CypD induced ROS output promotes intracranial aneurysm formation and rupture by 8-OHdG/NLRP3/MMP9 pathway

Cyclophilin D knockdown/knockout promotes microglia M2 polarization by inhibiting STAT1 to alleviate neuroinflammation in neonatal white matter injury

The activation of microglia cells is intimately associated with the pathophysiology of neuroinflammation and neonatal white matter injury (WMI). Cyclophilin D (CypD), a matrix cyclophilin, is known to be one of the important regulators of mitochondrial permeability transition pore. Currently, CypD has been discovered the function of regulating inflammation. However, its impact on microglia in the context of neonatal WMI remains unclear. In our study, CypD inhibition ameliorated microglia activation, decreased pro-inflammatory factor levels, and increased anti-inflammatory factor levels in both neonatal WMI mice and oxygen glucose deprivation/reperfusion (OGD/R)-induced BV2 microglial cells. CypD knockout promoted myelination and rescued neurological function in mice following hypoxic-ischemic injury. In addition, CypD knockdown alleviated mitochondrial dysfunction of BV2 microglial cells. RNA-Seq indicated that CypD inhibition downregulated STAT1. Western blotting results verified that CypD inhibition significantly downregulated the phosphorylation level of STAT1. Our research revealed the protective role of CypD inhibition in neuroinflammation and mitochondrial function of microglia. Targeting CypD expression in microglia may be a potential therapeutic option for neonatal WMI.

Mechanism of S-Palmitoylation in Polystyrene Nanoplastics-Induced Macrophage Cuproptosis Contributing to Emphysema through Alveolar Epithelial Cell Pyroptosis

More than microplastics, nanoplastics may pose a greater toxic effect on humans due to their unique physicochemical properties. Currently, research on lung diseases caused by respiratory exposure to nanoplastics is scarce, with epigenetic mechanisms warranting further investigation. In the present study, we exposed rats to polystyrene nanoplastics (PS-NPs) via an oral-nasal exposure system and found that PS-NPs exposure resulted in emphysema. Mechanistically, PS-NPs entered macrophages and competitively bound to sigma nonopioid intracellular receptor 1 (SIGMAR1), leading to an increase in free zDHHC palmitoyltransferase 14 (zDHHC14). This, in turn, caused elevated palmitoylation of solute carrier family 31 member 1 (SLC31A1) in macrophages, inhibiting its ubiquitination and degradation, thereby enhancing SLC31A1 expression. The increased expression of SLC31A1 promoted cuproptosis of macrophages and elevated tumor necrosis factor-α (TNF-α) secretion, which activated the NLR family pyrin domain containing 3/matrix metallopeptidase 9 (NLRP3/MMP-9) pathway in alveolar epithelial cells (AECs). This process mediated pyroptosis and degradation of extracellular matrix (ECM), resulting in the destruction of alveolar structure and development of emphysema. The findings demonstrate a previously unknown molecular mechanism by which PS-NPs induce emphysema. The findings have implications for the prevention and treatment of respiratory system damage caused by nanoparticles.

KLF15 prevents ferroptosis in vascular smooth muscle cells via interacting with p53

The formation of intracranial aneurysm (IA) is intimately linked to the progressive loss of vascular smooth muscle cells (VSMCs). Reactive oxygen species (ROS) play a pivotal role in inducing VSMC death during IA progression. Krüppel-like factor 15 (KLF15) plays a crucial role in preserving vascular homeostasis. However, the potential impact of KLF15 on ROS-triggered VSMC death remains unexplored. Analysis of microarray datasets from the GEO database suggests reduced KLF15 levels in human IA tissues. This study further confirms decreased KLF15 expression in ROS-treated human brain VSMCs (HBVSMCs). An unbiased examination of the transcriptome in HBVSMCs transfected with siKLF15 reveals that KLF15 regulates the ferroptosis pathway upon ROS stress. Silencing KLF15 results in the upregulation of genes promoting ferroptosis, such as SAT1, HMOX1, and MAP1LC3B, while downregulation of the ferroptosis regulatory gene SLC7A11. Cell death increases in KLF15-silenced HBVSMCs and is rescued by the ferroptosis inhibitor frerrostain-1. Co-immunoprecipitation and in situ proximity ligation assay indicate that KLF15 interacts with p53. Knockdown of p53 rescues the effects of siKLF15 on ROS-induced ferroptosis, including elevated cell death, lipid ROS levels, and the malondialdehyde content, as well as reduced SLC7A11protin levels in HBVSMCs. These findings suggest that KLF15 may lower cell sensitivity to ferroptosis by interacting with p53 and preventing p53-mediated transcriptional repression of SLC7A11. Overall, our results reveal a protective function of KLF15 in preventing ROS-induced ferroptosis in HBVSMCs.

Zn2+ regulates mitochondrial DNA efflux to inhibit AIM2-mediated ZBP1-PANoptosome pathway and alleviate septic myocardial injury

This study was performed to investigate the mechanism by which zinc ion regulated mitochondrial DNA (mtDNA) efflux to inhibit the AIM2-mediated ZBP1-PANoptosome pathway and alleviate sepsis-induced myocardial injury. Here we discovered that zinc ions suppressed mitochondrial DNA release, thereby protecting the heart from LPS-induced damage in mice. In addition, LPS induced mPTP opening and mediated mtDNA efflux in cardiomyocytes, which drove AIM2 activation and ZBP1-PANoptosome multiprotein complex formation, leading to pan-apoptotic cardiomyocyte death. Zn2+ prevented mPTP opening to inhibit mtDNA efflux-driven AIM2 and ZBP1-PANoptosome multiprotein complex formation and alleviate PANoptosis. Knockdown of AIM2 alleviated LPS-induced PANoptosis in cardiomyocytes. LPS-induced PANoptosis in cardiomyocytes by regulating the ZBP1/RIPK3 pathway. However, activation of the ZBP1/RIPK3 pathway partially reversed the inhibitory effect of Zn2+ on PANoptosis in cardiomyocytes. Taken together, Zn2+ regulated mitochondrial DNA efflux to inhibit the AIM2-mediated ZBP1-PANoptosome pathway to alleviate septic myocardial injury.

Differential Expression of LncRNA MIAT and Its Clinical Significance in Intracranial Aneurysms

PURPOSE

Intracranial aneurysm (IA) is characterized by localized dilation or ballooning of a blood vessel in the brain with life-threatening consequences. This study set out to investigate the value of Long noncoding RNA myocardial infarction associated transcript (LncRNA MIAT) in diagnosis, rupture prediction, and prognosis for IA patients.

METHODS

The clinical characteristics of controls (100 cases) and IA patients, including 88 cases of ruptured IA (RIA) and 132 cases of unruptured IA (UIA), were analyzed using the chi-square test and t-test. MIAT expression in the serum was detected. The diagnostic efficacy of MIAT for IA was assessed through receiver operating characteristic (ROC) curve analysis. IA patients were categorized into low-expression and high-expression groups, and the correlation between MIAT expression and clinical indicators in IA patients was analyzed. The risk factors for IA rupture were analyzed. The correlation between MIAT expression and the overall survival of IA patients was assayed. The risk factors for poor prognosis in IA patients were analyzed.

RESULTS

LncRNA MIAT was elevated in IA patients, with higher expression in RIA patients than in UIA patients. MIAT expression could distinguish between healthy control and IA patients (area under the curve, AUC = 0.794, cut-off value = 1.26, sensitivity = 68.64%, specificity = 83.00%, p < 0.001), healthy control and UIA patients (AUC = 0.782, cut-off value = 1.15, sensitivity = 75.76%, specificity = 68.00%, p < 0.001), and UIA patients and RIA patients (AUC = 0.690, cut-off value = 1.46, sensitivity = 76.14%, specificity = 68.94%, p < 0.001). MIAT expression was significantly associated with hypertension, IA location, and IA rupture status. MIAT was an independent risk factor for IA rupture. For every one-unit increase in the relative expression of MIAT, the risk of poor prognosis in IA patients increased by 2.415 times (p = 0.014, 95% CI: 1.192-4.890). MIAT expression was correlated with the overall survival of IA patients and IA rupture in UIA patients. MIAT was an independent risk factor for poor prognosis of IA patients. For every one-unit increase in the relative expression of MIAT, the risk of poor prognosis in IA patients increased by 2.415 times (p = 0.014, 95% CI: 1.192-4.890).

CONCLUSION

Highly expressed MIAT is an independent risk factor for poor prognosis of IA and can support IA diagnosis and rupture prediction.

Applications of Matrix Metalloproteinase-9-Related Nanomedicines in Tumors and Vascular Diseases

Matrix metalloproteinase-9 (MMP-9) is implicated in tumor progression and vascular diseases, contributing to angiogenesis, metastasis, and extracellular matrix degradation. This review comprehensively examines the relationship between MMP-9 and these pathologies, exploring the underlying molecular mechanisms and signaling pathways involved. Specifically, we discuss the contribution of MMP-9 to tumor epithelial-mesenchymal transition, angiogenesis, and metastasis, as well as its involvement in a spectrum of vascular diseases, including macrovascular, cerebrovascular, and ocular vascular diseases. This review focuses on recent advances in MMP-9-targeted nanomedicine strategies, highlighting the design and application of responsive nanoparticles for enhanced drug delivery. These nanotherapeutic strategies leverage MMP-9 overexpression to achieve targeted drug release, improved tumor penetration, and reduced systemic toxicity. We explore various nanoparticle platforms, such as liposomes and polymer nanoparticles, and discuss their mechanisms of action, including degradation, drug release, and targeting specificity. Finally, we address the challenges posed by the heterogeneity of MMP-9 expression and their implications for personalized therapies. Ultimately, this review underscores the diagnostic and therapeutic potential of MMP-9-targeted nanomedicines against tumors and vascular diseases.

Chaihuang Qingfu Pills Protect Against Acute Pancreatitis-Associated Acute Lung Injury Through MMP9-NLRP3-Pyroptosis Pathway

Background

Severe acute pancreatitis associated with acute lung injury (SAP-ALI) is a critical condition with a high mortality rate. Investigating the pathogenesis of SAP-ALI and developing effective treatments are urgently needed. Chaihuang Qingfu Pills (CHQF), a traditional Chinese medicine modified from Qingyi Decoction, has been approved for treating acute pancreatitis (AP). However, its role in SAP-ALI and the underlying mechanisms remain unclear.

Methods

92 AP patients were enrolled to observe the protective effect of CHQF on AP-ALI. L-arginine was used to establish the SAP-ALI animal model. UHPLC-MS/MS was used to identify the components of CHQF absorbed into the serum. Transcriptomics analysis, network pharmacology, and proteomics approaches were used to explore the underlying molecular mechanism. In vivo and in vitro experiments were conducted to validate the relevant findings.

Results

Clinical data indicated CHQF reduced the incidence of ALI from 58.33% to 36.36% in AP patients. Animal experiments demonstrated that CHQF decreased mortality, attenuated organ damage, inhibited systemic inflammation and reduced pathological injury in SAP mice. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) identified 146 SAP-related differentially expressed genes (DEGs) from the GSE194331 dataset. UHPLC-MS/MS analysis acquired 26 components absorbed into the blood and 271 associated therapeutic targets. Integrated analysis obtained 52 core targets of CHQF in treating SAP. Proteomic analysis identified 216 proteins associated with CHQF treatment in SAP-ALI. Joint analysis found that MMP9 and NLRP3 were the only common targets. Both in vivo and in vitro experiments confirmed that CHQF reduced the levels of MMP9 and NLRP3 and inhibited pyroptosis in alveolar macrophages (AMs) under SAP conditions. Moreover, the MMP9 inhibitor reduced NLRP3 expression and suppressed AMs pyroptosis.

Conclusion

CHQF exerted a protective role in SAP-ALI by inhibiting macrophage pyroptosis through the MMP9-NLRP3 pathway, providing a novel therapeutic strategy for SAP-ALI.

Synaptotagmin-1 attenuates myocardial programmed necrosis and ischemia/reperfusion injury through the mitochondrial pathway

Programmed necrosis/necroptosis greatly contributes to the pathogenesis of cardiac disorders including myocardial infarction, ischemia/reperfusion (I/R) injury and heart failure. However, the fundamental mechanism underlying myocardial necroptosis, especially the mitochondria-dependent death pathway, is poorly understood. Synaptotagmin-1 (Syt1), a Ca2+ sensor, is originally identified in nervous system and mediates synchronous neurotransmitter release. The later findings of Syt1 expressions in many non-neuronal tissues including muscles suggest that Syt1 may exert important functions beyond regulation of neurotransmitter release. Syt1 is highly expressed in cardiomyocytes and has been used as an extracellular molecular probe for SPECT imaging of cardiac cell death in acute myocardial infarction. However, whether Syt1 functions in the pathogenesis of cardiac disorders and what is the molecular etiology have not yet been clarified. We showed here that Syt1 expression was significantly down-regulated in mice I/R injured heart tissues, H2O2-challenged cardiomyocytes and hypoxia/reoxygenation (H/R)-damaged cardiomyocytes. Enforced expression of Syt1 significantly inhibited myocardial necrotic cell death and interstitial fibrosis, and improved cardiac function in mice subjected to I/R operation. In exploring the underlying mechanisms, we found that Syt1 interacted with Parkin and promoted Parkin-catalyzed CypD ubiquitination, thus inhibited mitochondrial membrane permeability transition pore (mPTP) opening and ultimately suppressed cardiomyocyte necrosis. We further found that Syt1 expression was negatively regulated by miR-193b-3p. MiR-193b-3p regulated cardiomyocyte necrosis and mPTP opening by targeting Syt1. Our present work revealed a novel regulatory model of myocardial necrosis composed of miR-193b-3p, Syt1, Parkin, and CypD, which may provide potential therapeutic targets and strategies for heart protection.

tRF-AspGTC Promotes Intracranial Aneurysm Formation by Controlling TRIM29-Mediated Galectin-3 Ubiquitination

Transfer RNA-derived small RNAs, a recently identified class of small noncoding RNAs, play a crucial role in regulating gene expression and are implicated in cerebrovascular diseases. However, the specific biological roles and mechanisms of transfer RNA-derived small RNAs in intracranial aneurysms (IAs) remain unclear. In this study, we identified that the transfer RNA-Asp-GTC derived fragment (tRF-AspGTC) is highly expressed in the IA tissues of both humans and mice. tRF-AspGTC promotes IA formation by facilitating the phenotypic switching of vascular smooth muscle cells, increasing of matrix metalloproteinase 9 expression, and inducing of oxidative stress and inflammatory responses. Mechanistically, tRF-AspGTC binds to galectin-3, inhibiting tripartite motif 29-mediated ubiquitination and stabilizing galectin-3. This stabilization activates the toll-like receptor 4/MyD88/nuclear factor kappa B pathway, further driving phenotypic switching and inflammation. Clinically, circulating exosomal tRF-AspGTC demonstrates strong diagnostic efficacy for IAs and is identified as an independent risk factor for IA occurrence. These findings highlight the potential of tRF-AspGTC as a promising diagnostic biomarker and therapeutic target for IAs.

Multiomics integrated analysis and experimental validation identify TLR4 and ALOX5 as oxidative stress-related biomarkers in intracranial aneurysms

BACKGROUND

Intracranial aneurysm (IA) is a severe cerebrovascular disease, and effective gene therapy and drug interventions for its treatment are still lacking. Oxidative stress (OS) is closely associated with the IA, but the key regulatory genes involved are still unclear. Through multiomics analysis and experimental validation, we identified two diagnostic markers for IA associated with OS.

METHODS

In this study, we first analyzed the IA dataset GSE75436 and conducted a joint analysis of oxidative stress-related genes (ORGs). Differential analysis, functional enrichment analysis, immune infiltration, WGCNA, PPI, LASSO, and other methods were used to identify IA diagnostic markers related to OS. Next, the functions of TLR4 and ALOX5 expression in IA and their potential targeted therapeutic drugs were analyzed. We also performed single-cell sequencing of patient IA and control (superficial temporal artery, STA) tissues. 23,342 cells were captured from 2 IA and 3 STA samples obtained from our center. Cell clustering and annotation were conducted using R software to observe the distribution of TLR4 and ALOX5 expression in IAs. Finally, the expression of TLR4 and ALOX5 were validated in IA patients and in an elastase-induced mouse IA model using experiments such as WB and immunofluorescence.

RESULTS

Through bioinformatics analysis, we identified 16 key ORGs associated with IA pathogenesis. Further screening revealed that ALOX5 and TLR4 were highly expressed to activate a series of inflammatory responses and reduce the production of myocytes. Methotrexate (MTX) may be a potential targeted drug. Single-cell analysis revealed a notable increase in immune cells in the IA group, with ALOX5 and TLR4 primarily localized to monocytes/macrophages. Validation through patient samples and mouse models confirmed high expression of ALOX5 and TLR4 in IAs.

CONCLUSIONS

Bioinformatics analysis indicated that ALOX5 and TLR4 are the most significant ORGs associated with the pathogenesis of IA. Single-cell sequencing and experiments revealed that the high expression of ALOX5 and TLR4 are closely related to IA. These two genes are promising new targets for IA therapy.

Integrated metagenomic and metabolomic analysis reveals distinctive stage-specific gut-microbiome-derived metabolites in intracranial aneurysms

OBJECTIVE

Our study aimed to explore the influence of gut microbiota and their metabolites on intracranial aneurysms (IA) progression and pinpoint-related metabolic biomarkers derived from the gut microbiome.

DESIGN

We recruited 358 patients with unruptured IA (UIA) and 161 with ruptured IA (RIA) from two distinct geographical regions for conducting an integrated analysis of plasma metabolomics and faecal metagenomics. Machine learning algorithms were employed to develop a classifier model, subsequently validated in an independent cohort. Mouse models of IA were established to verify the potential role of the specific metabolite identified.

RESULTS

Distinct shifts in taxonomic and functional profiles of gut microbiota and their related metabolites were observed in different IA stages. Notably, tryptophan metabolites, particularly indoxyl sulfate (IS), were significantly higher in plasma of RIA. Meanwhile, upregulated tryptophanase expression and indole-producing microbiota were observed in gut microbiome of RIA. A model harnessing gut-microbiome-derived tryptophan metabolites demonstrated remarkable efficacy in distinguishing RIA from UIA patients in the validation cohort (AUC=0.97). Gut microbiota depletion by antibiotics decreased plasma IS concentration, reduced IA formation and rupture in mice, and downregulated matrix metalloproteinase-9 expression in aneurysmal walls with elastin degradation reduction. Supplement of IS reversed the effect of gut microbiota depletion.

CONCLUSION

Our investigation highlights the potential of gut-microbiome-derived tryptophan metabolites as biomarkers for distinguishing RIA from UIA patients. The findings suggest a novel pathogenic role for gut-microbiome-derived IS in elastin degradation in the IA wall leading to the rupture of IA.

Mendelian randomization demonstrates a causal link between peripheral circulating acylcarnitines and intracranial aneurysms

Intracranial aneurysm (IA) is the most prevalent type of cerebral vascular disease causing life-threatening subarachnoid hemorrhages (SAH). A long-term vascular structure remodeling is considered as the main pathophysiological feature of IAs. However, the causal factors triggering the pathophysiological process are not clear. Recently, the abnormalities of peripheral circulating proteins and metabolites have been found in IAs patients and associated with the ruptures. We comprehensively investigated the potential causal relationship between blood metabolites and proteins and IAs using the mendelian randomization (MR) analysis. We applied two-sample MR to explore the potential causal association between peripheral circulating metabolites (191 blood metabolites) and proteins (1398 proteins) and IAs using data from the FinnGen study and the GWAS datasets published by Bakker et al. We identified palmitoylcarnitine, stearoylcarnitine and 2-tetradecenoylcarnitine as causal contributors of IAs and ruptures. Further two-step mediation MR analysis suggested that hypertension as one of the contributors of IAs and ruptures mediated the causal relationship between palmitoylcarnitine, stearoylcarnitine and 2-tetradecenoylcarnitine and IAs. Together, our study demonstrates that blood metabolic palmitoylcarnitine, stearoylcarnitine and 2-tetradecenoylcarnitine are causally linked to the formation and rupture of IAs. Hypertension partially mediates the causal effects.

Sodium tanshinone IIA sulfonate protects vascular relaxation in ApoE-knockout mice by inhibiting the SYK-NLRP3 inflammasome-MMP2/9 pathway

BACKGROUND

Hyperlipidemia damages vascular wall and serves as a foundation for diseases such as atherosclerosis, hypertension and stiffness. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is implicated in vascular dysfunction associated with hyperlipidemia-induced vascular injury. Sodium tanshinone IIA sulfonate (STS), a well-established cardiovascular protective drug with recognized anti-inflammatory, antioxidant, and vasodilatory properties, is yet to be thoroughly investigated for its impact on vascular relaxant imbalance induced by hyperlipidemia.

METHODS

In this study, we treated ApoE-knockout (ApoE-/-) mouse with STS and assessed the activation of the NLRP3 inflammasome, expression of MMP2/9, integrity of elastic fibers, and vascular constriction and relaxation.

RESULTS

Our findings reveal that STS intervention effectively preserves elastic fibers, significantly restores aortic relaxation function in ApoE-/- mice, and reduces their excessive constriction. Furthermore, STS inhibits the phosphorylation of spleen tyrosine kinase (SYK), suppresses NLRP3 inflammasome activation, and reduces MMP2/9 expression.

CONCLUSIONS

These results demonstrate that STS protects vascular relaxation against hyperlipidemia-induced damage through modulation of the SYK-NLRP3 inflammasome-MMP2/9 pathway. This research provides novel insights into the mechanisms underlying vascular relaxation impairment in a hyperlipidemic environment and uncovers a unique mechanism by which STS preserves vascular relaxation, offering valuable foundational research evidence for its clinical application in promoting vascular health.

Shank3 ameliorates neuronal injury after cerebral ischemia/reperfusion via inhibiting oxidative stress and inflammation

Shank3, a key molecule related to the development and deterioration of autism, has recently been found to downregulate in the murine brain after ischemia/reperfusion (I/R). Despite this discovery, however, its effects on neuronal injury and the mechanism underlying the effects remain to be clarified. To address this, in this study, based on genetically modified mice models, we revealed that the expression of Shank3 showed a time-dependent change in murine hippocampal neurons after I/R, and that conditional knockout (cko) of Shank3 in neurons resulted in aggravated neuronal injuries. The protective effects of Shank3 against oxidative stress and inflammation after I/R were achieved through direct binding STIM1 and subsequent proteasome-mediated degradation of STIM1. The STIM1 downregulation induced the phosphorylation of downstream Nrf2 Ser40, which subsequently translocated to the nucleus, and further increased the expression of antioxidant genes such as NQO1 and HO-1 in HT22 cells. In vivo, the study has further confirmed that double knockout of Shank3 and Stim1 alleviated oxidative stress and inflammation after I/R in Shank3cko mice. In conclusion, the present study has demonstrated that Shank3 interacts with STIM1 and inhibits post-I/R neuronal oxidative stress and inflammatory response via the Nrf2 pathway. This interaction can potentially contribute to the development of a promising method for I/R treatment.

Traumatic Aneurysm Involving the Posterior Communicating Artery

Traumatic intracranial aneurysms (TICAs) are rare, accounting for less than 1% of all intracranial aneurysms. However, they are associated with a mortality rate of over 50%. The case presented herein focuses on a posterior communicating artery TICA caused by violent aggression. A 41-year-old man with massive subarachnoid hemorrhage (SAH), on admission to hospital, had a CT angiography that showed a ruptured left posterior communicating artery aneurysm with continuous blood loss and underwent neurosurgical cooling. The CT scan also showed fractures of the mandible, mastoid and left styloid process, as well as brain contusions caused by blows and kicks. Despite medical treatment and surgery, after four days, he died. The assault dynamics were recorded by a camera in the bar. The damage was caused by kicks to the neck and head. The forensic neuropathological examination showed the primary injury (SAH, subdural hemorrhage, cerebral contusions, head-neck fractures), as well as secondary damage following the attack (cerebral infarcts, edema, supratentorial hernia, midbrain hemorrhage). The coil was intact and well positioned. In this case, circumstantial information, medical records, and the type of injury could shed light on the mechanism of the production of a TICA. In addition, the CT angiography and histological investigations helped to distinguish a recent and traumatic aneurysm from a pre-existing one. Following precise steps, the study of aneurysms can be helpful in clarifying their traumatic origin even when the victim was taking drugs. The aim of this study is also to share the diagnostic process that we used in the forensic field for the assessment of suspected traumatic aneurysms.