominal , Aneurisma da Aorta Abdominal/metabolismo , Catepsina K/metabolismo , Matriz Extracelular/metabolismo , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
4.
Acta Biomater ; 105: 180-190, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31982591

RESUMO

Intrinsically poor auto-regenerative repair of proteolytically-disrupted elastic matrix structures by resident SMCs in the wall of abdominal aortic aneurysms (AAAs) prevents growth arrest and regression of these wall expansions. Supporting their possible future use in a regenerative cell therapy for AAAs, in a prior study, we showed that bone marrow mesenchymal stem cell-derived Smooth Muscle Cells (BM-SMCs) secrete biological factors that have significant pro-elastogenic and anti-proteolytic effects on aneurysmal rat aortic SMCs (EaRASMCs) in non-contact co-cultures. We also identified one stable BM-SMC phenotype (cBM-SMC) generated by differentiating BM-MSCs on a 2D fibronectin substrate in the presence of PDGF (Platelet Derived Growth Factor) and TGF-ß1 (Transforming Growth Factor-ß1) that exhibited superior elastogenicity and pro-elastogenic/anti-proteolytic properties. In this study, we further investigated the ability of these cBM-SMCs to maintain these superior elastogenic properties in a 3D collagenous milieu alone and in co-culture with EaRASMC to evaluate their potential as an alternative cell source for cell therapy in AAA. Some of our key observations were higher contractility and greater amount of structurally intact elastin production in both standalone culture of cBM-SMCs as well as co-culture of cBM-SMCs with EaRASMCs as shown by VVG (Verhoeff-Van Gieson) staining and Pontamine Sky Blue labeling and lower MMP-9 protein expression in standalone culture in 3D collagenous environment. Our overall result indicates that cBM-SMCs possess the ability to provide elastogenic impetus in a 3D collagenous AAA milieu which is otherwise not conducive to elastogenesis. Therefore our study strongly suggest the utility of cBM-SMCs as a potential cell source for cell therapy to augment elastic matrix neo-assembly and fiber formation and attenuate proteolysis in a collagenous milieu that is evocative of the de-elasticized aneurysmal wall. STATEMENT OF SIGNIFICANCE: Abdominal aortic aneurysm (AAA) or ballooning of the aorta is one of the leading causes of cardiovascular disease (CVD) related death caused by significantly increased proteolytic activity in the aortic wall. Reversing pathophysiology of this condition is challenging due to intrinsically poor regeneration of elastin by aortic smooth muscle cells. Current management of AAA is limited to passive monitoring of the disease until it becomes large enough to receive surgical intervention and no drug based therapy currently exists. Cell based therapy can be a potential alternative treatment in this scenario because it provides elastogenic impetus to the aneurysmal SMCs, compensates for the dead SMCs and serves as a robust source of elastin while being delivered with minimal invasiveness. Hence this work will have significant impact in the field of tissue engineering and regenerative medicine.


Assuntos
Colágeno/farmacologia , Elasticidade , Células-Tronco Mesenquimais/citologia , Miócitos de Músculo Liso/citologia , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Desmosina/metabolismo , Elastina/metabolismo , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Fluorescência , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Ratos Sprague-Dawley , Alicerces Teciduais/química
5.
BMJ Case Rep ; 20152015 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-26009602

RESUMO

We describe the case of an 89-year-old woman (deceased) with a 60-year history of recurrent depressive disorder treated with electroconvulsive therapy (ECT). It is estimated that she received up to 400 ECTs over her life course as her symptoms would not respond to oral medication. Despite extensive exposure to ECT, there was only minimal cognitive impairment and an excellent safety record, even in later life, as she became increasingly frail from multiple comorbidities. Over the years, there has been a drive to reduce the frequency of ECT administration. However, this case illustrates how in some patients ECT may be vital for acute episodes of severe depression as well as for maintenance therapy. This case report adds to observational evidence that maintenance ECT may be an underused treatment for recurrent depression and also recommends that greater emphasis be given to incorporating carers' views when planning individualised treatment approaches.


Assuntos
Transtorno Depressivo Maior/terapia , Eletroconvulsoterapia/métodos , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Eletroconvulsoterapia/psicologia , Feminino , Humanos , Recidiva , Resultado do Tratamento
6.
Prim Health Care Res Dev ; 15(4): 452-63, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25146257

RESUMO

BACKGROUND: Lymphoedema secondary to cancer is a relatively neglected and under-researched condition. Few studies report people's experiences of care and treatment provision when living with the condition. Current practice focuses on the physical treatment yet psychosocial needs often remain unmet. A previous study examining the patient perspective identified the theme of being 'abandoned by medicine'. Perceived lack of support may result in a delayed adaptation and acceptance of this long-term condition and can significantly impact on psychological well-being. We explore this emerging theme alongside others in order to provide a guide to action for improvements for patient benefit. AIM: The central aim was to explore women's views of their care and treatment following a diagnosis with lymphoedema secondary to cancer. This forms part of a larger study aimed at assessing appropriate screening tools to measure psychosocial distress. METHODS: A mixed-methods approach was used for the main study. Here we report the qualitative component, derived from in-depth semi-structured interviews conducted in the homes of the participants (n = 14) and focus group discussions (n = 15). In addition, qualitative comments from questionnaire data from a large-scale postal survey are included (n = 104). FINDINGS: Participants identified considerable deficiencies in health care workers' knowledge and awareness of lymphoedema, which subsequently impacted on the patients' needs for information, support and understanding. Access to appropriate treatment was patchy and problems were identified with the process of obtaining compression garments, massage and other sources of help. Although lymphoedema is a long-term disfiguring condition, and much is known about how this impacts on patients' emotional well-being, little attention was paid by health professionals to potential psychosocial consequences. In essence women had to become experts of their own condition and cope as best as they could. We provide recommendations to improve service delivery and address these unmet needs.


Assuntos
Atitude Frente a Saúde , Neoplasias da Mama/complicações , Linfedema/etiologia , Linfedema/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Inglaterra , Feminino , Grupos Focais , Humanos , Entrevistas como Assunto , Pessoa de Meia-Idade , Inquéritos e Questionários
7.
Cochrane Database Syst Rev ; 12: CD001894, 2012 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-23235584

RESUMO

BACKGROUND: Failure of implantation and conception may result from an inability of the blastocyst to escape from its outer coat, which is known as the zona pellucida. Artificial disruption of this coat is known as assisted hatching and has been proposed as a method for improving the success of assisted conception by facilitating embryo implantation. OBJECTIVES: To determine the effect of assisted hatching (AH) of embryos from assisted conception on live birth and multiple pregnancy rates.  SEARCH METHODS: We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register (August 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (August 2012), MEDLINE (1966 to August 2012) and EMBASE (1980 to August 2012). SELECTION CRITERIA: Three authors identified and independently screened trials. We included randomised controlled trials (RCTs) of AH (mechanical, chemical or laser disruption of the zona pellucida prior to embryo replacement) versus no AH that reported live birth or clinical pregnancy. DATA COLLECTION AND ANALYSIS: Three authors independently performed quality assessments and data extraction. MAIN RESULTS: Thirty-one trials reported clinical pregnancy data, including 1992 clinical pregnancies in 5728 women. There was no significant difference in the odds of live birth in the AH group compared with the control group (9 RCTs; odds ratio (OR) 1.03, 95% confidence interval (CI) 0.85 to 1.26, moderate quality evidence), with no evidence of significant heterogeneity (P = 0.38) or inconsistency (I(2) = 6%). Analysis of the clinical pregnancy rates from the nine studies which reported live birth showed a non-significant result (OR 1.03, 95% CI 0.85 to 1.25 ).Analysis of all of the studies included in this update (31 RCTs) showed that the clinical pregnancy rate in women who underwent AH was slightly improved, but the level only just reached statistical significance (OR 1.13, 95% CI 1.01 to 1.27, moderate quality evidence). However, it is important to note that the heterogeneity for this combined analysis for clinical pregnancy rate was statistically significant (P = 0.001) and the I(2) was 49%. Subgroup analysis of women who had had a previous failed attempt at IVF found improved clinical pregnancy rates in the women undergoing AH compared with the women in the control group (9 RCTs, n = 1365; OR 1.42, 95% CI 1.11 to 1.81) with I(2) = 20%. Miscarriage rates per woman were similar in both groups (14 RCTs; OR 1.03, 95% CI 0.69 to 1.54, P = 0.90, moderate quality evidence). Multiple pregnancy rates per woman were significantly increased in women who were randomised to AH compared with women in the control groups (14 RCTs, 3447 women; OR 1.38, 95% CI 1.11 to 1.70, P = 0.004, low quality evidence). AUTHORS' CONCLUSIONS: This update has demonstrated that whilst assisted hatching (AH) does appear to offer a significantly increased chance of achieving a clinical pregnancy, the extent to which it may do so only just reaches statistical significance. The 'take home' baby rate was still not proven to be increased by AH. The included trials provided insufficient data to investigate the impact of AH on several important outcomes. Most trials still failed to report on live birth rates.


Assuntos
Implantação do Embrião/fisiologia , Fertilização in vitro/métodos , Zona Pelúcida/fisiologia , Feminino , Humanos , Gravidez , Resultado da Gravidez , Taxa de Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Injeções de Esperma Intracitoplásmicas/métodos
8.
J Clin Lab Anal ; 26(3): 130-5, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22628226

RESUMO

BACKGROUND: Benzoylecgonine (BE) is the primary urinary metabolite of cocaine. Two enzyme immunoassays were evaluated for the detection of BEin urine with a 300 ng/ml cutoff: the DRI® Cocaine Metabolite Assay and Lin-Zhi International's (LZ) Cocaine Metabolite Enzyme Immunoassay. METHODS: This study involved 1,398 urine specimens from criminal justice and pain management programs. Gas chromatography/mass spectrometry (GC/MS) data were obtained for presumptive positives, and for negative urine specimens yielding responses significantly above the negative control. RESULTS: Approximately 46% (644) of the specimens yielded positive results by DRI, and 47% (664) were positive by LZ. One specimen screened positive with both assays but was found to have a nondetectable BE concentration by GC/MS, indicating one false positive for each assay. Twenty-one specimens yielding negative DRIresults contained BEabove 300 ng/ml, and 29 specimens yielded false negatives with the LZassay. Therefore, the overall agreement between both immunoassays and GC/MSresults was 98%. Assay sensitivity was 0.968 (DRI) and 0.958 (LZ); the selectivity for both assays was 0.999. Urine specimens containing cocaine, additional cocaine metabolites, and other drugs were also tested. No cross-reactivity was observed. CONCLUSION: Both the DRIand LZassays provide a precise, reliable method for the routine detection of BEin urine.


Assuntos
Cocaína/análogos & derivados , Cocaína/metabolismo , Técnicas Imunoenzimáticas/métodos , Detecção do Abuso de Substâncias/métodos , Cocaína/urina , Reações Falso-Negativas , Reações Falso-Positivas , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Técnicas Imunoenzimáticas/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Detecção do Abuso de Substâncias/normas
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