pifithrin-beta and Disease-Models--Animal

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

To evaluate the effect of mitogen-activated protein kinase (MAPK) signal transduction pathway inhibitors against alveolar echinococcosis in vitro and in vivo, Echinococcus multilocularis metacestode cysts and protoscolices were obtained from infected mice. Protein chip technology was utilized to screen for key highly expressed target proteins in the MAPK pathway in this parasite and their corresponding inhibitors. Four-week-old Balb/c female mice used for the in vivo experiment underwent inoculation of E. multilocularis by intraperitoneal injection, as well as intragastric administration of MAPK inhibitors for 6 wk. We included 6 groups of mice: a phosphate-buffered saline (PBS) group (negative control); an albendazole-treated group (positive group); and 4 experimental groups treated with TRx0237 mesylate, GDC-0994, pifithrin-β hydrobromide, or Selonsertib. Echinococcus multilocularis protoscolices were collected and cultured in 1066 medium with penicillin/streptomycin and 10% fetal bovine serum. The in vitro experiment included a PBS group (negative control), a dimethyl sulfoxide-treated group (solvent group), and 4 inhibitor-treated groups as in the in vivo experiment (experimental groups). Each inhibitor group received 4 drug concentrations (5, 30, 55, and 80 μM), and the experiment was performed in triplicate per sample. Fluorescence microscopy was used to evaluate the survival rate of the protoscolices every 48 hr beginning from the first 24 hr. The same grouping was used to evaluate cytotoxicity on E. multilocularis germinal cells and L02 cells. The average weights of E. multilocularis metacestode cyst tissue from each group of the in vivo experiment were 873 mg (PBS), 335 mg (albendazole), 323 mg (TRx0237 mesylate), 420 mg (GDC-0994), 340 mg (pifithrin-β hydrobromide), and 642 mg (Selonsertib). Results showed albendazole, TRx0237 mesylate, and pifithrin-β hydrobromide had significant inhibitory effects on inhibition of E. multilocularis. We found a positive correlation between drug concentrations and the inhibitory effects seen in the in vitro experiment, with the differences in contrast with the control group becoming statistically significant after 72 hr of treatment ( P < 0.05). The inhibition rates of TRx0237 mesylate to germinal cells by drug concentration were 23.73, 46.59, 74.71, and 77.44%. Other drugs had no effect on germinal cells. All the inhibitors had low toxicity on L02 cells. Inhibitors of the MAPK signal transduction pathway showed

Topics: Albendazole; Animals; Anthelmintics; Benzamides; Body Weight; Cell Line; Disease Models, Animal; Echinococcosis; Echinococcus multilocularis; Female; Hepatocytes; Heterocyclic Compounds, 4 or More Rings; Humans; Imidazoles; Inhibitory Concentration 50; Methylene Blue; Mice; Mice, Inbred BALB C; Protein Array Analysis; Protein Kinase Inhibitors; Pyridines; Signal Transduction; Toluene

Since activation of p53 in response to cytotoxic stress may have proapoptotic or protective effects depending on the nature of the injury, inhibitors of p53 may have therapeutic interest as modulators of chemotherapy toxicity or efficacy. In an attempt to identify novel p53 inhibitors, a quality collection of compounds structurally related to pifithrin-β were designed and synthesized as potential inhibitors of p53. The biochemical and biological evaluations supported that compounds of the tetrahydrobenzothiazole series were inhibitors of the p53 transcriptional activity and were effective in enhancing paclitaxel-induced apoptosis. In contrast, in spite of the increased cytotoxic potency, selected compounds of the benzothiazole series were not able to modulate the transcriptional activity of p53, as indicated by lack of change of p21 expression. The therapeutic interest of the compounds of the former series in combination with taxanes was confirmed in a human tumor xenograft model.

Topics: Animals; Antineoplastic Agents; Benzothiazoles; Cell Line, Tumor; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Inhibitory Concentration 50; Ovarian Neoplasms; Toluene; Transplantation, Heterologous; Tumor Suppressor Protein p53