Penehyclidine Hydrochloride Alleviates Lipopolysaccharide-Induced Acute Lung Injury by Ameliorating Apoptosis and Endoplasmic Reticulum Stress

Penehyclidine hydrochloride alleviates lung ischemia-reperfusion injury by inhibiting pyroptosis

OBJECTIVE

The aim of this research was to examine how penehyclidine hydrochloride (PHC) impacts the occurrence of pyroptosis in lung tissue cells within a rat model of lung ischemia-reperfusion injury.

METHODS

Twenty-four Sprague Dawley (SD) rats, weighing 250 g to 270 g, were randomly distributed into three distinct groups as outlined below: a sham operation group (S group), a control group (C group), and a test group (PHC group). Rats in the PHC group received a preliminary intravenous injection of PHC at a dose of 3 mg/kg. At the conclusion of the experiment, lung tissue and blood samples were collected and properly stored for subsequent analysis. The levels of malondialdehyde, superoxide dismutase, and myeloperoxidase in the lung tissue, as well as IL-18 and IL-1β in the blood serum, were assessed using an Elisa kit. Pyroptosis-related proteins, including Caspase1 p20, GSDMD-N, and NLRP3, were detected through the western blot method. Additionally, the dry-to-wet ratio (D/W) of the lung tissue and the findings from the blood gas analysis were also documented.

RESULTS

In contrast to the control group, the PHC group showed enhancements in oxygenation metrics, reductions in oxidative stress and inflammatory reactions, and a decrease in lung injury. Additionally, the PHC group exhibited lowered levels of pyroptosis-associated proteins, including the N-terminal segment of gasdermin D (GSDMD-N), caspase-1p20, and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3).

CONCLUSION

Pre-administration of PHC has the potential to mitigate lung ischemia-reperfusion injuries by suppressing the pyroptosis of lung tissue cells, diminishing inflammatory reactions, and enhancing lung function. The primary mechanism behind anti-pyroptotic effect of PHC appears to involve the inhibition of oxidative stress.

Sivelestat sodium alleviated lipopolysaccharide-induced acute lung injury by improving endoplasmic reticulum stress

Acute lung injury (ALI) is a common inflammatory respiratory disorder characterized by a high incidence and mortality rate. This study aimed to investigate the potential therapeutic effects of the neutrophil elastase inhibitor Sivelestat sodium (SIV) in improving endoplasmic reticulum stress (ERS) while treating lipopolysaccharide (LPS)-induced ALI. An ALI model was established using LPS induction. The effects of SIV on ALI were observed both in vivo and in vitro, along with its impact on ERS. Lung tissue damage was assessed using Hematoxylin-eosin (H&E) staining. Lung edema was measured by the lung wet/dry weight ratio. The expression levels of protein kinase R-like ER kinase (PERK), Phospho-protein kinase R-like ER kinase (p-PERK), activating transcription factor 4 (ATF4), eukaryotic translation initiation factor 2α (EIF2a), phosphorylated α subunit of eukaryotic initiation factor 2α (P-EIF2a), and C/EBP homologous protein (CHOP) were analyzed by Western blotting in vivo and in vitro. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in Lung tissue samples supernatants were measured by ELISA. Oxidative stress markers were measured by ELISA. Apoptosis was measured using the TUNEL assay. Apoptosis-associated proteins B-cell lymphoma-2 (Bcl-2)、Bcl2-associated × (Bax)、caspase-3 were evaluated through Western blotting in vivo and in vitro. The expression levels of ERS-related proteins, including p-PERK, ATF4, P-EIF2a, and CHOP, were significantly increased in the LPS-induced ALI model. However, SIV markedly reduced the expression levels of these proteins, suppressing the LPS-induced ERS response. Further investigations revealed that SIV exerted a protective effect on ALI by alleviating lung tissue damage and apoptosis, improving lung function, and reducing inflammation and oxidative stress levels. However, when SIV was co-administered with Tunicamycin (TUN), TUN blocked the beneficial effects of SIV on ERS and reversed the protective effects of SIV on ALI. In conclusion, SIV alleviated lung tissue damage and apoptosis, improving lung function, and reducing inflammation and oxidative stress in LPS-induced ALI by improving ERS.

Artesunate reduces sepsis-mediated acute lung injury in a SIRT1-dependent manner

Introduction

Sepsis-mediated acute lung injury (ALI) is a critical clinical condition. Artesunate (AS) is a sesquiterpene lactone endoperoxide that was discovered in Artemisia annua, which is a traditional Chinese herb. AS has a broad set of biological and pharmacological actions; however, its protective effect on lipopolysaccharide (LPS)-induced ALI remains unclear.

Methods

LPS-mediated ALI was induced in rats through bronchial LPS inhalation. Then NR8383 cells were treated with LPS to establish an in vitro model. Further, we administered different AS doses in vivo and in vitro.

Results

AS administration significantly decreased LPS-mediated pulmonary cell death and inhibited pulmonary neutrophil infiltration. Additionally, AS administration increased SIRT1 expression in pulmonary sections. Administration of a biological antagonist or shRNA-induced reduction of SIRT1 expression significantly inhibited the protective effect of AS against LPS-induced cellular injury, pulmonary dysfunction, neutrophil infiltration, and apoptosis. This demonstrates that enhanced SIRT1 expression is crucially involved in the observed protective effects.

Conclusion

Our findings could suggest the use of AS for treating lung disorders through a mechanism involving SIRT1 expression.

Penehyclidine hydrochloride protects against lipopolysaccharide-induced acute lung injury by promoting the PI3K/Akt pathway

INTRODUCTION

Acute lung injury (ALI) attracted attention among physicians because of its high mortality. We aimed to determine whether the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt) pathway is involved in the protective effects of penehyclidine hydrochloride (PHC) against lipopolysaccharide (LPS)-induced ALI.

METHODS

H&E staining was used to observed pathological changes in the lung tissues. ELISA was used to evaluate the concentration of inflammatory mediators in the bronchoalveolar lavage fluid (BALF). White-light microscopy was performed to observe the TUNEL-positive nuclei. The viability of NR8383 alveolar macrophages was determined by using CCK-8. The levels of MPO, MDA, SOD, and GSH-Px were analyzed using ELISA kits. Western blotting was used to evaluate the ERS-associated protein levels and the phosphorylation of PI3K and Akt.

RESULTS

PHC administration defended against LPS-induced histopathological deterioration and increased pulmonary edema and lung injury scores, while all of these beneficial effects were inhibited by LY. In addition, PHC administration mitigated oxidative stress as indicated by decreases in lung myeloperoxidase (MPO) and malondialdehyde (MDA) concentrations, and increases in glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) concentrations. It also alleviated LPS-induced inflammation. PHC administration attenuated apoptosis-associated protein levels, improved cell viability, and decreased the number of TdT-mediated dUTP Nick-End Labeling (TUNEL)-positive cells. Furthermore, PHC inhibited ERS-associated protein levels. Meanwhile, the protection of PHC against inflammation, oxidative stress, apoptosis, and ERS was inhibited by LY. Moreover, PHC administration increased PI3K and Akt phosphorylation, indicating that the upregulation of the PI3K/Akt pathway, while this pathway was inhibited by LY.

CONCLUSION

PHC significantly activates the PI3K/Akt pathway to ameliorate the extent of damage to pulmonary tissue, inflammation, oxidative stress, apoptosis, and ERS in LPS-induced ALI.

ER Stress in Cardiometabolic Diseases: From Molecular Mechanisms to Therapeutics

The endoplasmic reticulum (ER) hosts linear polypeptides and fosters natural folding of proteins through ER-residing chaperones and enzymes. Failure of the ER to align and compose proper protein architecture leads to accumulation of misfolded/unfolded proteins in the ER lumen, which disturbs ER homeostasis to provoke ER stress. Presence of ER stress initiates the cytoprotective unfolded protein response (UPR) to restore ER homeostasis or instigates a rather maladaptive UPR to promote cell death. Although a wide array of cellular processes such as persistent autophagy, dysregulated mitophagy, and secretion of proinflammatory cytokines may contribute to the onset and progression of cardiometabolic diseases, it is well perceived that ER stress also evokes the onset and development of cardiometabolic diseases, particularly cardiovascular diseases (CVDs), diabetes mellitus, obesity, and chronic kidney disease (CKD). Meanwhile, these pathological conditions further aggravate ER stress, creating a rather vicious cycle. Here in this review, we aimed at summarizing and updating the available information on ER stress in CVDs, diabetes mellitus, obesity, and CKD, hoping to offer novel insights for the management of these cardiometabolic comorbidities through regulation of ER stress.

The Protective Activity of Penehyclidine Hydrochloride against Renal Ischemia/Reperfusion-Mediated NLRP3 Inflammasome Activation is Induced by SIRT1

Background: The activation of alveolar macrophages (AMs) modulated via leucine-rich repeat (NLR) pyrin domain containing 3 (NLRP3) inflammasome activation is key to the progression of renal ischemia/reperfusion (rI/R)-mediated acute lung injury (ALI). Sirtuin-1 (SIRT1) can attenuate NLRP3 inflammasome activation during I/R stress and may be an important mechanism underlying ALI pathogenesis. Penehyclidine hydrochloride (PHC), an anticholinergic drug, exerts protective effects against rI/R-mediated ALI. This study aimed to decipher the effects of PHC on SIRT1 activation and the underlying mechanism of the protective activity of PHC against rI/R-mediated ALI.Materials and methods: We used an ALI rat model and the rat AMs cell line NR8383 to assess the degree of lung injury in vivo and in vitro.Results: The results show that PHC attenuates rI/R-mediated lung injury indices, myeloperoxidase, and apoptosis in vivo. It decreases the rI/R-mediated release of prostaglandin E2 and nitric oxide, mitochondrial reactive oxygen species production, and the activity of NADPH oxidase-4 in vitro. PHC ameliorates the rI/R-induced activation of the thioredoxin-interacting protein, caspase 1 (P10 unit), and NLRP3 inflammasome, along with reduced activation of interleukin-1β and interleukin-18 in vitro. We show that PHC alleviates the rI/R-induced reduction of SIRT1 and the depletion of SIRT1 eliminates the ameliorating activity of PHC on the NLRP3 inflammasome activation in vitro. Conclusions: In summary, the findings suggest that PHC ameliorates the rI/R-mediated ALI through the SIRT1-mediated NLRP3 inflammasome activation.

Glycoproteins From Rabdosia japonica var. glaucocalyx Regulate Macrophage Polarization and Alleviate Lipopolysaccharide-Induced Acute Lung Injury in Mice via TLR4/NF-κB Pathway

Background and Aims:Rabdosia japonica var. glaucocalyx is a traditional Chinese medicine (TCM) for various inflammatory diseases. This present work aimed to investigate the protective effects of R. japonica var. glaucocalyx glycoproteins on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the potential mechanism.

Methods: Glycoproteins (XPS) were isolated from R. japonica var. glaucocalyx, and homogeneous glycoprotein (XPS5-1) was purified from XPS. ANA-1 cells were used to observe the effect of glycoproteins on the secretion of inflammatory mediators by enzyme-linked immunosorbent assay (ELISA). Flow cytometry assay, immunofluorescence assay, and Western blot analysis were performed to detect macrophage polarization in vitro. The ALI model was induced by LPS via intratracheal instillation, and XPS (20, 40, and 80 mg/kg) was administered intragastrically 2 h later. The mechanisms of XPS against ALI were investigated by Western blot, ELISA, and immunohistochemistry.

Results:In vitro, XPS and XPS5-1 downregulated LPS-induced proinflammatory mediators production including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and nitric oxide (NO) and upregulated LPS-induced IL-10 secretion. The LPS-stimulated macrophage polarization was also modulated from M1 to M2. In vivo, XPS maintained pulmonary histology with significantly reducing protein concentration and numbers of mononuclear cells in bronchoalveolar lavage fluid (BALF). The level of IL-10 in BALF was upregulated by XPS treatment. The level of cytokines including TNF-α, IL-1β, and IL-6 was downregulated. XPS also decreased infiltration of macrophages and polymorphonuclear leukocytes (PMNs) in lung. XPS suppressed the expression of key proteins in the TLR4/NF-κB signal pathway.

Conclusion: XPS was demonstrated to be a potential agent for treating ALI. Our findings might provide evidence supporting the traditional application of R. japonica var. glaucocalyx in inflammation-linked diseases.

The Mechanism of Penehyclidine Hydrochloride and Its Effect on the Inflammatory Response of Lung Tissue in Rats with Chronic Obstructive Pulmonary Disease During Mechanical Ventilation

Background

Penehyclidine hydrochloride is a selective antagonist of M1 and M3 receptors. Clinical studies suggest that it is a potential drug for the treatment of chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate the effect of penehyclidine hydrochloride on the inflammatory response of lung tissue during mechanical ventilation in rats with COPD and explore the role of the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) signaling pathway.

Methods

Eight-week-old male Sprague Dawley rats were exposed to cigarette smoke for 30 minutes every day for two months, and on the first and thirtieth days, 200 ug of lipopolysaccharide was injected into the trachea. Two months later, the rats were randomly divided into the control group (C), model group (M), model + normal saline group (N), and penehyclidine hydrochloride group (H) to undergo anesthesia and mechanical ventilation. In group H, 1 mg/kg of penehyclidine hydrochloride was injected intravenously.

Results

The results showed that: ① Compared with group C, the other groups all showed typical chronic obstructive pathological changes in the lung tissue; their wet/dry weight ratio (W/D), TNF-α, JNK, and p-JNK levels increased (P < 0.05), and their interleukin (IL)-10 levels decreased (P < 0.05). ② Compared with group M, there was no significant change in the lung tissue indexes in group N (P > 0.05). ③ Compared with group N, the W/D, TNF-α, JNK, and p-JNK levels in group H decreased (P < 0.05), while the levels of IL-10 increased (P < 0.05).

Conclusion

Penehyclidine hydrochloride can alleviate the pulmonary inflammatory response in rats with COPD undergoing mechanical ventilation. The JNK/SAPK signaling pathway may be involved in this process.

Chrysin prevents lipopolysaccharide-induced acute lung injury in mice by suppressing the IRE1α/TXNIP/NLRP3 pathway

Acute lung injury (ALI) remains a serious challenge in the intensive care unit. Inflammation plays a key role in the progression of ALI. Chrysin (CHR) is a natural flavonoid with anti-inflammatory functions. We investigated the anti-inflammatory effects in a mouse model of ALI induced by lipopolysaccharide (LPS), and identified the underlying mechanisms of its action. Following CHR administration, mice were challenged with LPS intratracheally for 6 h to induce ALI. Compared to mice challenged with LPS alone, the presence of CHR showed a reduction in the development of lung injuries, as confirmed by histopathological observation. Pre-treatment with CHR attenuated inflammation by reducing the production of myeloperosidase (MPO), and pro-inflammatory cytokine levels in the lung and bronchoalveolar lavage fluid (BALF). Furthermore, CHR improved lung edema by reducing the vascular permeability, as demonstrated by less evans blue staining in the lung tissue and low levels of protein in BALF. In addition, our results proved that CHR improved the antioxidant capacity by increasing the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the lung tissue. Results of western blot assays suggested that CHR suppressed the LPS-induced expression of glucose-regulated protein 78 (GRP78) and phosphorylated inositol-requiring enzyme 1α (p-IRE1α). We also found that CHR suppressed the expression of thioredoxin interaction protein (TXNIP), nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and cleaved caspase-1. In conclusion, CHR improved vascular permeability and mitigated the inflammatory response of lung tissue by suppressing the IRE1α/TXNIP/NLRP3 pathway, thereby alleviating LPS-induced ALI in the lungs of mice.

Penehyclidine hydrochloride inhibits renal ischemia/reperfusion-induced acute lung injury by activating the Nrf2 pathway

The nuclear factor (NF)-κB and NOD-like receptor protein 3 (NLRP3) pathways promote inflammatory signaling that injures the kidneys, whereas the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway promotes anti-inflammatory signaling that inhibits oxidative damage. Penehyclidine hydrochloride (PHC) inhibits NF-κB and activates Nrf2 signaling. We investigated whether PHC induces communication between the Nrf2 and NF-κB/NLRP3 pathways, thereby protecting against renal ischemia/reperfusion (rI/R)-induced lung inflammation. Rat alveolar macrophages (NR8383 cells) were stimulated for 24 h with PHC with or without brusatol (a Nrf2 antagonist), after which they were treated for 4 h with tert-butyl hydroperoxide (10 mM). PHC Nrf2-dependently alleviated tert-butyl hydroperoxide-induced reactive oxygen species production in alveolar macrophages. Additionally, wild-type and Nrf2^-/- rats were each divided into four groups: (1) sham, (2) PHC (1 mg/kg), (3) rI/R and (4) rI/R + PHC (1 mg/kg). PHC markedly induced the Nrf2 and adenosine monophosphate-activated protein kinase pathways and suppressed rI/R-induced NF-κB and NLRP3 activation in the lungs. Nrf2 deficiency diminished the ability of PHC to ameliorate rI/R-induced histopathological alterations and reactive oxygen species release in the lungs; however, PHC inhibited NLRP3 signaling Nrf2-dependently, while it inhibited NF-κB signaling Nrf2-independently. Our findings demonstrate the beneficial effects of PHC on rI/R-induced lung inflammation.

Penehyclidine hydrochloride defends against LPS-induced ALI in rats by mitigating endoplasmic reticulum stress and promoting the Hes1/Notch1 pathway

Penehyclidine hydrochloride (PHC) is a novel anticholinergic drug applied broadly in surgeries as a preanesthetic medication. A substantial amount of research indicates that PHC has lung defensive properties. Considering that endoplasmic reticulum (ER) stress exerts a crucial function in cell apoptosis associated with the lipopolysaccharides (LPS)-induced acute lung injury (ALI) model, we aimed to determine whether regulation of ER stress in the LPS-induced ALI model was associated with the lung defensive role of PHC. Adult male SD rats were administered LPS (5 mg/kg, intratracheally) followed by PHC (1.0 mg/kg, intravenously) for 24 h. The NR8383 alveolar macrophages were randomly separated into Sham, LPS (100 ng/mL), and PHC (1, 2.5, or 5 μg/mL) + LPS groups. PHC (1, 2.5, or 5 μg/mL) + LPS groups were treated with PHC alone for 1 h after LPS exposure. Posttreatment with PHC relieved LPS-induced pulmonary impairment and blocked LPS-mediated lung apoptosis, indicated by the downregulation of the lung apoptotic indicators malondialdehyde and superoxide dismutase in serum at 24 h after LPS-induced ALI. PHC (1-5 μg/mL) did not influence the activity of cultivated NR8383 alveolar macrophages in vitro. However, postconditioning with PHC dosage-dependently reduced LPS-mediated cell apoptosis. Additionally, many studies have indicated that PHC administration inhibits ER stress and initiates hairy and enhancer of split 1 (Hes1)/(Notch1) signaling by decreasing phosphorylated α subunit of eukaryotic initiation factor 2α (p-eIF2α)/eukaryotic translation initiation factor 2α (eIF2α) and Phospho-protein kinase R-like ER kinase (p-PERK)/ protein kinase R-like ER kinase (PERK) proportions; inhibiting C/EBP-homologous protein (CHOP), activating transcription factor 4 (ATF4), caspase-3, and Bcl2-associated x (Bax) activity; and enhancing notch1 intracellular domain (NICD), Notch1, B-cell lymphoma-2 (Bcl-2), and Hes1 activity in vivo and in vitro. In addition, the defensive functions of PHC on LPS-activated NR8383 alveolar macrophages were abrogated through the Notch1 pathway antagonist [(3,5-difluorophenacetyl)-1-alanyl] -phenylglycine-butyl ester (DAPT). In conclusion, PHC alleviates LPS-induced ALI by ameliorating ER stress-mediated apoptosis and promoting Hes1/Notch1 signaling in vivo and in vitro.