H₂S Protects against Cardiac Cell Hypertrophy through Regulation of Selenoproteins

Area of Science:

• Biochemistry
• Cardiovascular Biology
• Oxidative Stress Research

Background:

• Cardiac hypertrophy, an enlargement of cardiac myocytes, impairs heart function and is a precursor to myocardial infarction.
• Hydrogen sulfide (H2S), a gasotransmitter produced by cystathionine gamma-lyase (CSE), is crucial for cardiac function.
• Hydrogen selenide (H2Se), produced by selenocysteine lyase (SCLY), is the selenium analog of H2S, and selenium deficiency is linked to cardiomyopathy.

Purpose of the Study:

• To investigate the interaction between H2S and H2Se in the context of cardiac cell hypertrophy.
• To elucidate the protective mechanisms of H2S and H2Se against oxidative stress-induced cardiac hypertrophy.

Main Methods:

• Cell viability assessed using MTT assay.
• Oxidative stress and cell size evaluated via immunostaining.
• Gene and protein expression analyzed by real-time PCR and western blot.

Main Results:

• Hydrogen peroxide (H2O2) induced oxidative stress and increased cell surface area in rat cardiac cells (H9C2).
• Pretreatment with H2S or H2Se significantly attenuated H2O2-induced hypertrophy.
• H2S incubation upregulated SCLY/H2Se signaling, increasing selenoprotein expression and activity (e.g., glutathione peroxidase, thioredoxin reductase).
• CSE deficiency reduced SCLY and selenoprotein P expression in mouse hearts.
• Both H2S and H2Se stimulated Nrf2-targeted downstream genes.

Conclusions:

• H2S protects against cardiac hypertrophy by enhancing antioxidant protein expression through the SCLY/H2Se pathway.
• This study reveals a novel signaling axis involving H2S, H2Se, and antioxidant selenoproteins in cardiac protection.
• Targeting H2S and H2Se pathways may offer therapeutic strategies for managing cardiac hypertrophy and related diseases.