Biology subjects

Rotella, D. P.

Publications and source records attributed to Rotella, D. P..

3 recordsLinked to original sources

bioRxiv2025

Molecular mechanisms regulating PDE11A4 age-related liquid-liquid phase separation (LLPS) and its reversal by selective, potent and orally-available PDE11A4 small molecule inhibitors both in vitro and in vivo

PDE11A is a little-studied phosphodiesterase family that breaks down cAMP and cGMP, with the PDE11A4 isoform enriched in the memory-related hippocampus. Age-related increases in hippocampal PDE11A expression occur in human and rodents, causing age-related cognitive decline of social memories. Interestingly, this age-related increase triggers PDE11A4 liquid-liquid phase separation (LLPS), causing the enzyme to accumulate in the brain in filamentous structures termed "ghost axons". Here we sought to identify molecular mechanisms regulating PDE11A4 LLPS and therapeutic approaches capable of reversing it. PDE11A4 LLPS was reduced by phosphorylation of PDE11A4-S163 or-S239 and the D355A mutation that blocks the effect of cGMP binding the PDE11A4 GAF-A domain. PDE11A4 LLPS was increased by inhibiting kinases with staurosporine or stimulating packaging/repacking via the trans-Golgi network by overexpressing TGN38 or RhoB. 8 PDE11 inhibitors (MLG-122, MLG-185, MLG-199, SMQ-02-57, SMQ-03-30, SMQ-03-20, tadalafil, and BC11-38) across 3 scaffolds reverse overexpression-related PDE11A4 LLPS in HT22 mouse hippocampal neuronal cells. This effect of PDE11A4 inhibitors occurs within minutes, is reversed upon washout of lower but not higher concentrations, and occurs in part by reducing PDE11A4 homodimerization. PDE11A4 inhibitors also rescued exacerbated PDE11A4 LLPS triggered by aging-like S117D/S124D phosphomimic mutations, staurosporine, or TGN38/RhoB overexpression. In vivo, orally-administered 30mg/kg SMQ-03-20 reversed age-related increases in PDE11A4 ghost axons and neuroinflammation in old mice. Thus, PDE11A inhibitors that reverse age-related PDE11A4 LLPS in HT22 hippocampal cells also reduce PDE11A4 ghost axons and neuroinflammation in the aged mouse brain, indicating therapeutical potential.

neuroscience↗

bioRxiv2021

Discovery of imidazole-based inhibitors of P. falciparum cGMP-dependent protein kinase

The discovery of new targets for treatment of malaria and in particular those aimed at the pre-erythrocytic stage in the life cycle, advanced with the demonstration that orally administered inhibitors of Plasmodium falciparum cGMP-dependent protein kinase (PfPKG) could clear infection in a murine model. This enthusiasm was tempered by unsatisfactory safety and/or pharmacokinetic issues found with these chemotypes. To address the urgent need for new scaffolds, this manuscript presents initial structure-activity relationships in an imidazole scaffold at four positions, representative in vitro ADME, hERG characterization and cell-based anti-parasitic activity. This series of PfPKG inhibitors has good in vitro PfPKG potency, low hERG activity and cell-based anti-parasitic activity against multiple Plasmodium species that appears to correlate with in vitro potency.

pharmacology and toxicology↗

bioRxiv2021

Characterization of novel competitive inhibitors of P. falciparum cGMP-dependent protein kinase

P. falciparum cGMP-dependent protein kinase (PfPKG) is an enticing anti-malarial drug target. Structurally novel isoxazole-based compounds were shown to be ATP competitive inhibitors of PfPKG. Isoxazoles 3 and 5 had Ki values of 0.7 {+/-} 0.2 and 2.3 {+/-} 0.9 nM, respectively, that are comparable to a known standard, 4-[2-(4-fluorophenyl)-5-(1-methylpiperidine-4-yl)-1H pyrrol-3-yl] pyridine (1.4 {+/-} 0.5 nM). They also exhibited excellent selectivity for PfPKG over the human ortholog and the gatekeeper mutant T618Q PfPKG, which mimics the less accessible binding site of the human ortholog. The human orthologs larger binding site volume was predicted to explain the selectivity of the inhibitors for the P. falciparum enzyme. Analogs 4 and 6 were at least 20-fold less potent compared to 3 and 5, suggesting that removing the carbonyl group in 3 or altering the diethylamino moiety in 5 reduced affinity.

biochemistry↗