PTP1B inhibition ameliorates inflammatory injury and dysfunction in ox‑LDL‑induced HUVECs by activating the AMPK/SIRT1 signaling pathway via negative regulation of KLF2

From Tyrosine Kinases to Tyrosine Phosphatases: New Therapeutic Targets in Cancers and Beyond

Protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) regulate the level of tyrosine phosphorylation in proteins. PTKs are key enzymes that catalyze the transfer of an ATP phosphoric acid to a tyrosine residue on target protein substrates. Protein tyrosine phosphatases (PTPs) are responsible for the dephosphorylation of tyrosine residues and play a role in countering PTK overactivity. As widespread oncogenes, PTKs were once considered to be promising targets for therapy. However, tyrosine kinase inhibitors (TKIs) now face a number of challenges, including drug resistance and toxic side effects. Treatment strategies now need to be developed from a new perspective. In this review, we assess the current state of TKIs and highlight the role of PTPs in cancer and other diseases. With the advances of allosteric inhibition and the development of multiple alternative proprietary drug strategies, the reputation of PTPs as "undruggable" targets has been overturned, and they are now considered viable therapeutic targets. We also discuss the strategies and prospects of PTP-targeted therapy, as well as its future development.

Mild traumatic brain injury in Drosophila melanogaster alters reactive oxygen and nitrogen species in a sex-dependent manner

Traumatic brain injury (TBI) is an outside force causing a modification in brain function and/or structural brain pathology that upregulates brain inducible nitric oxide synthase (iNOS), instigating increased levels of nitric oxide activity which is implicated in secondary pathology leading to behavioral deficits (Hall et al., 2012; Garry et al., 2015; Kozlov et al., 2017). In mammals, TBI-induced NO production activates an immune response and potentiates metabolic crisis through mitochondrial dysfunction coupled with vascular dysregulation; however, the direct influence on pathology is complicated by the activation of numerous secondary cascades and activation of other reactive oxygen species. Drosophila TBI models have demonstrated key features of mammalian TBI, including temporary incapacitation, disorientation, motor deficits, activation of innate immunity (inflammation), and autophagy responses observed immediately after injury (Katzenberger et al., 2013; Barekat et al., 2016; Simon et al., 2017; Anderson et al., 2018; Buhlman et al., 2021b). We hypothesized that acute behavioral phenotypes would be associated with deficits in climbing behavior and increased oxidative stress. Because flies lack mammalian-like cardiovascular and adaptive immune systems, we were able to make our observations in the absence of vascular disruption and adaptive immune system interference in a system where highly targeted interventions can be rapidly evaluated. To demonstrate the induction of injury, ten-day-old transgenic flies received an injury of increasing angles from a modified high impact trauma (HIT) device where angle-dependent increases occurred for acute neurological behavior assessments and twenty-four-hour mortality, and survival was significantly decreased. Injury caused sex-dependent effects on climbing activity and measures of oxidative stress. Specifically, after a single 60-degree HIT, female flies exhibited significant impairments in climbing activity beyond that observed in male flies. We also found that several measures of oxidative stress, including Drosophila NOS (dNOS) expression, protein nitration, and hydrogen peroxide production were significantly decreased in female flies. Interestingly, protein nitration was also decreased in males, but surpassed sham levels with a more severe injury. We also observed decreased autophagy demand in vulnerable dopaminergic neurons in female, but not male flies. In addition, mitophagy initiation was decreased in females. Collectively, our data suggest that TBI in flies induces acute behavioral phenotypes and climbing deficits that are analogous to mammalian TBI. We also observed that various indices of oxidative stress, including dNOS expression, protein tyrosine nitration, and hydrogen peroxide levels, as well as basal levels of autophagy, are altered in response to injury, an effect that is more pronounced in female flies.

New Dawn for Atherosclerosis: Vascular Endothelial Cell Senescence and Death

Endothelial cells (ECs) form the inner linings of blood vessels, and are directly exposed to endogenous hazard signals and metabolites in the circulatory system. The senescence and death of ECs are not only adverse outcomes, but also causal contributors to endothelial dysfunction, an early risk marker of atherosclerosis. The pathophysiological process of EC senescence involves both structural and functional changes and has been linked to various factors, including oxidative stress, dysregulated cell cycle, hyperuricemia, vascular inflammation, and aberrant metabolite sensing and signaling. Multiple forms of EC death have been documented in atherosclerosis, including autophagic cell death, apoptosis, pyroptosis, NETosis, necroptosis, and ferroptosis. Despite this, the molecular mechanisms underlying EC senescence or death in atherogenesis are not fully understood. To provide a comprehensive update on the subject, this review examines the historic and latest findings on the molecular mechanisms and functional alterations associated with EC senescence and death in different stages of atherosclerosis.

Research Progress and Molecular Mechanisms of Endothelial Cells Inflammation in Vascular-Related Diseases

Endothelial cells (ECs) are widely distributed inside the vascular network, forming a vital barrier between the bloodstream and the walls of blood vessels. These versatile cells serve myriad functions, including the regulation of vascular tension and the management of hemostasis and thrombosis. Inflammation constitutes a cascade of biological responses incited by biological, chemical, or physical stimuli. While inflammation is inherently a protective mechanism, dysregulated inflammation can precipitate a host of vascular pathologies. ECs play a critical role in the genesis and progression of vascular inflammation, which has been implicated in the etiology of numerous vascular disorders, such as atherosclerosis, cardiovascular diseases, respiratory diseases, diabetes mellitus, and sepsis. Upon activation, ECs secrete potent inflammatory mediators that elicit both innate and adaptive immune reactions, culminating in inflammation. To date, no comprehensive and nuanced account of the research progress concerning ECs and inflammation in vascular-related maladies exists. Consequently, this review endeavors to synthesize the contributions of ECs to inflammatory processes, delineate the molecular signaling pathways involved in regulation, and categorize and consolidate the various models and treatment strategies for vascular-related diseases. It is our aspiration that this review furnishes cogent experimental evidence supporting the established link between endothelial inflammation and vascular-related pathologies, offers a theoretical foundation for clinical investigations, and imparts valuable insights for the development of therapeutic agents targeting these diseases.

Traumatic brain injury and immunological outcomes: the double-edged killer

Traumatic brain injury (TBI) is a significant cause of mortality and morbidity worldwide resulting from falls, car accidents, sports, and blast injuries. TBI is characterized by severe, life-threatening consequences due to neuroinflammation in the brain. Contact and collision sports lead to higher disability and death rates among young adults. Unfortunately, no therapy or drug protocol currently addresses the complex pathophysiology of TBI, leading to the long-term chronic neuroinflammatory assaults. However, the immune response plays a crucial role in tissue-level injury repair. This review aims to provide a better understanding of TBI's immunobiology and management protocols from an immunopathological perspective. It further elaborates on the risk factors, disease outcomes, and preclinical studies to design precisely targeted interventions for enhancing TBI outcomes.

Drug discovery and amyotrophic lateral sclerosis: Emerging challenges and therapeutic opportunities

Amyotrophic lateral sclerosis (ALS) is characterized by the degeneration of upper and lower motor neurons (MNs) leading to paralysis and, ultimately, death by respiratory failure 3-5 years after diagnosis. Edaravone and Riluzole, the only drugs currently approved for ALS treatment, only provide mild symptomatic relief to patients. Extraordinary progress in understanding the biology of ALS provided new grounds for drug discovery. Over the last two decades, mitochondria and oxidative stress (OS), iron metabolism and ferroptosis, and the major regulators of hypoxia and inflammation - HIF and NF-κB - emerged as promising targets for ALS therapeutic intervention. In this review, we focused our attention on these targets to outline and discuss current advances in ALS drug development. Based on the challenges and the roadblocks, we believe that the rational design of multi-target ligands able to modulate the complex network of events behind the disease can provide effective therapies in a foreseeable future.

Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities

Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.

Chromatographic measurement of 3-hydroxyanthranilate 3,4-dioxygenase activity reveals that edaravone can mitigate the formation of quinolinic acid through a direct enzyme inhibition

Herein it is reported the development and application of two chromatographic assays for the measurement of the activity of 3-Hydroxyanthranilate-3,4-dioxygenase (3HAO). Such an enzyme converts 3-Hydroxyanthranilic acid (3HAA) to 2-amino-3-carboxymuconic semialdehyde (ACMS), which undergo a spontaneous, non-enzymatic cyclization to produce quinolinic acid (QUIN). The enzyme activity was measured by quantitation of the substrate consumption over time either with spectrophotometric (UV) or mass spectrometric (MS) detection upon reversed-phase chromatographic separation. MS detection resulted more selective and sensitive, but less accurate and precise. However, both methods have sufficient sensitivity to allow the measurement of enzyme activity with consistent results compared to literature data. Since MS detection allowed less sample consumption it was used to calculate the kinetics parameters (i.e., Vmax and Kd) of recombinant 3HAO. Another MS-based method was then developed to measure the amount of QUIN produced, revealing an incomplete conversion of 3HAA to QUIN. As suggested by previous studies, the enzyme activity was apparently sensitive to the redox state of the enzyme thiols. In fact, thiol reducing agents such as dithiothreitol (DTT) and glutathione (GSH), can alter the enzyme activity although the investigation on the exact mechanism involved in such effect was beyond the scope of the research. Interestingly, edaravone (EDA) induced an in vitro suppression of QUIN production through direct, competitive 3HAO inhibition. EDA is a molecule approved for the treatment of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease associated with an increase of QUIN concentrations in both serum and cerebrospinal fluid. Although EDA was reported to mitigate ALS progression its mode of action is still largely unknown. Some studies reported antioxidant and radical scavenger properties of EDA, but none confirm a direct activity as 3HAO enzyme inhibitor. Since QUIN is reported to be a neurotoxic metabolite, 3HAO inhibition can contribute to the beneficial effect of EDA in ALS, although such a mechanism must be then confirmed in vivo. However, EDA might be a convenient scaffold for the design of selective 3HAO inhibitors with potential applications in ALS treatment.

Edaravone Improves the Post-traumatic Brain Injury Dysfunction in Learning and Memory by Modulating Nrf2/ARE Signal Pathway

OBJECTIVES

To investigate the molecular mechanism of edaravone (EDA) in improving the post-traumatic brain injury (TBI) dysfunction in learning and memory.

METHODS

In vitro and in vivo TBI models were established using hydrogen peroxide (H2O2) treatment for hippocampal nerve stem cells (NSCs) and surgery for rats, followed by EDA treatment. WST 1 measurement, methylthiazol tetrazolium assay, and flow cytometry were performed to determine the activity, proliferation, and apoptosis of NSCs, and malondialdehyde (MDA), lactic dehydrogenase (LDH), and reactive oxygen species (ROS) detection kits were used to analyze the oxides in NSCs.

RESULTS

Following EDA pretreatment, NSCs presented with promising resistance to H2O2-induced oxidative stress, whereas NSCs manifested significant increases in activity and proliferation and a decrease in apoptosis. Meanwhile, for NSCs, EDA pretreatment reduced the levels of MDA, LDH, and ROS, with a significant upregulation of Nrf2/antioxidant response element (ARE) signaling pathway, whereas for EDA-treated TBI rats, a significant reduction was observed in the trauma area and injury to the hippocampus, with improvement in memory and learning performance and upregulation of Nrf2/ARE signaling pathway.

CONCLUSIONS

EDA, by regulating the activity of Nrf2/ARE signal pathway, can improve the TBI-induced injury to NSCs and learning and memory dysfunction in rats.