Participation of bone marrow-derived cells in hippocampal vascularization after status epilepticus

Purpose: Diseases such as temporal lobe epilepsy, brain trauma and stroke can induce endothelial cell proliferation and angiogenesis in specific brain areas. During status epilepticus (SE), bone marrow-derived cells are able to infiltrate and proliferate, dramatically increasing at the site of injury. However, it is still unclear whether these cells directly participate in vascular changes induced by SE.Method: To investigate the possible role of bone marrow-derived cells in angiogenesis after seizures, we induced SE by pilocarpine injection in previously prepared chimeric mice. Mice were euthanized at 8 h, 7 d or 15 d after SE onset.Results: Our results indicated that SE modified hippocampal vascularization and induced angiogenesis. Further, bone marrow-derived GFP(+) cells penetrated through the parenchyma and participated in the formation of new vessels after SE. We detected bone marrow-derived cells closely associated with vessels in the hippocampus, increasing the density of blood vessels that had decreased immediately after pilocarpine-induced SE.Conclusion: We conclude that epileptic seizures directly affect vascularization in the hippocampus mediated by bone marrow-derived cells in a time-dependent manner. (C) 2014 British Epilepsy Association. Published by Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilWeb of Scienc

Effect of postnatal intermittent hypoxia on locomotor activity and neuronal development in rats tested in early adulthood

The present study evaluated the effects of postnatal intermittent hypoxia on locomotor activity and neuronal cell survival in early adulthood rats. During a critical period of brain development on postnatal day (PD) 7-11, male rat pups were exposed to intermittent hypoxia and randomly assigned to three experimental groups: (1) intermittent hypoxia, (2) normoxia, and (3) control (unhandled). One and a half months later on PD56, a behavioral test was conducted, and cell survival was estimated in the hilus, dental gyrus, and CA1 and CA3 subfields of the hippocampus, nucleus accumbens shell and core, dorsal and ventral striatum, and prefrontal cortex. Our results showed that intermittent hypoxia produced hyperactivity that correlated well with psychomotor agitation observed in patients with schizophrenia. Moreover, post-hypoxic rats exhibited a reduction of the number of neurons in the hilar region of the hippocampus and dorsal striatum, structures that have been neuropathologically associated with schizophrenia.These findings suggest that intermittent hypoxia can modify the pattern of locomotor activity and selectively affect neurons in rats tested in early adulthood.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Anticonvulsant activity of bone marrow cells in electroconvulsive seizures in mice

Background: Bone marrow is an accessible source of progenitor cells, which have been investigated as treatment for neurological diseases in a number of clinical trials. Here we evaluated the potential benefit of bone marrow cells in protecting against convulsive seizures induced by maximum electroconvulsive shock (MES), a widely used model for screening of anti-epileptic drugs. Behavioral and inflammatory responses were measured after MES induction in order to verify the effects promoted by transplantation of bone marrow cells. To assess the anticonvulsant effects of bone marrow cell transplantation, we measured the frequency and duration of tonic seizure, the mortality rate, the microglial expression and the blood levels of cytokine IL-1, IL-6, IL-10 and TNF-alpha after MES induction. We hypothesized that these behavioral and inflammatory responses to a strong stimulus such as a convulsive seizure could be modified by the transplantation of bone marrow cells.Results: Bone marrow transplanted cells altered the convulsive threshold and showed anticonvulsant effect by protecting from tonic seizures. Bone marrow cells modified the microglial expression in the analyzed brain areas, increased the IL-10 and attenuate IL-6 levels.Conclusions: Bone marrow cells exert protective effects by blocking the course of electroconvulsive seizures. Additionally, electroconvulsive seizures induced acute inflammatory responses by altering the pattern of microglia expression, as well as in IL-6 and IL-10 levels. Our findings also indicated that the anticonvulsant effects of these cells can be tested with the MES model following the same paradigm used for drug testing in pharmacological screening. Studies on the inflammatory reaction in response to acute seizures in the presence of transplanted bone marrow cells might open a wide range of discussions on the mechanisms relevant to the pathophysiology of epilepsies.Associacao Beneficente de Coleta de Sangue da Fundacao de Apoio a Pesquisa- UNIFESP (FAP-Colsan)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, UNIFESP, Dept Fisiol, Lab Neurofisiol, BR-04023066 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Imunol, Dept Microimunoparasitol, São Paulo, BrazilFundacao Oswaldo Cruz, Ctr Pesquisas Goncalo Moniz, Salvador, BA, BrazilHosp Sao Rafael, Ctr Biotecnol & Terapia Celular, Salvador, BA, BrazilUniversidade Federal de São Paulo, UNIFESP, Dept Fisiol, Lab Neurofisiol, BR-04023066 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Imunol, Dept Microimunoparasitol, São Paulo, BrazilWeb of Scienc

Long-lasting anxiolytic effect of neural precursor cells freshly prepared but not neurosphere-derived cell transplantation in newborn rats

Background: the GABAergic system plays an important role in modulating levels of anxiety. When transplanted into the brain, precursor cells from the medial ganglionic eminence (MGE) have the ability to differentiate into GABAergic interneurons and modify the inhibitory tone in the host brain. Currently, two methods have been reported for obtaining MGE precursor cells for transplantation: fresh and neurosphere dissociated cells. Here, we investigated the effects generated by transplantation of the two types of cell preparations on anxiety behavior in rats.Results: We transplanted freshly dissociated or neurosphere dissociated cells into the neonate brain of male rats on postnatal (PN) day 2-3. At early adulthood (PN 62-63), transplanted animals were tested in the Elevated Plus Maze (EPM). To verify the differentiation and migration pattern of the transplanted cells in vitro and in vivo, we performed immunohistochemistry for GFP and several interneuron-specific markers: neuropeptide Y (NPY), parvalbumin (PV) and calretinin (CR). Cells from both types of preparations expressed these interneuronal markers. However, an anxiolytic effect on behavior in the EPM was observed in animals that received the MGE-derived freshly dissociated cells but not in those that received the neurosphere dissociated cells.Conclusion: Our results suggest a long-lasting anxiolytic effect of transplanted freshly dissociated cells that reinforces the inhibitory function of the GABAergic neuronal circuitry in the hippocampus related to anxiety-like behavior in rats.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Fisiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Farmacol, BR-04023062 São Paulo, BrazilUNIFESP, Dept Biociencias, BR-11015020 Santos, SP, BrazilUniv Fed Rio Grande do Sul, Inst Ciencias Basicas Saude, Dept Bioquim, BR-90035003 Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Dept Fisiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Farmacol, BR-04023062 São Paulo, BrazilUNIFESP, Dept Biociencias, BR-11015020 Santos, SP, BrazilWeb of Scienc

Long-lasting anxiolytic effect of neural precursor cells freshly prepared but not neurosphere-derived cell transplantation in newborn rats

Background: The GABAergic system plays an important role in modulating levels of anxiety. When transplanted into the brain, precursor cells from the medial ganglionic eminence (MGE) have the ability to differentiate into GABAergic interneurons and modify the inhibitory tone in the host brain. Currently, two methods have been reported for obtaining MGE precursor cells for transplantation: fresh and neurosphere dissociated cells. Here, we investigated the effects generated by transplantation of the two types of cell preparations on anxiety behavior in rats. Results: We transplanted freshly dissociated or neurosphere dissociated cells into the neonate brain of male rats on postnatal (PN) day 2–3. At early adulthood (PN 62–63), transplanted animals were tested in the Elevated Plus Maze (EPM). To verify the differentiation and migration pattern of the transplanted cells in vitro and in vivo, we performed immunohistochemistry for GFP and several interneuron-specific markers: neuropeptide Y (NPY), parvalbumin (PV) and calretinin (CR). Cells from both types of preparations expressed these interneuronal markers. However, an anxiolytic effect on behavior in the EPM was observed in animals that received the MGE-derived freshly dissociated cells but not in those that received the neurosphere dissociated cells. Conclusion: Our results suggest a long-lasting anxiolytic effect of transplanted freshly dissociated cells that reinforces the inhibitory function of the GABAergic neuronal circuitry in the hippocampus related to anxiety-like behavior in rats

Therapeutic effects of the transplantation of VEGF overexpressing bone marrow mesenchymal stem cells in the hippocampus of murine model of Alzheimer's disease

Alzheimer's disease (AD) is clinically characterized by progressive memory loss, behavioral and learning dysfunction and cognitive deficits, such as alterations in social interactions. the major pathological features of AD are the formation of senile plaques and neurofibrillary tangles together with neuronal and vascular damage. the double transgenic mouse model of AD (2xTg-AD) with the APPswe/PS1dE9 mutations shows characteristics that are similar to those observed in AD patients, including social memory impairment, senile plaque formation and vascular deficits. Mesenchymal stem cells (MSCs), when transplanted into the brain, produce positive effects by reducing amyloid-beta (AN deposition in transgenic amyloid precursor protein (APP)/presenilins1 (PS1) mice. Vascular endothelial growth factor (VEGF), exhibits neuroprotective effects against the excitotoxicity implicated in the AD neurodegeneration. the present study investigates the effects of MSCs overexpressing VEGF in hippocampal neovascularization, cognitive dysfunction and senile plaques present in 2xTg-AD transgenic mice. MSC were transfected with vascular endothelial growth factor cloned in uP vector under control of modified CMV promoter (uP-VEGF) vector, by electroporation and expanded at the 14th passage. 2xTg-AD animals at 6, 9 and 12 months old were transplanted with MSC-VEGF or MSC. the animals were tested for behavioral tasks to access locomotion, novelty exploration, learning and memory, and their brains were analyzed by immunohistochemistry (IHC) for vascularization and A(3 plaques. MSC-VEGF treatment favored the neovascularization and diminished senile plaques in hippocampal specific layers. Consequently, the treatment was able to provide behavioral benefits and reduce cognitive deficits by recovering the innate interest to novelty and counteracting memory deficits present in these AD transgenic animals. Therefore, this study has important therapeutic implications for the vascular damage in the neurodegeneration promoted by AD.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Depto Fisiol, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, Depto Fisiol, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Neuroprotective effects of resistance physical exercise on the APP/PS1 mouse model of Alzheimer’s disease

IntroductionPhysical exercise has beneficial effects by providing neuroprotective and anti-inflammatory responses to AD. Most studies, however, have been conducted with aerobic exercises, and few have investigated the effects of other modalities that also show positive effects on AD, such as resistance exercise (RE). In addition to its benefits in developing muscle strength, balance and muscular endurance favoring improvements in the quality of life of the elderly, RE reduces amyloid load and local inflammation, promotes memory and cognitive improvements, and protects the cortex and hippocampus from the degeneration that occurs in AD. Similar to AD patients, double-transgenic APPswe/PS1dE9 (APP/PS1) mice exhibit Αβ plaques in the cortex and hippocampus, hyperlocomotion, memory deficits, and exacerbated inflammatory response. Therefore, the aim of this study was to investigate the effects of 4 weeks of RE intermittent training on the prevention and recovery from these AD-related neuropathological conditions in APP/PS1 mice.MethodsFor this purpose, 6-7-month-old male APP/PS1 transgenic mice and their littermates, negative for the mutations (CTRL), were distributed into three groups: CTRL, APP/PS1, APP/PS1+RE. RE training lasted four weeks and, at the end of the program, the animals were tested in the open field test for locomotor activity and in the object recognition test for recognition memory evaluation. The brains were collected for immunohistochemical analysis of Aβ plaques and microglia, and blood was collected for plasma corticosterone by ELISA assay.ResultsAPP/PS1 transgenic sedentary mice showed increased hippocampal Aβ plaques and higher plasma corticosterone levels, as well as hyperlocomotion and reduced central crossings in the open field test, compared to APP/PS1 exercised and control animals. The intermittent program of RE was able to recover the behavioral, corticosterone and Aβ alterations to the CTRL levels. In addition, the RE protocol increased the number of microglial cells in the hippocampus of APP/PS1 mice. Despite these alterations, no memory impairment was observed in APP/PS1 mice in the novel object recognition test.DiscussionAltogether, the present results suggest that RE plays a role in alleviating AD symptoms, and highlight the beneficial effects of RE training as a complementary treatment for AD