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Quambusch, L.

Publications and source records attributed to Quambusch, L..

2 recordsLinked to original sources

Selective covalent-allosteric tools to dissect Akt2

The protein kinase Akt and its isoforms play a crucial role in various diseases. Unique functions of the individual isoforms (Akt1, Akt2, Akt3) might be essential for survival in malignancies. Particularly for Akt2, it was reported that a knock-out led to diabetic phenotype and might be correlated with clinically adverse hyperglycemic effects observed in pan Akt-treatment. Enduring failure of Akt inhibitors in the clinic indicates the necessity for a thorough understanding of the underlying biology, preferably by using highly isoform-selective small molecules. Here we report the structure-guided development of Akt2-selective covalent-allosteric probe molecules, that can be successfully modified within a complex environment using biorthogonal chemistry. Thus, enabling first Akt2-specific pull-down studies and the use in functional studies, such as selective fluorescent labeling in cellular systems. These chemical probes expand our toolbox to dissect the critical questions of Akt2s function in health and disease, thereby paving the way for novel therapeutic strategies based on thorough mechanistic insights.

Cancer Biology↗

Profiling human hypothalamic neurons reveals a candidate combination drug therapy for weight loss

Obesity substantially increases the risk of type 2 diabetes, cardiovascular disease, and other diseases, making it a leading preventable cause of death in developed countries. It has a strong genetic basis, with obesity-associated genetic variants preferentially acting in the brain. This includes the hypothalamic pro-opiomelanocortin (POMC) neurons that inhibit food intake and are stimulated by drugs that agonise glucagon-like 1 peptide receptor (GLP1R) including Semaglutide (Ozempic/Wegovy). We therefore hypothesised that drugs which selectively activate human POMC neurons would suppress appetite and promote weight loss, and that focusing on drugs already approved for use would facilitate rapid clinical translation. We therefore generated POMC neurons from human pluripotent stem cells (hPSCs) and identified enriched genes that were genetically associated with obesity and targeted by approved drugs. We found that human POMC neurons are enriched in GLP1R, reliably activated by Semaglutide, and their responses are further increased by co-administration of Ceritinib, an FDA-approved drug potently and selectively inhibiting anaplastic lymphoma kinase (ALK). Ceritinib reduced food intake and body weight in obese but not lean mice, and upregulated the expression of GLP1R in the mouse hypothalamus and hPSC-derived human hypothalamic neurons. These studies reveal a new potential therapeutic strategy for reducing food intake and body weight, and demonstrate the utility of hPSC-derived hypothalamic neurons for drug discovery.

neuroscience↗