In mammals, olfaction is often used to distinguish individuals on the basis of their unique odor types (genetically programmed body odors). Parental-offspring recognition behavior is mediated, in ...part, by learning and processing of different odor types and is crucial for reproductive success. Maternal recognition behavior and associated brain plasticity has been well characterized, but paternal recognition behavior and brain plasticity is poorly understood. We found that paternal-adult offspring recognition behavior in mice was dependent on postnatal offspring interaction and was associated with increased neurogenesis in the paternal olfactory bulb and hippocampus. Newly generated paternal olfactory interneurons were preferentially activated by adult offspring odors. Disrupting prolactin signaling abolished increased paternal neurogenesis and adult offspring recognition. Rescuing this neurogenesis restored recognition behavior. Thus, neurogenesis in the paternal brain may be involved in offspring recognition.
The isolation and expansion of precursor cells in a serum-free culture system allows for the systematic characterization of their properties and the intrinsic and extrinsic signals that regulate ...their function. The discovery of neural stem cells in the adult mouse brain was made possible by the creation of a novel culture system subsequently termed the neurosphere assay. Therein, the dissociated adult mouse periventricular area was plated in the presence of epidermal growth factor, but in the absence of adhesive substrates, which resulted in the generation of spheres of proliferating cells that detached from the plate bottom and remained suspended in the media. Since its inception, the neurosphere culture system has been widely used in the neural precursor cell field and has been extensively adapted for the isolation and expansion of corneal, cardiac, skin, prostate, mammary and brain tumor stem cells. The original neurosphere culture protocol, which takes approximately 10 d to complete, is described here in detail.
The prognosis for patients diagnosed with glioblastoma multiforme (GBM) remains dismal, with current treatment prolonging survival only modestly. As such, there remains a strong need for novel ...therapeutic strategies. The janus kinase (JAK)2/signal transducer and activator of transcription (STAT)3 pathway regulates many cellular processes in GBM, including survival, proliferation, invasion, anti-apoptosis, and immune evasion. Here, we evaluated the preclinical efficacy of pacritinib, a novel compound targeting JAK2, using a collection of diverse patient-derived brain tumor initiating cells (BTICs).
The effects of pacritinib on BTIC viability and sphere forming capacity were evaluated in vitro using the alamarBlue and neurosphere assays, respectively. On-target inhibition of JAK2/STAT3 signaling was investigated using western blotting. The efficacy of pacritinib was tested in vivo in pharmacokinetic analyses, liver microsome analyses, and Kaplan-Meier survival studies.
In vitro, pacritinib decreased BTIC viability and sphere forming potential at low micromolar doses and demonstrated on-target inhibition of STAT3 signaling. Additionally, pacritinib was found to improve the response to temozolomide (TMZ) in TMZ-resistant BTICs. In vivo, systemic treatment with pacritinib demonstrated blood-brain barrier penetration and led to improved overall median survival in combination with TMZ, in mice orthotopically xenografted with an aggressive recurrent GBM BTIC culture.
This preclinical study demonstrates the efficacy of pacritinib and supports the feasibility of testing pacritinib for the treatment of GBM, in combination with the standard of care TMZ.
ABSTRACT Delayed pressure urticaria (DPU) is a subset of chronic inducible urticaria. It is characterized by the formation of wheals anytime between 30 minutes and 24 hours after stimulus exposure of ...localized pressure application. In this case report, we discuss a military flight crew member with no significant past medical history who developed DPU following rapid decompression in an altitude chamber. The chamber training included an uneventful ascent to 45,000 feet, higher than he had been previously, and a rapid decompression. About 16 hours later, he developed pruritic swelling of his hands and feet, along with diffuse deep nodular swelling, erythematous plaques, and erythematous nodules. His DPU was refractory to monotherapy treatment with antihistamines, and he continued to develop lesions in weight-bearing areas. Control of symptoms was achieved through combination treatment of a second-generation antihistamine, a leukotriene receptor antagonist, and an immunosuppressant (cyclosporine). His waiver to return to flight status was denied while on cyclosporine. He was transitioned to a monoclonal antibody that binds free immunoglobin E (omalizumab) with resolution of symptoms and was cleared to return to active duty.
Glioblastoma therapies have remained elusive due to limitations in understanding mechanisms of growth and survival of the tumorigenic population. Using CRISPR-Cas9 approaches in patient-derived GBM ...stem cells (GSCs) to interrogate function of the coding genome, we identify actionable pathways responsible for growth, which reveal the gene-essential circuitry of GBM stemness and proliferation. In particular, we characterize members of the SOX transcription factor family, SOCS3, USP8, and DOT1L, and protein ufmylation as important for GSC growth. Additionally, we reveal mechanisms of temozolomide resistance that could lead to combination strategies. By reaching beyond static genome analysis of bulk tumors, with a genome-wide functional approach, we reveal genetic dependencies within a broad range of biological processes to provide increased understanding of GBM growth and treatment resistance.
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•Genome-wide CRISPR-Cas9 screens in patient-derived glioblastoma stem cells•Identification of regulators of stemness governing glioblastoma stem cell growth•Multiple stress response pathways are genetic vulnerabilities in glioblastoma•Identification of modulators of sensitivity to standard of care chemotherapy
MacLeod et al. describe genome-wide CRISPR-Cas9 screens identifying genetic vulnerabilities across a panel of patient-derived glioblastoma stem cell cultures. Regulators of stemness (SOX2, SOX9, DOT1L, and SOCS3) and stress response (ufmylation and ERAD pathways) govern the growth of glioblastoma stem cells. Chemogenomic screens using temozolomide identify modulators of sensitivity to chemotherapy.
The identification of succinate dehydrogenase (SDH), fumarate hydratase (FH) and isocitrate dehydrogenase (IDH) mutations in human cancers has rekindled the idea that altered cellular metabolism can ...transform cells. Inactivating SDH and FH mutations cause the accumulation of succinate and fumarate, respectively, which can inhibit 2-oxoglutarate (2-OG)-dependent enzymes, including the EGLN prolyl 4-hydroxylases that mark the hypoxia inducible factor (HIF) transcription factor for polyubiquitylation and proteasomal degradation. Inappropriate HIF activation is suspected of contributing to the pathogenesis of SDH-defective and FH-defective tumours but can suppress tumour growth in some other contexts. IDH1 and IDH2, which catalyse the interconversion of isocitrate and 2-OG, are frequently mutated in human brain tumours and leukaemias. The resulting mutants have the neomorphic ability to convert 2-OG to the (R)-enantiomer of 2-hydroxyglutarate ((R)-2HG). Here we show that (R)-2HG, but not (S)-2HG, stimulates EGLN activity, leading to diminished HIF levels, which enhances the proliferation and soft agar growth of human astrocytes. These findings define an enantiomer-specific mechanism by which the (R)-2HG that accumulates in IDH mutant brain tumours promotes transformation and provide a justification for exploring EGLN inhibition as a potential treatment strategy.
Abstract
We discuss the design, construction, and operation of a new intensity interferometer, based on the campus of Southern Connecticut State University in New Haven, Connecticut. While this paper ...will focus on observations taken with an original two-telescope configuration, the current instrumentation consists of three portable 0.6 m Dobsonian telescopes with single-photon avalanche diode detectors located at the Newtonian focus of each telescope. Photons detected at each station are time stamped and read out with timing correlators that can give cross-correlations in timing to a precision of 48 ps. We detail our observations to date with the system, which has now been successfully used at our university in 16 nights of observing. Components of the instrument were also deployed on one occasion at Lowell Observatory, where the Perkins and Hall telescopes were made to function as an intensity interferometer. We characterize the performance of the instrument in detail. In total, the observations indicate the detection of a correlation peak at the level of 6.76
σ
when observing unresolved stars, and consistency with partial or no detection when observing at a baseline sufficient to resolve the star. Using these measurements, we conclude that the angular diameter of Arcturus is larger than 15 mas and that of Vega is between 0.8 and 17 mas. While the uncertainties are large at this point, both results are consistent with measures from amplitude-based long baseline optical interferometers.
Brain tumor initiating cells (BTICs) contribute to the genesis and recurrence of gliomas. We examined whether the microglia and macrophages that are abundant in gliomas alter BTIC growth. We found ...that microglia derived from non-glioma human subjects markedly mitigated the sphere-forming capacity of glioma patient-derived BTICs in culture by inducing the expression of genes that control cell cycle arrest and differentiation. This sphere-reducing effect was mimicked by macrophages, but not by neurons or astrocytes. Using a drug screen, we validated amphotericin B (AmpB) as an activator of monocytoid cells and found that AmpB enhanced the microglial reduction of BTIC spheres. In mice harboring intracranial mouse or patient-derived BTICs, daily systemic treatment with non-toxic doses of AmpB substantially prolonged life. Notably, microglia and monocytes cultured from glioma patients were inefficient at reducing the sphere-forming capacity of autologous BTICs, but this was rectified by AmpB. These results provide new insights into the treatment of gliomas.
Previous studies demonstrating olfactory interneuron involvement in olfactory discrimination and decreased proliferation in the forebrain subventricular zone with age led us to ask whether olfactory ...neurogenesis and, consequently, olfactory discrimination were impaired in aged mice. Pulse labeling showed that aged mice (24 months of age) had fewer new interneurons in the olfactory bulb than did young adult (2 months of age) mice. However, the aged mice had more olfactory interneurons in total than their younger counterparts. Aged mice exhibited no differences from young adult mice in their ability to discriminate between two discrete odors but were significantly poorer at performing discriminations between similar odors (fine olfactory discrimination). Leukemia inhibitory factor receptor heterozygote mice, which have less neurogenesis and fewer olfactory interneurons than their wild-type counterparts, performed more poorly at fine olfactory discrimination than the wild types, suggesting that olfactory neurogenesis, rather than the total number of interneurons, was responsible for fine olfactory discrimination. Immunohistochemistry and Western blot analyses revealed a selective reduction in expression levels of epidermal growth factor (EGF) receptor (EGFR) signaling elements in the aged forebrain subventricular zone. Waved-1 mutant mice, which express reduced quantities of transforming growth factor-alpha, the predominant EGFR ligand in adulthood, phenocopy aged mice in olfactory neurogenesis and performance on fine olfactory discrimination tasks. These results suggest that the impairment in fine olfactory discrimination with age may result from a reduction in EGF-dependent olfactory neurogenesis.
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