S1P d20:1, an endogenous modulator of S1P d18:1/S1P2 -dependent signaling.

Sphingosine 1-phosphate (S1P) signaling influences numerous cell biological mechanisms such as differentiation, proliferation, survival, migration, and angiogenesis. Intriguingly, our current knowledge is based solely on the role of S1P with an 18-carbon long-chain base length, S1P d18:1. Depending on the composition of the first and rate-limiting enzyme of the sphingolipid de novo metabolism, the serine palmitoyltransferase, other chain lengths have been described in vivo. While cells are also able to produce S1P d20:1, its abundance and function remains elusive so far. Our experiments are highlighting the role of S1P d20:1 in the mouse central nervous system (CNS) and human glioblastoma. We show here that S1P d20:1 and its precursors are detectable in both healthy mouse CNS-tissue and human glioblastoma. On the functional level, we focused our work on one particular, well-characterized pathway, the induction of cyclooxygenase (COX)-2 expression via the S1P receptor 2 (S1P2 ). Intriguingly, S1P d20:1 only fairly induces COX-2 expression and can block the S1P d18:1-induced COX-2 expression mediated via S1P2 activation in the human glioblastoma cell line LN229. This data indicates that S1P d20:1 might act as an endogenous modulator of S1P signaling via a partial agonism at the S1P2 receptor. While our findings might stimulate further research on the relevance of long-chain base lengths in sphingolipid signaling, the metabolism of S1P d20:1 has to be considered as an integral part of S1P signaling pathways in vivo.

Structure-Based Design of Dual Partial Peroxisome Proliferator-Activated Receptor γ Agonists/Soluble Epoxide Hydrolase Inhibitors.

Polypharmaceutical regimens often impair treatment of patients with metabolic syndrome (MetS), a complex disease cluster, including obesity, hypertension, heart disease, and type II diabetes. Simultaneous targeting of soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor γ (PPARγ) synergistically counteracted MetS in various in vivo models, and dual sEH inhibitors/PPARγ agonists hold great potential to reduce the problems associated with polypharmacy in the context of MetS. However, full activation of PPARγ leads to fluid retention associated with edema and weight gain, while partial PPARγ agonists do not have these drawbacks. In this study, we designed a dual partial PPARγ agonist/sEH inhibitor using a structure-guided approach. Exhaustive structure-activity relationship studies lead to the successful optimization of the designed lead. Crystal structures of one representative compound with both targets revealed potential points for optimization. The optimized compounds exhibited favorable metabolic stability, toxicity, selectivity, and desirable activity in adipocytes and macrophages.

Gene Expression Dynamics at the Neurovascular Unit During Early Regeneration After Cerebral Ischemia/Reperfusion Injury in Mice.

With increasing distribution of endovascular stroke therapies, transient middle cerebral artery occlusion (tMCAO) in mice now more than ever depicts a relevant patient population with recanalized M1 occlusion. In this case, the desired therapeutic effect of blood flow restauration is accompanied by breakdown of the blood-brain barrier (BBB) and secondary reperfusion injury. The aim of this study was to elucidate short and intermediate-term transcriptional patterns and the involved pathways covering the different cellular players at the neurovascular unit after transient large vessel occlusion. To achieve this, male C57Bl/6J mice were treated according to an intensive post-stroke care protocol after 60 min occlusion of the middle cerebral artery or sham surgery to allow a high survival rate. After 24 h or 7 days, RNA from microvessel fragments from the ipsilateral and the contralateral hemispheres was isolated and used for mRNA sequencing. Bioinformatic analyses allowed us to depict gene expression changes at two timepoints of neurovascular post-stroke injury and regeneration. We validated our dataset by quantitative real time PCR of BBB-associated targets with well-characterized post-stroke dynamics. Hence, this study provides a well-controlled transcriptome dataset of a translationally relevant mouse model 24 h and 7 days after stroke which might help to discover future therapeutic targets in cerebral ischemia/reperfusion injury.