Long-term modulations in the vertebral transcriptome of adolescent-stage rats exposed to binge alcohol

Dangerous alcohol consumption practices are common in adolescents, yet little is known about their consequences on attainment of peak bone mass and long-term skeletal integrity. We previously demonstrated that binge alcohol-exposed adolescent rats showed site-specific reductions in accruement of bone mineral density and bone strength, which were incompletely recovered following prolonged alcohol abstinence. Currently, we analysed the vertebral transcriptome of adolescent rats following alcohol treatment and abstinence to identify long-term molecular changes in the lumbar spine.

Sixty male adolescent Sprague-Dawley rats were assigned to one of six treatment groups receiving binge alcohol (3 g/kg) or saline i.p., 3 consecutive days (acute binge), 4 consecutive weekly (3-day) binge cycles (chronic binge) or 4 weekly binge cycles followed by a 30-day abstinence period (chronic binge with abstinence). Following treatment, lumbar vertebrae were assayed for global transcriptional changes using gene array technology.

Analysis of the adolescent rat vertebral transcriptome identified clusters of binge alcohol-sensitive genes displaying differential expression patterns starting before bone damage was seen and persisting after alcohol treatment was discontinued. Functional grouping of these gene clusters identified candidate cellular pathways affected following acute and chronic binge treatment, as well as pathways remaining modulated following abstinence.

These results demonstrate that binge alcohol exposure can produce disruptions of normal bone gene expression patterns in the adolescent rat that persist well beyond the period of active intoxication. This data may have relevance to peak bone mass attainment and future risk of skeletal disease in adolescents engaging in repeated binge-drinking episodes.