2-Methoxyestradiol prevents monocyte adhesion to vascular endothelial cells via downregulation of VCAM-1 expression

2-Methoxyestradiol inhibits high fat diet-induced obesity in rats through modulation of adipose tissue macrophage infiltration and immunophenotype

Recently, experimental studies demonstrated that 2-methoxyestradiol (2ME2) ameliorates high fat diet (HFD)-induced obesity and restores insulin sensitivity. However, the mechanisms underlying these effects are unveiled yet. The current study was undertaken to test the hypothesis that 2ME2 exerts its effects by modulating adipose tissue macrophages (ATMs) accumulation, polarization and immunophenotypes. The experiment was carried out in males Wistar rats (n = 28) for 13 consecutive weeks. In HFD-fed group; body weight, glucose intolerance, serum insulin, HOMA-IR, lipid profile and adipose tissue (AT) weight were significantly higher compared to normal standard diet (NSD)- fed rats. However, treatment of HFD-fed rats with 2ME2 (200 μg/kg/day; i.p. from the beginning of the 9th week) resulted in significant enhancements in all these parameters as compared to HFD-fed rats. Treatment with 2ME2 was associated with a significant reduction in macrophage infiltration in the AT, shifting macrophage polarization towards M2 phenotype as indicated by significant decrease in the expression of pro-inflammatory M1 macrophages markers (IL-6, IL-1β, CD11c and iNOS) and concurrent significant increase in the M2 anti-inflammatory macrophage markers (Arginase 1 and IL-10). 2ME2 ameliorates HFD-induced obesity and glucose intolerance through inhibition of ATM infiltration in AT and shifting macrophage polarization from pro-inflammatory M1 to M2 anti-inflammatory phenotypes.

[Vaspin protects against lipopolysaccharide-induced acute respiratory distress syndrome in mice by inhibiting inflammation and protecting vascular endothelium via PI3K/Akt signal pathway]

OBJECTIVE

To investigate the effects of Vaspin on lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) in mice and explore the possible mechanism.

METHODS

Forty male C57B/L6 mice were randomized equally into control group, LPS group, Vaspin group and wortmannin group with corresponding treatments. The pathological changes of the lung tissues were evaluated by HE staining, and the severity of pulmonary edema was measured according to the wet/dry ratio (W/D) of the lung tissue. The lung permeability was evaluated by detecting total protein concentrations in the bronchoalveolar lavage fluid (BALF) using bicinchoninic acid (BCA) assay. Myeloperoxidase (MPO) activity in the lung tissue was detected using a MPO assay kit, and the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the lungs were measured using ELISA. Immunohistochemical staining was performed to detect the expression of vascular cell adhesion molecule-1 (VCAM-1) and Western blotting was used to detect the protein expressions of cleaved caspase-3 and p-Akt in the lung tissues.

RESULTS

Compared with the control group, the mice in LPS group displayed typical ARDS pathological changes in the lungs with significantly increased W/D, total protein concentrations in BALF, lung MPO activity, levels of IL-1β and TNF-α, and pulmonary expressions of VCAM-1 and cleaved caspase-3 (P<0.05) but decreased expression of p-Akt (P<0.05). These changes induced by LPS were significantly alleviated by the administration of Vaspin (P<0.05). The protective effects of Vaspin against ARDS were obviously attenuated by the PI3K inhibitor wortmannin (P<0.05).

CONCLUSION

Vaspin protects against LPS-induced ARDS in mice possibly by inhibiting inflammation and protecting vascular endothelium through upregulation of the PI3K/Akt signal pathway.

Follicular Stimulating Hormone Accelerates Atherogenesis by Increasing Endothelial VCAM-1 Expression

Rationale: Postmenopausal atherosclerosis (AS) has for decades been attributed to estrogen deficiency. Although the follicular stimulating hormone (FSH) levels rise sharply in parallel, the direct effect of FSH on AS has never been investigated. In this study, we explored the possible role of FSH in the development of AS. Methods: This was a prospective cohort study of 48 healthy premenopausal and 15 postmenopausal women. ApoE knockout mice were used as atherosclerosis model and human umbilical vascular endothelial cells (HUVECs) were cultured as cell model. Serum hormones and vascular cell adhesion molecule-1 (VCAM-1) levels were measured. Real-time PCR, histology for atherosclerotic lesions, immunofluorescence, luciferase assay, transfection experiments, flow chamber adhesion assay and western blot were performed. Results: In ApoE knockout mice, administration of FSH increased the atherosclerotic lesions and serum VCAM-1 concentration. Importantly, in blood samples of postmenopausal women, we detected significantly higher levels of FSH and VCAM-1 compared with those from premenopausal women, and there was a positive correlation between these two molecules. In cultured HUVECs, FSH receptor (FSHR) mRNA and protein expression were detected and FSH enhanced VCAM-1 expression. This effect was mediated by the activation of nuclear factor κB (NF-κB), which was sequentially enhanced by the activation of PI3K/Akt/mTOR cascade. FSH first enhanced Gα_S activity resulting in elevated cAMP level and PKA activity, which relayed the signals from FSHR to the PI3K/Akt/mTOR cascade. Furthermore, FSHR was detected in endothelial caveolae fraction and interacted with caveolin-1 and Gα_S. The disruption of caveolae or the silencing of caveolin-1 blocked FSH effects on signaling activation and VCAM-1 expression, suggesting the existence of a functional signaling module in membrane caveolae. Finally, FSH increased human monocyte adhesion to HUVECs which was reversed by the VCAM-1 neutralizing antibody. Conclusion: FSHR was located in the membrane caveolae of HUVECs and FSH promoted VCAM-1 expression via FSHR/Gα_S /cAMP/PKA and PI3K/Akt/mTOR/NF-κB pathway. This may contribute to the deleterious role of FSH in the development of AS in postmenopausal women.