High-dose remifentanil exacerbates myocardial ischemia-reperfusion injury through activation of calcium-sensing receptor-mediated pyroptosis

by Selleckchem | Jan 15 2024

Background: The aim of this study was to investigate whether calcium-sensing receptor (CaSR) was involved in HRF-mediated exacerbation of MI/R injury through NLRP3 inflammasome activation and pyroptosis.

Methods: In vivo, a rat MI/R model was established by ligating the left coronary artery, and short-term HRF exposure was induced during reoxygenation. Then, TUNEL, H&E, Masson staining, immunohistochemical (IHC) and serum levels of lactate dehydrogenase (LDH) and creatine kinase isoenzyme (CK), as well as the expression levels of CaSR and pyroptosis-related proteins in heart tissues, were measured. H9c2 cells were cultured to create a hypoxia/reoxygenation (H/R) model and exposed to different concentrations of RF. After pretreatment with the CaSR activator gadolinium chloride (GdCl3) and inhibitor NPS2143 in the H/R model and treatment with HRF, we compared cellular viability, TUNEL, cytosolic [Ca2+]i, the levels of LDH and CK, pyroptosis-related proteins and CaSR in H9c2 cells. We further researched the mechanisms of CaSR-mediated pyroptosis in the H/R+HRF model by CaSR-shRNA, Ac-YVAD-CMK, MCC950 and NAC.

Results: We found that HRF significantly increased CaSR expression, rate of cell death, levels of CK and LDH, and exacerbated pyroptosis in MI/R model. In vitro, HRF increased CaSR expression, decreased viability, enhanced cytosolic [Ca2+]i and exacerbated pyroptosis in H/R cells. Pretreated with GdCl3 worsen these changes, and NPS2143, MCC950, Ac-YVAD-CMK, NAC and sh-CaSR can reversed these effects.

Conclusion: Exposure to HRF for a short time exacerbates MI/R-induced injury by targeting CaSR to increase cytosolic [Ca2+]i and ROS levels, which mediate the NLRP3 inflammasome and pyroptosis.

Comments:

This study delves deep into the role of calcium-sensing receptors (CaSR) in exacerbating myocardial ischemia/reperfusion (MI/R) injury through the activation of the NLRP3 inflammasome and pyroptosis in response to exposure to high radiofrequency (HRF). Here's a breakdown of the main points:

### **Key Findings:**
1. **In Vivo Studies:**
   - Established an MI/R rat model with HRF exposure during reoxygenation.
   - Observed increased CaSR expression and exacerbated tissue damage, cell death, CK and LDH levels, and pyroptosis in the heart tissues.

2. **In Vitro Studies (H9c2 Cells):**
   - Created a hypoxia/reoxygenation (H/R) model and exposed cells to varying HRF concentrations.
   - Noticed elevated CaSR expression, decreased cell viability, increased cytosolic [Ca2+]i, and exacerbated pyroptosis.

3. **Interventions and Mechanistic Insights:**
   - Pretreatment with CaSR activator GdCl3 worsened these effects, while the CaSR inhibitor NPS2143 reversed them.
   - Other interventions like MCC950, Ac-YVAD-CMK, NAC, and CaSR-shRNA showed promise in counteracting HRF-induced effects on pyroptosis.

### **Conclusion:**
The study concludes that short-term exposure to HRF exacerbates MI/R injury by targeting CaSR. This leads to increased cytosolic [Ca2+]i and ROS levels, triggering the NLRP3 inflammasome and subsequent pyroptosis, a form of inflammatory cell death.

This research sheds light on potential mechanisms linking HRF exposure, CaSR activation, and cellular responses in MI/R injury, which could be valuable in understanding and potentially developing interventions for cardiac injury exacerbated by such exposures.