An improved, scalable synthesis of Notum inhibitor LP-922056 using 1-chloro-1,2-benziodoxol-3-one as a superior electrophilic chlorinating agent

Background: The carboxylesterase Notum has been shown to act as a key negative regulator of the Wnt signalling pathway by mediating the depalmitoleoylation of Wnt proteins. LP-922056 (1) is an orally active inhibitor of Notum. We are investigating the role of Notum in modulating Wnt signalling in the central nervous system and wished to establish if 1 would serve as a peripherally restricted control. An accessible and improved synthetic route would allow 1 to become more readily available as a chemical tool to explore the fundamental biology of Notum and build target validation to underpin new drug discovery programs. Results: An improved, scalable synthesis of 1 is reported. Key modifications include: (1) the introduction of the C7-cyclopropyl group was most effectively achieved with a Suzuki–Miyaura cross-coupling reaction with MIDA-boronate 11 (5 → 6), and (2) C6 chlorination was performed with 1-chloro-1,2-benziodoxol-3-one (12) (6 → 7) as a mild and selective electrophilic chlorination agent. This 7-step route from 16 has been reliably performed on large scale to produce multigram quantities of 1 in good efficiency and high purity. Pharmacokinetic studies in mouse showed CNS penetration of 1 is very low with a brain/plasma concentration ratio of just 0.01. A small library of amides 17 were prepared from acid 1 to explore if 1 could be modified to deliver a CNS penetrant tool by capping off the acid as an amide. Although significant Notum inhibition activity could be achieved, none of these amides demonstrated the required combination of metabolic stability along with cell permeability without evidence of P-gp mediated efflux. Conclusion: Mouse pharmacokinetic studies demonstrate that 1 is unsuitable for use in models of disease where brain penetration is an essential requirement of the compound but would be an ideal peripherally restricted control. These data will contribute to the understanding of drug levels of 1 to overlay with appropriate in vivo efficacy endpoints, i.e., the PK-PD relationship. The identification of a suitable analogue of 1 (or 17) which combines Notum inhibition with CNS penetration would be a valuable chemical probe for investigating the role of Notum in disease models.

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An improved, scalable synthesis of Notum inhibitor LP-922056 using 1-chloro-1,2-benziodoxol-3-one as a superior electrophilic chlorinating agent

10.3762/bxiv.2019.70.v1 ◽

2019 ◽

Author(s):

Nicky J Willis ◽

Elliott D Bayle ◽

George Papageorgiou ◽

David Steadman ◽

Benjamin N Aktinson ◽

...

Keyword(s):

Wnt Signalling ◽

Negative Regulator ◽

Cell Permeability ◽

Pharmacokinetic Studies ◽

Good Efficiency ◽

Active Inhibitor ◽

Wnt Proteins ◽

Cns Penetration ◽

Scalable Synthesis

Background: The carboxylesterase Notum has been shown to act as a key negative regulator of the Wnt signalling pathway by mediating the depalmitoleoylation of Wnt proteins. LP-922056 (1) is an orally active inhibitor of Notum. We are investigating the role of Notum in modulating Wnt signalling in the central nervous system and wished to establish if 1 would serve as a peripherally restricted control. An accessible and improved synthetic route would allow 1 to become more readily available as a chemical tool to explore the fundamental biology of Notum and build target validation to underpin new drug discovery programs. Results: An improved, scalable synthesis of 1 is reported. Key modifications include: (1) the introduction of the C7-cyclopropyl group was most effectively achieved with a Suzuki–Miyaura cross-coupling reaction with MIDA-boronate 11 (5 → 6); and (2) C6 chlorination was performed with 1-chloro-1,2-benziodoxol-3-one (12) (6 → 7) as a mild selective electrophilic chlorination agent. This 7-step route has been reliably performed on large scale to produce multigram quantities of 1 in good efficiency and high purity. Pharmacokinetic studies in mouse showed CNS penetration of 1 is very low with brain:plasma concentration ratio of just 0.01. A small library of amides 17 were prepared from acid 1 to explore if 1 could be modified to deliver a CNS penetrant tool by capping off the acid as an amide. Although significant Notum inhibition activity could be achieved, none of these amides demonstrated the required combination of metabolic stability along with cell permeability without evidence of P-gp mediated efflux. Conclusion: Mouse pharmacokinetic studies demonstrate that 1 is unsuitable for use in models of disease where brain penetration is an essential requirement of the compound but would be an ideal peripherally restricted control. These data will contribute to the understanding of drug levels of 1 to overlay with appropriate in vivo efficacy endpoints, i.e. the PK-PD relationship. The identification of a suitable analogue of 1 (or 17) which combines Notum inhibition with CNS penetration would be a valuable chemical probe for investigating the role of Notum in disease models.

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GSK-3α Inhibition in Drug-Resistant CML Cells Promotes Susceptibility to NK Cell-Mediated Lysis in an NKG2D- and NKp30-Dependent Manner

Cancers ◽

10.3390/cancers13081802 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1802

Author(s):

Nayoung Kim ◽

Mi Yeon Kim ◽

Woo Seon Choi ◽

Eunbi Yi ◽

Hyo Jung Lee ◽

...

Keyword(s):

Nk Cells ◽

Nk Cell ◽

Negative Regulator ◽

Target Cells ◽

Dependent Manner ◽

Cell Functions ◽

Cell Based Therapy ◽

Activating Receptors ◽

Gsk 3Β

Natural killer (NK) cells are innate cytotoxic lymphocytes that provide early protection against cancer. NK cell cytotoxicity against cancer cells is triggered by multiple activating receptors that recognize specific ligands expressed on target cells. We previously demonstrated that glycogen synthase kinase (GSK)-3β, but not GSK-3α, is a negative regulator of NK cell functions via diverse activating receptors, including NKG2D and NKp30. However, the role of GSK-3 isoforms in the regulation of specific ligands on target cells is poorly understood, which remains a challenge limiting GSK-3 targeting for NK cell-based therapy. Here, we demonstrate that GSK-3α rather than GSK-3β is the primary isoform restraining the expression of NKG2D ligands, particularly ULBP2/5/6, on tumor cells, thereby regulating their susceptibility to NK cells. GSK-3α also regulated the expression of the NKp30 ligand B7-H6, but not the DNAM-1 ligands PVR or nectin-2. This regulation occurred independently of BCR-ABL1 mutation that confers tyrosine kinase inhibitor (TKI) resistance. Mechanistically, an increase in PI3K/Akt signaling in concert with c-Myc was required for ligand upregulation in response to GSK-3α inhibition. Importantly, GSK-3α inhibition improved cancer surveillance by human NK cells in vivo. Collectively, our results highlight the distinct role of GSK-3 isoforms in the regulation of NK cell reactivity against target cells and suggest that GSK-3α modulation could be used to enhance tumor cell susceptibility to NK cells in an NKG2D- and NKp30-dependent manner.

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Controlled Transcription of Regulator Gene carS by Tet-on or by a Strong Promoter Confirms Its Role as a Repressor of Carotenoid Biosynthesis in Fusarium fujikuroi

Microorganisms ◽

10.3390/microorganisms9010071 ◽

2020 ◽

Vol 9 (1) ◽

pp. 71

Author(s):

Julia Marente ◽

Javier Avalos ◽

M. Carmen Limón

Keyword(s):

Wild Strain ◽

Ring Finger ◽

Carotenoid Biosynthesis ◽

Negative Regulator ◽

Fusarium Fujikuroi ◽

Structural Genes ◽

Gene Encoding ◽

In The Wild ◽

Set Up

Carotenoid biosynthesis is a frequent trait in fungi. In the ascomycete Fusarium fujikuroi, the synthesis of the carboxylic xanthophyll neurosporaxanthin (NX) is stimulated by light. However, the mutants of the carS gene, encoding a protein of the RING finger family, accumulate large NX amounts regardless of illumination, indicating the role of CarS as a negative regulator. To confirm CarS function, we used the Tet-on system to control carS expression in this fungus. The system was first set up with a reporter mluc gene, which showed a positive correlation between the inducer doxycycline and luminescence. Once the system was improved, the carS gene was expressed using Tet-on in the wild strain and in a carS mutant. In both cases, increased carS transcription provoked a downregulation of the structural genes of the pathway and albino phenotypes even under light. Similarly, when the carS gene was constitutively overexpressed under the control of a gpdA promoter, total downregulation of the NX pathway was observed. The results confirmed the role of CarS as a repressor of carotenogenesis in F. fujikuroi and revealed that its expression must be regulated in the wild strain to allow appropriate NX biosynthesis in response to illumination.

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GSK3 takes centre stage more than 20 years after its discovery

Biochemical Journal ◽

10.1042/bj3590001 ◽

2001 ◽

Vol 359 (1) ◽

pp. 1-16 ◽

Cited By ~ 542

Author(s):

Sheelagh FRAME ◽

Philip COHEN

Keyword(s):

Substrate Specificity ◽

Therapeutic Potential ◽

Glycogen Synthase ◽

Glycogen Metabolism ◽

Wnt Signalling ◽

Signalling Pathway ◽

Dimensional Structure ◽

Entire Body ◽

Wnt Signalling Pathway ◽

Wnt Proteins

Identified originally as a regulator of glycogen metabolism, glycogen synthase kinase-3 (GSK3) is now a well-established component of the Wnt signalling pathway, which is essential for setting up the entire body pattern during embryonic development. It may also play important roles in protein synthesis, cell proliferation, cell differentiation, microtubule dynamics and cell motility by phosphorylating initiation factors, components of the cell-division cycle, transcription factors and proteins involved in microtubule function and cell adhesion. Generation of the mouse knockout of GSK3β, as well as studies in neurons, also suggest an important role in apoptosis. The substrate specificity of GSK3 is unusual in that efficient phosphorylation of many of its substrates requires the presence of another phosphorylated residue optimally located four amino acids C-terminal to the site of GSK3 phosphorylation. Recent experiments, including the elucidation of its three-dimensional structure, have enhanced our understanding of the molecular basis for the unique substrate specificity of GSK3. Insulin and growth factors inhibit GSK3 by triggering its phosphorylation, turning the N-terminus into a pseudosubstrate inhibitor that competes for binding with the ‘priming phosphate’ of substrates. In contrast, Wnt proteins inhibit GSK3 in a completely different way, by disrupting a multiprotein complex comprising GSK3 and its substrates in the Wnt signalling pathway, which do not appear to require a ‘priming phosphate’. These latest findings have generated an enormous amount of interest in the development of drugs that inhibit GSK3 and which may have therapeutic potential for the treatment of diabetes, stroke and Alzheimer's disease.

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Abstract P317: Cardiac Fibroblast GSK3α Promotes Myocardial Fibrotic Remodeling Through GSK3α-ERK-IL11 Signaling Circuit

Circulation Research ◽

10.1161/res.129.suppl_1.p317 ◽

2021 ◽

Vol 129 (Suppl_1) ◽

Author(s):

Prachi Umbarkar ◽

Sultan Tousif ◽

Anand P Singh ◽

Joshua C Anderson ◽

qinkun zhang ◽

...

Keyword(s):

Myocardial Fibrosis ◽

Cardiac Fibrosis ◽

Critical Role ◽

Flow Cytometric Analysis ◽

Collagen Gel ◽

Pressure Overload ◽

Negative Regulator ◽

Post Injury

Background: Myocardial fibrosis contributes significantly to heart failure (HF). Fibroblasts are among the predominant cell type in the heart and are primary drivers of fibrosis. To identify the kinases involved in fibrosis, we analyzed the kinome of mouse cardiac fibroblasts (CF) isolated from normal and failing hearts. This unbiased screening revealed the critical role of the GSK-3 family-centric pathways in fibrosis. Previously we have shown that among two isoforms of GSK3, CF-GSK3β acts as a negative regulator of fibrosis in the injured heart. However, the role of CF-GSK3α in the pathogenesis of cardiac diseases is completely unknown. Methods and Results: To define the role of CF-GSK3α in HF, we employed two novel fibroblast-specific KO mouse models. Specifically, GSK3α was deleted from fibroblasts or myofibroblasts with tamoxifen-inducible Tcf21- or periostin- promoter-driven Cre recombinase. In both models, GSK3α deletion restricted pressure overload-induced cardiac fibrosis and preserved cardiac function. We examined the effect of GSK3α deletion on myofibroblast transformation and pro-fibrotic TGFβ1-SMAD3 signaling in vitro . A significant reduction in cell migration, collagen gel contraction, and α-SMA expression in TGFβ1-treated KO CFs confirmed that GSK3α is required for myofibroblast transformation. Surprisingly, GSK3α deletion did not affect SMAD3 activation, indicating the pro-fibrotic role of GSK3α is SMAD3 independent. To further delineate the underlying mechanisms, proteins were isolated from CFs of WT and KO mice at 4 weeks post-injury, and kinome profiling was performed. The kinome analysis identified the downregulation of RAF family kinase activity in KO CFs. Moreover, mapping of significantly altered kinases against literature annotated interactions generated ERK-centric networks. Consistently, flow cytometric analysis of CFs confirmed significantly low levels of pERK in KO mice. Additionally, our in vitro studies demonstrated that GSK3α deletion prevents TGFβ1-induced ERK activation. Interestingly, IL-11, a pro-fibrotic downstream effector of TGFβ1, was remarkably reduced in KO CFs and ERK inhibition further decreased IL-11 expression. Taken together, herein, we discovered the GSK3α-ERK-IL-11 signaling as a critical pro-fibrotic pathway in the heart. Strategies to inhibit this pro-fibrotic network could prevent adverse fibrosis and HF. Conclusion: CF-GSK3α plays a causal role in myocardial fibrosis that could be therapeutically targeted for future clinical applications.

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QSAR Docking on Azoles as inhibitors of Notum carboxylesterase

Current Chemical Biology ◽

10.2174/2212796815666211026110125 ◽

2021 ◽

Vol 15 ◽

Author(s):

Amuthalakshmi Sivaperuman ◽

Ramalakshmi Natarajan ◽

Manimegalai P ◽

Arunkumar Subramani ◽

Puratchikody Ayarivan

Keyword(s):

Regression Analysis ◽

Linear Regression ◽

Wnt Signaling ◽

Multiple Linear Regression ◽

Inhibitory Activity ◽

Linear Regression Analysis ◽

External Validation ◽

Negative Regulator ◽

Qsar Analysis ◽

Wnt Proteins

Background: Carboxylesterase Notum is a negative regulator of Wnt signaling. Notum carboxylesterase is a carboxylic ester hydrolase enzyme that functions as a negative feedback regulator of Wnt proteins by depalmitoylation reaction. It is of great importance to understand the pathway of Wnt regulation because, conversely, misregulation of Wnt signaling is a telltale sign of cancer and other degenerative diseases. The Wnt inhibition is important in the control of colorectal cancer. Objective: In the present study, we carried out a QSAR analysis of a series of reported compounds with carboxylesterase Notum inhibitory activity using multiple regression analysis. A series of 83 compound datasets of pyrrole derivatives with carboxy Notum inhibitory values were taken from the reported literature. Methods: The study was performed by conducting multiple linear regression analysis followed by validation of the model. The multiple linear regression (MLR) models with the highest coefficients of correlation (R2) and explained variance in leave-one-out (Q2 LOO) prediction and leave-many-out (Q2 LMO) were selected for the whole dataset. The developed models were subjected to internal and external validation. The reliability of the predicted model was checked by plotting the Williams plot. The docking methodology was performed using Autodock 4 for the designed compounds to study the interaction between the ligand and the receptor. Results: The best model generated exhibited an r2 value of 0.7413, Q2LOO =0.6379, Q2LMO =0.6368. Novel compounds of phenyl pyrrolidine were designed based on generated QSAR equations. The carboxylesterase Notum inhibitory activity was predicted using the QSAR equations. The docking studies were carried out for designed compounds using Autodock against Carboxylesterase Notum esterase. Conclusion: From the results, the designed compounds were found to inhibit Notum Carboxylase. Thus, the study led to the development of a novel lead compound for Carboxylesterase Notum.

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Abstract 17597: Endogenous Del-1 is a Negative Regulator of Ischemia-induced Angiogenesis by Interacting With the Leukocytic LFA-1 Integrin

Circulation ◽

10.1161/circ.130.suppl_2.17597 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Sebastian Cremer ◽

Anne Klotzsche-von Ameln ◽

Alessia Orlandi ◽

Irina Korovina ◽

Bettina Gercken ◽

...

Keyword(s):

Endothelial Cell ◽

Hind Limb ◽

Hematopoietic Cells ◽

Limb Ischemia ◽

Inflammatory Cells ◽

Capillary Density ◽

Negative Regulator ◽

Hind Limb Ischemia ◽

Autonomous Pathway

Developmental endothelial locus-1 (Del-1) is an endothelial cell-derived secreted protein circulating in blood and associated with the cell surface and the extracellular matrix. As we previously demonstrated, Del-1 restricts leukocyte recruitment by inhibiting the β2-integrin, LFA-1. Leukocytes and progenitor cells (PC) may contribute to angiogenesis. The role of endogenous Del-1 in angiogenesis is elusive. We found, that physiological angiogenesis of the developing retina was not affected in the Del-1-/- mice compared to the wildtype (WT) mice. Surprisingly, Del-1-/- mice displayed a significantly increased angiogenic response compared to WT mice after induction of hind limb ischemia (144 ± 6 % increase of capillary density) and retinal ischemia (retinopathy of prematurity model) suggesting that endogenous Del-1 is an inhibitor of ischemia-induced neovascularization. Silencing of Del-1 with siRNA did not affect the angiogenic sprouting of endothelial cell (EC) spheroids, indicating that Del-1 blocks angiogenesis in a non-endothelial cell autonomous pathway. Soluble Del-1 blocked the adhesion of inflammatory cells on EC monolayers. In line with these results, ischemic muscles and ischemic retinae from Del-1-/- mice displayed an enhanced infiltration with inflammatory cells compared to the WT mice. Since Del-1 blocks inflammatory cell homing by inhibiting the leukocytic LFA-1-integrin, we addressed the role of the Del-1/LFA-1-integrin interaction on the inhibitory function of endogenous Del-1 on angiogenesis. Indeed, Del-1/LFA-1-double deficiency reversed the pro-angiogenic phenotype of the Del-1-/- mice to the level of WT mice in the model of hind limb ischemia. Thus, the inhibitory role of Del-1 on neovascularization is mediated by the interaction of Del-1 with the LFA-1-integrin. Moreover, Del-1-deficiency led to an increased homing of intravenously injected murine fluorescence-labeled WT Lin- BM PC in ischemic muscles in comparison to WT mice after the induction of hind limb ischemia. Taken together, Del-1 acts as a negative regulator of ischemia-induced angiogenesis by interacting with the LFA-1-integrin expressed in hematopoietic cells, thereby inhibiting the homing of hematopoietic cells to ischemic tissues.

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Evidence for a functional calcium-sensing receptor that modulates myogenic tone in rat subcutaneous small arteries

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00739.2004 ◽

2005 ◽

Vol 288 (4) ◽

pp. H1756-H1762 ◽

Cited By ~ 49

Author(s):

Jacqueline Ohanian ◽

Kelly M. Gatfield ◽

Donald T. Ward ◽

Vasken Ohanian

Keyword(s):

Vascular Tissue ◽

Immunoblot Analysis ◽

Negative Regulator ◽

Intraluminal Pressure ◽

Myogenic Tone ◽

Internal Diameter ◽

Calcium Sensing Receptor ◽

Small Arteries ◽

Calcium Sensing

Myogenic tone of small arteries is dependent on the presence of extracellular calcium ([Formula: see text]), and, recently, a receptor that senses changes in Ca2+, the calcium-sensing receptor (CaR), has been detected in vascular tissue. We investigated whether the CaR is involved in the regulation of myogenic tone in rat subcutaneous small arteries. Immunoblot analysis using a monoclonal antibody against the CaR demonstrated its presence in rat subcutaneous arteries. To determine whether the CaR was functionally active, segments of artery (<250 μm internal diameter) mounted in a pressure myograph with an intraluminal pressure of 70 mmHg were studied after the development of myogenic tone. Increasing [Formula: see text] concentration ([Ca2+]o) cumulatively from 0.5 to 10 mM induced an initial constriction (0.5–2 mM) followed by dilation (42 ± 5% loss of tone). The dose-dependent dilation was mimicked by other known CaR agonists including magnesium (1–10 mM) and the aminoglycosides neomycin (0.003–10 mM) and kanamycin (0.003–3 mM). PKC activation with the phorbol ester phorbol-12,13-dibutyrate (20nM) inhibited the dilation induced by high [Ca2+]o or neomycin, whereas inhibition of PKC with GF109203X (10 μM) increased the responses to [Formula: see text] or neomycin, consistent with the role of PKC as a negative regulator of the CaR. We conclude that rat subcutaneous arteries express a functionally active CaR that may be involved in the modulation of myogenic tone and hence the regulation of peripheral vascular resistance.

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A NOVEL ROLE OF PLASMA MEMBRANE CALCIUM ATPASE 4 AS A NEGATIVE-REGULATOR OF VEGF-INDUCED ANGIOGENESIS

Heart ◽

10.1136/heartjnl-2014-306916.50 ◽

2014 ◽

Vol 100 (Suppl 4) ◽

pp. A17.1-A17

Author(s):

RR Baggott ◽

A Alfranca ◽

MD López-Maderuelo ◽

TMA Mohamed ◽

A Escolano ◽

...

Keyword(s):

Plasma Membrane ◽

Calcium Atpase ◽

Negative Regulator ◽

Plasma Membrane Calcium Atpase

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Molecular Basis for CCRL2 Regulation of Leukocyte Migration

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2020.615031 ◽

2020 ◽

Vol 8 ◽

Author(s):

Tiziana Schioppa ◽

Francesca Sozio ◽

Ilaria Barbazza ◽

Sara Scutera ◽

Daniela Bosisio ◽

...

Keyword(s):

Cancer Progression ◽

Chemokine Receptors ◽

Transmembrane Domain ◽

Nk Cell ◽

Structural Features ◽

Negative Regulator ◽

Leukocyte Migration ◽

Genetic Ablation

CCRL2 is a seven-transmembrane domain receptor that belongs to the chemokine receptor family. At difference from other members of this family, CCRL2 does not promote chemotaxis and shares structural features with atypical chemokine receptors (ACKRs). However, CCRL2 also differs from ACKRs since it does not bind chemokines and is devoid of scavenging functions. The only commonly recognized CCRL2 ligand is chemerin, a non-chemokine chemotactic protein. CCRL2 is expressed both by leukocytes and non-hematopoietic cells. The genetic ablation of CCRL2 has been instrumental to elucidate the role of this receptor as positive or negative regulator of inflammation. CCRL2 modulates leukocyte migration by two main mechanisms. First, when CCRL2 is expressed by barrier cells, such endothelial, and epithelial cells, it acts as a presenting molecule, contributing to the formation of a non-soluble chemotactic gradient for leukocytes expressing CMKLR1, the functional chemerin receptor. This mechanism was shown to be crucial in the induction of NK cell-dependent immune surveillance in lung cancer progression and metastasis. Second, by forming heterocomplexes with other chemokine receptors. For instance, CCRL2/CXCR2 heterodimers were shown to regulate the activation of β2-integrins in mouse neutrophils. This mini-review summarizes the current understanding of CCRL2 biology, based on experimental evidence obtained by the genetic deletion of this receptor in in vivo experimental models. Further studies are required to highlight the complex functional role of CCRL2 in different organs and pathological conditions.

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