Neuroprotective Effect of miR-483-5p Against Cardiac Arrest-Induced Mitochondrial Dysfunction Mediated Through the TNFSF8/AMPK/JNK Signaling Pathway

JZL-184 Alleviate Neurological Impairment through Regulation of Mitochondrial Transfer and Lipid Droplet Accumulation after Cardiac Arrest

Astrocytes are abundant glial cells in the central nervous system (CNS) that play important roles in brain injury following cardiac arrest (CA). Following brain ischemia, astrocytes trigger endogenous neuroprotective mechanisms, such as fatty acid transport. Lipid droplets (LDs) are cellular structures involved in neutral lipid storage and play essential roles in many biological processes. However, whether lipid droplet metabolism is related to the neurological prognosis after CA remains unclear. JZL-184 is a selective irreversible inhibitor of monoacylglycerol lipase (MAGL), and previous investigations revealed that JZL-184 confers neuroprotection in the brain following stroke. However, further investigations are warranted to explore the effect and mechanism of JZL-184 after CA. Here, we reveal that JZL-184 is neuroprotective after cardiac arrest, as it alleviates astroglial activation by upregulating the expression of transforming growth factor beta 1 (TGF-β1), promotes the transfer of mitochondria from astrocytes to neurons in the astrocyte‒neuron coculture system, and reduces lipid droplet accumulation in neurons. Mechanistically, this protective effect depends on the downstream genes DUSP4 and Rab27b. This study provides additional insights into strategies for inhibiting neurological impairment and suggests a potential therapeutic target after cardiac arrest.

The Role of Extracellular-Vesicle-Derived miRNAs in Postoperative Organ Dysfunction in Neonates and Infants Undergoing Congenital Cardiac Surgery: An Exploratory Study

Despite significant advancements in medical and surgical care, the morbidity and mortality rates of neonates and infants undergoing congenital cardiac surgery remain high. To identify new pathomechanisms associated with postoperative organ dysfunction, extracellular vesicles (EVs) were isolated from plasma from neonates and infants with or without organ dysfunction at three different time points around congenital cardiac surgery, and the EV miRNA expression profiles in the plasma were analyzed. A clear distinction was observed between the organ dysfunction (OD) and non-organ dysfunction (NOD) groups based on their EV miRNA expression profiles. Apoptosis and proinflammatory pathways were consistently upregulated across all time points in the OD group. Complement and coagulation cascades unexpectedly displayed downregulation at the end of the surgery in the OD group, which was verified further at the proteomic level in an independent patient cohort. The neutrophil extracellular trap (NET) formation was enhanced in the OD group across all time points compared to that in the NOD group. As NETs are known to consume complement components, these observed events might be interconnected. A feature selection machine learning method identified miR-200b-5p, miR-4800-5p, miR-363-3p, and miR-483-5p as robustly linked to organ dysfunction following congenital cardiac surgery (accuracy score = 9; SD in accuracy = 0.3162). In conclusion, our study suggested that neonates and infants with postoperative organ dysfunction were associated with enhanced NET formation and complement consumption.

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

JOURNAL/nrgr/04.03/01300535-202504000-00027/figure1/v/2024-07-06T104127Z/r/image-tiff Cardiac arrest can lead to severe neurological impairment as a result of inflammation, mitochondrial dysfunction, and post-cardiopulmonary resuscitation neurological damage. Hypoxic preconditioning has been shown to improve migration and survival of bone marrow-derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest, but the specific mechanisms by which hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown. To this end, we established an in vitro co-culture model of bone marrow-derived mesenchymal stem cells and oxygen-glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis, possibly through inhibition of the MAPK and nuclear factor κB pathways. Subsequently, we transplanted hypoxia-preconditioned bone marrow-derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia. The results showed that hypoxia-preconditioned bone marrow-derived mesenchymal stem cells significantly reduced cardiac arrest-induced neuronal pyroptosis, oxidative stress, and mitochondrial damage, whereas knockdown of the liver isoform of phosphofructokinase in bone marrow-derived mesenchymal stem cells inhibited these effects. To conclude, hypoxia-preconditioned bone marrow-derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest, and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

Perivascular macrophages in cerebrovascular diseases

Cerebrovascular diseases are a major cause of stroke and dementia, both requiring long-term care. These diseases involve multiple pathophysiologies, with mitochondrial dysfunction being a crucial contributor to the initiation of inflammation, apoptosis, and oxidative stress, resulting in injuries to neurovascular units that include neuronal cell death, endothelial cell death, glial activation, and blood-brain barrier disruption. To maintain brain homeostasis against these pathogenic conditions, brain immune cells, including border-associated macrophages and microglia, play significant roles as brain innate immunity cells in the pathophysiology of cerebrovascular injury. Although microglia have long been recognized as significant contributors to neuroinflammation, attention has recently shifted to border-associated macrophages, such as perivascular macrophages (PVMs), which have been studied based on their crucial roles in the brain. These cells are strategically positioned around the walls of brain vessels, where they mainly perform critical functions, such as perivascular drainage, cerebrovascular flexibility, phagocytic activity, antigen presentation, activation of inflammatory responses, and preservation of blood-brain barrier integrity. Although PVMs act as scavenger and surveillant cells under normal conditions, these cells exert harmful effects under pathological conditions. PVMs detect mitochondrial dysfunction in injured cells and implement pathological changes to regulate brain homeostasis. Therefore, PVMs are promising as they play a significant role in mitochondrial dysfunction and, in turn, disrupt the homeostatic condition. Herein, we summarize the significant roles of PVMs in cerebrovascular diseases, especially ischemic and hemorrhagic stroke and dementia, mainly in correlation with inflammation. A better understanding of the biology and pathobiology of PVMs may lead to new insights on and therapeutic strategies for cerebrovascular diseases.

Potential diagnostic biomarkers: 6 cuproptosis- and ferroptosis-related genes linking immune infiltration in acute myocardial infarction

The current diagnostic biomarkers of acute myocardial infarction (AMI), troponins, lack specificity and exist as false positives in other non-cardiac diseases. Previous studies revealed that cuproptosis, ferroptosis, and immune infiltration are all involved in the development of AMI. We hypothesize that combining the analysis of cuproptosis, ferroptosis, and immune infiltration in AMI will help identify more precise diagnostic biomarkers. The results showed that a total of 19 cuproptosis- and ferroptosis-related genes (CFRGs) were differentially expressed between the healthy and AMI groups. Functional enrichment analysis showed that the differential CFRGs were mostly enriched in biological processes related to oxidative stress and the inflammatory response. The immune infiltration status analyzed by ssGSEA found elevated levels of macrophages, neutrophils, and CCR in AMI. Then, we screened 6 immune-related CFRGs (CXCL2, DDIT3, DUSP1, CDKN1A, TLR4, STAT3) to construct a nomogram for predicting AMI and validated it in the GSE109048 dataset. Moreover, we also identified 5 pivotal miRNAs and 10 candidate drugs that target the 6 feature genes. Finally, RT-qPCR analysis verified that all 6 feature genes were upregulated in both animals and patients. In conclusion, our study reveals the significance of immune-related CFRGs in AMI and provides new insights for AMI diagnosis and treatment.

Impacts of MicroRNA-483 on Human Diseases

MicroRNAs (miRNAs) are short non-coding RNA molecules that regulate gene expression by targeting specific messenger RNAs (mRNAs) in distinct cell types. This review provides a com-prehensive overview of the current understanding regarding the involvement of miR-483-5p and miR-483-3p in various physiological and pathological processes. Downregulation of miR-483-5p has been linked to numerous diseases, including type 2 diabetes, fatty liver disease, diabetic nephropathy, and neurological injury. Accumulating evidence indicates that miR-483-5p plays a crucial protective role in preserving cell function and viability by targeting specific transcripts. Notably, elevated levels of miR-483-5p in the bloodstream strongly correlate with metabolic risk factors and serve as promising diagnostic markers. Consequently, miR-483-5p represents an appealing biomarker for predicting the risk of developing diabetes and cardiovascular diseases and holds potential as a therapeutic target for intervention strategies. Conversely, miR-483-3p exhibits significant upregulation in diabetes and cardiovascular diseases and has been shown to induce cellular apoptosis and lipotoxicity across various cell types. However, some discrepancies regarding its precise function have been reported, underscoring the need for further investigation in this area.