The Metabolic Core and Catalytic Switches Are Fundamental Elements in the Self-Regulation of the Systemic Metabolic Structure of Cells

[Background] Experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a metabolic core formed by a set of enzymatic reactions which are always active under all environmental conditions, while the rest of catalytic processes are only intermittently active. The reactions of the metabolic core are essential for biomass formation and to assure optimal metabolic performance. The on-off catalytic reactions and the metabolic core are essential elements of a Systemic Metabolic Structure which seems to be a key feature common to all cellular organisms. [Methodology/Principal Findings] In order to investigate the functional importance of the metabolic core we have studied different catalytic patterns of a dissipative metabolic network under different external conditions. The emerging biochemical data have been analysed using information-based dynamic tools, such as Pearson's correlation and Transfer Entropy (which measures effective functionality). Our results show that a functional structure of effective connectivity emerges which is dynamical and characterized by significant variations of bio-molecular information flows. [Conclusions/Significance] We have quantified essential aspects of the metabolic core functionality. The always active enzymatic reactions form a hub –with a high degree of effective connectivity- exhibiting a wide range of functional information values being able to act either as a source or as a sink of bio-molecular causal interactions. Likewise, we have found that the metabolic core is an essential part of an emergent functional structure characterized by catalytic modules and metabolic switches which allow critical transitions in enzymatic activity. Both, the metabolic core and the catalytic switches in which also intermittently-active enzymes are involved seem to be fundamental elements in the self-regulation of the Systemic Metabolic Structure.Consejo Superior de Investigaciones Cientificas (CSIC),grant 201020I026. Ministerio de Ciencia e Innovacion (MICINN). Programa Ramon y Cajal. Campus de Excelencia Internacional CEI BioTIC GENIL, grant PYR-2010-14. Junta de Andalucia, grant P09-FQM-4682

The Coping Mechanisms of First-Year Students in the Online Classes

The study aimed to determine the coping mechanisms of first-year college students taking Bachelor of Special Needs Education in a state university in the online class setting. It utilized Colaizzi’s (1978) descriptive phenomenological method which followed his seven-step method. Three emergent themes were revealed (1) coping mechanisms, (2) adjustment of 1st-year students to online classes, (3) perception of the effects of coping mechanisms. Most participants applied three coping mechanisms, and these were (1) meditation and (2) spirituality which are considered adaptive coping mechanisms, and (3) late-night internet usage, a maladaptive coping mechanism. The participants expressed their vulnerability as a 1st-year student in terms of unfamiliarity due to the absence of face-to-face interaction, being unaccustomed to the new college environment, pressure due to unfamiliar teacher-student dynamic, and pressure in studying at a state university

The phylogenetically distinct early human embryo

The phylogenetic singularity of the human embryo remains unresolved as cell types of the human blastocyst have resisted classification. Combining clustering of single cellular transcriptomes and dynamically expressed genes we resolve the cell types. This unveils the missing inner cell mass (ICM) and reveals classical step-wise development. Conversely, numerous features render our blastocyst phylogenetically distinct: unlike mice, our epiblast is self-renewing and we have blastocyst non-committed cells (NCCs), part of an apoptosis-mediated quality control/purging process. At the transcriptome-level all primate embryos are distinct as the pluripotent cell types are uniquely fast evolving. A substantial fraction of gene expression gain and loss events between human and new-world monkeys involve endogenous retrovirus H (ERVH). Human pluripotent cells are unique in which (H)ERVH's are active, the extent to which these modulate neighbour gene expression and their ability to suppress mutagenic transposable elements. Current naive cultures are heterogeneous and both developmentally and phylogenetically "confused"

Procjena gama-aktina, beta-aktina, gliceraldehid-3-fosfat dehidrogenaze i 18S kao referentnih gena za qRT-PCR uporabom uzoraka krvi u istraživanju mliječnih žlijezda kujica

Mammary tumours are the most frequent group of neoplasia in female dogs. Tumorigenesis is associated with gene expression changes in a wide variety of genes. For this reason, real-time quantitative PCR (qRT-PCR) is used in routine diagnostic procedures in clinical practice due to its the specificity, sensitivity, simplicity, and high performance. qRT-PCR is also widely used to measure the expression of target genes compared to reference genes in several tissues. We collected blood samples from healthy female dogs and females with canine mammary cancer in Manizales, Colombia between June 2018 and January 2019, and mRNA was isolated from each sample for cDNA synthesis. qRT-PCR-based expression assays were performed using primers designed for gamma-actin, beta-actin, GAPDH, and 18S genes. We calculated the amplification efficiency, specificity, and stability using geNorm, NormFinder, BestKeeper, and the ΔCt comparative method. We obtained linear regressions to verify constant gene expression and conducted an ANOVA to detect expression differences regarding Ct values and healthy vs. ill conditions. We found stability for primers 18S-1, GAPDH-1, GAPDH-NM, and Gamma-actin-1 (in increasing order). Furthermore, these genes showed constant expression levels in patients (R2>0.80). We report novel primers for gamma-actin and GAPDH, which proved to be efficient endogenous control genes for qRT-PCR applications in blood tissue. These primers are useful for gene expression research in canine mammary cancer.Tumori mliječnih žlijezda najčešća su skupina neoplazija u kujica. Tumorogeneza je povezana s promjenama u ekspresiji gena u širokom rasponu gena. Iz tog razloga se rabi kvantitativna lančana reakcija polimerazom u stvarnom vremenu (qRT-PCR) u rutinskim dijagnostičkim postupcima u kliničkoj praksi, uslijed specifičnosti, osjetljivosti, jednostavnosti i visoke učinkovitosti ove tehnike. qRT-PCR se široko rabi i za mjerenje ekspresije ciljanih gena u usporedbi s referentnim genima u više vrsta tkiva. Prikupili smo uzorke krvi zdravih kujica i kujica s tumorom mliječnih žlijezda u Manizalesu, Kolumbiji, od lipnja 2018. do siječnja 2019. godine. Izolirali smo mRNK iz svakog uzorka za cDNK sintezu. Pokusi ekspresije na bazi qRT-PCR obavljeni su uporabom primera dizajniranih za gama-aktin, beta-aktin, gliceraldehid- 3-fosfat dehidrogenazu (GAPDH) i 18S gene. Izračunali smo pojačanu učinkovitost, specifičnost i stabilnost uporabom geNorm, NormFinder, BestKeeper i ΔCt komparativne metode. Dobili smo linearne regresije za potvrđivanje stalne ekspresije gena i proveli smo analizu varijance (ANOVA) za detekciju razlika u ekspresiji s obzirom na Ct vrijednosti te zdrava u usporedbi s bolesnim stanjima. Otkrili smo i stabilnost za primere 18S-1, GAPDH-1, GAPDH-NM i Gamma-actin-1 (rastućim redoslijedom). Nadalje, ovi geni su pokazali konstantne razine ekspresije u pacijenata (R2>0,80). Izvještavamo o novim primerima za gama-aktin i GAPDH, koji su se pokazali učinkovitim endogenim kontrolnim genima za qRT-PCR primjene u krvnom tkivu. Ti primeri su korisni za istraživanje ekspresije gena u tumora psećih mliječnih žlijezda

Pranlukast Antagonizes CD49f and Reduces Sternness in Triple-Negative Breast Cancer Cells

Introduction: Cancer stem cells (CSCs) drive the initiation, maintenance, and therapy response of breast tumors. CD49f is expressed in breast CSCs and functions in the maintenance of stemness. Thus, blockade of CD49f is a potential therapeutic approach for targeting breast CSCs. In the present study, we aimed to repurpose drugs as CD49f antagonists. Materials and Methods: We performed consensus molecular docking using a subdomain of CD49f that is critical for heterodimerization and a collection of pharmochemicals clini-cally tested. Molecular dynamics simulations were employed to further characterize drug-target binding. Using MDA-MB-231 cells, we evaluated the effects of potential CD49f antagonists on 1) cell adhesion to laminin; 2) mammosphere formation; and 3) cell viability. We analyzed the effects of the drug with better CSC-selectivity on the activation of CD49f-downstream signaling by Western blot (WB) and co-immunoprecipitation. Expressions of the stem cell markers CD44 and SOX2 were analyzed by flow cytometry and WB, respectively. Transactivation of SOX2 promoter was evaluated by luciferase reporter assays. Changes in the number of CSCs were assessed by limiting-dilution xenotransplantation. Results: Pranlukast, a drug used to treat asthma, bound to CD49f in silico and inhibited the adhesion of CD49f+ MDA-MB-231 cells to laminin, indicating that it antagonizes CD49f-containing integrins. Molecular dynamics analysis showed that pranlukast binding induces con-formational changes in CD49f that affect its interaction with β1-integrin subunit and constrained the conformational dynamics of the heterodimer. Pranlukast decreased the clonogenicity of breast cancer cells on mammosphere formation assay but had no impact on the viability of bulk tumor cells. Brief exposure of MDA-MB-231 cells to pranlukast altered CD49f-dependent signaling, reducing focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K) activation. Further, pranlukast-treated cells showed decreased CD44 and SOX2 expression, SOX2 promoter transacti-vation, and in vivo tumorigenicity, supporting that this drug reduces the frequency of CSC. Conclusion: Our results support the function of pranlukast as a CD49f antagonist that reduces the CSC population in triple-negative breast cancer cells. The pharmacokinetics and toxicology of this drug have already been established, rendering a potential adjuvant therapy for breast cancer patients

Trastuzumab and pertuzumab without chemotherapy in early-stage HER2+ breast cancer: a plain language summary of the PHERGain study

This is a summary of a publication about the PHERGain study, which was published in The Lancet Oncology in May 2021. The study includes 376 women with a type of breast cancer called HER2-positive breast cancer that can be removed by surgery. In the study, researchers wanted to learn if participants could be treated with two medicines called trastuzumab and pertuzumab without the need for chemotherapy. To identify HER2-positive tumors with more sensitivity to anti-HER2 therapies, the researchers used a type of imaging called a FDG-PET scan to check how well the treatments were working.Participants took a treatment before surgery, consisting of either chemotherapy (docetaxel and carboplatin) plus trastuzumab and pertuzumab (group A) or trastuzumab and pertuzumab alone (plus hormone therapy if the tumor was hormone receptor-positive; group B). After two cycles of treatment, participants underwent a FDG-PET scan. Participants assigned to group A completed 6 cycles of treatment regardless of 18F-FDG-PET results. Participants in group B continued the same treatment until surgery if their FDG-PET scan showed the treatment was working. While participants who did not show a response started treatment with chemotherapy in addition to trastuzumab and pertuzumab. All participants then had surgery.The results revealed that, of the participants in group B who showed a response using FDG-PET scan, 37.9% achieved a disappearance of all invasive cancer in the breast and axillary lymph nodes. This rate appears to be higher than those reported in previous studies evaluating the same treatment. These participants also had less side effects and improved overall quality of life compared with participants taking chemotherapy plus trastuzumab and pertuzumab.Early monitoring of how well participants respond to treatment by FDG-PET scan seems to identify participants with operable HER2-positive breast cancer who were more likely to benefit from trastuzumab and pertuzumab without the need to have chemotherapy. The PHERGain study is still ongoing and results on long-term survival are expected to be released in 2023. Clinical Trial Registration: NCT03161353 (ClinicalTrials.gov)

Risk factors for one-year mortality in hospitalized adults with severe covid-19 comment

As the body''s immunity declines with age, elderly-hospitalized patients due to COVID-19 might be at higher mortality risk. Therefore, the aim of this prospective study was to examine the possible risk factors (demographic, social or comorbidities) most associated with mortality one-year after diagnosis of COVID-19. Routine data were collected from a cohort of hospitalized adults with severe COVID-19. The primary endpoint was mortality at one-year after diagnosis of COVID-19. We used a Cox proportional hazard model to estimate the hazard ratios (HRs) for both all-cause and specific cardiorespiratory mortality. A fully adjusted model included sex, socioeconomic status, institutionalization status, disability, smoking habit, and comorbidities as confounders. A total of 368 severe cases hospitalized on average 67.3 +/- 15.9 years old were included. Participants aged >= 71 years had significantly higher HRs for all-cause mortality (adjusted HRs = 2.86, 95%CI: 2.01-4.07) and cardiorespiratory mortality (adjusted HRs = 2.86, 95%CI: 1.99-4.12). The association between age and mortality after diagnosis of COVID-19 due to both all-causes and cardiorespiratory mortality showed a consistent dose-response fashion. Institutionalization, disability, and socioeconomic status also showed a significant association with mortality. In conclusion, aging itself was the most important risk factor associated with mortality one year after diagnosis of COVID-19. People with disabilities, institutionalized or low socioeconomic status are significantly more likely to die after COVID-19

Role of C/EBPβ Transcription Factor in Adult Hippocampal Neurogenesis

[Background]: The dentate gyrus of the hippocampus is one of the regions in which neurogenesis takes place in the adult brain. We have previously demonstrated that CCAAT/enhancer binding protein β (C/EBPβ) is expressed in the granular layer of the dentate gyrus of the adult mouse hippocampus. Taking into account the important role of C/EBPβ in the consolidation of long term memory, the fact that newborn neurons in the hippocampus contribute to learning and memory processes, and the role of this transcription factor, previously demonstrated by our group, in regulating neuronal differentiation, we speculated that this transcription factor could regulate stem/progenitor cells in this region of the brain. [Methodologu/Principal Findings]: Here, we show, using C/EBPβ knockout mice, that C/EBPβ expression is observed in the subset of newborn cells that proliferate in the hippocampus of the adult brain. Mice lacking C/EBPβ present reduced survival of newborn cells in the hippocampus, a decrease in the number of these cells that differentiate into neurons and a diminished number of cells that are proliferating in the subgranular zone of the dentate gyrus. These results were further confirmed in vitro. Neurosphere cultures from adult mice deficient in C/EBPβ present less proliferation and neuronal differentiation than neurospheres derived from wild type mice. [Conclusions/Significance]: In summary, using in vivo and in vitro strategies, we have identified C/EBPβ as a key player in the proliferation and survival of the new neurons produced in the adult mouse hippocampus. Our results support a novel role of C/EBPβ in the processes of adult hippocampal neurogenesis, providing new insights into the mechanisms that control neurogenesis in this region of the brain.This work was supported by a postdoctoral fellowship of the Consejo Superior de Investigaciones Cientificas (M.C.-C.) Grant Sponsor: Ministerio de Investigación y Ciencia; Grant numbers: SAF2007-62811 and SAF2010-16365. CIBERNED is funded by the Instituto de Salud Carlos III.Peer reviewe