Indoxyl Sulfate Elevated Lnc-SLC15A1-1 Upregulating CXCL10/CXCL8 Expression in High-Glucose Endothelial Cells by Sponging MicroRNAs

Causal relationships between blood metabolites and diabetic retinopathy: a two-sample Mendelian randomization study

Background

Diabetic retinopathy (DR) is a microvascular complication of diabetes, severely affecting patients' vision and even leading to blindness. The development of DR is influenced by metabolic disturbance and genetic factors, including gene polymorphisms. The research aimed to uncover the causal relationships between blood metabolites and DR.

Methods

The two-sample mendelian randomization (MR) analysis was employed to estimate the causality of blood metabolites on DR. The genetic variables for exposure were obtained from the genome-wide association study (GWAS) dataset of 486 blood metabolites, while the genetic predictors for outcomes including all-stage DR (All DR), non-proliferative DR (NPDR) and proliferative DR (PDR) were derived from the FinnGen database. The primary analysis employed inverse variance weighted (IVW) method, and supplementary analyses were performed using MR-Egger, weighted median (WM), simple mode and weighted mode methods. Additionally, MR-Egger intercept test, Cochran's Q test, and leave-one-out analysis were also conducted to guarantee the accuracy and robustness of the results. Subsequently, we replicated the MR analysis using three additional datasets from the FinnGen database and conducted a meta-analysis to determine blood metabolites associated with DR. Finally, reverse MR analysis and metabolic pathway analysis were performed.

Results

The study identified 13 blood metabolites associated with All DR, 9 blood metabolites associated with NPDR and 12 blood metabolites associated with PDR. In summary, a total of 21 blood metabolites were identified as having potential causal relationships with DR. Additionally, we identified 4 metabolic pathways that are related to DR.

Conclusion

The research revealed a number of blood metabolites and metabolic pathways that are causally associated with DR, which holds significant importance for screening and prevention of DR. However, it is noteworthy that these causal relationships should be validated in larger cohorts and experiments.

Fecal Microbiota Transplantation in Reducing Uremic Toxins Accumulation in Kidney Disease: Current Understanding and Future Perspectives

During the past decades, the gut microbiome emerged as a key player in kidney disease. Dysbiosis-related uremic toxins together with pro-inflammatory mediators are the main factors in a deteriorating kidney function. The toxicity of uremic compounds has been well-documented in a plethora of pathophysiological mechanisms in kidney disease, such as cardiovascular injury (CVI), metabolic dysfunction, and inflammation. Accumulating data on the detrimental effect of uremic solutes in kidney disease supported the development of many strategies to restore eubiosis. Fecal microbiota transplantation (FMT) spread as an encouraging treatment for different dysbiosis-associated disorders. In this scenario, flourishing studies indicate that fecal transplantation could represent a novel treatment to reduce the uremic toxins accumulation. Here, we present the state-of-the-art concerning the application of FMT on kidney disease to restore eubiosis and reverse the retention of uremic toxins.

LINC00926 is involved in hypoxia-induced vascular endothelial cell dysfunction via miR-3194-5p regulating JAK1/STAT3 signaling pathway

Vascular endothelial cell (VEC) dysfunction is associated with the development of coronary heart disease (CHD). Long intergenic non-protein coding RNA 926 (LINC00926), a kind of long noncoding RNA (lncRNA), has been found to be abnormally expressed in CHD patients. However, the biological role of LINC00926 has not been reported. In our research, we intended to explore the regulatory mechanism of LINC00926 in hypoxia-exposed HUVEC cells (HUVECs). In our in vitro study, HUVECs were exposed under hypoxic conditions (5% O2) for 24 h. RT-qPCR and Western blotting assay were used to detect the mRNA and protein levels. CCK-8 assay, flow cytometry, transwell assay and in vitro angiogenesis assay were performed to measure cell proliferation, apoptosis, migration and tube formation, respectively. Bioinformatics analysis was applied to predict the target of LINC00926 and miR-3194-5p, which was verified by dual-luciferase reporter assays. The results showed that LINC00926 was highly expressed in CHD patients and hypoxia-exposed HUVECs. LINC00926 overexpression suppressed cell proliferation, migration and tube formation and increased cell apoptosis. MiR-3194-5p was a target of LINC00926 and can target binding to JAK1 3'UTR. LINC00926 could up-regulate JAK1 and p-STAT3 levels via miR-3194-5p. In addition, overexpressed LINC00926 suppressed cell proliferation, migration and tube formation and increased cell apoptosis via miR-3194-5p/JAK1/STAT3 axis. In summary, LINC00926 aggravated endothelial cell dysfunction via miR-3194-5p regulating JAK1/STAT3 signaling pathway in hypoxia-exposed HUVECs.

Kidney diseases and long non-coding RNAs in the limelight

The most extensively and well-investigated sequences in the human genome are protein-coding genes, while large numbers of non-coding sequences exist in the human body and are even more diverse with more potential roles than coding sequences. With the unveiling of non-coding RNA research, long-stranded non-coding RNAs (lncRNAs), a class of transcripts >200 nucleotides in length primarily expressed in the nucleus and rarely in the cytoplasm, have drawn our attention. LncRNAs are involved in various levels of gene regulatory processes, including but not limited to promoter activity, epigenetics, translation and transcription efficiency, and intracellular transport. They are also dysregulated in various pathophysiological processes, especially in diseases and cancers involving genomic imprinting. In recent years, numerous studies have linked lncRNAs to the pathophysiology of various kidney diseases. This review summarizes the molecular mechanisms involved in lncRNAs, their impact on kidney diseases, and associated complications, as well as the value of lncRNAs as emerging biomarkers for the prevention and prognosis of kidney diseases, suggesting their potential as new therapeutic tools.

Long Non-Coding RNAs in the Pathogenesis of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the major microvascular complications of diabetes mellitus, with relatively high morbidity and mortality globally but still in short therapeutic options. Over the decades, a large body of data has demonstrated that oxidative stress, inflammatory responses, and hemodynamic disorders might exert critical influence in the initiation and development of DKD, whereas the delicate pathogenesis of DKD remains profoundly elusive. Recently, long non-coding RNAs (lncRNAs), extensively studied in the field of cancer, are attracting increasing attentions on the development of diabetes mellitus and its complications including DKD, diabetic retinopathy, and diabetic cardiomyopathy. In this review, we chiefly focused on abnormal expression and function of lncRNAs in major resident cells (mesangial cell, endothelial cell, podocyte, and tubular epithelial cell) in the kidney, summarized the critical roles of lncRNAs in the pathogenesis of DKD, and elaborated their potential therapeutic significance, in order to advance our knowledge in this field, which might help in future research and clinical treatment for the disease.