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Cell Death Discovery Apr 2024Pancreatic cancer is one of the most fatal cancers in the world. A growing number of studies have begun to demonstrate that mitochondria play a key role in...
Pancreatic cancer is one of the most fatal cancers in the world. A growing number of studies have begun to demonstrate that mitochondria play a key role in tumorigenesis. Our previous study reveals that NDUFS2 (NADH: ubiquinone oxidoreductase core subunit S2), a core subunit of the mitochondrial respiratory chain complex I, is upregulated in Pancreatic adenocarcinoma (PAAD). However, its role in the development of PAAD remains unknown. Here, we showed that NDUFS2 played a critical role in the survival, proliferation and migration of pancreatic cancer cells by inhibiting mitochondrial cell death. Additionally, protein mass spectrometry indicated that the NDUFS2 was interacted with a deubiquitinase, OTUB1. Overexpression of OTUB1 increased NDUFS2 expression at the protein level, while knockdown of OTUB1 restored the effects in vitro. Accordingly, overexpression and knockdown of OTUB1 phenocopied those of NDUFS2 in pancreatic cancer cells, respectively. Mechanically, NDUFS2 was deubiquitinated by OTUB1 via K48-linked polyubiquitin chains, resulted in an elevated protein stability of NDUFS2. Moreover, the growth of OTUB1-overexpressed pancreatic cancer xenograft tumor was promoted in vivo, while the OTUB1-silenced pancreatic cancer xenograft tumor was inhibited in vivo. In conclusion, we revealed that OTUB1 increased the stability of NDUFS2 in PAAD by deubiquitylation and this axis plays a pivotal role in pancreatic cancer tumorigenesis and development.
PubMed: 38653740
DOI: 10.1038/s41420-024-01948-x -
Current Biology : CB May 2024Compacted soil layers adversely affect rooting depth and access to deeper nutrient and water resources, thereby impacting climate resilience of crop production and...
Compacted soil layers adversely affect rooting depth and access to deeper nutrient and water resources, thereby impacting climate resilience of crop production and global food security. Root hair plays well-known roles in facilitating water and nutrient acquisition. Here, we report that root hair also contributes to root penetration into compacted layers. We demonstrate that longer root hair, induced by elevated auxin response during a root compaction response, improves the ability of rice roots to penetrate harder layers. This compaction-induced auxin response in the root hair zone is dependent on the root apex-expressed auxin synthesis gene OsYUCCA8 (OsYUC8), which is induced by compaction stress. This auxin source for root hair elongation relies on the auxin influx carrier AUXIN RESISTANT 1 (OsAUX1), mobilizing this signal from the root apex to the root hair zone. Mutants disrupting OsYUC8 and OsAUX1 genes exhibit shorter root hairs and weaker penetration ability into harder layers compared with wild type (WT). Root-hair-specific mutants phenocopy these auxin-signaling mutants, as they also exhibit an attenuated root penetration ability. We conclude that compaction stress upregulates OsYUC8-mediated auxin biosynthesis in the root apex, which is subsequently mobilized to the root hair zone by OsAUX1, where auxin promotes root hair elongation, improving anchorage of root tips to their surrounding soil environment and aiding their penetration ability into harder layers.
Topics: Oryza; Plant Roots; Indoleacetic Acids; Plant Proteins; Gene Expression Regulation, Plant; Soil
PubMed: 38653244
DOI: 10.1016/j.cub.2024.03.064 -
Developmental Cell Jun 2024Patterning and growth are fundamental features of embryonic development that must be tightly coordinated. To understand how metabolism impacts early mesoderm...
Patterning and growth are fundamental features of embryonic development that must be tightly coordinated. To understand how metabolism impacts early mesoderm development, we used mouse embryonic stem-cell-derived gastruloids, that co-expressed glucose transporters with the mesodermal marker T/Bra. We found that the glucose mimic, 2-deoxy-D-glucose (2-DG), blocked T/Bra expression and abolished axial elongation in gastruloids. However, glucose removal did not phenocopy 2-DG treatment despite a decline in glycolytic intermediates. As 2-DG can also act as a competitive inhibitor of mannose in protein glycosylation, we added mannose together with 2-DG and found that it could rescue the mesoderm specification both in vivo and in vitro. We further showed that blocking production and intracellular recycling of mannose abrogated mesoderm specification. Proteomics analysis demonstrated that mannose reversed glycosylation of the Wnt pathway regulator, secreted frizzled receptor Frzb. Our study showed how mannose controls mesoderm specification in mouse gastruloids.
Topics: Animals; Mesoderm; Mice; Mannose; Glycosylation; Deoxyglucose; Wnt Signaling Pathway; Gastrula; Body Patterning; Gene Expression Regulation, Developmental; Cell Differentiation; Mouse Embryonic Stem Cells; Frizzled Receptors
PubMed: 38636516
DOI: 10.1016/j.devcel.2024.03.031 -
Journal of Neuropathology and... Jun 2024ZCCHC17 is a master regulator of synaptic gene expression and has recently been shown to play a role in splicing of neuronal mRNA. We previously showed that ZCCHC17...
ZCCHC17 is a master regulator of synaptic gene expression and has recently been shown to play a role in splicing of neuronal mRNA. We previously showed that ZCCHC17 protein declines in Alzheimer's disease (AD) brain tissue before there is significant gliosis and neuronal loss, that ZCCHC17 loss partially replicates observed splicing abnormalities in AD brain tissue, and that maintenance of ZCCHC17 levels is predicted to support cognitive resilience in AD. Here, we assessed the functional consequences of reduced ZCCHC17 expression in primary cortical neuronal cultures using siRNA knockdown. Consistent with its previously identified role in synaptic gene expression, loss of ZCCHC17 led to loss of synaptic protein expression. Patch recording of neurons shows that ZCCHC17 loss significantly disrupted the excitation/inhibition balance of neurotransmission, and favored excitatory-dominant synaptic activity as measured by an increase in spontaneous excitatory post synaptic currents and action potential firing rate, and a decrease in spontaneous inhibitory post synaptic currents. These findings are consistent with the hyperexcitable phenotype seen in AD animal models and in patients. We are the first to assess the functional consequences of ZCCHC17 knockdown in neurons and conclude that ZCCHC17 loss partially phenocopies AD-related loss of synaptic proteins and hyperexcitability.
Topics: Alzheimer Disease; Animals; Neurons; Synapses; Gene Knockdown Techniques; Cells, Cultured; Humans; Cerebral Cortex; Mice; Phenotype; Rats
PubMed: 38630575
DOI: 10.1093/jnen/nlae033 -
Cell Death and Differentiation Jun 2024The alternative splicing of PML precursor mRNA gives rise to various PML isoforms, yet their expression profile in breast cancer cells remains uncharted. We discovered...
The alternative splicing of PML precursor mRNA gives rise to various PML isoforms, yet their expression profile in breast cancer cells remains uncharted. We discovered that PML1 is the most abundant isoform in all breast cancer subtypes, and its expression is associated with unfavorable prognosis in estrogen receptor-positive (ER+) breast cancers. PML depletion reduces cell proliferation, invasion, and stemness, while heterologous PML1 expression augments these processes and fuels tumor growth and resistance to fulvestrant, an FDA-approved drug for ER+ breast cancer, in a mouse model. Moreover, PML1, rather than the well-known tumor suppressor isoform PML4, rescues the proliferation of PML knockdown cells. ChIP-seq analysis reveals significant overlap between PML-, ER-, and Myc-bound promoters, suggesting their coordinated regulation of target gene expression, including genes involved in breast cancer stem cells (BCSCs), such as JAG1, KLF4, YAP1, SNAI1, and MYC. Loss of PML reduces BCSC-related gene expression, and exogenous PML1 expression elevates their expression. Consistently, PML1 restores the association of PML with these promoters in PML-depleted cells. We identified a novel association between PML1 and WDR5, a key component of H3K4 methyltransferase (HMTs) complexes that catalyze H3K4me1 and H3K4me3. ChIP-seq analyses showed that the loss of PML1 reduces H3K4me3 in numerous loci, including BCSC-associated gene promoters. Additionally, PML1, not PML4, re-establishes the H3K4me3 mark on these promoters in PML-depleted cells. Significantly, PML1 is essential for recruiting WDR5, MLL1, and MLL2 to these gene promoters. Inactivating WDR5 by knockdown or inhibitors phenocopies the effects of PML1 loss, reducing BCSC-related gene expression and tumorsphere formation and enhancing fulvestrant's anticancer activity. Our findings challenge the conventional understanding of PML as a tumor suppressor, redefine its role as a promoter of tumor growth in breast cancer, and offer new insights into the unique roles of PML isoforms in breast cancer.
Topics: Humans; Breast Neoplasms; Female; Kruppel-Like Factor 4; Promyelocytic Leukemia Protein; Animals; Receptors, Estrogen; Mice; Neoplastic Stem Cells; Histones; Intracellular Signaling Peptides and Proteins; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic
PubMed: 38627584
DOI: 10.1038/s41418-024-01294-6 -
Nature Metabolism May 2024Nuclear receptor corepressors (NCoRs) function in multiprotein complexes containing histone deacetylase 3 (HDAC3) to alter transcriptional output primarily through...
Nuclear receptor corepressors (NCoRs) function in multiprotein complexes containing histone deacetylase 3 (HDAC3) to alter transcriptional output primarily through repressive chromatin remodelling at target loci. In the liver, loss of HDAC3 causes a marked hepatosteatosis largely because of de-repression of genes involved in lipid metabolism; however, the individual roles and contribution of other complex members to hepatic and systemic metabolic regulation are unclear. Here we show that adult loss of both NCoR1 and NCoR2 (double knockout (KO)) in hepatocytes phenocopied the hepatomegalic fatty liver phenotype of HDAC3 KO. In addition, double KO livers exhibited a dramatic reduction in glycogen storage and gluconeogenic gene expression that was not observed with hepatic KO of individual NCoRs or HDAC3, resulting in profound fasting hypoglycaemia. This surprising HDAC3-independent activation function of NCoR1 and NCoR2 is due to an unexpected loss of chromatin accessibility on deletion of NCoRs that prevented glucocorticoid receptor binding and stimulatory effect on gluconeogenic genes. These studies reveal an unanticipated, non-canonical activation function of NCoRs that is required for metabolic health.
Topics: Gluconeogenesis; Animals; Receptors, Glucocorticoid; Nuclear Receptor Co-Repressor 1; Mice; Histone Deacetylases; Mice, Knockout; Nuclear Receptor Co-Repressor 2; Liver; Hepatocytes; Nuclear Receptor Coactivator 2
PubMed: 38622413
DOI: 10.1038/s42255-024-01029-4 -
Cell Discovery Apr 2024Macroautophagy is a process that cells engulf cytosolic materials by autophagosomes and deliver them to lysosomes for degradation. The biogenesis of autophagosomes...
Macroautophagy is a process that cells engulf cytosolic materials by autophagosomes and deliver them to lysosomes for degradation. The biogenesis of autophagosomes requires ATG2 as a lipid transfer protein to transport lipids from existing membranes to phagophores. It is generally believed that endoplasmic reticulum is the main source for lipid supply of the forming autophagosomes; whether ATG2 can transfer lipids from other organelles to phagophores remains elusive. In this study, we identified a new ATG2A-binding protein, ANKFY1. Depletion of this endosome-localized protein led to the impaired autophagosome growth and the reduced autophagy flux, which largely phenocopied ATG2A/B depletion. A pool of ANKFY1 co-localized with ATG2A between endosomes and phagophores and depletion of UVRAG, ANKFY1 or ATG2A/B led to reduction of PI3P distribution on phagophores. Purified recombinant ANKFY1 bound to PI3P on membrane through its FYVE domain and enhanced ATG2A-mediated lipid transfer between PI3P-containing liposomes. Therefore, we propose that ANKFY1 recruits ATG2A to PI3P-enriched endosomes and promotes ATG2A-mediated lipid transfer from endosomes to phagophores. This finding implicates a new lipid source for ATG2A-mediated phagophore expansion, where endosomes donate PI3P and other lipids to phagophores via lipid transfer.
PubMed: 38622126
DOI: 10.1038/s41421-024-00659-y -
Molecular Metabolism Jun 2024Metamorphosis is a transition from growth to reproduction, through which an animal adopts adult behavior and metabolism. Yet the neural mechanisms underlying the switch...
OBJECTIVE
Metamorphosis is a transition from growth to reproduction, through which an animal adopts adult behavior and metabolism. Yet the neural mechanisms underlying the switch are unclear. Here we report that neuronal E93, a transcription factor essential for metamorphosis, regulates the adult metabolism, physiology, and behavior in Drosophila melanogaster.
METHODS
To find new neuronal regulators of metabolism, we performed a targeted RNAi-based screen of 70 Drosophila orthologs of the mammalian genes enriched in ventromedial hypothalamus (VMH). Once E93 was identified from the screen, we characterized changes in physiology and behavior when neuronal expression of E93 is knocked down. To identify the neurons where E93 acts, we performed an additional screen targeting subsets of neurons or endocrine cells.
RESULTS
E93 is required to control appetite, metabolism, exercise endurance, and circadian rhythms. The diverse phenotypes caused by pan-neuronal knockdown of E93, including obesity, exercise intolerance and circadian disruption, can all be phenocopied by knockdown of E93 specifically in either GABA or MIP neurons, suggesting these neurons are key sites of E93 action. Knockdown of the Ecdysone Receptor specifically in MIP neurons partially phenocopies the MIP neuron-specific knockdown of E93, suggesting the steroid signal coordinates adult metabolism via E93 and a neuropeptidergic signal. Finally, E93 expression in GABA and MIP neurons also serves as a key switch for the adaptation to adult behavior, as animals with reduced expression of E93 in the two subsets of neurons exhibit reduced reproductive activity.
CONCLUSIONS
Our study reveals that E93 is a new monogenic factor essential for metabolic, physiological, and behavioral adaptation from larval behavior to adult behavior.
Topics: Animals; Female; Male; Adaptation, Physiological; Behavior, Animal; Circadian Rhythm; Drosophila melanogaster; Drosophila Proteins; Metamorphosis, Biological; Neurons; Transcription Factors
PubMed: 38621602
DOI: 10.1016/j.molmet.2024.101939 -
Inhibition of Autophagy Alters Intracellular Transport of APP Resulting in Increased APP Processing.Traffic (Copenhagen, Denmark) Apr 2024Alzheimer's disease (AD) pathology is characterized by amyloid beta (Aβ) plaques and dysfunctional autophagy. Aβ is generated by sequential proteolytic cleavage of...
Alzheimer's disease (AD) pathology is characterized by amyloid beta (Aβ) plaques and dysfunctional autophagy. Aβ is generated by sequential proteolytic cleavage of amyloid precursor protein (APP), and the site of intracellular APP processing is highly debated, which may include autophagosomes. Here, we investigated the involvement of autophagy, including the role of ATG9 in APP intracellular trafficking and processing by applying the RUSH system, which allows studying the transport of fluorescently labeled mCherry-APP-EGFP in a systematic way, starting from the endoplasmic reticulum. HeLa cells, expressing the RUSH mCherry-APP-EGFP system, were investigated by live cell imaging, immunofluorescence, and Western blot. We found that mCherry-APP-EGFP passed through the Golgi faster in ATG9 knockout cells. Furthermore, ATG9 deletion shifted mCherry-APP-EGFP from early endosomes and lysosomes toward the plasma membrane concomitant with reduced endocytosis. Importantly, this alteration in mCherry-APP-EGFP transport resulted in increased secreted mCherry-soluble APP and C-terminal fragment-EGFP. These effects were also phenocopied by pharmacological inhibition of ULK1, indicating that autophagy is regulating the intracellular trafficking and processing of APP. These findings contribute to the understanding of the role of autophagy in APP metabolism and could potentially have implications for new therapeutic approaches for AD.
Topics: Humans; Amyloid beta-Protein Precursor; Amyloid beta-Peptides; HeLa Cells; Biological Transport; Autophagy; Alzheimer Disease
PubMed: 38613404
DOI: 10.1111/tra.12934 -
Current Problems in Cardiology Jun 2024Brugada syndrome (BrS) is a genetic disorder known for its characteristic electrocardiogram (ECG) patterns and increased risk of sudden cardiac death. Brugada phenocopy... (Review)
Review
Brugada syndrome (BrS) is a genetic disorder known for its characteristic electrocardiogram (ECG) patterns and increased risk of sudden cardiac death. Brugada phenocopy (BrP) presents similar ECG patterns but is distinguished by its reversible nature when the underlying conditions are resolved. This article delineates the intricacies of BrP, emphasizing its etiology, clinical presentation, diagnosis, treatment, and prognosis. The article categorizes BrP based on various underlying causes, including metabolic disturbances, myocardial infarction, and mechanical compression, among others. It also underscores the critical importance of differentiating BrP from BrS to avoid misdiagnosis and inappropriate treatment, such as unnecessary implantation of cardioverter-defibrillators. The reversible aspect of BrP underlines the necessity for an etiology-specific approach to treatment, which not only prevents cardiac death but also highlights the significance of understanding the dynamic nature of ECG patterns. Through an exploration of case studies and current research, this review advocates for increased awareness and further investigation into BrP. It aims to enhance the diagnostic accuracy and management strategies, thereby improving the prognosis for patients presenting with Brugada-like ECG patterns. The review culminates in a call for further research to close existing knowledge gaps and improve patient outcomes.
Topics: Brugada Syndrome; Humans; Electrocardiography; Phenotype; Diagnosis, Differential; Prognosis; Death, Sudden, Cardiac; Defibrillators, Implantable
PubMed: 38599558
DOI: 10.1016/j.cpcardiol.2024.102566