Protocol for a mixed-methods and multi-site assessment of the implementation process and outcomes of a new community-based frailty programme.

BACKGROUND: Frailty is increasing in prevalence internationally with population ageing. Frailty can be managed or even reversed through community-based interventions delivered by a multi-disciplinary team of professionals, but to varying degrees of success. However, many of these care models' implementation insights are contextual and may not be applicable in different cultural contexts. The Geriatric Service Hub (GSH) is a novel frailty care model in Singapore that focuses on identifying and managing frailty in the community. It includes key components of frailty care such as comprehensive geriatric assessments, care coordination and the assembly of a multi-disciplinary team. This study aims to gain insights into the factors influencing the development and implementation of the GSH. We also aim to determine the programme's effectiveness through patient-reported health-related outcomes. Finally, we will conduct a healthcare utilisation and cost analysis using a propensity score-matched comparator group. METHODS: We will adopt a mixed-methods approach that includes a qualitative evaluation among key stakeholders and participants in the programme, through in-depth interviews and focus group discussions. The main topics covered include factors that affected the development and implementation of each programme, operations and other contextual factors that influenced implementation outcomes. The quantitative evaluation monitors each programme's care process through quality indicators. It also includes a multiple-time point survey study to compare programme participants' pre- and post- outcomes on patient engagement, healthcare services experiences, health status and quality of life, caregiver burden and societal costs. A retrospective cohort study will compare healthcare and cost utilisation between participants of the programme and a propensity score-matched comparator group. DISCUSSION: The GSH sites share a common goal to increase the accessibility of essential services to frail older adults and provide comprehensive care. This evaluation study will provide invaluable insights into both the process and outcomes of the GSH and inform the design of similar programmes targeting frail older adults. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT04866316 . Date of Registration April 26, 2021. Retrospectively registered.

Identification of a Minimal Peptide Tag for in Vivo and in Vitro Loading of Encapsulin.

The encapsulation of enzymes and other proteins within a proteinaceous shell has been observed in many bacteria and archaea, but the function and utility of many such compartments are enigmatic. Efforts to study these functions have been complicated by the size and complexity of traditional protein compartments. One potential system for investigating the effect of compartmentalization is encapsulin, a large and newly discovered class of protein shells that are typically composed of two proteins: a protomer that assembles into the icosahedral shell and a cargo protein packaged inside. Encapsulins are some of the simplest known protein shell systems and readily self-assemble in vivo. Systematic characterization of the effects of compartmentalization requires the ability to load a wide range of cargo proteins. Here, we demonstrate that foreign cargo can be loaded into the encapsulin from Thermotoga maritima both in vivo and in vitro by fusion of the cargo protein with a short C-terminal peptide present in the native cargo. To facilitate biochemical characterization, we also develop a simple and rapid purification protocol and demonstrate the thermal and pH stability of the shell. Efforts to study the biophysical effects of protein encapsulation have been problematic in complex compartments, but the simplicity of assembling and loading encapsulin makes it an ideal system for future experiments exploring the effects of encapsulation on proteins.

Toxic fibrillar oligomers of amyloid-ß have cross-ß structure.

Although amyloid fibers are found in neurodegenerative diseases, evidence points to soluble oligomers of amyloid-forming proteins as the cytotoxic species. Here, we establish that our preparation of toxic amyloid-ß(1-42) (Abeta42) fibrillar oligomers (TABFOs) shares with mature amyloid fibrils the cross-ß structure, in which adjacent ß-sheets adhere by interpenetration of protein side chains. We study the structure and properties of TABFOs by powder X-ray diffraction, EM, circular dichroism, FTIR spectroscopy, chromatography, conformational antibodies, and celluar toxicity. In TABFOs, Abeta42 molecules stack into short protofilaments consisting of pairs of helical ß-sheets that wrap around each other to form a superhelix. Wrapping results in a hole along the superhelix axis, providing insight into how Abeta may form pathogenic amyloid pores. Our model is consistent with numerous properties of Abeta42 fibrillar oligomers, including heterogenous size, ability to seed new populations of fibrillar oligomers, and fiber-like morphology.

Modularity of a carbon-fixing protein organelle.

Bacterial microcompartments are proteinaceous complexes that catalyze metabolic pathways in a manner reminiscent of organelles. Although microcompartment structure is well understood, much less is known about their assembly and function in vivo. We show here that carboxysomes, CO(2)-fixing microcompartments encoded by 10 genes, can be heterologously produced in Escherichia coli. Expression of carboxysomes in E. coli resulted in the production of icosahedral complexes similar to those from the native host. In vivo, the complexes were capable of both assembling with carboxysomal proteins and fixing CO(2). Characterization of purified synthetic carboxysomes indicated that they were well formed in structure, contained the expected molecular components, and were capable of fixing CO(2) in vitro. In addition, we verify association of the postulated pore-forming protein CsoS1D with the carboxysome and show how it may modulate function. We have developed a genetic system capable of producing modular carbon-fixing microcompartments in a heterologous host. In doing so, we lay the groundwork for understanding these elaborate protein complexes and for the synthetic biological engineering of self-assembling molecular structures.

Appropriate Prescribing for older adults with Multimorbidity (Pro-M): protocol for a feasibility study.

BACKGROUND: Potentially inappropriate prescribing is common among older adults with multimorbidity due to various reasons, from concurrent application of multiple single-disease clinical guidelines to fragmentation of care. Interventions such as medication review have been implemented worldwide to reduce inappropriate prescribing for older adults. However, the implementability of such interventions are underexplored in the outpatient clinics in Singapore's public hospitals. Hence, the Pro-M study aims to assess the feasibility of implementing a physician-pharmacist collaborative care intervention in geriatric medicine outpatient clinics to facilitate appropriate prescribing for older adults in Singapore. METHODS: This is a single-arm, non-randomised feasibility study using a pre-post evaluation design. This study consists of two parts: (1) implementation phase of the intervention (6 months) and an (2) evaluation phase (3 months). Eligible patients will be recruited from geriatric medicine outpatient clinics at two public hospitals in Singapore through convenience sampling. The main components of the Pro-M intervention are: (1) pharmacist-facilitated medication reviews with feedback on any medication issues and potential recommendations to physicians, and (2) physicians communicating changes to other relevant prescribers. The evaluation phase will involve surveying and interviewing physicians and pharmacists involved in the implementation of the intervention. A mixed-method approach will be employed for data collection and analysis. The quantitative and qualitative findings will be triangulated and reported using Proctor's implementation outcomes: appropriateness, penetration, acceptability, fidelity, feasibility, and sustainability. A basic cost analysis will be conducted alongside the study. DISCUSSION: This is a phase 2 study to test the feasibility of implementing an intervention that was co-created with stakeholders during phase 1 development of an intervention to optimise prescribing for older adults with multimorbidity. The implementation will be assessed using Proctor's implementation outcomes to provide insights on the process and the feasibility of implementing medication reviews for older adults with multimorbidity as a routine practice in outpatient clinics. Data collected from this study will inform a subsequent scale-up study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05756478. Registered on 06 March 2023.

Identifying the amylome, proteins capable of forming amyloid-like fibrils.

The amylome is the universe of proteins that are capable of forming amyloid-like fibrils. Here we investigate the factors that enable a protein to belong to the amylome. A major factor is the presence in the protein of a segment that can form a tightly complementary interface with an identical segment, which permits the formation of a steric zipper-two self-complementary beta sheets that form the spine of an amyloid fibril. Another factor is sufficient conformational freedom of the self-complementary segment to interact with other molecules. Using RNase A as a model system, we validate our fibrillogenic predictions by the 3D profile method based on the crystal structure of NNQQNY and demonstrate that a specific residue order is required for fiber formation. Our genome-wide analysis revealed that self-complementary segments are found in almost all proteins, yet not all proteins form amyloids. The implication is that chaperoning effects have evolved to constrain self-complementary segments from interaction with each other.

Using multiple approaches to develop a physician-pharmacist collaborative care intervention to facilitate appropriate prescribing for older adults with multimorbidity.

BACKGROUND AND OBJECTIVES: This article discusses the development process of an intervention to facilitate appropriate prescribing for older adults with multimorbidity at geriatric medicine outpatient clinics. Both effectiveness and implementability were key aims, which were achieved by a systematic combination of different approaches guided by published guidance. METHODS: Various frameworks and tools were used to guide the intervention development. They include The Medical Research Council Framework for complex health interventions as the overarching framework, supplemented by the Framework of Actions for Intervention Development and a taxonomy of intervention development approaches. RESULTS: A combination of theory and evidence-based-, implementation-based and partnership approaches were used to develop the intervention. The Behaviour Change Wheel and Theoretical Domains Framework were used for intervention design. Three scoping reviews and two modified Delphi studies were conducted to build an evidence base on prescribing-related barriers and existing interventions. The findings were synthesised, assessed for implementability, and culminated in a co-creation exercise with physicians and pharmacists. The final intervention aims to facilitate collaboration between physicians and pharmacists and to improve communication and documentation of prescribing decisions. CONCLUSIONS: Multiple approaches may be required when developing interventions that are effective and implementable. The study team's experiences in using published guidance, integrating different approaches, and co-creating the intervention with healthcare professionals provide a useful case study with lessons and insights for developers of complex interventions. Furthermore, systematic reporting of such research-based efforts would contribute to advancement of intervention development in healthcare and reducing research waste.

Intervention elements and behavior change techniques to improve prescribing for older adults with multimorbidity in Singapore: a modified Delphi study.

PURPOSE: Potentially inappropriate prescribing among older adults is a rising concern, attributed mainly by polypharmacy and multimorbidity. We aimed to identify key components and strategies for construction of a context-relevant intervention to facilitate appropriate prescribing in outpatient clinics in Singapore. METHODS: The modified Delphi study was conducted in two rounds with 20 geriatricians from seven public hospitals in Singapore. Round one survey presented 69 statements formulated from a scoping review, while round two presented 23 statements with some modifications based on round one comments. The statements were rated against a 7-point Likert scale on their importance and impact on prescribing for older adults with multimorbidty. RESULTS: Consensus were achieved for 90% of the statements. Seven intervention elements were identified as being important: medication review, training, medication therapy management, shared decision making, patient interview, medication reconciliation, comprehensive geriatric assessment. In addition, some commonly identified behavior change techniques included goal setting (behavior), goal setting (outcome) and problem solving. CONCLUSIONS: This study identified important intervention elements and their potential strategies that could be adopted in an intervention to optimize appropriate prescribing for older adults with multimorbidity.

A novel CYR61-triggered 'CYR61-alphavbeta3 integrin loop' regulates breast cancer cell survival and chemosensitivity through activation of ERK1/ERK2 MAPK signaling pathway.

The angiogenic inducer CYR61 is differentially overexpressed in breast cancer cells exhibiting high levels of Heregulin (HRG), a growth factor closely associated with a metastatic breast cancer phenotype. Here, we examined whether CYR61, independently of HRG, actively regulates breast cancer cell survival and chemosensitivity, and the pathways involved. Forced expression of CYR61 in HRG-negative MCF-7 cells notably upregulated the expression of its own integrin receptor alphavbeta3 (>200 times). Small peptidomimetic alphavbeta3 integrin antagonists dramatically decreased cell viability of CYR61-overexpressing MCF-7 cells, whereas control MCF-7/V remained insensitive. Mechanistically, functional blockade of alphavbeta3 specifically abolished CYR6-induced hyperactivation of ERK1/ERK2 MAPK, whereas the activation status of AKT did not decrease. Moreover, CYR61 overexpression rendered MCF-7 cells significantly resistant (>10-fold) to Taxol-induced cytotoxicity. Remarkably, alphavbeta3 inhibition converted the CYR61-induced Taxol-resistant phenotype into a hypersensitive one. Thus, the augmentation of Taxol-induced apoptotic cell death in the presence of alphavbeta3 antagonists demonstrated a strong synergism as verified by the terminal transferase-mediated dUTP nick-end labeling (TUNEL) assay and by flow cytometric analysis for DNA content. Indeed, functional blockade of alphavbeta3, similarly to the pharmacological MAPK inhibitor U0126, synergistically increased both the proportion of CYR61-overexpressing breast cancer cells in the G2 phase of the cell cycle and the appearance of sub-G1 hypodiploid (apoptotic) cells caused by Taxol. Strikingly, CYR61 overexpression impaired the accumulation of wild-type p53 following Taxol exposure, while inhibition of alphavbeta3 or ERK1/ERK2 MAPK signalings completely restored Taxol-induced upregulation of p53. Moreover, antisense downregulation of CYR61 expression abolished the anchorage-independent growth of breast cancer cells engineered to overexpress HRG, and significantly increased their sensitivity to Taxol. Our data provide evidence that CYR61 is sufficient to promote breast cancer cell proliferation, cell survival, and Taxol resistance through a alphavbeta3-activated ERK1/ERK2 MAPK signaling. The identification of a 'CYR61-alphavbeta3 autocrine loop' in the epithelial compartment of breast carcinoma strongly suggests that targeting alphavbeta3 may simultaneously prevent breast cancer angiogenesis, growth, and chemoresistance.

Kimura's disease of the parapharyngeal space.

Kimura's disease is a fairly uncommon inflammatory condition of unknown etiology. It classically presents in young Asian males as tumorlike subcutaneous nodules in the head and neck with associated lymphadenopathy, peripheral eosinophilia, and an elevated serum IgE level. Kimura's disease affects the subcutaneous tissues, salivary glands, and lymph nodes; less common sites in the head and neck include the eyelid and tympanic membrane. We report a case of Kimura's disease of the parapharyngeal space in a 42-year-old Chinese woman. To the best of our knowledge, this is the first report of Kimura's disease at this site.

Programmed Ribosomal Frameshifting Mediates Expression of the α-Carboxysome.

Many bacteria employ a protein organelle, the carboxysome, to catalyze carbon dioxide fixation in the Calvin Cycle. Only 10 genes from Halothiobacillus neapolitanus are sufficient for heterologous expression of carboxysomes in Escherichia coli, opening the door to detailed mechanistic analysis of the assembly process of this complex (more than 200MDa). One of these genes, csoS2, has been implicated in assembly but ascribing a molecular function is confounded by the observation that the single csoS2 gene yields expression of two gene products and both display an apparent molecular weight incongruent with the predicted amino acid sequence. Here, we elucidate the co-translational mechanism responsible for the expression of the two protein isoforms. Specifically, csoS2 was found to possess -1 frameshifting elements that lead to the production of the full-length protein, CsoS2B, and a truncated protein, CsoS2A, which possesses a C-terminus translated from the alternate frame. The frameshifting elements comprise both a ribosomal slippery sequence and a 3' secondary structure, and ablation of either sequence is sufficient to eliminate the slip. Using these mutants, we investigated the individual roles of CsoS2B and CsoS2A on carboxysome formation. In this in vivo formation assay, cells expressing only the CsoS2B isoform were capable of producing intact carboxysomes, while those with only CsoS2A were not. Thus, we have answered a long-standing question about the nature of CsoS2 in this model microcompartment and demonstrate that CsoS2B is functionally distinct from CsoS2A in the assembly of α-carboxysomes.

Ribonuclease A suggests how proteins self-chaperone against amyloid fiber formation.

Genomic analyses have identified segments with high fiber-forming propensity in many proteins not known to form amyloid. Proteins are often protected from entering the amyloid state by molecular chaperones that permit them to fold in isolation from identical molecules; but, how do proteins self-chaperone their folding in the absence of chaperones? Here, we explore this question with the stable protein ribonuclease A (RNase A). We previously identified fiber-forming segments of amyloid-related proteins and demonstrated that insertion of these segments into the C-terminal hinge loop of nonfiber-forming RNase A can convert RNase A into the amyloid state through three-dimensional domain-swapping, where the inserted fiber-forming segments interact to create a steric zipper spine. In this study, we convert RNase A into amyloid-like fibers by increasing the loop length and hence conformational freedom of an endogenous fiber-forming segment, SSTSAASS, in the N-terminal hinge loop. This is accomplished by sandwiching SSTSAASS between inserted Gly residues. With these inserts, SSTSAASS is now able to form the steric zipper spine, allowing RNase A to form amyloid-like fibers. We show that these fibers contain RNase A molecules retaining their enzymatic activity and therefore native-like structure. Thus, RNase A appears to prevent fiber formation by limiting the conformational freedom of this fiber-forming segment from entering a steric zipper. Our observations suggest that proteins have evolved to self-chaperone by using similar protective mechanisms.

Atomic view of a toxic amyloid small oligomer.

Amyloid diseases, including Alzheimer's, Parkinson's, and the prion conditions, are each associated with a particular protein in fibrillar form. These amyloid fibrils were long suspected to be the disease agents, but evidence suggests that smaller, often transient and polymorphic oligomers are the toxic entities. Here, we identify a segment of the amyloid-forming protein αB crystallin, which forms an oligomeric complex exhibiting properties of other amyloid oligomers: ß-sheet-rich structure, cytotoxicity, and recognition by an oligomer-specific antibody. The x-ray-derived atomic structure of the oligomer reveals a cylindrical barrel, formed from six antiparallel protein strands, that we term a cylindrin. The cylindrin structure is compatible with a sequence segment from the ß-amyloid protein of Alzheimer's disease. Cylindrins offer models for the hitherto elusive structures of amyloid oligomers.

Short protein segments can drive a non-fibrillizing protein into the amyloid state.

Protein fibrils termed amyloid-like are associated with numerous degenerative diseases as well as some normal cellular functions. Specific short segments of amyloid-forming proteins have been shown to form fibrils themselves. However, it has not been shown in general that these segments are capable of driving a protein from its native structure into the amyloid state. We applied the 3D profile method to identify fibril-forming segments within the amyloid-forming human proteins tau, alpha-synuclein, PrP prion and amyloid-beta. Ten segments, six to eight residues in length, were chosen and inserted into the C-terminal hinge loop of the highly constrained enzyme RNase A, and tested for fibril growth and Congo red birefringence. We find that all 10 unique inserts cause RNase A to form amyloid-like fibrils which display characteristic yellow to apple-green Congo red birefringence when observed with cross polarizers. These six to eight residue inserts can fibrillize RNase A and are sufficient for amyloid fibril spine formation.

Pharmacological inhibition of fatty acid synthase (FAS): a novel therapeutic approach for breast cancer chemoprevention through its ability to suppress Her-2/neu (erbB-2) oncogene-induced malignant transformation.

We designed our experiments to evaluate whether fatty acid synthase (FAS), a lipogenic enzyme linked to tumor virulence in population studies of human cancer, is necessary for the malignant transformation induced by Her-2/neu (erbB-2) oncogene, which is overexpressed not only in invasive breast cancer but also in premalignant atypical duct proliferations and in ductal carcinoma in situ of the breast. To avoid the genetic complexities associated with established breast cancer cell lines, we employed NIH-3T3 mouse fibroblasts engineered to overexpress human Her-2/neu coding sequence. NIH-3T3/Her-2 cells demonstrated a significant upregulation of FAS protein expression, which was dependent on the upstream activation of mitogen-activated protein kinase and phosphatidylinositol 3'-kinase/AKT pathways. Remarkably, pharmacological FAS blockade using the mycotoxin cerulenin or the novel small compound C75 completely suppressed the state of Her-2/neu-induced malignant transformation by inhibiting the ability of NIH-3T3/Her-2 cells to grow under either anchorage-independent (i.e., to form colonies in soft agar) or low-serum monolayer conditions. Moreover, NIH-3T3/Her-2 fibroblasts were up to three times more sensitive to chemical FAS inhibitors relative to untransformed controls as determined by MTT-based cell viability assays. In addition, pharmacological FAS blockade preferentially induced apoptotic cell death of NIH-3T3/Her-2 fibroblasts, as determined by an ELISA for histone-associated DNA fragments and by the terminal deoxynucleotidyltransferase (TdT)-mediated nick end labeling assay (TUNEL). Interestingly, the degree of Her-2/neu oncogene expression in a panel of breast cancer cell lines was predictive of sensitivity to chemical FAS inhibitors-induced cytotoxicity, while low-FAS expressing and chemical FAS inhibitors-resistant MDA-MB-231 breast cancer cells became hypersensitive to FAS blockade when they were engineered to overexpress Her-2/neu. Our observations strongly suggest that inhibition of FAS activity may provide a new molecular avenue for chemotherapeutic prevention and/or treatment of Her-2/neu-related breast carcinomas.