Sekyu Choi, Bing Zhang, Sai Ma, Meryem Gonzalez-Celeiro, Daniel Stein, Xin Jin, Seung Tea Kim, Yuan-Lin Kang, Antoine Besnard, Amelie Rezza, Laura Grisanti, Jason D. Buenrostro, Michael Rendl, Matthias Nahrendorf, Amar Sahay, and Ya-Chieh Hsu. 2021. “Corticosterone inhibits GAS6 to govern hair follicle stem-cell quiescence.” Nature.Abstract
Chronic, sustained exposure to stressors can profoundly affect tissue homeostasis, although the mechanisms by which these changes occur are largely unknown. Here we report that the stress hormone corticosterone—which is derived from the adrenal gland and is the rodent equivalent of cortisol in humans—regulates hair follicle stem cell (HFSC) quiescence and hair growth in mice. In the absence of systemic corticosterone, HFSCs enter substantially more rounds of the regeneration cycle throughout life. Conversely, under chronic stress, increased levels of corticosterone prolong HFSC quiescence and maintain hair follicles in an extended resting phase. Mechanistically, corticosterone acts on the dermal papillae to suppress the expression of Gas6, a gene that encodes the secreted factor growth arrest specific 6. Restoring Gas6 expression overcomes the stress-induced inhibition of HFSC activation and hair growth. Our work identifies corticosterone as a systemic inhibitor of HFSC activity through its effect on the niche, and demonstrates that the removal of such inhibition drives HFSCs into frequent regeneration cycles, with no observable defects in the long-term.
Min Qiu, Zachary Glass, Jinjin Chen, Mary Haas, Xin Jin, Xuewei Zhao, Xuehui Rui, Zhongfeng Ye, Yamin Li, Feng Zhang, and Qiaobing Xu. 2021. “Lipid nanoparticle-mediated codelivery of Cas9 mRNA and single-guide RNA achieves liver-specific in vivo genome editing of Angptl3.” Proceedings of the National Academy of Sciences, 118, 10. Publisher's VersionAbstract
Genome editing technologies enable the permanent repair of disease-causing genetic mutations. However, the application of this technology has been limited by the technical challenge of achieving safe, effective, and specific in vivo delivery of the CRISPR-Cas9 genome editing components. Here, we report the development of a newly identified lipid nanoparticle (LNP) for specific delivery of CRISPR-Cas9 mRNA to the liver. While LNPs have been FDA approved for delivery of siRNA to the liver, here we examine their application for genome editing. When compared head-to-head, our delivery platform significantly outperforms the FDA-approved LNP in the efficient delivery of Cas9 mRNA for knockdown of the Angptl3 gene and subsequent regulation of hypercholesterolemia, while matching the safety and specificity of the approved platform.Loss-of-function mutations in Angiopoietin-like 3 (Angptl3) are associated with lowered blood lipid levels, making Angptl3 an attractive therapeutic target for the treatment of human lipoprotein metabolism disorders. In this study, we developed a lipid nanoparticle delivery platform carrying Cas9 messenger RNA (mRNA) and guide RNA for CRISPR-Cas9–based genome editing of Angptl3 in vivo. This system mediated specific and efficient Angptl3 gene knockdown in the liver of wild-type C57BL/6 mice, resulting in profound reductions in serum ANGPTL3 protein, low density lipoprotein cholesterol, and triglyceride levels. Our delivery platform is significantly more efficient than the FDA-approved MC-3 LNP, the current gold standard. No evidence of off-target mutagenesis was detected at any of the nine top-predicted sites, and no evidence of toxicity was detected in the liver. Importantly, the therapeutic effect of genome editing was stable for at least 100 d after a single dose administration. This study highlights the potential of LNP-mediated delivery as a specific, effective, and safe platform for Cas9-based therapeutics.All study data are included in the article and/or SI Appendix.
Maturada Patchsung, Krittapas Jantarug, Archiraya Pattama, Kanokpol Aphicho, Surased Suraritdechachai, Piyachat Meesawat, Khomkrit Sappakhaw, Nattawat Leelahakorn, Theerawat Ruenkam, Thanakrit Wongsatit, Niracha Athipanyasilp, Bhumrapee Eiamthong, Benya Lakkanasirorat, Thitima Phoodokmai, Nootaree Niljianskul, Danaya Pakotiprapha, Sittinan Chanarat, Aimorn Homchan, Ruchanok Tinikul, Philaiwarong Kamutira, Kochakorn Phiwkaow, Sahachat Soithongcharoen, Chadaporn Kantiwiriyawanitch, Vinutsada Pongsupasa, Duangthip Trisrivirat, Juthamas Jaroensuk, Thanyaporn Wongnate, Somchart Maenpuen, Pimchai Chaiyen, Sirichai Kamnerdnakta, Jirawat Swangsri, Suebwong Chuthapisith, Yongyut Sirivatanauksorn, Chutikarn Chaimayo, Ruengpung Sutthent, Wannee Kantakamalakul, Julia Joung, Alim Ladha, Xin Jin, Jonathan S. Gootenberg, Omar O. Abudayyeh, Feng Zhang, Navin Horthongkham, and Chayasith Uttamapinant. 2020. “Clinical validation of a Cas13-based assay for the detection of SARS-CoV-2 RNA.” Nature Biomedical Engineering.Abstract
Nucleic acid detection by isothermal amplification and the collateral cleavage of reporter molecules by CRISPR-associated enzymes is a promising alternative to quantitative PCR. Here, we report the clinical validation of the specific high-sensitivity enzymatic reporter unlocking (SHERLOCK) assay using the enzyme Cas13a from Leptotrichia wadei for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—the virus that causes coronavirus disease 2019 (COVID-19)—in 154 nasopharyngeal and throat swab samples collected at Siriraj Hospital, Thailand. Within a detection limit of 42 RNA copies per reaction, SHERLOCK was 100% specific and 100% sensitive with a fluorescence readout, and 100% specific and 97% sensitive with a lateral-flow readout. For the full range of viral load in the clinical samples, the fluorescence readout was 100% specific and 96% sensitive. For 380 SARS-CoV-2-negative pre-operative samples from patients undergoing surgery, SHERLOCK was in 100% agreement with quantitative PCR with reverse transcription. The assay, which we show is amenable to multiplexed detection in a single lateral-flow strip incorporating an internal control for ribonuclease contamination, should facilitate SARS-CoV-2 detection in settings with limited resources.
Xin Jin, Sean K. Simmons, Amy Guo, Ashwin S. Shetty, Michelle Ko, Lan Nguyen, Vahbiz Jokhi, Elise Robinson, Paul Oyler, Nathan Curry, Giulio Deangeli, Simona Lodato, Joshua Z. Levin, Aviv Regev, Feng Zhang, and Paola Arlotta. 2020. “In vivo Perturb-Seq reveals neuronal and glial abnormalities associated with autism risk genes.” Science, 370, 6520. Publisher's VersionAbstract
CRISPR targeting in vivo, especially in mammals, can be difficult and time consuming when attempting to determine the effects of a single gene. However, such studies may be required to identify pathological gene variants with effects in specific cells along a developmental trajectory. To study the function of genes implicated in autism spectrum disorders (ASDs), Jin et al. applied a gene-editing and single-cell–sequencing system, Perturb-Seq, to knock out 35 ASD candidate genes in multiple mice embryos (see the Perspective by Treutlein and Camp). This method identified networks of gene expression in neuronal and glial cells that suggest new functions in ASD-related genes.Science, this issue p. eaaz6063; see also p. 1038INTRODUCTIONHuman genetic studies have revealed long lists of genes and loci associated with risk for many diseases and disorders, but to systematically evaluate their phenotypic effects remains challenging. Without any a priori knowledge, these risk genes could affect any cellular processes in any cell type or tissue, which creates an enormous search space for identifying possible downstream effects. New high-throughput approaches are needed to functionally dissect these large gene sets across a spectrum of cell types in vivo.RATIONALEAnalysis of trio-based whole-exome sequencing has implicated a large number of de novo loss-of-function variants that contribute to autism spectrum disorder and developmental delay (ASD/ND) risk. Such de novo variants often have large effect sizes, thus providing a key entry point for mechanistic studies. We have developed in vivo Perturb-Seq to allow simultaneous assessment of the individual phenotypes of a panel of such risk genes in the context of the developing mouse brain.RESULTSUsing CRISPR-Cas9, we introduced frameshift mutations in 35 ASD/ND risk genes in pools, within the developing mouse neocortex in utero, followed by single-cell transcriptomic analysis of perturbed cells from the early postnatal brain. We analyzed five broad cell classes—cortical projection neurons, cortical inhibitory neurons, astrocytes, oligodendrocytes, and microglia—and selected cells that had received only single perturbations. Using weighted gene correlation network analysis, we identified 14 covarying gene modules that represent transcriptional programs expressed in different classes of cortical cells.These modules included both those affecting common biological processes across multiple cell subsets and others representing cell type–specific features restricted to certain subsets. We estimated the effect size of each perturbation on each of the 14 gene modules by fitting a joint linear regression model, estimating how module gene expression in cells from each perturbation group deviated from their expression level in internal control cells. Perturbations in nine ASD/ND genes had significant effects across five modules across four cell classes, including cortical projection neurons, cortical inhibitory neurons, astrocytes, and oligodendrocytes. Some of these results were validated by using a single-perturbation model as well as a germline-modified mutant mouse model.To establish whether the perturbation-associated gene modules identified in the mouse cerebral cortex are relevant to human biology and ASD/ND pathology, we performed co-analyses of data from ASD and control human brains and human cerebral organoids. Both gene expression and gene covariation (“modularity”) of several of the gene modules identified in the mouse Perturb-Seq analysis are conserved in human brain tissue. Comparison with single-cell data from ASD patients showed overlap in both affected cell types and transcriptomic phenotypes.CONCLUSIONIn vivo Perturb-Seq can serve as a scalable tool for systems genetic studies of large gene panels to reveal their cell-intrinsic functions at single-cell resolution in complex tissues. In this work, we demonstrated the application of in vivo Perturb-Seq to ASD/ND risk genes in the developing brain. This method can be applied across diverse diseases and tissues in the intact organism.In vivo Perturb-Seq identified neuron and glia-associated effects by perturbations of risk genes implicated in ASD/ND.De novo risk genes in this study were chosen from Satterstrom et al. (2018), and co-analysis with ASD patient data at bottom right is from Velmeshev et al. (2019); full citations for both are included in the full article online.The number of disease risk genes and loci identified through human genetic studies far outstrips the capacity to systematically study their functions. We applied a scalable genetic screening approach, in vivo Perturb-Seq, to functionally evaluate 35 autism spectrum disorder/neurodevelopmental delay (ASD/ND) de novo loss-of-function risk genes. Using CRISPR-Cas9, we introduced frameshift mutations in these risk genes in pools, within the developing mouse brain in utero, followed by single-cell RNA-sequencing of perturbed cells in the postnatal brain. We identified cell type–specific and evolutionarily conserved gene modules from both neuronal and glial cell classes. Recurrent gene modules and cell types are affected across this cohort of perturbations, representing key cellular effects across sets of ASD/ND risk genes. In vivo Perturb-Seq allows us to investigate how diverse mutations affect cell types and states in the developing organism.
William E. Allen, Han Altae-Tran, James Briggs, Xin Jin, Glen McGee, Andy Shi, Rumya Raghavan, Mireille Kamariza, Nicole Nova, Albert Pereta, Chris Danford, Amine Kamel, Patrik Gothe, Evrhet Milam, Jean Aurambault, Thorben Primke, Weijie Li, Josh Inkenbrandt, Tuan Huynh, Evan Chen, Christina Lee, Michael Croatto, Helen Bentley, Wendy Lu, Robert Murray, Mark Travassos, Brent A. Coull, John Openshaw, Casey S. Greene, Ophir Shalem, Gary King, Ryan Probasco, David R. Cheng, Ben Silbermann, Feng Zhang, and Xihong Lin. 2020. “Population-scale longitudinal mapping of COVID-19 symptoms, behaviour and testing.” Nature Human Behaviour.Abstract
Despite the widespread implementation of public health measures, coronavirus disease 2019 (COVID-19) continues to spread in the United States. To facilitate an agile response to the pandemic, we developed How We Feel, a web and mobile application that collects longitudinal self-reported survey responses on health, behaviour and demographics. Here, we report results from over 500,000 users in the United States from 2 April 2020 to 12 May 2020. We show that self-reported surveys can be used to build predictive models to identify likely COVID-19-positive individuals. We find evidence among our users for asymptomatic or presymptomatic presentation; show a variety of exposure, occupational and demographic risk factors for COVID-19 beyond symptoms; reveal factors for which users have been SARS-CoV-2 PCR tested; and highlight the temporal dynamics of symptoms and self-isolation behaviour. These results highlight the utility of collecting a diverse set of symptomatic, demographic, exposure and behavioural self-reported data to fight the COVID-19 pandemic.
William E Allen, Han Altae-Tran, James Briggs, Xin Jin, Glen McGee, Rumya Raghavan, Andy Shi, Mireille Kamariza, Nicole Nova, Albert Pereta, Chris Danford, Amine Kamel, Patrik Gothe, Evrhet Milam, Jean Aurambault, Thorben Primke, Claire Li, Josh Inkenbrandt, Tuan Huynh, Evan Chen, Christina Lee, Michael Croatto, Helen Bentley, Wendy Lu, Robert Murray, Mark Travassos, John Openshaw, Brent Coull, Casey Greene, Ophir Shalem, Gary King, Ryan Probasco, David Cheng, Ben Silbermann, Feng Zhang, and Xihong Lin. 2020. “Population-scale Longitudinal Mapping of COVID-19 Symptoms, Behavior, and Testing Identifies Contributors to Continued Disease Spread in the United States.” medRxiv. Publisher's VersionAbstract
Despite social distancing and shelter-in-place policies, COVID-19 continues to spread in the United States. A lack of timely information about factors influencing COVID-19 spread and testing has hampered agile responses to the pandemic. We developed How We Feel, an extensible web and mobile application that aggregates self-reported survey responses, to fill gaps in the collection of COVID-19-related data. How We Feel collects longitudinal and geographically localized information on users’ health, behavior, and demographics. Here we report results from over 500,000 users in the United States from April 2, 2020 to May 12, 2020. We show that self- reported surveys can be used to build predictive models of COVID-19 test results, which may aid in identification of likely COVID-19 positive individuals. We find evidence among our users for asymptomatic or presymptomatic presentation, as well as for household and community exposure, occupation, and demographics being strong risk factors for COVID-19. We further reveal factors for which users have been SARS-CoV-2 PCR tested, as well as the temporal dynamics of self- reported symptoms and self-isolation behavior in positive and negative users. These results highlight the utility of collecting a diverse set of symptomatic, demographic, and behavioral self- reported data to fight the COVID-19 pandemic.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThe How We Feel Project is a non-profit corporation. Funding and in-kind donations for the How We Feel Project came from Ben and Divya Silbermann, Feng Zhang and Yufen Shi, Lore Harp McGovern, David Cheng, Ari Azhir, and Kyung H. Yoon, and the Bill & Melinda Gates Foundation. X.L. acknowledges support from Harvard University and NCI R35-CA197449-05. F.Z. is supported by the Howard Hughes Medical Institute, the McGovern Foundation, and James and Patricia Poitras and the Poitras Center.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The How We Feel application was approved as exempt by the Ethical & Independent Review Services LLP IRB (Study ID: 20049 - 01). The analysis of HWF data was also approved as exempt by Harvard University Longwood Medical Area IRB (Protocol #: IRB20-0514) and the Broad Institute of MIT and Harvard IRB (Protocol #: EX-1653). Informed consent was obtained from all users and the data were collected in de-identified form.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesThis work used data from the How We Feel project ( The software used in analysis will be made available on Github upon final publication of the paper. Researchers with IRB approval to perform research involving human subjects can apply to obtain access to data used in the analysis.
Xin Jin, Sean K Simmons, Amy X Guo, Ashwin S Shetty, Michelle Ko, Lan Nguyen, Elise B Robinson, Paul Oyler, Nathan Curry, Giulio Deangeli, Simona Lodato, Joshua Z Levin, Aviv Regev, Feng Zhang, and Paola Arlotta. 2019. “In vivo Perturb-Seq reveals neuronal and glial abnormalities associated with Autism risk genes.” bioRxiv. bioRxiv PreprintAbstract
The thousands of disease risk genes and loci identified through human genetic studies far outstrip our current capacity to systematically study their functions. New experimental approaches are needed for functional investigations of large panels of genes in a biologically relevant context. Here, we developed a scalable genetic screen approach, in vivo Perturb-Seq, and applied this method to the functional evaluation of 35 autism spectrum disorder (ASD) de novo loss-of-function risk genes. Using CRISPR-Cas9, we introduced frameshift mutations in these risk genes in pools, within the developing brain in utero, and then performed single-cell RNA-Seq in the postnatal brain. We identified cell type-specific gene signatures from both neuronal and glial cell classes that are affected by genetic perturbations and pointed at elements of both convergent and divergent cellular effects across this cohort of ASD risk genes. In vivo Perturb-Seq pioneers a systems genetics approach to investigate at scale how diverse mutations affect cell types and states in the biologically relevant context of the developing organism.
E. J. Dennis, M. Dobosiewicz, X. Jin, L. B. Duvall, P. S. Hartman, C. I. Bargmann, and L. B. Vosshall. 2018. “A natural variant and an engineered mutation in a GPCR promote DEET resistance in C. elegans.” Nature, 562, Pp. 119. BioRxiv Preprint
He Liu, Wenxing Yang, Taihong Wu, Fengyun Duan, Edward Soucy, Xin Jin, and Yun Zhang. 2018. “Cholinergic Sensorimotor Integration Regulates Olfactory Steering.” Neuron, 97, 2, Pp. 390 - 405.e3. Publisher's Version
X. Jin, N. Pokala, and C. I. Bargmann. 2016. “Distinct circuits for the formation and retrieval of an imprinted olfactory memory.” Cell, 164, Pp. 632-43. Publisher's VersionAbstract

Memories formed early in life are particularly stable and influential, representing privileged experiences that shape enduring behaviors. We show that exposing newly hatched C. elegans to pathogenic bacteria results in persistent aversion to those bacterial odors, whereas adult exposure generates only transient aversive memory. Long-lasting imprinted aversion has a critical period in the first larval stage and is specific to the experienced pathogen. Distinct groups of neurons are required during formation (AIB, RIM) and retrieval (AIY, RIA) of the imprinted memory. RIM synthesizes the neuromodulator tyramine, which is required in the L1 stage for learning. AIY memory retrieval neurons sense tyramine via the SER-2 receptor, which is essential for imprinted, but not for adult-learned, aversion. Odor responses in several neurons, most notably RIA, are altered in imprinted animals. These findings provide insight into neuronal substrates of different forms of memory, and lay a foundation for further understanding of early learning.

S. Abrahamsson, R. Ilic, J. Wisniewski, B. Mehl, L. Yu, L. Chen, M. Davanco, L. Oudjedi, J. B. Fiche, B. Hajj, X. Jin, J. Pulupa, C. Cho, M. Mir, M. El Beheiry, X. Darzacq, M. Nollmann, M. Dahan, C. Wu, T. Lionnet, J. A. Liddle, and C. I. Bargmann. 2016. “Multifocus microscopy with precise color multi-phase diffractive optics applied in functional neuronal imaging.” Biomed Opt Express, 7, Pp. 855-69. Publisher's VersionAbstract

Multifocus microscopy (MFM) allows high-resolution instantaneous three-dimensional (3D) imaging and has been applied to study biological specimens ranging from single molecules inside cells nuclei to entire embryos. We here describe pattern designs and nanofabrication methods for diffractive optics that optimize the light-efficiency of the central optical component of MFM: the diffractive multifocus grating (MFG). We also implement a "precise color" MFM layout with MFGs tailored to individual fluorophores in separate optical arms. The reported advancements enable faster and brighter volumetric time-lapse imaging of biological samples. In live microscopy applications, photon budget is a critical parameter and light-efficiency must be optimized to obtain the fastest possible frame rate while minimizing photodamage. We provide comprehensive descriptions and code for designing diffractive optical devices, and a detailed methods description for nanofabrication of devices. Theoretical efficiencies of reported designs is approximately 90% and we have obtained efficiencies of > 80% in MFGs of our own manufacture. We demonstrate the performance of a multi-phase MFG in 3D functional neuronal imaging in living C. elegans.

J. Z. Long, M. LaCava, X. Jin, and B. F. Cravatt. 2011. “An anatomical and temporal portrait of physiological substrates for fatty acid amide hydrolase.” J Lipid Res, 52, Pp. 337-44. Publisher's VersionAbstract

Fatty acid amide hydrolase (FAAH) regulates amidated lipid transmitters, including the endocannabinoid anandamide and its N-acyl ethanolamine (NAE) congeners and transient receptor potential channel agonists N-acyl taurines (NATs). Using both the FAAH inhibitor PF-3845 and FAAH(-/-) mice, we present a global analysis of changes in NAE and NAT metabolism caused by FAAH disruption in central and peripheral tissues. Elevations in anandamide (and other NAEs) were tissue dependent, with the most dramatic changes occurring in brain, testis, and liver of PF-3845-treated or FAAH(-/-) mice. Polyunsaturated NATs accumulated to very high amounts in the liver, kidney, and plasma of these animals. The NAT profile in brain tissue was markedly different and punctuated by significant increases in long-chain NATs found exclusively in FAAH(-/-), but not in PF-3845-treated animals. Suspecting that this difference might reflect a slow pathway for NAT biosynthesis, we treated mice chronically with PF-3845 for 6 days and observed robust elevations in brain NATs. These studies, taken together, define the anatomical and temporal features of FAAH-mediated NAE and NAT metabolism, which are complemented and probably influenced by kinetically distinguishable biosynthetic pathways that produce these lipids in vivo.

X. Jin, C. Uttamapinant, and A. Y. Ting. 2011. “Synthesis of 7-aminocoumarin by Buchwald-Hartwig cross coupling for specific protein labeling in living cells.” Chembiochem, 12, Pp. 65-70. Publisher's VersionAbstract

We report the synthesis of a pH-insensitive blue fluorophore, 7-aminocoumarin, by using palladium- catalyzed Buchwald–Hartwig cross coupling. 7-Aminocoumarin can be used to tag recombinant proteins on the cell surface and inside living cells through PRIME (probe incorporation mediated by enzymes), and unlike 7-hydroxycoumarin, can be visualized in acidic organelles such as endosomes.

J. Z. Long, X. Jin, A. Adibekian, W. Li, and B. F. Cravatt. 2010. “Characterization of tunable piperidine and piperazine carbamates as inhibitors of endocannabinoid hydrolases.” J Med Chem, 53, Pp. 1830-42. Publisher's VersionAbstract

Monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH) are two enzymes from the serine hydrolase superfamily that degrade the endocannabinoids 2-arachidonoylglycerol and anandamide, respectively. We have recently discovered that MAGL and FAAH are both inhibited by carbamates bearing an N-piperidine/piperazine group. Piperidine/piperazine carbamates show excellent in vivo activity, raising brain endocannabinoid levels and producing CB1-dependent behavioral effects in mice, suggesting that they represent a promising class of inhibitors for studying the endogenous functions of MAGL and FAAH. Herein, we disclose a full account of the syntheses, structure-activity relationships, and inhibitory activities of piperidine/piperazine carbamates against members of the serine hydrolase family. These scaffolds can be tuned for MAGL-selective or dual MAGL-FAAH inhibition by the attachment of an appropriately substituted bisarylcarbinol or aryloxybenzyl moiety, respectively, on the piperidine/piperazine ring. Modifications to the piperidine/piperazine ring ablated inhibitory activity, suggesting a strict requirement for a six-membered ring to maintain potency.

J. Z. Long, D. K. Nomura, R. E. Vann, D. M. Walentiny, L. Booker, X. Jin, J. J. Burston, L. J. Sim-Selley, A. H. Lichtman, J. L. Wiley, and B. F. Cravatt. 2009. “Dual blockade of FAAH and MAGL identifies behavioral processes regulated by endocannabinoid crosstalk in vivo.” Proc Natl Acad Sci U S A, 106, Pp. 20270-5. Publisher's VersionAbstract

Delta(9)-tetrahydrocannabinol (THC), the psychoactive component of marijuana, and other direct cannabinoid receptor (CB1) agonists produce a number of neurobehavioral effects in mammals that range from the beneficial (analgesia) to the untoward (abuse potential). Why, however, this full spectrum of activities is not observed upon pharmacological inhibition or genetic deletion of either fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL), enzymes that regulate the two major endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG), respectively, has remained unclear. Here, we describe a selective and efficacious dual FAAH/MAGL inhibitor, JZL195, and show that this agent exhibits broad activity in the tetrad test for CB1 agonism, causing analgesia, hypomotilty, and catalepsy. Comparison of JZL195 to specific FAAH and MAGL inhibitors identified behavioral processes that were regulated by a single endocannabinoid pathway (e.g., hypomotility by the 2-AG/MAGL pathway) and, interestingly, those where disruption of both FAAH and MAGL produced additive effects that were reversed by a CB1 antagonist. Falling into this latter category was drug discrimination behavior, where dual FAAH/MAGL blockade, but not disruption of either FAAH or MAGL alone, produced THC-like responses that were reversed by a CB1 antagonist. These data indicate that AEA and 2-AG signaling pathways interact to regulate specific behavioral processes in vivo, including those relevant to drug abuse, thus providing a potential mechanistic basis for the distinct pharmacological profiles of direct CB1 agonists and inhibitors of individual endocannabinoid degradative enzymes.