Asphyxia Research Articles

Raynaud's Phenomenon: A Current Update on Pathogenesis, Diagnostic Workup, and Treatment.

Raynaud's phenomenon (RP) is a condition characterized by episodic, excessive vasoconstriction in the fingers and toes, triggered by cold or stress. This leads to a distinctive sequence of color changes in the digits. Pallor indicates reduced blood flow due to oxygen deprivation, while erythema appears as reperfusion. RP can be primary, with no identifiable underlying cause, or secondary, associated with other conditions. These conditions include autoimmune diseases, most commonly systemic sclerosis, vascular diseases; and neurological conditions. While the exact cause of RP remains unclear, genetic and hormonal (estrogen) factors are likely contributors. The pathogenesis of RP involves a complex interaction between the vascular wall, nerves, hormones, and humoral factors, disrupting the balance between vasoconstriction and vasodilation. In primary RP, the vascular abnormalities are primarily functional. However, in secondary RP, both functional and structural components occur in blood vessels. This explains why digital tissue damage frequently occurs in secondary RP but not primary RP. Diagnosis of RP is primarily clinical. Recent advancements in imaging techniques have aided in diagnosis and monitoring, but nail fold capillaroscopy remains the gold standard for distinguishing between primary and secondary RP. If there are signs of acute ischemic injury, vascular imaging, particularly preoperatively, is crucial to rule out other vaso-occlusive conditions. Management of RP focuses on alleviating symptoms and preventing tissue damage. Vasodilator medications are the first-line treatment when general measures like warmth and stress management are not sufficient. Dihydropyridine calcium channel blockers (CCBs), such as nifedipine, are commonly used for vasodilation. Phosphodiesterase-5 inhibitors and prostaglandin analogs are alternative options for patients who do not respond to CCBs or have ischemic tissue damage. Bosentan, an endothelin-1 receptor antagonist, has shown effectiveness in treating and preventing digital ulcers, especially in patients with multiple ulcers. For severe cases, botulinum toxin injections or sympathectomy surgery can be used to control RP symptoms. However, botulinum toxin injections require repeated administration, and sympathectomy's long-term effectiveness is uncertain. Fat grafting is a promising surgical therapy for promoting healing and preventing tissue injury.

Oxygen deprivation is a muscle revelation: hypoxia enhances motor unit firing after spinal cord injury.

Oxygen deprivation is a muscle revelation: hypoxia enhances motor unit firing after spinal cord injury.

Oxidative and Antioxidative Biomarker Profiles in Neonatal Hypoxic-Ischemic Encephalopathy: Insights for Pathophysiology and Treatment Strategies.

BACKGROUND Neonatal hypoxic-ischemic encephalopathy (HIE) is a significant cause of perinatal and postnatal morbidity and mortality worldwide. Catalase (CAT) activity detection is used to determine levels of inflammation and oxidative stress. Glutathione (GSH) is the most critical non-enzymatic endogenous antioxidant. Lipid peroxidation levels marked after hypoxia can be detected based on the level of malondialdehyde (MDA). Ischemia-modified albumin (IMA) is considered a biomarker for cardiac ischemia and is known to increase in the liver, brain, and kidney in states of insufficient oxygenation. We aimed to explain the results and relations between the oxidant and antioxidants to detail oxidant-antioxidant balance and cellular mechanisms. MATERIAL AND METHODS Serum levels of IMA and MDA, as an oxidative stress marker, and CAT and GSH, as antioxidant enzymes, were measured in first blood samples of 59 neonates diagnosed with HIE, with pH <7, base excess >12, and APGAR scores. RESULTS Neonates who were ≥37 weeks of gestation and had hypoxia were included. Compared with healthy newborns (n=32), CAT was statistically significantly lower in the hypoxia group (P=0.0001), while MDA serum levels were significantly higher in neonates with hypoxia (P=0.01). There was no difference between hypoxic and healthy neonates in GSH and IMA measurements (P=0.054, P=0.19 respectively). CONCLUSIONS HIE pathophysiology involves oxidative stress and mitochondrial energy production failure. Explaining the pathways between oxidant-antioxidant balance and cell death, which explains the pathophysiology of HIE, is essential to develop treatment strategies that will minimize the effects of oxygen deprivation on other body organs, especially the brain.

Renal protection after hemorrhagic shock in rats: Possible involvement of SUMOylation

Hemorrhagic shock (HS), a leading cause of preventable death, is characterized by severe blood loss and inadequate tissue perfusion. Reoxygenation of ischemic tissues exacerbates organ damage through ischemia–reperfusion injury. SUMOylation has been shown to protect neurons after stroke and is upregulated in response to cellular stress. However, the role of SUMOylation in organ protection after HS is unknown. This study aimed to investigate SUMOylation-mediated organ protection following HS. Male Wistar rats were subjected to HS (blood pressure of 40 ± 2 mmHg, for 90 min) followed by reperfusion. Blood, kidney, and liver samples were collected at various time points after reperfusion to assess organ damage and investigate the profile of SUMO1 and SUMO2/3 conjugation. In addition, human kidney cells (HK-2), treated with the SUMOylation inhibitor TAK-981 or overexpressing SUMO proteins, were subjected to oxygen and glucose deprivation to investigate the role of SUMOylation in hypoxia/reoxygenation injury. The animals presented progressive multiorgan dysfunction, except for the renal system, which showed improvement over time. Compared to the liver, the kidneys displayed distinct patterns in terms of oxidative stress, apoptosis activation, and tissue damage. The global level of SUMO2/3 in renal tissue was also distinct, suggesting a differential role. Pharmacological inhibition of SUMOylation reduced cell viability after hypoxia-reoxygenation damage, while overexpression of SUMO1 or SUMO2 protected the cells. These findings suggest that SUMOylation might play a critical role in cellular protection during ischemia–reperfusion injury in the kidneys, a role not observed in the liver. This difference potentially explains the renal resilience observed in HS animals when compared to other systems.

Evolution and development of Drosophila melanogaster under different thermal conditions affected cell sizes and sensitivity to paralyzing hypoxia

Environmental gradients cause evolutionary and developmental changes in the cellular composition of organisms, but the physiological consequences of these effects are not well understood. Here, we studied experimental populations of Drosophila melanogaster that had evolved in one of three selective regimes: constant 16 °C, constant 25 °C, or intergenerational shifts between 16 °C and 25 °C. Genotypes from each population were reared at three developmental temperatures (16 °C, 20.5 °C, and 25 °C). As adults, we measured thorax length and cell sizes in the Malpighian tubules and wing epithelia of flies from each combination of evolutionary and developmental temperatures. We also exposed flies from these treatments to a short period of nearly complete oxygen deprivation to measure hypoxia tolerance. For genotypes from any selective regime, development at a higher temperature resulted in smaller flies with smaller cells, regardless of the tissue. At every developmental temperature, genotypes from the warm selective regime had smaller bodies and smaller wing cells but had larger tubule cells than did genotypes from the cold selective regime. Genotypes from the fluctuating selective regime were similar in size to those from the cold selective regime, but their cells of either tissue were the smallest among the three regimes. Evolutionary and developmental treatments interactively affected a fly’s sensitivity to short-term paralyzing hypoxia. Genotypes from the cold selective regime were less sensitive to hypoxia after developing at a higher temperature. Genotypes from the other selective regimes were more sensitive to hypoxia after developing at a higher temperature. Our results show that thermal conditions can trigger evolutionary and developmental shifts in cell size, coupled with changes in body size and hypoxia tolerance. These patterns suggest links between the cellular composition of the body, levels of hypoxia within cells, and the energetic cost of tissue maintenance. However, the patterns can be only partially explained by existing theories about the role of cell size in tissue oxygenation and metabolic performance.

Autotrophic poly-3-hydroxybutyrate accumulation in Cupriavidus necator for sustainable bioplastic production triggered by nutrient starvation

Cupriavidus necator is a facultative chemolithoautotrophic bacterium able to convert carbon dioxide into poly-3-hydroxybutyrate. This is highly promising as the conversion process allows the production of sustainable and biodegradable plastics. Poly-3-hydroxybutyrate accumulation is known to be induced by nutrient starvation, but information regarding the optimal stress conditions controlling the process is still heterogeneous and fragmentary. This study presents a comprehensive comparison of the effects of nutrient stress conditions, namely nitrogen, hydrogen, phosphorus, oxygen, and magnesium deprivation, on poly-3-hydroxybutyrate accumulation in C. necator DSM545. Nitrogen starvation exhibited the highest poly-3-hydroxybutyrate accumulation, achieving 54% of total cell dry weight after four days of nutrient stress, and a carbon conversion efficiency of 85%. The gas consumption patterns indicated flexible physiological mechanisms underlying polymer accumulation and depolymerization. These findings provide insights into strategies for efficient carbon conversion into bioplastics, and highlight the key role of C. necator for future industrial-scale applications.

Effect of hypoxia on aquaporins and hepatobiliary transport systems in human hepatic cells.

Hepatic ischemia and hypoxia are accompanied by reduced bile flow, biliary sludge and cholestasis. Hepatobiliary transport systems, nuclear receptors and aquaporins were studied after hypoxia and reoxygenation in human hepatic cells. Expression of Aquaporin 8 (AQP8), Aquaporin 9 (AQP9), Pregnane X receptor (PXR), Farnesoid X receptor (FXR), Organic anion transporting polypeptide 1 (OATP1), and the Multidrug resistance-associated protein 4 (MRP4) were investigated in induced pluripotent stem cells (iPSCs) derived hepatic cells and the immortalized hepatic line HepG2. HepG2 was subjected to combined oxygen and glucose deprivation for 4 h followed by reoxygenation. Expression of AQP8 and AQP9 increased during differentiation in iPSC-derived hepatic cells. Hypoxia did not alter mRNA levels of AQP8, but reoxygenation caused a marked increase in AQP8 mRNA expression. While expression of OATP1 had a transient increase during reoxygenation, MRP4 showed a delayed downregulation. Knock-down of FXR did not alter the expression of AQP8, AQP9, MRP4, or OATP1. Post-hypoxic protein levels of AQP8 were reduced after 68 h of reoxygenation compared to normoxic controls. Post-transcriptional mechanisms rather than reduced transcription cause reduction in AQP8 protein concentration after hypoxia-reoxygenation in hepatic cells. Expression patterns differed between hepatobiliary transport systems during hypoxia and reoxygenation. Expression of AQP8 and AQP9 increased during differentiation in induced pluripotent stem cells. Expression of hepatobiliary transporters varies during hypoxia and reoxygenation. Post-hypoxic protein levels of AQP8 were reduced after 68 h of reoxygenation. Post-transcriptional mechanisms rather than reduced transcription cause reduction in AQP8 protein concentration after hypoxia-reoxygenation in hepatic cells. Hypoxia and reoxygenation may affect aquaporins in hepatic cells and potentially affect bile composition.

Proteomic investigation of acute and chronic hypoxia/reoxygenation responsive proteins and pathways in H9C2 cardiomyoblasts.

Ischemic heart diseases continue to be a significant global cardiovascular problem in today's world. Myocardial reperfusion (R) is provided with an effective and rapid treatment; however, it can lead to fatal results, as well as ischemia (I). This study aims to use proteomic analysis to assess proteins and pathways in H9C2 cardiomyoblast cells exposed to hypoxic conditions, followed by reoxygenation, representing I/R injury for both short and long terms, reflecting acute and chronic hypoxia, respectively. Utilizing advanced techniques, our goal is to identify and characterize key proteins undergoing alterations during these critical phases. H9C2 cardiomyoblasts, a commonly used cell line for simulating in vivo I/R damage, were exposed to normoxia and hypoxia (0.4% O2) in six experimental groups: normoxia (3h), acute hypoxia (3h), acute hypoxia (3h) + reoxygenation (3h), normoxia (21h), chronic hypoxia (21h), and chronic hypoxia (21h) + reoxygenation (3h). Analyses were conducted using Nano LC/MSMS from tryptic digest of the whole cell lysates. Proteins were quantified using the label-free quantification (LFQ) algorithm in Proteome Discoverer 2.4. Proteomic analysis resulted in identification of 2383 protein groups. Proteins that differentially expressed in the various groups were identified (p < 0.05 among mean values for groups). Short-term hypoxia induces mitochondrial damage, energy demand, and cytoskeletal modifications. Chronic hypoxia triggers metabolic shifts, stress-response proteins, and extracellular matrix alterations. Data are available via ProteomeXchange with identifier PXD047994. Our research provides in-depth insights into how H9C2 cardiomyoblasts respond to both short-term and prolonged oxygen deprivation. Understanding hypoxia-related pathophysiology provides avenues for therapeutic intervention in hypoxia-related disorders.

Current studies of cerebral infarction

Cerebral infarction, also known as stroke, is a serious medical condition resulting from the interruption of blood flow to the brain, either due to blockage or rupture of blood vessels. This interruption leads to localized ischemia and oxygen deprivation in the brain tissue, causing hypoxic-ischemic cell death and subsequent damage to brain function. Cerebral infarction is a leading cause of mortality and morbidity worldwide, particularly among the elderly, but recent research suggests that younger individuals are also increasingly affected. According to reports from the World Health Organization, cardiovascular diseases, including cerebral infarction, account for millions of deaths annually, posing a significant public health threat. The incidence of cerebral infarction among the younger generation is particularly noteworthy, with a significant proportion of patients aged 15-49 suffering from this condition. This trend underscores the need for greater awareness and prevention efforts across all age groups to address this global health challenge.

Head Injury and Associated Sequelae in Individuals Seeking Asylum in the United States: A Retrospective Mixed-Methods Review of Medico-Legal Affidavits.

People seeking asylum are susceptible to head injury (HI) due to exposure to various forms of violence including war, torture, or interpersonal violence. Yet, the extents to which clinicians assess HI, and if so, what the associated characteristics are, are not well known. We analyzed 200 U.S.-based medico-legal affidavits using descriptive, multivariate regression, and thematic analysis. Head injury was documented in 38% of affidavits. Those who experienced physical violence were eight times likelier to experience HI than those who did not experience physical violence. Five themes emerged: (1) HI occurred commonly in the context of interpersonal violence (44%), followed by militarized violence (33%); (2) mechanisms of HI included direct blows to the head and asphyxiation, suggesting potential for both traumatic brain injury and brain injury from oxygen deprivation; (3) HI was often recurrent and concurrent with other physical injuries; (4) co-morbid psychiatric and post-concussive symptoms made it challenging to assess neurological and psychiatric etiologies; and (5) overall, there was a paucity of assessments and documentation of HI and sequelae. Among individuals assessed for asylum claims, HI is common, often recurrent, occurring in the context of interpersonal violence, and concurrent with psychological and other physical trauma. Physical violence is an important risk factor for HI, which should be assessed when physical violence is reported.

Neurotoxicity by Hypoxia an Intermediate Between Alpha-synuclein and Mitochondrial Dysfunction in Parkinson’s Disease

This review article explores the relationship between alpha-synuclein and mitochondrial dysfunction in Parkinson’s disease (PD), focusing on the role of hypoxia as an intermediate factor. The interaction between alpha-synuclein and mitochondria, particularly through membranal lipids such as cardiolipins, is highlighted as a key factor in mitochondrial disruption and neurodegeneration. Hypoxia, caused by oxygen deprivation, is identified as a crucial link between alpha-synuclein and mitochondrial regulation, leading to neuronal death in PD. The article also discusses the involvement of other proteins, such as peroxisome proliferator-activated receptor gamma coactivator, Sirtuin-1, Sirtuin-3 and adenosine monophosphate-activated protein kinase, in maintaining mitochondrial biogenesis during hypoxia. The study emphasizes the need for further research to understand the complex molecular interactions causing Lewy body aggregation, improper mitochondrial functioning and neurodegeneration in PD, with a specific focus on the role of hypoxia. Alpha-synuclein aggregation disrupts mitochondrial respiration, leading to mitochondrial dysfunction and increased production of reactive oxygen species. Mitochondrial dysfunction, in turn, causes neurodegeneration in PD. Oligomeric alpha-synuclein results in mitochondrial dysfunction, lethal synaptic disruption and reduced adenosine triphosphate generation. Oligomeric alpha-synuclein also increases the accumulation of mitochondrial rho nucleotide guanosine triphosphate, leading to delayed mitophagy. Hypoxia, another factor in PD, alters both alpha-synuclein and mitochondria. Controlling hypoxia reduces the oligomerization of alpha-synuclein. The interaction between alpha-synuclein and mitochondria is complex, and determining the primary player in inducing the other is still debatable.

Isobolographic Analysis of the Cytoprotective Effect of Dapsone and Cannabidiol Alone or Combination upon Oxygen-Glucose Deprivation/Reoxygenation Model in SH-SY5Y Cells.

Oxidative stress and apoptosis cell death are critical secondary damage mechanisms that lead to losing neighboring healthy tissue after cerebral ischemia. This study aims to characterize the type of interaction between dapsone (DDS) and cannabidiol (CBD) and its cytoprotective effect in an in vitro model of oxygen and glucose deprivation for 6 h followed by 24 h of reoxygenation (OGD/R), using the SH-SY5Y cell line. For the combined concentrations, an isobolographic study was designed to determine the optimal concentration-response combinations. Cell viability was evaluated by measuring the lactate dehydrogenase (LDH) release and 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assays. Also, the reactive oxygen species (ROS) and reduced glutathione (GSH) levels were analyzed as oxidative stress markers. Finally, caspase-3 activity was evaluated as a marker cell death by apoptosis. The results showed a decrease in cell viability, an increase in oxidant stress, and the activity of caspase-3 by the effect of OGD/R. Meanwhile, both DDS and CBD demonstrated antioxidant, antiapoptotic, and cytoprotective effects in a concentration-response manner. The isobolographic study indicated that the concentration of 2.5 µM of DDS plus 0.05 µM of CBD presented a synergistic effect so that in treatment, cell death due to OGD/R decreased. The findings indicate that DDS-CBD combined treatment may be a helpful therapy in cerebral ischemia with reperfusion.

Pathophysiological Approach of Myocardial Infarction: A Review

Coronary artery disease (CAD) is the primary cause of myocardial infarction (MI), which is defined by a decreased or stopped blood supply to a portion of the heart myocardium, resulting in cardiac cell death. Because CAD robs the heart of oxygen supply, it frequently presents as silently or with symptoms like radiating chest pain to the shoulder, arm, neck, or jaw. Elevated cardiac troponins and ECG alterations are involved in the diagnosis. MI is caused by prolonged blockage of a major coronary artery; collateral circulation, hemodynamics, and residual blood flow all affect the size of the infarct. Atherosclerosis, thrombosis, and plaque erosion are the primary causes of ST-elevation MI (STEMI) and non-ST-elevation MI (NSTEMI). Male pattern baldness, advancing age, a family history of the condition, high cholesterol, smoking, hypertension, diabetes, obesity, and stress are risk factors for MI. Aortic dissection, drug misuse, and anomalies in the heart are further causes. Anaerobic respiration and lactate buildup are the results of tissue oxygen deprivation, which starts both reversible and irreversible phases of Myocardial infarction. Oxidative stress and endothelial dysfunction, in conjunction with inflammation and susceptible plaques, worsen the development of MI. Significant MI risks are highlighted by epidemiological research on smoking, obesity, diabetes, hypertension, and socioeconomic variables. Other factors include family history and genetic predisposition. Given that MI continues to be a major cause of morbidity and death worldwide, an understanding of its pathophysiology and risk factors is essential for both prevention and intervention. To lessen the effects of this terrible illness, effective strategies require prompt intervention and thorough risk factor control.

The phototrophic metabolic behaviour of Candidatus accumulibacter

The phototrophic capability of Candidatus Accumulibacter (Accumulibacter), a common polyphosphate accumulating organism (PAO) in enhanced biological phosphorus removal (EBPR) systems, was investigated in this study. Accumulibacter is phylogenetically related to the purple bacteria Rhodocyclus from the family Rhodocyclaceae, which belongs to the class Betaproteobacteria. Rhodocyclus typically exhibits both chemoheterotrophic and phototrophic growth, however, limited studies have evaluated the phototrophic potential of Accumulibacter. To address this gap, short and extended light cycle tests were conducted using a highly enriched Accumulibacter culture (95%) to evaluate its responses to illumination. Results showed that, after an initial period of adaptation to light conditions (approximately 4–5 h), Accumulibacter exhibited complete phosphorus (P) uptake by utilising polyhydroxyalkanoates (PHA), and additionally by consuming glycogen, which contrasted with its typical aerobic metabolism. Mass, energy, and redox balance analyses demonstrated that Accumulibacter needed to employ phototrophic metabolism to meet its energy requirements. Calculations revealed that the light reactions contributed to the generation of, at least more than 67% of the ATP necessary for P uptake and growth. Extended light tests, spanning 21 days with dark/light cycles, suggested that Accumulibacter generated ATP through light during initial operation, however, it likely reverted to conventional anaerobic/aerobic metabolism under dark/light conditions due to microalgal growth in the mixed culture, contributing to oxygen production. In contrast, extended light tests with an enriched Tetrasphaera culture, lacking phototrophic genes in its genome, clearly demonstrated that phototrophic P uptake did not occur. These findings highlight the adaptive metabolic capabilities of Accumulibacter, enabling it to utilise phototrophic pathways for energy generation during oxygen deprivation, which holds the potential to advance phototrophic-EBPR technology development.

PNPO-PLP axis senses prolonged hypoxia in macrophages by regulating lysosomal activity.

Oxygen is critical for all metazoan organisms on the earth and impacts various biological processes in physiological and pathological conditions. While oxygen-sensing systems inducing acute hypoxic responses, including the hypoxia-inducible factor pathway, have been identified, those operating in prolonged hypoxia remain to be elucidated. Here we show that pyridoxine 5'-phosphate oxidase (PNPO), which catalyses bioactivation of vitamin B6, serves as an oxygen sensor and regulates lysosomal activity in macrophages. Decreased PNPO activity under prolonged hypoxia reduced an active form of vitamin B6, pyridoxal 5'-phosphate (PLP), and inhibited lysosomal acidification, which in macrophages led to iron dysregulation, TET2 protein loss and delayed resolution of the inflammatory response. Among PLP-dependent metabolism, supersulfide synthesis was suppressed in prolonged hypoxia, resulting in the lysosomal inhibition and consequent proinflammatory phenotypes of macrophages. The PNPO-PLP axis creates a distinct layer of oxygen sensing that gradually shuts down PLP-dependent metabolism in response to prolonged oxygen deprivation.

A Contemporary Review of Trachea, Nose, and Ear Cartilage Bioengineering and Additive Manufacturing.

The complex structure, chemical composition, and biomechanical properties of craniofacial cartilaginous structures make them challenging to reconstruct. Autologous grafts have limited tissue availability and can cause significant donor-site morbidity, homologous grafts often require immunosuppression, and alloplastic grafts may have high rates of infection or displacement. Furthermore, all these grafting techniques require a high level of surgical skill to ensure that the reconstruction matches the original structure. Current research indicates that additive manufacturing shows promise in overcoming these limitations. Autologous stem cells have been developed into cartilage when exposed to the appropriate growth factors and culture conditions, such as mechanical stress and oxygen deprivation. Additive manufacturing allows for increased precision when engineering scaffolds for stem cell cultures. Fine control over the porosity and structure of a material ensures adequate cell adhesion and fit between the graft and the defect. Several recent tissue engineering studies have focused on the trachea, nose, and ear, as these structures are often damaged by congenital conditions, trauma, and malignancy. This article reviews the limitations of current reconstructive techniques and the new developments in additive manufacturing for tracheal, nasal, and auricular cartilages.

1D-CNN: Classification of normal delivery and cesarean section types using cardiotocography time-series signals

Abstract Cardiotocography (CTG) is considered the gold standard for monitoring fetal heart rate (FHR) during pregnancy and labor to estimate the danger of oxygen deprivation. Visual interpretation of CTG traces is complex and frequently results in high rates of false positives and false negatives, leading to unfavorable and unwanted outcomes such as fetal mortality or needless cesarean surgery. If the data are well-balanced, which is uncommon in medical datasets, machine learning techniques can be helpful in interpretation. This study is designed to determine classification performance under various data balance approaches. We propose a robust methodology for the automated extraction of features that use a deep learning model based on the one-dimensional convolutional neural network (1D-CNN). We used a public database containing 552 intrapartum CTG recordings. Due to the imbalance in the dataset, the experiments were conducted under a variety of conditions such as (i) an unbalanced dataset, (ii) undersampling, (iii) a weighted binary cross-entropy approach, and (iv) oversampling utilizing the synthetic minority oversampling technique (SMOTE). We found an excellent sensitivity (99.80% for the unbalanced dataset, 96.25% for the weighted binary cross-entropy approach, and 99.81% with SMOTE) except for the under sampling situation, in which the sensitivity was 85.71%. Moreover, the 1D-CNN model incorporating SMOTE yielded promising results in 88% specificity, 93.72% quality index (QI), and 95.10% area under the curve. The model exhibited excellent performance in terms of sensitivity in every scenario except for undersampling. The oversampling of training data with SMOTE yielded a decent level of specificity, demonstrating the model’s strong predictive capacity. In addition, the SMOTE scenario resulted in fewer training epochs, which is another accomplishment.

PHLDA1 contributes to hypoxic ischemic brain injury in neonatal rats via inhibiting FUNDC1-mediated mitophagy.

Hypoxia-ischemia (HI) is one of the main causes of neonatal brain injury. Mitophagy has been implicated in the degradation of damaged mitochondria and cell survival following neonatal brain HI injury. Pleckstrin homology-like domain family A member 1 (PHLDA1) plays vital roles in the progression of various disorders including the regulation of oxidative stress, the immune responses and apoptosis. In the present study we investigated the role of PHLDA1 in HI-induced neuronal injury and further explored the mechanisms underlying PHLDA1-regulated mitophagy in vivo and in vitro. HI model was established in newborn rats by ligation of the left common carotid artery plus exposure to an oxygen-deficient chamber with 8% O2 and 92% N2. In vitro studies were conducted in primary hippocampal neurons subjected to oxygen and glucose deprivation/-reoxygenation (OGD/R). We showed that the expression of PHLDA1 was significantly upregulated in the hippocampus of HI newborn rats and in OGD/R-treated primary neurons. Knockdown of PHLDA1 in neonatal rats via lentiviral vector not only significantly ameliorated HI-induced hippocampal neuronal injury but also markedly improved long-term cognitive function outcomes, whereas overexpression of PHLDA1 in neonatal rats via lentiviral vector aggravated these outcomes. PHLDA1 knockdown in primary neurons significantly reversed the reduction of cell viability and increase in intracellular reactive oxygen species (ROS) levels, and attenuated OGD-induced mitochondrial dysfunction, whereas overexpression of PHLDA1 decreased these parameters. In OGD/R-treated primary hippocampal neurons, we revealed that PHLDA1 knockdown enhanced mitophagy by activating FUNDC1, which was abolished by FUNDC1 knockdown or pretreatment with mitophagy inhibitor Mdivi-1 (25 μM). Notably, pretreatment with Mdivi-1 or the knockdown of FUNDC1 not only increased brain infarct volume, but also abolished the neuroprotective effect of PHLDA1 knockdown in HI newborn rats. Together, these results demonstrate that PHLDA1 contributes to neonatal HI-induced brain injury via inhibition of FUNDC1-mediated neuronal mitophagy.

Neuroprotective effects of apigenin on retinal ganglion cells in ischemia/reperfusion: modulating mitochondrial dynamics in in vivo and in vitro models

BackgroundRetinal ischemia/reperfusion (RIR) is implicated in various forms of optic neuropathies, yet effective treatments are lacking. RIR leads to the death of retinal ganglion cells (RGCs) and subsequent vision loss, posing detrimental effects on both physical and mental health. Apigenin (API), derived from a wide range of sources, has been reported to exert protective effects against ischemia/reperfusion injuries in various organs, such as the brain, kidney, myocardium, and liver. In this study, we investigated the protective effect of API and its underlying mechanisms on RGC degeneration induced by retinal ischemia/reperfusion (RIR).MethodsAn in vivo model was induced by anterior chamber perfusion following intravitreal injection of API one day prior to the procedure. Meanwhile, an in vitro model was established through 1% oxygen and glucose deprivation. The neuroprotective effects of API were evaluated using H&E staining, spectral-domain optical coherence tomography (SD-OCT), Fluoro-Gold retrograde labeling, and Photopic negative response (PhNR). Furthermore, transmission electron microscopy (TEM) was employed to observe mitochondrial crista morphology and integrity. To elucidate the underlying mechanisms of API, the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, flow cytometry assay, western blot, cell counting kit-8 (CCK-8) assay, lactate dehydrogenase (LDH) assay, JC-1 kit assay, dichlorofluorescein-diacetate (DCFH-DA) assay, as well as TMRE and Mito-tracker staining were conducted.ResultsAPI treatment protected retinal inner plexiform layer (IPL) and ganglion cell complex (GCC), and improved the function of retinal ganglion cells (RGCs). Additionally, API reduced RGC apoptosis and decreased lactate dehydrogenase (LDH) release by upregulating Bcl-2 and Bcl-xL expression, while downregulating Bax and cleaved caspase-3 expression. Furthermore, API increased mitochondrial membrane potential (MMP) and decreased extracellular reactive oxygen species (ROS) production. These effects were achieved by enhancing mitochondrial function, restoring mitochondrial cristae morphology and integrity, and regulating the expression of OPA1, MFN2, and DRP1, thereby regulating mitochondrial dynamics involving fusion and fission.ConclusionAPI protects RGCs against RIR injury by modulating mitochondrial dynamics, promoting mitochondrial fusion and fission.

Lipid nanoparticle-encapsulated lncRNA DLX6-AS1 knockdown ameliorates cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis

ABSTRACT Objective Cerebral ischemia is a neurological disorder that leads to permanent disability. This research focuses on exploring the ameliorative effects of lipid nanoparticle (LNP)-encapsulated lncRNA DLX6-AS1 knockdown in cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis. Methods LNP-encapsulated lncRNA DLX6-AS1 was prepared. Cerebral ischemic injury mouse models were established utilizing middle cerebral artery occlusion (MCAO). The mice were treated by intravenous injection of LNP-encapsulated lncRNA DLX6-AS1. The neurological deficits, Inflammatory factor levels, pathological characteristics were observed. In vitro N2a cell oxygen and glucose deprivation (OGD) models were established, and the cells were treated with LNP-encapsulated lncRNA DLX6-AS1 or Nrf2 inhibitor (ML385). Cell viability and apoptosis were tested. DLX6-AS1, Nrf2, HO-1, and NLRP3 expression levels were assessed. Results LncRNA DLX6-AS1 levels were elevated in the brain tissues of mice with cerebral ischemic injury and OGD-induced N2a cells. LNP-encapsulated DLX6-AS1 siRNA (si-DLX6-AS1) improved neurological deficit scores, reduced the levels of inflammatory factors, improved brain tissue pathological damage, and raised the number of survival neurons in CA1. LNP-encapsulated si-DLX6-AS1 ameliorated the OGD-induced N2a cell viability decrease and apoptosis rate increase, and ML385 (Nrf2 inhibitor) reversed the ameliorative effects of LNP-encapsulated si-DLX6-AS1. In cerebral ischemic injury mice and OGD-induced N2a cells, Nrf2 and HO-1 levels were reduced and NLRP3 levels were increased. LNP-encapsulated si-DLX6-AS1 raised Nrf2 and HO-1 levels and reduced NLRP3 levels. Nrf2 inhibitor ML385 treatment reversed the ameliorative effects of LNP-encapsulated si-DLX6-AS1 on OGD-induced N2a cell viability and apoptosis. Conclusion Lipid nanoparticle-encapsulated si-DLX6-AS1 ameliorates cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis.