piperidines and cyclopamine

The rising incidence of obesity and related disorders such as diabetes and heart disease has focused considerable attention on the discovery of new therapeutics. One promising approach has been to increase the number or activity of brown-like adipocytes in white adipose depots, as this has been shown to prevent diet-induced obesity and reduce the incidence and severity of type 2 diabetes. Thus, the conversion of fat-storing cells into metabolically active thermogenic cells has become an appealing therapeutic strategy to combat obesity. Here, we report a screening platform for the identification of small molecules capable of promoting a white-to-brown metabolic conversion in human adipocytes. We identified two inhibitors of Janus kinase (JAK) activity with no precedent in adipose tissue biology that stably confer brown-like metabolic activity to white adipocytes. Importantly, these metabolically converted adipocytes exhibit elevated UCP1 expression and increased mitochondrial activity. We further found that repression of interferon signalling and activation of hedgehog signalling in JAK-inactivated adipocytes contributes to the metabolic conversion observed in these cells. Our findings highlight a previously unknown role for the JAK-STAT pathway in the control of adipocyte function and establish a platform to identify compounds for the treatment of obesity.

Topics: Adipocytes, Brown; Adipocytes, White; Animals; Bone Morphogenetic Protein 7; Cell Differentiation; Cells, Cultured; Gene Expression Profiling; Hedgehog Proteins; Humans; Interferon-gamma; Ion Channels; Janus Kinase 1; Janus Kinase 3; Male; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Proteins; Obesity; Oxazines; Phosphorylation; Piperidines; Protein Kinase Inhibitors; Pyridines; Pyrimidines; Pyrroles; STAT1 Transcription Factor; STAT3 Transcription Factor; Tumor Necrosis Factor-alpha; Uncoupling Protein 1; Veratrum Alkaloids

Desmethylveramiline (1), an aza steroid analogue of veramiline was designed as a surrogate for cyclopamine, a reference antagonist of the Sonic Hedgehog (Shh) pathway. Desmethyveramiline (1) was prepared in seven steps from commercially available Fernholtz acid using the hydroformylation of a terminal olefine as the key step for the construction of the piperidine appendage. In two assays (i) the inhibition of the Shh-induced Gli-dependent luciferase activity in Shh-light2 cells, (ii) the inhibition of the SAG-induced differentiation of the mesenchymal C3H10T1/2 cells, desmethylveramiline (1) is an inhibitor in the μM range comparable to cyclopamine.

Topics: Animals; Cell Line; Cholesterol; Enzyme Inhibitors; Hedgehog Proteins; Mice; Models, Molecular; Molecular Structure; NIH 3T3 Cells; Piperidines; Signal Transduction; Veratrum Alkaloids

All four diastereomers of the trisubstituted piperidine-alkaloids of the veratramine and jervine type were synthesized with complete stereocontrol starting from enantiopure citronellic acids. The flexible, high-yielding, and scalable route described here will facilitate convergent syntheses and give access to analogues of cyclopamine and other biologically active and diverse steroid alkaloids.

Topics: Biological Products; Catalysis; Molecular Structure; Piperidines; Stereoisomerism; Veratrum Alkaloids

Golden hamster fetuses were extremely sensitive to the teratogenic action of jervine and cyclopamine, the steroidal alkaloid tetratogens from Veratrum californicum. Cebocephaly, harelip/cleft palate, exencephaly, and a cranial bled were the common deformities produced by dosing on the seventh day of gestation. Sprague-Dawley derived albino rats were susceptible to cyclopamine but not to jervine, and at an incidence very much lower than that of hamsters. Cebocephaly and microphthalmia were the common deformities. The terata were observed as a consequence of sixth to ninth-day dosings. Single-day dosings produced no terata. Swiss Webster mice were apparently resistant to the teratogens.

Topics: Animals; Brain; Cleft Lip; Cricetinae; Female; Furans; Gestational Age; Mice; Microphthalmos; Piperidines; Pregnancy; Rats; Teratogens; Veratrum Alkaloids