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Nitric oxide (NO) inhibits transient receptor potential channel 3 (TRPC3) channels via a PKG-dependent mechanism. We sought to determine 1) whether NO inhibition of TRPC3 occurs in freshly isolated smooth muscle cells (SMC); and 2) whether NO inhibition of TRPC3 channels contributes to NO-mediated vasorelaxation. We tested these hypotheses in freshly isolated rat carotid artery (CA) SMC using patch clamp and in intact CA by vessel myograph. We demonstrated TRPC3 expression in whole CA (mRNA and protein) that was localized to the smooth muscle layers. TRPC1 protein was also expressed and coimmunoprecipitated with TRPC3. Whole cell patch clamp demonstrated nonselective cation channel currents that were activated by UTP (60 μM) and completely inhibited by a TRPC channel inhibitor, La3+ (100 μM). The UTP-stimulated current (IUTP) was also inhibited by intracellular application of anti-TRPC3 or anti-TRPC1 antibody, but not by anti-TRPC6 or anti-TRPC4 control antibodies. We next evaluated the NO signaling pathway on `UTP. Exogenous NO [(Z)-l-{N-methyl-N-[6(N-methylammoniohexyl) amino]} diazen-1 -ium- 1 ,2-diolate (MAHMA NONOate)] or a cell-permeable cGMP analog (8-bromo-cGMP) significantly inhibited IUTP. Preapplication of a PKG inhibitor (KT5823) reversed the inhibition of MAHMA NONOate or 8-bromo-cGMP, demonstrating the critical role of PKG in NO inhibition of TRPC1/TRPC3. Intact CA segments were contracted with UTP (100 μM) in the presence or absence of La3+ (100 μM) and then evaluated for relaxation to an NO donor, sodium nitroprusside (1 nM to 1 μM). Relaxation to sodium nitroprusside was significantly reduced in the La3+ treatment group. We conclude that freshly isolated SMC express TRPCI/TRPC3 channels and that these channels are inhibited by NO/cGMP/PKG. Furthermore, NO contributes to vasorelaxation by inhibition of La3+- sensitive channels consistent with TRPC1/TRPC3. [ABSTRACT FROM AUTHOR]

Digital toxicologic histopathology has been broadly adopted in preclinical compound development for informal consultation and peer review. There is now increased interest in implementing the technology for good laboratory practice-regulated study evaluations. However, the implementation is not straightforward because systems and work processes require qualification and validation, with consideration also given to security. As a result of the high-throughput, high-volume nature of safety evaluations, computer performance, ergonomics, efficiency, and integration with laboratory information management systems are further key considerations. The European Society of Toxicologic Pathology organized an international expert workshop with participation by toxicologic pathologists, quality assurance/regulatory experts, and information technology experts to discuss qualification and validation of digital histopathology systems in a good laboratory practice environment, and to share the resulting conclusions broadly in the toxicologic pathology community.

Objective: To describe the implementation of multi-criteria decision analysis (MCDA) into a Canadian public drug reimbursement decision-making process, identifying the aspects of the MCDA approach, and the context that promoted uptake., Methods: Narrative summary of case study describing the how, when, and why of implementing MCDA., Results: Faced with a fixed budget, a pipeline of expensive but potentially valuable drugs, and potential delays to drug decision making, the Ministry of Health (i.e., decision makers) and its independent expert advisory committee (IAB) sought alternative values-based decision processes. MCDA was considered highly compatible with current processes, but the ability as a stand-alone intervention to address issues of opportunity cost was unclear. The IAB nevertheless collaboratively voted to implement an externally developed MCDA with support from decision makers. After several months of engagement and piloting, implementation was rapid and leveraged strong pre-existing formal and informal communication networks. The IAB as a whole rates new submissions which serves as an input into the deliberative process., Conclusions: MCDA can be a highly adaptable approach that can be implemented into a functioning drug reimbursement setting when facilitated by (i) a truly limited budget; (ii) a shared vision for change by end-users and decision makers; (iii) using pre-existing deliberative processes; and (iv) viewing the approach as a decision framework rather than the decision (when appropriate). Given the current limitations of MCDA, implementing an academically imperfect tool first and evaluating later reflects a practical solution to real-time fiscal constraints and impending delays to drug approvals that may be faced by decision makers.

Inhibition of monocarboxylate transporter 1 has been proposed as a therapeutic approach to perturb lactate shuttling in tumor cells that lack monocarboxylate transporter 4. We examined the monocarboxylate transporter 1 inhibitor AZD3965, currently in phase I clinical studies, as a potential therapy for diffuse large B-cell lymphoma and Burkitt lymphoma. Whilst extensive monocarboxylate transporter 1 protein was found in 120 diffuse large B-cell lymphoma and 10 Burkitt lymphoma patients' tumors, monocarboxylate transporter 4 protein expression was undetectable in 73% of the diffuse large B-cell lymphoma samples and undetectable or negligible in each Burkitt lymphoma sample. AZD3965 treatment led to a rapid accumulation of intracellular lactate in a panel of lymphoma cell lines with low monocarboxylate transporter 4 protein expression and potently inhibited their proliferation. Metabolic changes induced by AZD3965 in lymphoma cells were consistent with a feedback inhibition of glycolysis. A profound cytostatic response was also observed in vivo : daily oral AZD3965 treatment for 24 days inhibited CA46 Burkitt lymphoma growth by 99%. Continuous exposure of CA46 cells to AZD3965 for 7 weeks in vitro resulted in a greater dependency upon oxidative phosphorylation. Combining AZD3965 with an inhibitor of mitochondrial complex I (central to oxidative phosphorylation) induced significant lymphoma cell death in vitro and reduced CA46 disease burden in vivo These data support clinical examination of AZD3965 in Burkitt lymphoma and diffuse large B-cell lymphoma patients with low tumor monocarboxylate transporter 4 expression and highlight the potential of combination strategies to optimally target the metabolic phenotype of tumors., (Copyright© 2017 Ferrata Storti Foundation.)