Yong Zhao

Abstract 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 lgmn WT and lgmn KO 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 H 2 DCFDA 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 lgmn KO mRTECs compared with lgmn WT 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.

MicroRNAs (miRNAs) are a class of short noncoding RNAs that regulate protein-coding genes posttranscriptionally. In animals, most known miRNA targeting occurs within the 3'UTR of mRNAs, but the extent of biologically relevant targeting in the ORF or 5'UTR of mRNAs remains unknown. Here, we develop an algorithm (MinoTar-miRNA ORF Targets) to identify conserved regulatory motifs within protein-coding regions and use it to estimate the number of preferentially conserved miRNA-target sites in ORFs. We show that, in Drosophila, preferentially conserved miRNA targeting in ORFs is as widespread as it is in 3'UTRs and that, while far less abundant, conserved targets in Drosophila 5'UTRs number in the hundreds. Using our algorithm, we predicted a set of high-confidence ORF targets and selected seven miRNA-target pairs from among these for experimental validation. We observed down-regulation by the miRNA in five out of seven cases, indicating our approach can recover functional sites with high confidence. Additionally, we observed additive targeting by multiple sites within a single ORF. Altogether, our results demonstrate that the scale of biologically important miRNA targeting in ORFs is extensive and that computational tools such as ours can aid in the identification of such targets. Further evidence suggests that our results extend to mammals, but that the extent of ORF and 5'UTR targeting relative to 3'UTR targeting may be greater in Drosophila.

Very recent publications in Gut and elsewhere1 2 suggest that gut microbiota affects fertility. The application of faecal microbiota transplantation (FMT) to modify fertility is an emerging novel area of interest.3 FMT from women with polycystic ovary syndrome (PCOS) leads to the disruption of ovarian function and a decrease in fertility which indicates that modification of gut microbiota may be a valuable approach in the management of PCOS.2 FMT of gut microbes, that developed under a high-fat diet, into mice on a normal diet leads to the disruption of spermatogenesis and a reduction of sperm motility,1 which highlights that restoring gut microbiota may be a means of improving disturbed male infertility caused by environmental factors.1 However, to date, there are no reports that address improvements of fertility following FMT. In a recent study,4 we found that busulfan damages spermatogenesis and sperm quality, and disturbs gut microbiota as found in many other studies.5 6 Alginate oligosaccharides (AOS), a natural product with many benefits, rescues busulfan disrupted spermatogenesis by supporting gut microbiota through an increase in ‘beneficial’ bacteria4 such as Bacteroidales and Lactobacillaceae and a decrease in ‘harmful’ bacteria, such as Desulfovibrionaceae .7 Gut microbiota from AOS dosed animals may improve spermatogenesis through benefit to the recipients gut microbes. To test this hypothesis, we set out to explore the beneficial improvement of sperm quality and …

Caffeic acid (CA) is one of the major phenolic acids of coffee with multiple biological activities. Our previous study found that 500 mg/kg of chlorogenic acid (CGA) had the potential capacity of alleviating colonic inflammation. Moreover, CGA can be degraded into caffeic acid (CA) by the gut microbiota in the colon. Therefore, we hypothesize that CA can exert protective effects on colonic inflammation. To test the hypothesis, 251 mg/kg CA was supplemented to DSS-induced colitis mice. The results showed that CA treatment recovered DSS-induced disease activity index (DAI), colon length, and histopathology scores of colon tissue. Additionally, CA treatment significantly decreased pro-inflammatory cytokines and malondialdehyde (MDA) levels and increased the level of IL-10, total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in serum. qPCR results indicated that CA treatment dramatically downregulated mRNA expression of IL-1β , IL-6 , and TNF-α as well as upregulated SOD1 , GPX1 , GPX2 , CAT , and IL-10 . In addition, CA supplementation significantly increased mRNA expression of Nrf-2 , HO-1 , and NQO1 , which showed its antioxidant and anti-inflammatory capacities potentially by activating the Nrf-2/HO-1 pathway. Moreover, CA supplementation prevented gut barrier damage by enhancing Occludin gene expression. Furthermore, CA supplementation altered the gut microbiome composition by decreasing the relative abundance of Bacteroides and Turicibacter , and enhancing the relative abundance of Alistipes and Dubosiella . Meanwhile, CA supplementation increases the abundance of Dubosiella and Akkermansia . In conclusion, CA supplementation could effectively alleviate DSS-induced colitis by improving the defense against oxidative stress and inflammatory response.