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Journal of Medicinal Chemistry Jul 2024Using a multigram-scalable synthesis, we obtained nine dinuclear complexes based on nonendogenous iron(I) centers and featuring variable aminocarbyne and P-ligands. One...
1,3,5-Triaza-7-phosphaadamantane and Cyclohexyl Groups Impart to Di-Iron(I) Complex Aqueous Solubility and Stability, and Prominent Anticancer Activity in Cellular and Animal Models.
Using a multigram-scalable synthesis, we obtained nine dinuclear complexes based on nonendogenous iron(I) centers and featuring variable aminocarbyne and P-ligands. One compound from the series () emerged for its strong cytotoxicity in vitro against four human cancer cell lines, surpassing the activity of cisplatin by 3-6 times in three cell lines, with an average selectivity index of 6.2 compared to noncancerous HEK293 cells. demonstrated outstanding water solubility (15 g/L) and stability in physiological-like solutions. It confirmed its superior antiproliferative activity when tested in 3D spheroids of human pancreatic cancer cells and showed a capacity to inhibit thioredoxin reductase (TrxR) similar to auranofin. In vivo treatment of murine LLC carcinoma with (8 mg kg dose) led to excellent tumor growth suppression (88%) on day 15, with no signs of systemic toxicity and only limited body weight loss.
PubMed: 38951717
DOI: 10.1021/acs.jmedchem.4c00641 -
BioRxiv : the Preprint Server For... Feb 2024HO is a key oxidant in mammalian biology and a pleiotropic signaling molecule at the physiological level, and its excessive accumulation in conjunction with decreased...
HO is a key oxidant in mammalian biology and a pleiotropic signaling molecule at the physiological level, and its excessive accumulation in conjunction with decreased cellular reduction capacity is often found to be a common pathological marker. Here, we present a red fluorescent Genetically Encoded HO Indicator (GEHI) allowing versatile optogenetic dissection of redox biology. Our new GEHI, oROS-HT, is a chemigenetic sensor utilizing a HaloTag and Janelia Fluor (JF) rhodamine dye as fluorescent reporters. We developed oROS-HT through a structure-guided approach aided by classic protein structures and recent protein structure prediction tools. Optimized with JF, oROS-HT is a sensor with 635 nm excitation and 650 nm emission peaks, allowing it to retain its brightness while monitoring intracellular HO dynamics. Furthermore, it enables multi-color imaging in combination with blue-green fluorescent sensors for orthogonal analytes and low auto-fluorescence interference in biological tissues. Other advantages of oROS-HT over alternative GEHIs are its fast kinetics, oxygen-independent maturation, low pH sensitivity, lack of photo-artifact, and lack of intracellular aggregation. Here, we demonstrated efficient subcellular targeting and how oROS-HT can map inter and intracellular HO diffusion at subcellular resolution. Lastly, we used oROS-HT with the green fluorescent calcium indicator Fluo-4 to investigate the transient effect of the anti-inflammatory agent auranofin on cellular redox physiology and calcium levels via multi-parametric, dual-color imaging.
PubMed: 38370715
DOI: 10.1101/2024.02.06.579232 -
Nitric Oxide : Biology and Chemistry Apr 2024Neuronal differentiation of adipose tissue-derived stem cells (ASCs) is greatly promoted by valproic acid (VPA) with cAMP elevating agents thorough NO signaling...
Neuronal differentiation of adipose tissue-derived stem cells (ASCs) is greatly promoted by valproic acid (VPA) with cAMP elevating agents thorough NO signaling pathways, but its mechanism is not fully understood. In the present study, we investigate the involvement of protein S-nitrosylation in the VPA-promoted neuronal differentiation of ASCs. The whole amount of S-nitrosylated protein was increased by the treatment with VPA alone for three days in ASCs. An inhibitor of thioredoxin reductase (TrxR), auranofin, further increased the amount of S-nitrosylated protein and enhances the VPA-promoted neuronal differentiation in ASCs. On the contrary, another inhibitor of TrxR, dinitrochlorobenzene, inhibited the VPA-promoted neuronal differentiation in ASCs even with cAMP elevating agents, which was accompanied by unexpectedly decreased S-nitrosylated protein. It was considered from these results that increased protein S-nitrosylation is involved in VPA-promoted neuronal differentiation of ASCs. By the proteomic analysis of S-nitrosylated protein in VPA-treated ASCs, no identified proteins could be specifically related to VPA-promoted neuronal differentiation. The identified proteins, however, included those involved in the metabolism of substances regulating neuronal differentiation, such as aspartate and glutamate.
Topics: Valproic Acid; Neurons; Proteomics; Stem Cells; Adipose Tissue
PubMed: 38382865
DOI: 10.1016/j.niox.2024.02.004 -
Redox Biology Jun 2024Since the survival of lymphoma patients who experience disease progression or relapse remains very poor, new therapeutic approaches and effective drugs are urgently...
Since the survival of lymphoma patients who experience disease progression or relapse remains very poor, new therapeutic approaches and effective drugs are urgently needed. Here we show that auranofin (AF), an anti-rheumatoid drug thought to inhibit thioredoxin reductases (TXNRDs) as its mechanism of action, exhibited potent activity against multiple cancer types, especially effective against B cell lymphoma. Surprisingly, a knockdown of TXNRD1 and TXNRD2 did not cause significant cytotoxicity, suggesting that abrogation of TXNRD enzyme per se was insufficient to cause cancer cell death. Further mechanistic study showed that the interaction of AF with TXNRD could convert this antioxidant enzyme to a ROS-generating molecule via disrupting its electron transport, leading to a leak of electrons that interact with molecular oxygen to form superoxide. AF also suppressed energy metabolism by inhibiting both mitochondria complex II and the glycolytic enzyme GAPDH, leading to a significant depletion of ATP and inhibition of cancer growth in vitro and in vivo. Importantly, we found that the AF-mediated ROS stress could induce PD-L1 expression, revealing an unwanted effect of AF in causing immune suppression. We further showed that a combination of AF with anti-PD-1 antibody could enhance the anticancer activity in a syngeneic immune-competent mouse B-cell lymphoma model. Our study suggests that AF could be a potential drug for lymphoma treatment, and its combination with immune checkpoint inhibitors would be a logical strategy to increase the therapeutic activity.
PubMed: 38909408
DOI: 10.1016/j.redox.2024.103245 -
Free Radical Biology & Medicine Aug 2024The complex interplay between hydrogen peroxide (HO) and nitric oxide (NO) in endothelial cells presents challenges due to technical limitations in simultaneous...
The complex interplay between hydrogen peroxide (HO) and nitric oxide (NO) in endothelial cells presents challenges due to technical limitations in simultaneous measurement, hindering the elucidation of their direct relationship. Previous studies have yielded conflicting findings regarding the impact of HO on NO production. To address this problem, we employed genetically encoded biosensors, HyPer7 for HO and geNOps for NO, allowing simultaneous imaging in single endothelial cells. Optimization strategies were implemented to enhance biosensor performance, including camera binning, temperature regulation, and environmental adjustments to mimic physiological normoxia. Our results demonstrate that under ambient oxygen conditions, HO exhibited no significant influence on NO production. Subsequent exploration under physiological normoxia (5 kPa O) revealed distinct oxidative stress levels characterized by reduced basal HyPer7 signals, enhanced HO scavenging kinetics, and altered responses to pharmacological treatment. Investigation of the relationship between HO and NO under varying oxygen conditions revealed a lack of NO response to HO under hyperoxia (18 kPa O) but a modest NO response under physiological normoxia (5 kPa O). Importantly, the NO response was attenuated by l-NAME, suggesting activation of eNOS by endogenous HO generation upon auranofin treatment. Our study highlights the intricate interplay between HO and NO within the endothelial EA.hy926 cell line, emphasizing the necessity for additional research within physiological contexts due to differential response observed under physiological normoxia (5 kPa O). This further investigation is essential for a comprehensive understanding of the HO and NO signaling considering the physiological effects of ambient O levels involved.
Topics: Hydrogen Peroxide; Nitric Oxide; Humans; Oxygen; Endothelial Cells; Oxidative Stress; Nitric Oxide Synthase Type III; Biosensing Techniques; NG-Nitroarginine Methyl Ester
PubMed: 38735541
DOI: 10.1016/j.freeradbiomed.2024.05.021