Identification of highly potent 2,4-diarylaminopyrimidine analogs of a typical piperidinyl-4-ol moiety as promising antitumor ALK inhibitors

In light of the cocrystal structure of ceritinib with anaplastic lymphoma kinase (ALK)WT protein, a series of novel 2,4-diarylaminopyrimidine analogs (L1-L25) bearing a typical piperidinyl-4-ol moiety were designed and synthesized with improved biological and physicochemical properties. Satisfyingly, most compounds demonstrated moderate to excellent antitumor effects with IC50 values below 5 μM on ALK-positive Karpas299 and H2228 cells. In particular, L6 bearing the 1-(6-methoxy-pyridin-2-yl)-4-(morpholinomethyl)piperidinyl-4-ol moiety was detected as the optimal compound against ALK-dependent cell lines of Karpas299 (0.017 μM) and H2228 cells (0.052 μM), in company with encouraging ALK enzyme inhibition (ALKWT , IC50  = 1.8 nM). In addition, L6 was also capable of inhibiting ALK-resistant mutations, including ALKL1196M (3.9 nM) and ALKG1202R (5.2 nM). Remarkably, L6 typically repressed colony formation and migration of H2228 cells in a dose-dependent manner. Meanwhile, acridine orange-ethidium bromide staining analysis indicated that the proapoptotic effect of L6 was better than that of ceritinib at the same concentration (50 nM). Ultimately, the binding patterns of L6 to ALKWT and ALKG1202R were ideally established, which further confirmed the structural basis in accordance with the structure-activity relationship analysis.

Astragalus polysaccharide restores insulin secretion impaired by lipopolysaccharides through the protein kinase B /mammalian target of rapamycin/glucose transporter 2 pathway

BACKGROUND

Lipopolysaccharide (LPS)-induced dysfunction of pancreatic β-cells leads to impaired insulin (INS) secretion. Astragalus polysaccharide (APS) is a bioactive heteropolysaccharide extracted from Astragalus membranaceus and is a popular Chinese herbal medicine. This study aimed to elucidate the mechanisms by which APS affects INS secretion from β-cells under LPS stress.

METHODS

Rat insulinoma (INS-1) cells were treated with LPS at a low, medium, or high concentration of APS. Glucose-stimulated insulin secretion (GSIS) was evaluated using an enzyme-linked immunosorbent assay (ELISA). Transcriptome sequencing was used to assess genome-wide gene expression. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was used to determine the signaling pathways affected by APS. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to evaluate the gene expression of glucose transporter 2 (GLUT2), glucokinase (GCK), pancreatic duodenal homeobox-1 (PDX-1), and INS. Western blot analysis was used to detect the protein expression of phosphorylated protein kinase B (p-Akt), total Akt (t-Akt), phosphorylated mammalian target of rapamycin (p-mTOR), total mTOR (t-mTOR), and GLUT2.

RESULTS

LPS decreased GLUT2, GCK, PDX-1, and INS expression and reduced GSIS. These LPS-induced decreases in gene expression and GSIS were restored by APS treatment. In addition, transcriptome sequencing in combination with KEGG enrichment analysis revealed changes in the INS signaling pathway following APS treatment. LPS decreased p-Akt and p-mTOR expression, which was restored by APS treatment. The restorative effects of APS on GSIS as well as on the expression of GLUT2, GCK, PDX-1, and INS were abolished by treatment with the Akt inhibitor MK2206 or the mTOR inhibitor rapamycin (RPM).

CONCLUSIONS

APS restored GSIS in LPS-stimulated pancreatic β-cells by activating the Akt/mTOR/GLUT2 signaling pathway.

Surfactin inhibits the growth of Propionibacterium acnes by destroying the cell wall and membrane

Propionibacterium acnes plays a major role in acne vulgaris. In the pre-experiment, the growth of P. acnes was inhibited effectively using surfactin; however, the antibacterial mechanism has not been described. Therefore, the aim of this study was to evaluate antibacterial activity and analyse the mechanism of surfactin against P. acnes. Minimum inhibitory concentration, time-killing kinetics and scanning electron microscopy were used to evaluate the activity of surfactin against P. acnes, which showed that 128 μg ml^-1 effectively inhibited growth. Cell wall permeability was evaluated by detecting the extracellular alkaline phosphatase activity, which increased to 1·83- and 2·32-fold after incubating with 128 and 256 μg ml^-1 of surfactin for 10 h, respectively. Propidium iodide fluorescence, leakage of nucleic acid, protein, K⁺ , and Ca²⁺ , membrane potential and the leakage of calcein from small unilamellar vesicles all increased after incubation with surfactin, indicating that its strong biological activities act mainly by altering membrane integrity. In a mouse model of acne, surfactin significantly reduced P. acnes-induced epidermal swelling and erythema. These results indicate that surfactin effectively inhibited the growth of P. acnes by destroying the cell wall and membrane, and is a potential candidate for acne treatment.

Overexpression of LncRNA PSMG3-AS1 Distinguishes Glioblastomas from Sarcoidosis

In clinical practices, glioblastomas (GBM) in some cases can be misdiagnosed as sarcoidosis. This study aimed to develop a biomarker to distinguish GBM from sarcoidosis. In this study, we found that PSMG3-AS1 was upregulated in plasma of GBM patients in comparison with that in sarcoidosis patients and healthy controls. Receiver operating characteristic (ROC) curve analysis showed that upregulation of PSMG3-AS1 effectively separated GBM patients from sarcoidosis patients and healthy controls. In GBM cells, overexpression of PSMG3-AS1 led to downregulated miR-34a and increased methylation of miR-34a gene. In addition, overexpression of PSMG3-AS1 reduced the inhibitory effects of miR-34a on GBM cell proliferation. In conclusion, overexpression of PSMG3-AS1 distinguishes GBM patients from patients with sarcoidosis, and PSMG3-AS1 may promote GBM cell proliferation by downregulating miR-34a through methylation.

[Effects of ursolic acid on c-Cbl-associated protein expression in 3T3-L1 adipocytes with insulin resistance]

OBJECTIVE

To observe the effects of ursolic acid (UA) on insulin resistance and cell differentiation in 3T3-L1 adipocytes and to explore the mechanisms.

METHODS

3T3-L1 adipocytes were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with glucose (25 mmol/L) and insulin (10(-6) mol/L) to induce insulin resistance. After culture, glucose consumption of the adipocytes was detected by glucose oxidase method and glucose uptake was detected by using tritium-marked glucose. Drug concentration for following test was determined through detecting the effects of different concentrations of UA on the activity of 3T3-L1 adipocytes with insulin resistance by methyl thiazolyl tetrazolium (MTT) staining. 3T3-L1 adipocytes with insulin resistance were cultured with DMEM, rosiglitazone, and low- and high-dose UA, and then, glucose uptake and differentiation of 3T3-L1 adipocytes were detected. Finally, real-time fluorescence quantitative polymerase chain reaction and Western blot methods were used to detect the effects of UA on expressions of adipocyte lipid binding protein (aP2), c-Cbl-associated protein (CAP) and matrix metalloproteinase-1 (MMP-1) in 3T3-L1 cells with insulin resistance.

RESULTS

After dealing with high glucose/hyperinsulin for 24 h, insulin resistance was induced successfully in the 3T3-L1 adipocytes. The concentrations of UA were defined to be 4 to 20 μmol/L. Compared with the model group, the glucose uptake was significantly increased in the rosiglitazone group and groups treated with low- and high-dose UA (P<0.01). The differentiation levels of 3T3-L1 adipocytes in the UA groups were lower than those in the control group and the rosiglitazone group. Effects of UA on the expressions of aP2 and MMP-1 were not obvious, but UA could up-regulate expression of CAP both in mRNA and protein levels (P<0.01).

CONCLUSION

Low- and high-dose UA can improve the glycometabolism and differentiation of 3T3-L1 adipocytes with insulin resistance by up-regulating the expression of CAP.