Discovery and Characterization of the ddx41 Gene in Atlantic Salmon: Evolutionary Implications, Structural Functions, and Innate Immune Responses to Piscirickettsia salmonis and Renibacterium salmoninarum Infections.

The innate immune response in Salmo salar, mediated by pattern recognition receptors (PRRs), is crucial for defending against pathogens. This study examined DDX41 protein functions as a cytosolic/nuclear sensor for cyclic dinucleotides, RNA, and DNA from invasive intracellular bacteria. The investigation determined the existence, conservation, and functional expression of the ddx41 gene in S. salar. In silico predictions and experimental validations identified a single ddx41 gene on chromosome 5 in S. salar, showing 83.92% homology with its human counterpart. Transcriptomic analysis in salmon head kidney confirmed gene transcriptional integrity. Proteomic identification through mass spectrometry characterized three unique peptides with 99.99% statistical confidence. Phylogenetic analysis demonstrated significant evolutionary conservation across species. Functional gene expression analysis in SHK-1 cells infected by Piscirickettsia salmonis and Renibacterium salmoninarum indicated significant upregulation of DDX41, correlated with increased proinflammatory cytokine levels and activation of irf3 and interferon signaling pathways. In vivo studies corroborated DDX41 activation in immune responses, particularly when S. salar was challenged with P. salmonis, underscoring its potential in enhancing disease resistance. This is the first study to identify the DDX41 pathway as a key component in S. salar innate immune response to invading pathogens, establishing a basis for future research in salmonid disease resistance.

Arginyltransferase 1 modulates p62-driven autophagy via mTORC1/AMPk signaling.

BACKGROUND: Arginyltransferase (Ate1) orchestrates posttranslational protein arginylation, a pivotal regulator of cellular proteolytic processes. In eukaryotic cells, two interconnected systems-the ubiquitin proteasome system (UPS) and macroautophagy-mediate proteolysis and cooperate to maintain quality protein control and cellular homeostasis. Previous studies have shown that N-terminal arginylation facilitates protein degradation through the UPS. Dysregulation of this machinery triggers p62-mediated autophagy to ensure proper substrate processing. Nevertheless, how Ate1 operates through this intricate mechanism remains elusive. METHODS: We investigated Ate1 subcellular distribution through confocal microscopy and biochemical assays using cells transiently or stably expressing either endogenous Ate1 or a GFP-tagged Ate1 isoform transfected in CHO-K1 or MEFs, respectively. To assess Ate1 and p62-cargo clustering, we analyzed their colocalization and multimerization status by immunofluorescence and nonreducing immunoblotting, respectively. Additionally, we employed Ate1 KO cells to examine the role of Ate1 in autophagy. Ate1 KO MEFs cells stably expressing GFP-tagged Ate1-1 isoform were used as a model for phenotype rescue. Autophagy dynamics were evaluated by analyzing LC3B turnover and p62/SQSTM1 levels under both steady-state and serum-starvation conditions, through immunoblotting and immunofluorescence. We determined mTORC1/AMPk activation by assessing mTOR and AMPk phosphorylation through immunoblotting, while mTORC1 lysosomal localization was monitored by confocal microscopy. RESULTS: Here, we report a multifaceted role for Ate1 in the autophagic process, wherein it clusters with p62, facilitates autophagic clearance, and modulates its signaling. Mechanistically, we found that cell-specific inactivation of Ate1 elicits overactivation of the mTORC1/AMPk signaling hub that underlies a failure in autophagic flux and subsequent substrate accumulation, which is partially rescued by ectopic expression of Ate1. Statistical significance was assessed using a two-sided unpaired t test with a significance threshold set at P<0.05. CONCLUSIONS: Our findings uncover a critical housekeeping role of Ate1 in mTORC1/AMPk-regulated autophagy, as a potential therapeutic target related to this pathway, that is dysregulated in many neurodegenerative and cancer diseases.

StarD7 deficiency switches on glycolysis and promotes mitophagy flux in C2C12 myoblasts.

StarD7 is a member of the START protein family required for phosphatidylcholine delivery to the mitochondria, thus key to maintain mitochondrial structure. Its deficiency has been associated with an impairment of cellular processes, such as proliferation and migration, and it has also been reported that it is needed in myogenic differentiation. Here, we show that StarD7 deficiency in C2C12 muscle cells results in the accumulation of abnormal mitochondria, a reduced number of mitochondria per cell area and increased glycolysis. In addition, StarD7-deficient cells undergo an increase in mitochondria-ER contact sites, reduced connexin 43 expression, and disturbances in lipid handling, evidenced by lipid droplet accumulation and decreased levels in phosphatidylserine synthase 1 and 2 expression. Interestingly, StarD7-deficient cells showed alterations in mitophagy markers. We observed accumulation of LC3B-II and BNIP3 proteins in mitochondria-enriched fractions and accumulation of autophagolysosomal and lysosomal vesicles in StarD7-deficient cells. Furthermore, live-cell imaging experiments of StarD7 knockdown cells expressing mitochondria-targeted mKeima indicated an enhanced mitochondria delivery into lysosomes. Importantly, StarD7 reconstitution in StarD7-deficient cells restores LC3B-II expression in mitochondria-enriched fractions at similar levels to those observed in control cells. Collectively, these findings suggest that StarD7-deficient C2C12 myoblasts are associated with altered cristae structure, disturbances in neutral lipid accumulation, glucose metabolism, and increased mitophagy flux. The alterations mentioned above allow for the maintenance of mitochondrial function.

Effectiveness of Mepolizumab in Patients with Severe Eosinophilic Asthma with/without Nasal Polyposis: A Real-Life Study.

INTRODUCTION: Asthma is one of the most common chronic diseases and affects around 334 million people worldwide. The estimated prevalence of severe asthma is 3-10% of the asthmatic population. Mepolizumab has demonstrated efficacy in reducing exacerbations, oral corticosteroid use, and improving quality of life, asthma control, and lung function in patients with severe eosinophilic asthma (SEA). Our study aimed to check the response to mepolizumab in a series of severe asthma patients regarding exacerbations, oral corticosteroid use, asthma control, quality of life, and lung function and to compare the response between patients with and without nasal polyps. METHOD: This is a retrospective, multicenter study of RE-ASGRAMUR (Register of Severe Asthma of the Region of Murcia) performed in eight hospitals of the Region of Murcia (Spain) under routine clinical practice conditions. We included patients diagnosed with SEA who completed at least 1 year of treatment with mepolizumab. We analyzed clinical characteristics, drug tolerance, and effectiveness: exacerbations, ACT, miniAQLQ, forced expiratory volume in 1 s (FEV1), and use of oral corticosteroids. We also compared the results between patients with and without nasal polyps. RESULTS: The median of exacerbations before treatment was 3 and decreased to 0 after treatment (mean decrease of 77.4%). The median diary oral prednisone intake was 15 mg before treatment and 5 mg after treatment (mean 56% reduction). We have obtained a significant improvement in other variables: ED visits and hospitalizations, asthma control (ACT), quality of life (miniAQLQ), and lung function (FEV1). Thirty-four out of 70 patients (48.57%) fulfilled the criteria of super-responder, and 17 out of 70 (24.29%) had a complete response. More patients in the group with nasal polyps fulfilled the criteria of super-responder and complete response to mepolizumab. CONCLUSIONS: Mepolizumab is a safe and effective treatment for SEA patients, improving exacerbations, oral corticosteroid intake, asthma control, quality of life, and lung function. In patients with associated nasal polyposis, there is a statistically significant higher proportion of super-responders and complete responders.

Cross-cultural validation of the COVID-19 peritraumatic distress index (CPDI) among Spanish and Peruvian populations.

The COVID-19 pandemic has had a significant psychological impact worldwide. The COVID-19 Peritraumatic Distress Index (CPDI) is widely used to assess psychological stress during the COVID-19 pandemic. Although CPDI has been validated in Peru and Spain, no cross-cultural validation studies have been conducted. As an exploratory aim, differences in CPDI factorial scores between the most prevalent medical conditions in the two samples (arterial hypertension, respiratory diseases and anxious-depressive disorders) from a general population of Peru and Spain were investigated. We conducted secondary data analysis with data from Peru and Spain to validate the CPDI in a cross-cultural context. Exploratory factor analysis (EFA) and multigroup confirmatory factor analysis (MGCFA) were performed to evaluate the factor structure and measurement invariance of the CPDI across cultural contexts. Concerning the exploratory analysis, we performed a U-Mann-Whitney test to evaluate differences in the factorial scores in the two samples. This study revealed a two-factor solution (stress and rumination/information) for the CPDI that included 21 of the 24 original items, and consistent with previous studies. The MGCFA demonstrated measurement invariance across cultural contexts (scalar invariance), indicating that the CPDI construct has the same meaning across both groups, regardless of cultural context and language variations of Spanish. Patients with anxious-depressive disorders showed higher CPDI factorial scores for both factors, whereas patients with respiratory diseases were only associated with the stress factor. This study provides evidence for the cross-cultural validity of the CPDI, highlighting its utility as a reliable instrument for assessing psychological stress in the context of COVID-19 across different cultures. These findings have important implications for developing and validating measures to assess psychological distress in different cultural contexts.

Bibliometric review on microplastic contamination in the Pacific Alliance countries.

Microplastics, capable of absorbing persistent organic compounds, heavy metals, and emerging pollutants, are of global concern due to their potential to alter the behavior and metabolism of biota. In Latin America, the Pacific Alliance, comprising Mexico, Colombia, Peru, and Chile, stands out for its biological wealth and productive ecosystems, which account for 37% of the region's gross domestic product. The leaders of these countries expressed their concern about microplastic pollution and pledged to take joint action. We conducted an analysis of the scientific production of these countries and the collaborations of their researchers, focused on the period 2015-2023, using Scopus and SCImago. We observed that marine-coastal/wetland ecosystems are the most studied, with a focus on fish, and that Mexico leads in publications, followed by Colombia, Peru, and Chile. In addition, we note the absence of an inter-institutional group dedicated to microplastics research in these countries. We recommend promoting collaboration between academic institutions specialized in microplastic research and government agencies dedicated to the promotion of science and technology in the countries belonging to the Pacific Alliance.

Antibiotic discovery against Piscirickettsia salmonis using a combined in silico and in vitro approach.

Piscirickettsia salmonis is one of the main pathogens causing considerable economic losses in salmonid farming. The DNA gyrase of several pathogenic bacteria has been the target of choice for antibiotic design and discovery for years, due to its key function during DNA replication. In this study, we carried out a combined in silico and in vitro approach to antibiotic discovery targeting the GyrA subunit of Piscirickettsia salmonis. The in silico results of this work showed that flumequine (-6.6 kcal/mol), finafloxacin (-7.2 kcal/mol), rosoxacin (-6.6 kcal/mol), elvitegravir (-6.4 kcal/mol), sarafloxacin (-8.3 kcal/mol), orbifloxacin (-7.9 kcal/mol), and sparfloxacin (-7.2 kcal/mol) are docked with good affinities in the DNA binding domain of the Piscirickettsia salmonis GyrA subunit. In the in vitro inhibition assay, it was observed that most of these molecules inhibit the growth of Piscirickettsia salmonis, except for elvitegravir. We believe that this methodology could help to significantly reduce the time and cost of antibiotic discovery trials to combat Piscirickettsia salmonis within the salmonid farming industry.

Terrestrial mammals of the Americas and their interactions with plastic waste.

Plastics have brought many benefits to society, but their mismanagement has turned them into a serious environmental problem. Today, the effects of plastic waste on wildlife are becoming increasingly evident. Since studies on plastic pollution have focused on species in marine ecosystems, here we review current knowledge on interactions between terrestrial mammals and plastic waste in the countries of the Americas, which is a global hotspot of mammalian biodiversity and in turn has, among its member countries, nations with high per capita generations of plastic waste globally. We identified 46 scientific articles documenting plastic ingestion in 37 species and four species that used plastic waste for nest or burrow construction. Of the 46 investigations, seven focused on plastic contamination, while the others reported on the presence of plastics in wildlife, even though this was not the primary focus of the research. However, these publications lack analytical methods commonly used in plastic studies, and only one study applied a standardized methodology for plastic detection. Therefore, in general, plastic pollution research on terrestrial mammals is limited. We extend several recommendations such as designing methodologies that are adapted to terrestrial mammals for the identification of plastics in fecal matter or gastrointestinal contents, carrying out species-specific analyzes on the impacts of plastics in nests or burrows, and giving further attention to this understudied issue and taxa.

Genomic and proteomic aspects of p57 protein from Renibacterium salmoninarum: Characteristics in virulence patterns.

Renibacterium salmoninarum is one of the oldest known fish bacterial pathogens. This Gram-positive bacterium is the causative agent of Bacterial Kidney Disease (BKD), a chronic infection that primarily infects salmonids at low temperatures. Externally, infected fish may show exophthalmos, skin blisters, ulcerations, and hemorrhages at the base of the fins and along the lateral line. Internally, the kidney, heart, spleen, and liver may show signs of inflammation. The best characterized virulence factor of R. salmoninarum is p57, a 57 kDa protein located on the bacterial cell surface and secreted into surrounding fish tissue. The p57 protein in fish is the main mediator in suppressing the immune system, reducing antibody production, and intervening in cytokine activity. In this review, we will discuss aspects such as single nucleotide polymorphisms (SNPs) that modify the DNA sequence, variants in the number of copies of MSA genes, physical-chemical properties of the signal peptides, and the limited iron conditions that can modify p57 expression and increase the virulence of R. salmoninarum.

StarD7 deficiency hinders cell motility through p-ERK1/2/Cx43 reduction.

StarD7 belongs to START protein family involved in lipid traffic, metabolism, and signaling events. Its precursor, StarD7.I which is important for mitochondrial homeostasis, is processed to the StarD7.II isoform that lacks the mitochondrial targeting sequence and is mainly released to the cytosol. StarD7 knockdown interferes with cell migration by an unknown mechanism. Here, we demonstrate that StarD7 silencing decreased connexin 43 (Cx43), integrin ß1, and p-ERK1/2 expression in the non-tumoral migratory HTR-8/SVneo cells. StarD7-deficient cells exhibited Golgi disruption and reduced competence to reorient the microtubule-organizing center. The migratory capacity of StarD7-silenced cells was reestablished when Cx43 level was resettled, while p-ERK1/2 expression remained low. Importantly, ectopic expression of the StarD7.II isoform not only restored cell migration but also ERK1/2, Cx43, and integrin ß1 expression. Thus, StarD7 is implicated in cell migration through an ERK1/2/Cx43 dependent mechanism but independent of the StarD7.I function in the mitochondria.

Analysis of response of severe eosinophilic asthmatic patients to benralizumab.

INTRODUCTION: Clinical trials and real-life studies have been published showing effectiveness of benralizumab in severe eosinophilic asthmatic patients. The aim of the present study is to describe super-responders to benralizumab in a series of 79 patients who completed at least 1 year of treatment, and to compare super-responders with non super-responders. METHODS: This is a multicenter study of the Register of Severe Asthma of the Region of Murcia (RE-ASGRAMUR) Group performed in eight hospitals under the conditions of routine clinical practice. Patients with zero exacerbations and no oral corticosteroid therapy for asthma were considered super-responders. We analyzed clinical, functional, and inflammatory parameters of selected patients. RESULTS: In all, 50 of the 79 patients (63%) met the super-responder criteria. In addition, 36% of the patients (26/71) were considered as complete responders to treatment (super--responder + Asthma Control Test [ACT] ≥ 20 + forced expiratory volume in 1 s [FEV1] ≥ 80%). The super--responders were significantly older in age (P = 0.0029), had higher eosinophils count (P = 0.0423), higher proportion of nasal polyps (P = 0.036), and they had less severe disease at baseline. After 1 year of treatment, the super-responders had higher levels of ACT questionnaire (23 vs 19, P = 0.0007) and better percentage of FEV1 (83 vs 75, P = 0.0359). CONCLUSION: Almost two of the three patients treated with benralizumab were super--responders after 1 year of treatment and 36% had a complete response. Super-responders were associated with older age, higher eosinophils count, had nasal polyposis as comorbidity, and had less severe disease at baseline. This data illustrated the good real-life response of patients with severe eosinophilic asthma to the treatment with benralizumab.

Analysis of response of severe eosinophilic asthmatic patients to benralizumab

Introduction Clinical trials and real-life studies have been published showing effectiveness of benralizumab in severe eosinophilic asthmatic patients. The aim of the present study is to describe super-responders to benralizumab in a series of 79 patients who completed at least 1 year of treatment, and to compare super-responders with non super-responders. Methods This is a multicenter study of the Register of Severe Asthma of the Region of Murcia (RE-ASGRAMUR) Group performed in eight hospitals under the conditions of routine clinical practice. Patients with zero exacerbations and no oral corticosteroid therapy for asthma were considered super-responders. We analyzed clinical, functional, and inflammatory parameters of selected patients. Results In all, 50 of the 79 patients (63%) met the super-responder criteria. In addition, 36% of the patients (26/71) were considered as complete responders to treatment (super--responder + Asthma Control Test [ACT] ≥ 20 + forced expiratory volume in 1 s [FEV1] ≥ 80%). The super--responders were significantly older in age (P = 0.0029), had higher eosinophils count (P = 0.0423), higher proportion of nasal polyps (P = 0.036), and they had less severe disease at baseline. After 1 year of treatment, the super-responders had higher levels of ACT questionnaire (23 vs 19, P = 0.0007) and better percentage of FEV1 (83 vs 75, P = 0.0359). Conclusion Almost two of the three patients treated with benralizumab were super--responders after 1 year of treatment and 36% had a complete response. Super-responders were associated with older age, higher eosinophils count, had nasal polyposis as comorbidity, and had less severe disease at baseline. This data illustrated the good real-life response of patients with severe eosinophilic asthma to the treatment with benralizumab (AU)

Long-term survive of Aliarcobacter butzleri in two models symbiotic interaction with Acanthamoeba castellanii.

Aliarcobacter butzleri (formerly known as Arcobacter butzleri) is an emerging food-borne zoonotic pathogen that establishes in vitro endosymbiotic relationships with Acanthamoeba castellanii, a free-living amoeba. Previously, we described that this bacterium acts as an endocytobiont of A. castellanii, surviving for at least 10 days in absence of bacterial replication. Thus, the aim of this study was to evaluate the ability of A. butzleri to survive as a long-term endosymbiont of A. castellanii for 30 days in two models of symbiotic interaction with A. castellanii: (i) endosymbiotic culture followed by gentamicin protection assay and (ii) transwell co-culture assay. The results allow us to conclude that A. butzleri is capable of surviving as an endosymbiont of A. castellanii for at least 30 days, without multiplying, under controlled laboratory conditions. In addition, in the absence of nutrients and as both microorganisms remain in the same culture, separated by semi-permeable membranes, A. castellanii does not promote the survival of A. butzleri, nor does it multiply. Our findings suggest that the greater survival capacity of A. butzleri is associated with their endosymbiont status inside A. castellanii, pointing out the complexity of this type of symbiotic relationship.

Ionic complexation improves wound healing in deep second-degree burns and reduces in-vitro ciprofloxacin cytotoxicity in fibroblasts.

The development of new treatments capable of controlling infections and pain related to burns continues to be a challenge. Antimicrobials are necessary tools, but these can be cytotoxic for regenerating cells. In this study, antibiotic-anesthetic (AA) smart systems obtained by ionic complexation of polyelectrolytes with ciprofloxacin and lidocaine were obtained as films and hydrogels. Ionic complexation with sodium alginate and hyaluronate decreased cytotoxicity of ciprofloxacin above 70% in a primary culture of isolated fibroblasts (p < 0.05). In addition, the relative levels of the proteins involved in cell migration, integrin ß1 and p-FAK, increased above 1.5 times (p < 0.05) with no significant differences in cell mobility. Evaluation of the systems in a deep second-degree burn model revealed that reepithelization rate was AA-films = AA-hydrogels > control films > no treated > reference cream (silver sulfadiazine cream). In addition, appendage conservation and complete dermis organization were achieved in AA-films and AA-hydrogels. Encouragingly, both the films and the hydrogels showed a significantly superior performance compared to the reference treatment. This work highlights the great potential of this smart system as an attractive dressing for burns, which surpasses currently available treatments.

Asociación entre años de estudio y síntomas depresivos y ansiosos durante los primeros meses de confinamiento por la pandemia COVID-19, en una muestra de estudiantes de medicina de una universidad privada en Lima, Perú / Association between study year and depressive and anxious symptoms during the first months of confinement due to COVID-19 pandemic in a sample of medical students from a private university in Lima, Peru

RESUMEN Objetivos : Determinar la relación entre años de estudio y síntomas depresivos y ansiosos durante los primeros meses de la pandemia por COVID-19, en una muestra de estudiantes de medicina de Lima, controlando en particular las covariables sexo y enfermedades médicas previas. Material y métodos : Se realizó una encuesta en línea, que recolectó información de 250 estudiantes de medicina incluyendo datos generales, historia médica previa, síntomas de depresión (PHQ-9) y de ansiedad (GAD-7). Los datos se manejaron mediante un análisis multivariado. Resultados : Se encontraron diferencias entre años de estudios y los valores combinados de PHQ-9 y GAD-7 (Lambda de Wilks = 0,86; p = 1,68 x 10-4; η2p = 0,08). La presencia de enfermedades médicas previas mostró diferencias significativas en relación a los valores combinados de PHQ-9 y GAD-7 (Lambda de Wilks = 0,94, p = 4,43 x 10-4, η2p = 0,06). Las muestras univariadas mostraron diferencias en años de estudios para PHQ-9 (F6,241 = 4,12, p = 0,001, η2p = 0,09) y GAD-7 (F6,241 = 2,81, p = 0,01, η2p = 0,07). El análisis post hoc mostró diferencias estadísticamente significativas en los primeros años de estudio. Conclusiones : Estos resultados sugieren que estudiantes de medicina de los primeros años muestran mayores niveles de síntomas depresivos y ansiosos que los participantes de años superiores. Asimismo, la ocurrencia de enfermedades médicas previas explica también los valores altos de depresión y ansiedad.

SUMMARY Objective : To determine the relationship between year levels of medical studies and depressive and anxious symptoms during the first months of the COVID-19 pandemic in a sample of medical students in Lima, controlling specifically the variables sex and presence of underlying medical conditions. Material and Methods : An online survey collected information from 250 medical students, covering general data, previous medical history and symptoms of depression (PHQ-9) and anxiety (GAD-7). Data were managed using multivariate analysis of covariance. Results : Differences were found between years of study and the combined values of PHQ-9 and GAD-7 (Wilks' Λ = 0.86; p = 1.68 x 10-4; η2p = 0.08). Underlying medical conditions also showed significant differences for the combined values of PHQ-9 and GAD-7 (Wilks' Λ = 0.94, p = 4.43 x 10-4, η2p = 0.06). The univariate test for year of study showed differences for PHQ-9 (F6.241 = 4.12, p = 0.001, η2p = 0.09) and GAD-7 (F6.241 = 2.81, p = 0.01, η2p = 0.07). The post hoc analysis showed statistically significant differences in the first years of study. Conclusions : These results suggest that medical students of the first years show higher levels of depression and anxiety symptoms than participants from more advanced years of the medical career. Likewise, the occurrence of previous medical conditions also explained high levels of depression and anxiety.

[Medical conditions, symptoms of anxiety, and depression during the COVID-19 pandemic in a population sample of Lima, Peru]. / Condiciones médicas, síntomas de ansiedad y depresión durante la pandemia por COVID-19 en una muestra poblacional de Lima, Perú.

Introduction: This study aims to determine differences between the number of underlying medical conditions, depression, and anxiety, when controlling for the covariates of age, sex, and completed education.Methods: Participants (n=484) indicated the number of medical conditions present during the survey, also including the PHQ-9 and GAD-7, to assess depression and anxiety, respectively.Results: Differences were found between groups of medical conditions and the combined values of PHQ-9 and GAD-7 after controlling for the covariates mentioned above (F4,954=5.78; Wilks' Λ=0.95; P<0.0005). The univariate tests showed differences for PHQ-9 (F2,478=8.70; P<0.0005) and GAD-7 (F2,478=11.16; P<0.0005) between the 3 groups. Finally, post-hoc analysis showed differences between participants with one medical condition and with no medical condition (PHQ-9: MD=1.82; 95%CI, 0.25-3.40; GAD-7: MD=1.73; 95%CI, 0.55-2.91), and between participants with more than one medical condition and participants with no medical condition (PHQ-9: MD=3.10; 95%CI, 1.11-5.10; GAD-7: MD=2.46; 95%CI, 0.97-3.95).Conclusions: Our results suggest that people who had a medical condition during the COVID-19 pandemic were more prone to developing severe symptoms of anxiety and depression.