Abnormal expression of the E3 ubiquitin ligase A20 has been found in some malignant cancers, including hepatocellular carcinoma (HCC). Here, we discovered that A20 is an E3 ubiquitin ligase for phosphofructokinase, liver type (PFKL) in HCC A20 interacts with PFKL and promotes its degradation, therefore inhibiting glycolysis in HCC cell lines. Downregulation of A20 in HCC cells promotes proliferation, migration, and glycolysis, all of which can be inhibited by targeting PFKL with RNA interference. Importantly, A20 is downregulated in advanced HCC tissues and inversely correlated with PFKL expression. Thus, our findings establish A20 as a critical regulator of glycolysis and reveal a novel mechanism for A20 in tumor suppression and PFKL regulation. Given that an increased level of glycolysis is linked with HCC, this study also identifies potential therapeutic targets for HCC treatment.
Background: The overproliferation of pulmonary vascular cells is noted in pulmonary hypertension. The role of exosomes from pulmonary artery endothelial cells (PAEC) in the proliferation and apoptosis of pulmonary artery smooth muscle cells (PASMC) remains unclear. Methods: Exosomes were isolated and purified from the culture medium of PAEC using a commercial kit. Lipopolysaccharide (LPS), hypoxia, and hydrogen peroxide were utilized to induce PAEC injury. Coculture of PAEC and PASMC was conducted using Transwell plates, and GW4869 was applied to inhibit exosome release. The proliferation and apoptosis level of PASMC was assayed by MTT assay, apoptosis staining, and cleaved caspase-3 immunoblotting. Plasma exosomes were isolated by differential ultracentrifugation. Results: LPS or hypoxia enhance exosome release from PAEC. Release of PAEC-derived exosomes positively correlates with LPS concentration. The coculture of LPS-disposed PAEC with PASMC leads to overproliferation and apoptosis resistance in PASMC, and the exosome inhibitor GW4869 can partly cancel out this effect. Exosomes derived from PAEC could be internalized into PASMC, and thus promote proliferation and induce apoptosis resistance in PASMC. Idiopathic pulmonary arterial hypertension patients exhibit a higher circulation level of endothelium-derived exosomes. Conclusions: Inflammation and hypoxia could induce PAEC to release exosomes. PAEC- derived exosomes are involved in overproliferation and apoptosis resistance in PASMC, by which they may contribute to the pathogenesis of pulmonary hypertension.
In conclusion, we demonstrated, for the first time, that CFs participate in cardioprotective effects via an exosomes/microvesicles pathway during the acute phase of ischemia-reperfusion injury and Postcon can enhance this effect by upregulating the expression of CFs exosomes/microvesicles miR-423-3p, which targets the downstream effector RAP2C.
Galectin-3 (Gal-3) is highly expressed in fibrotic tissue related to diverse etiologies. endothelial-to-mesenchymal transition (EndoMT), A less well studied phenomenon serves as a critical process in pulmonary vascular remodeling associated with the development of pulmonary arterial hypertension (PAH). EndoMT is hypothesized to contribute to the over-proliferation of αSMA positive cells. We aim to investigate the potential role of Gal-3 in regulating EndoMT in PAH. We observed an upregulation in both Gal-3 and αSMA expression in the monocrotaline (MCT) and Hypoxia PAH model, accompanied with intimal thickening. For more profound vascular remodeling and endothelial layer lesion in former model, we employed Gal-3 knockdown and overexpression lentivirus methodology to the MCT rats to determine the mechanisms underlying abnormal endothelial cell transition in PAH. PAH was evaluated according to right ventricular systolic pressure, right heart hypertrophy and pulmonary artery remodeling. A reduction in Gal-3 was protective against the development of PAH, while Gal-3 upregulation aggravated pulmonary vascular occlusion. In addition, Gal-3 deficiency suppressed pulmonary vascular cell proliferation and macrophage infiltration. Finally, we revealed that in endothelial cells treated with tumor necrosis factor α and hypoxia (representing an
in vitro
model of PAH), inhibition of Gal-3 by siRNA was able to abolish the associated upregulation of αSMA. These observations suggesting Gal-3 serves as a critical mediator in PAH by regulating EndoMT. Inhibition of Gal-3 may represent a novel therapeutic target for PAH treatment.
Background
Vascular calcification is a major cause of the high morbidity and mortality of cardiovascular diseases and is closely associated with the intestinal microbiota. Short-chain fatty acids (SCFAs) are derived from the intestinal microbiota and can also regulate intestinal microbiota homeostasis. However, it remains unclear whether exogenous supplementation with propionate, a SCFA, can ameliorate vascular calcification by regulating the intestinal microbiota. This study was conducted to explore the roles of propionate and the intestinal microbiota in the process of vascular calcification.
Methods
In total, 92 patients were enrolled consecutively as the observational cohort to analyse the relationship between SCFAs and vascular calcification in both blood and faecal samples. A rat model of vascular calcification was induced by vitamin D3 and nicotine (VDN) to validate the effect of propionate. Differences in the intestinal microbiota were analysed by 16S ribosomal RNA gene sequencing. Faecal microbiota transplantation and Akkermansia muciniphila transplantation experiments were performed to evaluate the functions of the intestinal microbiota.
Results
The results of the observational cohort study revealed that the levels of SCFAs (particularly propionate) in both blood and faecal samples independently correlated negatively with calcification scores (P < 0.01). To verify the activities of propionate, it was provided to VDN-treated rats, and oral or rectal propionate delivery reshaped the intestinal microbiota, resulted in elevated SCFA production, improved intestinal barrier function and alleviated inflammation, ultimately ameliorating vascular calcification. Furthermore, we demonstrated that transplantation of the propionate-modulated intestinal microbiota induced beneficial outcomes similar to those with oral or rectal propionate administration. Interestingly, linear discriminant analysis (LDA) effect size (LEfSe) revealed that oral or rectal propionate administration and propionate-modulated intestinal microbiota transplantation both enriched primarily Akkermansia. Subsequently, we demonstrated that Akkermansia supplementation could ameliorate VDN-induced vascular calcification in rats.
Conclusions
Propionate can significantly ameliorate vascular calcification in VDN-treated rats, and this effect is mediated by intestinal microbiota remodelling. The findings in our study indicate that the intestinal tract-vessel axis is a promising target for alleviating vascular calcification.
Phosphoinositide 3‐kinase (PI3K) activation plays a critical role in the pulmonary vascular remodeling of pulmonary hypertension (PH). The nucleotide‐oligomerization domain (NOD)‐like receptor subfamily C3 (NLRC3) inhibits proliferation and inflammation via PI3K signaling in cancer. We previously showed NLRC3 was significantly reduced in PH patients, but the mechanism of function remains unclear. This study aimed to determine the potential role of NLRC3 in PH. We found that NLRC3 was downregulated in the pulmonary arteries of PH animal models and platelet‐derived growth factor‐BB (PDGF‐BB) stimulated pulmonary arterial smooth muscle cells (PASMCs). NLRC3 pretreatment reduced right ventricular systolic pressure, attenuated pulmonary vascular remodeling and RVHI, and ameliorated proliferation, migration, and inflammation. Monocrotaline (MCT)‐ and PDGF‐BB‐mediated PI3K activation were suppressed by NLRC3 pretreatment. 740Y‐P decreased the effect of NLRC3. Collectively, NLRC3 protected against MCT‐induced rat PH and PDGF‐BB‐induced PASMC proliferation, migration, and inflammation through a mechanism involving PI3K inhibition. NLRC3 may have a therapeutic effect on PH and provide a promising therapeutic strategy for PH.
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