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Redox Biology Jun 2024Tumors develop in an oxidative environment characterized by peroxynitrite production and downstream protein tyrosine (Y) nitration. We showed that tyrosine nitration...
Tumors develop in an oxidative environment characterized by peroxynitrite production and downstream protein tyrosine (Y) nitration. We showed that tyrosine nitration supports schwannoma cell proliferation and regulates cell metabolism in the inheritable tumor disorder NF2-related Schwannomatosis (NF2-SWN). Here, we identified the chaperone Heat shock protein 90 (Hsp90) as the first nitrated protein that acts as a metabolic switch to promote schwannoma cell proliferation. Doubling the endogenous levels of nitrated Hsp90 in schwannoma cells or supplementing nitrated Hsp90 into normal Schwann cells increased their proliferation. Metabolically, nitration on either Y33 or Y56 conferred Hsp90 distinct functions; nitration at Y33 (Hsp90) down-regulated mitochondrial oxidative phosphorylation, while nitration at Y56 (Hsp90) increased glycolysis by activating the purinergic receptor P2X7 in both schwannoma and normal Schwann cells. Hsp90 and Hsp90 showed differential subcellular and spatial distribution corresponding with their metabolic and proliferative functions in schwannoma three-dimensional cell culture models. Collectively, these results underscore the role of tyrosine nitration as a post-translational modification regulating critical cellular processes. Nitrated proteins, particularly nitrated Hsp90, emerge as a novel category of tumor-directed therapeutic targets.
PubMed: 38945076
DOI: 10.1016/j.redox.2024.103249 -
Journal of Colloid and Interface Science Jun 2024The present paper reports the fabrication of novel types of hybrid fibrous photocatalysts by combining block copolymer (BCP) templating, sol-gel processing, and coaxial...
The present paper reports the fabrication of novel types of hybrid fibrous photocatalysts by combining block copolymer (BCP) templating, sol-gel processing, and coaxial electrospinning techniques. Coaxial electrospinning produces core-shell nanofibers (NFs), which are converted into hollow porous TiO NFs using an oxidative calcination step. Hybrid BCP micelles comprising a single plasmonic nanoparticle (NP) in their core and thereof derived silica-coated core-shell particles are utilized as precursors to generate yolk-shell type particulate inclusions in photocatalytically active NFs. The catalytic and photocatalytic activity of calcined NFs comprising different types of yolk-shell particles is systematically investigated and compared. Interestingly, calcined NFs comprising silica-coated yolk-shells demonstrate enhanced catalytic and photocatalytic performance despite the presence of silica shell separating plasmonic NP from the TiO matrix. Electromagnetic simulations indicate that this enhancement is caused by a localized surface plasmon resonance and a confinement effect in silica-coated yolk-shells embedded in porous TiO NFs. Utilization of the coaxially electrospun TiO NFs in combination with yolk-shells comprising plasmonic NPs reveals to be a potent method for the photocatalytic decomposition of numerous pollutants. It is worth noting that this study stands as the first occurrence of combining yolk-shells (Au@void@SiO) with porous electrospun NFs (TiO) for photocatalytic purposes and gaining an understanding of plasmon and confinement effects for photocatalytic performance. This approach represents a promising route for fabricating highly active and up-scalable fibrous photocatalytic systems.
PubMed: 38945024
DOI: 10.1016/j.jcis.2024.06.133 -
Journal of Hazardous Materials Jun 2024In response to the need for trace arsenic removal and detoxification, an electro-assisted self-alkalization and oxidant-free processes (ESOP) cell was developed and...
In response to the need for trace arsenic removal and detoxification, an electro-assisted self-alkalization and oxidant-free processes (ESOP) cell was developed and investigated. It was found that the ESOP removed 90.3 % of arsenic and reduced the As(III) concentration from 150 µg L to less than 5 µg L in its cathode chamber. The As removal involved migration of As(III) and As(V) from the cathode to the anode driven by electrical current. In the ESOP cathode, As(III) was dissociated to As(III) oxyanions via alkalization and then oxidized into As(V) by HO. Nearly 80 % of As(III) migration could be attributed to the oxidation by HO and approximately 20 % dissociation by pH alkalization. The voltage-controlled conditions (1.2 -1.5 V) achieved a peak cumulative HO concentration of 10.9 mg L. The ESOP demonstrated a high As(III) oxidation to As(V) conversion efficiency of 97.0 % as well as a low energy cost of 0.013 kWh m at 1.2 V. The migrated arsenic was stabilized onto the anode electrode through in-situ electro-oxidation of As(III) and electrosorption of As(III, V); this would help with the post-treatment waste disposal. Those results have provided important insights into an electrochemical approach for highly efficient arsenic detoxification.
PubMed: 38944991
DOI: 10.1016/j.jhazmat.2024.135025 -
Cell Reports Jun 2024Vitamin D receptor (VDR) has been implicated in fatty liver pathogenesis, but its role in the regulation of organismal energy usage remains unclear. Here, we illuminate...
Vitamin D receptor (VDR) has been implicated in fatty liver pathogenesis, but its role in the regulation of organismal energy usage remains unclear. Here, we illuminate the evolutionary function of VDR by demonstrating that zebrafish Vdr coordinates hepatic and organismal energy homeostasis through antagonistic regulation of nutrient storage and tissue growth. Hepatocyte-specific Vdr impairment increases hepatic lipid storage, partially through acsl4a induction, while simultaneously diminishing fatty acid oxidation and liver growth. Importantly, Vdr impairment exacerbates the starvation-induced hepatic storage of systemic fatty acids, indicating that loss of Vdr signaling elicits hepatocellular energy deficiency. Strikingly, hepatocyte Vdr impairment diminishes diet-induced systemic growth while increasing hepatic and visceral fat in adult fish, revealing that hepatic Vdr signaling is required for complete adaptation to food availability. These data establish hepatocyte Vdr as a regulator of organismal energy expenditure and define an evolutionary function for VDR as a transcriptional effector of environmental nutrient supply.
PubMed: 38944835
DOI: 10.1016/j.celrep.2024.114393 -
Journal of Extracellular Vesicles Jul 2024Extracellular vesicles (EVs) play a crucial role in triggering tumour-aggressive behaviours. However, the energetic process by which tumour cells produce EVs remains...
Extracellular vesicles (EVs) play a crucial role in triggering tumour-aggressive behaviours. However, the energetic process by which tumour cells produce EVs remains poorly understood. Here, we demonstrate the involvement of β-hexosaminidase B (HEXB) in mediating EV release in response to oxidative stress, thereby promoting the development of hepatocellular carcinoma (HCC). Mechanistically, reactive oxygen species (ROS) stimulate the nuclear translocation of transcription factor EB (TFEB), leading to the upregulation of both HEXB and its antisense lncRNA HEXB-AS. HEXB-AS can bind HEXB to form a protein/RNA complex, which elevates the protein stability of HEXB. The stabilized HEXB interacts with lysosome-associated membrane glycoprotein 1 (LAMP1), disrupting lysosome-multivesicular body (MVB) fusion, which protects EVs from degradation. Knockdown of HEXB efficiently inhibits EV release and curbs HCC growth both in vitro and in vivo. Moreover, targeting HEXB by M-31850 significantly inhibits HCC growth, especially when combined with GW4869, an inhibitor of exosome release. Our results underscore the critical role of HEXB as a modulator that promotes EV release during HCC development.
Topics: Extracellular Vesicles; Carcinoma, Hepatocellular; Animals; Oxidative Stress; Humans; Liver Neoplasms; Mice; Up-Regulation; Cell Line, Tumor; Cell Proliferation; RNA, Long Noncoding; Reactive Oxygen Species; Gene Expression Regulation, Neoplastic; Male; Mice, Nude
PubMed: 38944674
DOI: 10.1002/jev2.12468 -
Nature Communications Jun 2024Dry reforming of methane (DRM) is a highly endothermic process, with its development hindered by the harsh thermocatalytic conditions required. We propose an innovative...
Dry reforming of methane (DRM) is a highly endothermic process, with its development hindered by the harsh thermocatalytic conditions required. We propose an innovative DRM approach utilizing a 16 W pulsed laser in combination with a cost-effective MoC catalyst, enabling DRM under milder conditions. The pulsed laser serves a dual function by inducing localized high temperatures and generating CH plasma on the MoC surface. This activates CH and CO, significantly accelerating the DRM reaction. Notably, the laser directly generates CH plasma from CH through thermionic emission and cascade ionization, bypassing the traditional step-by-step dehydrogenation process and eliminating the rate-limiting step of methane cracking. This method maintains a carbon-oxygen balanced environment, thus preventing the deactivation of the MoC catalyst due to CO oxidation. The laser-catalytic DRM achieves high yields of H (14300.8 mmol h g) and CO (14949.9 mmol h g) with satisfactory energy efficiency (0.98 mmol kJ), providing a promising alternative for high-energy-consuming catalytic systems.
PubMed: 38944644
DOI: 10.1038/s41467-024-49771-3 -
Journal of Ethnopharmacology Jun 2024Cistanche deserticola is a kind of parasitic plant living in the roots of desert trees. It is a rare Chinese medicine, which has the effect of tonifying kidney Yang,...
ETHNOPHARMACOLOGICAL RELEVANCE
Cistanche deserticola is a kind of parasitic plant living in the roots of desert trees. It is a rare Chinese medicine, which has the effect of tonifying kidney Yang, benefiting essence and blood and moistening the intestinal tract. Cistache deserticola phenylethanoid glycoside (PGS), an active component found in Cistanche deserticola Ma, have potential kidney tonifying, intellectual enhancing, and neuroprotective effects. Cistanche total glycoside capsule has been marketed to treat vascular dementia disease.
AIM OF THE STUDY
To identify the potential renal, intellectual enhancing and neuroprotective effects of PGS and explore the exact targets and mechanisms of PGS.
MATERIALS AND METHODS
This study systematically investigated the four types of pathways leading to ferroptosis through transcriptome, metabolome, ultrastructure and molecular biology techniques and explored the molecular mechanism by which multiple PGS targets and pathways synergistically exert neuroprotective effects on hypoxia.
RESULTS
PGS alleviated learning and memory dysfunction and pathological injury in mice exposed to hypobaric hypoxia by attenuating hypobaric hypoxia-induced hippocampal histopathological damage, impairing blood‒brain barrier integrity, increasing oxidative stress levels, and increasing the expression of cognitive proteins. PGS reduced the formation of lipid peroxides and improved ferroptosis by upregulating the GPX-4/SCL7A311 axis and downregulating the ACSL4/LPCAT3/LOX axis. PGS also reduced ferroptosis by facilitating cellular Fe efflux and regulating mitochondrial Fe transport and effectively antagonized cell ferroptosis induced by erastin (a ferroptosis inducer).
CONCLUSIONS
This study demonstrated the mechanism by which PGS prevents hypobaric hypoxic nerve injury through four types of ferroptosis pathways, achieved neuroprotective effects and alleviated learning and memory dysfunction in hypobaric hypoxia mice. This study provides a theoretical basis for the development and application of PGS.
PubMed: 38944360
DOI: 10.1016/j.jep.2024.118465 -
Pharmacological Research Jun 2024The global incidence of cardiac diseases is increasing, imposing a substantial socioeconomic burden on healthcare systems. The pathogenesis of cardiovascular disease is... (Review)
Review
The global incidence of cardiac diseases is increasing, imposing a substantial socioeconomic burden on healthcare systems. The pathogenesis of cardiovascular disease is complex and not fully understood, and the physiological function of the heart is inextricably linked to well-regulated cardiac muscle movement. Myosin light chain kinase (MLCK) is essential for myocardial contraction and diastole, cardiac electrophysiological homeostasis, vasoconstriction of vascular nerves and blood pressure regulation. In this sense, MLCK appears to be an attractive therapeutic target for cardiac diseases. MLCK participates in myocardial cell movement and migration through diverse pathways, including regulation of calcium homeostasis, activation of myosin light chain phosphorylation, and stimulation of vascular smooth muscle cell contraction or relaxation. Recently, phosphorylation of myosin light chains has been shown to be closely associated with the activation of myocardial exercise signaling, and MLCK mediates systolic and diastolic functions of the heart through the interaction of myosin thick filaments and actin thin filaments. It works by upholding the integrity of the cytoskeleton, modifying the conformation of the myosin head, and modulating innervation. MLCK governs vasoconstriction and diastolic function and is associated with the activation of adrenergic and sympathetic nervous systems, extracellular transport, endothelial permeability, and the regulation of nitric oxide and angiotensin II. Additionally, MLCK plays a crucial role in the process of cardiac aging. Multiple natural products/phytochemicals and chemical compounds, such as quercetin, cyclosporin, and ML-7 hydrochloride, have been shown to regulate cardiomyocyte MLCK. The MLCK-modifying capacity of these compounds should be considered in designing novel therapeutic agents. This review summarizes the mechanism of action of MLCK in the cardiovascular system and the therapeutic potential of reported chemical compounds in cardiac diseases by modifying MLCK processes.
PubMed: 38944220
DOI: 10.1016/j.phrs.2024.107276 -
Reproductive Toxicology (Elmsford, N.Y.) Jun 20243-chloro-1,2-propanediol (3-MCPD) is a newly discovered food process pollutant with nephrotoxicity. And the mechanism by which 3-MCPD affects male spermatogenesis has...
3-chloro-1,2-propanediol (3-MCPD) is a newly discovered food process pollutant with nephrotoxicity. And the mechanism by which 3-MCPD affects male spermatogenesis has not been fully studied. Cell viability, blood-testis barrier (BTB) related protein, progesterone content, reactive oxygen species (ROS) generation, and cell apoptosis were determined by a CCK8 assay, western blot, ELISA, flow cytometry, and TUNEL staining, respectively. Wistar rats were divided into three groups: low-dose 3-MCPD, high-dose 3-MCPD, and control. Sperm parameters, hormonal levels, and biomarkers of oxidative stress in the testis and epididymis were detected by ELISA. Multiple molecular experiments including molecular docking and western blot were used to elucidate the underlying mechanisms. 3-MCPD affects testicular cell activity, and promotes ROS production and apoptosis. Disrupting the integrity of BTB in the body, downregulating sex hormones and sperm quality, and promoting apoptosis. 3-MCPD may function through CYP2C9. This study preliminarily explores the mechanism by which 3-MCPD affects spermatogenesis. It was found that 3-MCPD destroys the structure and function of BTB and damages the testicular function of male mice, thus affecting the process of spermatogenesis via CYP2C9.
PubMed: 38944211
DOI: 10.1016/j.reprotox.2024.108633 -
The Journal of Biological Chemistry Jun 2024L-Fucose (6-deoxy-L-galactose), a monosaccharide abundant in glycolipids and glycoproteins produced by mammalian cells, has been extensively studied for its role in...
L-Fucose (6-deoxy-L-galactose), a monosaccharide abundant in glycolipids and glycoproteins produced by mammalian cells, has been extensively studied for its role in intracellular biosynthesis and recycling of GDP-L-fucose for fucosylation. However, in certain mammalian species, L-fucose is efficiently broken down to pyruvate and lactate in a poorly understood metabolic pathway. In the 1970s, L-fucose dehydrogenase, an enzyme responsible for the initial step of this pathway, was partially purified from pig and rabbit livers and characterized biochemically. However, its molecular identity remained elusive until recently. This study reports the purification, identification, and biochemical characterization of the mammalian L-fucose dehydrogenase. The enzyme was purified from rabbit liver approximately 340-fold. Mass spectrometry analysis of the purified protein preparation identified mammalian hydroxysteroid 17-β dehydrogenase 14 (HSD17B14) as the sole candidate enzyme. Rabbit and human HSD17B14 were expressed in HEK293T and Escherichia coli, respectively, purified and demonstrated to catalyze the oxidation of L-fucose to L-fucono-1,5-lactone, as confirmed by mass spectrometry and NMR analysis. Substrate specificity studies revealed that L-fucose is the preferred substrate for both enzymes. The human enzyme exhibited a catalytic efficiency for L-fucose that was 359-fold higher than its efficiency for estradiol. Additionally, recombinant rat HSD17B14 exhibited negligible activity towards L-fucose, consistent with the absence of L-fucose metabolism in this species. The identification of the gene encoding mammalian L-fucose dehydrogenase provides novel insights into the substrate specificity of enzymes belonging to the 17-β-hydroxysteroid dehydrogenase family. This discovery also paves the way for unraveling the physiological functions of the L-fucose degradation pathway, which remains enigmatic.
PubMed: 38944119
DOI: 10.1016/j.jbc.2024.107501