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Clinical and Translational Science Oct 2023Ferroptosis is an iron-dependent cell death process mainly triggered by reactive oxygen species (ROS) and lipid peroxidation. Thioredoxin domain protein 12 (TXNDC12)...
Ferroptosis is an iron-dependent cell death process mainly triggered by reactive oxygen species (ROS) and lipid peroxidation. Thioredoxin domain protein 12 (TXNDC12) promotes the development of some tumors; however, its function in tumor ferroptosis remains unclear. In this study, we found that knockdown of TXNDC12 promoted erastin-induced increase in ROS, lipid peroxidation, and Fe levels, and decreased glutathione content. TXNDC12 is involved in ferroptosis by regulating SLC7A11. Further studies showed that TXNDC12 knockdown promoted an erastin-induced decrease in glioma cell viability. Overall, TXNDC12 played a significant role in ferroptosis by modulating SLC7A11 expression. Thus, TXNDC12 and ferroptosis may provide new targets for the treatment of gliomas.
Topics: Humans; Ferroptosis; Reactive Oxygen Species; Cell Death; Iron; Glioma; Protein Disulfide Reductase (Glutathione); Amino Acid Transport System y+
PubMed: 37503932
DOI: 10.1111/cts.13604 -
Cancer Biology & Therapy Dec 2023In clear cell renal cell carcinoma (ccRCC), activation of hypoxic signaling induces NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2 (NDUFA4L2) expression....
In clear cell renal cell carcinoma (ccRCC), activation of hypoxic signaling induces NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2 (NDUFA4L2) expression. Over 90% of ccRCCs exhibit overexpression of NDUFA4L2, which we previously showed contributes to ccRCC proliferation and survival. The function of NDUFA4L2 in ccRCC has not been fully elucidated. NDUFA4L2 was reported to reduce mitochondrial respiration via mitochondrial complex I inhibition. We found that NDUFA4L2 expression in human ccRCC cells increases the extracellular acidification rate, indicative of elevated glycolysis. Conversely, NDUFA4L2 expression in non-cancerous kidney epithelial cells decreases oxygen consumption rate while increasing extracellular acidification rate, suggesting that a Warburg-like effect is induced by NDUFA4L2 alone. We performed mass-spectrometry (MS)-based proteomics of NDUFA4L2 associated complexes. Comparing RCC4-P (parental) ccRCC cells with RCC4 in which NDUFA4L2 is knocked out by CRISPR-Cas9 (RCC4-KO-643), we identified 3,215 proteins enriched in the NDUFA4L2 immunoprecipitates. Among the top-ranking pathways were "Metabolic Reprogramming in Cancer" and "Glycolysis Activation in Cancer (Warburg Effect)." We also show that NDUFA4L2 enhances mitochondrial fragmentation, interacts with lysosomes, and increases mitochondrial-lysosomal associations, as assessed by high-resolution fluorescence microscopy and live cell imaging. We identified 161 lysosomal proteins, including Niemann-Pick Disease Type C Intracellular Cholesterol Transporters 1 and 2 (NPC1, NPC2), that are associated with NDUFA4L2 in RCC4-P cells. RCC4-P cells have larger and decreased numbers of lysosomes relative to RCC4 NDUFA4L2 knockout cells. These findings suggest that NDUFA4L2 regulates mitochondrial-lysosomal associations and potentially lysosomal size and abundance. Consequently, NDUFA4L2 may regulate not only mitochondrial, but also lysosomal functions in ccRCC.
Topics: Humans; Carcinoma, Renal Cell; Electron Transport Complex I; Kidney Neoplasms; Lysosomes; Mitochondria
PubMed: 36722045
DOI: 10.1080/15384047.2023.2170669 -
Proceedings of the National Academy of... Aug 2023Traditionally, nuclear spin is not considered to affect biological processes. Recently, this has changed as isotopic fractionation that deviates from classical mass...
Traditionally, nuclear spin is not considered to affect biological processes. Recently, this has changed as isotopic fractionation that deviates from classical mass dependence was reported both in vitro and in vivo. In these cases, the isotopic effect correlates with the nuclear magnetic spin. Here, we show nuclear spin effects using stable oxygen isotopes (O, O, and O) in two separate setups: an artificial dioxygen production system and biological aquaporin channels in cells. We observe that oxygen dynamics in chiral environments (in particular its transport) depend on nuclear spin, suggesting future applications for controlled isotope separation to be used, for instance, in NMR. To demonstrate the mechanism behind our findings, we formulate theoretical models based on a nuclear-spin-enhanced switch between electronic spin states. Accounting for the role of nuclear spin in biology can provide insights into the role of quantum effects in living systems and help inspire the development of future biotechnology solutions.
Topics: Oxygen Isotopes; Oxygen; Biological Phenomena
PubMed: 37523549
DOI: 10.1073/pnas.2300828120 -
Journal of Pediatric Intensive Care Sep 2023In cases of critical injury or illness abroad, fixed-wing air ambulance aircraft is employed to repatriate children to their home country. Air ambulance aircraft also...
In cases of critical injury or illness abroad, fixed-wing air ambulance aircraft is employed to repatriate children to their home country. Air ambulance aircraft also transport children to foreign countries for treatment not locally available and newborns back home that have been born prematurely abroad. In this retrospective observational study, we investigated demographics, feasibility, and safety and outcomes of long-distance and international aeromedical transport of neonates and children. The study included 167 pediatric patients, 56 of those preterm neonates. A total of 41 patients were ventilated, 45 requiring oxygen prior to the transport, 57 transferred from an intensive care unit (ICU), and 48 to an ICU. Patients were transported by using Learjet 31A, Learjet 45, Learjet 55, and Bombardier Challenger 604, with a median transport distance of 1,008 nautical miles (NM), median transport time of 04:45 hours (median flight time = 03:00 hours), flight time ≥8 hours in 15 flights, and transport time ≥8 hours in 29 missions. All transports were accompanied by a pediatric physician/nurse team. An increase in FiO during the transport was documented in 47/167 patients (28%). Therapy escalation (other than increased oxygen) was reported in 18 patients, and technical adverse events in 3 patients. No patient required CPR or died during the transport. Clinical transport outcome was rated by the accompanying physician as unchanged in 163 transports, improved in 4, and deteriorated in none. In summary, international, long-distance transport of neonatal and pediatric patients performed by experienced and well-equipped transport teams is feasible. Neither major adverse events nor physician-rated clinical deteriorations were observed in this group of patients.
PubMed: 37565016
DOI: 10.1055/s-0041-1731681 -
Frontiers in Endocrinology 2023Allopregnanolone (Allo) is a neurosteroid with pleiotropic action in the brain that includes neurogenesis, oligogenesis, human and rodent neural stem cell regeneration,...
OBJECTIVE
Allopregnanolone (Allo) is a neurosteroid with pleiotropic action in the brain that includes neurogenesis, oligogenesis, human and rodent neural stem cell regeneration, increased glucose metabolism, mitochondrial respiration and biogenesis, improved cognitive function, and reduction of both inflammation and Alzheimer's disease (AD) pathology. Because the breadth of Allo-induced responses requires activation of multiple systems of biology in the absence of an Allo-specific nuclear receptor, analyses were conducted in both neurons and astrocytes to identify unifying systems and signaling pathways.
METHODS
Mechanisms of Allo action were investigated in embryonic hippocampal neurons and astrocytes cultured in an Aging Model (AM) media. Cellular morphology, mitochondrial function, and transcriptomics were investigated followed by mechanistic pathway analyses.
RESULTS
In hippocampal neurons, Allo significantly increased neurite outgrowth and synaptic protein expression, which were paralleled by upregulated synaptogenesis and long-term potentiation gene expression profiles. Mechanistically, Allo induced Ca/CREB signaling cascades. In parallel, Allo significantly increased maximal mitochondrial respiration, mitochondrial membrane potential, and Complex IV activity while reducing oxidative stress, which required both the GABA and L-type Ca channels. In astrocytes, Allo increased ATP generation, mitochondrial function and dynamics while reducing oxidative stress, inflammasome indicators, and apoptotic signaling. Mechanistically, Allo regulation of astrocytic mitochondrial function required both the GABA and L-type Ca channels. Furthermore, Allo activated NRF1-TFAM signaling and increased the DRP1/OPA1 protein ratio, which led to increased mitochondrial biogenesis and dynamics.
CONCLUSION
Collectively, the cellular, mitochondrial, transcriptional, and pharmacological profiles provide evidence in support of calcium signaling as a unifying mechanism for Allo pleiotropic actions in the brain.
Topics: Humans; Calcium Signaling; Astrocytes; Pregnanolone; Neurons; gamma-Aminobutyric Acid
PubMed: 38189047
DOI: 10.3389/fendo.2023.1286931 -
Archives of Biochemistry and Biophysics Sep 2023Ferritin is a spherical nanocage protein for iron storage, composed of 24 light- or heavy-polypeptide chain subunits. A single ferritin molecule can carry up to 4500... (Review)
Review
Ferritin is a spherical nanocage protein for iron storage, composed of 24 light- or heavy-polypeptide chain subunits. A single ferritin molecule can carry up to 4500 iron atoms in its core, which plays an important role in suppressing intracellular iron toxicity. Serum ferritin levels are used as a marker for the total amount of iron stored in the body. Most serum ferritin is iron-free (apo-ferritin) and it is unclear how ferritin is released from cells. Ferritin is secreted into serum via extracellular vesicles (EVs) or the secretory autophagy pathway but not via the classical endoplasmic reticulum (ER)-to-Golgi secretion pathway. We recently discovered that the level of tetraspanin CD63, a common EV marker, is post-transcriptionally regulated by the intracellular iron level and both CD63 and ferritin expression is induced by iron loading. Ferritin is incorporated into CD63(+)-EVs through the ferritin-specific autophagy adapter molecule, NCOA4, and then secreted from cells. EV production differs drastically depending on cell type and physiological conditions. Extracellular matrix detached cells express pentaspanin prominin 2 and prominin 2(+)-EVs secrete ferritin independently of NCOA4 trafficking. Ferritin is tightly bound to iron in EVs and functions as an iron-carrier protein in the extracellular environment. Cells can suppress ferroptosis by secreting holo-ferritin, which reduces intracellular iron concentration. However, this exposes the neighboring cells receiving the secreted holo-ferritin to a large excess of iron. This results in cellular toxicity through increased generation of reactive oxygen species (ROS). Here we review the machinery by which ferritin is incorporated into EVs and its role as an intercellular communication molecule.
Topics: AC133 Antigen; Biological Transport; Extracellular Vesicles; Autophagy; Ferritins
PubMed: 37683905
DOI: 10.1016/j.abb.2023.109737 -
Proceedings of the National Academy of... Oct 2023Energy conversion by electron transport chains occurs through the sequential transfer of electrons between protein complexes and intermediate electron carriers, creating...
Energy conversion by electron transport chains occurs through the sequential transfer of electrons between protein complexes and intermediate electron carriers, creating the proton motive force that enables ATP synthesis and membrane transport. These protein complexes can also form higher order assemblies known as respiratory supercomplexes (SCs). The electron transport chain of the opportunistic pathogen is closely linked with its ability to invade host tissue, tolerate harsh conditions, and resist antibiotics but is poorly characterized. Here, we determine the structure of a SC that forms between the quinol:cytochrome oxidoreductase (cytochrome ) and one of the organism's terminal oxidases, cytochrome , which is found only in some bacteria. Remarkably, the SC structure also includes two intermediate electron carriers: a diheme cytochrome and a single heme cytochrome . Together, these proteins allow electron transfer from ubiquinol in cytochrome to oxygen in cytochrome . We also present evidence that different isoforms of cytochrome can participate in formation of this SC without changing the overall SC architecture. Incorporating these different subunit isoforms into the SC would allow the bacterium to adapt to different environmental conditions. Bioinformatic analysis focusing on structural motifs in the SC suggests that cytochrome - SCs also exist in other bacterial pathogens.
Topics: Pseudomonas aeruginosa; Electron Transport; Biological Transport; Cytochromes c; Anti-Bacterial Agents
PubMed: 37751552
DOI: 10.1073/pnas.2307093120 -
BMC Anesthesiology Feb 2024Anemia, characterized by low hemoglobin levels, is a global public health concern. Anemia is an independent factor worsening outcomes in various patient groups. Blood... (Review)
Review
BACKGROUND
Anemia, characterized by low hemoglobin levels, is a global public health concern. Anemia is an independent factor worsening outcomes in various patient groups. Blood transfusion has been the traditional treatment for anemia; its triggers, primarily based on hemoglobin levels; however, hemoglobin level is not always an ideal trigger for blood transfusion. Additionally, blood transfusion worsens clinical outcomes in certain patient groups. This narrative review explores alternative triggers for red blood cell transfusion and their physiological basis.
MAIN TEXT
The review delves into the physiology of oxygen transport and highlights the limitations of using hemoglobin levels alone as transfusion trigger. The main aim of blood transfusion is to optimize oxygen delivery, necessitating an individualized approach based on clinical signs of anemia and the balance between oxygen delivery and consumption, reflected by the oxygen extraction rate. The narrative review covers different alternative triggers. It presents insights into their diagnostic value and clinical applications, emphasizing the need for personalized transfusion strategies.
CONCLUSION
Anemia and blood transfusion are significant factors affecting patient outcomes. While restrictive transfusion strategies are widely recommended, they may not account for the nuances of specific patient populations. The search for alternative transfusion triggers is essential to tailor transfusion therapy effectively, especially in patients with comorbidities or unique clinical profiles. Investigating alternative triggers not only enhances patient care by identifying more precise indicators but also minimizes transfusion-related risks, optimizes blood product utilization, and ensures availability when needed. Personalized transfusion strategies based on alternative triggers hold the potential to improve outcomes in various clinical scenarios, addressing anemia's complex challenges in healthcare. Further research and evidence are needed to refine these alternative triggers and guide their implementation in clinical practice.
Topics: Humans; Blood Transfusion; Erythrocyte Transfusion; Anemia; Hemoglobins; Oxygen
PubMed: 38395758
DOI: 10.1186/s12871-024-02447-3 -
Neurochemical Research Jul 2024Lactate has received attention as a potential therapeutic intervention for brain diseases, particularly those including energy deficit, exacerbated inflammation, and...
Lactate has received attention as a potential therapeutic intervention for brain diseases, particularly those including energy deficit, exacerbated inflammation, and disrupted redox status, such as cerebral ischemia. However, lactate roles in metabolic or signaling pathways in neural cells remain elusive in the hypoxic and ischemic contexts. Here, we tested the effects of lactate on the survival of a microglial (BV-2) and a neuronal (SH-SY5Y) cell lines during oxygen and glucose deprivation (OGD) or OGD followed by reoxygenation (OGD/R). Lactate signaling was studied by using 3,5-DHBA, an exogenous agonist of lactate receptor GPR81. Inhibition of lactate dehydrogenase (LDH) or monocarboxylate transporters (MCT), using oxamate or 4-CIN, respectively, was performed to evaluate the impact of lactate metabolization and transport on cell viability. The OGD lasted 6 h and the reoxygenation lasted 24 h following OGD (OGD/R). Cell viability, extracellular lactate concentrations, microglial intracellular pH and TNF-ɑ release, and neurite elongation were evaluated. Lactate or 3,5-DHBA treatment during OGD increased microglial survival during reoxygenation. Inhibition of lactate metabolism and transport impaired microglial and neuronal viability. OGD led to intracellular acidification in BV-2 cells, and reoxygenation increased the release of TNF-ɑ, which was reverted by lactate and 3,5-DHBA treatment. Our results suggest that lactate plays a dual role in OGD, acting as a metabolic and a signaling molecule in BV-2 and SH-SY5Y cells. Lactate metabolism and transport are vital for cell survival during OGD. Moreover, lactate treatment and GPR81 activation during OGD promote long-term adaptations that potentially protect cells against secondary cell death during reoxygenation.
Topics: Microglia; Glucose; Humans; Neurons; Oxygen; Lactic Acid; Cell Survival; Animals; Mice; Neuroprotective Agents; Cell Hypoxia; Tumor Necrosis Factor-alpha; Receptors, G-Protein-Coupled; Cell Line, Tumor; Cell Line; Monocarboxylic Acid Transporters
PubMed: 38551797
DOI: 10.1007/s11064-024-04135-7 -
Journal of Molecular Medicine (Berlin,... Nov 2023The red blood cells (RBCs) are essential to transport oxygen (O) and nutrients throughout the human body. Changes in the structure or functioning of the erythrocytes can... (Review)
Review
The red blood cells (RBCs) are essential to transport oxygen (O) and nutrients throughout the human body. Changes in the structure or functioning of the erythrocytes can lead to several deficiencies, such as hemolytic anemias, in which an increase in reactive oxidative species generation is involved in the pathophysiological process, playing a significant role in the severity of several clinical manifestations. There are important lines of defense against the damage caused by oxidizing molecules. Among the antioxidant molecules, the enzyme peroxiredoxin (Prx) has the higher decomposition power of hydrogen peroxide, especially in RBCs, standing out because of its abundance. This review aimed to present the recent findings that broke some paradigms regarding the three isoforms of Prxs found in RBC (Prx1, Prx2, and Prx6), showing that in addition to their antioxidant activity, these enzymes may have supplementary roles in transducing peroxide signals, as molecular chaperones, protecting from membrane damage, and maintenance of iron homeostasis, thus contributing to the overall survival of human RBCs, roles that seen to be disrupted in hemolytic anemia conditions.
Topics: Humans; Antioxidants; Peroxiredoxins; Oxidative Stress; Erythrocytes; Oxidation-Reduction; Hydrogen Peroxide; Oxygen; Hemolysis
PubMed: 37728644
DOI: 10.1007/s00109-023-02368-7