Project description:Longstanding evidence implicates glioma stem cells (GSCs) as the major driver for glioma propagation and recurrence. GSCs have a distinctive metabolic landscape characterized by elevated glycolysis. Lactate accumulation resulting from enhanced glycolytic activity can drive lysine lactylation to regulate protein functions, suggesting that elucidating the lactylation landscape in GSCs could provide insights into glioma biology. Herein, we demonstrated that global lactylation was significantly elevated in GSCs compared to differentiated glioma cells (DGCs). PTBP1, a central regulator of RNA processing, was hyperlactylated in GSCs, and SIRT1 induced PTBP1 delactylation. PTBP1-K436 lactylation supported glioma progression and GSC maintenance. Mechanistically, K436 lactylation inhibited PTBP1 proteasomal degradation by attenuating the interaction with TRIM21. Moreover, PTBP1 lactylation enhanced its RNA-binding capacity and facilitated PFKFB4 mRNA stabilization, which further increased glycolysis. Together, these findings uncovered a lactylation-mediated mechanism in GSCs driven by metabolic reprogramming that induces aberrant epigenetic modifications to further stimulate glycolysis, resulting in a vicious cycle to exacerbate tumorigenesis.
Project description:We have identified a new histone modification, which is derived from glycolysis end product, lactate. By SILAC-MS/MS based quantification, and U-13C6 glucose labeling experiments, we demonstrate that histone Kla is regulated by cellular glycolysis pathway
Project description:Mutations of the β-glucuronidase protein α-Klotho have been associated with premature aging, and altered cognitive function. Although highly expressed in specific areas of the brain, Klotho functions in the central nervous system remain unknow. Here, we show that cultured hippocampal neurons respond to insulin and glutamate stimulation by elevating Klotho protein levels. Conversely, AMPA and NMDA antagonism suppress neuronal Klotho expression. We also provide evidence that soluble Klotho enhances astrocytic aerobic glycolysis by hindering pyruvate metabolism through the mitochondria, and stimulating its processing by lactate dehydrogenase. Pharmacological inhibition of FGFR1, Erk phosphorylation, and monocarboxylic acid transporters prevents Klotho-induced lactate release from astrocytes. Taken together these data suggest Klotho is a potential new player in the metabolic coupling between neurons and astrocytes. Neuronal glutamatergic activity and insulin modulation elicit Klotho release, which in turn stimulates astrocytic lactate formation and release. Lactate can then be used by neurons as a metabolic substrate contributing to fulfill their elevated energy requirements.
Project description:Age-related macular degeneration (AMD) is a leading cause of blindness among the elderly. Using clinical samples and knockout mice, we reported that the m1A eraser ALKBH3 reshaped retinal metabolism to promote AMD. In retinal pigment epithelium (RPE), the dm1ACRISPR system demonstrated that ALKBH3 demethylated the glycolytic enzyme HK2 to activate anaerobic glycolysis, producing excessive lactate. The lactate promoted histone lactylation at H3K18, which in turn bound to ALKBH3 to amplify its transcription, establishing a positive feedback loop. The ALKBH3 inhibitor HUHS015 disrupted this loop, effectively mitigating RPE degeneration. Furthermore, ALKBH3 directly targeted the pro-angiogenic factor VEGFA to modulate the metabolic cross-talk between RPE and choroidal capillaries, thus promoting choroidal neovascularization (CNV). HUHS015 inhibited CNV synergistically with the anti-VEGF drug Aflibercept. Our study provides critical insights into the molecular mechanisms and metabolic events facilitating the progression from RPE degeneration to CNV in AMD, laying the groundwork for new treatments of AMD.
Project description:Embryonic stem cells (ESCs) favor glycolysis over oxidative phosphorylation for energy production, and glycolytic metabolism is critical for pluripotency establishment, maintenance and exit. However, how glycolysis regulates the self-renewal and differentiation of ESCs remains elusive. Here, we demonstrated that protein lactylation, regulated by intracellular lactate, contributes to the self-renewal of ESCs. Next, the lactylome profiles of ESCs with and without a lactate dehydrogenase (Ldh) inhibitor, which suppresses the conversion of pyruvate to lactate, were depicted. It was notable that many lactylated proteins are involved in the self-renewal and differentiation of ESCs. We further showed that Esrrb, an orphan nuclear receptor involved in pluripotency maintenance and extraembryonic endoderm stem cell (XEN) differentiation, is lactylated on K228 and K232. Lactylation of Esrrb enhances its activity in promoting ESC self-renewal in the absence of LIF and XEN differentiation of ESCs, through increasing its binding at target genes. Our studies reveal the importance of protein lactation in the self-renewal and XEN differentiation of ESCs, and the underlying mechanism for glycolytic metabolism regulating cell fate choice.
Project description:Aerobic glycolysis (the Warburg effect) has been demonstrated to facilitate tumor progression by producing lactate, which has important roles as a proinflammatory and immunosuppressive mediator. However, how aerobic glycolysis is directly regulated is largely unknown. Here, we show that ectopic Zeb1 directly increases the transcriptional expression of HK2, PFKP and PKM2, which are glycolytic rate-determining enzymes, thus promoting the Warburg effect and breast cancer proliferation, migration, and chemoresistance in vitro and in vivo. In addition, Zeb1 exerts its biological effects to induce glycolytic activity in response to hypoxia via the PI3K/Akt/HIF-1α signaling axis, which contributes to fostering an immunosuppressive tumor microenvironment (TME). Mechanistically, breast cancer cells with ectopic Zeb1 expression produce lactate in the acidic tumor milieu to induce the alternatively activated macrophage M2-like phenotype through stimulation of the PKA/CREB signaling pathway. Clinically, the expression of Zeb1 is positively correlated with dysregulation of aerobic glycolysis, accumulation of M2-like tumor-associated macrophages (TAMs) and a poor prognosis in patients with breast cancer. In conclusion, these findings identify a Zeb1-dependent mechanism as a driver of breast cancer progression that acts by stimulating tumor-macrophage interplay, which could be a viable therapeutic target for the treatment of advanced human cancers.
Project description:The naive embryonic stem cells (nESCs) display unique characteristics mirroring naive pluripotency in vivo, but the molecular mechanisms underlying the self-renewal of nESCs remain incompletely understood. Here we analyzed stranded transcriptomes in mouse nESCs and epiblast-like cells (EpiLCs), and identified 135 long non-coding RNAs (lncRNAs) preferentially expressed in nESCs. We further investigated the functions of Lncenc1, a highly abundant lncRNA in mouse nESCs. Knockdown or knockout of Lncenc1 in mouse nESCs leads to significantly decreased expression of core pluripotency genes and significant reduction of colony formation capability. Furthermore, depletion of Lncenc1 down-regulates the glycolysis pathway, as indicated by significant decreases of glycolysis genes expression, glucose consumption, lactate production and Seahorse data. Mechanically, Lncenc1 associates with RNA-binding proteins PTBP1 and HNRNPK functionally. Together, we demonstrate that Lncenc1 regulates the glycolysis in mouse nESCs, suggesting novel functions of lncRNAs in linking energy metabolism and pluripotent stem cells.
Project description:The naive embryonic stem cells (nESCs) display unique characteristics mirroring naive pluripotency in vivo, but the molecular mechanisms underlying the self-renewal of nESCs remain incompletely understood. Here we analyzed stranded transcriptomes in mouse nESCs and epiblast-like cells (EpiLCs), and identified 135 long non-coding RNAs (lncRNAs) preferentially expressed in nESCs. We further investigated the functions of Lncenc1, a highly abundant lncRNA in mouse nESCs. Knockdown or knockout of Lncenc1 in mouse nESCs leads to significantly decreased expression of core pluripotency genes and significant reduction of colony formation capability. Furthermore, depletion of Lncenc1 down-regulates the glycolysis pathway, as indicated by significant decreases of glycolysis genes expression, glucose consumption, lactate production and Seahorse data. Mechanically, Lncenc1 associates with RNA-binding proteins PTBP1 and HNRNPK functionally. Together, we demonstrate that Lncenc1 regulates the glycolysis in mouse nESCs, suggesting novel functions of lncRNAs in linking energy metabolism and pluripotent stem cells.
Project description:Mammalian retinal metabolism favors aerobic glycolysis. However, the role of glycolytic metabolism in retinal morphogenesis remains unknown. We report that aerobic glycolysis is necessary for the early stages of retinal development. Taking advantage of an unbiased approach that combines the use of eye organoids and single-cell RNA sequencing, we identify specific glucose transporters and glycolytic genes in retinal progenitors. Next, we determine that the optic vesicle territory of mouse embryos displays elevated levels of glycolytic activity. At the functional level, we show that removal of Glucose transporter 1 and Lactate dehydrogenase A gene activity from developing retinal progenitors arrests eye morphogenesis. Surprisingly, we uncover that lactate-mediated upregulation of key eye-field transcription factors is controlled by the epigenetic modification of histone H3 acetylation through histone deacetylase activity. Our results identify an unexpected bioenergetic independent role of lactate as a signaling molecule necessary for mammalian eye morphogenesis.