Glenn McEnroe - Academia.edu (original) (raw)
Papers by Glenn McEnroe
Science, 1987
A ring-deleted analog of atrial natriuretic factor--des[Gln18, Ser19, Gly20, Leu21, Gly22] ANF4-2... more A ring-deleted analog of atrial natriuretic factor--des[Gln18, Ser19, Gly20, Leu21, Gly22] ANF4-23-NH2 (C-ANF4-23)--binds with high affinity to approximately 99% of ANF receptors in the isolated perfused rat kidney. In this preparation, C-ANF4-23 is devoid of detectable renal effects and does not antagonize any of the known renal hemodynamic and natriuretic actions of biologically active ANF1-28. In contrast, both C-ANF4-23 and ANF1-28 increase sodium excretion and decrease blood pressure in intact anesthetized rats. This apparent contradiction is resolved by the finding that the ring-deleted analog markedly increases plasma levels of endogenous immunoreactive ANF in the rat. The results show that the majority of the renal receptors of ANF are biologically silent. This new class of receptors may serve as specific peripheral storage-clearance binding sites, acting as a hormonal buffer system to modulate plasma levels of ANF.
Proceedings of The National Academy of Sciences, 1984
Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been puri... more Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been purified by gel filtration and reversed-phase liquid chromatography. Based on analysis of the intact factors and their chymotryptic fragments, we have assigned the primary structure of these octapeptides as pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, designated periplanetin CC-1, and pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, designated periplanetin CC-2. They represent new members of a family of invertebrate peptides that includes locust adipokinetic hormone and crustacean red-pigment concentrating hormone. Both peptides show adipokinetic activity in grasshoppers and hyperglycemic activity in cockroaches. One of these peptides (CC-2) has provocative sequence homology with the NH2-terminal portion of glucagon.
The authors have shown that cultured bovine aortic smooth muscle (BASM) cells contain high affini... more The authors have shown that cultured bovine aortic smooth muscle (BASM) cells contain high affinity receptor sites for the ANP, auriculin (ANP(4-28)). Furthermore, ANP(4-28) causes cyclic GMP (cGMP) levels to increase in BASM. In the present study, the authors synthesized a series of NHâ and/or COOH truncated ANP(4-28) analogs and examined their ability to compete for ¹²âµI-ANP(4-28) binding to BASM and increase cGMP levels. ANP-mediated cGMP responses were reduced when amino acids were deleted from the NHâ and/or COOH termini of ANP(4-28). Removal of the NHâ terminal R, R-S, or R-S-S residues resulted in a 10X decrease in potency for cGMP stimulation. Deletion of the COOH terminal R-Y and F-R-Y residues resulted in a marked decline in potency. ANP's lacking the F-R-Y tripeptide were nearly inactive in stimulating cGMP accumulation. In contrast to the cGMP effects, NHâ and/or COOH truncations of ANP(4-28) did not alter apparent receptor binding affinities (Ki(app)). All of these peptide analogs exhibited Ki(app)'s of 1-5 nM. Furthermore, peptides that bound effectively and failed to elicit cGMP responses did not antagonize ANP(4-28)-mediated cGMP increases. These binding and functional data suggest the presence of a single class of ANP receptors on BASM is insufficient to explain the actions of ANP's in these cells.
Inflammation Research, 1997
Objective and Design: Peptides derived from neutrophil inhibitory factor (NIF), a known antagonis... more Objective and Design: Peptides derived from neutrophil inhibitory factor (NIF), a known antagonist of Mac-1, were evaluated as inhibitors of neutrophil adherence.¶Material: In vitro assays of adherence employed: 1) human polymorphonuclear cells (PMN), 2) human umbilical vein endothelial cells (HUVEC), and 3) CHO cells expressing ICAM-1 (CHO-ICAM cells).¶Treatment: Cells, pretreated with NIF-derived peptides (0.1–100 μM) for 10 minutes, were permitted to adhere for 20 min in the continued presence of peptide.¶Methods: Cell-based assays: 1) PMN adherence to HUVEC, 2) PMN adhesion to immobilized human serum proteins, and 3) adherence of CHO-ICAM cells to immobilized Mac-1.¶Results: A NIF-derived peptide of 29 amino acids blocked PMN adherence to HUVEC, but behaved somewhat differently than the parent NIF protein. NIF specifically antagonized Mac-1 dependent adherence, but the peptide blocked neutrophil adherence that was dependent upon both Mac-1 and LFA-1 integrins. CHO-ICAM adherence to Mac-1 was blocked by NIF, but not by the peptide. Binding studies with NIF and the peptide indicate that the molecules bind to different sites.¶Conclusions: A peptide derived from NIF blocks PMN adherence but, unlike NIF, the mechanism of action is not mediated by direct antagonism Mac-1.
Biochemical Pharmacology, 2004
Transforming growth factor (TGFβ) is a 25-kDa dimeric polypeptide that plays a key role in a vari... more Transforming growth factor (TGFβ) is a 25-kDa dimeric polypeptide that plays a key role in a variety of physiological processes and disease states. Blocking TGFβ signaling represents a potentially powerful and conceptually novel approach to the treatment of disorders in which the signaling pathway is constitutively activated, such as cancer, chronic inflammation with fibrosis and select immune disorders. In this paper, we describe the biological properties of a novel series of quinazoline-derived inhibitors of the type I transforming growth factor receptor kinase (TβKIs) that bind to the ATP-binding site and keep the kinase in its inactive conformation. These compounds effectively inhibited TGFβ-induced Smad2 phosphorylation in cultured cells in vitro with an IC50 between 20 and 300 nM. Moreover, TβKIs were able to broadly block TGFβ-induced reporter gene activation. Finally, TβKIs inhibited TGFβ-mediated growth inhibition of normal murine mammary epithelial cells (NMuMG) and mink lung epithelial cells (Mv1Lu), and TGFβ-induced epithelial-mesenchymal transdifferentiation (EMT) of NMuMG cells. Thus, these chemical TβKIs have the potential to be further developed as anti-cancer and -fibrosis agents. In addition, they represent valuable new tools for dissecting the biochemical mechanisms of TGFβ signal transduction and understanding the role of TGFβ signaling pathways in different physiological and disease processes.
Transforming growth factor- (TGF-) suppresses tumor formation by blocking cell cycle progressio... more Transforming growth factor- (TGF-) suppresses tumor formation by blocking cell cycle progression and maintaining tissue homeostasis. In pancreatic carcinomas, this tumor suppressive activity is often lost by inactivation of the TGF--signaling mediator, Smad4. We found that human pancreatic carcinoma cell lines that have undergone deletion of MADH4 constitutively expressed high endogenous levels of phosphorylated receptor-associated Smad proteins (pR-Smad2 and pR-Smad3), whereas Smad4-positive lines did not. These elevated pR-Smad levels could not be attributed to a decreased dephosphorylation rate nor to increased expression of TGF- type I (TR-I) or type II (TR-II) receptors. Although minimal amounts of free bioactive TGF-1 and TGF-2 were detected in conditioned medium, treatment with a pan-specific (but not a TGF-3 specific) TGF--neutralizing antibody and with anti-␣ V  6 integrin antibody decreased steady-state pSmad2 levels and activation of a TGF--inducible reporter gene in neighboring cells, respectively. Thus, activation of TGF- at the cell surface was responsible for the increased autocrine endogenous and paracrine signaling. Blocking TR-I activity using a selective kinase inhibitor (SD-093) strongly decreased the in vitro motility and invasiveness of the pancreatic carcinoma cells without affecting their growth characteristics, morphology, or the subcellular distribution of E-cadherin and F-actin. Moreover, exogenous TGF- strongly stimulated in vitro invasiveness of BxPC-3 cells, an effect that could also be blocked by SD-093. Thus, the motile and invasive properties of Smad4deficient pancreatic cancer cells are at least partly driven by activation of endogenous TGF- signaling. Therefore, targeting the TR-I kinase represents a potentially powerful novel therapeutic approach for the treatment of this disease.
Molecular Diversity, 1997
A simple and general approach to the synthesis of chemical libraries based on a universal anhydri... more A simple and general approach to the synthesis of chemical libraries based on a universal anhydride template allows the preparation of large number of compounds. Various cyclic/acyclic amines, primary/secondary amines, differentially protected bifunctional amines were used as nucleophiles to react with anhydrides. The free carboxylic acid generated was then coupled with solid-bound amines. The facile and rapid generation of compounds through this multi-component assembly can be accomplished in a combinatorial parallel synthesis.
Science, 1987
A ring-deleted analog of atrial natriuretic factor--des[Gln18, Ser19, Gly20, Leu21, Gly22] ANF4-2... more A ring-deleted analog of atrial natriuretic factor--des[Gln18, Ser19, Gly20, Leu21, Gly22] ANF4-23-NH2 (C-ANF4-23)--binds with high affinity to approximately 99% of ANF receptors in the isolated perfused rat kidney. In this preparation, C-ANF4-23 is devoid of detectable renal effects and does not antagonize any of the known renal hemodynamic and natriuretic actions of biologically active ANF1-28. In contrast, both C-ANF4-23 and ANF1-28 increase sodium excretion and decrease blood pressure in intact anesthetized rats. This apparent contradiction is resolved by the finding that the ring-deleted analog markedly increases plasma levels of endogenous immunoreactive ANF in the rat. The results show that the majority of the renal receptors of ANF are biologically silent. This new class of receptors may serve as specific peripheral storage-clearance binding sites, acting as a hormonal buffer system to modulate plasma levels of ANF.
Proceedings of The National Academy of Sciences, 1984
Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been puri... more Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been purified by gel filtration and reversed-phase liquid chromatography. Based on analysis of the intact factors and their chymotryptic fragments, we have assigned the primary structure of these octapeptides as pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, designated periplanetin CC-1, and pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, designated periplanetin CC-2. They represent new members of a family of invertebrate peptides that includes locust adipokinetic hormone and crustacean red-pigment concentrating hormone. Both peptides show adipokinetic activity in grasshoppers and hyperglycemic activity in cockroaches. One of these peptides (CC-2) has provocative sequence homology with the NH2-terminal portion of glucagon.
The authors have shown that cultured bovine aortic smooth muscle (BASM) cells contain high affini... more The authors have shown that cultured bovine aortic smooth muscle (BASM) cells contain high affinity receptor sites for the ANP, auriculin (ANP(4-28)). Furthermore, ANP(4-28) causes cyclic GMP (cGMP) levels to increase in BASM. In the present study, the authors synthesized a series of NHâ and/or COOH truncated ANP(4-28) analogs and examined their ability to compete for ¹²âµI-ANP(4-28) binding to BASM and increase cGMP levels. ANP-mediated cGMP responses were reduced when amino acids were deleted from the NHâ and/or COOH termini of ANP(4-28). Removal of the NHâ terminal R, R-S, or R-S-S residues resulted in a 10X decrease in potency for cGMP stimulation. Deletion of the COOH terminal R-Y and F-R-Y residues resulted in a marked decline in potency. ANP's lacking the F-R-Y tripeptide were nearly inactive in stimulating cGMP accumulation. In contrast to the cGMP effects, NHâ and/or COOH truncations of ANP(4-28) did not alter apparent receptor binding affinities (Ki(app)). All of these peptide analogs exhibited Ki(app)'s of 1-5 nM. Furthermore, peptides that bound effectively and failed to elicit cGMP responses did not antagonize ANP(4-28)-mediated cGMP increases. These binding and functional data suggest the presence of a single class of ANP receptors on BASM is insufficient to explain the actions of ANP's in these cells.
Inflammation Research, 1997
Objective and Design: Peptides derived from neutrophil inhibitory factor (NIF), a known antagonis... more Objective and Design: Peptides derived from neutrophil inhibitory factor (NIF), a known antagonist of Mac-1, were evaluated as inhibitors of neutrophil adherence.¶Material: In vitro assays of adherence employed: 1) human polymorphonuclear cells (PMN), 2) human umbilical vein endothelial cells (HUVEC), and 3) CHO cells expressing ICAM-1 (CHO-ICAM cells).¶Treatment: Cells, pretreated with NIF-derived peptides (0.1–100 μM) for 10 minutes, were permitted to adhere for 20 min in the continued presence of peptide.¶Methods: Cell-based assays: 1) PMN adherence to HUVEC, 2) PMN adhesion to immobilized human serum proteins, and 3) adherence of CHO-ICAM cells to immobilized Mac-1.¶Results: A NIF-derived peptide of 29 amino acids blocked PMN adherence to HUVEC, but behaved somewhat differently than the parent NIF protein. NIF specifically antagonized Mac-1 dependent adherence, but the peptide blocked neutrophil adherence that was dependent upon both Mac-1 and LFA-1 integrins. CHO-ICAM adherence to Mac-1 was blocked by NIF, but not by the peptide. Binding studies with NIF and the peptide indicate that the molecules bind to different sites.¶Conclusions: A peptide derived from NIF blocks PMN adherence but, unlike NIF, the mechanism of action is not mediated by direct antagonism Mac-1.
Biochemical Pharmacology, 2004
Transforming growth factor (TGFβ) is a 25-kDa dimeric polypeptide that plays a key role in a vari... more Transforming growth factor (TGFβ) is a 25-kDa dimeric polypeptide that plays a key role in a variety of physiological processes and disease states. Blocking TGFβ signaling represents a potentially powerful and conceptually novel approach to the treatment of disorders in which the signaling pathway is constitutively activated, such as cancer, chronic inflammation with fibrosis and select immune disorders. In this paper, we describe the biological properties of a novel series of quinazoline-derived inhibitors of the type I transforming growth factor receptor kinase (TβKIs) that bind to the ATP-binding site and keep the kinase in its inactive conformation. These compounds effectively inhibited TGFβ-induced Smad2 phosphorylation in cultured cells in vitro with an IC50 between 20 and 300 nM. Moreover, TβKIs were able to broadly block TGFβ-induced reporter gene activation. Finally, TβKIs inhibited TGFβ-mediated growth inhibition of normal murine mammary epithelial cells (NMuMG) and mink lung epithelial cells (Mv1Lu), and TGFβ-induced epithelial-mesenchymal transdifferentiation (EMT) of NMuMG cells. Thus, these chemical TβKIs have the potential to be further developed as anti-cancer and -fibrosis agents. In addition, they represent valuable new tools for dissecting the biochemical mechanisms of TGFβ signal transduction and understanding the role of TGFβ signaling pathways in different physiological and disease processes.
Transforming growth factor- (TGF-) suppresses tumor formation by blocking cell cycle progressio... more Transforming growth factor- (TGF-) suppresses tumor formation by blocking cell cycle progression and maintaining tissue homeostasis. In pancreatic carcinomas, this tumor suppressive activity is often lost by inactivation of the TGF--signaling mediator, Smad4. We found that human pancreatic carcinoma cell lines that have undergone deletion of MADH4 constitutively expressed high endogenous levels of phosphorylated receptor-associated Smad proteins (pR-Smad2 and pR-Smad3), whereas Smad4-positive lines did not. These elevated pR-Smad levels could not be attributed to a decreased dephosphorylation rate nor to increased expression of TGF- type I (TR-I) or type II (TR-II) receptors. Although minimal amounts of free bioactive TGF-1 and TGF-2 were detected in conditioned medium, treatment with a pan-specific (but not a TGF-3 specific) TGF--neutralizing antibody and with anti-␣ V  6 integrin antibody decreased steady-state pSmad2 levels and activation of a TGF--inducible reporter gene in neighboring cells, respectively. Thus, activation of TGF- at the cell surface was responsible for the increased autocrine endogenous and paracrine signaling. Blocking TR-I activity using a selective kinase inhibitor (SD-093) strongly decreased the in vitro motility and invasiveness of the pancreatic carcinoma cells without affecting their growth characteristics, morphology, or the subcellular distribution of E-cadherin and F-actin. Moreover, exogenous TGF- strongly stimulated in vitro invasiveness of BxPC-3 cells, an effect that could also be blocked by SD-093. Thus, the motile and invasive properties of Smad4deficient pancreatic cancer cells are at least partly driven by activation of endogenous TGF- signaling. Therefore, targeting the TR-I kinase represents a potentially powerful novel therapeutic approach for the treatment of this disease.
Molecular Diversity, 1997
A simple and general approach to the synthesis of chemical libraries based on a universal anhydri... more A simple and general approach to the synthesis of chemical libraries based on a universal anhydride template allows the preparation of large number of compounds. Various cyclic/acyclic amines, primary/secondary amines, differentially protected bifunctional amines were used as nucleophiles to react with anhydrides. The free carboxylic acid generated was then coupled with solid-bound amines. The facile and rapid generation of compounds through this multi-component assembly can be accomplished in a combinatorial parallel synthesis.