Publications by authors named "Corbett T Berry"

21 Publications

  • Page 1 of 1

Calcium signaling induces a partial EMT.

EMBO Rep 2021 Sep 29;22(9):e51872. Epub 2021 Jul 29.

Abramson Family Cancer Research Institute and Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Epithelial plasticity, or epithelial-to-mesenchymal transition (EMT), is a well-recognized form of cellular plasticity, which endows tumor cells with invasive properties and alters their sensitivity to various agents, thus representing a major challenge to cancer therapy. It is increasingly accepted that carcinoma cells exist along a continuum of hybrid epithelial-mesenchymal (E-M) states and that cells exhibiting such partial EMT (P-EMT) states have greater metastatic competence than those characterized by either extreme (E or M). We described recently a P-EMT program operating in vivo by which carcinoma cells lose their epithelial state through post-translational programs. Here, we investigate the underlying mechanisms and report that prolonged calcium signaling induces a P-EMT characterized by the internalization of membrane-associated E-cadherin (ECAD) and other epithelial proteins as well as an increase in cellular migration and invasion. Signaling through Gαq-associated G-protein-coupled receptors (GPCRs) recapitulates these effects, which operate through the downstream activation of calmodulin-Camk2b signaling. These results implicate calcium signaling as a trigger for the acquisition of hybrid/partial epithelial-mesenchymal states in carcinoma cells.
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http://dx.doi.org/10.15252/embr.202051872DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8419705PMC
September 2021

Analysis of Calcium Control of Canonical NF-κB Signaling in B Lymphocytes.

Methods Mol Biol 2021 ;2366:145-164

Department of Pathobiology, The University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA.

The central role of calcium (Ca) signaling in lymphocyte development and acquisition of functional immunity and tolerance is well established. Ca signals are initiated upon antigen binding to cognate receptors on lymphocytes that trigger store operated Ca entry (SOCE). The underlying mechanism of SOCE in lymphocytes involves TCR and BCR mediated activation of Stromal Interaction Molecule 1 and 2 (STIM1/2) embedded in the ER membrane. Once activated, STIM proteins oligomerize and re-localize to ER domains juxtaposed to the plasma membrane where they activate Orai channels to allow Ca to enter the cell across the plasma membrane. Importantly, STIM/Orai-dependent Ca signals guide antigen induced lymphocyte development and function principally by regulating the activity of transcription factors.The most widely studied of these transcription factors is the Nuclear Factor of Activated T cells (NFAT). NFAT is expressed ubiquitously and the mechanism by which Ca regulates NFAT activation and signaling is well known. By contrast, a mechanistic understanding of how Ca signals also shape the activation and specificity of NF-κB to control the expression of pro-inflammatory genes has lagged. Here we discuss the methodology used to investigate Ca dependent mechanisms of NF-κB activation in lymphocytes. Our approach focuses on three main areas of signal transduction and signaling: (1) antigen receptor engagement and Ca dependent initiation of NF-kB signaling, (2) Ca dependent induction of NF-κB heterodimer activation and nuclear localization, and (3) and how Ca regulates NF-κB dependent expression of target genes and proteins.
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http://dx.doi.org/10.1007/978-1-0716-1669-7_9DOI Listing
January 2021

Angiomotin regulates budding and spread of Ebola virus.

J Biol Chem 2020 06 7;295(25):8596-8601. Epub 2020 May 7.

Host-Pathogen Interactions, Texas Biomedical Research Institute, San Antonio, Texas, USA

The Ebola virus (EBOV) VP40 matrix protein (eVP40) orchestrates assembly and budding of virions in part by hijacking select WW-domain-bearing host proteins via its PPxY late (L)-domain motif. Angiomotin (Amot) is a multifunctional PPxY-containing adaptor protein that regulates angiogenesis, actin dynamics, and cell migration/motility. Amot also regulates the Hippo signaling pathway via interactions with the WW-domain-containing Hippo effector protein Yes-associated protein (YAP). In this report, we demonstrate that endogenous Amot is crucial for positively regulating egress of eVP40 virus-like particles (VLPs) and for egress and spread of authentic EBOV. Mechanistically, we show that ectopic YAP expression inhibits eVP40 VLP egress and that Amot co-expression rescues budding of eVP40 VLPs in a dose-dependent and PPxY-dependent manner. Moreover, results obtained with confocal and total internal reflection fluorescence microscopy suggested that Amot's role in actin organization and dynamics also contributes to promoting eVP40-mediated egress. In summary, these findings reveal a functional and competitive interplay between virus and host proteins involving the multifunctional PPxY-containing adaptor Amot, which regulates both the Hippo pathway and actin dynamics. We propose that our results have wide-ranging implications for understanding the biology and pathology of EBOV infections.
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http://dx.doi.org/10.1074/jbc.AC120.013171DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7307192PMC
June 2020

BCR-Induced Ca Signals Dynamically Tune Survival, Metabolic Reprogramming, and Proliferation of Naive B Cells.

Cell Rep 2020 04;31(2):107474

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address:

B cell receptor (BCR) engagement induces naive B cells to differentiate and perform critical immune-regulatory functions. Acquisition of functional specificity requires that a cell survive, enter the cell cycle, and proliferate. We establish that quantitatively distinct Ca signals triggered by variations in the extent of BCR engagement dynamically regulate these transitions by controlling nuclear factor κB (NF-κB), NFAT, and mTORC1 activity. Weak BCR engagement induces apoptosis by failing to activate NF-κB-driven anti-apoptotic gene expression. Stronger signals that trigger more robust Ca signals promote NF-κB-dependent survival and NFAT-, mTORC1-, and c-Myc-dependent cell-cycle entry and proliferation. Finally, we establish that CD40 or TLR9 costimulation circumvents these Ca-regulated checkpoints of B cell activation and proliferation. As altered BCR signaling is linked to autoimmunity and B cell malignancies, these results have important implications for understanding the pathogenesis of aberrant B cell activation and differentiation and therapeutic approaches to target these responses.
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http://dx.doi.org/10.1016/j.celrep.2020.03.038DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7301411PMC
April 2020

Activation of mosquito immunity blocks the development of transmission-stage filarial nematodes.

Proc Natl Acad Sci U S A 2020 02 3;117(7):3711-3717. Epub 2020 Feb 3.

Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104;

Mosquito-borne helminth infections are responsible for a significant worldwide disease burden in both humans and animals. Accordingly, development of novel strategies to reduce disease transmission by targeting these pathogens in the vector are of paramount importance. We found that a strain of that is refractory to infection by , the agent of canine heartworm disease, mounts a stronger immune response during infection than does a susceptible strain. Moreover, activation of the Toll immune signaling pathway in the susceptible strain arrests larval development of the parasite, thereby decreasing the number of transmission-stage larvae. Notably, this strategy also blocks transmission-stage , an agent of human lymphatic filariasis. Our data show that mosquito immunity can play a pivotal role in restricting filarial nematode development and suggest that genetically engineering mosquitoes with enhanced immunity will help reduce pathogen transmission.
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http://dx.doi.org/10.1073/pnas.1909369117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035481PMC
February 2020

Modular mimicry and engagement of the Hippo pathway by Marburg virus VP40: Implications for filovirus biology and budding.

PLoS Pathog 2020 01 6;16(1):e1008231. Epub 2020 Jan 6.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.

Ebola (EBOV) and Marburg (MARV) are members of the Filoviridae family, which continue to emerge and cause sporadic outbreaks of hemorrhagic fever with high mortality rates. Filoviruses utilize their VP40 matrix protein to drive virion assembly and budding, in part, by recruitment of specific WW-domain-bearing host proteins via its conserved PPxY Late (L) domain motif. Here, we screened an array of 115 mammalian, bacterially expressed and purified WW-domains using a PPxY-containing peptide from MARV VP40 (mVP40) to identify novel host interactors. Using this unbiased approach, we identified Yes Associated Protein (YAP) and Transcriptional co-Activator with PDZ-binding motif (TAZ) as novel mVP40 PPxY interactors. YAP and TAZ function as downstream transcriptional effectors of the Hippo signaling pathway that regulates cell proliferation, migration and apoptosis. We demonstrate that ectopic expression of YAP or TAZ along with mVP40 leads to significant inhibition of budding of mVP40 VLPs in a WW-domain/PPxY dependent manner. Moreover, YAP colocalized with mVP40 in the cytoplasm, and inhibition of mVP40 VLP budding was more pronounced when YAP was localized predominantly in the cytoplasm rather than in the nucleus. A key regulator of YAP nuclear/cytoplasmic localization and function is angiomotin (Amot); a multi-PPxY containing protein that strongly interacts with YAP WW-domains. Interestingly, we found that expression of PPxY-containing Amot rescued mVP40 VLP egress from either YAP- or TAZ-mediated inhibition in a PPxY-dependent manner. Importantly, using a stable Amot-knockdown cell line, we found that expression of Amot was critical for efficient egress of mVP40 VLPs as well as egress and spread of authentic MARV in infected cell cultures. In sum, we identified novel negative (YAP/TAZ) and positive (Amot) regulators of MARV VP40-mediated egress, that likely function in part, via competition between host and viral PPxY motifs binding to modular host WW-domains. These findings not only impact our mechanistic understanding of virus budding and spread, but also may impact the development of new antiviral strategies.
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http://dx.doi.org/10.1371/journal.ppat.1008231DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6977764PMC
January 2020

Dramatic changes in gene expression in different forms of Crithidia fasciculata reveal potential mechanisms for insect-specific adhesion in kinetoplastid parasites.

PLoS Negl Trop Dis 2019 07 29;13(7):e0007570. Epub 2019 Jul 29.

Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, United States of America.

Kinetoplastids are a group of parasites that includes several medically-important species. These human-infective species are transmitted by insect vectors in which the parasites undergo specific developmental transformations. For each species, this includes a stage in which parasites adhere to insect tissue via a hemidesmosome-like structure. Although this structure has been described morphologically, it has never been molecularly characterized. We are using Crithidia fasciculata, an insect parasite that produces large numbers of adherent parasites inside its mosquito host, as a model kinetoplastid to investigate both the mechanism of adherence and the signals required for differentiation to an adherent form. An advantage of C. fasciculata is that adherent parasites can be generated both in vitro, allowing a direct comparison to cultured swimming forms, as well as in vivo within the mosquito. Using RNAseq, we identify genes associated with adherence in C. fasciculata. As almost all of these genes have orthologs in other kinetoplastid species, our findings may reveal shared mechanisms of adherence, allowing investigation of a crucial step in parasite development and disease transmission. In addition, dual-RNAseq allowed us to explore the interaction between the parasites and the mosquito. Although the infection is well-tolerated, anti-microbial peptides and other components of the mosquito innate immune system are upregulated. Our findings indicate that C. fasciculata is a powerful model system for probing kinetoplastid-insect interactions.
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http://dx.doi.org/10.1371/journal.pntd.0007570DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6687205PMC
July 2019

Caspase-8 promotes c-Rel-dependent inflammatory cytokine expression and resistance against .

Proc Natl Acad Sci U S A 2019 06 30;116(24):11926-11935. Epub 2019 May 30.

Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104;

Caspase-8 is a key integrator of cell survival and cell death decisions during infection and inflammation. Following engagement of tumor necrosis factor superfamily receptors or certain Toll-like receptors (TLRs), caspase-8 initiates cell-extrinsic apoptosis while inhibiting RIPK3-dependent programmed necrosis. In addition, caspase-8 has an important, albeit less well understood, role in cell-intrinsic inflammatory gene expression. Macrophages lacking caspase-8 or the adaptor FADD have defective inflammatory cytokine expression and inflammasome priming in response to bacterial infection or TLR stimulation. How caspase-8 regulates cytokine gene expression, and whether caspase-8-mediated gene regulation has a physiological role during infection, remain poorly defined. Here we demonstrate that both caspase-8 enzymatic activity and scaffolding functions contribute to inflammatory cytokine gene expression. Caspase-8 enzymatic activity was necessary for maximal expression of and , but caspase-8 deficient cells exhibited a further decrease in expression of these genes. Furthermore, the ability of TLR stimuli to induce optimal IκB kinase phosphorylation and nuclear translocation of the nuclear factor kappa light chain enhancer of activated B cells family member c-Rel required caspase activity. Interestingly, overexpression of c-Rel was sufficient to restore expression of IL-12 and IL-1β in caspase-8-deficient cells. Moreover, mice were unable to control infection by the intracellular parasite , which corresponded to defects in monocyte recruitment to the peritoneal cavity, and exogenous IL-12 restored monocyte recruitment and protection of caspase-8-deficient mice during acute toxoplasmosis. These findings provide insight into how caspase-8 controls inflammatory gene expression and identify a critical role for caspase-8 in host defense against eukaryotic pathogens.
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http://dx.doi.org/10.1073/pnas.1820529116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6575527PMC
June 2019

Combined Menin and EGFR Inhibitors Synergize to Suppress Colorectal Cancer via EGFR-Independent and Calcium-Mediated Repression of SKP2 Transcription.

Cancer Res 2019 05 15;79(9):2195-2207. Epub 2019 Mar 15.

Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.

Menin is a nuclear epigenetic regulator that can both promote and suppress tumor growth in a highly tissue-specific manner. The role of menin in colorectal cancer, however, remains unclear. Here, we demonstrate that menin was overexpressed in colorectal cancer and that inhibition of menin synergized with small-molecule inhibitors of EGFR (iEGFR) to suppress colorectal cancer cells and tumor xenografts in an EGFR-independent manner. Mechanistically, menin bound the promoter of SKP2, a pro-oncogenic gene crucial for colorectal cancer growth, and promoted its expression. Moreover, the iEGFR gefitinib activated endoplasmic reticulum calcium channel inositol trisphosphate receptor 3 (IP3R3)-mediated release of calcium, which directly bound menin. Combined inhibition of menin and iEGFR-induced calcium release synergistically suppressed menin-mediated expression of SKP2 and growth of colorectal cancer. Together, these findings uncover a molecular convergence of menin and the iEGFR-induced, IP3R3-mediated calcium release on SKP2 transcription and reveal opportunities to enhance iEGFR efficacy to improve treatments for colorectal cancer. SIGNIFICANCE: Menin acts as a calcium-responsive regulator of SKP2 expression, and small molecule EGFR inhibitors, which induce calcium release, synergize with Menin inhibition to reduce SKP2 expression and suppress colorectal cancer.
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http://dx.doi.org/10.1158/0008-5472.CAN-18-2133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6996413PMC
May 2019

STIM- and Orai-mediated calcium entry controls NF-κB activity and function in lymphocytes.

Cell Calcium 2018 09 10;74:131-143. Epub 2018 Jul 10.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA. Electronic address:

The central role of Ca signaling in the development of functional immunity and tolerance is well established. These signals are initiated by antigen binding to cognate receptors on lymphocytes that trigger store operated Ca entry (SOCE). The underlying mechanism of SOCE in lymphocytes involves TCR and BCR mediated activation of Stromal Interaction Molecule 1 and 2 (STIM1/2) molecules embedded in the ER membrane leading to their activation of Orai channels in the plasma membrane. STIM/Orai dependent Ca signals guide key antigen induced lymphocyte development and function principally through direct regulation of Ca dependent transcription factors. The role of Ca signaling in NFAT activation and signaling is well known and has been studied extensively, but a wide appreciation and mechanistic understanding of how Ca signals also shape the activation and specificity of NF-κB dependent gene expression has lagged. Here we discuss and interpret what is known about Ca dependent mechanisms of NF-kB activation, including what is known and the gaps in our understanding of how these signals control lymphocyte development and function.
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http://dx.doi.org/10.1016/j.ceca.2018.07.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6415950PMC
September 2018

Host Protein BAG3 is a Negative Regulator of Lassa VLP Egress.

Diseases 2018 Jul 13;6(3). Epub 2018 Jul 13.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.

Lassa fever virus (LFV) belongs to the family and can cause acute hemorrhagic fever in humans. The LFV Z protein plays a central role in virion assembly and egress, such that independent expression of LFV Z leads to the production of virus-like particles (VLPs) that mimic egress of infectious virus. LFV Z contains both PTAP and PPPY L-domain motifs that are known to recruit host proteins that are important for mediating efficient virus egress and spread. The viral PPPY motif is known to interact with specific host WW-domain bearing proteins. Here we identified host WW-domain bearing protein BCL2 Associated Athanogene 3 (BAG3) as a LFV Z PPPY interactor using our proline-rich reading array of WW-domain containing mammalian proteins. BAG3 is a stress-induced molecular co-chaperone that functions to regulate cellular protein homeostasis and cell survival via Chaperone-Assisted Selective Autophagy (CASA). Similar to our previously published findings for the VP40 proteins of Ebola and Marburg viruses, our results using VLP budding assays, BAG3 knockout cells, and confocal microscopy indicate that BAG3 is a WW-domain interactor that negatively regulates egress of LFV Z VLPs, rather than promoting VLP release. Our results suggest that CASA and specifically BAG3 may represent a novel host defense mechanism, whereby BAG3 may dampen egress of several hemorrhagic fever viruses by interacting and interfering with the budding function of viral PPxY-containing matrix proteins.
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http://dx.doi.org/10.3390/diseases6030064DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6163595PMC
July 2018

Atypical pharmacology of schistosome TRPA1-like ion channels.

PLoS Negl Trop Dis 2018 05 10;12(5):e0006495. Epub 2018 May 10.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.

Parasitic flatworms of the genus Schistosoma cause schistosomiasis, a neglected tropical disease estimated to affect over 200 million people worldwide. Praziquantel is the only antischistosomal currently available for treatment, and there is an urgent need for new therapeutics. Ion channels play key roles in physiology and are targets for many anthelmintics, yet only a few representatives have been characterized in any detail in schistosomes and other parasitic helminths. The transient receptor potential (TRP) channel superfamily comprises a diverse family of non-selective cation channels that play key roles in sensory transduction and a wide range of other functions. TRP channels fall into several subfamilies. Members of both the TRPA and TRPV subfamilies transduce nociceptive and inflammatory signals in mammals, and often also respond to chemical and thermal signals. We previously showed that although schistosomes contain no genes predicted to encode TRPV channels, TRPV1-selective activators such as capsaicin and resiniferatoxin elicit dramatic hyperactivity in adult worms and schistosomula. Surprisingly, this response requires expression of a S. mansoni TRPA1-like orthologue (SmTRPA). Here, we show that capsaicin induces a rise in intracellular Ca2+ in mammalian cells expressing either SmTRPA or a S. haematobium TRPA1 orthologue (ShTRPA). We also test SmTRPA and ShTRPA responses to various TRPV1 and TRPA1 modulators. Interestingly, in contrast to SmTRPA, ShTRPA is not activated by the TRPA1 activator AITC (allyl isothiocyanate), nor do S. haematobium adult worms respond to this compound, a potentially intriguing species difference. Notably, 4-hydroxynonenal (4-HNE), a host-derived, inflammatory product that directly activates mammalian TRPA1, also activates both SmTRPA and ShTRPA. Our results point to parasite TRPA1-like channels which exhibit atypical, mixed TRPA1/TRPV1-like pharmacology, and which may also function to transduce endogenous host signals.
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http://dx.doi.org/10.1371/journal.pntd.0006495DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5963811PMC
May 2018

Acetyl-CoA promotes glioblastoma cell adhesion and migration through Ca-NFAT signaling.

Genes Dev 2018 04 19;32(7-8):497-511. Epub 2018 Apr 19.

Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA.

The metabolite acetyl-coenzyme A (acetyl-CoA) is the required acetyl donor for lysine acetylation and thereby links metabolism, signaling, and epigenetics. Nutrient availability alters acetyl-CoA levels in cancer cells, correlating with changes in global histone acetylation and gene expression. However, the specific molecular mechanisms through which acetyl-CoA production impacts gene expression and its functional roles in promoting malignant phenotypes are poorly understood. Here, using histone H3 Lys27 acetylation (H3K27ac) ChIP-seq (chromatin immunoprecipitation [ChIP] coupled with next-generation sequencing) with normalization to an exogenous reference genome (ChIP-Rx), we found that changes in acetyl-CoA abundance trigger site-specific regulation of H3K27ac, correlating with gene expression as opposed to uniformly modulating this mark at all genes. Genes involved in integrin signaling and cell adhesion were identified as acetyl-CoA-responsive in glioblastoma cells, and we demonstrate that ATP citrate lyase (ACLY)-dependent acetyl-CoA production promotes cell migration and adhesion to the extracellular matrix. Mechanistically, the transcription factor NFAT1 (nuclear factor of activated T cells 1) was found to mediate acetyl-CoA-dependent gene regulation and cell adhesion. This occurs through modulation of Ca signals, triggering NFAT1 nuclear translocation when acetyl-CoA is abundant. The findings of this study thus establish that acetyl-CoA impacts H3K27ac at specific loci, correlating with gene expression, and that expression of cell adhesion genes are driven by acetyl-CoA in part through activation of Ca-NFAT signaling.
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http://dx.doi.org/10.1101/gad.311027.117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5959234PMC
April 2018

Calorie Restriction Governs Intestinal Epithelial Regeneration through Cell-Autonomous Regulation of mTORC1 in Reserve Stem Cells.

Stem Cell Reports 2018 03 1;10(3):703-711. Epub 2018 Mar 1.

Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address:

Aging is a complex process associated with a decline in functionality of adult stem cells affecting tissue homeostasis and regeneration. Calorie restriction (CR) is the only experimental manipulation known to extend lifespan and reduce the incidence of age-related disorders across numerous species. These benefits are likely mediated, at least in part, through the preservation of stem cell function. Here, we show that CR enhances the regenerative capacity of the intestinal epithelium through preservation of an injury-resistant reserve intestinal stem cell (ISC) pool. Cell-autonomous activity of mechanistic target of rapamycin complex 1 (mTORC1) governs the sensitivity of reserve ISCs to injury. CR inhibits mTORC1 in these cells, protecting them against DNA damage, while mTORC1 stimulation, either genetically or through nutrient sensing, sensitizes reserve ISCs to injury, thus compromising regeneration of the epithelium. These data delineate a critical role for mTORC1 in epithelial regeneration and inform clinical strategies based on nutrient modulation.
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http://dx.doi.org/10.1016/j.stemcr.2018.01.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5919411PMC
March 2018

Ubiquitin Ligase WWP1 Interacts with Ebola Virus VP40 To Regulate Egress.

J Virol 2017 10 27;91(20). Epub 2017 Sep 27.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA

Ebola virus (EBOV) is a member of the family and the cause of hemorrhagic fever outbreaks. The EBOV VP40 (eVP40) matrix protein is the main driving force for virion assembly and budding. Indeed, expression of eVP40 alone in mammalian cells results in the formation and budding of virus-like particles (VLPs) which mimic the budding process and morphology of authentic, infectious EBOV. To complete the budding process, eVP40 utilizes its PPXY L-domain motif to recruit a specific subset of host proteins containing one or more modular WW domains that then function to facilitate efficient production and release of eVP40 VLPs. In this report, we identified additional host WW-domain interactors by screening for potential interactions between mammalian proteins possessing one or more WW domains and WT or PPXY mutant peptides of eVP40. We identified the HECT family E3 ubiquitin ligase WWP1 and all four of its WW domains as strong interactors with the PPXY motif of eVP40. The eVP40-WWP1 interaction was confirmed by both peptide pulldown and coimmunoprecipitation assays, which also demonstrated that modular WW domain 1 of WWP1 was most critical for binding to eVP40. Importantly, the eVP40-WWP1 interaction was found to be biologically relevant for VLP budding since (i) small interfering RNA (siRNA) knockdown of endogenous WWP1 resulted in inhibition of eVP40 VLP egress, (ii) coexpression of WWP1 and eVP40 resulted in ubiquitination of eVP40 and a subsequent increase in eVP40 VLP egress, and (iii) an enzymatically inactive mutant of WWP1 (C890A) did not ubiquitinate eVP40 or enhance eVP40 VLP egress. Last, our data show that ubiquitination of eVP40 by WWP1 enhances egress of VLPs and concomitantly decreases cellular levels of higher-molecular-weight oligomers of eVP40. In sum, these findings contribute to our fundamental understanding of the functional interplay between host E3 ligases, ubiquitination, and regulation of EBOV VP40-mediated egress. Ebola virus (EBOV) is a high-priority, emerging human pathogen that can cause severe outbreaks of hemorrhagic fever with high mortality rates. As there are currently no approved vaccines or treatments for EBOV, a better understanding of the biology and functions of EBOV-host interactions that promote or inhibit viral budding is warranted. Here, we describe a physical and functional interaction between EBOV VP40 (eVP40) and WWP1, a host E3 ubiquitin ligase that ubiquitinates VP40 and regulates VLP egress. This viral PPXY-host WW domain-mediated interaction represents a potential new target for host-oriented inhibitors of EBOV egress.
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http://dx.doi.org/10.1128/JVI.00812-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5625505PMC
October 2017

Intradiploic Epidermoid Tumors of the Cranium: Case Report with Review of the Literature.

J Neurol Surg A Cent Eur Neurosurg 2017 Mar 24;78(2):167-179. Epub 2016 Aug 24.

Department of Neurosurgery, Temple University, Philadelphia, Pennsylvania, United States.

 Epidermoid cysts are a rare intracranial tumor, mostly arising from the cerebellar pontine angle but sporadically arising from the cranial diploe. Intradiploic epidermoids were first described in 1838 and have since been reported in sporadic case reports and case series. Due to the scarcity of cases, no institution has a large enough case series to fully characterize this tumor. We review numerous case series to better describe intradiploic epidermoids.  Using a search for several case reports and series were found. References from these articles were reviewed for further cases.  A total of 169 cases of intradiploic epidermoids were reviewed. The average age of patients presenting with intradiploic epidermoids was 38.1 years (standard error of the mean: 1.56). Overall, 68.9% of these patients presented with localized swelling over the scalp, 32.3% with headaches, and 42.7% with other neurologic symptoms. The most common location of the tumor was the frontal bones, with the least common the sphenoid, zygomatic, and maxillary bone. Surgical resection was curative in most cases, with a 3.2% mortality. Recurrence rate was only 5.8%, with nearly all occurring before 1999. Of the recurrent cases, malignant transformation to squamous cell carcinoma was estimated at 44% (4/9). Most of these cases are thought to have occurred as a result of incomplete resection of a primary intradiploic epidermoid.  To date, this is the largest review of intradiploic epidermoids reported in the literature. In the reported cases, most had a benign course. However, there are occasional malignant transformations, and some patients have neurologic sequelae from mass effect or tumor infiltration. This is a surgically curative tumor in most cases.
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http://dx.doi.org/10.1055/s-0036-1585584DOI Listing
March 2017

T Cell Receptor-induced Nuclear Factor κB (NF-κB) Signaling and Transcriptional Activation Are Regulated by STIM1- and Orai1-mediated Calcium Entry.

J Biol Chem 2016 Apr 29;291(16):8440-52. Epub 2016 Jan 29.

From the Departments of Pathobiology and

T cell activation following antigen binding to the T cell receptor (TCR) involves the mobilization of intracellular Ca(2+) to activate the key transcription factors nuclear factor of activated T lymphocytes (NFAT) and NF-κB. The mechanism of NFAT activation by Ca(2+) has been determined. However, the role of Ca(2+) in controlling NF-κB signaling is poorly understood, and the source of Ca(2+) required for NF-κB activation is unknown. We demonstrate that TCR- but not TNF-induced NF-κB signaling upstream of IκB kinase activation absolutely requires the influx of extracellular Ca(2+) via STIM1-dependent Ca(2+) release-activated Ca(2+)/Orai channels. We further show that Ca(2+) influx controls phosphorylation of the NF-κB protein p65 on Ser-536 and that this posttranslational modification controls its nuclear localization and transcriptional activation. Notably, our data reveal that this role for Ca(2+) is entirely separate from its upstream control of IκBα degradation, thereby identifying a novel Ca(2+)-dependent distal step in TCR-induced NF-κB activation. Finally, we demonstrate that this control of distal signaling occurs via Ca(2+)-dependent PKCα-mediated phosphorylation of p65. Thus, we establish the source of Ca(2+) required for TCR-induced NF-κB activation and define a new distal Ca(2+)-dependent checkpoint in TCR-induced NF-κB signaling that has broad implications for the control of immune cell development and T cell functional specificity.
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http://dx.doi.org/10.1074/jbc.M115.713008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4861418PMC
April 2016

Developmental up-regulation of vesicular glutamate transporter-1 promotes neocortical presynaptic terminal development.

PLoS One 2012 30;7(11):e50911. Epub 2012 Nov 30.

Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, USA.

Presynaptic terminal formation is a complex process that requires assembly of proteins responsible for synaptic transmission at sites of axo-dendritic contact. Accumulation of presynaptic proteins at developing terminals is facilitated by glutamate receptor activation. Glutamate is loaded into synaptic vesicles for release via the vesicular glutamate transporters VGLUT1 and VGLUT2. During postnatal development there is a switch from predominantly VGLUT2 expression to high VGLUT1 and low VGLUT2, raising the question of whether the developmental increase in VGLUT1 is important for presynaptic development. Here, we addressed this question using confocal microscopy and quantitative immunocytochemistry in primary cultures of rat neocortical neurons. First, in order to understand the extent to which the developmental switch from VGLUT2 to VGLUT1 occurs through an increase in VGLUT1 at individual presynaptic terminals or through addition of VGLUT1-positive presynaptic terminals, we examined the spatio-temporal dynamics of VGLUT1 and VGLUT2 expression. Between 5 and 12 days in culture, the percentage of presynaptic terminals that expressed VGLUT1 increased during synapse formation, as did expression of VGLUT1 at individual terminals. A subset of VGLUT1-positive terminals also expressed VGLUT2, which decreased at these terminals. At individual terminals, the increase in VGLUT1 correlated with greater accumulation of other synaptic vesicle proteins, such as synapsin and synaptophysin. When the developmental increase in VGLUT1 was prevented using VGLUT1-shRNA, the density of presynaptic terminals and accumulation of synapsin and synaptophysin at terminals were decreased. Since VGLUT1 knock-down was limited to a small number of neurons, the observed effects were cell-autonomous and independent of changes in overall network activity. These results demonstrate that up-regulation of VGLUT1 is important for development of presynaptic terminals in the cortex.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0050911PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3511412PMC
May 2013

Facilitation of neocortical presynaptic terminal development by NMDA receptor activation.

Neural Dev 2012 Feb 16;7. Epub 2012 Feb 16.

Department of Pharmacology, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA.

Background: Neocortical circuits are established through the formation of synapses between cortical neurons, but the molecular mechanisms of synapse formation are only beginning to be understood. The mechanisms that control synaptic vesicle (SV) and active zone (AZ) protein assembly at developing presynaptic terminals have not yet been defined. Similarly, the role of glutamate receptor activation in control of presynaptic development remains unclear.

Results: Here, we use confocal imaging to demonstrate that NMDA receptor (NMDAR) activation regulates accumulation of multiple SV and AZ proteins at nascent presynaptic terminals of visual cortical neurons. NMDAR-dependent regulation of presynaptic assembly occurs even at synapses that lack postsynaptic NMDARs. We also provide evidence that this control of presynaptic terminal development is independent of glia.

Conclusions: Based on these data, we propose a novel NMDAR-dependent mechanism for control of presynaptic terminal development in excitatory neocortical neurons. Control of presynaptic development by NMDARs could ultimately contribute to activity-dependent development of cortical receptive fields.
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http://dx.doi.org/10.1186/1749-8104-7-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296626PMC
February 2012
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