Regions Of Hyper Research Articles

Longitudinal Analysis of Brain Function-Structure Dependencies in 22q11.2 Deletion Syndrome and Psychotic Symptoms

BackgroundCompared with conventional unimodal analysis, understanding how brain function and structure relate to one another opens a new biologically relevant assessment of neural mechanisms. However, how function-structure dependencies (FSDs) evolve throughout typical and abnormal neurodevelopment remains elusive. The 22q11.2 deletion syndrome (22q11.2DS) offers an important opportunity to study the development of FSDs and their specific association with the pathophysiology of psychosis. MethodsPreviously, we used graph signal processing to combine brain activity and structural connectivity measures in adults, quantifying FSD. Here, we combined FSD with longitudinal multivariate partial least squares correlation to evaluate FSD alterations across groups and among patients with and without mild to moderate positive psychotic symptoms. We assessed 391 longitudinally repeated resting-state functional and diffusion-weighted magnetic resonance images from 194 healthy control participants and 197 deletion carriers (ages 7–34 years, data collected over a span of 12 years). ResultsCompared with control participants, patients with 22q11.2DS showed a persistent developmental offset from childhood, with regions of hyper- and hypocoupling across the brain. Additionally, a second deviating developmental pattern showed an exacerbation during adolescence, presenting hypocoupling in the frontal and cingulate cortices and hypercoupling in temporal regions for patients with 22q11.2DS. Interestingly, the observed aggravation during adolescence was strongly driven by the group with positive psychotic symptoms. ConclusionsThese results confirm a central role of altered FSD maturation in the emergence of psychotic symptoms in 22q11.2DS during adolescence. The FSD deviations precede the onset of psychotic episodes and thus offer a potential early indication for behavioral interventions in individuals at risk.

Hypopigmented burn hypertrophic scar contains melanocytes that can be signaled to re-pigment by synthetic alpha-melanocyte stimulating hormone in vitro.

There are limited treatments for dyschromia in burn hypertrophic scars (HTSs). Initial work in Duroc pig models showed that regions of scar that are light or dark have equal numbers of melanocytes. This study aims to confirm melanocyte presence in regions of hypo- and hyper-pigmentation in an animal model and patient samples. In a Duroc pig model, melanocyte presence was confirmed using en face staining. Patients with dyschromic HTSs had demographic, injury details, and melanin indices collected. Punch biopsies were taken of regions of hyper-, hypo-, or normally pigmented scar and skin. Biopsies were processed to obtain epidermal sheets (ESs). A subset of ESs were en face stained with melanocyte marker, S100β. Melanocytes were isolated from a different subset. Melanocytes were treated with NDP α-MSH, a pigmentation stimulator. mRNA was isolated from cells, and was used to evaluate gene expression of melanin-synthetic genes. In patient and pig scars, regions of hyper-, hypo-, and normal pigmentation had significantly different melanin indices. S100β en face staining showed that regions of hyper- and hypo-pigmentation contained the same number of melanocytes, but these cells had different dendricity/activity. Treatment of hypo-pigmented melanocytes with NDP α-MSH produced melanin by microscopy. Melanin-synthetic genes were upregulated in treated cells over controls. While traditionally it may be thought that hypopigmented regions of burn HTS display this phenotype because of the absence of pigment-producing cells, these data show that inactive melanocytes are present in these scar regions. By treating with a pigment stimulator, cells can be induced to re-pigment.

55 Melanocytes in Hypopigmented Burn Scar Can Be Stimulated to Produce Melanin

Abstract Introduction Currently, there are limited clinical treatments for dyschromia in burn hypertrophic scars (HTSs). Initial pilot work in a Duroc pig model showed that melanocyte quantity does not influence pigmentation. Regions of scar that are light or dark have equal numbers of melanocytes. This study aims to confirm melanocyte presence in regions of hypo- and hyper-pigmentation. If melanocytes are present, pigmentation stimulators may be a useful therapy. Methods Following IRB approval, patients with dyschromic HTSs were enrolled and demographic, injury and treatment details, and melanin indices by Skin Color Catch probes (SCC) were collected. Punch biopsies were taken of distinct regions of hyper-, hypo-, or normally pigmented scar and skin. Biopsies were processed to obtain epidermal sheets (ESs). A subset of ESs were stained using en face staining with melanocyte marker, S100b. Melanocytes were isolated from a different subset. Melanocytes were treated with NDP a-MSH, a pigmentation stimulator. mRNA was isolated from cells, and qRT-PCR was used to evaluate gene expression of melanin-synthetic genes, tyrosinase (TYR), tyrosinase-related protein-1 (TYRP1) and dopachrome tautomerase (DCT). Results 8 patients were enrolled and the cohort included patients with Fitzpatrick skin types 5 (n=6) and 3 (n=2). HTSs ranged from 4 to 395 months old and dyschromia developed mainly due to healing by re-epithelialization and was refractory to prior scar treatments. By SCC, regions of hyper-, hypo-, and normal pigmentation had significantly different melanin indices (864.9 ± 19.8 vs. 627.1 ± 30.3 vs. 786.5 ± 21.4, p< 0.01). S100b en face staining showed that regions of hyper- and hypo-pigmentation contained the same number of melanocytes (14.6 ± 3.1 vs. 14.5 ± 3.2 melanocytes/HPF (n=5, p=0.99), but these cells had different dendricity, or activity (3.9 ± 0.5 vs. 0.4 ± 0.2 dendrites/cell (n=5, p< 0.0001). When hypo-pigmented melanocytes were treated with NDP a-MSH, cells produced melanin visible by bright-field microscopy (n=3). TYR, TYRP1, and DCT gene expression were upregulated in treated cells compared to controls. Conclusions While traditionally, it may be thought that hypo-pigmented regions of burn HTS display this phenotype because of the absence of pigment-producing cells, these data show that melanocytes are present in these scar regions. The cells are present, but they are inactive in pigment production. By treating the cells with a pigment stimulator, cells can be induced to re-pigment. Applicability of Research to Practice Patients were asked, on a scale of 1–10 with 1 being “no, not at all”, and 10 being “yes, very much”, “Is the scar color different from the color of your normal skin at present?” All patients rated this question as 10/10, indicating that scar dyschromia is a pervasive problem. Patients’ quality of life may be improved with the development of treatments for hypopigmentation.

Abstract B36: DNA methylation profiling describes Wilms tumor evolution from its precursor lesion

Abstract Wilms tumor (WT) is the most common pediatric renal cancer and represents a model of disruption in kidney development with observed lesions of undifferentiated embryonic kidney termed nephrogenic rests (NR) which are considered precursor lesions. Epigenetic dysregulation plays a large part in Wilms tumorigenesis as dysregulation of IGF2/H19 is the most common aberration observed in ~70% WT. To provide new insights into the molecular evolution of WT from its precursor lesions, genome-wide CpG methylation, which has frequently been shown to alter gene expression in cancer, was studied using the Illumina HumanMethylation 450 BeadChip array. Matched normal kidney (NK), NR and WT were sampled from 30 patient nephrectomies. To ensure precise microdissection, DNA was extracted from formalin-fixed paraffin embedded tissue after histological analysis. Analysis of methylation β-values revealed an increase in methylation variability in both the NR and WT tissue. Linear modeling further supported the role of NR as a precursor lesion however showed that, although morphologically similar to embryonic kidney, the NR tissue is a unique entity. Furthermore, drastic epigenetic restructuring is observed in NR tissue including large regions of hyper- and hypomethylation previously associated with cancer tissue. This novel data suggests the NR has a cancer-like methylome. Further changes in DNA methylation were observed upon evolution of NR to WT. These ‘late event' methylation variable positions have the potential to be developed into an assay for differential detection of NR or WT in diagnostically challenging cases. These results lead us to propose that during Wilms tumorigenesis, NR are prevented from completing nephrogenesis and continue divergent evolution into a separate entity distinct from the embryonic kidney. These NR are precancerous lesions that then evolve into WT. Citation Format: Jocelyn Charlton, Richard Williams, Marisa Alcaide-German, Neil Sebire, Sergey Popov, Kathy Pritchard-Jones, Stephan Beck. DNA methylation profiling describes Wilms tumor evolution from its precursor lesion. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Jun 19-22, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2013;73(13 Suppl):Abstract nr B36.

A quantitative spatiotemporal analysis of microglia morphology during ischemic stroke and reperfusion

BackgroundMicroglia cells continuously survey the healthy brain in a ramified morphology and, in response to injury, undergo progressive morphological and functional changes that encompass microglia activation. Although ideally positioned for immediate response to ischemic stroke (IS) and reperfusion, their progressive morphological transformation into activated cells has not been quantified. In addition, it is not well understood if diverse microglia morphologies correlate to diverse microglia functions. As such, the dichotomous nature of these cells continues to confound our understanding of microglia-mediated injury after IS and reperfusion. The purpose of this study was to quantitatively characterize the spatiotemporal pattern of microglia morphology during the evolution of cerebral injury after IS and reperfusion.MethodsMale C57Bl/6 mice were subjected to focal cerebral ischemia and periods of reperfusion (0, 8 and 24 h). The microglia process length/cell and number of endpoints/cell was quantified from immunofluorescent confocal images of brain regions using a skeleton analysis method developed for this study. Live cell morphology and process activity were measured from movies acquired in acute brain slices from GFP-CX3CR1 transgenic mice after IS and 24-h reperfusion. Regional CD11b and iNOS expressions were measured from confocal images and Western blot, respectively, to assess microglia proinflammatory function.ResultsQuantitative analysis reveals a significant spatiotemporal relationship between microglia morphology and evolving cerebral injury in the ipsilateral hemisphere after IS and reperfusion. Microglia were both hyper- and de-ramified in striatal and cortical brain regions (respectively) after 60 min of focal cerebral ischemia. However, a de-ramified morphology was prominent when ischemia was coupled to reperfusion. Live microglia were de-ramified, and, in addition, process activity was severely blunted proximal to the necrotic core after IS and 24 h of reperfusion. CD11b expression, but not iNOS expression, was increased in regions of hyper- and de-ramified microglia during the course of ischemic stroke and 24 h of reperfusion.ConclusionsOur findings illustrate that microglia activation after stroke includes both increased and decreased cell ramification. Importantly, quantitative analyses of microglial morphology and activity are feasible and, in future studies, would assist in the comprehensive identification and stratification of their dichotomous contribution toward cerebral injury and recovery during IS and reperfusion.