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Leander, D. C.

Publications and source records attributed to Leander, D. C..

2 recordsLinked to original sources

Legacy Effects of Early β-Adrenergic Stimulation Program Adipose Plasticity and Confer Metabolic Resilience in Obesity

Pathologic white adipose tissue (WAT) remodeling, characterized by fibrosis, inflammation, and adipocyte dysfunction, is a hallmark and driver of metabolic disease in obesity1. Here, we show that legacy effects of early physiological or pharmacological interventions driving adaptive adipose remodeling can mitigate maladaptive WAT remodeling and metabolic dysfunction when developing obesity later in life. Cold exposure or {beta}3-adrenergic receptor ({beta}3AR) agonism (CL316,243) induced thermogenic remodeling of WAT in male mice. After a prolonged recovery at room temperature, trained epididymal WAT reverted to an energy-storing state but retained a population of adipocytes resembling "metabolically flexible" visceral adipocytes found in human metabolically healthy obesity. The legacy of the antecedent treatment conferred lasting protection against glucose intolerance when later developing high fat diet (HFD)-induced obesity, with insulin sensitivity persisting for at least 20 weeks of overnutrition. This metabolic resilience was accompanied by healthy epididymal WAT expansion with reduced fibrosis and inflammation. Our findings demonstrate that short-term interventions, without genetic manipulation, can "train" adipose tissue, enhancing its long-term plasticity and conferring durable protection against future obesity-associated insulin resistance.

physiology↗

A Novel Swine Model of the Acute Respiratory Distress Syndrome Using Clinically-Relevant Injury Exposures

To date, existing animal models of the acute respiratory distress syndrome (ARDS) have failed to translate preclinical discoveries into effective pharmacotherapy or diagnostic biomarkers. To address this translational gap, we developed a high-fidelity swine model of ARDS utilizing clinically-relevant lung injury exposures. Fourteen male swine were anesthetized, mechanically ventilated, and surgically instrumented for hemodynamic monitoring, blood, and tissue sampling. Animals were allocated to one of three groups: 1) Indirect lung injury only: animals were inoculated by direct injection of E. coli into the kidney parenchyma, provoking systemic inflammation and distributive shock physiology; 2) Direct lung injury only: animals received volutrauma, hyperoxia, and bronchoscope-delivered gastric particles; 3) Combined indirect and direct lung injury: animals were administered both above-described indirect and direct lung injury exposures. Animals were monitored for up to 12 hours, with serial collection of physiologic data, blood samples, and radiographic imaging. Lung tissue was acquired post-mortem for pathological examination. In contrast to indirect lung injury only and direct lung injury only groups, animals in the combined indirect and direct lung injury group exhibited all of the physiological, radiographic, and histopathologic hallmarks of human ARDS: impaired gas exchange (mean PaO2/FiO2 ratio 124.8 {+/-} 63.8), diffuse bilateral opacities on chest radiographs, and extensive pathologic evidence of diffuse alveolar damage. Our novel porcine model of ARDS, built on clinically-relevant lung injury exposures, faithfully recapitulates the physiologic, radiographic, and histopathologic features of human ARDS, and fills a crucial gap in the translational study of human lung injury.

pathology↗