The serine protease, dipeptidyl peptidase IV as a myokine: dietary protein and exercise mimetics as a stimulus for transcription and release. Issue 12 (22nd June 2016)

• Record Type: Journal Article
• Authors: Neidert, Leslie E.; Mobley, C. Brooks; Kephart, Wesley C.; Roberts, Michael D.; Kluess, Heidi A.
• Is Part Of: Physiological reports. Volume 4:Issue 12(2016:Jun.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-06-22
• Subjects: DPP‐IV -- exercise -- whey protein; Physiology -- Periodicals; 571
• DOI: 10.14814/phy2.12827
• Languages: English
• ISSNs: 2051-817X

Abstract

Abstract: Dipeptidyl‐peptidase IV (DPP‐IV) is an enzyme with numerous roles within the body, mostly related to regulating energy metabolism. DPP‐IV is also a myokine, but the stimulus for its release is poorly understood. We investigated the transcription and release of DPP‐IV from skeletal muscle in a three‐part study using C2 C12 myotube cultures, an acute rat exercise and postexercise feeding model, and human feeding or human exercise models. When myotubes were presented with leucine only, hydrolyzed whey protein, or chemicals that cause exercise‐related signaling to occur in cell culture, all caused an increase in the mRNA expression of DPP‐IV (1.63 to 18.56 fold change, P < 0.05), but only whey protein caused a significant increase in DPP‐IV activity in the cell culture media. When rats were fed whey protein concentrate immediately following stimulated muscle contractions, DPP‐IV mRNA in both the exercised and nonexercised gastrocnemius muscles significantly increased 2.5‐ to 3.7‐fold ( P < 0.05) 3–6 h following the exercise/feeding bout; of note exercise alone or postexercise leucine‐only feeding had no significant effect. In humans, plasma and serum DPP‐IV activities were not altered by the ingestion of whey protein up to 1 h post consumption, after a 10 min bout of vigorous running, or during the completion of three repeated lower body resistance exercise bouts. Our cell culture and rodent data suggest that whey protein increases DPP‐IV mRNA expression and secretion from muscle cells. However, our human data suggest that DPP‐IV is not elevated in the bloodstream following acute whey protein ingestion or exercise. Abstract : Our cell culture and rat data suggest DPP‐IV is being produced by the skeletal muscle, and our in vitro data suggests that the DPP‐IV myokine is being released by skeletal muscle into the interstitial space. But the function outside of the muscle is inconclusive based on the lack of local measures of DPP‐IV in both the rat and human studies.