Quantitative intravitreal pharmacokinetics in mouse as a step towards inter-species translation

Puranen, Jooseppi; Ranta, Veli-Pekka; Ruponen, Marika; Urtti, Arto; Sadeghi, Amir

doi:10.1016/j.exer.2023.109638

Cited by 6 publications

(2 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…RGC degeneration after optic nerve crush (ONC) is highly dependent on (palmitoyl)-DLK (6, 7, 9, 27) and local, intravitreal delivery of compounds to the eye could circumvent potential issues with systemic instability. Because intravitreally injected compounds can rapidly drain from the eye (28, 29), we isolated retinas 15h post-ONC, after first confirming that ONC-induced c-Jun phosphorylation is robustly observed at this time point (Fig S4). Importantly, intravitreal injection of either 8 or 13 reduced DLK-dependent responses of RGCs (ONC-induced c-Jun phosphorylation) to a similar extent as GNE-3511 (Fig 8A, B; RGCs identified with the marker Brn3A).…”

Section: Resultsmentioning

confidence: 77%

“…For example, the extent to which these compounds can diffuse from the RGC soma into the proximal axon, where stimulus-dependent palmitoylation is most likely to occur in vivo, is unclear and may limit their therapeutic efficacy. A second issue is that small molecules are rapidly cleared from the mouse eye after intravitreal injection (28, 29) which likely limits the effective concentration of 8 and 13 in the hours after ONC. However, controlled release strategies using intravitreal implants e.g.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Novel inhibitors of acute, axonal DLK palmitoylation are neuroprotective and avoid the deleterious side effects of cell-wide DLK inhibition

Zhang,

Jeong,

Niu

et al. 2024

Preprint

View full text Add to dashboard Cite

Dual leucine-zipper kinase (DLK) drives acute and chronic forms of neurodegeneration, suggesting that inhibiting DLK signaling could ameliorate diverse neuropathological conditions. However, direct inhibition of the kinase domain of DLK in human patients and conditional knockout of DLK in mice both cause unintended side effects, including elevated plasma neurofilament levels, indicative of neuronal cytoskeletal disruption. Indeed, we found that a DLK kinase domain inhibitor acutely disrupted the axonal cytoskeleton and caused vesicle aggregation in cultured dorsal root ganglion (DRG) neurons, further cautioning against this therapeutic strategy. In seeking a more precise intervention, we found that retrograde (axon-to-soma) pro-degenerative signaling requires acute, axonal palmitoylation of DLK and hypothesized that modulating this post-translational modification might be more specifically neuroprotective than cell-wide DLK inhibition. To address this possibility, we screened >28,000 compounds using a high-content imaging assay that quantitatively evaluates the palmitoylation-dependent subcellular localization of DLK. Of the 33 hits that significantly altered DLK localization in non-neuronal cells, several reduced DLK retrograde signaling and protected cultured DRG neurons from DLK-dependent neurodegeneration. Mechanistically, the two most neuroprotective compounds selectively prevent stimulus-dependent palmitoylation of axonal pools of DLK, a process crucial for the recruitment of DLK to axonal vesicles. In contrast, these compounds minimally impact DLK localization and signaling in healthy neurons and avoid the cytoskeletal disruption associated with direct DLK inhibition. Importantly, our hit compounds also reduce pro-degenerative retrograde signaling in vivo, suggesting that modulating the palmitoylation-dependent localization of DLK could be a novel neuroprotective strategy.

show abstract