<div><b>Rationale:</b> Focal cortical dysplasia (FCD) is a neurodevelopmental disorder that is associated with abnormal cortical development and is one of the most common drug-resistant epilepsies. The mechanistic target of rapamycin (mTOR) pathway is a highly complex pathway </div><div>associated with cell proliferation, synaptic plasticity, neuroinflammation, and cortical development. Hyperactivation of this pathway has also been implicated in hyperexcitability, seizures, and accumulation of beta-amyloid (Aβ) plaques and neurofibrillary tangles (NFT) through hyperphosphorylation of tau. Interestingly, Aβ and hyperphosphorylated tau have been reported in both rodent models and human patients of temporal lobe epilepsy (TLE) and FCD however, the mechanisms through which this occurs are still yet to be defined. Therefore, to identify the possible link between Aβ and tau pathology in FCD, we determined the spatial distribution and protein levels of Aβ and phosphorylated tau (p-tau) along with mTOR signaling </div><div>molecules. We hypothesized that there would be presence of Aβ and tau pathology as well as an increase in Aβ and p-tau protein levels that would be correlated with hyperactivation of the mTOR and GSK3 signaling pathways in tissue biopsies from human FCD patients compared to brain tissues from non-epileptic (NE) individuals.</div><div><br></div><div><b>Methods:</b> Cortical brain samples surgically resected from patients with FCD were used and compared to NE samples surgically resected from glioblastoma patients with no history of seizures or epilepsy. Immunostaining was used to determine the distribution of phosphorylation of S6 (p-S6), a marker for mTOR activation, and NeuN, a marker for neurons, along with Aβ and p-tau. Additionally, western blotting (WB) was used to determine the levels of mTOR signaling through p-S6 and GSK3 (p-GSK) along with Aβ and p-tau.</div><div><br></div><div><b>Results:</b> We found cortical dyslamination, mTOR activation, p-tau, and Aβ accumulation in cortices of patients with FCD with drug-resistant epilepsy. However, we did not find a </div><div>significant difference in the protein levels of p-S6 (p = 0.422), p-GSK3 (p = 0.947), p-tau (p = 0.649), and Aβ (p = 0.852) in cortical tissue homogenates derived from FCD patients when compared to those of NE samples. Additionally, we did not find sex differences in the protein </div><div>levels of p-S6 (p = 0.401), p-GSK3 (p = 0.331), p-tau (p = 0.935), and Aβ (p = 0.526). There was no significant correlation between age and p-S6 (p = 0.920), age and p-GSK3 (p = 0.089), age and p-tau (p = 0.956), and age and Aβ (p = 0.889). Moreover, there was no significant correlation between mTOR activation (p-S6), Aβ (p = 0.586) and p-tau (p = 0.059) nor GSK3 activation (p-GSK3), Aβ (p = 0.326), and p-tau (p = 0.715). Lastly, there was no significant correlation within the mTOR and GSK3 pathway activation within the same patients (p = 0.602).</div><div><br></div><div><b>Conclusion:</b> These data suggest that mTOR hyperactivation occurs alongside the presence of Aβ and tau pathology. However, several unknown factors such as medical and medication history may be altering the expression or suppression of these proteins. Additionally, there may be alternative pathways that crosstalk with mTOR signaling therefore influencing Aβ and tau pathology in FCD patients with drug-resistant epilepsy. Further investigation will need to be conducted to understand the detailed mechanisms through which Aβ and tau pathology occur in </div><div>FCD.</div>

No description available.

BACKGROUND: The ultrasonic vibrations from the piezoelectric knife may amplify the natural response to surgical injury. This may lead to different clinical and biological outcomes when using the piezoelectric knife versus a surgical bur to create selective cortical penetrations for alveolar ridge augmentation surgeries. The first aim of this study was to analyze the differences in bone graft healing when selective cortical penetrations are created with a surgical bur and with a piezoelectric knife. The second aim of this pilot study was to see if enhanced new bone formation during bone regeneration procedures can be achieved with the use of a piezoelectric knife versus the conventional bur or onlay grafting techniques utilizing deep learning, a subset of machine learning. MATERIALS & METHODS: he project was approved by the Boston University Medical Center Institutional Animal Care and Use Committee (IACUC). Twenty, 9-10 week male Sprague Dawley rats, weighing approximately 300g, were used in this study. The rats were randomly divided into three groups: Xenograft, Alloplast, and Collagen. These groups were further divided by surgical technique: Bur, Piezo, and Onlay. For the Bur and Piezo groups, four equally-spaced selective cortical penetrations were made prior to bone graft stabilization. Three rats served as controls (Control group). Microcomputed tomography scans (µCT) were acquired for each sample, containing approximately 1,000 slices of data each. After 28 days of healing the volumes of and density of the newly formed bone were extracted and analyzed for each group. This was achieved with an innovative deep learning algorithm designed for multi-level segmentation and regional feature detection utilizing convolutional neural networks (CNN). RESULTS: Microcomputed tomography (µCT) of our samples yielded very localized, high-resolution scans of our surgical samples. The innovative deep learning algorithm was able to reliably produce highly accurate, unbiased segmentations of our samples. This study demonstrated that new bone formation was possible with all nine of the tested surgical techniques, however the differences were not statistically significant. Selective cortical penetrations with a piezoelectric knife (PIEZO) resulted in significantly more “cortical-like” new bone formation at 28 days. CONCLUSION: Within the limitations of this preliminary study, it is possible to conclude that the piezoelectric knife is a valid alternative to conventional carbide burs when making selective cortical penetrations prior to bone grafting surgery. Additionally, our deep learning algorithm successfully segmented thousands of slices of data and allowed for the calculation of porosity and new bone volume in our samples.

While physical rehabilitation facilitates some recovery, it is uncommon for patients to recover completely from stroke. Cell based therapies derived from stem cells have produced promising results in enhancing recovery in pre-clinical studies, but the mechanism is not yet completely understood. We previously evaluated human umbilical tissue-derived cells (hUTC) in our non-human primate model of cortical injury, limited to the hand area of primary motor cortex. hUTC treatment, injected intravenously 24 hours after injury, resulted in significantly greater recovery of fine motor function compared to treatment with vehicle. Based on these striking findings, in the current study, we investigated the hypothesis that hUTC treatment leads to functional recovery through reducing cytotoxic responses and enhancing neurorestorative processes following cortical injury. Brain sections were assessed using histological techniques to quantify perilesional oxidative damage, hemosiderin accumulation, microglial activation, Betz cell number, synaptic density, and astrocytic complexity. Brain sections outside of the primary area of injury were also assessed for microglial activation in white matter pathways, cell activation through c-Fos in premotor cortices, and neurogenesis in neurogenic niches. Finally, blood samples from throughout the recovery period and CSF samples from 16 weeks after injury were analyzed for BDNF levels. In the perilesional area, hUTC treatment was associated with lower oxidative damage and hemosiderin accumulation, but not with a difference in microglial activation. hUTC also resulted in a trend toward higher astrocyte complexity and synaptic density in the lesion area, but no difference in ipsilesional Betz cell number. Further, hUTC treatment led to more microglia in white matter pathways, higher c-Fos activation in ventral premotor cortex, and a trend toward higher neurogenesis in the hippocampus. Finally, BDNF levels were higher in blood with hUTC treatment one week after injury, but there was no change beyond one week in blood serum or in CSF, when compared with vehicle. Taken together, these results suggest that hUTC treatment modulates immune responses, limits perilesional damage and cell death, enables neuroplasticity and reorganization, and enhances acute neurotrophic factor secretion. While many cell therapies are currently undergoing clinical trials, this study advances our understanding of the mechanism of cell based therapies.

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第21218号 / 情博第671号 / 新制||情||116(附属図書館) / 京都大学大学院情報学研究科通信情報システム専攻 / (主査)教授 佐藤 亨, 教授 山本 衛, 教授 松田 哲也 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

Fundamental to mammalian brain development is the integration of cell intrinsic and extrinsic signals that direct the proliferation and differentiation of neural stem cells. Precise expression of transcription factors together with other intracellular components instruct progenitor cell fate, whereas interaction with extracellular signaling factors refines this process. We have elucidated the composition of the cerebrospinal fluid that is the source of multiple extrinsic cues during brain development. The choroid plexus, a highly vascularized tissue located in each ventricle of the brain, actively secretes cerebrospinal fluid. By RNA sequencing, we obtained transcriptome data on the choroid plexi from lateral and fourth ventricles of the mouse brain and discovered that they include transcripts unique to each tissue. Transcription factor expression in the macaque and human choroid plexi suggests that positional identities of these tissues are conserved in the primate brain. Based on transcriptional results, we defined the choroid plexus secretome, a prediction of secreted factors from the choroid plexus. By quantitative mass spectrometry, we detected proteins secreted by each choroid plexus, and comparison of these proteomic results with transcriptional profiling suggests that choroid plexus transcriptomes contribute to availability of regionalized cerebrospinal fluid factors during development. In the second part of my dissertation research, I studied the role of DNA repair mechanisms in regulating neural stem cells. These studies focused on DNA LigaseIV, an essential component of DNA double-stranded break repair, during cerebral cortical development. Deficiency of LigaseIV activity caused by a missense mutation leads to LigaseIV syndrome, in which a key clinical feature is microcephaly. Using the Lig4 R278H mouse mutant, we found increased cell death in the developing cortex, contributing to reduced cortical thickness and cellularity in the anterior cerebral cortex. These results indicate that DNA LigaseIV is essential for proper cortical development. Together, these findings illustrate the complexity of regulatory mechanisms that guide brain development, requiring the integration of mechanisms from within and outside the cell. We have investigated two such mechanisms, extrinsic cues from regionalized cerebrospinal fluid and DNA LigaseIV. These results should provide greater insight into mechanisms of normal brain development and neuropathological states. / 2017-11-02T00:00:00Z

No description available.

The Lateral Prefrontal Cortex (LPFC) and the Dorsal Premotor cortex (PMd) are two cortical structures that are involved in cognitive processes such as motor planning and decision-making. The LPFC is extensively connected to sensory, somatosensory, and motor cortices that help it control several cognitive functions [for review, see: (Tanji & Hoshi, 2008)]. Similarly, the PMd can integrate information from the prefrontal and motor cortex, acting as a link, in action planning and decision making [for review, see: (Hoshi & Tanji, 2007)]. Therefore, it is important to study the cortical pathways between these areas because of their common role in processing and selecting relevant information in tasks requiring decision-making. Using neural tract-tracing, immunolabeling and microscopy in rhesus monkeys (M. mulatta), we assessed the distribution and layer-specific organization of projection neurons from LPFC area 46 and PMd area 6 directed to the LPFC area 9. Our study revealed that projection neurons to area 9 were found originating from upper (L2-3) and deep (L5-6) layers of both areas, but with a slight upper layer bias. We found that the LPFC area 46 had a higher density of projection neurons directed to LPFC area 9 compared to the PMd area 6. Additionally, our data also revealed laminar differences in the perisomatic parvalbumin (PV) inhibitory inputs onto area 9 projection neurons, which were dependent on area of origin. Within ventral LPFC area 46, perisomatic PV+ inhibitory inputs onto upper layer projection neurons to area 9 was greater than those onto deep layer projection neurons. The opposite pattern was found for PMd area 6DR, where perisomatic PV+ inhibition onto deep layer projection neurons to area 9 was greater than those onto upper layer neurons. These findings provide additional insights into the layer-specific organization of prefrontal and premotor pathways that play an important role in action planning and decision-making.

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality around the world. It has multiple causative factors including sports injuries, vehicular accidents, war, and other forms of trauma. Though patients can recover, it has the potential to cause mild to severe persistent cognitive deficits. Medical treatment involves treating individual problems as they arise; this treatment is based upon clinical signs. Developing a standard of care for TBI is complex due to the difficulty in finding common cell and molecular changes in TBI variants that can be prevented or ameliorated. Tumor necrosis factor (TNF) is a prominent inflammatory cytokine present in all forms of traumatic brain injury. It is the target of multiple therapies in other disease processes. As TNF inhibitors lead to billions of dollars in worldwide sales, their use in neuropathologies is an active research area. XPro1595, a preclinical drug developed by Xencor, uniquely inhibits more than 99% of soluble TNF. However, there is only one published study to date on the effects of XPro1595 in any model of traumatic brain injury. The purpose of this study was to characterize the presence of TNF and the proinflammatory TNFR1 pathway in a controlled cortical impact (CCI) mouse model of TBI and to determine if XPro1595 could improve behavioral and neuropathological outcomes. TNF and the TNFR1 pathway have shown to be chronically present in a CCI mouse model for at least two weeks. Injured animals treated with one course of the drug did not show any improvements in spatial learning or memory. However, decreased activity in the TNFR1 pathway and changes in glial markers indicated that XPro1595 lessened neuroinflammation via this mechanism. This study suggests potential benefits of XPro1595 in TBI that could lead to a common standard of care.

No description available.