AimsVascular calcification is strongly linked to the development of major adverse cardiovascular events, but effective treatments are lacking. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are an emerging category of oral hypoglycemic drugs that have displayed marked effects on metabolic and cardiovascular diseases, including recently reported vascular medial calcification. However, the roles and underlying mechanisms of SGLT2 inhibitors in vascular calcification have not been fully elucidated. Thus, we aimed to further determine whether SGLT2 inhibitors protect against vascular calcification and to investigate the mechanisms involved.Methods and ResultsA computed tomography angiography investigation of coronary arteries from 1554 patients with type 2 diabetes revealed that SGLT2 inhibitor use was correlated with a lower Agatston calcification score. In the vitamin D3 overdose, 5/6 nephrectomy chronic kidney disease -induced medial calcification and Western diet-induced atherosclerotic intimal calcification models, dapagliflozin (DAPA) substantially alleviated vascular calcification in the aorta. Furthermore, we showed that DAPA reduced vascular calcification via Runx2-dependent osteogenic transdifferentiation in vascular smooth muscle cells (VSMCs). Transcriptome profiling revealed that thioredoxin domain containing 5 (TXNDC5) was involved in the attenuation of vascular calcification by DAPA. Rescue experiments showed that DAPA-induced TXNDC5 downregulation in VSMCs blocked the protective effect on vascular calcification. Furthermore, TXNDC5 downregulation disrupted protein folding-dependent Runx2 stability and promoted subsequent proteasomal degradation. Moreover, DAPA downregulated TXNDC5 expression via amelioration of oxidative stress and ATF6-dependent endoplasmic reticulum stress. Consistently, the class effects of SGLT2 inhibitors on vascular calcification were validated with empagliflozin in intimal and medial calcification models.ConclusionsSGLT2 inhibitors ameliorate vascular calcification through blocking endoplasmic reticulum stress-dependent TXNDC5 upregulation and promoting subsequent Runx2 proteasomal degradation, suggesting that SGLT2 inhibitors are potentially beneficial for vascular calcification treatment and prevention.

Although accumulating evidence has highlighted the molecular mechanisms by which hTERT promotes tumour cell invasion and metastasis, the molecular mechanisms of the properties enabling hTERT to contribute to invasion and metastasis have not been clearly illustrated. Here, we report that hTERT promotes gastric cancer invasion and metastasis by recruiting p50 to synergistically inhibit PLEKHA7 expression. We observed that the expression of PLEKHA7 in gastric cancer was significantly negatively associated with the TNM stage and lymphatic metastasis and that decreased PLEKHA7 expression dramatically increased invasion and metastasis in gastric cancer cells. Further mechanistic research showed that hTERT directly regulates PLEKHA7 expression by binding p50 and recruiting the hTERT/p50 complex to the PLEKHA7 promoter. Increased hTERT dramatically decreased PLEKHA7 expression and promoted invasion and metastasis in gastric cancer cells. The hTERT-mediated invasion/metastasis properties at least partially depended on PLEKHA7. Our work uncovers a novel molecular mechanism underlying invasion/metastasis in gastric cancer orchestrated by hTERT and p50.

The decrease of forkhead box P3-positive (FOXP3 + ) regulatory T cells (Tregs) causes an immune imbalance with effector T cells in psoriasis. Previous studies have demonstrated that in addition to its known effects on keratinocytes and effector T cells, ultraviolet (UV) irradiation alleviates psoriasis via the upregulation of FOXP3 + Tregs. However, the mechanism is unclear. Here, we found that FOXP3 + T cells were increased in psoriatic lesions after UVB irradiation (t' = 3.7006, P < 0.01), as determined by immunohistochemical staining. In addition, the levels of FOXP3 and p53, one of the downstream targets of UV irradiation, showed accordant changes after UV irradiation. Experiments that used a MAPK inhibitor, p53 mutant cell lines, p53 inhibitor and p53 shRNA showed a decrease in FOXP3 levels, suggesting that p53 is required for UV-induced FOXP3 transcription. Next, we demonstrated that there are two binding sites for p53 on FOXP3 by informatics tools, a dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay. One binding site (-1771 to -1583) is located at the promoter region and is adjacent to a previously reported p53-binding region in breast cancer cells. The other (+3845 to +4042) is located within the first intron and has not been previously reported. Our study demonstrated that FOXP3 is regulated, at least in part, by the binding of p53 to several binding sites in the promoter and intron regions following UV irradiation in psoriasis. It will be helpful to further clarify the regulatory mechanism of FOXP3 transcription and to provide new insights into the mechanisms that mediate the effects of UV irradiation in autoimmune skin disorders.

BACKGROUND: Nuclear factor erythroid-2-related factor-2 (NF-E2-related factor-2) is an important transcription factor to regulate anti-oxidative stress reaction. Some researches indicate that NF-E2-related factor-2 can be phosphorylated by numerous members of protein kinase C family. In order to investigate generant mechanism of microwave radiation on oxidative stress injury, whether microwave radiation can influence on anti-oxidative regulating system through NF-E2-related factor-2 or not should be further studied.OBJ ECTIVE: To analyze the effect of microwave radiation on phosphorylation of NF-E2-related factor-2 and activity of protein kinase C in vascular endothelial cells.DESIGN: Observational-contrast study.SETTING : Department of Labor Hygiene, the Third Military Medical University of Chinese PLA.MATERIALS: Vascular endothelial cell strain; H332PO4; Protein-A Sepharose (Sigma Company); mono-antibody of NF-E2-related factor-2 (H-300, Santa Cruz); α-mono-antibody of protein kinase C (Santa Cruz); glass microfiber filters(Whatman Company); gel scanning system (Gel Doc 2000, Bio-Rad); liquid scintillation spectrometer (LKB-117, Sweden).METHODS: The experiment was carried out in Laboratory of Electromagnetic radiation and Biological Effect, Department of Labor Hygiene, the Third Military Medical University of Chinese PLA from March to July 2003. ① Analysis of phosphorylation of NF-E2-related factor-2: Vascular endothelial cells were cultured with DMEM medium till the period of productive growth and incubated with 32Pi for 2 hours. And then, cultured bottle was maintained in water bath at 37℃ and performed with microwave radiation in dark chamber, whose reflectivity was about zero. It was regarded as radiation group, and the average power density of radiation was 30 mW/cm2; in addition, the duration of radiation was 30 minutes.Cells did not deal with microwave radiation were regarded as control group. Phosphorylation level of NF-E2-related factor-2 was measured at 2, 4, 8 and 24 hours after radiation with immune coprecipitation-autoradiography technique and dealt with semi-quantitative analysis with gel scanning system. Cells in the control group were analyzed directly. ②Active analysis and expressional measurement of protein kinase C: Cells in the radiation group and the control group were dealt with the same cultured method, condition, radiation styles, dosage and environment as mentioned above. At 2, 4, 8 and 24 hours after radiation, cells were split to extract plasma and membrane protein. Furthermore, activity of protein kinase C was measured with r-32P-ATP labeled liquid scintillation spectrometer; gray value of protein strap was dealt with semi-quantitative analysis with gel scanning system; staining degree of plasma was observed after immunocytochemical staining of protein kinase C. In addition, cells in the control group were measured and observed directly.MAIN OUTCOME MEASURES: ① Phosphorylation level of NF-E2-related factor-2 in radiation group and control group; ②Results of active analysis and expressional measurement of protein kinase C in radiation group and control group.RESULTS: ① Phosphorylation level of NF-E2-related factor-2 in radiation group and control group: Gray value of NF-E2-related factor-2 was higher in radiation group than that in control group at 2, 4 and 8 hours after radiation.Phosphorylation level of NF-E2-related factor-2 reached the peak at four hours after radiation. In addition, results of semi-quantitative scanning analysis showed that, at 2, 4 and 8 hours after radiation, phosphorylation level of NF-E2-related factor-2 was increased 33%, 261% and 141% in radiation group as compared with that in control group,respectively (t = 2.974, 4.209, 4.047, P ＜ 0.05), and then, fallen down to normal value 24 hours later. ② Results of active analysis and expressional measurement of protein kinase C in radiation group and control group: At 2, 4 and 8 hours after microwave radiation, expression of protein kinase C in radiation group was higher than that in control group,especially at the 4 hour. In addition, at 24 hours after radiation, expression of protein kinase C recovered the normal value. Results of immunocytochemical staining showed that staining of plasma was deeper in radiation group than that in control group at 4 hours after radiation. Moreover, results of r-32P-ATP labeled liquid scintillation spectrometer also suggested that, at 2, 4 and 8 hours after radiation, activity of protein kinase C was increased 36%, 93% and 47% in radiation group as compared with that in control group, respectively (t =2.801, 3.654, 3.035, P ＜ 0.05). And then, activity of protein kinase C was decreased after 24 hours, otherwise, activity of protein kinase C reached the peak at 4 hours after radiation.CONCLUSION: Microwave radiation can strengthen the phosphorylation level of NF-E2-related factor-2 in vascular endothelial cells during a special period; meanwhile, it can also cause the increase of expression of protein kinase C.Time effect of activity of protein kinase C is coincidence with phosphorylation level of NF-E2-related factor-2.