L-Citrulline Ameliorates Iron Metabolism and Mitochondrial Quality Control via Activating AMPK Pathway in Intestine and Improves Microbiota in Mice with Iron Overload.

SCOPE: Oxidative stress caused by iron overload tends to result in intestinal mucosal barrier dysfunction and intestinal microbiota imbalance. As a neutral and nonprotein amino acid, L-Citrulline (L-cit) has been implicated in antioxidant and mitochondrial amelioration properties. This study investigates whether L-cit can alleviate iron overload-induced intestinal injury and explores the underlying mechanisms. METHODS AND RESULTS: C57BL/6J mice are intraperitoneally injected with iron dextran, then gavaged with different dose of L-cit for 2 weeks. L-cit treatment significantly alleviates intestine pathological injury, oxidative stress, ATP level, and mitochondrial respiratory chain complex activities, accompanied by ameliorating mitochondrial quality control. L-cit-mediated protection is associated with the upregulation of Glutathione Peroxidase 4 (GPX4) expression, inhibition Nuclear Receptor Coactivator 4 (NCOA4)-mediated ferritinophagy and ferroptosis, and improvement of gut microbiota. To investigate the underlying molecular mechanisms, Intestinal Porcine Epithelial Cell line-J2 (IPEC-J2) cells are treated with L-cit or AMP-activated Protein Kinase (AMPK) inhibitor. AMPK signaling has been activated by L-cit. Notably, Compound C abolishes L-cit's protection on intestinal barrier, mitochondrial function, and antioxidative capacity in IPEC-J2 cells. CONCLUSION: L-cit may restrain ferritinophagy and ferroptosis to regulate iron metabolism, and induce AMPK pathway activation, which contributes to exert antioxidation, ameliorate iron metabolism and mitochondrial quality control, and improve intestinal microbiota. L-cit is a promising therapeutic strategy for iron overload-induced intestinal injury.

[Outcomes and measurements of randomized controlled trial for traditional Chinese medicine in treatment of endometriosis].

This study aims to analyze the outcomes and measurements of randomized controlled trial(RCT) for traditional Chinese medicine(TCM) treatment of endometriosis(EM) and provide a basis for the building of the core outcome set(COS) of EM. The RCT for TCM treatment of EM was retrieved from medical literature databases with the time interval from inception to February 3, 2022. The Cochrane risk of bias assessment tool was employed to evaluate the risk of bias of the included RCT, and descriptive analyses of the extracted information were carried out. A total of 519 RCTs were included, with the sample sizes ranging from 28-582 patients and 239 outcome indicators(8 outcome indicators per RCT on average). According to the functional properties, the reported outcome indicators were classified into 7 indicators: clinical efficacy assessment, indicators of clinical symptoms and signs, TCM symptom efficacy indicators, physical and chemical examinations, quality of life, long-term prognosis, and safety events. All the 519 RCTs had problems, such as the lack of differentiation between primary and secondary outcome indicators(1.73% RCTs reported such differen-tiation), poor quality, confused criteria for composite outcome indicators and arbitrary combination of indicators(45 criteria for the single outcome indicator of efficiency), and messy measurements(as many as 18 measurements for TCM symptom score). In addition, as a chronic disease, EM requires long-term management. The outcome indicators vary for the patients in different disease stages, such as EM pain, EM infertility, and post-operative EM, while the specific outcome indicator sets for different EM populations remain to be developed. In addition, the time point of measurement for EM long-term outcomes remains unclear, and the definition of TCM syndromes lacks standards. The RCT for TCM treatment had a variety of problems, such as the lack of differentiation of outcome indicators, confusion in criteria and measurements, lack of specific outcome indicator sets for different EM populations, and unclear time points for long-term outcomes. Therefore, the studies about COS need to be carried out urgently.

CXCR3 Inhibition Blocks the NF-κB Signaling Pathway by Elevating Autophagy to Ameliorate Lipopolysaccharide-Induced Intestinal Dysfunction in Mice.

Autophagy is a cellular catabolic process in the evolutionarily conservative turnover of intracellular substances in eukaryotes, which is involved in both immune homeostasis and injury repairment. CXCR3 is an interferon-induced chemokine receptor that participates in immune regulation and inflammatory responses. However, CXCR3 regulating intestine injury via autophagy along with the precise underlying mechanism have yet to be elucidated. In the current study, we employed an LPS-induced inflammatory mouse model and confirmed that CXCR3 knockout significantly attenuates intestinal mucosal structural damage and increases tight junction protein expression. CXCR3 knockout alleviated the LPS-induced increase in the expression of inflammatory factors including TNF-α, IL-6, p-65, and JNK-1 and enhanced autophagy by elevating LC3II, ATG12, and PINK1/Parkin expression. Mechanistically, the function of CXCR3 regarding autophagy and immunity was investigated in IPEC-J2 cells. CXCR3 inhibition by AMG487 enhanced autophagy and reduced the inflammatory response, as well as blocked the NF-κB signaling pathway and elevated the expression of the tight junction protein marker Claudin-1. Correspondingly, these effects were abolished by autophagy inhibition with the selective blocker, 3-MA. Moreover, the immunofluorescence assay results further demonstrated that CXCR3 inhibition-mediated autophagy blocked p65 nuclear translocation, and the majority of Claudin-1 was located at the tight junctions. In conclusion, CXCR3 inhibition reversed LPS-induced intestinal barrier damage and alleviated the NF-κB signaling pathway via enhancing autophagy. These data provided a theoretical basis for elucidating the immunoregulatory mechanism by targeting CXCR3 to prevent intestinal dysfunction.