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International Journal of Molecular... Jun 2024Bacterial nitroreductase enzymes capable of activating imaging probes and prodrugs are valuable tools for gene-directed enzyme prodrug therapies and targeted cell...
Bacterial nitroreductase enzymes capable of activating imaging probes and prodrugs are valuable tools for gene-directed enzyme prodrug therapies and targeted cell ablation models. We recently engineered a nitroreductase ( NfsB F70A/F108Y) for the substantially enhanced reduction of the 5-nitroimidazole PET-capable probe, SN33623, which permits the theranostic imaging of vectors labeled with oxygen-insensitive bacterial nitroreductases. This mutant enzyme also shows improved activation of the DNA-alkylation prodrugs CB1954 and metronidazole. To elucidate the mechanism behind these enhancements, we resolved the crystal structure of the mutant enzyme to 1.98 Å and compared it to the wild-type enzyme. Structural analysis revealed an expanded substrate access channel and new hydrogen bonding interactions. Additionally, computational modeling of SN33623, CB1954, and metronidazole binding in the active sites of both the mutant and wild-type enzymes revealed key differences in substrate orientations and interactions, with improvements in activity being mirrored by reduced distances between the N5-H of isoalloxazine and the substrate nitro group oxygen in the mutant models. These findings deepen our understanding of nitroreductase substrate specificity and catalytic mechanisms and have potential implications for developing more effective theranostic imaging strategies in cancer treatment.
Topics: Nitroreductases; Nitroimidazoles; Metronidazole; Prodrugs; Escherichia coli Proteins; Positron-Emission Tomography; Escherichia coli; Catalytic Domain; Protein Engineering; Models, Molecular; Aziridines
PubMed: 38928299
DOI: 10.3390/ijms25126593 -
International Journal of Molecular... Jun 2024Epidemiological data suggest that moderate hyperoxemia may be associated with an improved outcome after traumatic brain injury. In a prospective, randomized...
Epidemiological data suggest that moderate hyperoxemia may be associated with an improved outcome after traumatic brain injury. In a prospective, randomized investigation of long-term, resuscitated acute subdural hematoma plus hemorrhagic shock (ASDH + HS) in 14 adult, human-sized pigs, targeted hyperoxemia (200 < PO < 250 mmHg vs. normoxemia 80 < PO < 120 mmHg) coincided with improved neurological function. Since brain perfusion, oxygenation and metabolism did not differ, this post hoc study analyzed the available material for the effects of targeted hyperoxemia on cerebral tissue markers of oxidative/nitrosative stress (nitrotyrosine expression), blood-brain barrier integrity (extravascular albumin accumulation) and fluid homeostasis (oxytocin, its receptor and the HS-producing enzymes cystathionine-β-synthase and cystathionine-γ-lyase). After 2 h of ASDH + HS (0.1 mL/kgBW autologous blood injected into the subdural space and passive removal of 30% of the blood volume), animals were resuscitated for up to 53 h by re-transfusion of shed blood, noradrenaline infusion to maintain cerebral perfusion pressure at baseline levels and hyper-/normoxemia during the first 24 h. Immediate postmortem, bi-hemispheric (i.e., blood-injected and contra-lateral) prefrontal cortex specimens from the base of the sulci underwent immunohistochemistry (% positive tissue staining) analysis of oxidative/nitrosative stress, blood-brain barrier integrity and fluid homeostasis. None of these tissue markers explained any differences in hyperoxemia-related neurological function. Likewise, hyperoxemia exerted no deleterious effects.
Topics: Animals; Swine; Hematoma, Subdural, Acute; Shock, Hemorrhagic; Brain; Blood-Brain Barrier; Immunohistochemistry; Oxidative Stress; Resuscitation; Disease Models, Animal; Oxygen; Tyrosine
PubMed: 38928283
DOI: 10.3390/ijms25126574 -
International Journal of Molecular... Jun 2024Targeted cancer therapy aims to disrupt the functions of proteins that regulate cancer progression, mainly by using small molecule inhibitors (SMIs). SMIs exert their...
Disarib, a Specific BCL2 Inhibitor, Induces Apoptosis in Triple-Negative Breast Cancer Cells and Impedes Tumour Progression in Xenografts by Altering Mitochondria-Associated Processes.
Targeted cancer therapy aims to disrupt the functions of proteins that regulate cancer progression, mainly by using small molecule inhibitors (SMIs). SMIs exert their effect by modulating signalling pathways, organelle integrity, chromatin components, and several biosynthetic processes essential for cell division and survival. Antiapoptotic protein BCL2 is highly upregulated in many cancers compared with normal cells, making it an ideal target for cancer therapy. Around 75% of primary breast cancers overexpress , providing an opportunity to explore BCL2 inhibitors as a therapeutic option. Disarib is an SMI that has been developed as a selective BCL2 inhibitor. Disarib works by disrupting BCL2-BAK interaction and activating intrinsic apoptotic pathways in leukemic cells while sparing normal cells. We investigated the effects of Disarib, a BCL2 specific inhibitor, on breast cancer cells and xenografts. Cytotoxicity and fluorometric assays revealed that Disarib induced cell death by increasing reactive oxygen species and activating intrinsic apoptotic pathways in Triple-Negative Breast Cancer cells (MDA-MB-231 and MDA-MB-468). Disarib also affected the colony-forming properties of these cells. MDA-MB-231- and MDA-MB-468-derived xenografts showed a significant reduction in tumours upon Disarib treatment. Through the transcriptomics approach, we also explored the influence of BCL2 inhibitors on energy metabolism, mitochondrial dynamics, and epithelial-to-mesenchymal transition (EMT). Mitochondrial dynamics and glucose metabolism mainly regulate energy metabolism. The change in energetics regulates tumour growth through epithelial-mesenchymal transition, and angiogenesis. RNA sequencing (RNAseq) analysis revealed that BCL2 inhibitors ABT-199 and Disarib maintain Oxphos levels in MDA-MB-231. However, key glycolytic genes were significantly downregulated. Mitochondrial fission genes were seen to be downregulated both in RNAseq data and semi quantitative real time polymerase chain reaction (qRTPCR) in Disarib-treated TNBC cells and xenografts. Lastly, Disarib inhibited wound healing and epithelial-to-mesenchymal transition. This study showed that Disarib disrupts mitochondrial function, activates the intrinsic apoptotic pathway in breast cancer, and inhibits epithelial-to-mesenchymal transition both in vitro and in vivo. These findings highlight Disarib's potential as a multifaceted therapeutic strategy for patients with Triple-Negative Breast Cancer.
Topics: Triple Negative Breast Neoplasms; Humans; Animals; Apoptosis; Female; Proto-Oncogene Proteins c-bcl-2; Mitochondria; Mice; Xenograft Model Antitumor Assays; Cell Line, Tumor; Antineoplastic Agents; Reactive Oxygen Species; Cell Proliferation; Epithelial-Mesenchymal Transition
PubMed: 38928195
DOI: 10.3390/ijms25126485 -
International Journal of Molecular... Jun 2024In different areas of the heart, action potential waveforms differ due to differences in the expressions of sodium, calcium, and potassium channels. One of the... (Review)
Review
In different areas of the heart, action potential waveforms differ due to differences in the expressions of sodium, calcium, and potassium channels. One of the characteristics of myocardial infarction (MI) is an imbalance in oxygen supply and demand, leading to ion imbalance. After MI, the regulation and expression levels of K, Ca, and Na ion channels in cardiomyocytes are altered, which affects the regularity of cardiac rhythm and leads to myocardial injury. Myocardial fibroblasts are the main effector cells in the process of MI repair. The ion channels of myocardial fibroblasts play an important role in the process of MI. At the same time, a large number of ion channels are expressed in immune cells, which play an important role by regulating the in- and outflow of ions to complete intracellular signal transduction. Ion channels are widely distributed in a variety of cells and are attractive targets for drug development. This article reviews the changes in different ion channels after MI and the therapeutic drugs for these channels. We analyze the complex molecular mechanisms behind myocardial ion channel regulation and the challenges in ion channel drug therapy.
Topics: Myocardial Infarction; Humans; Ion Channels; Animals; Myocytes, Cardiac; Myocardium; Signal Transduction; Fibroblasts
PubMed: 38928173
DOI: 10.3390/ijms25126467 -
International Journal of Molecular... Jun 2024Photodynamic Therapy (PDT) is recognized for its exceptional effectiveness as a promising cancer treatment method. However, it is noted that overexposure to the dosage...
Photodynamic Therapy (PDT) is recognized for its exceptional effectiveness as a promising cancer treatment method. However, it is noted that overexposure to the dosage and sunlight in traditional PDT can result in damage to healthy tissues, due to the low tumor selectivity of currently available photosensitizers (PSs). To address this challenge, we introduce herein a new strategy where the small molecule-targeted agent, erlotinib, is integrated into a boron dipyrromethene (BODIPY)-based PS to form conjugate to enhance the precision of PDT. This conjugate demonstrates optical absorption, fluorescence emission, and singlet oxygen generation efficiency comparable to the reference compound , which lacks erlotinib. In vitro studies reveal that, after internalization, conjugate predominantly accumulates in the lysosomes of HepG2 cells, exhibiting significant photocytotoxicity with an IC value of 3.01 µM. A distinct preference for HepG2 cells over HELF cells is observed with conjugate but not with compound . In vivo experiments further confirm that conjugate has a specific affinity for tumor tissues, and the combination treatment of conjugate with laser illumination can effectively eradicate H22 tumors in mice with outstanding biosafety. This study presents a novel and potential PS for achieving precise PDT against cancer.
Topics: Humans; Photochemotherapy; Animals; Mice; Porphobilinogen; Photosensitizing Agents; Hep G2 Cells; Liver Neoplasms; Erlotinib Hydrochloride; Boron Compounds
PubMed: 38928126
DOI: 10.3390/ijms25126421 -
International Journal of Molecular... Jun 2024Age-related macular degeneration (AMD) is strictly linked to chronic oxidative stress, inflammation, loss of epithelial barrier integrity, and often with abnormal new...
Vitamin D and Sulforaphane Decrease Inflammatory Oxidative Stress and Restore the Markers of Epithelial Integrity in an In Vitro Model of Age-Related Macular Degeneration.
Age-related macular degeneration (AMD) is strictly linked to chronic oxidative stress, inflammation, loss of epithelial barrier integrity, and often with abnormal new blood vessel development. In this study, the retinal epithelial cell line ARPE-19 was treated with pro-inflammatory transforming growth factor-beta (TGF-β) to investigate the activity of vitamin D (VD) and sulforaphane (SF) in abating the consequences of oxidative stress and inflammation. The administration of VD and SF lowered reactive oxygen species (ROS) levels, and abated the related expression of the pro-inflammatory cytokines interleukin-6 and interleukin-8 induced by TGF-β. We evaluated mitochondrial respiration as a source of ROS production, and we discovered that the increased transcription of respiratory elements triggered by TGF-β was prevented by VD and SF. In this model of inflamed epithelium, the treatment with VD and SF also reduced the secretion of VEGF, a key angiogenic factor, and restored the markers of epithelial integrity. Remarkably, all the observed biological effects were potentiated by the co-stimulation with the two compounds and were not mediated by VD receptor expression but rather by the ERK 1/2 pathway. Altogether, the results of this study reveal the powerful synergistic anti-inflammatory activity of SF and VD and lay the foundation for future clinical assessment of their efficacy in AMD.
Topics: Humans; Macular Degeneration; Isothiocyanates; Oxidative Stress; Sulfoxides; Vitamin D; Reactive Oxygen Species; Cell Line; Vascular Endothelial Growth Factor A; Inflammation; Retinal Pigment Epithelium; Epithelial Cells; Transforming Growth Factor beta; Biomarkers; Interleukin-8
PubMed: 38928111
DOI: 10.3390/ijms25126404 -
International Journal of Molecular... Jun 2024An ischemic stroke, one of the leading causes of morbidity and mortality, is caused by ischemia and hemorrhage resulting in impeded blood supply to the brain. According...
An ischemic stroke, one of the leading causes of morbidity and mortality, is caused by ischemia and hemorrhage resulting in impeded blood supply to the brain. According to many studies, blueberries have been shown to have a therapeutic effect in a variety of diseases. Therefore, in this study, we investigated whether blueberry-treated mesenchymal stem cell (MSC)-derived extracellular vesicles (B-EVs) have therapeutic effects in in vitro and in vivo stroke models. We isolated the extracellular vesicles using cryo-TEM and characterized the particles and concentrations using NTA. MSC-derived extracellular vesicles (A-EVs) and B-EVs were round with a lipid bilayer structure and a diameter of ~150 nm. In addition, A-EVs and B-EVs were shown to affect angiogenesis, cell cycle, differentiation, DNA repair, inflammation, and neurogenesis following KEGG pathway and GO analyses. We investigated the protective effects of A-EVs and B-EVs against neuronal cell death in oxygen-glucose deprivation (OGD) cells and a middle cerebral artery occlusion (MCAo) animal model. The results showed that the cell viability was increased with EV treatment in HT22 cells. In the animal, the size of the cerebral infarction was decreased, and the behavioral assessment was improved with EV injections. The levels of NeuN and neurofilament heavy chain (NFH)-positive cells were also increased with EV treatment yet decreased in the MCAo group. In addition, the number of apoptotic cells was decreased with EV treatment compared with ischemic animals following TUNEL and Bax/Bcl-2 staining. These data suggested that EVs, especially B-EVs, had a therapeutic effect and could reduce apoptotic cell death after ischemic injury.
Topics: Extracellular Vesicles; Animals; Mesenchymal Stem Cells; Mice; Ischemic Stroke; Blueberry Plants; Male; Disease Models, Animal; Cell Survival; Cell Line; Infarction, Middle Cerebral Artery
PubMed: 38928069
DOI: 10.3390/ijms25126362 -
Cancers Jun 2024Cancers can manifest large variations in tumor phenotypes due to genetic and microenvironmental factors, which has motivated the development of quantitative...
Cancers can manifest large variations in tumor phenotypes due to genetic and microenvironmental factors, which has motivated the development of quantitative radiomics-based image analysis with the aim to robustly classify tumor phenotypes in vivo. Positron emission tomography (PET) imaging can be particularly helpful in elucidating the metabolic profiles of tumors. However, the relatively low resolution, high noise, and limited PET data availability make it difficult to study the relationship between the microenvironment properties and metabolic tumor phenotype as seen on the images. Most of previously proposed digital PET phantoms of tumors are static, have an over-simplified morphology, and lack the link to cellular biology that ultimately governs the tumor evolution. In this work, we propose a novel method to investigate the relationship between microscopic tumor parameters and PET image characteristics based on the computational simulation of tumor growth. We use a hybrid, multiscale, stochastic mathematical model of cellular metabolism and proliferation to generate simulated cross-sections of tumors in vascularized normal tissue on a microscopic level. The generated longitudinal tumor growth sequences are converted to PET images with realistic resolution and noise. By changing the biological parameters of the model, such as the blood vessel density and conditions for necrosis, distinct tumor phenotypes can be obtained. The simulated cellular maps were compared to real histology slides of SiHa and WiDr xenografts imaged with Hoechst 33342 and pimonidazole. As an example application of the proposed method, we simulated six tumor phenotypes that contain various amounts of hypoxic and necrotic regions induced by a lack of oxygen and glucose, including phenotypes that are distinct on the microscopic level but visually similar in PET images. We computed 22 standardized Haralick texture features for each phenotype, and identified the features that could best discriminate the phenotypes with varying image noise levels. We demonstrated that "cluster shade" and "difference entropy" are the most effective and noise-resilient features for microscopic phenotype discrimination. Longitudinal analysis of the simulated tumor growth showed that radiomics analysis can be beneficial even in small lesions with a diameter of 3.5-4 resolution units, corresponding to 8.7-10.0 mm in modern PET scanners. Certain radiomics features were shown to change non-monotonically with tumor growth, which has implications for feature selection for tracking disease progression and therapy response.
PubMed: 38927921
DOI: 10.3390/cancers16122215 -
Cancers Jun 2024Cancer cells show altered antioxidant defense systems, dysregulated redox signaling, and increased generation of reactive oxygen species (ROS). Targeting cancer cells... (Review)
Review
Cancer cells show altered antioxidant defense systems, dysregulated redox signaling, and increased generation of reactive oxygen species (ROS). Targeting cancer cells through ROS-mediated mechanisms has emerged as a significant therapeutic strategy due to its implications in cancer progression, survival, and resistance. Extensive research has focused on selective generation of HO in cancer cells for selective cancer cell killing by employing various strategies such as metal-based prodrugs, photodynamic therapy, enzyme-based systems, nano-particle mediated approaches, chemical modulators, and combination therapies. Many of these HO-amplifying approaches have demonstrated promising anticancer effects and selectivity in preclinical investigations. They selectively induce cytotoxicity in cancer cells while sparing normal cells, sensitize resistant cells, and modulate the tumor microenvironment. However, challenges remain in achieving selectivity, addressing tumor heterogeneity, ensuring efficient delivery, and managing safety and toxicity. To address those issues, HO-generating agents have been combined with other treatments leading to optimized combination therapies. This review focuses on various chemical agents/approaches that kill cancer cells via HO-mediated mechanisms. Different categories of compounds that selectively generate HO in cancer cells are summarized, their underlying mechanisms and function are elucidated, preclinical and clinical studies as well as recent advancements are discussed, and their prospects as targeted therapeutic agents and their therapeutic utility in combination with other treatments are explored. By understanding the potential of these compounds, researchers can pave the way for the development of effective and personalized cancer treatments.
PubMed: 38927877
DOI: 10.3390/cancers16122171 -
Genes May 2024Chronic granulomatous disease (CGD) is an inherited immunodeficiency disease mainly caused by mutations in the X-linked gene that abrogate reactive oxygen species (ROS)...
Chronic granulomatous disease (CGD) is an inherited immunodeficiency disease mainly caused by mutations in the X-linked gene that abrogate reactive oxygen species (ROS) production in phagocytes and microbial defense. Gene repair using the CRISPR/Cas9 system in hematopoietic stem and progenitor cells (HSPCs) is a promising technology for therapy for CGD. To support the establishment of efficient and safe gene therapies for CGD, we generated a mouse model harboring a patient-derived mutation in the gene. Our CybbC517del mouse line shows the hallmarks of CGD and provides a source for Cybb-deficient HSPCs that can be used to evaluate gene-therapy approaches in vitro and in vivo. In a setup using Cas9 RNPs and an AAV repair vector in HSPCs, we show that the mutation can be repaired in 19% of treated cells and that treatment restores ROS production by macrophages. In conclusion, our CybbC517del mouse line provides a new platform for refining and evaluating novel gene therapies and studying X-CGD pathophysiology.
Topics: Granulomatous Disease, Chronic; Animals; Genetic Therapy; Mice; CRISPR-Cas Systems; Disease Models, Animal; NADPH Oxidase 2; Reactive Oxygen Species; Hematopoietic Stem Cells; Humans; Macrophages; Mutation
PubMed: 38927642
DOI: 10.3390/genes15060706