Benzene-induced pulmonary dysfunction in diabetic mice.

Area of Science:

• Environmental Health
• Toxicology
• Pulmonary Medicine

Background:

• Benzene exposure is linked to impaired pulmonary function.
• The impact of pre-existing metabolic diseases, like diabetes, on benzene susceptibility is not well understood.

Purpose of the Study:

• To investigate the effects of inhaled benzene on pulmonary mechanics and surfactant homeostasis in diabetic mice with varying glycemic severity.
• To determine if diabetes exacerbates benzene-induced respiratory toxicity.

Main Methods:

• Diabetic mice (mildly hyperglycemic KK and severely hyperglycemic KK-Ay) were exposed to filtered air or 50 ppm benzene for two weeks.
• Pulmonary function was assessed using the forced-oscillation technique.
• Bronchoalveolar lavage fluid was analyzed for surfactant proteins and lipids; whole-lung transcriptomes were profiled.

Main Results:

• Benzene exposure increased respiratory system resistance and Newtonian resistance in severely hyperglycemic KK-Ay mice.
• Methacholine challenge revealed exaggerated bronchoconstriction in benzene-exposed KK-Ay mice.
• Benzene altered surfactant protein and lipid composition, correlating with increased airway resistance.

Conclusions:

• Severe hyperglycemia and insulin resistance in KK-Ay mice exacerbate benzene-induced airway hyperresponsiveness.
• Benzene disrupts surfactant homeostasis, contributing to respiratory toxicity.
• Poorly controlled diabetes is identified as a risk factor for benzene-related respiratory toxicity.