Background: Transport inhibitors modulate endocannabinoid signaling by inhibiting their uptake through unknown mechanisms. Results: Effects of transport inhibitors upon endocannabinoid uptake and intracellular trafficking were lost in the absence of fatty acid-binding proteins. Conclusion: Fatty acid-binding proteins are physiological targets of transport inhibitors. Significance: These findings identify drug targets for modulating endocannabinoid signaling.

Fatty acid binding proteins (FABPs), in particular FABP5 and FABP7, have recently been identified by us as intracellular transporters for the endocannabinoid anandamide (AEA). Furthermore, animal studies by others have shown that elevated levels of endocannabinoids resulted in beneficial pharmacological effects on stress, pain and inflammation and also ameliorate the effects of drug withdrawal. Based on these observations, we hypothesized that FABP5 and FABP7 would provide excellent pharmacological targets. Thus, we performed a virtual screening of over one million compounds using DOCK and employed a novel footprint similarity scoring function to identify lead compounds with binding profiles similar to oleic acid, a natural FABP substrate. Forty-eight compounds were purchased based on their footprint similarity scores (FPS) and assayed for biological activity against purified human FABP5 employing a fluorescent displacement-binding assay. Four compounds were found to exhibit approximately 50% inhibition or greater at 10 µM, as good as or better inhibitors of FABP5 than BMS309403, a commercially available inhibitor. The most potent inhibitor, γ-truxillic acid 1-naphthyl ester (ChemDiv 8009-2334), was determined to have Ki value of 1.19±0.01 µM. Accordingly a novel α-truxillic acid 1-naphthyl mono-ester (SB-FI-26) was synthesized and assayed for its inhibitory activity against FABP5, wherein SB-FI-26 exhibited strong binding (Ki 0.93±0.08 µM). Additionally, we found SB-FI-26 to act as a potent anti-nociceptive agent with mild anti-inflammatory activity in mice, which strongly supports our hypothesis that the inhibition of FABPs and subsequent elevation of anandamide is a promising new approach to drug discovery. Truxillic acids and their derivatives were also shown by others to have anti-inflammatory and anti-nociceptive effects in mice and to be the active component of Chinese a herbal medicine (Incarvillea sinensis) used to treat rheumatism and pain in humans. Our results provide a likely mechanism by which these compounds exert their effects.

In addition to binding intracellular fatty acids, fatty-acid-binding proteins (FABPs) have recently been reported to also transport the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG), arachidonic acid derivatives that function as neurotransmitters and mediate a diverse set of physiological and psychological processes. To understand how the endocannabinoids bind to FABPs, the crystal structures of FABP5 in complex with AEA, 2-AG and the inhibitor BMS-309403 were determined. These ligands are shown to interact primarily with the substrate-binding pocket via hydrophobic interactions as well as a common hydrogen bond to the Tyr131 residue. This work advances our understanding of FABP5-endocannabinoid interactions and may be useful for future efforts in the development of small-molecule inhibitors to raise endocannabinoid levels.

Cytochrome P450 proteins, widely distributed multifunctional enzymes, are mainly involved in biosynthetic and degradative pathways of endogenous compounds and the detoxification of xenobiotics in insects. Moreover, these enzymes exhibit peroxidase-like activity, therefore they may be involved in protecting organisms against the toxicity of reactive oxygen species (ROS). In the present study, we cloned a CYP4G11 gene--AccCYP4G11--from the Chinese honey-bee (Apis cerana cerana). The open reading frame of the cDNA was 1656 bp long and encoded a 551 amino acids polypeptide, which shared high sequence identity with homologous cytochrome P450 proteins. In the genomic DNA sequence, a 5'-flanking region consisting of 1168 bp was obtained, and some putative transcription factor binding sites were predicted. Quantitative polymerase chain reaction (Q-PCR) revealed that the level of AccCYP4G11 was higher in the epidermis than in other tissues, and AccCYP4G11 was expressed in all stages with the highest level in two-week-old adult worker honey-bees. Moreover, the expression patterns under oxidative stress indicated that AccCYP4G11 transcription was significantly influenced by external factors, such as temperature challenges, ultraviolet (UV) light, and insecticide treatment. AccCYP4G11 was regulated differentially in response to oxidative stress and may be involved in protecting honey-bees from oxidative injury.

Purpose: Because the quality of medical resources is extremely uneven across China, it is nearly impossible to implement a unified emergency triage program. The aim of the study is to examine triage using the "two-step four-level + " triage model in a hospital in Southern China, with an emphasis on hand, foot, and mouth disease. Design and Methods: This was a retrospective study of all patients seen in the pediatric emergency room (ER) between January 1, 2012 and December 31, 2018, at the Guangzhou Women and Children's Medical Center. The "two-step and four-level + " was manually implemented in 2012, and an electronic triage system was developed and applied since 2015. Emergency quality control indicators were analyzed.