# Molecular hydrogen protects chondrocytes from oxidative stress and indirectly alters gene expressions through reducing peroxynitrite derived from nitric oxide.
> 分子状水素はペルオキシナイトライトを介した酸化ストレスから軟骨細胞を保護し遺伝子発現を間接的に調節する


## Abstract

This study investigated whether molecular hydrogen (H2) could counteract cytotoxicity and transcriptional dysregulation in chondrocytes caused by peroxynitrite (ONOO−) generated from nitric oxide radical (NO•). Cultured chondrocytes derived from porcine hindlimb cartilage and rat meniscus fibrocartilage were exposed to the NO• donor SNAP, with or without H2. H2 reduced nitrated protein levels and suppressed cell death. Regarding gene expression, ONOO−-induced downregulation of cartilage matrix proteins aggrecan and type II collagen was reversed by H2, while upregulation of matrix metalloproteinases MMP3 and MMP13 was attenuated. These findings indicate that H2 exerts cytoprotective and transcription-restoring effects in chondrocytes primarily through selective scavenging of ONOO−, suggesting a potential role for ONOO−-targeted strategies in joint disease research.

### Mechanism

H2 directly scavenges peroxynitrite (ONOO−) formed from NO• and superoxide, thereby reducing protein nitration and restoring chondrocyte gene expression: upregulating aggrecan and type II collagen while downregulating MMP3 and MMP13.

## Bibliographic

- **Authors**: Hanaoka T, Kamimura N, Yokota T, Takai S, Ohta S
- **Journal**: Med Gas Res
- **Year**: 2011 (2011-08-04)
- **PMID**: [22146365](https://pubmed.ncbi.nlm.nih.gov/22146365/)
- **DOI**: [10.1186/2045-9912-1-18](https://doi.org/10.1186/2045-9912-1-18)
- **PMC**: [PMC3231990](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3231990/)
- **Study type**: in vitro study
- **Delivery route**: in vitro
- **Effect reported**: positive

## Delivery context

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 22146365. https://h2-papers.org/en/papers/22146365
> **Source**: PubMed PMID [22146365](https://pubmed.ncbi.nlm.nih.gov/22146365/)