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Obesity is associated with adipose tissue dysfunction through the differentiation and expansion of pre-adipocytes to adipocytes (hyperplasia) and/or increases in size of pre-existing adipocytes (hypertrophy). A cascade of transcriptional events coordinates the differentiation of pre-adipocytes into fully differentiated adipocytes; the process of adipogenesis. Although nicotinamide N-methyltransferase (NNMT) has been associated with obesity, how NNMT is regulated during adipogenesis, and the underlying regulatory mechanisms, remain undefined. In present study we used genetic and pharmacological approaches to elucidate the molecular signals driving NNMT activation and its role during adipogenesis. Firstly, we demonstrated that during the early phase of adipocyte differentiation NNMT is transactivated by CCAAT/Enhancer Binding Protein beta (CEBPB) in response to glucocorticoid (GC) induction. We found that Nnmt knockout, using CRISPR/Cas9 approach, impaired terminal adipogenesis by influencing the timing of cellular commitment and cell cycle exit during mitotic clonal expansion, as demonstrated by cell cycle analysis and RNA sequencing experiments. Biochemical and computational methods showed that a novel small molecule, called CC-410, stably binds to and highly specifically inhibits NNMT. CC-410 was, therefore, used to modulate protein activity during pre-adipocyte differentiation stages, demonstrating that, in line with the genetic approach, chemical inhibition of NNMT at the early stages of adipogenesis impairs terminal differentiation by deregulating the GC network. These congruent results conclusively demonstrate that NNMT is a key component of the GC-CEBP axis during the early stages of adipogenesis and could be a potential therapeutic target for both early-onset obesity and glucocorticoid-induced obesity.

Obesity is associated with adipose tissue dysfunction through the differentiation and expansion of pre-adipocytes to adipocytes (hyperplasia) and/or increases in size of pre-existing adipocytes (hypertrophy). A cascade of transcriptional events coordinates the differentiation of pre-adipocytes into fully differentiated adipocytes; the process of adipogenesis. Although nicotinamide N-methyltransferase (NNMT) has been associated with obesity, how NNMT is regulated during adipogenesis, and the underlying regulatory mechanisms, remain undefined. In present study we used genetic and pharmacological approaches to elucidate the molecular signals driving NNMT activation and its role during adipogenesis. Firstly, we demonstrated that during the early phase of adipocyte differentiation NNMT is transactivated by CCAAT/Enhancer Binding Protein beta (CEBPB) in response to glucocorticoid (GC) induction. We found that Nnmt knockout, using CRISPR/Cas9 approach, impaired terminal adipogenesis by influencing the timing of cellular commitment and cell cycle exit during mitotic clonal expansion, as demonstrated by cell cycle analysis and RNA sequencing experiments. Biochemical and computational methods showed that a novel small molecule, called CC-410, stably binds to and highly specifically inhibits NNMT. CC-410 was, therefore, used to modulate protein activity during pre-adipocyte differentiation stages, demonstrating that, in line with the genetic approach, chemical inhibition of NNMT at the early stages of adipogenesis impairs terminal differentiation by deregulating the GC network. These congruent results conclusively demonstrate that NNMT is a key component of the GC-CEBP axis during the early stages of adipogenesis and could be a potential therapeutic target for both early-onset obesity and glucocorticoid-induced obesity.

Inspired by natural molecular recognition processes, many research efforts have been routed in recent years toward the design of new host–guest molecular systems based on non-covalent interactions. Within this field, 2-aminopyridines (2APs) have been widely studied due to their tunable spectroscopic response in the presence of carboxylic acids. Herein, we present and analyze a novel family of 2AP core compounds based on 2-phosphorylamidopyridine (2PAP). Linear response time-dependent density functional theory (TD-DFT) has been used to characterize and model several spectroscopic properties of 2PAP. Our results, validated through experiments, show that TD-DFT can provide a reliable description of the electronic excited states of these aromatic systems. In addition, we have also studied the amino–imino tautomerization of 2AP and 2PAP in light of TD-DFT tools. We show that the presence of a carboxylic acid has a catalytic effect on the tautomerization reaction, which otherwise does not occur spontaneously at room temperature. These results suggest that this low-cost computational approach can be applied to more complex organic systems derived from 2-aminopyridine, paving the way for the development of potentially useful sensing materials and organic species for molecular recognition.

A chromium-mediated synthesis of enantiopure sugar-based halocyclopropanecarboxamides is reported. This reaction can be stereospecifically carried out on (E)- or (Z)-¿,ß-unsaturated amides and takes place with the formation of a new C-Hal stereogenic center, which is generated with total stereoselectivity. Synthetic applications of the obtained halocyclopropanecarboxamides are also reported. The structure of the halocyclopropanes and derivatives were established by X-ray analysis. A mechanism to explain these transformations is proposed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel reaction of iodomethyllithium with a variety of sugar-derived N-sulfinyl imines, under very mild conditions, is described. N-Sulfonyl aziridines were easily obtained in high yields and in moderate to good stereoselectivities through an addition/oxidation protocol. A mechanism is proposed that is supported by the results of X-ray diffraction studies. © Georg Thieme Verlag Stuttgart · New York.