Publications by authors named "Jorge Bernardino De La Serna"

Article Synopsis
  • GLP-1 receptor agonists are effective for treating type 2 diabetes and obesity, but patient responses vary due to genetic differences.
  • A specific genetic variant (A316T) shows protective effects against T2D and cardiovascular disease and leads to improved blood glucose and insulin levels in a mouse model.
  • However, this variant results in reduced effectiveness when using GLP-1R agonist medications, highlighting the need to understand genetic variations for personalized treatment strategies.
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  • The study investigates the biological effects of two water-soluble organic cations based on polypyridyl structures, finding that they have cytotoxic effects on cancer cells while being less harmful to noncancerous cells.
  • One of the cations shows enhanced effectiveness when exposed to visible light, allowing it to operate at very low concentrations, and is more easily internalized by cells compared to its less effective counterpart.
  • The active compound causes lysosomal swelling and disrupts mitochondrial function, leading to cell death through mechanisms like necrosis and apoptosis, yet shows no significant toxicity in animal models at tested levels.
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Over the past decade, there has been a significant rise in the use of vaping devices, particularly among adolescents, raising concerns for effects on respiratory health. Pressingly, many recent vaping-related lung injuries are unexplained by current knowledge, and the overall implications of vaping for respiratory health are poorly understood. This study investigates the effect of hydrophobic vaping liquid chemicals on the pulmonary surfactant biophysical function.

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Humans are exposed to micro-and-nano plastics (MNPs) through various routes, but the adverse health effects of MNPs on different organ systems are not yet fully understood. This review aims to provide an overview of the potential impacts of MNPs on various organ systems and identify knowledge gaps in current research. The summarized results suggest that exposure to MNPs can lead to health effects through oxidative stress, inflammation, immune dysfunction, altered biochemical and energy metabolism, impaired cell proliferation, disrupted microbial metabolic pathways, abnormal organ development, and carcinogenicity.

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  • Filaggrin (FLG) protein is crucial for maintaining the skin's barrier, but its buildup in a single form can lead to early cell death in skin cells (keratinocytes).
  • The study finds that small extracellular vesicles (sEVs) secreted by keratinocytes carry filaggrin and help remove excess levels, as blocking these vesicles causes cell damage.
  • S. aureus bacteria boost the packaging and release of filaggrin-related substances in sEVs through a specific mechanism, which may help the bacteria survive by promoting filaggrin removal from the skin.
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The use of electronic cigarettes (e-cigs) is rapidly increasing worldwide and is promoted as a smoking cessation tool. The impact of traditional cigs on human health has been well-defined in both animal and human studies. In contrast, little is known about the adverse effects of e-cigs exposure on human health.

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The synthesis of a new heterodinuclear Re Ru metallointercalator containing Ru (dppz) and Re (dppn) moieties is reported. Cell-free studies reveal that the complex has similar photophysical properties to its homoleptic M(dppz) analogue and it also binds to DNA with a similar affinity. However, the newly reported complex has very different in-cell properties to its parent.

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The lining of the alveoli is covered by pulmonary surfactant, a complex mixture of surface-active lipids and proteins that enables efficient gas exchange between inhaled air and the circulation. Despite decades of advancements in the study of the pulmonary surfactant, the molecular scale behavior of the surfactant and the inherent role of the number of different lipids and proteins in surfactant behavior are not fully understood. The most important proteins in this complex system are the surfactant proteins SP-B and SP-C.

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The incretin receptors, glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR), are prime therapeutic targets for the treatment of type 2 diabetes (T2D) and obesity. They are expressed in pancreatic beta cells where they potentiate insulin release in response to food intake. Despite GIP being the main incretin in healthy individuals, GLP-1R has been favored as a therapeutic target due to blunted GIPR responses in T2D patients and conflicting effects of GIPR agonists and antagonists in improving glucose tolerance and preventing weight gain.

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  • Sphingolipids, ceramides, and cholesterol are key components of cell membranes that influence how cells signal and move by affecting the fluidity of these membranes.
  • The study used various assays and tracking methods to show that the lipid environment impacts the organization and function of the CXCR4 receptor, which is crucial for cell migration toward chemical signals.
  • Treatment with bacterial sphingomyelinase led to significant changes in the cell membrane's lipid composition, causing altered receptor dynamics and impaired cell migration despite some retained signaling ability.
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The cytokine interferon-gamma (IFN-γ) is a master regulator of innate and adaptive immunity involved in a broad array of human diseases that range from atherosclerosis to cancer. IFN-γ exerts it signaling action by binding to a specific cell surface receptor, the IFN-γ receptor (IFN-γR), whose activation critically depends on its partition into lipid nanodomains. However, little is known about the impact of specific lipids on IFN-γR signal transduction activity.

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Despite more than 20 years of work since the lipid raft concept was proposed, the existence of these nanostructures remains highly controversial due to the lack of noninvasive methods to investigate their native nanorganization in living unperturbed cells. There is an unmet need for probes for direct imaging of nanoscale membrane dynamics with high spatial and temporal resolution in living cells. In this paper, a bioorthogonal-based cholesterol probe (chol-N ) is developed that, combined with nanoscopy, becomes a new powerful method for direct visualization and characterization of lipid raft at unprecedented resolution in living cells.

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Lipid liquid-liquid immiscibility and its consequent lateral heterogeneity have been observed under thermodynamic equilibrium in model and native membranes. However, cholesterol-rich membrane domains, sometimes referred to as lipid rafts, are difficult to observe spatiotemporally in live cells. Despite their importance in many biological processes, robust evidence for their existence remains elusive.

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With the aim of developing photostable near-infrared cell imaging probes, a convenient route to the synthesis of heteroleptic Os complexes containing the Os(TAP) fragment is reported. This method was used to synthesize the dinuclear Os complex, [{Os(TAP)}tpphz] (where tpphz = tetrapyrido[3,2-a:2',3'-c:3″,2''-h:2‴,3'''-j]phenazine and TAP = 1,4,5,8- tetraazaphenanthrene). Using a combination of resonance Raman and time-resolved absorption spectroscopy, as well as computational studies, the excited state dynamics of the new complex were dissected.

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The primary cilium is a specialized plasma membrane protrusion with important receptors for signalling pathways. In polarized epithelial cells, the primary cilium assembles after the midbody remnant (MBR) encounters the centrosome at the apical surface. The membrane surrounding the MBR, namely remnant-associated membrane patch (RAMP), once situated next to the centrosome, releases some of its lipid components to form a centrosome-associated membrane patch (CAMP) from which the ciliary membrane stems.

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Six luminescent, mononuclear ruthenium(ii) complexes based on the tetrapyridophenazine (tpphz) and dipyridophenazine (dppz) ligands are reported. The therapeutic activities of the complexes against Gram-negative bacteria (, , ) and Gram-positive bacteria ( and ) including pathogenic multi- and pan-drug resistant strains were assessed. Estimated minimum inhibitory and bactericidal concentrations show the activity of the lead compound is comparable to ampicillin and oxacillin in therapeutically sensitive strains and this activity was retained in resistant strains.

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Pulmonary surfactant is a complex mixture of lipids and proteins lining the interior of the alveoli, and constitutes the first barrier to both oxygen and pathogens as they progress toward blood circulation. Despite decades of study, the behavior of the pulmonary surfactant at the molecular scale is poorly understood, which hinders the development of effective surfactant replacement therapies, useful in the treatment of several lung-related diseases. In this work, we combined all-atom molecular dynamics simulations, Langmuir trough measurements, and AFM imaging to study synthetic four-component lipid monolayers designed to model protein-free pulmonary surfactant.

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Objectives: SARS-Cov-2 virus preferentially binds to the Angiotensin Converting Enzyme 2 (ACE2) on alveolar epithelial type II cells, initiating an inflammatory response and tissue damage which may impair surfactant synthesis contributing to alveolar collapse, worsening hypoxia and leading to respiratory failure. The objective of this study is to evaluate the feasibility, safety and efficacy of nebulised surfactant in COVID-19 adult patients requiring mechanical ventilation for respiratory failure.

Trial Design: This study is a dose-escalating randomized open-label clinical trial of 20 COVID-19 patients.

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The 1980s mark the starting point of nanotechnology: the capacity to synthesise, manipulate and visualise matter at the nanometre scale. New powers to reach the nanoscale brought us the unprecedented possibility to directly target at the scale of biomolecular interactions, and the motivation to create smart nanostructures that could circumvent the hurdles hindering the success of traditional pharmacological approaches. Forty years on, the progressive integration of bio- and nanotechnologies is starting to produce a transformation of the way we detect, treat and monitor diseases and unresolved medical problems [ 1].

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Differentiation of keratinocytes is critical for epidermal stratification and formation of a protective . It involves a series of complex processes leading through gradual changes in characteristics and functions of keratinocytes up to their programmed cell death via cornification. The is a relatively impermeable barrier, comprised of dead cell remnants (corneocytes) embedded in lipid matrix.

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Unlabelled: T-cell receptor stimulation induces the convergence of multivesicular bodies towards the microtubule-organizing centre (MTOC) and the polarization of the MTOC to the immune synapse (IS). These events lead to exosome secretion at the IS. We describe here that upon IS formation centrosomal area F-actin decreased concomitantly with MTOC polarization to the IS.

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Background And Purpose: Amino acid substitutions at the N-termini of glucagon-like peptide-1 (GLP-1) receptor agonist peptides result in distinct patterns of intracellular signalling, sub-cellular trafficking and efficacy in vivo. Here, we to determine whether sequence differences at the ligand C-termini of clinically approved GLP-1 receptor agonists exendin-4 and lixisenatide lead to similar phenomena.

Experimental Approach: Exendin-4, lixisenatide and N-terminally substituted analogues with biased signalling characteristics were compared across a range of in vitro trafficking and signalling assays in different cell types.

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In previous studies we reported that specific dinuclear Ru complexes are particularly active against pathogenic Gram-negative bacteria and, unusually for this class of compounds, appeared to display lowered activity against Gram-positive bacteria. With the aim of identifying resistance mechanisms specific to Gram-positive bacteria, the uptake and antimicrobial activity of the lead complex against SH1000 and other isolates, including MRSA was investigated. This revealed differential, strain specific, sensitivity to the complex.

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The synthesis of new dinuclear complexes containing linked Ru(dppz) and Re(dppz) moieties is reported. The photophysical and biological properties of the new complex, which incorporates a ,'-bis(4-pyridylmethyl)-1,6-hexanediamine tether ligand, are compared to a previously reported Ru/Re complex linked by a simple dipyridyl alkane ligand. Although both complexes bind to DNA with similar affinities, steady-state and time-resolved photophysical studies reveal that the nature of the linker affects the excited state dynamics of the complexes and their DNA photocleavage properties.

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Medicinal leads that are also compatible with imaging technologies are attractive, as they facilitate the development of therapeutics through direct mechanistic observations at the molecular level. In this context, the uptake and antimicrobial activities of several luminescent dinuclear Ru complexes against E. coli were assessed and compared to results obtained for another ESKAPE pathogen, the Gram-positive major opportunistic pathogen Enterococcus faecalis, V583.

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