Intrinsic disorder in proteins associated with oxidative stress-induced JNK signaling

Characterization of tumor necrosis factor receptor-associated factor 2 (TRAF2) in red-spotted grouper (Epinephelus akaara): In vivo and in vitro investigation of its role in the regulation of antiviral immunity and cell death

Tumor necrosis factor receptor-associated factor 2 (TRAF2) is a key adaptor molecule in tumor necrosis factor receptor signaling complexes, facilitating downstream immune-related signaling cascades. This study aimed to elucidate its function in teleost fish by characterizing the TRAF2 homolog of the red-spotted grouper (Epinephelus akaara, EaTraf2). The open reading frame of EaTraf2 encodes a putative protein of 520 amino acids, containing several characteristic domains of TRAF2. These structural features of EaTraf2 are conserved across diverse organisms, with a relatively higher sequence identity to TRAF2 orthologs from other bony fish. Transcriptional analysis demonstrated that EaTraf2 was ubiquitously expressed in all examined tissues, with the highest level observed in blood. Upon immune challenge, EaTraf2 expression significantly increased in the early stages of stimulation in both blood and spleen. Subcellular localization analysis revealed that EaTraf2 is predominantly localized in the cytoplasm. Overexpression of EaTraf2 in fathead minnow (FHM) cells resulted in elevated levels of interferon and inflammation-associated genes following viral hemorrhagic septicemia virus (VHSV) infection, along with reduced viral gene expression. This provided compelling evidence that EaTraf2 possesses antiviral properties. Furthermore, EaTraf2 demonstrated the ability to promote cell death induced by oxidative stress. Additionally, luciferase reporter assays revealed that EaTraf2 activates the NF-κB signaling pathway upon poly(I:C) stimulation and the Jun N-terminal kinase (JNK) signaling pathway in response to H2O2 treatment. Overall, our study elucidated the role of EaTraf2 in regulating innate immune responses and mediating stress-induced cell death. These findings enhance our understanding of TRAF2 in fish and may contribute to improved health management strategies in finfish aquaculture.

New insights of DsbA-L in the pathogenesis of metabolic diseases

Metabolic diseases, such as obesity, diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD), are abnormal conditions that result from disturbances of metabolism. With the improvement of living conditions, the morbidity and mortality rates of metabolic diseases are steadily rising, posing a significant threat to human health worldwide. Therefore, identifying novel effective targets for metabolic diseases is crucial. Accumulating evidence has indicated that disulfide bond A oxidoreductase-like protein (DsbA-L) delays the development of metabolic diseases. However, the underlying mechanisms of DsbA-L in metabolic diseases remain unclear. In this review, we will discuss the roles of DsbA-L in the pathogenesis of metabolic diseases, including obesity, diabetes mellitus, and NAFLD, and highlight the potential mechanisms. These findings suggest that DsbA-L might provide a novel therapeutic strategy for metabolic diseases.

Identification of oxidative stress-related genes differentially expressed in Alzheimer's disease and construction of a hub gene-based diagnostic model

Alzheimer's disease (AD) is the most prevalent dementia disorder globally, and there are still no effective interventions for slowing or stopping the underlying pathogenic mechanisms. There is strong evidence implicating neural oxidative stress (OS) and ensuing neuroinflammation in the progressive neurodegeneration observed in the AD brain both during and prior to symptom emergence. Thus, OS-related biomarkers may be valuable for prognosis and provide clues to therapeutic targets during the early presymptomatic phase. In the current study, we gathered brain RNA-seq data of AD patients and matched controls from the Gene Expression Omnibus (GEO) to identify differentially expressed OS-related genes (OSRGs). These OSRGs were analyzed for cellular functions using the Gene Ontology (GO) database and used to construct a weighted gene co-expression network (WGCN) and protein-protein interaction (PPI) network. Receiver operating characteristic (ROC) curves were then constructed to identify network hub genes. A diagnostic model was established based on these hub genes using Least Absolute Shrinkage and Selection Operator (LASSO) and ROC analyses. Immune-related functions were examined by assessing correlations between hub gene expression and immune cell brain infiltration scores. Further, target drugs were predicted using the Drug-Gene Interaction database, while regulatory miRNAs and transcription factors were predicted using miRNet. In total, 156 candidate genes were identified among 11046 differentially expressed genes, 7098 genes in WGCN modules, and 446 OSRGs, and 5 hub genes (MAPK9, FOXO1, BCL2, ETS1, and SP1) were identified by ROC curve analyses. These hub genes were enriched in GO annotations "Alzheimer's disease pathway," "Parkinson's Disease," "Ribosome," and "Chronic myeloid leukemia." In addition, 78 drugs were predicted to target FOXO1, SP1, MAPK9, and BCL2, including fluorouracil, cyclophosphamide, and epirubicin. A hub gene-miRNA regulatory network with 43 miRNAs and hub gene-transcription factor (TF) network with 36 TFs were also generated. These hub genes may serve as biomarkers for AD diagnosis and provide clues to novel potential treatment targets.

Fear-of-intimacy-mediated zinc transport is required for Drosophila fat body endoreplication

BACKGROUND

Endoreplication is involved in the development and function of many organs, the pathologic process of several diseases. However, the metabolic underpinnings and regulation of endoreplication have yet to be well clarified.

RESULTS

Here, we showed that a zinc transporter fear-of-intimacy (foi) is necessary for Drosophila fat body endoreplication. foi knockdown in the fat body led to fat body cell nuclei failure to attain standard size, decreased fat body size and pupal lethality. These phenotypes could be modulated by either altered expression of genes involved in zinc metabolism or intervention of dietary zinc levels. Further studies indicated that the intracellular depletion of zinc caused by foi knockdown results in oxidative stress, which activates the ROS-JNK signaling pathway, and then inhibits the expression of Myc, which is required for tissue endoreplication and larval growth in Drosophila.

CONCLUSIONS

Our results indicated that FOI is critical in coordinating fat body endoreplication and larval growth in Drosophila. Our study provides a novel insight into the relationship between zinc and endoreplication in insects and may provide a reference for relevant mammalian studies.

Microalgae as a Nutraceutical Tool to Antagonize the Impairment of Redox Status Induced by SNPs: Implications on Insulin Resistance

Microalgae represent a growing innovative source of nutraceuticals such as carotenoids and phenolic compound which are naturally present within these single-celled organisms or can be induced in response to specific growth conditions. The presence of the unfavourable allelic variant in genes involved in the control of oxidative stress, due to one or more SNPs in gene encoding protein involved in the regulation of redox balance, can lead to pathological conditions such as insulin resistance, which, in turn, is directly involved in the pathogenesis of type 2 diabetes mellitus. In this review we provide an overview of the main SNPs in antioxidant genes involved in the promotion of insulin resistance with a focus on the potential role of microalgae-derived antioxidant molecules as novel nutritional tools to mitigate oxidative stress and improve insulin sensitivity.

JNK-JUN-NCOA4 axis contributes to chondrocyte ferroptosis and aggravates osteoarthritis via ferritinophagy

Interruption of iron homeostasis is correlated with cell ferroptosis and degenerative diseases. Nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy has been reported as a vital mechanism to control cellular iron levels, but its impact on osteoarthritis (OA) pathology and the underline mechanism are unknown. Herein we aimed to investigate the role and regulatory mechanism of NCOA4 in chondrocyte ferroptosis and OA pathogenesis. We demonstrated that NCOA4 was highly expressed in cartilage of patients with OA, aged mice, post-traumatic OA mice, and inflammatory chondrocytes. Importantly, Ncoa4 knockdown inhibited IL-1β-induced chondrocyte ferroptosis and extracellular matrix degradation. Contrarily, overexpression of NCOA4 promoted chondrocyte ferroptosis and the delivery of Ncoa4 adeno-associated virus 9 into knee joint of mice aggravated post-traumatic OA. Mechanistic study revealed that NCOA4 was upregulated in a JNK-JUN signaling-dependent manner in which JUN could directly bind to the promoter of Ncoa4 and initial the transcription of Ncoa4. NCOA4 could interact with ferritin and increase autophagic degradation of ferritin and iron levels, which caused chondrocyte ferroptosis and extracellular matrix degradation. In addition, inhibition of JNK-JUN-NCOA4 axis by SP600125, a specific inhibitor of JNK, attenuated development of post-traumatic OA. This work highlights the role of JNK-JUN-NCOA4 axis and ferritinophagy in chondrocyte ferroptosis and OA pathogenesis, suggesting this axis as a potential target for OA treatment.

Assessing the Progression of Early Atherosclerosis Mice Using a Fluorescence Nanosensor for the Simultaneous Detection and Imaging of pH and Phosphorylation

The inflammatory microenvironment involves changes in pH and protein phosphorylation state and is closely related to the occurrence and development of atherosclerosis (AS). Herein, we constructed a dual-detection fluorescence nanosensor PCN-NP-HPZ based on post modification of MOFs, which realized the simultaneous detection and imaging of pH and phosphorylation through the pH-sensitive group piperazine and the Zr^IV node of the MOFs. The sensors were used to monitor changes in blood pH and phosphate levels at different time stages during atherosclerotic plaque formation. Two-photon fluorescence imaging was also performed in the vascular endothelium. Blood tests combined with two-photon fluorescence images indicated that in the early stage of AS, blood and tissue pH levels were lower than that of the normal mice, while phosphate and tissue phosphorylation levels were higher than that of the normal mice. The present study provides a new analysis method for the assessment of early atherosclerotic disease.