Single-cell multiome uncovers differences in glycogen metabolism underlying species-specific speed of development [mTORi]
Ontology highlight
ABSTRACT: Embryos from different mammalian species develop at characteristic timescales. These timescales are recapitulated during the differentiation of pluripotent stem cells in vitro. Specific genes and molecular pathways that modulate cell differentiation speed between mammalian species remain to be identified. Here we use single-cell multi-omic analysis of neural differentiation of mouse, cynomolgus monkey and human pluripotent cells to identify new regulators for differentiation speed. We demonstrate that species-specific differences in transcriptome dynamics are mirrored at the chromatin level, but that, contrary to other developmental contexts, the speed of neural differentiation is insensitive to manipulations of cell growth and cycling. Exploiting the single-cell resolution of our data, we identify glycogen storage levels regulated by UGP2 expression as a new species-specific trait of pluripotent cells, and show that lowered glycogen storage in UGP2 mutant cells is associated with accelerated neural differentiation. The control of energy storage could be a general strategy for the regulation of cell differentiation speed.
ORGANISM(S): Mus musculus Homo sapiens Macaca fascicularis
Project description:Embryos from different mammalian species develop at characteristic timescales. These timescales are recapitulated during the differentiation of pluripotent stem cells in vitro. Specific genes and molecular pathways that modulate cell differentiation speed between mammalian species remain to be identified. Here we use single-cell multi-omic analysis of neural differentiation of mouse, cynomolgus monkey and human pluripotent cells to identify new regulators for differentiation speed. We demonstrate that species-specific differences in transcriptome dynamics are mirrored at the chromatin level, but that, contrary to other developmental contexts, the speed of neural differentiation is insensitive to manipulations of cell growth and cycling. Exploiting the single-cell resolution of our data, we identify glycogen storage levels regulated by UGP2 expression as a new species-specific trait of pluripotent cells, and show that lowered glycogen storage in UGP2 mutant cells is associated with accelerated neural differentiation. The control of energy storage could be a general strategy for the regulation of cell differentiation speed.
Project description:Embryos from different mammalian species develop at characteristic timescales. These timescales are recapitulated during the differentiation of pluripotent stem cells in vitro. Specific genes and molecular pathways that modulate cell differentiation speed between mammalian species remain to be identified. Here we use single-cell multi-omic analysis of neural differentiation of mouse, cynomolgus monkey and human pluripotent cells to identify new regulators for differentiation speed. We demonstrate that species-specific differences in transcriptome dynamics are mirrored at the chromatin level, but that, contrary to other developmental contexts, the speed of neural differentiation is insensitive to manipulations of cell growth and cycling. Exploiting the single-cell resolution of our data, we identify glycogen storage levels regulated by UGP2 expression as a new species-specific trait of pluripotent cells, and show that lowered glycogen storage in UGP2 mutant cells is associated with accelerated neural differentiation. The control of energy storage could be a general strategy for the regulation of cell differentiation speed.
Project description:Background: Exercise mimetics is a proposed class of therapeutics that specifically mimics or enhances the therapeutic effects of exercise. Muscle glycogen and lactate extrusion are critical for physical performance. The mechanism by which glycogen and lactate metabolism are manipulated during exercise remains unclear. This study aimed to assess the effect of miR-92b on the upregulation of exercise training-induced physical performance. Methods: Adeno-associated virus (AAV)-mediated skeletal muscle miR-92b overexpression in C57BLKS/J mice, and global knockout of miR-92b mice were used to explore the function of miR-92b in glycogen and lactate metabolism in skeletal muscle. AAV-mediated UGP2 or MCT4 knockdown in WT or miR-92 knockout mice was used to confirm whether miR-92b regulates glycogen and lactate metabolism in skeletal muscle through UGP2 and MCT4. Body weight, muscle weight, grip strength, running time and distance to exhaustion, and muscle histology were assessed. The expression levels of muscle mass-related and functionrelated proteins were analysed by immunoblotting or immunostaining. Results: Global knockout of miR-92b resulted in normal body weight and insulin sensitivity, but higher glycogen content before exercise exhaustion (0.8538 ± 0.0417 vs 1.043 ± 0.040, **P=0.0087), lower lactate levels after exercise exhaustion (4.133 ± 0.2589 vs 3.207 ± 0.2511, *P=0.0279), and better exercise capacity (running distance to exhaustion, 3616 ± 86.71 vs 4231 ± 90.29, ***P=0.0006; running time to exhaustion, 186.8 ± 8.027 vs 220.8 ± 3.156, **P=0.0028), as compared to those observed in the control mice. Mice skeletal muscle overexpressing miR-92b (both miR-92b-3p and miR-92b-5p) displayed lower glycogen content before exercise exhaustion (0.6318 ± 0.0231 vs 0.535 ± 0.0194, **P=0.0094), and higher lactate accumulation after exercise exhaustion (4.5 ± 0.2394 vs 5.467 ± 0.1892, *P=0.01), and poorer exercise capacity (running distance to exhaustion, 4005 ± 81.65 vs 3228 ± 149.8, ***P<0.0001; running time to exhaustion, 225.5 ± 7.689 vs 163 ± 6.476, **P=0.001). Mechanistic analysis revealed that miR-92b-3p targets UDP-glucose pyrophosphorylase 2 (UGP2) expression to inhibit glycogen synthesis, while miR-92b-5p represses lactate extrusion by directly target monocarboxylate transporter 4 (MCT4). Knockdown of UGP2 and MCT4 reversed the effects observed in the absence of miR-92b in vivo. Conclusions: This study revealed regulatory pathways, including miR-92b-3p/UGP2/glycogen synthesis and miR-92b-5p/MCT4/lactate extrusion, which could be targeted to control exercise capacity.
Project description:We report transcriptome analysis of human embryonic stem cells and in vitro differentiated neural stem cells, comparing wild type H9, UGP2 homozygous knock-out and UGP2 mutant cells harboring a homozygous A>G nucleotide change affecting the start codon of UGP2 isoform 2 that was introduced by CRISPR-Cas9 engineering
Project description:Glycogen is the largest soluble cytosolic macromolecule and considered as the principal storage form of glucose. Cancer cells generally increase their glucose consumption and rewire their metabolism towards aerobic glycolysis to promote growth. Here we report that glycogen accumulation is a key initiating oncogenic event and essential for malignant transformation. RNA-sequencing analysis reveals that G6PC, an enzyme catalyzing the last step of glycogenolysis, is frequently downregulated to augment glucose storage in pro-tumor cells. Accumulated glycogen undergoes liquid-liquid phase separation undergoes liquid-liquid phase separation, which results in the assembly of the laforin-Mst1/2 complex and consequently traps Hippo kinases Mst1/2 in glycogen liquid droplets to relieve their inhibition on Yap. Moreover, G6PC or another glycogenolysis enzyme PYGL deficiency in both human and mice result in glycogen storage disease with enlarged liver size and cancer development, phenocopying Hippo deficiency. Consistently, elimination of glycogen accumulation abrogates liver enlargement and cancer incidence, whereas increasing glycogen storage accelerates tumorigenesis. Thus, we concluded that glycogen not only provides nutrition and energy to the cells but also functions as a key initiating oncogenic metabolite, which physically blocks Hippo signaling through glycogen phase separation to augment pro-tumor cell initiation and progression.
Project description:Single-cell multiome uncovers differences in glycogen metabolism underlying species-specific speed of development [scRNAseq and scATACseq]