Thymoquinone ameliorates symptoms of Parkinson's disease in a 6-OHDA rat model by downregulation of miR-204-3p.

microRNAs (miRNAs) play a significant role in the pathophysiology of Parkinson's disease. In this study, we evaluated the neuroprotective effect of thymoquinone on the expression profiles of miRNA and cognitive functions in the 6-hydroxydopamine (6-OHDA)-induced Parkinson's model. Male adult Wistar albino rats (200-230 g, n = 36) were randomly assigned to six groups: Sham, thymoquinone (10 mg/kg, p.o.), 6-OHDA, 6-OHDA + thymoquinone (10 mg/kg), 6-OHDA + thymoquinone (20 mg/kg), and 6-OHDA + thymoquinone (50 mg/kg). Behavioral changes were detected using the open field and the elevated plus maze tests. The mature 728 miRNA expressions were evaluated by miRNA microarray (GeneChip miRNA 4.0). Ten miRNAs were selected (rno-miR-212-5p, rno-miR-146b-5p, rno-miR-150-5p, rno-miR-29b-2-5p, rno-miR-126a-3p, rno-miR-187-3p, rno-miR-34a-5p, rno-miR-181d-5p, rno-miR-204-3p, and rno-miR-30c-2-3p) and confirmed by real-time PCR. Striatum samples were stained with hematoxylin-eosin to determine the effect of dopaminergic lesions. One-way ANOVA test and independent sample t-test were used for statistical analyses. rno-miR-204-3p was upregulated at 6-OHDA and downregulated at the 50 mg/kg dose of thymoquinone. In conclusion, thymoquinone at a dose of 50 mg/kg ameliorates symptoms of Parkinson's disease in a 6-OHDA rat model by downregulation of miR-204-3p. Also, the results showed that thymoquinone can improve locomotor activity and willing exploration and decreased anxiety. Therefore, thymoquinone can be used as a therapeutic agent.

Deep phenotyping of miRNAs in exercise-induced cardiac hypertrophy and fibrosis.

Cardiac hypertrophy (CH) is an adaptational enlargement of the myocardium, in exposure to altered stress conditions or in case of injury which can lead to heart failure and death. MicroRNAs (miRNAs) are noncoding RNAs that play a significant role in modulating gene expression. Here, we aimed to identify new miRNAs effective in an experimental CH model and to find an epigenetic biomarker that could demonstrate therapeutic targets responsible for the pathology of heart tissue and serum. In this study, Sprague-Dawley male rats were divided into the training group (TG, n=9) and the control group (CG, n=6). Systolic and diastolic dimensions of the left ventricle and myocardial wall thickness were measured by echocardiography to assess CH. After the exercise program of the rats, miRNA expression measurements and histological analyses were performed. The 25,000 genes in the rat genome were searched using microarray analysis. A total of 128 miRNAs were selected according to the fold change rates, and nine miRNAs were validated for expression analysis. The terminal deoxynucleotidyl transferase dUTP nick (TUNEL) method was used to detect apoptotic cells. Cell proliferation was evaluated by the proliferative cell nuclear antigen (PCNA) method. Necrosis, bleeding, and intercellular edema were detected in TG. The mean histopathological score was higher in TG (p=0.03). There were rarely positive cells for apoptosis of both groups in cardiomyocytes. In the receiver characteristic curve analysis (ROC), the heart tissue rno-miR-290 had an area under the curve (AUC) of 0.920 with 100% sensitivity and 89.90% specificity (p=0.045), rno-miR-194-5p had AUC of 0.940 with 83.33% sensitivity and 100% specificity (p=0.003), and the serum rno-miR-132-3p AUC was 0.880 with 66.67% sensitivity and 100% specificity (p=0.004) in TG. miR-194-5p was used as a therapeutic target for remodeling the cardiac process. While miR-290 contributes to CH as a negative regulator, miR-132 in serum is effective in the pathological and physiological cardiac remodeling process and is a candidate biomarker.

Downregulatory effect of miR-342-3p on epileptogenesis in the PTZ-kindling model.

BACKGROUND: Epileptogenesis is a process that results in neurons firing abnormally, causing seizures. Increasing evidence has shown that miRNAs expressed in the epileptic hippocampus are involved in epileptogenesis. We demonstrated the expression changes of miRNAs that may be effective in epileptogenesis in silico analysis in the kindling model created with Pentylenetetrazole (PTZ). Thus, we aimed to identify the target genes responsible for epileptogenesis. METHODS AND RESULTS: Fifteen male Wistar-albino rats (200-230 g) were randomly divided into two groups control (n = 6) and PTZ (n = 9). The control group received 0.5 ml saline, and the PTZ group (35 mg/kg i.p.) intraperitoneally (i.p.) (11 times, every other day) to induce tonic-clonic seizures. Seizures were observed and scored 30 min after PTZ injection. After the last dose of PTZ (75 mg/kg) administration, the hippocampus tissues of the rats were removed by anesthesia. Analysis of miRNAs was performed with the Affymetrix gene chip miRNA sequence (728 miRNA) and confirmed by the Real-Time Polymerase Chain Reaction (Real-Time PCR) method (29 miRNAs). We evaluated the expression change of the target gene of miRNA, whose expression change was detected using in silico analysis, by q-RT PCR. Eight miRNAs with changes in expression were detected. Of these miRNAs, miR-342-p was downregulated in the PTZ group and was statistically significant (p < 0.005). Ultimately, we determined that the target gene of miR-342-p is a metabotropic glutamate receptor 2 (GRM2) and that GRM2 expression is upregulated. CONCLUSIONS: Downregulation of miR-342-3p in the PTZ kindling model may result in the upregulation of GRM2.

Pentylenetetrazole-induced kindling rat model: miR-182 and miR-27b-3p mediated neuroprotective effect of thymoquinone in the hippocampus.

OBJECTIVES: Epilepsy is a neurological disease that pathologically affects brain functions. The epileptic hippocampus has modified microRNA(miRNA) levels. Therefore, we aimed to evaluate the neuroprotective effect of thymoquinone (TQ) in PTZ-induced epilepsy and to demonstrate the overlap between miRNA and mRNA expression profiles. METHODS: Male adult Wistar albino rats (200-230 g, n = 20) were divided into three groups as control (n = 6), PTZ (n = 7), and TQ + PTZ (n = 7). The PTZ kindling model was created by injecting PTZ in sub convulsive doses to rats on days 1, 3, 5, 8, 10, 12, 15, 17, 19, 22, and 24 of the study into animals. Clonic and tonic seizures were induced by injecting a convulsive dose of PTZ on day 26 of the study. Rats in the TQ+PTZ group were treated by oral gavage with a 20 mg/kg TQ 2 h before each PTZ injection. The rats in the control group were treated with 0.5 ml saline. Seizure severity was evaluated with the Racine scale. The genes and signaling pathways targeted by miRNAs were determined by bioinformatics analysis. RESULTS: In the rat hippocampus, mature 728 miRNAs were analyzed by microarray and the nine miRNA were verified by quantitative Real-Time PCR. rno-miR-182 and rno-miR-27b-3p were up-regulated in the PTZ group and down-regulated in the TQ + PTZ group. DISCUSSION: In the PTZ kindling epilepsy model, the expression of these two miRNAs was regulated by TQ and exerted a neuroprotective effect by controlling the activities of target genes.

Remote myocardial injury: the protective role of fluoxetine.

Aortic cross-clamping-induced ischemia-reperfusion (IR) is an important factor in the development of postoperative acute cardiac injury following abdominal aortic surgery. We investigated the possible anti-oxidant/anti-inflammatory effects of fluoxetine (FLX), which is used widely as a preoperative anxiolytic on cardiac injury induced by IR of the infrarenal abdominal aorta. FLX was administered to IR-performed (60 min of ischemia and 120 min of reperfusion) rats for 3 days, once daily at 20 mg/kg i.p. dosage. Results were compared to control and non-FLX-treated IR-performed rats. Serum creatine kinase (CK) and CK-MB levels, lipid hydroperoxide, thiobarbituric acid reactive substances, and pro-oxidant/anti-oxidant balance levels in the IR group were significantly higher whereas superoxide dismutase activity, glutathione, and ferric reducing/anti-oxidant power levels were lower than for the control. IR also increased myeloperoxidase activity, tumor necrosis factor-α, interleukin-1ß, and interleukin-6 and decreased interleukin-10 levels. FLX decreased CK, CK-MB, lipid hydroperoxide, thiobarbituric acid reactive substances, and pro-oxidant/anti-oxidant balance levels while increasing superoxide dismutase activity, glutathione, and ferric reducing/anti-oxidant power levels. FLX also decreased myeloperoxidase activity, tumor necrosis factor-α, interleukin-1ß, and interleukin-6 levels and increased interleukin-10 levels compared to IR. FLX attenuated the morphological changes associated with cardiac injury. Our study clearly demonstrates that FLX confers protection against aortic IR-induced cardiac injury, tissue leucocyte infiltration, and cellular integrity via its anti-oxidant/anti-inflammatory effects.