Ghrelin regulates the proliferation and apoptosis of high glucose-induced islet cells through the PI3K-Akt signaling pathway

Ghrelin inhibits myocardial pyroptosis in diabetic cardiomyopathy by regulating ERS and NLRP3 inflammasome crosstalk through the PI3K/AKT pathway

AIMS

Endoplasmic reticulum stress(ERS) can induce inflammation mediated by NLRP3 inflammatory bodies and link inflammation with oxidative stress in myocardial tissue. Ghrelin is an endogenous growth hormone-releasing peptide that has been proven to have multiple effects, such as regulating energy metabolism and inhibiting inflammation. However, the role of ghrelin in myocardial injury in diabetic rats and the mechanism have not been reported.

RESULTS

We found that ghrelin could improve endoplasmic reticulum stress and inflammatory pyroptosis in the myocardial tissue of diabetic rats and reduce ERS and NLRP3 inflammasome crosstalk in H9C2 cardiomyocytes. Interestingly, ghrelin could activate the PI3K/AKT signalling pathway, playing a role in inhibiting endoplasmic reticulum stress and reducing the expression of pyroptosis-related proteins. However, these protective effects could be largely eliminated by LY294002.

CONCLUSIONS

In summary, we demonstrated that ghrelin inhibited myocardial pyroptosis in diabetic cardiomyopathy by regulating ERS and NLRP3 inflammasome crosstalk through the PI3K/AKT pathway. Our results provide new insights into the mechanism of diabetic myocardial injury induced by high glucose and high palmitic acid and ghrelin-mediated anti-inflammatory protection and provide potential therapeutic targets and strategies for diabetic cardiomyopathy.

The Importance of Intra-Islet Communication in the Function and Plasticity of the Islets of Langerhans during Health and Diabetes

Islets of Langerhans are anatomically dispersed within the pancreas and exhibit regulatory coordination between islets in response to nutritional and inflammatory stimuli. However, within individual islets, there is also multi-faceted coordination of function between individual beta-cells, and between beta-cells and other endocrine and vascular cell types. This is mediated partly through circulatory feedback of the major secreted hormones, insulin and glucagon, but also by autocrine and paracrine actions within the islet by a range of other secreted products, including somatostatin, urocortin 3, serotonin, glucagon-like peptide-1, acetylcholine, and ghrelin. Their availability can be modulated within the islet by pericyte-mediated regulation of microvascular blood flow. Within the islet, both endocrine progenitor cells and the ability of endocrine cells to trans-differentiate between phenotypes can alter endocrine cell mass to adapt to changed metabolic circumstances, regulated by the within-islet trophic environment. Optimal islet function is precariously balanced due to the high metabolic rate required by beta-cells to synthesize and secrete insulin, and they are susceptible to oxidative and endoplasmic reticular stress in the face of high metabolic demand. Resulting changes in paracrine dynamics within the islets can contribute to the emergence of Types 1, 2 and gestational diabetes.

Multi-Omics Approaches for Liver Reveal the Thromboprophylaxis Mechanism of Aspirin Eugenol Ester in Rat Thrombosis Model

Aspirin eugenol ester (AEE) is a novel medicinal compound synthesized by esterifying aspirin with eugenol using the pro-drug principle. Pharmacological and pharmacodynamic experiments showed that AEE had excellent thromboprophylaxis and inhibition of platelet aggregation. This study aimed to investigate the effect of AEE on the liver of thrombosed rats to reveal its mechanism of thromboprophylaxis. Therefore, a multi-omics approach was used to analyze the liver. Transcriptome results showed 132 differentially expressed genes (DEGs) in the AEE group compared to the model group. Proteome results showed that 159 differentially expressed proteins (DEPs) were identified in the AEE group compared to the model group. Six proteins including fibrinogen alpha chain (Fga), fibrinogen gamma chain (Fgg), fibrinogen beta chain (Fgb), orosomucoid 1 (Orm1), hemopexin (Hpx), and kininogen-2 (Kng2) were selected for parallel reaction monitoring (PRM) analysis. The results showed that the expression of all six proteins was upregulated in the model group compared with the control group. In turn, AEE reversed the upregulation trend of these proteins to some degree. Metabolome results showed that 17 metabolites were upregulated and 38 were downregulated in the model group compared to the control group. AEE could reverse the expression of these metabolites to some degree and make them back to normal levels. The metabolites were mainly involved in metabolic pathways, including linoleic acid metabolism, arachidonic acid metabolism, and the tricarboxylic acid (TCA) cycle. Comprehensive analyses showed that AEE could prevent thrombosis by inhibiting platelet activation, decreasing inflammation, and regulating amino acid and energy metabolism. In conclusion, AEE can have a positive effect on thrombosis-related diseases.