Effects of 3-HAA on HCC by Regulating the Heterogeneous Macrophages-A scRNA-Seq Analysis

Alterations of serum metabolic profile in major depressive disorder: A case-control study in the Chinese population

BACKGROUND

Major depressive disorder (MDD) is characterized by persistent depressed mood and cognitive symptoms. This study aimed to discover biomarkers for MDD, explore its pathological mechanisms, and examine the associations of the identified biomarkers with clinical and psychological variables.

AIM

To discover candidate biomarkers for MDD identification and provide insight into the pathological mechanism of MDD.

METHODS

The current study adopted a single-center cross-sectional case-control design. Serum samples were obtained from 100 individuals diagnosed with MDD and 97 healthy controls (HCs) aged between 18 to 60 years. Metabolomics was performed on an Ultimate 3000 UHPLC system coupled with Q-Exactive MS (Thermo Scientific). The online software Metaboanalyst 6.0 was used to process and analyze the acquired raw data of peak intensities from the instrument.

RESULTS

The study included 100 MDD patients and 97 HCs. Metabolomic profiling identified 35 significantly different metabolites (e.g., cortisol, sebacic acid, and L-glutamic acid). Receiver operating characteristic curve analysis highlighted 8-HETE, 10-HDoHE, cortisol, 12-HHTrE, and 10-hydroxydecanoic acid as top diagnostic biomarkers for MDD. Significant correlations were found between metabolites (e.g., some lipids, steroids, and amino acids) and clinical and psychological variables.

CONCLUSION

Our study reported metabolites (some lipids, steroids, amino acids, carnitines, and alkaloids) responsible for discriminating MDD patients and HCs. This metabolite profile may enable the development of a laboratory-based diagnostic test for MDD. The mechanisms underlying the association between psychological or clinical variables and differential metabolites deserve further exploration.

Targeting the kynurenine pathway in gliomas: Insights into pathogenesis, therapeutic targets, and clinical advances

Gliomas, the most prevalent primary brain tumors, continue to present significant challenges in oncology due to poor patient prognosis despite advances in treatment such as immunotherapy and cancer vaccines. Recent research highlights the potential of targeting tryptophan metabolism, particularly the kynurenine pathway (KP) and combinatorial approaches with immunotherapies, as a promising strategy in cancer research. The key enzymes of the kynurenine pathway, such as IDO1, IDO2, and TDO, and metabolites like kynurenine, kynurenic acid, and quinolinic acid, are implicated in fostering an immunosuppressive tumor microenvironment and promoting glioma cell survival. In glioblastoma, a highly aggressive glioma subtype, elevated IDO and TDO expression correlates with reduced survival rates. KP metabolites, such as kynurenine (KYN), 3-hydroxykynurenine (3-HK), kynurenic acid (KYNA), and quinolinic acid (QUIN), are involved in modulating immune responses, oxidative stress, neuroprotection, and neurotoxicity. This review synthesizes recent findings on the kynurenine pathway involvement in glioma pathogenesis, examining potential therapeutic targets within this pathway and discussing ongoing clinical trials that draw attention to treatments based on this pathway. Furthermore, it highlights novel findings on the post-translational modifications of kynurenine pathway enzymes and their regulatory roles, presenting their potential as therapeutic targets in gliomas.

Integration of bulk RNA-seq and scRNA-seq reveals transcriptomic signatures associated with deep vein thrombosis

Background

Deep vein thrombosis (DVT) is a prevalent peripheral vascular disease. The intricate and multifaceted nature of the associated mechanisms hinders a comprehensive understanding of disease-relevant targets. This study aimed to identify and examine the most distinctive genes linked to DVT.

Methods

In this study, the bulk RNA sequencing (bulk RNA-seq) analysis was conducted on whole blood samples from 11 DVT patients and six control groups. Topology analysis was performed using seven protein-protein interaction (PPI) network algorithms. The combination of weighted correlation network analysis (WGCNA) and clinical prediction models was employed to validate hub DEGs. Furthermore, single-cell RNA sequencing (scRNA-seq) was performed on peripheral blood samples from 3 DVT patients and three control groups to probe the cellular localization of target genes. Based on the same methodology as the internal test set, 12 DVT patients and six control groups were collected to construct an external test set and validated using machine learning (ML) algorithms and immunofluorescence (IF). Concurrently, the examination of the pathways in disparate cell populations was conducted on the basis of the CellChat pathway.

Results

A total of 193 DEGs were identified in the internal test set. Additionally, a total of eight highly characteristic genes (including TLR1, TLR7, TLR8, CXCR4, DDX58, TNFSF10, FCGR1A and CD36) were identified by the PPI network algorithm. In accordance with the WGCNA model, the aforementioned genes were all situated within the blue core module, exhibiting a correlation coefficient of 0.84. The model demonstrated notable disparities in TLR8 (P = 0.018, AUC = 0.847), CXCR4 (P = 0.00088, AUC = 1.000), TNFSF10 (P = 0.00075, AUC = 0.958), and FCGR1A (P = 0.00022, AUC = 0.986). Furthermore, scRNA-seq demonstrated that B cells, T cells and monocytes play an active role in DVT. In the external validation set, CXCR4 was validated as a potential target by the ML algorithm and IF. In the context of the CellChat pathway, it indicated that MIF - (CD74 + CXCR4) plays a potential role.

Conclusion

The findings of this study indicate that CXCR4 may serve as a potential genetic marker for DVT, with MIF - (CD74 + CXCR4) potentially implicated in the regulatory mechanisms underlying DVT.

Promising Gastric Cancer Biomarkers-Focus on Tryptophan Metabolism via the Kynurenine Pathway

Currently, gastric cancer treatment remains an enormous challenge and requires a multidisciplinary approach. Globally, the incidence and prevalence of gastric cancer vary, with the highest rates found in East Asia, Central Europe, and Eastern Europe. Early diagnosis is critical for successful surgical removal of gastric cancer, but the disease often develops asymptomatically. Therefore, many cases are diagnosed at an advanced stage, resulting in poor survival. Metastatic gastric cancer also has a poor prognosis. Therefore, it is urgent to identify reliable molecular disease markers and develop an effective medical treatment for advanced stages of the disease. This review summarizes potential prognostic or predictive markers of gastric cancer. Furthermore, the role of tryptophan metabolites from the kynurenine pathway as prognostic, predictive, and diagnostic factors of gastric cancer is discussed, as this metabolic pathway is associated with tumor immune resistance.

Analysis of Tryptophan Metabolic Profile Characteristics and Clinical Value in Differentiated Thyroid Cancer Patients

BACKGROUND

Differentiated thyroid cancer (DTC) is the primary subtype of thyroid cancer. Timely diagnosis and intervention are crucial for improving prognosis and survival. However, the effectiveness of existing serum markers is limited, necessitating the discovery of new biomarkers.

METHODS

This study utilized liquid chromatography-tandem mass spectrometry to analyze tryptophan metabolic profiles in serum samples from 105 DTC patients and 50 healthy controls. Independent predictors of DTC were identified through univariate intergroup comparisons and multivariate logistic regression analysis, leading to the development and validation of a new diagnostic model.

RESULTS

Significant differences were observed in 11 tryptophan metabolites between DTC patients and controls. Logistic regression identified nicotinamide, 3-hydroxyanthranilic acid, 5-hydroxytryptophan, melatonin, and indole-3-propionic acid as independent predictors. The nomogram prediction model was established based on these five metabolites, and according to the Hosmer-Lemeshow test, the model showed good fit. The five-metabolite diagnostic model demonstrated 84.8% sensitivity, 90.0% specificity, and an area under the ROC curve of 0.932. Decision curve analysis indicated that the model had significant advantages over serum thyroglobulin.

DISCUSSION

Tryptophan metabolism exhibits distinct changes in DTC patients, with specific metabolites serving as early diagnostic markers. The five-metabolite panel demonstrates potential for improving early detection and management of DTC.

Aromatic Amino Acid Metabolites: Molecular Messengers Bridging Immune-Microbiota Communication

Aromatic amino acid (AAA) metabolites, derived from tryptophan, phenylalanine, and tyrosine through coordinated host and microbial metabolism, have emerged as critical modulators of immune function. We examine the complex journey of AAAs from dietary intake through intestinal absorption and metabolic transformation, highlighting the crucial role of host-microbe metabolic networks in generating diverse immunomodulatory compounds. This review provides a unique integrative perspective by mapping the molecular mechanisms through which these metabolites orchestrate immune responses. Through detailed analysis of metabolite-receptor and metabolite-transporter interactions, we reveal how specific molecular recognition drives cell type-specific immune responses. Our comprehensive examination of signaling networks-from membrane receptor engagement to nuclear receptor activation to post-translational modifications- demonstrates how the same metabolite can elicit distinct functional outcomes in different immune cell populations. The context-dependent nature of these molecular interactions presents both challenges and opportunities for therapeutic development, particularly in inflammatory conditions where metabolite signaling pathways are dysregulated. Understanding the complexity of these regulatory networks and remaining knowledge gaps is fundamental for advancing metabolite-based therapeutic strategies in immune-mediated disorders.

Role of Kynurenine and Its Derivatives in Liver Diseases: Recent Advances and Future Clinical Perspectives

Liver health is integral to overall human well-being and the pathogenesis of various diseases. In recent years, kynurenine and its derivatives have gradually been recognized for their involvement in various pathophysiological processes, especially in the regulation of liver diseases, such as acute liver injury, non-alcoholic fatty liver disease, cirrhosis, and liver cancer. Kynurenine and its derivatives are derived from tryptophan, which is broken down by the enzymes indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO), converting the essential amino acid tryptophan into kynurenine (KYN) and other downstream metabolites, such as kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), xanthurenic acid (XA), and quinolinic acid (QA). In liver diseases, kynurenine and its derivatives can promote the activity of the transcription factor aryl hydrocarbon receptor (AhR), suppress T cell activity for immune modulation, inhibit the activation of inflammatory signaling pathways, such as NF-κB for anti-inflammatory effects, and inhibit the activation of hepatic stellate cells to slow down fibrosis progression. Additionally, kynurenine and other downstream metabolites can influence the progression of liver diseases by modulating the gut microbiota. Therefore, in this review, we summarize and explore the mechanisms by which kynurenine and its derivatives regulate liver diseases to help develop new diagnostic or prognostic biomarkers and effective therapies targeting the kynurenine pathway for liver disease treatment.

A chimeric peptide promotes immune surveillance of senescent cells in injury, fibrosis, tumorigenesis and aging

The accumulation of senescent cells can lead to tissue degeneration, chronic inflammatory disease and age-related tumorigenesis. Interventions such as senolytics are currently limited by off-target toxicity, which could be circumvented by instead enhancing immune-mediated senescent cell clearance; however, immune surveillance of senescent cells is often impeded by immunosuppressive factors in the inflammatory microenvironment. Here, we employ a chimeric peptide as a 'matchmaker' to bind to the urokinase-type plasminogen activator receptor, a cell surface marker of senescent cells. This peptide modifies the cell surface with polyglutamic acid, promoting immune cell-mediated responses through glutamate recognition. By enhancing the recruitment of immune cells and directly coupling senescent cells and immune cells, we show that this chimeric peptide induces immune clearance of senescent cells and restores tissue homeostasis in conditions such as liver fibrosis, lung injury, cancer and natural aging in mice. This chimeric peptide introduces an immunological conversion strategy that rebalances the senescent immune microenvironment, offering a promising direction for aging immunotherapy.

Redefining Roles: A Paradigm Shift in Tryptophan-Kynurenine Metabolism for Innovative Clinical Applications

The tryptophan-kynurenine (KYN) pathway has long been recognized for its essential role in generating metabolites that influence various physiological processes. Traditionally, these metabolites have been categorized into distinct, often opposing groups, such as pro-oxidant versus antioxidant, excitotoxic/neurotoxic versus neuroprotective. This dichotomous framework has shaped much of the research on conditions like neurodegenerative and neuropsychiatric disorders, as well as cancer, where metabolic imbalances are a key feature. The effects are significantly influenced by various factors, including the concentration of metabolites and the particular cellular milieu in which they are generated. A molecule that acts as neuroprotective at low concentrations may exhibit neurotoxic effects at elevated levels. The oxidative equilibrium of the surrounding environment can alter the function of KYN from an antioxidant to a pro-oxidant. This narrative review offers a comprehensive examination and analysis of the contemporary understanding of KYN metabolites, emphasizing their multifaceted biological functions and their relevance in numerous physiological and pathological processes. This underscores the pressing necessity for a paradigm shift in the comprehension of KYN metabolism. Understanding the context-dependent roles of KYN metabolites is vital for novel therapies in conditions like Alzheimer's disease, multiple sclerosis, and cancer. Comprehensive pathway modulation, including balancing inflammatory signals and enzyme regulation, offers promising avenues for targeted, effective treatments.

Immune cell dynamics and the impact on the efficiency of transvascular antitumor interventional therapies in hepatocellular carcinoma patients

Objective

This study investigates the impact of transvascular antitumor interventional therapies on immune cell dynamics and its correlation with disease control and progression-free survival (PFS) in hepatocellular carcinoma (HCC) patients.

Methods

A single-center observational case-control study was conducted with 119 HCC patients. Transvascular antitumor interventional therapy were administered based on patient-specific evaluations. Peripheral blood samples were collected before and within 28 days after the first treatment to analyze lymphocyte subsets and other immune cells.

Results

Higher counts of total white blood cells (WBCs), lymphocytes, monocytes, and basophils were significantly associated with disease control rate. Subgroup analysis revealed that abnormal BMI, diabetes, infection, and multiple lesions were significantly associated with T cell abnormalities. Age, abnormal BMI, hypertension, and abnormal AFP were linked to total T cell abnormalities. NK cells, B cells, Th cells, Tc/Ts cells, and CD4/CD8 ratios did not show significant differences in PFS probabilities.

Conclusion

Higher counts of WBCs, lymphocytes, monocytes, and basophils, play a crucial role in the effectiveness of HCC interventional therapy.

Causal Effect of Immunocytes, Plasma Metabolites, and Hepatocellular Carcinoma: A Bidirectional Two-Sample Mendelian Randomization Study and Mediation Analysis in East Asian Populations

Background: Hepatocellular carcinoma (HCC) is a primary malignant liver tumor characterized by a low survival rate and high mortality. This study aimed to investigate the causal effect of immune cell phenotypes, plasma metabolites, and HCC in East Asian populations. Methods: The summary results for 731 immunocytes, 1400 plasma metabolites, and HCCs were acquired from publicly available genome-wide association studies (GWASs). This study utilized two-sample Mendelian randomization (MR) analysis to establish causal relationships, which was achieved by employing various statistical methods including inverse variance-weighted, simple mode, MR-Egger, weighted median, and weighted mode. Multiple sensitivity analyses were conducted to confirm the reliability of the MR data. Ultimately, mediation analysis was employed to ascertain the path that leads from immunocytes to plasma metabolites. Results: Among the 20 immune cells and HCC for East Asians, causal links were found, with one showing an inverse correlation. In addition, 36 metabolites were significantly associated with HCC for East Asians. Through analysis of established causative metabolites, we identified a strong correlation between the glycerophospholipid metabolic pathway and HCC for East Asians. By employing a two-step MR analysis, we identified 11 immunocytes that are causally linked to HCC for East Asians through the mediation of 14 plasma metabolites, with Linolenate [α or γ; (18:3n3 or 6)] levels showing the highest mediation proportion (19.3%). Conclusions: Our findings affirm the causal links among immunocytes, plasma metabolites, and HCC in eastern Asia populations by calculating the percentage of the impact that is influenced by plasma metabolites. This study offers innovative perspectives on the early detection, diagnosis, and therapy of HCC.

Icaritin Exerts Anti-Cancer Effects through Modulating Pyroptosis and Immune Activities in Hepatocellular Carcinoma

Icaritin (ICT), a natural compound extracted from the dried leaves of the genus Epimedium, possesses antitumor and immunomodulatory properties. However, the mechanisms through which ICT modulates pyroptosis and immune response in hepatocellular carcinoma (HCC) remain unclear. This study demonstrated that ICT exhibits pyroptosis-inducing and anti-hepatocarcinoma effects. Specifically, the caspase1-GSDMD and caspase3-GSDME pathways were found to be involved in ICT-triggered pyroptosis. Furthermore, ICT promoted pyroptosis in co-cultivation of HepG2 cells and macrophages, regulating the release of inflammatory cytokines and the transformation of macrophages into a proinflammatory phenotype. In the Hepa1-6+Luc liver cancer model, ICT treatment significantly increased the expression of cleaved-caspase1, cleaved-caspase3, and granzyme B, modulated cytokine secretion, and stimulated CD8+ T cell infiltration, resulting in a reduction in tumor growth. In conclusion, the findings in this research suggested that ICT may modulate cell pyroptosis in HCC and subsequently regulate the immune microenvironment of the tumor. These observations may expand the understanding of the pharmacological mechanism of ICT, as well as the therapy of liver cancer.

Tryptophan metabolism and piglet diarrhea: Where we stand and the challenges ahead

The intestinal architecture of piglets is vulnerable to disruption during weaning transition and leads to diarrhea, frequently accompanied by inflammation and metabolic disturbances (including amino acid metabolism). Tryptophan (Trp) plays an essential role in orchestrating intestinal immune tolerance through its metabolism via the kynurenine, 5-hydroxytryptamine, or indole pathways, which could be dictated by the gut microbiota either directly or indirectly. Emerging evidence suggests a strong association between piglet diarrhea and Trp metabolism. Here we aim to summarize the intricate balance of microbiota-host crosstalk by analyzing alterations in both the host and microbial pathways of Trp and discuss how Trp metabolism may affect piglet diarrhea. Overall, this review could provide valuable insights to explore effective strategies for managing piglet diarrhea and the related challenges.

Cancer immunometabolism: advent, challenges, and perspective

For decades, great strides have been made in the field of immunometabolism. A plethora of evidence ranging from basic mechanisms to clinical transformation has gradually embarked on immunometabolism to the center stage of innate and adaptive immunomodulation. Given this, we focus on changes in immunometabolism, a converging series of biochemical events that alters immune cell function, propose the immune roles played by diversified metabolic derivatives and enzymes, emphasize the key metabolism-related checkpoints in distinct immune cell types, and discuss the ongoing and upcoming realities of clinical treatment. It is expected that future research will reduce the current limitations of immunotherapy and provide a positive hand in immune responses to exert a broader therapeutic role.

Single-cell RNA-Seq Elucidates the Crosstalk Between Cancer Stem Cells and the Tumor Microenvironment in Hepatocellular Carcinoma

Background: The challenge of systemic treatment for hepatocellular carcinoma (HCC) stems from the development of drug resistance, primarily driven by the interplay between cancer stem cells (CSCs) and the tumor microenvironment (TME). However, there is a notable dearth of comprehensive research investigating the crosstalk between CSCs and stromal cells or immune cells within the TME of HCC. Methods: We procured single-cell RNA sequencing (scRNA-Seq) data from 16 patients diagnosed with HCC. Employing meticulous data quality control and cell annotation procedures, we delineated distinct CSCs subtypes and performed multi-omics analyses encompassing metabolic activity, cell communication, and cell trajectory. These analyses shed light on the potential molecular mechanisms governing the interaction between CSCs and the TME, while also identifying CSCs' developmental genes. By combining these developmental genes, we employed machine learning algorithms and RT-qPCR to construct and validate a prognostic risk model for HCC. Results: We successfully identified CSCs subtypes residing within malignant cells. Through meticulous enrichment analysis and assessment of metabolic activity, we discovered anomalous metabolic patterns within the CSCs microenvironment, including hypoxia and glucose deprivation. Moreover, CSCs exhibited aberrant activity in signaling pathways associated with lipid metabolism. Furthermore, our investigations into cell communication unveiled that CSCs possess the capacity to modulate stromal cells and immune cells through the secretion of MIF or MDK, consequently exerting regulatory control over the TME. Finally, through cell trajectory analysis, we found developmental genes of CSCs. Leveraging these genes, we successfully developed and validated a prognostic risk model (APCS, ADH4, FTH1, and HSPB1) with machine learning and RT-qPCR. Conclusions: By means of single-cell multi-omics analysis, this study offers valuable insights into the potential molecular mechanisms governing the interaction between CSCs and the TME, elucidating the pivotal role CSCs play within the TME. Additionally, we have successfully established a comprehensive clinical prognostic model through bulk RNA-Seq data.

Tryptophan metabolism in health and disease

Tryptophan (Trp) metabolism primarily involves the kynurenine, 5-hydroxytryptamine, and indole pathways. A variety of bioactive compounds produced via Trp metabolism can regulate various physiological functions, including inflammation, metabolism, immune responses, and neurological function. Emerging evidence supports an intimate relationship between Trp metabolism disorder and diseases. The levels or ratios of Trp metabolites are significantly associated with many clinical features. Additionally, studies have shown that disease progression can be controlled by modulating Trp metabolism. Indoleamine-2,3-dioxygenase, Trp-2,3-dioxygenase, kynurenine-3-monooxygenase, and Trp hydroxylase are the rate-limiting enzymes that are critical for Trp metabolism. These key regulatory enzymes can be targeted for treating several diseases, including tumors. These findings provide novel insights into the treatment of diseases. In this review, we have summarized the recent research progress on the role of Trp metabolites in health and disease along with their clinical applications.