Mouse models of neurodegenerative disease: preclinical imaging and neurovascular component.

Neurodegenerative diseases represent great challenges for basic science and clinical medicine because of their prevalence, pathologies, lack of mechanism-based treatments, and impacts on individuals. Translational research might contribute to the study of neurodegenerative diseases. The mouse has become a key model for studying disease mechanisms that might recapitulate in part some aspects of the corresponding human diseases. Neurode- generative disorders are very complicated and multifacto- rial. This has to be taken in account when testing drugs. Most of the drugs screening in mice are very di cult to be interpretated and often useless. Mouse models could be condiderated a ‘pathway models’, rather than as models for the whole complicated construct that makes a human disease. Non-invasive in vivo imaging in mice has gained increasing interest in preclinical research in the last years thanks to the availability of high-resolution single-photon emission computed tomography (SPECT), positron emission tomography (PET), high eld Magnetic resonance, Optical Imaging scanners and of highly speci c contrast agents. Behavioral test are useful tool to characterize di erent ani- mal models of neurodegenerative pathology. Furthermore, many authors have observed vascular pathological features associated to the di erent neurodegenerative disorders. Aim of this review is to focus on the di erent existing animal models of neurodegenerative disorders, describe behavioral tests and preclinical imaging techniques used for diagnose and describe the vascular pathological features associated to these diseases

The Effect of Estrogen on Bone Marrow-Derived Rat Mesenchymal Stem Cell Maintenance: Inhibiting Apoptosis Through the Expression of Bcl-x L and Bcl-2

Mesenchymal Stem Cells (MSCs) have high therapeutic value for regenerative medicine and tissue engineering due to their differentiation potential and non-immunogenic characteristics. They are also considered as an effective in vivo delivery agent because of their ability to migrate to the site of injury. A major roadblock in their use for cell-based therapies is their rareness in vivo. Therefore, it is important to obtain increased number of functional MSCs in vitro in order to have adequate numbers for therapeutic regiments. We aimed to investigate the role of estrogen and its mechanism in obtaining more MSCs. MSCs were isolated from female and ovariectomized rats and cultured in the presence and absence of 10 -7 M estrogen. In the presence of estrogen, not only their CFU-F activity increased but also apoptotic rate decreased as shown by TUNEL staining leading to obtain more MSCs. Also the number of the cells in the colonies increased upon estrogen treatment. To reveal the mechanism of this effect, we focused on Bcl-2 family of proteins. Our immunoblotting experiments combined with knockdown studies suggested a critical role for anti-apoptotic Bcl-x L and Bcl-2. Estrogen treatment up regulated the expression Bcl-x L and Bcl-2. When we knocked down the expression of bcl-x L and bcl-2, MSCs lacking these genes showed an increase in the apoptotic rate in contrast to normal MSCs following estrogen treatment. Therefore, estrogen treatment will be of great advantage for cell-based therapies in order to get more functional MSCs and may provide opportunities to develop new strategies for debilitating diseases. © 2011 Springer Science+Business Media, LLC

Timing of induction of cardiomyocyte differentiation for in vitro cultured mesenchymal stem cells: A perspective for emergencies

Mesenchymal stem cells (MSCs) have the capacity to differentiate into osteoblasts, chondrocytes, adipocytes, myocytes, and cardiomyocytes. Several established methods are presently available for in vitro isolation of MSCs from bone marrow. However, the duration necessary to culture them can be a major handicap to cell-based therapies needed for such urgent cardiovascular conditions as acute myocardial infarction and acute hindlimb ischemia. The best timing of car- diomyocyte differentiation induction after MCS isolation and expansion is still an unresolved issue. Our goal was to investigate the possibility of obtaining functional cardiomyocytes from rat MSC within a shorter time period. We examined MSCs' colony-forming capacity, CD90 and CD34 immunoreactivity during the 14 days of culturing. Cardiomyocyte differentiation was induced by 5-azacytidine. Immunohistochemic staining, together with intracellular Ca2+ measurement experiments, revealed that MSCs do not differentiate into any specific cell lineage but show the characteristics of MSCs on both the 9th and 14th days of the culture. To check the potential for differentiation into cardiomyocytes, experiments with caffeine application and depolarization with KCl were performed. The cells possessed some of the specific biochemical features of contracting cells, with slightly higher capacities on the 14th day. Cells from 9th and 14th days of the culture that were treated with 5-azacytidine had a higher expression of cardiac-specific markers such as troponin I, α-sarcomeric actin, and MEF2D compared with the control groups. This study illustrates that it is possible to get functional cardiomyocytes from in vitro MSC culture in a shorter time period than previously achieved. This reduction in time may provide emergency cases with access to cell-based therapies that may have previously been unavailable