Healthy Human Brain Tissue Research Articles

Spatiotemporal expression and coexpression patterns of SRPK1 in the human brain: A neurodevelopmental perspective.

SRPK1 is a splicing-related protein that plays an important role in the development and function of the human brain. This article presents evidence that SRPK1 has distinct spatiotemporal expression patterns enriched in processes related to neurodevelopmental disorders across development. We used the BrainSpan growing mammalian brain transcriptome to evaluate the distribution of SRPK1 throughout the entire brain. RNA-sequencing data were gathered from 524 tissue samples recovered from 41 postmortem brains of physiologically normal individuals spanning early developing fetus (8 postconception weeks, PCW) to later life (40 years of age). Using the Allen Human Brain Atlas (AHBA) dataset, we analyzed the spatial gene expression of 15 adult human brains. Using Toppgene, we identified genes that exhibit significant coexpression with SRPK1. We found evidence that analyzing the spatiotemporal gene expression profile and identifying coexpressed genes reveals that SRPK1 expression is involved in various neurodevelopmental and somatic events throughout the lifetime. Our findings highlight the importance of detailed maps of gene expression in the human brain for improved human-to-human translation and illustrate differences in SRPK1 expression across anatomical areas and developmental stages in healthy human brain tissue.

Different Approaches for the Profiling of Cancer Pathway-Related Genes in Glioblastoma Cells.

Deregulation of signalling pathways that regulate cell growth, survival, metabolism, and migration can frequently lead to the progression of cancer. Brain tumours are a large group of malignancies characterised by inter- and intratumoral heterogeneity, with glioblastoma (GBM) being the most aggressive and fatal. The present study aimed to characterise the expression of cancer pathway-related genes (n = 84) in glial tumour cell lines (A172, SW1088, and T98G). The transcriptomic data obtained by the qRT-PCR method were compared to different control groups, and the most appropriate control for subsequent interpretation of the obtained results was chosen. We analysed three widely used control groups (non-glioma cells) in glioblastoma research: Human Dermal Fibroblasts (HDFa), Normal Human Astrocytes (NHA), and commercially available mRNAs extracted from healthy human brain tissues (hRNA). The gene expression profiles of individual glioblastoma cell lines may vary due to the selection of a different control group to correlate with. Moreover, we present the original multicriterial decision making (MCDM) for the possible characterization of gene expression profiles. We observed deregulation of 75 genes out of 78 tested in the A172 cell line, while T98G and SW1088 cells exhibited changes in 72 genes. By comparing the delta cycle threshold value of the tumour groups to the mean value of the three controls, only changes in the expression of 26 genes belonging to the following pathways were identified: angiogenesis FGF2; apoptosis APAF1, CFLAR, XIAP; cellular senescence BM1, ETS2, IGFBP5, IGFBP7, SOD1, TBX2; DNA damage and repair ERCC5, PPP1R15A; epithelial to mesenchymal transition SNAI3, SOX10; hypoxia ADM, ARNT, LDHA; metabolism ATP5A1, COX5A, CPT2, PFKL, UQCRFS1; telomeres and telomerase PINX1, TINF2, TNKS, and TNKS2. We identified a human astrocyte cell line and normal human brain tissue as the appropriate control group for an in vitro model, despite the small sample size. A different method of assessing gene expression levels produced the same disparities, highlighting the need for caution when interpreting the accuracy of tumorigenesis markers.

ZSCAN1 Autoantibodies Are Associated with Pediatric Paraneoplastic ROHHAD.

ObjectiveRapid‐onset Obesity with Hypothalamic Dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD), is a severe pediatric disorder of uncertain etiology resulting in hypothalamic dysfunction and frequent sudden death. Frequent co‐occurrence of neuroblastic tumors have fueled suspicion of an autoimmune paraneoplastic neurological syndrome (PNS); however, specific anti‐neural autoantibodies, a hallmark of PNS, have not been identified. Our objective is to determine if an autoimmune paraneoplastic etiology underlies ROHHAD.MethodsImmunoglobulin G (IgG) from pediatric ROHHAD patients (n = 9), non‐inflammatory individuals (n = 100) and relevant pediatric controls (n = 25) was screened using a programmable phage display of the human peptidome (PhIP‐Seq). Putative ROHHAD‐specific autoantibodies were orthogonally validated using radioactive ligand binding and cell‐based assays. Expression of autoantibody targets in ROHHAD tumor and healthy brain tissue was assessed with immunohistochemistry and mass spectrometry, respectively.ResultsAutoantibodies to ZSCAN1 were detected in ROHHAD patients by PhIP‐Seq and orthogonally validated in 7/9 ROHHAD patients and 0/125 controls using radioactive ligand binding and cell‐based assays. Expression of ZSCAN1 in ROHHAD tumor and healthy human brain tissue was confirmed.InterpretationOur results support the notion that tumor‐associated ROHHAD syndrome is a pediatric PNS, potentially initiated by an immune response to peripheral neuroblastic tumor. ZSCAN1 autoantibodies may aid in earlier, accurate diagnosis of ROHHAD syndrome, thus providing a means toward early detection and treatment. This work warrants follow‐up studies to test sensitivity and specificity of a novel diagnostic test. Last, given the absence of the ZSCAN1 gene in rodents, our study highlights the value of human‐based approaches for detecting novel PNS subtypes. ANN NEUROL 2022;92:279–291

Upregulation of miR-144-3p expression attenuates glioma cell viability and invasion by targeting BCL6.

Glioma remains to be an aggressive type of cancer with poor prognosis irrespective of the type of standard treatment applied. Therefore, identification of accurate early diagnostic methods and therapeutic strategies for glioma is imperative for the treatment of this disease. The expression of a number of miRNAs in glioma have been reported to be associated with the regulation of tumorigenic progression, cancer cell proliferation, metastasis, invasion, angiogenesis and drug resistance. The aim of the present study was to assess the function of the microRNA (miR/miRNA)-144-3p/BCL6 axis in glioma. Reverse transcription-quantitative PCR was used to measure miR-144-3p and BCL6 expression. Western blotting was used for measuring BCL6 expression. Luciferase reporter assay was used to assess the association between miR-144-3p and BCL6 and a tumor xenograft model was established for assess tumor growth. The data demonstrated that miR-144-3p was decreased whereas BCL6 expression was increased in glioma tissues compared with those in healthy human brain tissues, where miR-144-3p suppressed BCL6 expression by targeting the 3'-UTR sequence of BCL6. miR-144-3p overexpression alleviated proliferation and invasion in U251 cells whereas transfection with the BCL6-overexpressing plasmid rescued the suppressive effects of miR-144-3p upregulation on the proliferation and invasion of U251 cells. In addition, miR-144-3p overexpression and BCL6 downregulation inhibited tumor progression in a mouse tumor xenograft model. The present findings suggest that miR-144-3p and BCL6 may serve to be indicator of proliferation and invasion for patients with glioma. Furthermore, BCL6 may serve an important role in the miR-144-3p-mediated regulation of proliferation and invasion of glioma cells, where the miR-144-3p/BCL6 axis can be used to target patients with glioma therapeutically.

Nanomechanics and Histopathology as Diagnostic Tools to Characterize Freshly Removed Human Brain Tumors.

BackgroundThe tissue-mechanics environment plays a crucial role in human brain physiological development and the pathogenesis of different diseases, especially cancer. Assessment of alterations in brain mechanical properties during cancer progression might provide important information about possible tissue abnormalities with clinical relevance.MethodsWith atomic force microscopy (AFM), the stiffness of freshly removed human brain tumor tissue was determined on various regions of the sample and compared to the stiffness of healthy human brain tissue that was removed during neurosurgery to gain access to tumor mass. An advantage of indentation measurement using AFM is the small volume of tissue required and high resolution at the single-cell level.ResultsOur results showed great heterogeneity of stiffness within metastatic cancer or primary high-grade gliomas compared to healthy tissue. That effect was not clearly visible in lower-grade tumors like meningioma.ConclusionCollected data indicate that AFM might serve as a diagnostic tool in the assessment of human brain tissue stiffness in the process of recognizing tumors.

Abstract 1721: Hypoxia penetrating ultra-small nanoparticle for anti-cancer effect in Glioblastoma

Abstract Glioblastoma multiforme (GBM) is a lethal brain tumor currently without successful treatment options. Chemotherapeutic agents are the frontline in the management of GBM. Nonetheless, accessibility of the brain tumor is greatly impeded by the poor blood-brain barrier (BBB) penetration of drugs, which needs immediate attention. Ultra-small multifunctional nanoparticle offers a great promise in overcoming the delivery barriers to GBM. The primary goal of our research is to develop BBB targeted nanoparticle that can selectively deliver drugs to GBM and trigger cell death. We developed Anti-GBM drug, such as temozolomide (TMZ) encapsulated biocompatible, ultra-small nanoparticle using Lactoferrin (LAC) protein. Further, we chemically conjugated LAC with tumor hypoxia biomarker homing molecule, Acetazolamide (ATZ) to obtain LAC-ATZ nanoparticle. To validate our hypothesis of hypoxia targeting, we evaluated the carbonic anhydrase-IX (CAIX) receptor expression in human brain tumor section. The IHC data demonstrated significant overexpression of CAIX in tumor tissue compared to healthy human brain tissue section. Literatures have reported overexpression of LRP-1 in endothelial blood vessel of GBM tumor. Thus, use of LAC-ATZ will enhance its penetration across the BBB and delivery of TMZ in hypoxic core of GBM. To achieve the effective BBB penetration, we engineered LAC-ATZ@TMZ nanoparticle that demonstrated homogenous ultra-small particle size of average diameter of 20-30 nm using TEM analysis. The SDS-PAGE analysis demonstrated the conjugation of LAC with ATZ. Our preliminary data in GBM cells, U87MG suggested the dose dependent cell uptake of DiD-fluorescence labeled LAC-ATZ nanoparticle. The nanoparticles are selective in targeting the U87MG cell when compared to healthy microglial BV2 cells. Thus, it is supporting the potential of LAC-ATZ nanoparticle for targeting the GBM tumor with limited effect in healthy brain tissue. We developed conditioned BBB cell culture model to demonstrate the penetration of LAC-ATZ across the BBB. Based on the exciting preliminary outcome in this study builds a strong rational of using LAC-ATZ nanoparticle for overcoming the bottle neck barrier of BBB with improved anti-GBM response. Keywords: Glioblastoma multiforme (GBM), blood-brain barrier (BBB), Lactoferrin (LAC), Acetazolamide (ATZ) Citation Format: Mohd A. Rauf, Katyayani Tatiparti, Samaresh Sau, Arun K. Iyer. Hypoxia penetrating ultra-small nanoparticle for anti-cancer effect in Glioblastoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1721.

Non-Invasive RF Technique for Detecting Different Stages of Alzheimer's Disease and Imaging Beta-Amyloid Plaques and Tau Tangles in the Brain.

This paper describes a novel approach of detecting different stages of Alzheimer's disease (AD) and imaging beta-amyloid plaques and tau tangles in the brain using RF sensors. Dielectric measurements were obtained from grey matter and white matter regions of brain tissues with severe AD pathology at a frequency range of 200 MHz to 3 GHz using a vector network analyzer and dielectric probe. Computational models were created on CST Microwave Suite using a realistic head model and the measured dielectric properties to represent affected brain regions at different stages of AD. Simulations were carried out to test the performance of the RF sensors. Experiments were performed using textile-based RF sensors on fabricated phantoms, representing a human brain with different volumes of AD-affected brain tissues. Experimental data was collected from the sensors and processed in an imaging algorithm to reconstruct images of the affected areas in the brain. Measured dielectric properties in brain tissues with AD pathology were found to be different from healthy human brain tissues. Simulation and experimental results indicated a correlated shift in the captured reflection coefficient data from RF sensors as the amount of affected brain regions increased. Finally, images reconstructed from the imaging algorithm successfully highlighted areas of the brain affected by plaques and tangles as a result of AD. The results from this study show that RF sensing can be used to identify areas of the brain affected by AD pathology. This provides a promising new non-invasive technique for monitoring the progression of AD.

Recombinant Analogue of the Human Protein SLURP-1 Inhibits the Growth of U251 MG and A172 Glioma Cells.

The alpha7 nicotinic acetylcholine receptor (α7-nAChR) is considered a promising pharmacological target for the carcinoma therapy. We have previously shown that the recombinant analogue of the human protein SLURP-1 (rSLURP-1) effectively inhibits the growth of carcinomas of various origins via the interaction with α7-nAChR and down-regulation of expression of this receptor. Expression of α7-nAChR is increased in gliomas compared to healthy human brain tissues; however, the role of this receptor in the gliomas development is poorly understood. It was shown for the first time that rSLURP-1 significantly inhibits the growth of glioma model cells U251 MG and A172 up to ∼70%, which is comparable with the effect of α-bungarotoxin, a selective α7-nAChR inhibitor. The half-maximum effective concentrations of rSLURP-1 for U251 MG and A172 cells were 2.82 ± 0.2 and 8.9 ± 0.3 nM, respectively. Coincubation of U251 MG cells with rSLURP-1 and the nAChR inhibitor mecamylamine attenuates the antiproliferative activity of rSLURP-1, indicating nAChR as a molecular target for the rSLURP-1 action in gliomas.

Spectroscopic imaging with spectral domain visible light optical coherence microscopy in Alzheimer's disease brain samples.

A visible light spectral domain optical coherence microscopy system was developed. A high axial resolution of 0.88 μm in tissue was achieved using a broad visible light spectrum (425 – 685 nm). Healthy human brain tissue was imaged to quantify the difference between white (WM) and grey matter (GM) in intensity and attenuation. The high axial resolution enables the investigation of amyloid-beta plaques of various sizes in human brain tissue and animal models of Alzheimer’s disease (AD). By performing a spectroscopic analysis of the OCM data, differences in the characteristics for WM, GM, and neuritic amyloid-beta plaques were found. To gain additional contrast, Congo red stained AD brain tissue was investigated. A first effort was made to investigate optically cleared mouse brain tissue to increase the penetration depth and visualize hyperscattering structures in deeper cortical regions.

Fractal dimension and lacunarity of tractography images of the human brain

Tractography images produced by Magnetic Resonance Imaging scans have been used to calculate the topology of the neuron tracts in the human brain. This technique gives neuroanatomical details, limited by the system resolution properties. In the observed scales the images demonstrated the statistical self-similar structure of the neuron axons and its fractal dimensions were estimated using the classic Box Counting technique. To assess the degree of clustering in the neural tracts network, lacunarity was calculated using the Gliding Box method. The twodimensional tractography images were taken from four subjects using various angles and different parts in the brain. The results demonstrated that the average estimated fractal dimension of tractography images is approximately Df =1 .60 with standard deviation 0.11 for healthy human-brain tissues, and it presents statistical self-similarity features similar to many other biological root-like structures.

Revisiting Glycogen Content in the Human Brain.

Glycogen provides an important glucose reservoir in the brain since the concentration of glucosyl units stored in glycogen is several fold higher than free glucose available in brain tissue. We have previously reported 3-4µmol/g brain glycogen content using in vivo (13)C magnetic resonance spectroscopy (MRS) in conjunction with [1-(13)C]glucose administration in healthy humans, while higher levels were reported in the rodent brain. Due to the slow turnover of bulk brain glycogen in humans, complete turnover of the glycogen pool, estimated to take 3-5days, was not observed in these prior studies. In an attempt to reach complete turnover and thereby steady state (13)C labeling in glycogen, here we administered [1-(13)C]glucose to healthy volunteers for 80h. To eliminate any net glycogen synthesis during this period and thereby achieve an accurate estimate of glycogen concentration, volunteers were maintained at euglycemic blood glucose levels during [1-(13)C]glucose administration and (13)C-glycogen levels in the occipital lobe were measured by (13)C MRS approximately every 12h. Finally, we fitted the data with a biophysical model that was recently developed to take into account the tiered structure of the glycogen molecule and additionally incorporated blood glucose levels and isotopic enrichments as input function in the model. We obtained excellent fits of the model to the (13)C-glycogen data, and glycogen content in the healthy human brain tissue was found to be 7.8±0.3µmol/g, a value substantially higher than previous estimates of glycogen content in the human brain.

Element imaging in formalin fixed slices of human mesencephalon

The scarcity of native frozen pathological and healthy human brain tissue is actually one of the major bottlenecks concerning the investigation of neuropsychiatric diseases. Therefore it is of some interest to make formalin fixed tissue specimens accessible to mass spectrometric analytical techniques. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and matrix matched standards were employed to generate quantitative element maps of human mesencephalon slices that had been stored in formalin for more than 10 years of a single subject. The characteristic distribution patterns of Cu and Zn were completely blunted but Fe was clearly enriched in the substantia nigra (SN) – especially in the matrix of the pars compacta – and the nucleus ruber (NR) at concentrations of 179 μg g −1, 231 μg g −1 and 187 μg g −1 (wet weight), respectively, very similar to literature values obtained from homogenates of fresh tissue. Mn and Ca congruently reflected the distribution of melanised SN neurons. Interestingly, the distribution of Pb was congruent to that of Fe reaching 0.8 μg g −1 in the SN, 1.1 μg g −1 in the matrix and 0.9 μg g −1 in the NR. Images of C and P reflected the gray matter-white matter partition of the tissue. These results suggest that a meaningful quantitative assessment of Fe, Mn and Pb is possible in tissue samples which have previously been stored in buffered formalin solution.

Studies of anomalous diffusion in the human brain using fractional order calculus

It is well known that diffusion-induced MR signal loss deviates from monoexponential decay, particularly at high b-values (e.g., >1500 sec/mm(2) for human brain tissues). A number of models have been developed to describe this anomalous diffusion behavior and relate the diffusion measurements to tissue structures. Recently, a new diffusion model was proposed by solving the Bloch-Torrey equation using fractional order calculus with respect to time and space (Magin et al., J Magn Reson 2008;190:255-270; Zhou et al., Proc Int'l Soc Magn Reson Med 2008). Using a spatial Laplacian [symbol: see text], this model yields a new set of parameters to describe anomalous diffusion: diffusion coefficient D, fractional order derivative in space beta, and a spatial parameter mu (in units of microm). In this study, we demonstrate that the fractional calculus model can be successfully applied to analyzing diffusion images of healthy human brain tissues in vivo. Five human volunteers were scanned on a commercial 3-T scanner using a customized single-shot echo-planar imaging diffusion sequence with 15 b values ranging from 0 to 4700 sec/mm(2). The set of images was analyzed using the fractional calculus model, producing spatially resolved maps of D, beta, and mu. The beta and mu maps showed notable contrast between white and gray matter. The contrast has been attributed to the varying degree of complexity of the underlying tissue structures and microenvironment. Although the biophysical basis of beta and mu remains elusive, the potential utility of these parameters to characterize the environment for molecular diffusion, as a complement to apparent diffusion coefficient, may lead to a new way to investigate tissue structural changes in disease progression, intervention, and regression.

FRACTAL DIMENSION AND LACUNARITY OF TRACTOGRAPHY IMAGES OF THE HUMAN BRAIN

Tractography images produced by Magnetic Resonance Imaging scans have been used to calculate the topology of the neuron tracts in the human brain. This technique gives neuroanatomical details, limited by the system resolution properties. In the observed scales the images demonstrated the statistical self-similar structure of the neuron axons and its fractal dimensions were estimated using the classic Box Counting technique. To assess the degree of clustering in the neural tracts network, lacunarity was calculated using the Gliding Box method. The two-dimensional tractography images were taken from four subjects using various angles and different parts in the brain. The results demonstrated that the average estimated fractal dimension of tractography images is approximately Df = 1.60 with standard deviation 0.11 for healthy human-brain tissues, and it presents statistical self-similarity features similar to many other biological root-like structures.

Detecting Morphologically Distinct Oligomeric Forms of α-Synuclein

Neuropathologic and genetics studies as well as transgenic animal models have provided strong evidence linking misfolding and aggregation of alpha-synuclein to the progression of Parkinson disease (PD) and other related disorders. A growing body of evidence implicates various oligomeric forms of alpha-synuclein as the toxic species responsible for neurodegeneration and neuronal cell death. Although numerous different oligomeric forms of alpha-synuclein have been identified in vitro, it is not known which forms are involved in PD or how, when, and where different forms contribute to the progression of PD. Reagents that can interact with specific aggregate forms of alpha-synuclein would be very useful not only as tools to study how different aggregate forms affect cell function, but also as potential diagnostic and therapeutic agents for PD. Here we show that a single chain antibody fragment (syn-10H scFv) isolated from a phage display antibody library binds to a larger, later stage oligomeric form of alpha-synuclein than a previously reported oligomeric specific scFv isolated in our laboratory. The scFv described here inhibits aggregation of alpha-synuclein in vitro, blocks extracellular alpha-synuclein-induced toxicity in both undifferentiated and differentiated human neuroblastoma cell lines (SH-SY5Y), and specifically recognizes naturally occurring aggregates in PD but not in healthy human brain tissue.

Characterization of human creatine kinase BB and MB isoforms by means of isoelectric focusing

Isoforms of creatine kinase (creatine- N-phosphotransferase, CK, EC 2.7.3.2), BB and MB, were isolated from healthy human brain tissue and cardiac muscle, respectively, and were characterized by means of isoelectric focusing (IEF). CK-BB isoforms in Tris-HCl buffer were focused at p I 4.5 (a tissue form) and those in fresh sera from healthy adults were focused at p I 5.0, 5.1 and 5.2 (plasma forms). The IEF patterns of CK-BB isoforms were not altered following treatment with carboxypeptidase B and incubation in fresh serum at 37°C; thus, it was found that there was no lysine at the C-terminal of the CK-B subunit and CK-BB isoforms were not results of the removal of lysine. Three CK-BB isoforms in fresh sera were identified to be oxidized, intermediate and reduced forms from the anodal side, respectively, by treatment with hydrogen peroxide and 2-mercaptoethanol. The oxidized form of CK-BB seemed to have higher affinity to IgG than the other two plasma forms of CK-BB. On the other hand, CK-MB isoforms in Tris-HCl buffer were focused at p I 5.4 (a tissue form) with a minor band at p I 5.2 and those in sera were focused at p I 5.0, 5.1, 5.2 (plasma forms) and 5.4. Four CK-MB isoforms were identified to be reduced, intermediate and oxidized forms without lysine from the anodal side, respectively, and the cathodal band was a tissue form with lysine.