Legumain is required for maintenance of normal kidney homeostasis. However, its role in acute kidney injury (AKI) is still unclear. Here, we induced AKI by bilateral ischemia-reperfusion injury (IRI) of renal arteries or folic acid in lgmnWT and lgmnKO mice. We assessed serum creatinine, blood urea nitrogen, histological indexes of tubular injury, and expression of KIM-1 and NGAL. Inflammatory infiltration was evaluated by immunohistological staining of CD3 and F4/80, and expression of TNF-α, CCL-2, IL-33, and IL-1α. Ferroptosis was evaluated by Acsl4, Cox-2, reactive oxygen species (ROS) indexes H2DCFDA and DHE, MDA and glutathione peroxidase 4 (GPX4). We induced ferroptosis by hypoxia or erastin in primary mouse renal tubular epithelial cells (mRTECs). Cellular survival, Acsl4, Cox-2, LDH release, ROS, and MDA levels were measured. We analyzed the degradation of GPX4 through inhibition of proteasomes or autophagy. Lysosomal GPX4 was assessed to determine GPX4 degradation pathway. Immunoprecipitation (IP) was used to determine the interactions between legumain, GPX4, HSC70, and HSP90. For tentative treatment, RR-11a was administrated intraperitoneally to a mouse model of IRI-induced AKI. Our results showed that legumain deficiency attenuated acute tubular injury, inflammation, and ferroptosis in either IRI or folic acid-induced AKI model. Ferroptosis induced by hypoxia or erastin was dampened in lgmnKO mRTECs compared with lgmnWT control. Deficiency of legumain prevented chaperone-mediated autophagy of GPX4. Results of IP suggested interactions between legumain, HSC70, HSP90, and GPX4. Administration of RR-11a ameliorated ferroptosis and renal injury in the AKI model. Together, our data indicate that legumain promotes chaperone-mediated autophagy of GPX4 therefore facilitates tubular ferroptosis in AKI.

Effects of M2 tumour-associated macrophages on the pathogenesis of diffuse large B cell lymphoma (DLBCL) are still controversial. Our data showed that the number of CD163-positive M2 macrophages correlated negatively with DLBCL prognosis. Macrophage depletion by clodronate liposomes significantly suppressed tumour growth in a xenograft mouse model of DLBCL using OCI-Ly3 cells. Moreover, M2 polarization of macrophages induced legumain expression in U937 cells. Exogenous legumain promoted degradation of fibronectin and collagen I, which was abolished by administration of a legumain inhibitor RR-11a. Overexpression of legumain in Raw 264.7 cells also induced tube formation of endothelial cells in matrigel. In the xenograft mouse model of DLBCL, decreased fibronectin and collagen I, as well as increased legumain expression and angiogenesis were found at the late stage tumours compared with early stage tumours. Co-localization of legumain and fibronectin was observed in the extracellular matrix of tumour tissues. Administration of the legumain inhibitor to the xenograft DLBCL model suppressed tumour growth, angiogenesis and collagen deposition compared with the control. Taken together, our results suggest that M2 tumour-associated macrophages affect degradation of the extracellular matrix and angiogenesis via overexpression of legumain, and therefore play an active role in the progression of DLBCL.

Through proliferation and differentiation, a single cell, the zygote, can give rise to a complex organism composed of many types of cells. Up to the eight-cell embryo stage, the blastomeres are morphologically identical and distributed symmetrically in the mammalian embryo. Functionally, in some species, they are all totipotent. However, due to the compaction of blastomeres and the asymmetrical cell division at the late phase of the eight-cell embryo, the blastomeres of the morula are no longer identical. During the transition from morula to blastocyst, blastomeres differentiate, resulting in the first cell fate decision in embryogenesis, namely, the segregation of the inner cell mass and the trophectoderm. In this review, we will discuss the regulatory mechanisms essential for the cell fate choice during blastocyst development, including transcriptional regulation, epigenetic regulation, microRNAs, and signal transduction.

Rationale: Differential activation of macrophages correlates closely with tumor progression, and the epigenetic factor lysine demethylase 6B (KDM6B, previously named JMJD3) mediates the regulation of macrophage polarization through an unknown mechanism. Methods: We developed a suspension coculture system comprising breast cancer cells and macrophages and used RT-qPCR and western blotting to measure KDM6B expression. Bioinformatics and luciferase reporter assays were used to identify candidate microRNAs of cancer cells responsible for the downregulation of KDM6B. To determine if exosomes mediated the transfer of miR-138-5p between cancer cells to macrophages, we treated macrophages with exosomes collected from the conditioned medium of cancer cells. The effects of exosomal miR-138-5p on macrophage polarization were measured using RT-qPCR, flow cytometry, and chromatin immunoprecipitation assays. We employed a mouse model of breast cancer, metastatic to the lung, to evaluate the effects on tumor metastasis of macrophages treated with miR-138-5p-enriched exosomes. To develop a diagnostic evaluation index, the levels of exosomal miR-138-5p in samples from patients with breast cancer were compared to those of controls. Results: Coculture of breast cancer cells led to downregulation of KDM6B expression in macrophages. Cancer cell-derived exosomal miR-138-5p inhibited M1 polarization and promoted M2 polarization through inhibition of KDM6B expression in macrophages. Macrophages treated with exosomal miR-138-5p promoted lung metastasis, and the level of circulating exosomal miR-138-5p positively correlated with the progression of breast cancer. Conclusion: Our data suggest that miR-138-5p was delivered from breast cancer cells to tumor-associated macrophages via exosomes to downregulate KDM6B expression, inhibit M1 polarization, and stimulate M2 polarization. Therefore, exosomal miR-138-5p represents a promising prognostic marker and target for the treatment of breast cancer.

We have evaluated the performance of 3 new EBV ELISA for the diagnosis of nasopharyngeal carcinoma (NPC). The tests were specific for EBNA 1 IgA, EBNA 1 IgG and zta IgG, respectively. Their distinct antigenic specificity permits these assays to be used in concert in an approach that differentiates patients and apparently healthy subjects on the basis of their antibody spectrum. By so exploiting a distinguishing feature of NPC first described by the late Werner Henle that the patients sustain high levels of a broad spectrum of serum EBV antibodies, this approach achieved a sensitivity of 92% and a specificity of 93%, surpassing the performance of each of these assays individually. The enhanced performance is especially useful in population screening. It was shown that relative risk of NPC sustained by apparently healthy subjects residing in a high incidence area for NPC in the Pearl River estuary in Southern China may vary according to EBV antibody spectrum. The risk of the cancer was markedly reduced with odds ratios of 0.009 for 59% of those who had low level of all 3 antibodies. The risk was increased as antibody spectrum broadens and the risk was the highest with an odds ratio of 138 for 0.4% of those who had high levels of all 3 antibodies. Thus, EBV antibody spectrum may serve to guide follow-up measures for early detection of the cancer and/or risk counseling according to level of the risk of the cancer sustained by the screened individuals.