Gabriel Méndez-Valdés

Mr. Gabriel Méndez-Valdés

Laboratorio de Estrés Oxidativo y Nefrotoxicidad, Universidad de Chile, Santiago, Región Metropolitana, Chile
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Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 February 2023 in Biomedicines
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Journal Article
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Gabriel Méndez-ValdésGabriel Méndez-Valdés
Gabriel Méndez-Valdés
FGFrancisca Gómez-Hevia
Francisca Gómez-Hevia
José Lillo-MoyaJosé Lillo-Moya
José Lillo-Moya
TFTommy Gonzalez Fernández
Tommy Gonzalez Fernández
JAJoaquin Abelli
Joaquin Abelli
RRRamón Rodrigo
Ramón Rodrigo
Angiogenesis is a physiological process that consists of the formation of new blood vessels from preexisting ones. Angiogenesis helps in growth, development, and wound healing through the formation of granulation tissue. However, this physiological process has also been linked to tumor growth and metastasis formation. Indeed, angiogenesis has to be considered as a fundamental step to the evolution of benign tumors into malignant neoplasms. The main mediator of angiogenesis is vascular endothelial growth factor (VEGF), which is overexpressed in certain cancers. Thus, there are anti-VEGF monoclonal antibodies, such as bevacizumab, used as anti-cancer therapies. However, bevacizumab has shown adverse events, such as hypertension and proteinuria, which in the most severe cases can lead to cessation of therapy, thus contributing to worsening patients’ prognosis. On the other hand, endostatin is an endogenous protein that strongly inhibits VEGF expression and angiogenesis and shows a better safety profile. Moreover, endostatin has already given promising results on small scale clinical studies. Hence, in this review, we present data supporting the use of endostatin as a replacement for anti-VEGF monoclonal antibodies.

1 December 2022 in Biomedicines
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Journal Article
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JAJoaquin Abelli
Joaquin Abelli
Gabriel Méndez-ValdésGabriel Méndez-Valdés
Gabriel Méndez-Valdés
FGFrancisca Gómez-Hevia
Francisca Gómez-Hevia
MBMaria Chiara Bragato
Maria Chiara Bragato
Silvia ChichiarelliSilvia Chichiarelli
Silvia Chichiarelli
RRRamón Rodrigo
Ramón Rodrigo
Septic shock currently represents one of the main causes of mortality in critical patient units with an increase in its incidence in recent years, and it is also associated with a high burden of morbidity in surviving patients. Within the pathogenesis of sepsis, oxidative stress plays an important role. The excessive formation of reactive oxygen species (ROS) leads to mitochondrial damage and vasomotor dysfunction that characterizes those patients who fall into septic shock. Currently, despite numerous studies carried out in patients with septic shock of different causes, effective therapies have not yet been developed to reduce the morbidity and mortality associated with this pathology. Despite the contribution of ROS in the pathophysiology of sepsis and septic shock, most studies performed in humans, with antioxidant monotherapies, have not resulted in promising data. Nevertheless, some interventions with compounds such as ascorbate, N-acetylcysteine, and selenium would have a positive effect in reducing the morbidity and mortality associated with this pathology. However, more studies are required to demonstrate the efficacy of these therapies. Taking into account the multifactorial features of the pathophysiology of sepsis, we put forward the hypothesis that a supplementation based on the association of more than one antioxidant compound should result in a synergistic or additive effect, thus improving the beneficial effects of each of them alone, potentially serving as a pharmacological adjunct resource to standard therapy to reduce sepsis complications. Therefore, in this review, it is proposed that the use of combined antioxidant therapies could lead to a better clinical outcome of patients with sepsis or septic shock, given the relevance of oxidative stress in the pathogenesis of this multi-organ dysfunction.

22 December 2022 in Biomedicines
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Journal Article
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Gabriel Méndez-ValdésGabriel Méndez-Valdés
Gabriel Méndez-Valdés
VPVicente Pérez
Vicente Pérez
MBMaria Chiara Bragato
Maria Chiara Bragato
MHMalthe Hundahl
Malthe Hundahl
Silvia ChichiarelliSilvia Chichiarelli
Silvia Chichiarelli
RRRamón Rodrigo
Ramón Rodrigo
Ischemia/reperfusion injury is a process associated with cardiologic interventions, such as percutaneous coronary angioplasty after an acute myocardial infarction. Blood flow restoration causes a quick burst of reactive oxygen species (ROS), which generates multiple organelle damage, leading to the activation of cell death pathways. Therefore, the intervention contributes to a greater necrotic zone, thus increasing the risk of cardiovascular complications. A major cardiovascular ROS source in this setting is the activation of multiple NADPH oxidases, which could result via the occupancy of type 1 angiotensin II receptors (AT1R); hence, the renin angiotensin system (RAS) is associated with the generation of ROS during reperfusion. In addition, ROS can promote the expression of NF-κΒ, a proinflammatory transcription factor. Recent studies have described an intracellular RAS pathway that is associated with increased intramitochondrial ROS through the action of isoform NOX4 of NADPH oxidase, thereby contributing to mitochondrial dysfunction. On the other hand, the angiotensin II/ angiotensin type 2 receptor (Ang II/AT2R) axis exerts its effects by counter-modulating the action of AT1R, by activating endothelial nitric oxide synthase (eNOS) and stimulating cardioprotective pathways such as akt. The aim of this review is to discuss the possible use of AT1R blockers to hamper both the Ang II/AT1R axis and the associated ROS burst. Moreover; we suggest that AT1R antagonist drugs should act synergistically with other cardioprotective agents, such as ascorbic acid, N-acetylcysteine and deferoxamine, leading to an enhanced reduction in the reperfusion injury. This therapy is currently being tested in our laboratory and has shown promising outcomes in experimental studies.

10 February 2023 in Antioxidants
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Gabriel Méndez-ValdésGabriel Méndez-Valdés
Gabriel Méndez-Valdés
FGFrancisca Gómez-Hevia
Francisca Gómez-Hevia
MBMaria Chiara Bragato
Maria Chiara Bragato
José Lillo-MoyaJosé Lillo-Moya
José Lillo-Moya
Catalina Rojas-SoléCatalina Rojas-Solé
Catalina Rojas-Solé
RRRamón Rodrigo
Ramón Rodrigo
Breast cancer is the most frequent malignant neoplastic disease in women, with an estimated 2.3 million cases in 2020 worldwide. Its treatment depends on characteristics of the patient and the tumor. In the latter, characteristics include cell type and morphology, anatomical location, and immunophenotype. Concerning this latter aspect, the overexpression of the HER2 receptor, expressed in 15–25% of tumors, is associated with greater aggressiveness and worse prognosis. In recent times some monoclonal antibodies have been developed in order to target HER2 receptor overexpression. Trastuzumab is part of the monoclonal antibodies used as targeted therapy against HER2 receptor, whose major problem is its cardiac safety profile, where it has been associated with cardiotoxicity. The appearance of cardiotoxicity is an indication to stop therapy. Although the pathophysiological mechanism is poorly known, evidence indicates that oxidative stress plays a fundamental role causing DNA damage, increased cytosolic and mitochondrial ROS production, changes in mitochondrial membrane potential, intracellular calcium dysregulation, and the consequent cell death through different pathways. The aim of this review was to explore the use of antioxidants as adjuvant therapy to trastuzumab to prevent its cardiac toxicity, thus leading to ameliorate its safety profile in its administration.

16 September 2022 in Vaccines
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RCRene Clavero
Rene Clavero
APAlfredo Parra-Lucares
Alfredo Parra-Lucares
GMGabriel Méndez-Valdés
Gabriel Méndez-Valdés
Gabriel Méndez-ValdésGabriel Méndez-Valdés
Gabriel Méndez-Valdés
KBKarin Bravo
Karin Bravo
LTLuis Toro
Luis Toro
The CoronaVac vaccine is the most used anti-SARS-CoV-2 vaccine worldwide. Previous data indicate that this vaccine produces a lower immune response than RNA vaccines such as BNT162b2. End-stage renal disease (ESRD) patients have an increased rate of COVID-19 and a reduced immune response to vaccinations. Currently, there is little data on this population’s immune response induced by CoronaVac. Methods: This study involved a prospective cohort of ESRD patients in chronic hemodialysis who received a two-dose immunization scheme of either CoronaVac (Sinovac Biotech) or BNT162b2 vaccines (Pfizer-BioNTech). We measured the plasma levels of anti-SARS-CoV-2 IgG antibodies. We determined antibody titers before immunization, 2 and 4 months after two doses, plus 4 months after a booster dose. Results: We evaluated 208 patients in three hemodialysis centers. The mean age was 62.6 ± 15.6 years, of whom 91 were female (41.75%). Eighty-one patients (38.94%) received the BNT162b2 vaccine and 127 (61.06%) received the CoronaVac vaccine. Patients who received the BNT162b2 vaccine had a higher humoral response compared to those who received the CoronaVac vaccine (4 months after the second dose: BNT162b2: 88.89%, CoronaVac: 51.97%, p < 0.001; 4 months after the booster: BNT162b2: 98.77%, CoronaVac: 86.61%, p < 0.001). Conclusions: Our results suggest that the CoronaVac vaccine induced a lower humoral response than the BNT162b2 vaccine in ESRD patients on hemodialysis.

16 December 2025 in Medicina
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Journal Article
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SGSantiago Gelerstein
Santiago Gelerstein
Gabriel Méndez-ValdésGabriel Méndez-Valdés
Gabriel Méndez-Valdés
RRRamón Rodrigo
Ramón Rodrigo
Nuclear factor erythroid 2-related factor 2 (NRF2) orchestrates redox balance, metabolism, and cellular stress responses, acting as both a tumor suppressor and promoter depending on the disease stage. In advanced cancers, persistent NRF2 activation—through KEAP1/NFE2L2 mutations or oxidative adaptation—drives epithelial-to-mesenchymal transition, metabolic reprogramming, and immune evasion, promoting tumor invasion (T) and metastasis (M). Recent pharmacologic efforts seek to exploit this duality. NRF2 inhibitors such as brusatol, halofuginone, and ML385 suppress NRF2 transcriptional activity or disrupt DNA binding, reducing motility, invasion, and metastatic dissemination in preclinical models. In contrast, NRF2 activators, such as bardoxolone methyl (CDDO-Me), sulforaphane, and dimethyl fumarate, exhibit chemopreventive effects by enhancing detoxification and mitigating oxidative DNA damage during early tumorigenesis. Furthermore, metabolic interventions, such as glutaminase or G6PD inhibitors, target NRF2-driven anabolic and antioxidant pathways essential for metastatic fitness. Therefore, understanding the temporal and contextual effects of NRF2 signaling is crucial for therapeutic design. The aim of this review is to examine how pharmacological modulation of NRF2 influences the invasive and metastatic dimensions of tumor progression, in addition to discussing its potential integration into TNM-based prognostic and treatment frameworks.