MDM2 and MDMX promote ferroptosis by PPARα-mediated lipid remodeling.

MDM2 and MDMX, negative regulators of the tumor suppressor p53, can work separately and as a heteromeric complex to restrain p53's functions. MDM2 also has pro-oncogenic roles in cells, tissues, and animals that are independent of p53. There is less information available about p53-independent roles of MDMX or the MDM2-MDMX complex. We found that MDM2 and MDMX facilitate ferroptosis in cells with or without p53. Using small molecules, RNA interference reagents, and mutant forms of MDMX, we found that MDM2 and MDMX, likely working in part as a complex, normally facilitate ferroptotic death. We observed that MDM2 and MDMX alter the lipid profile of cells to favor ferroptosis. Inhibition of MDM2 or MDMX leads to increased levels of FSP1 protein and a consequent increase in the levels of coenzyme Q10, an endogenous lipophilic antioxidant. This suggests that MDM2 and MDMX normally prevent cells from mounting an adequate defense against lipid peroxidation and thereby promote ferroptosis. Moreover, we found that PPARα activity is essential for MDM2 and MDMX to promote ferroptosis, suggesting that the MDM2-MDMX complex regulates lipids through altering PPARα activity. These findings reveal the complexity of cellular responses to MDM2 and MDMX and suggest that MDM2-MDMX inhibition might be useful for preventing degenerative diseases involving ferroptosis. Furthermore, they suggest that MDM2/MDMX amplification may predict sensitivity of some cancers to ferroptosis inducers.

Human papillomavirus vaccine beliefs and practice characteristics in rural and urban adolescent care providers.

BACKGROUND: The human papillomavirus (HPV) vaccine is recommended for all adolescents age 11-12 years. HPV vaccine coverage remains suboptimal in the United States though, particularly in rural areas. We surveyed adolescent immunization providers in two Midwestern states to assess rural vs. urban differences in HPV vaccine resources, practices, and attitudes. METHODS: A cross-sectional survey was sent to all licensed adolescent care providers in a subset of urban and rural counties in Minnesota and Wisconsin during 2019. Multivariable regression was used to identify attitudes and practices that differentiated rural vs. urban providers. RESULTS: There were 437 survey respondents (31% rural). Significantly fewer rural providers had evening/weekend adolescent vaccination appointments available (adjusted odds ratio (aOR) = 0.21 [95% confidence interval (CI): 0.12, 0.36]), had prior experience with adolescent vaccine quality improvement projects (aOR = 0.52 [95% CI: 0.28, 0.98]), and routinely recommended HPV vaccine during urgent/acute care visits (aOR = 0.37 [95% CI: 0.18, 0.79]). Significantly more rural providers had standing orders to administer all recommended adolescent vaccines (aOR = 2.81 [95% CI: 1.61, 4.91]) and reported giving HPV vaccine information to their patients/families before it is due (aOR = 3.10 [95% CI: 1.68, 5.71]). CONCLUSIONS: Rural vs. urban differences in provider practices were mixed in that rural providers do not implement some practices that may promote HPV vaccination, but do implement other practices that promote HPV vaccination. It remains unclear how the observed differences would affect HPV vaccine attitudes or adolescent vaccination decisions for parents in rural areas.

IKKß and mutant huntingtin interactions regulate the expression of IL-34: implications for microglial-mediated neurodegeneration in HD.

Neuronal interleukin-34 (IL-34) promotes the expansion of microglia in the central nervous system-microglial activation and expansion are in turn implicated in the pathogenesis of Huntington's disease (HD). We thus examined whether the accumulation of an amyloidogenic exon-1 fragment of mutant huntingtin (mHTTx1) modulates the expression of IL-34 in dopaminergic neurons derived from a human embryonic stem cell line. We found that mHTTx1 aggregates induce IL-34 production selectively in post-mitotic neurons. Exposure of neurons to DNA damaging agents or the excitotoxin NMDA elicited similar results suggesting that IL-34 induction may be a general response to neuronal stress including the accumulation of misfolded mHTTx1. We further determined that knockdown or blocking the activity of IκB kinase beta (IKKß) prevented the aggregation of mHTTx1 and subsequent IL-34 production. While elevated IL-34 itself had no effect on the aggregation or the toxicity of mHTTx1 in neuronal culture, IL-34 expression in a rodent brain slice model with intact neuron-microglial networks exacerbated mHTTx1-induced degeneration of striatal medium-sized spiny neurons. Conversely, an inhibitor of the IL-34 receptor reduced microglial numbers and ameliorated mHTTx1-mediated neurodegeneration. Together, these findings uncover a novel function for IKKß/mHTTx1 interactions in regulating IL-34 production, and implicate a role for IL-34 in non-cell-autonomous, microglial-dependent neurodegeneration in HD.

Small molecule-induced oxidation of protein disulfide isomerase is neuroprotective.

Protein disulfide isomerase (PDI) is a chaperone protein in the endoplasmic reticulum that is up-regulated in mouse models of, and brains of patients with, neurodegenerative diseases involving protein misfolding. PDI's role in these diseases, however, is not fully understood. Here, we report the discovery of a reversible, neuroprotective lead optimized compound (LOC)14, that acts as a modulator of PDI. LOC14 was identified using a high-throughput screen of ∼10,000 lead-optimized compounds for potent rescue of viability of PC12 cells expressing mutant huntingtin protein, followed by an evaluation of compounds on PDI reductase activity in an in vitro screen. Isothermal titration calorimetry and fluorescence experiments revealed that binding to PDI was reversible with a Kd of 62 nM, suggesting LOC14 to be the most potent PDI inhibitor reported to date. Using 2D heteronuclear single quantum correlation NMR experiments, we were able to map the binding site of LOC14 as being adjacent to the active site and to observe that binding of LOC14 forces PDI to adopt an oxidized conformation. Furthermore, we found that LOC14-induced oxidation of PDI has a neuroprotective effect not only in cell culture, but also in corticostriatal brain slice cultures. LOC14 exhibited high stability in mouse liver microsomes and blood plasma, low intrinsic microsome clearance, and low plasma-protein binding. These results suggest that LOC14 is a promising lead compound to evaluate the potential therapeutic effects of modulating PDI in animal models of disease.

Measles Outbreak - Minnesota April-May 2017.

On April 10, 2017, the Minnesota Department of Health (MDH) was notified about a suspected measles case. The patient was a hospitalized child aged 25 months who was evaluated for fever and rash, with onset on April 8. The child had no history of receipt of measles-mumps-rubella (MMR) vaccine and no travel history or known exposure to measles. On April 11, MDH received a report of a second hospitalized, unvaccinated child, aged 34 months, with an acute febrile rash illness with onset on April 10. The second patient's sibling, aged 19 months, who had also not received MMR vaccine, had similar symptoms, with rash onset on March 30. Real-time reverse transcription-polymerase chain reaction (rRT-PCR) testing of nasopharyngeal swab or throat specimens performed at MDH confirmed measles in the first two patients on April 11, and in the third patient on April 13; subsequent genotyping identified genotype B3 virus in all three patients, who attended the same child care center. MDH instituted outbreak investigation and response activities in collaboration with local health departments, health care facilities, child care facilities, and schools in affected settings. Because the outbreak occurred in a community with low MMR vaccination coverage, measles spread rapidly, resulting in thousands of exposures in child care centers, schools, and health care facilities. By May 31, 2017, a total of 65 confirmed measles cases had been reported to MDH (Figure 1); transmission is ongoing.

Evaluation of Huddles: A Multisite Study.

Regular, interdisciplinary group meetings, "huddles," may be useful in improving communication among disciplines, resolving problems, and sharing information. Daily use of huddles may contribute to the development of a highly reliable health care organization. The purpose of this study was to describe safety huddles in relation to (1) problem type, (2) timeliness of resolution, (3) attendance of representatives from each discipline, (4) amount of information sharing, and (5) attendees' satisfaction with the process. Overall, results demonstrated that the primary function of huddles was the exchange of information that posed or had the potential to pose safety risks to patients. Across seven hospitals, the range of information sharing during huddles was 61.0% to 95.6%. Regarding satisfaction with the huddle process, staff reported that huddles were useful in improving awareness of safety concerns and also improved communication between disciplines. Huddles provide a structured format in which staff can positively impact safety concerns, form a greater sense of medical community, increase sharing of information between disciplines, quickly resolve discipline-based problems, and increase awareness of safety concerns. Given the results of this study, it is recommended that health care administrators and managers develop a huddle process.

BDNF mediates neuroprotection against oxygen-glucose deprivation by the cardiac glycoside oleandrin.

We have previously shown that the botanical drug candidate PBI-05204, a supercritical CO2 extract of Nerium oleander, provides neuroprotection in both in vitro and in vivo brain slice-based models for focal ischemia (Dunn et al., 2011). Intriguingly, plasma levels of the neurotrophin BDNF were increased in patients treated with PBI-05204 in a phase I clinical trial (Bidyasar et al., 2009). We thus tested the hypothesis that neuroprotection provided by PBI-05204 to rat brain slices damaged by oxygen-glucose deprivation (OGD) is mediated by BDNF. We found, in fact, that exogenous BDNF protein itself is sufficient to protect brain slices against OGD, whereas downstream activation of TrkB receptors for BDNF is necessary for neuroprotection provided by PBI-05204, using three independent methods. Finally, we provide evidence that oleandrin, the principal cardiac glycoside component of PBI-05204, can quantitatively account for regulation of BDNF at both the protein and transcriptional levels. Together, these findings support further investigation of cardiac glycosides in providing neuroprotection in the context of ischemic stroke.

Ferrostatins inhibit oxidative lipid damage and cell death in diverse disease models.

Ferrostatin-1 (Fer-1) inhibits ferroptosis, a form of regulated, oxidative, nonapoptotic cell death. We found that Fer-1 inhibited cell death in cellular models of Huntington's disease (HD), periventricular leukomalacia (PVL), and kidney dysfunction; Fer-1 inhibited lipid peroxidation, but not mitochondrial reactive oxygen species formation or lysosomal membrane permeability. We developed a mechanistic model to explain the activity of Fer-1, which guided the development of ferrostatins with improved properties. These studies suggest numerous therapeutic uses for ferrostatins, and that lipid peroxidation mediates diverse disease phenotypes.

Coenzyme A protects against ferroptosis via CoAlation of thioredoxin reductase 2.

The Cystine-xCT transporter-Glutathione (GSH)-GPX4 axis is the canonical pathway to protect against ferroptosis. While not required for ferroptosis-inducing compounds (FINs) targeting GPX4, FINs targeting the xCT transporter require mitochondria and its lipid peroxidation to trigger ferroptosis. However, the mechanism underlying the difference between these FINs is still unknown. Given that cysteine is also required for coenzyme A (CoA) biosynthesis, here we show that CoA supplementation specifically prevents ferroptosis induced by xCT inhibitors but not GPX4 inhibitors. We find that, auranofin, a thioredoxin reductase inhibitor, abolishes the protective effect of CoA. We also find that CoA availability determines the enzymatic activity of thioredoxin reductase, but not thioredoxin. Importantly, the mitochondrial thioredoxin system, but not the cytosolic thioredoxin system, determines CoA-mediated ferroptosis inhibition. Our data show that the CoA regulates the in vitro enzymatic activity of mitochondrial thioredoxin reductase (TXNRD2) by covalently modifying the thiol group of cysteine (CoAlation) on Cys-483. Replacing Cys-483 with alanine on TXNRD2 abolishes its in vitro enzymatic activity and ability to protect cells from ferroptosis. Targeting xCT to limit cysteine import and, therefore, CoA biosynthesis reduced CoAlation on TXNRD2, an effect that was rescued by CoA supplementation. Furthermore, the fibroblasts from patients with disrupted CoA metabolism demonstrate increased mitochondrial lipid peroxidation. In organotypic brain slice cultures, inhibition of CoA biosynthesis leads to an oxidized thioredoxin system, mitochondrial lipid peroxidation, and loss in cell viability, which were all rescued by ferrostatin-1. These findings identify CoA-mediated post-translation modification to regulate the thioredoxin system as an alternative ferroptosis protection pathway with potential clinical relevance for patients with disrupted CoA metabolism.

A living ex vivo platform for functional, personalized brain cancer diagnosis.

Functional precision medicine platforms are emerging as promising strategies to improve pre-clinical drug testing and guide clinical decisions. We have developed an organotypic brain slice culture (OBSC)-based platform and multi-parametric algorithm that enable rapid engraftment, treatment, and analysis of uncultured patient brain tumor tissue and patient-derived cell lines. The platform has supported engraftment of every patient tumor tested to this point: high- and low-grade adult and pediatric tumor tissue rapidly establishes on OBSCs among endogenous astrocytes and microglia while maintaining the tumor's original DNA profile. Our algorithm calculates dose-response relationships of both tumor kill and OBSC toxicity, generating summarized drug sensitivity scores on the basis of therapeutic window and allowing us to normalize response profiles across a panel of U.S. Food and Drug Administration (FDA)-approved and exploratory agents. Summarized patient tumor scores after OBSC treatment show positive associations to clinical outcomes, suggesting that the OBSC platform can provide rapid, accurate, functional testing to ultimately guide patient care.

CalDAG-GEFI down-regulation in the striatum as a neuroprotective change in Huntington's disease.

Huntingtin protein (Htt) is ubiquitously expressed, yet Huntington's disease (HD), a fatal neurologic disorder produced by expansion of an Htt polyglutamine tract, is characterized by neurodegeneration that occurs primarily in the striatum and cerebral cortex. Such discrepancies between sites of expression and pathology occur in multiple neurodegenerative disorders associated with expanded polyglutamine tracts. One possible reason is that disease-modifying factors are tissue-specific. Here, we show that the striatum-enriched protein, CalDAG-GEFI, is severely down-regulated in the striatum of mouse HD models and is down-regulated in HD individuals. In the R6/2 transgenic mouse model of HD, striatal neurons with the largest aggregates of mutant Htt have the lowest levels of CalDAG-GEFI. In a brain-slice explant model of HD, knock-down of CalDAG-GEFI expression rescues striatal neurons from pathology induced by transfection of polyglutamine-expanded Htt exon 1. These findings suggest that the striking down-regulation of CalDAG-GEFI in HD could be a protective mechanism that mitigates Htt-induced degeneration.

Spatiotemporal analysis of induced neural stem cell therapy to overcome advanced glioblastoma recurrence.

Genetically engineered neural stem cells (NSCs) are a promising therapy for the highly aggressive brain cancer glioblastoma (GBM); however, treatment durability remains a major challenge. We sought to define the events that contribute to dynamic adaptation of GBM during treatment with human skin-derived induced NSCs releasing the pro-apoptotic agent TRAIL (iNSC-TRAIL) and develop strategies that convert initial tumor kill into sustained GBM suppression. In vivo and ex vivo analysis before, during, and after treatment revealed significant shifts in tumor transcriptome and spatial distribution as the tumors adapted to treatment. To address this, we designed iNSC delivery strategies that increased spatiotemporal TRAIL coverage and significantly decreased GBM volume throughout the brain, reducing tumor burden 100-fold as quantified in live ex vivo brain slices. The varying impact of different strategies on treatment durability and median survival of both solid and invasive tumors provides important guidance for optimizing iNSC therapy.

Factors associated with human papillomavirus and meningococcal vaccination among adolescents living in rural and urban areas.

Background: Studies have shown that adolescent vaccination rates with human papillomavirus (HPV) and quadrivalent meningococcal conjugate (MenACWY) vaccines are lower in rural areas of the U.S. than in urban areas. We sought to determine factors associated with vaccine acceptance in these two settings. Methods: We conducted a cross-sectional survey of 536 parents or guardians of teens age 13 through 15 years in select rural and urban counties of Minnesota and Wisconsin. We collected information on demographic variables, receipt of adolescent vaccines, and attitudes toward HPV vaccine in particular. Multivariable logistic regression models were used to assess associations between covariates and outcomes of interest (HPV vaccine receipt and MenACWY receipt). Results: Of the 536 respondents, 267 (50%) resided in a rural county. Most respondents were female (78%) and non-Hispanic White (88%). About half (52%) of teens of the surveyed parents received the three vaccines recommended specifically for adolescents: 90% received tetanus-diphtheria-acellular pertussis (Tdap), 84% received MenACWY, and 60% received one or more doses of HPV vaccine. Rural and urban parents surveyed differed on several covariates relating to teen's health services, parent's demographics, and household characteristics. Parent's perception of the importance that their healthcare providers placed on vaccination with HPV and MenACWY were independently associated with receipt of each of those vaccines (odds ratio [OR] 6.37, 95% confidence interval [CI] 2.90-13.96 and OR 2.15, 95% CI 1.07-4.31, respectively). Parents of vaccinated teens were less likely to report concerns about potential harm from the HPV vaccine or having heard stories about health problems caused by the HPV vaccine. Conclusion: Teen receipt of HPV vaccine and MenACWY appears to be influenced by parents' perception of vaccine importance, provider recommendations, and concerns regarding potential harm from the HPV vaccine. Continued education of providers and parents of the importance of adolescent vaccinations is warranted.

In vitro and in vivo neuroprotective activity of the cardiac glycoside oleandrin from Nerium oleander in brain slice-based stroke models.

The principal active constituent of the botanical drug candidate PBI-05204, a supercritical CO(2) extract of Nerium oleander, is the cardiac glycoside oleandrin. PBI-05204 shows potent anticancer activity and is currently in phase I clinical trial as a treatment for patients with solid tumors. We have previously shown that neriifolin, which is structurally related to oleandrin, provides robust neuroprotection in brain slice and whole animal models of ischemic injury. However, neriifolin itself is not a suitable drug development candidate and the FDA-approved cardiac glycoside digoxin does not cross the blood-brain barrier. We report here that both oleandrin as well as the full PBI-05204 extract can also provide significant neuroprotection to neural tissues damaged by oxygen and glucose deprivation as occurs in ischemic stroke. Critically, we show that the neuroprotective activity of PBI-05204 is maintained for several hours of delay of administration after oxygen and glucose deprivation treatment. We provide evidence that the neuroprotective activity of PBI-05204 is mediated through oleandrin and/or other cardiac glycoside constituents, but that additional, non-cardiac glycoside components of PBI-05204 may also contribute to the observed neuroprotective activity. Finally, we show directly that both oleandrin and the protective activity of PBI-05204 are blood brain barrier penetrant in a novel model for in vivo neuroprotection. Together, these findings suggest clinical potential for PBI-05204 in the treatment of ischemic stroke and prevention of associated neuronal death.

Identification of anti-inflammatory targets for Huntington's disease using a brain slice-based screening assay.

Huntington's disease (HD) is a late-onset, neurodegenerative disease for which there are currently no cures nor disease-modifying treatments. Here we report the identification of several potential anti-inflammatory targets for HD using an ex vivo model of HD that involves the acute transfection of human mutant huntingtin-based constructs into rat brain slices. This model recapitulates key components of the human disease, including the formation of intracellular huntingtin protein (HTT)-containing inclusions and the progressive neurodegeneration of striatal neurons-both occurring within the native tissue context of these neurons. Using this "high-throughput biology" screening platform, we conducted a hypothesis-neutral screen of a collection of drug-like compounds which identified several anti-inflammatory targets that provided neuroprotection against HTT fragment-induced neurodegeneration. The nature of these targets provide further support for non-cell autonomous mechanisms mediating significant aspects of neuropathogenesis induced by mutant HTT fragment proteins.

Intrabodies binding the proline-rich domains of mutant huntingtin increase its turnover and reduce neurotoxicity.

Although expanded polyglutamine (polyQ) repeats are inherently toxic, causing at least nine neurodegenerative diseases, the protein context determines which neurons are affected. The polyQ expansion that causes Huntington's disease (HD) is in the first exon (HDx-1) of huntingtin (Htt). However, other parts of the protein, including the 17 N-terminal amino acids and two proline (polyP) repeat domains, regulate the toxicity of mutant Htt. The role of the P-rich domain that is flanked by the polyP domains has not been explored. Using highly specific intracellular antibodies (intrabodies), we tested various epitopes for their roles in HDx-1 toxicity, aggregation, localization, and turnover. Three domains in the P-rich region (PRR) of HDx-1 are defined by intrabodies: MW7 binds the two polyP domains, and Happ1 and Happ3, two new intrabodies, bind the unique, P-rich epitope located between the two polyP epitopes. We find that the PRR-binding intrabodies, as well as V(L)12.3, which binds the N-terminal 17 aa, decrease the toxicity and aggregation of HDx-1, but they do so by different mechanisms. The PRR-binding intrabodies have no effect on Htt localization, but they cause a significant increase in the turnover rate of mutant Htt, which V(L)12.3 does not change. In contrast, expression of V(L)12.3 increases nuclear Htt. We propose that the PRR of mutant Htt regulates its stability, and that compromising this pathogenic epitope by intrabody binding represents a novel therapeutic strategy for treating HD. We also note that intrabody binding represents a powerful tool for determining the function of protein epitopes in living cells.

Tumoricidal stem cell therapy enables killing in novel hybrid models of heterogeneous glioblastoma.

BACKGROUND: Tumor-homing tumoricidal neural stem cell (tNSC) therapy is a promising new strategy that recently entered human patient testing for glioblastoma (GBM). Developing strategies for tNSC therapy to overcome intratumoral heterogeneity, variable cancer cell invasiveness, and differential drug response of GBM will be essential for efficacious treatment response in the clinical setting. The aim of this study was to create novel hybrid tumor models and investigate the impact of GBM heterogeneity on tNSC therapies. METHODS: We used organotypic brain slice explants and distinct human GBM cell types to generate heterogeneous models ex vivo and in vivo. We then tested the efficacy of mono- and combination therapy with primary NSCs and fibroblast-derived human induced neural stem cells (iNSCs) engineered with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or enzyme-prodrug therapy. RESULTS: Optical imaging, molecular assays, and immunohistochemistry revealed that the hybrid models recapitulated key aspects of patient GBM, including heterogeneity in TRAIL sensitivity, proliferation, migration patterns, hypoxia, blood vessel structure, cancer stem cell populations, and immune infiltration. To explore the impact of heterogeneity on tNSC therapy, testing in multiple in vivo models showed that tNSC-TRAIL therapy potently inhibited tumor growth and significantly increased survival across all paradigms. Patterns of tumor recurrence varied with therapeutic (tNSC-TRAIL and/or tNSC-thymidine kinase), dose, and route of administration. CONCLUSIONS: These studies report new hybrid models that accurately capture key aspects of GBM heterogeneity which markedly impact treatment response while demonstrating the ability of tNSC mono- and combination therapy to overcome certain aspects of heterogeneity for robust tumor kill.

B7-H3-redirected chimeric antigen receptor T cells target glioblastoma and neurospheres.

BACKGROUND: The dismal survival of glioblastoma (GBM) patients urgently calls for the development of new treatments. Chimeric antigen receptor T (CAR-T) cells are an attractive strategy, but preclinical and clinical studies in GBM have shown that heterogeneous expression of the antigens targeted so far causes tumor escape, highlighting the need for the identification of new targets. We explored if B7-H3 is a valuable target for CAR-T cells in GBM. METHODS: We compared mRNA expression of antigens in GBM using TCGA data, and validated B7-H3 expression by immunohistochemistry. We then tested the antitumor activity of B7-H3-redirected CAR-T cells against GBM cell lines and patient-derived GBM neurospheres in vitro and in xenograft murine models. FINDINGS: B7-H3 mRNA and protein are overexpressed in GBM relative to normal brain in all GBM subtypes. Of the 46 specimens analyzed by immunohistochemistry, 76% showed high B7-H3 expression, 22% had detectable, but low B7-H3 expression and 2% were negative, as was normal brain. All 20 patient-derived neurospheres showed ubiquitous B7-H3 expression. B7-H3-redirected CAR-T cells effectively targeted GBM cell lines and neurospheres in vitro and in vivo. No significant differences were found between CD28 and 4-1BB co-stimulation, although CD28-co-stimulated CAR-T cells released more inflammatory cytokines. INTERPRETATION: We demonstrated that B7-H3 is highly expressed in GBM specimens and neurospheres that contain putative cancer stem cells, and that B7-H3-redirected CAR-T cells can effectively control tumor growth. Therefore, B7-H3 represents a promising target in GBM. FUND: Alex's Lemonade Stand Foundation; Il Fondo di Gio Onlus; National Cancer Institute; Burroughs Wellcome Fund.

Identifying therapeutic targets by combining transcriptional data with ordinal clinical measurements.

The immense and growing repositories of transcriptional data may contain critical insights for developing new therapies. Current approaches to mining these data largely rely on binary classifications of disease vs. control, and are not able to incorporate measures of disease severity. We report an analytical approach to integrate ordinal clinical information with transcriptomics. We apply this method to public data for a large cohort of Huntington's disease patients and controls, identifying and prioritizing phenotype-associated genes. We verify the role of a high-ranked gene in dysregulation of sphingolipid metabolism in the disease and demonstrate that inhibiting the enzyme, sphingosine-1-phosphate lyase 1 (SPL), has neuroprotective effects in Huntington's disease models. Finally, we show that one consequence of inhibiting SPL is intracellular inhibition of histone deacetylases, thus linking our observations in sphingolipid metabolism to a well-characterized Huntington's disease pathway. Our approach is easily applied to any data with ordinal clinical measurements, and may deepen our understanding of disease processes.Identifying gene subsets affecting disease phenotypes from transcriptome data is challenge. Here, the authors develop a method that combines transcriptional data with disease ordinal clinical measurements to discover a sphingolipid metabolism regulator involving in Huntington's disease progression.

IKK/NF-κB signaling contributes to glioblastoma stem cell maintenance.

Glioblastoma multiforme (GBM) carries a poor prognosis and continues to lack effective treatments. Glioblastoma stem cells (GSCs) drive tumor formation, invasion, and drug resistance and, as such, are the focus of studies to identify new therapies for disease control. Here, we identify the involvement of IKK and NF-κB signaling in the maintenance of GSCs. Inhibition of this pathway impairs self-renewal as analyzed in tumorsphere formation and GBM expansion as analyzed in brain slice culture. Interestingly, both the canonical and non-canonical branches of the NF-κB pathway are shown to contribute to this phenotype. One source of NF-κB activation in GBM involves the TGF-ß/TAK1 signaling axis. Together, our results demonstrate a role for the NF-κB pathway in GSCs and provide a mechanistic basis for its potential as a therapeutic target in glioblastoma.