Traumatic brain injury alterations in the functional connectome are associated with neuroinflammation but not tau in a P30IL tauopathy mouse model.

INTRODUCTION: Traumatic Brain Injury (TBI) is often associated with long-term cognitive deficits and altered brain networks which have been linked with accumulation of neurofibrillary tau tangles and neuroinflammation. In this work, we investigated the changes in the brain post-TBI in an Alzheimer's disease pR5 tauopathy model and evaluated the contribution of tauopathy and neuroinflammation to connectivity alterations using resting-state functional Magnetic Resonance Imaging (rs-fMRI). METHOD: 26 P301L tau transgenic mice of 8-9 months of age (21-35 g) expressing the human tau isoform carrying the pathogenic P301L mutation were used for the study. Animals were assessed at day 1 and 7 post-injury/craniotomy and were randomly divided into four groups. All animals underwent an MRI scan on a 9.4T Bruker system where rsfMRI was acquired. Following imaging, brains were stained with pSer (396 + 404), glial fibrillary acidic protein (GFAP), and ionised calcium-binding adaptor molecule-1 (Iba-1). Group-information-guided Independent Component Analysis (GIG-ICA) and region-of-interest (ROI)-based network connectivity approaches were applied. Principal Component Regression was applied to predict connectivity network strength from the corresponding ROIs. RESULTS: TBI mice showed decreased functional connectivity in the dentate gyrus, thalamus, and other areas compared to sham animals at day 1 post-injury with the majority of changes resolving at day 7. Principal Component Regression showed only the contralateral CA1 network strength was correlated with the CA1's astrocyte and microglia cell density and the ipsilateral thalamus network strength was correlated with the ipsilateral thalamus' astrocyte and microglia cell density. CONCLUSION: We present the first report on the temporal alterations in functional connectivity in a P30IL mouse model following TBI. Connectivity between key regions known to be affected in Alzheimer's disease were short-term and reversible following injury. Connectivity strength in CA1 and thalamus showed significant correlation with astrocyte and microglial cell density but not tau density.

Study of immediate neurological and autonomic changes during kapalbhati pranayama in yoga practitioners.

Background: Kapalbhati is a fast pace respiratory exercise or pranayam, which is supposed to be practiced by yogis to clean their brain. Pranayamas are well known to improve heart rate variability (HRV) ultimately leading to better autonomic functions. Other studies have observed the immediate effect of kapalbhati on various neurological (brain and spine) and autonomic functions, but their results are varied and inconclusive. Objective: The aim of this study is to find out the changes in HRV and brain waves during and after practice of kapalbhati as compared with the baseline values of different parameters. Methods: Various parameters were measured at baseline, during and after kapalbhati pranayam with the help of Dinamika HRV-Advanced HRV Test System, Moscow, Russia. Statistical analysis was accomplished employing repeated measures analysis of variance with Bonferroni post-hoc analysis and Holm's multiple comparisons using the Version 28.0.0.0 of the Statistical Package for the Social Sciences (SPSS) for Windows (190) SPSS Inc., Chicago. Results: We found that during and after kapalbhati, changes in HRV were significant in time and frequency domain showing parasympathetic withdrawal and insignificant changes in brain waves as compared with reference point values. Conclusion: Kapalbhati is initially energizing, cleansing, and heating. There occurs parasympathetic withdrawal and sympathetic activation during pranayama. There is an increase gamma wave activation post pranayama showing control of the default mode network.

Diffusion Tensor Imaging Detects Acute Pathology-Specific Changes in the P301L Tauopathy Mouse Model Following Traumatic Brain Injury.

Traumatic brain injury (TBI) has been linked with tauopathy. However, imaging methods that can non-invasively detect tau-protein abnormalities following TBI need further investigation. This study aimed to investigate the potential of diffusion tensor imaging (DTI) to detect tauopathy following TBI in P301L mutant-tau-transgenic-pR5-mice. A total of 24 9-month-old pR5 mice were randomly assigned to sham and TBI groups. Controlled cortical injuries/craniotomies were performed for TBI/sham groups followed by DTI data acquisition on days 1 and 7 post-injury. DTI data were analyzed by using voxelwise analysis and track-based spatial statistics for gray matter and white matter. Further, immunohistochemistry was performed for total-tau and phosphorylated-tau, astrocytes, and microglia. To detect the association of DTI with these pathological markers, a correlation analysis was performed between DTI and histology findings. At day 1 post-TBI, DTI revealed a widespread reduction in fractional anisotropy (FA) and axial diffusivity (AxD) in the TBI group compared to shams. On day 7, further reduction in FA, AxD, and mean diffusivity and increased radial diffusivity were observed. FA was significantly increased in the amygdala and cortex. Correlation results showed that in the ipsilateral hemisphere FA reduction was associated with increased phosphorylated-tau and glial-immunoreactivity, whereas in the contralateral regions, the FA increase was associated with increased immunostaining for astrocytes. This study is the first to exploit DTI to investigate the effect of TBI in tau-transgenic mice. We show that alterations in the DTI signal were associated with glial activity following TBI and would most likely reflect changes that co-occur with/without phosphorylated-tau. In addition, FA may be a promising measure to identify discrete pathological processes such as increased astroglia activation, tau-hyperphosphorylation or both in the brain following TBI.

Ultra-High-Field Diffusion Tensor Imaging Identifies Discrete Patterns of Concussive Injury in the Rodent Brain.

Although concussions can result in persistent neurological post-concussion symptoms, they are typically invisible on routine magnetic resonance imaging (MRI) scans. Our study aimed to investigate the use of ultra-high-field diffusion tensor imaging (UHF-DTI) in discerning severity-dependent microstructural changes in the mouse brain following a concussion. Twenty-three C57BL/6 mice were randomly allocated into three groups: the low concussive (LC, n = 9) injury group, the high concussive (HC, n = 6) injury group, and the sham control (SC, n = 7) group. Mice were perfused on day 2 post-injury, and the brains were scanned on a 16.4T MRI scanner with UHF-DTI and neurite orientation dispersion imaging (NODDI). Finite element analysis (FEA) was performed to determine the pattern and extent of the physical impact on the brain tissue. MRI findings were correlated with histopathological analysis in a subset of mice. In the LC group, increased fractional anisotropy (FA) and decreased orientation dispersion index (ODI) but limited neurite density index (NDI) changes were found in the gray matter, and minimal changes to white matter (WM) were observed. The HC group presented increased mean diffusivity (MD), decreased NDI, and decreased ODI in the WM and gray matter (GM); decreased FA was also found in a small area of the WM. WM changes were associated with WM degeneration and neuroinflammation. FEA showed varying region-dependent degrees of stress, in line with the different imaging findings. This study provides evidence that UHF-DTI combined with NODDI can detect concussions of variable intensities. This has significant implications for the diagnosis of concussion in humans.

Combined Diffusion Tensor Imaging and Quantitative Susceptibility Mapping Discern Discrete Facets of White Matter Pathology Post-injury in the Rodent Brain.

Early loss of white matter microstructure integrity is a significant cause of long-term neurological disorders following traumatic brain injury (TBI). White matter abnormalities typically involve axonal loss and demyelination. In-vivo imaging tools to detect and differentiate such microstructural changes are not well-explored. This work utilizes the conjoint potential offered by advanced magnetic resonance imaging techniques, including quantitative susceptibility mapping (QSM) and diffusion tensor imaging (DTI), to discern the underlying white matter pathology at specific time points (5 h, 1, 3, 7, 14, and 30 days) post-injury in the controlled cortical impact mouse model. A total of 42 animals were randomized into six TBI groups (n = 6 per group) and one sham group (n = 6). Histopathology was performed to validate in-vivo findings by performing myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) immunostaining for the assessment of changes to myelin and astrocytes. After 5 h of injury radial diffusivity (RD) was increased in white matter without a significant change in axial diffusivity (AxD) and susceptibility values. After 1 day post-injury RD was decreased. AxD and susceptibility changes were seen after 3 days post-injury. Susceptibility increases in white matter were observed in both ipsilateral and contralateral regions and persisted for 30 days. In histology, an increase in GFAP immunoreactivity was observed after 3 days post-injury and remained high for 30 days in both ipsilateral and contralateral white matter regions. A loss in MBP signal was noted after 3 days post-injury that continued up to 30 days. In conclusion, these results demonstrate the complementary ability of DTI and QSM in discerning the micro-pathological processes triggered following TBI. While DTI revealed acute and focal white matter changes, QSM mirrored the temporal demyelination in the white matter tracts and diffuse regions at the chronic state.

Evaluating spatiotemporal microstructural alterations following diffuse traumatic brain injury.

BACKGROUND: Diffuse traumatic brain injury (TBI) is known to lead to microstructural changes within both white and grey matter detected in vivo with diffusion tensor imaging (DTI). Numerous studies have shown alterations in fractional anisotropy (FA) and mean diffusivity (MD) within prominent white matter tracts, but few have linked these to changes within the grey matter with confirmation via histological assessment. This is especially important as alterations in the grey matter may be predictive of long-term functional deficits. METHODS: A total of 33 male Sprague Dawley rats underwent severe closed-head TBI. Eight animals underwent tensor-based morphometry (TBM) and DTI at baseline (pre-TBI), 24 hours (24 h), 7, 14, and 30 days post-TBI. Immunohistochemical analysis for the detection of ionised calcium-binding adaptor molecule 1 (IBA1) to assess microglia number and percentage of activated cells, ß-amyloid precursor protein (APP) as a marker of axonal injury, and myelin basic protein (MBP) to investigate myelination was performed at each time-point. RESULTS: DTI showed significant alterations in FA and RD in numerous white matter tracts including the corpus callosum, internal and external capsule, and optic tract and in the grey-matter in the cortex, thalamus, and hippocampus, with the most significant effects observed at 14 D post-TBI. TBM confirmed volumetric changes within the hippocampus and thalamus. Changes in DTI were in line with significant axonal injury noted at 24 h post-injury via immunohistochemical analysis of APP, with widespread microglial activation seen within prominent white matter tracts and the grey matter, which persisted to 30 D within the hippocampus and thalamus. Microstructural alterations in MBP+ve fibres were also noted within the hippocampus and thalamus, as well as the cortex. CONCLUSION: This study confirms the widespread effects of diffuse TBI on white matter tracts which could be detected via DTI and extends these findings to key grey matter regions, with a comprehensive investigation of the whole brain. In particular, the hippocampus and thalamus appear to be vulnerable to ongoing pathology post-TBI, with DTI able to detect these alterations supporting the clinical utility in evaluating these regions post-TBI.

Anti-B-cell Maturation Antigen Chimeric Antigen Receptor T cell Function against Multiple Myeloma Is Enhanced in the Presence of Lenalidomide.

Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T cells have shown promising clinical responses in patients with relapsed/refractory multiple myeloma. Lenalidomide, an immunomodulatory drug, potentiates T cell functionality, drives antimyeloma activity, and alters the suppressive microenvironment; these properties may effectively combine with anti-BCMA CAR T cells to enhance function. Using an anti-BCMA CAR T, we demonstrated that lenalidomide enhances CAR T cell function in a concentration-dependent manner. Lenalidomide increased CAR T effector cytokine production, particularly under low CAR stimulation or in the presence of inhibitory ligand programmed cell death 1 ligand 1. Notably, lenalidomide also enhanced CAR T cytokine production, cytolytic activity, and activation profile relative to untreated CAR T cells in chronic stimulation assays. This unique potentiation of both short-term CAR T activity and long-term functionality during chronic stimulation prompted investigation of the molecular profile of lenalidomide-treated CAR T cells. Signatures from RNA sequencing and assay for transposase-accessible chromatin using sequencing indicated that pathways associated with T-helper 1 response, cytokine production, T cell activation, cell-cycle control, and cytoskeletal remodeling were altered with lenalidomide. Finally, study of lenalidomide and anti-BCMA CAR T cells in a murine, disseminated, multiple myeloma model indicated that lenalidomide increased CAR T cell counts in blood and significantly prolonged animal survival. In summary, preclinical studies demonstrated that lenalidomide potentiated CAR T activity in vivo in low-antigen or suppressive environments and delayed onset of functional exhaustion. These results support further investigation of lenalidomide and anti-BCMA CAR T cells in the clinic.

Diffusion Magnetic Resonance Imaging Unveils the Spatiotemporal Microstructural Gray Matter Changes following Injury in the Rodent Brain.

Traumatic brain injury (TBI) is associated with gray and white matter alterations in brain tissue. Gray matter alterations are not yet as well studied as those of the white matter counterpart. This work utilized T2-weighted structural imaging, diffusion tensor imaging (DTI), and diffusion kurtosis imaging to unveil the gray matter changes induced in a controlled cortical impact (CCI) mouse model of TBI at 5 h, 1 day, 3 days, 7 days, 14 days, and 30 days post-CCI. A cross-sectional histopathology approach was used to confer validity of the magnetic resonance imaging (MRI) data by performing cresyl violet staining and glial fibrillary acidic protein (GFAP) immunohistochemistry. The results demonstrated a significant increase in lesion volume up to 3 days post-injury followed by a significant decrease in the cavity volume for the period of 1 month. GFAP signals peaked on Day 7 and persisted until Day 30 in both ipsilateral and contralateral hippocampus, ipsilateral cortex, and thalamic areas. An increase in fractional anisotropy (FA) was seen at Day 7 in the pericontusional area but decreased FA in the contralateral cortex, hippocampus, and thalamus. Mean diffusivity (MD) was significantly lower in the pericontusional cortex. Increased MD and decreased mean kurtosis were limited to the injury site on Days 7 to 30 and to the contralateral hippocampus and thalamus on Days 3 and 7. This work is one of the few cross-sectional studies to demonstrate a link between MRI measures and histopathological readings to track gray matter changes in the progression of TBI.

Effect of GLT-1 modulator and P2X7 antagonists alone and in combination in the kindling model of epilepsy in rats.

INTRODUCTION: Multiple lines of investigation have explored the role of glutamatergic and purinergic systems in epilepsy, related cognitive impairment, and oxidative stress. Glutamate transporters, particularly GLT-1 expression, were found to be decreased, and purinergic receptor, P2X7 expression, was found to be increased in brain tissue associated with epilepsy. The present study was carried out to investigate the effect of ceftriaxone (GLT-1 upregulator) and Brilliant Blue G (P2X7 antagonist) against PTZ-induced kindling in rats. The study was further extended to elucidate the cross-link between glutamatergic and purinergic pathways in epilepsy. MATERIAL AND METHODS: Systemic administration of subconvulsant dose of PTZ (30 mg/kg) every other day for 27days (14 injections) significantly increased the mean kindling, and developed generalized tonic-clonic seizures, and reduced motor co-ordination, cognitive skills, oxidative defense (increases lipid peroxidation, nitrite levels and decreases GSH level) and acetylcholinesterase enzyme activities in the cortex and subcortical region. Treatments with CEF (100 and 200mg/kg) and BBG (15 and 30 mg/kg) alone and in combination (CEF 100mg/kg and BBG 15 mg/kg) significantly decreased the mean kindling score and restored behavioral and oxidative defense activities compared with treatment with PTZ. CONCLUSIONS: The combination of both the drugs was shown to have better effect in preventing kindled seizures and a significantly synergistic effect compared with their effect alone in PTZ-kindled rats. The present study elucidated the mechanistic role of GLT-1 modulator and selective P2X7 antagonist and their combination against PTZ-induced kindling. The study for the first time demonstrated the cross-link between glutamatergic and purinergic pathways in epilepsy treatment.

GLT-1 transporter: an effective pharmacological target for various neurological disorders.

L-Glutamate is the predominant excitatory neurotransmitter in the central nervous system (CNS) and is directly and indirectly involved in a variety of brain functions. Glutamate is released in the synaptic cleft at a particular concentration that further activates the various glutaminergic receptors. This concentration of glutamate in the synapse is maintained by either glutamine synthetase or excitatory amino acid proteins which reuptake the excessive glutamate from the synapse and named as excitatory amino acid transporters (EAATs). Out of all the subtypes GLT-1 (glutamate transporter 1) is abundantly distributed in the CNS. Down-regulation of GLT-1 is reported in various neurological diseases such as, epilepsy, stroke, Alzheimer's disease and movement disorders. Therefore, positive modulators of GLT-1 which up-regulate the GLT-1 expression can serve as a potential target for the treatment of neurological disorders. GLT-1 translational activators such as ceftriaxone are found to have significant protective effects in ALS and epilepsy animal models, suggesting that this translational activation approach works well in rodents and that these compounds are worth further pursuit for various neurological disorders. This drug is currently in human clinical trials for ALS. In addition, a thorough understanding of the mechanisms underlying translational regulation of GLT-1, such as identifying the molecular targets of the compounds, signaling pathways involved in the regulation, and translational activation processes, is very important for this novel drug-development effort. This review mainly emphasizes the role of glutamate and its transporter, GLT-1 subtype in excitotoxicity. Further, recent reports on GLT-1 transporters for the treatment of various neurological diseases, including a summary of the presumed physiologic mechanisms behind the pharmacology of these disorders are also explained.

A cell-based high-throughput screening assay for posttranscriptional utrophin upregulation.

Duchenne muscular dystrophy (DMD) is a devastating muscle-wasting disease caused by mutations in the dystrophin gene. Utrophin is a homologue of dystrophin that can compensate for its absence when overexpressed in DMD animal models. Utrophin upregulation is therefore a promising therapeutic approach for DMD. Utrophin is regulated at both transcriptional and posttranscriptional levels. Transcriptional regulation has been studied extensively, and assays have been described for the identification of utrophin promoter-targeting molecules. However, despite the profound impact that posttranscriptional regulation has on utrophin expression, screening assays have not yet been described that could be used to discover pharmaceuticals targeting this key phase of regulation. We describe the development and validation of a muscle cell line-based assay in which a stably expressed luciferase coding sequence is flanked by the utrophin 5'- and 3'-untranslated regions (UTRs). The assay was validated using the posttranscriptional regulation of utrophin by miR-206. The assay has a Z' of 0.7, indicating robust performance in high-throughput format. This assay can be used to study utrophin regulatory mechanisms or to screen chemical libraries for compounds that upregulate utrophin posttranscriptionally via its UTRs. Compounds identified via this assay, used alone or in a synergistic combination with utrophin promoter-targeting molecules, would be predicted to have therapeutic potential for DMD.

High AU content: a signature of upregulated miRNA in cardiac diseases.

MicroRNAs have been implicated for the regulation of gene expression. These miRNA are a class of single stranded non coding RNAs, formed from endogenous transcripts and measure typically about 19-25 nucleotides in length. They are important regulators of the various biological and metabolic functions taking place in humans. Many miRNAs show tissue specific expression. Human heart is a complex organ which during various diseased and developed conditions shows differential expression of miRNA. Here, we overview the recent findings on miRNA in cardiac diseases and report the presence of high AU content in differentially expressed miRNA in developed and diseased condition of heart as compared to all the miRNA present in the human. A total of 905 human miRNA sequences taken from miRBase were computationally analyzed. Trend analysis was performed to study the influence of positional frequency of the nucleotides. This study will help us in understanding the significance of AU rich elements in miRNA during the development of cardiac diseases.

Recurrent acute interstitial nephritis induced by azithromycin.

A 14-year-old girl is reported with recurrent, azithromycin-induced, acute interstitial nephritis. The second episode was more severe than the first; and although both were treated with intensive corticosteroid therapy, renal function remained impaired. Although most cases of antibiotic induced acute interstitial nephritis are benign and self-limited, some patients are at risk for permanent renal injury.