Inhibition of miR-17~92 Cluster Ameliorates High Glucose-Induced Podocyte Damage

STAT3-induced upregulation of lncRNA TTN-AS1 aggravates podocyte injury in diabetic nephropathy by promoting oxidative stress

Background

Diabetic nephropathy (DN) is the most common microvascular complication of diabetes mellitus (DM), being the second cause of end-stage renal disease globally. Podocyte injury is closely associated with DN developmen. Our study aimed to investigate the role of long non-coding RNA (lncRNA) TTN-AS1 in DN-associated podocyte injury.

Methods

The mouse podocyte cell line (MPC5) and human primary podocytes were stimulated by high glucose (HG; 30 nM glucose) to establish the cellular model of DN. Before HG stimulation, both podocytes were transfected with sh-TTN-AS1#1/2 or pcDNA3.1/STAT3 to evaluate the influence of TTN-AS1 knockdown or STAT3 overexpression on HG-induced podocyte injury. TTN-AS1 and STAT3 expression in both podocytes was examined by RT-qPCR. Cell viability and death were assessed by CCK-8 and LDH release assay. ELISA was adopted for testing IL-6 and TNF-α contents in cell supernatants. The levels of oxidative stress markers (ROS, MDA, SOD, and GSH) in cell supernatants were determined by commercial kits. Western blotting was used for measuring the expression of fibrosis markers (fibronectin and α-SMA and podocyte function markers (podocin and nephrin) in podocytes.

Results

HG stimulation led to decreased cell viability, increased cell death, fibrosis, inflammation, cell dysfunction and oxidative stress in podocytes. However, knockdown of TTN-AS1 ameliorated HG-induced podocyte injury. Mechanically, the transcription factor STAT3 interacted with TTN-AS1 promoter and upregulated TTN-AS1 expression. STAT3 overexpression offset the protective effect of TTN-AS1 silencing on HG-induced podocyte damage.

Conclusion

Overall, STAT3-mediated upregulation of lncRNA TTN-AS1 could exacerbate podocyte injury in DN through suppressing inflammation and oxidative stress.

miRNAs from Inflamed Gingiva Link Gene Signaling to Increased MET Expression

Several array-based microRNA (miRNA) expression studies independently showed increased expression of miRNAs hsa-miR-130a-3p, -142-3p, -144-3p, -144-5p, -223-3p, -17-5p, and -30e-5p in gingiva affected by periodontal inflammation. We aimed to determine direct target genes and signaling pathways regulated by these miRNAs to identify processes relevant to gingival inflammatory responses and tissue homeostasis. We transfected miRNA mimics (mirVana) for each of the 7 miRNAs separately into human primary gingival fibroblasts cultured from 3 different donors. Following RNA sequencing, differential gene expression and second-generation gene set enrichment analyses were performed. miRNA inhibition and upregulation was validated at the transcript and protein levels using quantitative reverse transcriptase polymerase chain reaction, Western blotting, and reporter gene assays. All 7 miRNAs significantly increased expression of the gene MET proto-oncogene, receptor tyrosine kinase (MET). Expression of known periodontitis risk genes CPEB1, ABCA1, and ATP6V1C1 was significantly repressed by hsa-miR-130a-3p, -144-3p, and -144-5p, respectively. The genes WASL, ENPP5, ARL6IP1, and IDH1 showed the most significant and strongest downregulation after hsa-miR-142-3p, -17-5p, -223-3p, and -30e-5p transfection, respectively. The most significantly regulated gene set of each miRNA related to cell cycle (hsa-miRNA-144-3p and -5p [Padj = 4 × 10-40 and Padj = 4 × 10-6], -miR-17-5p [Padj = 9.5 × 10-23], -miR-30e-5p [Padj = 8.2 × 10-18], -miR-130a-3p [Padj = 5 × 10-15]), integrin cell surface interaction (-miR-223-3p [Padj = 2.4 × 10-7]), and interferon signaling (-miR-142-3p [Padj = 5 × 10-11]). At the end of acute inflammation, gingival miRNAs bring together complex regulatory networks that lead to increased expression of the gene MET. This underscores the importance of mesenchymal cell migration and invasion during gingival tissue remodeling and proliferation in restoring periodontal tissue homeostasis after active inflammation. MET, a receptor of the mitogenic hepatocyte growth factor fibroblast secreted, is a core gene of this process.

Triptolide protects against podocyte injury in diabetic nephropathy by activating the Nrf2/HO-1 pathway and inhibiting the NLRP3 inflammasome pathway

Objectives: Diabetic nephropathy (DN) is the most common microvascular complication of diabetes mellitus. This study investigated the mechanism of triptolide (TP) in podocyte injury in DN.Methods: DN mouse models were established by feeding with a high-fat diet and injecting with streptozocin and MPC5 podocyte injury models were induced by high-glucose (HG), followed by TP treatment. Fasting blood glucose and renal function indicators, such as 24 h urine albumin (UAlb), serum creatinine (SCr), blood urea nitrogen (BUN), and kidney/body weight ratio of mice were examined. H&E and TUNEL staining were performed for evaluating pathological changes and apoptosis in renal tissue. The podocyte markers, reactive oxygen species (ROS), oxidative stress (OS), serum inflammatory cytokines, nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway-related proteins, and pyroptosis were detected by Western blotting and corresponding kits. MPC5 cell viability and pyroptosis were evaluated by MTT and Hoechst 33342/PI double-fluorescence staining. Nrf2 inhibitor ML385 was used to verify the regulation of TP on Nrf2.Results: TP improved renal function and histopathological injury of DN mice, alleviated podocytes injury, reduced OS and ROS by activating the Nrf2/heme oxygenase-1 (HO-1) pathway, and weakened pyroptosis by inhibiting the nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome pathway. In vitro experiments further verified the inhibition of TP on OS and pyroptosis by mediating the Nrf2/HO-1 and NLRP3 inflammasome pathways. Inhibition of Nrf2 reversed the protective effect of TP on MPC5 cells.Conclusions: Overall, TP alleviated podocyte injury in DN by inhibiting OS and pyroptosis via Nrf2/ROS/NLRP3 axis.

Holistic expression of miR-17-92 cluster in obesity, kidney diseases, cardiovascular diseases, and diabetes

miR-17-92 cluster encodes six micro RNAs (miRNAs) and plays a crucial role in the regulation of various cellular processes. Aberrant expression of this cluster may result in the onset of several diseases. Initially, the role of miR-17-92 cluster in tumorigenesis was discovered but recent research has also uncovered its role in other diseases. Members of the cluster may serve as potential biomarkers in the prognosis, diagnosis, and treatment of several diseases and their complications. In this article, we have reviewed the recent research carried out on the expression pattern of miR-17-92 cluster in non-communicable diseases i.e., obesity, cardiovascular diseases (CVD), kidney diseases (KD) and diabetes mellitus (DM). We examined miR-17-92 role in pathological processes and their potential importance as biomarkers. Each member of the cluster miR-17-92 was upregulated in obesity. miR-18a, miR-19b-3p, miR20a, and miR92a were significantly upregulated in CVD. An equal fraction of the cluster was dysregulated (upregulated and downregulated) in diabetes; however, miR-17-92 was downregulated in most studies on CKD.

Role of Bioinformatics Analysis in Early Differential Diagnosis of Ovarian Cancer

In order to solve the problem of early differential diagnosis of ovarian cancer, this paper proposes the role of bioinformatics analysis in early differential diagnosis of ovarian cancer. This method uses bioinformatics methods to mine the existing data in the tumor database and obtain tumor-related molecules. It is an efficient method to obtain effective biomarkers, screen signal pathway molecules, and reveal the internal mechanism of tumor occurrence and development. Using this method can greatly improve the efficiency and reliability of screening diagnosis, prognosis, and treatment targets. The results showed that 5821 new lncRNA transcripts and 4611 new lncRNA genes were identified by lncScore from the assembled transcripts. 10 new lncRNA transcripts and 174 new lncRNA genes were found to be differentially expressed in ovarian cancer.

Triptolide inhibits oxidative stress and inflammation via the microRNA-155-5p/brain-derived neurotrophic factor to reduce podocyte injury in mice with diabetic nephropathy

Diabetic nephropathy (DN) is a complication of diabetes. This study sought to explore the mechanism of triptolide (TP) in podocyte injury in DN. DN mice were induced by high-fat diet&streptozocin and treated with TP. Fasting blood glucose, 24 h urine microalbumin (UMA), the pathological changes of renal tissues, and ultrastructure of renal podocytes were observed. Podocytes (MPC5) were induced by high-glucose (HG) in vitro and treated with TP or microRNA (miR)-155-5p mimics, with Irbesartan as positive control. Reactive oxygen species (ROS) and levels of oxidative stress (OS) and inflammatory factors in MPC5 were detected. The levels of miR-155-5p, podocyte marker protein Nephrin, and inflammatory factors in mice and MPC5 were detected. The targeting relationship between miR-155-5p and brain-derived neurotrophic factor (BDNF) was verified. The expression levels of BDNF were detected. miR-155-5p mimics and overexpressed (oe)-BDNF plasmids were co-transfected into mouse podocytes treated with HG and TP. TP reduced fasting glucose and 24 h UMA of DN mice, alleviated the pathological damage and podocyte injury, up-regulated Nephrin level, and down-regulated miR-155-5p. TP down-regulated the high expression of miR-155-5p in HG-induced MPC5 cells and inhibited HG-induced OS and inflammatory injury, and the improvement effect of TP was better than Irbesartan. Overexpression of miR-155-5p reversed the protective effect of TP on injured mouse podocytes. miR-155-5p targeted BDNF. oe-BDNF reversed the inhibitory effect of oe-miR-155-5p on TP protection on podocyte injury in mice. Overall, TP up-regulated BDNF by inhibiting miR-155-5p, thus inhibiting OS and inflammatory damage and alleviating podocyte injury in DN mice.

STAT1 mediates the PI3K/AKT pathway through promoting microRNA-18a in nasal polyps

BACKGROUND

Epithelial to mesenchymal transition (EMT) is linked to the pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwNP). The involvement of STAT1 has been reported in CRSwNP. However, its specific role in regulating EMT in CRSwNP is not clear. We sought to evaluate the role of STAT1 in EMT in CRSwNP using clinical samples and a murine model.

METHODS

Comprehensive analysis of differentially expressed genes was performed in nasal polyps from the CRSwNP patients, followed by pathway enrichment analysis. After bioinformatics prediction, the relationships between microRNA-18a (miR-18a) and PTEN or STAT1 were examined using dual-luciferase and RIP assays, respectively. The expression of STAT1, PTEN, and miR-18a in nasal tissues was detected using RT-qPCR, immunohistochemistry, and in situ hybridization. After the alteration of gene expression in mice with CRSwNP, western blot, RT-qPCR, and HE staining were conducted to detect EMT-related proteins, inflammatory factor secretion, inflammatory cell infiltration, and the PI3K/AKT pathway activity in nasal tissues.

RESULTS

STAT1 and miR-18a were highly expressed, and PTEN was poorly expressed in the nasal polyp. STAT1 promoted transcription of miR-18a, which targeted PTEN. Downregulation of STAT1 and miR-18a inhibited the EMT and inflammatory cell infiltration, while depletion of PTEN promoted the EMT and inflammatory cell infiltration in the nasal polyp. The PI3K/AKT pathway was activated in the nasal polyp and regulated by the STAT1/miR-18a/PTEN axis.

CONCLUSIONS

STAT1 acts as a transcription factor to promote transcription of miR-18a, and miR-18a targets PTEN to exacerbate the inflammatory response and EMT in CRSwNP.

MiR-17-5p downregulation alleviates apoptosis and fibrosis in high glucose-induced human mesangial cells through inactivation of Wnt/β-catenin signaling by targeting KIF23

Diabetic nephropathy (DN) remains the major cause of end-stage renal disease. MicroRNAs (miRNAs) have been reported to perform biological functions in many diseases. This investigation elucidated the biological role of miR-17-5p in DN. In this study, high glucose-cultured human mesangial cells (HMCs) were used as a cell model of DN. The miR-17-5p and KIF23 expression was measured by RT-qPCR. Cell apoptosis was detected by flow cytometry. The protein levels of apoptosis markers, fibrosis markers, and Wnt/β-catenin signaling-related genes were assessed using western blotting. The interaction of miR-17-5p with KIF23 was tested by a luciferase reporter assay. We found that miR-17-5p was upregulated in both DN patients and high glucose-treated HMCs. Silencing miR-17-5p attenuated the apoptosis and fibrosis in high glucose-treated HMCs. MiR-17-5p binds to KIF23 3'UTR and negatively regulates KIF23 expression. KIF23 knockdown could suppress the role of miR-17-5p inhibition in high glucose-treated HMCs. Additionally, inhibition of miR-17-5p activated Wnt/β-catenin signaling in HMCs through upregulating KIF23 expression. Suppression of Wnt/β-catenin signaling antagonized the effect of miR-17-5p in HMCs. In conclusion, miR-17-5p inhibition alleviates the apoptosis and fibrosis in high glucose-treated HMCs by targeting KIF23 activating Wnt/β-catenin signaling.

Long non-coding RNA H19 promotes myoblast fibrogenesis via regulating the miR-20a-5p-Tgfbr2 axis

Emerging evidence has indicated long non-coding RNAs (lncRNAs) play important roles in diverse biological processes, including fibrosis. Here, we report that lncRNA H19 is able to promote skeletal muscle fibrosis. lnc-H19 was identified to be highly expressed in skeletal muscle fibrosis in vivo and in vitro; while lnc-H19 knockdown attenuated fibrosis in vitro. The knockdown of lnc-H19 was proved to inhibit the activation of the TGFβ/Smad pathway in C2C12 myoblasts by sponging miR-20a-5p to regulate Tgfbr2 expression through the competing endogenous RNA function. Our study elucidates the roles of the lnc-H19-miR-20a-5p-Tgfbr2 axis in regulating the TGFβ/Smad pathway of myoblast fibrogenesis, which might provide a promising therapeutic target for skeletal muscle fibrosis.

Circulating exosomal microRNA-18a-5p accentuates intestinal inflammation in Hirschsprung-associated enterocolitis by targeting RORA

The relevance of stem cell-derived exosomes has been implicated in necrotizing enterocolitis, while the involvement of serum-derived exosomes from children with Hirschsprung-associated enterocolitis (HAEC) in pathogenesis of HAEC remains unclear. This study set to identify the roles of exosomal microRNA (miR)-18a-5p from sera of HAEC patients in human-derived colonic epithelial NCM460 cells and in mice with HAEC. Exosomes were isolated from the sera of healthy children (Healthy-exo), patients with Hirschsprung's disease (HSCR) (HSCR-exo) or HAEC (HAEC-exo). A microarray analysis of miRNAs was implemented to assess the enrichment of miRNAs in these exosomes. HAEC-exo was significantly enriched in miR-18a-5p. HAEC-exo led to the generation of a pro-inflammatory microenvironment, inhibition of cellular DNA synthesis, and promotion of apoptosis in NCM460 cells. Mechanistically, miR-18a-5p targeted and repressed retinoid-related orphan receptor α (RORA) expression, thereby regulating the Sirtuin 1 (SIRT1)/nuclear factor-kappa B (NFκB) pathway. Overexpression of RORA ameliorated inflammatory damage in NCM460 cells caused by exosomal miR-18a-5p. HAEC-exo exacerbated inflammatory damage in HAEC mice, and this facilitation was reversed after RORA overexpression. Collectively, exosomal miR-18a-5p was a promoter of HAEC, which induces the intestine cell apoptosis and inflammatory responses through the inhibition of SIRT1/NFκB pathway by targeting RORA.

Epigenetics and Inflammation in Diabetic Nephropathy

Diabetic nephropathy (DN) leads to high morbidity and disability. Inflammation plays a critical role in the pathogenesis of DN, which involves renal cells and immune cells, the microenvironment, as well as extrinsic factors, such as hyperglycemia, chemokines, cytokines, and growth factors. Epigenetic modifications usually regulate gene expression via DNA methylation, histone modification, and non-coding RNAs without altering the DNA sequence. During the past years, numerous studies have been published to reveal the mechanisms of epigenetic modifications that regulate inflammation in DN. This review aimed to summarize the latest evidence on the interplay of epigenetics and inflammation in DN, and highlight the potential targets for treatment and diagnosis of DN.

Sp1-mediated upregulation of Prdx6 expression prevents podocyte injury in diabetic nephropathy via mitigation of oxidative stress and ferroptosis

Glomerular podocyte damage is considered to be one of the main mechanisms leading to Diabetic nephropathy (DN). However, the relevant mechanism of podocyte injury is not yet clear. This study aimed to investigate the effect of peroxiredoxin 6 (Prdx6) on the pathogenesis of podocyte injury induced by high glucose (HG). The mouse glomerular podocyte MPC5 was stimulated with 30 nM glucose, and the Prdx6 overexpression vector or specificity protein 1 (Sp1) overexpression vector was transfected into MPC5 cells before the high glucose stimulation. As results, HG treatment significantly reduced the expression of Prdx6 and Sp1 in MPC5 cells. Prdx6 overexpression increased cell viability, while inhibited podocyte death, inflammation and podocyte destruction in HG-induced MPC5 cells. Prdx6 overexpression inhibited HG-induced ROS and MDA production, while restored SOD and GSH activity in MPC5 cells. Prdx6 overexpression also eliminated ferroptosis caused by HG, which was reflected in the suppression of iron accumulation and the increase in SLC7A11 and GPX4 expression. The improvement effect of Prdx6 on HG-induced podocyte damage could be eliminated by erastin. Moreover, Sp1 could bind to the three Sp1 response elements in the Prdx6 promoter, thereby directly regulating the transcriptional activation of Prdx6 in podocytes. Silencing Sp1 could eliminate the effect of Prdx6 on HG-induced podocyte damage. Further, Prdx6 overexpression attenuated renal injuries in streptozotocin-induced DN mice. Sp1-mediated upregulation of Prdx6 expression prevents podocyte injury in diabetic nephropathy via mitigation of oxidative stress and ferroptosis, which may provide new insights for the study of the mechanism of DN.

Recent advances in the regulation of ABCA1 and ABCG1 by lncRNAs

Coronary heart disease (CHD) with atherosclerosis is the leading cause of death worldwide. ABCA1 and ABCG1 promote cholesterol efflux to suppress foam cell generation and reduce atherosclerosis development. Long noncoding RNAs (lncRNAs) are emerging as a unique group of RNA transcripts that longer than 200 nucleotides and have no protein-coding potential. Many studies have found that lncRNAs regulate cholesterol efflux to influence atherosclerosis development. ABCA1 is regulated by different lncRNAs, including MeXis, GAS5, TUG1, MEG3, MALAT1, Lnc-HC, RP5-833A20.1, LOXL1-AS1, CHROME, DAPK1-IT1, SIRT1 AS lncRNA, DYNLRB2-2, DANCR, LeXis, LOC286367, and LncOR13C9. ABCG1 is also regulated by different lncRNAs, including TUG1, GAS5, RP5-833A20.1, DYNLRB2-2, ENST00000602558.1, and AC096664.3. Thus, various lncRNAs are associated with the roles of ABCA1 and ABCG1 on cholesterol efflux in atherosclerosis regulation. However, some lncRNAs play dual roles in ABCA1 expression and atherosclerosis, and the functions of some lncRNAs in atherosclerosis have not been investigated in vivo. In this article, we review the roles of lncRNAs in atherosclerosis and focus on new insights into lncRNAs associated with the roles of ABCA1 and ABCG1 on cholesterol efflux and the potential of these lncRNAs as novel therapeutic targets in atherosclerosis.