The tumor microenvironment (TME) represents a metabolic battleground where immune cells and cancer cells vie for essential nutrients, ultimately influencing antitumor immunity and treatment outcomes. Recent advancements have shed light on how the metabolic reprogramming of immune cells, including macrophages, T cells, and DCs, determines their functional polarization, survival, and interactions within the TME. Factors such as hypoxia, acidosis, and nutrient deprivation drive immune cells toward immunosuppressive phenotypes, while metabolic interactions between tumors and stromal cells further entrench therapeutic resistance. This review synthesizes new insights into the metabolic checkpoints that regulate immune cell behavior, focusing on processes like glycolysis, oxidative phosphorylation (OXPHOS), lipid oxidation, and amino acid dependencies. We emphasize how metabolic enzymes (e.g., IDO1, ACLY, CPT1A) and metabolites (e.g., lactate, kynurenine) facilitate immune evasion, and we propose strategies to reverse these pathways. Innovations such as single-cell metabolomics, spatial profiling, and AI-driven drug discovery are transforming our understanding of metabolic heterogeneity and its clinical implications. Furthermore, we discuss cutting-edge therapeutic approaches—from dual-targeting metabolic inhibitors to biomaterial-based delivery systems—that aim to reprogram immune cell metabolism and enhance the effectiveness of immunotherapy. Despite the promise in preclinical studies, challenges persist in translating these findings to clinical applications, including biomarker validation, metabolic plasticity, and interpatient variability. By connecting mechanistic discoveries with translational applications, this review highlights the potential of immunometabolic targeting to overcome resistance and redefine precision oncology.

Subarachnoid hemorrhage (SAH) is a devastating stroke, in which acidosis is one of detrimental complications. The extracellular pH reduction can activate G protein-coupled receptor 4 (GPR4) in the brain. Yet, the extent to which proton-activated GPR4 contributes to the early brain injury (EBI) post-SAH remains largely unexplored. Ferroptosis, iron-dependent programmed cell death, has recently been shown to contribute to EBI. We aimed to investigate the effects of GPR4 inhibition on neurological deficits and neuronal ferroptosis after SAH in rats. A total 253 Sprague Dawley (SD) male rats (weighing 275-330g) were utilized in this study. SAH was induced by endovascular perforation. NE-52-QQ57 (NE), a selective antagonist of GPR4 was administered intraperitoneally 1-hour post-SAH. To explore the mechanisms, RhoA activator U-46619 and YAP activator PY-60 were delivered intracerebroventricularly. Short- and long-term neurobehavior, SAH grading, western blot assay, ELISA assay, immunofluorescence staining, and transmission electron microscopy was performed post-SAH. Following SAH, there was an upregulation of GPR4 expression in neurons. GPR4 inhibition by NE improved both short-term and long-term neurological outcomes post-SAH. NE also reduced neuronal ferroptosis, as evidenced by decreased lipid peroxidation products 4HNE and MDA levels in brain tissues, and reduced mitochondrial shrinkage, increased mitochondria crista and decreased membrane density. The application of either U-46619 or PY-60 partially offset the neuroprotective effects of NE on neuronal ferroptosis in SAH rats. This study demonstrated that acid-sensing receptor GPR4 contributed to neuronal ferroptosis after SAH via RhoA/YAP pathway, and NE may be a potential therapeutic strategy to attenuate GPR4 mediated neuronal ferroptosis and EBI after SAH.

Objectives: Poor immune-nutritional status has been associated with an unfavorable outcome in critical illness. The Osaka prognostic score (OPS) and the Naples prognostic score (NPS), based on inflammatory and nutritional status, has been shown to predict prognosis following cancer and other diseases. The aim of this study was to investigate the relationship between the OPS and NPS and the short-term outcomes of patients with intracerebral hemorrhage (ICH). Methods: We retrospectively analyzed the clinical data of patients hospitalized with spontaneous ICH (n = 340) at The Second Affiliated Hospital of Chongqing Medical University between August 2016 and August 2021. Inclusion criteria included patients aged between 18 and 70, and if a blood sample was taken for laboratory testing within 24 h of admission (serum C-reactive protein, albumin, total cholesterol, and counts for neutrophils, lymphocytes, and monocytes were collected on admission). Exclusion criteria included a non-spontaneous cause of ICH and patient death during hospitalization. Patients were divided into four groups based on OPS or five groups according to NPS. Outcomes were evaluated by the modified Rankin Scale (mRS) at six months post-ICH hospitalization. An unfavorable outcome was defined as a mRS score ≥ 3. Results: A total of 289 patients met our inclusion criteria. The unfavorable outcome group had older age, a lower Glasgow Coma Scale score, a higher rate of complications and cerebral herniation, a longer hospital stay, and higher OPS and NPS when compared with the favorable outcome group. Univariate analysis showed that both OPS and NPS were strongly correlated with mRS (r = 0.196,P < 0.001; r = 0.244, P = 0.001, respectively). Multivariate analysis further showed that OPS and NPS were both independent predictors of unfavorable outcomes for patients with ICH with adjusted odds ratios of 1.802 (95% confidence interval [CI]:1.140–2.847, P = 0.012) and 1.702 (95% CI: 1.225–2.635, P = 0.02), respectively. The area under the curve (AUC) of NPS for predicting a poor outcome was 0.732 (95% CI: 0.665–0.799), which was similar to the AUC of OPS 0.724 (95% CI: 0.657–0.792). Conclusions: In this cohort, a higher OPS and NPS on admission was associated with poor outcome at six months following ICH, supporting their potential role as markers for predicting the outcome of patients with ICH.

Ferroptosis contributes to brain injury after germinal matrix hemorrhage (GMH). Mitochondrial ferritin (FTMT), a novel mitochondrial outer membrane protein, reduces oxidative stress in neurodegenerative diseases. In vitro, Deferiprone has been shown to upregulate FTMT. However, the effects of FTMT upregulation by Deferiprone on neuronal ferroptosis after GMH and its underlying mechanism has not been investigated. In our study, 389 Sprague-Dawley rat pups of postnatal day 7 were used to establish a collagenase-induced GMH model and an iron-overload model of intracerebral FeCl₂ injection. The brain expressions of FTMT, N-myc downstream-regulated gene-1 (NDGR1), Yes-associated protein (YAP), ferroptosis-related molecules including transferrin receptor (TFR) and acyl-CoA synthase long-chain family member 4 (ACSL4) were increased after GMH. FTMT agonist Deferiprone improved neurological deficits and hydrocephalus after GMH. Deferiprone or Adenovirus-FTMT enhanced YAP phosphorylation at the Ser¹²⁷ site and attenuated ferroptosis, which was reversed by NDRG1 CRISPR Knockout. Iron overload induced neuronal ferroptosis and neurological deficits, which were improved by YAP CRISPR Knockout. Collectively, FTMT upregulation by Deferiprone reduced neuronal ferroptosis and neurological deficits via the NDRG1/YAP signaling pathway after GMH. Deferiprone may serve as a potential non-invasive treatment for GMH patients.