Background: Cellular senescence is defined as an irreversible cell cycle arrest caused by various internal and external insults. While the metabolic dysfunction of senescent cells in normal tissue is relatively well-established, there is a lack of information regarding the metabolic features of senescent tumor cells.Methods: Publicly available single-cell RNA-sequencing data from the GSE166555 and GSE178341 datasets were utilized to investigate the metabolic features of senescent tumor cells. To validate the single-cell RNA-sequencing data, we performed senescence-associated β-galactosidase (SA-β-Gal) staining to identify senescent tumor cells in fresh frozen colorectal cancer tissue. We also evaluated nicotinamide adenine dinucleotide dehydrogenase–tetrazolium reductase (NADH-TR) and succinate dehydrogenase (SDH) activity using enzyme histochemical methods and compared the staining with SA-β-Gal staining. MTT assay was performed to reveal the complex 1 activity of the respiratory chain in in-vitro senescence model.Results: Single-cell RNA-sequencing data revealed an upregulation in the activity of complexes 1 and 2 in oxidative phosphorylation, despite overall mitochondrial dysfunction in senescent tumor cells. Both SA-β-Gal and enzyme histochemical staining using fresh frozen colorectal cancer tissues indicated a high correlation between SA-β-Gal positivity and NADH-TR/SDH staining positivity. MTT assay showed that senescent colorectal cancer cells exhibit higher absorbance in 600 nm wavelength.Conclusions: Senescent tumor cells exhibit distinct metabolic features, characterized by upregulation of complexes 1 and 2 in the oxidative phosphorylation pathway. NADH-TR and SDH staining represent efficient methods for detecting senescent tumor cells in colorectal cancer.

Secreted phosphoprotein 1 (SPP1), also known as osteopontin (OPN), is a multifunctional secreted factor implicated in inflammatory remodeling of adipose tissue. Here, we applied untargeted liquid chromatography–mass spectrometry (LC–MS)-based metabolomics to examine how different concentrations of SPP1 influence metabolism in differentiated 3T3-L1 adipocytes. We found that low-dose SPP1 (100 ng/mL) was associated with more pronounced intracellular metabolic remodeling than higher-dose SPP1 (500 ng/mL). Multivariate analyses, including principal component analysis (PCA), partial least squares–discriminant analysis (PLS-DA), and sparse PLS-DA, revealed a distinct metabolic profile in the low-dose group, whereas the high-dose group showed a comparatively attenuated metabolic response. Pathway enrichment analysis identified alterations in carbohydrate- and amino acid-related metabolic networks, including the pentose phosphate pathway; pentose and glucuronate interconversions; and alanine, aspartate, and glutamate metabolism. In contrast, higher-dose SPP1 was associated with selective induction of matrix metalloproteinase-12 (MMP-12), suggesting the engagement of remodeling-associated responses at elevated SPP1 levels. Together, these findings identify SPP1 as a modulator of metabolic programs in mature adipocytes and highlight its capacity to influence intracellular metabolic remodeling.

Drug-induced liver injury accounts for approximately 10% of acute hepatitis and up to 50% of acute liver failure. Despite its clinical significance, treatment remains largely limited to cessation of the offending agent. SLIT/ROBO signaling, known for roles in organ development, angiogenesis, leukocyte migration, and cancer metastasis, has demonstrated protective effects against various organ damage. In mouse models of liver injury induced by acetaminophen (APAP), thioacetamide, bile duct ligation, and serum from patients with toxic liver disease, Slit2 expression significantly increases, while Slit1 and Slit3 remain unchanged. Liver-specific Slit2 knockdown exacerbates liver injury, whereas recombinant SLIT2 alleviates liver damage by reducing oxidative stress via CYP2E1 downregulation and suppressing inflammation through NF-κB inhibition. Notably, among ROBO receptors, only ROBO4 was induced in hepatocytes after APAP exposure. ROBO4 knockdown eliminates the hepatoprotective effects of SLIT2, highlighting the importance of SLIT2/BOBO4 signaling in toxic liver injury. Furthermore, a novel Slit2-derived peptide-5 (SP5), designed from the ROBO4-binding LRR2 domain, significantly reduces liver damage and inflammation. Notably, both recombinant SLIT2 and SP5 confer hepatoprotection even when administered 24 hours after APAP challenge. These findings suggest that SLIT2/ROBO4-targeted therapies may offer a promising approach for preventing fulminant hepatitis in the context of toxic liver injury.