RESUMEN
Many behaviors require the coordinated actions of somatic and autonomic functions. However, the underlying mechanisms remain elusive. By opto-stimulating different populations of descending spinal projecting neurons (SPNs) in anesthetized mice, we show that stimulation of excitatory SPNs in the rostral ventromedial medulla (rVMM) resulted in a simultaneous increase in somatomotor and sympathetic activities. Conversely, opto-stimulation of rVMM inhibitory SPNs decreased both activities. Anatomically, these SPNs innervate both sympathetic preganglionic neurons and motor-related regions in the spinal cord. Fiber-photometry recording indicated that the activities of rVMM SPNs correlate with different levels of muscle and sympathetic tone during distinct arousal states. Inhibiting rVMM excitatory SPNs reduced basal muscle and sympathetic tone, impairing locomotion initiation and high-speed performance. In contrast, silencing the inhibitory population abolished muscle atonia and sympathetic hypoactivity during rapid eye movement (REM) sleep. Together, these results identify rVMM SPNs as descending spinal projecting pathways controlling the tone of both the somatomotor and sympathetic systems.
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Bulbo Raquídeo , Médula Espinal , Sistema Nervioso Simpático , Animales , Masculino , Ratones , Locomoción/fisiología , Bulbo Raquídeo/fisiología , Ratones Endogámicos C57BL , Neuronas Motoras/fisiología , Neuronas/fisiología , Sueño REM/fisiología , Médula Espinal/fisiología , Sistema Nervioso Simpático/fisiología , Conducta Animal , Recuento de Células , Músculo EsqueléticoRESUMEN
Interspecies blastocyst complementation (IBC) provides a unique platform to study development and holds the potential to overcome worldwide organ shortages. Despite recent successes, brain tissue has not been achieved through IBC. Here, we developed an optimized IBC strategy based on C-CRISPR, which facilitated rapid screening of candidate genes and identified that Hesx1 deficiency supported the generation of rat forebrain tissue in mice via IBC. Xenogeneic rat forebrain tissues in adult mice were structurally and functionally intact. Cross-species comparative analyses revealed that rat forebrain tissues developed at the same pace as the mouse host but maintained rat-like transcriptome profiles. The chimeric rate of rat cells gradually decreased as development progressed, suggesting xenogeneic barriers during mid-to-late pre-natal development. Interspecies forebrain complementation opens the door for studying evolutionarily conserved and divergent mechanisms underlying brain development and cognitive function. The C-CRISPR-based IBC strategy holds great potential to broaden the study and application of interspecies organogenesis.
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Prosencéfalo , Animales , Prosencéfalo/metabolismo , Prosencéfalo/embriología , Ratones , Ratas , Blastocisto/metabolismo , Femenino , Sistemas CRISPR-Cas/genética , Transcriptoma , Organogénesis , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , Masculino , Ratones Endogámicos C57BLRESUMEN
Neuroimmune interactions mediate intercellular communication and underlie critical brain functions. Microglia, CNS-resident macrophages, modulate the brain through direct physical interactions and the secretion of molecules. One such secreted factor, the complement protein C1q, contributes to complement-mediated synapse elimination in both developmental and disease models, yet brain C1q protein levels increase significantly throughout aging. Here, we report that C1q interacts with neuronal ribonucleoprotein (RNP) complexes in an age-dependent manner. Purified C1q protein undergoes RNA-dependent liquid-liquid phase separation (LLPS) in vitro, and the interaction of C1q with neuronal RNP complexes in vivo is dependent on RNA and endocytosis. Mice lacking C1q have age-specific alterations in neuronal protein synthesis in vivo and impaired fear memory extinction. Together, our findings reveal a biophysical property of C1q that underlies RNA- and age-dependent neuronal interactions and demonstrate a role of C1q in critical intracellular neuronal processes.
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Envejecimiento , Encéfalo , Complemento C1q , Homeostasis , Microglía , Neuronas , Ribonucleoproteínas , Animales , Complemento C1q/metabolismo , Ratones , Microglía/metabolismo , Envejecimiento/metabolismo , Encéfalo/metabolismo , Ribonucleoproteínas/metabolismo , Neuronas/metabolismo , Ratones Endogámicos C57BL , HumanosRESUMEN
In the prevailing model, Lgr5+ cells are the only intestinal stem cells (ISCs) that sustain homeostatic epithelial regeneration by upward migration of progeny through elusive upper crypt transit-amplifying (TA) intermediates. Here, we identify a proliferative upper crypt population marked by Fgfbp1, in the location of putative TA cells, that is transcriptionally distinct from Lgr5+ cells. Using a kinetic reporter for time-resolved fate mapping and Fgfbp1-CreERT2 lineage tracing, we establish that Fgfbp1+ cells are multi-potent and give rise to Lgr5+ cells, consistent with their ISC function. Fgfbp1+ cells also sustain epithelial regeneration following Lgr5+ cell depletion. We demonstrate that FGFBP1, produced by the upper crypt cells, is an essential factor for crypt proliferation and epithelial homeostasis. Our findings support a model in which tissue regeneration originates from upper crypt Fgfbp1+ cells that generate progeny propagating bi-directionally along the crypt-villus axis and serve as a source of Lgr5+ cells in the crypt base.
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Mucosa Intestinal , Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/metabolismo , Animales , Ratones , Mucosa Intestinal/metabolismo , Mucosa Intestinal/citología , Células Madre/metabolismo , Células Madre/citología , Linaje de la Célula , Regeneración , Proliferación Celular , Células Epiteliales/metabolismo , Células Epiteliales/citología , Ratones Endogámicos C57BL , HomeostasisRESUMEN
Purine nucleotides are vital for RNA and DNA synthesis, signaling, metabolism, and energy homeostasis. To synthesize purines, cells use two principal routes: the de novo and salvage pathways. Traditionally, it is believed that proliferating cells predominantly rely on de novo synthesis, whereas differentiated tissues favor the salvage pathway. Unexpectedly, we find that adenine and inosine are the most effective circulating precursors for supplying purine nucleotides to tissues and tumors, while hypoxanthine is rapidly catabolized and poorly salvaged in vivo. Quantitative metabolic analysis demonstrates comparative contribution from de novo synthesis and salvage pathways in maintaining purine nucleotide pools in tumors. Notably, feeding mice nucleotides accelerates tumor growth, while inhibiting purine salvage slows down tumor progression, revealing a crucial role of the salvage pathway in tumor metabolism. These findings provide fundamental insights into how normal tissues and tumors maintain purine nucleotides and highlight the significance of purine salvage in cancer.
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Neoplasias , Nucleótidos de Purina , Purinas , Animales , Ratones , Purinas/metabolismo , Purinas/biosíntesis , Neoplasias/metabolismo , Neoplasias/patología , Nucleótidos de Purina/metabolismo , Humanos , Inosina/metabolismo , Hipoxantina/metabolismo , Ratones Endogámicos C57BL , Adenina/metabolismo , Línea Celular Tumoral , FemeninoRESUMEN
The currently accepted intestinal epithelial cell organization model proposes that Lgr5+ crypt-base columnar (CBC) cells represent the sole intestinal stem cell (ISC) compartment. However, previous studies have indicated that Lgr5+ cells are dispensable for intestinal regeneration, leading to two major hypotheses: one favoring the presence of a quiescent reserve ISC and the other calling for differentiated cell plasticity. To investigate these possibilities, we studied crypt epithelial cells in an unbiased fashion via high-resolution single-cell profiling. These studies, combined with in vivo lineage tracing, show that Lgr5 is not a specific ISC marker and that stemness potential exists beyond the crypt base and resides in the isthmus region, where undifferentiated cells participate in intestinal homeostasis and regeneration following irradiation (IR) injury. Our results provide an alternative model of intestinal epithelial cell organization, suggesting that stemness potential is not restricted to CBC cells, and neither de-differentiation nor reserve ISC are drivers of intestinal regeneration.
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Homeostasis , Mucosa Intestinal , Receptores Acoplados a Proteínas G , Regeneración , Células Madre , Animales , Células Madre/metabolismo , Células Madre/citología , Ratones , Mucosa Intestinal/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Intestinos/citología , Diferenciación Celular , Ratones Endogámicos C57BL , Células Epiteliales/metabolismo , Análisis de la Célula Individual , MasculinoRESUMEN
The vasculature of the central nervous system is a 3D lattice composed of laminar vascular beds interconnected by penetrating vessels. The mechanisms controlling 3D lattice network formation remain largely unknown. Combining viral labeling, genetic marking, and single-cell profiling in the mouse retina, we discovered a perivascular neuronal subset, annotated as Fam19a4/Nts-positive retinal ganglion cells (Fam19a4/Nts-RGCs), directly contacting the vasculature with perisomatic endfeet. Developmental ablation of Fam19a4/Nts-RGCs led to disoriented growth of penetrating vessels near the ganglion cell layer (GCL), leading to a disorganized 3D vascular lattice. We identified enriched PIEZO2 expression in Fam19a4/Nts-RGCs. Piezo2 loss from all retinal neurons or Fam19a4/Nts-RGCs abolished the direct neurovascular contacts and phenocopied the Fam19a4/Nts-RGC ablation deficits. The defective vascular structure led to reduced capillary perfusion and sensitized the retina to ischemic insults. Furthermore, we uncovered a Piezo2-dependent perivascular granule cell subset for cerebellar vascular patterning, indicating neuronal Piezo2-dependent 3D vascular patterning in the brain.
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Cerebelo , Neuronas , Retina , Animales , Femenino , Masculino , Ratones , Cerebelo/metabolismo , Cerebelo/irrigación sanguínea , Cerebelo/citología , Canales Iónicos/metabolismo , Ratones Endogámicos C57BL , Neuronas/metabolismo , Retina/citología , Retina/metabolismo , Células Ganglionares de la Retina/metabolismo , Vasos Retinianos/metabolismoRESUMEN
A central question for regenerative neuroscience is whether synthetic neural circuits, such as those built from two species, can function in an intact brain. Here, we apply blastocyst complementation to selectively build and test interspecies neural circuits. Despite approximately 10-20 million years of evolution, and prominent species differences in brain size, rat pluripotent stem cells injected into mouse blastocysts develop and persist throughout the mouse brain. Unexpectedly, the mouse niche reprograms the birth dates of rat neurons in the cortex and hippocampus, supporting rat-mouse synaptic activity. When mouse olfactory neurons are genetically silenced or killed, rat neurons restore information flow to odor processing circuits. Moreover, they rescue the primal behavior of food seeking, although less well than mouse neurons. By revealing that a mouse can sense the world using neurons from another species, we establish neural blastocyst complementation as a powerful tool to identify conserved mechanisms of brain development, plasticity, and repair.
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Neuronas , Animales , Ratones , Ratas , Neuronas/metabolismo , Neuronas/citología , Neuronas/fisiología , Blastocisto/metabolismo , Blastocisto/citología , Células Madre Pluripotentes/citología , Células Madre Pluripotentes/metabolismo , Encéfalo/citología , Encéfalo/fisiología , Femenino , Hipocampo/citología , Hipocampo/fisiología , Especificidad de la Especie , Ratones Endogámicos C57BL , MasculinoRESUMEN
Platelet dysregulation is drastically increased with advanced age and contributes to making cardiovascular disorders the leading cause of death of elderly humans. Here, we reveal a direct differentiation pathway from hematopoietic stem cells into platelets that is progressively propagated upon aging. Remarkably, the aging-enriched platelet path is decoupled from all other hematopoietic lineages, including erythropoiesis, and operates as an additional layer in parallel with canonical platelet production. This results in two molecularly and functionally distinct populations of megakaryocyte progenitors. The age-induced megakaryocyte progenitors have a profoundly enhanced capacity to engraft, expand, restore, and reconstitute platelets in situ and upon transplantation and produce an additional platelet population in old mice. The two pools of co-existing platelets cause age-related thrombocytosis and dramatically increased thrombosis in vivo. Strikingly, aging-enriched platelets are functionally hyper-reactive compared with the canonical platelet populations. These findings reveal stem cell-based aging as a mechanism for platelet dysregulation and age-induced thrombosis.
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Envejecimiento , Plaquetas , Diferenciación Celular , Células Madre Hematopoyéticas , Trombosis , Animales , Células Madre Hematopoyéticas/metabolismo , Plaquetas/metabolismo , Trombosis/patología , Trombosis/metabolismo , Ratones , Humanos , Megacariocitos/metabolismo , Ratones Endogámicos C57BL , Células Progenitoras de Megacariocitos/metabolismo , MasculinoRESUMEN
Brown adipose tissue (BAT) is best known for thermogenesis. Rodent studies demonstrated that enhanced BAT thermogenesis is tightly associated with increased energy expenditure, reduced body weight, and improved glucose homeostasis. However, human BAT is protective against type 2 diabetes, independent of body weight. The mechanism underlying this dissociation remains unclear. Here, we report that impaired mitochondrial catabolism of branched-chain amino acids (BCAAs) in BAT, by deleting mitochondrial BCAA carriers (MBCs), caused systemic insulin resistance without affecting energy expenditure and body weight. Brown adipocytes catabolized BCAA in the mitochondria as nitrogen donors for the biosynthesis of non-essential amino acids and glutathione. Impaired mitochondrial BCAA-nitrogen flux in BAT resulted in increased oxidative stress, decreased hepatic insulin signaling, and decreased circulating BCAA-derived metabolites. A high-fat diet attenuated BCAA-nitrogen flux and metabolite synthesis in BAT, whereas cold-activated BAT enhanced the synthesis. This work uncovers a metabolite-mediated pathway through which BAT controls metabolic health beyond thermogenesis.
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Tejido Adiposo Pardo , Aminoácidos de Cadena Ramificada , Resistencia a la Insulina , Mitocondrias , Nitrógeno , Termogénesis , Tejido Adiposo Pardo/metabolismo , Animales , Aminoácidos de Cadena Ramificada/metabolismo , Ratones , Nitrógeno/metabolismo , Mitocondrias/metabolismo , Masculino , Humanos , Metabolismo Energético , Ratones Endogámicos C57BL , Estrés Oxidativo , Insulina/metabolismo , Dieta Alta en Grasa , Adipocitos Marrones/metabolismo , Transducción de SeñalRESUMEN
Cancer immunotherapy has transformed treatment possibilities, but its effectiveness differs significantly among patients, indicating the presence of alternative pathways for immune evasion. Here, we show that ITPRIPL1 functions as an inhibitory ligand of CD3ε, and its expression inhibits T cells in the tumor microenvironment. The binding of ITPRIPL1 extracellular domain to CD3ε on T cells significantly decreased calcium influx and ZAP70 phosphorylation, impeding initial T cell activation. Treatment with a neutralizing antibody against ITPRIPL1 restrained tumor growth and promoted T cell infiltration in mouse models across various solid tumor types. The antibody targeting canine ITPRIPL1 exhibited notable therapeutic efficacy against naturally occurring tumors in pet clinics. These findings highlight the role of ITPRIPL1 (or CD3L1, CD3ε ligand 1) in impeding T cell activation during the critical "signal one" phase. This discovery positions ITPRIPL1 as a promising therapeutic target against multiple tumor types.
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Complejo CD3 , Activación de Linfocitos , Linfocitos T , Escape del Tumor , Microambiente Tumoral , Animales , Complejo CD3/metabolismo , Complejo CD3/inmunología , Humanos , Ratones , Linfocitos T/inmunología , Linfocitos T/metabolismo , Microambiente Tumoral/inmunología , Perros , Neoplasias/inmunología , Línea Celular Tumoral , Femenino , Unión Proteica , Proteína Tirosina Quinasa ZAP-70/metabolismo , Anticuerpos Neutralizantes/inmunología , Ratones Endogámicos C57BLRESUMEN
Antigen presentation defects in tumors are prevalent mechanisms of adaptive immune evasion and resistance to cancer immunotherapy, whereas how tumors evade innate immunity is less clear. Using CRISPR screens, we discovered that IGSF8 expressed on tumors suppresses NK cell function by interacting with human KIR3DL2 and mouse Klra9 receptors on NK cells. IGSF8 is normally expressed in neuronal tissues and is not required for cell survival in vitro or in vivo. It is overexpressed and associated with low antigen presentation, low immune infiltration, and worse clinical outcomes in many tumors. An antibody that blocks IGSF8-NK receptor interaction enhances NK cell killing of malignant cells in vitro and upregulates antigen presentation, NK cell-mediated cytotoxicity, and T cell signaling in vivo. In syngeneic tumor models, anti-IGSF8 alone, or in combination with anti-PD1, inhibits tumor growth. Our results indicate that IGSF8 is an innate immune checkpoint that could be exploited as a therapeutic target.
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Inmunidad Innata , Inmunoterapia , Células Asesinas Naturales , Neoplasias , Animales , Femenino , Humanos , Ratones , Presentación de Antígeno , Línea Celular Tumoral , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Neoplasias/inmunología , Neoplasias/terapiaRESUMEN
Hypothalamic neural circuits regulate instinctive behaviors such as food seeking, the fight/flight response, socialization, and maternal care. Here, we identified microdeletions on chromosome Xq23 disrupting the brain-expressed transient receptor potential (TRP) channel 5 (TRPC5). This family of channels detects sensory stimuli and converts them into electrical signals interpretable by the brain. Male TRPC5 deletion carriers exhibited food seeking, obesity, anxiety, and autism, which were recapitulated in knockin male mice harboring a human loss-of-function TRPC5 mutation. Women carrying TRPC5 deletions had severe postpartum depression. As mothers, female knockin mice exhibited anhedonia and depression-like behavior with impaired care of offspring. Deletion of Trpc5 from oxytocin neurons in the hypothalamic paraventricular nucleus caused obesity in both sexes and postpartum depressive behavior in females, while Trpc5 overexpression in oxytocin neurons in knock-in mice reversed these phenotypes. We demonstrate that TRPC5 plays a pivotal role in mediating innate human behaviors fundamental to survival, including food seeking and maternal care.
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Depresión Posparto , Neuronas , Obesidad , Canales Catiónicos TRPC , Animales , Femenino , Ratones , Obesidad/metabolismo , Obesidad/genética , Masculino , Humanos , Canales Catiónicos TRPC/metabolismo , Canales Catiónicos TRPC/genética , Depresión Posparto/metabolismo , Neuronas/metabolismo , Núcleo Hipotalámico Paraventricular/metabolismo , Ratones Endogámicos C57BL , Oxitocina/metabolismo , Conducta MaternaRESUMEN
Leveraging AAVs' versatile tropism and labeling capacity, we expanded the scale of in vivo CRISPR screening with single-cell transcriptomic phenotyping across embryonic to adult brains and peripheral nervous systems. Through extensive tests of 86 vectors across AAV serotypes combined with a transposon system, we substantially amplified labeling efficacy and accelerated in vivo gene delivery from weeks to days. Our proof-of-principle in utero screen identified the pleiotropic effects of Foxg1, highlighting its tight regulation of distinct networks essential for cell fate specification of Layer 6 corticothalamic neurons. Notably, our platform can label >6% of cerebral cells, surpassing the current state-of-the-art efficacy at <0.1% by lentivirus, to achieve analysis of over 30,000 cells in one experiment and enable massively parallel in vivo Perturb-seq. Compatible with various phenotypic measurements (single-cell or spatial multi-omics), it presents a flexible approach to interrogate gene function across cell types in vivo, translating gene variants to their causal function.
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Redes Reguladoras de Genes , Análisis de la Célula Individual , Animales , Femenino , Humanos , Ratones , Corteza Cerebral/metabolismo , Corteza Cerebral/citología , Sistemas CRISPR-Cas/genética , Dependovirus/genética , Factores de Transcripción Forkhead/metabolismo , Factores de Transcripción Forkhead/genética , Vectores Genéticos/metabolismo , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/genética , Neuronas/metabolismo , Neuronas/citología , Análisis de la Célula Individual/métodos , Transcriptoma/genética , Línea Celular , Transcripción GenéticaRESUMEN
Alterations in extracellular matrix (ECM) architecture and stiffness represent hallmarks of cancer. Whether the biomechanical property of ECM impacts the functionality of tumor-reactive CD8+ T cells remains largely unknown. Here, we reveal that the transcription factor (TF) Osr2 integrates biomechanical signaling and facilitates the terminal exhaustion of tumor-reactive CD8+ T cells. Osr2 expression is selectively induced in the terminally exhausted tumor-specific CD8+ T cell subset by coupled T cell receptor (TCR) signaling and biomechanical stress mediated by the Piezo1/calcium/CREB axis. Consistently, depletion of Osr2 alleviates the exhaustion of tumor-specific CD8+ T cells or CAR-T cells, whereas forced Osr2 expression aggravates their exhaustion in solid tumor models. Mechanistically, Osr2 recruits HDAC3 to rewire the epigenetic program for suppressing cytotoxic gene expression and promoting CD8+ T cell exhaustion. Thus, our results unravel Osr2 functions as a biomechanical checkpoint to exacerbate CD8+ T cell exhaustion and could be targeted to potentiate cancer immunotherapy.
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Linfocitos T CD8-positivos , Factores de Transcripción , Animales , Femenino , Humanos , Ratones , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Línea Celular Tumoral , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Matriz Extracelular/metabolismo , Histona Desacetilasas/metabolismo , Ratones Endogámicos C57BL , Neoplasias/inmunología , Neoplasias/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de Señal , Agotamiento de Células T , Factores de Transcripción/metabolismo , Microambiente Tumoral , Estrés MecánicoRESUMEN
Inflammation-induced neurodegeneration is a defining feature of multiple sclerosis (MS), yet the underlying mechanisms remain unclear. By dissecting the neuronal inflammatory stress response, we discovered that neurons in MS and its mouse model induce the stimulator of interferon genes (STING). However, activation of neuronal STING requires its detachment from the stromal interaction molecule 1 (STIM1), a process triggered by glutamate excitotoxicity. This detachment initiates non-canonical STING signaling, which leads to autophagic degradation of glutathione peroxidase 4 (GPX4), essential for neuronal redox homeostasis and thereby inducing ferroptosis. Both genetic and pharmacological interventions that target STING in neurons protect against inflammation-induced neurodegeneration. Our findings position STING as a central regulator of the detrimental neuronal inflammatory stress response, integrating inflammation with glutamate signaling to cause neuronal cell death, and present it as a tractable target for treating neurodegeneration in MS.
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Inflamación , Proteínas de la Membrana , Esclerosis Múltiple , Neuronas , Animales , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple/patología , Proteínas de la Membrana/metabolismo , Neuronas/metabolismo , Neuronas/patología , Ratones , Humanos , Inflamación/metabolismo , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Transducción de Señal , Autofagia , Ratones Endogámicos C57BL , Ácido Glutámico/metabolismo , Ferroptosis , Modelos Animales de Enfermedad , Femenino , MasculinoRESUMEN
Defective host defenses later in life are associated with changes in immune cell activities, suggesting that age-specific considerations are needed in immunotherapy approaches. In this study, we found that PD-1 and CTLA4-based cancer immunotherapies are unable to eradicate tumors in elderly mice. This defect in anti-tumor activity correlated with two known age-associated immune defects: diminished abundance of systemic naive CD8+ T cells and weak migratory activities of dendritic cells (DCs). We identified a vaccine adjuvant, referred to as a DC hyperactivator, which corrects DC migratory defects in the elderly. Vaccines containing tumor antigens and DC hyperactivators induced T helper type 1 (TH1) CD4+ T cells with cytolytic activity that drive anti-tumor immunity in elderly mice. When administered early in life, DC hyperactivators were the only adjuvant identified that elicited anti-tumor CD4+ T cells that persisted into old age. These results raise the possibility of correcting age-associated immune defects through DC manipulation.
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Linfocitos T CD4-Positivos , Células Dendríticas , Ratones Endogámicos C57BL , Células Dendríticas/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Ratones , Envejecimiento/inmunología , Linfocitos T CD8-positivos/inmunología , Inmunoterapia/métodos , Vacunas contra el Cáncer/inmunología , Femenino , Neoplasias/inmunología , Neoplasias/terapia , Receptor de Muerte Celular Programada 1/metabolismo , Antígeno CTLA-4/metabolismo , Movimiento Celular , Antígenos de Neoplasias/inmunologíaRESUMEN
Insufficient telomerase activity, stemming from low telomerase reverse transcriptase (TERT) gene transcription, contributes to telomere dysfunction and aging pathologies. Besides its traditional function in telomere synthesis, TERT acts as a transcriptional co-regulator of genes pivotal in aging and age-associated diseases. Here, we report the identification of a TERT activator compound (TAC) that upregulates TERT transcription via the MEK/ERK/AP-1 cascade. In primary human cells and naturally aged mice, TAC-induced elevation of TERT levels promotes telomere synthesis, blunts tissue aging hallmarks with reduced cellular senescence and inflammatory cytokines, and silences p16INK4a expression via upregulation of DNMT3B-mediated promoter hypermethylation. In the brain, TAC alleviates neuroinflammation, increases neurotrophic factors, stimulates adult neurogenesis, and preserves cognitive function without evident toxicity, including cancer risk. Together, these findings underscore TERT's critical role in aging processes and provide preclinical proof of concept for physiological TERT activation as a strategy to mitigate multiple aging hallmarks and associated pathologies.
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Envejecimiento , Metilación de ADN , Telomerasa , Telomerasa/metabolismo , Telomerasa/genética , Humanos , Animales , Ratones , ADN (Citosina-5-)-Metiltransferasas/metabolismo , ADN (Citosina-5-)-Metiltransferasas/genética , Senescencia Celular , Regiones Promotoras Genéticas , ADN Metiltransferasa 3B , Encéfalo/metabolismo , Telómero/metabolismo , Ratones Endogámicos C57BL , Masculino , Factor de Transcripción AP-1/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , NeurogénesisRESUMEN
Spatial transcriptomics (ST) methods unlock molecular mechanisms underlying tissue development, homeostasis, or disease. However, there is a need for easy-to-use, high-resolution, cost-efficient, and 3D-scalable methods. Here, we report Open-ST, a sequencing-based, open-source experimental and computational resource to address these challenges and to study the molecular organization of tissues in 2D and 3D. In mouse brain, Open-ST captured transcripts at subcellular resolution and reconstructed cell types. In primary head-and-neck tumors and patient-matched healthy/metastatic lymph nodes, Open-ST captured the diversity of immune, stromal, and tumor populations in space, validated by imaging-based ST. Distinct cell states were organized around cell-cell communication hotspots in the tumor but not the metastasis. Strikingly, the 3D reconstruction and multimodal analysis of the metastatic lymph node revealed spatially contiguous structures not visible in 2D and potential biomarkers precisely at the 3D tumor/lymph node boundary. All protocols and software are available at https://rajewsky-lab.github.io/openst.
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Imagenología Tridimensional , Transcriptoma , Animales , Ratones , Humanos , Transcriptoma/genética , Imagenología Tridimensional/métodos , Programas Informáticos , Perfilación de la Expresión Génica/métodos , Ganglios Linfáticos/patología , Ganglios Linfáticos/metabolismo , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/patología , Encéfalo/metabolismo , Ratones Endogámicos C57BL , Metástasis Linfática , FemeninoRESUMEN
Taurine is used to bolster immunity, but its effects on antitumor immunity are unclear. Here, we report that cancer-related taurine consumption causes T cell exhaustion and tumor progression. The taurine transporter SLC6A6 is correlated with aggressiveness and poor outcomes in multiple cancers. SLC6A6-mediated taurine uptake promotes the malignant behaviors of tumor cells but also increases the survival and effector function of CD8+ T cells. Tumor cells outcompete CD8+ T cells for taurine by overexpressing SLC6A6, which induces T cell death and malfunction, thereby fueling tumor progression. Mechanistically, taurine deficiency in CD8+ T cells increases ER stress, promoting ATF4 transcription in a PERK-JAK1-STAT3 signaling-dependent manner. Increased ATF4 transactivates multiple immune checkpoint genes and induces T cell exhaustion. In gastric cancer, we identify a chemotherapy-induced SP1-SLC6A6 regulatory axis. Our findings suggest that tumoral-SLC6A6-mediated taurine deficiency promotes immune evasion and that taurine supplementation reinvigorates exhausted CD8+ T cells and increases the efficacy of cancer therapies.