Asphyxia Research Articles

Neuroprotective Effect of Flavonoid Agathisflavone in the Ex Vivo Cerebellar Slice Neonatal Ischemia.

Agathisflavone is a flavonoid that exhibits anti-inflammatory and anti-oxidative properties. Here, we investigated the neuroprotective effects of agathisflavone on central nervous system (CNS) neurons and glia in the cerebellar slice ex vivo model of neonatal ischemia. Cerebellar slices from neonatal mice, in which glial fibrillary acidic protein (GFAP) and SOX10 drive expression of enhanced green fluorescent protein (EGFP), were used to identify astrocytes and oligodendrocytes, respectively. Agathisflavone (10 μM) was administered preventively for 60 min before inducing ischemia by oxygen and glucose deprivation (OGD) for 60 min and compared to controls maintained in normal oxygen and glucose (OGN). The density of SOX-10+ oligodendrocyte lineage cells and NG2 immunopositive oligodendrocyte progenitor cells (OPCs) were not altered in OGD, but it resulted in significant oligodendroglial cell atrophy marked by the retraction of their processes, and this was prevented by agathisflavone. OGD caused marked axonal demyelination, determined by myelin basic protein (MBP) and neurofilament (NF70) immunofluorescence, and this was blocked by agathisflavone preventative treatment. OGD also resulted in astrocyte reactivity, exhibited by increased GFAP-EGFP fluorescence and decreased expression of glutamate synthetase (GS), and this was prevented by agathisflavone pretreatment. In addition, agathisflavone protected Purkinje neurons from ischemic damage, assessed by calbindin (CB) immunofluorescence. The results demonstrate that agathisflavone protects neuronal and myelin integrity in ischemia, which is associated with the modulation of glial responses in the face of ischemic damage.

Adipose Mesenchymal Stem Cell-derived Exosomes Enhanced Glycolysis through the SIX1/HBO1 Pathway against Oxygen and Glucose Deprivation Injury in Human Umbilical Vein Endothelial Cells.

Angiogenesis and energy metabolism mediated by adipose mesenchymal stem cell-derived exosomes (AMSC-exos) are promising therapeutics for vascular diseases. The current study aimed to explore whether AMSC-exos have therapeutic effects on oxygen and glucose deprivation (OGD) human umbilical vein endothelial cells (HUVECs) injury by modulating the SIX1/HBO1 signaling pathway to upregulate endothelial cells (E.C.s) glycolysis and angiogenesis. AMSC-exos were isolated and characterized following standard protocols. AMSC-exos cytoprotective effects were evaluated in the HUVECs-OGD model. The proliferation, migration, and tube formation abilities of HUVECs were assessed. The glycolysis level was evaluated by detecting lactate production and ATP synthesis. The expressions of HK2, PKM2, VEGF, HIF-1α, SIX1, and HBO1 were determined by western blotting, and finally, the SIX1 overexpression vector or small interfering RNA (siRNA) was transfected into HUVECs to assess the change in HBO1 expression. Our study revealed that AMSC-exos promotes E.C.s survival after OGD, reducing E.C.s apoptosis while strengthening E.C.'s angiogenic ability. AMSC-exos enhanced glycolysis and reduced OGD-induced ECs injury by modulation of the SIX1/HBO1 signaling pathway, which is a novel anti-endothelial cell injury role of AMSC-exos that regulates glycolysis via activating the SIX1/HBO1 signaling pathway. The current study findings demonstrate a useful angiogenic therapeutic strategy for AMSC-exos treatment in vascular injury, thus providing new therapeutic ideas for treating ischaemic diseases.

Inflammatory setting, therapeutic strategies targeting some pro-inflammatory cytokines and pathways in mitigating ischemia/reperfusion-induced hepatic injury: a comprehensive review.

Ischemia/reperfusion injury (IRI) is a key determining agent in the pathophysiology of clinical organ dysfunction. It is characterized by an aseptic local inflammatory reaction due to a decrease in blood supply, hence deprivation of dependent oxygen and nutrients. In instances of liver transplantation, this injury may have irreversible implications, resulting in eventual organ rejection. The deterioration associated with IRI is affected by the hepatic health status and various factors such as alterations in metabolism, oxidative stress, and pro-inflammatory cytokines. The primary cause of inflammation is the initial immune response of pro-inflammatory cytokines, while Kupffer cells (KFCs) and neutrophil-produced chemokines also play a significant role. Upon reperfusion, the activation of inflammatory responses can elicit further cellular damage and organ dysfunction. This review discusses the interplay between chemokines, pro-inflammatory cytokines, and other inflammatory mediators that contribute to the damage to hepatocytes and liver failure in rats following IR. Furthermore, it delves into the impact of anti-inflammatory therapies in safeguarding against liver failure and hepatocellular damage in rats following IR. This review investigates the correlation between cytokine factors and liver dysfunction via examining databases, such as PubMed, Google Scholar, Science Direct, Egyptian Knowledge Bank (EKB), and Research Gate.

Phase-Amplitude Coupling in Theta and Beta Bands: A Potential Electrophysiological Marker for Obstructive Sleep Apnea.

Phase-amplitude coupling (PAC) between the phase of low-frequency signals and the amplitude of high-frequency activities plays many physiological roles and is involved in the pathological processed of various neurological disorders. However, how low-frequency and high-frequency neural oscillations or information synchronization activities change under chronic central hypoxia in OSA patients and whether these changes are closely associated with OSA remains largely unexplored. This study arm to elucidate the long-term consequences of OSA-related oxygen deprivation on central nervous system function. : We screened 521 patients who were clinically suspected of having OSA at our neurology and sleep centers. Through polysomnography (PSG) and other clinical examinations, 103 patients were ultimately included in the study and classified into mild, moderate, and severe OSA groups based on the severity of hypoxia determined by PSG. We utilized the phase-amplitude coupling (PAC) method to analyze the modulation index (MI) trends between different frequency bands during NREM (N1/N2/N3), REM, and wakefulness stages in OSA patients with varying severity levels. We also examined the correlation between the MI index and OSA hypoxia indices. Apart from reduced N2 sleep duration and increased microarousal index, the sleep architecture remained largely unchanged among OSA patients with varying severity levels. Compared to the mild OSA group, patients with moderate and severe OSA exhibited higher MI values of PAC in the low-frequency theta phase and high-frequency beta amplitude in the frontal and occipital regions during N1 sleep and wakefulness. No significant differences in the MI of phase-amplitude coupling were observed during N2/3 and REM sleep. Moreover, the MI of phase-amplitude coupling in theta and beta bands positively correlated with hypoxia-related indices, including the apnea-hypopnea index (AHI) and oxygenation desaturation index (ODI), and the percentage of oxygen saturation below 90% (SaO2<90%). OSA patients demonstrated increased MI values of theta phase and beta amplitude in the frontal and occipital regions during N1 sleep and wakefulness. This suggests that cortical coupling is prevalent and exhibits sleep-stage-specific patterns in OSA. Theta-beta PAC during N1 and wakefulness was positively correlated with hypoxia-related indices, suggesting a potential relationship between these neural oscillations and OSA severity. The present study provides new insights into the relationship between neural oscillations and respiratory hypoxia in OSA patients.

Acute Kidney Injury Among Asphyxiated Neonates In Sokoto, North West Nigeria

Background: Birth asphyxia and its attendant complications remain a common problem in our neonatal intensive care units. Compelling evidence from various epidemiologic studies shows that Acute Kidney Injury (AKI) is indeed one of the commonest complications of birth asphyxia. The kidneys are sensitive to oxygen deprivation, renal insult may occur within few hours of hypoxic-ischemic episode, which if prolonged could lead to irreversible cortical and or tubular necrosis. Aim: To determine the prevalence and factors associated with AKI among asphyxiated term neonates in Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto, Nigeria Materials and methods: One hundred and nineteen asphyxiated term neonates admitted into the special care baby unit of UDUTH Sokoto participated in the study. Birth asphyxia was defined as failure to initiate and sustain breathing at birth with Apgar scores ≤ 5 at 5 minutes in the presence of arterial cord blood pH &lt; 7 and base deficit &gt;12mmol. Blood samples were taken for arterial blood gas analysis within one hour of life. Moderately and severely asphyxiated neonates who satisfied the inclusion criteria were consecutively recruited into the study and serum creatinine assay was done on day 3 and day 5 of life. AKI was defined as a rise in serum creatinine ≥ 0.3mg/dl over 48 hours. Quantitative variables such as birth weight, length, occipitofrontal circumference (OFC) were expressed using mean, standard deviation and range, while qualitative variables like gender, mode of delivery and grade of asphyxia were summarised using frequency and percentages. Chisquare and fisher’s exact tests were applied to determine if any relationship exists between sociodemographic/clinical factors and AKI. A p-value of &lt; 0.05 was considered statistically significant. Results: Of the 119 asphyxiated term neonates 74 (62.2%) were males while 45 (37.8%) were females giving a M:F ratio of 1.6:1. Majority 96 (80.7%) of the subjects had normal birth weight with a mean birth weight of 3.1 ± 0.6kg. The mean gestational age recorded was 38.2 ± 1.1 months The prevalence of AKI in the study subjects was 42.9%. The grade of birth asphyxia was significantly associated with AKI with a prevalence odds ratio of 7.2 (95CI 2.8-18). Conclusion: The prevalence of AKI in asphyxiated term neonates in UDUTH Sokoto was high and the grade of birth asphyxia was found to be significantly associated with AKI

Formononetin inhibits neuroinflammation in BV2 microglia induced by glucose and oxygen deprivation reperfusion through TLR4/NF-κB signaling pathway

Ischemic stroke, caused by diminished or interrupted cerebral blood flow, triggers the activation of microglial cells and subsequent inflammatory responses. Formononetin (FMN) has been observed to inhibit BV2 microglial cell activation and alleviate ensuing neuroinflammatory reactions. Despite extensive research, the precise underlying mechanism remains unclear. To investigate the neuroinflammatory response following FMN-mediated inhibition of BV2 microglial activation, we employed an in vitro oxygen-glucose deprivation/reperfusion (OGD/R) model. BV2 microglial cells were categorized into four groups: control, FMN, OGD/R, and OGD/R+FMN. Cell viability was assessed using the CCK-8 assay, while flow cytometry assessed M1 and M2 cell populations within BV2 cells. Immunofluorescence was utilized to detect the expression levels of apoptosis-inducing factor (AIF), p53, Toll-like receptor 4 (TLR4), and NF-κB p65. Western blotting (WB) was conducted to quantify p65/p-p65, IκB-α/p-IκB-α, and TLR4 protein levels in each group. Additionally, ELISA was employed to measure IL-1β and TNF-α levels in cell supernatants from each group. The results revealed a significant increase in the proportion of iNOS/CD206-positive M1/M2 cells in the OGD/R group compared to the control group (p < 0.05). There was also a notable increase in nuclear translocation of NF-κB p65 and elevated expression of inflammatory factors IL-1β and TNF-α in cell supernatants. Moreover, levels of p-p65, p-IκB-α, and TLR4 proteins were significantly elevated in the OGD/R group (p < 0.05). However, the addition of FMN reversed these effects. Specifically, FMN administration notably attenuated cell death and inflammation in BV2 microglia induced by OGD/R through modulation of the TLR4/NF-κB signaling pathway.These findings suggest that FMN may serve as a potential therapeutic agent against neuroinflammation associated with ischemic stroke by targeting microglial activation pathways.

Altered muscle fibre activation in an antagonistic muscle pair due to perturbed afferent feedback caused by blood flow restriction

PurposeThis study aimed to better understand the coping strategy of the neuromuscular system under perturbed afferent feedback. To this end, the neuromechanical effects of transient blood flow restriction (BFR) compared to atmospheric pressure were investigated in an antagonistic muscle pair. MethodsPerceived discomfort and neuromechanical parameters (torque and high-density electromyography) were recorded during submaximal isometric ankle dorsiflexion before, during and after BFR. The tibialis anterior and gastrocnemius lateralis muscles were studied in 14 healthy young adults. ResultsDiscomfort increased during BFR and decreased to baseline level afterwards. The exerted torque and the co-activation index remained constant, whereas the EMG signal energy increased significantly during BFR. Coherence analysis of the delta band remained constant, whereas the alpha band shows an increase during BFR. Median frequency and muscle fibre conduction velocity showed a positive trend during the first minutes of BFR before significantly decreasing. Both parameters exceeded baseline values after cuff deflation. ConclusionPerturbed afferent feedback leads to altered neuromechanical parameters. We assume that increased central drive is required to maintain force output, resulting in changed muscle fibre activity. Glycolytic fast-switch fibres are only active for a short time due to oxygen deprivation and hyperacidity, but fatigue effects predominate in the long term.

A Preliminary Finding: N-butyl-phthalide Plays a Neuroprotective Role by Blocking the TLR4/HMGB1 Pathway and Improves Mild Cognitive Impairment Induced by Acute Cerebral Infarction.

Most acute cerebral infarctions (ACI) may develop vascular dementia (VD), which involves almost all types of cognitive impairment. Unfortunately, there is currently no effective treatment for VD. Most patients exhibit mild cognitive impairment (MCI) before the development of VD. N-butyl-phthalide (NBP) is used to treat ACI and improve cognitive function. The oxygen and glucose deprivation (OGD) model of neurons is an in vitro model of ischemia, hypoxia, and cognitive dysfunction. We conducted clinical studies and in vitro experiments to investigate the clinical efficacy and mechanism of action of NBP for treating ACI-induced MCI. Patients with ACI-induced MCI were randomly divided into control (Ctrl) and NBP groups. We assessed various indicators, such as clinical efficacy, montreal cognitive assessment scale (MOCA), activities of daily living (ADL), and cerebral infarct size in both groups before and after treatment. We observed the morphology of neurons and detected the survival rate, action potentials (APs), expression of high mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), and the interaction between TLR4 and HMGB1. The MOCA and ADL scores increased significantly after treatment in the NBP group. A OGD model of neurons was established, and the neurons were divided into Ctrl and NBP groups. We observed that the survival rate and APs amplitude of the neurons were significantly increased in the NBP group, whereas TNF-α expression was decreased. Furthermore, the interaction between TLR4 and HMGB1 decreased in the NBP group. NBP plays a neuroprotective role by inhibiting the TLR4/HMGB1 pathway and ameliorating ACI-induced MCI.

Atmospheric pressure plasma preconditioning reduces oxygen and glucose deprivation induced human neuronal SH-SY5Y cells apoptosis by activating protective autophagy and ROS/AMPK/mTOR pathway

Reactive oxygen species (ROS)/reactive nitrogen species (RNS) exert a “double edged” effect on the occurrence and development of ischemic stroke. We previously indicate that atmospheric pressure plasma (APP) shows a neuroprotective effect in vitro based on the ROS/RNS generations. However, the mechanism is still unknown. In this work, SH-SY5Y cells were treated with oxygen and glucose deprivation (OGD) injuries for stimulating the ischemic stroke pathological injury process. A helium APP was used for SH-SY5Y cell treatment for evaluating the neuroprotective impacts of APP preconditioning against OGD injuries with the optimized parameters. During the preconditioning, APP significantly raised the extracellular and intracellular ROS/RNS production. As a result, APP preconditioning increased SH-SY5Y cell autophagy by elevating LC3-II/LC3-I ratio and autophagosome formation. Meanwhile, APP preconditioning reduced cell apoptosis caused by OGD with the increased APP treatment time, which was abolished by pretreatment with autophagy inhibitor 3-methyladenine (3-MA). The ROS scavenger N-acetyl-L-cysteine (NAC) alone or combined with NO scavenger carboxy-PTIO abolished the APP preconditioning induced SH-SY5Y autophagy and the cytoprotection, whereas the NO scavenger alone did not. In addition, we observed the elevated phosphorylation of AMP-activated protein kinase (AMPK) and decreased phosphorylation of mammalian target of rapamycin (mTOR) in APP treated SH-SY5Y cells. This effect was attenuated by AMPK inhibitor Compound C (CC), the ROS scavenger NAC and autophagy inhibitor 3-MA. Furthermore, the cytoprotective effect of APP was preliminarily confirmed in the rats of middle cerebral artery occlusion (MCAO) model. Results showed that APP inhalation by rats during MCAO process could improve neurological functions, reduce cell apoptosis in brain tissues and decrease cerebral infarct volume. Our data suggested that ROS produced by APP preconditioning played a vital role in the neuroprotective effect of SH-SY5Y cells against OGD injuries by activating autophagy and ROS/AMPK/mTOR pathway.

Pretreatment with oleuropein protects the neonatal brain from hypoxia-ischemia by inhibiting apoptosis and neuroinflammation.

Hypoxic-ischemic (HI) encephalopathy is a cerebrovascular injury caused by oxygen deprivation to the brain and remains a major cause of neonatal mortality and morbidity worldwide. Therapeutic hypothermia is the current standard of care but it does not provide complete neuroprotection. Our aim was to investigate the neuroprotective effect of oleuropein (Ole) in a neonatal (seven-day-old) mouse model of HI. Ole, a secoiridoid found in olive leaves, has previously shown to reduce damage against cerebral and other ischemia/reperfusion injuries. Here, we administered Ole as a pretreatment prior to HI induction at 20 or 100 mg/kg. A week after HI, Ole significantly reduced the infarct area and the histological damage as well as white matter injury, by preserving myelination, microglial activation and the astroglial reactive response. Twenty-four hours after HI, Ole reduced the overexpression of caspase-3 and the proinflammatory cytokines IL-6 and TNF-α. Moreover, using UPLC-MS/MS we found that maternal supplementation with Ole during pregnancy and/or lactation led to the accumulation of its metabolite hydroxytyrosol in the brains of the offspring. Overall, our results indicate that pretreatment with Ole confers neuroprotection and can prevent HI-induced brain damage by modulating apoptosis and neuroinflammation.

MicroRNA-128-3p Affects Neuronal Apoptosis and Neurobehavior in Cerebral Palsy Rats by Targeting E3 Ubiquitin-Linking Enzyme Smurf2 and Regulating YY1 Expression.

This study was dedicated to investigating the effects of microRNA-128-3p (miR-128-3p) on neuronal apoptosis and neurobehavior in cerebral palsy (CP) rats via the Smurf2/YY1 axis.In vivo modeling of hypoxic-ischemic (HI) CP was established in neonatal rats. Neurobehavioral tests (geotaxis reflex, cliff avoidance reaction, and grip test) were measured after HI induction. The HI-induced neurological injury was evaluated by HE staining, Nissl staining, TUNEL staining, immunohistochemical staining, and RT-qPCR. The expression of miR-128-3p, Smurf2, and YY1 was determined by RT-qPCR and western blot techniques. Moreover, primary cortical neurons were used to establish the oxygen and glucose deprivation (OGD) model in vitro, cell viability was detected by CCK-8 assay, neuronal apoptosis was assessed by flow cytometry and western blot, and the underlying mechanism between miR-128-3p, Smurf2 and YY1 was verified by bioinformatics analysis, dual luciferase reporter assay, RIP, Co-IP, ubiquitination assay, western blot, and RT-qPCR.In vivo, miR-128-3p and YY1 expression was elevated, and Smurf2 expression was decreased in brain tissues of hypoxic-ischemic CP rats. Downregulation of miR-128-3p or overexpression of Smurf2 improved neurobehavioral performance, reduced neuronal apoptosis, and elevated Nestin and NGF expression in hypoxic-ischemic CP rats, and downregulation of Smurf2 reversed the effects of downregulation of miR-128-3p on neurobehavioral performance, neuronal apoptosis, and Nestin and NGF expression in hypoxic-ischemic CP rats, while overexpression of YY1 reversed the effects of Smurf2 on neurobehavioral performance, neuronal apoptosis, and Nestin and NGF expression in hypoxic-ischemic CP rats. In vitro, downregulation of miR-128-3p effectively promoted the neuronal survival, reduced the apoptosis rate, and decreased caspase3 protein expression after OGD, and overexpression of YY1 reversed the ameliorative effect of downregulation of miR-128-3p on OGD-induced neuronal injury. miR-128-3p targeted to suppress Smurf2 to lower YY1 ubiquitination degradation and decrease its expression.Inhibition of miR-128-3p improves neuronal apoptosis and neurobehavioral changes in hypoxic-ischemic CP rats by promoting Smurf2 to promote YY1 ubiquitination degradation and reduce YY1 expression.

Engineered nanovesicles mediated cardiomyocyte survival and neovascularization for the therapy of myocardial infarction

Myocardial infarction (MI) leads to substantial cellular necrosis as a consequence of reduced blood flow and oxygen deprivation. Stimulating cardiomyocyte proliferation and angiogenesis can promote functional recovery after cardiac events. In this study, we explored a novel therapeutic strategy for MI by synthesizing a biomimetic nanovesicle (NV). This biomimetic NVs are composed of exosomes sourced from umbilical cord mesenchymal stem cells, which have been loaded with placental growth factors (PLGF) and surface-engineered with a cardiac-targeting peptide (CHP) through covalent bonding, termed Exo-P-C NVs. With the help of the myocardial targeting effect of homing peptides, NVs can be enriched in the MI site, thus improve cardiac regeneration, reduce fibrosis, stimulate cardiomyocyte proliferation, and promote angiogenesis, ultimately resulted in improved cardiac functional recovery. It was demonstrated that Exo-P-C NVs have the potential to offer novel therapeutic strategies for the improvement of cardiac function and management of myocardial infarction.

Ginsenoside CK cooperates with bone mesenchymal stem cells to enhance angiogenesis post-stroke via GLUT1 and HIF-1α/VEGF pathway.

The transplantation of bone marrow mesenchymal stem cells (MSCs) in stroke is hindered by the restricted rates of survival and differentiation. Ginsenoside compound K (CK), is reported to have a neuroprotective effect and regulate energy metabolism. We applied CK to investigate if CK could promote the survival of MSCs and differentiation into brain microvascular endothelial-like cells (BMECs), thereby alleviating stroke symptoms. Therefore, transwell and middle cerebral artery occlusion (MCAO) models were used to mimic oxygen and glucose deprivation (OGD) in vitro and in vivo, respectively. Our results demonstrated that CK had a good affinity for GLUT1, which increased the expression of GLUT1 and the production of ATP, facilitated the proliferation and migration of MSCs, and activated the HIF-1α/VEGF signaling pathway to promote MSC differentiation. Moreover, CK cooperated with MSCs to protect BMECs, promote angiogenesis and vascular density, enhance neuronal and astrocytic proliferation, thereby reducing infarct volume and consequently improving neurobehavioral outcomes. These results suggest that the synergistic effects of CK and MSCs could potentially be a promising strategy for stroke.

Myelin endocytosis by brain endothelial cells causes endothelial iron overload and oligodendroglial iron hunger in hypoperfusion-induced white matter injury.

Hypoperfusion induces significant white matter injury in cerebral vascular disorders, including arteriosclerotic cerebral small vessel disease (aCSVD), which is prevalent among the elderly. Iron transport by blood vessel endothelial cells (BVECs) from the periphery supports oligodendrocyte maturation and white matter repair. This study aims to elucidate the association between iron homeostasis changes and white matter injury severity, and explore the crosstalk between BVECs and oligodendroglial lineage cells. In vivo: C57BL/6 mice were subjected to unilateral common carotid artery occlusion (UCCAO). Invitro: BVECs with myelin pretreatment were co-cultured with oligodendrocyte progenitor cells (OPCs) or organotypic cerebellar slices subjected to oxygen and glucose deprivation. Circulatory iron tends to be stored in aCSVD patients with white matter injury. Myelin debris endocytosis by BVECs impairs iron transport, trapping iron in the blood and away from the brain, worsening oligodendrocyte iron deficiency in hypoperfusion-induced white matter injury. Iron accumulation in BVECs triggers ferroptosis, suppressing iron transport and hindering white matter regeneration. Intranasal holo-transferrin (hTF) administration bypassing the BBB alleviates oligodendrocyte iron deficiency and promotes myelin regeneration in hypoperfusion-induced white matter injury. The iron imbalance between BVECs and oligodendroglial lineage cells is a potential therapeutic target in hypoperfusion-induced white matter injury.

Deciphering the neuroprotective mechanisms of RACK1 in cerebral ischemia-reperfusion injury: Pioneering insights into mitochondrial autophagy and the PINK1/Parkin axis.

Cerebral ischemia-reperfusion injury (CIRI) is a common and debilitating complication of cerebrovascular diseases such as stroke, characterized by mitochondrial dysfunction and cell apoptosis. Unraveling the molecular mechanisms behind these processes is essential for developing effective CIRI treatments. This study investigates the role of RACK1 (receptor for activated C kinase 1) in CIRI and its impact on mitochondrial autophagy. We utilized high-throughput transcriptome sequencing and weighted gene co-expression network analysis (WGCNA) to identify core genes associated with CIRI. Invitro experiments used human neuroblastoma SK-N-SH cells subjected to oxygen and glucose deprivation (OGD) to simulate ischemia, followed by reperfusion (OGD/R). RACK1 knockout cells were created using CRISPR/Cas9 technology, and cell viability, apoptosis, and mitochondrial function were assessed. Invivo experiments involved middle cerebral artery occlusion/reperfusion (MCAO/R) surgery in rats, evaluating neurological function and cell apoptosis. Our findings revealed that RACK1 expression increases during CIRI and is protective by regulating mitochondrial autophagy through the PINK1/Parkin pathway. Invitro, RACK1 knockout exacerbated cell apoptosis, while overexpression of RACK1 reversed this process, enhancing mitochondrial function. Invivo, RACK1 overexpression reduced cerebral infarct volume and improved neurological deficits. The regulatory role of RACK1 depended on the PINK1/Parkin pathway, with RACK1 knockout inhibiting PINK1 and Parkin expression, while RACK1 overexpression restored them. This study demonstrates that RACK1 safeguards against neural damage in CIRI by promoting mitochondrial autophagy through the PINK1/Parkin pathway. These findings offer crucial insights into the regulation of mitochondrial autophagy and cell apoptosis by RACK1, providing a promising foundation for future CIRI treatments.

Role of mitochondria in neonatal hypoxic-ischemic encephalopathy.

Neonatal hypoxic-ischemic encephalopathy, an important cause of death as well as long-term disability in survivors, is caused by oxygen and glucose deprivation, and limited blood flow. Following hypoxic-ischemic injury in the neonatal brain, three main biochemical damages (excitotoxicity, oxidative stress, and exacerbated inflammation) are triggered. Mitochondria are involved in all three cascades. Mitochondria are the nexus of metabolic pathways to offer most of the energy that our body needs. Hypoxic-ischemic injury affects the characteristics of mitochondria, including dynamics, permeability, and ATP production, which also feed back into the process of neonatal hypoxic-ischemic encephalopathy. Mitochondria can be a cellular hub in inflammation, which is another main response of the injured neonatal brain. Some treatments for neonatal hypoxic-ischemic encephalopathy affect the function of mitochondria or target mitochondria, including therapeutic hypothermia and erythropoietin. This review presents the main roles of mitochondria in neonatal hypoxic-ischemic encephalopathy and discusses some potential treatments directed at mitochondria, which may foster the development of new therapeutic strategies for this encephalopathy.

Pharmacological induction of the hypoxia response pathway in Huh7 hepatoma cells limits proliferation but increases resilience under metabolic stress

The hypoxia response pathway enables adaptation to oxygen deprivation. It is mediated by hypoxia-inducible factors (HIF), which promote metabolic reprogramming, erythropoiesis, angiogenesis and tissue remodeling. This led to the successful development of HIF-inducing drugs for treating anemia and some of these molecules are now in clinic. However, elevated levels of HIFs are frequently associated with tumor growth, poor prognosis, and drug resistance in various cancers, including hepatocellular carcinoma (HCC). Consequently, there are concerns regarding the recommendation of HIF-inducing drugs in certain clinical situations. Here, we analyzed the effects of two HIF-inducing drugs, Molidustat and Roxadustat, in the well-characterized HCC cell line Huh7. These drugs increased HIF-1α and HIF-2α protein levels which both participate in inducing hypoxia response genes such as BNIP3, SERPINE1, LDHA or EPO. Combined transcriptomics, proteomics and metabolomics showed that Molidustat increased the expression of glycolytic enzymes, while the mitochondrial network was fragmented and cellular respiration decreased. This metabolic remodeling was associated with a reduced proliferation and a lower demand for pyrimidine supply, but an increased ability of cells to convert pyruvate to lactate. This was accompanied by a higher resistance to the inhibition of mitochondrial respiration by antimycin A, a phenotype confirmed in Roxadustat-treated Huh7 cells and Molidustat-treated hepatoblastoma cells (Huh6 and HepG2). Overall, this study shows that HIF-inducing drugs increase the metabolic resilience of liver cancer cells to metabolic stressors, arguing for careful monitoring of patients treated with HIF-inducing drugs, especially when they are at risk of liver cancer.

Hypoxic-Ischemic Encephalopathy: Pathogenesis and Promising Therapies.

Hypoxic-ischemic encephalopathy (HIE) is a brain lesion caused by inadequate blood supply and oxygen deprivation, often occurring in neonates. It has emerged as a grave complication of neonatal asphyxia, leading to chronic neurological damage. Nevertheless, the precise pathophysiological mechanisms underlying HIE are not entirely understood. This paper aims to comprehensively elucidate the contributions of hypoxia-ischemia, reperfusion injury, inflammation, oxidative stress, mitochondrial dysfunction, excitotoxicity, ferroptosis, endoplasmic reticulum stress, and apoptosis to the onset and progression of HIE. Currently, hypothermia therapy stands as the sole standard treatment for neonatal HIE, albeit providing only partial neuroprotection. Drug therapy and stem cell therapy have been explored in the treatment of HIE, exhibiting certain neuroprotective effects. Employing drug therapy or stem cell therapy as adjunctive treatments to hypothermia therapy holds great significance. This article presents a systematic review of the pathogenesis and treatment strategies of HIE, with the goal of enhancing the effect of treatment and improving the quality of life for HIE patients.

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.