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2.
Nurs Inq ; 31(2): e12594, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37602952

ABSTRACT

The study discusses a new approach to parental agency in pediatric palliative care based on an active form of caregiving. It also explores the possibility of a positive conceptualization of parental agency in its relational context. The paper begins with an illustrative case study based on a clinical situation. This is followed by an analysis of various aspects of parental agency based on empirical studies that disclose the insufficiencies of the traditional approach to parental agency. In the next step, parental agency is analyzed from a reality-based perspective as an activity focused on relationships and the cognitive capacity of parents vis-a-vis their seriously ill children. The paper also considers the importance of the cultural and social contexts in which parental agency and decision-making take place. This agency is addressed not as individualistic in form, and nor is it exercised in terms of fixed choices. Rather, the focus is on its dynamic and future-oriented aspects. Consequently, parental agency should be comprehended not only as a form of proxy agency representing the child's best interests but also as a complex decision-making process in which the parents learn from their child how to become good, compassionate caregivers and at the same time good parents.

3.
Immunity ; 56(2): 406-419.e7, 2023 02 14.
Article in English | MEDLINE | ID: mdl-36792574

ABSTRACT

Malaria transmission-blocking vaccines (TBVs) aim to induce antibodies that interrupt malaria parasite development in the mosquito, thereby blocking onward transmission, and provide a much-needed tool for malaria control and elimination. The parasite surface protein Pfs48/45 is a leading TBV candidate. Here, we isolated and characterized a panel of 81 human Pfs48/45-specific monoclonal antibodies (mAbs) from donors naturally exposed to Plasmodium parasites. Genetically diverse mAbs against each of the three domains (D1-D3) of Pfs48/45 were identified. The most potent mAbs targeted D1 and D3 and achieved >80% transmission-reducing activity in standard membrane-feeding assays, at 10 and 2 µg/mL, respectively. Co-crystal structures of D3 in complex with four different mAbs delineated two conserved protective epitopes. Altogether, these Pfs48/45-specific human mAbs provide important insight into protective and non-protective epitopes that can further our understanding of transmission and inform the design of refined malaria transmission-blocking vaccine candidates.


Subject(s)
Culicidae , Malaria Vaccines , Malaria, Falciparum , Malaria , Animals , Humans , Plasmodium falciparum , Culicidae/metabolism , Protozoan Proteins , Antibodies, Monoclonal , Malaria, Falciparum/prevention & control , Antibodies, Protozoan
4.
Immunity ; 56(2): 420-432.e7, 2023 02 14.
Article in English | MEDLINE | ID: mdl-36792575

ABSTRACT

Pfs230 is essential for Plasmodium falciparum transmission to mosquitoes and is the protein targeted by the most advanced malaria-transmission-blocking vaccine candidate. Prior understanding of functional epitopes on Pfs230 is based on two monoclonal antibodies (mAbs) with moderate transmission-reducing activity (TRA), elicited from subunit immunization. Here, we screened the B cell repertoire of two naturally exposed individuals possessing serum TRA and identified five potent mAbs from sixteen Pfs230 domain-1-specific mAbs. Structures of three potent and three low-activity antibodies bound to Pfs230 domain 1 revealed four distinct epitopes. Highly potent mAbs from natural infection recognized a common conformational epitope that is highly conserved across P. falciparum field isolates, while antibodies with negligible TRA derived from natural infection or immunization recognized three distinct sites. Our study provides molecular blueprints describing P. falciparum TRA, informed by contrasting potent and non-functional epitopes elicited by natural exposure and vaccination.


Subject(s)
Malaria Vaccines , Malaria, Falciparum , Humans , Animals , Plasmodium falciparum , Epitopes , Protozoan Proteins , Antigens, Protozoan , Antibodies, Monoclonal , Antibodies, Protozoan , Malaria, Falciparum/prevention & control
5.
Int J Mol Sci ; 23(24)2022 Dec 14.
Article in English | MEDLINE | ID: mdl-36555559

ABSTRACT

The relationship between conserved structural motifs and their biological function in the virus replication cycle is the interest of many researchers around the world. RNA structure is closely related to RNA function. Therefore, technological progress in high-throughput approaches for RNA structure analysis and the development of new ones are very important. In this mini review, we discuss a few perspectives on the structural elements of viral genomes and some methods used for RNA structure prediction and characterization. Based on the recent literature, we describe several examples of studies concerning the viral genomes, especially severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus (IAV). Herein, we emphasize that a better understanding of viral genome architecture allows for the discovery of the structure-function relationship, and as a result, the discovery of new potential antiviral therapeutics.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/genetics , Genome, Viral , RNA, Viral/genetics , RNA, Viral/chemistry , Antiviral Agents , Virus Replication/genetics
6.
J Mol Biol ; 434(18): 167632, 2022 09 30.
Article in English | MEDLINE | ID: mdl-35588868

ABSTRACT

RNA folding free energy change parameters are widely used to predict RNA secondary structure and to design RNA sequences. These parameters include terms for the folding free energies of helices and loops. Although the full set of parameters has only been traditionally available for the four common bases and backbone, it is well known that covalent modifications of nucleotides are widespread in natural RNAs. Covalent modifications are also widely used in engineered sequences. We recently derived a full set of nearest neighbor terms for RNA that includes N6-methyladenosine (m6A). In this work, we test the model using 98 optical melting experiments, matching duplexes with or without N6-methylation of A. Most experiments place RRACH, the consensus site of N6-methylation, in a variety of contexts, including helices, bulge loops, internal loops, dangling ends, and terminal mismatches. For matched sets of experiments that include either A or m6A in the same context, we find that the parameters for m6A are as accurate as those for A. Across all experiments, the root mean squared deviation between estimated and experimental free energy changes is 0.67 kcal/mol. We used the new experimental data to refine the set of nearest neighbor parameter terms for m6A. These parameters enable prediction of RNA secondary structures including m6A, which can be used to model how N6-methylation of A affects RNA structure.


Subject(s)
Adenosine , RNA Folding , RNA , Adenosine/analogs & derivatives , Adenosine/chemistry , Entropy , RNA/chemistry
7.
Nat Commun ; 13(1): 1271, 2022 03 11.
Article in English | MEDLINE | ID: mdl-35277476

ABSTRACT

There is increasing interest in the roles of covalently modified nucleotides in RNA. There has been, however, an inability to account for modifications in secondary structure prediction because of a lack of software and thermodynamic parameters. We report the solution for these issues for N6-methyladenosine (m6A), allowing secondary structure prediction for an alphabet of A, C, G, U, and m6A. The RNAstructure software now works with user-defined nucleotide alphabets of any size. We also report a set of nearest neighbor parameters for helices and loops containing m6A, using experiments. Interestingly, N6-methylation decreases folding stability for adenosines in the middle of a helix, has little effect on folding stability for adenosines at the ends of helices, and increases folding stability for unpaired adenosines stacked on a helix. We demonstrate predictions for an N6-methylation-activated protein recognition site from MALAT1 and human transcriptome-wide effects of N6-methylation on the probability of adenosine being buried in a helix.


Subject(s)
RNA , Software , Adenosine/analogs & derivatives , Base Sequence , Humans , Nucleic Acid Conformation , RNA/chemistry , Thermodynamics
8.
Int J Mol Sci ; 22(11)2021 Jun 02.
Article in English | MEDLINE | ID: mdl-34199658

ABSTRACT

Influenza A virus (IAV) causes seasonal epidemics and sporadic pandemics, therefore is an important research subject for scientists around the world. Despite the high variability of its genome, the structure of viral RNA (vRNA) possesses features that remain constant between strains and are biologically important for virus replication. Therefore, conserved structural motifs of vRNA can represent a novel therapeutic target. Here, we focused on the presence of G-rich sequences within the influenza A/California/07/2009(H1N1) genome and their ability to form RNA G-quadruplex structures (G4s). We identified 12 potential quadruplex-forming sequences (PQS) and determined their conservation among the IAV strains using bioinformatics tools. Then we examined the propensity of PQS to fold into G4s by various biophysical methods. Our results revealed that six PQS oligomers could form RNA G-quadruplexes. However, three of them were confirmed to adopt G4 structures by all utilized methods. Moreover, we showed that these PQS motifs are present within segments encoding polymerase complex proteins indicating their possible role in the virus biology.


Subject(s)
G-Quadruplexes , Influenza A Virus, H1N1 Subtype/genetics , Influenza A virus/genetics , Influenza, Human/genetics , Computational Biology , Genome, Viral/drug effects , Genome, Viral/genetics , Humans , Influenza A virus/drug effects , Influenza, Human/pathology , RNA, Viral/genetics , Virus Replication/drug effects , Virus Replication/genetics
9.
Med Health Care Philos ; 24(4): 529-542, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34173124

ABSTRACT

This article examines the compatibility and relevance of Gabriel Marcel's phenomenology of hope in interdisciplinary research on the role of hope in end-of-life (EOL) care. Our analysis is divided into three thematic topics which examine the various shades of hope observed in Marcel's phenomenology of hope and in the collection of 20 EOL studies on hope as experienced by adult palliative care (PC) patients, health care professionals (HCP) and parents of terminally ill children. The three topics defining the shades of hope are: the meaning of hope in its dynamic aspects, the dialectics of hope and despair, and the transcendent facets of hope. We analyse how Marcel's understanding of hope is reflected in EOL studies, and how this perception can enrich the philosophy of PC and significantly deepen and broaden HCPs' understanding of hope. Our findings prove that despite terminological differences between Marcelian phenomenology and the concepts of hope in the 20 EOL studies, hope emerges as a resourceful movement towards being. Implementing Marcelian hope within communication in EOL care could help in HCPs' interpersonal approach to patients as his concept harbors a holistic perception of the existential situation of a person. Equally, introducing Marcel's phenomenology of hope into the clinical encounter could play a beneficial role in improving the ability of patients to adapt to the difficult conditions of their disease and PC treatment.


Subject(s)
Hospice Care , Terminal Care , Adult , Child , Existentialism , Humans , Palliative Care , Terminally Ill
10.
Pathogens ; 9(11)2020 Nov 07.
Article in English | MEDLINE | ID: mdl-33171815

ABSTRACT

Influenza is an important research subject around the world because of its threat to humanity. Influenza A virus (IAV) causes seasonal epidemics and sporadic, but dangerous pandemics. A rapid antigen changes and recombination of the viral RNA genome contribute to the reduced effectiveness of vaccination and anti-influenza drugs. Hence, there is a necessity to develop new antiviral drugs and strategies to limit the influenza spread. IAV is a single-stranded negative sense RNA virus with a genome (viral RNA-vRNA) consisting of eight segments. Segments within influenza virion are assembled into viral ribonucleoprotein (vRNP) complexes that are independent transcription-replication units. Each step in the influenza life cycle is regulated by the RNA and is dependent on its interplay and dynamics. Therefore, viral RNA can be a proper target to design novel therapeutics. Here, we briefly described examples of anti-influenza strategies based on the antisense oligonucleotide (ASO), small interfering RNA (siRNA), microRNA (miRNA) and catalytic nucleic acids. In particular we focused on the vRNA structure-function relationship as well as presented the advantages of using secondary structure information in predicting therapeutic targets and the potential future of this field.

11.
Nurs Inq ; 27(2): e12341, 2020 04.
Article in English | MEDLINE | ID: mdl-31899851

ABSTRACT

The purpose of this study is to analyze the experience of hope that appears in a parent's blog presenting everyday life while caring for a child with Trisomy 18 (Edwards syndrome). The author, Rebekah Peterson, began her blog on 17 March 2011 and continues to post information on her son Aaron's care. The analysis of hope in the blog is carried out using a mixed methodology: initial and focused coding using Charmaz's constructed grounded theory and elements of Colaizzi's method. Each aspect of hope is coded through the blog author's statements, from which three main aspects of hope emerge: hope for the longest possible presence of Aaron with his family, hope for control over situations, pain, and symptoms, and existential facets of hope. These various aspects reveal to what extent the experience of hope is unique. Additionally, analyzing the experience of parental hope uncovers the additional problem of inappropriate communication by health care professionals (HCPs) in intensive care units, particularly when discussing the termination of causal treatment. The problem may be solved through proper education for HCPs and serious consideration of parental involvement in order to properly elaborate guidelines on this issue. The three main aspects of parental hope discussed in this paper might expand knowledge on the issue, helping HCPs to better understand the parents' experience of care and to help sustain parental hope in pediatric palliative care.


Subject(s)
Hope , Palliative Care , Parents/psychology , Pediatrics , Professional-Family Relations , Trisomy 18 Syndrome , Blogging , Child , Communication , Female , Grounded Theory , Humans , Longitudinal Studies , Male , Qualitative Research , Trisomy 18 Syndrome/mortality , Trisomy 18 Syndrome/psychology
12.
Sci Rep ; 8(1): 13023, 2018 08 29.
Article in English | MEDLINE | ID: mdl-30158667

ABSTRACT

The occurrence of triplexes in vivo has been well documented and is determined by the presence of long homopurine-homopyrimidine tracts. The formation of these structures is the result of conformational changes that occur in the duplex, which allow the binding of a third strand within the major groove of the helix. Formation of these noncanonical forms by introducing synthetic triplex-forming oligonucleotides (TFOs) into the cell may have applications in molecular biology, diagnostics and therapy. This study focused on the formation of RNA triplexes as well as their thermal stability and biological potential in the HeLa cell line. Thermodynamics studies revealed that the incorporation of multiple locked nucleic acid (LNA) and 2-thiouridine (2-thioU) residues increased the stability of RNA triplexes. These data suggest that the number and position of the modified nucleotides within TFOs significantly stabilize the formed structures. Moreover, specificity of the interactions between the modified TFOs and the RNA hairpin was characterized using electrophoretic mobility-shift assay (EMSA), and triplex dissociation constants have been also determined. Finally, through quantitative analysis of GFP expression, the triplex structures were shown to regulate GFP gene silencing. Together, our data provide a first glimpse into the thermodynamic, structural and biological properties of LNA- and 2-thioU modified RNA triplexes.


Subject(s)
Biological Products/chemistry , HeLa Cells/drug effects , Nucleic Acid Hybridization , RNA/chemistry , RNA/genetics , Thermodynamics , Biological Products/metabolism , Humans , Molecular Structure , RNA/metabolism , RNA Stability
13.
FASEB J ; 32(3): 1196-1206, 2018 03.
Article in English | MEDLINE | ID: mdl-29122848

ABSTRACT

Excess circulating insulin is associated with obesity in humans and in animal models. However, the physiologic causality of hyperinsulinemia in adult obesity has rightfully been questioned because of the absence of clear evidence that weight loss can be induced by acutely reversing diet-induced hyperinsulinemia. Herein, we describe the consequences of inducible, partial insulin gene deletion in a mouse model in which animals have already been made obese by consuming a high-fat diet. A modest reduction in insulin production/secretion was sufficient to cause significant weight loss within 5 wk, with a specific effect on visceral adipose tissue. This result was associated with a reduction in the protein abundance of the lipodystrophy gene polymerase I and transcript release factor ( Ptrf; Cavin) in gonadal adipose tissue. RNAseq analysis showed that reduced insulin and weight loss also associated with a signature of reduced innate immunity. This study demonstrates that changes in circulating insulin that are too fine to adversely affect glucose homeostasis nonetheless exert control over adiposity.-Page, M. M., Skovsø, S., Cen, H., Chiu, A. P., Dionne, D. A., Hutchinson, D. F., Lim, G. E., Szabat, M., Flibotte, S., Sinha, S., Nislow, C., Rodrigues, B., Johnson, J. D. Reducing insulin via conditional partial gene ablation in adults reverses diet-induced weight gain.


Subject(s)
Diet, High-Fat/adverse effects , Gene Deletion , Homeostasis , Insulin/physiology , Obesity/prevention & control , Weight Gain/genetics , Adiposity , Animals , Body Weight , Male , Mice , Mice, Knockout , Obesity/etiology , Obesity/pathology
14.
FEBS J ; 284(23): 3986-3998, 2017 12.
Article in English | MEDLINE | ID: mdl-28771935

ABSTRACT

Nowadays, decades after the discovery of the right-handed B form of DNA, it is well known that nucleic acids have great conformational flexibility, exhibiting a large degree of variation in their structure. In nature, DNA and RNA exist in an antiparallel orientation, stabilized by Watson-Crick base pairs. However, in some cases, nucleic acid fragments with specific nucleotide sequences can adopt a parallel orientation involving non-canonical base pairing. Interestingly, parallel-stranded duplexes have been found in specific chromosome regions. Furthermore, parallel oriented regions have also been found in bacterial (Escherichia coli, Listeria innocua) and insect genomes (Drosophila melanogaster). These unusual structures could have a remarkable evolutionary role, as well as significant impact on biological processes. For example, parallel stretches were shown to be involved in processing the 3' ends of mRNAs and in specific gene silencing. Moreover, certain types of parallel-stranded duplexes may be useful tools, with several practical applications. They can constitute excellent templates for the formation of other structures and for the development of antigene and antisense approaches.


Subject(s)
Base Pairing , DNA/chemistry , RNA/chemistry , Animals , Base Sequence , DNA/genetics , Humans , Models, Molecular , Nucleic Acid Conformation , RNA/genetics , Thermodynamics
15.
PLoS One ; 11(2): e0149478, 2016.
Article in English | MEDLINE | ID: mdl-26908023

ABSTRACT

This is the first report to provide comprehensive thermodynamic and structural data concerning duplex, hairpin, quadruplex and i-motif structures in ß-L-RNA series. Herein we confirm that, within the limits of experimental error, the thermodynamic stability of enantiomeric structural motifs is the same as that of naturally occurring D-RNA counterparts. In addition, formation of D-RNA/L-RNA heterochiral duplexes is also observed; however, their thermodynamic stability is significantly reduced in reference to homochiral D-RNA duplexes. The presence of three locked nucleic acid (LNA) residues within the D-RNA strand diminishes the negative effect of the enantiomeric, complementary L-RNA strand in the formation of heterochiral RNA duplexes. Similar behavior is also observed for heterochiral LNA-2'-O-methyl-D-RNA/L-RNA duplexes. The formation of heterochiral duplexes was confirmed by 1H NMR spectroscopy. The CD curves of homochiral L-RNA structural motifs are always reversed, whereas CD curves of heterochiral duplexes present individual features dependent on the composition of chiral strands.


Subject(s)
RNA/chemistry , Circular Dichroism , Magnetic Resonance Spectroscopy , Nucleic Acid Conformation , Nucleotide Motifs , Oligonucleotides/chemistry , RNA Stability , Thermodynamics
16.
Cell Metab ; 23(1): 179-93, 2016 Jan 12.
Article in English | MEDLINE | ID: mdl-26626461

ABSTRACT

Pancreatic ß cells are mostly post-mitotic, but it is unclear what locks them in this state. Perturbations including uncontrolled hyperglycemia can drive ß cells into more pliable states with reduced cellular insulin levels, increased ß cell proliferation, and hormone mis-expression, but it is unknown whether reduced insulin production itself plays a role. Here, we define the effects of ∼50% reduced insulin production in Ins1(-/-):Ins2(f/f):Pdx1Cre(ERT):mTmG mice prior to robust hyperglycemia. Transcriptome, proteome, and network analysis revealed alleviation of chronic endoplasmic reticulum (ER) stress, indicated by reduced Ddit3, Trib3, and Atf4 expression; reduced Xbp1 splicing; and reduced phospho-eIF2α. This state was associated with hyper-phosphorylation of Akt, which is negatively regulated by Trib3, and with cyclinD1 upregulation. Remarkably, ß cell proliferation was increased 2-fold after reduced insulin production independently of hyperglycemia. Eventually, recombined cells mis-expressed glucagon in the hyperglycemic state. We conclude that the normally high rate of insulin production suppresses ß cell proliferation in a cell-autonomous manner.


Subject(s)
Cell Proliferation , Endoplasmic Reticulum Stress , Insulin-Secreting Cells/physiology , Insulin/biosynthesis , Animals , Cells, Cultured , Metabolome , Mice, Inbred NOD , Mice, Knockout , Mice, SCID , Protein Interaction Maps , Proteome/metabolism , Signal Transduction , Transcriptome
17.
PLoS One ; 10(11): e0143354, 2015.
Article in English | MEDLINE | ID: mdl-26579720

ABSTRACT

This study investigated the influence of the nature of oligonucleotides on the abilities to form antiparallel and parallel duplexes. Base pairing of homopurine DNA, 2'-O-MeRNA and RNA oligonucleotides with respective homopyrimidine DNA, 2'-O-MeRNA and RNA as well as chimeric oligonucleotides containing LNA resulted in the formation of 18 various duplexes. UV melting, circular dichroism and fluorescence studies revealed the influence of nucleotide composition on duplex structure and thermal stability depending on the buffer pH value. Most duplexes simultaneously adopted both orientations. However, at pH 5.0, parallel duplexes were more favorable. Moreover, the presence of LNA nucleotides within a homopyrimidine strand favored the formation of parallel duplexes.


Subject(s)
DNA/chemistry , Oligonucleotides/chemistry , RNA/chemistry , Circular Dichroism , Hydrogen-Ion Concentration
18.
R Soc Open Sci ; 2(12): 150306, 2015 Dec.
Article in English | MEDLINE | ID: mdl-27019722

ABSTRACT

Insulin production is the central feature of functionally mature and differentiated pancreatic ß-cells. Reduced insulin transcription and dedifferentiation have been implicated in type 2 diabetes, making drugs that could reverse these processes potentially useful. We have previously established ratiometric live-cell imaging tools to identify factors that increase insulin promoter activity and promote ß-cell differentiation. Here, we present a single vector imaging tool with eGFP and mRFP, driven by the Pdx1 and Ins1 promoters, respectively, targeted to the nucleus to enhance identification of individual cells in a high-throughput manner. Using this new approach, we screened 1120 off-patent drugs for factors that regulate Ins1 and Pdx1 promoter activity in MIN6 ß-cells. We identified a number of compounds that positively modulate Ins1 promoter activity, including several drugs known to modulate ion channels. Carbamazepine was selected for extended follow-up, as our previous screen also identified this use-dependent sodium channel inhibitor as a positive modulator of ß-cell survival. Indeed, carbamazepine increased Ins1 and Ins2 mRNA in primary mouse islets at lower doses than were required to protect ß-cells. We validated the role of sodium channels in insulin production by examining Nav1.7 (Scn9a) knockout mice and remarkably islets from these animals had dramatically elevated insulin content relative to wild-type controls. Collectively, our experiments provide a starting point for additional studies aimed to identify drugs and molecular pathways that control insulin production and ß-cell differentiation status. In particular, our unbiased screen identified a novel role for a ß-cell sodium channel gene in insulin production.

19.
Mol Plant ; 7(6): 960-976, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24637173

ABSTRACT

Ethylene plays a crucial role in various biological processes and therefore its biosynthesis is strictly regulated by multiple mechanisms. Posttranslational regulation, which is pivotal in controlling ethylene biosynthesis, impacts 1-aminocyclopropane 1-carboxylate synthase (ACS) protein stability via the complex interplay of specific factors. Here, we show that the Arabidopsis thaliana protein phosphatase type 2C, ABI1, a negative regulator of abscisic acid signaling, is involved in the regulation of ethylene biosynthesis under oxidative stress conditions. We found that ABI1 interacts with ACS6 and dephosphorylates its C-terminal fragment, a target of the stress-responsive mitogen-activated protein kinase, MPK6. In addition, ABI1 controls MPK6 activity directly and by this means also affects the ACS6 phosphorylation level. Consistently with this, ozone-induced ethylene production was significantly higher in an ABI1 knockout strain (abi1td) than in wild-type plants. Importantly, an increase in stress-induced ethylene production in the abi1td mutant was compensated by a higher ascorbate redox state and elevated antioxidant activities. Overall, the results of this study provide evidence that ABI1 restricts ethylene synthesis by affecting the activity of ACS6. The ABI1 contribution to stress phenotype underpins its role in the interplay between the abscisic acid (ABA) and ethylene signaling pathways.


Subject(s)
Arabidopsis Proteins/metabolism , Ethylenes/biosynthesis , Lyases/metabolism , Ozone , Phosphoprotein Phosphatases/metabolism , Arabidopsis , Gene Expression Regulation, Plant/drug effects , Protein Binding , Protein Phosphatase 2C , Signal Transduction/drug effects
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