HIF-1, an important regulator in potential new therapeutic approaches to ischemic stroke

SLC15A3 is transcriptionally regulated by HIF1α and p65 to worsen neuroinflammation in experimental ischemic stroke

Systemic inflammatory stimulus is a risk factor for the incidence of ischemic stroke and contributes to poorer clinical outcomes. Solute carrier 15A3 (SLC15A3) is a peptide/histidine transporter that is implicated in regulating inflammatory responses. However, whether SLC15A3 affects the progression of ischemic stroke associated with systemic inflammation is unclear. The transient middle cerebral artery occlusion (tMCAO) mice with LPS administration (LPS/tMCAO) were prepared as an in vivo model, and LPS-induced BV2 cells under oxygen-glucose deprivation (OGD) exposure were utilized as an in vitro model. We found that SLC15A3 was highly expressed in the ischemic penumbra of LPS/tMCAO mice, and its inhibition reduced infarct area, attenuated neurological deficit, recovered motor function, and mitigated apoptotic neurons. Knockdown of SLC15A3 suppressed the proinflammatory M1-type markers and promoted the levels of M2-associated genes. The in vitro results confirmed that SLC15A3 overexpression promoted microglia polarizing towards M1 subtypes, while SLC15A3 inhibition exerted an opposite effect. In addition, we demonstrated that the p65 signaling pathway and HIF1α were activated by LPS/OGD. Luciferase reporter assay showed that inhibiting p65 using its specific inhibitor BAY 11-7082 or silencing HIF1α using siRNAs reduced the transcriptional activity of SLC15A3 in LPS/OGD-induced BV2 cells. Results in NIH 3T3 cells also confirmed that p65 and HIF1α directly bound to the SLC15A3 promoter to activate SLC15A3 transcription. In conclusion, this work shows that SLC15A3, transcriptionally activated by p65 and HIF1α, contributes to poor outcomes in ischemic stroke associated with systemic inflammation by promoting microglial cells polarizing towards M1 types.

Intrathecal lactate dehydrogenase A inhibitors FX11 and oxamate alleviate chronic constriction injury-induced nociceptive sensitization through neuroinflammation and angiogenesis

BACKGROUND

Neuropathic pain involves neuroinflammation and upregulation of glycolysis in the central nervous system. Unfortunately, few effective treatments are available for managing this type of pain. The overactivation of lactate dehydrogenase A (LDHA), an essential enzyme in glycolysis, can cause neuroinflammation and nociception. This study investigated the spinal role of LDHA in neuropathic pain.

METHOD

Using immunohistochemical analysis, nociceptive behavior, and western blotting, we evaluated the cellular mechanisms of intrathecal administration of LDHA inhibitors, including FX11 and oxamate, in chronic constriction injury (CCI)-induced neuropathic rats.

RESULT

FX11 and oxamate attenuated CCI-induced neuronal LDHA upregulation and nociceptive sensitization. Moreover, CCI-induced neuroinflammation, microglial polarization, and angiogenesis were attenuated by LDHA inhibitors. These inhibitors regulate the TANK binding kinase-1 (TBK1)/hypoxia-inducible factor 1 subunit alpha (HIF-1α) axis, crucial for controlling inflammation and new blood vessel growth. Additionally, CCI-induced nuclear LDHA translocation, as associated with oxidative stress resistance, was attenuated by LDHA inhibitors.

CONCLUSION

In conclusion, LDHA may be a potential therapeutic target for treating neuropathic pain by regulating neuroinflammation and angiogenesis.

Lactylation and Ischemic Stroke: Research Progress and Potential Relationship

Ischemic stroke is caused by interrupted cerebral blood flow and is a leading cause of mortality and disability worldwide. Significant advancements have been achieved in comprehending the pathophysiology of stroke and the fundamental mechanisms responsible for ischemic damage. Lactylation, as a newly discovered post-translational modification, has been reported to participate in several physiological and pathological processes. However, research on lactylation and ischemic stroke is scarce. This review summarized the current function of protein lactylation in other diseases or normal physiological processes and explored their potential link with the pathophysiological process and the reparative mechanism of ischemic stroke. We proposed that neuroinflammation, regulation of metabolism, regulation of messenger RNA translation, angiogenesis, and neurogenesis might be the bridge linking lactylation and ischemic stroke. Our study provided a novel perspective for comprehending the role of protein lactylation in the pathophysiological processes underlying ischemic stroke. Lactylation might be a promising target in drug development of ischemic stroke.

The role of ACSL4 in stroke: mechanisms and potential therapeutic target

Stroke, as a neurological disorder with a poor overall prognosis, has long plagued the patients. Current stroke therapy lacks effective treatments. Ferroptosis has emerged as a prominent subject of discourse across various maladies in recent years. As an emerging therapeutic target, notwithstanding its initial identification in tumor cells associated with brain diseases, it has lately been recognized as a pivotal factor in the pathological progression of stroke. Acyl-CoA synthetase long-chain family member 4 (ACSL4) is a potential target and biomarker of catalytic unsaturated fatty acids mediating ferroptosis in stroke. Specifically, the upregulation of ACSL4 leads to heightened accumulation of lipid peroxidation products and reactive oxygen species (ROS), thereby exacerbating the progression of ferroptosis in neuronal cells. ACSL4 is present in various tissues and involved in multiple pathways of ferroptosis. At present, the pharmacological mechanisms of targeting ACSL4 to inhibit ferroptosis have been found in many drugs, but the molecular mechanisms of targeting ACSL4 are still in the exploratory stage. This paper introduces the physiopathological mechanism of ACSL4 and the current status of the research involved in ferroptosis crosstalk and epigenetics, and summarizes the application status of ACSL4 in modern pharmacology research, and discusses the potential application value of ACSL4 in the field of stroke.

Development of a new paradigm model for deciphering action mechanism of Danhong injection using a combination of isothermal shift assay and database interrogation

BACKGROUND

Identification of active components of traditional Chinese Medicine (TCM) and their respective targets is important for understanding the mechanisms underlying TCM efficacy. However, there are still no effective technical methods to achieve this.

METHODS

Herein, we have established a method for rapidly identifying targets of a specific TCM and interrogating the targets with their corresponding active components based on Isothermal Shift Assay (iTSA) and database interrogation.

RESULTS

We optimized iTSA workflow and identified 110 targets for Danhong injection (DHI) which is used as an effective remedy for cardiovascular and cerebrovascular diseases. Moreover, we identified the targets of the nine major ingredients found in DHI. Database interrogation found that the potential targets for DHI, in which we verified that ADK as the target for salvianolic acid A and ALDH1B1 as the target for protocatechualdehyde in DHI, respectively.

CONCLUSION

Overall, we established a novel paradigm model for the identification of targets and their respective ingredients in DHI, which facilitates the discovery of drug candidates and targets for improving disease management and contributes to revealing the underlying mechanisms of TCM and fostering TCM development and modernization.

Hypoxia Pathways in Parkinson's Disease: From Pathogenesis to Therapeutic Targets

The human brain is highly dependent on oxygen, utilizing approximately 20% of the body's oxygen at rest. Oxygen deprivation to the brain can lead to loss of consciousness within seconds and death within minutes. Recent studies have identified regions of the brain with spontaneous episodic hypoxia, referred to as "hypoxic pockets". Hypoxia can also result from impaired blood flow due to conditions such as heart disease, blood clots, stroke, or hemorrhage, as well as from reduced oxygen intake or excessive oxygen consumption caused by factors like low ambient oxygen, pulmonary diseases, infections, inflammation, and cancer. Severe hypoxia in the brain can manifest symptoms similar to Parkinson's disease (PD), including cerebral edema, mood disturbances, and cognitive impairments. Additionally, the development of PD appears to be closely associated with hypoxia and hypoxic pathways. This review seeks to investigate the molecular interactions between hypoxia and PD, emphasizing the pathological role of hypoxic pathways in PD and exploring their potential as therapeutic targets.

Mechanisms underlying delirium in patients with critical illness

Delirium is an acute, global cognitive disorder syndrome, also known as acute brain syndrome, characterized by disturbance of attention and awareness and fluctuation of symptoms. Its incidence is high among critically ill patients. Once patients develop delirium, it increases the risk of unplanned extubation, prolongs hospital stay, increases the risk of nosocomial infection, post-intensive care syndrome-cognitive impairment, and even death. Therefore, it is of great importance to understand how delirium occurs and to reduce the incidence of delirium in critically ill patients. This paper reviews the potential pathophysiological mechanisms of delirium in critically ill patients, with the aim of better understanding its pathophysiological processes, guiding the formulation of effective prevention and treatment strategies, providing a basis for clinical medication.

Characteristics of two different immune infiltrating pyroptosis subtypes in ischemic stroke

Background

Ischemic stroke (IS) is a serious health hazard and identified as the second leading cause of mortality around the world. However, the role of pyroptosis in the immune microenvironment regulation in IS is still unclear. Here, our study aims to elucidate the effect of pyroptosis on immune microenvironment in IS.

Methods

The regulation mode of pyroptosis in IS was systematically evaluated, and its effects on immune microenvironment were explored, including infiltration of immune cells, immune response gene sets, and human leukocyte antigen (HLA) gene. The genes and drugs related to pyroptosis phenotype were also identified. An MCAO rat model was constructed, and the mRNA expression levels in the classifier model were validated by qRT-PCR.

Results

The separator is composed of 11 pyroptosis genes, out of which 10 genes could distinguish between ischemic stroke and control samples. CHMP2A, CHMP4A, and NAIP genes are significantly related to immune infiltrating cells, immune response gene sets, and HLA. However, two different pyroptosis subtypes mediated by 10 pyroptosis genes were identified, which were different in immune cell abundance, HLA genes, and immune response gene sets. Furthermore, 199 genes associated with pyroptosis phenotype was identified along with the analysis of biological functions.

Conclusion

These findings reveal the potential mechanism of pyroptosis in the immune microenvironment of IS, indicating that pyroptosis functions as a vital component in the complexity and diversity of the immune microenvironment in patients with IS.

Anaerobic Glycolysis and Ischemic Stroke: From Mechanisms and Signaling Pathways to Natural Product Therapy

Ischemic stroke is a serious condition that results in high rates of illness and death. Anaerobic glycolysis becomes the primary means of providing energy to the brain during periods of low oxygen levels, such as in the aftermath of an ischemic stroke. This process is essential for maintaining vital brain functions and has significant implications for recovery following a stroke. Energy supply by anaerobic glycolysis and acidosis caused by lactic acid accumulation are important pathological processes after ischemic stroke. Numerous natural products regulate glucose and lactate, which in turn modulate anaerobic glycolysis. This article focuses on the relationship between anaerobic glycolysis and ischemic stroke, as well as the associated signaling pathways and natural products that play a therapeutic role. These natural products, which can regulate anaerobic glycolysis, will provide new avenues and perspectives for the treatment of ischemic stroke in the future.

Unraveling the Triad: Hypoxia, Oxidative Stress and Inflammation in Neurodegenerative Disorders

The mammalian brain's complete dependence on oxygen for ATP production makes it highly susceptible to hypoxia, at high altitudes or in clinical scenarios including anemia or pulmonary disease. Hypoxia plays a crucial role in the development of various brain disorders, such as Alzheimer's, Parkinson's, and other age-related neurodegenerative diseases. On the other hand, a decrease in environmental oxygen levels, such as prolonged stays at high elevations, may have beneficial impacts on the process of ageing and the likelihood of death. Additionally, the utilization of controlled hypoxia exposure could potentially serve as a therapeutic approach for age-related brain diseases. Recent findings indicate that the involvement of HIF-1α and the NLRP3 inflammasome is of significant importance in the development of Alzheimer's disease. HIF-1α serves as a pivotal controller of various cellular reactions to oxygen deprivation, exerting influence on a multitude of physiological mechanisms such as energy metabolism and inflammatory responses. The NLRP3 plays a crucial role in the innate immune system by coordinating the initiation of inflammatory reactions through the assembly of the inflammasome complex. This review examines the information pertaining to the contrasting effects of hypoxia on the brain, highlighting both its positive and deleterious effects and molecular pathways that are involved in mediating these different effects. This study explores potential strategies for therapeutic intervention that focus on restoring cellular balance and reducing neuroinflammation, which are critical aspects in addressing this severe neurodegenerative condition and addresses crucial inquiries that warrant further future investigations.

Intrathecal Fumagillin Alleviates Chronic Neuropathy-Induced Nociceptive Sensitization and Modulates Spinal Astrocyte-Neuronal Glycolytic and Angiogenic Proteins

Nociceptive sensitization is accompanied by the upregulation of glycolysis in the central nervous system in neuropathic pain. Growing evidence has demonstrated glycolysis and angiogenesis to be related to the inflammatory processes. This study investigated whether fumagillin inhibits neuropathic pain by regulating glycolysis and angiogenesis. Fumagillin was administered through an intrathecal catheter implanted in rats with chronic constriction injury (CCI) of the sciatic nerve. Nociceptive, behavioral, and immunohistochemical analyses were performed to evaluate the effects of the inhibition of spinal glycolysis-related enzymes and angiogenic factors on CCI-induced neuropathic pain. Fumagillin reduced CCI-induced thermal hyperalgesia and mechanical allodynia from postoperative days (POD) 7 to 14. The expression of angiogenic factors, vascular endothelial growth factor (VEGF) and angiopoietin 2 (ANG2), increased in the ipsilateral lumbar spinal cord dorsal horn (SCDH) following CCI. The glycolysis-related enzymes, pyruvate kinase M2 (PKM2) and lactate dehydrogenase A (LDHA) significantly increased in the ipsilateral lumbar SCDH following CCI on POD 7 and 14 compared to those in the control rats. Double immunofluorescence staining indicated that VEGF and PKM2 were predominantly expressed in the astrocytes, whereas ANG2 and LDHA were predominantly expressed in the neurons. Intrathecal infusion of fumagillin significantly reduced the expression of angiogenic factors and glycolytic enzymes upregulated by CCI. The expression of hypoxia-inducible factor-1α (HIF-1α), a crucial transcription factor that regulates angiogenesis and glycolysis, was also upregulated after CCI and inhibited by fumagillin. We concluded that intrathecal fumagillin may reduce the expression of ANG2 and LDHA in neurons and VEGF and PKM2 in the astrocytes of the SCDH, further attenuating spinal angiogenesis in neuropathy-induced nociceptive sensitization. Hence, fumagillin may play a role in the inhibition of peripheral neuropathy-induced neuropathic pain by modulating glycolysis and angiogenesis.

Cerebral endothelial cells mediated enhancement of brain pericyte number and migration in oxygen-glucose deprivation involves the HIF-1α/PDGF-β signaling

The present study focused on whether hypoxia-inducible factor-1alpha (HIF-1α) and platelet-derived factor-beta (PDGF-β) are involved in the crosstalk between brain microvascular endothelial cells (BMECs) and brain vascular pericytes (BVPs) under ischaemic-hypoxic conditions. Mono-cultures or co-cultures of BVPs and BMECs were made for the construction of the blood-brain barrier (BBB) model in vitro and then exposed to control and oxygen-glucose deprivation (OGD) conditions. BBB injury was determined by assessing the ability, apoptosis, and migration of BVPs and the transendothelial electrical resistance and horseradish peroxidase permeation of BMECs. Relative mRNA and protein levels of HIF-1α and PDGF-β, as well as tight junction proteins ZO-1 and claudin-5 were analyzed by western blotting, reverse transcription quantitative PCR, and/or immunofluorescence staining. Dual-luciferase reporter assays assessed the relationship between PDGF-β and HIF-1α. Co-culturing with BMECs alleviated OGD-induced reduction in BVP viability, elevation in BVP apoptosis, and repression in BVP migration. Co-culturing with BVPs protected against OGD-induced impairment on BMEC permeability. OGD-induced HIF-1α upregulation enhanced PDGF-β expression in mono-cultured BMECs and co-cultured BMECs with BVPs. Knockdown of HIF-1α impaired the effect of BMECs on BVPs under OGD conditions, and PDGFR-β silencing in BVPs blocked the crosstalk between BMECs and BVPs under OGD conditions. The crosstalk between BMECs and BVPs was implicated in OGD-induced BBB injury through the HIF-1α/PDGF-β signaling.

A New Perspective in the Treatment of Ischemic Stroke: Ferroptosis

Ischemic stroke is a common neurological disease. Currently, there are no Food and Drug Administration-approved drugs that can maximize the improvement in ischemic stroke-induced nerve damage. Hence, treating ischemic stroke remains a clinical challenge. Ferroptosis has been increasingly studied in recent years, and it is closely related to the pathophysiological process of ischemic stroke. Iron overload, reactive oxygen species accumulation, lipid peroxidation, and glutamate accumulation associated with ferroptosis are all present in ischemic stroke. This article focuses on describing the relationship between ferroptosis and ischemic stroke and summarizes the relevant substances that ameliorate ischemic stroke-induced neurological damage by inhibiting ferroptosis. Finally, the problems in the treatment of ischemic stroke targeting ferroptosis are discussed, hoping to provide a new direction for its treatment.

The Inhibitory Effects of Propofol on Colorectal Cancer Progression through the NF-κB/HIF-1α Signaling Pathway

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) is a neoplastic disease that gradually develops due to genetic variations and epigenetic changes. Surgical excision is the first-line treatment for CRC. Accumulating evidence has shown that total intravenous anesthesia has beneficial effects for CRC patients as it decreases the probability of tumor recurrence and metastasis. Propofol is one of the most frequently used intravenous anesthetics in clinical practice. However, it remains unknown whether it can reduce recurrence and metastasis after surgery in cancer patients.

METHODS

CRC cell lines (HCT116 and SW480) were cultured in vitro, and different concentrations of propofol were added to the cell culture medium. The proliferation effect of propofol on CRC cell lines was evaluated by CCK-8 assay. The effect of propofol on the migration and invasion of CRC cells was evaluated by scratch healing and Transwell experiments. The inhibitory effects of propofol on NF-κB and HIF-1α expressions in CRC cell lines were determined by Western blotting and immunofluorescence assays to further clarify the regulatory effects of propofol on NF-κB and HIF-1α.

RESULTS

Compared to the control, propofol significantly inhibited the proliferation, migration, and invasion abilities of CRC cells (HCT116 and SW480) (p < 0.0001). The expression levels of NF-κB and HIF-1α gradually decreased with increasing propofol concentration in both cell lines. After activation and inhibition of NF-κB, the expression of HIF-1α changed. Further studies showed that propofol inhibited LPS-activated NF-κB-induced expression of HIF-1α, similar to the NF-κB inhibitor Bay17083 (p < 0.0001).

CONCLUSION

In vitro, propofol inhibited the proliferation, migration, and invasion of CRC cells (HCT116 and SW480) in a dose-dependent manner, possibly by participating in the regulation of the NF-κB/HIF-1α signaling pathway.