RESUMO
BACKGROUND@#Ferroptosis is an iron-dependent, non-apoptotic programmed cell death. Cellular senescence contributes to aging and various age-related diseases through the expression of a senescence-associated secretory phenotype (SASP). Senescent cells are often resistant to ferroptosis via increased ferritin and impaired ferritinophagy. In this study, we investigated whether treatment with JQ1 could remove senescent cells by inducing ferroptosis. @*METHODS@#Senescence of human dermal fibroblasts was induced in vitro by treating the cells with bleomycin. The senolytic effects of JQ1 were evaluated using a SA-β gal assay, annexin V analysis, cell counting kit-8 assay, and qRT-PCR. Ferroptosis following JQ1 treatment was evaluated with qRT-PCR and BODIPY staining. @*RESULTS@#At a certain range of JQ1 concentrations, JQ1 treatment reduced the viability of bleomycin-treated cells (senescent cells) but did not reduce that of untreated cells (non-senescent cells), indicating that JQ1 treatment can selectively eliminate senescent cells. JQ1 treatment also decreased SASP expression only in senescent cells. Subsequently, JQ1 treatment reduced the expression of ferroptosis-resistance genes in senescent cells. JQ1 treatment induced lipid peroxidation in senescent cells but not in non-senescent cells. @*CONCLUSION@#The data indicate that JQ1 can eliminate senescent cells via ferroptosis. This study suggests ferroptosis as a new mechanism of senolytic therapy.
RESUMO
BACKGROUND@#Ferroptosis is an iron-dependent, non-apoptotic programmed cell death. Cellular senescence contributes to aging and various age-related diseases through the expression of a senescence-associated secretory phenotype (SASP). Senescent cells are often resistant to ferroptosis via increased ferritin and impaired ferritinophagy. In this study, we investigated whether treatment with JQ1 could remove senescent cells by inducing ferroptosis. @*METHODS@#Senescence of human dermal fibroblasts was induced in vitro by treating the cells with bleomycin. The senolytic effects of JQ1 were evaluated using a SA-β gal assay, annexin V analysis, cell counting kit-8 assay, and qRT-PCR. Ferroptosis following JQ1 treatment was evaluated with qRT-PCR and BODIPY staining. @*RESULTS@#At a certain range of JQ1 concentrations, JQ1 treatment reduced the viability of bleomycin-treated cells (senescent cells) but did not reduce that of untreated cells (non-senescent cells), indicating that JQ1 treatment can selectively eliminate senescent cells. JQ1 treatment also decreased SASP expression only in senescent cells. Subsequently, JQ1 treatment reduced the expression of ferroptosis-resistance genes in senescent cells. JQ1 treatment induced lipid peroxidation in senescent cells but not in non-senescent cells. @*CONCLUSION@#The data indicate that JQ1 can eliminate senescent cells via ferroptosis. This study suggests ferroptosis as a new mechanism of senolytic therapy.
RESUMO
BACKGROUND AND OBJECTIVES@#We sought to investigate an anti-atherosclerotic and anti-inflammatory effect of sodium-glucose cotransporter-2 (SGLT-2) inhibitors in normoglycemic atherosclerotic rabbit model.@*METHODS@#Male New Zealand white rabbits (n=26) were fed with a 1% high-cholesterol diet for 7 weeks followed by normal diet for 2 weeks. After balloon catheter injury, the rabbits were administered with the Dapagliflozin (1mg/kg/day) or control-medium for 8 weeks (n=13 for each group). All lesions were assessed with angiography, optical coherence tomography (OCT), and histological assessment.@*RESULTS@#Atheroma burden (38.51±3.16% vs. 21.91±1.22%, p<0.01) and lipid accumulation (18.90±3.63% vs. 10.20±2.03%, p=0.047) was significantly decreased by SGLT-2 inhibitor treatment. The SGLT-2 inhibitor group showed lower macrophage infiltration (20.23±1.89% vs. 12.72±1.95%, p=0.01) as well as tumor necrosis factor (TNF)-α expression (31.17±4.40% vs. 19.47±2.10%, p=0.025). Relative area of inducible nitric oxide synthase+ macrophages was tended to be lower in the SGLT-2 inhibitor-treated group (1.00±0.16% vs. 0.71±0.10%, p=0.13), while relative proportion of Arg1⺠macrophage was markedly increased (1.00±0.27% vs. 2.43±0.64%, p=0.04). As a result, progression of atherosclerosis was markedly attenuated in SGLT-2 inhibitor treated group (OCT area stenosis, 32.13±1.20% vs. 22.77±0.88%, p<0.01). Mechanistically, SGLT-2 treatment mitigated the inflammatory responses in macrophage. Especially, Toll-like receptor 4uclear factor-kappa B signaling pathway, and their downstream effectors such as interleukin-6 and TNF-α were markedly suppressed by SGLT-2 inhibitor treatment.@*CONCLUSIONS@#These results together suggest that SGLT-2 inhibitor exerts an anti-atherosclerotic effect through favorable modulation of inflammatory response as well as macrophage characteristics in non-diabetic situation.
RESUMO
BACKGROUND AND OBJECTIVES: We sought to investigate an anti-atherosclerotic and anti-inflammatory effect of sodium-glucose cotransporter-2 (SGLT-2) inhibitors in normoglycemic atherosclerotic rabbit model.METHODS: Male New Zealand white rabbits (n=26) were fed with a 1% high-cholesterol diet for 7 weeks followed by normal diet for 2 weeks. After balloon catheter injury, the rabbits were administered with the Dapagliflozin (1mg/kg/day) or control-medium for 8 weeks (n=13 for each group). All lesions were assessed with angiography, optical coherence tomography (OCT), and histological assessment.RESULTS: Atheroma burden (38.51±3.16% vs. 21.91±1.22%, p<0.01) and lipid accumulation (18.90±3.63% vs. 10.20±2.03%, p=0.047) was significantly decreased by SGLT-2 inhibitor treatment. The SGLT-2 inhibitor group showed lower macrophage infiltration (20.23±1.89% vs. 12.72±1.95%, p=0.01) as well as tumor necrosis factor (TNF)-α expression (31.17±4.40% vs. 19.47±2.10%, p=0.025). Relative area of inducible nitric oxide synthase+ macrophages was tended to be lower in the SGLT-2 inhibitor-treated group (1.00±0.16% vs. 0.71±0.10%, p=0.13), while relative proportion of Arg1⁺ macrophage was markedly increased (1.00±0.27% vs. 2.43±0.64%, p=0.04). As a result, progression of atherosclerosis was markedly attenuated in SGLT-2 inhibitor treated group (OCT area stenosis, 32.13±1.20% vs. 22.77±0.88%, p<0.01). Mechanistically, SGLT-2 treatment mitigated the inflammatory responses in macrophage. Especially, Toll-like receptor 4/nuclear factor-kappa B signaling pathway, and their downstream effectors such as interleukin-6 and TNF-α were markedly suppressed by SGLT-2 inhibitor treatment.CONCLUSIONS: These results together suggest that SGLT-2 inhibitor exerts an anti-atherosclerotic effect through favorable modulation of inflammatory response as well as macrophage characteristics in non-diabetic situation.