Increased ROS Production Research Articles

The Trx-Prx redox pathway and PGR5/PGRL1-dependent cyclic electron transfer play key regulatory roles in poplar drought stress.

Understanding drought resistance mechanisms is crucial for breeding poplar species suited to arid and semi-arid regions. This study explored the drought responses of three newly developed 'Zhongxiong' series poplars using integrated transcriptomic and physiological analyses. Under drought stress, poplar leaves showed significant changes in differentially expressed genes (DEGs) linked to photosynthesis-related pathways, including photosynthesis-antenna proteins and carbon fixation, indicating impaired photosynthetic function and carbon assimilation. Additionally, drought stress triggered oxidative damage through increased ROS production, leading to malondialdehyde (MDA) accumulation. Weighted gene co-expression network analysis (WGCNA) revealed that DEGs closely associated with physiological responses were enriched in cell redox homeostasis pathways, specifically the thioredoxin-peroxiredoxin (Trx-Prx) pathway. Key genes in this pathway and in cyclic electron flow (CEF), such as PGR5-L1A, were downregulated, suggesting compromised ROS scavenging and photoprotection under drought stress. Notably, ZX4 poplar exhibited higher drought tolerance, maintaining stronger activity in CEF and the Trx-Prx pathway compared to ZX3 and ZX5. Genes like PGR5-L1A, 2-Cys Prx BAS1, PrxQ, and TPX are promising candidates for enhancing drought resistance in poplars through genetic improvement, with potential applications for developing resilient forestry varieties.

Single-Cell RNA sequencing reveals mitochondrial dysfunction in microtia chondrocytes

Microtia is a congenital malformation characterized by underdevelopment of the external ear. While chondrocyte dysfunction has been implicated in microtia, the specific cellular abnormalities remain poorly understood. This study aimed to investigate mitochondrial dysfunction in microtia chondrocytes using single-cell RNA sequencing. Cartilage samples were obtained from patients with unilateral, non-syndromic microtia and healthy controls. Single-cell RNA sequencing was performed using the 10 × Genomics platform. Bioinformatic analyses including cell type identification, trajectory analysis, and gene co-expression network analysis were conducted. Mitochondrial function was assessed through ROS levels, membrane potential, and transmission electron microscopy. Chondrocytes from microtia samples showed lower mitochondrial function scores compared to normal samples. Trajectory analysis revealed more disorganized differentiation patterns in microtia chondrocytes. Mitochondrial dysfunction in microtia chondrocytes was confirmed by increased ROS production, decreased membrane potential, and altered mitochondrial structure. Gene co-expression network analysis identified hub genes associated with mitochondrial function, including SDHA, SIRT1, and PGC1A, which showed reduced expression in microtia chondrocytes. This study provides evidence of mitochondrial dysfunction in microtia chondrocytes and identifies potential key genes involved in this process. These findings offer new insights into the pathogenesis of microtia and may guide future therapeutic strategies.

Re-thinking the link between exposure to mercury and blood pressure.

Hypertension or high blood pressure (BP)is a prevalent and manageable chronic condition which is a significant contributor to the total global disease burden. Environmental chemicals, including mercury (Hg), may contribute to hypertension onset and development. Hg is a global health concern, listed by the World Health Organization (WHO) as a top ten chemical of public health concern. Most people are exposed to some level of Hg, with vulnerable groups, including Indigenous peoples and small-scale gold miners, at a higher risk for exposure. We published a systematic review and meta-analysis in 2018 showing a dose-response relationship between Hg exposure and hypertension. This critical review summarizes the biological effects of Hg (both organic and inorganic form) on the underlying mechanisms that may facilitate the onset and development of hypertension and related health outcomes and updates the association between Hg exposure (total Hg concentrations in hair) and BP outcomes. We also evaluated the weight of evidence using the Bradford Hill criteria. There is a strong dose-response relationship between Hg (both organic and inorganic) exposure and BP in animal studies and convincing evidence that Hg contributes to hypertension by causing structural and functional changes, vascular reactivity, vasoconstriction, atherosclerosis, dyslipidemia, and thrombosis. The underlying mechanisms are vast and include impairments in antioxidant defense mechanisms, increased ROS production, endothelial dysfunction, and alteration of the renin-angiotensin system. We found additional 16 recent epidemiological studies that have reported the relationship between Hg exposure and hypertension in the last 5years. Strong evidence from epidemiological studies shows a positive association between Hg exposure and the risk of hypertension and elevated BP. The association is mixed at lower exposure levels but suggests that Hg can affect BP even at low doses when co-exposed with other metals. Further research is needed to develop robust conversion factors among different biomarkers and standardized measures of Hg exposure. Regulatory agencies should consider adopting a 2µg/g hair Hg level as a cut-off for public health regulation, especially for adults older than child-bearing age.

Vitamin C as Prevention in Burn Sepsis

Background: Burns is a severe public health problem. Its poor treatment can lead to the worst complication called sepsis. Since sepsis decreases the immune system, the critical therapy management of burn sepsis ensures adequate end-organ perfusion. According to the Surviving Sepsis Campaign Bundle, immediate identification and management in the initial hours generate a better outcome. The inflammation of burn injury is known to increase ROS production, which causes cellular damage, sepsis, and MODS. This condition initiates the importance of ROS scavenger. Methods: This literature reviewed from relevant works of literature which searched from major journal databases of WHO, Pubmed, Elsevier, JAMA, Springer, NEJM, which published from 2013 until 2018 Results: Vitamin C is a cheap but effective antioxidant, which acts as a ROS scavenger and reduces the fluid requirement in burn resuscitation for the prevention of burn sepsis Conclusion: Vitamin C could be recommended as adjuvant therapy in the prevention of burn sepsis

KSRP Deficiency Attenuates the Course of Pulmonary Aspergillosis and Is Associated with the Elevated Pathogen-Killing Activity of Innate Myeloid Immune Cells.

The mRNA-binding protein KSRP (KH-type splicing regulatory protein) is known to modulate immune cell functions post-transcriptionally, e.g., by reducing the mRNA stability of cytokines. It is known that KSRP binds the AU-rich motifs (ARE) that are often located in the 3'-untranslated part of mRNA species, encoding dynamically regulated proteins as, for example, cytokines. Innate myeloid immune cells, such as polymorphonuclear neutrophils (PMNs) and macrophages (MACs), eliminate pathogens by multiple mechanisms, including phagocytosis and the secretion of chemo- and cytokines. Here, we investigated the role of KSRP in the phenotype and functions of both innate immune cell types in the mouse model of invasive pulmonary aspergillosis (IPA). Here, KSRP-/- mice showed lower levels of Aspergillus fumigatus conidia (AFC) and an increase in the frequencies of PMNs and MACs in the lungs. Our results showed that PMNs and MACs from KSRP-/- mice exhibited an enhanced phagocytic uptake of AFC, accompanied by increased ROS production in PMNs upon stimulation. A comparison of RNA sequencing data revealed that 64 genes related to inflammatory and immune responses were shared between PMNs and MACs. The majority of genes upregulated in PMNs were involved in metabolic processes, cell cycles, and DNA repair. Similarly, KSRP-deficient PMNs displayed reduced levels of apoptosis. In conclusion, our results indicate that KSRP serves as a critical negative regulator of PMN and MAC anti-pathogen activity.

In Vitro and In Silico Evaluation of Syzygium aromaticum Essential Oil: Effects on Mitochondrial Function and Cytotoxic Potential Against Cancer Cells.

The current study proposes the in vitro and in silico anticancer evaluation of clove (Syzygium aromaticum L.) essential oil (CEO). The steam hydrodistillation method used yielded 10.7% (wt) CEO. GC-MS analysis revealed that the obtained oil is rich in eugenol (75%), β-caryophyllene (20%), and α- caryophyllene (2.8%) and also contains several other minor components accounting for approximately 1.5%. The DPPH-based scavenging antioxidant activity was assessed for the obtained CEO, exhibiting an IC50 value of 158 μg/mL. The cytotoxic effects of CEO, its major component eugenol, and CEO solubilized with Tween-20 and PEG-400 were tested against both noncancerous HaCaT cells and HT-29 human colorectal adenocarcinoma, RPMI-7951 melanoma, A431 skin carcinoma, and NCI-H460 non-small lung cancer cells, using the Alamar Blue and LDH assay after 48 h treatment. The Tween-20 and PEG-400 CEO formulations, at 200 μg/mL, recorded the highest cytotoxic and selective effects against RPMI-7951 (72.75% and 71.56%), HT-29 (71.51% and 45.43%), and A431 cells (61.62% and 59.65%). Furthermore, CEO disrupted mitochondrial function and uncoupled oxidative phosphorylation. This effect was more potent for the CEO against the RPMI-7951 and HT-29 cells, whereas for the other two tested cell lines, a more potent inhibition of mitochondrial function was attributed to eugenol. The present study is the first to specifically investigate the effects of CEO and Tween-20 and PEG-400 CEO formulations on the mitochondrial function of RPMI-7951, HT-29, A431, and NCI-H460 cancer cell lines using high-resolution respirometry, providing novel insights into their impact on mitochondrial respiration and bioenergetics in cancer cells. The results obtained may explain the increased ROS production observed in cancer cell lines treated with eugenol and CEO. Molecular docking identified potential protein targets, related to the CEO anticancer activity, in the form of PI3Kα, where the highest active theoretical inhibitor was calamenene (-7.5 kcal/mol). Docking results also showed that calamenene was the overall most active theoretical inhibitor for all docked proteins and indicated a potential presence of synergistic effects among all CEO constituents.

Nrf2 depletion enhanced curcumin therapy effect in gastric cancer by inducing the excessive accumulation of ROS

Gastric cancer (GC) is the most common malignant tumor of the gastrointestinal tract and currently has a poor clinical outcome. Turmeric’s rhizome contains a polyphenolic component called curcumin (Cur), which has been demonstrated to inhibit a variety of tumor cells, such as pancreatic, colon, lung and gastric cancers. However, it remains to be elucidated how Cur functions in GC and what molecular processes underlie it. Here, Cur showed a stronger inhibitory effect on GC cells AGS and HGC27. In addition, Cur’s inhibition of GC cells growth was accompanied by increased ROS production, triggering of the Keap1-Nrf2 signaling pathway, and increased transcription of its downstream antioxidant genes HO-1, GCLM, and NQO1. However, when a ROS scavenger NAC was used, the inhibitory effect of Cur on GC cells was reversed. Nuclear factor erythroid 2-related factor 2 (Nrf2) is overexpressed or activated in cancers to shield cancer cells from oxidative damage by responding to oxidative stress (OS). Cur has been found to act as an activator of Nrf2. Notably, compared with Nrf2 knockdown and Cur alone, the combination of the two dramatically increased Cur-induced ROS overaccumulation and inhibition of GC cells proliferation, migration, and invasive abilities. Consistent with in vitro experiments, Cur combined with Nrf2 knockdown significantly inhibited tumor growth in nude mice transplanted with AGS cells. Therefore, we concluded that Nrf2 depletion enhanced Cur therapy effect in GC by inducing the excessive accumulation of ROS, indicating that this is a promising treatment strategy.

Nonthermal Plasma Boosted Dichloroacetate Induces Metabolic Shifts to Combat Glioblastoma CSCs via Oxidative Stress.

Glioblastoma (GBM) remains a formidable clinical challenge, with cancer stem cells (CSCs) contributing to treatment resistance and tumor recurrence. Conventional treatments often fail to eradicate these CSCs characterized by enhanced resistance to standard therapies through metabolic plasticity making them key targets for novel treatment approaches. Addressing this challenge, this study introduces a novel combination therapy of dichloroacetate (DCA), a metabolic modulator and nonthermal plasma to induce oxidative stress in glioblastomas. Our results demonstrate that DCA and nonthermal plasma (NTP) synergistically increase ROS production, resulting in endoplasmic reticulum (ER) stress and mitochondrial reprogramming, key factors in the initiation of programmed cell death. Furthermore, the combination downregulated key stemness markers indicating effective CSCs suppression. Upregulation of pro-apoptotic proteins and downregulation of anti-apoptotic factors highlight the induction of apoptosis in glioma cells. This study provides compelling evidence that the combination of DCA and NTP offers a novel and effective strategy for targeting glioma CSCs by inducing oxidative and metabolic stress, underscoring potential therapeutic advancements in glioblastoma treatment.

DNA Damage, Transposable Element Expression and Their Associated Factors in Aging

Aging is a spontaneous and permanent physiological process that leads to declines in tissue and cell functions, along with an increased risk of developing various age-related diseases. The primary driving force associated with aging is the accumulation of damaged genetic material in the cell, such as DNA. DNA damage can be caused by endogenous and exogenous factors, which leads to genome instability, mitochondrial dysfunction, epigenetic modifications, and proteostatic disturb. Another driving force associated with aging is the disruption of cellular metabolism. This disruption is closely linked to alterations in the role of metabolic pathways, including insulin/IGF-1 and mTOR, which regulate crucial cellular processes like cell growth, cell proliferation, and apoptosis. The activation of the insulin/IGF-1 signaling pathway highly promotes cell growth and proliferation, while also inhibits autophagy and increasing ROS production. This ultimately leads to accelerated aging. Another crucial signaling pathway is the mTOR signaling pathway. It is responsible for detecting nutrient availability and controlling cell growth and metabolism. The dysregulation of mTOR function can lead to the development of neurodegenerative diseases, which are characterized by the aggregation of protein. Activation of transposable elements is the other driving force of aging, caused by changes in DNA methylation and the loss of heterochromatin. As a result, this leads to DNA damage, genomic instability, and inflammation. The aim of this review is to elucidate the consequence of DNA damage and other associated factors drive aging.

Ethyltoluenes Regulate Inflammatory and Cell Fibrosis Signaling in the Liver Cell Model.

Crude oil naphtha fraction C9 alkylbenzenes consist of trimethylbenzenes, ethyltoluenes, cumene, and n-propylbenzene. The major fraction of C9 alkylbenzenes is ethyltoluenes (ETs) consisting of three isomers: 2-ethyltoluene (2-ET), 3-ethyltoluene (3-ET), and 4-ethyltoluene (4-ET). Occupational and environmental exposure to ETs can occur via inhalation and ingestion and cause several health problems. Exposure to ETs causes eye and upper respiratory tract irritation, coughing, gagging, vomiting, griping, diarrhea, distress, and depressed respiration. Previous studies suggest that ETs target the respiratory tract and liver and produce several lesions in the nose, lungs, and liver areas. In the current study, we investigated the impact of low concentrations of ETs on cell metabolism, cell inflammation, steatosis, and fibrosis signaling in liver cell models in vitro. Dose-dependent exposure of 2-ET, 3-ET, and 4-ET to HepaRG and hepatocellular carcinoma (HCC) HepG2 and SK-Hep1 cells affects cell survival/real-time proliferation and increases ROS production. ETs induce inflammatory CAT, SOD1, CXCL8, IL1B, HMOX1, NAT1 (3), and STAT3 gene expression. Exposure of 2-ET, 3-ET, and 4-ET to HepaRG and HCC HepG2 and SK-Hep1 cells affects mitochondrial respiration/cellular energetics and upregulates metabolic CYP1-A1, CYP1-A2, CYP2-D6, CYP2-E1, CYP3-A4, CYP3-B4, and VEGFA gene expression. However, no significant change in lipogenesis-related gene expression and modulation of cell steatosis was observed after ET exposure. Acute exposure to induvial ETs and in combination or chronic 2-ET exposure alone modulates cell fibrosis markers such as AST, FGF-23, Cyt-7 p21, TGFβ, TIMP2, and MMP2 in liver cell models, suggesting that ETs target liver cells and may dysregulate liver function.

Investigating the sorption of Zinc-Oxide nanoparticles on Tire-wear particles and their toxic effects on Chlorella vulgaris: Insights from toxicological models and physiological analysis

This study investigated the interaction of Tire-wear particles (TWPs) with Zinc-Oxide nanoparticles (ZNPs) and studied their individual and combined toxic effects on Chlorella vulgaris in the co-presence of Humics. Physiological parameters, including growth, photosynthetic pigments, oxidative stress, and membrane damage, were analysed using Flow cytometry. Adsorption experiments exhibited that ZNPs were significantly absorbed by TWPs (qmax= 312.49 mg/g). A positive dose-response relation concerning inhibition in growth was observed in all treatment groups, and it was associated with reduced chlorophyll levels and damaged cell membranes. A negative impact of increased concentrations of TWPs and ZNPs was observed on anti-oxidant enzymes CAT and SOD; however, the impact was more severe when combined with exposure to both contaminants. Elevated concentrations of ZNPs and TWPs led to increased ROS production, lipid peroxidation and membrane damage, which could be contributing to the observed inhibition in growth. In the combined exposure groups, the Independent Action and the Abbott toxicity models revealed a synergistic effect on growth rates, which agreed with the Integrated Biomarker model results. The current study could enhance our understanding of the interaction between TWPs and metal nanoparticles in aquatic systems and offer novel understandings of the mechanisms underlying their combined toxic effects on microalgae.

Empagliflozin prevents TNF-α induced endothelial dysfunction under flow -the potential involvement of calcium and sodium-hydrogen exchanger

BackgroundEmpagliflozin (EMPA) attenuates inflammation-induced ROS generation in static endothelial cells through inhibition of sodium hydrogen exchanger 1 (NHE1) and modulation of ion homeostasis. We hypothesize that EMPA will alleviate TNF-α stimulated endothelial dysfunction under flow conditions, and that this might be mediated by NHE1 and intracellular Ca2+. MethodsHuman coronary artery endothelial cells were pre-treated with EMPA or vehicle before starting flow with or without TNF-α. Intracellular Ca2+ was recorded for 5 min at the start of flow. ROS generation and NO bioavailability, Piezo-1, cytokines, adhesion molecules, VE-cadherin and eNOS were detected after 6 h. BAPTA-AM was applied to chelate intracellular Ca2+ and NHE1 was knocked down with specific siRNA. ResultsUnder flow conditions, EMPA inhibited ROS production and [Ca2+] increase in cells exposed to TNF-α (P < 0.05). BAPTA-AM and NHE1 knockdown both reduced ROS generation (P < 0.05), and genetical inhibition of NHE1 led to reduction of intracellular [Ca2+] in HCAECs receiving TNF-α (P < 0.05). Yet, EMPA showed no effect on the increased cytokine production, adhesion molecule expression and phosphorylation of eNOS in endothelial cells exposed to TNF-α. ConclusionEMPA mitigates increased ROS production and impaired NO bioavailability in TNF-α stimulated cells under flow. The anti-oxidative effect of EMPA is mediated by the decreased intracellular [Ca2+] following NHE1 inhibition.

Facet Engineering Modulates d‐π* Hybridization for Boosting Antimicrobial Activity

AbstractReactive oxygen species (ROS) have been growing as an emerging “hot” topic in antimicrobial applications. However, optimizing antimicrobial activity by enhancing ROS generation remains a formidable challenge. Here, using bassanite as a proof of concept, the facet engineering of bassanite matrix can enhance the ROS generation efficiency via tuning the d‐band center of Cu atom is proposed. Theoretical calculation and experimental investigations reveal that the d‐band center of Cu atoms is significantly shifted upward when Cu doped into the (204) facet of bassanite compared to the (400) facet. A higher d‐band center facilitates adsorption and activation between Cu and O2 through the formation of stronger d‐π* orbital hybridization, resulting in increased ROS production. Through engineering, the material exhibits better antimicrobial activity when Cu doped into the (204) facet, which presents a clear potential in construction materials and personal protection. This work shed light on designing new materials with high antimicrobial activity and the application of facet engineering.

Oxidative Stress Mechanism by Gold Compounds: A Close Look at Total ROS Increase and the Inhibition of Antioxidant Enzymes.

The antitumor activity of various gold compounds is a promising field of investigation, attracting researchers seeking potential clinical candidates. To advance this research, they explore the complex mechanisms of action of these compounds. Since the discovery of the strong inhibition of thioredoxin reductase by auranofin, the primary mechanism explored has been the inhibition of this enzyme. This inhibition disrupts the redox balance in cells, promoting oxidative stress and triggering cell death. In this review, we analyzed studies from the past decade that measured cellular ROS increase and examined the coordination structures of gold compounds. We also correlate ROS increase with the inhibition of redox-regulating enzymes, thioredoxin reductase, and glutathione reductase, to elucidate the relationship between these cellular effects and chemical structures. Our data compilation reveals that different structures exhibit varying efficacy: some significantly increase ROS production and inhibit thioredoxin reductase or glutathione reductase, while others elevate ROS levels without affecting these target enzymes, suggesting alternative mechanisms of action. This review consolidates critical evidence, enhancing our understanding of the mechanisms by which these gold complexes act and providing valuable insights for developing new therapeutic strategies against tumor cells.

Interleukin-10 inhibits important components of trained immunity in human monocytes.

Trained immunity induces antigen-agnostic enhancement of host defense and protection against secondary infections, but inappropriate activation can contribute to the pathophysiology of inflammatory diseases. Tight regulation of trained immunity is therefore needed to avoid pathology, but little is known about the endogenous processes that modulate it. Here, we investigated the potential of IL-10, a prototypical anti-inflammatory cytokine, to inhibit trained immunity. IL-10 induced tolerance and inhibited trained immunity in primary human monocytes at both functional and transcriptional levels. Inhibition of STAT3, a signaling route that mediates IL-10 signals, induced trained immunity. IL-10 downregulated glycolytic and oxidative metabolism in monocytes, but did not impact the metabolic effects of β-glucan-induced trained immunity. Furthermore, IL-10 prevented increased ROS production in BCG-induced training, but did not influence phagocytosis upregulation. In a cohort study of healthy volunteers vaccinated with BCG, genetic variants that influenced IL-10 or its receptor modulated BCG-induced trained immunity. Furthermore, circulating IL-10 concentrations were negatively correlated with induction of trained immunity after BCG vaccination in a sex-specific manner. In conclusion, IL-10 inhibited several, albeit not all, immunological functions amplified after induction of trained immunity. Follow-up studies should explore the precise molecular mechanism that mediate the effects of IL-10 on trained immunity. Addressing these knowledge gaps is an important step towards optimizing IL-10's potential as a therapeutic target in diseases characterized by inappropriate induction of trained immunity.

Effect of Combination of Blue and Red Light with Terbinafine on Cell Viability and Reactive Oxygen Species in Human Keratinocytes: Potential Implications for Cutaneous Mycosis.

Cutaneous mycoses are common infections whose treatment has become more complex due to increasing antifungal resistance and the need for prolonged therapies, hindering patient adherence and increasing the incidence of adverse effects. Consequently, the use of physical therapies, especially photodynamic therapy (PDT), has increased for the treatment of onychomycosis due to its antimicrobial capacity being mediated by the production of reactive oxygen species. This study investigates the in vitro effect of applying blue light (448 nm) or red light (645 nm), alone or together with terbinafine, on the viability of human keratinocytes and the production of reactive oxygen species. The combination of terbinafine and blue light significantly increases ROS production and caspase-3 expression, while red light together with terbinafine increases catalase, superoxide dismutase (SOD) and PPARγ expression, which reduces the amount of ROS in the cultures. The effect of both treatments could be useful in clinical practice to improve the response of cutaneous mycoses to pharmacological treatment, reduce their toxicity and shorten their duration.

Integrative Gut Microbiota and Metabolomic Analyses Reveal the PANoptosis- and Ferroptosis-Related Mechanisms of Chrysoeriol in Inhibiting Melanoma.

Chrysoeriol, a natural flavonoid, has shown potential in inhibiting melanoma. However, the detailed molecular mechanisms of its action still need to be clarified. In this study, chrysoeriol showed significant suppressive effects on melanoma progression in a mouse model. The integrative gut microbiota and metabolomic analyses revealed that chrysoeriol modulates multiple pathways associated with apoptosis, necroptosis, pyroptosis, and ferroptosis. Morphological changes in chrysoeriol-treated melanoma cells showed PANoptosis- and ferroptosis-related characteristics. Additionally, chrysoeriol induced apoptosis, altered mitochondrial membrane potential, increased ROS production, promoted necroptosis, and also upregulated molecules linked to pyroptosis and ferroptosis. Molecular-level experiments confirmed that chrysoeriol promoted the upregulation of crucial proteins associated with the PANoptosis and ferroptosis pathways. Inhibition of PANoptosis and ferroptosis pathways by inhibitors or gene knockdown significantly attenuated the inhibitory effects of chrysoeriol on melanoma cell viability. This study provides robust evidence that chrysoeriol triggers both PANoptosis and ferroptosis in melanoma cells, underscoring its promise as a treatment option for melanoma.

Quinoline- and coumarin-based ligands and their rhenium(I) tricarbonyl complexes: synthesis, spectral characterization and antiproliferative activity on T-cell lymphoma

Novel 6-substituted 2-(trifluoromethyl)quinoline 5a–5e and coumarin 6a–6d ligands with aldoxime ether linked pyridine moiety were synthesized by O-alkylation of quinoline and coumarin with (E)-picolinaldehyde oxime and subsequently with [Re(CO)5Cl] gave rhenium(I) tricarbonyl complexes 5aRe–5eRe and 6aRe–6dRe that were fully characterized by NMR, single-crystal X-ray diffraction, IR and UV–Vis spectroscopy. The results of antiproliferative evaluation of quinoline and coumarin ligands and their rhenium(I) tricarbonyl complexes on various human tumor cell lines, including acute lymphoblastic leukemia (CCRF-CEM), acute monocytic leukemia (THP1), cervical adenocarcinoma (HeLa), colon adenocarcinoma (CaCo-2), T-cell lymphoma (HuT78), and non-tumor human fibroblasts (BJ) showed that the quinoline complexes 5aRe–5eRe had higher inhibitory activity than coumarin complexes 6aRe–6dRe, particularly against T-cell lymphoma (HuT78) cells. 6-Methoxy-2-(trifluoromethyl)quinoline 5e and 6-methylcoumarin 6d, and their rhenium(I) tricarbonyl complexes 5eRe and 6dRe were found to arrest the cell cycle of HuT78 cells by causing a significant accumulation of cells in the G0/G1 phase and a marked decrease in the number of cells in the G2/M phase. These rhenium(I) tricarbonyl complexes also slightly increased ROS production and significantly decreased the mitochondrial membrane potential by 50 % (5eRe) and 45 % (6dRe) compared to untreated cells and cells treated with 5e and 6d. These results suggest that the cytotoxic effects of these compounds are mediated by their effects on mitochondrial membrane potential and the subsequent increase in ROS production.

Advancing cardiac 3D organoid-on-chip: integrating iPSC-derived MELAS syndrome models to study electromechanical synchronicity and cardiac memory using contactless technology

Abstract Background Mitochondrial DNA mutations affect 1:5000 newborns, posing life-threatening risks, especially to high-energy organs such as the brain, heart, and muscles. Mortality rates can reach 71% when cardiomyopathy is present. MELAS syndrome (Mitochondrial Encephalopathy with Lactic Acidosis and Stroke-like Episodes), primarily affecting protein synthesis (MTTL1 gene, tRNALeu(UUR)), disrupts the electron transport chain complex I and is associated with cardiac conduction defects and hypertrophy. Manifesting symptoms typically appear between ages 3 and adulthood, presenting a complex clinical scenario. Human induced pluripotent stem cells (hiPSCs) offer a unique platform for studying cardiac manifestations of this disease when differentiated into cardiomyocytes. Purpose We adopted a highly adaptable in-vitro model, organized in 3D cardioids, to explore potential impairments in electromechanical coupling of cells. Methods We utilized hiPSCs carrying the MELAS mutation and their respective isogenic controls differentiated into cardiomyocytes, cultured in 3D cardioids. Electromechanical coupling was assessed using laser-poration technology combined with video kinematics evaluation under various stimulation patterns. Results Morphological analysis revealed a statistically significant reduction in the diameter of MELAS cardioids compared to the isogenic 3D structures (368±17.15 μm vs. 527±36.76 μm). In a spontaneous regimen, MELAS samples exhibited higher beating frequency (0.88±0.28 Hz vs. 0.17±0.05 Hz) and contractile speed (99.35±39.11 μm/s vs. 33.46±5.57 μm/s). Additionally, the response to different electric field stimulation protocols varied significantly, with the isogenic cell line showing better adaptation to sinusoidal stimuli than the pathological one, characterized by rectangular monophasic stimuli. Laser-poration technology, combined with MEA chips and video kinematic evaluation, revealed modulation of electromechanical coupling, affecting action potential upstroke and duration, reducing contraction velocity, and altering electromechanical delay. Furthermore, MELAS hiPSCs and primary cardiomyocytes exhibited reduced protein levels of various OXPHOS subunits (SDHB, ATPB, and COX IV) compared to isogenic controls. The mutated cell line also showed increased ROS production in non-stimulated samples compared to stimulated ones (1.3-fold vs. 1.2-fold), with this difference magnifying after 24 hours from stimulation (1.8-fold vs. 1.3-fold). Conclusions This study characterizes MELAS hiPSCs differentiated into cardiac organoids, offering insight into the cardiac aspect of this complex syndrome. Our findings deepen understanding of the syndrome's cardiac impact and response to extracellular stimuli, potentially benefiting affected tissues. This research defines critical physiological and kinematic parameters for MELAS, paving the way for future investigations.

Apelin regulates mitochondrial dynamics by inhibiting Mst1-JNK-Drp1 signaling pathway to reduce neuronal apoptosis after spinal cord injury

In the secondary injury stage of spinal cord injury, mitochondrial dysfunction leads to decreased ATP production, increased ROS production, and activation of the mitochondria-mediated apoptosis signaling pathway. This ultimately intensifies neuronal death and promotes the progression of the injury. Apelin, a peptide produced by the APLN gene, has demonstrated promise in the treatment of spinal cord injury. The aim of this study was to investigate how Apelin protects neurons after spinal cord injury by influencing the mitochondrial dynamics. The results showed that Apelin has the ability to reduce mitochondrial fission, enhance the mitochondrial membrane potential, improve antioxidant capacity, facilitate the clearance of excess ROS, and ultimately decrease apoptosis in PC12 cells. Moreover, Apelin is overexpressed in neurons in the damaged part of the spinal cord, contributing to reduce mitochondrial fission, improve antioxidant capacity, increase ATP production, decrease apoptosis, promote spinal cord morphological repair, maintain the number of nissl bodies, and enhance signal transduction in the descending spinal cord pathway. Apelin exerts its protective effect by inhibiting the Mst1-JNK-Drp1 signaling pathway. In summary, our study further improved the effect of Apelin in the treatment of spinal cord injury, revealed the mechanism of Apelin in protecting damaged neurons after spinal cord injury by maintaining mitochondrial homeostasis, and provided a new therapeutic mechanism for Apelin in spinal cord injury.