LC-MS/MS-based arachidonic acid metabolomics in acute spinal cord injury reveals the upregulation of 5-LOX and COX-2 products

Ferroptosis in the neurovascular unit after spinal cord injury

The mechanisms of secondary injury following spinal cord injury are complicated. The role of ferroptosis, which is a newly discovered form of regulated cell death in the neurovascular unit(NVU), is increasingly important. Ferroptosis inhibitors have been shown to improve neurovascular homeostasis and attenuate secondary spinal cord injury(SCI). This review focuses on the mechanisms of ferroptosis in NVU cells and NVU-targeted therapeutic strategies according to the stages of SCI, and analyzes possible future research directions.

Breast cancer colonization by Malassezia globosa accelerates tumor growth

Malassezia globosa is a lipophilic basidiomycetous yeast that occurs abundantly in breast tumors and that may contribute to a shortened overall survival of breast cancer (BRAC) patients, suggesting that the yeast may participate in the carcinogenesis of BRAC. However, the mechanisms involved in the M. globosa-based acceleration of BRAC are unknown. Here, we show that M. globosa can colonize mammary tissue in 7,12-dimethylbenz[a] anthracene-induced mice. The abundance of M. globosa shortened the overall survival and increased the tumor incidence. Transcriptome data illustrated that IL-17A plays a key role in tumor growth due to M. globosa colonization, and tumor-associated macrophage infiltration was elevated during M. globosa colonization which triggers M2 polarization of macrophages via toll-like receptors 4/nuclear factor kappa-B (Nf-κB) signaling. Our results show that the expression of sphingosine kinase 1 (Sphk1) is increased in breast tumors after inoculation with M. globosa. Moreover, we discovered that Sphk1-specific small interfering RNA blocked the formation of lipid droplets, which can effectively alleviate the expression of the signal transducer and activator of the transcription 3 (STAT3)/Nf-κB pathway. Taken together, our results demonstrate that M. globosa could be a possible factor for the progression of BRAC. The mechanisms by which M. globosa promotes BRAC development involve the IL-17A/macrophage axis. Meanwhile, Sphk1 overexpression was induced by M. globosa infection, which also promoted the proliferation of MCF-7 cells.IMPORTANCELiterature has suggested that Malassezia globosa is associated with breast tumors; however, this association has not been confirmed. Here, we found that M. globosa colonizes in breast fat pads leading to tumor growth. As a lipophilic yeast, the expression of sphingosine kinase 1 (Sphk1) was upregulated to promote tumor growth after M. globosa colonization. Moreover, the IL-17A/macrophages axis plays a key role in mechanisms involved in the M. globosa-induced breast cancer acceleration from the tumor immune microenvironment perspective.

Puerarin: a hepatoprotective drug from bench to bedside

Pueraria is a time-honored food and medicinal plant, which is widely used in China. Puerarin, the main component extracted from pueraria, has a variety of pharmacological characteristics. In recent years, puerarin has received increasing attention for its significant hepatoprotective effects, such as metabolic dysfunction-associated steatotic liver disease, alcohol-related liver disease, and hepatic carcinoma. This paper explores the pharmacological effects of puerarin on various liver diseases through multiple mechanisms, including inflammation factors, oxidative stress, lipid metabolism, apoptosis, and autophagy. Due to its restricted solubility, pharmacokinetic studies revealed that puerarin has a low bioavailability. However, combining puerarin with novel drug delivery systems can improve its bioavailability. Meanwhile, puerarin has very low toxicity and high safety, providing a solid foundation for its further. In addition, this paper discusses puerarin's clinical trials, highlighting its unique advantages. Given its excellent pharmacological effects, puerarin is expected to be a potential drug for the treatment of various liver diseases.

Spatial multi-omics analysis of the microenvironment in traumatic spinal cord injury: a narrative review

Traumatic spinal cord injury (tSCI) is a severe injury to the central nervous system that is categorized into primary and secondary injuries. Among them, the local microenvironmental imbalance in the spinal cord caused by secondary spinal cord injury includes accumulation of cytokines and chemokines, reduced angiogenesis, dysregulation of cellular energy metabolism, and dysfunction of immune cells at the site of injury, which severely impedes neurological recovery from spinal cord injury (SCI). In recent years, single-cell techniques have revealed the heterogeneity of multiple immune cells at the genomic, transcriptomic, proteomic, and metabolomic levels after tSCI, further deepening our understanding of the mechanisms underlying tSCI. However, spatial information about the tSCI microenvironment, such as cell location and cell-cell interactions, is lost in these approaches. The application of spatial multi-omics technology can solve this problem by combining the data obtained from immunohistochemistry and multiparametric analysis to reveal the changes in the microenvironment at different times of secondary injury after SCI. In this review, we systematically review the progress of spatial multi-omics techniques in the study of the microenvironment after SCI, including changes in the immune microenvironment and discuss potential future therapeutic strategies.

Therapeutic application of nicotinamide: As a potential target for inhibiting fibrotic scar formation following spinal cord injury

AIM

We aimed to confirm the inhibitory effect of nicotinamide on fibrotic scar formation following spinal cord injury in mice using functional metabolomics.

METHODS

We proposed a novel functional metabolomics strategy to establish correlations between gene expression changes and metabolic phenotypes using integrated multi-omics analysis. Through the integration of quantitative metabolites analysis and assessments of differential gene expression, we identified nicotinamide as a functional metabolite capable of inhibiting fibrotic scar formation and confirmed the effect in vivo using a mouse model of spinal cord injury. Furthermore, to mimic fibrosis models in vitro, primary mouse embryonic fibroblasts and spinal cord fibroblasts were stimulated by TGFβ, and the influence of nicotinamide on TGFβ-induced fibrosis-associated genes and its underlying mechanism were examined.

RESULTS

Administration of nicotinamide led to a reduction in fibrotic lesion area and promoted functional rehabilitation following spinal cord injury. Nicotinamide effectively downregulated the expression of fibrosis genes, including Col1α1, Vimentin, Col4α1, Col1α2, Fn1, and Acta2, by repressing the TGFβ/SMADs pathway.

CONCLUSION

Our functional metabolomics strategy identified nicotinamide as a metabolite with the potential to inhibit fibrotic scar formation following SCI by suppressing the TGFβ/SMADs signaling. This finding provides new therapeutic strategies and new ideas for clinical treatment.

Sarsasapogenin regulates the immune microenvironment through MAPK/NF-kB signaling pathway and promotes functional recovery after spinal cord injury

Spinal cord injury (SCI) occurs as a result of traumatic events that damage the spinal cord, leading to motor, sensory, or autonomic function impairment. Sarsasapogenin (SA), a natural steroidal compound, has been reported to have various pharmacological applications, including the treatment of inflammation, diabetic nephropathy, and neuroprotection. However, the therapeutic efficacy and underlying mechanisms of SA in the context of SCI are still unclear. This research aimed to investigate the therapeutic effects and mechanisms of SA against SCI by integrating network pharmacology analysis and experimental verification. Network pharmacology results suggested that SA may effectively treat SCI by targeting key targets such as TNF, RELA, JUN, MAPK14, and MAPK8. The underlying mechanism of this treatment may involve the MAPK (JNK) signaling pathway and inflammation-related signaling pathways such as TNF and Toll-like receptor signaling pathways. These findings highlight the therapeutic potential of SA in SCI treatment and provide valuable insights into its molecular mechanisms of action. In vivo experiments confirmed the reparative effect of SA on SCI in rats and suggested that SA could repair SCI by modulating the immune microenvironment. In vitro experiments further investigated how SA regulates the immune microenvironment by inhibiting the MAPK/NF-kB pathways. Overall, this study successfully utilized a combination of network pharmacology and experimental verification to establish that SA can regulate the immune microenvironment via the MAPK/NF-kB signaling pathway, ultimately facilitating functional recovery from SCI. Furthermore, these findings emphasize the potential of natural compounds from traditional Chinese medicine as a viable therapy for SCI treatment.

Aspirin eugenol ester ameliorates LPS-induced inflammatory responses in RAW264.7 cells and mice

Introduction: Inflammation is a defensive response of the body and the pathological basis of many diseases. However, excessive inflammation and chronic inflammation impair the homeostasis of the organism. Arachidonic acid (AA) has a close relationship with inflammation and is the main mediator of the pro-inflammatory response. Based on the prodrug principle, the new pharmaceutical compound aspirin eugenol ester (AEE) was designed and synthesized. However, the effects of AEE on key enzymes, metabolites and inflammatory signaling pathways in the AA metabolic network have not been reported. Methods: In this study, the anti-inflammation effects of AEE were first investigated in mice and RAW264.7 cells in LPS induced inflammation model. Then, the changes of the key enzymes and AA metabolites were explored by RT-PCR and targeted metabolomics. Moreover, the regulatory effects on NF-kB and MAPKS signaling pathways were explored by Western Blotting. Results: Results indicated that AEE significantly reduced the number of leukocyte and increased the lymphocyte percentage. AEE decreased the expression levels of IL-1β, IL-6, IL-8 and TNF-α both in vivo and in vitro. In the liver of mice, AEE downregulated the levels of AA, prostaglandin D2 (PGD2) and upregulated 12- hydroxyeicosatetraenoic acid (12-HETE). However, the changes of PGE2, PGF2α, 6-keto-prostaglandin F1α (6-KETO-PGF1α), 9-hydroxy-octadecenoic acid (9- HODE), 13-HODE, 15-HETE, docosahexaenoic acid (DHA) and thromboxane B2 (TXB2) were not significant. Additionally, it was found that AEE decreased the relative mRNA expression levels of p65 and p38 and the ratio of p-p65/p65. Discussion: It was concluded that AEE might inhibit the LPS-induced inflammatory response through the regulation of AA metabolism. This study provides the theoretical foundation for the development of AEE as a medicinal anti-inflammatory drug.

Metabolomics of the anti-inflammatory effect of Pueraria lobata and Pueraria lobata var. Thomsonii in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Pueraria lobata (Willd.) Ohwi and Pueraria lobata var. Thomsonii (Benth.) Maesen are essential medicinal and edible homologous plants widely cultivated in Asian countries. Therefore, P. lobata and P. thomsonii are widely used in the food, health products and pharmaceutical industries and have significant domestic and international market potential and research value. P. lobata and P. thomsonii have pharmacological effects in the clinic, such as antipyretic, analgesic, anti-inflammatory and antioxidant effects. These plants are commonly used in the treatment of inflammatory diseases and other related diseases. However, the potential mechanisms of the anti-inflammatory effects of P. lobata and P. thomsonii have not been elucidated.

AIM OF THE STUDY

This study aimed to confirm the anti-inflammatory effects of P. lobata and P. thomsonii on inflammatory model diseases and to investigate the mechanism of their anti-inflammatory effects from the perspective of plasma metabolomics.

MATERIALS AND METHODS

First, P. lobata and P. thomsonii were identified by high‒performance liquid chromatography (HPLC). Second, we established the following three inflammation models: an acute inflammation model of auricular swelling in mice induced by xylene, an acute inflammation model of foot swelling in rats induced by carrageenan gum, and a chronic inflammation model of cotton ball granuloma in rats. Then we examined the weight and swelling rate of auricular swelling in mice; the residence time, contact area, and mean contact pressure in rats on the gait meter; and the weight of granulomas in rats and the content of IL-1β and TNF-α in plasma to investigate the anti-inflammatory pharmacodynamics of P. lobata and P. thomsonii. Third, we used LC‒MS‒based plasma metabolomics techniques to obtain potential biomarkers of P. lobata and P. thomsonii related to inflammation. Then, the potential biomarkers were enriched by MetaboAnalyst and KEGG metabolomics analysis tools to obtain metabolic pathways related to inflammation. Finally, we tested the indicators of COX-2, 5-LOX, GSH, GSSG and γ⁃GCL in rat plasma from the granuloma model by enzyme-linked immunosorbent assays (ELISAs) to verify the inflammation-related metabolic pathway.

RESULTS

The experimental results showed that P. lobata and P. thomsonii could reduce the swollen weight and swelling rate of the auricle in mice, and could increase the residence time, contact area and mean contact pressure in rats on the gait meter. Moreover, P. lobata and P. thomsonii could inhibit the growth of granulomas and reduce the content of IL-1β and TNF-α in plasma in rats. The above results preliminarily verified that P. lobata and P. thomsonii have different anti-inflammatory effects. We identified eighteen plasma biomarkers associated with P. lobata and sixteen plasma biomarkers related to P. thomsonii in regulating inflammation by a plasma metabolomics analysis. The following two major metabolic pathways were further screened and enriched: arachidonic acid metabolism and glutathione metabolism. Then we noted that P. lobata and P. thomsonii could reduce the COX-2, 5-LOX and GSSG levels and increase the GSH, GSH/GSSG and γ⁃GCL levels based on the ELISA results, which demonstrated that P. lobata and P. thomsonii affect the anti-inflammatory mechanism through arachidonic acid metabolism and glutathione metabolism.

CONCLUSIONS

The results of this study further elucidate the anti-inflammatory mechanism of action of P. lobata and P. thomsonii, providing a scientific basis for developing new drugs for the treatment of inflammation-related diseases and laying a foundation for the development of herbal resources, such as P. lobata and P. thomsonii.