Prokineticin 2 (PK2) Rescues Cardiomyocytes from High Glucose/High Palmitic Acid-Induced Damage by Regulating the AKT/GSK3β Pathway In Vitro

Abstract

Prokineticin 2 (PK2) is a small 8 kDa protein that participates in many physiological processes, such as angiogenesis, inflammation, and neurogenesis. This experiment investigated the effect of PK2 on high glucose/high palmitic acid-induced oxidative stress, apoptosis, and autophagy in cardiomyocytes and the AKT/GSK3β signalling pathway. H9c2 cells were exposed to normal and high concentrations (33 mM) of glucose and palmitic acid (150 μM) with or without PK2 (10 nM) for 48 h. Reactive oxygen species were detected using the fluorescent probes DCFH-DA and DHE. Changes in apoptosis were assessed using flow cytometry, and autophagosomes were detected using Ad-GFP-LC3. Apoptotic proteins, such as Cleaved Caspase3, Bax, and Bcl-2; autophagy proteins, including Beclin-1 and LC3B; and PK2/PKR/AKT/GSK3β signals were evaluated using western blotting. Cardiomyocytes exposed to high glucose/high palmitic acid exhibited increases in intracellular ROS, apoptosis, and autophagosomes, and these increases were robustly prevented by PK2. In addition, high glucose/high palmitic acid remarkably suppressed PK2, PKR1, and PKR2 expression and p-AKT/AKT and p-GSK3β/GSK3β ratios, and these effects were significantly prevented by PK2. Moreover, an AKT1/2 kinase inhibitor (AKT inhibitor, 10 μM) blocked the effects of PK2 on the changes in cardiomyocyte exposure to high glucose/high palmitic acid. These results suggest that PK2 attenuates high glucose/high palmitic acid-induced cardiomyocyte apoptosis by inhibiting oxidative stress and autophagosome accumulation and that this protective effect is most likely mediated by the AKT-related signalling pathway.

High glucose suppresses autophagy through the AMPK pathway while it induces autophagy via oxidative stress in chondrocytes

“…A study by Ribeiro et al revealed that HG inhibited autophagy to accelerate cartilage degradation, and pharmacological autophagy activation inversely attenuated the harmful effects on chondrocytes 22 . Adversely, other studies reported that autophagy as a response mechanism was upregulated to offer protection against HG-induced apoptosis and senescence, which means completely reverse result 21 , 26 , 41 . In the present study, the results of in vitro experiments revealed that autophagy levels changed dynamically with increase in glucose concentration.…”

The Role of Prokineticin 2 in Oxidative Stress and in Neuropathological Processes

“…In the same work, in an in vivo animal model of myocardial infarction, induced by coronary ligation, the authors demonstrated that PKR1 gene therapy preserved the myocardial function by blocking the apoptosis and stimulating angiogenesis (Urayama et al, 2007;Urayama et al, 2008). In line with this data, recent studies have confirmed that PROK2 exerts its protective role on cardiomyocytes by activating the Akt/mTOR (Su et al, 2020) and AKT/GSK3β (Yang et al, 2020) signaling pathways.…”

“…Oxidative stress Neurotoxic -Primary cortical cell cultures -Hypoxia and ROS: ↑ PROK2 mRNA mainly in neurons (Cheng et al, 2012) -in vivo stroke models -Ischemic cortex and striatum: ↑ PROK2 mRNA (Cheng et al, 2012) -PROK2 i.c.v. injection after stroke: ↑ infarct volume (Cheng et al, 2012) -PKRs antagonist: ↓ infarct volume, ↓ central inflammation and improves behavioral outcome (Cheng et al, 2012) Neuroprotective -in vitro model of focal cerebral ischemia -Bv8: ↓ the OGD-induced necrotic neuronal death in cortical cultures and hippocampal slices activating ERK, Akt and GSK3-β pathways (Landucci et al, 2016) -PKRs antagonist reverts the Bv8 effects (Landucci et al, 2016) -in vitro model of ischemic tolerance (NMDA preconditioning) -Hippocampal slices: ↑ PROK2, PKR1 and PKR2 mRNA and protein (Landucci et al, 2016) -PKRs antagonist: ↓ PROK2 protein in hippocampal slices (Landucci et al, 2016) -H9c2 cardiomyocytes cell line from rat heart -PROK2 treatment or PKR1 overexpression: ↓ oxidative stress-induced apoptotic cell death activating the Akt/mTOR and AKT/GSK3β pathways (Urayama et al, 2007;Su et al, 2020;Yang et al, 2020) Beta amyloid Neurotoxic -Primary cortical cell cultures -Aβ 1-42 : ↑ PROK2, PKR1 and PKR2 mRNA and protein levels in neurons and astrocytes (Severini et al, 2015) -Bv8, at pM concentrations, ↑ neuronal apoptosis (Severini et al, 2015) -PKRs antagonist: ↓ Aβ-and Bv8-induced neuronal apoptosis (Severini et al, 2015) and ↓ kainate-evoked current increase Aβ-induced (Caioli et al, 2017) -Tg2576 transgenic mouse model of AD↓ -Cortex and hippocampus: ↑ PROK2 mRNA (Lattanzi et al, 2019) -PKRs antagonist: ↓ LTP impairment in hippocampal slices (Severini et al, 2015) -in vivo non-transgenic rat model of AD -Aβ 1-42 i.c.v. injection: ↑ PROK2, PKR1 and PKR2 mRNA and protein in prefrontal cortex and hippocampus (Severini et al, 2015;Lattanzi et al, 2019;Maftei et al, 2019) -PKRs antagonist: ↓ PROK2 levels, ↓ glial activation and neuronal death, restores the neurogenesis in DG and ↓ the Aβ-induced memory deficits (Maftei et al, 2019) -AD patients -↑ PROK2 mRNA in hippocampus and ↑ PROK2 protein in serum (Lattanzi et al, 2019) Glutamate Neurotoxic -Primary cortical cell cultures -NMDA and excitotoxic glutamate: ↑ PROK2 mRNA mainly in neurons…”

Curcumin Conjugated Gold Nanoclusters as Perspective Therapeutics for Diabetic Cardiomyopathy

“…The excessive accumulation of lipids can directly lead to the imbalance between the production and clearance of reactive oxygen species, which is the occurrence of oxidative stress reaction. Studies have shown that reducing ROS production protects cardiomyocytes damaged by glycolipid toxicity ( Kolleritsch et al, 2020 ; Yang et al, 2020 ). In our study, AuCur successfully reduced the accumulation of lipid droplets and the increase of ROS in cardiomyocytes due to high lipid levels.…”