OBJECTIVE To investigate the protective effect of artesunate(Art)against apoptosis and mitophagy induced by NaF in osteocytes MLO-Y4,and to explore the molecular mechanism.METHODS MLO-Y4 cells were treated with NaF(2 mmol·L-1)for 48 h to establish an in vitro model of osteocytes injuries,and the cells were divided into the cell control group,NaF(2 mmol·L-1)group and NaF+Art 0.25,0.50 and 1.00 μmol·L-1 groups.The cells were pretreated for 2 h and NaF was added for 48 h.The cell survival of MLO-Y4 cells was detected by MTT assay.The cell viability of MLO-Y4 cells was measured by Calcein-AM staining.The lactate dehydrogenase(LDH)content in the supernatant was examined by the LDH detection kit.The level of intracellular reactive oxygen species(ROS)was examined by DCFH-DA staining.The malondialdehyde(MDA)content and superoxide dismutase(SOD)activity were detected by chemical colorimetry.Apoptosis was measured by Hoechst33342 staining and Annexin-V/PI staining.The level of mitochondrial membrane potential(MMP)was measured by JC-1 staining.The formation of autophagic vacuoles and morphological mitochondrial changes were observed via Lyso-tracker staining and Mito-Tracker staining.The ATP content was detected with the luciferase method.The expression of microtubule-associated protein light chain 3(LC-3)in mitochon-dria was examined by immunofluorescence staining.Protein expressions of LC-3,P62,E3 ubiquitin-ligase(Parkin)and PTEN-induced putative kinase 1(PINK1)were detected by Western blotting.RESULTS Compared with the cell control group,the cell survival rate and cell viability were significantly reduced in the NaF group(P<0.01),LDH content in the supernatant,the level of intracellular ROS,the MDA content,apoptosis rate and autophagic vesicle formation were remarkably increased(P<0.01),protein levels of Parkin and PINK1,and the conversion of LC-3Ⅱ from LC-3Ⅰ were markedly upregulated along with the elevation of LC-3 in damaged mitochondria(P<0.01),while P62 levels,SOD activity,MMP and ATP contents were reduced in NaF cells(P<0.05,P<0.01).Compared with NaF group,the cell viability and survival rate of MLO-Y4 cells in NaF+Art 0.25,0.50 and 1.00 μmol·L-1 groups were significantly increased(P<0.01);the content of LDH in supernatants was decreased obviously(P<0.01);the levels of intracellular ROS and MDA content were markedly reduced(P<0.05,P<0.01);the apoptosis rate and autophagic vesicle formation were remarkably decreased(P<0.05,P<0.01);protein levels of Parkin and PINK1,and the conversion of LC-3Ⅱ from LC-3Ⅰ were markedly down-regulated along with the accumulation of LC-3 in damaged mitochondria(P<0.01);MMP and ATP content were also reduced(P<0.05,P<0.01);while SOD activityand P62 levelwere significantly increased(P<0.05,P<0.01).CONCLU-SION Art has a protective effect against oxidative damage induced by NaF in MLO-Y4 cells,which might be related to the inhibition of apoptosis and mitophagy.

Loofah seeds ribosome inactivating protein luffin-α was fused with a tumor-targeting peptide NGR to create a recombinant protein, and its inhibitory activity on tumor cells and angiogenesis were assessed. luffin-α-NGR fusion gene was obtained by PCR amplification. The fusion gene was ligated with pGEX-6p-1 vector to create a recombinant plasmid pGEX-6p-1/luffin-α-NGR. The plasmid was transformed into E. coli BL21, and the target protein was isolated and purified by GST affinity chromatography. The luffin-α-NGR fusion gene with a full length of 849 bp was successfully obtained, and the optimal soluble expression of the target protein was achieved under the conditions of 16 ℃, 0.5 mmol/L IPTG after 16 h induction. SDS-PAGE and Western blotting confirmed the recombinant protein has an expected molecular weight of 56.6 kDa. Subsequently, the recombinant protein was de-tagged by precision protease digestion. The inhibitory effects of the recombinant protein on liver tumor cells HepG2 and breast cancer cells MDA-MB-231 were significantly stronger than that of luffin-α. The Transwell and CAM experiment proved that the recombinant protein luffin-α-NGR also had a significant inhibitory effect on tumor cells migration and neovascularization. The inhibitory activity on tumor cells and angiogenesis of the recombinant luffin-α-NGR protein lays a foundation for the development of subsequent recombinant tumor-targeting drugs.
Electrophoresis, Polyacrylamide Gel ; Escherichia coli/metabolism* ; Plasmids ; Recombinant Proteins/pharmacology* ; Saporins/metabolism*

Inflammatory bowel disease (IBD) is a formidable disease due to its complex pathogenesis. Macrophages, as a major immune cell population in IBD, are crucial for gut homeostasis. However, it is still unveiled how macrophages modulate IBD. Here, we found that LIM domain only 7 (LMO7) was downregulated in pro-inflammatory macrophages, and that LMO7 directly degraded 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) through K48-mediated ubiquitination in macrophages. As an enzyme that regulates glycolysis, PFKFB3 degradation led to the glycolytic process inhibition in macrophages, which in turn inhibited macrophage activation and ultimately attenuated murine colitis. Moreover, we demonstrated that PFKFB3 was required for histone demethylase Jumonji domain-containing protein 3 (JMJD3) expression, thereby inhibiting the protein level of trimethylation of histone H3 on lysine 27 (H3K27me3). Overall, our results indicated the LMO7/PFKFB3/JMJD3 axis is essential for modulating macrophage function and IBD pathogenesis. Targeting LMO7 or macrophage metabolism could potentially be an effective strategy for treating inflammatory diseases.