Mitochondrial dysfunction of induced pluripotent stem cells-based neurodegenerative disease modeling and therapeutic strategy.

Neurodegenerative diseases (NDDs) are disorders in which neurons are lost owing to various factors, resulting in a series of dysfunctions. Their rising prevalence and irreversibility have brought physical pain to patients and economic pressure to both individuals and society. However, the pathogenesis of NDDs has not yet been fully elucidated, hampering the use of precise medication. Induced pluripotent stem cell (IPSC) modeling provides a new method for drug discovery, and exploring the early pathological mechanisms including mitochondrial dysfunction, which is not only an early but a prominent pathological feature of NDDs. In this review, we summarize the iPSC modeling approach of Alzheimer's disease, Parkinson's disease, and Amyotrophic lateral sclerosis, as well as outline typical mitochondrial dysfunction and recapitulate corresponding therapeutic strategies.

[Optimize concentrate process of alkaloid from Leonurus japonicus by ultrafultration-nanofiltration coupling technology].

To optimize the concentrate process of alkaloid from Leonurus japonicus by nanofiltration-ultrafiltration coupling technology with response surface methodology. The experiment showed that after ultrafiltration pre-treatment, the total protein removal rate was 94.38% in aqueous extract from L. japonicus, and the nanofiltration technology had obvious advantages over the conventional concentrate process. The optimal concentrate conditions were as follows：molecular weight cut-off 450, pH 3.07, concentration of stachydrine hydrochloride 80.15 mg•L⁻¹, and concentration of the total alkaloid 285.73 mg•L⁻¹. The cut-off rate was 93.37% and 95.85% respectively for stachydrine hydrochloride and the total alkaloid under the optimum conditions, with a relative error of 0.79% and 1.16% respectively. The combination of Box-Behnken design and response surface analysis can well optimize the concentrate process of L. japonicus by nanofiltration, and the results provide the basis for nanofiltration concentrate for heat-sensitive traditional Chinese medicine.

De novo design of VEGFR-2 tyrosine kinase inhibitors based on a linked-fragment approach.

Vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase inhibitors have been demonstrated to possess substantial antitumor activity. VEGFR-2 tyrosine kinase inhibitors are crucial for development of antitumor drugs. Based on the crystal structure of VEGFR-2 tyrosine kinase, a linked-fragment strategy was employed to design novel VEGFR-2 tyrosine kinase inhibitors, and 1000 compounds were generated in this process. Absorption, distribution, metabolism, excretion and toxicity (ADMET) were used to screen the 1000 compounds, and 59 compounds were acceptable. Scaffold hopping was then used for further screening, and only four compounds were obtained in this way. Then, the binding energy of the four molecules to VEGFR-2 tyrosine kinase was calculated using molecular docking, and their values were found to be lower than that of Sorafenib. Finally, molecular dynamics simulations were performed on the complex of the compound with the lowest binding energy with VEGFR-2 tyrosine kinase, and the binding model was analyzed. At the end, four chemical entities with novel structures were obtained, and were suggested for experimental testing in future studies.