1.Exploring the mechanism of moxibustion in myocardial protection of rats with long-term fatigue exercise based on the classical pyroptosis pathway
Shiling LÜ ; Ruida LI ; Zemin ZHANG ; Xin WANG ; Yulei LIANG ; Wenli LI ; Dongyun SUN
Journal of Acupuncture and Tuina Science 2023;21(2):121-128
Objective: To explore the possible mechanism of moxibustion in myocardial protection of rats undergoing long-term fatigue exercise based on observing the classical pyroptosis pathway mediated by nuclear factor kappa-B (NF-κB)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)/cysteinyl aspartate specific proteinase 1 (Caspase-1).Methods: A total of 50 specific-pathogen-free male Sprague-Dawley rats were bought. Ten unqualified rats were excluded, and the remaining 40 rats were divided into a normal group, a normal + Shenque (CV8) group, a model group, a model + non-meridian non-point group, and a model + Shenque (CV8) group according to the random number table method, with 8 rats in each group. Except for rats in the normal group and the normal + Shenque (CV8) group, rats in the other three groups were trained with an incline running table exercise protocol to create a long-term fatigue exercise model, 1 h/time, once a day for 5 d with 2 d off, for a total of 8 weeks. Rats in the normal group received no modeling or intervention. Rats in the normal + Shenque (CV8) group were not modeled but received mild moxibustion at Shenque (CV8); those in the model group were modeled only without intervention; those in the model + non-meridian non-point group received moxibustion at non-meridian and non-point spots after the modeling; those in the model + Shenque (CV8) group received moxibustion at Shenque (CV8) after modeling. The above moxibustion interventions were performed for 15 min/time once daily, for 5 d with 2 d off per week and a total of 8 weeks. Blood was collected from the femoral artery 4 h after the last exercise, and the serum interleukin (IL)-1β and IL-18 levels were measured. The NF-κB, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Caspase-1, and gasdermin D (GSDMD) expression levels were detected by Western blotting. Myocardial morphology and pyroptosis were observed by hematoxylin-eosin (HE) staining and electron microscopy. Results: The HE staining results showed that the myocardial cells in the model group and the model + non-meridian non-point group were disorganized with blurred transverse lines, widened interstitial spaces, interstitial edema, and inflammatory cell infiltration. The structure of myocardial cells in the model + Shenque (CV8) group was clearly visible, with slightly widened interstitial spaces and occasional infiltration of inflammatory cells in the interstitium. Compared with the normal group, the serum IL-1β and IL-18 levels were increased, and myocardial NF-κB, NLRP3, ASC, Caspase-1, and GSDMD expression levels were elevated in the model group and the model + non-meridian non-point group (P<0.01). Compared with the model group, the above indicators did not change significantly in the model + non-meridian non-point group, while all the above indicators were decreased in the model + Shenque (CV8) group (P<0.01). Compared with the model + non-meridian non-point group, all the above biochemical indicators were decreased in the model + Shenque (CV8) group (P<0.01). Transmission electron microscopy showed that the mitochondria number was increased in the model group and the model + non-meridian non-point group, some of the mitochondrial lumen was irregularly enlarged, the cell membrane structure was unclear, and chromatin was aggregated. The mitochondria number was increased, the swelling was reduced, and the nuclear membrane structure was more intact in the model + Shenque (CV8) group. Conclusion: Moxibustion at Shenque (CV8) regulates the NF-κB/NLRP3/Caspase-1 pathway and reduces the pyroptosisin the myocardium of rats with long-term fatigue exercise, thus reducing the myocardial injury caused by long-term fatigue exercise.