Hsa_circ_0000231 knockdown inhibits the glycolysis and progression of colorectal cancer cells by regulating miR-502-5p/MYO6 axis.

BACKGROUND: Colorectal cancer (CRC) poses a heavy threat to human health owing to its high incidence and mortality. Circular RNAs (circRNAs) were investigated to participate in the progression of CRC, whereas there was no revenant data on the CRC process regulated by hsa_circ_0000231. This study aimed to explore the effects of hsa_circ_0000231 on CRC progression and underneath regulatory mechanism. METHODS: The expression levels of hsa_circ_0000231, miR-502-5p, and Myosin VI (MYO6) mRNA were detected by quantitative real time polymerase chain reaction (qRT-PCR). Western blot was employed to determine the protein expression levels of MYO6 and proliferating cell nuclear antigen (PCNA). The effects of hsa_circ_0000231 on cell proliferation, apoptosis, migration, and invasive in CRC were determined by cell counting kit-8 proliferation (CCK-8) and colony formation assays, flow cytometry analysis, wound-healing assay, and transwell invasion assay, respectively. Glucose uptake and lactate production were severally illustrated by glucose assay kit and lactate assay kit. The relationship between miR-502-5p and hsa_circ_0000231 or MYO6 was predicted by circular RNA interactome or targetScan online databases, and identified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. In vivo tumor formation assay was carried out to determine the effects of hsa_circ_0000231 knockdown on tumor growth in vivo. RESULTS: Hsa_circ_0000231 expression was dramatically upregulated while miR-502-5p was obviously downregulated in CRC tissues and cells compared with control groups. Hsa_circ_0000231 knockdown repressed the expression levels of MYO6 and PCNA protein. Functionally, hsa_circ_0000231 knockdown repressed cell glycolysis, proliferation, migration and invasion, and induced cell apoptosis, whereas these effects were decreased by miR-502-5p inhibitor. Mechanistically, hsa_circ_0000231 acted as a sponge of miR-502-5p and miR-502-5p bound to MYO6. Furthermore, hsa_circ_0000231 knockdown decreased tumor volume and weight of CRC in vivo. CONCLUSION: Hsa_circ_0000231 knockdown inhibited CRC progression and glycolysis by downregulating MYO6 expression through sponging miR-502-5p, which might provide a theoretical basis in further studying circ_0000231-directed therapy in CRC.

Ubiquitin-specific protease 22 enhances intestinal cell proliferation and tissue regeneration after intestinal ischemia reperfusion injury.

BACKGROUND: Intestinal ischemia reperfusion (I/R) injury is a serious but common pathophysiological process of many diseases, resulting in a high mortality rate in clinical practice. Ubiquitin-specific protease 22 (USP22) acts as regulator of cell cycle progression, proliferation, and tumor invasion. Depleted USP22 expression has been reported to contribute to arrested cell cycle and disrupted generation of differentiated cell types in crypts and villi. However, the role of USP22 in intestinal damage recovery has not been investigated. Therefore, elucidation of the underlying mechanism of USP22 in intestinal I/R injury may help to improve the tissue repair and patient prognosis in clinical practice. AIM: To investigate the role of USP22 in intestinal cell proliferation and regeneration after intestinal I/R injury. METHODS: An animal model of intestinal I/R injury was generated in male Sprague-Dawley rats by occlusion of the superior mesenteric artery followed by reperfusion. Chiu's scoring system was used to grade the damage to the intestinal mucosa. An in vitro model was developed by incubating rat intestinal epithelial IEC-6 cells in hypoxia/reoxygenation conditions in order to simulate I/R in vivo. siRNA and overexpression plasmid were used to regulate the expression of USP22. USP22, Cyclin D1, and proliferating cell nuclear antigen (PCNA) expression levels were measured by Western blot analysis and immunohistochemistry staining. Cell survival (viability) and cell cycle were evaluated using the Cell Counting Kit-8 and flow cytometry, respectively. RESULTS: USP22 expression was positively correlated with the expression levels of PCNA and Cyclin D1 both in vivo and in vitro, which confirmed that USP22 was involved in cell proliferation and intestinal regeneration after intestinal I/R injury. Decreased levels of Cyclin D1 and cell cycle arrest were observed in the USP22 knockdown group (P < 0.05), while opposite results were observed in the USP22 overexpression group (P < 0.05). In addition, increased expression of USP22 was related to improved intestinal pathology or IEC-6 cell viability after I/R or hypoxia/reoxygenation. These results suggested that USP22 may exert a protective effect on intestinal I/R injury by regulating cell proliferation and facilitating tissue regeneration. CONCLUSION: USP22 is correlated with promoting intestinal cell proliferation and accelerating intestinal tissue regeneration after intestinal I/R injury and may serve as a potential target for therapeutic development for tissue repair during intestinal I/R injury.

Salvianolic acid A alleviates chronic ethanol-induced liver injury via promotion of ß-catenin nuclear accumulation by restoring SIRT1 in rats.

In recent years, alcoholic liver disease (ALD) has emerged as a growing public health problem worldwide. ß-catenin plays an important role in the growth, development, regeneration and metabolic activity of the liver. Salvianolic acid A (SalA) is a water-soluble component from the root extract of Salvia miltiorrhiza Bunge, and its effect on ALD has not yet been investigated. This study aimed to investigate the effect of SalA on chronic alcohol-induced liver injury and to explore the role of SIRT1-mediated ß-catenin deacetylation in such an effect. In this study, SalA treatment significantly alleviated the accumulation of lipid droplets and reduced the plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), alcohol and ammonia levels in rats. SalA enhanced ethanol and ammonia metabolism and maintained mitochondrial homeostasis. Moreover, SalA restored the activity of the major ethanol-metabolizing enzymes and oxidative stress functions in the liver. Importantly, we found that SalA treatment effectively inhibited the ethanol-mediated decrease in nuclear ß-catenin by upregulating SIRT1 in the liver. SIRT1 then deacetylated ß-catenin to promote its accumulation in the nucleus, thereby preventing alcohol-induced liver injury. The results demonstrate that the SIRT1/ß-catenin pathway is a key therapeutic target in liver injury caused by chronic alcohol exposure and that SalA protects against alcohol-induced liver injury via the SIRT1-mediated deacetylation of ß-catenin.

Nurr1 promotes intestinal regeneration after ischemia/reperfusion injury by inhibiting the expression of p21 (Waf1/Cip1).

Intestinal ischemia/reperfusion (I/R) injury is a potentially life-threatening condition that can cause injuries to remote organs at the end stage. The damage caused by intestinal I/R insult induces changes in the barrier functions of the intestine, and the intrinsic mechanism of regeneration is often insufficient to restore barrier functions, as indicated by the high mortality rate of patients experiencing intestinal I/R injury. However, little is known about the mechanisms of intestinal regeneration after I/R injury. Here, we reported that nuclear receptor-related protein 1 (Nurr1), a nuclear orphan receptor, was induced during intestinal regeneration after I/R. Our findings showed that Nurr1 expression was consistent with the expression of Ki-67 and phosphorylated histone H3 (pH 3) in the intestine after I/R injury. Nurr1 knockdown led to G1-phase arrest mediated by p21 (Waf1/Cip1) activation, but Nurr1 overexpression reduced the proportion of IEC-6 cells in G1 phase as a result of p21 inhibition in a p53-independent manner. Using chromatin immunoprecipitation assays, luciferase assays, and mutational analysis, we demonstrated that Nurr1 directly inhibited the transcription of p21. These results define a novel Nurr1/p21 pathway that is involved in intestinal regeneration after I/R injury. These findings provide novel molecular insights into the pathogenesis of intestinal regeneration after I/R and possibly support the development of new potential therapies for intestinal I/R injury. KEY MESSAGE: Nurr1 was induced during intestinal regeneration after I/R injury. Nurr1 promoted proliferation of intestinal epithelial cells after H/R injury. Nurr1 inhibited p21 expression in a p53-independent manner. Nurr1 inhibited p21 gene transcription by binding to p21 promoter directly.

Protective effects of ginsenoside Rg1 on intestinal ischemia/reperfusion injury-induced oxidative stress and apoptosis via activation of the Wnt/ß-catenin pathway.

Ginsenoside Rg1 (Rg1) is one of the major bioactive ingredients in Panax ginseng, and it attenuates inflammation and apoptosis. The aims of our study were to explore the potential of Rg1 for the treatment of intestinal I/R injury and to determine whether the protective effects of Rg1 were exerted through the Wnt/ß-catenin signaling pathway. In this study, Rg1 treatment ameliorated inflammatory factors, ROS and apoptosis that were induced by intestinal I/R injury. Cell viability was increased and cell apoptosis was decreased with Rg1 pretreatment following hypoxia/reoxygenation (H/R) in the in vitro study. Rg1 activated the Wnt/ß-catenin signaling pathway in both the in vivo and in vitro models, and in the in vitro study, the activation was blocked by DKK1. Our study provides evidence that pretreatment with Rg1 significantly reduces ROS and apoptosis induced by intestinal I/R injury via activation of the Wnt/ß-catenin pathway. Taken together, our results suggest that Rg1 could exert its therapeutic effects on intestinal I/R injury through the Wnt/ß-catenin signaling pathway and provide a novel treatment modality for intestinal I/R injury.

Clinicopathological significance of SIRT1 expression in colorectal cancer: A systematic review and meta analysis.

PURPOSE: The relationship between SIRT1 and clinicopathological parameters of colorectal cancer (CRC) is controversial. To evaluate the clinicopathological and prognostic value of silent mating type information regulation 2 homolog-1 (SIRT1) expressions in patients with CRC, a meta-analysis was performed. METHODS: We conducted a meta-analysis to investigate the impact of SIRT1 on clinicopathological parameters and prognosis in CRC patients. Studies assessing the relationship between these parameters and SIRT1 expression in CRC were identified up to September, 2015. RESULTS: Seven studies met the inclusion criteria. Our results showed that SIRT1 expression was correlated with depth of invasion (OR = 0.922, 95% CI: 0.646-1.316, P = 0.005), lymph node metastasis (OR = 1.001, 95% CI: 0.781-1.283, P = 0.000) and TNM stage (OR = 1.103, 95% CI: 0.892-1.365, P = 0.008). Furthermore, we found that SIRT1 expression predicted a poor overall survival (OS) in CRC patients (OR = 1.220, 95% CI: 0.955-1.558, P = 0.037, fixed-effect). CONCLUSIONS: The overall data of the present meta-analysis showed that SIRT1 expression was not correlated with clinicopathological features except for depth of invasion, lymph node metastasis and TNM stage. Simultaneously, SIRT1 overexpression predicted a poor OS in CRC patients, and SIRT1 is a candidate negative prognostic biomarker for CRC patients.

Serum MicroRNA-4521 is a Potential Biomarker for Focal Cortical Dysplasia with Refractory Epilepsy.

Early biomarker-based diagnosis of focal cortical dysplasia (FCD) represents a major clinical challenge. The aim of this study was to identify novel brain microRNAs (miRNAs) in patients with refractory epilepsy and FCD as potential biomarkers. We evaluated serum hsa-miR-4521 as a promising novel biomarker in patients with FCD. Tissue for microarray was obtained from nine patients with temporal lobe refractory epilepsy who underwent surgery to remove epileptic foci identified by cortical video electroencephalogram monitoring. Control tissue was collected from eight patients with hypertension who required emergency surgery to remove an intracranial hematoma. The Affymetrix® GeneChip® Command Console® Software (Affymetrix miRNA 4.0) was used to compare miRNA expression in the cerebral cortex of experimental and control patients. Temporal cortex tissue and serum samples were taken from the same patients for verification of hsa-miR-4521 expression by real-time quantitative polymerase chain reaction (RT-qPCR). The experimental and control patients did not differ significantly in terms of age and gender. 19.4 % (148/764) of the total miRNAs were differentially expressed in experimental and control tissue, which is in agreement with the existing literature. We selected miRNA-4521 for further analysis; the fold-change in expression was 14.4707 and the q value was almost 0, which confirmed up-regulation. Significant up-regulation of hsa-miR-4521 was further validated by RT-qPCR. miRNA microarrays can efficiently and conveniently identify differentially expressed miRNAs in epilepsy brain tissue. This is the first study to identify differential expression of hsa-miR-4521 in brain tissue and serum of refractory epilepsy patients and suggests that serum hsa-miR-4521 may represent a potential diagnostic biomarker for FCD with refractory epilepsy.