Discovery of pyrazole carboxylic acids as potent inhibitors of rat long chain L-2-hydroxy acid oxidase

Long chain L-2-hydroxy acid oxidase 2 (Hao2) is a peroxisomal enzyme expressed in the kidney and the liver. Hao2 was identified as a candidate gene for blood pressure (BP) quantitative trait locus (QTL) but the identity of its physiological substrate and its role in vivo remains largely unknown. To define a pharmacological role of this gene product, we report the development of selective inhibitors of Hao2. We identified pyrazole carboxylic acid hits 1 and 2 from screening of a compound library. Lead optimization of these hits led to the discovery of 15-XV and 15-XXXII as potent and selective inhibitors of rat Hao2. This report details the structure activity relationship of the pyrazole carboxylic acids as specific inhibitors of Hao2.     

Synthesis and structure–activity relationships of 2-(1,4′-bipiperidin-1′-yl)thiazolopyridine as H3 receptor antagonists

A series of 2-(1,4′-bipiperidine-1′-yl)thiazolopyridines was synthesized and evaluated as a new lead of non-imidazole histamine H₃ receptor antagonists. Introduction of diversity at the 6-position of the pyridine ring was designed to enhance in vitro potency and decrease hERG activity. The structure–activity relationships for these new thiazolopyridine antagonists are discussed.     

A systematic review and meta-analysis on the prevalence of infectious diseases of Duck: A world perspective

The Indian poultry industry is one of the fast-growing sectors of which duck farming plays an important role. Duck population in India is 33.51 million that is concentrated towards north-east and southern parts of the country who rears mainly for eggs and meat. Duck diseases are of great concern as they badly affect the financial status of the small, landless farmers. Databases such as Google Scholar, PubMed, J gate were used to search articles between 2000 and 2019 that showed the prevalence of viral, bacterial, and parasitic duck diseases. R open source software was used to derive forest plots by statistical analysis. Pooled prevalence estimates of duck diseases worldwide was found to be 20% (95%-CI:15–26). Also, continent-wise analysis of all duck diseases has revealed highest prevalence in North America, followed by Asia, Africa, Europe,Oceania and South America. This prevalence of data would be helpful to the policymakers to develop appropriate intervention strategies to prevent and control diseases in their respective locations.     

Expression, purification, stability optimization and characterization of human Aurora B kinase domain from E. coli

Aurora B kinase plays a critical role in regulating mitotic progression, and its dysregulation has been linked to tumorigenesis. The structure of the kinase domain of human Aurora B and the complementary information of binding thermodynamics of known Aurora inhibitors is lacking. Towards that effort, we sought to identify a human Aurora B construct that would be amenable for large-scale protein production for biophysical and structural studies. Although the designed AurB_69-333 construct expressed at high levels in Escherichia coli, the purified protein was largely unstable and prone to aggregation. We employed thermal-shift assay for high-throughput screening of 192 conditions to identify optimal pH and salt conditions that increased the stability and minimized aggregation of AurB_69-333. Direct ligand binding analyses using temperature-dependent circular dichroism (TdCD) and TR-FRET-based Lanthascreen™ binding assay showed that the purified protein was folded and functional. The affinity rank-order obtained using TdCD and Lanthascreen™ binding assay correlated with enzymatic IC50 values measured using full-length Aurora B protein for all the inhibitors tested except for AZD1152. The direct binding results support the hypothesis that the purified human AurB_69-333 fragment is a good surrogate for its full-length counterpart for biophysical and structural analyses.     

Molecular mediators of cell death in multistep carcinogenesis: a path to targeted therapy

A consistent, if not invariant, feature of cancer cells is the acquired ability to evade apoptosis. The pioneering work of Dr. Stan Korsmeyer was invaluable in characterizing the molecular foundations of cell death signaling mechanisms during normal development and during multistep carcinogenesis. This foundation now forms the basis for the rational design of therapeutic strategies to selectively activate cell death in cancer cell populations. These strategies are currently being evaluated in an increasing number of clinical trials targeting diverse tumor types.     

Thioredoxin-interacting protein deficiency disrupts the fasting-feeding metabolic transition

Through a positional cloning approach, the thioredoxin-interacting protein gene (Txnip) was recently identified as causal for a form of combined hyperlipidemia in mice (Bodnar, J. S., A. Chatterjee, L. W. Castellani, D. A. Ross, J. Ohmen, J. Cavalcoli, C. Wu, K. M. Dains, J. Catanese, M. Chu, S. S. Sheth, K. Charugundla, P. Demant, D. B. West, P. de Jong, and A. J. Lusis. 2002. Positional cloning of the combined hyperlipidemia gene Hyplip1. Nat. Genet. 30: 110-116). We now show that Txnip-deficient mice in the fed state exhibit a metabolic profile similar to fasted mice, including increased levels of plasma ketone bodies and free fatty acids, decreased glucose, and increased hepatic expression of peroxisome proliferator-activated receptor-gamma coactivator-1alpha, phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and acyl-CoA oxidase. Dramatic differences in the expression of key metabolic enzymes were also observed in other tissues, and the fat-to-muscle ratio of Txnip-deficient mice was increased by approximately 40%. We demonstrate an effect of Txnip on the redox status, as the Txnip-deficient mice in the fed state had a significant increase in the ratio of NADH to NAD(+). Surprisingly, we observed that Txnip-deficient mice and wild-type mice had similar levels of thioredoxin activity, suggesting that the effects of Txnip deficiency may be mediated in part by other interactions. These results indicate a role for Txnip in the metabolic response to feeding and the maintenance of the redox status.     

Template-based docking of a prolactin receptor proline-rich motif octapeptide to FKBP12: implications for cytokine receptor signaling.

A conserved proline-rich motif (PRM) in the cytoplasmic domain of cytokine receptors has been suggested to be a signaling switch regulated by the action of the FK506 binding protein (FKBP) family of peptidylprolyl isomerases (O'Neal KD, Yu-Lee LY, Shearer WT, 1995, Ann NY Acad Sci 766:282-284). We have docked the prolactin receptor PRM (Ile1-Phe2-Pro3-Pro4-Val5-Pro6-Gly7-Pro8) to the ligand binding site of FKBP12. The procedure involved conformational search restricted by NMR restraints (O'Neal KD et al., 1996, Biochem J 315:833-844), energy minimization of the octapeptide conformers so obtained, template-based docking of a selected conformer to FKBP12, and energy refinement of the resulting complex. The template used was the crystal structure of a cyclic FK506-peptide hybrid bound to FKBP12. Val5-Pro6 of the PRM was taken to be the biologically relevant Xaa-Pro bond. The docked conformer is stabilized by two intramolecular hydrogen bonds, N7H7-->O4 and N2H2-->O8, and two intermolecular ones, Ile56; N-H-->O = C:Pro6 and Tyr82:O-H-->O = C:Gly7. This conformer features a Type I beta-turn and has extensive hydrophobic contacts with the FKBP12 binding surface. The observed interactions support the hypothesis that FKBP12 catalyzes cis-trans isomerization in the PRM when it is part of the longer cytoplasmic domain of a cytokine receptor, and suggest a significant role for the PRM in signal transduction.     

MED12 somatic mutations encompassing exon 2 associated with benign breast fibroadenomas and not breast carcinoma in Indian women

Fibroadenoma is the most common type of benign breast tumor, accounting for 90% of benign lesions in India. Somatic mutations in the mediator complex subunit 12 (MED12) gene play a critical role in fibroepithelial tumorigenesis. The current study evaluated the hotspot region encompassing exon 2 of the MED12 gene, in benign and malignant breast tumor tissue from women who presented for breast lump evaluation. A total of 100 (80 fibroadenoma and 20 breast cancer) samples were analyzed by polymerase chain reaction-Sanger sequencing. Sequence variant analysis showed that 68.75% of nucleotide changes were found in exon 2 and the remaining in the adjacent intron 1. Codon 44 was implicated as a hotspot mutation in benign tumors, and 86.36% of the identified mutations involved this codon. An in silico functional analysis of missense mutations using consensus scoring sorting intolerant from tolerant (SIFT), SIFT seq, Polyphen2, Mutation Assessor, SIFT transFIC, Polyphen2 transFIC, Mutation Assesor transFIC, I-Mutant, DUET, PON-PS, SNAP2, and protein variation effect analyzer] revealed that apart from variants involving codon 44 (G44S; G44H), others like V41A and E55D were also predicted to be deleterious. Most of the missense mutations appeared in the loop region of the MED12 protein, which is expected to affect its functional interaction with cyclin C–CDK8/CDK19, causing loss of mediator-associated cyclin depended kinase (CDK) activity. These results suggest a key role of MED12 somatic variations in the pathogenesis of fibroadenoma. For the first time, it was demonstrated that MED12 sequence variations are present in benign breast tumors in the south Indian population.     

A systematic proteomic study of seed filling in soybean. Establishment of high-resolution two-dimensional reference maps, expression profiles, and an interactive proteome database

A high-throughput proteomic approach was employed to determine the expression profile and identity of hundreds of proteins during seed filling in soybean (Glycine max) cv Maverick. Soybean seed proteins were analyzed at 2, 3, 4, 5, and 6 weeks after flowering using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. This led to the establishment of high-resolution proteome reference maps, expression profiles of 679 spots, and corresponding matrix-assisted laser desorption ionization time-of-flight mass spectrometry spectra for each spot. Database searching with these spectra resulted in the identification of 422 proteins representing 216 nonredundant proteins. These proteins were classified into 14 major functional categories. Proteins involved in metabolism, protein destination and storage, metabolite transport, and disease/defense were the most abundant. For each functional category, a composite expression profile is presented to gain insight into legume seed physiology and the general regulation of proteins associated with each functional class. Using this approach, an overall decrease in metabolism-related proteins versus an increase in proteins associated with destination and storage was observed during seed filling. The accumulation of unknown proteins, sucrose transport and cleavage enzymes, cysteine and methionine biosynthesis enzymes, 14-3-3-like proteins, lipoxygenases, storage proteins, and allergenic proteins during seed filling is also discussed. A user-intuitive database (http://oilseedproteomics.missouri.edu) was developed to access these data for soybean and other oilseeds currently being investigated.