# PNA5, a glycosylated angiotensin-(1−7) mas receptor agonist for vascular dementia: A two species toxicology and toxicokinetic study

**Authors:** Christina Hoyer-Kimura, John P. Konhilas, Meredith Hay

PMC · DOI: 10.1016/j.toxrep.2025.102151 · Toxicology Reports · 2025-10-28

## TL;DR

PNA5 is a new brain-targeted peptide that reduces inflammation and improves cognitive function in a mouse model of vascular dementia and shows no toxicity in rats and dogs.

## Contribution

PNA5 is a novel glycosylated-Angiotensin-(1−7) derivative with demonstrated safety and efficacy in preclinical models of vascular dementia.

## Key findings

- PNA5 was well tolerated in rats and dogs with no adverse effects at all tested doses.
- Systemic exposure to PNA5 increased with dose in rats but not in dogs.
- Accumulation of PNA5 was observed in rats but not in dogs after repeated administration.

## Abstract

PNA5 is a novel pleotropic anti-inflammatory glycosylated-Angiotensin-(1−7) peptide derivative with outstanding brain penetration and enhanced bioavailability. PNA5, via the Mas receptor, decreases brain and cerebrovascular inflammation, reduces reactive oxygen species and inflammatory cytokines production, improves cerebral blood flow, and restores cognitive function in our mouse model of VCID (Vascular contributions to cognitive impairment and dementia). This study evaluated the potential systemic and local toxicity and toxicokinetic (TK) of PNA5 following daily subcutaneous administration in Sprague Dawley rats and Beagle dogs for 28 consecutive days. PNA5 was given at 1, 5, 40 mg/kg/day to rats (n = 12) and at 1, 5, and 20 mg/kg/day in dogs (n = 6) once daily for 28 consecutive days. Blood samples were collected on days 1 and 28 for TK analysis. PNA5 was well tolerated at all doses in both species, with no test article-related mortality or adverse effects. Systemic exposure to PNA5 appeared to be independent of sex. In rats, Cmax and AUC0–2hr values increased with increasing doses. Systemic exposure to PNA5 in rats was greater on day 28 compared to day 1 following repeated administration of PNA5. In dogs, Cmax values increased less than dose-proportionally, and AUC0–2hr increased approximately dose-proportionally on days 1 and 28. Systemic exposure to PNA5 in dogs was similar on days 1 and 28 following repeated administration. These results show that PNA5 has no toxicological effects at the highest doses tested in rats or dogs and is well tolerated with repeated exposure for 28 days. Accumulation was observed in rats but not in dogs.

•PNA5: a novel pleotropic glycosylated-Angiotensin-(1−7) peptide derivative.•PNA5 was well tolerated at all doses in rats and dogs, with no adverse effects.•Cmax and AUC0–2hr are dose-proportional in rats.•Cmax is dose proportional, and AUC0–2hr is dose-proportional in dogs.•Accumulation was observed in rats but not in dogs.

PNA5: a novel pleotropic glycosylated-Angiotensin-(1−7) peptide derivative.

PNA5 was well tolerated at all doses in rats and dogs, with no adverse effects.

Cmax and AUC0–2hr are dose-proportional in rats.

Cmax is dose proportional, and AUC0–2hr is dose-proportional in dogs.

Accumulation was observed in rats but not in dogs.

## Linked entities

- **Chemicals:** PNA5 (PubChem CID 162623682), Angiotensin-(1−7) (PubChem CID 123805)
- **Diseases:** vascular dementia (MONDO:0004648)
- **Species:** Mus musculus (taxon 10090)

## Full-text entities

- **Diseases:** dementia (MESH:D003704), VCID (MESH:D003072), vascular dementia (MESH:D015140), inflammation (MESH:D007249), toxicity (MESH:D064420)
- **Chemicals:** reactive oxygen species (MESH:D017382), Angiotensin-(1-7) peptide (-)
- **Species:** Rattus norvegicus (brown rat, species) [taxon 10116], Mus musculus (house mouse, species) [taxon 10090], Canis lupus familiaris (dog, subspecies) [taxon 9615]

## Full text

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## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12612990/full.md

## References

32 references — full list in the complete paper: https://tomesphere.com/paper/PMC12612990/full.md

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Source: https://tomesphere.com/paper/PMC12612990