Cathelicidin attenuates hyperoxia-induced kidney injury in newborn rats.
Chou. Hsiu-Chu HC; Chen. Chung-Ming CM
Key Findings
- High‑oxygen exposure caused kidney damage, weight loss, increased oxidative stress (8‑OHdG), collagen buildup, and NF‑κB activation in newborn rats
- LL‑37 treatment (4 mg/kg or 8 mg/kg IP) lowered kidney injury scores, oxidative DNA damage, collagen deposition, and NF‑κB levels
- LL‑37 shifted macrophage balance toward anti‑inflammatory M2 type, reducing pro‑inflammatory M1 macrophages
Practical Outcomes
- The results suggest LL‑37 has antioxidant and anti‑inflammatory properties that could protect kidneys, but the work is limited to newborn rats and requires injections at doses far above typical human use. Biohackers should view this as early mechanistic evidence rather than a ready‑to‑use protocol; more research is needed before considering supplementation or dosing in humans.
Summary
In newborn rats exposed to high oxygen, which damages kidneys, giving the natural peptide LL‑37 reduced the injury, lowered oxidative stress and inflammation, and helped the kidneys stay healthier. The study used injections of 4‑8 mg/kg for the first week after birth, showing the peptide can counteract the harmful effects of excess oxygen in this animal model.
Abstract
<b>Aim:</b> Supplemental oxygen is often used to treat neonates with respiratory disorders. Human and animal studies have demonstrated that neonatal hyperoxia increases oxidative stress and induces damage and collagen deposition in kidney during the perinatal period. Cathelicidin LL-37 is one important group of human antimicrobial peptides which exhibits antioxidant activity and its overexpression resists hyperoxia-induced oxidative stress. This study was designed to evaluate the protective effects of cathelicidin in hyperoxia-induced kidney injury in newborn rats. <b>Methods:</b> Sprague-Dawley rat pups were reared in either room air (RA) or hyperoxia (85% O<sub>2</sub>) and were randomly treated with low-dose (4 mg/kg) and high-dose (8 mg/kg) cathelicidin in normal saline (NS) administered intraperitoneally on postnatal days 1-6. The following six groups were obtained: RA + NS, RA + low-dose cathelicidin, RA + high-dose cathelicidin, O<sub>2</sub> + NS, O<sub>2</sub> + low-dose cathelicidin, and O<sub>2</sub> + high-dose cathelicidin. Kidneys were taken for Western blot and histological analyses on postnatal day 7. <b>Results:</b> The hyperoxia-reared rats exhibited significantly lower body weights and anti-inflammatory M2 macrophages, but the kidney injury scores, oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-OHdG)-positive cells, pro-inflammatory M1 macrophages, collagen deposition, and NF-κB expression were higher than did the RA-reared rats. <b>Conclusions:</b> Cathelicidin treatment attenuated kidney injury as evidenced by lower kidney injury scores, 8-OHdG-positive cells, collagen deposition, and reversion of hyperoxia-induced M1/M2 macrophage polarization. The role of Cathelicidin in ameliorates kidney injury of the hyperoxia newborn rats was accompanied by decreased NF-κB expression, which probably through the modulating NF-κB activity in the kidney.
Study Information
pubmed
2019
10.1080/0886022x.2019.1651741