E.L., a modern-day Phineas Gage: Revisiting frontal lobe injury.

Background: How the prefrontal cortex (PFC) recovers its functionality following lesions remains a conundrum. Recent work has uncovered the importance of transient low-frequency oscillatory activity (LFO; < 4 Hz) for the recovery of an injured brain. We aimed to determine whether persistent cortical oscillatory dynamics contribute to brain capability to support 'normal life' following injury. Methods: In this 9-year prospective longitudinal study (08/2012-2021), we collected data from the patient E.L., a modern-day Phineas Gage, who suffered from lesions, impacting 11% of his total brain mass, to his right PFC and supplementary motor area after his skull was transfixed by an iron rod. A systematic evaluation of clinical, electrophysiologic, brain imaging, neuropsychological and behavioural testing were used to clarify the clinical significance of relationship between LFO discharge and executive dysfunctions and compare E.L.´s disorders to that attributed to Gage (1848), a landmark in the history of neurology and neuroscience. Findings: Selective recruitment of the non-injured left hemisphere during execution of unimanual right-hand movements resulted in the emergence of robust LFO, an EEG-detected marker for disconnection of brain areas, in the damaged right hemisphere. In contrast, recruitment of the damaged right hemisphere during contralateral hand movement, resulted in the co-activation of the left hemisphere and decreased right hemisphere LFO to levels of controls enabling performance, suggesting a target for neuromodulation. Similarly, transcranial magnetic stimulation (TMS), used to create a temporary virtual-lesion over E.L.'s healthy hemisphere, disrupted the modulation of contralateral LFO, disturbing behaviour and impairing executive function tasks. In contrast to Gage, reasoning, planning, working memory, social, sexual and family behaviours eluded clinical inspection by decreasing LFO in the delta frequency range during motor and executive functioning. Interpretation: Our study suggests that modulation of LFO dynamics is an important mechanism by which PFC accommodates neurological injuries, supporting the reports of Gage´s recovery, and represents an attractive target for therapeutic interventions. Funding: Fundação de Amparo Pesquisa Rio de Janeiro (FAPERJ), Universidade Federal do Rio de Janeiro (intramural), and Fiocruz/Ministery of Health (INOVA Fiocruz).

Genetic modifiers regulating DNA replication and double-strand break repair are associated with differences in mammary tumors in mouse models of Li-Fraumeni syndrome.

Breast cancer is the most common tumor among women with inherited variants in the TP53 tumor suppressor, but onset varies widely suggesting interactions with genetic or environmental factors. Rodent models haploinsufficent for Trp53 also develop a wide variety of malignancies associated with Li-Fraumeni syndrome, but BALB/c mice are uniquely susceptible to mammary tumors and is genetically linked to the Suprmam1 locus on chromosome 7. To define mechanisms that interact with deficiencies in p53 to alter susceptibility to mammary tumors, we fine mapped the Suprmam1 locus in females from an N2 backcross of BALB/cMed and C57BL/6J mice. A major modifier was localized within a 10 cM interval on chromosome 7. The effect of the locus on DNA damage responses was examined in the parental strains and mice that are congenic for C57BL/6J alleles on the BALB/cMed background (SM1-Trp53+/-). The mammary epithelium of C57BL/6J-Trp53+/- females exhibited little radiation-induced apoptosis compared to BALB/cMed-Trp53+/- and SM1-Trp53+/- females indicating that the Suprmam1B6/B6 alleles could not rescue repair of radiation-induced DNA double-strand breaks mostly relying on non-homologous end joining. In contrast, the Suprmam1B6/B6 alleles in SM1-Trp53+/- mice were sufficient to confer the C57BL/6J-Trp53+/- phenotypes in homology-directed repair and replication fork progression. The Suprmam1B6/B6 alleles in SM1-Trp53+/- mice appear to act in trans to regulate a panel of DNA repair and replication genes which lie outside the locus.

Enrichment of genes associated with squamous differentiation in cancer initiating cells isolated from urothelial cells transformed by the environmental toxicant arsenite.

Arsenic is an environmental toxicant with long-term exposure associated with the development of urothelial carcinomas. Our lab has developed an in-vitro model of urothelial carcinoma by exposing the immortal, but non-tumorigenic bladder cell line, the UROtsa, to arsenite (As3+). These transformed cells form tumors in immune-compromised mice, which resemble urothelial carcinomas with components of the tumor exhibiting squamous differentiation. The goal of the present study was to determine the differences in global gene expression patterns between the As3+-transformed UROtsa cells and the urospheres (spheroids containing putative cancer initiating cells) isolated from these cell lines and to determine if the genes involved in the development of squamous differentiation were enriched in the urospheres. The results obtained in this study show an enrichment of genes such as KRT1, KRT5, KRT6A, KRT6B, KRT6C, KRT14 and KRT16 associated with squamous differentiation, a characteristic feature seen in aggressive basal subtypes of urothelial cell carcinoma (UCC) in the urospheres isolated from As3+-transformed UROtsa cells. In addition, there is increased expression of several of the small proline-rich proteins (SPRR) in the urospheres and overexpression of these genes occur in UCC's displaying squamous differentiation. In conclusion, the cancer initiating cells present in the urospheres are enriched with genes associated with squamous differentiation.

Human renal tubular cells contain CD24/CD133 progenitor cell populations: Implications for tubular regeneration after toxicant induced damage using cadmium as a model.

The proximal tubules of the kidney are target sites of injury by various toxicants. Cadmium (Cd+2), an environmental nephrotoxicant can cause adverse effects and overt renal damage. To decipher the mechanisms involved in nephrotoxicity, an in vitro model system is required. Mortal cultures of human proximal tubule (HPT) cells have served, as models but are difficult to acquire and do not lend themselves to stable transfection. The immortalized human proximal tubule cell line HK-2, has served as a model but it lacks vectorial active transport and shows signs of lost epithelial features. Recently a new proximal tubule cell line was developed, the RPTEC/TERT1, and the goal of this study was to determine if this cell line could serve as a model to study nephrotoxicity. Global gene expression analysis of this cell line in comparison to the HK-2 and HPT cells showed that the RPTEC/TERT1 cells had gene expression patterns similar to HPT cells when compared to the HK-2 cells. The HPT and the RPTEC/TERT1 cell line had an increased population of stem/progenitor cells co-expressing CD24 and CD133 when compared to the HK-2 cells. The level of expression of cadherins, claudins and occludin molecules was also similar between the RPTEC/TERT1 and the HPT cells. Acute exposure to Cd+2 resulted in necrosis of the RPTEC/TERT1 cells when compared to the HK-2 cells which died by apoptosis. Thus, the RPTEC/TERT1 cells are similar to HPT cells and can serve as a good model system to study mechanisms involved in toxicant induced renal damage.

Biomarkers of Resilience in Stress Reduction for Caregivers of Alzheimer's Patients.

Caregiving for a dementia patient is associated with increased risk of psychological and physical health problems. We investigated whether a mindfulness-based stress reduction (MBSR) training course for caregivers that closely models the MBSR curriculum originally established by the Center of Mindfulness at the University of Massachusetts may improve the psychological resilience of non-professional caregivers of Alzheimer's disease patients. Twenty adult non-professional caregivers of dementia patients participated in an 8-week MBSR training course. Caregiver stress, depression, burden, grief, and gene expression profiles of blood mononuclear cells were assessed at baseline and following MBSR. MBSR training significantly improved the psychological resilience of some of the caregivers. We identified predictive biomarkers whose expression is associated with the likelihood of caregivers to benefit from MBSR, and biomarkers whose expression is associated with MBSR psychological benefits. Our biomarker studies provide insight into the mechanisms of health benefits of MBSR and a basis for developing a personalized medicine approach for applying MBSR for promoting psychological and cognitive resilience in caregivers of dementia patients.

Select small nucleolar RNAs in blood components as novel biomarkers for improved identification of comorbid traumatic brain injury and post-traumatic stress disorder in veterans of the conflicts in Afghanistan and Iraq.

BACKGROUND: The present study was designed to validate the ability of our recently identified set of small noncoding RNA candidate mild traumatic brain injury (mTBI) biomarkers to diagnose mTBI in the presence or absence of post-traumatic stress disorder (PTSD) comorbidity. Using qPCR, we explored the regulation of the candidate biomarkers in peripheral blood mononuclear cells (PBMC) from 58 veterans. RESULTS: We confirmed that 4 small nucleolar RNAs (snoRNAs), ACA48, U35, U55, and U83A, are significantly down-regulated in PBMC from veterans with mTBI and PTSD compared to non-TBI, control subjects with PTSD only. We found that the snoRNA biomarkers are able to dissect subjects with comorbid mTBI and PTSD from PTSD subjects without mTBI with 100% sensitivity, 81% accuracy, and 72% specificity. No significant differential expression of snoRNA biomarkers was found in mTBI subjects without comorbid PTSD. However, we found significantly lower U55 contents in subjects with PTSD. We explored the regulation of ACA48 in rodent models of PTSD or blast-induced mTBI to gather proof-of-concept evidence that would connect the regulation of the biomarkers and the development of mTBI or PTSD. We found no change in the regulation of ACA48 in the mTBI rat model. We did, however, find significant down-regulation of ACA48 in the PTSD mouse model 24 hours following psychological trauma exposure. This may reflect a short-term response to trauma exposure, since we found no change in the regulation of ACA48 in veteran PTSD subjects 3.6 years post-deployment. CONCLUSIONS: Additional application of the 4 snoRNA biomarker to current diagnostic criteria may provide an objective biomarker pattern to help identify veterans with comorbid mTBI and PTSD. Our observations suggest that biological interactions between TBI and PTSD may contribute to the clinical features of veterans with comorbid mTBI and PTSD. Future investigations on mTBI mechanisms or TBI biomarkers should consider their interactions with PTSD.

CM156, a sigma receptor ligand, reverses cocaine-induced place conditioning and transcriptional responses in the brain.

Repeated exposure to cocaine induces neuroadaptations which contribute to the rewarding properties of cocaine. Using cocaine-induced conditioned place preference (CPP) as an animal model of reward, earlier studies have shown that sigma (σ) receptor ligands can attenuate the acquisition, expression and reactivation of CPP. However, the underlying molecular mechanisms that are associated with these changes are not yet understood. In the present study, CM156, a novel antagonist with high selectivity and affinity for σ receptors was used to attenuate the expression of cocaine-induced CPP in mice. Immediately following the behavioral evaluations, mouse brain tissues were collected and alterations in gene expression in half brain samples were profiled by cDNA microarray analysis. Microarray data was analyzed by three distinct normalization methods and four genes were consistently found to be upregulated by cocaine when compared to saline controls. Each of these gene changes were found by more than one normalization method to be reversed by at least one dose of CM156. Quantitative real time PCR confirmed that a single administration of CM156 was able to reverse the cocaine-induced increases in three of these four genes: metastasis associated lung adenocarcinoma transcript 1 (malat1), tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein (ywhaz), and transthyretin (ttr). These genes are involved in processes related to neuroplasticity and RNA editing. The data presented herein provides evidence that pharmacological intervention with a putative σ receptor antagonist reverses alterations in gene expression that are associated with cocaine-induced reward.

The viral theory of schizophrenia revisited: abnormal placental gene expression and structural changes with lack of evidence for H1N1 viral presence in placentae of infected mice or brains of exposed offspring.

Researchers have long noted an excess of patients with schizophrenia were born during the months of January and March. This winter birth effect has been hypothesized to result either from various causes such as vitamin D deficiency (McGrath, 1999; McGrath et al., 2010), or from maternal infection during pregnancy. Infection with a number of viruses during pregnancy including influenza, and rubella are known to increase the risk of schizophrenia in the offspring (Brown, 2006). Animal models using influenza virus or Poly I:C, a viral mimic, have been able to replicate many of the brain morphological, genetic, and behavioral deficits of schizophrenia (Meyer et al., 2006, 2008a, 2009; Bitanihirwe et al., 2010; Meyer and Feldon, 2010; Short et al., 2010). Using a murine model of prenatal viral infection, our laboratory has shown that viral infection on embryonic days 9, 16, and 18 leads to abnormal expression of brain genes and brain structural abnormalities in the exposed offspring (Fatemi et al., 2005, 2008a,b, 2009a,b). The purpose of the current study was to examine gene expression and morphological changes in the placenta, hippocampus, and prefrontal cortex as a result of viral infection on embryonic day 7 of pregnancy. Pregnant mice were either infected with influenza virus [A/WSN/33 strain (H1N1)] or sham-infected with vehicle solution. At E16, placentas were harvested and prepared for either microarray analysis or for light microscopy. We observed significant, upregulation of 77 genes and significant downregulation of 93 genes in placentas. In brains of exposed offspring following E7 infection, there were changes in gene expression in prefrontal cortex (6 upregulated and 24 downregulated at P0; 5 upregulated and 14 downregulated at P56) and hippocampus (4 upregulated and 6 downregulated at P0; 6 upregulated and 13 downregulated at P56). QRT-PCR verified the direction and magnitude of change for a number of genes associated with hypoxia, inflammation, schizophrenia, and autism. Placentas from infected mice showed a number of morphological abnormalities including presence of thrombi and increased presence of immune cells. Additionally, we searched for presence of H1N1 viral-specific genes for M1/M2, NA, and NS1 in placentas of infected mice and brains of exposed offspring and found none. Our results demonstrate that prenatal viral infection disrupts structure and gene expression of the placenta, hippocampus, and prefrontal cortex potentially explaining deleterious effects in the exposed offspring without evidence for presence of viral RNAs in the target tissues.

Dietary olive oil and menhaden oil mitigate induction of lipogenesis in hyperinsulinemic corpulent JCR:LA-cp rats: microarray analysis of lipid-related gene expression.

In the corpulent James C. Russell corpulent (JCR:LA-cp) rat, hyperinsulinemia leads to induction of lipogenic enzymes via enhanced expression of sterol-regulatory-binding protein (SREBP)-1c. This results in increased hepatic lipid production and hypertriglyceridemia. Information regarding down-regulation of SREBP-1c and lipogenic enzymes by dietary fatty acids in this model is limited. We therefore assessed de novo hepatic lipogenesis and hepatic and plasma lipids in corpulent JCR rats fed diets enriched in olive oil or menhaden oil. Using microarray and Northern analysis, we determined the effect of these diets on expression of mRNA for lipogenic enzymes and other proteins related to lipid metabolism. In corpulent JCR:LA-cp rats, both the olive oil and menhaden oil diets reduced expression of SREBP-1c, with concomitant reductions in hepatic triglyceride content, lipogenesis, and expression of enzymes related to lipid synthesis. Unexpectedly, expression of many peroxisomal proliferator-activated receptor-dependent enzymes mediating fatty acid oxidation was increased in livers of corpulent JCR rats. The menhaden oil diet further increased expression of these enzymes. Induction of SREBP-1c by insulin is dependent on liver x receptor (LXR)alpha. Although hepatic expression of mRNA for LXR itself was not increased in corpulent rats, expression of Cyp7a1, an LXR-responsive gene, was increased, suggesting increased LXR activity. Expression of mRNA encoding fatty acid translocase and ATP-binding cassette subfamily DALD member 3 was also increased in livers of corpulent JCR rats, indicating a potential role for these fatty acid transporters in the pathogenesis of disordered lipid metabolism in obesity. This study clearly demonstrates that substitution of dietary polyunsaturated fatty acid for carbohydrate in the corpulent JCR:LA-cp rat reduces de novo lipogenesis, at least in part, by reducing hepatic expression of SREBP-1c and that strategies directed toward reducing SREBP-1c expression in the liver may mitigate the adverse effects of hyperinsulinemia on hepatic lipid production.

Shaping gene expression in activated and resting primary macrophages by IL-10.

IL-10 regulates inflammation by reducing cytokine and chemokine production from activated macrophages. We performed microarray experiments to identify possible effector molecules of IL-10 and to investigate the global effect of IL-10 on the transcriptional response induced in LPS-activated macrophages. To exclude background effects of endogenous IL-10, macrophages from IL-10-deficient mice were used. IL-10 up-regulated expression of a small number of genes (26 and 37 after 45 min and 3 h, respectively), including newly identified and previously documented targets such as suppressor of cytokine signaling-3 and IL-1 receptor antagonist. However, the activation program triggered by LPS was profoundly affected by IL-10. IL-10 repressed 62 and further increased 15 of 259 LPS-induced genes. For all genes examined, the effects of IL-10 were determined to be STAT3-dependent. These results suggest that IL-10 regulates STAT3-dependent pathways that selectively target a broad component of LPS-induced genes at the mRNA level.

Classification, subtype discovery, and prediction of outcome in pediatric acute lymphoblastic leukemia by gene expression profiling.

Treatment of pediatric acute lymphoblastic leukemia (ALL) is based on the concept of tailoring the intensity of therapy to a patient's risk of relapse. To determine whether gene expression profiling could enhance risk assignment, we used oligonucleotide microarrays to analyze the pattern of genes expressed in leukemic blasts from 360 pediatric ALL patients. Distinct expression profiles identified each of the prognostically important leukemia subtypes, including T-ALL, E2A-PBX1, BCR-ABL, TEL-AML1, MLL rearrangement, and hyperdiploid >50 chromosomes. In addition, another ALL subgroup was identified based on its unique expression profile. Examination of the genes comprising the expression signatures provided important insights into the biology of these leukemia subgroups. Further, within some genetic subgroups, expression profiles identified those patients that would eventually fail therapy. Thus, the single platform of expression profiling should enhance the accurate risk stratification of pediatric ALL patients.