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1.
Molecules ; 29(3)2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38338484

RESUMO

The molecular events of protein misfolding and self-aggregation of tau and amylin are associated with the progression of Alzheimer's and diabetes, respectively. Recent studies suggest that tau and amylin can form hetero-tau-amylin oligomers. Those hetero-oligomers are more neurotoxic than homo-tau oligomers. So far, the detailed interactions between the hetero-oligomers and the neuronal membrane are unknown. Using multiscale MD simulations, the lipid binding and protein folding behaviors of hetero-oligomers on asymmetric lipid nanodomains or raft membranes were examined. Our raft membranes contain phase-separated phosphatidylcholine (PC), cholesterol, and anionic phosphatidylserine (PS) or ganglioside (GM1) in one leaflet of the lipid bilayer. The hetero-oligomers bound more strongly to the PS and GM1 than other lipids via the hydrophobic and hydrophilic interactions, respectively, in the raft membranes. The hetero-tetramer disrupted the acyl chain orders of both PC and PS in the PS-containing raft membrane, but only the GM1 in the GM1-containing raft membrane as effectively as the homo-tau-tetramer. We discovered that the alpha-helical content in the heterodimer was greater than the sum of alpha-helical contents from isolated tau and amylin monomers on both raft membranes, indicative of a synergetic effect of tau-amylin interactions in surface-induced protein folding. Our results provide new molecular insights into understanding the cross-talk between Alzheimer's and diabetes.


Assuntos
Doença de Alzheimer , Diabetes Mellitus , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Peptídeos beta-Amiloides/metabolismo , Gangliosídeo G(M1)/química , Bicamadas Lipídicas/química , Fosfatidilcolinas
2.
Molecules ; 28(10)2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37241931

RESUMO

The aggregation of human Islet Amyloid Polypeptide (hIAPP) on cell membranes is linked to amyloid diseases. However, the physio-chemical mechanisms of how these hIAPP aggregates trigger membrane damage are unclear. Using coarse-grained and all-atom molecular dynamics simulations, we investigated the role of lipid nanodomains in the presence or absence of anionic lipids, phosphatidylserine (PS), and a ganglioside (GM1), in the membrane disruption and protein folding behaviors of hIAPP aggregates on phase-separated raft membranes. Our raft membranes contain liquid-ordered (Lo), liquid-disordered (Ld), mixed Lo/Ld (Lod), PS-cluster, and GM1-cluster nanosized domains. We observed that hIAPP aggregates bound to the Lod domain in the absence of anionic lipids, but also to the GM1-cluster- and PS-cluster-containing domains, with stronger affinity in the presence of anionic lipids. We discovered that L16 and I26 are the lipid anchoring residues of hIAPP binding to the Lod and PS-cluster domains. Finally, significant lipid acyl chain order disruption in the annular lipid shells surrounding the membrane-bound hIAPP aggregates and protein folding, particularly beta-sheet formation, in larger protein aggregates were evident. We propose that the interactions of hIAPP and both non-anionic and anionic lipid nanodomains represent key molecular events of membrane damage associated with the pathogenesis of amyloid diseases.


Assuntos
Polipeptídeo Amiloide das Ilhotas Pancreáticas , Simulação de Dinâmica Molecular , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Gangliosídeo G(M1) , Membrana Celular/metabolismo , Dobramento de Proteína , Amiloide/química
3.
J Immunother Cancer ; 11(5)2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37258040

RESUMO

BACKGROUND: Treatment of some blood cancers with T cells that express a chimeric antigen receptor (CAR) against CD19 have shown remarkable results. In contrast, CAR-T cell efficacy against solid tumors has been difficult to achieve. METHODS: To examine the potential of CAR-T cell treatments against ovarian cancers, we used the mouse ovarian cancer cell line ID8 in an intraperitoneal model that exhibits disseminated solid tumors in female C57BL/6J mice. The CAR contained a single-chain Fv from antibody 237 which recognizes a Tn-glycopeptide-antigen expressed by ID8 due to aberrant O-linked glycosylation in the absence of the transferase-dependent chaperone Cosmc. The efficacy of four Tn-dependent CARs with varying affinity to Tn antigen, and each containing CD28/CD3ζ cytoplasmic domains, were compared in vitro and in vivo in this study. RESULTS: In line with many observations about the impact of aberrant O-linked glycosylation, the ID8Cosmc knock-out (ID8Cosmc-KO) exhibited more rapid tumor progression compared with wild-type ID8. Despite the enhanced tumor growth in vivo, 237 CAR and a mutant with 30-fold higher affinity, but not CARs with lower affinity, controlled advanced ID8Cosmc-KO tumors. Tumor regression could be achieved with a single intravenous dose of the CARs, but intraperitoneal administration was even more effective. The CAR-T cells persisted over a period of months, allowing CAR-treated mice to delay tumor growth in a re-challenge setting. The most effective CARs exhibited the highest affinity for antigen. Antitumor effects observed in vivo were associated with increased numbers of T cells and macrophages, and higher levels of cleaved caspase-3, in the tumor microenvironment. Notably, the least therapeutically effective CAR mediated tonic signaling leading to antigen-independent cytokine expression and it had higher levels of the immunosuppressive cytokine interleukin10. CONCLUSION: The findings support the development of affinity-optimized CAR-T cells as a potential treatment for established ovarian cancer, with the most effective CARs mediating a distinct pattern of inflammatory cytokine release in vitro. Importantly, the most potent Tn-dependent CAR-T cells showed no evidence of toxicity in tumor-bearing mice in a syngeneic, immunocompetent system.


Assuntos
Neoplasias Ovarianas , Receptores de Antígenos Quiméricos , Humanos , Feminino , Camundongos , Animais , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T , Imunoterapia Adotiva/métodos , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos Endogâmicos C57BL , Citocinas/metabolismo , Microambiente Tumoral
4.
J Couns Psychol ; 70(3): 276-292, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37023277

RESUMO

Anti-Black racism (ABR) contributes to racial trauma and to the disproportionate negative mental, physical, and social outcomes faced by Black populations (Hargons et al., 2017; Wun, 2016a). The previous literature demonstrates that storytelling and other narrative interventions are often used to promote collective healing among Black people (Banks-Wallace, 2002; Moors, 2019). Storying survival (i.e., the utilization of stories to promote liberation from racial trauma) is one such narrative intervention (Mosley et al., 2021); however, little is known about the processes by which Black people utilize storying survival to promote radical healing. Using an intersectional framework and thematic analysis from a phenomenological perspective (Braun & Clarke, 2006), the present study analyzed interviews from 12 racial justice activists in order to understand how these activists engage in storying survival to foster Black survival and healing. Results show that storying survival includes five interconnected components: storying influences, mechanisms of storying survival, content of storying survival, context of storying survival, and impact of storying survival. Each of these categories and subcategories are detailed herein and are supported with quotations. The findings and related discussion explore the concept of storying survival and its contributions to critical consciousness, radical hope, strength and resistance, cultural self-knowledge, and collectivism among participants and their communities. This study therefore provides important and practical information about how Black people and the counseling psychologists who aim to serve them can utilize storying survival to resist and heal from ABR. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Narração , Racismo , Humanos , Comunicação , Autoimagem , Racismo/psicologia
5.
Biophys Chem ; 296: 106993, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36898349

RESUMO

The misfolding and self-aggregation of human Islet Amyloid Polypeptide (hIAPP) are linked to the onset of type 2 diabetes (T2D). However, the mechanism of how the disordered hIAPP aggregates trigger membrane damage leading to the loss of Islet cells in T2D is unknown. Using coarse-grained (CG) and all-atom (AA) molecular dynamics simulations, we have investigated the membrane-disruption behaviors of hIAPP oligomers on the phase-separated lipid nanodomains that mimic the highly heterogeneous lipid raft structures of cell membranes. Our results revealed that hIAPP oligomers preferentially bind to the liquid-ordered and liquid-disordered domain boundary around two hydrophobic residues at L16 and I26, and lipid acyl chain order disruption and beta-sheet formation occur upon hIAPP binding to the membrane surface. We propose that the lipid order disruption and surface-induced beta-sheet formation on the lipid domain boundary represent the early molecular events of membrane damage associated with the early pathogenesis of T2D.


Assuntos
Amiloidose , Diabetes Mellitus Tipo 2 , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Humanos , Amiloide/química , Amiloidose/metabolismo , Membrana Celular/química , Diabetes Mellitus Tipo 2/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Lipídeos , Dobramento de Proteína
6.
Membranes (Basel) ; 12(11)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36363654

RESUMO

The self-aggregation of tau, a microtubule-binding protein, has been linked to the onset of Alzheimer's Disease. Recent studies indicate that the disordered tau aggregates, or oligomers, are more toxic than the ordered fibrils found in the intracellular neurofibrillary tangles of tau. At present, details of tau oligomer interactions with lipid rafts, a model of neuronal membranes, are not known. Using molecular dynamics simulations, the lipid-binding events, membrane-damage, and protein folding of tau oligomers on various lipid raft surfaces were investigated. Tau oligomers preferred to bind to the boundary domains (Lod) created by the coexisting liquid-ordered (Lo) and liquid-disordered (Ld) domains in the lipid rafts. Additionally, stronger binding of tau oligomers to the ganglioside (GM1) and phosphatidylserine (PS) domains, and subsequent protein-induced lipid chain order disruption and beta-sheet formation were detected. Our results suggest that GM1 and PS domains, located exclusively in the outer and inner leaflets, respectively, of the neuronal membranes, are specific membrane domain targets, whereas the Lod domains are non-specific targets, of tau oligomers binding to neurons. The molecular details of these specific and non-specific tau bindings to lipid rafts may provide new insights into understanding membrane-associated tauopathies leading to Alzheimer's Disease.

7.
J Ocul Pharmacol Ther ; 38(10): 657-663, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36327101

RESUMO

Background: This phase 2 study evaluated the therapeutic potential of netarsudil to reduce corneal edema and to improve vision in patients with Fuchs corneal dystrophy (FCD). Methods: Patients (N = 40) with baseline central corneal thickness (CCT) of ≥600 µm and best-corrected visual acuity (BCVA) of 70-20 letters (20/40-20/400 Snellen equivalent) were randomized 1:1 to receive netarsudil once a day (QD) or twice a day (BID) for 8 weeks. Primary endpoint was mean CCT change from baseline at week 4. Results: Netarsudil QD and BID significantly reduced CCT at week 4 [mean change (standard error of mean), 28.4 (7.99) µm, P = 0.0021; and 20.1 (8.75) µm, P = 0.0335, respectively]. Five (12.5%) patients achieved complete resolution of corneal edema at week 4. BCVA improved by 3.2 (2.76) letters with QD and 1.5 (2.84) letters with BID, and 10 (25%) patients [5 with QD (P = 0.0078) and 5 with BID (P = 0.0096)] gained ≥10 letters at week 4. Improvements in CCT and vision were observed at week 2 and persisted at week 8, without significant differences between the 2 doses at any time point. Netarsudil QD significantly improved visual acuity and glare factor scores on the Visual Function and Corneal Health Status (V-FUCHS) questionnaire at weeks 4 and 8 (mean change, -0.4 to -0.3; P ≤ 0.0200). Netarsudil was well tolerated. Reticular edema developed in one (2.5%) patient with BID, which resolved with treatment discontinuation. Conclusions: Netarsudil QD led to significant reductions in corneal edema as well as improvements in vision and patient-reported symptoms of glare and visual impairment in patients with FCD. Clinical Trial Registration Number: NCT04498169.


Assuntos
Edema da Córnea , Distrofia Endotelial de Fuchs , Humanos , Edema da Córnea/tratamento farmacológico
8.
Ocul Surf ; 26: 166-173, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35970431

RESUMO

PURPOSE: Dry eye disease (DED) symptoms can negatively impact quality of life (QoL). AR-15512, a transient receptor potential melastatin 8 (TRPM8) agonist, was evaluated as a potential therapy for DED. METHODS: In a Phase 2b study, patients with DED were randomized 1:1:1 to 0.0014% AR-15512, 0.003% AR-15512, or vehicle twice daily for 12 weeks. Eligibility criteria included DED signs and symptoms of prespecified severity levels. Outcomes assessed were DED signs (Schirmer score ± anesthetic, ocular surface staining, hyperemia), symptoms (Ocular Discomfort [ODS-VAS], Symptoms Assessment iN Dry Eye [SANDE], Eye Dryness-VAS, Ocular Pain-VAS), QoL-VAS, and adverse events. Co-primary endpoints were changes from baseline in ODS-VAS and anesthetized Schirmer score at Day 28. RESULTS: 0.003% AR-15512 (n = 122) was associated with early and sustained improvements in unanesthetized Schirmer score (Days 1 and 14, p < 0.0001), as well as improvements in ocular surface staining (Days 14 and 84, p ≤ 0.0365) and hyperemia (Day 84, p < 0.0215). Statistically significant improvements in symptoms were observed for the 0.003% concentration on SANDE (Days 14, 28, and 84, p ≤ 0.0254), ODS-VAS (Day 84, p = 0.0281), Eye Dryness-VAS (Day 84, p = 0.0302), and multiple QoL measures (Days 14, 28, and 84, p < 0.05). There were no significant differences between active and vehicle groups for the co-primary endpoints. The most common adverse events were burning and stinging upon instillation. CONCLUSIONS: Although predefined co-primary study endpoints were not met, AR-15512 demonstrated statistically significant improvements in DED signs, symptoms, and disease-related QoL.


Assuntos
Síndromes do Olho Seco , Hiperemia , Canais de Cátion TRPM , Humanos , Método Duplo-Cego , Síndromes do Olho Seco/tratamento farmacológico , Proteínas de Membrana , Qualidade de Vida , Lágrimas , Canais de Cátion TRPM/agonistas
9.
J Nurs Care Qual ; 37(2): 110-116, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34775418

RESUMO

BACKGROUND: Second victims (SVs) are health care workers traumatized by unanticipated, adverse patient events. These experiences can have personal and professional effects on SVs. Research indicates that SVs experience inadequate support following adverse events. PURPOSE: To determine the prevalence of nurses who identified as SVs and their awareness and use of supportive resources. METHODS: A convenience sample of nurses was surveyed, and SV responses were compared with those who did not identify as a SV. Responses were analyzed using nonparametric methods. RESULTS: One hundred fifty-nine (44.3%) of 359 participants identified as SVs. There was a significant relationship between work tenure and SVs (P = .009). A relationship was found between SVs and awareness and use of support resources, with debriefing being the preferred method after an event. CONCLUSIONS: Adverse events trigger emotional trauma in SVs who require administrative awareness, support, and follow-up to minimize psychological trauma in the clinical nurse.


Assuntos
Pessoal de Saúde , Enfermeiras e Enfermeiros , Pessoal de Saúde/psicologia , Hospitais , Humanos , Inquéritos e Questionários
10.
Yale J Biol Med ; 94(4): 693-702, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34970108

RESUMO

Rare diseases affect an estimated 6-10% of the Australian population, a prevalence similar to that seen in other regions worldwide. These multi-system conditions are often severely debilitating and affect multiple domains of a person's life. A salient necessity for effective care provision thus, is holistic care, achieved by appropriate and continual multi-disciplinary and cross-sectoral collaboration. Synonymous with this priority for collaborative care, is the need for increased partnerships between the health and education sectors. This partnership has the potential to benefit people with rare disease of all educational ages, but in particular, school-aged children and young adults. More than 70% of rare diseases affect children, and this population often experiences difficulties with overall well-being and functioning, including impaired school performance and confounding mental and social comorbidities. Ensuring adequate schooling needs and experiences along with provision of adequate medical care, is crucial in ensuring overall well-being for this population. For this, effective partnerships between the health and education sectors are paramount. This article highlights fundamental elements of health and education priorities, ingrained in current strategic documents, to build a policy foundation that informs and supports increased inter-sectoral partnerships between health and education services. Shared priorities identified in both sectors' guidelines, co-developed with those with lived experience of rare diseases, build a strong policy base for future advocative initiatives to mold better integration between the sectors, a partnership which is vital to improving the overall quality of life, experiences and journeys of people living with rare disease.


Assuntos
Prestação Integrada de Cuidados de Saúde , Doenças Raras , Austrália , Criança , Humanos , Políticas , Qualidade de Vida , Doenças Raras/terapia , Adulto Jovem
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