Evaluation of miR-302 promoter activity in transgenic mice and pluripotent stem cell lines.

Some miRNAs, including the miR-302 cluster, are critical regulators of the stemness state of embryonic stem cells and cell fate patterning. In this study, we evaluated the activity of the miR-302 core promotor in mice and human pluripotent stem cells, somatic tissue derivatives, and generated transgenic mice expressing EGFP under a miR-302 promoter. The expression of EGFP under the control of the miR-302 promotor was examined in the cell lines and somatic tissues of transgenic mice, transgenic blastocysts, and embryonic stem cells derived from transgenic blastocysts. Our results showed that the miR-302 promoter is highly expressed in the mouse and human pluripotent cells, weakly expressed in the somatic tissue derivatives, is highly expressed in both blastocysts and the first passages of transgenic embryonic stem cells, and lowly expressed in the somatic tissues of transgenic mice. It can be concluded that different temporal and spatial gene expression patterns occur during the embryonic and adult stages of cells in mice.

A novel splicing variant in FLNC gene responsible for a highly penetrant familial dilated cardiomyopathy in an extended Iranian family.

Recent achievements in the genetic diagnosis of Dilated Cardiomyopathy (DCM) have disclosed rare variants in numerous genes encoding different types of myocardial proteins. However, the causative gene underlying the pathogenesis of about 60% of familial cases with DCM has not been identified. One novel gene introduced in 2016 for cardiac-restricted DCM is FLNC. In this study, we applied Whole Exome Sequencing (WES) and bioinformatics-based methods to a member of an extended non-consanguineous family with DCM history accompanied with fatal arrhythmia in at least four consecutive generations. We found a novel splice-site mutation in FLNC gene (c.2389+1G>A) which cosegregated with all symptomatic individuals in the family. Computational prediction software tools as well as RT-PCR method were used to evaluate the impact of the FLNC splice site mutation. This substitution leads to exon 15th donor-site disruption and exon skipping, which would result in a premature stop codon three aminocids downstream of the mutation site. The aberrantly mRNA transcript can induce nonsense-mediated mRNA decay. Although carrier individuals show remarkable variable expression regarding the severity of DCM as well as the disease age of onset, a highly penetrant fatal arrhythmia was found to be shared between them. We strongly suggest that the involvement of FLNC gene, due to haploinsufficiency, should be considered in familial cases with DCM, especially if accompanied with arrhythmia and increased incidence of sudden cardiac death.

Neuroprotection of donepezil against morphine-induced apoptosis is mediated through Toll-like receptors.

Previously, we had shown that donepezil provides anti-apoptotic effects associated with the prevention of morphine tolerance to the analgesic effect. In this regard, the present study aimed to evaluate the molecular mechanisms involved in this effect considering the possible role of Toll-like receptor (TLR) 2,4, and the balance between pre-apoptotic and anti-apoptotic Bcl family proteins. To this end, male Wistar rats received daily morphine in combination with either normal saline or donepezil (0.5, 1, or 1.5 mg/kg, ip). The analgesic effect was assessed by the plantar test apparatus. The latency was recorded when the animal responded to the light stimulus. On the 15th day, when no significant difference was observed between morphine and saline groups in terms of analgesia, the frontal cortex and lumbar spinal cord of the animals were dissected. Then, TLR2 and 4, Bcl2, and Bax mRNA fold changes were calculated using Real-time PCR method. The results indicated no significant analgesic effect in the morphine group compared with the saline treated animals after 15 days of injection, while daily co-administration of donepezil with morphine preserved significant analgesia. Moreover, Quantitative PCR showed that morphine significantly increased TLRs and Bax gene expressions and decreased the anti-apoptotic Bcl2. In contrast, donepezil prevented these morphine induced changes in the mentioned gene expressions. Taken together, the results suggest that the neuroprotective effects of donepezil in attenuating morphine-induced tolerance and apoptosis are mediated by preventing morphine-induced changes in TLR2 and 4 gene expressions.

Effect of selegiline on neural stem cells differentiation: a possible role for neurotrophic factors.

OBJECTIVES: The stimulation of neural stem cells (NSCs) differentiation into neurons has attracted great attention in management of neurodegenerative disease and traumatic brain injury. It has been reported that selegiline could enhance the morphologic differentiation of embryonic stem cells. Therefore this study aimed to investigate the effects of selegiline on NSCs differentiation with focus on the role of neurotrophic factor gene expression. MATERIALS AND METHODS: The NSCs were isolated from lateral ventricle of C57 mice brain. The cells were exposed to selegiline in nano to micromolar concentrations for 24 hr or 72 hr. In order to assay the effect of selegiline on NSCs differentiation into neurons, astrocytes and oligodendrocytes, immunocytochemical techniques were utilized. Samples were exposed to specific antibodies against neurons (ß tubulin), astrocytes (GFAP) and oligodendrocytes (OSP). The expression of BDNF, NGF and NT3 genes was investigated using Real-Time PCR. RESULTS: Our findings revealed that selegiline increased NSCs differentiation into neurons at 10(-7) and 10(-8) M and decreased the differentiation into astrocytes at 10(-9), while oligodendrocyte did not significantly change in any of the used concentrations. In addition data analyses showed that selegiline increased BDNF, NGF and NT3 gene expression at 24 hr, but did not change them in the other time of exposure (72 hr) except 10(-7) M concentration of selegiline, which increased NT3 expression. CONCLUSION: Our results indicate selegiline induced the differentiation of NSCs into neurons and in this context the role of neurotrophic factors is important and should be considered.

The chemokine receptor CXCR4 is associated with the staging of gastric cancer.

BACKGROUND: CXCR4 is a cognitive receptor for stromal-derived factor-1 (SDF-1) and has been previously shown to be associated with tumor growth and invasion of many cancers. However, its expression and function in gastric cancer has not been well clarified. MATERIALS AND METHODS: Herein, we studied the expression of CXCR4 on gastric samples from patients with gastric adenocarcinoma in comparison with precancerous lesions by employing qRT-PCR. RESULTS: Our qRT-PCR data show that CXCR4 is highly expressed in tissue samples from patients with gastric cancer than precancerous lesions (2.4 times higher, P value < 0.05). When we correlated the level of CXCR4 with clinicopathological findings, we observed that CXCR4 level is associated with staging of the disease and lymphatic invasion. IN CONCLUSION: We present evidence that CXCR4 level is significantly elevated in later stages of gastric cancer. Thus, CXCR4 may play a crucial role in gastric cancer progression.

Effect of Helicobacter pylori infection on stromal-derived factor-1/CXCR4 axis in bone marrow-derived mesenchymal stem cells.

BACKGROUND: Recent studies have demonstrated that during chronic Helicobacter pylori (H. pylori) infection bone marrow-derived-mesenchymal stem cells (BMD-MSCs) migrate to the gastric tissue and could be also the origin of gastric adenocarcinoma. The chemokine CXCR4 through binding to its ligand stromal-derived factor (SDF-1) plays a crucial role in migration of inflammatory and stem cells. However, the possible effect of H. pylori infection on the SDF-1/CXCR4 axis has not yet been elucidated. MATERIALS AND METHODS: Gastric epithelial cell line, AGS, and BMD-MSCs were cocultured with H. pylori for 24 h. The expression of CXCR4 was examined in BMD-MSCs by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and flow cytometry, and SDF-1 expression in AGS cells was detected by qRT-PCR and enzyme-linked immunosorbent assay. Further, migration of BMD-MSCs toward SDF-1 was evaluated by chemotaxis assay. RESULTS: We found that coculture of H. pylori with BMD-MSCs or AGS: (i) enhanced CXCR4 expression on the cell surface of BMD-MSCs and (ii) increased SDF-1 secretion by AGS cells. Consistently, we observed that H. pylori-treated BMD-MSCs showed a higher capability to migrate toward SDF-1 gradient compared with untreated cells. CONCLUSION: We found that H. pylori upregulates CXCR4 expression in BMD-MSCs and enhance their migration toward SDF-1. This study provides the first evidence that H. pylori infection may enhance BMD-MSC migration through acting on the SDF-1/CXCR4 axis.

Nuclear pattern of CXCR4 expression is associated with a better overall survival in patients with gastric cancer.

Introduction. Previous studies have shown that stromal-derived factor-1 (CXCL12) and its receptor, CXCR4, play a crucial role in metastasis of various tumors. Similarly, it has been cleared that CXCR4 is expressed on the cell surface of gastric cancers. However, nuclear expression of CXCR4 and its clinical importance have not been yet studied. Materials and Methods. Herein, we studied the expression of CXCR4 in gastric samples from patients with gastric adenocarcinoma as well as human gastric carcinoma cell line, AGS, by employing RT-PCR, immunohistochemistry, and flow cytometry techniques. Results. RT-PCR data showed that CXCR4 is highly expressed on AGS cells. This was confirmed by IHC and FACS as CXCR4 was detected on cell membrane, in cytoplasm, and in nucleus of AGS cells. Moreover, we found that both cytoplasmic and nuclear CXCR4 are strongly expressed in primary gastric cancer and the cytoplasmic pattern of CXCR4 tends to be associated with a shorter overall survival than nuclear staining. In conclusion, we present evidence for the first time that both cytoplasmic and nuclear expression of CXCR4 are detectable in gastric cancer tissues. However, the role of both cytoplasmic and nuclear CXCR4 needs to be further elucidated.