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Anti-Ki-67 antibody

RRID:AB_2142366

Antibody ID

AB_2142366

Target Antigen

Ki-67 human, mouse, rat

Proper Citation

(Millipore Cat# AB9260, RRID:AB_2142366)

Clonality

polyclonal antibody

Comments

Applications: IHC(P) & WB. The following antibodies were determined to be duplicates and consolidated by curator on 10/2018: AB_2142366, AB_10141019, AB_11214025.

Host Organism

rabbit

Vendor

Millipore

Stable STIM1 Knockdown in Self-Renewing Human Neural Precursors Promotes Premature Neural Differentiation.

  • Gopurappilly R
  • Front Mol Neurosci
  • 2018 Jun 27

Literature context:


Abstract:

Ca2+ signaling plays a significant role in the development of the vertebrate nervous system where it regulates neurite growth as well as synapse and neurotransmitter specification. Elucidating the role of Ca2+ signaling in mammalian neuronal development has been largely restricted to either small animal models or primary cultures. Here we derived human neural precursor cells (NPCs) from human embryonic stem cells to understand the functional significance of a less understood arm of calcium signaling, Store-operated Ca2+ entry or SOCE, in neuronal development. Human NPCs exhibited robust SOCE, which was significantly attenuated by expression of a stable shRNA-miR targeted toward the SOCE molecule, STIM1. Along with the plasma membrane channel Orai, STIM is an essential component of SOCE in many cell types, where it regulates gene expression. Therefore, we measured global gene expression in human NPCs with and without STIM1 knockdown. Interestingly, pathways down-regulated through STIM1 knockdown were related to cell proliferation and DNA replication processes, whereas post-synaptic signaling was identified as an up-regulated process. To understand the functional significance of these gene expression changes we measured the self-renewal capacity of NPCs with STIM1 knockdown. The STIM1 knockdown NPCs demonstrated significantly reduced neurosphere size and number as well as precocious spontaneous differentiation toward the neuronal lineage, as compared to control cells. These findings demonstrate that STIM1 mediated SOCE in human NPCs regulates gene expression changes, that in vivo are likely to physiologically modulate the self-renewal and differentiation of NPCs.

Funding information:
  • NIAID NIH HHS - U54 AI057153(United States)

EGFR-Phosphorylated Platelet Isoform of Phosphofructokinase 1 Promotes PI3K Activation.

  • Lee JH
  • Mol. Cell
  • 2018 Apr 19

Literature context:


Abstract:

EGFR activates phosphatidylinositide 3-kinase (PI3K), but the mechanism underlying this activation is not completely understood. We demonstrated here that EGFR activation resulted in lysine acetyltransferase 5 (KAT5)-mediated K395 acetylation of the platelet isoform of phosphofructokinase 1 (PFKP) and subsequent translocation of PFKP to the plasma membrane, where the PFKP was phosphorylated at Y64 by EGFR. Phosphorylated PFKP binds to the N-terminal SH2 domain of p85α, which is distinct from binding of Gab1 to the C-terminal SH2 domain of p85α, and recruited p85α to the plasma membrane resulting in PI3K activation. PI3K-dependent AKT activation results in enhanced phosphofructokinase 2 (PFK2) phosphorylation and production of fructose-2,6-bisphosphate, which in turn promotes PFK1 activation. PFKP Y64 phosphorylation-enhanced PI3K/AKT-dependent PFK1 activation and GLUT1 expression promoted the Warburg effect, tumor cell proliferation, and brain tumorigenesis. These findings underscore the instrumental role of PFKP in PI3K activation and enhanced glycolysis through PI3K/AKT-dependent positive-feedback regulation.

Funding information:
  • NCI NIH HHS - T32 CA121938(United States)

Long-term effects of autoimmune CNS inflammation on adult hippocampal neurogenesis.

  • Giannakopoulou A
  • J. Neurosci. Res.
  • 2018 Mar 12

Literature context:


Abstract:

Neurogenesis is a well-characterized phenomenon within the dentate gyrus (DG) of the adult hippocampus. Aging and chronic degenerative disorders have been shown to impair hippocampal neurogenesis, but the consequence of chronic inflammation remains controversial. In this study the chronic experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis was used to investigate the long-term effects of T cell-mediated central nervous system inflammation on hippocampal neurogenesis. 5-Bromodeoxyuridine (BrdU)-labeled subpopulations of hippocampal cells in EAE and control mice (coexpressing GFAP, doublecortin, NeuN, calretinin, and S100) were quantified at the recovery phase, 21 days after BrdU administration, to estimate alterations on the rate and differentiation pattern of the neurogenesis process. The core features of EAE mice DG are (i) elevated number of newborn (BrdU+) cells indicating vigorous proliferation, which in the long term subsided; (ii) enhanced migration of newborn cells into the granule cell layer; (iii) increased level of immature neuronal markers (including calretinin and doublecortin); (iv) trending decrease in the percentage of newborn mature neurons; and (v) augmented gliogenesis and differentiation of newborn neural precursor cells (NPCs) to mature astrocytes (BrdU+/S100+). Although the inflammatory environment in the brain of EAE mice enhances the proliferation of hippocampal NPCs, in the long term neurogenesis is progressively depleted, giving prominence to gliogenesis. The discrepancy between the high number of immature cells and the low number of mature newborn cells could be the result of a caused defect in the maturation pathway. © 2016 Wiley Periodicals, Inc.

MST4 Phosphorylation of ATG4B Regulates Autophagic Activity, Tumorigenicity, and Radioresistance in Glioblastoma.

  • Huang T
  • Cancer Cell
  • 2017 Dec 11

Literature context:


Abstract:

ATG4B stimulates autophagy by promoting autophagosome formation through reversible modification of ATG8. We identify ATG4B as a substrate of mammalian sterile20-like kinase (STK) 26/MST4. MST4 phosphorylates ATG4B at serine residue 383, which stimulates ATG4B activity and increases autophagic flux. Inhibition of MST4 or ATG4B activities using genetic approaches or an inhibitor of ATG4B suppresses autophagy and the tumorigenicity of glioblastoma (GBM) cells. Furthermore, radiation induces MST4 expression, ATG4B phosphorylation, and autophagy. Inhibiting ATG4B in combination with radiotherapy in treating mice with intracranial GBM xenograft markedly slows tumor growth and provides a significant survival benefit. Our work describes an MST4-ATG4B signaling axis that influences GBM autophagy and malignancy, and whose therapeutic targeting enhances the anti-tumor effects of radiotherapy.

Funding information:
  • NCI NIH HHS - P01 CA163205()
  • NCI NIH HHS - R01 CA159467()
  • NCI NIH HHS - R21 CA175875()
  • NCI NIH HHS - T32 CA070085()
  • NIAAA NIH HHS - R01 AA021751()
  • NIGMS NIH HHS - R01 GM038660(United States)
  • NIMHD NIH HHS - L32 MD010147()
  • NINDS NIH HHS - P30 NS081774()
  • NINDS NIH HHS - R01 NS080619()
  • NINDS NIH HHS - R01 NS083767()
  • NINDS NIH HHS - R01 NS093843()
  • NINDS NIH HHS - R01 NS095634()
  • NINDS NIH HHS - R01 NS102669()
  • NLM NIH HHS - K99 LM011673()
  • NLM NIH HHS - R00 LM011673()
  • NLM NIH HHS - R01 LM012011()

The Primate-Specific Gene TMEM14B Marks Outer Radial Glia Cells and Promotes Cortical Expansion and Folding.

  • Liu J
  • Cell Stem Cell
  • 2017 Nov 2

Literature context:


Abstract:

Human brain evolution is associated with expansion and folding of the neocortex. Increased diversity in neural progenitor (NP) populations (such as basally located radial glia [RG], which reside in an enlarged outer subventricular zone [OSVZ]) likely contributes to this evolutionary expansion, although their characteristics and relative contributions are only partially understood. Through single-cell transcriptional profiling of sorted human NP subpopulations, we identified the primate-specific TMEM14B gene as a marker of basal RG. Expression of TMEM14B in embryonic NPs induces cortical thickening and gyrification in postnatal mice. This is accompanied by SVZ expansion, the appearance of outer RG-like cells, and the proliferation of multiple NP subsets, with proportional increases in all cortical layers and normal lamination. TMEM14B drives NP proliferation by increasing the phosphorylation and nuclear translocation of IQGAP1, which in turn promotes G1/S cell cycle transitions. These data show that a single primate-specific gene can drive neurodevelopmental changes that contribute to brain evolution.

Postinjury Induction of Activated ErbB2 Selectively Hyperactivates Denervated Schwann Cells and Promotes Robust Dorsal Root Axon Regeneration.

  • Han SB
  • J. Neurosci.
  • 2017 Nov 8

Literature context:


Abstract:

Following nerve injury, denervated Schwann cells (SCs) convert to repair SCs, which enable regeneration of peripheral axons. However, the repair capacity of SCs and the regenerative capacity of peripheral axons are limited. In the present studies we examined a potential therapeutic strategy to enhance the repair capacity of SCs, and tested its efficacy in enhancing regeneration of dorsal root (DR) axons, whose regenerative capacity is particularly weak. We used male and female mice of a doxycycline-inducible transgenic line to induce expression of constitutively active ErbB2 (caErbB2) selectively in SCs after DR crush or transection. Two weeks after injury, injured DRs of induced animals contained far more SCs and SC processes. These SCs had not redifferentiated and continued to proliferate. Injured DRs of induced animals also contained far more axons that regrew along SC processes past the transection or crush site. Remarkably, SCs and axons in uninjured DRs remained quiescent, indicating that caErbB2 enhanced regeneration of injured DRs, without aberrantly activating SCs and axons in intact nerves. We also found that intraspinally expressed glial cell line-derived neurotrophic factor (GDNF), but not the removal of chondroitin sulfate proteoglycans, greatly enhanced the intraspinal migration of caErbB2-expressing SCs, enabling robust penetration of DR axons into the spinal cord. These findings indicate that SC-selective, post-injury activation of ErbB2 provides a novel strategy to powerfully enhance the repair capacity of SCs and axon regeneration, without substantial off-target damage. They also highlight that promoting directed migration of caErbB2-expressing SCs by GDNF might be useful to enable axon regrowth in a non-permissive environment.SIGNIFICANCE STATEMENT Repair of injured peripheral nerves remains a critical clinical problem. We currently lack a therapy that potently enhances axon regeneration in patients with traumatic nerve injury. It is extremely challenging to substantially increase the regenerative capacity of damaged nerves without deleterious off-target effects. It was therefore of great interest to discover that caErbB2 markedly enhances regeneration of damaged dorsal roots, while evoking little change in intact roots. To our knowledge, these findings are the first demonstration that repair capacity of denervated SCs can be efficaciously enhanced without altering innervated SCs. Our study also demonstrates that oncogenic ErbB2 signaling can be activated in SCs but not impede transdifferentiation of denervated SCs to regeneration-promoting repair SCs.

Nucleus-Translocated ACSS2 Promotes Gene Transcription for Lysosomal Biogenesis and Autophagy.

  • Li X
  • Mol. Cell
  • 2017 Jun 1

Literature context:


Abstract:

Overcoming metabolic stress is a critical step in tumor growth. Acetyl coenzyme A (acetyl-CoA) generated from glucose and acetate uptake is important for histone acetylation and gene expression. However, how acetyl-CoA is produced under nutritional stress is unclear. We demonstrate here that glucose deprivation results in AMP-activated protein kinase (AMPK)-mediated acetyl-CoA synthetase 2 (ACSS2) phosphorylation at S659, which exposed the nuclear localization signal of ACSS2 for importin α5 binding and nuclear translocation. In the nucleus, ACSS2 binds to transcription factor EB and translocates to lysosomal and autophagy gene promoter regions, where ACSS2 incorporates acetate generated from histone acetylation turnover to locally produce acetyl-CoA for histone H3 acetylation in these regions and promote lysosomal biogenesis, autophagy, cell survival, and brain tumorigenesis. In addition, ACSS2 S659 phosphorylation positively correlates with AMPK activity in glioma specimens and grades of glioma malignancy. These results underscore the significance of nuclear ACSS2-mediated histone acetylation in maintaining cell homeostasis and tumor development.

Funding information:
  • NCI NIH HHS - R01 CA109035()
  • NCI NIH HHS - R01 CA169603()
  • NCI NIH HHS - R01 CA204996()
  • NINDS NIH HHS - R01 NS094615()

SoxC Transcription Factors Promote Contralateral Retinal Ganglion Cell Differentiation and Axon Guidance in the Mouse Visual System.

  • Kuwajima T
  • Neuron
  • 2017 Mar 8

Literature context:


Abstract:

Transcription factors control cell identity by regulating diverse developmental steps such as differentiation and axon guidance. The mammalian binocular visual circuit is comprised of projections of retinal ganglion cells (RGCs) to ipsilateral and contralateral targets in the brain. A transcriptional code for ipsilateral RGC identity has been identified, but less is known about the transcriptional regulation of contralateral RGC development. Here we demonstrate that SoxC genes (Sox4, 11, and 12) act on the progenitor-to-postmitotic transition to implement contralateral, but not ipsilateral, RGC differentiation, by binding to Hes5 and thus repressing Notch signaling. When SoxC genes are deleted in postmitotic RGCs, contralateral RGC axons grow poorly on chiasm cells in vitro and project ipsilaterally at the chiasm midline in vivo, and Plexin-A1 and Nr-CAM expression in RGCs is downregulated. These data implicate SoxC transcription factors in the regulation of contralateral RGC differentiation and axon guidance.

Funding information:
  • NEI NIH HHS - R01 EY012736()
  • NEI NIH HHS - R01 EY015290()
  • NIAMS NIH HHS - R01 AR046249()
  • NIAMS NIH HHS - R01 AR060016()

Role of Mitochondrial Metabolism in the Control of Early Lineage Progression and Aging Phenotypes in Adult Hippocampal Neurogenesis.

  • Beckervordersandforth R
  • Neuron
  • 2017 Feb 8

Literature context:


Abstract:

Precise regulation of cellular metabolism is hypothesized to constitute a vital component of the developmental sequence underlying the life-long generation of hippocampal neurons from quiescent neural stem cells (NSCs). The identity of stage-specific metabolic programs and their impact on adult neurogenesis are largely unknown. We show that the adult hippocampal neurogenic lineage is critically dependent on the mitochondrial electron transport chain and oxidative phosphorylation machinery at the stage of the fast proliferating intermediate progenitor cell. Perturbation of mitochondrial complex function by ablation of the mitochondrial transcription factor A (Tfam) reproduces multiple hallmarks of aging in hippocampal neurogenesis, whereas pharmacological enhancement of mitochondrial function ameliorates age-associated neurogenesis defects. Together with the finding of age-associated alterations in mitochondrial function and morphology in NSCs, these data link mitochondrial complex function to efficient lineage progression of adult NSCs and identify mitochondrial function as a potential target to ameliorate neurogenesis-defects in the aging hippocampus.

Funding information:
  • NIMH NIH HHS - R01 MH105128()
  • NINDS NIH HHS - P01 NS097206()
  • NINDS NIH HHS - R35 NS097370()
  • NINDS NIH HHS - R37 NS047344()

Exercise protects against chronic restraint stress-induced oxidative stress in the cortex and hippocampus.

  • Gerecke KM
  • Brain Res.
  • 2013 May 6

Literature context:


Abstract:

Chronic stress induces high levels of reactive oxygen species, creating a neurotoxic environment. Because exercise protects against the neurodegenerative effects of oxidative stress, we investigated the protective effects of exercise against chronic restraint stress (CRS)-induced expression of the proapoptotic cortical B-cell associated X protein (Bax) and cyclooxegenase-2 (Cox-2) as well as microglial/macrophage proliferation and co-expression of Cox-2 in the cortex and hippocampus of mice. CRS induced a large, moderately significant increase in protein levels of Bax 1 h following stress. However, exercised mice had significantly lower cortical levels of Bax at both the 1 and 24 h time points. The level of Cox-2 protein was also significantly lower in the cortex of exercised mice. While no significant changes in microglia/macrophage proliferation were observed in either brain region, CRS induced significant increases of Cox-2 labeling on microglia/macrophages in both the hippocampus and cortex of stressed mice. In the cortex, stressed mice showed significantly greater numbers of Iba1/Cox-2 co-labeled cells than non-stressed mice; however, exercise alone did not induce any changes. In the hippocampus, CRS induced significantly greater numbers of Cox-2 labeled microglia/macrophages in stressed sedentary animals as compared to non-stressed controls. However, exercised mice were protected against these increases, as there was no significant difference in the numbers of Iba1/Cox-2 co-labeled cells between stressed and non-stressed exercised mice. Therefore, exercise protects against CRS-induced increases in levels of Bax in the cortex, and microglial/macrophage expression of Cox-2 in the hippocampus. Taken together, these data suggest that exercise may confer neuroprotection by acting to increase the resilience of the brain against CRS-induced oxidative stress.

Funding information:
  • NIDA NIH HHS - U54 DA021519(United States)
  • NIEHS NIH HHS - 1RC2 ES018736(United States)