Cell metabolism最新文献

Recurrent spontaneous abortion (RSA), often linked to defective endometrial stromal cell (ESC) decidualization, lacks effective metabolism-targeted therapies. Here, we identify the in situ synthesis of trimethylamine N-oxide (TMAO) in human decidua as a critical safeguard. Metabolomics revealed significantly lower TMAO levels in decidual tissues of individuals experiencing RSA. Mechanistically, cyclic AMP (cAMP)-protein kinase A (PKA)-cAMP-responsive element-binding protein 1 (CREB1) signaling upregulated flavin-containing monooxygenase 3 (FMO3) in ESCs, driving local TMAO accumulation. TMAO directly bound the C terminus of 14-3-3η, enhancing its interaction with phosphoinositide-dependent protein kinase 1 (PDK1) to relieve PDK1-mediated suppression of forkhead box protein O1 (FOXO1). This promoted FOXO1 nuclear translocation and the activation of decidualization markers. Through mouse models employing dietary choline restriction, and FMO3 inhibition via pharmacological or genetic knockout, we demonstrated that endometrial TMAO deficiency impairs decidualization and increases pregnancy loss. Strikingly, TMAO restored decidualization capacity in 15% of patient-derived ESCs with inherent dysfunction. Our findings unveil endometrial TMAO synthesis as a metabolic checkpoint for decidualization and propose it as a therapeutic candidate for RSA.

Therapeutic resistance in solid tumors frequently stems from enhanced homologous recombination (HR) repair capacity, yet systemic regulators of this pathway remain poorly defined. Here, we identify a serotonin-sensitive tumor-associated macrophage (TAM) subpopulation that orchestrates inositol metabolic crosstalk to potentiate HR repair in cancer cells. This TAM subset exhibited marked enrichment in ovarian tumors with low response to chemotherapy. Mechanistically, peripheral serotonin activates these TAMs via serotonin receptor HTR7, triggering extracellular vesicle (EV) secretion enriched with inositol metabolic enzymes PI4K2A and ITPKC. EV-mediated transfer of these metabolic enzymes elevates nuclear inositol-1,3,4,5-tetraphosphate (IP4) in cancer cells, where IP4 directly binds MRE11 and facilitates MRE11-DNA binding and HR repair. Attenuating peripheral serotonin using fluoxetine-a selective serotonin reuptake inhibitor (SSRI) antidepressant-ablates TAM-derived EV delivering of inositol metabolic enzymes and sensitizes tumors to cisplatin/PARP inhibitor (PARPi). Our study unveils a systemic serotonin-primed metabolic crosstalk within the tumor microenvironment that potentiates chemoresistance, revealing targetable HR repair regulation beyond cancer-cell-autonomous mechanisms.

Under normoxia, von Hippel-Lindau (VHL) protein targets the oxygen-induced, hydroxylated α subunits of hypoxia-inducible factors (HIFs) for degradation to orchestrate mammalian oxygen sensing. However, whether VHL plays non-canonical roles in hypoxia, when protein hydroxylation is attenuated, remains elusive. Here, we show that most cytosolic VHL is degraded under chronic hypoxia, with the remaining VHL pool primarily translocating to the mitochondria. Mitochondrial VHL binds and inhibits 3-methylcrotonyl-coenzyme A carboxylase subunit 2 (MCCC2), an essential subunit of the leucine catabolic machinery. Accumulated leucine allosterically activates glutamate dehydrogenase to promote glutaminolysis, generating sufficient lipids and nucleotides to support hypoxic cell growth. Furthermore, SRC-mediated VHL phosphorylation and protein arginine methyltransferase 5 (PRMT5)-mediated MCCC2 methylation synergistically regulate the VHL-MCCC2 interaction and concomitant metabolic changes, which are recapitulated in animal models of ischemic injury and functionally associated with VHL mutations in cancer. Our study highlights VHL as a bona fide regulator of hypoxic metabolism within mitochondria, rather than a solely "standby adaptor" for HIFs under hypoxia.

Mutations that impair the function of the melanocortin 4 receptor (MC4R) cause severe obesity in both heterozygous and homozygous carriers. However, recent findings indicate that individuals with this form of monogenic obesity may be unexpectedly protected against dyslipidemia and cardiovascular diseases.

Lipogenesis is one of the main drivers of metabolic dysfunction-associated steatotic liver disease (MASLD). The previewed work decreased acetyl-CoA by inhibiting ATP citrate lyase (ACLY) and acyl-CoA synthetase short-chain family member 2 (ACSS2) via EVT0185, thus inhibiting lipogenesis, hepatocyte metabolic stress, and hepatic stellate cell activation, reducing liver fibrosis.

Immune checkpoint blockade (ICB) faces limitations owing to high cost and restricted efficacy. This study identifies SNX17 as a key mediator of ICB resistance. Elevated SNX17 correlates with poor anti-PD-1 response in humans and mice. SNX17 deletion in tumor cells inhibits tumor growth via CD8⁺ T cell-dependent mechanisms. SNX17 reduces uridine in the tumor microenvironment (TME), suppressing IFN-γ and upregulating PD1 in CD8⁺ T cells. Exogenous uridine shows antitumor efficacy comparable to anti-PD-1/PD-L1 in low-SNX17 tumors and overcomes resistance in high-SNX17 models. Uridine enhances CD8⁺ T cell function by promoting CD45 N-glycosylation and LCK phosphorylation. Mechanistically, SNX17 stabilizes RUNX2, promoting UPP1 transcription and uridine degradation in the TME. These findings position SNX17 as an ICB response biomarker and nominate uridine as a cost-effective immunotherapeutic strategy.

Westernization of diet, partly characterized by long-chain fatty acid excess, perturbs intestinal immune responses in Crohn's disease (CD). The cellular and molecular framework of lipid sensing in intestinal inflammation remains enigmatic. By small intestinal transcriptional profiling of CD, we identified increased transcriptional activity of retinoid X receptor alpha (RXRα) specifically in intestinal epithelial cells (IECs). Transcriptional RXRα activity was induced in IECs of mice by ω-3 and ω-6 polyunsaturated fatty acid (PUFA) excess in a Western diet. PUFA-induced RXRα activity in Paneth cells governed chronic transmural enteritis by enabling the expression of CXCL1. Oral exposure to isotretinoin ameliorated PUFA-induced metabolic enteritis in two mouse models, and isotretinoin therapy reduced the odds of developing CD in an analysis of electronic health care records from 170,597 patients. Collectively, we identify RXRα in Paneth cells as a metabolic stress sensor that enables enteritis, providing novel perspectives for the prevention and treatment of CD.

Quercetin, a dietary flavonol, shows promise in cancer prevention, though its effects on the immune compartment within the tumor microenvironment are not fully understood. Here, we identify 3,4-dihydroxyphenylacetic acid (DOPAC), a microbial metabolite of quercetin, as a critical mediator of its anti-tumor effects in a CD8⁺ T cell-dependent manner. Mechanistically, DOPAC directly binds to Kelch-like epichlorohydrin-associated protein 1 (KEAP1), disrupting its interaction with nuclear factor erythroid 2-related factor 2 (NRF2) and preventing KEAP1-mediated degradation of NRF2 in CD8⁺ T cells. Elevated NRF2 transcriptionally enhances the expression of B cell lymphoma 2-interacting protein 3, promoting mitophagy and mitochondrial functionality, which improves CD8⁺ T cell fitness within the tumor microenvironment. Furthermore, DOPAC synergizes with immune checkpoint blockade to suppress tumor growth. Our findings underscore the role of microbial metabolites of dietary nutrients in modulating anti-tumor immune responses, positioning DOPAC as a promising candidate for cancer immunotherapy.