García Martín, María Luisa & Pilar López Larrubia (eds.). 2018. Preclinical MRI. Methods in Molecular Biology series. Springer New York. DOI: 10.1007/978-1-4939-7531-0
This book was conceived with the idea of providing an update on a wide variety of preclinical MRI methods and protocols to help technicians and researchers interested in this technology. The basics of MRI physics are introduced, followed by chapters describing updated methodology and protocols for some standard and more advanced MRI techniques covering diffusion, perfusion, functional imaging, in-vivo spectroscopy (proton and heteronuclear), susceptibility contrast MRI… The book also contains some chapters where some applications of those methods are illustrated in animal models of several diseases including cancer, stroke and neurodegeneration. Protocols are described in a step-by-step approach, with interesting notes and tips at the end of each chapter, which -a priori- should allow the new worker to obtain successful results with the first attempt ;o) .
“Assessment of biodistribution using mesenchymal stromal cells: Algorithm for study design and challenges in detection methodologies” by Reyes B, Coca MI, Codinach M, López-Lucas MD, Del Mazo-Barbara A, Caminal M, Oliver-Vila I, Cabañas V, S. Lope-Piedrafita, García-López J, Moraleda JM, Fontecha CG, Vives J. Cytotherapy. 2017 :1060-1069. doi: 10.1016/j.jcyt.2017.06.004.
Biodistribution of candidate cell-based therapeutics is a critical safety concern that must be addressed in the preclinical development program. We aimed to design a decision tree based on a series of studies included in actual dossiers approved by competent regulatory authorities, noting that the design, execution and interpretation of pharmacokinetics studies using this type of therapy is not straightforward and presents a challenge for both developers and regulators. This work contributes to the standardization in the design of biodistribution studies by improving methods for accurate assessment of safety.
Eight studies were evaluated for the definition of a decision tree, in which mesenchymal stromal cells (MSCs) were administered to mouse, rat and sheep models using diverse routes (local or systemic), cell labeling (chemical or genetic) and detection methodologies (polymerase chain reaction (PCR), immunohistochemistry (IHC), fluorescence bioimaging, and magnetic resonance imaging (MRI). Moreover, labeling and detection methodologies were compared in terms of cost, throughput, speed, sensitivity and specificity.
“Metronomic treatment in immunocompetent preclinical GL261 glioblastoma: effects of cyclophosphamide and temozolomide” by by L. Ferrer-Font, N. Arias-Ramos, S. Lope-Piedrafita, M. Julià-Sapé , M. Pumarola, C. Arús and A. P. Candiota. NMR Biomed. 2017. DOI: 10.1002/nbm.3748.
Glioblastoma (GBM) causes poor survival in patients even when applying aggressive treatment. In preceding years, efforts have focused in new therapeutic regimens with conventional drugs to activate immune responses that may enhance tumor regression and prevent regrowth, as for example the “metronomic” approaches.
We have evaluated whether metronomic CPA or TMZ administration could increase survival in orthotopic GL261 in C57BL/6 mice, an immunocompetent model. Longitudinal in vivo studies with CPA (140 mg/Kg) or TMZ (range 140-240 mg/Kg) metronomic administration (every 6 days) were performed in tumor-bearing mice. Tumor evolution was monitored at 7T with T2-weighted MRI, Diffusion weighted imaging and MRSI-based nosological images of response to therapy. Obtained results demonstrated that both treatments resulted in increased survival (38.6+21.0 days, n=30) compared to control (19.4+2.4 days, n=18). Also, it was found a clear edema appearance during chemotherapeutic treatment suggesting inflammatory associated processes. The necropsy performed in mice cured from GBM after high TMZ cumulative dosage (980-1400 mg/Kg) revealed lymphoma incidence.
“Generation of a new model of patellar tendinopathy in rats which mimics the human sports pathology: A pilot study” by David Domínguez, Paola Contreras-Muñoz, Silvia Lope, Gil Rodas, G. and Mario Marotta. Apunts. Medicina de l’Esport, 2017, 52:194, 53-59. DOI: 10.1016/j.apunts.2017.01.002
Introduction: Patellar tendon pathophysiology is not still fully understood. The collection of clinical samples from athletes that could permit the analysis of the tendinopathy progression, especially in the early stages, is difficult. For that reason, the purpose of this study is to develop a new experimental animal model of patellar tendinopathy in rats which mimics the human tendinopathy by in vivo intratendinous collagenase injection in the proximal portion of the patellar tendon. Material and methods: The experimental model used was 8-week-old male Wistar rats (N = 4). The administration of collagenase was performed by ultrasound-guided puncture at the level of the proximal and deep portion of the patellar tendon in anesthetized animals. The tendon lesion was evaluated 48 h after injury by magnetic resonance and then, the animals were euthanized and the patellar tendons were collected for histological evaluation. Results: The collagenase-induced lesion model demonstrated important similarities with the human patellar tendinopathy in the region of the proximal insertion. Conclusions: The experimental model of patellar tendinopathy in rat model induces a degeneration and distortion of the patellar tendon architecture in its proximal portion, which closely mimics to that seen in human patellar tendinopathy, and could represent an excellent preclinical model for the study of new therapies focused on treatment of tendinopathy.
“Metabolomics of Therapy Response in Preclinical Glioblastoma: A Multi-Slice MRSI-Based Volumetric Analysis for Noninvasive Assessment of Temozolomide Treatment” by N. Arias-Ramos, L. Ferrer-Font, S. Lope-Piedrafita, V. Mocioiu, M. Julià-Sapé , M. Pumarola, C. Arús and A. P. Candiota. Metabolites, 2017, 18;7(2). pii: E20. DOI: 10.3390/metabo7020020.
Glioblastoma (GBM) is the most common and aggressive glial primary tumor with a survival average of 14-15 months, even after application of standard treatment. Non-invasive surrogate biomarkers of therapy response may be relevant for improving patient survival. Nosological images of therapy response using a semi-supervised source extraction approach in preclinical GBM based on single slice Magnetic Resonance Spectroscopic Imaging (MRSI) was previously describe by our group. However, because of GBM heterogeneity, relevant response information could be missed just by studying one slice. Therefore, the goal of this work was to acquire 3D-like information from preclinical GBM under a longitudinal treatment protocol, using a multi-slice MRSI approach.
Nosological maps were obtained based on semi-supervised convex Non-negative Matrix Factorization and each voxel was colored according to the contribution to the spectral pattern of each one of the three sources or characteristic spectral patterns: Normal brain, actively proliferating tumour or responding tumour.
Heterogeneous response levels were observed and three arbitrary groups of treated animals were defined as: high response, intermediate response, and low response. Histopathological studies showed an inverse correlation between the responding pattern level and Ki67 proliferation rate.
“Neonatal handling enduringly decreases anxiety and stress responses and reduces hippocampus and amygdala volume in agenetic model of differential anxiety: Behavioral-volumetric associations in the Roman rats trains” by C. Río-Álamos, I. Oliveras, M. A. Piludu, C. Gerbolés, T. Cañete, G. Blázquez, S. Lope-Piedrafita, E. Martínez-Membrives, R. Torrubia, A. Tobeña, and A. Fernández-Teruel. European Neuropsychopharmacology, 2017, 27: 146–158. DOI: 10.1016/j.euroneuro.2016.12.003
The hippocampus and amygdala have been proposed as key neural structures related to anxiety. A more active hippocampus/amygdala system has been related to greater anxious responses in situations involving conflict/novelty. The Roman Low- (RLA) and High-avoidance (RHA) rat strains constitute a genetic model of differential anxiety. Relative to RHA rats, RLA rats exhibit enhanced anxiety/fearfulness, augmented hippocampal/amygdala c-Fos expression following exposure to novelty/conflict, increased hippocampal neuronal density and higher endocrine responses to stress. Neonatal handling (NH) is an environmental treatment with long-lasting anxiety/stress-reducing effects in rodents. Since hippocampus and amygdala volume are supposed to be related to anxiety/fear, it was hypothesized a greater volume of both areas in RLA than in RHA rats, as well as that NH treatment would reduce anxiety and the volume of both structures. Adult untreated and NH-treated RHA and RLA rats were tested for anxiety, sensorimotor gating (PPI), stress-induced corticosterone and prolactin responses, two-way active avoidance acquisition and in vivo 7 T 1H-Magnetic resonance image.
As expected, untreated RLA rats showed higher anxiety and post-stress hormone responses, as well as greater hippocampus and amygdala volumes than untreated RHA rats. NH decreased anxiety/stress responses, especially in RLA rats, and significantly reduced hippocampus and amygdala volumes in this strain. Dorsal striatum volume was not different between the strains nor it was affected by NH. Finally, there were positive associations (as shown by correlations, factor analysis and multiple regression) between anxiety and PPI and hippocampus/amygdala volumes.
“Mutation of the 3-Phosphoinositide-Dependent Protein Kinase 1
(PDK1) Substrate-Docking Site in the Developing Brain Causes
Microcephaly with Abnormal Brain Morphogenesis Independently of
Akt, Leading to Impaired Cognition and Disruptive Behaviors” by Lluís Cordón-Barris, Sònia Pascual-Guiral, Shaobin Yang, Lydia Giménez-Llort, Silvia Lope-Piedrafita, Carlota Niemeyer, Enrique Claro, Jose M. Lizcano, and Jose R. Bayascas.Mol Cell Biol (2016), 36:2967–2982. DOI:10.1128/MCB.00230-16.
This report shows the involvement of PDK1 downstream effectors other than Akt in mouse neuropsychiatric-like disorders, with potential face and construct validity for negative and cognitive symptoms of schizophrenia. Results point to a prominent function for PIF pocket-dependent kinases as major effectors of this signaling hub downstream of Akt in the etiopathogenesis of schizophrenia that might provide construct validity to the PDK1 L155E mutants.
The phosphoinositide (PI) 3-kinase/Akt signaling pathway plays essential roles during neuronal development. 3-Phosphoinositide-dependent protein kinase 1 (PDK1) coordinates the PI 3-kinase signals by activating 23 kinases of the AGC family, includingAkt. Phosphorylation of a conserved docking site in the substrate is a requisite for PDK1 to recognize, phosphorylate, and activate most of these kinases, with the exception of Akt. This differential mechanism of regulation it has been exploited by generating neuron-specific conditional knock-in mice expressing a mutant form of PDK1, L155E, in which the substrate-docking site binding motif, termed the PIF pocket, was disrupted. As a consequence, activation of all the PDK1 substrates tested except Akt was abolished. The mice exhibited microcephaly, altered cortical layering, and reduced circuitry, leading to cognitive deficits and exacerbated disruptive behavior combined with diminished motivation. The abnormal patterning of the adult brain arises from the reduced ability of the embryonic neurons to polarize and extend their axons, highlighting the essential roles that the PDK1 signaling beyond Akt plays in mediating the neuronal responses that regulate brain development.
Workshop limited to 4 participants (first come, first served)
Silvia Lope-Piedrafita, PhD ()
This course combines a comprehensive series of lectures on the technology of Magnetic resonance spectroscopy and imaging (MRS/MRI) with hands-on laboratory sessions to provide practical demonstrations of key concepts and procedures for preclinical studies.
Whether you are considering MRI as a research tool in your lab or just would like to learn more about MRI, this workshop addresses practical aspects of experimental MRI with laboratory animals and provide valuable hands-on experience on a 7 Tesla Bruker BioSpec spectrometer.
An extraordinary atlas of mouse anatomy which includes more than 2,200 original images over 600 pages to show the anatomy, histology and cellular structure of mouse organs. This book attempts to provide an overview of the different levels of morphology of the mouse, ranging from gross anatomy and topographical anatomy (to explain the relative position of the organs and structures of a particular body region) down to the microscopic anatomy. Imaging technologies used for that include magnetic resonance imaging (MRI), computed tomography (CT), ultrasonography, angiography, X-ray, and electron microscopy. Also, classical anatomical techniques such as conventional dissection, skeletal preparations, vascular injections, histology and immunohistochemistry have been employed to characterize the mouse morphology.
All MRI images included in this book were acquired at our NMR facility (SeRMN, Universitat Autònoma de Barcelona) in a 7 Tesla Bruker BioSpec spectrometer.
“In vivo and ex vivo Magnetic Resonance Spectroscopy of the Infarct and the Subventricular Zone in Experimental Stroke” by E. Jiménez-Xarrié, M. Davila, S. Gil-Perotín, A. Jurado-Rodríguez, A.P. Candiota, R. Delgado-Mederos, S. Lope-Piedrafita, J.M. García-Verdugo, C. Arús, J. Martí-Fàbregas. Journal of Cerebral Blood Flow & Metabolism, 2015, 35:828–834. DOI: 10.1038/jcbfm.2014.257
Ischemic stroke changes the metabolic pattern in the infarct area and also in other regions such as the ipsilateral subventricular zone (SVZi) where neural progenitor cells (NPCs) proliferation is enhanced in the mammalian and human brains. Magnetic resonance spectroscopy (MRS) provides metabolic information in vivo. With regard to NPCs proliferation, a resonance at 1.28 ppm has been described as an in vivo MRS biomarker of NPCs in the hippocampus of rats and humans. Continue reading In vivo MRS and ex vivo HRMAS in an Ischemic Rat Stroke Model→