Geddo Federica, Antoniotti Susanna, Querio Giulia, Salaroglio Iris Chiara, Costamagna Costanzo, Riganti Chiara, Gallo Maria Pia
Department of Life Sciences and Systems Biology, University of Turin, Via Accademia Albertina 13, 10123 Turin, Italy.
Department of Oncology, University of Turin, Via Santena 5/bis, 10126 Turin, Italy.
Nutrients. 2021 Mar 12;13(3):916. doi: 10.3390/nu13030916.
Skeletal muscle plays a pivotal role in whole-body glucose metabolism, accounting for the highest percentage of glucose uptake and utilization in healthy subjects. Impairment of these key functions occurs in several conditions including sedentary lifestyle and aging, driving toward hyperglycemia and metabolic chronic diseases. Therefore, strategies pointed to improve metabolic health by targeting skeletal muscle biochemical pathways are extremely attractive. Among them, we focused on the natural sesquiterpene and cannabinoid type 2 (CB2) receptor agonist β-caryophyllene (BCP) by analyzing its role in enhancing glucose metabolism in skeletal muscle cells. Experiments were performed on C2C12 myotubes. CB2 receptor membrane localization in myotubes was assessed by immunofluorescence. Within glucose metabolism, we evaluated glucose uptake (by the fluorescent glucose analog 2-NBDG), key enzymes of both glycolytic and oxidative pathways (by spectrophotometric assays and metabolic radiolabeling) and ATP production (by chemiluminescence-based assays). In all experiments, CB2 receptor involvement was tested with the CB2 antagonists AM630 and SR144528. Our results show that in myotubes, BCP significantly enhances glucose uptake, glycolytic and oxidative pathways, and ATP synthesis through a CB2-dependent mechanism. Giving these outcomes, CB2 receptor stimulation by BCP could represent an appealing tool to improve skeletal muscle glucose metabolism, both in physiological and pathological conditions.
骨骼肌在全身葡萄糖代谢中起关键作用，在健康受试者中占葡萄糖摄取和利用的比例最高。这些关键功能的损害发生在多种情况下，包括久坐不动的生活方式和衰老，会导致血糖升高和代谢性慢性疾病。因此，通过靶向骨骼肌生化途径来改善代谢健康的策略极具吸引力。其中，我们通过分析天然倍半萜烯和大麻素2型（CB2）受体激动剂β-石竹烯（BCP）在增强骨骼肌细胞葡萄糖代谢中的作用，对其进行了研究。实验在C2C12肌管上进行。通过免疫荧光评估CB2受体在肌管中的膜定位。在葡萄糖代谢方面，我们评估了葡萄糖摄取（通过荧光葡萄糖类似物2-NBDG）、糖酵解和氧化途径的关键酶（通过分光光度法测定和代谢放射性标记）以及ATP生成（通过基于化学发光的测定）。在所有实验中，使用CB2拮抗剂AM630和SR144528测试CB2受体的参与情况。我们的结果表明，在肌管中，BCP通过CB2依赖性机制显著增强葡萄糖摄取、糖酵解和氧化途径以及ATP合成。基于这些结果，BCP对CB2受体的刺激可能是一种在生理和病理条件下改善骨骼肌葡萄糖代谢的有吸引力的工具。
