Erratum: A tetracationic porphyrin with dual anti-prion activity.

[This corrects the article DOI: 10.1016/j.isci.2023.107480.].

Understanding the key features of the spontaneous formation of bona fide prions through a novel methodology that enables their swift and consistent generation.

Among transmissible spongiform encephalopathies or prion diseases affecting humans, sporadic forms such as sporadic Creutzfeldt-Jakob disease are the vast majority. Unlike genetic or acquired forms of the disease, these idiopathic forms occur seemingly due to a random event of spontaneous misfolding of the cellular PrP (PrPC) into the pathogenic isoform (PrPSc). Currently, the molecular mechanisms that trigger and drive this event, which occurs in approximately one individual per million each year, remain completely unknown. Modelling this phenomenon in experimental settings is highly challenging due to its sporadic and rare occurrence. Previous attempts to model spontaneous prion misfolding in vitro have not been fully successful, as the spontaneous formation of prions is infrequent and stochastic, hindering the systematic study of the phenomenon. In this study, we present the first method that consistently induces spontaneous misfolding of recombinant PrP into bona fide prions within hours, providing unprecedented possibilities to investigate the mechanisms underlying sporadic prionopathies. By fine-tuning the Protein Misfolding Shaking Amplification method, which was initially developed to propagate recombinant prions, we have created a methodology that consistently produces spontaneously misfolded recombinant prions in 100% of the cases. Furthermore, this method gives rise to distinct strains and reveals the critical influence of charged surfaces in this process.

A tetracationic porphyrin with dual anti-prion activity.

Prions are deadly infectious agents made of PrPSc, a misfolded variant of the cellular prion protein (PrPC) which self-propagates by inducing misfolding of native PrPC. PrPSc can adopt different pathogenic conformations (prion strains), which can be resistant to potential drugs, or acquire drug resistance, hampering the development of effective therapies. We identified Zn(II)-BnPyP, a tetracationic porphyrin that binds to distinct domains of native PrPC, eliciting a dual anti-prion effect. Zn(II)-BnPyP binding to a C-terminal pocket destabilizes the native PrPC fold, hindering conversion to PrPSc; Zn(II)-BnPyP binding to the flexible N-terminal tail disrupts N- to C-terminal interactions, triggering PrPC endocytosis and lysosomal degradation, thus reducing the substrate for PrPSc generation. Zn(II)-BnPyP inhibits propagation of different prion strains in vitro, in neuronal cells and organotypic brain cultures. These results identify a PrPC-targeting compound with an unprecedented dual mechanism of action which might be exploited to achieve anti-prion effects without engendering drug resistance.

Role of personal aptitudes as determinants of incident morbidity, lifestyles, quality of life, use of the health services and mortality (DESVELA cohort): qualitative study protocol for a prospective cohort study in a hybrid analysis.

Introduction: Maintaining or acquiring healthier health-oriented behaviours and promoting physical and mental health amongst the Spanish population is a significant challenge for Primary Health Care. Although the role of personal aptitudes (characteristics of each individual) in influencing health behaviours is not yet clear, these factors, in conjunction with social determinants such as gender and social class, can create axes of social inequity that affect individuals' opportunities to engage in health-oriented behaviours. Additionally, lack of access to health-related resources and opportunities can further exacerbate the issue for individuals with healthy personal aptitudes. Therefore, it is crucial to investigate the relationship between personal aptitudes and health behaviours, as well as their impact on health equity. Objectives: This paper outlines the development, design and rationale of a descriptive qualitative study that explores in a novel way the views and experiences on the relationship between personal aptitudes (activation, health literacy and personality traits) and their perception of health, health-oriented behaviours, quality of life and current health status. Method and analysis: This qualitative research is carried out from a phenomenological perspective. Participants will be between 35 and 74 years of age, will be recruited in Primary Health Care Centres throughout Spain from a more extensive study called DESVELA Cohort. Theoretical sampling will be carried out. Data will be collected through video and audio recording of 16 focus groups in total, which are planned to be held in 8 different Autonomous Communities, and finally transcribed for a triangulated thematic analysis supported by the Atlas-ti program. Discussion: We consider it essential to understand the interaction between health-related behaviours as predictors of lifestyles in the population, so this study will delve into a subset of issues related to personality traits, activation and health literacy.Clinical trial registration: ClinicalTrials.gov, identifier NCT04386135.

Female BMI and Body Weight Is Not Associated with Oocyte Yield and Maturation in hCG, Agonist or Dual Trigger Cycles: A Large Observational Study including 5000 Cycles.

BACKGROUND: Triggering final oocyte maturation is a key step of ovarian stimulation. Although previous studies demonstrated a negative association between female BMI and serum hCG levels, little evidence is available regarding the association between oocyte yield and patients' BMI. The scope of the current study was to examine whether the efficiency of the r-hCG and triptorelin to trigger final oocyte maturation may be associated with patients' BMI or weight. METHODS: This is a retrospective observational study including 5190 ovarian stimulation cycles performed between January 2019 and September 2022 in the Reproductive Medicine Department of Dexeus University Hospital. Cycles were analyzed according to the type of trigger (triptorelin vs. r-hCG vs. dual). The primary outcome measures were oocyte maturation rate (MII/oocytes) and FOI (oocytes/AFC); secondary outcomes were oocyte and MII yield. RESULTS: Multivariable regression analysis, adjusting for confounding factors, demonstrated that BMI was not associated with oocyte maturation rate (OR: 1.00 [95%CI: 0.99; 1.01]), FOI (Beta 0.52 [95%CI: -0.49; 1.54]), number of oocytes (Beta 0.02 [95%CI: -0.08; 0.13]) or MIIs (Beta 0.01 [95%CI: -0.08; 0.10]) retrieved. Similarly, all analyses conducted considering patients' weight failed to reveal any association. CONCLUSION: Our study demonstrates that, independent of the type of trigger, patients' BMI and weight are not associated with oocyte yield, maturation, or FOI.

The effect of late-follicular phase progesterone elevation on embryo ploidy and cumulative live birth rates.

RESEARCH QUESTION: Does late-follicular phase progesterone elevation have a deleterious effect on embryo euploidy, blastocyst formation rate and cumulative live birth rates (CLBR)? DESIGN: A multicentre retrospective cross-sectional study including infertile patients aged 18-40 years who underwent ovarian stimulation in a gonadotrophin-releasing hormone antagonist protocol and preimplantation genetic testing for aneuploidies (PGT-A) followed by a freeze-all strategy and euploid embryo transfer between August 2017 and December 2019. The sample was stratified according to the progesterone concentrations on the day of trigger: normal (≤1.50 ng/ml) and high (>1.50 ng/ml). Moreover, sensitivity analyses were performed to determine whether different conclusions would have been drawn if different cut-offs had been adopted. The primary outcome was the embryo euploidy rate. Secondary outcomes were the blastocyst formation rate, the number of euploid blastocysts and CLBR. RESULTS: Overall 1495 intracytoplasmic sperm injection PGT-A cycles were analysed. Late-follicular phase progesterone elevation was associated with significantly higher late-follicular oestradiol concentrations (2847.56 ± 1091.10 versus 2240.94 ± 996.37 pg/ml, P < 0.001) and significantly more oocytes retrieved (17.67 ± 8.86 versus 12.70 ± 7.00, P < 0.001). The number of euploid embryos was significantly higher in the progesterone elevation group (2.32 ± 1.74 versus 1.86 ± 1.42, P = 0.001), whereas the blastocyst formation rate (47.1% [43.7-50.5%] versus 51.0% [49.7-52.4%]), the embryo euploidy rate (48.3% [44.9-51.7%] versus 49.1% [47.7-50.6%], the live birth rate in the first frozen embryo transfer (34.1% versus 31.1%, P = 0.427) and CLBR (38.9% versus 37.0%, P = 0.637) were not significantly different between the two groups. CONCLUSIONS: Euploidy rate and CLBR do not significantly differ among PGT-A cycles with and without late-follicular progesterone elevation in a freeze-all approach.

Improving the Pharmacological Properties of Ciclopirox for Its Use in Congenital Erythropoietic Porphyria.

Congenital erythropoietic porphyria (CEP), also known as Günther's disease, results from a deficient activity in the fourth enzyme, uroporphyrinogen III synthase (UROIIIS), of the heme pathway. Ciclopirox (CPX) is an off-label drug, topically prescribed as an antifungal. It has been recently shown that it also acts as a pharmacological chaperone in CEP, presenting a specific activity in deleterious mutations in UROIIIS. Despite CPX is active at subtoxic concentrations, acute gastrointestinal (GI) toxicity was found due to the precipitation in the stomach of the active compound and subsequent accumulation in the intestine. To increase its systemic availability, we carried out pharmacokinetic (PK) and pharmacodynamic (PD) studies using alternative formulations for CPX. Such strategy effectively suppressed GI toxicity in WT mice and in a mouse model of the CEP disease (UROIIISP248Q/P248Q). In terms of activity, phosphorylation of CPX yielded good results in CEP cellular models but showed limited activity when administered to the CEP mouse model. These results highlight the need of a proper formulation for pharmacological chaperones used in the treatment of rare diseases.

A Novel, Reliable and Highly Versatile Method to Evaluate Different Prion Decontamination Procedures.

Transmissible spongiform encephalopathies (TSEs) are a group of invariably fatal neurodegenerative disorders. The causal agent is an aberrantly folded isoform (PrPSc or prion) of the endogenous prion protein (PrPC) which is neurotoxic and amyloidogenic and induces misfolding of its physiological counterpart. The intrinsic physical characteristics of these infectious proteinaceous pathogens makes them highly resistant to the vast majority of physicochemical decontamination procedures used typically for standard disinfection. This means prions are highly persistent in contaminated tissues, the environment (surfaces) and, of great concern, on medical and surgical instruments. Traditionally, decontamination procedures for prions are tested on natural isolates coming from the brain of infected individuals with an associated high heterogeneity resulting in highly variable results. Using our novel ability to produce highly infectious recombinant prions in vitro we adapted the system to enable recovery of infectious prions from contaminated materials. This method is easy to perform and, importantly, results in highly reproducible propagation in vitro. It exploits the adherence of infectious prion protein to beads of different materials allowing accurate and repeatable assessment of the efficacy of disinfectants of differing physicochemical natures to eliminate infectious prions. This method is technically easy, requires only a small shaker and a standard biochemical technique and could be performed in any laboratory.

Detection of Pathognomonic Biomarker PrPSc and the Contribution of Cell Free-Amplification Techniques to the Diagnosis of Prion Diseases.

Transmissible spongiform encephalopathies or prion diseases are rapidly progressive neurodegenerative diseases, the clinical manifestation of which can resemble other promptly evolving neurological maladies. Therefore, the unequivocal ante-mortem diagnosis is highly challenging and was only possible by histopathological and immunohistochemical analysis of the brain at necropsy. Although surrogate biomarkers of neurological damage have become invaluable to complement clinical data and provide more accurate diagnostics at early stages, other neurodegenerative diseases show similar alterations hindering the differential diagnosis. To solve that, the detection of the pathognomonic biomarker of disease, PrPSc, the aberrantly folded isoform of the prion protein, could be used. However, the amounts in easily accessible tissues or body fluids at pre-clinical or early clinical stages are extremely low for the standard detection methods. The solution comes from the recent development of in vitro prion propagation techniques, such as Protein Misfolding Cyclic Amplification (PMCA) and Real Time-Quaking Induced Conversion (RT-QuIC), which have been already applied to detect minute amounts of PrPSc in different matrixes and make early diagnosis of prion diseases feasible in a near future. Herein, the most relevant tissues and body fluids in which PrPSc has been detected in animals and humans are being reviewed, especially those in which cell-free prion propagation systems have been used with diagnostic purposes.

Development of a new largely scalable in vitro prion propagation method for the production of infectious recombinant prions for high resolution structural studies.

The resolution of the three-dimensional structure of infectious prions at the atomic level is pivotal to understand the pathobiology of Transmissible Spongiform Encephalopathies (TSE), but has been long hindered due to certain particularities of these proteinaceous pathogens. Difficulties related to their purification from brain homogenates of disease-affected animals were resolved almost a decade ago by the development of in vitro recombinant prion propagation systems giving rise to highly infectious recombinant prions. However, lack of knowledge about the molecular mechanisms of the misfolding event and the complexity of systems such as the Protein Misfolding Cyclic Amplification (PMCA), have limited generating the large amounts of homogeneous recombinant prion preparations required for high-resolution techniques such as solid state Nuclear Magnetic Resonance (ssNMR) imaging. Herein, we present a novel recombinant prion propagation system based on PMCA that substitutes sonication with shaking thereby allowing the production of unprecedented amounts of multi-labeled, infectious recombinant prions. The use of specific cofactors, such as dextran sulfate, limit the structural heterogeneity of the in vitro propagated prions and makes possible, for the first time, the generation of infectious and likely homogeneous samples in sufficient quantities for studies with high-resolution structural techniques as demonstrated by the preliminary ssNMR spectrum presented here. Overall, we consider that this new method named Protein Misfolding Shaking Amplification (PMSA), opens new avenues to finally elucidate the three-dimensional structure of infectious prions.

Impact of aging on obstetric outcomes: defining advanced maternal age in Barcelona.

BACKGROUND: Women of advanced maternal age (AMA) are a growing population, with higher obstetric risks. The Mediterranean population has specific characteristics different from other areas. Thus, the objective of this study was to establish a cut-off to define AMA in a selected mediterranean population coming from a tertiary referral private/mutual health hospital in Barcelona. METHODS: Retrospective cohort of euploid singleton pregnancies delivered from January 2007 to June 2017. Main maternal outcomes were: gestational diabetes, preeclampsia, placenta previa, c-section and prolonged hospitalization (≥ 7 days). Main adverse perinatal outcomes were: stillbirth, prematurity, preterm prelabor rupture of membranes, low birth weight, need of admission at a neonatal intensive care unit and perinatal mortality. Adjustment for confounding factors (smoking, previous comorbilities, parity, assisted reproductive techniques (ART) and obesity) was performed. RESULTS: A total of 25054 pregnancies were included. Mean maternal age was 34.7 ± 4.2 years, with 2807 patients in the group of age between 40 and 44 years (11.2%) and 280 patients ≥45 years (1.1%). Women at AMA had higher incidence of previous comorbilities (compared to the reference group of women < 30 years): prior c-section, chronic hypertension and obesity. In addition, they were more likely to use ART. After adjusting for confounding factors, maternal age was an independent and statistically significant risk factor for gestational diabetes (OR 1.66/2.80/3.14) for ages 30-39, 40-44 and ≥ 45 years respectively, c-section (OR 1.28/2.41/7.27) and placenta previa (OR 2.56/4.83) for ages 40-44 and ≥ 45 years respectively, but not for preeclampsia (neither early-onset nor late-onset). Risk of emergency c-section was only increased in women ≥45 years (OR, 2.03 (95% CI, 1.50-2.74). In the other groups of age, the increase in c-section rate was because of elective indications. Age ≥ 45 years was associated with iatrogenic prematurity < 37 weeks (OR 2.62, 95% CI 1.30-5.27). No other relevant associations between AMA and maternal or neonatal outcomes were found. CONCLUSIONS: Maternal age is an independent risk factor for adverse obstetric outcomes. Age ≥ 40 years was associated to relevant increased risks and reveals to be an adequate cut-off to define AMA in our population.

What is the clinical impact of the endometrial receptivity array in PGT-A and oocyte donation cycles?

PURPOSE: To evaluate the influence of the endometrial receptivity array (ERA) test on the implantation rate (IR) and pregnancy rate (PR) in patients with previous failed euploid embryo transfers (Euploid-ET) or oocyte donation embryo transfers (Donor-ET). METHODS: Single-center retrospective study of patients with ≥ 1 previous failed Euploi-ET (n = 24) or ≥ 2 failed Donor-ET (n = 32) who underwent an ERA test and a post-ERA Euploid-ET/Donor-ET between 2012 and 2018. Controls were patients with ≥ 1 previously failed Euploid-ET (n = 119) or ≥ 2 failed Donor-ET (n = 158) who underwent Euploid-ET/Donor-ET during the same period without performing an ERA test. Only blastocyst stage embryos were included. IR/PR was compared between the post-ERA ET and the last ET in the control group. RESULTS: There was no statistically significant difference regarding IR [55.6% (34.6-76.5%) vs. 65.0% (56.9-73.1%)] nor PR (58.3% vs.70.6%, p = 0.238) in the Euploid-ET ERA vs. Euploid-ET control groups. In the Donor-ET arm, both IR [26.8% (12.3-41.4%) vs. 57.2% (50.1-64.3%)] and PR (34.4% vs. 65.2%, p = 0.001) were significantly lower in the ERA group. Multivariate analysis confirmed that performing an ERA test did not influence the PR in the Euploid-ET arm and was associated with a diminished PR in the Donor-ET arm. In the ERA group, 41.1% patients were non-receptive (NR). No significant difference was found regarding IR/PR in NR vs. receptive patients in both Euploid-ET/Donor-ET arms. CONCLUSIONS: In our sample, the performance of an ERA test did not improve pregnancy outcomes. Future prospective studies in larger samples are needed to confirm the role of the ERA test in Euploid-ET/Donor-ET.

Recombinant PrP and Its Contribution to Research on Transmissible Spongiform Encephalopathies.

The misfolding of the cellular prion protein (PrPC) into the disease-associated isoform (PrPSc) and its accumulation as amyloid fibrils in the central nervous system is one of the central events in transmissible spongiform encephalopathies (TSEs). Due to the proteinaceous nature of the causal agent the molecular mechanisms of misfolding, interspecies transmission, neurotoxicity and strain phenomenon remain mostly ill-defined or unknown. Significant advances were made using in vivo and in cellula models, but the limitations of these, primarily due to their inherent complexity and the small amounts of PrPSc that can be obtained, gave rise to the necessity of new model systems. The production of recombinant PrP using E. coli and subsequent induction of misfolding to the aberrant isoform using different techniques paved the way for the development of cell-free systems that complement the previous models. The generation of the first infectious recombinant prion proteins with identical properties of brain-derived PrPSc increased the value of cell-free systems for research on TSEs. The versatility and ease of implementation of these models have made them invaluable for the study of the molecular mechanisms of prion formation and propagation, and have enabled improvements in diagnosis, high-throughput screening of putative anti-prion compounds and the design of novel therapeutic strategies. Here, we provide an overview of the resultant advances in the prion field due to the development of recombinant PrP and its use in cell-free systems.