Objective To study the effects of 17estradiol on chemokine receptor CXCR2 expression in monocytes incubated with oxidized low density lipoproteins (oxLDL). Methods Human monocytic U937 cells were used as a model of monocytes. Expressions of CXC chemokine receptor CXCR2 mRNA and protein were measured by RT-PCR and FACS, respectively. Results The oxLDL(50 ?g/ml) significantly upregulated CXCR2 expression in U937 cells. 17estradiol (50 nmol/L) reduced expressions of CXCR2 mRNA and protein in U937 cells incubated with oxLDL (50 ?g/ml) , and the decrease of the CXCR2 protein was dependent on the concentration of 17estradiol (5-500 nmol/L). Conclusions 17estradiol can obviously reverse oxLDL-induced CXC chemokine receptor CXCR2 expression in U937 cells.

14 aged patients received radiofrequency current ablation(RFCA)to treat drug-refractory tachycardia. The success rate was 97%(13/14).In conjunction with the charcteristicaof aged patients often with long clinical history and apt to be complicated,the paper especially discussed the distinctive feature of application of RFCA to aged patients.

Objective: To investigate the effects of hypoxia on the phenotype transformation of human dermal fibroblasts to myofibroblasts and the mechanism. Methods: The third passage of healthy adult human dermal fibroblasts in logarithmic phase were cultured in DMEM medium containing 10% fetal bovine serum for the following five experiments. (1) In experiments 1, 2, and 3, cells were divided into normoxia group and hypoxia group according to the random number table, with 10 dishes in each group. Cells of normoxia group were cultured in incubator containing 21% oxygen, while those of hypoxia group with 1% oxygen. At post culture hour (PCH) 0 and 48, 5 dishes of cells were collected from each group, respectively. mRNA expressions of markers of myofibroblasts including alpha smooth muscle actin (α-SMA), type Ⅰ collagen, and type Ⅲ collagen of cells were determined with real time fluorescent quantitative reverse transcription polymerase chain reaction in experiment 1. Protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen of cells were determined with Western blotting in experiment 2. The protein expression of nuclear factor-kappa B (NF-κB) of cells was determined with Western blotting in experiment 3. (2) In experiment 4, cells were divided into normoxia group, hypoxia group, and hypoxia+ pyrrolidine dithiocarbamate (PDTC) group according to the random number table, with 5 dishes in each group. Cells in the former two groups were treated the same as those in experiment 1. Cells in hypoxia+ PDTC group were treated the same as those in hypoxia group plus adding 4 mL PDTC with a final molarity of 10 μmol/L in the culture medium. At PCH 48, the protein expression of NF-κB of cells was determined with Western blotting. (3) In experiment 5, cells were divided into normoxia group, hypoxia group, hypoxia+ PDTC group, and normoxia+ PDTC group according to the random number table, with 5 dishes in each group. Cells in the former three groups were treated the same as those in experiment 4. Cells in normoxia+ PDTC group were treated the same as those in normoxia group plus adding 4 mL PDTC with a final molarity of 10 μmol/L in the culture medium. At PCH 48, protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen of cells were determined with Western blotting. Data were processed with analysis of variance of factorial design, one-way analysis of variance, and LSD-t test. Results: (1) Compared with those of normoxia group at corresponding time point, mRNA expressions and protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen and the protein expression of NF-κB in fibroblasts of hypoxia group were not changed obviously at PCH 0 (with t values from -1.21 to 2.04, P values above 0.05), while mRNA expressions and protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen and the protein expression of NF-κB significantly increased at PCH 48 (with t values from -12.57 to -3.44, P values below 0.01). (2) At PCH 48, the protein expression of NF-κB in fibroblasts of hypoxia group was 0.83±0.12, significantly higher than that of normoxia group (0.17±0.06, t=-16.96, P<0.001). The protein expression of NF-κB in fibroblasts of hypoxia+ PDTC group was 0.31±0.08, significantly lower than that of hypoxia group (t=12.73, P<0.001). (3) At PCH 48, protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen in fibroblasts of hypoxia group were 0.73±0.09, 1.25±0.10, and 1.16±0.07, respectively, significantly higher than those of normoxia group (0.14±0.06, 0.87±0.08, and 0.77±0.13, respectively, with t values from 9.24 to 11.24, P values below 0.001). The protein expression of α-SMA in fibroblasts of normoxia+ PDTC group was 0.24±0.07, significantly higher than that of normoxia group (t=4.22, P<0.01). Protein expressions of type Ⅰ collagen and type Ⅲ collagen in fibroblasts of normoxia+ PDTC group were 0.25±0.06 and 0.32±0.11, respectively, significantly lower than those of normoxia group (with t values respectively -4.31 and -3.88, P values below 0.01). Protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen in fibroblasts of hypoxia+ PDTC group were 0.09±0.08, 0.38±0.12, and 0.47±0.08, respectively, significantly lower than those of hypoxia group (with t values from 11.78 to 22.98, P values below 0.001). Conclusions Hypoxia can significantly up-regulate the expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen in human dermal fibroblasts, which may promote the phenotype transformation of fibroblasts to myofibroblasts, and this is likely to be associated with the activation of NF-κB signal pathway.

Metabolic-associated fatty liver disease (MAFLD), which is previously known as non-alcoholic fatty liver disease (NAFLD), represents a major health concern worldwide with limited therapy. Here, we provide evidence that ferroptosis, a novel form of regulated cell death characterized by iron-driven lipid peroxidation, was comprehensively activated in liver tissues from MAFLD patients. The canonical-GPX4 (cGPX4), which is the most important negative controller of ferroptosis, is downregulated at protein but not mRNA level. Interestingly, a non-canonical GPX4 transcript-variant is induced (inducible-GPX4, iGPX4) in MAFLD condition. The high fat-fructose/sucrose diet (HFFD) and methionine/choline-deficient diet (MCD)-induced MAFLD pathologies, including hepatocellular ballooning, steatohepatitis and fibrosis, were attenuated and aggravated, respectively, in cGPX4-and iGPX4-knockin mice. cGPX4 and iGPX4 isoforms also displayed opposing effects on oxidative stress and ferroptosis in hepatocytes. Knockdown of iGPX4 by siRNA alleviated lipid stress, ferroptosis and cell injury. Mechanistically, the triggered iGPX4 interacts with cGPX4 to facilitate the transformation of cGPX4 from enzymatic-active monomer to enzymatic-inactive oligomers upon lipid stress, and thus promotes ferroptosis. Co-immunoprecipitation and nano LC-MS/MS analyses confirmed the interaction between iGPX4 and cGPX4. Our results reveal a detrimental role of non-canonical GPX4 isoform in ferroptosis, and indicate selectively targeting iGPX4 may be a promising therapeutic strategy for MAFLD.