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PloS One 2019African trypanosomiasis remains a lethal disease to both humans and livestock. The disease persists due to limited drug availability, toxicity and drug resistance, hence...
African trypanosomiasis remains a lethal disease to both humans and livestock. The disease persists due to limited drug availability, toxicity and drug resistance, hence the need for a better understanding of the parasite's biology and provision of alternative forms of therapy. In this study, the in vitro effects of phenolic acids were assessed for their trypanocidal activities against Trypanosoma brucei brucei. The effect of the phenolic acids on Trypanosoma brucei brucei was determined by the alamarBlue assay. The cell cycle effects were determined by flow cytometry and parasite morphological analysis was done by microscopy. Effect on cell proliferation was determined by growth kinetic analysis. Reverse Transcriptase quantitative Polymerase Chain Reaction was used to determine expression of iron dependent enzymes and iron distribution determined by atomic absorption spectroscopy. Gallic acid gave an IC50 of 14.2±1.5 μM. Deferoxamine, gallic acid and diminazene aceturate showed a dose dependent effect on the cell viability and the mitochondrion membrane integrity. Gallic acid, deferoxamine and diminazene aceturate caused loss of kinetoplast in 22%, 26% and 82% of trypanosomes respectively and less than 10% increase in the number of trypanosomes in S phase was observed. Gallic acid caused a 0.6 fold decrease, 50 fold increase and 7 fold increase in the expression levels of the transferrin receptor, ribonucleotide reductase and cyclin 2 genes respectively while treatment with deferoxamine and diminazene aceturate also showed differential expressions of the transferrin receptor, ribonucleotide reductase and cyclin 2 genes. The data suggests that gallic acid possibly exerts its effect on T. brucei via iron chelation leading to structural and morphological changes and arrest of the cell cycle. These together provide information on the cell biology of the parasite under iron starved conditions and provide leads into alternative therapeutic approaches in the treatment of African trypanosomiasis.
Topics: Animals; Cell Proliferation; Cell Survival; Deferoxamine; Diminazene; Drug Resistance; Gallic Acid; Humans; Hydroxybenzoates; Iron; Mitochondrial Membranes; Trypanocidal Agents; Trypanosoma; Trypanosoma brucei brucei; Trypanosomiasis, African
PubMed: 31048849
DOI: 10.1371/journal.pone.0216078 -
Oxidative Medicine and Cellular... 2015The high incidence of cardiomyopathy in patients with hemosiderosis, particularly in transfusional iron overload, strongly indicates that iron accumulation in the heart... (Review)
Review
The high incidence of cardiomyopathy in patients with hemosiderosis, particularly in transfusional iron overload, strongly indicates that iron accumulation in the heart plays a major role in the process leading to heart failure. In this context, iron-mediated generation of noxious reactive oxygen species is believed to be the most important pathogenetic mechanism determining cardiomyocyte damage, the initiating event of a pathologic progression involving apoptosis, fibrosis, and ultimately cardiac dysfunction. However, recent findings suggest that additional mechanisms involving subcellular organelles and inflammatory mediators are important factors in the development of this disease. Moreover, excess iron can amplify the cardiotoxic effect of other agents or events. Finally, subcellular misdistribution of iron within cardiomyocytes may represent an additional pathway leading to cardiac injury. Recent advances in imaging techniques and chelators development remarkably improved cardiac iron overload detection and treatment, respectively. However, increased understanding of the pathogenic mechanisms of iron overload cardiomyopathy is needed to pave the way for the development of improved therapeutic strategies.
Topics: Animals; Cardiomyopathies; Deferoxamine; Disease Models, Animal; Humans; Iron; Iron Overload; Iron-Regulatory Proteins; Oxidative Stress; Reactive Oxygen Species; Siderophores
PubMed: 25878762
DOI: 10.1155/2015/230182 -
Molecular Imaging and Biology Dec 2023Site-specific approaches to bioconjugation produce well-defined and homogeneous immunoconjugates with potential for superior in vivo behavior compared to analogs...
PURPOSE
Site-specific approaches to bioconjugation produce well-defined and homogeneous immunoconjugates with potential for superior in vivo behavior compared to analogs synthesized using traditional, stochastic methods. The possibility of incorporating photoaffinity chemistry into a site-specific bioconjugation strategy is particularly enticing, as it could simplify and accelerate the preparation of homogeneous immunoconjugates for the clinic. In this investigation, we report the synthesis, in vitro characterization, and in vivo evaluation of a site-specifically modified, Zr-labeled radioimmunoconjugate created via the reaction between an mAb and an Fc-binding protein bearing a photoactivatable 4-benzoylphenylalanine residue.
PROCEDURES
A variant of the Fc-binding Z domain of protein A containing a photoactivatable, 4-benzoylphenylalanine residue - Z(35BPA) - was modified with desferrioxamine (DFO), combined with the A33 antigen-targeting mAb huA33, and irradiated with UV light. The resulting immunoconjugate - DFO-huA33 - was purified and characterized via SDS-PAGE, MALDI-ToF mass spectrometry, surface plasmon resonance, and flow cytometry. The radiolabeling of DFO-huA33 was optimized to produce [Zr]Zr-DFO-huA33, and the immunoreactivity of the radioimmunoconjugate was determined with SW1222 human colorectal cancer cells. Finally, the in vivo performance of [Zr]Zr-DFO-huA33 in mice bearing subcutaneous SW1222 xenografts was interrogated via PET imaging and biodistribution experiments and compared to that of a stochastically labeled control radioimmunoconjugate, [Zr]Zr-DFO-huA33.
RESULTS
HuA33 was site-specifically modified with Z(35BPA)-DFO, producing an immunoconjugate with on average 1 DFO/mAb, high in vitro stability, and high affinity for its target. [Zr]Zr-DFO-huA33 was synthesized in 95% radiochemical yield and exhibited a specific activity of 2 mCi/mg and an immunoreactive fraction of ~ 0.85. PET imaging and biodistribution experiments revealed that high concentrations of the radioimmunoconjugate accumulated in tumor tissue (i.e., ~ 40%ID/g at 120 h p.i.) but also that the Z(35BPA)-bearing immunoPET probe produced higher uptake in the liver, spleen, and kidneys than its stochastically modified cousin, [Zr]Zr-DFO-huA33.
CONCLUSIONS
Photoaffinity chemistry and an Fc-binding variant of the Z domain were successfully leveraged to create a novel site-specific strategy for the synthesis of radioimmunoconjugates. The probe synthesized using this method - DFO-huA33 - was well-defined and homogeneous, and the resulting radioimmunoconjugate ([Zr]Zr-DFO-huA33) boasted high specific activity, stability, and immunoreactivity. While the site-specifically modified radioimmunoconjugate produced high activity concentrations in tumor tissue, it also yielded higher uptake in healthy organs than a stochastically modified analog, suggesting that optimization of this system is necessary prior to clinical translation.
Topics: Humans; Animals; Mice; Immunoconjugates; Tissue Distribution; Positron-Emission Tomography; Neoplasms; Zirconium; Cell Line, Tumor; Deferoxamine
PubMed: 37052759
DOI: 10.1007/s11307-023-01818-5 -
Molecules (Basel, Switzerland) May 2020High expression levels of the tumor-associated antigen MUC1 have been correlated with tumor aggressiveness, poor response to therapy, and poor survival in several tumor...
High expression levels of the tumor-associated antigen MUC1 have been correlated with tumor aggressiveness, poor response to therapy, and poor survival in several tumor types, including breast, pancreatic, and epithelial ovarian cancer. Herein, we report the synthesis, characterization, and in vivo evaluation of a novel radioimmunoconjugate for the immuno-positron emission tomography (immunoPET) imaging of MUC1 expression based on the AR20.5 antibody. To this end, we modified AR20.5 with the chelator desferrioxamine (DFO) and labeled it with the positron-emitting radiometal zirconium-89 (t ~3.3 d) to produce [Zr]Zr-DFO-AR20.5. In subsequent in vivo experiments in athymic nude mice bearing subcutaneous MUC1-expressing ovarian cancer xenografts, [Zr]Zr-DFO-AR20.5 clearly delineated tumor tissue, producing a tumoral activity concentration of 19.1 ± 6.4 percent injected dose per gram (%ID/g) at 120 h post-injection and a tumor-to-muscle activity concentration ratio of 42.4 ± 10.6 at the same time point. Additional PET imaging experiments in mice bearing orthotopic MUC1-expressing ovarian cancer xenografts likewise demonstrated that [Zr]Zr-DFO-AR20.5 enables the visualization of tumor tissue-including metastatic lesions-with promising tumor-to-background contrast.
Topics: Animals; Antibodies, Monoclonal; Antibodies, Neoplasm; Biological Availability; Deferoxamine; Female; Gene Expression; Heterografts; Humans; Immunoconjugates; Lymphatic Metastasis; Mice; Mice, Nude; Mucin-1; Neoplasms; Positron-Emission Tomography; Protein Binding; Radioisotopes; Signal-To-Noise Ratio; Tissue Distribution; Zirconium
PubMed: 32429033
DOI: 10.3390/molecules25102315 -
Microbiology Spectrum Oct 2022This study aimed to investigate the antibacterial mechanism of cefiderocol (CFDC) using data-independent acquisition quantitative proteomics combined with cellular and...
This study aimed to investigate the antibacterial mechanism of cefiderocol (CFDC) using data-independent acquisition quantitative proteomics combined with cellular and molecular biological assays. Numerous differentially expressed proteins related to the production of NADH, reduced cofactor flavin adenine dinucleotide (FADH), NADPH and reactive oxygen species (ROS), iron-sulfur cluster binding, and iron ion homeostasis were found to be upregulated by CFDC. Furthermore, parallel reaction monitoring analysis validated these results. Meanwhile, we confirmed that the levels of NADH, ROS, HO, and iron ions were induced by CFDC, and the sensitivity of Escherichia coli to CFDC was inhibited by the antioxidant vitamin C, -acetyl-l-cysteine, and deferoxamine. Moreover, deferoxamine also suppressed the HO stress induced by CFDC. In addition, knockout of the NADH-quinone oxidoreductase genes (, , , , , , , ) in the respiratory chain attenuated the sensitivity of E. coli to CFDC far beyond the effects of cefepime and ceftazidime; in particular, the E. coli BW25113 Δ strain produced 60-fold increases in MIC to CFDC compared to that of the wild-type E. coli BW25113 strain. The present study revealed that CFDC exerts its antibacterial effects by inducing ROS stress by elevating the levels of NADH and iron ions in E. coli. CFDC was the first FDA-approved siderophore cephalosporin antibiotic in 2019 and is known for its Trojan horse tactics and broad antimicrobial activity against Gram-negative bacteria. However, its antibacterial mechanism is not fully understood, and whether it has an impact on iron ion homeostasis remains unknown. To comprehensively reveal the antibacterial mechanisms of CFDC, data-independent acquisition quantitative proteomics combined with cellular and molecular biological assays were performed in this study. The findings will further facilitate our understanding of the antibacterial mechanism of CFDC and may provide a theoretical foundation for controlling CFDC resistance in the future.
Topics: Escherichia coli; Reactive Oxygen Species; Ceftazidime; Siderophores; Proteomics; NAD; Cefepime; NADP; Flavin-Adenine Dinucleotide; Acetylcysteine; Antioxidants; Deferoxamine; Hydrogen Peroxide; Cephalosporins; Anti-Bacterial Agents; Iron; Sulfur; Ascorbic Acid; Quinones; Cefiderocol
PubMed: 35980225
DOI: 10.1128/spectrum.01093-22 -
Molecules (Basel, Switzerland) Oct 2022Positron emission tomography (PET) imaging is a powerful non-invasive method to determine the in vivo behavior of biomolecules. Determining biodistribution and...
Positron emission tomography (PET) imaging is a powerful non-invasive method to determine the in vivo behavior of biomolecules. Determining biodistribution and pharmacokinetic (PK) properties of targeted therapeutics can enable a better understanding of in vivo drug mechanisms such as tumor uptake, off target accumulation and clearance. Zirconium-89 (Zr) is a readily available tetravalent PET-enabling radiometal that has been used to evaluate the biodistribution and PK of monoclonal antibodies. In the current study, we performed in vitro and in vivo characterization of Zr-lintuzumab, a radiolabeled anti-CD33 antibody, as a model to evaluate the in vivo binding properties in preclinical models of AML. Lintuzumab was conjugated to p-SCN-Bn-deferoxamine (DFO) and labeled with Zr using a 5:1 µCi:µg specific activity at 37 °C for 1h. The biological activity of Zr-lintuzumab was evaluated in a panel of CD33 positive cells using flow cytometry. Fox Chase SCID mice were injected with 2 × 10 OCI-AML3 cells into the right flank. After 12 days, a cohort of mice ( = 4) were injected with Zr-lintuzumab via tail vein. PET/CT scans of mice were acquired on days 1, 2, 3 and 7 post Zr-lintuzumab injection. To demonstrate Zr-lintuzumab specific binding to CD33 expressing tumors in vivo, a blocking study was performed. This cohort of mice ( = 4) was injected with native lintuzumab and 24 h later Zr-lintuzumab was administered. This group was imaged 3 and 7 days after injection of Zr-lintuzumab. A full ex vivo biodistribution study on both cohorts was performed on day 7. The results from the PET image and ex vivo biodistribution studies were compared. Lintuzumab was successfully radiolabeled with Zr resulting in a 99% radiochemical yield. The Zr-lintuzumab radioconjugate specifically binds CD33 positive cells in a similar manner to native lintuzumab as observed by flow cytometry. PET imaging revealed high accumulation of Zr-lintuzumab in OCI-AML3 tumors within 24h post-injection of the radioconjugate. The Zr-lintuzumab high tumor uptake remains for up to 7 days. Tumor analysis of the PET data using volume of interest (VOI) showed significant blocking of Zr-lintuzumab in the group pre-treated with native lintuzumab (pre-blocked group), thus indicating specific targeting of CD33 on OCI-AML3 cells in vivo. The tumor uptake findings from the PET imaging study are in agreement with those from the ex vivo biodistribution results. PET imaging of Zr-lintuzumab shows high specific uptake in CD33 positive human OCI-AML3 tumors. The results from the image study agree with the observations from the ex vivo biodistribution study. Our findings collectively suggest that PET imaging using Zr-lintuzumab could be a powerful drug development tool to evaluate binding properties of anti-CD33 monoclonal antibodies in preclinical cancer models.
Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Cell Line, Tumor; Deferoxamine; Humans; Mice; Mice, SCID; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Tissue Distribution; Zirconium
PubMed: 36235126
DOI: 10.3390/molecules27196589 -
Journal of Reconstructive Microsurgery Oct 2022Radiation-associated soft tissue injury is a potentially devastating complication for head and neck cancer patients. The damage can range from minor sequelae such as... (Review)
Review
BACKGROUND
Radiation-associated soft tissue injury is a potentially devastating complication for head and neck cancer patients. The damage can range from minor sequelae such as xerostomia, which requires frequent daily maintenance, to destructive degenerative processes such as osteoradionecrosis, which can contribute to flap failure and delay or reverse oral rehabilitation. Despite the need for effective radioprotectants, the literature remains sparse, primarily focused on interventions beyond the surgeon's control, such as maintenance of good oral hygiene or modulation of radiation dose.
METHODS
This narrative review aggregates and explores noninvasive, systemic treatment modalities for prevention or amelioration of radiation-associated soft tissue injury.
RESULTS
We highlighted nine modalities with the most clinical potential, which include amifostine, melatonin, palifermin, hyperbaric oxygen therapy, photobiomodulation, pentoxifylline-tocopherol-clodronate, pravastatin, transforming growth factor-β modulators, and deferoxamine, and reviewed the benefits and limitations of each modality. Unfortunately, none of these modalities are supported by strong evidence for prophylaxis against radiation-associated soft tissue injury.
CONCLUSION
While we cannot endorse any of these nine modalities for immediate clinical use, they may prove fruitful areas for further investigation.
Topics: Amifostine; Deferoxamine; Fibroblast Growth Factor 7; Humans; Melatonin; Pravastatin; Soft Tissue Injuries; Transforming Growth Factors
PubMed: 35213927
DOI: 10.1055/s-0042-1742731 -
Indian Pediatrics Mar 2016
Topics: Deferoxamine; Humans; Iron; Iron Chelating Agents; Iron Overload; Thalassemia; beta-Thalassemia
PubMed: 27029678
DOI: 10.1007/s13312-016-0819-y -
Journal of Cerebral Blood Flow and... Feb 2020Intracerebral hemorrhage is associated with significant morbidity and mortality. Some clinical trials demonstrated a trend towards benefit with surgical evacuation of... (Review)
Review
Intracerebral hemorrhage is associated with significant morbidity and mortality. Some clinical trials demonstrated a trend towards benefit with surgical evacuation of intracerebral hemorrhage, without strong statistically significant results. Subsequent studies focused on minimally invasive techniques. Improved outcomes were more likely with surgical reduction of intracerebral hemorrhage volume to ≤15 mL. Deferoxamine is currently being evaluated as a therapeutic tool in intracerebral hemorrhage with promising results. There continues to be a lack of level I evidence supporting medical and surgical tools for intracerebral hemorrhage evacuation. Could a combination of minimally invasive surgery with hematoma lysis and Deferoxamine result in more effective hematoma evacuation?
Topics: Clinical Trials as Topic; Deferoxamine; Female; Humans; Intracranial Hemorrhages; Male; Minimally Invasive Surgical Procedures
PubMed: 31791162
DOI: 10.1177/0271678X19892660 -
Plastic and Reconstructive Surgery Mar 2018Radiation therapy is a mainstay in the treatment of many malignancies, but collateral damage to surrounding tissue, with resultant hypovascularity, fibrosis, and...
BACKGROUND
Radiation therapy is a mainstay in the treatment of many malignancies, but collateral damage to surrounding tissue, with resultant hypovascularity, fibrosis, and atrophy, can be difficult to reconstruct. Fat grafting has been shown to improve the quality of irradiated skin, but volume retention of the graft is significantly decreased. Deferoxamine is a U.S. Food and Drug Administration-approved iron-chelating medication for acute iron intoxication and chronic iron overload that has also been shown to increase angiogenesis. The present study evaluates the effects of deferoxamine treatment on irradiated skin and subsequent fat graft volume retention.
METHODS
Mice underwent irradiation to the scalp followed by treatment with deferoxamine or saline and perfusion and were analyzed using laser Doppler analysis. Human fat grafts were then placed beneath the scalp and retention was also followed up to 8 weeks radiographically. Finally, histologic evaluation of overlying skin was performed to evaluate the effects of deferoxamine preconditioning.
RESULTS
Treatment with deferoxamine resulted in significantly increased perfusion, as demonstrated by laser Doppler analysis and CD31 immunofluorescent staining (p < 0.05). Increased dermal thickness and collagen content secondary to irradiation, however, were not affected by deferoxamine (p > 0.05). Importantly, fat graft volume retention was significantly increased when the irradiated recipient site was preconditioned with deferoxamine (p < 0.05).
CONCLUSIONS
The authors' results demonstrated increased perfusion with deferoxamine treatment, which was also associated with improved fat graft volume retention. Preconditioning with deferoxamine may thus enhance fat graft outcomes for soft-tissue reconstruction following radiation therapy.
Topics: Adipose Tissue; Animals; Deferoxamine; Female; Graft Survival; Healthy Volunteers; Humans; Male; Mice, SCID; Middle Aged; Radiation-Protective Agents; Scalp; Surgical Flaps
PubMed: 29135894
DOI: 10.1097/PRS.0000000000004167