Biology subjects

Hernandez Garcia, M.

Publications and source records attributed to Hernandez Garcia, M..

2 recordsLinked to original sources

bioRxiv2025

Exogenous Thyroxine Increases Cardiac Nrf2-TRX in Insulin Resistant OLETF Rats

Cardiovascular disease (CVD) is the leading cause of death among individuals with Type II diabetes (T2D), affecting approximately 30 million people in the United States. During insulin resistance, the heart undergoes a metabolic shift, leading to increased reactive oxygen species (ROS) generation, lipotoxicity, and mitochondrial dysfunction, ultimately contributing to cardiovascular dysfunction. The effects of thyroid hormones (THs) on redox biology and oxidative stress remain inconclusive, necessitating further investigation. In this study, insulin-resistant Otsuka Long Evans Tokushima Fatty (OLETF) rats were used to assess the impact of exogenous thyroxine (exoT4) on NADPH oxidases (NOX) and antioxidant defenses in the heart. Rats were assigned to four groups: (1) lean control, Long Evans Tokushima Otsuka (LETO; n=6), (2) LETO + T4 (8 g/100g BM/day for 5 weeks; n=7), (3) untreated OLETF (n=6), and (4) OLETF + T4 (n=7). NOX4 mRNA expression was two-fold greater in OLETF rats compared to LETO. T4 treatment increased NOX4 protein abundance by 56% in OLETF. Additionally, T4 normalized lipid peroxidation (4-hydroxynonenal) and tumor necrosis factor- (TNF-) levels while increasing nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expression by 158% compared to LETO and enhancing nuclear Nrf2 protein expression by 45% compared to untreated OLETF. Thioredoxin (TRX) expression, suppressed in OLETF, was increased by 88% following T4 treatment. ExoT4 increased mitofusin 2 (Mfn2) protein abundance in OLETF by 49% compared to LETO. These findings suggest that thyroid hormone treatment may have cardioprotective effects mediated by Nrf2 in the heart during metabolic syndrome (MetS).

physiology↗

bioRxiv2021

Antibody Conversion rates to SARS-CoV-2 in Saliva from Children Attending Summer Schools in Barcelona, Spain

Surveillance tools to estimate infection rates in young populations are essential to guide recommendations for school reopening and management during viral epidemics. Ideally, field-deployable non-invasive, sensitive techniques are required to detect low viral load exposures among asymptomatic children. We determined SARS-CoV-2 antibody conversion by high-throughput Luminex assays in saliva samples collected weekly in 1,509 children and 396 adults in 22 Summer schools and 2 pre-schools in 27 venues in Barcelona, Spain, from June 29th to July 31st 2020, between the first and second COVID-19 pandemic waves. Saliva antibody conversion defined as [≥]4-fold increase in IgM, IgA and/or IgG levels to SARS-CoV-2 antigens between two visits over a 5-week period was 3.22% (49/1518), or 2.36% if accounting for potentially cross-reactive antibodies, six times higher than the cumulative infection rate (0.53%) by weekly saliva RT-PCR screening. IgG conversion was higher in adults (2.94%, 11/374) than children (1.31%, 15/1144) (p=0.035), IgG and IgA levels moderately increased with age, and antibodies were higher in females. Most antibody converters increased both IgG and IgA antibodies but some augmented either IgG or IgA, with a faster decay over time for IgA than IgG. Nucleocapsid rather than spike was the main antigen target. Anti-spike antibodies were significantly higher in individuals not reporting symptoms than symptomatic individuals, suggesting a protective role against COVID-19. To conclude, saliva antibody profiling including three isotypes and multiplexing antigens is a useful and more user-friendly tool for screening pediatric populations to determine SARS-CoV-2 exposure and guide public health policies during pandemics.

immunology↗