Sex and ovarian hormone cycles alter effects of stimulant drugs on mouse dopaminergic signaling

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Abstract

Stimulant medications are widely prescribed for attention deficit hyperactivity disorder (ADHD) and have significant abuse liability. Here we show that - consistent with clinical data - females exhibit enhanced behavioral sensitivity to stimulants and define sex- and hormone-dependent adaptations in the dopamine system that contribute to these effects. Single-nucleus RNA sequencing of ventral tegmental area dopamine neurons revealed that projections to the nucleus accumbens (NAc) core - compared to other projection populations - were a hub of sexually dimorphic gene expression, including transcripts regulating dopamine synthesis, and transport. These molecular differences coincided with enhanced dopamine release and clearance in females, particularly during phases of the estrous cycle when estradiol levels were high. The stimulants amphetamine (a releaser) and methylphenidate (a reuptake inhibitor) more effectively increased dopamine levels in females under certain conditions. However, amphetamine showed more robust hormone-sensitive regulation, with potency reduced by ovariectomy and restored by direct estradiol replacement in the NAc core. Together, the findings indicate that even within a drug class, drugs with different mechanisms of action can leverage different aspects of sexually dimorphic dopamine function. This distinction highlights that sex differences are not uniform but can be differentially sensitive to drug pharmacology.

Authors

Brooke A. Christensen, Jennifer Tat, Michael Z. Leonard, Soren D. Emerson, Shemuel Roberts, Eleanor B. Holmgren, Ainoa Konomi-Pilkati, Hannah B. Elam, Devan M. Gomez, Lin Zheng, Hye Jean Yoon, Sofia H. Lago, Abigail L. Carr, Lillian J. Brady, Maxime Chevée, Erin S. Calipari

Targeting Wnt/β-Catenin and circadian regulator restores PRC2/EZH2 controlled chromatin bivalency and suppresses cell state diversity

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Abstract

PRC2/EZH2 inhibitors (PRC2i/EZH2i) are promising for treatment of advanced cancers including metastatic prostate cancer. Here we show that PRC2i/EZH2i alone or in combination with AR inhibitors induce diverse cell state programs (CSP) (e.g., response to stress or interferon, MYC targets, stem cell, EMT and multiple developmental programs) which led to increased tumor cell invasion, metastasis and resistance to other drugs, in addition to modest suppression of tumor growth. In contrast to the current perception, our comprehensive, integrated genomics and epigenomics profiling of PDX and clinical tumors revealed that PRC2/EZH2 suppresses CSP genes through maintaining chromatin bivalency. Hyperactive Wnt/β-catenin signaling and inhibitors of PRC2/EZH2 and AR alter chromatin bivalency through antagonizing PRC2 and stimulating MLL2/KMT2B in a feedforward manner. Circadian rhythm regulator REV-ERBα unexpectedly reprograms β-catenin in promoting bivalency resolution and CSP gene expression. Dual targeting of Wnt/β-catenin and EZH2 diminishes diverse cell states through restoring bivalency and effectively block tumor growth. Our findings provide unexpected insights of chromatin bivalency and dysregulated circadian rhythm in control of cell state diversity and offer alternative therapeutic strategies targeting PRC2/EZH2 for advanced malignancies.

Authors

Yatian Yang, Xiong Zhang, Varadha Balaji Venkadakrishnan, Hongye Zou, Xingling Zheng, Shiyao Guo, Christopher Z. Chen, Alexander D. Borowsky, Eva Corey, Ronald M. Evans, Allen C. Gao, Marc A. Dall'Era, Amina Zoubeidi, Primo N. Lara, Hsing-Jien Kung, Xinbin Chen, Himisha Beltran, Hong-Wu Chen

Chloride homeostasis dysfunction drives hyperactivation of corticotropin-releasing factor-expressing neurons in the amygdala in stress-induced hypertension

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Abstract

Stress promotes the progression from borderline hypertension to sustained hypertension, but the mechanism remains unclear. We investigated the role of corticotropin-releasing factor (CRF)-expressing neurons in the central nucleus of amygdala (CeA) on arterial blood pressure (ABP) and sympathetic activity of borderline hypertensive rats (BHRs) subjected to chronic unpredictable mild stress (CUMS). CUMS induced sustained hypertension, and led to increased delta-FosB expression as well as enhanced spontaneous and evoked firing of CeA CRF-expressing neurons in BHRs. Furthermore, optogenetic activation of CeA CRF-expressing neurons significantly increased the sympathetic outflow and ABP in BHRs. Impaired GABAergic inhibition, a depolarizing shift of GABA reversal potential (EGABA), disrupted chloride homeostasis and increased NKCC1 expression were observed in CeA CRF-expressing neurons in BHRs subjected to CUMS. NKCC1 inhibition with bumetanide restored GABAergic inhibition and chloride homeostasis, normalized neuronal excitability, leading to reduced sympathetic vasomotor tone in CUMS BHRs. These results indicate that NKCC1-mediated disruption of chloride homeostasis in CeA CRF-expressing neurons contributes to elevated sympathetic activity and hypertension under chronic stress. These findings enhance our understanding of the neuronal and molecular mechanisms underlying stress-induced hypertension and reveal potential targets for its prevention and treatment.

Authors

Hongyu Ma, Ying Zhang, Xinqi Guo, Qiyue Zhao, Peiyun Yang, Yan Liu, Yue Guan, Yan Wei, Huijie Ma

SHMT2 deficiency disrupts transcriptional regulation through homocysteine-mediated suppression of histone lactylation in Huntington’s disease models

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Abstract

Huntington’s disease (HD) is a fatal neurodegenerative disorder characterized by progressive motor dysfunction, cognitive decline, and striatal neuron degeneration, primarily affecting medium spiny neurons (MSNs). Despite extensive research, the underlying metabolic vulnerabilities contributing to HD pathogenesis remain poorly understood. In this study, we employ RNA sequencing (RNA-seq) and metabolomics analyses to identify marked dysregulation of one-carbon metabolism in HD. We validate that SHMT2, a key mitochondrial enzyme in the mitochondrial one-carbon (mt-1C) pathway, is substantially downregulated in HD patient-derived iPSC-differentiated human striatal organoids (hSOs) and YAC128 mice. Functionally, pharmacological inhibition or genetic deletion of SHMT2 exacerbates mutant huntingtin (mHTT) aggregation, induces MSN degeneration in hSOs, and impairs motor function in WT mice. Conversely, SHMT2 overexpression attenuates MSN degeneration in HD-hSOs and improves motor performance in YAC128 mice. Mechanistically, SHMT2 deficiency leads to homocysteine (HCY) accumulation, which interacts with AARS1 and suppresses histone lactylation, thereby perturbing transcriptional regulation and associating with neurodegenerative phenotypes. Finally, we demonstrate that the HD clinical drug haloperidol modulates SHMT2 expression and restores histone lactylation, providing a pharmacological tool to probe SHMT2-dependent metabolic and epigenetic regulation in HD models. These findings highlight a metabolic-epigenetic axis as a promising therapeutic target for HD.

Authors

Mingqin Lu, Kexin Li, Shanshan Wu, Zhilong Zheng, Xinyue Li, Shengda Wang, Hanwen Yu, Chunyue Liu, Yueqing Jiang, Xueqin Song, Yan Liu, Xing Guo

Methyltransferase complex subunit METTL3 maintains genome stability of erythroid cells via MTHFD1-mediated nucleotide biosynthesis

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Abstract

N6-methyladenosine (m6A) is a prevalent modification of mammalian mRNA. Increasing evidence has documented diverse roles of m6A in normal cell physiology and diseases. However, its functional role in erythropoiesis remains poorly understood. In this study, we found that deletion of Mettl3 using EpoR-Cre mouse led to microcytic/hypochromic anemia due to defective erythropoiesis along with impaired hemoglobin biosynthesis. Mechanically, Mettl3 deficiency disrupted nucleotide biosynthesis which induced DNA damage, leading to apoptosis of CFU-E cells and cell cycle arrest of erythroblasts. Integrated m6A sequencing and RNA-seq analysis along with biochemical studies identified Mthfd1, a key enzyme involved in nucleotide biosynthesis, as a Mettl3 direct target gene. Furthermore, deletion of Mettl3 led to decreased expression of Mthfd1 accompanied by a shortage of nucleotides dTMP and IMP in erythroid cells. Additionally, inhibition of METTL3 in human erythroid cells led to similar phenotypic and molecular changes, indicating conserved role of METTL3 in human and murine erythropoiesis. Our findings have identified a METTL3-m6A-MTHFD1 axis that plays a critical role in erythropoiesis by maintaining genome stability of erythroid cells via regulation of nucleotide biosynthesis. These findings provide important insights into the regulatory mechanisms of erythropoiesis and may have implications for underlying the mechanisms of anemias.

Authors

Linlin Zhang, Huizhi Zhao, Shihui Wang, Xueting Wu, Donghao Liu, Hengchao Zhang, Qianqian Yang, Ying Cheng, Xiuyun Wu, Jiangwei Zhao, Shijie Zhang, Huan Zhang, Haojian Zhang, Qiaozhen Kang, Lixiang Chen, Xiuli An, Xiaoli Qu

N-acetyl-l-leucine lowers α-synuclein levels and improves synaptic function in Parkinson’s disease models

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Abstract

N-acetyl-l-leucine (NALL), a derivative of the branched-chain amino acid leucine, has shown therapeutic potential for neurodegenerative diseases, including in prodromal stages of Parkinson’s disease (PD). However, the mechanism of its protective effects has been largely unknown. Using human induced pluripotent stem cell–derived dopaminergic neurons from patients carrying GBA1, LRRK2, or VPS35 mutations, as well as from sporadic PD cases, we found that NALL treatment markedly reduced Ser129 phosphorylated α-synuclein (pS129-syn). Discovery-based proteomic analysis revealed that NALL treatment upregulated lysosomal, mitochondrial, and synaptic proteins without inducing cytotoxicity. The reduction of pS129-syn was dependent on serine protease HTRA1, which was robustly induced by NALL. Moreover, NALL increased the expression of wild-type parkin in mutant dopaminergic neurons, leading to increased glycosylated dopamine transporter, elevated synaptic membrane-associated synaptojanin-1, and accelerated synaptic vesicle endocytosis, suggesting improved synaptic function. Furthermore, in LRRK2R1441C knockin mice, NALL administration decreased pS129-syn, elevated parkin levels, and ameliorated dopamine-dependent motor learning deficits. These findings highlight the therapeutic potential of NALL for PD by its protective effects on α-synuclein pathology and synaptic function in vulnerable dopaminergic neurons.

Authors

Pingping Song, Chuyu Chen, Rossella Franchini, Bryan Duong, Yi-Zhi Wang, Robert Coukos, Zhong Xie, Jeffrey N. Savas, Yueqin Zhou, Mariarita Bertoldi, D. James Surmeier, Loukia Parisiadou, Dimitri Krainc

RNA-binding protein LARP6 coordinates hepatic stellate cell activation and liver fibrosis

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Abstract

Metabolic syndrome and excessive alcohol consumption (MetALD) result in liver injury and fibrosis, which is driven by increased collagen production by activated hepatic stellate cells (HSCs). Our previous studies demonstrated that LARP6, an RNA-binding protein, may facilitate collagen production. However, the expression and function of LARP6 as a regulator of fibrosis development in a disease-relevant model remain poorly understood. We demonstrated that LARP6 was upregulated in human activated HSCs in metabolic dysfunction-associated steatohepatitis (MASH) and MetALD. By using snRNA/ATAC-sequencing, we showed that JUNB upregulated LARP6 expression in activated HSCs. Moreover, LARP6 knockdown in human HSCs suppressed fibrogenic gene expression. By integrating eCLIP analysis and ribosome profiling in HSCs, we showed that LARP6 interacted with mature mRNAs comprising over 300 genes, including RNA structural elements within COL1A1, COL1A2, and COL3A1 to regulate mRNA expression and translation. IP-MS analysis demonstrated LARP6 protein–protein interactions with mRNA translation components and the actin cytoskeleton. Furthermore, dsiRNA-based HSC-specific gene knockdown or pharmacological inhibition of LARP6 attenuated fibrosis development in human MASH and MetALD liver spheroids. Our results suggest LARP6 plays a key role in fibrogenic gene regulation and that targeting LARP6 in human HSCs may represent a therapeutic approach for liver fibrosis.

Authors

Hyun Young Kim, Orel Mizrahi, Wonseok Lee, Sara B. Rosenthal, Cuijuan Han, Brian A. Yee, Steven M. Blue, Jesiel Diaz, Jyotiprakash P. Jonnalagadda, Lena A. Street, Kanani Hokutan, Haeum Jang, Charlene Miciano, Chen-Ting Ma, Andrey A. Bobkov, Eduard Sergienko, Michael R. Jackson, Marko Jovanovic, Branko Stefanovic, Tatiana Kisseleva, Gene W. Yeo, David A. Brenner

Disruption of CSF-1 receptor-mediated metal ion homeostasis in the murine brain promotes neurodegenerative disease

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Abstract

Dominant-inactivating mutations in the colony stimulating factor-1 receptor (CSF1R) cause CSF-1R related leukoencephalopathy (CRL), an adult-onset neurodegenerative disease that is modeled in the Csf1r+/– mouse. CRL is caused by microglial dysfunction. However, the primary microglial deficit, is unknown. To address this question, we employed single-nucleus RNA sequencing of brains from young Csf1r+/– mice without pathological or behavioral alterations. Reduction of CSF-1R signaling caused metal ion accumulation in brain macrophages, with concomitant activation of cell death and stress response pathways in oligodendrocytes and neuronal subpopulations. Reduction of metallothionein 1 (Mt1) and 3 (Mt3) gene expression was a common feature in glial and neuronal cells of Csf1r+/– mice. Overexpression of Mt1 restored metal ion homeostasis, normalized ROS production in microglia, and prevented the development of behavioral deficits, while Mt3 deletion had disease-enhancing effects. These findings demonstrate CSF-1R regulation of metal ion homeostasis via metallothioneins in the brain.

Authors

Violeta Chitu, Julia Alvarenga, Wenna Chen, David Reynolds, Yang Liu, Daqian Sun, Anders Sandell, Virginjia Danylaite Karrenbauer, Per Uvdal, Iran A.N. da Silva, Christophe Sandt, Oxana Klementieva, Ulf Johansson, Kavitha Subramanian Vignesh, Zbigniew K. Wszolek, Dennis W. Dickson, Jennifer Aguilan, Simone Sidoli, Deyou Zheng, E. Richard Stanley

Neuronal SEL1L-HRD1 ER-associated degradation is essential for motor function and survival in mice

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Abstract

Hypomorphic variants in the SEL1L-HRD1 ER-associated degradation (ERAD) complex have been linked to severe neurological syndromes in children, including neurodevelopmental delay, intellectual disability, motor dysfunction, and early death. Despite this association, its physiological importance and underlying mechanisms in neurons remain poorly understood. Here, we show that neuronal SEL1L-HRD1 ERAD is essential for maintaining one-carbon metabolism, motor function, and overall viability. Neuron-specific deletion of Sel1L in mice (Sel1LSynCre) resulted in growth retardation, severe motor impairments, and early mortality by 9 weeks of age—mirroring core clinical features observed in affected patients—despite preserved neuronal numbers and only modest ER stress. Multi-omics analyses, including single-nucleus RNA sequencing and metabolomics, revealed significant dysregulation of one-carbon metabolism in ERAD-deficient brains. This included activation of the serine, folate, and methionine pathways, accompanied by elevated levels of S-adenosylmethionine and related metabolites, likely resulted from induction of the integrated stress response (ISR). Together, these findings uncover a previously unappreciated role for neuronal SEL1L-HRD1 ERAD in coordinating ER protein quality control with metabolic adaptation, providing new insight into the molecular basis of ERAD-related neurodevelopmental disease.

Authors

Mauricio Torres, You Lu, Brent Pederson, Hui Wang, Anna Gretzinger, Liangguang Lin, Jiwon Hwang, Xinxin Chen, Alan C. Rupp, Abigail J. Tomlinson, Andrew J. Scott, Zhen Zhao, Daniel R. Wahl, Martin Myers, Jr, Costas A. Lyssiotis, Ling Qi

Cardiac radiotherapy-induced epigenetic memory underlies electrophysiologic and metabolic reprogramming

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Abstract

Stereotactic arrhythmia radiotherapy (STAR) is emerging as a highly effective treatment for ventricular tachycardia (VT). Growing evidence indicates that STAR favorably reprograms the electrical substrate by speeding conduction and/or prolonging repolarization via modulating ion channel expression, though the mechanisms whereby single-fraction radiation mediates durable changes in gene expression are incompletely understood. Here, we identify dynamic changes in the cardiomyocyte epigenome and transcriptome after irradiation (IR) in vivo and in vitro, including durably increased expression and chromatin accessibility of Scn5a (encoding the alpha subunit of the sodium channel, NaV1.5), demonstrating a role for epigenetic memory in conduction velocity (CV) increases observed after STAR. Transcriptomic and epigenetic sequencing further identify dynamic changes to gene expression and regulatory regions involved in cellular repolarization, calcium handling, and metabolism after IR. These changes are mirrored by dose-dependent and cell-autonomous changes in repolarization, calcium flux, and mitochondrial respiration, highlighting important cellular processes which may mediate therapeutic effects of STAR. Overall, we find that cardiomyocytes exposed to a single fraction of high-dose IR exhibit epigenetic reprogramming that mediates broad and dynamic physiologic responses.

Authors

Samuel D. Jordan, Shuhua Fu, Abigail Fulkerson, Donghua Hu, Sherwin Ng, David M. Zhang, Sneha Manikandan, Jeffrey Szymanski, Nan Hu, Yuqian Xie, Anish Bedi, James J. Tabor, Lauren Boggs-Bailey, Lori Strong, Stephanie Hicks, Lavanya Aryan, Nishanth Gabriel, Geoffrey D. Hugo, Kuo-Chan Weng, Nathaniel Huebsch, Julie K. Schwarz, Bo Zhang, Stacey L. Rentschler