Serum myoglobin modulates kidney injury via inducing ferroptosis after exertional heatstroke

Screening Differentially Expressed Proteins in Areca Nut-Related Oral Squamous Cell Carcinoma Using Tandem Mass Tag Proteomics

OBJECTIVE

Areca nut chewing has been associated with a poor prognosis in oral squamous cell carcinoma (OSCC). This study seeks to identify differentially expressed proteins among areca nut-related OSCC,non-areca nut-related OSCC and adjacent normal epithelial tissues, with the aim of providing novel insights for the investigation of areca nut-related OSCC.

METHODS

Using Tandem mass tag (TMT)-based proteomic analysis, a comparative proteomic profiling was conducted among areca nut-related OSCC, non-areca nut-related OSCC, and adjacent normal epithelial tissues (n=15). GO and KEGG enrichment analyses were then employed to identify significant proteins pertinent to the pathogenesis of OSCC for further study. Western Blot (WB) and Immunohistochemistry (IHC) techniques were used to preliminary validate the expression patterns of LZTS1, MMP10, MYH6, MB, and TNNC1 among various groups (n=30).

RESULTS

27 differentially expressed proteins were identified when comparing the areca nut-related OSCC group with both the non-areca nut-related OSCC and normal epithelial tissue groups. Among these, 15 proteins were upregulated, while 12 were downregulated. LZTS1 and MMP10 were included in the upregulated proteins, whereas MYH6, MB, and TNNC1 were downregulated. WB and IHC analyses corroborated the proteomic findings, revealing consistent expression trends for these 5 proteins across the studied groups.

CONCLUSION

LZTS1, MMP10, MYH6, MB and TNNC1 emerge as promising biomarkers for assessing disease progression, prognosis, and potential targeted therapies in areca nut-related OSCC.

Tubular specific glutathione peroxidase 3 deletion exacerbates kidney damage in IRI-AKI mice

Ischemia-reperfusion injury stands as a primary instigator of acute kidney injury (AKI), prominently driven by oxidative stress. Among the critical antioxidant defenses is glutathione peroxidase 3 (GPX3), an enzyme generated by renal tubular epithelial cells. Our prior investigations have unveiled a substantial downregulation of GPX3 in renal tissues gleaned from AKI patients and murine models. This study aims to investigate the role of tubular cell-specific Gpx3 deletion on ischemia-reperfusion injury-induced AKI (IRI-AKI) in a murine model and delineate the potential underlying mechanisms. By generating renal tubular epithelial cell-specific Gpx3 knockout mice and inducing IRI-AKI, we assessed a spectrum of kidney injury indices including renal function, oxidative stress, apoptosis and mitochondrial dynamics. Additionally, we conducted transcriptome sequencing and bioinformatics analyses. The outcomes underscore that the deficiency of GPX3 in tubular cells exacerbates tubular injury, renal dysfunction, oxidative stress, apoptosis, and mitochondrial dynamic disturbances in the context of IRI-AKI. Sequencing and bioinformatics analysis suggest that the Gpx3 deletion predominantly impacts pathways associated with metabolism and inflammation. In conclusion, the tubular cell-specific deficiency of GPX3 exacerbates renal injury by intensifying oxidative stress, fostering mitochondrial impairment, perturbing metabolic processes and fueling inflammation. The targeted restoration of GPX3 in the renal tubular emerges as a potential therapeutic avenue for mitigating IRI-AKI.

Major heme proteins hemoglobin and myoglobin with respect to their roles in oxidative stress - a brief review

Oxidative stress is considered as the root-cause of different pathological conditions. Transition metals, because of their redox-active states, are capable of free radical generation contributing oxidative stress. Hemoglobin and myoglobin are two major heme proteins, involved in oxygen transport and oxygen storage, respectively. Heme prosthetic group of heme proteins is a good reservoir of iron, the most abundant transition metal in human body. Although iron is tightly bound in the heme pocket of these proteins, it is liberated under specific circumstances yielding free ferrous iron. This active iron can react with H2O2, a secondary metabolite, forming hydroxyl radical via Fenton reaction. Hydroxyl radical is the most harmful free radical among all the reactive oxygen species. It causes oxidative stress by damaging lipid membranes, proteins and nucleic acids, activating inflammatory pathways and altering membrane channels, resulting disease conditions. In this review, we have discussed how heme-irons of hemoglobin and myoglobin can promote oxidative stress under different pathophysiological conditions including metabolic syndrome, diabetes, cardiovascular, neurodegenerative and renal diseases. Understanding the association of heme proteins to oxidative stress may be important for knowing the complications as well as therapeutic management of different pathological conditions.

HDAC6 deacetylates TRIM56 to negatively regulate cGAS-STING-mediated type I interferon responses

Histone deacetylase HDAC6 has been implicated in regulating antiviral innate immunity. However, its precise function in response to DNA virus infection remains elusive. Herein, we find that HDAC6 deficiency promotes the activation of cGAS-STING signaling and type I interferon (IFN) production, both in vitro and in vivo, resulting in a decrease in HSV-1 infection. Mechanistically, HDAC6 deacetylates tripartite motif protein 56 (TRIM56) at K110 in mice, thereby impairing the monoubiquitination cGAS and its DNA binding ability. Overexpression of TRIM56 K110Q protects mice against HSV-1 infection. Notably, different amino acids at position 110 of TRIM56 in human and mouse cause species-specific IFN responses. Further, we show that during early stages of HSV-1 infection, the viral protein US3 phosphorylates HDAC6 to inhibit the cGAS-mediated antiviral response. Our results suggest that HDAC6 inhibits cGAS activation through TRIM56 deacetylation in a species-specific manner.

Targeting regulated cell death: Apoptosis, necroptosis, pyroptosis, ferroptosis, and cuproptosis in anticancer immunity

In the evolving landscape of cancer treatment, the strategic manipulation of regulated cell death (RCD) pathways has emerged as a crucial component of effective anti-tumor immunity. Evidence suggests that tumor cells undergoing RCD can modify the immunogenicity of the tumor microenvironment (TME), potentially enhancing its ability to suppress cancer progression and metastasis. In this review, we first explore the mechanisms of apoptosis, necroptosis, pyroptosis, ferroptosis, and cuproptosis, along with the crosstalk between these cell death modalities. We then discuss how these processes activate antigen-presenting cells, facilitate the cross-priming of CD8+ T cells, and trigger anti-tumor immune responses, highlighting the complex effects of novel forms of tumor cell death on TME and tumor biology. Furthermore, we summarize potential drugs and nanoparticles that can induce or inhibit these emerging RCD pathways and their therapeutic roles in cancer treatment. Finally, we put forward existing challenges and future prospects for targeting RCD in anti-cancer immunity. Overall, this review enhances our understanding of the molecular mechanisms and biological impacts of RCD-based therapies, providing new perspectives and strategies for cancer treatment.

Rescue RM/CS-AKI by blocking strategy with one-dose anti-myoglobin RabMAb

Rhabdomyolysis or Crush syndrome-related AKI (RM/CS-AKI) has high mortality, and there is no effective early on-site treatment method. The critical pathogenic factor of RM/CS-AKI is the excessive free myoglobin (Mb) in blood circulation. Here, based on the concept of creating a "mobile barrier", we develop an anti-Mb rabbit monoclonal antibody (RabMAb) with high specificity, affinity, stability, and broad species reactivity. A single dose of anti-Mb RabMAb injection is sufficient for emergency rescue in both homologous and heterologous RM/CS-AKI male animal models. The main goal of blocking the passage of free Mb through the glomerular filtration barrier has been achieved by using the anti-Mb RabMAb, which has a long-term stable therapeutic effect within 14 days and promotes phagocytosis of Mb. The optimal administration strategy, pharmacokinetic analysis, toxicity evaluation for anti-Mb RabMAb, and the distribution of its immune complexes in RM/CS-AKI mice are investigated. Thus, we develop effective prevention and control strategies for RM/CS-AKI.

Targeting SphK1/S1PR3 axis ameliorates sepsis-induced multiple organ injury via orchestration of macrophage polarization and glycolysis

Sepsis is a heterogeneous and imprecise disorder characterized by aberrant response to infection which has been accredited for detrimental impact on immune homeostasis. Recently, macrophage metabolism has been recognized as attractive targets to develop novel immunomodulatory therapy for sepsis research. However, the fine-tuning regulators dictating macrophage functions and the specific mechanisms underlying macrophage metabolic reprogramming remain largely obscure. Sphingosine-1-phosphate (S1P), a metabolic mediator of sphingolipid catabolism, predominantly formed through sphingosine kinase 1 (SphK1) catalyzing, mediates inflammation in sepsis by binding to S1P receptor 3 (S1PR3) expressed in macrophages. Here we demonstrate that SphK1/S1PR3 axis was upregulated in lipopolysaccharide (LPS)-induced macrophages and septic mice lungs, cascading the activation of proglycolytic signaling such as HIF-1α, HK2 and PFKFB3. Targeted inhibition of Sphk1 by PF-543 effectively abrogated upregulated SphK1/S1PR3 axis in vitro and in vivo. In addition, PF-543 significantly suppressed sepsis-related inflammation and multi-organ injury in vivo. Furthermore, PF-543 not only blunted key glycolytic enzymes HIF-1α, HK2, and PFKFB3 in LPS-treated macrophages but also inhibited HK2 and PFKFB3 in septic mice. Silencing or inhibiting SphK1 tempered pro-inflammatory M1 macrophages while boosted anti-inflammatory M2 macrophages. Intriguingly, S1PR3 knockdown proficiently dampened glycolysis-associated markers, retrieved LPS-modulated M1/M2 polarization and attenuated NF-κB p65 activation. In conclusion, our study provides the first evidence that PF-543 orchestrates proportional imbalance of macrophage polarization and the Warburg effect in a SphK1/S1PR3 dependent manner during sepsis, mitigating both hyperinflammation and multi-organ failure, adding a novel puzzle piece to pharmacologically exploitable therapy for sepsis.

Receptor-Interacting Protein Kinase 3-Mediated Modulation of Endothelial Cell Necroptosis and Mitochondrial Dysfunction through AMPK/Drp1 Signaling Pathway: Insights into the Pathophysiological Mechanisms of Lipopolysaccharide-Induced Acute Lung Injury

Receptor-interacting protein 3 (Ripk3) plays a crucial part in acute lung injury (ALI) by regulating inflammation-induced endothelial damage in the lung tissue. The precise mechanisms through which Ripk3 contributes to the endothelial injury in ALI still remain uncertain. In the current research, we employed Ripk3-deficient (Ripk3-/-) mice to examine the role of Ripk3 in ALI progression, focusing on its effects on endothelial cells (ECs), mitochondrial damage and necroptosis. Our study observed significant Ripk3 upregulation in lipopolysaccharide- (LPS-) treated lung tissues, as well as in murine pulmonary microvascular endothelial cells (PMVECs). Ripk3 deletion improved lung tissue morphology, reduced inflammation, oxidative stress and endothelial dysfunction under LPS challenge. It also mitigated LPS-induced necroptosis and mitochondrial damage in PMVECs. Ripk3 upregulation suppressed the AMP-activated protein kinase (AMPK) pathway and activated Drp1-mediated mitochondrial fission, increasing mitochondrial permeability transition pore (mPTP) opening and PMVEC necroptosis. Conversely, Ripk3 deletion activated the AMPK/Drp1-mitochondrial fission pathway, preventing mPTP opening and PMVEC necroptosis in ALI. These findings demonstrated that Ripk3 promotes necroptosis through the AMPK/Drp1/mPTP opening pathway, identifying a potential therapeutic target for ALI treatment.

Investigating the Process of Autoimmune Inner Ear Disease: Unveiling the Intricacies of Pathogenesis and Therapeutic Strategies

Autoimmune inner ear disease (AIED) is a rare condition characterized by immune-mediated damage to the inner ear, leading to progressive sensorineural hearing loss (SNHL) and vestibular symptoms such as vertigo and tinnitus. This study investigates the pathogenesis and therapeutic strategies for AIED through the analysis of three cases with different underlying autoimmune disorders: rheumatoid arthritis, relapsing polychondritis, and IgG4-related disease. The etiology of AIED involves complex immunopathological mechanisms, including molecular mimicry and the "bystander effect," with specific autoantibodies, such as those against heat shock protein 70 (HSP70), playing a potential role in cochlear damage. Diagnosis remains challenging due to nonspecific symptoms and the lack of distinct biomarkers, emphasizing the need for comprehensive clinical evaluation and exclusion of other hearing loss causes. Treatment primarily involves immunosuppressive therapies, with glucocorticoids as the first line, effective in 70% of cases. However, resistance or partial response necessitates the use of additional agents like methotrexate and biologics such as anti-TNF and IL-6 receptor antagonists. Early intervention is crucial for favorable outcomes, as demonstrated in the studied cases, where timely corticosteroid and immunosuppressive treatments led to significant hearing improvement. The study underscores the importance of personalized treatment strategies based on individual immunologic profiles and comorbidities. Our findings highlight the heterogeneity of AIED and the potential for biologic therapies in refractory cases.

Research Progress of Regulatory Cell Death in Coronary Microembolization

Coronary microembolization (CME) is defined as atherosclerotic plaque erosion, spontaneous rupture, or rupture of the plaque while undergoing interventional therapy resulting in the formation of tiny emboli that obstruct the coronary microcirculatory system. For percutaneous coronary intervention, CME is a major complication, with a periprocedural incidence of up to 25%. Recent studies have demonstrated that regulatory cell death (RCD) exerts a profound influence on CME through its modulation of inflammatory responses, oxidative stress, cell death, and angiogenesis. RCD, including apoptosis, autophagy, and pyroptosis, is a unique class of genetically highly regulated death patterns pervasive in instances of coronary microembolization. The aim of this review is to summarize the currently known molecular mechanisms underlying CME. Further investigations of the RCD mechanisms may unravel new avenues for the prevention and treatment of CME.

Evaluation of severe rhabdomyolysis on day 30 mortality in trauma patients admitted to intensive care: a propensity score analysis of the Traumabase registry

BACKGROUND

Traumatic rhabdomyolysis (RM) is common and associated with the development of acute kidney injury and potentially with other organ dysfunctions. Thus, RM may increase the risk of death. The primary objective was to assess the effect of severe RM (Creatine Kinase [CK] > 5000 U/L) on 30-day mortality in trauma patients using a causal inference approach.

METHODS

In this multicenter cohort study conducted in France using a national major trauma registry (Traumabase) between January 1, 2012, and July 1, 2023, all patients admitted to a participating major trauma center hospitalized in intensive care unit (ICU) and with CK measurement were included. Confounding variables for both 30-day mortality and exposure were used to establish a propensity score. A doubly robust approach with inverse treatment weighting enabled the calculation of the average treatment effect on the treated (ATT). Analyses were performed in the overall cohort as well as in two subgroups: hemorrhagic shock subgroup (HS) and traumatic brain injury subgroup (TBI). Sensitivity analyses were conducted.

RESULTS

Among the 8592 patients included, 1544 (18.0%) had severe RM. They were predominantly males (78.6%) with median [IQR] age of 41 [27-58] years and severely injured (ISS 20 [13 - 29]) mainly from blunt trauma (90.8%). In the entire cohort, the ATT, expressed as a risk difference, was 0.073 [-0.054 to 0.200]. Considering the 1311 patients in the HS subgroup, the ATT was 0.039 [0.014 to 0.063]. As in the overall cohort, there was no effect on mortality in the TBI subgroup. Severe RM was associated with greater severity of trauma and more complications (whether related to renal function or not) during the ICU stay. Mortality due to multiorgan failure (39.9% vs 12.4%) or septic shock (2.6% vs 0.8%) was more frequent among patients with severe RM.

CONCLUSIONS

Severe RM was not associated with 30-day mortality considering the overall cohort. However, it was associated with a 4.0% increase in 30-day mortality among patients with concurrent hemorrhagic shock. Severe RM plays a significant role in ICU morbidity.

The biology of ferroptosis in kidney disease

Ferroptosis is a regulated cell death modality triggered by iron-dependent lipid peroxidation. Ferroptosis plays a causal role in the pathophysiology of various diseases, making it a promising therapeutic target. Unlike all other cell death modalities dependent on distinct signaling cues, ferroptosis occurs when cellular antioxidative defense mechanisms fail to suppress the oxidative destruction of cellular membranes, eventually leading to cell membrane rupture. Physiologically, only two such surveillance systems are known to efficiently prevent the lipid peroxidation chain reaction by reducing (phospho)lipid hydroperoxides to their corresponding alcohols or by reducing radicals in phospholipid bilayers, thus maintaining the integrity of lipid membranes. Mechanistically, these two systems are linked to the reducing capacity of glutathione peroxidase 4 (GPX4) by consuming glutathione (GSH) on one hand and ferroptosis suppressor protein 1 (FSP1, formerly AIFM2) on the other. Notably, the importance of ferroptosis suppression in physiological contexts has been linked to a particular vulnerability of renal tissue. In fact, early work has shown that mice genetically lacking Gpx4 rapidly succumb to acute renal failure with pathohistological features of acute tubular necrosis. Promising research attempting to implicate ferroptosis in various renal disease entities, particularly those with proximal tubular involvement, has generated a wealth of knowledge with widespread potential for clinical translation. Here, we provide a brief overview of the involvement of ferroptosis in nephrology. Our goal is to introduce this expanding field for clinically versed nephrologists in the hope of spurring future efforts to prevent ferroptosis in the pathophysiological processes of the kidney.

Targeting mitochondria by lipid-selenium conjugate drug results in malate/fumarate exhaustion and induces mitophagy-mediated necroptosis suppression

Atherosclerosis (AS) is a chronic vascular disease primarily affecting large and medium-sized arteries and involves various complex pathological mechanisms and factors. Previous studies have demonstrated a close association between atherosclerosis and inflammatory damage, metabolic disorders, and gut microbiota. It is also closely linked to several cellular processes, such as endothelial cell pyroptosis, ferroptosis, mitophagy, mitochondrial dynamics, and mitochondrial biogenesis. Mitophagy has been recognized as a previously unexplored mechanism contributing to endothelial injury in atherosclerosis. Our study aims to further elucidate the potential relationship and mechanisms between AS-induced mitophagy dysfunction and the interaction of TMBIM6 and NDUFS4. Data from the study demonstrated that atherosclerosis in AS mice was associated with substantial activation of inflammatory and oxidative stress damage, along with a marked reduction in endothelial mitophagy expression and increased pathological mitochondrial fission, leading to mitochondrial homeostasis disruption. However, under pharmacological intervention, mitophagy levels significantly increased, pathological mitochondrial fission was notably reduced, and oxidative stress and inflammatory damage were suppressed, while necroptotic pathways in endothelial cells were significantly blocked. Interestingly, the deletion of TMBIM6 or NDUFS4 in animal models or cell lines markedly impaired the therapeutic effects of the drug, disrupting its regulation of mitophagy and mitochondrial fission, and leading to the re-emergence of inflammatory responses and oxidative stress damage. Metabolomics analysis further revealed that autophagy plays a pivotal regulatory role during drug intervention and after genetic modification of TMBIM6 and NDUFS4. The activation of autophagy (macroautophagy/mitophagy) alleviated the negative effects of mitochondrial fission and inflammatory damage induced by lipid stress in endothelial cells, a regulatory mechanism likely associated with the TMBIM6-NDUFS4 axis. Subsequent animal gene modification experiments demonstrated that knocking out TMBIM6-NDUFS4 negates the therapeutic effects of the drug on lipid-induced damage and metabolic function. In summary, our research reveals a phenotypic regulatory mechanism of endothelial cell stress damage through mitophagy, influenced by the interaction of TMBIM6 and NDUFS4. Pharmacological intervention can restore mitochondrial homeostasis in endothelial cells by regulating mitophagy via the TMBIM6-NDUFS4 pathway. This novel insight suggests that TMBIM6-NDUFS4 may serve as a key therapeutic target for atherosclerosis.

Mechanism and Application Prospects of NLRC3 Regulating cGAS-STING Pathway in Lung Cancer Immunotherapy

NLRC3, a negative regulator, exhibits considerable potential in the realm of lung cancer immunotherapy by virtue of its profound impact on the immune response intensity, primarily through its regulatory effects on the cGAS-STING pathway. The inhibition of NLRC3 has been found to augment the activity of the aforementioned pathway, thereby enhancing the anti-tumor immune response. This comprehensive review endeavors to elucidate the molecular and genetic structures of NLRC3, its role within the immune system, and its interaction with the cGAS-STING pathway, with a particular emphasis on its potential applications in lung cancer immunotherapy. Existing research underscores NLRC3's capacity to mitigate excessive immune responses via the negative regulation of the cGAS-STING pathway, thus underscoring its significant regulatory role in lung cancer immunotherapy. The development of pharmaceutical interventions and gene therapy strategies targeting NLRC3 presents a promising avenue for the creation of novel therapeutic options for individuals afflicted with lung cancer. Nonetheless, the clinical application of these therapies is confronted with both technical and biological challenges. This review aims to provide a theoretical foundation for related research endeavors and delineate future research directions in this field.

Exploring the Mechanism of Ferroptosis Induction by Sappanone A in Cancer: Insights into the Mitochondrial Dysfunction Mediated by NRF2/xCT/GPX4 Axis

Non-small cell lung cancer (NSCLC), a major subtype of lung cancer, encompasses squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Compared to small cell lung cancer, NSCLC cells grow and divide more slowly, and their metastasis occurs at a later stage. Currently, chemotherapy is the primary treatment for this disease. Sappanone A (SA) is a flavonoid compound extracted from the plant Caesalpinia sappan, known for its antitumor, redox-regulating, and anti-inflammatory properties. Recent studies have investigated the interaction of SA with mitochondrial pathways in regulating cell death through the Nrf-2/GPX-4/xCT axis. This study specifically explores the mechanism by which SA affects mitochondrial morphology and structure through the regulation of mitophagy and mitochondrial biogenesis in tumor cells. The study primarily utilizes second-generation transcriptomic sequencing data and molecular docking techniques to elucidate the role of SA in regulating programmed cell death in tumor cells. The omics results indicate that SA treatment significantly targets genes involved in oxidative phosphorylation, mitophagy, mitochondrial dynamics, and oxidative stress. Further findings confirmed that the Nrf-2/GPX4/xCT pathway serves as a crucial target of SA in the treatment of NSCLC. Knockdown of Nrf-2 (si-Nrf-2) and Nrf-2 overexpression (ad-Nrf-2) were shown to modulate the therapeutic efficacy of SA to varying degrees. Additionally, modifications to the GPX4/xCT genes significantly affected the regulatory effects of SA on mitochondrial autophagy, biogenesis, and energy metabolism. These regulatory mechanisms may be mediated through the caspase pathway and ferroptosis-related signaling. Molecular biology experiments have demonstrated that SA intervention further inhibits the phosphorylation of FUNDC1 at Tyr18 and downregulates TOM20 expression. SA treatment was found to reduce the expression of PGC1α, Nrf-1, and Tfam, resulting in a decrease in mitochondrial respiration and energy metabolism. Overexpression of Nrf-2 was shown to counteract the regulatory effects of SA on mitophagy and mitochondrial biogenesis. Confocal microscopy experiments further revealed that SA treatment increases mitochondrial fragmentation, subsequently inducing mitochondrial pathway-mediated programmed cell death. However, genetic modification of the Nrf-2/GPX4/xCT pathway significantly altered the regulatory effects of SA on tumor cells. In conclusion, SA has been identified as a promising therapeutic agent for NSCLC. The mitochondrial pathway-mediated apoptosis and ferroptosis may represent key mechanisms in regulating tumor cell death. Targeting the Nrf-2/GPX-4/xCT axis offers a novel therapeutic approach for maintaining mitochondrial homeostasis within the cellular microenvironment.

Mitochondrial Stress as a Central Player in the Pathogenesis of Hypoxia-Related Myocardial Dysfunction: New Insights

Hypoxic injury is a critical pathological factor in the development of various cardiovascular diseases, such as congenital heart disease, myocardial infarction, and heart failure. Mitochondrial quality control is essential for protecting cardiomyocytes from hypoxic damage. Under hypoxic conditions, disruptions in mitochondrial homeostasis result in excessive reactive oxygen species (ROS) production, imbalances in mitochondrial dynamics, and initiate pathological processes including oxidative stress, inflammatory responses, and apoptosis. Targeted interventions to enhance mitochondrial quality control, such as coenzyme Q10 and statins, have shown promise in mitigating hypoxia-induced mitochondrial dysfunction. These treatments offer potential therapeutic strategies for hypoxia-related cardiovascular diseases by regulating mitochondrial fission and fusion, restoring mitochondrial biogenesis, reducing ROS production, and promoting mitophagy.

BuyangHuanwu Decoction alleviates Endothelial Cell Apoptosis and Coronary Microvascular Dysfunction via Regulation of the MAPKK4/p38 Signaling Axis

MAPKK4 has been implicated in the pathological mechanisms underlying myocardial and vascular injury, specifically influencing endothelial cell damage and programmed cell death via subcellular pathways. Nevertheless, the regulatory role of MAPKK4 in coronary microvascular injury following myocardial infarction remains unconfirmed, and the exploration of targeted mitochondrial protective therapeutic agents remains unaddressed. In light of this gap, we established a MAPKK4 gene-modified mouse model of ischemia-reperfusion injury and employed Buyang Huanwu decoction (BYHW), a traditional cardiovascular therapeutic formula, to assess its efficacy in treating coronary microvascular injury post-ischemia-reperfusion. The study aimed to elucidate the mechanism by which BYHW mitigates coronary microvascular injury induced by ischemia-reperfusion through the attenuation of endothelial cell apoptosis. Experimental outcomes revealed that high-dose BYHW significantly ameliorated coronary microvascular injury post-ischemia-reperfusion, restoring the structural integrity of the coronary microvasculature and reducing inflammation and oxidative stress. Contrarily, in transgenic mice overexpressing MAPKK4, BYHW intervention failed to attenuate microvascular inflammation and oxidative stress. To further investigate, we simulated hypoxia/reoxygenation injury in vascular endothelial cells using a MAPKK4-related cellular gene modification model. The results indicated that BYHW attenuates inflammatory damage and enhances the viability of vascular endothelial cells following hypoxic stress, inhibiting apoptosis via the mitochondrial pathway. However, overexpression of MAPKK4/p38 negated the therapeutic effects of BYHW, showing no impact on endothelial cell apoptosis and oxidative stress under hypoxic conditions. Molecular interaction studies confirmed that the active components of BYHW, Astragaloside IV and Ligustrazine, interact with the MAPKK4/P38 axis. In vitro experiments further suggested that the interaction between MAPKK4 and P38 play a crucial role in the ability of BYHW to inhibit apoptosis in coronary microvascular endothelial cells. Therapeutically, MAPKK4 may potentiate the apoptotic pathway in microvascular endothelial cells by modulating downstream P38 expression and phosphorylation, thereby exacerbating ischemia-reperfusion-induced coronary microvascular endothelial injury. From an in vivo perspective, the transgenic overexpression of MAPKK4 and P38 inhibited the microvascular protective effects of BYHW. These findings collectively underscore the significance of the MAPKK4-P38 axis in the protection of coronary microvascular endothelial cells.

A Circular Network of Coregulated L-Threonine and L-Tryptophan Metabolism Dictates Acute Lower Limb Ischemic Injury

Lower limb ischemia is characterized by reduced arterial perfusion in the lower limbs, leading to tissue ischemia and cell death. It is primarily caused by thrombosis and the rupture of arterial plaques, resulting in damage to ischemic muscle tissues. Metabolic processes are crucial in its development. Herein we combined single-cell data with metabolomics data to explore the pathways and mechanisms influencing lower limb ischemia. We analyzed single-cell and metabolomics data. In single-cell analysis, we identified different cell subpopulations and key regulatory genes, and biological enrichment analysis was performed to understand their functions and relationships. For metabolomics, mass spectrometry and chromatography techniques were employed to analyze metabolites in clinical samples. We performed differential analysis, correlation analysis, and Mendelian randomization to determine the relationships between key metabolites and genes. Nebl, Dapl1, Igfbp4, Lef1, Klrd1, Ciita, Il17f, Cd8b1, Il17a, Cd180, Il17re, Trim7, and Slc6a19 were identified to play a crucial role in lower limb ischemia. Important metabolites included L-threonine and L-tryptophan. The metabolism of L-threonine and L-tryptophan is linked to lower limb ischemia and thrombosis. B0AT1, encoded by SLC6A19, is closely related to these metabolites and appears to play a key role in lower limb ischemia development. Our analysis revealed the roles of key genes and metabolites in lower limb ischemia. These findings enhance our understanding of the pathogenesis of lower limb ischemia and provide new insights into its prevention and treatment.

The significant mechanism and treatments of cell death in heatstroke

With global warming, extreme environmental heat is becoming a social issue of concern, which can cause adverse health results including heatstroke (HS). Severe heat stress is characterized by cell death of direct heat damage, excessive inflammatory responses, and coagulation disorders that can lead to multiple organ dysfunction (MODS) and even death. However, the significant pathophysiological mechanism and treatment of HS are still not fully clear. Various modes of cell death, including apoptosis, pyroptosis, ferroptosis, necroptosis and PANoptosis are involved in MODS induced by heatstroke. In this review, we summarized molecular mechanism, key transcriptional regulation as for HSF1, NRF2, NF-κB and PARP-1, and potential therapies of cell death resulting in CNS, liver, intestine, reproductive system and kidney injury induced by heat stress. Understanding the mechanism of cell death provides new targets to protect multi-organ function in HS.

The role of serum magnesium in the prediction of acute kidney injury after total aortic arch replacement: A prospective observational study

Background

Considerable morbidity and death are associated with acute kidney damage (AKI) following total aortic arch replacement (TAAR). The relationship between AKI following TAAR and serum magnesium levels remains unknown. The intention of this research was to access the predictive value of serum magnesium levels on admission to the Cardiovascular Surgical Intensive Care Unit (CSICU) for AKI in patients receiving TAAR.

Methods

From May 2018 to January 2020, a prospective, observational study was performed in the Guangdong Provincial People's Hospital CSICU. Patients accepting TAAR admitted to the CSICU were studied. The Kidney Disease: Improving Global Outcomes (KDIGO) definition of serum creatinine was used to define AKI, and KDIGO stages two or three were used to characterize severe AKI. Multivariable logistic regression and area under the curve receiver-operator characteristic curve (AUC-ROC) analysis were conducted to assess the predictive capability of the serum magnesium for AKI detection. Finally, the prediction model for AKI was established and internally validated.

Results

Of the 396 enrolled patients, AKI occurred in 315 (79.5%) patients, including 154 (38.8%) patients with severe AKI. Serum magnesium levels were independently related to the postoperative AKI and severe AKI (both, P < 0.001), and AUC-ROCs for predicting AKI and severe AKI were 0.707 and 0.695, respectively. Across increasing quartiles of serum magnesium, the multivariable-adjusted odds ratios (95% confidence intervals) of postoperative AKI were 1.00 (reference), 1.04 (0.50-2.82), 1.20 (0.56-2.56), and 6.19 (2.02-23.91) (P for Trend < 0.001). When serum magnesium was included to a baseline model with established risk factors, AUC-ROC (0.833 vs 0.808, P = 0.050), reclassification (P < 0.001), and discrimination (P = 0.002) were further improved.

Conclusions

Serum magnesium levels on admission are an independent predictor of AKI. In TAAR patients, elevated serum magnesium levels were linked to an increased risk of AKI. In addition, the established risk factor model for AKI can be considerably improved by the addition of serum magnesium in TAAR patients hospitalized in the CSICU.

Myoglobin improves doxycycline sensitivity in pancreatic cancer through promoting heme oxygenase-1-mediated ferroptosis

Ferroptosis is expected to be a therapeutic target for cancers including pancreatic cancer. We aimed to screen genes that regulate ferroptosis and doxycycline resistance in pancreatic cancer and to explore the underlying mechanisms. Bioinformatics analysis was performed to identify genes that respond to ferroptosis in two human pancreatic cancer cells with GOT1 knocked down or not. 325 and 842 genes were upregulated in MiaPaCa and Tu8902 cells in response to GOT1 knockdown, with 43 genes shared. Among the 43 genes, 14 genes were identified to interact with ferroptosis key genes. MB and HMOX1 were the genes most sensitive to Erastin and doxycycline. Moreover, MB and HMOX1 expression was higher in human normal pancreatic duct epithelial cells than in pancreatic cancer cells. MB and HMOX1 proteins physically bound and promoted each other's expression. By interacting with HMOX1, MB suppressed pancreatic cancer cell proliferation, colony formation and invasion, and promoted cell ferroptosis and sensitivity to erastin and doxycycline. Silencing HMOX1 reversed the promoting effect of MB on cell ferroptosis and sensitivity to doxycycline. A pancreatic cancer xenograft model was established by subcutaneous injection of Panc-1 cells transfected with or without Ad-MB, and doxycycline was administered intraperitoneally. Overexpression of MB enhanced the inhibitory effect of doxycycline on xenograft growth. In conclusion, MB facilitated doxycycline sensitivity in pancreatic cancer cells through promoting HMOX1-mediated ferroptosis.

Phenylbutyric acid inhibits hypoxia-induced trophoblast apoptosis and autophagy in preeclampsia via the PERK/ATF-4/CHOP pathway

Preeclampsia (PE) is a common pregnancy complication with a high mortality rate. Abnormally activated endoplasmic reticulum stress (ERS) is believed to be responsible for the destruction of key placental cells-trophoblasts. Phenylbutyric acid (4-PBA), an ERS inhibitor, is involved in regulating the development of ERS-related diseases. At present, how 4-PBA affects trophoblasts and its mechanisms is still unclear. In this study, PE cell models were established by stimulating HTR-8/SVneo cells with hypoxia. To verify the underlying mechanisms of 4-PBA on PE, CCT020312, an activator of PERK, was also used. The results showed that 4-PBA restored hypoxia-induced trophoblast viability, inhibited HIF-1α protein expression, inflammation, and PERK/ATF-4/CHOP pathway. Hoechst 33342 staining and flow cytometry results confirmed that 4-PBA decreased hypoxia-induced apoptosis in trophoblasts. The results of the JC-1 analysis and apoptosis initiation enzyme activity assay also demonstrated that 4-PBA inhibited apoptosis related to the mitochondrial pathway. Furthermore, by detecting autophagy in trophoblasts, an increased number of autophagic vesicles, damaged mitochondria, enhanced dansylcadaverine fluorescence, enhanced levels of autophagy proteins Beclin-1, LC3II, and decreased p62 were seen in hypoxia-stimulated cells. These changes were reversed by 4-PBA. Furthermore, it was observed that CCT020312 reversed the effects of 4-PBA on the viability, apoptosis, and autophagosome number of hypoxia-induced trophoblasts. In summary, 4-PBA reduces autophagy and apoptosis via the PERK/ATF-4/CHOP pathway and mitochondrial pathway, thereby restoring the viability of hypoxic trophoblasts. These findings provide a solid evidence base for the use of 4-PBA in PE treatment and guide a new direction for improving the outcomes of patients with PE.

Cordyceps sinensis extract protects against acute kidney injury by inhibiting perforin expression in NK cells via the STING/IRF3 pathway

Acute kidney injury (AKI) is associated with immune cell activation and inflammation. However, the putative pathogenic mechanisms of this injury have not been thoroughly investigated. Natural killer (NK) cells play an important role in immune regulation; however, whether NK cells regulate AKI remains unclear. Cordyceps sinensis (CS), a modern Chinese patented medicine preparation, has been widely used in treating patients with chronic kidney disease (CKD) owing to its anti-inflammatory effects and maintenance of immune homeostasis. Whether 2'-deoxyadenosine, a major active component in CS, can ameliorate renal AKI by regulating immunity, particularly in NK cells, has not been reported. This study is the first to demonstrate how NK cells promote AKI by releasing perforin, interferon-gamma (IFN-γ) and other inflammatory factors in vivo and in vitro. Differential gene expression between AKI and normal tissues was assessed using bioinformatic analyses. Quantitative real-time PCR, western blotting, and immunohistochemical staining were used to detect target protein mRNA and protein expression. Levels of inflammatory factors were measured using enzyme-linked immunosorbent assay. We found the high doses of the 2'-deoxyadenosine treatment significantly alleviated FA-induced renal damage in vivo, and alleviated the NK cells of renal injury by activating the STING/IRF3 pathway to inhibit perforin release in vitro. The results showed that 2'-deoxyadenosine could mitigate AKI by downregulating the activity of NK cells (by decreasing the expressions of perforin and IFN-γ) and inhibiting the stimulator of interferon genes and phosphorylated IFN regulatory factor 3. This may provide valuable evidence supporting the clinical use of CS in treating patients with AKI.

Prediction of acute kidney injury after cardiac surgery with fibrinogen-to-albumin ratio: a prospective observational study

Background

The occurrence of acute kidney injury (AKI) following cardiac surgery is common and linked to unfavorable consequences while identifying it in its early stages remains a challenge. The aim of this research was to examine whether the fibrinogen-to-albumin ratio (FAR), an innovative inflammation-related risk indicator, has the ability to predict the development of AKI in individuals after cardiac surgery.

Methods

Patients who underwent cardiac surgery from February 2023 to March 2023 and were admitted to the Cardiac Surgery Intensive Care Unit of a tertiary teaching hospital were included in this prospective observational study. AKI was defined according to the KDIGO criteria. To assess the diagnostic value of the FAR in predicting AKI, calculations were performed for the area under the receiver operating characteristic curve (AUC), continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Results

Of the 260 enrolled patients, 85 developed AKI with an incidence of 32.7%. Based on the multivariate logistic analyses, FAR at admission [odds ratio (OR), 1.197; 95% confidence interval (CI), 1.064-1.347, p = 0.003] was an independent risk factor for AKI. The receiver operating characteristic (ROC) curve indicated that FAR on admission was a significant predictor of AKI [AUC, 0.685, 95% CI: 0.616-0.754]. Although the AUC-ROC of the prediction model was not substantially improved by adding FAR, continuous NRI and IDI were significantly improved.

Conclusions

FAR is independently associated with the occurrence of AKI after cardiac surgery and can significantly improve AKI prediction over the clinical prediction model.

Serum procalcitonin levels are associated with rhabdomyolysis following exertional heatstroke: an over 10-year intensive care survey

BACKGROUND

Heatstroke has become a common emergency event in hospitals. Procalcitonin (PCT) is used as a biomarker of infection in the emergency department (ED), but its role in rhabdomyolysis (RM) following exertional heatstroke (EHS) remains unclear.

METHODS

A retrospective cohort study enrolled patients with EHS from the intensive care unit (ICU). We collected RM biomarkers, inflammation markers, critical disease scores at admission, 24 h, 48 h, and discharge, and 90-day mortality. Correlation analysis, linear regression and curve fitting were used to identify the relationship between PCT and RM.

RESULTS

A total of 162 patients were recruited and divided into RM (n=56) and non-RM (n=106) groups. PCT was positively correlated with myoglobin (Mb), acute hepatic injury, disseminated intravascular coagulation (DIC), Sequential Organ Failure Assessment (SOFA) score, and Acute Physiology and Chronic Health Evaluation II (APACHE II) score, with correlation coefficients of 0.214, 0.237, 0.285, 0.454, and 0.368, respectively (all P<0.05). Interestingly, the results of curve fitting revealed a nonlinear relationship between PCT and RM, and a two-piecewise linear regression model showed that PCT was related to RM with an odds ratio of 1.3 and a cut-off of <4.6 ng/mL. Survival analysis revealed that RM was associated with higher mortality compared to non-RM cases (P=0.0093).

CONCLUSION

High serum PCT concentrations are associated with RM after EHS in critically ill patients. Elevated PCT concentrations should be interpreted cautiously in patients with EHS in the ED.

Construction of a ferroptosis-based prognostic model for breast cancer helps to discriminate high/low risk groups and treatment priority

Introduction

Breast cancer is a common malignant tumor associated with high morbidity and mortality. The role of ferroptosis, a regulated form of cell death, in breast cancer development and prognosis remains unclear. This study aims to investigate the relationship between ferroptosis-related genes and breast cancer and develop a prognostic model.

Methods

RNA-seq expression datasets and clinical samples of breast cancer patients were obtained from public databases. Immunity- and drug resistance-related data were integrated. A preliminary screening was performed, resulting in the identification of 73 candidate ferroptosis factors. Univariate Cox regression analysis was conducted to select 12 genes, followed by LASSO Cox regression analysis to construct a prognostic risk prediction model consisting of 10 ferroptosis-related genes. The model was further characterized by immune cell infiltration. The expression levels of ferroptosis-related genes were validated in human breast cancer cell lines, and immunohistochemical (IHC) analysis was conducted on cancer specimens to assess ferroptosis-related protein expression.

Results

The study identified 10 ferroptosis-related genes that were significantly associated with breast cancer prognosis. The constructed prognostic risk prediction model showed potential for predicting the prognostic value of these genes. In addition, the infiltration of immune cells was observed to be a characteristic of the model. The expression levels of ferroptosis-related genes were confirmed in human breast cancer cell lines, and IHC analysis provided evidence of ferroptosis-related protein expression in cancer specimens.

Discussion

This study provides a novel prognostic model for breast cancer, incorporating 10 ferroptosis-related genes. The model demonstrates the potential for predicting breast cancer prognosis and highlights the involvement of immune cell infiltration. The expression levels of ferroptosis-related genes and proteins further support the association between ferroptosis and breast cancer development.