MicroRNA-223-3p inhibits oxidized low-density lipoprotein-mediated NLRP3 inflammasome activation via directly targeting NLRP3 and FOXO3

Renoprotective effect of a novel combination of 6-gingerol and metformin in high-fat diet/streptozotocin-induced diabetic nephropathy in rats via targeting miRNA-146a, miRNA-223, TLR4/TRAF6/NLRP3 inflammasome pathway and HIF-1α

BACKGROUND

MiRNA-146a and miRNA-223 are key epigenetic regulators of toll-like receptor 4 (TLR4)/tumor necrosis factor-receptor-associated factor 6 (TRAF6)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome pathway, which is involved in diabetic nephropathy (DN) pathogenesis. The currently available oral anti-diabetic treatments have been insufficient to halt DN development and progression. Therefore, this work aimed to assess the renoprotective effect of the natural compound 6-gingerol (GR) either alone or in combination with metformin (MET) in high-fat diet/streptozotocin-induced DN in rats. The proposed molecular mechanisms were also investigated.

METHODS

Oral gavage of 6-gingerol (100 mg/kg) and metformin (300 mg/kg) were administered to rats daily for eight weeks. MiRNA-146a, miRNA-223, TLR4, TRAF6, nuclear factor-kappa B (NF-κB) (p65), NLRP3, caspase-1, and hypoxia-inducible factor-1 alpha (HIF-1α) mRNA expressions were measured using real-time PCR. ELISA was used to measure TLR4, TRAF6, NLRP3, caspase-1, tumor necrosis factor-alpha (TNF-α), and interleukin-1-beta (IL-1β) renal tissue levels. Renal tissue histopathology and immunohistochemical examination of fibronectin and NF-κB (p65) were performed.

RESULTS

6-Gingerol treatment significantly reduced kidney tissue damage and fibrosis. 6-Gingerol up-regulated miRNA-146a and miRNA-223 and reduced TLR4, TRAF6, NF-κB (p65), NLRP3, caspase-1, TNF-α, IL-1β, HIF-1α and fibronectin renal expressions. 6-Gingerol improved lipid profile and renal functions, attenuated renal hypertrophy, increased reduced glutathione, and decreased blood glucose and malondialdehyde levels. 6-Gingerol and metformin combination showed superior renoprotective effects than either alone.

CONCLUSION

6-Gingerol demonstrated a key protective role in DN by induction of miRNA-146a and miRNA-223 expression and inhibition of TLR4/TRAF6/NLRP3 inflammasome signaling. 6-Gingerol, a safe, affordable, and abundant natural compound, holds promise for use as an adjuvant therapy with metformin in diabetic patients to attenuate renal damage and stop the progression of DN.

Integrating network pharmacology and experimental models to identify notoginsenoside R1 ameliorates atherosclerosis by inhibiting macrophage NLRP3 inflammasome activation

Atherosclerosis is a cardiovascular disease, accounting for the most common mortality cause worldwide. Notoginsenoside R1 (NGR1) is a characteristic saponin of Radix notoginseng that exhibits anti-inflammatory and antioxidant effects while modulating lipid metabolism. Evidence suggests that NGR1 exerts cardioprotective, neuroprotective, and anti-atherosclerosis effects. However, underlying NGR1 mechanisms alleviating atherosclerosis (AS) have not been examined. This study used a network pharmacology approach to construct the drug-target-disease correlation and protein-protein interaction (PPI) network of NGR1 and AS. Moreover, functional annotation and pathway enrichment analyses deciphered the critical biological processes and signaling pathways potentially regulated by NGR1. The protective effect of NGR1 against AS and the underlying mechanism(s) was assessed in an atherogenic apolipoprotein E-deficient (ApoE-/-) mice in vivo and an oxidized low-density lipoprotein (ox-LDL)-induced macrophage model in vitro. The network pharmacology and molecular docking analyses revealed that NGR1 protects against AS by targeting the NLRP3/caspase-1/IL-1β pathway. NGR1 reduced foam cell formation in ox-LDL-induced macrophages and decreased atherosclerotic lesion formation, serum lipid metabolism, and inflammatory cytokines in AS mice in vivo. Therefore, NGR1 downregulates the NLRP3 inflammasome complex gene expression of NLRP3, caspase-1, ASC, IL-1β, and IL-18, in vivo and in vitro.

Identification of circular RNA hsa_circ_0034621 as a novel biomarker for carotid atherosclerosis and the potential function as a regulator of NLRP3 inflammasome

BACKGROUND AND AIMS

NLRP3 inflammasome plays a key role in vascular inflammation and atherosclerosis. Circular RNAs (circRNAs) are involved in disease development by regulating gene expression, and have emerged as promising novel disease biomarkers. This study aimed to identify the NLRP3 inflammasome-associated circRNA biomarkers of carotid atherosclerosis.

METHODS

Based on the differential expression profiles of circRNAs in patients with carotid artery plaque (CAP) and healthy controls, hsa_circ_0043621, hsa_circ_0051995, and hsa_circ_0123388 were screened and validated using real-time quantitative polymerase chain reaction (RT-qPCR). Potential circRNA-miRNA-mRNA interactions were explored using a luciferase assay. The biological roles of the validated circRNAs were investigated in human umbilical vein endothelial cells (HUVECs) using Western blotting, transwell, and CCK-8 assays. Clinical significance was assessed using receiver operating characteristic (ROC) curves and logistic regression analysis.

RESULTS

The expression levels of all candidate circRNAs were significantly higher in patients with CAP than in controls (p<0.05), which was consistent with the results of the microarray analysis. Overexpression of hsa_circ_0043621 significantly increased the expression of NLRP3, induced migration of HUVECs, and inhibited cell proliferation. hsa_circ_0043621 demonstrated reasonable diagnostic accuracy for CAP detection and increased intima-media thickness (IMT). hsa_circ_0043621 upregulation was an independent predictor of an increased risk of CAP and increased IMT.

CONCLUSIONS

hsa_circ_0043621 is a valuable circulating biomarker of carotid atherosclerosis and may contribute to its pathogenesis by regulating the NLRP3 inflammasome.

The regulatory role and mechanism of USP14 in endothelial cell pyroptosis induced by coronary heart disease

OBJECTIVE

The present study probes into the role and mechanism of ubiquitin specific peptidase 14 (USP14) in coronary heart disease (CHD)-triggered endothelial cell pyroptosis.

METHODS

An in vitro CHD model was established by inducing human coronary artery endothelial cells (HCAECs) with oxidized low-density lipoprotein (ox-LDL). HCAECs were transfected with si-USP14, followed by evaluation of cell viability by CCK-8 assay, detection of lactate dehydrogenase (LDH) activity by assay kit, detection of USP14, miR-15b-5p, NLRP3, GSDMD-N, and Cleaved-Caspase-1 expressions by qRT-PCR or Western blot, as well as IL-1β and IL-18 concentrations by ELISA. Co-IP confirmed the binding between USP14 and NLRP3. The ubiquitination level of NLRP3 in cells was measured after protease inhibitor MG132 treatment. Dual-luciferase reporter assay verified the targeting relationship between miR-15b-5p and USP14.

RESULTS

USP14 and NLRP3 were highly expressed but miR-15b-5p was poorly expressed in ox-LDL-exposed HCAECs. USP14 silencing strengthened the viability of ox-LDL-exposed HCAECs, reduced the intracellular LDH activity, and diminished the NLRP3, GSDMD-N, Cleaved-Caspase-1, IL-1β, and IL-18 expressions. USP14 bound to NLRP3 protein and curbed its ubiquitination. Repression of NLRP3 ubiquitination counteracted the inhibitory effect of USP14 silencing on HCAEC pyroptosis. miR-15b-5p restrained USP14 transcription and protein expression. miR-15b-5p overexpression alleviated HCAEC pyroptosis by suppressing USP14/NLRP3.

CONCLUSION

USP14 stabilizes NLRP3 protein expression through deubiquitination, thereby facilitating endothelial cell pyroptosis in CHD. miR-15b-5p restrains endothelial cell pyroptosis by targeting USP14 expression.

Circ_HECW2 regulates ox-LDL-induced dysfunction of cardiovascular endothelial cells by miR-942-5p/TLR4 axis

BACKGROUND

Coronary artery disease (CAD) is a common coronary artery disease. The functional mechanism of circular RNA (circRNA) HECT, C2 and WW domain containing E3 ubiquitin protein ligase 2 (circ_HECW2, hsa_circ_0057583) in ox-LDL-treated human cardiac microvascular endothelial cells (hCMECs) is still unclear.

METHODS

Expression levels of circ_HECW2, microRNA (miR)-942-5p, and toll-like receptor 4 (TLR4) were analyzed by quantitative real-time PCR (qRT-PCR) and western blot assays. Cell proliferation and apoptosis were analyzed by 5-ethynyl-2'-deoxyuridine (EdU) assay, cell counting kit-8 (CCK8) assay, and flow cytometry, respectively. Tube formation assay was performed to analyze the angiogenesis of cells. Luciferase reporter and RNA pull-down assays were performed to analyze the target relationship among circ_HECW2, miR-942-5p and TLR4.

RESULTS

Circ_HECW2 and TLR4 expression levels were up-regulated and miR-942-5p expression was decreased in the serum of CAD patients and oxidized low-density lipoprotein (ox-LDL)-induced hCMECs. Knockdown of circ_HECW2 enhanced cell proliferation and inhibited cell apoptosis in ox-LDL-treated hCMECs. MiR-942-5p was the target of circ_HECW2 and directly targeted TLR4. Moreover, the effect of circ_HECW2 knockdown could be weakened by anti-miR-942-5p, and TLR4 could restore the function of miR-942-5p on cell damage of ox-LDL-induced hCMECs.

CONCLUSION

Circ_HECW2 could regulate ox-LDL-induced cardiovascular endothelial cell dysfunction through targeting miR-942-5p/TLR4 axis.

Transcription factor GATA1 represses oxidized-low density lipoprotein-induced pyroptosis of human coronary artery endothelial cells

BACKGROUND

Atherosclerosis (AS) is defined as a chronic inflammatory disorder underly the pathogenesis of cardiovascular diseases (CVDs). Endothelial pyroptosis is associated with AS-like diseases and other CVDs.

OBJECTIVE

This work was designed to expound on the effect of GATA-binding protein 1 (GATA1) on pyroptosis of human coronary artery endothelial cells (HCAECs) in AS.

METHODS

HCAECs were treated with oxidized-low density lipoprotein (ox-LDL) to establish HCAEC injury models. Plasmids for overexpressing GATA1 or silencing retinoic acid-related orphan receptor α (RORα) were transfected into HCAECs. Thereafter, the mRNA levels of GATA1 and RORα in HCAECs were detected using real-time quantitative polymerase chain reaction. HCAEC viability was examined using the cell counting kit-8 method. The levels of pyroptosis-related proteins NOD-like receptor protein 3 (NLRP3), cleaved-Caspase-1, N-terminal of gasdermin D (GSDMD-N), and pyroptosis-related inflammatory cytokines interleukin (IL)-1β and IL-18 were determined using Western blot and enzyme-linked immunosorbent assays, respectively. The targeting relationship between GATA1 and RORα was verified using the chromatin-immunoprecipitation assay. Then, the rescue experiment was conducted to explore the effect of RORα on pyroptosis of ox-LDL-treated HCAECs.

RESULTS

In ox-LDL-treated HCAECs, GATA1 and RORα expressions were decreased, HCAEC viability was reduced, and the levels of NLRP3, cleaved-Caspase1, GSDMD-N, IL-1β, and IL-18 were elevated. GATA1 overexpression increased HCAEC viability and attenuated pyroptosis. GATA1 bound to the RORα promoter region to stimulate RORα transcription, and RORα suppression facilitated ox-LDL-induced pyroptosis of HCAECs.

CONCLUSIONS

GATA1 activated RORα transcription and therefore limited pyroptosis of ox-LDL-treated HCAECs.

Circ_ARHGAP32 acts as miR-665 sponge to upregulate FGF2 to promote ox-LDL induced vascular smooth muscle cells proliferation and migration

BACKGROUND: Circular RNA (circRNA) is considered to be an important regulator of human diseases, including atherosclerosis (AS). However, the role of circ_ARHGAP32 in AS formation needs further confirmation. OBJECTIVE: To explore the role of circ_ARHGAP32 in AS formation. METHODS: Oxidized low density lipoprotein (ox-LDL) was used to treat vascular smooth muscle cells (VSMCs) to mimic AS cell models in vitro. The expression of circ_ARHGAP32, microRNA (miR)-665, and fibroblast growth factor 2 (FGF2) was analyzed by quantitative real-time PCR. VSMCs function was measured by EdU assay, cell counting kit 8 assay and transwell assay. Protein expression was determined using western blot analysis. Dual-luciferase reporter assay and RNA pull-down assay were performed to verify RNA interaction. RESULTS: Circ_ARHGAP32 was highly expressed in AS patients and ox-LDL-induced VSMCs. Knockdown of circ_ARHGAP32 repressed ox-LDL-induced proliferation and migration in VSMCs. Circ_ARHGAP32 sponged miR-665 to positively regulate FGF2. MiR-665 inhibitor reversed the regulation of sh-circ_ARHGAP32 on ox-LDL-induced VSMCs proliferation and migration. MiR-665 also had a suppressive effect on the proliferation and migration of ox-LDL-induced VSMCs, and this effect could be reversed by FGF2 overexpression. CONCLUSIONS: Circ_ARHGAP32 might be a potential target for AS treatment, which promoted ox-LDL-induced VSMCs proliferation and migration by regulating miR-665/FGF2 network.