Discovery and characterization of potent small molecule inhibitors of the high affinity proline transporter.

The mammalian proline transporter (PROT) is a high affinity Na(+)/Cl(-)-dependent transporter expressed in specific regions of the brain. It is homologous to other neurotransmitter transporters such as glycine, norepinephrine, serotonin, and dopamine transporters. PROT is enriched in glutamatergic synaptic terminals and may play an important role in the regulation of excitatory neurotransmission. No non-peptide small molecule inhibitors have been described for this transporter. To study its physiological role in the central nervous system and evaluate its potential as a therapeutic target, we established cell lines that stably express recombinant hPROT and characterized its kinetic properties for proline uptake. We then screened for inhibitors and identified a series of compounds that inhibit hPROT-mediated proline uptake. A known compound, benztropine, was found to inhibit hPROT with an IC(50) of 0.75microM. A series of novel compounds were also found, one of which, LP-403812, showed an IC(50) of approximately 0.1microM on both recombinant human and mouse PROT without significant inhibition of glycine and dopamine transporters at concentrations up to 10microM. This compound also inhibited proline transporter activity of mouse brain synaptosomes with the same potency. These inhibitors provide important tools for the understanding of PROT functions in the brain and may lead to the development of therapeutic agents for certain neurological disorders.

Changes in serum receptor activator of nuclear factor-kappaB ligand, osteoprotegerin, and interleukin-6 levels in patients with glucocorticoid-induced osteoporosis treated with human parathyroid hormone (1-34).

Changes in biochemical markers of bone turnover following intermittent injections of human (h)PTH (1-34) suggest that bone formation is initially favored over bone resorption. hPTH (1-34) is also known to influence osteoclast maturation and activity through modulation of osteoblast-derived cytokines, such as receptor activator of nuclear factor-kappaB ligand (RANKL), osteoprotegerin (OPG), IL-6, and IL-6 soluble receptor (IL-6sR). In this experiment, we investigated the changes in serum levels of soluble RANKL (sRANKL), OPG, IL-6, and IL-6sR in patients with glucocorticoid-induced osteoporosis treated with hPTH (1-34). Fifty-one postmenopausal women with glucocorticoid-induced osteoporosis were randomized to receive 12 months of 400 U hPTH (1-34) ( approximately 40 microg) daily and standard hormone replacement therapy, or hormone replacement therapy alone. Serum levels of sRANKL, OPG, IL-6, and IL-6sR were measured at baseline, 1 month, and every 3 months thereafter for a total of 24 months. hPTH (1-34) caused a rapid and significant increase in sRANKL within 1 month, and the levels remained elevated throughout the duration of therapy. IL-6 and IL-6sR increased significantly within 1 month, but returned to baseline levels more rapidly. In contrast, OPG was mildly suppressed beginning 6 months after hPTH therapy. These data support the hypothesis that hPTH (1-34) initially stimulates osteoblast maturation and function, which in turn leads to osteoclast activation and a gradual rebalancing of bone formation and resorption.

Pharmacists' perception of synchronous versus asynchronous distance learning for continuing education programs.

OBJECTIVE: To evaluate and compare pharmacists' satisfaction with the content and learning environment of a continuing education program series offered as either synchronous or asynchronous webinars. METHODS: An 8-lecture series of online presentations on the topic of new drug therapies was offered to pharmacists in synchronous and asynchronous webinar formats. Participants completed a 50-question online survey at the end of the program series to evaluate their perceptions of the distance learning experience. RESULTS: Eighty-two participants completed the survey instrument (41 participants from the live webinar series and 41 participants from the asynchronous webinar series.) Responses indicated that while both groups were satisfied with the program content, the asynchronous group showed greater satisfaction with many aspects of the learning environment. CONCLUSION: The synchronous and asynchronous webinar participants responded positively regarding the quality of the programming and the method of delivery, but asynchronous participants rated their experience more positively overall.

Pharmacists' perceptions of a live continuing education program comparing distance learning versus local learning.

BACKGROUND: Constraints in geography and time require cost efficiencies in professional development for pharmacists. Distance learning, with its growing availability and lower intrinsic costs, will likely become more prevalent. OBJECTIVE: The objective of this nonexperimental, postintervention study was to examine the perceptions of pharmacists attending a continuing education program. One group participated in the live presentation, whereas the second group joined via a simultaneous webcast. METHODS: After the presentation, both groups were surveyed with identical questions concerning their perceptions of their learning environment, course content, and utility to their work. Comparisons across group responses to the summated scales were conducted through the use of Kruskal-Wallis tests. RESULTS: Analysis of the data showed that both the distance and local groups were demographically similar and that both groups were satisfied with the presentation method, audio and visual quality, and both felt that they would be able to apply what they learned in their practice. However, the local group was significantly more satisfied with the learning experience. CONCLUSIONS: Distance learning does provide a viable and more flexible method for pharmacy professional development, but does not yet replace the traditional learning environment in all facets of learner preference.

Professional development webinars for pharmacists.

OBJECTIVES: To evaluate pharmacists' satisfaction with and reasons for enrolling in a series of continuing education webinars. DESIGN: Webinars intended to provide timely and practical information for practicing pharmacists on a specific therapeutic area were created and presented monthly throughout 2011. ASSESSMENT: Survey responses of volunteers who completed at least 1 webinar were positive regarding the quality of the programming and the method of delivery. No significant differences were found in demographics or reasons for enrolling between participants who completed a single webinar and those who completed 2 or more. CONCLUSIONS: While the webinars received positive evaluations for quality, value, and relevance, the limited average number of webinars attended by each pharmacist was a concern, and several tactics will be implemented to address scheduling conflicts and other deterrents to repeat participation.

Modulation of peripheral serotonin levels by novel tryptophan hydroxylase inhibitors for the potential treatment of functional gastrointestinal disorders.

The discovery of a novel class of peripheral tryptophan hydroxylase (TPH) inhibitors is described. This class of TPH inhibitors exhibits excellent potency in in vitro biochemical and cell-based assays, and it selectively reduces serotonin levels in the murine intestine after oral administration without affecting levels in the brain. These TPH1 inhibitors may provide novel treatments for gastrointestinal disorders associated with dysregulation of the serotonergic system, such as chemotherapy-induced emesis and irritable bowel syndrome.

Wnk1 kinase deficiency lowers blood pressure in mice: a gene-trap screen to identify potential targets for therapeutic intervention.

The availability of both the mouse and human genome sequences allows for the systematic discovery of human gene function through the use of the mouse as a model system. To accelerate the genetic determination of gene function, we have developed a sequence-tagged gene-trap library of >270,000 mouse embryonic stem cell clones representing mutations in approximately 60% of mammalian genes. Through the generation and phenotypic analysis of knockout mice from this resource, we are undertaking a functional screen to identify genes regulating physiological parameters such as blood pressure. As part of this screen, mice deficient for the Wnk1 kinase gene were generated and analyzed. Genetic studies in humans have shown that large intronic deletions in WNK1 lead to its overexpression and are responsible for pseudohypoaldosteronism type II, an autosomal dominant disorder characterized by hypertension, increased renal salt reabsorption, and impaired K+ and H+ excretion. Consistent with the human genetic studies, Wnk1 heterozygous mice displayed a significant decrease in blood pressure. Mice homozygous for the Wnk1 mutation died during embryonic development before day 13 of gestation. These results demonstrate that Wnk1 is a regulator of blood pressure critical for development and illustrate the utility of a functional screen driven by a sequence-based mutagenesis approach.