Cell metabolism最新文献

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.

An abundance of publications is drawing attention to the decrements in skeletal muscle mass accompanying weight loss mediated by glucagon-like peptide-1 receptor agonists. Herein we advance three suggestions for improving the clarity of these reports that will lead to their improved interpretation by the scientific community.

Purified diets offer compositionally defined platforms that improve causal inference in nutrition studies. When aligned with the biological question, they enable targeted nutrient loss- and gain-of-function experiments, systematic lipid-source swaps, and the discovery of diet-microbiome-drug interactions. We recommend complementary validation in grain-based chow or human-relevant diets to maximize translational relevance.

Purified diets widely used in rodent studies lack bioactive compounds from whole foods that affect gut microbiota and host physiology; this may cause contradictory outcomes in some studies. Prioritizing biological relevance over compositional reproducibility and reassessing dietary models are crucial for improving scientific rigor.

Dietary interventions hold promise for cancer therapy but often require prolonged, poorly tolerated regimens. Furthermore, how transient nutrient deprivation affects the metabolic interplay between tumor and immune cells within the tumor microenvironment (TME) remains unknown. Here, we introduce a brief, 16-h fasting regimen that enhances immunotherapy efficacy in both mice and humans. We found that this transient nutrient stress alters tumor-cell nutrient preferences, creating a metabolic window that can be leveraged to augment treatment. Mechanistically, short-term fasting induces intratumoral accumulation of isoleucine, which reconfigures CD8⁺ T cell epigenetic programs and phospholipid remodeling, thereby licensing enhanced anti-tumor capacity. In patients receiving neoadjuvant immunotherapy, short-term fasting was able to enhance CD8⁺ clonal expansion and cytotoxic programs. These findings establish a clinically feasible, well-tolerated dietary regimen that counters nutrient competition in the TME and that provides a tractable path to strengthen existing immunotherapy regimens.

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.

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.

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.

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.