Objective:

2

To investigate the mechanism of electroacupuncture (EA) in treating diabetic gastroparesis (DGP) by inhibiting the activation of Nod-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome and pyroptosis mediated via NLRP3/cysteinyl aspartate specific proteinase-1 (caspase-1)/gasdermin D (GSDMD) signaling pathway.

Methods:

2

Forty Sprague-Dawley rats were randomly divided into 4 groups including the control

DGP model

EA

and MCC950 groups. The DGP model was established by a one-time high-dose intraperitoneal injection of 2% streptozotocin and a high-glucose and high-fat diet for 8 weeks. EA intervention was conducted at Zusanli (ST 36)

Liangmen (ST 21) and Sanyinjiao (SP 6) with sparse-dense wave for 15 min

and was administered for 3 courses of 5 days. After intervention

the blood glucose

urine glucose

gastric emptying

and intestinal propulsive rate were observed. Besides

HE staining was used to observe histopathological changes in gastric antrum tissues

and TUNEL staining was utilized to detect DNA damage. Protein expression levels of NLRP3

apoptosis-associated speck-like protein containing CARD (ASC)

pro-caspase-1

caspase-1 and GSDMD were measured by Western blot. Immunofluorescence staining was employed to assess the activity of GSDMD-N. Lactate dehydrogenase (LDH) levels were detected by using a biochemical kit.

Results:

2

DGP rats showed persistent hyperglycemia and a significant decrease in gastrointestinal motility (

P

<

0.05 or

P

<

0.01)

accompanied by pathological damage in their gastric antrum tissues. Cellular DNA was obviously damaged

and the expressions of NLRP3

ASC

pro-caspase-1

caspase-1 and GSDMD proteins were significantly elevated

along with enhanced fluorescence signals of GSDMD-N and increased LDH release (

P

<

0.01). EA mitigated hyperglycemia

improved gastrointestinal motility in DGP rats and alleviated their pathological injury (

P

<

0.05). Furthermore

EA reduced cellular DNA damage

lowered the protein levels of NLRP3

ASC

pro-caspase-1

caspase-1 and GSDMD

suppressed GSDMD-N activity

and decreased LDH release (

P

<

0.05 or

P

<

0.01)

demonstrating effects comparable to MCC950.

Conclusion:

2

EA promotes gastrointestinal motility and repairs the pathological damage in DGP rats

and its mechanism may be related to the inhibition of NLRP3 inflammasome and pyroptosis mediated by NLRP3/caspase-1/GSDMD pathway.