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TREX1 is an exonuclease that degrades extranuclear DNA species in mammalian cells. Herein, we show a novel mechanism by which TREX1 interacts with the BiP/GRP78 and TREX1 deficiency triggers ER stress through the accumulation of single-stranded DNA and activates unfolded protein response (UPR) signaling via the disruption of the TREX1-BiP/GRP78 interaction. In TREX1 knockdown cells, the activation of ER stress signaling disrupted ER Ca2+ homeostasis via the ERO1α-IP3R1-CaMKII pathway, leading to neuronal cell death. Moreover, TREX1 knockdown dysregulated the Golgi-microtubule network through Golgi fragmentation and decreased Ac-α-tubulin levels, contributing to neuronal injury. These alterations were also observed in neuronal cells harboring a TREX1 mutation (V91M) that has been identified in hereditary spastic paraplegia (HSP) patients in Korea. Notably, this mutation leads to defects in the TREX1-BiP/GRP78 interaction and mislocalization of TREX1 from the ER and possible disruption of the Golgi-microtubule network. In summary, the current study reveals TREX1 as a novel regulator of the BiP/GRP78 interaction and shows that TREX1 deficiency promotes ER stress-mediated neuronal cell death, which indicates that TREX1 may hold promise as a therapeutic target for neurodegenerative diseases such as HSP.

Intellectual disability (ID) is a neurodevelopmental disorder defined by below-average intelligence (intelligence quotient of

The neural circuits of the infant brain are rapidly established near 6 months of age, but neurodevelopmental disorders can be diagnosed only at the age of 2–3 years using existing diagnostic methods. Early diagnosis is very important to alleviate life-long disability in patients through appropriate early intervention, and it is imperative to develop new diagnostic methods for early detection of neurodevelopmental disorders. We examined the serum level of secretogranin II (SCG2) in pediatric patients to evaluate its potential role as a biomarker for neurodevelopmental disorders. A plasmonic immunosensor performing an enzyme-linked immunosorbent assay (ELISA) on a gold nanodot array was developed to detect SCG2 in small volumes of serum. This nanoplasmonic immunosensor combined with tyramide signal amplification was highly sensitive to detect SCG2 in only 5 μL serum samples. The analysis using the nanoplasmonic immunosensor revealed higher serum SCG2 levels in pediatric patients with developmental delay than in the control group. Overexpression or knockdown of SCG2 in hippocampal neurons significantly attenuated dendritic arborization and synaptic formation. These results suggest that dysregulated SCG2 expression impairs neural development. In conclusion, we developed a highly sensitive nanoplasmonic immunosensor to detect serum SCG2, a candidate biomarker for the early diagnosis of neurodevelopmental disorders.

As global plastic production continues to grow, microplastics released from a massive quantity of plastic wastes have become a critical environmental concern. These microplastic particles are found in a wide range of living organisms in a diverse array of ecosystems. In this study, we investigated the biological effects of polystyrene nanoplastics (PSNPs) on development of the central nervous system using cultured neural stem cells (NSCs) and mice exposed to PSNPs during developmental stages. Our study demonstrates that maternal administration of PSNPs during gestation and lactating periods altered the functioning of NSCs, neural cell compositions, and brain histology in progeny. Similarly, our in vitro study also shows PSNP-induced molecular and functional defects in NSCs. Finally, we show that the abnormal brain development caused by exposure to high concentrations of PSNPs results in neurophysiological and cognitive deficits in a gender-specific manner. Our data demonstrate the possibility that exposure to high amounts of PSNPs may increase the risk of neurodevelopmental defects.

Metabolic syndrome (MetS) is a group of risk factors that causes cardiovascular and diabetic morbidity and mortality, which is diagnosed by central obesity, dyslipidemia, hyperglycemia, and hypertension. Increasing epidemiological data and experimental results indicate that the presence of MetS increases the incidence of common malignancies and related mortality. Epidemiological studies have previously reported an association of endometrial cancer occurrence with MetS. Aromatization of androstenedione to estrogen, insulin resistance, and diabetes can cause increased levels of free estrogen, and the detrimental effect of elevated estrogen as a carcinogen is well studied in endometrial cancer. Medications used to manage MetS such as metformin and statins are suggested to reduce endometrial cancer risk and improve survival. Some large population-based epidemiological studies have suggested that the MetS is related to an increased risk of cervical carcinoma. MetS may contribute to viral-host interactions, which lead to persistent human papilloma virus (HPV) infection, although limited epidemiological data are available. Specific effects of obesity and diabetes on the occurrence of ovarian cancer have been suggested. However, the direct correlation between MetS and ovarian cancer is still lacking. Previous retrospective studies reported that the use of metformin, statins, and beta-blockers could be associated with cancer prevention or better prognosis. Proper diagnosis and management of the MetS should be a part of the strategies undertaken to prevent and treat gynecologic cancer. So far, only limited data is available on this subject, and further clinical and fundamental research is required to further clarify the effect of these therapies on gynecologic cancer treatment.

TMEM16A, a Ca(2+)‐activated Cl(−) channel, is known to modulate the excitability of various types of cells; however, its function in central neurons is largely unknown. Here, we show the specific expression of TMEM16A in the medial habenula (mHb) via RNAscope in situ hybridization, immunohistochemistry, and electrophysiology. When TMEM16A is ablated in the mHb cholinergic neurons (TMEM16A cKO mice), the slope of after‐hyperpolarization of spontaneous action potentials decreases and the firing frequency is reduced. Reduced mHb activity also decreases the activity of the interpeduncular nucleus (IPN). Moreover, TMEM16A cKO mice display anxiogenic behaviors and deficits in social interaction without despair‐like phenotypes or cognitive dysfunctions. Finally, chemogenetic inhibition of mHb cholinergic neurons using the DREADD (Designer Receptors Exclusively Activated by Designer Drugs) approach reveals similar behavioral phenotypes to those of TMEM16A cKO mice. We conclude that TMEM16A plays a key role in anxiety‐related behaviors regulated by mHb cholinergic neurons and could be a potential therapeutic target against anxiety‐related disorders.

Summary Schwann cells play a crucial role in successful nerve repair and regeneration by supporting both axonal growth and myelination. However, the sources of human Schwann cells are limited both for studies of Schwann cell development and biology and for the development of treatments for Schwann cell-associated diseases. Here, we provide a rapid and scalable method to produce self-renewing Schwann cell precursors (SCPs) from human pluripotent stem cells (hPSCs), using combined sequential treatment with inhibitors of the TGF-β and GSK-3 signaling pathways, and with neuregulin-1 for 18 days under chemically defined conditions. Within 1 week, hPSC-derived SCPs could be differentiated into immature Schwann cells that were functionally confirmed by their secretion of neurotrophic factors and their myelination capacity in vitro and in vivo. We propose that hPSC-derived SCPs are a promising, unlimited source of functional Schwann cells for treating demyelination disorders and injuries to the peripheral nervous system., Highlights • hPSC-SCPs are highly expandable under chemically defined medium condition • hPSC-SCPs can rapidly and efficiently differentiate into functional Schwann cells • SCP-SCs myelinate axon and secrete various neurotrophic factors • SCP-SCs promote axonal regeneration in sciatic nerve-damaged mice, In this article, Cho and colleagues show that an efficient strategy for producing directly an unlimited supply of functional human Schwann cells (SCs) via successful derivation of expandable Schwann cell precursors (SCPs) from human pluripotent stem cells (hPSC-SCPs). Functional and molecular characteristic of SCs from hPSC-SCPs (SCP-SCs) were shown both in vitro and in vivo.

Low-grade gliomas are one of the most common brain tumors in children, where they frequently form within the optic pathway (optic pathway gliomas; OPGs). Since many OPGs occur in the context of the Neurofibromatosis Type 1 (NF1) cancer predisposition syndrome, we have previously employed Nf1 genetically-engineered mouse (GEM) strains to study the pathogenesis of these low-grade glial neoplasms. In the light of the finding that human and mouse low-grade gliomas are composed of Olig2+ cells and that Olig2+ oligodendrocyte precursor cells (OPCs) give rise to murine high-grade gliomas, we sought to determine whether Olig2+ OPCs could be tumor-initiating cells for Nf1 optic glioma. Similar to the GFAP-Cre transgenic strain previously employed to generate Nf1 optic gliomas, Olig2+ cells also give rise to astrocytes in the murine optic nerve in vivo. However, in contrast to the GFAP-Cre strain where somatic Nf1 inactivation in embryonic neural progenitor/stem cells (Nf1flox/mut; GFAP-Cre mice) results in optic gliomas by 3 months of age in vivo, mice with Nf1 gene inactivation in Olig2+ OPCs (Nf1flox/mut; Olig2-Cre mice) do not form optic gliomas until 6 months of age. These distinct patterns of glioma latency do not reflect differences in the timing or brain location of somatic Nf1 loss. Instead, they most likely reflect the cell of origin, as somatic Nf1 loss in CD133+ neural progenitor/stem cells during late embryogenesis results in optic gliomas at 3 months of age. Collectively, these data demonstrate that the cell of origin dictates the time to tumorigenesis in murine optic glioma.

mTOR is a serine/threonine kinase composed of multiple protein components. Intracellular signaling of mTOR complexes is involved in many of physiological functions including cell survival, proliferation and differentiation through the regulation of protein synthesis in multiple cell types. During brain development, mTOR-mediated signaling pathway plays a crucial role in the process of neuronal and glial differentiation and the maintenance of the stemness of neural stem cells. The abnormalities in the activity of mTOR and its downstream signaling molecules in neural stem cells result in severe defects of brain developmental processes causing a significant number of brain disorders, such as pediatric brain tumors, autism, seizure, learning disability and mental retardation. Understanding the implication of mTOR activity in neural stem cells would be able to provide an important clue in the development of future brain developmental disorder therapies.

Adenomyosis is a common gynecological disorder characterized by the presence of endometrial glands and stroma deep within the myometrium associated with myometrial hypertrophy and hyperplasia. Focal uterine infarction after IVF-ET in a patient with adenomyosis following biochemical pregnancy has not been previously reported, although it occurs after uterine artery embolization in order to control symptoms caused by fibroids or adenomyosis. We report a case of a nulliparous woman who had uterine adenomyosis presenting with fever, pelvic pain and biochemical abortion after undergoing an IVF-ET procedure and the detection of a slightly elevated serum hCG. Focal uterine infarction was suspected after a pelvic magnetic resonance imaging demonstrated preserved myometrium between the endometrial cavity and inner margin of the necrotic myometrium. This case demonstrates that focal uterine infarction should be considered in the differential diagnosis of acute abdominal pain, vaginal bleeding and infectious signs in women experiencing biochemical abortion after an IVF-ET procedure.

In Alzheimer's disease (AD), memory impairment is the most prominent feature that afflicts patients and their families. Although reactive astrocytes have been observed around amyloid plaques since the disease was first described, their role in memory impairment has been poorly understood. Here, we show that reactive astrocytes aberrantly and abundantly produce the inhibitory gliotransmitter GABA by monoamine oxidase-B (Maob) and abnormally release GABA through the bestrophin 1 channel. In the dentate gyrus of mouse models of AD, the released GABA reduces spike probability of granule cells by acting on presynaptic GABA receptors. Suppressing GABA production or release from reactive astrocytes fully restores the impaired spike probability, synaptic plasticity, and learning and memory in the mice. In the postmortem brain of individuals with AD, astrocytic GABA and MAOB are significantly upregulated. We propose that selective inhibition of astrocytic GABA synthesis or release may serve as an effective therapeutic strategy for treating memory impairment in AD.

Neural epidermal growth factor-like protein-like 2 (NELL2) is a secreted glycoprotein that is predominantly expressed in the nervous system, but little is known about the intracellular movement and secretion mechanism of this protein. By monitoring the localization and movements of enhanced green fluorescent protein (EGFP)-labeled NELL2 in living cultured hippocampal neuroprogenitor HiB5 cells, we determined the subcellular localization of NELL2 and its intracellular movement and secretion mechanism. C-terminal EGFP-fused NELL2 showed a typical expression pattern of secreted proteins, especially with respect to its localization in the endoplasmic reticulum, Golgi apparatus, and punctate structures. Vesicles containing NELL2 exhibited bidirectional movement in HiB5 cells. The majority of the vesicles (70.1%) moved in an anterograde direction with an average velocity of 0.454 μm/s, whereas some vesicles (28.7%) showed retrograde movement with an average velocity of 0.302 μm/s. The movement patterns of NELL2 vesicles were dependent upon the presence of microtubules in HiB5 cells. Anterograde movement of NELL2 did not lead to a detectable accumulation of NELL2 in the peripheral region of the cell, indicating that it was secreted into the culture medium. We also showed that the N-terminal 29 amino acids of NELL2 were important for secretion of this protein. Taken together, these results strongly suggest that the N-terminal region of NELL2 determines both the pattern of its intracellular expression and transport of NELL2 vesicles by high-velocity movement. Therefore, NELL2 may affect the cellular activity of cells in a paracrine or autocrine manner.

SummaryThe concept that gliomas comprise a heterogeneous group of diseases distinguished by their developmental origin raises the intriguing possibility that neural stem cells (NSCs) from different germinal zones have differential capacities to respond to glioma-causing genetic changes. We demonstrate that lateral ventricle subventricular zone NSCs are molecularly and functionally distinct from those of the third ventricle. Consistent with a unique origin for pediatric low-grade glioma, third ventricle, but not lateral ventricle, NSCs hyperproliferate in response to mutations characteristic of childhood glioma. Finally, we demonstrate that pediatric optic gliomas in Nf1 genetically engineered mice arise from the third ventricle. Collectively, these observations establish the importance of innate brain region NSC heterogeneity in the patterning of gliomagenesis in children and adults.

Recent evidence indicates differences in neural stem cell biology in different brain regions. For example, we demonstrated that neurofibromatosis 1 (NF1) tumor suppressor gene inactivation leads to increased neural stem cell proliferation and gliogenesis in the optic chiasm and brainstem but not in the cerebral cortex. The differential effect of Nf1 inactivation in the optic nerve and brainstem (in which gliomas commonly form in children with NF1) versus the cortex (in which gliomas rarely develop) suggests the existence of distinct ventricular zones for gliomagenesis in children and in adults. Here, we characterized the third ventricle subventricular zone (tv-SVZ) in young and adult mouse and human brains. In children, but not adult humans, the tv-SVZ contains nestin-positive, glial fibrillary acidic protein-positive, brain fatty acid binding protein-positive, and sox2-positive cells with radial processes and prominent cilia. In contrast, the tv-SVZ in young mice contains sox2-positive progenitor cells and ciliated ependymal lining cells but lacks glial fibrillary acidic protein-positive, nestin-positive radial glia. As in the lateral ventricle SVZ, proliferation in the human and murine tv-SVZ decreases with age. The tv-SVZ in adult mice lacks the hypocellular subventricular zone observed in adult human specimens. Collectively, these data indicate the existence of a subventricular zone relevant to our understanding of glioma formation in children and will assist interpretation of genetically engineered mouse glioma models.

Recent studies have shown that neuroglial progenitor/stem cells (NSCs) from different brain regions exhibit varying capacities for self-renewal and differentiation. In this study, we used neurofibromatosis-1 (NF1) as a model system to elucidate a novel molecular mechanism underlying brain region-specific NSC functional heterogeneity. We demonstrate that Nf1 loss leads to increased NSC proliferation and gliogenesis in the brainstem, but not in the cortex. Using Nf1 genetically engineered mice and derivative NSC neurosphere cultures, we show that this brain region-specific increase in NSC proliferation and gliogenesis results from selective Akt hyperactivation. The molecular basis for the increased brainstem-specific Akt activation in brainstem NSCs is the consequence of differential rictor expression, leading to region-specific mammalian target of rapamycin (mTOR)/rictor-mediated Akt phosphorylation and Akt-regulated p27 phosphorylation. Collectively, these findings establish mTOR/rictor-mediated Akt activation as a key driver of NSC proliferation and gliogenesis, and identify a unique mechanism for conferring brain region-specific responses to cancer-causing genetic changes.

Numerous studies have suggested that astrocytes in the central nervous system (CNS) exhibit molecular and functional heterogeneity. In this regard, astroglia from different CNS locations express distinct immune system, and neurotransmitter proteins, have varying levels of gap junction coupling and respond differently to injury. However, the relevance of these differences to human disease is unclear. As brain tumors in children arise in specific CNS locations, we hypothesized that regional astroglial cell heterogeneity might partly underlie the propensity for gliomas to arise in these areas. In this study, we performed high-density RNA microarray profiling on astrocytes from postnatal day 1 optic nerve, cerebellum, brainstem, and neocortex. We showed that astroglia from each region are molecularly distinct, and we were able to develop gene expression patterns that distinguish astroglia, but not neural stem cells, from these different brain regions. We next used these microarray data to determine whether brain tumor suppressor genes were differentially expressed in these distinct populations of astroglia. Interestingly, neurofibromatosis type 1 (NF1) gene expression was decreased at both the RNA and protein levels in neocortical astroglia relative to astroglia from the other brain regions. To determine the functional significance of this finding, we found increased astroglial cell proliferation in optic nerve, brainstem, and cerebellum, but not neocortex, following Nf1 inactivation in vitro and in vivo. These findings provide molecular evidence for CNS astroglial cell heterogeneity, and suggest that differences in tumor suppressor gene expression might contribute to the regional localization of human brain tumors.

Background Two-pore domain K+ (K2P) channels have been shown to modulate neuronal excitability. However, physiological function of TWIK-1, the first identified member of the mammalian K2P channel family, in neuronal cells is largely unknown. Results We found that TWIK-1 proteins were expressed and localized mainly in the soma and proximal dendrites of dentate gyrus granule cells (DGGCs) rather than in distal dendrites or mossy fibers. Gene silencing demonstrates that the outwardly rectifying K+ current density was reduced in TWIK-1-deficient granule cells. TWIK-1 deficiency caused a depolarizing shift in the resting membrane potential (RMP) of DGGCs and enhanced their firing rate in response to depolarizing current injections. Through perforant path stimulation, TWIK-1-deficient granule cells showed altered signal input-output properties with larger EPSP amplitude values and increased spiking compared to control DGGCs. In addition, supra-maximal perforant path stimulation evoked a graded burst discharge in 44% of TWIK-1-deficient cells, which implies impairment of EPSP-spike coupling. Conclusions These results showed that TWIK-1 is functionally expressed in DGGCs and contributes to the intrinsic excitability of these cells. The TWIK-1 channel is involved in establishing the RMP of DGGCs; it attenuates sub-threshold depolarization of the cells during neuronal activity, and contributes to EPSP-spike coupling in perforant path-to-granule cell synaptic transmission. Electronic supplementary material The online version of this article (doi:10.1186/s13041-014-0080-z) contains supplementary material, which is available to authorized users.

Objective To investigate individual pretreatment serum human chorionic gonadotropin (hCG) cutoff value for medical treatment success with single-dose and multi-dose regimen of methotrexate in tubal ectopic pregnancy. Methods Eighty-five women who received methotrexate for the treatment of tubal ectopic pregnancy during 2003 to 2015 were selected. Fifty-three women received a single-dose regimen and 32 women received a multi-dose regimen. Medical treatment failure was defined as necessity of surgical treatment. The medical treatment success rate was estimated in both regimens and the pretreatment serum hCG titer to predict the success was assessed by receiver operating characteristics curve analysis. Results Pretreatment clinical and laboratory parameters were similar between group of single-dose regimen and multi-dose regimen. Treatment success rate was 64.2% in the single-dose regimen group and 71.9% in the multi-dose regimen group (P>0.05). Pretreatment serum hCG titer was an independent prognostic factor for treatment success in each regimen. Serum hCG cutoff value to predict the treatment success was 3,026 IU/L in single-dose regimen group and 3,711 IU/L in multi-dose regimen group. Conclusion We recommend use of single-dose regimen when pretreatment serum hCG

The availability of adult malignant glioma stem cells (GSCs) has provided unprecedented opportunities to identify the mechanisms underlying treatment resistance. Unfortunately, there is a lack of comparable reagents for the study of pediatric low-grade glioma (LGG). Leveraging a neurofibromatosis-1 (Nf1) genetically-engineered mouse LGG model, we report the isolation of CD133+ multi-potent low-grade glioma stem cells (LG-GSCs), which generate glioma-like lesions histologically similar to the parent tumor following injection into immunocompetent hosts. In addition, we demonstrate that these LG-GSCs harbor selective resistance to currently-employed conventional and biologically-targeted anti-cancer agents, which reflect the acquisition of new targetable signaling pathway abnormalities. Using transcriptomal analysis to identify additional molecular properties, we discovered that mouse and human LG-GSCs harbor high levels of Abcg1 expression critical for protecting against endoplasmic reticulum (ER) stress-induced mouse LG-GSC apoptosis. Collectively, these findings establish that LGG cancer stem cells have unique molecular and functional properties relevant to brain cancer treatment.

Objective To evaluate the clinical and pathologic factors associated with survival in patients with neuroendocrine cervical carcinoma (NECC). Methods The records of 61 patients with NECC diagnosed between 2000 and 2014 at Seoul National University Hospital and the National Cancer Center were retrospectively reviewed. Kaplan-Meier and Cox regression methods were used for analyses. Results Of the 61 patients, 67.2% were diagnosed at early stage (I to IIA) with a median age of 49 years. Of those, 78% underwent surgery and 75.6% received postoperative adjuvant treatment. For patients diagnosed at advanced stage, 60.0% received chemotherapy only and 25.0% received concurrent chemoradiation therapy. In the univariate analysis, advanced stage (77 vs. 40 months, P=0.013), tumor size ≥2 cm (133 vs. 47 months, P=0.002) and mixed tumor (101 vs. 34 months, P=0.004) were shown to be poor prognostic factors. In the multivariate analysis, tumor stage, tumor size and tumor homology were shown to be independent prognostic factors for overall survival. Of the total, 39.3% of the patients experienced recurrence, and 54.1% of the patients had metastasis. Of the patients diagnosed at early stage, 51.2% experienced recurrence. Conclusion Tumor stage, tumor size and tumor homology were found to be independent prognostic factors in patients with NECC. Even in patients diagnosed at early stage, recurrence and distant metastasis were frequently observed.

Objective To estimate the incidence of falsely elevated risk of ovarian malignancy algorithm (ROMA) in a group of women with pathologically confirmed endometrioma and to investigate the associated factors. Methods One hundred premenopausal women surgically diagnosed with ovarian endometrioma were selected. Preoperative clinical, laboratory, and surgical characteristics were compared between the elevated-risk group (ROMA-premenopausal value, ≥7.4%) and normal-risk group (ROMA-premenopausal value, 82.3 U/mL and serum level of human epididymis protein 4 (HE4) >46 pmol/L could predict an elevated ROMA test with a statistical significance. When serum level of HE4 ≤46 pmol/L, none of the women showed an elevated ROMA test, regardless of serum level of CA 125; however, 55.6% of the women showed an elevated ROMA test when serum level of HE4 >46 pmol/L and CA 125 ≤82.3 U/mL and all women showed an elevated ROMA test when serum level of HE4 >46 pmol/L and CA 125 >82.3 U/mL. Conclusion The incidence of falsely elevated ROMA was 15% in the group of women with pathologically confirmed endometrioma. Interpretation of the ROMA results should be cautious when serum level of HE4 >46 pmol/L and CA 125 >82.3 U/mL in women with suspicious ovarian endometrioma.

To study the role of the neurofibromatosis-1 (NF1) gene in mammalian brain development, we recently generated mice in which Nf1 gene inactivation occurs in neuroglial progenitor cells using the brain lipid binding protein (BLBP) promoter. We found that Nf1(BLBP)CKO mice exhibit significantly reduced body weights and anterior pituitary gland sizes. We further demonstrate that the small anterior pituitary size reflects loss of neurofibromin expression in the hypothalamus, leading to reduced growth hormone releasing hormone, pituitary growth hormone (GH) and liver insulin-like growth factor-1 (IGF1) production. Since neurofibromin both negatively regulates Ras activity and positively modulates cAMP levels, we examined the signaling pathway responsible for these abnormalities. While BLBP-mediated expression of an activated Ras molecule did not recapitulate the body weight and hypothalamic/pituitary defects, treatment of Nf1(BLBP)CKO mice with rolipram to increase cAMP levels resulted in a partial restoration of the body weight phenotype. Furthermore, conditional expression of the Ras regulatory GAP domain of neurofibromin also did not rescue the body weight or Igf1 mRNA defects in Nf1(BLBP)CKO mice. Collectively, these data demonstrate a critical role for neurofibromin in hypothalamic-pituitary axis function and provide further insights into the short stature and GH deficits seen in children with NF1.

The present study investigated whether thrombin, a potent microglial activator, can induce reactive oxygen species (ROS) generation through activation of microglial NADPH oxidase and if this may contribute to oxidative damage and consequent neurodegeneration. Seven days after intrahippocampal injection of thrombin, Nissl staining and immunohistochemistry using the neuronal-specific nuclear protein NeuN revealed a significant loss in hippocampal CA1 neurons. In parallel, thrombin-activated microglia, assessed by OX-42 and OX-6 immunohistochemistry, and ROS production, assessed by hydroethidine histochemistry, were observed in the hippocampal CA1 area in which degeneration of hippocampal neurons occurred. Reverse transcription-PCR at various time points after thrombin administration demonstrated an early and transient expression of inducible nitric oxide synthase (iNOS) and several proinflammatory cytokines. Western blot analysis and double-label immunohistochemistry showed an increase in the expression of and the localization of iNOS within microglia. Additional studies demonstrated that thrombin induced the upregulation of membrane (gp91phox) and cytosolic (p47phoxand p67phox) components, translocation of cytosolic proteins (p47phox, p67phox, and Rac1) to the membrane, and p67phoxexpression of the NADPH oxidase in microglia in the hippocampusin vivo, indicating the activation of NADPH oxidase. The thrombin-induced oxidation of proteins and loss of hippocampal CA1 neurons were partially inhibited by an NADPH oxidase inhibitor and by an antioxidant. To our knowledge, the present study is the first to demonstrate that thrombin-induced neurotoxicity in the hippocampusin vivois caused by microglial NADPH oxidase-mediated oxidative stress. This suggests that thrombin inhibition or enhancing antioxidants may be beneficial for the treatment of neurodegenerative diseases, such as Alzheimer's disease, that are associated with microglial-derived oxidative damage.

Solid tumors are complex ecosystems, composed of a heterogeneous ensemble of cells that comprise the tumor mass (neoplastic compartment) and the surrounding stroma (non-neoplastic compartment). Currently, research efforts are aimed at defining the individual contributions of each cell type to tumor development and maintenance. Previous studies using a genetically-engineered mouse model of Neurofibromatosis type 1 (NF1)-associated optic glioma have underscored the critical role of one stromal cell type (microglia) in the growth of these tumors. In the current study, we analyze neoplastic cell heterogeneity and demonstrate that two distinct proliferating populations of neoplastic cells exist in the tumor. These distinct cell types, neuroglial progenitors and differentiated astrocytes, are distinguished by their sensitivity to rapamycin. The molecular basis for this differential sensitivity to rapamycin reflects dramatic differences in mammalian target of rapamycin (mTOR) complex protein expression and basal mTOR activation. We leverage this cell type-specific sensitivity to target neuroglial progenitor cells in the tumor and inhibit optic glioma formation in vivo. Collectively, these findings emphasize the importance of cellular diversity in glioma formation and growth, and highlight the importance of developing novel treatment strategies that co-target multiple cell populations for maximal therapeutic benefit. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2498. doi:1538-7445.AM2012-2498