Elabela, a Novel Peptide, Exerts Neuroprotective Effects Against Ischemic Stroke Through the APJ/miR-124-3p/CTDSP1/AKT Pathway.

Elabela (ELA), which is the second endogenous peptide ligand of the apelin receptor (APJ) to be discovered, has been widely studied for potential use as a therapeutic peptide. However, its role in ischemic stroke (IS), which is a leading cause of disability and death worldwide and has limited therapeutic options, is uncertain. The aim of the present study was to investigate the beneficial effects of ELA on neuron survival after ischemia and the underlying molecular mechanisms. Primary cortical neurons were isolated from the cerebral cortex of pregnant C57BL/6J mice. Flow cytometry and immunofluorescence showed that ELA inhibited oxygen-glucose deprivation (OGD) -induced apoptosis and axonal damage in vitro. Additionally, analysis of the Gene Expression Omnibus database revealed that the expression of microRNA-124-3p (miR-124-3p) was decreased in blood samples from patients with IS, while the expression of C-terminal domain small phosphatase 1 (CTDSP1) was increased. These results indicated that miR-124-3p and CTDSP1 were related to ischemic stroke, and there might be a negative regulatory relationship between them. Then, we found that ELA significantly elevated miR-124-3p expression, suppressed CTDSP1 expression, and increased p-AKT expression by binding to the APJ receptor under OGD in vitro. A dual-luciferase reporter assay confirmed that CTDSP1 was a direct target of miR-124-3p. Furthermore, adenovirus-mediated overexpression of CTDSP1 exacerbated neuronal apoptosis and axonal damage and suppressed AKT phosphorylation, while treatment with ELA or miR-124-3p mimics reversed these effects. In conclusion, these results indicated that ELA could alleviate neuronal apoptosis and axonal damage by upregulating miR-124-3p and activating the CTDSP1/AKT signaling pathway. This study, for the first time, verified the protective effect of ELA against neuronal injury after ischemia and revealed the underlying mechanisms. We demonstrated the potential for the use of ELA as a therapeutic agent in the treatment of ischemic stroke.

Synthetic studies on (+)-biotin, part 15: A chiral squaramide-mediated enantioselective alcoholysis approach toward the total synthesis of (+)-biotin.

An efficient stereocontrolled total synthesis of (+)-biotin (1) has been achieved via the intermediacy of Roche's lactone 5 starting from cis-1,3-dibenzyl-2-imidazole-4,5-dicarboxylic acid (2). The bifunctional cinchona alkaloid-derived squaramide-promoted enantioselective alcoholysis was utilizing as a tool for the construction of two contiguous stereocenters of C-3a and C-6a in biotin molecular with excellent enantioselectivity. In addition, the 4-carboxybutyl side chain was assembled by first using C4+C1 approach via a novel tricyclic thiophanium salt intermediate.

Nonnucleoside HIV-1 reverse-transcriptase inhibitors, part 5. Synthesis and anti-HIV-1 activity of novel 6-naphthylthio HEPT analogues.

As part of a series of studies to discover new HIV reverse-transcriptase inhibitors, various novel 6alpha- and 6beta-naphthylthio 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio) thymine (HEPT) derivatives were synthesized, and in vitro anti-HIV-1 activity was evaluated. The results revealed that most of 6alpha-naphthylthio HEPT derivatives (7a-w) showed good activity [for 7e, IC50 value of 0.048 microM and selectivity index (SI) value of 735; for 7h, IC50 value of 0.057 microM and SI value of 579; for 7k, IC50 value of 0.063 microM and SI value of 565], 6beta-naphthylthio HEPT derivatives (8a-f) showed low activity, but the introduction of alpha nitro group to the C-1 position of the 6beta-naphthyl ring in the 6beta-naphthylthio series (11a-c) resulted in a dramatic increase in anti-HIV-1 activity.

Synthetic studies on d-biotin, part 9. An improved asymmetric synthetic route to d-biotin via Hoffmann-Roche lactone-thiolactone approach.

An efficient and highly stereoselective total synthesis of d-biotin has been achieved starting from cis-1,3-dibenzyl-2-imidazolidone-4,5-dicarboxylic acid (2) with an overall yield of 33%. Polymer-supported oxazaborolidine-catalyzed asymmetric reduction of meso-cyclic imide 4 constitutes the key synthetic step in introducing stereogenic centers into the d-biotin molecule.