Postnatal Changes of Neural Stem Cells in the Mammalian Auditory Cortex

Our previous study reported neural stem cells (NSCs) in the auditory cortex (AC) of postnatal day 3 (P3) mice in vitro. It is unclear whether AC-NSCs exist in vivo. This study aims to determine the presence and changes of AC-NSCs during postnatal development and maturation both in vitro and in vivo. P3, postnatal day 14 (P14), 2-month-old (2M), and 4-month-old (4M) mouse brain tissues were fixed and cryosectioned for NSC marker immunostaining. In vitro, P3, P14, and 2M AC tissues were dissected and cultured in suspension to study NSCs. NSC proliferation was examined by EdU incorporation and cell doubling time assays in vitro. The results show that Nestin and Sox2 double expressing NSCs were observed in the AC area from P3 to 4M in vivo, in which the number of NSCs remarkably reduced with age. In vitro, the neurosphere forming capability, cell proliferation, and percentage of Nestin and Sox2 double expressing NSCs significantly diminished with age. These results suggest that AC-NSCs exist in the mouse AC area both in vitro and in vivo, and the percentage of AC-NSCs decreases during postnatal development and maturation. The results may provide important cues for the future research of the central auditory system.

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Isoflurane Decreases Self-renewal Capacity of Rat Cultured Neural Stem Cells

Anesthesiology ◽

10.1097/aln.0b013e318223b78b ◽

2011 ◽

Vol 115 (4) ◽

pp. 754-763 ◽

Cited By ~ 45

Author(s):

Deborah J. Culley ◽

Justin D. Boyd ◽

Arvind Palanisamy ◽

Zhongcong Xie ◽

Koji Kojima ◽

...

Keyword(s):

Stem Cells ◽

Cell Proliferation ◽

Neural Stem Cells ◽

Sprague Dawley ◽

Behavioral Deficits ◽

Lactate Dehydrogenase Release ◽

Propidium Iodide Staining ◽

End Of Treatment

Background In models, isoflurane produces neural and behavioral deficits in vitro and in vivo. This study tested the hypothesis that neural stem cells are adversely affected by isoflurane such that it inhibits proliferation and kills these cells. Methods Sprague-Dawley rat embryonic neural stem cells were plated onto 96-well plates and treated with isoflurane, 0.7, 1.4, or 2.8%, in 21% oxygen for 6 h and fixed either at the end of treatment or 6 or 24 h later. Control plates received 21% oxygen under identical conditions. Cell proliferation was assessed immunocytochemically using 5-ethynyl-2'-deoxyuridine incorporation and death by propidium iodide staining, lactate dehydrogenase release, and nuclear expression of cleaved caspase 3. Data were analyzed at each concentration using an ANOVA; P < 0.05 was considered significant. Results Isoflurane did not kill neural stem cells by any measure at any time. Isoflurane, 1.4 and 2.8%, reduced cell proliferation based upon 5-ethynyl-2'-deoxyuridine incorporation, whereas isoflurane, 0.7%, had no effect. At 24 h after treatment, the net effect was a 20-30% decrease in the number of cells in culture. Conclusions Isoflurane does not kill neural stem cells in vitro. At concentrations at and above the minimum alveolar concentrations required for general anesthesia (1.4 and 2.8%), isoflurane inhibits proliferation of these cells but has no such effect at a subminimum alveolar concentration (0.7%). These data imply that dosages of isoflurane at and above minimum alveolar concentrations may reduce the pool of neural stem cells in vivo but that lower dosages may be devoid of such effects.

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EXTH-07. TUMOR-HOMING INDUCED NEURAL STEM CELLS SECRETING A CYTOTOXIC PAYLOAD AS AN ADJUVANT TREATMENT FOR NON-SMALL CELL LUNG CANCER BRAIN METASTASES

Neuro-Oncology ◽

10.1093/neuonc/noaa215.361 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii88-ii88

Author(s):

Alison Mercer-Smith ◽

Wulin Jiang ◽

Alain Valdivia ◽

Juli Bago ◽

Scott Floyd ◽

...

Keyword(s):

Stem Cells ◽

Brain Metastases ◽

Neural Stem Cells ◽

Adjuvant Treatment ◽

Small Cell ◽

Small Cell Lung ◽

Tumor Homing ◽

Induced Neural Stem Cells

Abstract INTRODUCTION Non-small cell lung cancer (NSCLC) is the most common cancer to form brain metastases. Radiation treatment is standard-of-care, but recurrence is still observed in 40% of patients. An adjuvant treatment is desperately needed to track down and kill tumor remnants after radiation. Tumoritropic neural stem cells (NSCs) that can home to and deliver a cytotoxic payload offer potential as such an adjuvant treatment. Here we show the transdifferentiation of human fibroblasts into tumor-homing induced neural stem cells (hiNSCs) that secrete the cytotoxic protein TRAIL (hiNSC-TRAIL) and explore the use of hiNSC-TRAIL to treat NSCLC brain metastases. METHODS To determine the migratory capacity of hiNSCs, hiNSCs were infused intracerebroventricularly (ICV) into mice bearing established bilateral NSCLC H460 brain tumors. hiNSC accumulation at tumor foci was monitored using bioluminescent imaging and post-mortem fluorescent analysis. To determine synergistic effects of radiation with TRAIL on NSCLC, we performed in vitro co-culture assays and isobologram analysis. In vivo, efficacy was determined by tracking the progression and survival of mice bearing intracranial H460 treated with hiNSC-TRAIL alone or in combination with 2 Gy radiation. RESULTS/CONCLUSION Following ICV infusion, hiNSCs persisted in the brain for > 1 week and migrated from the ventricles to colocalize with bilateral tumor foci. In vitro, viability assays and isobologram analysis revealed the combination treatment of hiNSC-TRAIL and 2 Gy radiation induced synergistic killing (combination index=0.64). In vivo, hiNSC-TRAIL/radiation combination therapy reduced tumor volumes > 90% compared to control-treated animals while radiation-only and hiNSC-TRAIL-only treated mice showed 21% and 52% reduced volumes, respectively. Dual-treatment extended survival 40%, increasing survival from a median of 20 days in controls to 28 days in the treatment group. These results suggest hiNSC-TRAIL can improve radiation therapy for NSCLC brain metastases and could potentially improve outcomes for patients suffering from this aggressive form of cancer.

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Immunosuppressants Affect Human Neural Stem Cells In Vitro but Not in an In Vivo Model of Spinal Cord Injury

Stem Cells Translational Medicine ◽

10.5966/sctm.2012-0175 ◽

2013 ◽

Vol 2 (10) ◽

pp. 731-744 ◽

Cited By ~ 21

Author(s):

Christopher J. Sontag ◽

Hal X. Nguyen ◽

Noriko Kamei ◽

Nobuko Uchida ◽

Aileen J. Anderson ◽

...

Keyword(s):

Spinal Cord ◽

Stem Cells ◽

Spinal Cord Injury ◽

Neural Stem Cells ◽

In Vivo Model ◽

Human Neural Stem Cells ◽

Cord Injury

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CBIO-13. THOC1 DRIVES GBM AGGRESSION THROUGH MODULATION OF R-LOOPS AND GENOMIC STABILITY

Neuro-Oncology ◽

10.1093/neuonc/noab196.113 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi29-vi30

Author(s):

Shreya Budhiraja ◽

Shivani Baisiwala ◽

Khizar Nandoliya ◽

Li Chen ◽

Crismita Dmello ◽

...

Keyword(s):

Stem Cells ◽

Dna Damage ◽

Neural Stem Cells ◽

Histone Deacetylase ◽

Genomic Stability ◽

Loop Formation ◽

Driver Genes ◽

A Genome

Abstract Glioblastoma (GBM) is the most aggressive and common type of adult malignant brain tumor, with a median survival of only 21 months. To identify which genes drive its highly aggressive phenotype, we performed a genome-wide CRISPR-Cas9 knockout screen. Results showed substantial enrichment of ~160 novel essential oncogenic driver genes and pathways, including a previously unstudied gene THOC1—involved in RNA processing—that showed significant elevations in expression at RNA and protein levels (p< 0.05) in GBM, as well as a significant survival benefit in patient datasets when downregulated (p< 0.05). Knocking out THOC1 resulted in cell death in multiple GBM patient-derived xenograft (PDX) lines and extended survival compared to the controls (p< 0.01) in vivo. Overexpression of THOC1 in neural stem cells resulted in transformation to a cancerous phenotype, as evidenced by sphere formation in a soft agar assay (p< 0.01) and in vivo tumor engraftment assays. Further investigation of THOC1 through immunoprecipitation in neural stem cells and multiple GBM lines showed significant interaction in GBM with histone deacetylase complex SIN3A, involved in recruiting major histone deacetylases in order to close the DNA and prevent the accumulation of R-loops, RNA:DNA hybrids that pose a threat to genomic stability. Additional investigation revealed that THOC1-knockdowns in vitro induced R-loop formation and DNA damage, while THOC1-overexpression in vitro resulted in an untenable decrease in R-loops and DNA damage, suggesting that the THOC1-SIN3A axis is elevated in GBM in order to prevent the accumulation of genotoxic R-loops. Additionally, histone deacetylase activity was shown to be elevated in THOC1-overexpression conditions and reduced in THOC1-knockdown conditions, confirming that the THOC1-SIN3A axis functions to prevent R-loop accumulation through the epigenetic regulation. In summary, our whole-genome CRISPR-Cas9 knockout screen has identified a promising therapeutic target for GBM—a disease desperately in need of therapeutic innovations.

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