Photoacoustic molecular imaging for in vivo liver iron quantitation

Maccarinelli, F.; et al. Photoacoustic molecular imaging for in vivo liver iron quantitation. Journal of Biomedical Optics 21(5): 056008 (2016). (Mar 1, 2016). DOI: http://dx.doi.org/10.1117/1.JBO.21.5.056008Copyright 2017 Society of Photo Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, or modification of the contents of the publication are prohibited.A recent study showed that ferritin is a suitable endogenous contrast agent for photoacoustic molecular imaging in cultured mammalian cells. We have therefore tested whether this imaging technique can be used for in vivo quantification of iron in mouse livers. To verify this hypothesis, we used multispectral optoacoustic tomography (MSOT) to image albino CD1 mice before and after experimental iron loading. Postmortem assays showed that the iron treatment caused a 15-fold increase in liver iron and a 40-fold increase in liver ferritin levels, while in vivo longitudinal analysis using MSOT revealed just a 1.6-fold increase in the ferritin/iron photoacoustic signal in the same animals. We conclude that MSOT can monitor changes in ferritin/iron levels in vivo, but its sensitivity is much lower than that of ex vivo iron assays.The work was partially supported by PRIN10-11 grant to P.A. F.M. was partially supported by a fellowship by Consorzio Interuniversitario Biotecnologie

The role of iron in anthracycline cardiotoxicity

The clinical use of the antitumor anthracycline Doxorubicin is limited by the risk of severe cardiotoxicity. The mechanisms underlying anthracycline-dependent cardiotoxicity are multiple and remain uncompletely understood, but many observations indicate that interactions with cellular iron metabolism are important. Convincing evidence showing that iron plays a role in Doxorubicin cardiotoxicity is provided by the protecting efficacy of iron chelation in patients and experimental models, and studies showing that iron overload exacerbates the cardiotoxic effects of the drug, but the underlying molecular mechanisms remain to be completely characterized. Since anthracyclines generate reactive oxygen species, increased iron-catalyzed formation of free radicals appears an obvious explanation for the aggravating role of iron in Doxorubicin cardiotoxicity, but antioxidants did not offer protection in clinical settings. Moreover, how the interaction between reactive oxygen species and iron damages heart cells exposed to Doxorubicin is still unclear. This review discusses the pathogenic role of the disruption of iron homeostasis in Doxorubicin-mediated cardiotoxicity in the context of current and future pharmacologic approaches to cardioprotection

Mitochondrial ferritin deficiency reduces male fertility in mice

Mitochondrial ferritin (FtMt) is a functional ferritin targeted to mitochondria that is highly expressed in the testis. To investigate the role of FtMt in the testis we set up a series of controlled matings between FtMt gene-deletion mice (FtMt–/–) with FtMt+/+ mice. We found that the number of newborns per litter and the fertility rate were strongly reduced for the FtMt–/– males, but not for the females, indicating that FtMt has an important role for male fertility. The morphology of the testis and of the spermatozoa of FtMt–/– mice was normal and we did not detect alterations in sperm parameters or in oxidative stress indices. In contrast, we observed that the cauda epididymides of FtMt–/– mice were significantly lighter and contained a lower number of spermatozoa compared with the controls. Also, the ATP content of FtMt–/– spermatozoa was found to be lower than that of FtMt+/+ spermatozoa. These data show that FtMt contributes to sperm epididymis maturation and to male fertility.The work was partially supported by MIUR grant PRIN10–11 to P. A. and by Telethon grant GGP1099 to P. A

Analysis of Nucleotide Variations in Genes of Iron Management in Patients of Parkinson's Disease and Other Movement Disorders

The capacity to act as an electron donor and acceptor makes iron an essential cofactor of many vital processes. Its balance in the body has to be tightly regulated since its excess can be harmful by favouring oxidative damage, while its deficiency can impair fundamental activities like erythropoiesis. In the brain, an accumulation of iron or an increase in its availability has been associated with the development and/or progression of different degenerative processes, including Parkinson's disease, while iron paucity seems to be associated with cognitive deficits, motor dysfunction, and restless legs syndrome. In the search of DNA sequence variations affecting the individual predisposition to develop movement disorders, we scanned by DHPLC the exons and intronic boundary regions of ceruloplasmin, iron regulatory protein 2, hemopexin, hepcidin and hemojuvelin genes in cohorts of subjects affected by Parkinson's disease and idiopathic neurodegeneration with brain iron accumulation (NBIA). Both novel and known sequence variations were identified in most of the genes, but none of them seemed to be significantly associated to the movement diseases of interest

Synthesis, in vitro and in vivo biological evaluation of substituted 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones as new potent anticancer agents

A small library of 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones has been synthesized and screened according to protocols available at the National Cancer Institute (NCI). Some derivatives were potent antiproliferative agents, showing GI50 values in the nanomolar range. Remarkably, when most active compounds against leukemia cells were tested in human peripheral blood lymphocytes from healthy donors, were 100–200 times less cytotoxic. Some compounds, selected by the Biological Evaluation Committee of NCI, were examined to determine tubulin assembly inhibition. Furthermore, flow cytometric studies performed on HeLa, HT-29, and A549 cells, showed that compounds 14 and 25 caused a block in the G2/M phase. Interestingly, these derivatives induced apoptosis through the mitochondrial death pathway, causing in parallel significant activation of both caspase-3 and -9, PARP cleavage and down-regulation of the anti-apoptotic proteins Bcl-2 and Mcl-1. Finally, compound 25 was also tested in vivo in the murine BL6-B16 melanoma and E0771 breast cancer cells, causing in both cases a significant reduction in tumor volume

Mice lacking mitochondrial ferritin are more sensitive to doxorubicin-mediated cardiotoxicity

15noMitochondrial ferritin is a functional ferritin that localizes in themitochondria.Itisexpressedinthetestis, heart,brain,and cells with active respiratory activity. Its overexpression in culturedcellsprotectedagainstoxidativedamageandreduced cytosolic iron availability. However, no overt phenotype was describedinmicewithinactivationoftheFtMtgene.Here,we usedthe doxorubicin model ofcardiac injuryina novel strain of FtMt-null mice to investigate the antioxidant role of FtMt. These mice did not show any evident phenotype, but after acute treatment to doxorubicin, they showed enhanced mortalityandaltered heartmorphologywithfibrildisorganization and severe mitochondrial damage. Signs of mitochondrial damage were present also in mock-treated FtMt−/− mice. The hearts of saline- and doxorubicin-treated FtMt−/− mice had higher thiobarbituric acid reactive substance levels, heme oxygenase 1 expression, and protein oxidation, but did not differ from FtMt+/+ in the cardiac damage marker B-type natriureticpeptide(BNP),ATP levels, and apoptosis.However,the autophagy marker LC3 was activated. The results show that the absence of FtMt, which is highly expressed in the heart, increases the sensitivity of heart mitochondria to the toxicity of doxorubicin. This study represents the first in vivo evidence of the antioxidant role of FtMt.openopenMaccarinelli, Federica; Gammella, Elena; Asperti, Michela; Mariaregon, ; Donetti, Elena; Recalcati, Stefania; Poli, Maura; Finazzi, Dario; Arosio, Paolo; Biasiotto, Giorgio; Emiliaturco, ; Altruda, Fiorella; Lonardi, Silvia; Cornaghi, Laura; Cairo, GaetanoMaccarinelli, Federica; Gammella, Elena; Asperti, Michela; Mariaregon, ; Donetti, Elena; Recalcati, Stefania; Poli, Maura; Finazzi, Dario; Arosio, Paolo; Biasiotto, Giorgio; Emiliaturco, ; Altruda, Fiorella; Lonardi, Silvia; Cornaghi, Laura; Cairo, Gaetan

Modeling acquired resistance to the second-generation androgen receptor antagonist enzalutamide in the TRAMP model of prostate cancer

Enzalutamide (MDV3100) is a potent second-generation androgen receptor antagonist approved for the treatment of castration-resistant prostate cancer (CRPC) in chemotherapy-naïve as well as in patients previously exposed to chemotherapy. However, resistance to enzalutamide and enzalutamide withdrawal syndrome have been reported. Thus, reliable and integrated preclinical models are required to elucidate the mechanisms of resistance and to assess therapeutic settings that may delay or prevent the onset of resistance. In this study, the prostate cancer multistage murine model TRAMP and TRAMP-derived cells have been used to extensively characterize in vitro and in vivo the response and resistance to enzalutamide. The therapeutic profile as well as the resistance onset were characterized and a multiscale stochastic mathematical model was proposed to link the in vitro and in vivo evolution of prostate cancer. The model showed that all therapeutic strategies that use enzalutamide result in the onset of resistance. The model also showed that combination therapies can delay the onset of resistance to enzalutamide, and in the best scenario, can eliminate the disease. These results set the basis for the exploitation of this "TRAMP-based platform" to test novel therapeutic approaches and build further mathematical models of combination therapies to treat prostate cancer and CRPC.Significance: Merging mathematical modeling with experimental data, this study presents the "TRAMP-based platform" as a novel experimental tool to study the in vitro and in vivo evolution of prostate cancer resistance to enzalutamide

Long pentraxin-3 follows and modulates bladder cancer progression

Bladder tumors are a diffuse type of cancer. Long pentraxin-3 (PTX3) is a component of the innate immunity with pleiotropic functions in the regulation of immune response, tissue remodeling, and cancer progression. PTX3 may act as an oncosuppressor in different contexts, functioning as an antagonist of the fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) system, rewiring the immune microenvironment, or acting through mechanisms not yet fully clarified. In this study we used biopsies and data mining to assess that PTX3 is differentially expressed during the different stages of bladder cancer (BC) progression. BC cell lines, representative of different tumor grades, and transgenic/carcinogen-induced models were used to demonstrate in vitro and in vivo that PTX3 production by tumor cells decreases along the progression from low-grade to high-grade advanced muscle invasive forms (MIBC). In vitro and in vivo data revealed for the first time that PTX3 modulation and the consequent impairment of FGF/FGR systems in BC cells have a significant impact on different biological features of BC growth, including cell proliferation, motility, metabolism, stemness, and drug resistance. PTX3 exerts an oncosuppressive effect on BC progression and may represent a potential functional biomarker in BC evolution. Moreover, FGF/FGFR blockade has an impact on drug resistance and stemness features in BC

The importance of eukaryotic ferritins in iron handling and cytoprotection

Ferritins, the main intracellular iron storage proteins, have been studied for over 60years, mainly focusing on the mammalian ones.Thisallowedtheelucidationofthestructureoftheseproteins and the mechanisms regulating their iron incorporation and mineralization.However,ferritinispresentinmost,althoughnot all, eukaryotic cells, comprising monocellular and multicellular invertebratesandvertebrates.Theaimofthisreviewistoprovide anupdateonthegeneralpropertiesofferritinsthatarecommonto variouseukaryoticphyla(exceptplants),andtogiveanoverview on the structure, function and regulation of ferritins. An update on the animal models that were used to characterize H, L and mitochondrialferritinsisalsoprovided.Thedatashowthatferritin structure is highly conserved among different phyla. It exerts an important cytoprotective function against oxidative damage and playsaroleininnateimmunity,whereitalsocontributestoprevent parenchymal tissue from the cytotoxicity of pro-inflammatory agonists released by the activation of the immune response activation. Less clear are the properties of the secretory ferritins expressed by insects and molluscs, which may be important for understanding the role played by ferritin in mammals