Thomas Seng - Academia.edu (original) (raw)
Papers by Thomas Seng
Journal of Biological Chemistry, 1993
We have reported previously the isolation and preliminary characterization of a 40-kDa cyclospori... more We have reported previously the isolation and preliminary characterization of a 40-kDa cyclosporin A (CsA)-binding protein, cyclophilin-40 (CyP-40). To determine the sequence of this protein, degenerate oligonucleotide primers based on bovine brain CyP-40 tryptic peptides were used to generate a polymerase chain reaction fragment of CyP-40 cDNA. This was used to isolate the complete cDNA from a human pancreatic islet cell library. Northern analysis indicated ubiquitous distribution of CyP-40 mRNA throughout human tissues. The CyP-18 domain of CyP-40 is most similar to maize CyP (64.3% identity), whereas 150 amino acids of the non-CyP-18 domain of CyP-40 share 30.7% identity with P59, a member of the steroid receptor complex. Failure to detect glycosylation and mass spectroscopy with isolated CyP-40 indicate minimal, if any, posttranslational modification. Employing a new assay for calcineurin protein phosphatase activity to compare the effects of CyP-40.CsA and CyP-18.CsA complexes, IC50 values of 320 nM +/- 20 and 195 nM +/- 15, respectively, were obtained. A chemical cross-linking study revealed that CyP-40 competes for 125I-CyP-18 binding to calcineurin in the presence of CsA. The homology of CyP-40 to P59 suggests that CyP-40 might be involved in modulating the activity of biologically important receptors.
Journal of Pharmacology and Experimental Therapeutics, 2016
Prostaglandin (PG) E 2 plays a critical role in eliciting inflammation. Nonsteroidal anti-inflamm... more Prostaglandin (PG) E 2 plays a critical role in eliciting inflammation. Nonsteroidal anti-inflammatory drugs and selective inhibitors of cyclooxygenase, which block PGE 2 production, have been used as key agents in treating inflammation and pain associated with arthritis and other conditions. However, these agents have significant side effects such as gastrointestinal bleeding and myocardial infarction, since they also block the production of prostanoids that are critical for other normal physiologic functions. Microsomal prostaglandin E 2 synthase-1 is a membrane-bound terminal enzyme in the prostanoid pathway, which acts downstream of cyclooxygenase 2 and is responsible for PGE 2 production during inflammation. Thus, inhibition of this enzyme would be expected to block PGE 2 production without inhibiting other prostanoids and would provide analgesic efficacy without the side effects. In this report, we describe novel microsomal prostaglandin E 2 synthase-1 inhibitors that are potent in blocking PGE 2 production and are efficacious in a guinea pig monoiodoacetate model of arthralgia. These molecules may be useful in treating the signs and symptoms associated with arthritis.
Prostaglandin E 2 (PGE 2) plays a critical role in eliciting inflammation. Non-steroidal antiinfl... more Prostaglandin E 2 (PGE 2) plays a critical role in eliciting inflammation. Non-steroidal antiinflammatory drugs and selective inhibitors of cyclooxygenase, which block PGE 2 production, have been used as key agents in treating inflammation and pain associated with arthritis and other conditions. However, these agents have significant side effects such as gastro-intestinal bleeding and myocardial infarction, since they also block the production of prostanoids that are critical for other normal physiological functions. Microsomal prostaglandin E 2 synthase (mPGES-1) is a membrane bound terminal enzyme in the prostanoid pathway, which acts downstream of cyclooxygenase 2 and is responsible for PGE 2 production during inflammation. Thus inhibition of this enzyme would be expected to block PGE 2 production without inhibiting other prostanoids and would provide analgesic efficacy without the side-effects. In this report, we describe novel mPGES-1 inhibitors that are potent in blocking PGE 2 production and are efficacious in a guinea pig monoiodoacetate model of arthralgia. These molecules may be useful in treating the signs and symptoms associated with arthritis.
Journal of medicinal chemistry, Jun 23, 2016
In order to develop novel treatments for type II diabetes and dyslipidemia we pursued inhibitors ... more In order to develop novel treatments for type II diabetes and dyslipidemia we pursued inhibitors of serine palmitoyl transferase (SPT). To this end compounds 1 and 2 were developed as potent SPT inhibitors in vitro. 1 and 2 reduce plasma ceramides in rodents, have a slight trend toward enhanced insulin sensitization in DIO mice and reduce triglycerides and raise HDL in cholesterol/cholic acid fed rats. Unfortunately these molecules cause a gastric enteropathy after chronic dosing in rats.
The Journal of pharmacology and experimental therapeutics, Jan 6, 2016
Prostaglandin E2 (PGE2) plays a critical role in eliciting inflammation. Non-steroidal anti-infla... more Prostaglandin E2 (PGE2) plays a critical role in eliciting inflammation. Non-steroidal anti-inflammatory drugs and selective inhibitors of cyclooxygenase, which block PGE2 production, have been used as key agents in treating inflammation and pain associated with arthritis and other conditions. However, these agents have significant side effects such as gastro-intestinal bleeding and myocardial infarction, since they also block the production of prostanoids that are critical for other normal physiological functions. Microsomal prostaglandin E2 synthase (mPGES-1) is a membrane bound terminal enzyme in the prostanoid pathway, which acts downstream of cyclooxygenase 2 and is responsible for PGE2 production. Thus inhibition of this enzyme would be expected to block PGE2 production without inhibiting other prostanoids and would provide analgesic efficacy without the side-effects. In this report, we describe novel mPGES-1 inhibitors that are potent in blocking PGE2 production and are effic...
Journal of medicinal chemistry, Jan 18, 2015
As part of a program aimed at the discovery of antinociceptive therapy for inflammatory condition... more As part of a program aimed at the discovery of antinociceptive therapy for inflammatory conditions, a screening hit was found to inhibit microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 17.4 μM. Structural information was used to improve enzyme potency by over 1000-fold. Addition of an appropriate substituent alleviated time-dependent cytochrome P450 3A4 (CYP3A4) inhibition. Further structure-activity relationship (SAR) studies led to 8, which had desirable potency (IC50 = 12 nM in an ex vivo human whole blood (HWB) assay) and absorption, distribution, metabolism, and excretion (ADME) properties. Studies on the formulation of 8 identified 8·H3PO4 as suitable for clinical development. Omission of a lipophilic portion of the compound led to 26, a readily orally bioavailable inhibitor with potency in HWB comparable to celecoxib. Furthermore, 26 was selective for mPGES-1 inhibition versus other mechanisms in the prostanoid pathway. These factors led to the selection of 26...
International Journal of Experimental Diabetes Research, 2000
We have screened a subtracted cDNA library in order to identify differentially expressed genes in... more We have screened a subtracted cDNA library in order to identify differentially expressed genes in omental adipose tissue of human patients with Type 2 diabetes. One clone (#1738) showed a marked reduction in omental adipose tissue from patients with Type 2 diabetes. Sequencing and BLAST analysis revealed clone #1738 was the adipocyte-specific secreted protein gene apM1 (synonyms ACRP30, AdipoQ, GBP28). Consistent with the murine orthologue, apM1 mRNA was expressed in cultured human adipocytes and not in preadipocytes. Using RT-PCR we confirmed that apM1 mRNA levels were significantly reduced in omental adipose tissue of obese patients with Type 2 diabetes compared with lean and obese normoglycemic subjects. Although less pronounced, apM1 mRNA levels were reduced in subcutaneous adipose tissue of Type 2 diabetic patients. Whereas the biological function of apM1 is presently unknown, the tissue specific expression, structural similarities to TNFα and the dysregulated expression observ...
Virology, 1992
The primary 2A/2B cleavage within cardiovirus polyprotein was examined by construction of cDNA pl... more The primary 2A/2B cleavage within cardiovirus polyprotein was examined by construction of cDNA plasmids which linked fragments from the P2 region of encephalomyocarditis virus (EMCV) and Mengovirus genomes to the EMCV 5' nontranslated region. When RNA transcripts from these clones were tested in reticulocyte extracts, the synthesized proteins were cotranslationally processed at the 2A/2B site. No viral segments outside of the P2 region were required for this activity. Engineered deletions which removed the amino-terminal two-thirds of protein 2A or the carboxyl half of protein 2B had no effect on this scission, nor did insertions into a Ser-Ala-Phe sequence (SAF) within 28, which is conserved in most cardio-and aphthoviruses.
![Research paper thumbnail of C75 [4-Methylene-2-octyl-5-oxo-tetrahydro-furan-3-carboxylic Acid] Activates Carnitine Palmitoyltransferase-1 in Isolated Mitochondria and Intact Cells without Displacement of Bound Malonyl CoA](https://attachments.academia-assets.com/66564340/thumbnails/1.jpg)
](Journal of Pharmacology and Experimental Therapeutics, 2004
Carnitine palmitoyltransferase 1β (CPT-1 β) is a key regulator of the β oxidation of long chain f... more Carnitine palmitoyltransferase 1β (CPT-1 β) is a key regulator of the β oxidation of long chain fatty acids in skeletal muscle and therefore a potential therapeutic target for diseases associated with defects in lipid metabolism such as obesity and type 2 diabetes.
Bioorganic & Medicinal Chemistry Letters, 2005
4,5-Disubstituted cis-pyrrolidinones were investigated as inhibitors of type II 17b-hydroxysteroi... more 4,5-Disubstituted cis-pyrrolidinones were investigated as inhibitors of type II 17b-hydroxysteroid dehydrogenase (17b-HSD). Early structure-activity relationship patterns for this class of compounds are discussed.
Bioorganic & Medicinal Chemistry Letters, 2003
Acetyl CoA carboxylase (ACC) catalyzes the carboxylation of acetyl CoA to form malonyl CoA. In sk... more Acetyl CoA carboxylase (ACC) catalyzes the carboxylation of acetyl CoA to form malonyl CoA. In skeletal muscle and heart, malonyl CoA functions to regulate lipid oxidation by inhibition of carnitine palmitoyltransferase-1, an enzyme which controls the entry of long chain fatty acids into mitochondria. We have found that several members of the cyclohexanedione class of herbicides are competitive inhibitors of rat heart ACC. These compounds constitute valuable reagents for drug development and the study of ACCb, a validated anti-obesity target. #
International Journal of Experimental Diabetes Research, 2000
We have screened a subtracted cDNA library in order to identify differentially expressed genes in... more We have screened a subtracted cDNA library in order to identify differentially expressed genes in omental adipose tissue of human patients with Type 2 diabetes. One clone (#1738) showed a marked reduction in omental adipose tissue from patients with Type 2 diabetes. Sequencing and BLAST analysis revealed clone #1738 was the adipocyte-specific secreted protein gene apM1 (synonyms ACRP30, AdipoQ, GBP28). Consistent with the murine orthologue, apM1 mRNA was expressed in cultured human adipocytes and not in preadipocytes. Using RT-PCR we confirmed that apM1 mRNA levels were significantly reduced in omental adipose tissue of obese patients with Type 2 diabetes compared with lean and obese normoglycemic subjects. Although less pronounced, apM1 mRNA levels were reduced in subcutaneous adipose tissue of Type 2 diabetic patients. Whereas the biological function of apM1 is presently unknown, the tissue specific expression, structural similarities to TNFα and the dysregulated expression observ...
Journal of Biological Chemistry, 1993
We have reported previously the isolation and preliminary characterization of a 40-kDa cyclospori... more We have reported previously the isolation and preliminary characterization of a 40-kDa cyclosporin A (CsA)-binding protein, cyclophilin-40 (CyP-40). To determine the sequence of this protein, degenerate oligonucleotide primers based on bovine brain CyP-40 tryptic peptides were used to generate a polymerase chain reaction fragment of CyP-40 cDNA. This was used to isolate the complete cDNA from a human pancreatic islet cell library. Northern analysis indicated ubiquitous distribution of CyP-40 mRNA throughout human tissues. The CyP-18 domain of CyP-40 is most similar to maize CyP (64.3% identity), whereas 150 amino acids of the non-CyP-18 domain of CyP-40 share 30.7% identity with P59, a member of the steroid receptor complex. Failure to detect glycosylation and mass spectroscopy with isolated CyP-40 indicate minimal, if any, posttranslational modification. Employing a new assay for calcineurin protein phosphatase activity to compare the effects of CyP-40.CsA and CyP-18.CsA complexes, IC50 values of 320 nM +/- 20 and 195 nM +/- 15, respectively, were obtained. A chemical cross-linking study revealed that CyP-40 competes for 125I-CyP-18 binding to calcineurin in the presence of CsA. The homology of CyP-40 to P59 suggests that CyP-40 might be involved in modulating the activity of biologically important receptors.
Journal of Pharmacology and Experimental Therapeutics, 2016
Prostaglandin (PG) E 2 plays a critical role in eliciting inflammation. Nonsteroidal anti-inflamm... more Prostaglandin (PG) E 2 plays a critical role in eliciting inflammation. Nonsteroidal anti-inflammatory drugs and selective inhibitors of cyclooxygenase, which block PGE 2 production, have been used as key agents in treating inflammation and pain associated with arthritis and other conditions. However, these agents have significant side effects such as gastrointestinal bleeding and myocardial infarction, since they also block the production of prostanoids that are critical for other normal physiologic functions. Microsomal prostaglandin E 2 synthase-1 is a membrane-bound terminal enzyme in the prostanoid pathway, which acts downstream of cyclooxygenase 2 and is responsible for PGE 2 production during inflammation. Thus, inhibition of this enzyme would be expected to block PGE 2 production without inhibiting other prostanoids and would provide analgesic efficacy without the side effects. In this report, we describe novel microsomal prostaglandin E 2 synthase-1 inhibitors that are potent in blocking PGE 2 production and are efficacious in a guinea pig monoiodoacetate model of arthralgia. These molecules may be useful in treating the signs and symptoms associated with arthritis.
Prostaglandin E 2 (PGE 2) plays a critical role in eliciting inflammation. Non-steroidal antiinfl... more Prostaglandin E 2 (PGE 2) plays a critical role in eliciting inflammation. Non-steroidal antiinflammatory drugs and selective inhibitors of cyclooxygenase, which block PGE 2 production, have been used as key agents in treating inflammation and pain associated with arthritis and other conditions. However, these agents have significant side effects such as gastro-intestinal bleeding and myocardial infarction, since they also block the production of prostanoids that are critical for other normal physiological functions. Microsomal prostaglandin E 2 synthase (mPGES-1) is a membrane bound terminal enzyme in the prostanoid pathway, which acts downstream of cyclooxygenase 2 and is responsible for PGE 2 production during inflammation. Thus inhibition of this enzyme would be expected to block PGE 2 production without inhibiting other prostanoids and would provide analgesic efficacy without the side-effects. In this report, we describe novel mPGES-1 inhibitors that are potent in blocking PGE 2 production and are efficacious in a guinea pig monoiodoacetate model of arthralgia. These molecules may be useful in treating the signs and symptoms associated with arthritis.
Journal of medicinal chemistry, Jun 23, 2016
In order to develop novel treatments for type II diabetes and dyslipidemia we pursued inhibitors ... more In order to develop novel treatments for type II diabetes and dyslipidemia we pursued inhibitors of serine palmitoyl transferase (SPT). To this end compounds 1 and 2 were developed as potent SPT inhibitors in vitro. 1 and 2 reduce plasma ceramides in rodents, have a slight trend toward enhanced insulin sensitization in DIO mice and reduce triglycerides and raise HDL in cholesterol/cholic acid fed rats. Unfortunately these molecules cause a gastric enteropathy after chronic dosing in rats.
The Journal of pharmacology and experimental therapeutics, Jan 6, 2016
Prostaglandin E2 (PGE2) plays a critical role in eliciting inflammation. Non-steroidal anti-infla... more Prostaglandin E2 (PGE2) plays a critical role in eliciting inflammation. Non-steroidal anti-inflammatory drugs and selective inhibitors of cyclooxygenase, which block PGE2 production, have been used as key agents in treating inflammation and pain associated with arthritis and other conditions. However, these agents have significant side effects such as gastro-intestinal bleeding and myocardial infarction, since they also block the production of prostanoids that are critical for other normal physiological functions. Microsomal prostaglandin E2 synthase (mPGES-1) is a membrane bound terminal enzyme in the prostanoid pathway, which acts downstream of cyclooxygenase 2 and is responsible for PGE2 production. Thus inhibition of this enzyme would be expected to block PGE2 production without inhibiting other prostanoids and would provide analgesic efficacy without the side-effects. In this report, we describe novel mPGES-1 inhibitors that are potent in blocking PGE2 production and are effic...
Journal of medicinal chemistry, Jan 18, 2015
As part of a program aimed at the discovery of antinociceptive therapy for inflammatory condition... more As part of a program aimed at the discovery of antinociceptive therapy for inflammatory conditions, a screening hit was found to inhibit microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 17.4 μM. Structural information was used to improve enzyme potency by over 1000-fold. Addition of an appropriate substituent alleviated time-dependent cytochrome P450 3A4 (CYP3A4) inhibition. Further structure-activity relationship (SAR) studies led to 8, which had desirable potency (IC50 = 12 nM in an ex vivo human whole blood (HWB) assay) and absorption, distribution, metabolism, and excretion (ADME) properties. Studies on the formulation of 8 identified 8·H3PO4 as suitable for clinical development. Omission of a lipophilic portion of the compound led to 26, a readily orally bioavailable inhibitor with potency in HWB comparable to celecoxib. Furthermore, 26 was selective for mPGES-1 inhibition versus other mechanisms in the prostanoid pathway. These factors led to the selection of 26...
International Journal of Experimental Diabetes Research, 2000
We have screened a subtracted cDNA library in order to identify differentially expressed genes in... more We have screened a subtracted cDNA library in order to identify differentially expressed genes in omental adipose tissue of human patients with Type 2 diabetes. One clone (#1738) showed a marked reduction in omental adipose tissue from patients with Type 2 diabetes. Sequencing and BLAST analysis revealed clone #1738 was the adipocyte-specific secreted protein gene apM1 (synonyms ACRP30, AdipoQ, GBP28). Consistent with the murine orthologue, apM1 mRNA was expressed in cultured human adipocytes and not in preadipocytes. Using RT-PCR we confirmed that apM1 mRNA levels were significantly reduced in omental adipose tissue of obese patients with Type 2 diabetes compared with lean and obese normoglycemic subjects. Although less pronounced, apM1 mRNA levels were reduced in subcutaneous adipose tissue of Type 2 diabetic patients. Whereas the biological function of apM1 is presently unknown, the tissue specific expression, structural similarities to TNFα and the dysregulated expression observ...
Virology, 1992
The primary 2A/2B cleavage within cardiovirus polyprotein was examined by construction of cDNA pl... more The primary 2A/2B cleavage within cardiovirus polyprotein was examined by construction of cDNA plasmids which linked fragments from the P2 region of encephalomyocarditis virus (EMCV) and Mengovirus genomes to the EMCV 5' nontranslated region. When RNA transcripts from these clones were tested in reticulocyte extracts, the synthesized proteins were cotranslationally processed at the 2A/2B site. No viral segments outside of the P2 region were required for this activity. Engineered deletions which removed the amino-terminal two-thirds of protein 2A or the carboxyl half of protein 2B had no effect on this scission, nor did insertions into a Ser-Ala-Phe sequence (SAF) within 28, which is conserved in most cardio-and aphthoviruses.
Journal of Pharmacology and Experimental Therapeutics, 2004
Carnitine palmitoyltransferase 1β (CPT-1 β) is a key regulator of the β oxidation of long chain f... more Carnitine palmitoyltransferase 1β (CPT-1 β) is a key regulator of the β oxidation of long chain fatty acids in skeletal muscle and therefore a potential therapeutic target for diseases associated with defects in lipid metabolism such as obesity and type 2 diabetes.
Bioorganic & Medicinal Chemistry Letters, 2005
4,5-Disubstituted cis-pyrrolidinones were investigated as inhibitors of type II 17b-hydroxysteroi... more 4,5-Disubstituted cis-pyrrolidinones were investigated as inhibitors of type II 17b-hydroxysteroid dehydrogenase (17b-HSD). Early structure-activity relationship patterns for this class of compounds are discussed.
Bioorganic & Medicinal Chemistry Letters, 2003
Acetyl CoA carboxylase (ACC) catalyzes the carboxylation of acetyl CoA to form malonyl CoA. In sk... more Acetyl CoA carboxylase (ACC) catalyzes the carboxylation of acetyl CoA to form malonyl CoA. In skeletal muscle and heart, malonyl CoA functions to regulate lipid oxidation by inhibition of carnitine palmitoyltransferase-1, an enzyme which controls the entry of long chain fatty acids into mitochondria. We have found that several members of the cyclohexanedione class of herbicides are competitive inhibitors of rat heart ACC. These compounds constitute valuable reagents for drug development and the study of ACCb, a validated anti-obesity target. #
International Journal of Experimental Diabetes Research, 2000
We have screened a subtracted cDNA library in order to identify differentially expressed genes in... more We have screened a subtracted cDNA library in order to identify differentially expressed genes in omental adipose tissue of human patients with Type 2 diabetes. One clone (#1738) showed a marked reduction in omental adipose tissue from patients with Type 2 diabetes. Sequencing and BLAST analysis revealed clone #1738 was the adipocyte-specific secreted protein gene apM1 (synonyms ACRP30, AdipoQ, GBP28). Consistent with the murine orthologue, apM1 mRNA was expressed in cultured human adipocytes and not in preadipocytes. Using RT-PCR we confirmed that apM1 mRNA levels were significantly reduced in omental adipose tissue of obese patients with Type 2 diabetes compared with lean and obese normoglycemic subjects. Although less pronounced, apM1 mRNA levels were reduced in subcutaneous adipose tissue of Type 2 diabetic patients. Whereas the biological function of apM1 is presently unknown, the tissue specific expression, structural similarities to TNFα and the dysregulated expression observ...