Unlocking SGK1 inhibitor potential of bis-[1-N,7-N, pyrazolo tetraethoxyphthalimido{-4-(3,5-Dimethyl-4-(spiro-3-methylpyazolo)-1,7-dihydro-1H-dipyrazolo[3,4-b;4',3'-e]pyridin-8-yl)}]p-disubstituted phenyl compounds: a computational study

SGK1 (Serum and Glucocorticoid Regulated Kinase 1), a serine/threonine kinase that is activated by various stimuli, including serum and glucocorticoids. It controls inflammation, apoptosis, hormone release, neuro-excitability and cell proliferation, all of which play an important role in cancer progression and metastasis. SGK1 was recently proposed as a potential drug target for cancer, diabetes, and neurodegenerative diseases. In this study, molecular docking, physiochemical, toxicological properties and molecular dynamic simulation of the Bis-[1-N,7-N, Pyrazolo tetraethoxyphthalimido{-4-(3,5-Dimethyl-4-(spiro-3-methylpyazolo)-1,7-dihydro-1H-dipyrazolo[3,4-b;4',3'-e]pyridin-8-yl)}]p-disubstituted phenyl compoundsand reference EMD638683 against new SGK1 target protein. Compared to the reference inhibitor EMD638683, we choose the best compounds (series 2-6) based on the binding energy (in the range from -11.0 to -10.6 kcal/mol). With the exception of compounds 2 and 6, none of the compounds posed a risk for AMES toxicity or carcinogenicity due to their toxicological properties. 100 ns MD simulation accompanied by MM/PBSA energy calculations and PCA. According to MD simulation results, the binding of compounds 3, 4 and 5 stabilizes the SGK1 structure and causes febrile conformational changes compared to EMD638683. As a result of this research, the final selected compounds 3, 4 and 5 can be used as scaffolds to develop promising SGK1 inhibitors for the treatment of related diseases such as cancer.Communicated by Ramaswamy H. Sarma.

Rational Design of Highly Potent, Selective, and Bioavailable SGK1 Protein Kinase Inhibitors for the Treatment of Osteoarthritis

The serine/threonine kinase SGK1 is an activator of the β-catenin pathway and a powerful stimulator of cartilage degradation that is found to be upregulated under genomic control in diseased osteoarthritic cartilage. Today, no oral disease-modifying treatments are available and chronic treatment in this indication sets high requirements for the drug selectivity, pharmacokinetic, and safety profile. We describe the identification of a highly selective druglike 1H-pyrazolo[3,4-d]pyrimidine SGK1 inhibitor 17a that matches both safety and pharmacokinetic requirements for oral dosing. Rational compound design was facilitated by a novel hSGK1 co-crystal structure, and multiple ligand-based computer models were applied to guide the chemical optimization of the compound ADMET and selectivity profiles. Compounds were selected for subchronic proof of mechanism studies in the mouse femoral head cartilage explant model, and compound 17a emerged as a druglike SGK1 inhibitor, with a highly optimized profile suitable for oral dosing as a novel, potentially disease-modifying agent for osteoarthritis.