[Interleukin 33 inhibits lipopolysaccharide-induced high permeability of cardiac microvascular endothelial cells]

Objective: To investigate the effect of interleukin-33 (IL-33) on lipopolysaccharide (LPS)-induced permeability of rat cardiac microvascular endothelial cells (RCMECs). Methods: RCMECs were cultured in vitro to be divided into control group, LPS group, IL-33 group and LPS+IL-33 group. The effect of IL-33 on the proliferation of RCMECs was detected by cell counting reagent (CCK8). Fluorescein isothiocyanate (FITC)-dextran assay was used to evaluate the permeability of RCMECs. The expression of vascular endothelial calmodulin, ras homologous gene family (Rho) member A (RhoA) and phosphorylated Rho-associated coiled-coil-containing protein kinase (p-ROCK2) proteins were tested by western blot. High-throughput sequencing and gene ontology (GO) were performed for gene expression in LPS and LPS+IL-33 groups. Results: No significant effect of IL-33 at 10-50 ng/ml on the proliferation of RCMECs was observed (P>0.05). Compared with the control group, the permeability of RCMECs (permeability coefficient ratio 1.404±0.029 vs. 1.000±0.200, P<0.05) was significantly increased in LPS group and the expression of vascular endothelial calmodulin (relative gray value 0.429 5±0.012 9 vs. 0.594 9±0.014 2, P<0.05) was down-regulated, while the permeability of monolayers (permeability coefficient ratio, 0.948±0.013, P<0.01) was decreased in LPS+IL-33 group and the expression of vascular endothelial calmodulin (relative grayscale value 0.549 1±0.012 0, P<0.005) was up-regulated compared with the LPS group. High-throughput sequencing data revealed that the differential genes downregulated in the LPS and LPS+IL-33 groups were associated with cytoskeleton and Rho signaling pathway. Compared with the control group, RhoA (relative gray value 0.211 4±0.009 9 vs. 0.135 0±0.007 6, P<0.000 1) and p-ROCK (relative gray value 0.656 3±0.013 2 vs. 0.503 6±0.036 2, P<0.000 1) protein expression was upregulated in the LPS group. When compared with LPS group, RhoA (relative gray value 0.157 7±0.010 7, P=0.000 2), p-ROCK (relative gray value 0.427 7±0.003 8, P<0.000 1) protein expression was decreased in LPS+IL-33 group. Conclusion: IL-33 may improve LPS-induced hyperpermeability of RCMECs by inhibiting RhoA and p-ROCK protein expression in Rho/Rho-associated coiled-coil-containing protein kinase signaling pathway.

Salidroside protects against premature senescence induced by ultraviolet B irradiation in human dermal fibroblasts

OBJECTIVES

Salidroside, the predominant component of a Chinese herbal medicine, Rhodiola rosea L., becomes an attractive bio-agent due to its multifunction. Although it is well proposed that this herbal medicine may have photoprotective effect according to the folk hearsay, the direct supportive experimental evidences linking the drug with skin ageing have rarely been reported so far. The study was conducted to investigate the photoprotective role of salidrosdie and its related mechanisms in vitro.

METHODS

First, a premature senescence model induced by UVB irradiation (250 mJ cm(-2)) in human dermal fibroblasts (HDFs) was established, and senescent phenotypes were evaluated by cell morphology, cell proliferation, senescence-associated beta-galactosidase (SA-β-gal) activity and cell cycle distribution. Then the photoprotective effect of salidroside was investigated. Cells were pre-treated with various doses of salidroside (1, 5 and 10 μM) followed by the sublethal dosage of UVB exposure and then were harvested for various detections, including senescence-associated phenotypes and molecules, alteration of oxidative stress, matrix metalloproteinase-1 (MMP-1) secretion and inflammatory response.

RESULTS

Pre-treatment of salidroside dose dependently reversed the senescent state of HDFs induced by UVB as evidenced by elevated cell viability, decreased SA-β-gal activity and relieving of G1/G0 cell cycle arrest. UVB-induced increased protein expression of cyclin-dependent kinase (CDK) inhibitors p21(WAF) (1) and p16(INK) (4) was also repressed by salidrosdie treatment in a dose-dependent manner. Meanwhile, the increment of malondialdehyde (MDA) level in UVB-irradiated HDFs was inhibited upon salidroside treatment. Additionally, salidroside significantly attenuated UVB-induced synthesis of MMP-1 as well as the production of IL-6 and TNF-α in HDFs.

CONCLUSION

Our data provided the evidences for the protective role of salidroside against UVB-induced premature senescence in HDFs probably via its anti-oxidative property and inhibition on production of MMP-1 and pro-inflammatory cytokines, which indicated its potential utilization as an active ingredient in the preparation of photoprotective formulation.

Marrow mesenchymal stem cells transduced with TPO/FL genes as support for ex vivo expansion of hematopoietic stem/progenitor cells

A new marrow-derived mesenchymal stem cell (hMSC) line that could support expansion of hematopoietic stem/progenitor cells (HSPCs) was developed. Primary hMSCs were infected with retrovirus containing Flt-3 ligand and thrombopoietin genes. CD34+ cells from cord blood were expanded with primary hMSCs or transduced hMSCs. The expansion of total nucleated cells, CD34+ cells and mixed colonies containing erythroid and myeloid cells and megakaryocytes for 2 weeks coculture with transduced hMSCs was remarkably increased. The outputs of long-term culture-initiating cells for 2 and 4 weeks coculture with transduced hMSCs were also largely increased. The expansion rates of HSPCs with transduced hMSCs were unchanged for 6 weeks. In contrast, the expansion rates of HSPCs with primary hMSCs declined drastically through 6 weeks. SCID-repopulating cell expansion with transduced hMSCs for 4 weeks was significantly higher than that of uncultured CD34,+ cells and HSPCs expanded with primary hMSCs.