Racemic and enantiomerically pure titanium(IV) complexes with ortho‐bromo‐para‐methyl‐substituted diaminobis(phenolato) ligands were prepared with NH‐, NMe‐, and bipyrrolidine‐based diamino bridges through ligand‐to‐metal chiral induction. The hydrolytic stability of the complexes was evaluated, and their cytotoxicity was measured using HT‐29 human colon cancer cells based on the MTT assay. All stereochemical forms of the NMe‐based complexes, although demonstrating the highest hydrolytic stability, were biologically inactive. For the NH and bipyrrolidine‐based active complexes, the pure enantiomers exhibited high cytotoxicity whereas the racemic mixtures were inactive, supporting the involvement of a polynuclear active species. The bipyrrolidine complexes appear to provide the best combination of hydrolytic stability and biological activity, presumably by minimizing steric bulk and consequently enabling biological accessibility.

PhenolaTi is an advanced non-toxic anticancer chemotherapy; this inert bis(phenolato)bis(alkoxo) Ti(IV) complex demonstrates the intriguing combination of high and wide efficacy with no detected toxicity in animals. Here we unravel the cellular pathways involved in its mechanism of action by a first genome study on Ti(IV)-treated cells, using an attuned RNA sequencing-based available technology. First, phenolaTi induced apoptosis and cell-cycle arrest at the G2/M phase in MCF7 cells. Second, the transcriptome of the treated cells was analyzed, identifying alterations in pathways relating to protein translation, DNA damage, and mitochondrial eruption. Unlike for common metallodrugs, electrophoresis assay showed no inhibition of DNA polymerase activity. Reduced in vitro cytotoxicity with added endoplasmic reticulum (ER) stress inhibitor supported the ER as a putative cellular target. Altogether, this paper reveals a distinct ER-related mechanism by the Ti(IV) anticancer coordination complex, paving the way for wider applicability of related techniques in mechanistic analyses of metallodrugs.

Reacting variously substituted dianionic tridentate ONO-type acylhydrazone ligands with titanium(iv) tetra(isopropoxide) gave a new class of eight homoleptic titanium(iv) compounds showing exceptional stability and promising cytotoxicity.

Objective The endocannabinoid (eCB) system is increasingly recognized as being crucially important in obesity-related hepatic steatosis. By activating the hepatic cannabinoid-1 receptor (CB 1 R), eCBs modulate lipogenesis and fatty acid oxidation. However, the underlying molecular mechanisms are largely unknown. Methods We combined unbiased bioinformatics techniques, mouse genetic manipulations, multiple pharmacological, molecular, and cellular biology approaches, and genomic sequencing to systematically decipher the role of the hepatic CB 1 R in modulating fat utilization in the liver and explored the downstream molecular mechanisms. Results Using an unbiased normalized phylogenetic profiling analysis, we found that the CB 1 R evolutionarily coevolves with peroxisome proliferator-activated receptor-alpha (PPARα), a key regulator of hepatic lipid metabolism. In diet-induced obese (DIO) mice, peripheral CB 1 R blockade (using AM6545) induced the reversal of hepatic steatosis and improved liver injury in WT, but not in PPARα −/− mice. The antisteatotic effect mediated by AM6545 in WT DIO mice was accompanied by increased hepatic expression and activity of PPARα as well as elevated hepatic levels of the PPARα-activating eCB-like molecules oleoylethanolamide and palmitoylethanolamide. Moreover, AM6545 was unable to rescue hepatic steatosis in DIO mice lacking liver sirtuin 1 (SIRT1), an upstream regulator of PPARα. Both of these signaling molecules were modulated by the CB 1 R as measured in hepatocytes exposed to lipotoxic conditions or treated with CB 1 R agonists in the absence/presence of AM6545. Furthermore, using microRNA transcriptomic profiling, we found that the CB 1 R regulated the hepatic expression, acetylation, and transcriptional activity of p53, resulting in the enhanced expression of miR-22, which was found to specifically target SIRT1 and PPARα. Conclusions We provide strong evidence for a functional role of the p53/miR-22/SIRT1/PPARα signaling pathway in potentially mediating the antisteatotic effect of peripherally restricted CB 1 R blockade.

Summary The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spillover infection in December 2019 has caused an unprecedented pandemic. SARS-CoV-2, as other coronaviruses, binds its target cells through the angiotensin-converting enzyme 2 (ACE2) receptor. Accordingly, this makes ACE2 research essential for understanding the zoonotic nature of coronaviruses and identifying novel drugs. Here we present a systematic analysis of the ACE2 conservation and co-evolution protein network across 1,671 eukaryotes, revealing an unexpected conservation pattern in specific metazoans, plants, fungi, and protists. We identified the co-evolved protein network and pinpointed a list of drugs that target this network by using data integration from different sources. Our computational analysis found widely used drugs such as nonsteroidal anti-inflammatory drugs and vasodilators. These drugs are expected to perturb the ACE2 network affecting infectivity as well as the pathophysiology of the disease.