Penehyclidine hydrochloride prevents anoxia/reoxygenation injury and induces H9c2 cardiomyocyte apoptosis via a mitochondrial pathway

SIRT3 and RORα are two prospective targets against mitophagy during simulated ischemia/reperfusion injury in H9c2 cells

Autophagy during myocardial ischemia/reperfusion (MI/R) exacerbates cardiomyocyte injury. Melatonin (Mel) alleviates myocardial damage by regulating mitochondrial function and mitophagy, but the role of mitophagy in melatonin-induced cardioprotection remains unclear. This study aimed to explore the roles of sirtuin3 (SIRT3) and retinoid-related orphan nuclear receptor-α (RORα) in mitophagy during simulated ischemia reperfusion (SIR) in H9c2 cells. Our data showed that mitophagy was excessively activated after SIR injury, which was consistent with reduced cell survival, enhanced oxidative responses and mitochondrial dysfunction in H9c2 myocytes. Melatonin greatly enhanced cell viability, reduced oxidative stress and improved mitochondrial function. The effects of melatonin protection were involved in excessive mitophagy inhibition, as demonstrated by the reduced levels of mitophagy-linked proteins, including Parkin, Beclin1, NIX and BNIP3, and the LC3 II/LC3 I ratio and elevations in p62. Additionally, the decreases in SIRT3 and RORα in H9c2 myocytes after SIR were reversed by melatonin, and the above effects of melatonin were eliminated by small interfering RNA (siRNA)-mediated knockdown of SIRT3 and RORα. In brief, SIRT3 and RORα are two prospective targets in the cardioprotection of melatonin against mitophagy during SIR in H9c2 myocytes.

Blockade of Hepatocyte PCSK9 Ameliorates Hepatic Ischemia-Reperfusion Injury by Promoting Pink1-Parkin-Mediated Mitophagy

BACKGROUND & AIMS

Hepatic ischemia-reperfusion injury is a significant complication of partial hepatic resection and liver transplantation, impacting the prognosis of patients undergoing liver surgery. The protein proprotein convertase subtilisin/kexin type 9 (PCSK9) is primarily synthesized by hepatocytes and has been implicated in myocardial ischemic diseases. However, the role of PCSK9 in hepatic ischemia-reperfusion injury remains unclear. This study aims to investigate the role and mechanism of PCSK9 in hepatic ischemia-reperfusion injury.

METHODS

We first examined the expression of PCSK9 in mouse warm ischemia-reperfusion models and AML12 cells subjected to hypoxia/reoxygenation. Subsequently, we explored the impact of PCSK9 on liver ischemia-reperfusion injury by assessing mitochondrial damage and the resulting inflammatory response.

RESULTS

Our findings reveal that PCSK9 is up-regulated in response to ischemia-reperfusion injury and exacerbates hepatic ischemia-reperfusion injury. Blocking PCSK9 can alleviate hepatocyte mitochondrial damage and the consequent inflammatory response mediated by ischemia-reperfusion. Mechanistically, this protective effect is dependent on mitophagy.

CONCLUSIONS

Inhibiting PCSK9 in hepatocytes attenuates the inflammatory responses triggered by reactive oxygen species and mitochondrial DNA by promoting PINK1-Parkin-mediated mitophagy. This, in turn, ameliorates hepatic ischemia-reperfusion injury.

Temporal Effect of Melatonin Posttreatment on Anoxia/Reoxygenation Injury in H9c2 Cells

Melatonin has been proven to reduce myocardial ischemia-reperfusion (MI/R) injury. However, in most studies, melatonin was administered prior to MI/R, thus, the results lack clinical significance in patients with acute myocardial infarction. We hypothesize that melatonin posttreatment at different times has different curative effects. Administered of Melatonin (150 μM) at different times after the onset of reoxygenation (t=-15, 0, 5, 10, 15, 30 min). Cellular apoptosis, oxidative stress and mitochondrial function were assessed. Mitophagy-related protein levels, the mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (mPTP) activity were also measured. A/R injury upregulated mitophagy, which was associated with increased cellular apoptosis, oxidative stress and mitochondrial dysfunction. Melatonin posttreatment (t= -15, 0, 5, 10, 15, 30 min) significantly inhibited excessive mitophagy after A/R injury, reduced cellular apoptosis and oxidative stress, restored mitochondrial function and MMP, and restrained mPTP opening. The therapeutic time window in which melatonin posttreatment protected H9c2 cells against A/R injury was large (from -15 to 30 min after the onset of reperfusion), but the earlier the melatonin administration was, the better its protective effect was. This mechanism is likely due to a reduction in mPTP activity and MMP collapse, which lead to the inhibition of mitophagy. This article is protected by copyright. All rights reserved.

Melatonin postconditioning ameliorates anoxia/reoxygenation injury by regulating mitophagy and mitochondrial dynamics in a SIRT3-dependent manner

Ischaemia/reperfusion (I/R) injury is accompanied by excessive mitochondrial autophagy (mitophagy) and an imbalance in mitochondrial dynamics. Melatonin has been reported to alleviate I/R injury by regulating mitophagy and mitochondrial dynamics. However, the underlying mechanism associated with this activity is not fully understood. The goal of the present study was to investigate whether and how melatonin administration at the beginning of reoxygenation exerts protective effects by regulating mitophagy and mitochondrial dynamics. H9c2 cells were transfected with sirtuin 3 (SIRT3)-targeting siRNA and then subjected to anoxia/reoxygenation (A/R) injury, with melatonin (150 μM) administered at the onset of reoxygenation. Biomarkers related to cellular apoptosis, oxidative stress, mitochondrial function, mitophagy and mitochondrial dynamics were assessed, and the expression and activity of SIRT3 was also measured. Mitochondrial fission and mitophagy were activated after A/R injury and were accompanied by cellular apoptosis, oxidative stress, and mitochondrial dysfunction. However, melatonin postconditioning inhibited excessive mitochondrial fission and mitophagy, promoted mitochondrial fusion, restored mitochondrial function and reduced cellular apoptosis, and the mitophagy inhibitor 3-methyladenine (3-MA) also attenuated A/R-induced apoptosis. Moreover, the A/R-induced decreases in SIRT3 and manganese superoxide dismutase (SOD2) activities were ameliorated by melatonin. However, SIRT3 silencing abolished the beneficial effects of melatonin, eliminated the inhibitory effects of melatonin on mitochondrial fission and mitophagy, and reversed the melatonin-induced increase in SOD2 activity. These results indicate that melatonin postconditioning protects H9c2 cells from A/R injury by inhibiting excessive mitophagy and maintaining the balance of mitochondrial fission and fusion in a SIRT3-dependent manner.

Increased blood lactate levels during exercise and mitochondrial DNA alterations converge on mitochondrial dysfunction in schizophrenia

BACKGROUND

Mitochondrial dysfunction and an elevation of lactate are observed in patients with schizophrenia (SZ). However, it is unknown whether mitochondrial dysfunction is associated with the presence of mitochondrial DNA (mtDNA) alterations and comorbid clinical conditions. We aimed to identify systemic mitochondrial abnormalities in blood samples of patients with SZ that may have a high impact on the brain due to its high bioenergetic requirements.

METHODS

Case/control study between 57 patients with SZ and 33 healthy controls (HCs). We measured lactate levels at baseline, during 15 min of exercise (at 5, 10 and 15 min) and at rest. We also evaluated the presence of clinical conditions associated with mitochondrial disorders (CAMDs), measured the neutrophil to lymphocyte ratio (NLR, a subclinical inflammatory marker), and analyzed mtDNA variation and copy number.

RESULTS

Linear models adjusting for covariates showed that patients with SZ exhibited higher elevation of lactate than HCs during exercise but not at baseline or at rest. In accordance, patients showed higher number of CAMDs and lower mtDNA copy number. Interestingly, CAMDs correlated with both lactate levels and mtDNA copy number, which in turn correlated with the NLR. Finally, we identified 13 putative pathogenic variants in the mtDNA of 11 participants with SZ not present in HCs, together with a lactate elevation during exercise that was significantly higher in these 11 carriers than in the noncarriers.

CONCLUSIONS

These results are consistent with systemic mitochondrial malfunctioning in SZ and pinpoint lactate metabolism and mtDNA as targets for potential therapeutic treatments.

Melatonin Attenuates Anoxia/Reoxygenation Injury by Inhibiting Excessive Mitophagy Through the MT2/SIRT3/FoxO3a Signaling Pathway in H9c2 Cells

Purpose

Autophagy caused by ischemia/reperfusion (I/R) increases the extent of cardiomyocyte damage. Melatonin (Mel) diminishes cardiac injury through regulating autophagy and mitochondrial dynamics. However, illustrating the specific role of mitophagy in the cardioprotective effects of melatonin remains a challenge. The aim of our research was to investigate the impact and underlying mechanisms of melatonin in connection with mitophagy during anoxia/reoxygenation (A/R) injury in H9c2 cells.

Methods

H9c2 cells were pretreated with melatonin with or without the melatonin membrane receptor 2 (MT2) antagonist 4-P-PDOT, the MT2 agonist IIK7 and the sirtuin 3 (SIRT3) inhibitor 3-TYP for 4 hours and then subjected to A/R injury. Cell viability, cellular apoptosis, necrosis levels and oxidative markers were assessed. The expression of SIRT3 and forkhead box O3a (FoxO3a), mitochondrial function and the levels of mitophagy-related proteins were also evaluated.

Results

A/R injury provoked enhanced mitophagy in H9c2 myocytes. In addition, increased mitophagy was correlated with decreased cellular viability, increased oxidative stress and mitochondrial dysfunction in H9c2 cells. However, melatonin pretreatment notably increased cell survival and decreased cell apoptosis and oxidative response after A/R injury, accompanied by restored mitochondrial function. The inhibition of excessive mitophagy is involved in the cardioprotective effects of melatonin, as shown by the decreased expression of the mitophagy-related molecules Parkin, Beclin1, and BCL2-interacting protein 3-like (BNIP3L, best known as NIX) and decreased light chain 3 II/light chain 3 I (LC3 II/LC3 I) ratio and upregulation of p62 expression. Moreover, the decreased expression of SIRT3 and FoxO3a in A/R-injured H9c2 cells was abrogated by melatonin, but these beneficial effects were attenuated by the MT2 antagonist 4-P-PDOT or the SIRT3 inhibitor 3-TYP and enhanced by the MT2 agonist IIK7.

Conclusion

These results indicate that melatonin protects H9c2 cells during A/R injury through suppressing excessive mitophagy by activating the MT2/SIRT3/FoxO3a pathway. Melatonin may be a useful candidate for alleviating myocardial ischemia/reperfusion (MI/R) injury in the future, and the MT2 receptor might become a therapeutic target.

Penehyclidine hydrochloride protects against anoxia/reoxygenation injury in cardiomyocytes through ATP-sensitive potassium channels, and the Akt/GSK-3β and Akt/mTOR signaling pathways

Penehyclidine hydrochloride (PHC) can protect against myocardial ischemia/reperfusion (I/R) injury. However, the possible mechanisms of PHC in anoxia/reoxygenation (A/R)-induced injury in H9c2 cells remain unclear. In the present study, H9c2 cells were pretreated with PI3K/Akt inhibitor LY294002, ATP-sensitive K⁺ (KATP) channel blocker 5-hydroxydecanoate (5-HD), PHC, or KATP channel opener diazoxide (DZ) before subjecting to A/R injury. Cell viability and cell apoptosis were determined by cell counting kit-8 assay and annexin V/PI assay, respectively. Myocardial injury was evaluated by measuring creatine kinase (CK) and lactate dehydrogenase (LDH) activities. Intracellular Ca²⁺ levels, reactive oxygen species (ROS) generation, mitochondrial membrane potential (ΔΨ_m ), and mitochondrial permeability transition pore (mPTP) were measured. The levels of cytoplasmic/mitochondrial cytochrome c (Cyt-C), Bax, Bcl-2, cleaved caspase-3, KATP channel subunits (Kir6.2 and SUR2A), and the members of the Akt/GSK-3β and Akt/mTOR signaling pathways were determined by western blotting. We found that PHC preconditioning alleviated A/R-induced cell injury by increasing cell viability, reducing CK and LDH activities, and inhibiting cell apoptosis. In addition, PHC preconditioning ameliorated intracellular Ca²⁺ overload and ROS production, accompanied by inhibition of both mPTP opening and Cyt-C release into cytoplasm, and maintenance of ΔΨ_m . Moreover, PHC preconditioning activated mitochondrial KATP channels, and modulated the Akt/GSK-3β and Akt/mTOR signaling pathways. Similar effects were observed upon treatment with DZ. Pretreatment with LY294002 or 5-HD blocked the beneficial effects of PHC. These results suggest that the protective effects of PHC preconditioning on A/R injury may be related to mitochondrial KATP channels, as well as the Akt/GSK-3β and Akt/mTOR signaling pathways.

Postconditioning Protection Against Myocardiocyte Anoxia/Reoxygenation Injury From Penehyclidine Hydrochloride

BACKGROUND/AIMS

To investigate the postconditioning protective effect of penehyclidine hydrochloride (PHC) against anoxia/reoxygenation (A/R) injury in H9c2 cells along with the involved mechanism and timing effect.

METHODS

We divided H9c2 cells into 7 groups: control group, A/R group and PHC+A/R groups at 0 min, 5 mins, 10 mins, 20 mins, 30 mins, respectively (treated with 0.1 μm/L PHC at 0 min, 5 mins, 10 mins, 20 mins, 30 mins after the reoxygenation procedure began). Cell apoptosis, oxidative stress, intracellular Ca2+ concentration, mitochondrial membrane potential and mitochondrial permeability transition pore (MPTP) opening were explored. Bcl-2, Bax, Cyt C, caspase-3 and caspase-9 levels were measured.

RESULTS

A/R significantly increased both cell injury and cell apoptosis. PHC showed postconditioning protective effect by attenuating superoxide production, decreasing Ca2+ overload, restraining MPTP activities, restoring mitochondrial membrane potential, regulating cell apoptosis proteins and modulation of mitochondrial pathway. Earlier administration of PHC offered greater postconditioning protective effect.

CONCLUSION

H9c2 cells were protected by PHC from A/R injury regardless of timing of PHC administration (0 min, 5 mins, 10 mins, 20 mins, 30 mins). However, earlier administration of PHC resulted in better PHC postconditioning protection.

Regulation of TBBPA-induced oxidative stress on mitochondrial apoptosis in L02 cells through the Nrf2 signaling pathway

Tetrabromobisphenol A (TBBPA) is a commonly used brominated flame retardant, which has a wide range of toxic effects on organisms. This study investigated the cytotoxic effects on human hepatocytes (L02 cells) after treated with 0, 5, 10, 20, and 40 μM of TBBPA. Results showed that TBBPA significantly increased intracellular reactive oxygen species (ROS), malondialdehyde (MDA) and the ratio of oxidized/reduced glutathione (GSSG/GSH) dose-dependently. TBBPA also decreased the cell mitochondrial membrane potential (MMP), caused the release of cytochrome C (Cyt C) to cytoplasm and promoted the expression of caspase-9 and caspase-3, and finally increased the level of apoptosis. The ROS inhibitor N-acetyl-L-cysteine (NAC) relieved the oxidative stress responses, and prevented the decrease of MMP and increase of apoptosis. In addition, TBBPA promoted the expression of antioxidant genes related to Nrf2, such as quinone oxidoreductase 1 (NQO1), catalase (CAT), and heme oxygenase 1 (HO-1). Oxidative stress initiated by TBBPA, activated mitochondrial apoptosis and Nrf2 pathway, and increased the degree of apoptosis in L02 cells.

Penehyclidine hydrochloride exerts protective effects in rats with acute lung injury via the Fas/FasL signaling pathway

Acute lung injury (ALI) is a critical syndrome that is associated with high morbidity and mortality rates. The activation of the Fas/Fas ligand (FasL) signaling pathway may be an important pathophysiological mechanism during ALI development. Penehyclidine hydrochloride (PHC) has been revealed to exhibit anti-apoptotic properties and may attenuate the observed systemic inflammatory response. The present study was performed to elucidate the molecular mechanism of PHC in the regulation of the Fas/FasL signaling pathway in rats with ALI. An ALI rat model was constructed by inducing blunt chest trauma and hemorrhagic shock (T/HS), with PHC administration prior to or following T/HS. At 6 h following T/HS, blood samples and lung tissues were collected. Western blotting, arterial blood gas analysis, ELISA, hematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining and biochemical indicator analysis were performed to determine the degree of lung injury and the key signaling pathways associated with lung damage. The results indicated that the administration of PHC following T/HS effectively attenuates lung injury by improving pulmonary oxygenation, decreasing histopathological damage, decreasing polymorphonuclear neutrophil count and decreasing Fas, FasL, caspase-8, caspase-3, tumor necrosis factor-α, interleukin (IL)-6 and IL-1β expression. The results indicated that PHC exhibits anti-apoptotic functions and exerts protective effects in ALI rats induced by T/HS, which may be attributed to the inhibition of the Fas/FasL signaling pathway.

Penehyclidine effects the angiogenic potential of pulmonary microvascular endothelial cells

The present study sought to determine the pharmacological effects of penehyclidine, an anticholinergic agent, on the angiogenic capacity of pulmonary microvascular endothelial cells (PMVECs). In vitro Matrigel network formation assay, cell proliferation assay, cell-matrix adhesion assay, and wound-healing assay were performed in PMVECs with or without exposure to penehyclidine or, in some cases, glycopyrrolate or acetylcholine, over a concentration range. In addition, the phosphorylation state of Akt and ERK, as well as the endogenous level of mTOR and RICTOR were examined in PMVECs by Western blot following the cells exposure to penehyclidine or, for some proteins, glycopyrrolate or acetylcholine. Finally, Western blot for Akt phosphorylation and in vitro Matrigel network formation assay were performed in PMVECs following their exposure to penehyclidine with or without phosphoinositide 3-kinase (PI3K) inhibitor LY294002 or mTOR inhibitor torin-1. We found that, in PMVECs, penehyclidine affected the network formation and cell migration, but not proliferation or cell-matrix adhesion, in a concentration-specific manner, i.e., penehyclidine increased the network formation and cell migration at lower concentrations but increased these processes at higher concentrations. Coincidentally, we observed that penehyclidine concentration-specifically affected the phosphorylation state of Akt in PMVECs, i.e., increased Akt phosphorylation at lower concentrations and decreased it at higher concentrations. In contrast, glycopyrrolate was found straightly to decrease network formation and Akt phosphorylation in a concentration-dependent manner. Further, we demonstrated that PI3K or mTOR blockade abolished both the enhanced network formation and the increased Akt phosphorylation by penehyclidine. Hence, penehyclidine may differentially alter the angiogenic capacity of PMVECs through affecting the Akt signaling pathway downstream of PI3K and mTOR. Findings from this study suggest a unique pharmacological feature of penehyclidine, which may imply its clinical and therapeutic value in modulating angiogenesis.

Penehyclidine Hydrochloride Decreases Pulmonary Microvascular Endothelial Inflammatory Injury Through a Beta-Arrestin-1-Dependent Mechanism

Penehyclidine hydrochloride (PHC), a type of hyoscyamus drug, has both antimuscarinic and antinicotinic activities and retains potent central and peripheral anticholinergic activities. Compared with other hyoscyamine, the notable advantage of PHC is that it has few M₂ receptor-associated cardiovascular side effects. Recent studies and clinical trials have suggested that treatment with penehyclidine hydrochloride may also possess good effects in the treatment of lung injury. The mechanism responsible for this effect has yet to be determined; however, one possibility is that they might do so by a direct effect on pulmonary vascular endothelium. Since inflammatory reactions of the endothelium are signs of endothelial injury in the pathogenesis of lung injury, we determined the effects of penehyclidine hydrochloride on endothelial inflammatory injury in cultured human pulmonary microvascular endothelial cells (HPMVEC). Furthermore, human pulmonary microvascular endothelial cells were transfected with a shRNA-containing plasmid that specifically targets beta-arrestin-1 mRNA, to test whether the effect of penehyclidine hydrochloride on lipopolysaccharide (LPS)-induced endothelial cell injury is dependent on its upregulation of beta-arrestin-1 or not. Penehyclidine hydrochloride reduced the inflammatory responses to LPS stimulation, as evidenced by reduced lactate dehydrogenase (LDH), tumor necrosis factor-alpha (TNF-α), and interleukelin-6 (IL-6) levels, as well as vascular cell adhesion molecule 1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) expressions. This was found to result from increased beta-arrestin-1 expression and decreased nuclear transcription factor-κB (NF-κB) activation. Expression of a shRNA-containing plasmid that specifically targets beta-arrestin-1 mRNA nullified these effects of penehyclidine hydrochloride. The results indicate that penehyclidine hydrochloride exerts a protective effect on pulmonary microvascular endothelial inflammatory injury induced by LPS. We also demonstrate that this is due to its ability to increase beta-arrestin-1, which in turn inhibits NF-κB activation.

Silica nanoparticles induce cardiomyocyte apoptosis via the mitochondrial pathway in rats following intratracheal instillation

Diseases of the cardiac system caused by silicon dioxide exposure have captured wide public attention. Upon entering the blood circulation, ultrafine particles have the potential to influence cardiomyocytes, leading to myocardial ischemia or even cardiac failure, and the molecular mechanisms remain to be completely elucidated. In this study, the toxicity of ultrafine particles on cardiomyocytes from rats exposed to silica nanoparticles was observed. Rats were randomly divided into a normal saline control group and three exposure groups (2, 5 and 10 mg/kg·body weight) that were intratracheally treated with 60-nm silica nanoparticles. Alterations in body weight, routine blood factors and myocardial enzymes, histopathological and microstructural alterations, apoptosis and the expression of apoptosis-associated proteins were assessed at the end of the exposure period. The silicon levels in the heart and serum, and myocardial enzymes in exposed rats were significantly increased in a dose-dependent manner. In addition, exposure to the silica nanoparticles caused notable histological and ultrastructural alterations in the hearts of these animals. Furthermore, a significant apoptotic effect was observed in the exposure groups. The present data suggest that silica nanoparticles may enter the circulatory system through the lungs, and are distributed to the heart causing cardiovascular injury. Silica nanoparticle-induced apoptosis via the mitochondrial pathway may serve an important role in observed cardiac damage.

Analyses of changes in myocardial long non-coding RNA and mRNA profiles after severe hemorrhagic shock and resuscitation via RNA sequencing in a rat model

Background

Ischemia–reperfusion injury has been proven to induce organ dysfunction and death, although the mechanism is not fully understood. Long non-coding RNAs (lncRNAs) have drawn wide attention with their important roles in the gene expression of some biological processes and diseases, including myocardial ischemia–reperfusion (I/R) injury. In this paper, a total of 26 Sprague–Dawley (SD) rats were randomized into two groups: sham and ischemia–reperfusion (I/R) injury. Hemorrhagic shock was induced by removing 45% of the estimated total blood volume followed by reinfusion of shed blood. High-throughput RNA sequencing was used to analyze differentially expressed (DE) lncRNAs and messenger RNAs (mRNAs) in the heart tissue 4 h after reperfusion. Myocardial function was also evaluated.

Results

After resuscitation, the decline of myocardial function of shocked animals, expressed by cardiac output, ejection fraction, and myocardial performance index (MPI), was significant (p < 0.05). DE lncRNAs and mRNAs were identified by absolute value of fold change ≥ 2 and the false discovery rate ≤ 0.001. In rats from the I/R injury group, 851 lncRNAs and 1015 mRNAs were significantly up-regulated while 1533 lncRNAs and 1702 m RNAs were significantly down-regulated when compared to the sham group. Among the DE lncRNAs, we found 12 location-associated with some known apoptosis-related protein-coding genes which were up-regulated or down-regulated accordingly, including STAT3 and Il1r1. Real time PCR assays confirmed that the expression levels of five location-associated lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2, NONRATT006035.2 and NONRATT029969.2) and their location-associated mRNAs (STAT3 and Il1r1) in the rats from the I/R injury group were all significantly up-regulated versus the sham group.

Conclusions

The DE lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2 and NONRATT006035.2) could be compatible with their role in myocardial protection by stimulating their co-located gene (STAT3) after hemorrhagic shock and resuscitation. The final prognosis of I/R injury might be regulated by different genes, which is regarded as a complex network.

Electronic supplementary material

The online version of this article (10.1186/s12867-018-0113-8) contains supplementary material, which is available to authorized users.

Pleiotropic effects and pharmacological properties of penehyclidine hydrochloride

Background

Penehyclidine hydrochloride (PHC) is an anticholinergic drug manufactured in China. It is used widely in clinics as a reversal agent in cases of organic phosphorus poisoning and as a preanesthetic medication. Compared with other anticholinergic agents, PHC confers substantial advantages. Here, in this review, we focus on its important clinical effects for organic phosphorus poisoning, preanesthetic medication, and the protective effects on certain visceral organs.

Materials and methods

Our bibliographic sources include the PubMed and China National Knowledge Infrastructure (CNKI) databases, updated in March 2018. To assess the data in detail, we used the search terms “penehyclidine hydrochloride,” “preanesthetic medication,” and “organic phosphorus.” Papers were restricted to those published in the English and Chinese languages, and to “paper” and “review” as the document type.

Results

PHC can effectively antagonize the symptoms of central and peripheral poisoning caused by organophosphorus poisoning. As a preanesthetic medication, it can not only effectively reduce mucus secretion and vascular infiltration but can also relax airway smooth muscles, dilate bronchioles in pulmonary conditions such as bronchiectasis, and increase pulmonary dynamic compliance. It can also prevent reflexive actions of the vagus nerve caused by excessive acetylcholine release such as abnormal airway contraction. Furthermore, it can strengthen sedation, bidirectionally regulate heart rate, and effectively inhibit respiratory secretions. In recent studies, PHC was shown to also have protective effects on various organs, such as the heart, lungs, brain, kidneys, intestines, and liver.

Conclusion

PHC has beneficial pharmacological properties used in the treatment of organophosphorus poisoning and as a preanesthetic medication for its few side effects. It also has protective effects on multiple organs, suggesting that PHC has extensive clinical application value which is worth further research. This review should be of help to those intending to research these topics further.

Penehyclidine hydrochloride regulates mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provides cardioprotection in rats with myocardial ischemia-reperfusion injury

AIM

The potential mechanism of penehyclidine hydrochloride (PHC) against myocardial ischemia-reperfusion (I/R) injury has not been fully elucidated. The aim of the present study was to reveal whether mitochondrial dynamics, apoptosis, and MAPKs were involved in the cardioprotective effect of this drug on myocardial I/R injury.

METHODS

Ninety healthy adult male Wistar rats were separately pretreated with normal saline (0.9%); PHC; and signal pathway blockers of MAPKs, Drp1, and Bcl-2. Coronary artery ligation and subsequent reperfusion were performed to induce myocardial I/R injury. Echocardiography was performed. Myocardial enzymes and oxidative stress markers were detected. Myocardial cell apoptotic rates and infarct sizes were measured. Mitochondrial function was evaluated. Expression levels of MAPKs, mitochondria regulatory proteins (Drp1, Mfn1/2), and apoptosis-related proteins (Bcl-2, Bax) were determined.

RESULTS

PHC pretreatment improved myocardial abnormalities (dysfunction, injury, infarct size, and apoptotic rate), mitochondrial abnormalities (dysfunction and fission), and excessive oxidative stress and inhibited the activities of p38MAPK and JNK signal pathways in rats with myocardial I/R injury (P < 0.05). Additionally, p38MAPK and JNK blockers (SB239063 and SP600125, respectively) had an effect on rats same as that of PHC. Although Drp1 blocker (Mdivi-1) showed a similar cardioprotective effect (P < 0.05), it did not affect the expression of MAPKs and apoptosis-related proteins (P > 0.05). In addition, Bcl-2 blocker (ABT-737) caused a high expression of Drp1 and a low expression of Mfn1/2 (P < 0.05).

CONCLUSION

PHC regulated mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provided cardioprotection in rats with myocardial I/R injury.

Regulation of VDAC1 contributes to the cardioprotective effects of penehyclidine hydrochloride during myocardial ischemia/reperfusion

Penehyclidine hydrochloride (PHC) preconditioning can alleviate myocardial ischemia/reperfusion (I/R) injury and inhibits the upregulation of voltage-dependent anion channel 1 (VDAC1) during I/R. To validate that VDAC1 is a bona fide target of PHC for the protection against myocardial I/R injury, VDAC1 expression construct was delivered by lentiviruses into rat left ventricular myocardium before PHC preconditioning and myocardial I/R. Overexpression of VDAC1 exacerbated cardiac dysfunction and myocardial injury following I/R, and abolished the cardioprotective effect of PHC during I/R injury. Moreover, VDAC1 overexpression with myocardial I/R further increased cytochrome c release from mitochondria to cytoplasm, elevated the levels of cleaved caspase-3 and Bax, and decreased the level of Bcl-2 as compared with I/R alone, and PHC-mediated inhibition of mitochondria-dependent apoptosis during myocardial I/R was abolished by VDAC1 overexpression. In addition, VDAC1 was overexpressed in H9c2 cardiomyocytes undergoing anoxia/reoxygenation (A/R) with or without PHC pretreatment. The in vitro results showed that overexpression of VDAC1 further reduced mitochondrial membrane potential, increased mitochondrial membrane permeability and enhanced mitochondria-dependent apoptosis in H9c2 cells after A/R, and VDAC1 overexpression abrogated the protective effect of PHC on the mitochondrial function and integrity during A/R. In conclusion, exogenous overexpression of VDAC1 during myocardial I/R inhibits the cardioprotective effects of PHC. These effects may be associated with the suppression of VDAC1 expression.

Penehyclidine hydrochloride preconditioning provides cardiac protection in a rat model of myocardial ischemia/reperfusion injury via the mechanism of mitochondrial dynamics mechanism

To investigate that penehyclidine hydrochloride (PHC) plays a cardiac protection role in myocardial ischemia/reperfusion injury (IRI) through mitochondrial dynamics mechanism. Rat model of myocardial I/R injury was established by the ligation of left anterior descending coronary artery for 30min followed by 3h perfusion. Before I/R, the rats were pretreated with or without PHC. Cardiac function was measured by echocardiography. The activities/levels of myocardial enzymes, oxidants and antioxidant enzymes were detected. Evans blue/TTC double staining was performed to assess infarct size. Cell apoptosis was evaluated by TUNEL assay. Western blot and real time fluorescent quantitative PCR was performed to analyze the expression of Drp₁, Mfn₁, Mfn₂. Meanwhile, the rats were given a single injection of PHC before I/R. The effects of PHC on myocardial infarct and cardiac function were investigated after 7 days post-reperfusion. Our results showed that PHC pretreatment improved imbalance of mitochondrial dynamics induced by oxidative stressor in IRI. PHC preconditioning alleviated apoptotic rate of cell by improving the imbalance of mitochondrial dynamics in IRI. Meanwhile, we showed that PHC remarkably improved cardiac function, myocardial injury by decreasing infarct size and attenuated levels of myocardial enzyme. Additionally, PHC also exerted long-term cardiac protection in a rat model of I/R injury by decreasing infarct size and improving cardiac function. These results suggested that PHC could efficiently protect the rats against I/R-induced myocardial injury via the mechanism of mitochondrial dynamics.

Cardioprotective time-window of Penehyclidine hydrochloride postconditioning: A rat study

Pharmacological postconditioning offers a clinical perspective for all patients with ischemic heart disease. Penehyclidine hydrochloride (PHC) is a new type of anticholinergic drug. We previously reported that PHC preconditioning protects against I/R injury in rat hearts in vivo. Ischemic heart disease often occurs suddenly, so postconditioning is more significant than preconditioning. However, studies evaluating myocardial protective effects of PHC postconditioning are unavailable. We explored the effects and time-window of cardioprotection of PHC postconditioning in myocardial I/R injury. PHC was administered by intravenous at various times (t = -5, 0, 5, 10, 15, or 30min) after the onset of reperfusion in addition to I/R rat. We observed five different indicators including infarct size, inflammatory response, myocardial enzyme, oxidative stress, and Ca²⁺ overload to quantify the effect of cardioprotection. Evans blue and TTC staining were used to measure myocardial infarct size. The expression of NF-κ B and IκB-α was analyzed using Western blot. ELISA was conducted to detect inflammatory and anti-inflammatory mediators. The Ca²⁺ level was determined using assay kit. PHC postconditioning (from -5 to 10min after the onset of reperfusion) significantly reduced infarct size, downregulated NF-κ B expression, and decreased the release of inflammatory mediators, while significantly upregulating IκB-α expression and increasing the release of anti-inflammatory mediators. All PHC postconditioning groups significantly reduced Ca²⁺ level. PHC postconditioning is cardioprotective over a larger time-window (from -5 to 10min after the onset of reperfusion). The probable mechanism is inhibition of NF-кB regulated inflammatory response pathway.