PULMONARY NEUTROPHILIC INFLAMMATION IN MICE FED AN OBESOGENIC DIET

FLORENCIA S. BARRERA; CARLA F. GUZMAN; INALEN DEL V. CHACON; JONATHAN M. RAMIREZ; MARIA A. MATTAR DOMINGUEZ; LUCILA RIVEROS; IVANA MORALES; SONIA BARBIERIS; DARIO C RAMIREZ; GOMEZ MEJIBA, SANDRA;

Congreso; SAIC; 2024

A dietary chronic positive-energy balance causes low-grade systemicinflammation. Neutrophilic inflammation (NI) is the homing andactivation of neutrophils in tissues with local release of myeloperoxidase(MPO) and generation of HOCl causing chlorinating stress, amarker of NI. Herein we hypothesized that a dietary chronic positiveenergy balance can cause pulmonary NI. To test this we fed, adlibitum, 2 groups of male C57 mice (n=32 each) for 24 weeks with eitheran obesogenic diet (ObD) consisting of rodent chow containinga 22% bovine fat (483 kCal/100g) and 10% fructose in drinking water(3.9 Kcal/ml), or a control diet (CoD) containing rodent chow (329Kcal/100g) and tap drinking water. Weight gain, blood pressure, insulinresistance, and adiposity index were higher in ObD comparedto CoD. Plasma concentrations of total cholesterol, triglycerides,glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvictransaminase (GPT) were higher in ObD compared to CoD mice.Compared to the lungs of CoD, ObD mice had a higher number ofBALF neutrophils, content, and activity of MPO, chlorotyrosine-modifiedproteins, inducible nitric oxide synthase, and IL-6. Interestingly,when instilled with bacterial lipopolysaccharide or dead Pseudomonasaeruginosa, ObD mice had higher MPO content and activity,and chlorinated proteins than CoD mice. These data corroboratea higher content and activation of neutrophils in the lung of ObDmice than in the CoD mice. A chronic dietary positive energy balancecauses pulmonary neutrophilic inflammation in mice.