Exosomal miR-17-5p from adipose-derived mesenchymal stem cells inhibits abdominal aortic aneurysm by suppressing TXNIP-NLRP3 inflammasome

Abstract

Background Preclinical studies have suggested that adipose-derived mesenchymal stem cells (ADSCs) transplantation can suppress abdominal aortic inflammation and aneurysm expansion through paracrine factors. Yet, the mechanism of action is not fully understood. In the present study, we further examined the function and mechanism of ADSC-derived exosomes (ADSC-exos) and their microRNA-17-5p (miR-17-5p) on the abdominal aortic aneurysm (AAA) progression. Methods ADSC-exos were isolated and identified. DiR and PKH67 staining were used to trace ADSC-exo in vivo and in vitro. Raw264.7 cells were applied to perform in vitro experiments, while a murine AAA model induced using angiotensin II (Ang II) was used for in vivo testing. The expression level of miR-17-5p in macrophages and Ang II-treated macrophages after ADSC-exos treatment was determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The target relation between miR-17-5p and thioredoxin-interacting protein (TXNIP) was identified by a dual-luciferase reporter gene assay. Artificial activation and block of experiments of miR-17-5p and TXNIP were conducted to clarify their functions in inflammation during AAA progression. The severity of AAA between groups was assessed by maximal aorta diameter, AAA incidence, survival rate, and histological stainings. Besides, inflammasome-related proteins and macrophage pyroptosis were further evaluated using western blot, RT-qPCR, and enzyme-linked immunosorbent assay (ELISA). Results The ADSC-exos were isolated and identified. In vivo testing showed that ADSC-exos were mainly distributed in the liver. Meanwhile, in vitro experiments suggested that ADSC-derived exosomes were taken up by macrophages, while inside, ADSC-exos miR-17-5p decreased a TXNIP induced by Ang II by directly binding to its 3′-untranslated region (3’UTR). Furthermore, overexpression of miR-17-5p enhanced the therapeutic function of ADSC-exos on inflammation during AAA expansion in vivo, while its inhibition reversed this process. Finally, overexpressed TXNIP triggered macrophage pyroptosis and was alleviated by ADSC-derived exosomes in vitro. Conclusion ADSC-exos miR-17-5p regulated AAA progression and inflammation via the TXNIP-NLRP3 signaling pathway, thus providing a novel insight in AAA treatment.

Identification of core cuprotosis-correlated biomarkers in abdominal aortic aneurysm immune microenvironment based on bioinformatics

“…Furthermore, inflammation has been demonstrated to play vital role in AAA pathology. Our previous study confirmed that inactivate TXNIP-NLRP3 inflammasome of macrophages helped inhibit the chronic inflammation of aorta thus decreasing the incidence of AAA ( 5 ). In addition, one of the key mechanisms is vascular smooth muscle cell (VSMC) apoptosis, which is considered as the critical pathogenesis of the weakness of aorta wall ( 6 , 7 ).…”

“…In this study, we found that CRGs were correlated with inflammatory response and oxidative response, including NLRP3 and FDX1. In our previous study, macrophage NLRP3 inflammasome plays a significant role in promoting the progress of AAA (5). Furthermore, NLRP3 inflammasome activation regulates vascular smooth muscle cells phenotypic switch (49), which ultimately leads to AAA development through tunica medium elastin degradation (4).…”

“…NOD-like receptor protein 3 (NLRP3) inflammasome, a potential therapeutic target for a variety of cardiovascular diseases, can sense pathogen-related molecular patterns and endogenous danger signals ( 67 , 68 ). Our previous work demonstrated that exosomes from adipose-derived mesenchymal stem cells inhibit AAA chronic inflammation by the blockade TXNIP-NLRP3 inflammasome ( 5 ). What is noteworthy, NLRP3/IL-1β signaling pathway can be used to promote vascular adventitia remodeling in the case of PVAT dysfunction ( 69 ).…”

“…12-week-old ApoE -/- knockout C57BL/6 mice were purchased from Shanghai Research Center for Model Organism and fed with high fat diet (HFD) under athogen-free conditions with a 12h dark/12h light cycle. As described in our previous study ( 5 ), the AAA was induced by implanting osmotic minipumps (#Alzet Model 2004, Charles River Laboratories, Inc). In detail, the mice were randomly allocated into groups and anesthetized by peritoneal injection with pentobarbital sodium (50 mg/kg; Boster, Wuhan, China).…”

“…Consequently, the sections were incubated with secondary antibodies for 1h under room temperature. Image J software (Rawak Software, Inc. Germany) was then utilized for quantitative analysis of immunofluorescence intensity as described in our previous study ( 5 ).…”