Mitochondrial Dehydrogenase Activity Research Articles

Meliponini Geopropolis Extracts Induce ROS Production and Death in Leishmania amazonensis Promastigotes and Axenic Amastigotes In Vitro

Leishmania amazonensis, a cause of cutaneous leishmaniasis in Brazil, is a neglected disease with toxic and inconsistently effective treatments. The parasite’s survival depends on managing oxidative stress, making redox-regulating enzymes potential therapeutic targets. Geopropolis, a resinous product from native stingless bees, shows promising antiparasitic effects. This study aims to evaluate the anti-L. amazonensis activity of geopropolis produced by Melipona bicolor, M. marginara, M. mondury, and M. quadrifasciata (two samples), targeting enzymes responsible for the parasite’s redox balance. Ethanol extracts of geopropolis produced by each bee (BCRL, MRGT, MNDY, MNDA(1), and MNDA(2), respectively) were analyzed for total phenolics and flavonoids. Promastigotes and axenic amastigotes were treated with various extract concentrations, and parasite viability was assessed using the resazurin reduction method. Cytotoxicity was tested on peritoneal macrophages, RAW 264.7, VERO cell lines (MTT assay), and erythrocytes (hemolysis assay). Additionally, mitochondrial dehydrogenase activity, reactive oxygen species (ROS) production, the inhibition of recombinant arginase, and autophagic activity were also evaluated in treated parasites. MRGT showed the highest levels of phenolics (762 mg GAE/g) and flavonoids (345 mg QE/g). MDRY was more effective against promastigote and axenic amastigote forms (IC50 = 168 and 19.7 µg/mL, respectively). MRGT showed lower cytotoxicity against RAW 264.7 and VERO (CC50 = 654 µg/mL and 981 µg/mL, respectively). Erythrocytes exhibited reduced sensitivity to MNDA(2) (HC50 = 710 µg/mL). The activity of dehydrogenases and LiARG was reduced by treating the parasites with the extracts following the induction of ROS and autophagic activity. These results highlight geopropolis extracts as a source of substances with anti-L. amazonensis activity capable of inducing oxidative stress on the parasite.

Nanostructural Modulation of G-Quadruplex DNA in Neurodegeneration: Orotate Interaction Revealed Through Experimental and Computational Approaches.

The natural compound orotic acid and its anionic form, orotate, play a pivotal role in various biological processes, serving as essential intermediates in pyrimidine de novo synthesis, with demonstrated connections to dietary, supplement, and neurodrug applications. A novel perspective on biomolecular aggregation at the nanoscale, particularly pertinent to neurodegeneration, challenges the established paradigm positing that peptide (amyloid beta) and protein (tau) aggregation mainly govern the molecular events underlying prevalent neuropathologies. Emerging biological evidence indicates a notable role for G-quadruplex (G4) DNA aggregation in neurodegenerative processes affecting neuronal cells, particularly in the presence of extended (G4C2)n repeats in nuclear DNA sequences. Our study concerns d[(GGGGCC)3GGGG], a G4-forming DNA model featuring G4C2 repeats that is in correlation with neurodegeneration. Through different investigations utilizing spectroscopic techniques (CD, UV, and thermal denaturations), PAGE electrophoresis, and molecular docking, the study explores the influence of orotate on the aggregation of this neurodegeneration-associated DNA. A computational approach was employed to construct an in silico model of the DNA aggregate, which involved the docking of multiple G4 units and subsequent integration of the ligand into both the DNA monomer and its in silico aggregated model. The convergence of computational analyses and empirical data collectively supports the hypothesis that orotate possesses the capability to modulate the aggregation of neurodegeneration-related DNA. Notably, the findings suggest the potential utility of orotate as a neurodrug, especially for the therapy of amyotrophic lateral sclerosis (ALS) and Frontotemporal Dementia (FTD), with its current status as a dietary supplement indicating minimal safety concerns. Additionally, orotate demonstrated a slight increase in mitochondrial dehydrogenase activity as assessed by the MTT assay, which is beneficial for a neurodrug as it suggests a potential role in enhancing mitochondrial function and supporting neuronal health.

Establishment of embryogenic Pinus thunbergii Parl. suspension cultures: growth parameters, dynamic analysis, and plant regenerative capacities

BackgroundPinus thunbergii is an economically important conifer species that plays a fundamental role in forest ecosystems. However, the population has declined dramatically in recent years as a result of the pine wilt disease outbreak. Thus, developing pine wilt-resistant P. thunbergii is an effective strategy for combating this epidemic.ResultsThe somatic embryogenesis of nematode-resistant P. thunbergii was previously reported by our group. The current study looked into the potential commercialization of suspension cultures as a means of large-scale production of nematode-resistant P. thunbergii seedlings. According to our findings, P. thunbergii suspension cultures were suitable for an initial inoculum of embryogenic tissue (2 g) and a subculture inoculum (6.7% (v/v)). Suspension cultures were cultivated for 8–10 days in a 30 mL liquid medium (Gupta and Durzan medium, DCR medium) to facilitate their maturation. The suspension cultures produced a large number of high-quality somatic embryos, which were then used to regenerate the plants and move them into the field. A more accurate assessment of the quality of suspension cultures for somatic embryogenesis could come from the suspension’s dynamics. The results showed that the medium’s phosphate, ammonium, nitrate, and carbohydrates were quickly eaten from day 0 to day 10. In terms of the absorption of nitrogen sources, the ammonium (NH4+) was absorbed prior to nitrate (NO3−). Additionally, the activity of mitochondrial succinate dehydrogenase and superoxide dismutase was directly related to cell growth.ConclusionsThis study presents an approach for selecting appropriate suspension cultures for efficient somatic maturation of P. thunbergii that can also be applied to other conifers. Furthermore, it is possible to commercialize nematode-resistant P. thunbergii seedlings using bioreactors, according to the suspension culture system we describe. To the best of our knowledge, this is the first work to describe a P. thunbergii suspension culture.

Influence of the Microbial Metabolite Acetyl Phosphate on Mitochondrial Functions Under Conditions of Exogenous Acetylation and Alkalization.

Acetyl phosphate (AcP) is a microbial intermediate involved in the central bacterial metabolism. In bacteria, it also functions as a donor of acetyl and phosphoryl groups in the nonenzymatic protein acetylation and signal transduction. In host, AcP was detected as an intermediate of the pyruvate dehydrogenase complex, and its appearance in the blood was considered as an indication of mitochondrial breakdown. In vitro experiments showed that AcP is a powerful agent of nonenzymatic acetylation of proteins. The influence of AcP on isolated mitochondria has not been previously studied. In this work, we tested the influence of AcP on the opening of the mitochondrial permeability transition pore (mPTP), respiration, and succinate dehydrogenase (SDH) activity under neutral and alkaline conditions stimulating the nonenzymatic acetylation using polarographic, cation-selective, and spectrophotometric methods. It was found that AcP slowed down the opening of the mPTP by calcium ions and decreased the efficiency of oxidative phosphorylation and the activity of SDH. These effects were observed only at neutral pH, whereas alkaline pH by itself caused a decrease in these functions to a much greater extent than AcP. AcP at a concentration of 0.5-1 mM decreased the respiratory control and the swelling rate by 20-30%, while alkalization decreased them twofold, thereby masking the effect of AcP. Presumably, the acetylation of adenine nucleotide translocase involved in both the opening of mPTP and oxidative phosphorylation underlies these changes. The intermediate electron carrier phenazine methosulfate (PMS), removing SDH inhibition at the ubiquinone-binding site, strongly activated SDH under alkaline conditions and, partially, in the presence of AcP. It can be assumed that AcP weakly inhibits the oxidation of succinate, while alkalization slows down the electron transfer from the substrate to the acceptor. The results show that both AcP and alkalization, by promoting nonmetabolic and nonenzymatic acetylation from the outside, retard mitochondrial functions.

Muscle type-specific effects of bilateral abobotulinumtoxinA injection on muscle growth and contractile function in spastic mice.

Intramuscular injection of botulinum neurotoxin type A (BoNT-A) is commonly used to improve or maintain the joint range of motion in young children with spasticity. However, the effectiveness of BoNT-A treatment is variable and movement limitations are recurrent. Here we show long-term effects of a single, bilateral abobotulinumtoxinA (aboBoNT-A) injection in the gastrocnemius medialis and soleus muscles of wild-type and spastic (B6.Cg-Glrbspa/J with a mutation in the glycine receptor) mice at a young age (6-7 days). Specifically, we evaluated the impact of aboBoNT-A-A on gait, physical performance, and spontaneous physical behavior, as well as on contractile force characteristics, morphology, and histological phenotype of soleus and gastrocnemius muscles by comparing their results to those of saline-injected controls up to 9 weeks after the injection. The detailed time course of the study specifies the timing of the aboBoNT-A injection at 1 week, the period of behavioral studies from 4-9 weeks, and the age of the mice (10 weeks) at the time of contractile force characteristics and histology assessments. In spastic mice, aboBoNT-A injection had a minor and very specific effect on physical performance, by only modestly increasing stride length as a function of age. aboBoNT-A injection caused a reduction in the force-generating capacity and a slightly smaller physiological cross-sectional area in gastrocnemius medialis, but not in soleus. Reduced physiological cross-sectional area in aboBoNT-A-injected muscles was due to a lower number of muscle fibers, rather than reduced muscle fiber cross-sectional area. The percentage of slow-type muscle fibers and mitochondrial succinate dehydrogenase activity were increased, which was associated with an improved muscle endurance capacity. In conclusion, aboBoNT-A injection reduced the number of muscle fibers, causing muscle hypertrophy in remaining fibers and a shift towards more oxidative fibers, resulting in an improved endurance capacity and gait. This study proposed potential cellular mechanisms for the therapeutic efficacy of aboBoNT-A in spasticity.

Assessing cytotoxicity and biocompatibility of cellulose nanofibrils on alveolar macrophages

Cellulose nanofibrils (CNFs) are a promising new material derived from biomass, known for their lightweight, high strength, and low thermal expansion properties. However, concerns have been raised about their potential health impact due to their fibrous and ultrafine nature. This study aimed to evaluate the effects of different types of CNFs on rat alveolar macrophages (NR8383). The CNFs tested included TEMPO-oxidized CNFs (CNF1), phosphorylated CNFs (CNF2), mechanically fibrillated CNFs from softwood bleached kraft pulp (CNF3), CNFs derived from citrus peels (CNF4), and two size fractions (coarse and ultrafine) of softwood bleached kraft pulp obtained by aqueous counter collision processing (CNF5 and CNF6). The findings showed no significant production of reactive oxygen species in any of the CNF exposure groups. However, exposure to CNF1, CNF2, and CNF3 led to increased mitochondrial dehydrogenase activity, elevated pro-inflammatory cytokine production, and upregulation of inflammation-related genes. These effects were less pronounced in the CNF4, CNF5, and CNF6 groups. Cellular uptake of CNFs was observed across all groups, and the response to CNF exposure differed from the response to microcrystalline cellulose, which was used as a reference material. No clear correlation was found between the observed effects and the presence of biological contaminants, such as bacteria and endotoxins, in the CNF dispersions. These findings suggest that CNFs may either activate macrophages or demonstrate biocompatibility rather than cytotoxicity. The impact and biocompatibility of CNFs on alveolar macrophages appear to be influenced by various factors, including the source of the CNF raw material, the manufacturing process, physicochemical properties, and biological characteristics of the CNF dispersion. This study provides valuable insights into the potential inhalation effects of CNFs.Graphic abstract

Multiomics Studies on Metabolism Changes in Alcohol-Associated Liver Disease.

Metabolic dysfunction in the liver represents a predominant feature in the early stages of alcohol-associated liver disease (ALD). However, the mechanisms underlying this are only partially understood. To investigate the metabolic characteristics of the liver in ALD, we did a relative quantification of polar metabolites and lipids in the liver of mice with experimental ALD using untargeted metabolomics and untargeted lipidomics. A total of 99 polar metabolites had significant abundance alterations in the livers of alcohol-fed mice. Pathway analysis revealed that amino acid metabolism was the most affected by alcohol in the mouse liver. Metabolites involved in glycolysis and the TCA cycle were decreased, while glycerol 3-phosphate (G3P) and long-chain fatty acids were increased. Relative quantification of lipids unveiled an upregulation of multiple lipid classes, suggesting that alcohol consumption drives metabolism toward lipid synthesis. Results from enzyme expression and activity detection indicated that the decreased activity of mitochondrial glycerol 3-phosphate dehydrogenase contributed to the disordered metabolism.

Bictegravir alters glucose tolerance in vivo and causes hepatic mitochondrial dysfunction

Growing evidence associates antiretroviral therapies containing integrase strand transfer inhibitors or tenofovir alafenamide (TAF) with increased weight gain and metabolic diseases, but the underlying mechanisms remain unclear. This study evaluated the impact of lamivudine, dolutegravir (DTG), bictegravir (BIC), tenofovir disoproxil fumarate, and TAF on metabolic alterations, and explored glucose homeostasis and mitochondrial stress as potential mechanisms. These pathways were analyzed both in vivo (C57BL/6J mice treated with the abovementioned drugs or vehicle for 16 weeks) and in vitro (in Hep3B cells). Mice treated with BIC exhibited higher glucose levels and a slower decrease during a glucose tolerance test. Functional enrichment analyses of livers from antiretroviral-treated mice revealed that only BIC altered the cellular response to insulin and induced a gluconeogenic-favoring profile, with Fgf21 playing a significant role. In vitro, BIC significantly reduced hepatocyte glucose uptake in a concentration-dependent manner, both under basal conditions and post-insulin stimulation, while the other drugs produced no significant changes. Hep3B cells treated with clinically relevant concentrations of BIC exhibited significant alterations in the mRNA expression of enzymes related to glucose metabolism. Both DTG and BIC reduced mitochondrial dehydrogenase activity, but only BIC increased reactive oxygen species, mitochondrial membrane potential, and cellular granularity, thereby indicating mitochondrial stress. BIC promoted mitochondrial dysfunction, modified carbohydrate metabolism and glucose consumption in hepatocytes, and altered glucose tolerance and gluconeogenesis regulation in mice. These findings suggest that BIC contributes to insulin resistance and diabetes in people living with HIV, warranting clinical studies to clarify its association with carbohydrate metabolism disorders.

Exploring the Potential of Synthetic Cannabinoids: Modulation of Biological Activity of Normal and Cancerous Human Colon Epithelial Cells.

Colorectal cancer (CRC) is a global problem. Oncology currently practices conventional methods of treating this carcinoma, including surgery, chemotherapy, and radiotherapy. Unfortunately, their efficacy is low; hence, the exploration of new therapies is critical. Recently, many efforts have focused on developing safe and effective anticancer compounds. Some of them include cannabinoids. In the present study, we obtained cannabinoids, such as cannabidiol (CBD), abnormal cannabigerol (abn-CBG), cannabichromene (CBC), and cannabicitran (CBT), by chemical synthesis and performed the biological evaluation of their activity on colon cancer cells. In this study, we analyzed the effects of selected cannabinoids on the lifespan and metabolic activity of normal colonic epithelial cells and cancer colon cells. This study demonstrated that cannabinoids can induce apoptosis in cancer cells by modulating mitochondrial dehydrogenase activity and cellular membrane integrity. The tested cannabinoids also influenced cell cycle progression. We also investigated the antioxidant activity of cannabinoids and established a relationship between the type of cannabinoid and nitric oxide (NO) production in normal and cancerous colon cells. To conclude, it seems that, due to their interesting properties, the cannabinoids studied may constitute an interesting target for further research aimed at their use in alternative or combined therapies for human colon cancer.

Simultaneous use of venlafaxine and calcium channel blockers on tolerance to morphine: The role of mitochondrial damage and oxidative stress in the brain

BackgroundOne of the reasons for tolerance to morphine is increased oxidative stress and dysfunction of cell mitochondria in the hippocampus. Venlafaxine and calcium channel blockers can protect mitochondrial function. The investigation of the role of mitochondrial damage and oxidative stress in the simultaneous use of venlafaxine and calcium channel blockers on the acute analgesic effects of morphine and the induction of tolerance to its effects in mice was assessed. MethodIn this experimental study, to induce tolerance to morphine, NMRI mice were treated with 50 mg/kg morphine for three consecutive days and 5 mg/kg morphine on the fourth day. Venlafaxine (20 mg/kg) alone or in combination with calcium channel blockers, nimodipine (10 mg/kg), and diltiazem (40 mg/kg) was administered 30 min before morphine, and the hot plate test was used. Then, hippocampal mitochondria were isolated by differential centrifugation method, and the levels of mitochondrial dehydrogenase activity, mitochondrial membrane potential, mitochondrial ROS production rate, as well as the content of glutathione and malondialdehyde in hippocampal mitochondria, were measured. ResultsThe administration of venlafaxine-nimodipine and venlafaxine-diltiazem increased morphine's acute analgesic effects (P < 0.05) and reduced the induction and expression of tolerance to the analgesic effects of morphine (P < 0.05). Morphine significantly decreased MTT and GSH and increased MDA, mitochondrial membrane damage, and ROS compared to the control group (P < 0.01). Injection of venlafaxine-nimodipine and also venlafaxine-diltiazem 30 min before morphine can improve these alterations (P < 0.05). Discussion and conclusionOur data showed that the simultaneous use of venlafaxine with calcium channel blockers could increase the acute analgesic effects of morphine and reduce the induction and expression of tolerance to it. Also, the preventive and protective roles of simultaneous administration of venlafaxine and calcium channel blockers on morphine-induced mitochondrial oxidative stress and damage during the tolerance test were achieved.

Effect of short-term fasting on the cisplatin activity in human oral squamous cell carcinoma cell line HN5 and chemotherapy side effects

BackgroundKetogenic interventions like short-term fasting show potential as complementary therapies to enhance the effectiveness of chemotherapy for cancer. However, the specific effects of fasting on head and neck squamous cell carcinoma (HNSCC) cells and healthy oral mucosa cells during these treatments are not well understood. This study investigates whether short-term fasting can differentially impact HNSCC cell survival and viability compared to healthy keratinocytes while undergoing standard chemotherapy regimens.MethodsThis study investigated the effects of fasting on cell viability in HN5 cell line and healthy oral keratinocyte cells. The HN5 cell line, derived from human tongue squamous cell carcinoma, and primary human keratinocytes isolated from the basal layer of gingival epithelium were divided into three groups: (1) control, (2) treated with the standard chemotherapeutic agent cisplatin, and (3) treated with cisplatin under fasting conditions achieved through 48-hour glucose restriction mimicking the blood glucose levels of fasted individuals. Cell proliferation was assessed at 48 and 72 h using the MTT assay, a colorimetric method based on mitochondrial dehydrogenase activity. Flow cytometry analysis with specific apoptosis and necrosis markers distinguished between early and late apoptotic, necrotic, and viable cells.ResultsCell viability in HN5 and healthy keratinocyte cells decreased in cisplatin with low glucose groups compared to cisplatin and control groups. The same results were observed for healthy keratinocyte cells; only a decrease in cell viability in cisplatin groups compared to control groups was observed, which was not statistically significant. Cell apoptosis in HN5 and healthy keratinocyte cells increased in cisplatin with low glucose groups compared to cisplatin and control groups. In healthy keratinocyte cells, the cisplatin with low glucose group showed an impressive increase in necrosis, late apoptosis, and early apoptosis and a significant decrease in live cells compared with other groups.ConclusionThis study revealed that short-term fasting chemotherapy significantly improved HNSCC cell line apoptosis and necrosis.

2D TiO2 Nanosheets Decorated Via Sphere-Like BiVO4: A Promising Non-Toxic Material for Liquid Phase Photocatalysis and Bacterial Eradication.

An in-depth investigation was conducted on a promising composite material (BiVO4/TiO2), focusing on its potential toxicity, photoinduced catalytic properties, as well as its antibiofilm and antimicrobial functionalities. The preparation process involved the synthesis of 2D TiO2 using the lyophilization method, which was subsequently functionalized with sphere-like BiVO4 through wet impregnation. Finally, we developed BiVO4/TiO2 S-scheme heterojunctions which can greatly promote the separation of electron-hole pairs to achieve high photocatalytic performance. The evaluation of concentration- and time-dependent viability inhibition was performed on human lung carcinoma epithelial A549 cells. This assessment included the estimation of glutathione levels and mitochondrial dehydrogenase activity. Significantly, the BiVO4/TiO2 composite demonstrated minimal toxicity towards A549 cells. Impressively, the BiVO4/TiO2 composite exhibited notable photocatalytic performance in the degradation of rhodamine B (k=0.135 min-1) and phenol (k=0.016 min-1). In terms of photoinduced antimicrobial performance, the composite effectively inactivated both gram-negative E. coli and gram-positive E. faecalis bacteria upon 60 minutes of UV-A light exposure, resulting in a significant log 6 (log 10 CFU/mL) reduction in bacterial count. In addition, a 49 % reduction of E. faecalis biofilm was observed. These promising results can be attributed to the unique 2D morphology of TiO2 modified by sphere-like BiVO4, leading to an increased generation of (intracellular) hydroxyl radicals, which plays a crucial role in the treatments of both organic pollutants and bacteria. This research has significant potential for various applications, particularly in addressing environmental contamination and microbial infections.

The Novel Platinum Analog Dicycloplatin Provides Reliable Growth Inhibition of Urothelial Carcinoma Cells In Vitro.

Platinum-based chemotherapies are a component of standard-of-care regimens for urothelial carcinoma (UC). These nephrotoxic drugs are often dose-limiting, with cisplatin and carboplatin being the most commonly used. Dicycloplatin (DCP) has better solubility and stability, with comparable efficacy and better tolerability. Some suggest the use of DCP as primary treatment for non-muscle-invasive bladder cancer. We exposed UC cell lines to DCP in vitro to assess its efficacy. A high grade (IV) in vitro UC cell line (TCCSUP) was exposed to varying concentrations of cisplatin (0-600 μg/ml), carboplatin (0-600 μg/ml), oxaliplatin (0-4.0 μg/ml), and DCP (0-350 μg/ml). Grade II-IV cells were exposed to varying concentrations of DCP (0-350 μg/ml) to assess time- and concentration-dependent growth inhibition, and simulate intravesical treatment. Growth inhibition was determined following 24, 48, and 72 h of exposure, using a tetrazolium dye to assess mitochondrial dehydrogenase activity. DCP, cisplatin, and carboplatin effectively achieved >90% cell kill at 72 h. Concentrations of 325 μg/ml DCP, 50 μg/ml cisplatin, and 600 μg/ml carboplatin were sufficient for >90% cell-kill, with cisplatin demonstrating the highest efficacy at the lowest concentration/time intervals. Dose- and time-dependent cell kill were demonstrated at varying concentrations of DCP in grade II-IV cell lines, including cells exposed intravesically. In vitro, DCP demonstrates cell-killing efficacy in a time- and concentration-dependent manner in grade II-IV UC cell lines, showing promise for its intravenous, oral, and intravesical use for bladder UC in both primary and adjuvant/neoadjuvant settings.

The protection role of human growth hormone on skin cells following ultraviolet B exposure

BackgroundUltraviolet-B (UVB) radiation is the leading environmental cause of skin damage and photoaging. The epidermis and dermis layers of the skin mainly absorb UVB. UVB stimulates apoptosis, cell cycle arrest, generation of reactive oxygen species, and degradation of collagen and elastin fibers. ObjectiveThis study investigated the potential of human growth hormone (hGH) in protecting the skin fibroblasts and keratinocytes (HFFF-2 and HaCaT cell lines) from UVB-induced damage. MethodsThe MTT assay was performed to evaluate UVB-induced mitochondrial damage via assessing the mitochondrial dehydrogenase activity, and flow cytometry was carried out to investigate the effects of UVB and hGH on the cell cycle and apoptosis of UVB-irradiated cells. In addition, the fold change mRNA expression levels of Type I collagen and elastin in HFFF-2 cells were evaluated using the qRT-PCR method following UVB exposure. ResultsWe observed that treatment of cells with hGH before UVB exposure inhibited UVB-induced loss of mitochondrial dehydrogenase activity, apoptosis, and sub-G1 population formation in both cell lines. We also found that hGH-treated HFFF-2 cells showed up-regulated mRNA expression of Type I collagen, elastin, and IGF-1 in response to UVB irradiation. ConclusionThese findings suggest hGH as a potential anti-UVB compound that can protect skin cells from UVB-induced damage. Our findings merit further investigation and can be used to better understand the role of hGH in skin photoaging.

Nutrient-sensitizing drug repurposing screen identifies lomerizine as a mitochondrial metabolism inhibitor of chronic myeloid leukemia.

In chronic myeloid leukemia (CML), the persistence of leukemic stem cells (LSCs) after treatment with tyrosine kinase inhibitors (TKIs), such as imatinib, can lead to disease relapse. It is known that therapy-resistant LSCs rely on oxidative phosphorylation (OXPHOS) for their survival and that targeting mitochondrial respiration sensitizes CML LSCs to imatinib treatment. However, current OXPHOS inhibitors have demonstrated limited efficacy or have shown adverse effects in clinical trials, highlighting that identification of clinically safe oxidative pathway inhibitors is warranted. We performed a high-throughput drug repurposing screen designed to identify mitochondrial metabolism inhibitors in myeloid leukemia cells. This identified lomerizine, a US Food and Drug Administration (FDA)-approved voltage-gated Ca2+ channel blocker now used for the treatment of migraines, as one of the top hits. Transcriptome analysis revealed increased expression of voltage-gated CACNA1D and receptor-activated TRPC6 Ca2+ channels in CML LSCs (CD34+CD38-) compared with normal counterparts. This correlated with increased endoplasmic reticulum (ER) mass and increased ER and mitochondrial Ca2+ content in CML stem/progenitor cells. We demonstrate that lomerizine-mediated inhibition of Ca2+ uptake leads to ER and mitochondrial Ca2+ depletion, with similar effects seen after CACNA1D and TRPC6 knockdown. Through stable isotope-assisted metabolomics and functional assays, we observe that lomerizine treatment inhibits mitochondrial isocitrate dehydrogenase activity and mitochondrial oxidative metabolism and selectively sensitizes CML LSCs to imatinib treatment. In addition, combination treatment with imatinib and lomerizine reduced CML tumor burden, targeted CML LSCs, and extended survival in xenotransplantation model of human CML, suggesting this as a potential therapeutic strategy to prevent disease relapse in patients.

Effect of fructose on anthracycline and HER-2 blocking agent mediated cardiotoxicity through NLRP3 and MyD88 mediated pathways: New roles of sweeteners in cardio-oncology.

e24020 Background: Combinatorial therapy based on anthracyclines and HER-2 blocking agents increases the risk of cardiomyopathy in women with breast cancer. Fructose is a monosaccharide associated with high risk of diabetes, non-alcoholic fatty liver disease, atherosclerosis and visceral obesity. A high fructose diet is a potential cardiometabolic risk factor and may increase cardiac risk in women with breast cancer treated with cardiotoxic drugs. In this study, we highlighted the role of sweeteners fructose in the worsening of cardiotoxicity induced by combinatorial therapy anthracycline-HER2-blocking agents. Methods: Human cardiomyocytes were pre-exposed with doxorubicin combined to trastuzumab (at 300 and 1000 nM) for 48 and 72h alone or combined to fructose at 0.25, 1 and 2.5 mM. After the incubation period, we performed the following tests: determination of cell viability, through mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4-hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro-inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of peroxisome proliferator-activated receptor-α; transcriptional activation of p65/NF-κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6, CXCL-12). Results: High fructose increases significantly cell mortality of cardiomyocytes exposed to doxorubicin and trastuzumab through the activation of NLRP-3 and Myd-88 expression. Intracellular Ca++ levels were also increased of 4 times compared to non-fructose exposed cardiomyocytes; MDA and 4-HNA levels were increased of 48,3 and 51,2 % compared to non-fructose exposed cells (p&lt;0.001). Fructose increases IL-1, IL-6 and CXCL-12 expression in cardiomyocytes in a concentration dependent manner, compared to doxorubicin-trastuzumab group (p&lt;0.05). Conclusions: Data of the present study indicate that fructose induces a pro-inflammatory phenotype in human cardiac cells exposed to anticancer cardiotoxic drugs, providing even more data on the harmful role of fructose as a key player of cardiotoxic phenomena.

Anti-cancer activities based on ZnII complex of potassium 5-thiophen-2-yl-[1,3,4]-oxadiazole-2-thiolate: Synthesis, crystal structure, photoluminescence study and Hirshfeld analysis

Recent advancements in developing the most suitable drug for humankind to cure cancer have paved the way to synthesize an alternative to platinum-based drugs. Herein, the synthesis of novel polymeric complex [Zn(thot)2]n (1) derived from potassium 5-thiophen-2-yl-[1,3,4]-oxadiazole-2-thiolate (Kthot) is reported. The synthesized ligand and complex were characterized by infrared, NMR, Mass and UV–vis. spectrometry. Moreover, single-crystal X-ray analysis revealed the polymeric nature of the [Zn(thot)2]n (1). Complex 1 is stabilized via various types of intermolecular interactions. The intermolecular interaction found in complex 1 was further investigated through Hirshfeld surface analysis. Emission spectra data showed that complex [Zn(thot)2]n (1) exhibits higher fluorescent intensity than Kthot. The cytotoxicity of complex 1 and Kthot was evaluated against MDA-MB-231 breast cancer cells, which was determined by measuring mitochondrial dehydrogenase activity using MTT as substrate. The result showed that they both suppressed the viability of cancer cells. Moreover, complex 1 was found to be more effective than ligand salt Kthot. The IC50 value for complex 1 was found around 37.43 μM whereas for Kthot it is 69.24 μM which suggests that complex 1 reduces the cell viability more effectively in comparison to the ligand salt.

FRUCTOSE EXACERBATES ANTHRACYCLINE AND HER–2 BLOCKING AGENT MEDIATED CARDIOTOXICITY THROUGH NLRP3 AND MYD88 MEDIATED PATHWAYS: NEW ROLES OF SWEETENERS IN CARDIO–ONCOLOGY

Abstract Background Combinatorial therapy based on anthracyclines and HER–2 blocking agents increases the risk of cardiomyopathy in women with breast cancer. Fructose is a monosaccharide associated with high risk of diabetes, non–alcoholic fatty liver disease, atherosclerosis and visceral obesity. A high fructose diet is a potential cardiometabolic risk factor and may increase cardiac risk in women with breast cancer treated with cardiotoxic drugs. Purpose In this study, we highlighted the role of sweeteners fructose in the worsening of cardiotoxicity induced by combinatorial therapy anthracycline–HER2–blocking agents. Methods Human cardiomyocytes were pre–exposed with doxorubicin combined to trastuzumab (at 300 and 1000 nM) for 48 and 72h alone or combined to fructose at 0.25, 1 and 2.5 mM. After the incubation period, we performed the following tests: determination of cell viability, through mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4–hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro–inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of peroxisome proliferator–activated receptor–α; transcriptional activation of p65/NF–κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6, CXCL–12). Results High fructose increases significantly cell mortality of cardiomyocytes exposed to doxorubicin and trastuzumab thorugh the activation of NLRP–3 and Myd–88 expression. Intracellular Ca++ levels were also increased of 4 times compared to non–fructose exposed cardiomyocytes; MDA and 4–HNA levels were increased of 48,3 and 51,2 % compared to non–fructose exposed cells (p&amp;lt;0.001). Fructose increases IL–1, IL–6 and CXCL–12 expression in cardiomyocytes in a concentration dependent manner, compard to doxorubicin–trastuzumab group (p&amp;lt;0.05). Conclusion Data of the present study indicate that fructose induces a pro–inflammatory phenotype in human cardiac cells exposed to anticancer cardiotoxic drugs, providing even more data on the harmful role of fructose as a key player of cardiotoxic phenomena.

TRPA1 up-regulation mediates oxidative stress in a pulpitis model in vitro.

Pulpitis is associated with tooth hypersensitivity and results in pulpal damage. Thermosensitive transient receptor potential (TRP) ion channels expressed in the dental pulp may be key transducers of inflammation and nociception. We aimed at investigating the expression and role of thermo-TRPs in primary human dental pulp cells (hDPCs) in normal and inflammatory conditions. Inflammatory conditions were induced in hDPC cultures by applying polyinosinic:polycytidylic acid (poly(I:C)). Gene expression and pro-inflammatory cytokine release were measured by RT-qPCR and ELISA. Functions of TRPA1 channels were investigated by monitoring changes in intracellular Ca2+ concentration. Mitochondrial superoxide production was measured using a fluorescent substrate. Cellular viability was assessed by measuring the activity of mitochondrial dehydrogenases and cytoplasmic esterases. TRPA1 activity was modified by agonists, antagonists, and gene silencing. Transcripts of TRPV1, TRPV2, TRPV4, TRPC5, and TRPA1 were highly expressed in control hDPCs, whereas TRPV3, TRPM2, and TRPM3 expressions were much lower, and TRPM8 was not detected. Poly(I:C) markedly up-regulated TRPA1 but not other thermo-TRPs. TRPA1 agonist-induced Ca2+ signals were highly potentiated in inflammatory conditions. Poly(I:C)-treated cells displayed increased Ca2+ responses to H2O2, which was abolished by TRPA1 antagonists. Inflammatory conditions induced oxidative stress, stimulated mitochondrial superoxide production, resulted in mitochondrial damage, and decreased cellular viability of hDPCs. This inflammatory cellular damage was partly prevented by the co-application of TRPA1 antagonist or TRPA1 silencing. Pharmacological blockade of TRPA1 channels may be a promising therapeutic approach to alleviate pulpitis and inflammation-associated pulpal damage.

In Vitro Hepatotoxicity of Routinely Used Opioids and Sedative Drugs.

A hepatocyte cell line was used to determine the hepatotoxicity of sedatives and opioids, as the hepatotoxicity of these drugs has not yet been well characterized. This might pose a threat, especially to critically ill patients, as they often receive high cumulative doses for daily analgosedation and often already have impaired liver function due to an underlying disease or complications during treatment. A well-established biosensor based on HepG2/C3A cells was used for the determination of the hepatotoxicity of commonly used sedatives and opioids in the intensive care setting (midazolam, propofol, s-ketamin, thiopental, fentanyl, remifentanil, and sufentanil). The incubation time was 2 × 3 days with clinically relevant (Cmax) and higher concentrations (C5× and C10×) of each drug in cell culture medium or human plasma. Afterward, we measured the cell count, vitality, lactate dehydrogenase (LDH), mitochondrial dehydrogenase activity, cytochrome P 450 1A2 (CYP1A2), and albumin synthesis. All tested substances reduced the viability of hepatocyte cells, but sufentanil and remifentanil showed more pronounced effects. The cell count was diminished by sufentanil in both the medium and plasma and by remifentanil only in plasma. Sufentanil and remifentanil also led to higher values of LDH in the cell culture supernatant. A reduction of mitochondrial dehydrogenase activity was seen with the use of midazolam and s-ketamine. Microalbumin synthesis was reduced in plasma after its incubation with higher concentrations of sufentanil and remifentanil. Remifentanil and s-ketamine reduced CYP1A2 activity, while propofol and thiopental increased it. Our findings suggest that none of the tested sedatives and opioids have pronounced hepatotoxicity. Sufentanil, remifentanil, and s-ketamine showed moderate hepatotoxic effects in vitro. These drugs should be given with caution to patients vulnerable to hepatotoxic drugs, e.g., patients with pre-existing liver disease or liver impairment as part of their underlying disease (e.g., hypoxic hepatitis or cholestatic liver dysfunction in sepsis). Further studies are indicated for this topic, which may use more complex cell culture models and global pharmacovigilance reports, addressing the limitation of the used cell model: HepG2/C3A cells have a lower metabolic capacity due to their low levels of CYP enzymes compared to primary hepatocytes. However, while the test model is suitable for parental substances, it is not for toxicity testing of metabolites.