{"title":"Conversations with JCI editors in chief.","authors":"Ushma S Neill","doi":"10.1172/jci187017","DOIUrl":"https://doi.org/10.1172/jci187017","url":null,"abstract":"","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As epigenetic therapies continue to gain ground as potential treatment strategies for cancer and other diseases, compounds that target histone lysine methylation and the enzyme complexes represent a major frontier for therapeutic development. Clinically viable therapies targeting the activities of histone lysine methyltransferases (HKMT) and demethylases (HKDMs) have only recently begun to emerge following FDA approval of the EZH2 inhibitor tazemetostat in 2020 and remain limited to compounds targeting the well-studied SET domain-containing HKMTs and their opposing HKDMs. These include the H3K27 methyltransferases EZH2/EZH1, the singular H3K79 methyltransferase DOT1L, and the H3K4 methyltransferase MLL1/COMPASS as well as H3K9 and H3K36 methyltransferases. They additionally include the H3K4/9-preferential demethylase LSD1 and the H3K4-, H3K27-, and H3K36-preferential KDM5, KDM6, and KDM2 demethylase subfamilies, respectively. This Review discusses the results of recent clinical and preclinical studies relevant to all of these existing and potential therapies. It provides an update on advancements in therapeutic development, as well as more basic molecular understanding, within the past 5 years approximately. It also offers a perspective on histone lysine methylation that departs from the long-predominant "histone code" metaphor, emphasizing complex-disrupting inhibitors and proximity-based approaches rather than catalytic domain inhibitors in the outlook for future therapeutic development.
{"title":"Epigenetic therapies targeting histone lysine methylation: complex mechanisms and clinical challenges.","authors":"Sarah Gold,Ali Shilatifard","doi":"10.1172/jci183391","DOIUrl":"https://doi.org/10.1172/jci183391","url":null,"abstract":"As epigenetic therapies continue to gain ground as potential treatment strategies for cancer and other diseases, compounds that target histone lysine methylation and the enzyme complexes represent a major frontier for therapeutic development. Clinically viable therapies targeting the activities of histone lysine methyltransferases (HKMT) and demethylases (HKDMs) have only recently begun to emerge following FDA approval of the EZH2 inhibitor tazemetostat in 2020 and remain limited to compounds targeting the well-studied SET domain-containing HKMTs and their opposing HKDMs. These include the H3K27 methyltransferases EZH2/EZH1, the singular H3K79 methyltransferase DOT1L, and the H3K4 methyltransferase MLL1/COMPASS as well as H3K9 and H3K36 methyltransferases. They additionally include the H3K4/9-preferential demethylase LSD1 and the H3K4-, H3K27-, and H3K36-preferential KDM5, KDM6, and KDM2 demethylase subfamilies, respectively. This Review discusses the results of recent clinical and preclinical studies relevant to all of these existing and potential therapies. It provides an update on advancements in therapeutic development, as well as more basic molecular understanding, within the past 5 years approximately. It also offers a perspective on histone lysine methylation that departs from the long-predominant \"histone code\" metaphor, emphasizing complex-disrupting inhibitors and proximity-based approaches rather than catalytic domain inhibitors in the outlook for future therapeutic development.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eric O Johnson,Heidi S Fisher,Kyle A Sullivan,Olivia Corradin,Sandra Sanchez-Roige,Nathan C Gaddis,Yasmine N Sami,Alice Townsend,Erica Teixeira Prates,Mirko Pavicic,Peter Kruse,Elissa J Chesler,Abraham A Palmer,Vanessa Troiani,Jason A Bubier,Daniel A Jacobson,Brion S Maher
Opioid misuse, addiction, and associated overdose deaths remain global public health crises. Despite the tremendous need for pharmacological treatments, current options are limited in number, use, and effectiveness. Fundamental leaps forward in our understanding of the biology driving opioid addiction are needed to guide development of more effective medication-assisted therapies. This Review focuses on the omics-identified biological features associated with opioid addiction. Recent GWAS have begun to identify robust genetic associations, including variants in OPRM1, FURIN, and the gene cluster SCAI/PPP6C/RABEPK. An increasing number of omics studies of postmortem human brain tissue examining biological features (e.g., histone modification and gene expression) across different brain regions have identified broad gene dysregulation associated with overdose death among opioid misusers. Drawn together by meta-analysis and multi-omic systems biology, and informed by model organism studies, key biological pathways enriched for opioid addiction-associated genes are emerging, which include specific receptors (e.g., GABAB receptors, GPCR, and Trk) linked to signaling pathways (e.g., Trk, ERK/MAPK, orexin) that are associated with synaptic plasticity and neuronal signaling. Studies leveraging the agnostic discovery power of omics and placing it within the context of functional neurobiology will propel us toward much-needed, field-changing breakthroughs, including identification of actionable targets for drug development to treat this devastating brain disease.
{"title":"An emerging multi-omic understanding of the genetics of opioid addiction.","authors":"Eric O Johnson,Heidi S Fisher,Kyle A Sullivan,Olivia Corradin,Sandra Sanchez-Roige,Nathan C Gaddis,Yasmine N Sami,Alice Townsend,Erica Teixeira Prates,Mirko Pavicic,Peter Kruse,Elissa J Chesler,Abraham A Palmer,Vanessa Troiani,Jason A Bubier,Daniel A Jacobson,Brion S Maher","doi":"10.1172/jci172886","DOIUrl":"https://doi.org/10.1172/jci172886","url":null,"abstract":"Opioid misuse, addiction, and associated overdose deaths remain global public health crises. Despite the tremendous need for pharmacological treatments, current options are limited in number, use, and effectiveness. Fundamental leaps forward in our understanding of the biology driving opioid addiction are needed to guide development of more effective medication-assisted therapies. This Review focuses on the omics-identified biological features associated with opioid addiction. Recent GWAS have begun to identify robust genetic associations, including variants in OPRM1, FURIN, and the gene cluster SCAI/PPP6C/RABEPK. An increasing number of omics studies of postmortem human brain tissue examining biological features (e.g., histone modification and gene expression) across different brain regions have identified broad gene dysregulation associated with overdose death among opioid misusers. Drawn together by meta-analysis and multi-omic systems biology, and informed by model organism studies, key biological pathways enriched for opioid addiction-associated genes are emerging, which include specific receptors (e.g., GABAB receptors, GPCR, and Trk) linked to signaling pathways (e.g., Trk, ERK/MAPK, orexin) that are associated with synaptic plasticity and neuronal signaling. Studies leveraging the agnostic discovery power of omics and placing it within the context of functional neurobiology will propel us toward much-needed, field-changing breakthroughs, including identification of actionable targets for drug development to treat this devastating brain disease.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"229 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rachel L Kember,Christal N Davis,Kyra L Feuer,Henry R Kranzler
Substance use disorders (SUDs) are highly prevalent and associated with excess morbidity, mortality, and economic costs. Thus, there is considerable interest in the early identification of individuals who may be more susceptible to developing SUDs and in improving personalized treatment decisions for those who have SUDs. SUDs are known to be influenced by both genetic and environmental factors. Polygenic scores (PGSs) provide a single measure of genetic liability that could be used as a biomarker in predicting disease development, progression, and treatment response. Although PGSs are rapidly being integrated into clinical practice, there is little information to guide clinicians in their responsible use and interpretation. In this Review, we discuss the potential benefits and pitfalls of the use of PGSs in the clinical care of SUDs, highlighting current research. We also provide suggestions for important considerations prior to implementing the clinical use of PGSs and recommend future directions for research.
{"title":"Considerations for the application of polygenic scores to clinical care of individuals with substance use disorders.","authors":"Rachel L Kember,Christal N Davis,Kyra L Feuer,Henry R Kranzler","doi":"10.1172/jci172882","DOIUrl":"https://doi.org/10.1172/jci172882","url":null,"abstract":"Substance use disorders (SUDs) are highly prevalent and associated with excess morbidity, mortality, and economic costs. Thus, there is considerable interest in the early identification of individuals who may be more susceptible to developing SUDs and in improving personalized treatment decisions for those who have SUDs. SUDs are known to be influenced by both genetic and environmental factors. Polygenic scores (PGSs) provide a single measure of genetic liability that could be used as a biomarker in predicting disease development, progression, and treatment response. Although PGSs are rapidly being integrated into clinical practice, there is little information to guide clinicians in their responsible use and interpretation. In this Review, we discuss the potential benefits and pitfalls of the use of PGSs in the clinical care of SUDs, highlighting current research. We also provide suggestions for important considerations prior to implementing the clinical use of PGSs and recommend future directions for research.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Parkinson's disease (PD) is characterized by age-dependent neurodegeneration and the accumulation of toxic phosphorylated α-synuclein (pS129-α-syn). The mechanisms underlying these crucial pathological changes remain unclear. Mutations in parkin RBR E3 ubiquitin protein ligase (PARK2), the gene encoding parkin that is phosphorylated by PTEN-induced putative kinase 1 (PINK1) to participate in mitophagy, cause early onset PD. However, current parkin-KO mouse and pig models do not exhibit neurodegeneration. In the current study, we utilized CRISPR/Cas9 technology to establish parkin-deficient monkey models at different ages. We found that parkin deficiency leads to substantia nigra neurodegeneration in adult monkey brains and that parkin phosphorylation decreases with aging, primarily due to increased insolubility of parkin. Phosphorylated parkin is important for neuroprotection and the reduction of pS129-α-syn. Consistently, overexpression of WT parkin, but not a mutant form that cannot be phosphorylated by PINK1, reduced the accumulation of pS129-α-syn. These findings identify parkin phosphorylation as a key factor in PD pathogenesis and suggest it as a promising target for therapeutic interventions.
{"title":"Deficiency of parkin causes neurodegeneration and accumulation of pathological α-synuclein in monkey models.","authors":"Rui Han,Qi Wang,Xin Xiong,Xiusheng Chen,Zhuchi Tu,Bang Li,Fei Zhang,Chunyu Chen,Mingtian Pan,Ting Xu,Laiqiang Chen,Zhifu Wang,Yanting Liu,Dajian He,Xiangyu Guo,Feng He,Peng Wu,Peng Yin,Yunbo Liu,Xiaoxin Yan,Shihua Li,Xiao-Jiang Li,Weili Yang","doi":"10.1172/jci179633","DOIUrl":"https://doi.org/10.1172/jci179633","url":null,"abstract":"Parkinson's disease (PD) is characterized by age-dependent neurodegeneration and the accumulation of toxic phosphorylated α-synuclein (pS129-α-syn). The mechanisms underlying these crucial pathological changes remain unclear. Mutations in parkin RBR E3 ubiquitin protein ligase (PARK2), the gene encoding parkin that is phosphorylated by PTEN-induced putative kinase 1 (PINK1) to participate in mitophagy, cause early onset PD. However, current parkin-KO mouse and pig models do not exhibit neurodegeneration. In the current study, we utilized CRISPR/Cas9 technology to establish parkin-deficient monkey models at different ages. We found that parkin deficiency leads to substantia nigra neurodegeneration in adult monkey brains and that parkin phosphorylation decreases with aging, primarily due to increased insolubility of parkin. Phosphorylated parkin is important for neuroprotection and the reduction of pS129-α-syn. Consistently, overexpression of WT parkin, but not a mutant form that cannot be phosphorylated by PINK1, reduced the accumulation of pS129-α-syn. These findings identify parkin phosphorylation as a key factor in PD pathogenesis and suggest it as a promising target for therapeutic interventions.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"95 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nonalcoholic steatohepatitis (NASH) is a chronic progressive liver disease and highly prevalent worldwide. NASH is characterized by hepatic steatosis, inflammation, fibrosis and liver damage, which eventually results in liver dysfunction due to cirrhosis or hepatocellular carcinoma. However, the cellular and molecular mechanisms underlying NASH progression remain largely unknown. Here, we found an increase of Nr4a family of orphan nuclear receptors expression in intrahepatic T cells from mice with diet-induced NASH. Loss of Nr4a1 and Nr4a2 in T cell (dKO) ameliorated liver cell death and fibrosis, thereby mitigating liver dysfunction in NASH mice. dKO resulted in reduction of infiltrated macrophages and Th1/Th17 cells, whereas massive accumulation of T regulatory (Treg) cells in the liver of NASH mice. Combined single-cell RNA transcriptomic and TCR sequencing analysis revealed that intrahepatic dKO Tregs exhibited enhanced TIGIT and IL10 expression and were clonally expanded during NASH progression. Mechanistically, we found that dKO Tregs expressed high levels of Batf which promotes Treg cell proliferation and function upon TCR stimulation. Collectively, our findings not only provide an insight into the impact of intrahepatic Treg cells on NASH pathogenesis, but also suggest a therapeutic potential of targeting of Nr4a family to treat the disease.
{"title":"The Nr4a family regulates intrahepatic Treg proliferation and liver fibrosis in MASLD models.","authors":"Daisuke Aki,Taeko Hayakawa,Tanakorn Srirat,Shigeyuki Shichino,Minako Ito,Shin-Ichiroh Saitoh,Setsuko Mise-Omata,Akihiko Yoshimura","doi":"10.1172/jci175305","DOIUrl":"https://doi.org/10.1172/jci175305","url":null,"abstract":"Nonalcoholic steatohepatitis (NASH) is a chronic progressive liver disease and highly prevalent worldwide. NASH is characterized by hepatic steatosis, inflammation, fibrosis and liver damage, which eventually results in liver dysfunction due to cirrhosis or hepatocellular carcinoma. However, the cellular and molecular mechanisms underlying NASH progression remain largely unknown. Here, we found an increase of Nr4a family of orphan nuclear receptors expression in intrahepatic T cells from mice with diet-induced NASH. Loss of Nr4a1 and Nr4a2 in T cell (dKO) ameliorated liver cell death and fibrosis, thereby mitigating liver dysfunction in NASH mice. dKO resulted in reduction of infiltrated macrophages and Th1/Th17 cells, whereas massive accumulation of T regulatory (Treg) cells in the liver of NASH mice. Combined single-cell RNA transcriptomic and TCR sequencing analysis revealed that intrahepatic dKO Tregs exhibited enhanced TIGIT and IL10 expression and were clonally expanded during NASH progression. Mechanistically, we found that dKO Tregs expressed high levels of Batf which promotes Treg cell proliferation and function upon TCR stimulation. Collectively, our findings not only provide an insight into the impact of intrahepatic Treg cells on NASH pathogenesis, but also suggest a therapeutic potential of targeting of Nr4a family to treat the disease.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Immunological self-tolerance is established in the thymus by the expression of virtually all self-antigens, including tissue-restricted antigens (TRAs) and cell-type-restricted antigens (CRAs). Despite a wealth of knowledge about the transcriptional regulation of TRA genes, posttranscriptional regulation remains poorly understood. Here, we show that protein arginine methylation plays an essential role in central immune tolerance by maximizing the self-antigen repertoire in medullary thymic epithelial cells (mTECs). Protein arginine methyltransferase-5 (Prmt5) was required for pre-mRNA splicing of certain key genes in tolerance induction, including Aire as well as various genes encoding TRAs. Mice lacking Prmt5 specifically in thymic epithelial cells exhibited an altered thymic T cell selection, leading to the breakdown of immune tolerance accompanied by both autoimmune responses and enhanced antitumor immunity. Thus, arginine methylation and transcript splicing are essential for establishing immune tolerance and may serve as a therapeutic target in autoimmune diseases as well as cancer immunotherapy.
胸腺中几乎所有自身抗原（包括组织限制性抗原（TRA）和细胞类型限制性抗原（CRA））的表达都建立了免疫自身耐受。尽管人们对 TRA 基因的转录调控有丰富的了解，但对其转录后的调控仍然知之甚少。在这里，我们发现蛋白精氨酸甲基化在中枢免疫耐受中发挥着重要作用，它能最大限度地增加髓质胸腺上皮细胞（mTECs）的自身抗原库。精氨酸甲基转移酶-5（Prmt5）是某些诱导耐受的关键基因（包括 Aire 和各种编码 TRAs 的基因）的前核糖核酸剪接所必需的。胸腺上皮细胞中特异性缺乏 Prmt5 的小鼠表现出胸腺 T 细胞选择的改变，导致免疫耐受的破坏，同时伴有自身免疫反应和抗肿瘤免疫的增强。因此，精氨酸甲基化和转录本剪接是建立免疫耐受的关键，可作为自身免疫性疾病和癌症免疫疗法的治疗靶点。
{"title":"Transcript splicing optimizes the thymic self-antigen repertoire to suppress autoimmunity.","authors":"Ryunosuke Muro,Takeshi Nitta,Sachiko Nitta,Masayuki Tsukasaki,Tatsuo Asano,Kenta Nakano,Tadashi Okamura,Tomoki Nakashima,Kazuo Okamoto,Hiroshi Takayanagi","doi":"10.1172/jci179612","DOIUrl":"https://doi.org/10.1172/jci179612","url":null,"abstract":"Immunological self-tolerance is established in the thymus by the expression of virtually all self-antigens, including tissue-restricted antigens (TRAs) and cell-type-restricted antigens (CRAs). Despite a wealth of knowledge about the transcriptional regulation of TRA genes, posttranscriptional regulation remains poorly understood. Here, we show that protein arginine methylation plays an essential role in central immune tolerance by maximizing the self-antigen repertoire in medullary thymic epithelial cells (mTECs). Protein arginine methyltransferase-5 (Prmt5) was required for pre-mRNA splicing of certain key genes in tolerance induction, including Aire as well as various genes encoding TRAs. Mice lacking Prmt5 specifically in thymic epithelial cells exhibited an altered thymic T cell selection, leading to the breakdown of immune tolerance accompanied by both autoimmune responses and enhanced antitumor immunity. Thus, arginine methylation and transcript splicing are essential for establishing immune tolerance and may serve as a therapeutic target in autoimmune diseases as well as cancer immunotherapy.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrew LaPoint,Jason M Singer,Daniel Ferguson,Trevor M Shew,M Katie Renkemeyer,Hector H Palacios,Rachael L Field,Sireeesha Yerrathota,Roshan Kumari,Mahalakshmi Shankaran,Gordon I Smith,Jun Yoshino,Mai He,Gary J Patti,Marc K Hellerstein,Samuel Klein,E Matthew Morris,Jonathan R Brestoff,Brian N Finck,Andrew Lutkewitte
Dysfunctional adipose tissue is believed to promote the development of hepatic steatosis and systemic insulin resistance, but many of the mechanisms involved are still unclear. Lipin 1 catalyzes the conversion of phosphatidic acid to diacylglycerol (DAG), the penultimate step of triglyceride synthesis, which is essential for lipid storage. Herein we found that adipose tissue LPIN1 expression is decreased in people with obesity compared to lean subjects, and low LPIN1 expression correlated with multi-tissue insulin resistance and increased rates of hepatic de novo lipogenesis. Comprehensive metabolic and multi-omic phenotyping demonstrated that adipocyte-specific Lpin1-/- mice had a metabolically-unhealthy phenotype, including liver and skeletal muscle insulin resistance, hepatic steatosis, increased hepatic de novo lipogenesis, and transcriptomic signatures of metabolically associated steatohepatitis that was exacerbated by high-fat diets. We conclude that adipocyte lipin 1-mediated lipid storage is vital for preserving adipose tissue and systemic metabolic health, and its loss predisposes mice to metabolically associated steatohepatitis.
{"title":"Adipocyte lipin 1 expression associates with human metabolic health and regulates systemic metabolism in mice.","authors":"Andrew LaPoint,Jason M Singer,Daniel Ferguson,Trevor M Shew,M Katie Renkemeyer,Hector H Palacios,Rachael L Field,Sireeesha Yerrathota,Roshan Kumari,Mahalakshmi Shankaran,Gordon I Smith,Jun Yoshino,Mai He,Gary J Patti,Marc K Hellerstein,Samuel Klein,E Matthew Morris,Jonathan R Brestoff,Brian N Finck,Andrew Lutkewitte","doi":"10.1172/jci169722","DOIUrl":"https://doi.org/10.1172/jci169722","url":null,"abstract":"Dysfunctional adipose tissue is believed to promote the development of hepatic steatosis and systemic insulin resistance, but many of the mechanisms involved are still unclear. Lipin 1 catalyzes the conversion of phosphatidic acid to diacylglycerol (DAG), the penultimate step of triglyceride synthesis, which is essential for lipid storage. Herein we found that adipose tissue LPIN1 expression is decreased in people with obesity compared to lean subjects, and low LPIN1 expression correlated with multi-tissue insulin resistance and increased rates of hepatic de novo lipogenesis. Comprehensive metabolic and multi-omic phenotyping demonstrated that adipocyte-specific Lpin1-/- mice had a metabolically-unhealthy phenotype, including liver and skeletal muscle insulin resistance, hepatic steatosis, increased hepatic de novo lipogenesis, and transcriptomic signatures of metabolically associated steatohepatitis that was exacerbated by high-fat diets. We conclude that adipocyte lipin 1-mediated lipid storage is vital for preserving adipose tissue and systemic metabolic health, and its loss predisposes mice to metabolically associated steatohepatitis.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bernard Le Foll,Victor M Tang,Sergio Rueda,Leanne V Trick,Isabelle Boileau
Cannabis has been legalized for medical and recreational purposes in multiple countries. A large number of people are using cannabis and some will develop cannabis use disorder (CUD). There is a growing recognition that CUD requires specific interventions. This Review will cover this topic from a variety of perspectives, with a particular emphasis on neurobiological findings and innovative treatment approaches that are being pursued. We will first describe the epidemiology and burden of disease of CUD, including risk factors associated with CUD (both in terms of general risk and genetic risk variants). Neurobiological alterations identified in brain imaging studies will be presented. Several psychosocial interventions that are useful for the management of CUD, including motivational enhancement therapy, behavioral and cognitive therapy, and contingency management, will be covered. Although no pharmacological interventions are yet approved for CUD, we present the most promising pharmacological interventions being tested.
{"title":"Cannabis use disorder: from neurobiology to treatment.","authors":"Bernard Le Foll,Victor M Tang,Sergio Rueda,Leanne V Trick,Isabelle Boileau","doi":"10.1172/jci172887","DOIUrl":"https://doi.org/10.1172/jci172887","url":null,"abstract":"Cannabis has been legalized for medical and recreational purposes in multiple countries. A large number of people are using cannabis and some will develop cannabis use disorder (CUD). There is a growing recognition that CUD requires specific interventions. This Review will cover this topic from a variety of perspectives, with a particular emphasis on neurobiological findings and innovative treatment approaches that are being pursued. We will first describe the epidemiology and burden of disease of CUD, including risk factors associated with CUD (both in terms of general risk and genetic risk variants). Neurobiological alterations identified in brain imaging studies will be presented. Several psychosocial interventions that are useful for the management of CUD, including motivational enhancement therapy, behavioral and cognitive therapy, and contingency management, will be covered. Although no pharmacological interventions are yet approved for CUD, we present the most promising pharmacological interventions being tested.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Activated mTORC2/AKT signaling plays a role in hepatocellular carcinoma (HCC). Research has shown that TSC/mTORC1 and FOXO1 are distinct downstream effectors of AKT signaling in liver regeneration and metabolism. However, the mechanisms by which these pathways mediate mTORC2/AKT activation in HCC are not yet fully understood. Amplification and activation of c-MYC is a key molecular event in HCC. In this study, we explored the roles of TSC/mTORC1 and FOXO1 as downstream effectors of mTORC2/AKT1 in c-MYC-induced hepatocarcinogenesis. Using various genetic approaches in mice, we found that manipulating the FOXO pathway had minimal impact on c-MYC-induced HCC. In contrast, loss of mTORC2 inhibited c-MYC-induced HCC, an effect that was completely reversed by ablating TSC2, which activated mTORC1. Additionally, we discovered that p70/RPS6 and 4EBP1/eIF4E act downstream of mTORC1, regulating distinct molecular pathways. Notably, the 4EBP1/eIF4E cascade is crucial for cell proliferation and glycolysis in c-MYC-induced HCC. We also identified centromere protein M (CENPM) as a downstream target of the TSC2/mTORC1 pathway in c-MYC-driven hepatocarcinogenesis, and its ablation entirely inhibited c-MYC-dependent HCC formation. Our findings demonstrate that the TSC/mTORC1/CENPM pathway, rather than the FOXO cascade, is the primary signaling pathway regulating c-MYC-driven hepatocarcinogenesis. Targeting CENPM holds therapeutic potential for treating c-MYC-driven HCC.
{"title":"TSC/mTORC1 mediates mTORC2/AKT1 signaling in c-MYC-induced murine hepatocarcinogenesis via centromere protein M.","authors":"Yi Zhou,Shu Zhang,Guoteng Qiu,Xue Wang,Andrew Yonemura,Hongwei Xu,Guofei Cui,Shanshan Deng,Joanne Chun,Nianyong Chen,Meng Xu,Xinhua Song,Jingwen Wang,Zijing Xu,Youping Deng,Matthias Evert,Diego F Calvisi,Shumei Lin,Haichuan Wang,Xin Chen","doi":"10.1172/jci174415","DOIUrl":"https://doi.org/10.1172/jci174415","url":null,"abstract":"Activated mTORC2/AKT signaling plays a role in hepatocellular carcinoma (HCC). Research has shown that TSC/mTORC1 and FOXO1 are distinct downstream effectors of AKT signaling in liver regeneration and metabolism. However, the mechanisms by which these pathways mediate mTORC2/AKT activation in HCC are not yet fully understood. Amplification and activation of c-MYC is a key molecular event in HCC. In this study, we explored the roles of TSC/mTORC1 and FOXO1 as downstream effectors of mTORC2/AKT1 in c-MYC-induced hepatocarcinogenesis. Using various genetic approaches in mice, we found that manipulating the FOXO pathway had minimal impact on c-MYC-induced HCC. In contrast, loss of mTORC2 inhibited c-MYC-induced HCC, an effect that was completely reversed by ablating TSC2, which activated mTORC1. Additionally, we discovered that p70/RPS6 and 4EBP1/eIF4E act downstream of mTORC1, regulating distinct molecular pathways. Notably, the 4EBP1/eIF4E cascade is crucial for cell proliferation and glycolysis in c-MYC-induced HCC. We also identified centromere protein M (CENPM) as a downstream target of the TSC2/mTORC1 pathway in c-MYC-driven hepatocarcinogenesis, and its ablation entirely inhibited c-MYC-dependent HCC formation. Our findings demonstrate that the TSC/mTORC1/CENPM pathway, rather than the FOXO cascade, is the primary signaling pathway regulating c-MYC-driven hepatocarcinogenesis. Targeting CENPM holds therapeutic potential for treating c-MYC-driven HCC.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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