101
|
Eisenman ST, Gibbons SJ, Verhulst PJ, Cipriani G, Saur D, Farrugia G. Tumor necrosis factor alpha derived from classically activated "M1" macrophages reduces interstitial cell of Cajal numbers. Neurogastroenterol Motil 2017; 29:10.1111/nmo.12984. [PMID: 27781339 PMCID: PMC5367986 DOI: 10.1111/nmo.12984] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/20/2016] [Accepted: 09/28/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND Delayed gastric emptying in diabetic mice and humans is associated with changes in macrophage phenotype and loss of interstitial cells of Cajal (ICC) in the gastric muscle layers. In diabetic mice, classically activated M1 macrophages are associated with delayed gastric emptying, whereas alternatively activated M2 macrophages are associated with normal gastric emptying. This study aimed to determine if secreted factors from M1 macrophages could injure mouse ICC in primary culture. METHODS Cultures of gastric ICC were treated with conditioned medium (CM) from activated bone marrow-derived macrophages (BMDMs) and the effect of CM was quantified by counting ICC per high-powered field. KEY RESULTS Bone marrow-derived macrophages were activated to a M1 or M2 phenotype confirmed by qRT-PCR. Conditioned medium from M1 macrophages reduced ICC numbers by 41.1%, whereas M2-CM had no effect as compared to unconditioned, control media. Immunoblot analysis of 40 chemokines/cytokines found 12 that were significantly increased in M1-CM, including tumor necrosis factor alpha (TNF-α). ELISA detected 0.697±0.03 ng mL-1 TNF-α in M1-CM. Recombinant mouse TNF-α reduced Kit expression and ICC numbers in a concentration-dependent manner (EC50 = 0.817 ng mL-1 ). Blocking M1-CM TNF-α with a neutralizing antibody preserved ICC numbers. The caspase inhibitor Z-VAD.fmk partly preserved ICC numbers (cells/field; 6.63±1.04, 9.82±1.80 w/Z-VAD.fmk, n=6, P<.05). CONCLUSIONS & INFERENCES This work demonstrates that TNF-α secreted from M1 macrophages can result in Kit loss and directly injure ICC in vitro partly through caspase-dependent apoptosis and may play an important role in ICC depletion in diabetic gastroparesis.
Collapse
|
102
|
Malysz J, Gibbons SJ, Saravanaperumal SA, Du P, Eisenman ST, Cao C, Oh U, Saur D, Klein S, Ordog T, Farrugia G. Conditional genetic deletion of Ano1 in interstitial cells of Cajal impairs Ca 2+ transients and slow waves in adult mouse small intestine. Am J Physiol Gastrointest Liver Physiol 2017; 312:G228-G245. [PMID: 27979828 PMCID: PMC5401988 DOI: 10.1152/ajpgi.00363.2016] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/05/2016] [Accepted: 12/12/2016] [Indexed: 01/31/2023]
Abstract
Myenteric plexus interstitial cells of Cajal (ICC-MY) in the small intestine are Kit+ electrical pacemakers that express the Ano1/TMEM16A Ca2+-activated Cl- channel, whose functions in the gastrointestinal tract remain incompletely understood. In this study, an inducible Cre-LoxP-based approach was used to advance the understanding of Ano1 in ICC-MY of adult mouse small intestine. KitCreERT2/+;Ano1Fl/Fl mice were treated with tamoxifen or vehicle, and small intestines (mucosa free) were examined. Quantitative RT-PCR demonstrated ~50% reduction in Ano1 mRNA in intestines of conditional knockouts (cKOs) compared with vehicle-treated controls. Whole mount immunohistochemistry showed a mosaic/patchy pattern loss of Ano1 protein in ICC networks. Ca2+ transients in ICC-MY network of cKOs displayed reduced duration compared with highly synchronized controls and showed synchronized and desynchronized profiles. When matched, the rank order for Ano1 expression in Ca2+ signal imaged fields of view was as follows: vehicle controls>>>cKO(synchronized)>cKO(desynchronized). Maintenance of Ca2+ transients' synchronicity despite high loss of Ano1 indicates a large functional reserve of Ano1 in the ICC-MY network. Slow waves in cKOs displayed reduced duration and increased inter-slow-wave interval and occurred in regular- and irregular-amplitude oscillating patterns. The latter activity suggested ongoing interaction by independent interacting oscillators. Lack of slow waves and depolarization, previously reported for neonatal constitutive knockouts, were also seen. In summary, Ano1 in adults regulates gastrointestinal function by determining Ca2+ transients and electrical activity depending on the level of Ano1 expression. Partial Ano1 loss results in Ca2+ transients and slow waves displaying reduced duration, while complete and widespread absence of Ano1 in ICC-MY causes lack of slow wave and desynchronized Ca2+ transients.NEW & NOTEWORTHY The Ca2+-activated Cl- channel, Ano1, in interstitial cells of Cajal (ICC) is necessary for normal gastrointestinal motility. We knocked out Ano1 to varying degrees in ICC of adult mice. Partial knockout of Ano1 shortened the widths of electrical slow waves and Ca2+ transients in myenteric ICC but Ca2+ transient synchronicity was preserved. Near-complete knockout was necessary for transient desynchronization and loss of slow waves, indicating a large functional reserve of Ano1 in ICC.
Collapse
|
103
|
Trinkmann F, Götzmann J, Schroeter M, Saur D, Roth K, Akin I, Borggrefe M, Saur J, Michels JD. Neue Lungenfunktionsparameter zur Evaluation von Patienten mit interstitiellen Lungenerkrankungen. Pneumologie 2017. [DOI: 10.1055/s-0037-1598559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
104
|
Schneeweis C, Wirth M, Saur D, Reichert M, Schneider G. Oncogenic KRAS and the EGFR loop in pancreatic carcinogenesis-A connection to licensing nodes. Small GTPases 2017; 9:457-464. [PMID: 27880072 DOI: 10.1080/21541248.2016.1262935] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
EGFR signaling has a critical role in oncogenic KRAS-driven tumorigenesis of the pancreas, whereas it is dispensable in other organs. The complex signaling network engaged by oncogenic KRAS and its modulation by EGFR signaling, remains incompletely understood. In order to study early signaling events activated by oncogenic KRAS in the pancreas, we recently developed a novel model system based on murine primary pancreatic epithelial cells enabling the time-specific expression of mutant KrasG12D from its endogenous promoter. Here, we discuss our findings of a KrasG12D-induced autocrine EGFR loop, how this loop is integrated by the MYC oncogene, and point to possible translational implications.
Collapse
|
105
|
Friedrich MJ, Rad L, Bronner IF, Strong A, Wang W, Weber J, Mayho M, Ponstingl H, Engleitner T, Grove C, Pfaus A, Saur D, Cadiñanos J, Quail MA, Vassiliou GS, Liu P, Bradley A, Rad R. Genome-wide transposon screening and quantitative insertion site sequencing for cancer gene discovery in mice. Nat Protoc 2017; 12:289-309. [PMID: 28079877 DOI: 10.1038/nprot.2016.164] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Transposon-mediated forward genetics screening in mice has emerged as a powerful tool for cancer gene discovery. It pinpoints cancer drivers that are difficult to find with other approaches, thus complementing the sequencing-based census of human cancer genes. We describe here a large series of mouse lines for insertional mutagenesis that are compatible with two transposon systems, PiggyBac and Sleeping Beauty, and give guidance on the use of different engineered transposon variants for constitutive or tissue-specific cancer gene discovery screening. We also describe a method for semiquantitative transposon insertion site sequencing (QiSeq). The QiSeq library preparation protocol exploits acoustic DNA fragmentation to reduce bias inherent to widely used restriction-digestion-based approaches for ligation-mediated insertion site amplification. Extensive multiplexing in combination with next-generation sequencing allows affordable ultra-deep transposon insertion site recovery in high-throughput formats within 1 week. Finally, we describe principles of data analysis and interpretation for obtaining insights into cancer gene function and genetic tumor evolution.
Collapse
|
106
|
Lange S, Saur D, Rad R. siRNA-coupled nanoparticles for improved therapeutic targeting of pancreatic cancer. Gut 2016; 65:1780-1781. [PMID: 27436269 DOI: 10.1136/gutjnl-2016-312092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 06/16/2016] [Indexed: 12/08/2022]
|
107
|
Goldstein BJ, Goss GM, Choi R, Saur D, Seidler B, Hare JM, Chaudhari N. Contribution of Polycomb group proteins to olfactory basal stem cell self-renewal in a novel c-KIT+ culture model and in vivo. Development 2016; 143:4394-4404. [PMID: 27789621 DOI: 10.1242/dev.142653] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 10/18/2016] [Indexed: 01/14/2023]
Abstract
Olfactory epithelium (OE) has a lifelong capacity for neurogenesis due to the presence of basal stem cells. Despite the ability to generate short-term cultures, the successful in vitro expansion of purified stem cells from adult OE has not been reported. We sought to establish expansion-competent OE stem cell cultures to facilitate further study of the mechanisms and cell populations important in OE renewal. Successful cultures were prepared using adult mouse basal cells selected for expression of c-KIT. We show that c-KIT signaling regulates self-renewal capacity and prevents neurodifferentiation in culture. Inhibition of TGFβ family signaling, a known negative regulator of embryonic basal cells, is also necessary for maintenance of the proliferative, undifferentiated state in vitro Characterizing successful cultures, we identified expression of BMI1 and other Polycomb proteins not previously identified in olfactory basal cells but known to be essential for self-renewal in other stem cell populations. Inducible fate mapping demonstrates that BMI1 is expressed in vivo by multipotent OE progenitors, validating our culture model. These findings provide mechanistic insights into the renewal and potency of olfactory stem cells.
Collapse
|
108
|
Xu C, Krabbe S, Gründemann J, Botta P, Fadok JP, Osakada F, Saur D, Grewe BF, Schnitzer MJ, Callaway EM, Lüthi A. Distinct Hippocampal Pathways Mediate Dissociable Roles of Context in Memory Retrieval. Cell 2016; 167:961-972.e16. [PMID: 27773481 DOI: 10.1016/j.cell.2016.09.051] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 06/29/2016] [Accepted: 09/17/2016] [Indexed: 12/15/2022]
Abstract
Memories about sensory experiences are tightly linked to the context in which they were formed. Memory contextualization is fundamental for the selection of appropriate behavioral reactions needed for survival, yet the underlying neuronal circuits are poorly understood. By combining trans-synaptic viral tracing and optogenetic manipulation, we found that the ventral hippocampus (vHC) and the amygdala, two key brain structures encoding context and emotional experiences, interact via multiple parallel pathways. A projection from the vHC to the basal amygdala mediates fear behavior elicited by a conditioned context, whereas a parallel projection from a distinct subset of vHC neurons onto midbrain-projecting neurons in the central amygdala is necessary for context-dependent retrieval of cued fear memories. Our findings demonstrate that two fundamentally distinct roles of context in fear memory retrieval are processed by distinct vHC output pathways, thereby allowing for the formation of robust contextual fear memories while preserving context-dependent behavioral flexibility.
Collapse
|
109
|
Klingbeil J, Stockert A, Wawrzyniak M, Wrede K, Saur D. EP 6. Longitudinal resting state functional connectivity patterns in the early phase of recovery from Aphasia in temporoparietal stroke. Clin Neurophysiol 2016. [DOI: 10.1016/j.clinph.2016.05.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
110
|
Pelz J, Henn P, Saur D, Classen J, Weise D. EP 17. High-resolution ultrasound of the vagus nerve in healthy subjects. Clin Neurophysiol 2016. [DOI: 10.1016/j.clinph.2016.05.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
111
|
Stockert A, Klingbeil J, Wawrzyniak M, Wrede K, Saur D. FV 1. Perilesional activation in poststroke language recovery. Clin Neurophysiol 2016. [DOI: 10.1016/j.clinph.2016.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
112
|
Flisikowska T, Wander C, Wagner A, Bruening F, Kind A, Flisikowski K, Schnieke A, Wurmser C, Fries R, Stachowiak M, Perkowska A, Switonski M, Bauersachs S, Saur D. P7009 Precancerous molecular features committing development of colonic polyps revealed by studies on the porcine model of human familial adenomatous polyposis. J Anim Sci 2016. [DOI: 10.2527/jas2016.94supplement4179b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
113
|
Lesina M, Wörmann SM, Morton J, Diakopoulos KN, Korneeva O, Wimmer M, Einwächter H, Sperveslage J, Demir IE, Kehl T, Saur D, Sipos B, Heikenwälder M, Steiner JM, Wang TC, Sansom OJ, Schmid RM, Algül H. RelA regulates CXCL1/CXCR2-dependent oncogene-induced senescence in murine Kras-driven pancreatic carcinogenesis. J Clin Invest 2016; 126:2919-32. [PMID: 27454298 PMCID: PMC4966329 DOI: 10.1172/jci86477] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/13/2016] [Indexed: 12/12/2022] Open
Abstract
Tumor suppression that is mediated by oncogene-induced senescence (OIS) is considered to function as a safeguard during development of pancreatic ductal adenocarcinoma (PDAC). However, the mechanisms that regulate OIS in PDAC are poorly understood. Here, we have determined that nuclear RelA reinforces OIS to inhibit carcinogenesis in the Kras mouse model of PDAC. Inactivation of RelA accelerated pancreatic lesion formation in Kras mice by abrogating the senescence-associated secretory phenotype (SASP) gene transcription signature. Using genetic and pharmacological tools, we determined that RelA activation promotes OIS via elevation of the SASP factor CXCL1 (also known as KC), which activates CXCR2, during pancreatic carcinogenesis. In Kras mice, pancreas-specific inactivation of CXCR2 prevented OIS and was correlated with increased tumor proliferation and decreased survival. Moreover, reductions in CXCR2 levels were associated with advanced neoplastic lesions in tissue from human pancreatic specimens. Genetically disabling OIS in Kras mice caused RelA to promote tumor proliferation, suggesting a dual role for RelA signaling in pancreatic carcinogenesis. Taken together, our data suggest a pivotal role for RelA in regulating OIS in preneoplastic lesions and implicate the RelA/CXCL1/CXCR2 axis as an essential mechanism of tumor surveillance in PDAC.
Collapse
|
114
|
Hatzistergos KE, Saur D, Seidler B, Balkan W, Breton M, Valasaki K, Takeuchi LM, Landin AM, Khan A, Hare JM. Stimulatory Effects of Mesenchymal Stem Cells on cKit+ Cardiac Stem Cells Are Mediated by SDF1/CXCR4 and SCF/cKit Signaling Pathways. Circ Res 2016; 119:921-30. [PMID: 27481956 DOI: 10.1161/circresaha.116.309281] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 07/29/2016] [Indexed: 01/13/2023]
Abstract
RATIONALE Culture-expanded cells originating from cardiac tissue that express the cell surface receptor cKit are undergoing clinical testing as a cell source for heart failure and congenital heart disease. Although accumulating data support that mesenchymal stem cells (MSCs) enhance the efficacy of cardiac cKit(+) cells (CSCs), the underlying mechanism for this synergistic effect remains incompletely understood. OBJECTIVE To test the hypothesis that MSCs stimulate endogenous CSCs to proliferate, migrate, and differentiate via the SDF1/CXCR4 and stem cell factor/cKit pathways. METHODS AND RESULTS Using genetic lineage-tracing approaches, we show that in the postnatal murine heart, cKit(+) cells proliferate, migrate, and form cardiomyocytes, but not endothelial cells. CSCs exhibit marked chemotactic and proliferative responses when cocultured with MSCs but not with cardiac stromal cells. Antagonism of the CXCR4 pathway with AMD3100 (an SDF1/CXCR4 antagonist) inhibited MSC-induced CSC chemotaxis but stimulated CSC cardiomyogenesis (P<0.0001). Furthermore, MSCs enhanced CSC proliferation via the stem cell factor/cKit and SDF1/CXCR4 pathways (P<0.0001). CONCLUSIONS Together these findings show that MSCs exhibit profound, yet differential, effects on CSC migration, proliferation, and differentiation and suggest a mechanism underlying the improved cardiac regeneration associated with combination therapy using CSCs and MSCs. These findings have important therapeutic implications for cell-based therapy strategies that use mixtures of CSCs and MSCs.
Collapse
|
115
|
Saur D. Abstract IA22: Modeling and targeting the tumor microenvironment of pancreatic cancer. Cancer Res 2016. [DOI: 10.1158/1538-7445.tme16-ia22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Maintenance and drug resistance of pancreatic ductal adenocarcioma (PDAC) depends on cancer cell intrinsic mechanisms and a stroma that supports tumor growth. Mouse models of human PDAC have provided important insights into the evolution of this highly lethal tumor, but there are no models that allow secondary genetic manipulation of autochthonous tumors, the tumor microenvironment or the metastatic host niche once the tumor has formed.
We generated an inducible dual-recombinase system by combining Flp/frt and Cre/loxP. This novel PDAC model permits spatial and temporal control of gene expression enabling unbiased genetic approaches to study the role of tumor cell-autonomous and non-autonomous functions in endogenous cancers. This tool provides unparalleled access to the native biology of cancer cells and their hosting stroma, and rigorous genetic validation of candidate therapeutic targets. We performed tumor cell-autonomous and non-autonomous targeting, uncovered hallmarks of human multistep carcinogenesis, validated genetic tumor therapy, and showed that mast cells in the tumor microenvironment, which had been thought to be key oncogenic players, are in fact dispensable for tumor formation.
Citation Format: Dieter Saur. Modeling and targeting the tumor microenvironment of pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr IA22.
Collapse
|
116
|
Hatzistergos KE, Valasaki K, Jiang Z, Takeuchi LM, Balkan W, Saur D, Seidler B, DiFede DL, Hare JM. Abstract 323: Loss of Gravity Impairs Cardiac Neural Crest Cell Lineage Development and Function. Circ Res 2016. [DOI: 10.1161/res.119.suppl_1.323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
A multitude of structural, haemodynamic and electromechanical cardiovascular disorders have been observed in humans following space-travel. These abnormalities are thought to emerge from transient alterations in autonomic nervous system (ANS). However, since the ANS is cardiac neural crest (CNC)-derived, whether microgravity-induced cardiomyopathies reflect CNC dysfunction, is unknown.
Hypothesis:
Impairment of CNCs underlies microgravity-induced cardiomyopathies.
Methods:
Myocardial explants from adult
cKit
CreERT2/+
;IRG
mice (n=5/group), as well as
cKit
CreERT2/+
;IRG-
derived (iPSC
Kit-Cre
; n=6/group) and
Wnt1-Cre;tdTomato
-derived (iPSC
Wnt1-Cre
; n=18/group) induced pluripotent stem cells, were cultured under static (SC) or simulated microgravity conditions (rotary cell-culture system; RCCS).
Results:
CNC lineage-tracing in cardiac explants illustrated that, compared to SC, RCCS abolished the pool of
cKit
+
CNCs in adult hearts, indicated by quantitation of
cKit
CreERT2
-
mediated EGFP expression (
p
<0.05). Cardiogenesis modeling experiments with iPSC
Kit-Cre
yielded fewer beating EBs (
p
=0.0005), and ~10-fold reduction in EGFP
+
cardiomyocytes (
p
=0.01), in RCCS
vs
. SC. Microarray analyses suggested that RCCS-mediated alterations in BMP and Wnt/β-catenin pathways, downregulated ANS and CNC-related gene programs, and enhanced vasculogenic differentiation without affecting the expression of cardiac mesoderm-related genes. Differences were verified by quantitative PCR. Modeling CNC development in iPSC
Wnt1-Cre
further confirmed an RCCS-mediated dramatic impairment in development and function of CNCs, indicated by quantitation of tdTomato expression in day-10 and day-21 beating embryoid bodies (
p
<0.0001). Intriguingly, the effect of RCCS in CNCs could be only partially rescued upon transfer to SC.
Conclusions:
Together these data indicate that microgravity negatively regulates the development and function of CNCs, thus partly explaining the cellular and molecular mechanisms of microgravity-induced cardiomyopathies. Moreover, these findings are expected to have important implications in space exploration, since they suggest an essential role for gravity in vertebrate development.
Collapse
|
117
|
Saalfrank A, Janssen KP, Ravon M, Flisikowski K, Eser S, Steiger K, Flisikowska T, Müller-Fliedner P, Schulze É, Brönner C, Gnann A, Kappe E, Böhm B, Schade B, Certa U, Saur D, Esposito I, Kind A, Schnieke A. A porcine model of osteosarcoma. Oncogenesis 2016; 5:e210. [PMID: 26974205 PMCID: PMC4815050 DOI: 10.1038/oncsis.2016.19] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 12/15/2022] Open
Abstract
We previously produced pigs with a latent oncogenic TP53 mutation. Humans with TP53 germline mutations are predisposed to a wide spectrum of early-onset cancers, predominantly breast, brain, adrenal gland cancer, soft tissue sarcomas and osteosarcomas. Loss of p53 function has been observed in >50% of human cancers. Here we demonstrate that porcine mesenchymal stem cells (MSCs) convert to a transformed phenotype after activation of latent oncogenic TP53R167H and KRASG12D, and overexpression of MYC promotes tumorigenesis. The process mimics key molecular aspects of human sarcomagenesis. Transformed porcine MSCs exhibit genomic instability, with complex karyotypes, and develop into sarcomas on transplantation into immune-deficient mice. In pigs, heterozygous knockout of TP53 was sufficient for spontaneous osteosarcoma development in older animals, whereas homozygous TP53 knockout resulted in multiple large osteosarcomas in 7–8-month-old animals. This is the first report that engineered mutation of an endogenous tumour-suppressor gene leads to invasive cancer in pigs. Unlike in Trp53 mutant mice, osteosarcoma developed in the long bones and skull, closely recapitulating the human disease. These animals thus promise a model for juvenile osteosarcoma, a relatively uncommon but devastating disease.
Collapse
|
118
|
Baker SA, Drumm BT, Saur D, Hennig GW, Ward SM, Sanders KM. Spontaneous Ca(2+) transients in interstitial cells of Cajal located within the deep muscular plexus of the murine small intestine. J Physiol 2016; 594:3317-38. [PMID: 26824875 DOI: 10.1113/jp271699] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 01/24/2016] [Indexed: 01/13/2023] Open
Abstract
KEY POINTS Interstitial cells of Cajal at the level of the deep muscular plexus (ICC-DMP) in the small intestine generate spontaneous Ca(2+) transients that consist of localized Ca(2+) events and limited propagating Ca(2+) waves. Ca(2+) transients in ICC-DMP display variable characteristics: from discrete, highly localized Ca(2+) transients to regionalized Ca(2+) waves with variable rates of occurrence, amplitude, duration and spatial spread. Ca(2+) transients fired stochastically, with no cellular or multicellular rhythmic activity being observed. No correlation was found between the firing sites in adjacent cells. Ca(2+) transients in ICC-DMP are suppressed by the ongoing release of inhibitory neurotransmitter(s). Functional intracellular Ca(2+) stores are essential for spontaneous Ca(2+) transients, and the sarco/endoplasmic reticulum Ca(2+) -ATPase (SERCA) pump is necessary for maintenance of spontaneity. Ca(2+) release mechanisms involve both ryanodine receptors (RyRs) and inositol triphosphate receptors (InsP3 Rs). Release from these channels is interdependent. ICC express transcripts of multiple RyRs and InsP3 Rs, with Itpr1 and Ryr2 subtypes displaying the highest expression. ABSTRACT Interstitial cells of Cajal in the deep muscular plexus of the small intestine (ICC-DMP) are closely associated with varicosities of enteric motor neurons and generate responses contributing to neural regulation of intestinal motility. Responses of ICC-DMP are mediated by activation of Ca(2+) -activated Cl(-) channels; thus, Ca(2+) signalling is central to the behaviours of these cells. Confocal imaging was used to characterize the nature and mechanisms of Ca(2+) transients in ICC-DMP within intact jejunal muscles expressing a genetically encoded Ca(2+) indicator (GCaMP3) selectively in ICC. ICC-DMP displayed spontaneous Ca(2+) transients that ranged from discrete, localized events to waves that propagated over variable distances. The occurrence of Ca(2+) transients was highly variable, and it was determined that firing was stochastic in nature. Ca(2+) transients were tabulated in multiple cells within fields of view, and no correlation was found between the events in adjacent cells. TTX (1 μm) significantly increased the occurrence of Ca(2+) transients, suggesting that ICC-DMP contributes to the tonic inhibition conveyed by ongoing activity of inhibitory motor neurons. Ca(2+) transients were minimally affected after 12 min in Ca(2+) free solution, indicating these events do not depend immediately upon Ca(2+) influx. However, inhibitors of sarco/endoplasmic reticulum Ca(2+) -ATPase (SERCA) pump and blockers of inositol triphosphate receptor (InsP3 R) and ryanodine receptor (RyR) channels blocked ICC Ca(2+) transients. These data suggest an interdependence between RyR and InsP3 R in the generation of Ca(2+) transients. Itpr1 and Ryr2 were the dominant transcripts expressed by ICC. These findings provide the first high-resolution recording of the subcellular Ca(2+) dynamics that control the behaviour of ICC-DMP in situ.
Collapse
|
119
|
Jung B, Messias AC, Schorpp K, Geerlof A, Schneider G, Saur D, Hadian K, Sattler M, Wanker EE, Hasenöder S, Lickert H. Novel small molecules targeting ciliary transport of Smoothened and oncogenic Hedgehog pathway activation. Sci Rep 2016; 6:22540. [PMID: 26931153 PMCID: PMC4773810 DOI: 10.1038/srep22540] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/15/2016] [Indexed: 01/04/2023] Open
Abstract
Trafficking of the G protein-coupled receptor (GPCR) Smoothened (Smo) to the primary cilium (PC) is a potential target to inhibit oncogenic Hh pathway activation in a large number of tumors. One drawback is the appearance of Smo mutations that resist drug treatment, which is a common reason for cancer treatment failure. Here, we undertook a high content screen with compounds in preclinical or clinical development and identified ten small molecules that prevent constitutive active mutant SmoM2 transport into PC for subsequent Hh pathway activation. Eight of the ten small molecules act through direct interference with the G protein-coupled receptor associated sorting protein 2 (Gprasp2)-SmoM2 ciliary targeting complex, whereas one antagonist of ionotropic receptors prevents intracellular trafficking of Smo to the PC. Together, these findings identify several compounds with the potential to treat drug-resistant SmoM2-driven cancer forms, but also reveal off-target effects of established drugs in the clinics.
Collapse
|
120
|
Michels J, Saur D, Roth K, Saur J, Trinkmann F. Lung Clearance Index bei Patienten mit obstruktiven Ventilationsstörungen. Pneumologie 2016. [DOI: 10.1055/s-0036-1572015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
121
|
Sano MB, Arena CB, Bittleman KR, DeWitt MR, Cho HJ, Szot CS, Saur D, Cissell JM, Robertson J, Lee YW, Davalos RV. Bursts of Bipolar Microsecond Pulses Inhibit Tumor Growth. Sci Rep 2015; 5:14999. [PMID: 26459930 PMCID: PMC4602310 DOI: 10.1038/srep14999] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 09/02/2015] [Indexed: 02/06/2023] Open
Abstract
Irreversible electroporation (IRE) is an emerging focal therapy which is demonstrating utility in the treatment of unresectable tumors where thermal ablation techniques are contraindicated. IRE uses ultra-short duration, high-intensity monopolar pulsed electric fields to permanently disrupt cell membranes within a well-defined volume. Though preliminary clinical results for IRE are promising, implementing IRE can be challenging due to the heterogeneous nature of tumor tissue and the unintended induction of muscle contractions. High-frequency IRE (H-FIRE), a new treatment modality which replaces the monopolar IRE pulses with a burst of bipolar pulses, has the potential to resolve these clinical challenges. We explored the pulse-duration space between 250 ns and 100 μs and determined the lethal electric field intensity for specific H-FIRE protocols using a 3D tumor mimic. Murine tumors were exposed to 120 bursts, each energized for 100 μs, containing individual pulses 1, 2, or 5 μs in duration. Tumor growth was significantly inhibited and all protocols were able to achieve complete regressions. The H-FIRE protocol substantially reduces muscle contractions and the therapy can be delivered without the need for a neuromuscular blockade. This work shows the potential for H-FIRE to be used as a focal therapy and merits its investigation in larger pre-clinical models.
Collapse
|
122
|
Pelz JO, Weinreich A, Fritzsch D, Saur D. Quantification of Internal Carotid Artery Stenosis with 3D Ultrasound Angiography. ULTRASCHALL IN DER MEDIZIN (STUTTGART, GERMANY : 1980) 2015; 36:487-493. [PMID: 25607630 DOI: 10.1055/s-0034-1398749] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE The aim of this study was to evaluate a new method of three-dimensional ultrasound (3D-US) angiography of carotid vessels including 3D-US quantification of internal carotid artery (ICA) stenosis (ICAS). MATERIALS AND METHODS Two neurologists performed native ultrasound scans of the brain-supplying carotid arteries in 73 probands (including 22 patients with 25 cases of ICAS) using a Toshiba Aplio 500 ultrasound machine equipped with the 3 D application of Curefab CS. Additionally, 25 probands underwent contrast-enhanced magnetic resonance angiography (CE-MRA) of the neck vessels. RESULTS The mean length of the proximal ICA was 32.1 mm ± 9.8 mm & 31.3 mm ± 9.0 mm (each n = 97). The interrater reliability (intraclass correlation, ICC) was 0.75 ± 0.23 for the common carotid artery (CCA, n = 90) and 0.78 ± 0.21 (n = 92) for the ICA. The intermethod agreement between 3D-US angiography and CE-MRA was 0.67 ± 0.19 (n = 45) & 0.66 ± 0.19 (n = 44) for the CCA and 0.79 ± 0.17 (n = 47) & 0.75 ± 0.19 (n = 46) for the ICA. Quantification of ICAS applying 3D-US in comparison to 2D color-coded duplexsonography (2D-CDS) showed a moderate to good intermethod agreement both by the Bland and Altman analysis and by ICC (0.8 & 0.72; with each p < 0.001). The interrater reliability for quantification of ICAS was 0.79; p < 0.001. CONCLUSION Native 3D-US angiography of carotid vessels shows good interrater and intermethod agreement in comparison to CE-MRA. Together with a moderate to good intermethod and interrater agreement in the quantification of ICAS, when compared to 2D-CDS, 3D-US angiography is thus a promising complementary imaging technique for carotid artery disease.
Collapse
|
123
|
Dietlein F, Kalb B, Jokic M, Noll EM, Strong A, Tharun L, Ozretić L, Künstlinger H, Kambartel K, Randerath WJ, Jüngst C, Schmitt A, Torgovnick A, Richters A, Rauh D, Siedek F, Persigehl T, Mauch C, Bartkova J, Bradley A, Sprick MR, Trumpp A, Rad R, Saur D, Bartek J, Wolf J, Büttner R, Thomas RK, Reinhardt HC. A Synergistic Interaction between Chk1- and MK2 Inhibitors in KRAS-Mutant Cancer. Cell 2015; 162:146-59. [PMID: 26140595 DOI: 10.1016/j.cell.2015.05.053] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 02/13/2015] [Accepted: 05/05/2015] [Indexed: 01/22/2023]
Abstract
KRAS is one of the most frequently mutated oncogenes in human cancer. Despite substantial efforts, no clinically applicable strategy has yet been developed to effectively treat KRAS-mutant tumors. Here, we perform a cell-line-based screen and identify strong synergistic interactions between cell-cycle checkpoint-abrogating Chk1- and MK2 inhibitors, specifically in KRAS- and BRAF-driven cells. Mechanistically, we show that KRAS-mutant cancer displays intrinsic genotoxic stress, leading to tonic Chk1- and MK2 activity. We demonstrate that simultaneous Chk1- and MK2 inhibition leads to mitotic catastrophe in KRAS-mutant cells. This actionable synergistic interaction is validated using xenograft models, as well as distinct Kras- or Braf-driven autochthonous murine cancer models. Lastly, we show that combined checkpoint inhibition induces apoptotic cell death in KRAS- or BRAF-mutant tumor cells directly isolated from patients. These results strongly recommend simultaneous Chk1- and MK2 inhibition as a therapeutic strategy for the treatment of KRAS- or BRAF-driven cancers.
Collapse
|
124
|
Fichna J, Poole DP, Veldhuis N, MacEachern SJ, Saur D, Zakrzewski PK, Cygankiewicz AI, Mokrowiecka A, Małecka-Panas E, Krajewska WM, Liedtke W, Steinhoff MS, Timmermans JP, Bunnett NW, Sharkey KA, Storr MA. Transient receptor potential vanilloid 4 inhibits mouse colonic motility by activating NO-dependent enteric neurotransmission. J Mol Med (Berl) 2015; 93:1297-309. [PMID: 26330151 DOI: 10.1007/s00109-015-1336-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/12/2015] [Accepted: 08/17/2015] [Indexed: 01/15/2023]
Abstract
UNLABELLED Recent studies implicate TRPV4 receptors in visceral pain signaling and intestinal inflammation. Our aim was to evaluate the role of TRPV4 in the control of gastrointestinal (GI) motility and to establish the underlying mechanisms. We used immunohistochemistry and PCR to study TRPV4 expression in the GI tract. The effect of TRPV4 activation on GI motility was characterized using in vitro and in vivo motility assays. Calcium and nitric oxide (NO) imaging were performed to study the intracellular signaling pathways. Finally, TRPV4 expression was examined in the colon of healthy human subjects. We demonstrated that TRPV4 can be found on myenteric neurons of the colon and is co-localized with NO synthase (NOS-1). In vitro, the TRPV4 agonist GSK1016790A reduced colonic contractility and increased inhibitory neurotransmission. In vivo, TRPV4 activation slowed GI motility and reduced stool production in mouse models mimicking pathophysiological conditions. We also showed that TRPV4 activation inhibited GI motility by reducing NO-dependent Ca(2+) release from enteric neurons. In conclusion, TRPV4 is involved in the regulation of GI motility in health and disease. KEY MESSAGES • Recent studies implicate TRPV4 in pain signaling and intestinal inflammation. • Our aim was to characterize the role of TRPV4 in the control of GI motility. • We found that TRPV4 activation reduced colonic contractility. • Our studies also showed altered TRPV4 mRNA expression in IBS-C patients. • TRPV4 may be a novel pharmacological target in functional GI diseases.
Collapse
|
125
|
Lies B, Beck K, Keppler J, Saur D, Groneberg D, Friebe A. Nitrergic signalling via interstitial cells of Cajal regulates motor activity in murine colon. J Physiol 2015; 593:4589-601. [PMID: 26227063 DOI: 10.1113/jp270511] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/16/2015] [Indexed: 12/11/2022] Open
Abstract
In the enteric nervous systems, NO is released from nitrergic neurons as a major inhibitory neurotransmitter. NO acts via NO-sensitive guanylyl cyclase (NO-GC), which is found in different gastrointestinal (GI) cell types including smooth muscle cells (SMCs) and interstitial cells of Cajal (ICC). The precise mechanism of nitrergic signalling through these two cell types to regulate colonic spontaneous contractions is not fully understood yet. In the present study we investigated the impact of endogenous and exogenous NO on colonic contractile motor activity using mice lacking nitric oxide-sensitive guanylyl cyclase (NO-GC) globally and specifically in SMCs and ICC. Longitudinal smooth muscle of proximal colon from wild-type (WT) and knockout (KO) mouse strains exhibited spontaneous contractile activity ex vivo. WT and smooth muscle-specific guanylyl cyclase knockout (SMC-GCKO) colon showed an arrhythmic contractile activity with varying amplitudes and frequencies. In contrast, colon from global and ICC-specific guanylyl cyclase knockout (ICC-GCKO) animals showed a regular contractile rhythm with constant duration and amplitude of the rhythmic contractions. Nerve blockade (tetrodotoxin) or specific blockade of NO signalling (L-NAME, ODQ) did not significantly affect contractions of GCKO and ICC-GCKO colon whereas the arrhythmic contractile patterns of WT and SMC-GCKO colon were transformed into uniform motor patterns. In contrast, the response to electric field-stimulated neuronal NO release was similar in SMC-GCKO and global GCKO. In conclusion, our results indicate that basal enteric NO release acts via myenteric ICC to influence the generation of spontaneous contractions whereas the effects of elevated endogenous NO are mediated by SMCs in the murine proximal colon.
Collapse
|
126
|
Sibaev A, Fichna J, Saur D, Yuece B, Timmermans JP, Storr M. Nociceptin effect on intestinal motility depends on opioid-receptor like-1 receptors and nitric oxide synthase co-localization. World J Gastrointest Pharmacol Ther 2015; 6:73-83. [PMID: 26261735 PMCID: PMC4526842 DOI: 10.4292/wjgpt.v6.i3.73] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/10/2015] [Accepted: 05/18/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the effect of the opioid-receptor like-1 (ORL1) agonist nociceptin on gastrointestinal (GI) myenteric neurotransmission and motility.
METHODS: Reverse transcriptase - polymerase chain reaction and immunohistochemistry were used to localize nociceptin and ORL1 in mouse tissues. Intracellular electrophysiological recordings of excitatory and inhibitory junction potentials (EJP, IJP) were made in a chambered organ bath. Intestinal motility was measured in vivo.
RESULTS: Nociceptin accelerated whole and upper GI transit, but slowed colonic expulsion in vivo in an ORL1-dependent manner, as shown using [Nphe1]NOC and AS ODN pretreatment. ORL1 and nociceptin immunoreactivity were found on enteric neurons. Nociceptin reduced the EJP and the nitric oxide-sensitive slow IJP in an ORL1-dependent manner, whereas the fast IJP was unchanged. Nociceptin further reduced the spatial spreading of the EJP up to 2 cm.
CONCLUSION: Compounds acting at ORL1 are good candidates for the future treatment of disorders associated with increased colonic transit, such as diarrhea or diarrhea-predominant irritable bowel syndrome.
Collapse
|
127
|
Pelz J, Busch M, Weinreich A, Saur D. P15. Evaluation and comparison of 3D-ultrasound of the median nerve with common 2D-ultrasound. Clin Neurophysiol 2015. [DOI: 10.1016/j.clinph.2015.04.135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
128
|
Klingbeil J, Henseler I, Wawrzyniak M, Wendt C, Hartwigsen G, Saur D. P110. Networks for semantic integration in auditory speech comprehension. Clin Neurophysiol 2015. [DOI: 10.1016/j.clinph.2015.04.152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
129
|
Dietlein F, Kalb B, Jokic M, Noll E, Strong A, Tharun L, Ozretić L, Künstlinger H, Kambartel K, Randerath W, Jüngst C, Schmitt A, Torgovnick A, Richters A, Rauh D, Siedek F, Persigehl T, Mauch C, Bartkova J, Bradley A, Sprick M, Trumpp A, Rad R, Saur D, Bartek J, Wolf J, Büttner R, Thomas R, Reinhardt H. A Synergistic Interaction between Chk1- and MK2 Inhibitors in KRAS-Mutant Cancer. Cell 2015. [DOI: 10.1016/j.cell.2015.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
130
|
Hatzistergos KE, Takeuchi LM, Saur D, Seidler B, Dymecki SM, Mai JJ, Kanashiro-Takeuchi R, Balkan W, Hare JM. Abstract 394: Transient Bone Morphogenic Protein Antagonism Directs Differentiation of iPSCs into the Cardiac Neural Crest and cKit+ Myocardial Progenitor Lineages. Circ Res 2015. [DOI: 10.1161/res.117.suppl_1.394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
The capability of cKit+ cardiac progenitor cells (CPCs) to participate in cardiomyocyte regeneration remains controversial, despite basic and clinical studies supporting such a role.
Hypothesis:
A non-permissive cardiac milieu minimizes the generation of cardiomyocytes from CPCs.
Methods:
We lineage-traced CPCs using novel dual-recombinase responsive indicator mice (cKitCreERT2;Wnt1::Flpe;RC::Fela) and iPSCs derived from cKitCreERT2;IRG (iPSCKit) mice.
Results:
Intersectional genetic fate-mapping of cKitCreERT2;Wnt1:: Flpe;RC::Fela embryos supported that cKit marks Wnt1-expressing cardiac neural crest (CNC) progenitors, emerging at ~E9.5 and contributing a limited number of cardiomyocytes. To decipher the mechanisms underlying cardiomyocyte differentiation of CPCs, we lineage-traced CPCs during stage-specific cardiogenic differentiation of iPSCKit. Ascorbate treatment promoted differentiation of cKit+ iPSC-derived embryoid bodies (EBs) into Nkx2.5+ myocardium, 45.5%±6.7% of which co-expressed the Cre-reporter EGFP (n=154 EBs; 12 preparations), suggesting that CPCs encompass fully competent cardiomyogenic progenitors. Noggin (or Dorsomorphin), a BMP antagonist transiently expressed in the heart at E7.5-E8.5 but not during CNC invasion, directed the differentiation of iPSCkit-EBs into Mesp1+/Isl1+/Nkx2.5+ cardiac mesoderm progenitors (p≤0.0001). Remarkably, the same signaling pathway subsequently directed EBs into the cKit+/Wnt1+/Pax3+/Mitf-H+/Isl1+/Nkx2.5+ CNC lineage (p≤0.0001), while suppressing the generation of WT1+/Tbx18+ epicardium (p<0.05). Stage-specific induction of Cre-recombination delineated that iPSCkit-derived CPCs encompass Mesp1–/cKit+/Nkx2.5+ CNC progenitors which contributed EGFP+ CNC derivatives, including Nkx2-5+ cardiomyocytes, to 60.7%±7.3% of spontaneously beating EBs (n=147 EBs; 12 preparations).
Conclusions:
Collectively, our data show that CPCkit are fully competent CNC-derived cardiomyogenic progenitors, whose differentiation to cardiomyocytes is minimized by a latent Noggin-mediated signaling pathway. Therefore exploiting CPCkit therapeutically, provides an important strategy for maximizing myocardial regeneration.
Collapse
|
131
|
Goss GM, Chaudhari N, Hare JM, Nwojo R, Seidler B, Saur D, Goldstein BJ. Differentiation potential of individual olfactory c-Kit+ progenitors determined via multicolor lineage tracing. Dev Neurobiol 2015; 76:241-51. [PMID: 26016700 DOI: 10.1002/dneu.22310] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/14/2015] [Accepted: 05/22/2015] [Indexed: 11/10/2022]
Abstract
Olfactory tissue undergoes lifelong renewal, due to the presence of basal neural stem cells. Multiple categories of globose basal stem cells have been identified, expressing markers such as Lgr5, Ascl1, GBC-2, and c-Kit. The differentiation potential of individual globose cells has remained unclear. Here, we utilized Cre/loxP lineage tracing with a multicolor reporter system to define c-Kit+ cell contributions at clonal resolution. We determined that reporter expression permitted identification of c-Kit derived progeny with fine cellular detail, and that clones were found to be comprised by neurons only, microvillar cells only, microvillar cells and neurons, or gland/duct cells. Quantification of reporter-labeled cells indicated that c-Kit+ cells behave as transit amplifying or immediate precursors, although we also found evidence for longer-term c-Kit+ cell contributions. Our results from the application of multicolor fate mapping delineate the clonal contributions of c-Kit+ cells to olfactory epithelial renewal, and provide novel insight into tissue maintenance of an adult neuroepithelium.
Collapse
|
132
|
Stanczuk L, Martinez-Corral I, Ulvmar MH, Zhang Y, Laviña B, Fruttiger M, Adams R, Saur D, Betsholtz C, Ortega S, Alitalo K, Graupera M, Mäkinen T. cKit Lineage Hemogenic Endothelium-Derived Cells Contribute to Mesenteric Lymphatic Vessels. Cell Rep 2015; 10:1708-1721. [DOI: 10.1016/j.celrep.2015.02.026] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 12/29/2014] [Accepted: 02/05/2015] [Indexed: 10/23/2022] Open
|
133
|
Li S, Edlinger M, Saalfrank A, Flisikowski K, Tschukes A, Kurome M, Zakhartchenko V, Kessler B, Saur D, Kind A, Wolf E, Schnieke A, Flisikowska T. Viable pigs with a conditionally-activated oncogenic KRAS mutation. Transgenic Res 2015; 24:509-17. [PMID: 25716163 DOI: 10.1007/s11248-015-9866-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/05/2015] [Indexed: 01/07/2023]
Abstract
Oncogenic mutations of KRAS play a major role in human carcinogenesis. Here we describe viable gene-targeted pigs carrying a latent KRAS (G12D) mutant allele that can be activated by Cre recombination. These have been produced as part of a program to model human cancers in pigs by replicating genetic lesions known to initiate and drive human disease. Cre-activated KRAS (G12D) animals add to a growing set of gene-targeted pigs that includes a Cre-activated oncogenic mutant TP53, a Cre-responsive dual fluorescent reporter and two truncating mutations of APC (adenomatous polyposis coli). These alleles can be combined and activated in various tissues to produce new models for cancer research.
Collapse
|
134
|
Becker V, Drabner R, Graf S, Schlag C, Nennstiel S, Buchberger AM, Schmid RM, Saur D, Bajbouj M. New aspects in the pathomechanism and diagnosis of the laryngopharyngeal reflux-clinical impact of laryngeal proton pumps and pharyngeal pH metry in extraesophageal gastroesophageal reflux disease. World J Gastroenterol 2015; 21:982-987. [PMID: 25624734 PMCID: PMC4299353 DOI: 10.3748/wjg.v21.i3.982] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/22/2014] [Accepted: 10/15/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine the laryngeal H+K+-ATPase and pharyngeal pH in patients with laryngopharyngeal reflux (LPR)-symptoms as well as to assess the symptom scores during PPI therapy.
METHODS: Endoscopy was performed to exclude neoplasia and to collect biopsies from the posterior cricoid area (immunohistochemistry and PCR analysis). Immunohistochemical staining was performed with monoclonal mouse antibodies against human H+K+-ATPase. Quantitative real-time RT-PCR for each of the H+K+-ATPase subunits was performed. The pH values were assessed in the aerosolized environment of the oropharynx (DxpH Catheter) and compared to a subsequently applied combined pH/MII measurement.
RESULTS: Twenty patients with LPR symptoms were included. In only one patient, the laryngeal H+K+-ATPase was verified by immunohistochemical staining. In another patient, real-time RT-PCR for each H+K+-ATPase subunit was positive. Fourteen out of twenty patients had pathological results in DxpH, and 6/20 patients had pathological results in pH/MII. Four patients had pathological results in both functional tests. Nine out of twenty patients responded to PPIs.
CONCLUSION: The laryngeal H+K+-ATPase can only be sporadically detected in patients with LPR symptoms and is unlikely to cause the LPR symptoms. Alternative hypotheses for the pathomechanism are needed. The role of pharyngeal pH-metry remains unclear and its use can only be recommended for patients in a research study setting.
Collapse
|
135
|
Goldstein BJ, Goss GM, Hatzistergos KE, Rangel EB, Seidler B, Saur D, Hare JM. Adult c-Kit(+) progenitor cells are necessary for maintenance and regeneration of olfactory neurons. J Comp Neurol 2015. [DOI: 10.1002/cne.23709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
136
|
Rad R, Rad L, Wang W, Strong A, Ponstingl H, Bronner IF, Mayho M, Steiger K, Weber J, Hieber M, Veltkamp C, Eser S, Geumann U, Öllinger R, Zukowska M, Barenboim M, Maresch R, Cadiñanos J, Friedrich M, Varela I, Constantino-Casas F, Sarver A, Ten Hoeve J, Prosser H, Seidler B, Bauer J, Heikenwälder M, Metzakopian E, Krug A, Ehmer U, Schneider G, Knösel T, Rümmele P, Aust D, Grützmann R, Pilarsky C, Ning Z, Wessels L, Schmid RM, Quail MA, Vassiliou G, Esposito I, Liu P, Saur D, Bradley A. A conditional piggyBac transposition system for genetic screening in mice identifies oncogenic networks in pancreatic cancer. Nat Genet 2014; 47:47-56. [PMID: 25485836 DOI: 10.1038/ng.3164] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/12/2014] [Indexed: 01/02/2023]
Abstract
Here we describe a conditional piggyBac transposition system in mice and report the discovery of large sets of new cancer genes through a pancreatic insertional mutagenesis screen. We identify Foxp1 as an oncogenic transcription factor that drives pancreatic cancer invasion and spread in a mouse model and correlates with lymph node metastasis in human patients with pancreatic cancer. The propensity of piggyBac for open chromatin also enabled genome-wide screening for cancer-relevant noncoding DNA, which pinpointed a Cdkn2a cis-regulatory region. Histologically, we observed different tumor subentities and discovered associated genetic events, including Fign insertions in hepatoid pancreatic cancer. Our studies demonstrate the power of genetic screening to discover cancer drivers that are difficult to identify by other approaches to cancer genome analysis, such as downstream targets of commonly mutated human cancer genes. These piggyBac resources are universally applicable in any tissue context and provide unique experimental access to the genetic complexity of cancer.
Collapse
|
137
|
Groneberg D, Zizer E, Lies B, Seidler B, Saur D, Wagner M, Friebe A. Dominant role of interstitial cells of Cajal in nitrergic relaxation of murine lower oesophageal sphincter. J Physiol 2014; 593:403-14. [PMID: 25630261 DOI: 10.1113/jphysiol.2014.273540] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 10/24/2014] [Indexed: 12/20/2022] Open
Abstract
Oesophageal achalasia is a disease known to result from reduced relaxation of the lower oesophageal sphincter (LES). Nitric oxide (NO) is one of the main inhibitory transmitters. NO-sensitive guanylyl cyclase (NO-GC) acts as the key target of NO and, by the generation of cGMP, mediates nitrergic relaxation in the LES. To date, the exact mechanism of nitrergic LES relaxation is still insufficiently elucidated. To clarify the role of NO-GC in LES relaxation, we used cell-specific knockout (KO) mouse lines for NO-GC. These include mice lacking NO-GC in smooth muscle cells (SMC-GCKO), in interstitial cells of Cajal (ICC-GCKO) and in both SMC/ICC (SMC/ICC-GCKO). We applied oesophageal manometry to study the functionality of LES in vivo. Isometric force studies were performed to monitor LES responsiveness to exogenous NO and electric field stimulation of intrinsic nerves in vitro. Cell-specific expression/deletion of NO-GC was monitored by immunohistochemistry. Swallowing-induced LES relaxation is strongly reduced by deletion of NO-GC in ICC. Basal LES tone is affected by NO-GC deletion in either SMC or ICC. Lack of NO-GC in both cells leads to a complete interruption of NO-induced relaxation and, therefore, to an achalasia-like phenotype similar to that seen in global GCKO mice. Our data indicate that regulation of basal LES tone is based on a dual mechanism mediated by NO-GC in SMC and ICC whereas swallow-induced LES relaxation is mainly regulated by nitrergic mechanisms in ICC.
Collapse
|
138
|
Baer R, Cintas C, Dufresne M, Cassant-Sourdy S, Schönhuber N, Planque L, Lulka H, Couderc B, Bousquet C, Garmy-Susini B, Vanhaesebroeck B, Pyronnet S, Saur D, Guillermet-Guibert J. Pancreatic cell plasticity and cancer initiation induced by oncogenic Kras is completely dependent on wild-type PI 3-kinase p110α. Genes Dev 2014; 28:2621-35. [PMID: 25452273 PMCID: PMC4248293 DOI: 10.1101/gad.249409.114] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 10/27/2014] [Indexed: 12/22/2022]
Abstract
Increased PI 3-kinase (PI3K) signaling in pancreatic ductal adenocarcinoma (PDAC) correlates with poor prognosis, but the role of class I PI3K isoforms during its induction remains unclear. Using genetically engineered mice and pharmacological isoform-selective inhibitors, we found that the p110α PI3K isoform is a major signaling enzyme for PDAC development induced by a combination of genetic and nongenetic factors. Inactivation of this single isoform blocked the irreversible transition of exocrine acinar cells into pancreatic preneoplastic ductal lesions by oncogenic Kras and/or pancreatic injury. Hitting the other ubiquitous isoform, p110β, did not prevent preneoplastic lesion initiation. p110α signaling through small GTPase Rho and actin cytoskeleton controls the reprogramming of acinar cells and regulates cell morphology in vivo and in vitro. Finally, p110α was necessary for pancreatic ductal cancers to arise from Kras-induced preneoplastic lesions by increasing epithelial cell proliferation in the context of mutated p53. Here we identify an in vivo context in which p110α cellular output differs depending on the epithelial transformation stage and demonstrate that the PI3K p110α is required for PDAC induced by oncogenic Kras, the key driver mutation of PDAC. These data are critical for a better understanding of the development of this lethal disease that is currently without efficient treatment.
Collapse
|
139
|
Schönhuber N, Seidler B, Schuck K, Veltkamp C, Schachtler C, Zukowska M, Eser S, Feyerabend TB, Paul MC, Eser P, Klein S, Lowy AM, Banerjee R, Yang F, Lee CL, Moding EJ, Kirsch DG, Scheideler A, Alessi DR, Varela I, Bradley A, Kind A, Schnieke AE, Rodewald HR, Rad R, Schmid RM, Schneider G, Saur D. A next-generation dual-recombinase system for time- and host-specific targeting of pancreatic cancer. Nat Med 2014; 20:1340-1347. [PMID: 25326799 DOI: 10.1038/nm.3646] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 07/01/2014] [Indexed: 02/07/2023]
Abstract
Genetically engineered mouse models (GEMMs) have dramatically improved our understanding of tumor evolution and therapeutic resistance. However, sequential genetic manipulation of gene expression and targeting of the host is almost impossible using conventional Cre-loxP-based models. We have developed an inducible dual-recombinase system by combining flippase-FRT (Flp-FRT) and Cre-loxP recombination technologies to improve GEMMs of pancreatic cancer. This enables investigation of multistep carcinogenesis, genetic manipulation of tumor subpopulations (such as cancer stem cells), selective targeting of the tumor microenvironment and genetic validation of therapeutic targets in autochthonous tumors on a genome-wide scale. As a proof of concept, we performed tumor cell-autonomous and nonautonomous targeting, recapitulated hallmarks of human multistep carcinogenesis, validated genetic therapy by 3-phosphoinositide-dependent protein kinase inactivation as well as cancer cell depletion and show that mast cells in the tumor microenvironment, which had been thought to be key oncogenic players, are dispensable for tumor formation.
Collapse
|
140
|
Eser S, Schnieke A, Schneider G, Saur D. Oncogenic KRAS signalling in pancreatic cancer. Br J Cancer 2014. [PMID: 24755884 DOI: 10.1158/10.1038/bjc.2014.215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is almost universally fatal. The annual number of deaths equals the number of newly diagnosed cases, despite maximal treatment. The overall 5-year survival rate of <5% has remained stubbornly unchanged over the last 30 years, despite tremendous efforts in preclinical and clinical science. There is unquestionably an urgent need to further improve our understanding of pancreatic cancer biology, treatment response and relapse, and to identify novel therapeutic targets. Rigorous research in the field has uncovered genetic aberrations that occur during PDAC development and progression. In most cases, PDAC is initiated by oncogenic mutant KRAS, which has been shown to drive pancreatic neoplasia. However, all attempts to target KRAS directly have failed in the clinic and KRAS is widely assumed to be undruggable. This has led to intense efforts to identify druggable critical downstream targets and nodes orchestrated by mutationally activated KRAS. This includes context-specific KRAS effector pathways, synthetic lethal interaction partners and KRAS-driven metabolic changes. Here, we review recent advances in oncogenic KRAS signalling and discuss how these might benefit PDAC treatment in the future.
Collapse
|
141
|
Goldstein BJ, Goss GM, Hatzistergos KE, Rangel EB, Seidler B, Saur D, Hare JM. Adult c-Kit(+) progenitor cells are necessary for maintenance and regeneration of olfactory neurons. J Comp Neurol 2014; 523:15-31. [PMID: 25044230 DOI: 10.1002/cne.23653] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/15/2014] [Accepted: 07/16/2014] [Indexed: 12/28/2022]
Abstract
The olfactory epithelium houses chemosensory neurons, which transmit odor information from the nose to the brain. In adult mammals, the olfactory epithelium is a uniquely robust neuroproliferative zone, with the ability to replenish its neuronal and non-neuronal populations due to the presence of germinal basal cells. The stem and progenitor cells of these germinal layers, and their regulatory mechanisms, remain incompletely defined. Here we show that progenitor cells expressing c-Kit, a receptor tyrosine kinase marking stem cells in a variety of embryonic tissues, are required for maintenance of the adult neuroepithelium. Mouse genetic fate-mapping analyses show that embryonically, a c-Kit(+) population contributes to olfactory neurogenesis. In adults under conditions of normal turnover, there is relatively sparse c-Kit(+) progenitor cell (ckPC) activity. However, after experimentally induced neuroepithelial injury, ckPCs are activated such that they reconstitute the neuronal population. There are also occasional non-neuronal cells found to arise from ckPCs. Moreover, the selective depletion of the ckPC population, utilizing temporally controlled targeted diphtheria toxin A expression, results in failure of neurogenesis after experimental injury. Analysis of this model indicates that most ckPCs reside among the globose basal cell populations and act downstream of horizontal basal cells, which can serve as stem cells. Identification of the requirement for olfactory c-Kit-expressing progenitors in olfactory maintenance provides new insight into the mechanisms involved in adult olfactory neurogenesis. Additionally, we define an important and previously unrecognized site of adult c-Kit activity.
Collapse
|
142
|
Wirth M, Stojanovic N, Christian J, Paul MC, Stauber RH, Schmid RM, Häcker G, Krämer OH, Saur D, Schneider G. MYC and EGR1 synergize to trigger tumor cell death by controlling NOXA and BIM transcription upon treatment with the proteasome inhibitor bortezomib. Nucleic Acids Res 2014; 42:10433-47. [PMID: 25147211 PMCID: PMC4176343 DOI: 10.1093/nar/gku763] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The c-MYC (MYC afterward) oncogene is well known for driving numerous oncogenic programs. However, MYC can also induce apoptosis and this function of MYC warrants further clarification. We report here that a clinically relevant proteasome inhibitor significantly increases MYC protein levels and that endogenous MYC is necessary for the induction of apoptosis. This kind of MYC-induced cell death is mediated by enhanced expression of the pro-apoptotic BCL2 family members NOXA and BIM. Quantitative promoter-scanning chromatin immunoprecipitations (qChIP) further revealed binding of MYC to the promoters of NOXA and BIM upon proteasome inhibition, correlating with increased transcription. Both promoters are further characterized by the presence of tri-methylated lysine 4 of histone H3, marking active chromatin. We provide evidence that in our apoptosis models cell death occurs independently of p53 or ARF. Furthermore, we demonstrate that recruitment of MYC to the NOXA as well as to the BIM gene promoters depends on MYC's interaction with the zinc finger transcription factor EGR1 and an EGR1-binding site in both promoters. Our study uncovers a novel molecular mechanism by showing that the functional cooperation of MYC with EGR1 is required for bortezomib-induced cell death. This observation may be important for novel therapeutic strategies engaging the inherent pro-death function of MYC.
Collapse
|
143
|
Sano MB, Arena CB, DeWitt MR, Saur D, Davalos RV. In-vitro bipolar nano- and microsecond electro-pulse bursts for irreversible electroporation therapies. Bioelectrochemistry 2014; 100:69-79. [PMID: 25131187 DOI: 10.1016/j.bioelechem.2014.07.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 07/18/2014] [Accepted: 07/25/2014] [Indexed: 12/18/2022]
Abstract
Under the influence of external electric fields, cells experience a rapid potential buildup across the cell membrane. Above a critical threshold of electric field strength, permanent cell damage can occur, resulting in cell death. Typical investigations of electroporation effects focus on two distinct regimes. The first uses sub-microsecond duration, high field strength pulses while the second uses longer (50 μs+) duration, but lower field strength pulses. Here we investigate the effects of pulses between these two extremes. The charging behavior of the cell membrane and nuclear envelope is evaluated numerically in response to bipolar pulses between 250 ns and 50 μs. Typical irreversible electroporation protocols expose cells to 90 monopolar pulses, each 100 μs in duration with a 1 second inter-pulse delay. Here, we replace each monopolar waveform with a burst of alternating polarity pulses, while keeping the total energized time (100 μs), burst number (80), and inter-burst delay (1s) the same. We show that these bursts result in instantaneous and delayed cell death mechanisms and that there exists an inverse relationship between pulse-width and toxicity despite the delivery of equal quantities of energy. At 1500 V/cm only treatments with bursts containing 50 μs pulses (2×) resulted in viability below 10%. At 4000 V/cm, bursts with 1 μs (100×), 2 μs (50×), 5 μs (20×), 10 μs (10×), and 50 μs (2×) duration pulses reduced viability below 10% while bursts with 500 ns (200×) and 250 ns (400×) pulses resulted in viabilities of 31% and 92%, respectively.
Collapse
|
144
|
Lies B, Gil V, Groneberg D, Seidler B, Saur D, Wischmeyer E, Jiménez M, Friebe A. Interstitial cells of Cajal mediate nitrergic inhibitory neurotransmission in the murine gastrointestinal tract. Am J Physiol Gastrointest Liver Physiol 2014; 307:G98-106. [PMID: 24833707 DOI: 10.1152/ajpgi.00082.2014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nitric oxide (NO) is a major inhibitory neurotransmitter in the gastrointestinal (GI) tract. Its main effector, NO-sensitive guanylyl cyclase (NO-GC), is expressed in several GI cell types, including smooth muscle cells (SMC), interstitial cells of Cajal (ICC), and fibroblast-like cells. Up to date, the interplay between neurons and these cells to initiate a nitrergic inhibitory junction potential (IJP) is unclear. Here, we investigate the origin of the nitrergic IJP in murine fundus and colon. IJPs were determined in fundus and colon SMC of mice lacking NO-GC globally (GCKO) and specifically in SMC (SM-GCKO), ICC (ICC-GCKO), and both SMC/ICC (SM/ICC-GCKO). Nitrergic IJP was abolished in ICC-GCKO fundus and reduced in SM-GCKO fundus. In the colon, the amplitude of nitrergic IJP was reduced in ICC-GCKO, whereas nitrergic IJP in SM-GCKO was reduced in duration. These results were corroborated by loss of the nitrergic IJP in global GCKO. In conclusion, our results prove the obligatory role of NO-GC in ICC for the initiation of an IJP. NO-GC in SMC appears to enhance the nitrergic IJP, resulting in a stronger and prolonged hyperpolarization in fundus and colon SMC, respectively. Thus NO-GC in both cell types is mandatory to induce a full nitrergic IJP. Our data from the colon clearly reveal the nitrergic IJP to be biphasic, resulting from individual inputs of ICC and SMC.
Collapse
|
145
|
Wirth M, Stojanovic N, Schmid R, Krämer O, Saur D, Schneider G. 260: A novel MYC directed apoptosis pathway controls NOXA and BIM transcription. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)50229-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
146
|
Eser S, Schnieke A, Schneider G, Saur D. Oncogenic KRAS signalling in pancreatic cancer. Br J Cancer 2014; 111:817-22. [PMID: 24755884 PMCID: PMC4150259 DOI: 10.1038/bjc.2014.215] [Citation(s) in RCA: 365] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 03/19/2014] [Accepted: 03/26/2014] [Indexed: 12/15/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is almost universally fatal. The annual number of deaths equals the number of newly diagnosed cases, despite maximal treatment. The overall 5-year survival rate of <5% has remained stubbornly unchanged over the last 30 years, despite tremendous efforts in preclinical and clinical science. There is unquestionably an urgent need to further improve our understanding of pancreatic cancer biology, treatment response and relapse, and to identify novel therapeutic targets. Rigorous research in the field has uncovered genetic aberrations that occur during PDAC development and progression. In most cases, PDAC is initiated by oncogenic mutant KRAS, which has been shown to drive pancreatic neoplasia. However, all attempts to target KRAS directly have failed in the clinic and KRAS is widely assumed to be undruggable. This has led to intense efforts to identify druggable critical downstream targets and nodes orchestrated by mutationally activated KRAS. This includes context-specific KRAS effector pathways, synthetic lethal interaction partners and KRAS-driven metabolic changes. Here, we review recent advances in oncogenic KRAS signalling and discuss how these might benefit PDAC treatment in the future.
Collapse
|
147
|
Fichna J, Sałaga M, Stuart J, Saur D, Sobczak M, Zatorski H, Timmermans JP, Bradshaw HB, Ahn K, Storr MA. Selective inhibition of FAAH produces antidiarrheal and antinociceptive effect mediated by endocannabinoids and cannabinoid-like fatty acid amides. Neurogastroenterol Motil 2014; 26:470-81. [PMID: 24460851 DOI: 10.1111/nmo.12272] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 11/08/2013] [Indexed: 12/21/2022]
Abstract
BACKGROUND The endogenous cannabinoid system (ECS) plays a crucial role in multiple physiological processes in the central nervous system and in the periphery. The discovery that selective cannabinoid (CB) receptor agonists exert a potent inhibitory action on gastrointestinal (GI) motility and pain has placed the ECS in the center of attention as a possible target for the treatment of functional GI diseases. However, side effects of CB agonists prompted the search for novel therapeutic targets. Here, the effect of PF-3845, a potent and selective fatty acid amide hydrolase (FAAH) inhibitor in the GI tract was investigated. METHODS The effect of PF-3845 on GI motility was characterized in vitro and in vivo, using mouse models that mimic physiological and pathophysiological conditions. The antinociceptive action of PF-3845 was evaluated on the basis of behavioral pain models. Endocannabinoid degradation product levels after inhibition of FAAH were quantified using HPLC-MS/MS. KEY RESULTS PF-3845 significantly inhibited mouse colonic motility in vitro and in vivo. Selective inhibition of FAAH reversed hypermotility and reduced pain in mouse models mimicking functional GI disorders. The effects of PF-3845 were mediated by endogenous CBs and non-CB lipophilic compounds via classical (CB1) and atypical CB receptors. CONCLUSIONS & INFERENCES These data expand our understanding of the ECS function and provide a novel framework for the development of future potential treatments of functional GI disorders.
Collapse
|
148
|
Sibaev A, Yuece B, Allescher HD, Saur D, Storr M, Kurjak M. The endocannabinoid anandamide regulates the peristaltic reflex by reducing neuro-neuronal and neuro-muscular neurotransmission in ascending myenteric reflex pathways in rats. Pharmacol Rep 2014; 66:256-63. [DOI: 10.1016/j.pharep.2013.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 08/19/2013] [Accepted: 09/06/2013] [Indexed: 10/25/2022]
|
149
|
Sun Y, Nguyen AQ, Nguyen JP, Le L, Saur D, Choi J, Callaway EM, Xu X. Cell-type-specific circuit connectivity of hippocampal CA1 revealed through Cre-dependent rabies tracing. Cell Rep 2014; 7:269-80. [PMID: 24656815 DOI: 10.1016/j.celrep.2014.02.030] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 01/06/2014] [Accepted: 02/20/2014] [Indexed: 10/25/2022] Open
Abstract
We developed and applied a Cre-dependent, genetically modified rabies-based tracing system to map direct synaptic connections to specific CA1 neuron types in the mouse hippocampus. We found common inputs to excitatory and inhibitory CA1 neurons from CA3, CA2, the entorhinal cortex (EC), the medial septum (MS), and, unexpectedly, the subiculum. Excitatory CA1 neurons receive inputs from both cholinergic and GABAergic MS neurons, whereas inhibitory neurons receive a great majority of inputs from GABAergic MS neurons. Both cell types also receive weaker input from glutamatergic MS neurons. Comparisons of inputs to CA1 PV+ interneurons versus SOM+ interneurons showed similar strengths of input from the subiculum, but PV+ interneurons received much stronger input than SOM+ neurons from CA3, the EC, and the MS. Thus, rabies tracing identifies hippocampal circuit connections and maps how the different input sources to CA1 are distributed with different strengths on each of its constituent cell types.
Collapse
|
150
|
Pelz J, Weinreich A, Fritzsch D, Saur D. Comparison of 3D-ultrasound of the carotid vessels with contrast enhanced magnetic resonance angiography. KLIN NEUROPHYSIOL 2014. [DOI: 10.1055/s-0034-1371239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|