Identification of ANXA3 as a biomarker associated with pyroptosis in ischemic stroke.

BACKGROUND: Pyroptosis plays an important role in the pathological process of ischemic stroke (IS). However, the exact mechanism of pyroptosis remains unclear. This paper aims to reveal the key molecular markers associated with pyroptosis in IS. METHODS: We used random forest learning, gene set variation analysis, and Pearson correlation analysis to screen for biomarkers associated with pyroptosis in IS. Middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen and glucose deprivation/reoxygenation (OGD/R) models were constructed in vitro and in vivo. Cells were transfected with an Annexin A3 silencing (si-ANXA3) plasmid to observe the effects of ANXA3 on OGD/R + lipopolysaccharides (LPS)-induced pyroptosis. qRT‒PCR and western blotting were used to detect the expression of potential biomarkers and pyroptotic pathways. RESULTS: Samples from a total of 170 IS patients and 109 healthy individuals were obtained from 5 gene expression omnibus databases. Thirty important genes were analyzed by random forest learning from the differentially expressed genes. Then, we investigated the relationship between the above genes and the pyroptosis score, obtaining three potential biomarkers (ANXA3, ANKRD22, ADM). ANXA3 and ADM were upregulated in the MCAO/R model, and the fold difference in ANXA3 expression was greater. Pyroptosis-related factors (NLRP3, NLRC4, AIM2, GSDMD-N, caspase-8, pro-caspase-1, cleaved caspase-1, IL-1ß, and IL-18) were upregulated in the MCAO/R model. Silencing ANXA3 alleviated the expression of pyroptosis-related factors (NLRC4, AIM2, GSDMD-N, caspase-8, pro-caspase-1, cleaved caspase-1, and IL-18) induced by OGD/R + LPS or MCAO/R. CONCLUSION: This study identified ANXA3 as a possible pyroptosis-related gene marker in IS through bioinformatics and experiments. ANXA3 could inhibit pyroptosis through the NLRC4/AIM2 axis.

[Aucubin combined with ADSCs-exos protects TBHP-induced nucleus pulposus cells via TLR4/NF-κB pathway].

This paper aims to investigate the effects and mechanisms of adipose-derived stem cells-exosomes(ADSCs-exos) toge-ther with aucubin in protecting human-derived nucleus pulposus cells(NPCs) from inflammatory injury, senescence, and apoptosis. The tert-butyl hydroperoxide(TBHP)-induced NPCs were assigned into normal, model, aucubin, ADSCs-exos, and aucubin+ADSCs-exos groups. The cell viability was examined by cell counting kit-8(CCK-8), cell proliferation by EdU staining, cell senescence by senescence-associated-ß-galactosidase(SA-ß-Gal), and cell cycle and apoptosis by flow cytometry. Enzyme-linked immunosorbent assay was employed to examine the expression of interleukin-1ß(IL-1ß), IL-10, and tumor necrosis factor-α(TNF-α). Real-time fluorescence quantitative PCR and Western blot were employed to determine the mRNA and protein levels of aggregated proteoglycan(aggrecan), type Ⅱ collagen alpha 1(COL2A1), Toll-like receptor 4(TLR4), and nuclear factor-kappa B(NF-κB). The results showed that compared with the model group, the aucubin or ADSCs-exos group showed enhanced viability and proliferation of NPCs, decreased proportion of G_0/G_1 phase cells, increased proportion of S phase cells, reduced apoptosis and proportion of cells in senescence, lowered IL-1ß and TNF-α levels, elevated IL-10 level, down-regulated mRNA and protein levels of TLR4 and NF-κB, and up-regulated mRNA and protein levels of aggrecan and COL2A1. Compared with the aucubin or ADSCs-exos group, the aucubin+ADSCs-exos combination further increased the viability and proliferation of NPCs, decreased the proportion of G_0/G_1 phase cells, increased the proportion of S phase cells, reduced the apoptosis and proportion of cells in senescence, lowered the IL-1ß and TNF-α levels, elevated the IL-10 level, down-regulated the mRNA and protein levels of TLR4 and NF-κB, and up-regulated the mRNA and protein levels of aggrecan and COL2A1. In summary, both aucubin and ADSCs-exos could exert protective effects by inhibiting inflammatory responses, reducing apoptosis and senescence of NPCs, improving cell viability and proliferation as well as extracellular matrix synthesis, which may be associated with the inhibition of TLR4/NF-κB signaling pathway activation. The combination of both plays a synergistic role in the protective effects.

[EPCs-exos combined with tanshinone â ¡_A protect vascular endothelium cells from oxidative damage via PI3K/Akt pathway].

This study aims to investigate the molecular mechanism of tanshinone Ⅱ_(A )(TaⅡ_A) combined with endothelial progenitor cells-derived exosomes(EPCs-exos) in protecting the aortic vascular endothelial cells(AVECs) from oxidative damage via the phosphatidylinositol 3 kinase(PI3K)/protein kinase B(Akt) pathway. The AVECs induced by 1-palmitoyl-2-(5'-oxovaleroyl)-sn-glycero-3-phosphocholine(POVPC) were randomly divided into model, TaⅡ_A, EPCs-exos, and TaⅡ_A+EPCs-exos groups, and the normal cells were taken as the control group. The cell counting kit-8(CCK-8) was used to examine the cell proliferation. The lactate dehydrogenase(LDH) cytotoxicity assay kit, Matrigel assay, DCFH-DA fluorescent probe, and laser confocal microscopy were employed to examine the LDH release, tube-forming ability, cellular reactive oxygen species(ROS) level, and endothelial cell skeleton morphology, respectively. The enzyme-linked immunosorbent assay was employed to measure the expression of interleukin(IL)-1ß, IL-6, and tumor necrosis factor(TNF)-α. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to determine the mRNA and protein levels, respectively, of PI3K and Akt. Compared with the control group, the model group showed decreased cell proliferation and tube-forming ability, increased LDH release, elevated ROS level, obvious cytoskeletal disruption, increased expression of IL-1ß, IL-6, and TNF-α, and down-regulated mRNA and protein levels of PI3K and Akt. Compared with the model group, TaⅡ_A or EPCs-exos alone increased the cell proliferation and tube-forming ability, reduced LDH release, lowered the ROS level, repaired the damaged skeleton, decreased the expression of IL-1ß, IL-6, and TNF-α, and up-regulated the mRNA and protein levels of PI3K and Akt. TaⅡ_A+EPCs-exos outperformed TaⅡ_A or EPCs-exos alone in regulating the above indexes. The results demonstrated that TaⅡ_A and EPCs-exos exerted a protective effect on POVPC-induced AVECs by activating the PI3K/Akt pathway, and the combination of the two had stronger therapeutic effect.