T1AM Attenuates the Hypoxia/Reoxygenation-Induced Necroptosis of H9C2 Cardiomyocytes via RIPK1/RIPK3 Pathway

Area of Science:

• Cardiology
• Cell Biology
• Biochemistry

Background:

• Hypoxia/reoxygenation (H/R) induces significant injury to cardiomyocytes.
• Understanding the mechanisms of H/R-induced cell death, including apoptosis and programmed necrosis, is crucial for developing therapeutic strategies.
• H9C2 cells serve as a valuable model for studying cardiomyocyte responses to injury.

Purpose of the Study:

• To investigate the protective mechanisms of 3-iodothyronamine (T1AM) against hypoxia/reoxygenation (H/R)-induced injury in H9C2 cells.
• To elucidate the role of T1AM in modulating apoptosis and programmed necrosis (necroptosis) pathways.
• To examine the effect of T1AM on key signaling molecules such as RIPK1, RIPK3, and CAMKII.

Main Methods:

• Establishment of an in vitro H/R model using cultured H9C2 cardiomyocyte cells.
• Assessment of cell viability and injury using CCK8 assay and lactate dehydrogenase (LDH) release.
• Quantification of apoptosis via TUNEL assay and flow cytometry.
• Detection of RIPK1, RIPK3, and CAMKII protein and mRNA levels using Western blotting and qRT-PCR.

Main Results:

• H/R significantly increased H9C2 cell inhibition rate and LDH release, indicating substantial cell injury.
• H/R exposure led to enhanced protein and mRNA expression of RIPK1, RIPK3, and CAMKII.
• T1AM pretreatment significantly reduced cell inhibition, LDH release, and necroptosis rates in H/R-treated H9C2 cells.
• T1AM pretreatment also significantly decreased the elevated protein and mRNA levels of RIPK1, RIPK3, and CAMKII.

Conclusions:

• Pretreatment with 3-iodothyronamine (T1AM) effectively alleviates H/R-induced injury in H9C2 cardiomyocytes.
• T1AM demonstrates a protective effect by inhibiting necroptosis, potentially through the modulation of the RIPK1/RIPK3 signaling pathway.
• These findings suggest T1AM as a potential therapeutic agent for mitigating cardiac injury.