ERK Inhibition Promotes Engraftment of Allografts by Reprogramming T-Cell Metabolism

Research progress and prospect of MAPK signaling pathway in knee osteoarthritis

The knee joint, one of the most vulnerable joints in the human body, is susceptible to degenerative changes due to factors such as aging, obesity, trauma, inflammation, and genetic predisposition. These factors contribute to primary or secondary degeneration of knee joint cartilage and bone hyperplasia. Knee osteoarthritis (KOA), a prevalent condition particularly among the elderly, significantly impacts patients' quality of life. Aberrant activation of cellular signaling pathways, namely the NF-κB, MAPK, and Wnt pathways, has been identified as a key factor in the pathogenesis of KOA. These pathways contribute to inflammation, cartilage degradation, and disruption of the anabolic-catabolic balance within articular cartilage. Understanding the precise roles of these pathways is crucial for developing targeted therapies to prevent and treat knee OA. Therefore, further exploration of the pathogenesis of knee osteoarthritis is essential to develop more effective therapeutic strategies.

Integrating bioinformatics and machine learning to identify AhR-related gene signatures for prognosis and tumor microenvironment modulation in melanoma

Background

The Aryl Hydrocarbon Receptor (AhR) pathway significantly influences immune cell regulation, impacting the effectiveness of immunotherapy and patient outcomes in melanoma. However, the specific downstream targets and mechanisms by which AhR influences melanoma remain insufficiently understood.

Methods

Melanoma samples from The Cancer Genome Atlas (TCGA) and normal skin tissues from the Genotype-Tissue Expression (GTEx) database were analyzed to identify differentially expressed genes, which were intersected with a curated list of AhR-related pathway genes. Prognostic models were subsequently developed, and feature genes were identified. Advanced methodologies, including Gene Set Enrichment Analysis (GSEA) and immune cell infiltration analysis, were employed to explore the biological significance of these genes. The stability of the machine learning models and the relationship between gene expression and immune infiltrating cells were validated using three independent melanoma datasets. A mouse melanoma model was used to validate the dynamic changes of the feature genes during tumor progression. The relationship between the selected genes and drug sensitivity, as well as non-coding RNA interactions, was thoroughly investigated.

Results

Our analysis identified a robust prognostic model, with four AhR-related genes (MAP2K1, PRKACB, KLF5, and PIK3R2) emerging as key contributors to melanoma progression. GSEA revealed that these genes are involved in primary immunodeficiency. Immune cell infiltration analysis demonstrated enrichment of CD4+ naïve and memory T cells, macrophages (M0 and M2), and CD8+ T cells in melanoma, all of which were associated with the expression of the four feature genes. Importantly, the diagnostic power of the prognostic model and the relevance of the feature genes were validated in three additional independent melanoma datasets. In the mouse melanoma model, Map2k1 and Prkacb mRNA levels exhibited a progressive increase with tumor progression, supporting their role in melanoma advancement.

Conclusions

This study presents a comprehensive analysis of AhR-related genes in melanoma, highlighting MAP2K1, PRKACB, KLF5, and PIK3R2 as key prognostic markers and potential therapeutic targets. The integration of bioinformatics and machine learning provides a robust framework for enhancing prognostic evaluation in melanoma patients and offers new avenues for the development of treatments, particularly for those resistant to current immunotherapies.

Uncover the anticancer potential of lycorine

BACKGROUND

Natural products have a long history in drug discovery. Lycorine is an alkaloid derived from Amaryllidaceae plants, demonstrating significant pharmacological potential. Lycorine and its hydrochloride salt, lycorine hydrochloride, have shown outstanding anticancer effects both in vitro and in vivo.

PURPOSE

This review aims to comprehensively summarize recent research advancements regarding the anticancer potential of lycorine and lycorine hydrochloride. It intends to elucidate current research limitations, optimization strategies, and future research directions to guide clinical translation.

METHODS

Various databases, e.g., Web of Science, PubMed, and Chinese National Knowledge Infrastructure, are systematically searched for relevant articles using keywords such as lycorine, cancer, pharmacokinetics, and toxicity. The retrieved literature is then categorized and summarized to provide an overview of the research advancements in the anticancer potential of lycorine and lycorine hydrochloride.

RESULTS

Lycorine and lycorine hydrochloride demonstrate significant anticancer activities against various types of cancer both in vitro and in vivo, employing diverse mechanisms such as inducing cell cycle arrest, triggering cellular senescence, regulating programmed cell death, inhibiting angiogenesis, suppressing metastasis, and modulating immune system. Furthermore, pharmacokinetic profiles and toxicity data are summarized. Additionally, this review discusses the druggability, limitations, optimization strategies, and target identification of lycorine, offering insights for future preclinical studies.

CONCLUSION

The anticancer effects and safety profile of lycorine and lycorine hydrochloride suggest promising potential for clinical applications. Further research on their in-depth mechanisms and optimization strategies targeting their limitations will enhance the understanding and druggability of lycorine and lycorine hydrochloride.

FOS+ Macrophages Promote Chronic Rejection of Cardiac Transplantation

OBJECTIVES

Chronic rejection remains the leading cause of progressive decline in graft function. Accumulating evidence indicates that macrophages participate in chronic rejection dependent on CD40-CD40L. The FOS family members are critical in inflammatory and immune responses. However, the mechanisms underlying the role of FOS family members in chronic rejection remain unclear. In this study, we aimed to elucidate the role and underlying mechanisms of FOS-positive macrophages regulated by CD40 that mediate chronic allograft rejection.

MATERIALS AND METHODS

We downloaded publicly accessible chronic rejection kidney transplant single-cell sequencing datasets from the gene expression omnibus database. Differentially expressed genes between the CD40hi and CD40low macrophage chronic rejection groups were analyzed. We established a chronic rejection mouse model by using CTLA-4-Ig. We treated bone marrow-derived macrophages with an anti-CD40 antibody. We assessed expression of the FOS family by flow cytometry, real-time quantitative polymerase chain reaction, Western blotting, and immunofluorescence. We identified altered signaling pathways by using RNA sequencing analysis. We detected DNA specifically bound to transcription factors by using ChIP-sequencing, with detection of the degree of graft fibrosis and survival.

RESULTS

FOS was highly expressed on CD40hi macrophages in patients with chronic transplantrejection. Mechanistically, we showed that CD40 activated NF-κB2 translocation into the nucleus to upregulate c-Fos and FosB expression, thus promoting chronic rejection of cardiac transplant.We showed thatNF-κB2 regulated c-Fos and FosB expression by binding to the c-fos and fosb promoter regions. Inhibition of c-Fos/activator protein-1 decreased graft fibrosis and prolonged graft survival.

CONCLUSIONS

CD40 may activate transcription factor NF-κB2 translocation into the nucleus of macrophages to upregulate c-Fos and FosB expression, thus promoting chronic rejection of cardiac transplant. Inhibition of c-Fos/activator protein-1 decreased grafts fibrosis and prolonged graft survival.

[A highly sensitive approach for the analysis of tyrosine phosphoproteome in primary T cells]

Tyrosine phosphorylation, a common post-translational modification process for proteins, is involved in a variety of biological processes. However, the abundance of tyrosine-phosphorylated proteins is very low, making their identification by mass spectrometry (MS) is difficult; thus, milligrams of the starting material are often required for their enrichment. For example, tyrosine phosphorylation plays an important role in T cell signal transduction. However, the number of primary T cells derived from biological tissue samples is very small, and these cells are difficult to culture and expand; thus, the study of T cell signal transduction is usually carried out on immortalized cell lines, which can be greatly expanded. However, the data from immortalized cell lines cannot fully mimic the signal transduction processes observed in the real physiological state, and they usually lead to conclusions that are quite different from those of primary T cells. Therefore, a highly sensitive proteomic method was developed for studying tyrosine phosphorylation modification signals in primary T cells. To address the issue of the limited T cells numbers, a comprehensive protocol was first optimized for the isolation, activation, and expansion of primary T cells from mouse spleen. CD3+ primary T cells were successfully sorted; more than 91% of the T cells collected were well activated on day 2, and the number of T cells expanded to over 7-fold on day 4. Next, to address the low abundance of tyrosine-phosphorylated proteins, we used SH2-superbinder affinity enrichment and immobilized Ti4+affinity chromatography (Ti4+-IMAC) to enrich the tyrosine-phosphorylated polypeptides of primary T cells that were co-stimulated with anti-CD3 and anti-CD28. These polypeptides were resolved using nanoscale liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS). Finally, 282 tyrosine phosphorylation sites were successfully identified in 1 mg of protein, including many tyrosine phosphorylation sites on the immunoreceptor tyrosine-based activation motif (ITAM) in the intracellular region of the T cell receptor membrane protein CD3, as well as the phosphotyrosine sites of ZAP70, LAT, VAV1, and other proteins related to signal transduction under costimulatory conditions. In summary, to solve the technical problems of the limited number of primary cells, low abundance of tyrosine-phosphorylated proteins, and difficulty of detection by MS, we developed a comprehensive proteomic method for the in-depth analysis of tyrosine phosphorylation modification signals in primary T cells. This protocol may be applied to map signal transduction networks that are closely related to physiological states.

Discovery of adamantane-type polycyclic polyprenylated acylphloroglucinols that can prevent concanavalin A-induced autoimmune hepatitis in mice

Hyperadamans A-G (1-7), seven new adamantane type polycyclic polyprenylated acylphloroglucinols (PPAPs), were isolated from Hypericum wilsonii N. Robson. Structurally, 1-4 were the first adamantanes bearing an unusual 2,7-dioxabicyclo-[2.2.1]-heptane fragment, and compound 5 was the first adamantane with a rare 1,6-dioxaspiro[4.4]nonane section. Importantly, 1-7 exhibited significant immunosuppressive activity on Con A-induced T-lymphocyte proliferation in vitro, with IC50 values ranging from 3.97 ± 0.10 to 18.12 ± 1.07 μM. Pretreatment with 1 in Con A-challenged autoimmune hepatitis mice could dramatically ameliorate the levels of hepatic injury indexes (ALT and AST) and reduce the product of proinflammatory cytokines (COX-2, IL-6, IL-1β, IL-18, IL-23A and TNF-α). Furthermore, the protective effect of 1 on the Con A-induced liver injury was corroborated by the histological analysis and the immunohistochemistry.

Prenyllongnols A-D, New Prenylated Acylphloroglucinols that Fight Concanavalin A-Induced Autoimmune Hepatitis

Autoimmune hepatitis is a serious hepatic disorder with unknown nosogenesis, and natural products have been deemed to be one of the most significant sources of new drugs against this disease. Prenyllongnols A-D (1-4), four undescribed prenylated acylphloroglucinols, were isolated from Hypericum longistylum. Compounds 1-4 exhibited remarkable immunosuppressive activities in murine splenocyte proliferation under the induction of concanavalin A (Con A), and IC50 values ranged from 2.98 ± 0.21 to 6.34 ± 0.72 μM. Furthermore, in a Con A-challenged autoimmune hepatitis mouse model, the mice in the group that were pretreated with isolate 2 significantly ameliorated liver injury and decreased proinflammatory cytokine production. Notably, natural product 2 was the first prenylated acylphloroglucinol to protect against concanavalin A-induced autoimmune hepatitis. This finding underscores the potential of prenylated acylphloroglucinol-type metabolites as promising candidates for designing novel immunosuppressors in the quest for new antiautoimmune hepatitis drugs.

Targeting Alpha-Ketoglutarate Disruption Overcomes Immunoevasion and Improves PD-1 Blockade Immunotherapy in Renal Cell Carcinoma

The Warburg effect-related metabolic dysfunction of the tricarboxylic acid (TCA) cycle has emerged as a hallmark of various solid tumors, particularly renal cell carcinoma (RCC). RCC is characterized by high immune infiltration and thus recommended for immunotherapeutic interventions at an advanced stage in clinical guidelines. Nevertheless, limited benefits of immunotherapy have prompted investigations into underlying mechanisms, leading to the proposal of metabolic dysregulation-induced immunoevasion as a crucial contributor. In this study, a significant decrease is found in the abundance of alpha-ketoglutarate (αKG), a crucial intermediate metabolite in the TCA cycle, which is correlated with higher grades and a worse prognosis in clinical RCC samples. Elevated levels of αKG promote major histocompatibility complex-I (MHC-I) antigen processing and presentation, as well as the expression of β2-microglobulin (B2M). While αKG modulates broad-spectrum demethylation activities of histone, the transcriptional upregulation of B2M is dependent on the demethylation of H3K4me1 in its promoter region. Furthermore, the combination of αKG supplementation and PD-1 blockade leads to improved therapeutic efficacy and prolongs survival in murine models when compared to monotherapy. Overall, the findings elucidate the mechanisms of immune evasion in anti-tumor immunotherapies and suggest a potential combinatorial treatment strategy in RCC.

Bioactive Indole Alkaloid from Aspergillus amoenus TJ507 That Ameliorates Hepatic Ischemia/Reperfusion Injury

Hepatic ischemia/reperfusion injury (IRI) is a major factor contributing to the failure of hepatic resection and liver transplantation. As part of our ongoing investigation into bioactive compounds derived from fungi, we isolated eight indole alkaloids (1-8) from the endophytic fungus Aspergillus amoenus TJ507. Among these alkaloids, one previously undescribed compound, amoenamide D (1), was identified. The planar structure of 1 was elucidated by extensive spectroscopic analysis, including HRESIMS and NMR spectra. The absolute configuration of 1 was elucidated by using electronic circular dichroism calculations. Notably, in the CoCl2-induced hepatocyte damage model, notoamide Q (3) exhibited significant anti-hypoxia injury activity. Furthermore, in a murine hepatic ischemia/reperfusion injury model, treatment with 3 prevents IRI-induced liver damage and hepatocellular apoptosis. Consequently, 3 might serve as a potential lead compound to prevent hepatic ischemia/reperfusion injury.

Discovery of ergosterol derivative from Aspergillus sp. TJ507 that protects against hepatic ischemia/reperfusion injury

Hepatic ischemia/reperfusion injury is a major cause of hypohepatia after surgical procedures such as hypovolemic shock, transplantation, and so on. In our continuous study of bioactive natural products from fungus, eight ergosterol-type sterides (1-8), including two undescribed compounds, sterolaspers A (1) and B (2), were isolated from Aspergillus sp. TJ507. Structure elucidation was accomplished by extensive spectroscopic analysis and comparison with the reported NMR data as well as X-Ray single crystal diffraction tests. Activity screen of these isolates showed 5α-stigmast-3,6-dione (3) possessing anti-hypoxia injury effects against CoCl₂-induced hypoxia damage in hepatocytes. More importantly, compound 3 could improve liver function, alleviate liver damage, and restrain the hepatocellular apoptosis in hepatic ischemia/reperfusion injury murine model. As such, this ergosterol-type steride, 5α-stigmast-3,6-dione (3), might serve as lead structure for the development of novel hepatoprotective agents in the clinical treatment of hepatic ischemia/reperfusion injury.

Current Situation and Prospect of Adoptive Cellular Immunotherapy for Malignancies

Adoptive cell immunotherapy (ACT) is an innovative promising treatment for tumors. ACT is characterized by the infusion of active anti-tumor immune cells (specific and non-specific) into patients to kill tumor cells either directly or indirectly by stimulating the body's immune system. The patient's (autologous) or a donor's (allogeneic) immune cells are used to improve immune function. Chimeric antigen receptor (CAR) T cells (CAR-T) is a type of ACT that has gained attention. T cells from the peripheral blood are genetically engineered to express CARs that rapidly proliferate and specifically recognize target antigens to exert its anti-tumor effects. Clinical application of CAR-T therapy for hematological tumors has shown good results, but adverse reactions and recurrence limit its applicability. Tumor infiltrating lymphocyte (TIL) therapy is effective for solid tumors. TIL therapy exhibits T cell receptor (TCR) clonality, superior tumor homing ability, and low targeted toxicity, but its successful application is limited to a number of tumors. Regardless, TIL and CAR-T therapies are effective for treating cancer. Additionally, CAR-natural killer (NK), CAR-macrophages (M), and TCR-T therapies are currently being researched. In this review, we highlight the current developments and limitations of several types of ACT.