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European Journal of Pharmacology Jun 2024Breast cancer is one of the most common cancers globally and a leading cause of cancer-related deaths among women. Despite the combination of chemotherapy with targeted...
Breast cancer is one of the most common cancers globally and a leading cause of cancer-related deaths among women. Despite the combination of chemotherapy with targeted therapy, including monoclonal antibodies and kinase inhibitors, drug resistance and treatment failure remain a common occurrence. Copper, complexed to various organic ligands, has gained attention as potential chemotherapeutic agents due to its perceived decreased toxicity to normal cells. The cytotoxic efficacy and the mechanism of cell death of an 8-aminoquinoline-naphthyl copper complex (Cu8AqN) in MCF-7 and MDA-MB-231 breast cancer cell lines was investigated. The complex inhibited the growth of MCF-7 and MDA-MB-231 cells with IC values of 2.54 ± 0.69 μM and 3.31 ± 0.06 μM, respectively. Nuclear fragmentation, annexin V binding, and increased caspse-3/7 activity indicated apoptotic cell death. The loss of mitochondrial membrane potential, an increase in caspase-9 activity, the absence of active caspase-8 and a decrease of tumour necrosis factor receptor 1(TNFR1) expression supported activation of the intrinsic apoptotic pathway. Increased ROS formation and increased expression of haem oxygenase-1 (HMOX-1) indicated activation of cellular stress pathways. Expression of p21 protein in the nuclei was increasedindicating cell cycle arrest, whilst the expression of inhibitor of apoptosis proteins (IAPs), cIAP1, XIAP and survivin were decreased creating a pro-apoptotic environment. Phosphorylated p53 species; phospho-p53(S15), phospho-p53(S46), and phospho-p53(S392) accumulated in MCF-7 cells indicating the potential of Cu8AqN to restore p53 function in the cells. In combination, the data indicates that Cu8AqN is a useful lead molecule worthy of further exploration as a potential anti-cancer drug.
PubMed: 38908670
DOI: 10.1016/j.ejphar.2024.176764 -
Current Opinion in Chemical Biology Jun 2024The accumulation of lipid hydroperoxides (LOOHs) has long been associated with numerous pathologies and has more recently been shown to drive a specific type of cell... (Review)
Review
The accumulation of lipid hydroperoxides (LOOHs) has long been associated with numerous pathologies and has more recently been shown to drive a specific type of cell death known as ferroptosis. In competition with their detoxification by glutathione peroxidases, LOOHs can react with both one-electron reductants and one-electron oxidants to afford radicals that initiate lipid peroxidation (LPO) chain reactions leading to more LOOH. These radicals can alternatively undergo a variety of (primarily unimolecular) reactions leading to electrophilic species that destabilize the membrane and/or react with cellular nucleophiles. While some reaction mechanisms leading to lipid-derived electrophiles have been known for some time, others have only recently been elucidated. Since LOOH (and related peroxides, LOOL) undergo these various reactions at different rates to afford distinct product distributions specific to their structures, not all LOOHs (and LOOLs) should be equivalently problematic for the cell - be it in their propensity to initiate further LPO or fragment to electrophiles, drive membrane permeabilization and eventual cell death. Herein we briefly review the fates of LOOH and discuss how they may contribute to the modulation of cell sensitivity to ferroptosis by different lipids.
PubMed: 38908300
DOI: 10.1016/j.cbpa.2024.102478 -
Animal Reproduction Science Jun 2024Oocyte cryopreservation is increasingly being used in reproductive technologies for conservation and breeding purposes. Further development of oocyte cryopreservation... (Review)
Review
Oocyte cryopreservation is increasingly being used in reproductive technologies for conservation and breeding purposes. Further development of oocyte cryopreservation techniques requires interdisciplinary insights in the underlying principles of cryopreservation. This review aims to serve this purpose by: (1) highlighting that preservation strategies can be rationally designed, (2) presenting mechanistic insights in volume and osmotic stress responses associated with CPA loading strategies and cooling, and (3) giving a comprehensive listing of oocyte specific biophysical membrane characteristics and commonly used permeation model equations. It is shown how transport models can be used to simulate the behavior of oocytes during cryopreservation processing steps, i.e., during loading of cryoprotective agents (CPAs), cooling with freezing as well as vitrification, warming and CPA unloading. More specifically, using defined cellular and membrane characteristics, the responses of oocytes during CPA (un)loading were simulated in terms of temperature- and CPA type-and-concentration-dependent changes in cell volume and intracellular solute concentration. In addition, in order to determine the optimal cooling rate for slow programmable cooling cryopreservation, the freezing-induced cell volume response was simulated at various cooling rates to estimate rates with tolerable limits. For vitrification, special emphasis was on prediction of the timing of reaching osmotic tolerance limits during CPA exposure, and the need to use step-wise CPA addition/removal protocols. In conclusion, we present simulations and schematic illustrations that explain the timing of events during slow cooling cryopreservation as well as vitrification, important for rationally designing protocols taking into account how different CPA types, concentrations and temperatures affect the oocyte.
PubMed: 38908169
DOI: 10.1016/j.anireprosci.2024.107536 -
Redox Biology May 2024Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is... (Review)
Review
Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is uncontrolled and overwhelming peroxidation of polyunsaturated fatty acids contained in membrane phospholipids, which eventually leads to rupture of the plasma membrane. Ferroptosis is unique in that it is essentially a spontaneous, uncatalyzed chemical process based on perturbed iron and redox homeostasis contributing to the cell death process, but that it is nonetheless modulated by many metabolic nodes that impinge on the cells' susceptibility to ferroptosis. Among the various nodes affecting ferroptosis sensitivity, several have emerged as promising candidates for pharmacological intervention, rendering ferroptosis-related proteins attractive targets for the treatment of numerous currently incurable diseases. Herein, the current members of a Germany-wide research consortium focusing on ferroptosis research, as well as key external experts in ferroptosis who have made seminal contributions to this rapidly growing and exciting field of research, have gathered to provide a comprehensive, state-of-the-art review on ferroptosis. Specific topics include: basic mechanisms, in vivo relevance, specialized methodologies, chemical and pharmacological tools, and the potential contribution of ferroptosis to disease etiopathology and progression. We hope that this article will not only provide established scientists and newcomers to the field with an overview of the multiple facets of ferroptosis, but also encourage additional efforts to characterize further molecular pathways modulating ferroptosis, with the ultimate goal to develop novel pharmacotherapies to tackle the various diseases associated with - or caused by - ferroptosis.
PubMed: 38908072
DOI: 10.1016/j.redox.2024.103211 -
Ferroptosis inhibitor improves outcome after early and delayed treatment in mild spinal cord injury.Acta Neuropathologica Jun 2024We show that redox active iron can induce a regulated form of non-apoptotic cell death and tissue damage called ferroptosis that can contribute to secondary damage and...
We show that redox active iron can induce a regulated form of non-apoptotic cell death and tissue damage called ferroptosis that can contribute to secondary damage and functional loss in the acute and chronic periods after spinal cord injury (SCI) in young, adult, female mice. Phagocytosis of red blood cells at sites of hemorrhage is the main source of iron derived from hemoglobin after SCI. Expression of hemeoxygenase-1 that induces release of iron from heme, is increased in spinal cord macrophages 7 days after injury. While iron is stored safely in ferritin in the injured spinal cord, it can, however, be released by NCOA4-mediated shuttling of ferritin to autophagosomes for degradation (ferritinophagy). This leads to the release of redox active iron that can cause free radical damage. Expression of NCOA4 is increased after SCI, mainly in macrophages. Increase in the ratio of redox active ferrous (Fe) to ferric iron (Fe) is also detected after SCI by capillary electrophoresis inductively coupled mass spectrometry. These changes are accompanied by other hallmarks of ferroptosis, i.e., deficiency in various elements of the antioxidant glutathione (GSH) pathway. We also detect increases in enzymes that repair membrane lipids (ACSL4 and LPCAT3) and thus promote on-going ferroptosis. These changes are associated with increased levels of 4-hydroxynonenal (4-HNE), a toxic lipid peroxidation product. Mice with mild SCI (30 kdyne force) treated with the ferroptosis inhibitor (UAMC-3203-HCL) either early or delayed times after injury showed improvement in locomotor recovery and secondary damage. Cerebrospinal fluid and serum samples from human SCI cases show evidence of increased iron storage (ferritin), and other iron related molecules, and reduction in GSH. Collectively, these data suggest that ferroptosis contributes to secondary damage after SCI and highlights the possible use of ferroptosis inhibitors to treat SCI.
Topics: Ferroptosis; Animals; Spinal Cord Injuries; Mice; Female; Mice, Inbred C57BL; Iron; Treatment Delay
PubMed: 38907771
DOI: 10.1007/s00401-024-02758-2 -
Biomolecules & Biomedicine Jun 2024Silibinin (SIL), the most active phytocompound from Silybum marianum (L.), exerts many biological effects but has low stability and bioavailability. To overcome these...
Silibinin (SIL), the most active phytocompound from Silybum marianum (L.), exerts many biological effects but has low stability and bioavailability. To overcome these drawbacks, the current research proposed the synthesis of silibilin oleate (SIL-O) and silibilin linoleate (SIL-L) derivatives as prodrugs with potentially optimized properties for biomedical applications, and the establishment of their in vitro-in ovo safety profiles. The physicochemical characterization of the obtained compounds using density functional theory (DFT) calculations, and Raman and 1H liquid-state nuclear magnetic resonance (NMR) spectroscopy confirmed the formation of SIL-O and SIL-L complexes. Computational predictions revealed that these lipophilic derivatives present a lower drug-likeness score (-29.96 for SIL-O and -23.55 for SIL-L) compared to SIL, but an overall positive drug score (0.07) and no risk for severe adverse effects. SIL-O and SIL-L showed no cytotoxicity or impairment in cell migration at low concentrations, but at the highest concentration (100 µM), they displayed distinct toxicological profiles. SIL-L was more cytotoxic (on cardiomyoblasts - H9c2(2-1), hepatocytes - HepaRG, and keratinocytes - HaCaT) than SIL-O or SIL, significantly inhibiting cell viability (< 60%), altering cellular morphology, reducing cell confluence (< 70%), and inducing prominent apoptotic-like nuclear features. At the concentration of 100 µM, SIL-O presented an irritation score (IS) of 0.61, indicating a lack of irritant effect on the chorioallantoic membrane (CAM), while SIL-L was classified as a slight irritant with an IS of 1.99. These findings outline a more favorable in vitro and in ovo biocompatibility for SIL-O compared to SIL-L, whose applications are dosage-limited due to potential toxicity.
PubMed: 38907734
DOI: 10.17305/bb.2024.10600 -
Cell Communication and Signaling : CCS Jun 2024Mitochondria are central to endothelial cell activation and angiogenesis, with the RNA polymerase mitochondrial (POLRMT) serving as a key protein in regulating...
Mitochondria are central to endothelial cell activation and angiogenesis, with the RNA polymerase mitochondrial (POLRMT) serving as a key protein in regulating mitochondrial transcription and oxidative phosphorylation. In our study, we examined the impact of POLRMT on angiogenesis and found that its silencing or knockout (KO) in human umbilical vein endothelial cells (HUVECs) and other endothelial cells resulted in robust anti-angiogenic effects, impeding cell proliferation, migration, and capillary tube formation. Depletion of POLRMT led to impaired mitochondrial function, characterized by mitochondrial depolarization, oxidative stress, lipid oxidation, DNA damage, and reduced ATP production, along with significant apoptosis activation. Conversely, overexpressing POLRMT promoted angiogenic activity in the endothelial cells. In vivo experiments demonstrated that endothelial knockdown of POLRMT, by intravitreous injection of endothelial specific POLRMT shRNA adeno-associated virus, inhibited retinal angiogenesis. In addition, inhibiting POLRMT with a first-in-class inhibitor IMT1 exerted significant anti-angiogenic impact in vitro and in vivo. Significantly elevated expression of POLRMT was observed in the retinal tissues of streptozotocin-induced diabetic retinopathy (DR) mice. POLRMT endothelial knockdown inhibited pathological retinal angiogenesis and mitigated retinal ganglion cell (RGC) degeneration in DR mice. At last, POLRMT expression exhibited a substantial increase in the retinal proliferative membrane tissues of human DR patients. These findings collectively establish the indispensable role of POLRMT in angiogenesis, both in vitro and in vivo.
Topics: Humans; Animals; Human Umbilical Vein Endothelial Cells; Mice; Mitochondria; DNA-Directed RNA Polymerases; Diabetic Retinopathy; Mice, Inbred C57BL; Cell Proliferation; Neovascularization, Pathologic; Male; Neovascularization, Physiologic; Cell Movement; Apoptosis; Angiogenesis
PubMed: 38907279
DOI: 10.1186/s12964-024-01712-9 -
Journal of Translational Medicine Jun 2024Patients with hemorrhagic shock and trauma (HS/T) are vulnerable to the endotheliopathy of trauma (EOT), characterized by vascular barrier dysfunction, inflammation, and...
BACKGROUND
Patients with hemorrhagic shock and trauma (HS/T) are vulnerable to the endotheliopathy of trauma (EOT), characterized by vascular barrier dysfunction, inflammation, and coagulopathy. Cellular therapies such as mesenchymal stem cells (MSCs) and MSC extracellular vesicles (EVs) have been proposed as potential therapies targeting the EOT. In this study we investigated the effects of MSCs and MSC EVs on endothelial and epithelial barrier integrity in vitro and in vivo in a mouse model of HS/T. This study addresses the systemic effects of HS/T on multiorgan EOT.
METHODS
In vitro, pulmonary endothelial cell (PEC) and Caco-2 intestinal epithelial cell monolayers were treated with control media, MSC conditioned media (CM), or MSC EVs in varying doses and subjected to a thrombin or hydrogen peroxide (HO) challenge, respectively. Monolayer permeability was evaluated with a cell impedance assay, and intercellular junction integrity was evaluated with immunofluorescent staining. In vivo, a mouse model of HS/T was used to evaluate the effects of lactated Ringer's (LR), MSCs, and MSC EVs on endothelial and epithelial intercellular junctions in the lung and small intestine as well as on plasma inflammatory biomarkers.
RESULTS
MSC EVs and MSC CM attenuated permeability and preserved intercellular junctions of the PEC monolayer in vitro, whereas only MSC CM was protective of the Caco-2 epithelial monolayer. In vivo, both MSC EVs and MSCs mitigated the loss of endothelial adherens junctions in the lung and small intestine, though only MSCs had a protective effect on epithelial tight junctions in the lung. Several plasma biomarkers including MMP8 and VEGF were elevated in LR- and EV-treated but not MSC-treated mice.
CONCLUSIONS
In conclusion, MSC EVs could be a potential cell-free therapy targeting endotheliopathy after HS/T via preservation of the vascular endothelial barrier in multiple organs early after injury. Further research is needed to better understand the immunomodulatory effects of these products following HS/T and to move toward translating these therapies into clinical studies.
Topics: Extracellular Vesicles; Animals; Shock, Hemorrhagic; Humans; Mesenchymal Stem Cells; Mice, Inbred C57BL; Caco-2 Cells; Endothelium, Vascular; Male; Wounds and Injuries; Culture Media, Conditioned; Mice; Endothelial Cells; Lung; Hydrogen Peroxide; Intercellular Junctions
PubMed: 38907252
DOI: 10.1186/s12967-024-05406-1 -
The EMBO Journal Jun 2024Cell polarity networks are defined by quantitative features of their constituent feedback circuits, which must be tuned to enable robust and stable polarization, while...
Cell polarity networks are defined by quantitative features of their constituent feedback circuits, which must be tuned to enable robust and stable polarization, while also ensuring that networks remain responsive to dynamically changing cellular states and/or spatial cues during development. Using the PAR polarity network as a model, we demonstrate that these features are enabled by the dimerization of the polarity protein PAR-2 via its N-terminal RING domain. Combining theory and experiment, we show that dimer affinity is optimized to achieve dynamic, selective, and cooperative binding of PAR-2 to the plasma membrane during polarization. Reducing dimerization compromises positive feedback and robustness of polarization. Conversely, enhanced dimerization renders the network less responsive due to kinetic trapping of PAR-2 on internal membranes and reduced sensitivity of PAR-2 to the anterior polarity kinase, aPKC/PKC-3. Thus, our data reveal a key role for a dynamically oligomeric RING domain in optimizing interaction affinities to support a robust and responsive cell polarity network, and highlight how optimization of oligomerization kinetics can serve as a strategy for dynamic and cooperative intracellular targeting.
PubMed: 38907033
DOI: 10.1038/s44318-024-00123-3 -
The EMBO Journal Jun 2024Dynamin 1 mediates fission of endocytic synaptic vesicles in the brain and has two major splice variants, Dyn1xA and Dyn1xB, which are nearly identical apart from the...
Dynamin 1 mediates fission of endocytic synaptic vesicles in the brain and has two major splice variants, Dyn1xA and Dyn1xB, which are nearly identical apart from the extended C-terminal region of Dyn1xA. Despite a similar set of binding partners, only Dyn1xA is enriched at endocytic zones and accelerates vesicle fission during ultrafast endocytosis. Here, we report that Dyn1xA achieves this localization by preferentially binding to Endophilin A1 through a newly defined binding site within its long C-terminal tail extension. Endophilin A1 binds this site at higher affinity than the previously reported site, and the affinity is determined by amino acids within the Dyn1xA tail but outside the binding site. This interaction is regulated by the phosphorylation state of two serine residues specific to the Dyn1xA variant. Dyn1xA and Endophilin A1 colocalize in patches near the active zone, and mutations disrupting Endophilin A binding to the long tail cause Dyn1xA mislocalization and stalled endocytic pits on the plasma membrane during ultrafast endocytosis. Together, these data suggest that the specificity for ultrafast endocytosis is defined by the phosphorylation-regulated interaction of Endophilin A1 with the C-terminal extension of Dyn1xA.
PubMed: 38907032
DOI: 10.1038/s44318-024-00145-x