Pharmacological targeting of glutamatergic neurons within the brainstem for weight reduction.

Food intake and body weight are tightly regulated by neurons within specific brain regions, including the brainstem, where acute activation of dorsal raphe nucleus (DRN) glutamatergic neurons expressing the glutamate transporter Vglut3 (DRNVglut3) drive a robust suppression of food intake and enhance locomotion. Activating Vglut3 neurons in DRN suppresses food intake and increases locomotion, suggesting that modulating the activity of these neurons might alter body weight. Here, we show that DRNVglut3 neurons project to the lateral hypothalamus (LHA), a canonical feeding center that also reduces food intake. Moreover, chronic DRNVglut3 activation reduces weight in both leptin-deficient (ob/ob) and leptin-resistant diet-induced obese (DIO) male mice. Molecular profiling revealed that the orexin 1 receptor (Hcrtr1) is highly enriched in DRN Vglut3 neurons, with limited expression elsewhere in the brain. Finally, an orally bioavailable, highly selective Hcrtr1 antagonist (CVN45502) significantly reduces feeding and body weight in DIO. Hcrtr1 is also co-expressed with Vglut3 in the human DRN, suggesting that there might be a similar effect in human. These results identify a potential therapy for obesity by targeting DRNVglut3 neurons while also establishing a general strategy for developing drugs for central nervous system disorders.

Prostatic acid phosphatase expression in human tissues.

Prostate cancer is the most common cancer and the second leading cause of cancer deaths among males in most Western countries. Autologous cellular immunotherapy for the treatment of cancer seeks to induce tumor-specific immunity in the patient and is consequently dependent on a suitable target antigen and effective presentation of that antigen to the patient's immune system. Prostatic acid phosphatase (PAP) has been tested as a target antigen due to its high and apparently specific expression in the prostate. We used a variety of approaches to analyze PAP expression, including immunohistochemistry, in situ hybridization, and quantitative polymerase chain reaction. We complemented these laboratory-based techniques with an in silico analysis of reported PAP expression in human cDNA libraries. Our studies confirmed that, while PAP expression is not restricted to prostate tissues, its expression in other human tissues is approximately 1-2 orders of magnitude less than that observed in the prostate. The relative specificity of PAP expression in the prostate supports its use as a target of autologous cellular immunotherapy. The approach described here, involving the use of multiple correlates of tissue-specific expression, is warranted as a prerequisite in selecting any suitable target for immunotherapy.

Expression and functions of the duodenal peptide secretin and its receptor in human lung.

The physiological role of the duodenal peptide secretin is as a potent stimulant of electrolyte and water movement in pancreatic and biliary epithelium, via activation of G protein-coupled secretin receptors (hSCTR). However, the distribution and potential function of hSCTR in human lung has not previously been addressed. Using real-time quantitative reverse transcriptase-polymerase chain reaction profiling, in situ hybridization, and immunohistochemistry, we demonstrated that the hSCTR is abundantly expressed within the distal regions of human lung (tertiary bronchus and parenchyma), with negligible expression detected in more proximal regions (trachea, primary, and secondary bronchus). Expression was observed predominantly on the basolateral membrane of the bronchial epithelial layer, with some expression also observed in bronchial smooth muscle. In primary cultures of human tertiary bronchial epithelial cells, secretin was demonstrated to potently stimulate channel-mediated Cl- efflux in a concentration-dependent manner. Secretin was also shown to cause concentration-dependent relaxation of human tertiary bronchial smooth muscle. In summary, these data demonstrate that secretin receptors are present in human lung, and that activation of these receptors with human secretin potently stimulates concentration-dependent Cl- efflux from bronchial epithelial cells and bronchorelaxation.