Pinacidil ameliorates cardiac microvascular ischemia-reperfusion injury by inhibiting chaperone-mediated autophagy of calreticulin.
Muyin LiuSu LiMing YinYouran LiJinxiang ChenYuqiong ChenYou ZhouQiyu LiFei XuChunfeng DaiYan XiaAo ChenDanbo LuZhangwei ChenJuying QianJunbo GePublished in: Basic research in cardiology (2024)
Calcium overload is the key trigger in cardiac microvascular ischemia-reperfusion (I/R) injury, and calreticulin (CRT) is a calcium buffering protein located in the endoplasmic reticulum (ER). Additionally, the role of pinacidil, an antihypertensive drug, in protecting cardiac microcirculation against I/R injury has not been investigated. Hence, this study aimed to explore the benefits of pinacidil on cardiac microvascular I/R injury with a focus on endothelial calcium homeostasis and CRT signaling. Cardiac vascular perfusion and no-reflow area were assessed using FITC-lectin perfusion assay and Thioflavin-S staining. Endothelial calcium homeostasis, CRT-IP3Rs-MCU signaling expression, and apoptosis were assessed by real-time calcium signal reporter GCaMP8, western blotting, and fluorescence staining. Drug affinity-responsive target stability (DARTS) assay was adopted to detect proteins that directly bind to pinacidil. The present study found pinacidil treatment improved capillary density and perfusion, reduced no-reflow and infraction areas, and improved cardiac function and hemodynamics after I/R injury. These benefits were attributed to the ability of pinacidil to alleviate calcium overload and mitochondria-dependent apoptosis in cardiac microvascular endothelial cells (CMECs). Moreover, the DARTS assay showed that pinacidil directly binds to HSP90, through which it inhibits chaperone-mediated autophagy (CMA) degradation of CRT. CRT overexpression inhibited IP3Rs and MCU expression, reduced mitochondrial calcium inflow and mitochondrial injury, and suppressed endothelial apoptosis. Importantly, endothelial-specific overexpression of CRT shared similar benefits with pinacidil on cardiovascular protection against I/R injury. In conclusion, our data indicate that pinacidil attenuated microvascular I/R injury potentially through improving CRT degradation and endothelial calcium overload.
Keyphrases
- endothelial cells
- oxidative stress
- cardiac resynchronization therapy
- left ventricular
- endoplasmic reticulum
- cell death
- endoplasmic reticulum stress
- signaling pathway
- high throughput
- cell proliferation
- poor prognosis
- blood pressure
- cell cycle arrest
- heat shock
- emergency department
- transcription factor
- computed tomography
- magnetic resonance
- big data
- machine learning
- single molecule
- contrast enhanced
- small molecule
- electronic health record
- high resolution
- binding protein
- long non coding rna
- atrial fibrillation
- cancer therapy
- vascular endothelial growth factor
- mouse model
- amino acid
- adverse drug
- quantum dots