miR-31-5p Regulates Type I Interferon by Targeting SLC15A4 in Plasmacytoid Dendritic Cells of Systemic Lupus Erythematosus

Comprehensive analysis of circRNA-miRNA-mRNA regulatory network and novel potential biomarkers in eutopic endometrium of adenomyosis

Adenomyosis (ADS) is a common gynecological disorder, and its pathogenesis remains unclear. This study explores the functions of circRNAs in the eutopic endometrium of ADS and their diagnostic efficacy for ADS. High-throughput RNA sequencing was performed on 12 eutopic endometrial samples from ADS patients and 3 control endometrial samples. Additionally, circRNAs were analyzed in conjunction with clinical features. A competitive endogenous RNA network was established based on bioinformatics analysis, comprising 3 circRNAs, 1 miRNA, and 13 mRNAs. In the ADS group, the expression levels of hsa_circ_0008959 and SLC15A4 were significantly reduced, while hsa-miR-124-3p expression was increased. SLC15A4 was associated with cell proliferation and invasion. Decreased expression of hsa_circ_0008959 and SLC15A4, along with high VAS scores and elevated hsa-miR-124-3p levels, were identified as risk factors for ADS development. The combination of hsa_circ_0008959 and VAS scores demonstrated the highest diagnostic value for ADS.

LncRNA SNHG16 Knockdown Promotes Diabetic Foot Ulcer Wound Healing via Sponging MiR-31-5p

Diabetic foot ulcers are caused by nerve abnormalities and vascular lesions in the distal lower limbs of diabetic patients. However, the causes of diabetic foot ulcers are diverse and the treatment process is complex. Therefore, understanding the pathogenesis of diabetic foot ulcers through lncRNA and formulating effective means are the key to the cure of patients. Tissues were collected from 76 diabetic foot ulcer patients and 50 non-diabetic patients undergoing traumatic amputation. Human dermal fibroblasts (HDFs) were induced by high glucose to obtain diabetic foot ulcer cell model. The lncRNA SNHG16 (SNHG16) and miR-31-5p expression in tissues and cells was detected by real-time quantitative reverse transcription PCR (RT-qPCR). Cell Counting Kit-8 (CCK-8) and Transwell assays were used to evaluate the biological behavior of the cells, and the association between SNHG16 and miR-31-5p was explored by luciferase reporting assay. SNHG16 was distinctly expressed in diabetic foot ulcer tissue samples, while miR-31-5p was decreased. In vitro cell function assays confirmed that the proliferation level was inhibited in the constructed diabetic foot ulcer cell model (HG group), as was the migration and invasion ability. After transfection with silencing SNHG16, the biological behavior of the cells was promoted. Mechanistically, SNHG16 sponge miR-31-5p regulated disease progression. Recovery experiments revealed that miR-31-5p inhibitor counteracted the effect of silencing SNHG16 on cell viability. SNHG16 knockdown may regulate the biological function of cells by targeting miR-31-5p to promote wound healing and ameliorate the condition of diabetic foot ulcer patients.

The crucial regulatory role of type I interferon in inflammatory diseases

Type I interferon (IFN-I) plays crucial roles in the regulation of inflammation and it is associated with various inflammatory diseases including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and periodontitis, impacting people's health and quality of life. It is well-established that IFN-Is affect immune responses and inflammatory factors by regulating some signaling. However, currently, there is no comprehensive overview of the crucial regulatory role of IFN-I in distinctive pathways as well as associated inflammatory diseases. This review aims to provide a narrative of the involvement of IFN-I in different signaling pathways, mainly mediating the related key factors with specific targets in the pathways and signaling cascades to influence the progression of inflammatory diseases. As such, we suggested that IFN-Is induce inflammatory regulation through the stimulation of certain factors in signaling pathways, which displays possible efficient treatment methods and provides a reference for the precise control of inflammatory diseases.

A Non-Coding Variant in SLC15A4 Modulates Enhancer Activity and Lysosomal Deacidification Linked to Lupus Susceptibility

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with a strong genetic basis. Despite the identification of several single nucleotide polymorphisms (SNPs) near the SLC15A4 gene that are significantly associated with SLE across multiple populations, specific causal SNP(s) and molecular mechanisms responsible for disease susceptibility are unknown. To address this gap, we employed bioinformatics, expression quantitative trait loci (eQTLs), and 3D chromatin interaction analysis to nominate a likely functional variant, rs35907548, in an active intronic enhancer of SLC15A4. Through luciferase reporter assays followed by chromatin immunoprecipitation (ChIP)-qPCR, we observed significant allele-specific enhancer effects of rs35907548 in diverse cell lines. The rs35907548 risk allele T is associated with increased regulatory activity and target gene expression, as shown by eQTLs and chromosome conformation capture (3C)-qPCR. The latter revealed long-range chromatin interactions between the rs35907548 enhancer and the promoters of SLC15A4, GLTLD1, and an uncharacterized lncRNA. The enhancer-promoter interactions and expression effects were validated by CRISPR/Cas9 knock-out (KO) of the locus in HL60 promyeloblast cells. KO cells also displayed dramatically dysregulated endolysosomal pH regulation. Together, our data show that the rs35907548 risk allele affects multiple aspects of cellular physiology and may directly contribute to SLE.

Oligopeptide/Histidine Transporter PHT1 and PHT2 - Function, Regulation, and Pathophysiological Implications Specifically in Immunoregulation

The oligopeptide/histidine transporters PHT1 and PHT2, two mammalian solute carrier family 15A proteins, mediate the transmembrane transport of histidine and some di/tripeptides via proton gradient. PHT1 and PHT2 are distributed in a variety of tissues but are preferentially expressed in immune cells and localize to the lysosome-related organelles. Studies have reported the relationships between PHT1/PHT2 and immune diseases. PHT1 and PHT2 participate in the regulation of lysosomal homeostasis and lysosome-associated signaling pathways through their transport and nontransport functions, playing important roles in inflammatory diseases. In this review, we summarize recent research on PHT1 and PHT2, aiming to provide reference for their further biological research and as targets for drug design.

Amino acid metabolism in immune cells: essential regulators of the effector functions, and promising opportunities to enhance cancer immunotherapy

Amino acids are basic nutrients for immune cells during organ development, tissue homeostasis, and the immune response. Regarding metabolic reprogramming in the tumor microenvironment, dysregulation of amino acid consumption in immune cells is an important underlying mechanism leading to impaired anti-tumor immunity. Emerging studies have revealed that altered amino acid metabolism is tightly linked to tumor outgrowth, metastasis, and therapeutic resistance through governing the fate of various immune cells. During these processes, the concentration of free amino acids, their membrane bound transporters, key metabolic enzymes, and sensors such as mTOR and GCN2 play critical roles in controlling immune cell differentiation and function. As such, anti-cancer immune responses could be enhanced by supplement of specific essential amino acids, or targeting the metabolic enzymes or their sensors, thereby developing novel adjuvant immune therapeutic modalities. To further dissect metabolic regulation of anti-tumor immunity, this review summarizes the regulatory mechanisms governing reprogramming of amino acid metabolism and their effects on the phenotypes and functions of tumor-infiltrating immune cells to propose novel approaches that could be exploited to rewire amino acid metabolism and enhance cancer immunotherapy.