Biology subjects

Moreno, S.

Publications and source records attributed to Moreno, S..

25 records · Page 2Linked to original sources

bioRxiv2022

Identification of small molecules with virus growth enhancement properties

The novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused the pandemic disease known as coronavirus disease 2019 (COVID-19). COVID-19 vaccines were developed at record speed and were authorized approximately a year after the original outbreak. This fast response saved the lives of countless individuals and reduced the disease burden of many more. The experience has served as a reminder of the necessity to implement solid vaccine development platforms and fast production pipelines. Manufacturing vaccines for enveloped viruses, including some SARS-CoV-2 vaccines, often relies on the production of large quantities of viruses in vitro. Thus, speeding up or increasing virus production would expedite vaccine development. With this objective in mind, we established a high throughput screening (HTS) to identify small molecules that enhance or speed up host-virus membrane fusion. Among the HTS hits, we identified that ethynylestradiol augments SARS-CoV-2 fusion activity in both the absence and presence of TMPRSS2. Furthermore, we confirmed that ethynylestradiol can boost the growth of not only SARS-CoV-2 but also Influenza A virus in vitro. A small molecule with these characteristics could be implemented to improve vaccines production. ImportanceThe (COVID-19) pandemic had a tremendous impact on our healthcare systems and the global economy. The rapid development of effective vaccines saved the lives of countless individuals and reduced the disease burden of many more. Intending to increase vaccine production, we developed and performed a high-throughput screening (HTS) to identify small molecules that enhance viral and cellular membrane fusion. Among the HTS hits, we confirmed that Ethynylestradiol can boost the growth of SARS-CoV-2 and Influenza A virus in vitro.

microbiology↗

bioRxiv2022

Lipid homeostasis is essential for a maximal ER stress response

Changes in lipid metabolism are associated with aging and age-related diseases, including proteopathies. The endoplasmic reticulum (ER) is uniquely a major hub for protein and lipid synthesis, making its function essential for both protein and lipid homeostasis. However, it is less clear how lipid metabolism and protein quality may impact each other. Here, we identity let-767, a putative hydroxysteroid dehydrogenase, as an essential gene for both lipid and ER protein homeostasis. Knockdown of let-767 reduces lipid stores, alters ER morphology in a lipid-dependent manner, and also blocks induction of the Unfolded Protein Response of the ER (UPRER). Interestingly, a global reduction in lipogenic pathways restores UPRER induction in animals with reduced let-767. Specifically, we find that supplementation of 3-oxoacyl, the predicted metabolite directly upstream of let-767, is sufficient to block induction of the UPRER. This study highlights a novel interaction through which changes in lipid metabolism can alter a cells response to protein-induced stress.

cell biology↗

bioRxiv2022

Age-dependent NMDA receptor function is regulated by the Amyloid Precursor Protein

N-methyl-D-aspartate receptors (NMDARs) are critical for the maturation and plasticity of glutamatergic synapses. In the hippocampus, NMDARs mainly contain GluN2A and/or GluN2B regulatory subunits. The amyloid precursor protein (APP) has emerged as a putative regulator of NMDARs, but the impact of this interaction to their function is largely unknown. By combining patch-clamp electrophysiology and molecular approaches, we unravel a dual mechanism by which APP controls GluN2B-NMDARs, depending on the life stage. We show that APP is highly abundant specifically at the postnatal postsynapse. It interacts with GluN2B-NMDARs, controlling its synaptic content and mediated currents, both in infant mice and primary neuronal cultures. Upon aging, the APP amyloidogenic derived C-terminal fragments, rather than APP full length, contribute to aberrant GluN2B-NMDAR currents. Accordingly, we found that the APP processing is increased upon aging, both in mice and human brain, and interfering with this mechanism normalized the aberrant currents. While the first mechanism might be essential for synaptic maturation during development, the latter could contribute to age-related synaptic impairments. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=99 SRC="FIGDIR/small/500736v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@1c4d540org.highwire.dtl.DTLVardef@18c7b67org.highwire.dtl.DTLVardef@1f9e482org.highwire.dtl.DTLVardef@109274f_HPS_FORMAT_FIGEXP M_FIG C_FIG In briefRajao-Saraiva et al. identified the APP full-length protein as a regulator of glutamatergic transmission in immature synapses, by controlling GluN2B synaptic content and mediated currents during postnatal development. Upon aging, the APP amyloidogenic derived C-terminal fragments, rather than APP full length, contribute to aberrant GluN2B-NMDAR currents. Our work highlights the importance of keeping APP processing under tight control, to ensure the normal functioning of glutamatergic synapses, being particularly relevant to understand age-related synaptic impairments and AD.

neuroscience↗

bioRxiv2021

Metabolic snapshot of plasma samples reveals new pathways implicated in SARS-CoV-2 pathogenesis

Despite of the scientific and human efforts to understand COVID-19, there are questions still unanswered. Variations in the metabolic reaction to SARS-CoV-2 infection could explain the striking differences in the susceptibility to infection and the risk of severe disease. Here, we used untargeted metabolomics to examine novel metabolic pathways related to SARS-CoV-2 susceptibility and COVID-19 clinical severity using capillary electrophoresis coupled to a time-of-flight mass spectrometer (CE-TOF-MS) in plasma samples. We included 27 patients with confirmed COVID-19 early after symptom onset who were prospectively followed and 29 healthcare workers heavily exposed to SARS-CoV-2 but with low susceptibility to infection ( nonsusceptible). We found that the metabolite profile was predictive of the study group. We identified a total of 55 metabolites as biomarkers of SARS-CoV-2 susceptibility or COVID-19 clinical severity. We report the discovery of new plasma biomarkers for COVID-19 that provide mechanistic explanations for the clinical consequences of SARS-CoV-2, including mitochondrial and liver dysfunction as a consequence of hypoxemia (citrulline, citrate, and BAIBA), energy production and amino acid catabolism (L-glycine, L-alanine, L-serine, L-proline, L-aspartic acid and L-histidine), endothelial dysfunction and thrombosis (citrulline, L-ADMA, 2-AB, and Neu5Ac), and we found interconnections between these pathways. In summary, in this first report of the metabolomic profile of individuals with severe COVID-19 and SARS-CoV-2 susceptibility by CE-MS, we define several metabolic pathways implicated in SARS-CoV-2 susceptibility and COVID-19 clinical progression that could be developed as biomarkers of COVID-19.

biochemistry↗

bioRxiv2020

Calcium signaling through a Transient Receptor Channel is important for Toxoplasma gondii growth

Transient Receptor Potential (TRP) channels participate in ion calcium (Ca2+) influx and intracellular Ca2+ release. TRP channels have not been studied in Toxoplasma gondii or any other Apicomplexan parasite. We characterized a protein predicted to possess a TRP domain (TgTRPPL-2) and determined its role in Ca2+ signaling in T. gondii, the causative agent of toxoplasmosis. TgTRPPL-2 localized to the plasma membrane and the endoplasmic reticulum of T. gondii. The{Delta} TgTRPPL-2 mutant was defective in growth and Ca2+ influx. Heterologous expression of TgTRPPL-2 in HEK-3KO cells allowed its functional characterization. Patching of ER-nuclear membranes demonstrated that TgTRPPL-2 is a non-selective cation channel that conducts Ca2+. Pharmacological blockers of TgTRPPL-2 inhibited Ca2+ influx and parasite growth. This is the first report of an Apicomplexan channel that conducts Ca2+ and initiates the Ca2+ signaling cascade that culminates in the stimulation of motility, invasion and egress. TgTRPPL-2 is a potential target for combating toxoplasmosis.

microbiology↗

bioRxiv2020

A NKp80-based identification strategy reveals that CD56neg NK cells are not completely dysfunctional in health and disease.

Natural killer (NK) cells are usually identified by the absence of other lineage markers, due to the lack of a cell surface specific marker. CD56neg NK cells, classically identified as CD56negCD16+ are known to be expanded in some pathological conditions. However, studies on CD56neg NK cells had revealed different results regarding the phenotype and functionality of these cells. This could be due to, among others, the unstable expression of CD16, which hinders CD56neg NK cells identification. Hence, we aim to determine an alternative surface marker to CD16 to better identify CD56neg NK cells. Using multiparametric flow cytometry, we have found that NKp80 is a good alternative to CD16 not only in healthy donors but also in HIV-1 infected subjects and multiple myeloma patients. Furthermore, we found differences between the functionality of CD56negNKp80+ and CD56negCD16+ NK cells both in healthy donors and patients, suggesting that the effector functions of CD56neg NK cells are not as diminished as previously thought. We proposed NKp80 as a noteworthy marker to identify and accurately re-characterize human CD56neg NK cells.

immunology↗

bioRxiv2019

The Toxoplasma Vacuolar H+-ATPase regulates intracellular pH, and impacts the maturation of essential secretory proteins

Vacuolar-proton ATPases (V-H+-ATPases) are conserved complexes that couple the hydrolysis of ATP to the pumping of protons across membranes. V-H+-ATPases are known to play diverse roles in cellular physiology. We studied the Toxoplasma gondii V-H+-ATPase complex and discovered a novel dual role of the pump in protecting parasites against ionic stress and in the maturation of secretory proteins in endosomal-like compartments. Toxoplasma V-H+-ATPase subunits localize to the plasma membrane and to acidic vesicles and characterization of conditional mutants of the a1 subunit highlighted the functionality of the complex at both locations. Microneme and rhoptry proteins are required for invasion and modulation of host cells and they traffic via endosome-like compartments in which proteolytic maturation occurs. We show that the V-H+-ATPase supports the maturation of rhoptry and microneme proteins, and their maturases, during their traffic to their corresponding organelles. This work underscores a novel role for V-H+-ATPases in regulating virulence pathways.

microbiology↗