Conjugated linoleic acid (CLA) influences muscle metabolism via stimulating mitochondrial biogenesis signaling in adult‐onset inactivity induced obese mice

Abstract

Recently, conjugated linoleic acid (CLA) has been reported to prevent body weight gain and fat accumulation in part by improving physical activity in mice. The current study was conducted to determine the role of CLA on skeletal muscle metabolism in nescient basic helix‐loop‐helix 2 knock‐out (N2KO) mice, an adult‐onset inactivity induced obese model. Five‐week‐old female N2KO and wild type mice were fed either control or CLA containing diet (0.5%) for 10 wk. Voluntary activity was determined biweekly and markers for muscle metabolisms were determined from the gastrocnemius muscle. CLA fed N2KO animals showed significant increased voluntary movement and gastrocnemius muscle mass compared to control group, whereas in wild type animals, no differences were observed. CLA treatment up‐regulated AMP‐activated protein kinase (AMPK), mitochondria biogenic markers, peroxisome proliferator‐activated receptor‐δ (PPARδ), and mitochondrial transcription factor A (Tfam) compared to control animals. These observations indicate that CLA supplementation activates AMPKα‐PPARδ and/or ‐Tfam signaling cascade for stimulating mitochondria biogenesis. Taken together, these results suggest that CLA may in part activate the underlying biomarkers involved in muscle metabolism via stimulation of mitochondrial biogenesis, resulting in increased voluntary activity and muscle mass, potentially contributing to regulating weight gain.Practical applications: Lack of physical activity is a global public health problem, which induces obesity and its associated pathologies. Approximately, 3.2 million deaths per year are attributable to lack of physical activity. CLA has previously been reported to increase voluntary and endurance activities in mice. However, the exact mode of action is not completely understood. Thus, the purpose of the study was to shed light on positive effects of CLA on physical activity through modulation of molecular targets in skeletal muscle of Nhlh2 knockout mice, which are an adult‐onset inactivity induced obesity model. The current results suggest that CLA acts as a potential exercise‐mimetic, resulting in increased voluntary activity and muscle mass, potentially contributing to regulating weight gain.Conjugated linoleic acid partially improves muscle metabolism via stimulation of mitochondrial biogenesis, resulting in increased voluntary activity.