[Exploration of mechanism of total triterpenoids from fruits of Chaenomeles speciosa against senescent GES-1 cells induced by D-galactose based on Gln/GLS1/α-KG metabolic axis and mitochondrial apoptosis signaling pathway].

Total triterpenoids from the fruits of Chaenomeles speciosa(TCS) are active components in the prevention and treatment of gastric mucosal damage, which have potential anti-aging effects. However, it is still unclear whether TCS can improve gastric aging, especially its molecular mechanism against gastric aging. On this basis, this study explored the effect and mechanism of TCS on senescent GES-1 cells induced by D-galactose(D-gal) to provide scientific data for the clinical use of TCS to prevent gastric aging. GES-1 cells cultured in vitro and those transfected with overexpression GLS1(GLS1-OE) plasmid of glutaminase 1(GLS1) were induced to aging by D-gal, and then TCS and or GLS1 inhibitor bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl) ethyl sulfide(BPTES) were given. Cell survival rate, positive rate of ß-galactosidase(SA-ß-gal) staining, mitochondrial membrane potential(MMP), and apoptosis were investigated. GLS1 activity, levels of glutamine(Gln), glutamate(Glu), α-ketoglutarate(α-KG), urea, and ammonia in supernatant and cells were detected by enzyme-linked immunosorbent assay(ELISA) and colorimetric methods. The mRNA and protein expressions of GLS1 and the related genes of the mitochondrial apoptosis signaling pathway were measured by real-time fluorescence quantitative PCR and Western blot. The results manifested that compared with the D-gal model group and GLS1-OE D-gal model group, TCS significantly decreased the SA-ß-gal staining positive cell rate and MMP of D-gal-induced senescent GES-1 cells and GLS1-OE senescent GES-1 cells, inhibited the survival of senescent cells, and promoted their apoptosis(P<0.01). It decreased the activity of GLS1 and the content of Gln, Glu, α-KG, urea, and ammonia in supernatant and cell(P<0.01), reduced the concentration of cytochrome C(Cyto C) in mitochondria and the mRNA and protein expressions of GLS1 and proliferating nuclear antigen in cells(P<0.01). The mRNA expression of Bcl-2 and Bcl-xl, the protein expression of pro-caspase-9 and pro-caspase-3, and the ratio of Bcl-2/Bax and Bcl-xl/Bad in cells were decreased(P<0.01). Cyto C concentration in the cytoplasm, the mRNA expressions of Bax, Bad, apoptosis protease activating factor 1(Apaf-1), and protein expressions of cleaved-caspase-9, cleaved-caspase-3, cleaved-PARP-1 were increased(P<0.01). The aforementioned results indicate that TCS can counteract the senescent GES-1 cells induced by D-gal, and its mechanism may be closely related to suppressing the Gln/GLS1/α-KG metabolic axis, activating the mitochondrial apoptosis pathway, and thereby accelerating the apoptosis of the senescent cells and eliminating senescent cells.

[Expression and significance of interleukin-6, interferon-inducible protein-10 and interleukin-17 in serum and synovial fluid of patients with juvenile idiopathic arthritis].

OBJECTIVE: To detect the disparity of three cytokines interleukin-6 (IL-6), interferon-inducible protein 10 (IP-10) and interleukin-17 (IL-17) in peripheral blood (PB) and synovial fluid (SF) of patients with juvenile idiopathic arthritis (JIA). METHOD: Serum concentrations of the three cytokines were measured in 27 patients with 13 systemic-onset JIA (sJIA), 14 polyarticular JIA (pJIA) and 28 healthy controls using enzyme-linked immunosorbent assay (ELISA). Nineteen patients with no marked arthritis symptom or only temporary arthralgia were enrolled in probable sJIA group. SF from 18 patients with 7 sJIA, 11 pJIA were examined for cytokine levels. RESULT: (1) The statistically significant difference in serum IL-6 was detected between sJIA and healthy control group [28.0(4.2-59.2) ng/L vs. 12.3 (2.1-13.8) ng/L, P < 0.05], but no significant difference between probable sJIA and healthy control group [11.8(7.7-39.2) ng/L vs. 12.3 (2.1-13.8) ng/L, P > 0.05] was found. There were statistically significant differences between sJIA group and healthy control group in serum concentrations of IL-17 [14.0(9.8-34.3) ng/L vs. 9.8 (7.9-16.2) ng/L, P < 0.05], yet compared to healthy control group, no significant difference in concentration level of IL-17 was found in pJIA Group [14.2(9.9-16.9) ng/L vs. 9.8(7.9-16.2) ng/L, P > 0.05].(2) In sJIA and pJIA SF, the median IP-10 level was significantly higher compared to respective PB levels [619.7 (160.9, 873.1) ng/L vs. 64.8 (27.4-111.9) ng/L;660.9 (401.9, 1349.8) ng/L vs. 97.4 (41.9-222.1) ng/L, P < 0.01, respectively], but there was only significant difference in IL-17 between pJIA SF and PB [22.9 (17.1, 45.8) ng/L vs. 14.2 (9.9-16.9) ng/L, P < 0.01]. CONCLUSION: IL-6 may play more important role in the pathogenesis of sJIA. Moreover, IL-6 may be the biomarker associated with arthritis in early JIA stage. Both autoinflammation and autoimmune response may be involved in the pathogenesis of sJIA. IL-17 enrichment may only occur in local joint, the levels of IL-17 in PB may not be significantly increased. The prominent expression gradient between SF and PB of IP-10 maybe the basis of performing chemotaxis and further causing joint damage.