Precise Cerebral Vascular Atlas in Stereotaxic Coordinates of Whole Mouse Brain

Understanding amazingly complex brain functions and pathologies requires a complete cerebral vascular atlas in stereotaxic coordinates. Making a precise atlas for cerebral arteries and veins has been a century-old objective in neuroscience and neuropathology. Using micro-optical sectioning tomography (MOST) with a modified Nissl staining method, we acquired five mouse brain data sets containing arteries, veins, and microvessels. Based on the brain-wide vascular spatial structures and brain regions indicated by cytoarchitecture in one and the same mouse brain, we reconstructed and annotated the vascular system atlas of both arteries and veins of the whole mouse brain for the first time. The distributing patterns of the vascular system within the brain regions were acquired and our results show that the patterns of individual vessels are different from each other. Reconstruction and statistical analysis of the microvascular network, including derivation of quantitative vascular densities, indicate significant differences mainly in vessels with diameters less than 8 μm and large than 20 μm across different brain regions. Our precise cerebral vascular atlas provides an important resource and approach for quantitative studies of brain functions and diseases.

A platform for efficient identification of molecular phenotypes of brain-wide neural circuits

A neural circuit is a structural-functional unit of achieving particular information transmission and processing, and have various inputs, outputs and molecular phenotypes. Systematic acquisition and comparative analysis of the molecular features of neural circuits are crucial to elucidating the operating mechanisms of brain function. However, no efficient, systematic approach is available for describing the molecular phenotypes of specific neural circuits at the whole brain scale. In this study, we developed a rapid whole-brain optical tomography method and devised an efficient approach to map brain-wide structural and molecular information in the same brain: rapidly imaging and sectioning the whole brain as well as automatically collecting all slices; conveniently selecting slices of interest through quick data browsing and then performing post hoc immunostaining of selected slices. Using this platform, we mapped the brain-wide distribution of inputs to motor, sensory and visual cortices and determined their molecular phenotypes in several subcortical regions. Our platform significantly enhances the efficiency of molecular phenotyping of neural circuits and provides access to automation and industrialization of cell type analyses for specific circuits.

A Quantitative Analysis of the Distribution of CRH Neurons in Whole Mouse Brain

Corticotropin-releasing hormone (CRH), with widespread expression in the brain, plays a key role in modulating a series of behaviors, including anxiety, arousal, motor function, learning and memory. Previous studies have focused on some brain regions with densely distributed CRH neurons such as paraventricular hypothalamic nucleus (PVH) and bed nuclei of the stria terminalis (BST) and revealed some basic structural and functional knowledge of CRH neurons. However, there is no systematic analysis of brain-wide distribution of CRH neurons. Here, we performed a comprehensive study of CRH neurons in CRH-IRES-Cre;Ai3 mice via automatic imaging and stereoscopic cell counting in a whole mouse brain. We acquired four datasets of the CRH distributions with co-localized cytoarchitecture at a voxel resolution of 0.32 μm × 0.32 μm × 2 μm using brain-wide positioning system (BPS). Next, we precisely located and counted the EYFP-labeled neurons in different regions according to propidium iodide counterstained anatomical reference using Neuronal Global Position System. In particular, dense EYFP expression was found in piriform area, BST, central amygdalar nucleus, PVH, Barrington's nucleus, and inferior olivary complex. Considerable CRH neurons were also found in main olfactory bulb, medial preoptic nucleus, pontine gray, tegmental reticular nucleus, external cuneate nucleus, and midline thalamus. We reconstructed and compared the soma morphology of CRH neurons in 11 brain regions. The results demonstrated that CRH neurons had regional diversities of both cell distribution and soma morphology. This anatomical knowledge enhances the current understanding of the functions of CRH neurons. These results also demonstrated the ability of our platform to accurately orient, reconstruct and count neuronal somas in three-dimension for type-specific neurons in the whole brain, making it feasible to answer the fundamental neuroscience question of exact numbers of various neurons in the whole brain.

Early-stage reduction of the dendritic complexity in basolateral amygdala of a transgenic mouse model of Alzheimer's disease

Alzheimer's disease is a representative age-related neurodegenerative disease that could result in loss of memory and cognitive deficiency. However, the precise onset time of Alzheimer's disease affecting neuronal circuits and the mechanisms underlying the changes are not clearly known. To address the neuroanatomical changes during the early pathologic developing process, we acquired the neuronal morphological characterization of AD in APP/PS1 double-transgenic mice using the Micro-Optical Sectioning Tomography system. We reconstructed the neurons in 3D datasets with a resolution of 0.32 × 0.32 × 1 μm and used the Sholl method to analyze the anatomical characterization of the dendritic branches. The results showed that, similar to the progressive change in amyloid plaques, the number of dendritic branches were significantly decreased in 9-month-old mice. In addition, a distinct reduction of dendritic complexity occurred in third and fourth-order dendritic branches of 9-month-old mice, while no significant changes were identified in these parameters in 6-month-old mice. At the branch-level, the density distribution of dendritic arbors in the radial direction decreased in the range of 40-90 μm from the neuron soma in 6-month-old mice. These changes in the dendritic complexity suggest that these reductions contribute to the progressive cognitive impairment seen in APP/PS1 mice. This work may yield insights into the early changes in dendritic abnormality and its relevance to dysfunctional mechanisms of learning, memory and emotion in Alzheimer's disease.

The anti-cancer effects of cisplatin on hepatic cancer are associated with modulation of miRNA-21 and miRNA-122 expression

OBJECTIVE

Cisplatin is an effective chemotherapeutic drug to treat hepatic cancer, but its efficacy is marred by extensive adverse effects. Micro (mi) RNAs are small regulatory RNAs that may be used as molecular targets to better fine-tune chemotherapy in hepatic cancer. In this study, we examined to what extent the anti-cancer effects of cisplatin are associated with expressions of miRNA (miR)-21 and miR-122.

MATERIALS AND METHODS

The growth-inhibiting effects of cisplatin on the human hepatic cell line HepG2 were assessed by MTT assay, while cell apoptosis was documented using DAPI staining. Also, we tested the effects of cisplatin on tumour growth in a mouse tumour xenograft model. Finally, we quantified expression levels of miR-21 and miR-122 in cisplatin-treated HepG2 cells.

RESULTS

We observed that cisplatin significantly decreased the growth of HepG2 cells (p < 0.05 vs control cells) at all tested concentration (5-80 µg/ml) after 24 or 48 hours of treatment. Microscopic studies demonstrated apoptotic signs in cisplatin-treated cells. In the mouse tumour xenograft model, tumour weights and volumes were significantly (p < 0.05 untreated animals) lower after treatment with cisplatin. Also, treatment of HepG2 cells for 48 hours with 20 µg/ml cisplatin was associated with significant decreases in miR-21 expression levels and up-regulation of miR-122.

CONCLUSIONS

The anti-cancer effects of cisplatin are associated with down-regulation of miR-21 expression and up-regulation of miR-122.

NFAT4-dependent miR-324-5p regulates mitochondrial morphology and cardiomyocyte cell death by targeting Mtfr1

Emerging evidence suggest that the abnormal mitochondrial fission participates in pathogenesis of cardiac diseases, including myocardial infarction and heart failure. However, the molecular components regulating mitochondrial network in heart remain largely unidentified. Here we report that NFAT4, miR-324-5p and mitochondrial fission regulator 1 (Mtfr1) function in one signaling axis that regulates mitochondrial morphology and cardiomyocyte cell death. Knocking down Mtfr1 suppresses mitochondrial fission, apoptosis and myocardial infarction. Mtfr1 is a direct target of miR-324-5p, and miR-324-5p attenuates mitochondrial fission, cardiomyocyte apoptosis and myocardial infarction by suppressing Mtfr1 translation. Finally, we show that transcription factor NFAT4 inhibits miR-324-5p expression. Knockdown of NFAT4 suppresses mitochondrial fission and protects cardiomyocyte from apoptosis and myocardial infarction. Our study defines the NFAT4/ miR-324-5p/Mtfr1 axis, which participates in the regulation of mitochondrial fission and cardiomyocyte apoptosis, and suggests potential new treatment avenues for cardiac diseases.

Rapid decomposition and visualisation of protein-ligand binding free energies by residue and by water

Recent advances in computational hardware, software and algorithms enable simulations of protein-ligand complexes to achieve timescales during which complete ligand binding and unbinding pathways can be observed. While observation of such events can promote understanding of binding and unbinding pathways, it does not alone provide information about the molecular drivers for protein-ligand association, nor guidance on how a ligand could be optimised to better bind to the protein. We have developed the waterswap (C. J. Woods et al., J. Chem. Phys., 2011, 134, 054114) absolute binding free energy method that calculates binding affinities by exchanging the ligand with an equivalent volume of water. A significant advantage of this method is that the binding free energy is calculated using a single reaction coordinate from a single simulation. This has enabled the development of new visualisations of binding affinities based on free energy decompositions to per-residue and per-water molecule components. These provide a clear picture of which protein-ligand interactions are strong, and which active site water molecules are stabilised or destabilised upon binding. Optimisation of the algorithms underlying the decomposition enables near-real-time visualisation, allowing these calculations to be used either to provide interactive feedback to a ligand designer, or to provide run-time analysis of protein-ligand molecular dynamics simulations.

Prognostic value of clinical and immunological markers in acute phase of SFTS virus infection

SFTS virus (SFTSV) is a novel bunyavirus that causes severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease that occurred in China in recent years, with an average case fatality rate of 10-12%. Intervention in the early clinical stage is the most effective measure to reduce the mortality rate of disease. To elucidate the natural course of and immune mechanisms associated with the pathogenesis of SFTSV, 59 laboratory-confirmed SFTS patients in the acute phase, who were hospitalized between October 2010 and September 2011, were enrolled in this study, and the patients sera were dynamically collected and tested for SFTSV viral RNA load, 34 cytokines or chemokines and other related laboratory parameters. All clinical diagnostic factors in the acute phase of SFTS were evaluated and assessed. The study showed that the severity of the disease in 11 (18.6%) patients was associated with abdominal pain (p 0.007; OR = 21.95; 95% CI, 2.32-208.11) and gingival bleeding (p 0.001; OR=122.11; 95% CI, 6.41-2328). The IP-10, TNF-α, IL-6, IL-10, granzyme B and HSP70 levels were higher over the 7-8 days in severe cases, accompanied by altered AST, CK and LDH levels. HSP70 (p 0.012; OR=8.29; 95% CI, 1.58-43.40) was independently correlated with the severity of the early acute phase of SFTSV infection. The severity of SFTS can be predicted based on the presence of symptoms such as abdominal pain and gingival bleeding and on the level of HSP70 in the acute phase of the disease.

Cardiac hypertrophy is negatively regulated by miR-541

Heart failure is a leading cause of death in aging population. Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading, but continuous cardiac hypertrophy is able to induce heart failure. We found that the level of miR-541 was decreased in angiotensin II (Ang-II) treated cardiomyocytes. Enforced expression of miR-541 resulted in a reduced hypertrophic phenotype upon Ang-II treatment in cellular models. In addition, we generated miR-541 transgenic mice that exhibited a reduced hypertrophic response upon Ang-II treatment. Furthermore, we found miR-541 is the target of microphthalmia-associated transcription factor (MITF) in the hypertrophic pathway and MITF can negatively regulate the expression of miR-541 at the transcriptional levels. MITF(ce/ce) mice exhibited a reduced hypertrophic phenotype upon Ang-II treatment. Knockdown of MITF also results in a reduction of hypertrophic responses after Ang-II treatment. Knockdown of miR-541 can block the antihypertrophic effect of MITF knockdown in cardiomyocytes upon Ang-II treatment. This indicates that the effect of MITF on cardiac hypertrophy relies on the regulation of miR-541. Our present study reveals a novel cardiac hypertrophy regulating pathway that was composed of miR-541 and MITF. Modulation of their levels may provide a new approach for tackling cardiac hypertrophy.

Disparities in uterine cancer epidemiology, treatment, and survival among African Americans in the United States

OBJECTIVE

The objective of this article is to comprehensively review the scientific literature and summarize the available data regarding the outcome disparities of African American women with uterine cancer.

METHODS

Literature on disparities in uterine cancer was systematically reviewed using the PubMed search engine. Articles from 1992 to 2012 written in English were reviewed. Search terms included endometrial cancer, uterine cancer, racial disparities, and African American.

RESULTS

Twenty-four original research articles with a total of 366,299 cases of endometrial cancer (337,597 Caucasian and 28,702 African American) were included. Compared to Caucasian women, African American women comprise 7% of new endometrial cancer cases, while accounting for approximately 14% of endometrial cancer deaths. They are diagnosed with later stage, higher-grade disease, and poorer prognostic histologic types compared to their Caucasian counterparts. They also suffer worse outcomes at every stage, grade, and for every histologic type. The cause of increased mortality is multifactorial. African American and white women have varying incidence of comorbid conditions, genetic susceptibility to malignancy, access to care and health coverage, and socioeconomic status; however, the most consistent contributors to incidence and mortality disparities are histology and socioeconomics. More robust genetic and molecular profile studies are in development to further explain histologic differences.

CONCLUSIONS

Current studies suggest that histologic and socioeconomic factors explain much of the disparity in endometrial cancer incidence and mortality between white and African American patients. Treatment factors likely contributed historically to differences in mortality; however, studies suggest most women now receive equal care. Molecular differences may be an important factor to explain the racial inequities. Coupled with a sustained commitment to increasing access to appropriate care, on-going research in biologic mechanisms underlying histopathologic differences will help address and reduce the number of African American women who disproportionately suffer and die from endometrial malignancy.

LOX-1 abrogation reduces cardiac hypertrophy and collagen accumulation following chronic ischemia in the mouse

We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were subjected to occlusion of left coronary artery for 3 weeks. Markers of cardiac hypertrophy, fibrosis-related signals (collagen IV, collagen-1 and fibronectin) and oxidant load (nicotinamide adenine dinucleotide phosphate oxidase expression, activity of mitogen-activated protein kinases and left ventricular (LV) tissue thiobarbituric acid reactive substances) were analyzed. In in vitro experiments, HL-1 cardiomyocytes were transfected with angiotensin II (Ang II) type 1 receptor (AT1R) or type 2 receptor (AT2R) genes to determine their role in the cardiomyocyte hypertrophy. LOX-1 KO mice had 25% improvement in survival over the 3-week period of chronic ischemia. LOX-1 deletion reduced collagen deposition and cardiomyocyte hypertrophy (∼75%) in association with a decrease in oxidant load and AT1R upregulation (all P<0.05). The LOX-1 KO mice hearts exhibited a disintegrin and metalloproteinase 10 (ADAM10) and a disintegrin and metalloproteinase 17 (ADAM17) expression and matrix metalloproteinase 2 activity, and increased AT2R expression (P<0.05). Attenuation of cardiac remodeling was associated with improved cardiac hemodynamics (LV ±dp/dt and cardiac ejection fraction). In vitro studies showed that it is AT1R, and not AT2R overexpression that induces cardiomyocyte hypertrophy. We demonstrate for the first time that LOX-1 deletion reduces oxidative stress and related intracellular signaling, which leads to attenuation of the positive feedback loop involving AT1R and LOX-1. This results in reduced chronic cardiac remodeling.

Correlation between promoter methylation of glutathione-S-tranferase P1 and oxidative stress in acute-on-chronic hepatitis B liver failure

Promoter methylation of glutathione-S-transferase P1 (GSTP1) may be involved in liver damage caused by oxidative stress in acute-on-chronic hepatitis B-induced liver failure (ACHBLF). This study aimed to explore GSTP1 promoter methylation status and oxidative stress in such patients. DNA was extracted from peripheral blood mononuclear cells (PBMCs) of patients with acute-on-chronic liver hepatitis B-induced liver failure, chronic hepatitis B (CHB) and normal controls, followed by sodium-bisulfite treatment and methylation-specific PCR (MSP) analysis. Plasma malondialdehyde (MDA) adducts levels were detected by enzyme-linked immunosorbent assay as oxidative stress marker. Model for end-stage liver disease (MELD) score was employed to estimate the severity of the liver failure. Eleven of 35 patients with acute-on-chronic liver failure and 3 of 35 patients with stab le hepatitis B displayed GSTP1 promoter methylation, and the difference was significant (χ2)  = 5.71, P = 0.02). No differences in standard liver function tests were found in patients with acute-on-chronic liver failure with and without GSTP1 promoter methylation although the levels of total bilirubin were greater in those with methylation. The levels of MDA adducts were significantly higher in patients with liver failure when compared to those with CHB (12.44 ± 5.38 pmol/mg vs 8.42 ± 5.49 pmol/mg, P < 0.01), and in the patients with liver failure who had promoter methylation the levels were higher than in those who did not (15.2 ± 4.68 pmol/mg vs 11.17 ± 5.29 pmol/mg, P < 0.01). The MELD score was not significantly different between methylated and unmethylated patients with liver failure (P > 0.05), although MDA adducts were correlated with MELD scores in patients with acute-on-chronic liver failure (r = 0.579, P < 0.01). GSTP1 promoter methylation may facilitate oxidative stress-associated liver damage in ACHBLF, and oxidative stress is correlated with ACHBLF severity.