Inflammasome activation mediated by oxidised low-density lipoprotein in patients with sleep apnoea and early subclinical atherosclerosis

Exosomes from IH- Induced bEnd3 Cells Promote OSA Cognitive Impairment via miR-20a-5p/MFN2 Mediated Pyroptosis of HT22 Cells

Background

OSA can cause cognitive impairment (CI). The aim of this study was to investigate whether miR-20a-5p in exosomes derived from bEnd3 cells with IH mediates intercellular crosstalk and induces CI through hippocampal neuronal cell pyroptosis.

Materials and Methods

BEnd3-derived exosomes were isolated from the normal oxygen control group (NC-EXOS) and IH group (IH-EXOS). In vitro, exosomes were cocultured with HT22 cells. Meanwhile, in vivo, exosomes were injected into mice via the caudal vein. The spatial memory ability of mice was tested by MWM method to evaluate the effect of exosomes on the cognitive function of mice. Adults diagnosed with OSA underwent the MoCA and ESS tests to assess cognitive function and daytime sleepiness. Spearman's rank correlation analysis was used to evaluate the correlation between miR-20a-5p and candidate proteins and clinical parameters. Transfection using small interfering RNAs, miRNA mimics, and plasmids to evaluate the role of miR-20a-5p and its target genes. Dual luciferase reporter gene assay was used to confirm the binding of miR-20a-5p to its target gene.

Results

IH could cause pyroptosis and inflammation in bEnd3 cells, and promote the expression of miR-20a-5p. Isolated IH-EXOS induced increased pyroptosis and activation of inflammatory response in vitro and in vivo, accompanied by increased expression of miR-20a-5p. In addition, IH-EXOS led to decreased learning and memory ability in mice. Interestingly, AHI was higher and MoCA scores were lower in severe OSA compared to healthy comparisons. In addition, miR-20a-5p and GSDMD were positively correlated with AHI but negatively correlated with MoCA in severe OSA. IH-induced exosomes were rich in miR-20a-5p, and these exosomes were found to deliver miR-20a-5p to HT22 cells, playing a key role in the induction of OSA-CI by directly targeting MFN2.

Conclusion

Exosome miR-20a-5p from IH-stimulated bEnd3 cells can promote OSA-CI by increasing HT22 cells pyroptosis through its target MFN2.

Mechanism of Valeriana officinalis L. extract improving atherosclerosis by regulating PGC-1α/Sirt3/Epac1 pathway

Objective

To investigate the protective effect of the of Valeriana officinalis L. extract on mitochondrial injury in AS mice and the underlying mechanism.

Methods

Firstly, Ultra-High performance liquid chromatography-quadrupole time-of-flight mass spectrometer (UPLC / Q-TOF-MS) was proposed to explore the chemical composition of Valeriana officinalis L. extract. ApoE-/- mice were employed for in vivo experiments. The efficacy of Valeriana officinalis L. extract was detected by B-ultrasound, Biochemical, Oil Red O staining, HE staining and Masson staining analysis. The molecular mechanism of Valeriana officinalis L. extract in regulating mitochondrial energy metabolism for the treatment of atherosclerosis was elucidated after Monitoring System of Vascular Microcirculation in Vivo and transmission electron microscopy. Use the corresponding reagent kit to detect ACTH level, CHRNα1 level and ATP level, and measure the expression levels of PGC-1α, Sirt3, Epac1, Caspase-3, and Caspase-9 through real-time qPCR, and Western blot.

Results

A total of 29 metabolites were newly discovered from KYXC using UPLC-MS. The drug had a significant positive effect on the growth of atherosclerotic plaque in mice. It also improved the microcirculation of the heart and mesentery, reduced the levels of CHOL, TG, and VLDL in the serum, and increased the levels of HDL-C to maintain normal lipid metabolism in the body. Additionally, it increased the levels of ATP, improved the ultrastructure of mitochondria to maintain mitochondrial energy metabolism, and increased the levels of T-SOD to combat oxidative stress of the organism. Furthermore, the drug significantly increased the mRNA and protein expression of PGC-1α and Sirt3 in aortic tissue, while decreasing the mRNA and protein expression of Epac1, Caspase-3, and Caspase-9.

Conclusion

This study has verified that the extract of Valeriana officinalis L. is highly effective in enhancing atherosclerosis disease. The mechanism is suggested through the PGC-1α/Sirt3/Epac1 signaling pathway, which improves mitochondrial energy metabolism.

Unraveling the complex interplay between Mitochondria-Associated Membranes (MAMs) and cardiovascular Inflammation: Molecular mechanisms and therapeutic implications

Cardiovascular diseases (CVDs) represent a significant public health concern because of their associations with inflammation, oxidative stress, and abnormal remodeling of the heart and blood vessels. In this review, we discuss the intricate interplay between mitochondria-associated membranes (MAMs) and cardiovascular inflammation, highlighting their role in key cellular processes such as calcium homeostasis, lipid metabolism, oxidative stress management, and ERS. We explored how these functions impact the pathogenesis and progression of various CVDs, including myocardial ischemia-reperfusion injury, atherosclerosis, diabetic cardiomyopathy, cardiovascular aging, heart failure, and pulmonary hypertension. Additionally, we examined current therapeutic strategies targeting MAM-related pathways and proteins, emphasizing the potential of MAMs as therapeutic targets. Our review aims to provide new insights into the mechanisms of cardiovascular inflammation and propose novel therapeutic approaches to improve cardiovascular health outcomes.

Pyroptosis: An Accomplice in the Induction of Multisystem Complications Triggered by Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common respiratory disorder, primarily characterized by two pathological features: chronic intermittent hypoxia (CIH) and sleep deprivation (SD). OSA has been identified as a risk factor for numerous diseases, and the inflammatory response related to programmed cell necrosis is believed to play a significant role in the occurrence and progression of multisystem damage induced by OSA, with increasing attention being paid to pyroptosis. Recent studies have indicated that OSA can elevate oxidative stress levels in the body, activating the process of pyroptosis within different tissues, ultimately accelerating organ dysfunction. However, the molecular mechanisms of pyroptosis in the multisystem damage induced by OSA remain unclear. Therefore, this review focuses on four major systems that have received concentrated attention in existing research in order to explore the role of pyroptosis in promoting renal diseases, cardiovascular diseases, neurocognitive diseases, and skin diseases in OSA patients. Furthermore, we provide a comprehensive overview of methods for inhibiting pyroptosis at different molecular levels, with the goal of identifying viable targets and therapeutic strategies for addressing OSA-related complications.

Guizhitongluo Tablet inhibits atherosclerosis and foam cell formation through regulating Piezo1/NLRP3 mediated macrophage pyroptosis

BACKGROUND

Atherosclerosis (AS) is the main pathological basis for the development of cardiovascular diseases. Vascular inflammation is an important factor in the formation of AS, and macrophage pyroptosis plays a key role in AS due to its unique inflammatory response. Guizhitongluo Tablet (GZTLT) has shown clinically effective in treating patients with AS, but its mechanism is elusive.

PURPOSE

This study was to determine the effects of GZTLT on atherosclerotic vascular inflammation and pyroptosis and to understand its underlying mechanism.

MATERIALS AND METHODS

The active constituents of GZTLT were analysed by means of UPLC-HRMS. In vivo experiments were performed using ApoE-/- mice fed a high fat diet for 8 weeks, followed by treatment with varying concentrations of GZTLT orally by gavage and GsMTx4 (GS) intraperitoneally and followed for another 8 weeks. Oil red O, Haematoxylin-eosin (HE) and Masson staining were employed to examine the lipid content, plaque size, and collagen fibre content of the mouse aorta. Immunofluorescence staining was utilised to identify macrophage infiltration, as well as the expression of Piezo1 and NLRP3 proteins in aortic plaques. The levels of aortic inflammatory factors were determined using RT-PCR and ELISA. In vitro, foam cell formation in bone marrow-derived macrophages (BMDMs) was observed using Oil Red O staining. Intracellular Ca2+ measurements were performed to detect the calcium influx in BMDMs, and the expression of NLRP3 and its related proteins were detected by Western blot.

RESULTS

The UPLC-HRMS analysis revealed 31 major components of GZTLT. Our data showed that GZTLT inhibited aortic plaque formation in mice and increased plaque collagen fibre content to stabilise plaques. In addition, GZTLT could restrain the expression of serum lipid levels and suppress macrophage foam cell formation. Further studies found that GZTLT inhibited macrophage infiltration in aortic plaques and suppressed the expression of inflammatory factors. It is noteworthy that GZTLT can restrain Piezo1 expression and reduce Ca2+ influx in BMDMs. Additionally, we found that GZTLT could regulate NLRP3 activation and pyroptosis by inhibiting Piezo1.

CONCLUSION

The present study suggests that GZTLT inhibits vascular inflammation and macrophage pyroptosis through the Piezo1/NLRP3 signaling pathway, thereby delaying AS development. Our finding provides a potential target for AS treatment and drug discovery.

Association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and obstructive sleep apnea: a cross-sectional study from NHANES

BACKGROUND

Obstructive Sleep Apnea (OSA) is a widespread sleep disturbance linked to metabolic and cardiovascular conditions. The Non-High-Density Lipoprotein Cholesterol to High-Density Lipoprotein Cholesterol Ratios (NHHR) has been proposed as being a potential biomarker to gauge cardiovascular risk. However, its relationship with OSA remains unclear.

METHODS

This survey investigated the link NHHR to OSA in American citizens aged 20 and older using information collected via the National Health and Nutrition Examination Survey (NHANES) during the years 2017 to 2020. Logistic regression models with multivariable adjustments were employed to assess this relationship. Nonlinear associations were explored using smooth curve fitting, with a two-part linear regression model identifying a threshold effect. Subgroup analyses were conducted to evaluate population-specific differences.

RESULTS

The survey encompassed 6763 participants, with an average age of 50.75 ± 17.32. The average NHHR stood at 2.74, accompanied by a standard deviation of 1.34, while the average frequency of OSA was 49.93%. Upon adjusting for covariates, each unit increase in NHHR may be associated with a 9% rise in OSA incidence. (95% confidence intervals 1.04-1.14; P < 0.0001). Notably, a U-shaped curve depicted the NHHR-OSA relationship, with an inflection point at 4.12. Subgroup analyses revealed consistent associations, with educational attainment and diabetes status modifying the NHHR-OSA relationship.

CONCLUSION

The study highlights NHHR as a potential tool for OSA prediction, presenting avenues for advanced risk evaluation, tailored interventions, personalized treatment approaches, and preventive healthcare.

Obstructive sleep apnea hypopnea syndrome and vascular lesions: An update on what we currently know

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is the most prevalent sleep and respiratory disorder. This syndrome can induce severe cardiovascular and cerebrovascular complications, and intermittent hypoxia is a pivotal contributor to this damage. Vascular pathology is closely associated with the impairment of target organs, marking a focal point in current research. Vascular lesions are the fundamental pathophysiological basis of multiorgan ailments and indicate a shared pathogenic mechanism among common cardiovascular and cerebrovascular conditions, suggesting their importance as a public health concern. Increasing evidence shows a strong correlation between OSAHS and vascular lesions. Previous studies predominantly focused on the pathophysiological alterations in OSAHS itself, such as intermittent hypoxia and fragmented sleep, leading to vascular disruptions. This review aims to delve deeper into the vascular lesions affected by OSAHS by examining the microscopic pathophysiological mechanisms involved. Emphasis has been placed on examining how OSAHS induces vascular lesions through disruptions in the endothelial barrier, metabolic dysregulation, cellular phenotype alterations, neuroendocrine irregularities, programmed cell death, vascular inflammation, oxidative stress and epigenetic modifications. This review examines the epidemiology and associated risk factors for OSAHS and vascular diseases and subsequently describes the existing evidence on vascular lesions induced by OSAHS in the cardiovascular, cerebrovascular, retinal, renal and reproductive systems. A detailed account of the current research on the pathophysiological mechanisms mediating vascular lesions caused by OSAHS is provided, culminating in a discussion of research advancements in therapeutic modalities to mitigate OSAHS-related vascular lesions and the implications of these treatment strategies.

Exogenous NADPH could mitigate pyroptosis-induced brain injury in fetal mice exposed to gestational intermittent hypoxia

OBJECTIVE

Obstructive Sleep Apnea (OSA) during pregnancy is characterized by intermittent hypoxia (IH) during sleep and will lead to the rise of oxidative stress in the fetal body. Pyroptosis, a type of inflammatory and programmable cell death mediated by Gasdermin D (GSDMD), plays a substantial role in oxygen deprivation's contribution to neural system damage. Existing research shows that Nicotinamide Adenine Dinucleotide Phosphate (NADPH) plays a protective role in alleviating brain tissue pyroptosis. We speculate that exogenous NADPH may play a protective role in OSA during pregnancy.

METHODS

A model of GIH group was established to simulate the pathophysiological mechanisms of OSA during pregnant and AIR group was established by giving the same frequency. Sham group was established by injecting NS and the NADPH group was established and given exogenous NADPH. We utilized the Morris Water Maze to assess cognitive function impairment, Luxol Fast Blue (LBF) staining to confirm myelin sheath formation, TUNEL staining to examine cell death in fetal mice brain tissue, and Western blotting to detect pertinent protein expressions.

RESULTS

The GIH group offspring exhibited decreases in spatial learning and memory abilities, reduced numbers of oligodendrocytes and formed myelin, as well as increased expression of pyroptosis-related proteins. The NADPH group offspring showed restoration in spatial learning and memory abilities increased counts of oligodendrocytes and formed myelin sheaths, in addition to decreased expression of pyroptosis-related.

CONCLUSIONS

This study demonstrates that early injection of exogenous NADPH can alleviate the damage to fetal brain development caused by gestational intermittent hypoxia (GIH).

An ethanolic extract of Arctium lappa L. leaves ameliorates experimental atherosclerosis by modulating lipid metabolism and inflammatory responses through PI3K/Akt and NF-κB singnaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Atherosclerosis (AS), a lipid-induced inflammatory condition of the arteries, is a primary contributor to atherosclerotic cardiovascular diseases including stroke. Arctium lappa L. leaf (ALL), an edible and medicinal herb in China, has been documented and commonly used for treating stroke since the ancient times. However, the elucidations on its anti-AS effects and molecular mechanism remain insufficient.

AIM OF THE STUDY

To investigate the AS-ameliorating effects and the underlying mechanism of action of an ethanolic extract of leaves of Arctium lappa L. (ALLE).

MATERIALS AND METHODS

ALLE was reflux extracted using with 70% ethanol. An HPLC method was established to monitor the quality of ALLE. High fat diet (HFD) and vitamin D3-induced experimental AS in rats were used to determine the in vivo effects; and oxidized low-density lipoprotein-induced RAW264.7 macrophage foam cells were used for in vitro assays. Simvatatin was used as positive control. Biochemical assays were implemented to ascertain the secretions of lipids and pro-inflammatory mediators. Haematoxylin-eosin (H&E) and Oil red O stains were employed to assess histopathological alterations and lipid accumulation conditions, respectively. CCK-8 assays were used to measure cytotoxicity. Immunoblotting assay was conducted to measure protein levels.

RESULTS

ALLE treatment significantly ameliorated lipid deposition and histological abnormalities of aortas and livers in AS rats; improved the imbalances of serum lipids including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C); notably attenuated serum concentrations of inflammation-associated cytokines/molecules including TNF-α, IL-6, IL-1β, VCAM-1, ICAM-1and MMP-9. Mechanistic studies demonstrated that ALLE suppressed the phosphorylation/activation of PI3K, Akt and NF-κB in AS rat aortas and in cultured foam cells. Additionally, the PI3K agonist 740Y-P notably reversed the in vitro inhibitory effects of ALLE on lipid deposition, productions of TC, TNF-α and IL-6, and protein levels of molecules of PI3K/Akt and NF-κB singnaling pathways.

CONCLUSIONS

ALLE ameliorates HFD- and vitamin D3-induced experimental AS by modulating lipid metabolism and inflammatory responses, and underlying mechanisms involves inhibition of the PI3K/Akt and NF-κB singnaling pathways. The findings of this study provide scientific justifications for the traditional application of ALL in managing atherosclerotic diseases.

Obstructive Sleep Apnea-Associated Intermittent Hypoxia-Induced Immune Responses in Males, Pregnancies, and Offspring

Obstructive sleep apnea (OSA), a respiratory sleep disorder associated with cardiovascular diseases, is more prevalent in men. However, OSA occurrence in pregnant women rises to a level comparable to men during late gestation, creating persistent effects on both maternal and offspring health. The exact mechanisms behind OSA-induced cardiovascular diseases remain unclear, but inflammation and oxidative stress play a key role. Animal models using intermittent hypoxia (IH), a hallmark of OSA, reveal several pro-inflammatory signaling pathways at play in males, such as TLR4/MyD88/NF-κB/MAPK, miRNA/NLRP3, and COX signaling, along with shifts in immune cell populations and function. Limited evidence suggests similarities in pregnancies and offspring. In addition, suppressing these inflammatory molecules ameliorates IH-induced inflammation and tissue injury, providing new potential targets to treat OSA-associated cardiovascular diseases. This review will focus on the inflammatory mechanisms linking IH to cardiovascular dysfunction in males, pregnancies, and their offspring. The goal is to inspire further investigations into the understudied populations of pregnant females and their offspring, which ultimately uncover underlying mechanisms and therapeutic interventions for OSA-associated diseases.

Identification of pyroptosis-associated genes with diagnostic value in calcific aortic valve disease

Background

Calcific aortic valve disease (CAVD) is one of the most prevalent valvular diseases and is the second most common cause for cardiac surgery. However, the mechanism of CAVD remains unclear. This study aimed to investigate the role of pyroptosis-related genes in CAVD by performing comprehensive bioinformatics analysis.

Methods

Three microarray datasets (GSE51472, GSE12644 and GSE83453) and one RNA sequencing dataset (GSE153555) were obtained from the Gene Expression Omnibus (GEO) database. Pyroptosis-related differentially expressed genes (DEGs) were identified between the calcified and the normal valve samples. LASSO regression and random forest (RF) machine learning analyses were performed to identify pyroptosis-related DEGs with diagnostic value. A diagnostic model was constructed with the diagnostic candidate pyroptosis-related DEGs. Receiver operating characteristic (ROC) curve analysis was performed to estimate the diagnostic performances of the diagnostic model and the individual diagnostic candidate genes in the training and validation cohorts. CIBERSORT analysis was performed to estimate the differences in the infiltration of the immune cell types. Pearson correlation analysis was used to investigate associations between the diagnostic biomarkers and the immune cell types. Immunohistochemistry was used to validate protein concentration.

Results

We identified 805 DEGs, including 319 down-regulated genes and 486 up-regulated genes. These DEGs were mainly enriched in pathways related to the inflammatory responses. Subsequently, we identified 17 pyroptosis-related DEGs by comparing the 805 DEGs with the 223 pyroptosis-related genes. LASSO regression and RF algorithm analyses identified three CAVD diagnostic candidate genes (TREM1, TNFRSF11B, and PGF), which were significantly upregulated in the CAVD tissue samples. A diagnostic model was constructed with these 3 diagnostic candidate genes. The diagnostic model and the 3 diagnostic candidate genes showed good diagnostic performances with AUC values >0.75 in both the training and the validation cohorts based on the ROC curve analyses. CIBERSORT analyses demonstrated positive correlation between the proportion of M0 macrophages in the valve tissues and the expression levels of TREM1, TNFRSF11B, and PGF.

Conclusion

Three pyroptosis-related genes (TREM1, TNFRSF11B and PGF) were identified as diagnostic biomarkers for CAVD. These pyroptosis genes and the pro-inflammatory microenvironment in the calcified valve tissues are potential therapeutic targets for alleviating CAVD.

Hypoxia-inducible factor 1α activates the NLRP3 inflammasome to regulate epithelial differentiation in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is an upper airway inflammation disease associated with hypoxia-mediated inflammation. The effect of hypoxia-inducible factor 1α (HIF-1α) on NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation in the pathogenesis of sinonasal mucosa is unclear.

OBJECTIVE

We investigated the effect and mechanism of HIF-1α on NLRP3 inflammasome activation in the primary human nasal epithelial cells (hNECs).

METHODS

We measured the expression levels of HIF-1α and the NLRP3 inflammasome in nasal biopsy samples and hNECs derived from negative controls (healthy) and patients with CRS with and without nasal polyps, then further analyzed the specific mechanism of HIF-1α regulation of the NLRP3 inflammasome and its effect on hNEC differentiation.

RESULTS

Increased mRNA and protein expression levels of HIF-1α and the NLRP3 inflammasome were found in all CRS biopsy samples. HIF-1α enhanced expression of phosphorylated NLRP3 (S295) in both HEK293T cells and hNECs; it also promoted recruitment of caspase-1 and apoptotic speck-like protein containing caspase recruitment domain (aka ASC) by NLRP3. HIF-1α also improved NLRP3's stability by preventing NLRP3 degradation caused by hypoxia-mediated inflammation. In addition, HIF-1α could also increase expression of Mucin5AC and decrease expression of α-tubulin by promoting activation of the NLRP3 inflammasome in hNECs. In addition, HIF-1α could also directly promote P63 expression in hNECs.

CONCLUSION

HIF-1α could potentially induce cilia loss and enhance the proliferation of goblet cells, possibly mediated by the regulation of NLRP3 phosphorylation in CRS inflammation.

Macrophage polarization and metabolism in atherosclerosis

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of fatty deposits in the inner walls of vessels. These plaques restrict blood flow and lead to complications such as heart attack or stroke. The development of atherosclerosis is influenced by a variety of factors, including age, genetics, lifestyle, and underlying health conditions such as high blood pressure or diabetes. Atherosclerotic plaques in stable form are characterized by slow growth, which leads to luminal stenosis, with low embolic potential or in unstable form, which contributes to high risk for thrombotic and embolic complications with rapid clinical onset. In this complex scenario of atherosclerosis, macrophages participate in the whole process, including the initiation, growth and eventually rupture and wound healing stages of artery plaque formation. Macrophages in plaques exhibit high heterogeneity and plasticity, which affect the evolving plaque microenvironment, e.g., leading to excessive lipid accumulation, cytokine hyperactivation, hypoxia, apoptosis and necroptosis. The metabolic and functional transitions of plaque macrophages in response to plaque microenvironmental factors not only influence ongoing and imminent inflammatory responses within the lesions but also directly dictate atherosclerotic progression or regression. In this review, we discuss the origin of macrophages within plaques, their phenotypic diversity, metabolic shifts, and fate and the roles they play in the dynamic progression of atherosclerosis. It also describes how macrophages interact with other plaque cells, particularly T cells. Ultimately, targeting pathways involved in macrophage polarization may lead to innovative and promising approaches for precision medicine. Further insights into the landscape and biological features of macrophages within atherosclerotic plaques may offer valuable information for optimizing future clinical treatment for atherosclerosis by targeting macrophages.

PSGL-1: a novel immune checkpoint driving T-cell dysfunction in obstructive sleep apnea

Introduction

Although higher incidence of cancer represents a major burden for obstructive sleep apnea (OSA) patients, the molecular pathways driving this association are not completely understood. Recently, the adhesion receptor P-selectin glycoprotein-1 (PSGL 1) has been identified as a novel immune checkpoint, which are recognized major hallmarks in several types of cancer and have revolutionized cancer therapy.

Methods

The expression of PSGL-1 and its ligands VISTA and SIGLEC-5 was assessed in the leucocytes of OSA patients and control subjects exploring the role of intermittent hypoxia (IH) using in vitro models. In addition, PSGL-1 impact on T-cells function was evaluated by ex vivo models.

Results

Data showed PSGL-1 expression is upregulated in the T-lymphocytes from patients with severe OSA, indicating a relevant role of hypoxemia mediated by intermittent hypoxia. Besides, results suggest an inhibitory role of PSGL-1 on T-cell proliferation capacity. Finally, the expression of SIGLEC-5 but not VISTA was increased in monocytes from OSA patients, suggesting a regulatory role of intermittent hypoxia.

Discussion

In conclusion, PSGL-1 might constitute an additional immune checkpoint leading to T-cell dysfunction in OSA patients, contributing to the disruption of immune surveillance, which might provide biological plausibility to the higher incidence and aggressiveness of several tumors in these patients.