Development of Droplet Digital PCR-Based Assays to Quantify HIV Proviral and Integrated DNA in Brain Tissues from Viremic Individuals with Encephalitis and Virally Suppressed Aviremic Individuals

We developed ddPCR assays to quantitatively measure HIV DNA and used this ddPCR assays to detect and quantitatively measure HIV DNA in the archived brain tissues from HIV patients. The tissue viral loads assessed by ddPCR was highly correlative with those assessed by qPCR.

Brain Tissues Affection After Oral Tramadol: An Experiment Study

Tramadol may lead to the accumulation of toxic components in the body. This study aims to detect the toxic effect of tramadol on brain tissues. The clinical experiment was carried out at the Department of Neurosurgery, Ibn Sina Hospital. Ten rats of both sex weighing (180-300 g) were selected from the veterinary house. Brain tissues were immediately removed and put into 10% neutral buffer formalin for fixation, then stained with Hematoxylin-Eosin stain. A significant decrease in the brain weight in rats when given the tramadol in dose 50 mg/ kg. Changes included a mild degree of tissue injury in the cerebral cortex, increase in vacuolar degeneration, with atrophy and degeneration of neurons. There are toxic effects when tramadol describes for a long time on the brain tissues.

Meta-Analysis of Transcriptome-Wide Association Studies across 13 Brain Tissues Identified Novel Clusters of Genes Associated with Nicotine Addiction

Genome-wide association studies (GWAS) have identified and reproduced thousands of diseases associated loci, but many of them are not directly interpretable due to the strong linkage disequilibrium among variants. Transcriptome-wide association studies (TWAS) incorporated expression quantitative trait loci (eQTL) cohorts as a reference panel to detect associations with the phenotype at the gene level and have been gaining popularity in recent years. For nicotine addiction, several important susceptible genetic variants were identified by GWAS, but TWAS that detected genes associated with nicotine addiction and unveiled the underlying molecular mechanism were still lacking. In this study, we used eQTL data from the Genotype-Tissue Expression (GTEx) consortium as a reference panel to conduct tissue-specific TWAS on cigarettes per day (CPD) over thirteen brain tissues in two large cohorts: UK Biobank (UKBB; number of participants (N) = 142,202) and the GWAS & Sequencing Consortium of Alcohol and Nicotine use (GSCAN; N = 143,210), then meta-analyzing the results across tissues while considering the heterogeneity across tissues. We identified three major clusters of genes with different meta-patterns across tissues consistent in both cohorts, including homogenous genes associated with CPD in all brain tissues; partially homogeneous genes associated with CPD in cortex, cerebellum, and hippocampus tissues; and, lastly, the tissue-specific genes associated with CPD in only a few specific brain tissues. Downstream enrichment analyses on each gene cluster identified unique biological pathways associated with CPD and provided important biological insights into the regulatory mechanism of nicotine dependence in the brain.

Capping Protein Regulator and Myosin 1 Linker 3 (CARMIL3) as a Molecular Signature of Ischemic Neurons in the DWI-T2 Mismatch Areas After Stroke

Ischemic stroke with a mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) or T2-weighted images indicates onset within 4.5 h, but the pathological substrates in the DWI-T2 mismatch and T2(+) areas remain elusive. In this study, proteomics was used to explore (1) the protein expression profiles in the T2(+), mismatch, and contralateral areas, and (2) the protein with the highest expression in the T2(+) area in the brains of male Sprague-Dawley rats within 4.5 h after middle cerebral artery occlusion (MCAO). The expression of the candidate protein was further validated in (1) rat brain subjected to MCAO, (2) rat primary cortical neuronal culture with oxygen-glucose deprivation (OGD), and (3) infarcted human brain tissues. This study showed that apoptosis was observed in the T2(+) and mismatch regions and necroptosis in the T2(+) region of rat brains after MCAO. We identified capping protein regulator and myosin 1 linker 3 (CARMIL3) as the candidate molecule in the T2(+) and mismatch areas, exclusively in neurons, predominantly in the cytoplasm, and most abundant in the mismatch area. The CARMIL3(+) neurons and neurites in the mismatch and T2(+) areas were larger than those in the control area, and associated with (1) increased expression of sulfonylurea receptor 1 (SUR1), indicating edema, (2) accumulation of p62, indicating impaired autophagy, and (3) increase in 8-hydroxy-2′-deoxyguanosine (8-OHdG), indicating oxidative stress. The increased expression of CARMIL3 was validated in a cell model of cortical neurons after OGD and in infarcted human brain tissues. In conclusion, this study shows that the mismatch and T2(+) areas within 4.5 h after ischemia are characterized by upregulated expression of CARMIL3 in neurons, particularly the mismatch area, which is associated with neuronal edema, impaired autophagy, and oxidative stress, indicating that CARMIL3 serves as a molecular signature of brain ischemia.

Regulatory mechanism of the SNHG3/miR-302a-3p/E2F1 feedback loop in nerve repair post cerebral ischemic stroke

Objective: Cerebral ischemic stroke (CIS) remains a primary cause of death worldwide. The current knowledge has identified the implication of microRNAs (miRNAs) in the pathophysiology of CIS. This study investigated the mechanism of miR-302a-3p in nerve repair post-CIS. Methods: A middle cerebral artery occlusion (MCAO) model was established in mice to simulate CIS. miR-302a-3p expression in brain tissues of MCAO mice was up-regulated by injecting agomiR-302a-3p. The neurological deficit of MCAO mice was evaluated through neurological function score, forelimb placing test, and balance beam walking test. Neuronal damage was measured using Nissl staining. The concentrations of nerve injury-related factors (S100B and GFAP) and the contents of neuroinflammatory factors (TNF-α and IL-1β) in serum were examined using ELISA kits. miR-302a-3p, E2F1, and long non-coding RNA (lncRNA) SNHG3 expressions in brain tissues of MCAO mice were determined using RT-qPCR and Western blot. The binding relationships between miR-302a-3p and E2F1 and E2F1 and SNHG3 were validated using dual-luciferase and ChIP assays, respectively. Results: miR-302a-3p expression was reduced in brain tissues of MCAO mice. miR-302a-3p overexpression increased the number of neurons, decreased the concentrations of S100B and GFAP, reduced the contents of TNF-α and IL-1β, promoted nerve repair, and alleviated CIS-induced brain injury. miR-302a-3p targeted E2F1 expression, and E2F1 activated SNHG3 transcription. E2F1 overexpression or SNHG3 overexpression reversed the effect of miR-302a-3p overexpression on nerve repair in MCAO mice. Conclusion: miR-302a-3p overexpression repressed SNHG3 transcription by targeting E2F1 expression, thereby promoting nerve repair and alleviating CIS.