The study finds a marked reduction in the activity of mitochondrial genes located within obesity in fat tissue. In contrast, the genome-level changes in muscle mitochondria are relatively smaller. Hence, the researchers conclude a connection exists with adverse health effects and the mitochondria of fat tissue.
Research into obesity is of societal importance, with many high-income countries witnessing a surge in cases. Medically, obesity is associated with a range of metabolic diseases (as are certain foods, such as the finding that eating processed meat and a higher risk of cardiovascular disease). Causes of obesity are varied. One common pattern relates to disruption occurring with the neurocircuitry midbrain structures that control feeding behaviors that are under modulatory control by the hormone leptin.
Obesity, a challenging condition for many people, often as much psychological and physiological. For example, recent research finds that those with obesity are more responsive to food marketing adverts (especially for unhealthy foods). However, when their weight drops significantly, so too does their responsiveness to fast-food marketing.
While both of these examples focus on the bio-psychological, there are also physiological processes that determine whether one person becomes obese and where another does not do so.
With the new research, which comes from the University of Helsinki, scientists have discovered that obesity lowers mitochondrial gene expression in fat tissue (adipose tissue). Mitochondria process cell energy intake. The study reveals that when the pathways associated with breaking down nutrients are slow, the associated changes tend to lead towards different health-related consequences.
The data was revealed in a study using 49 pairs of identical twins, selected because they were discordant for body weight. Over time, measures were taken of body composition and metabolism, plus biopsies from adipose and muscle tissue were collected. The samples were assessed for genome-wide gene expression, the proteome and the metabolome. This revealed that the pathways triggering mitochondrial metabolism in adipose tissue were significantly reduced by obesity.
The new research appears in the journal Cell Reports Medicine, where the study is titled “Molecular pathways behind acquired obesity: adipose tissue and skeletal muscle multiomics in monozygotic twin pairs discordant for BMI.”
