Normal Iron Homeostasis Requires the Transporter SLC48A1 for Efficient Heme-Iron Recycling in Mammals

The regulation and function of Nrf2 signaling in ferroptosis-activated cancer therapy

Ferroptosis is an iron-dependent programmed cell death process that involves lipid oxidation via the Fenton reaction to produce lipid peroxides, causing disruption of the lipid bilayer, which is essential for cellular survival. Ferroptosis has been implicated in the occurrence and treatment response of various types of cancer, and targeting ferroptosis has emerged as a promising strategy for cancer therapy. However, cancer cells can escape cellular ferroptosis by activating or remodeling various signaling pathways, including oxidative stress pathways, thereby limiting the efficacy of ferroptosis-activating targeted therapy. The key anti-oxidative transcription factor, nuclear factor E2 related factor 2 (Nrf2 or NFE2L2), plays a dominant role in defense machinery by reprogramming the iron, intermediate, and glutathione peroxidase 4 (GPX4)-related network and the antioxidant system to attenuate ferroptosis. In this review, we summarize the recent advances in the regulation and function of Nrf2 signaling in ferroptosis-activated cancer therapy and explore the prospect of combining Nrf2 inhibitors and ferroptosis inducers as a promising cancer treatment strategy.

In situ tissue profile of rat trigeminal nerve in trigeminal neuralgia using spatial transcriptome sequencing

BACKGROUND

Trigeminal neuralgia (TN) is the most common neuropathic disorder in the maxillofacial region. The etiology and pathogenesis of TN have not been clearly determined to date, although there are many hypotheses.

OBJECTIVE

The goal of this study was to investigate the interactions between different types of cells in TN, particularly the impact and intrinsic mechanism of demyelination on the trigeminal ganglion, and to identify new important target genes and regulatory pathways in TN.

METHODS

TN rat models were prepared by trigeminal root compression, and trigeminal nerve tissues were isolated for spatial transcriptome sequencing. The gene expression matrix was reduced dimensionally by PCA and presented by UMAP. Gene function annotation was analyzed by Metascape. The progression of certain clusters and the developmental pseudotime were analyzed using the Monocle package. Modules of the gene coexpression network between different groups were analyzed based on weighted gene coexpression network analysis and assigned AddModuleScore values. The intercellular communication of genes in these networks via ligand-receptor interactions was analyzed using CellPhoneDB analysis.

RESULTS

The results suggested that the trigeminal ganglion could affect Schwann cell demyelination and remyelination responses through many ligand-receptor interactions, while the effect of Schwann cells on the trigeminal ganglion was much weaker. Additionally, ferroptosis may be involved in the demyelination of Schwann cells.

CONCLUSIONS

This study provides spatial transcriptomics sequencing data on TN, reveals new markers, and redefines the relationship between the ganglion and myelin sheath, providing a theoretical basis and supporting data for future mechanistic research and drug development.

Anti-Inflammatory Activation of Phellodendri Chinensis Cortex is Mediated by Berberine Erythrocytes Self-Assembly Targeted Delivery System

Background

Berberine (BBR) is the primary active component of Phellodendri Chinensis Cortex (PCC), which has been traditionally used to treat inflammatory diseases. However, the discrepancy between its low bioavailability and significant therapeutic effect remains obscure. The purpose of this study was to explore the previously unsolved enigma of the low bioavailability of BBR and its appreciable anti-inflammatory effect to reveal the action mechanism of BBR and PCC.

Methods

The quantitative analysis of BBR and its metabolite oxyberberine (OBB) in blood and tissues was performed using high-performance liquid chromatography to investigate the conversion and distribution of BBR/OBB mediated by erythrocytes. Routine blood tests and immunohistochemical staining were used to explore the potential relationship between the amounts of monocyte/macrophage and the drug concentration in erythrocytes and tissues (liver, heart, spleen, lung, kidney, intestine, muscle, brain and pancreas). To comparatively explore the anti-inflammatory effects of BBR and OBB, the acetic acid-induced vascular permeability mice model and lipopolysaccharide-induced RAW 264.7 macrophages were employed.

Results

Nearly 92% of BBR existed in the erythrocytes in rats. The partition coefficient of BBR between plasma and erythrocytes (Kp/b) decreased with time. OBB was found to be the oxidative metabolite of BBR in erythrocytes. Proportion of BBR/OBB in erythrocytes changed from 9.38% to 16.30% and from 13.50% to 46.24%, respectively. There was a significant relationship between the BBR/OBB concentration in blood and monocyte depletion after a single administration of BBR. BBR/OBB was transported via erythrocytes to various tissues (liver, kidney, spleen, lung, and heart, etc), with the liver achieving the highest concentration. OBB exhibited similar anti-inflammatory effect in vitro and in vivo as BBR with much smaller dosage.

Conclusion

BBR was prodominantly found in erythrocytes, which was critically participated in the biodistribution, pharmacokinetics, metabolism and target delivery of BBR and its metabolite. The anti-inflammatory activity of BBR and PCC was intimately associated with the metabolism into the active congener OBB and the targeted delivery to monocytes/macrophages mediated by the erythrocytes.

Iron metabolism: pathways and proteins in homeostasis

Iron is essential to human survival. The biological role and trafficking of this trace essential inorganic element which is also a potential toxin is constantly being researched and unfolded. Vital for oxygen transport, DNA synthesis, electron transport, neurotransmitter biosynthesis and present in numerous other heme and non-heme enzymes the physiological roles are immense. Understanding the molecules and pathways that regulate this essential element at systemic and cellular levels are of importance in improving therapeutic strategies for iron related disorders. This review highlights the progress in understanding the metabolism and trafficking of iron along with the pathophysiology of iron related disorders.