Identification of a Novel Homozygous Mutation in PRDM12 Gene in a Patient with Hereditary Sensory and Autonomic Neuropathy Type VIII.

Hereditary sensory autonomic neuropathy type VIII (HSAN-VIII) is a rare genetic disease that occurs due to mutations in the PRDM12 gene. Here, we describe a novel homozygous mutation c.826_840dupTGCAACCGCCGCTTC (p.Cys276_Phe280dup) on exon 5 in the PRDM12 gene identified by WES and confirmed using Sanger sequencing method.

Transcriptional Regulation of the Colorectal Cancer Stem Cell Markers, Nanog and Oct4, Induced by a Thermodynamic-Based Therapy Approach.

Background: Cancer stem cells (CSC), as responsible issues to cancer development and progression, play a crucial role in tumorigenesis, recurrence, metastasis, and chemoresistance. Both hyperthermia and photodynamic therapy (PDT) may be effective for cancer treatment, particularly when combined with other therapeutic approaches. This study aimed to evaluate the effect of hyperthermia combined with PDT on colorectal CSC and the gene expression of the CSC markers, presenting a more effective approach for cancer therapy. Methods: The study was conducted in the Pasteur institute of Iran, Tehran, Iran in 2018. We evaluated the anticancer role of hyperthermia, Gold nanoparticles coated with curcumin (Cur-GNPs) in PDT and combination of the two approaches on cell viability and the expression of CSC markers, Nanog and Oct4 in colorectal cancer cell line HT-29. The cytotoxicity effect of Cur-GNPs against the cells was assessed in vitro. The cell viability was assessed using MTT assay, and the expression analysis of the CSC genes was evaluated using a q-real-time PCR. Results: Cell viability was decreased by PDT (P=0.015) and the combination therapy (P=0.006) but not by hyperthermia alone (P=0.4), compared to control. Also, the expression of CSC markers, Nanog and Oct4 was shown to significantly down-regulate in all hyperthermia, PDT and combination groups. Conclusion: Hyperthermia combined with PDT was indicated to be more efficient in eliminating tumors than hyperthermia or PDT alone.

Prevalence of Chromosomal Abnormalities in Iranian Patients with Infertility.

BACKGROUND: The numerical and structural abnormalities of chromosomes are the most common cause of infertility. Here, we evaluated the prevalence and types of chromosomal abnormalities in Iranian infertile patients. METHODS: We enrolled 1750 couples of reproductive age with infertility, who referred to infertility clinics in Tehran during 2014- 2019, in order to perform chromosomal analysis. Peripheral blood samples were obtained from all couples and chromosomal abnormalities were evaluated by G-banded metaphase karyotyping. In some cases, the detected abnormalities were confirmed using fluorescence in-situ hybridization (FISH). RESULTS: We detected various chromosomal abnormalities in 114/3500 (3.257%) patients with infertility. The prevalence of chromosomal abnormalities was 44/114 (38.596%) among infertile females and 70/114 (61.403%) among infertile males. Structural chromosomal abnormalities were found in 27/1750 infertile females and 35/1750 infertile males. Numerical chromosomal abnormalities were found in 17/1750 of females and 35/1750 of males. The 45, XY, rob (13;14) (p10q10) translocation and Klinefelter syndrome (47, XXY) were the most common structural and numerical chromosomal abnormalities in the Iranian infertile patients, respectively. CONCLUSION: In general, we found a high prevalence of chromosomal abnormalities in Iranian patients with reproductive problems. Our study highlights the importance of cytogenetic studies in infertile patients before starting infertility treatments approaches.

The relationship between common mutations in CFTR, AR genes, Y chromosome microdeletions and karyotyping abnormalities with very severe oligozoospermia in Iranian men.

BACKGROUND: Male infertility due to very severe oligozoospermia has been associated with some genetic risk factors. OBJECTIVE: To investigate the distribution of the mutations in the CFTR gene, the CAG-repeat expansion of the AR gene, also Y chromosome microdeletions and karyotyping abnormalities in very severe oligozoospermia patients. METHODS: In the present case-control study, 200 patients and 200 fertile males were enrolled. All patients and control group were karyotyped. Microdeletions were evaluated using multiplex PCR. Five common CFTR mutations were genotyped using the ARMS-PCR technique. The CAG-repeat expansion in the AR gene was evaluated for each individual using sequencing. RESULTS: Overall 4% of cases shows a numerical and structural abnormality. 7.5% of patients had a deletion in one of the AZF regions on Yq, and 3.5% had a deletion in two regions. F508del was the most common (4.5%) CFTR gene mutation; G542X, and W1282X were detected with 1.5% and 1% respectively. One patient was found to have AZFa microdeletion and F508del in heterozygote form; one patient had AZFb microdeletion with F508del. F508del was seen as compound heterozygous with G542X in one patient and with W1282X in the other patient. The difference in the mean of the CAG-repeats in the AR gene in patients and control groups was statistically significant (P = 0.04). CONCLUSION: Our study shows the genetic mutations in men with severe oligozoospermia and given the possibility of transmission of these disorders to the next generation by fertilization, counseling and genetic testing are suggested for these couples before considering ICSI.

The prevalence of common CFTR gene mutations and polymorphisms in infertile Iranian men with very severe oligozoospermia.

Due to progress in infertility etiology, several genetic bases of infertility are revealed today. This study aimed to investigate the distribution of mutations in the CFTR gene, M470V polymorphism, and IVS8 poly T. Furthermore, we aimed to examine the hotspot exons (4, 7, 9, 10, 11, 20, and 21 exons) to find a new mutation in cystic fibrosis transmembrane conductance regulator (CFTR) gene among infertile Iranian men very severe oligozoospermia (<1 million sperm/mL ejaculate fluid). In the present case-control study, 200 very severe oligozoospermia (20-60s) and 200 fertile men (18-65s) were registered. Five common CFTR mutations were genotyped using the ARMS-PCR technique. The M470V polymorphism was checked out by real-time PCR, and poly T and exons were sequenced. The F508del was the most common (4.5%) CFTR gene mutation; G542X and W1282X were detected with 1.5% and 1%, respectively. N1303K and R117H were detected in 0.5% of cases. F508del was seen as a heterozygous compound with G542X in one patient and with W1282X in the other patient. Also, in the case of M470V polymorphism, there are differences between the case and control groups (p=0.013). Poly T assay showed statistical differences in some genotypes. The study showed no new mutation in the exons mentioned above. Our results shed light on the genetic basis of men with very severe oligozoospermia in the Iranian population, which will support therapy decisions among infertile men.

Identification of a compound heterozygous missense mutation in LAMA2 gene from a patient with merosin-deficient congenital muscular dystrophy type 1A.

BACKGROUND: Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is occurred by mutations in LAMA2 gene that encodes the laminin α2 chain (merosin). MDC1A is a predominant subtype of congenital muscular dystrophy. Herein, we identified two missense mutations in LAMA2 gene in compound heterozygous status in an Iranian patient with MDC1A using whole-exome sequencing (WES). METHODS: In the present study, we evaluated genetic alterations in an Iranian 35-month-old boy with MDC1A and his healthy family using WES method. The identified mutations further confirmed by Sanger sequencing method. Finally, in silico analysis was conducted to further evaluation of molecular function of the identified genetic variants. RESULTS: We identified two potentially pathogenic missense mutations in compound heterozygous state (c.7681G>A p.Gly2561Ser and c.4840A>G p.Asn1614Asp) in LAMA2 gene as contributing to the MDC1A phenotype. The healthy parents of our proband are single heterozygous for identified mutations. These variants were found to be pathogenic by in silico analysis. CONCLUSIONS: In general, we successfully identified LAMA2 gene mutations in an Iranian patient with MDC1A using WES. The identified mutations in LAMA2 gene can be useful in genetic counseling, prenatal diagnosis, and predicting prognosis of MDC1A.

Identification of a novel homozygous mutation in the DDR2 gene from a patient with spondylo-meta-epiphyseal dysplasia by whole exome sequencing.

OBJECTIVES: The spondylo-meta-epiphyseal dysplasia (SMED) short limbs-hand type is a rare autosomal recessive disease, which is characterized by premature calcification leading to severe disproportionate short stature and various skeletal changes. Defective function of a conserved region encoding discoidin domain receptor tyrosine kinase 2 (DDR2 protein) by the discoidin domain-containing receptor 2 (DDR2 gene) is cause of this disease. The purpose of present study was to investigate disease-causing mutations on DDR2 gene in an Iranian family with SMED, and predict the DDR2 protein molecular mechanism in development of SMED. MATERIALS AND METHODS: In the present study, we evaluated a 2-year-old male with SMED. Detection of genetic changes in the studied patient was performed using Whole-Exome Sequencing (WES). PCR direct sequencing was performed for analysis of co-segregation of variants with the disease in family. Finally, in silico study was performed for further identification of molecular function of the identified genetic variant. RESULTS: We detected a novel splice-site mutation (NM_001014796: exon9: c.855+1G>A; NM_006182: exon8: c.855+1G>A) in DDR2 gene of the studied patient using WES. This mutation was exclusively detected in patients with homozygous SMED, not in healthy people. The effects of detected mutation on functions of DDR2 protein was predicted using in silico study. CONCLUSION: The causative mutation in studied patient with SMED was identified using Next-generation sequencing (NGS), successfully. The identified novel mutation in DDR2 gene can be useful in prenatal diagnosis (PND) of SMED, preimplantation genetic diagnosis (PGD), and genetic counseling.

Identification of Two Novel Mutations in PKHD1 Gene from Two Families with Polycystic Kidney Disease by Whole Exome Sequencing.

BACKGROUND: Polycystic kidney disease (PKD) is an autosomal recessive disorder resulting from mutations in the PKHD1 gene on chromosome 6 (6p12), a large gene spanning 470 kb of genomic DNA. OBJECTIVE: The aim of the present study was to report newly identified mutations in the PKHD1 gene in two Iranian families with PKD. MATERIALS AND METHODS: Genetic alterations of a 3-month-old boy and a 27-year-old girl with PKD were evaluated using whole-exome sequencing. The PCR direct sequencing was performed to analyse the co-segregation of the variants with the disease in the family. Finally, the molecular function of the identified novel mutations was evaluated by in silico study. RESULTS: In the 3 month-old boy, a novel homozygous frameshift mutation was detected in the PKHD1 gene, which can cause PKD. Moreover, we identified three novel heterozygous missense mutations in ATIC, VPS13B, and TP53RK genes. In the 27-year-old woman, with two recurrent abortions history and two infant mortalities at early weeks due to metabolic and/or renal disease, we detected a novel missense mutation on PKHD1 gene and a novel mutation in ETFDH gene. CONCLUSION: In general, we have identified two novel mutations in the PKHD1 gene. These molecular findings can help accurately correlate genotype and phenotype in families with such disease in order to reduce patient births through preoperative genetic diagnosis or better management of disorders.

Induction of Apoptosis in the U937 Cell Line Co-cultured with Adipose-derived Stem Cells Secreting Bone Morphogenetic Protein-4.

Transforming growth factor-beta (TGF-ß) plays a significant role in tumorigenesis. MiR-181b is a multifunctional miRNA involved in numerous cellular processes, such as cell fate and cell invasion. This study aimed to examine whether the co-culture of adipose-derived stem cells (ADSCs), highly expressing bone morphogenetic protein-4, with the U937 cell line, which is a human myeloid leukemia cell line, is able to induce cell death in this cancer cell line, considering the potential ability of ADSCs to migrate from tumor sites. Cell surface markers, namely CD73 and CD105, were analyzed to verify the identity of mesenchymal stem cells isolated from adipose tissue. Besides, the osteogenic and adipogenic differentiation potentials of ADSCs were evaluated. The induction of cell death and apoptosis in the U937 cell line was assessed using MTT and annexin V/ PI assays, respectively. The expression levels of miR-181 and TGF-ß were determined in the co-culture system using real-time PCR. The results of MTT and annexin V/ PI assays showed that BMP4-expressing ADSCs could inhibit cell viability and induce apoptosis in U937 cells in the co-culture system. The co-culture of ADSCs, highly expressing BMP-4, with the U937 cell line led to the downregulation of miR-181 and TGF-ß genes in the human cancer cell line. ADSCs may further be studied as a candidate for the treatment of hematological cancers.

Association of a novel homozygous mutation in the HMGCS2 gene with an HMGCSD in an Iranian patient.

BACKGROUND: 3-Hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase 2 gene (HMGCS2) encodes a mitochondrial enzyme catalyzing the first reaction of ketogenesis metabolic pathway which provides lipid-derived energy for various organs during times of carbohydrate deprivation, such as fasting. Mutations in this gene are responsible for HMG-CoA synthase deficiency (HMGCSD). The aim of present study was to investigate the association of mutation in the HMGCS2 gene with HMGCSD in a patient with atypical symptoms. METHODS: The clinical and genetic features of an 8-months-old girl with HMGCSD were evaluated. Molecular genetic testing was conducted using whole-exome sequencing (WES) in order to identify potential disease-causing mutation. The WES finding was confirmed by the polymerase chain reaction (PCR) amplification of the target sequence carried out for the patient and her parents. The PCR products were subjected to direct sequencing using forward and reverse specific primers corresponding to the HMGCS2 gene. RESULTS: A novel homozygous missense mutation (c.266G>A p.Gly89Asp) was detected in the HMGCS2 gene. Sanger sequencing along with co-segregation analysis of all family members confirmed this novel pathogenic germline mutation. The mutant gene was found to be pathogenic by bioinformatics analysis. CONCLUSION: To our best knowledge, this is the first report of HMGCSD in Iran which would expand our knowledge about the mutational spectrum of the HMGCS2 gene and the phenotype variations of the disease.

Identification of Two Novel Mutations in the ATM Gene from Patients with Ataxia-Telangiectasia by Whole Exome Sequencing.

BACKGROUND: Ataxia telangiectasia (AT) is one of the most common autosomal recessive hereditary ataxia presenting in childhood. The responsible gene for AT designated ATM (AT, mutated) encodes a protein which is involved in cell cycle checkpoints and other responses to genotoxicity. We describe two novel disease-causing mutations in two unrelated Iranian families with Ataxia-telangiectasia. METHODS: The probands including a 6-year-old female and an 18-year-old boy were diagnosed with Ataxia-telangiectasia among two different Iranian families. In this study, Whole-Exome Sequencing (WES) was employed for the detection of genetic changes in probands. The analysis of the co-segregation of the variants with the disease in families was conducted using PCR direct sequencing. RESULTS: Two novel frameshift mutations, (c.4236_4236del p. Pro1412fs) and (c.8907T>G p. Tyr2969Ter) in the ataxia telangiectasia mutated ATM gene were detected using Whole-Exome Sequencing (WES) in the probands. These mutations were observed in two separate A-T families. CONCLUSION: Next-generation sequencing successfully identified the causative mutation in families with ataxia-telangiectasia. These novel mutations in the ATM gene reported in the present study could assist genetic counseling, Preimplantation Genetic Diagnosis (PGD) and prenatal diagnosis (PND) of AT.

Thalidomide attenuates the hyporesponsiveness of isolated atria to chronotropic stimulation in BDL rats: The involvement of TNF-α, IL-6 inhibition, and SOCS1 activation.

OBJECTIVES: Cirrhotic cardiomyopathy is a complication of uncured cirrhosis which is associated with hyporesponsiveness of the heart to sympathetic stimulation. The enhancement of portal pressure, nitric oxide (NO) level, pro-inflammatory mediators and down-regulation of Suppressor of Cytokine Signaling 1 (SOCS1) are involved in this situations. The present study seeks to examine the beneficial effect of thalidomide on cirrhotic cardiomyopathy. MATERIALS AND METHODS: The male rats were grouped as: Sham/saline, Sham/Thalidomide, Bile Duct Ligation (BDL)/saline and BDL/Thalidomide. BDL model of cirrhosis was used. In the treatment groups, thalidomide (200 mg/kg/day) was administrated by intragastrial gavage for 28 consecutive days, the chronotropic response was assessed in isolated atria by isoproterenol stimulation. Serum levels of NO, IL-6 and TNF-α hepatic level were evaluated. The intrasplenic pulp pressure (ISPP) as the portal pressure and histopathologic assessment were assessed. Real time RT-PCR was used for the evaluation of SOCS1 gene expression. RESULTS: Our results showed that thalidomide administration could significantly increase the atrial chronotropic response in BDL animals. The increased level of portal pressure decreased by thalidomide in BDL animals. Thalidomide could ameliorate the histopathological conditions of BDL rats. Furthermore, the chronic treatment by this drug diminished the elevated levels of NO, TNF-α and IL-6 in BDL animals. On the other hand, hepatic SOCS1 expression was up-regulated by thalidomide treatment in this group. CONCLUSION: Thalidomide improves the chronotropic hyporesponsiveness of isolated atria in BDL. This effect is probably mediated by the inhibiting NO, TNF-α and IL-6 production, reducing portal pressure and increasing the expression of SOCS1.

In vivo identification of novel TGIF2LX target genes in colorectal adenocarcinoma using the cDNA-AFLP method.

BACKGROUND AND STUDY AIMS: Homeobox-containing genes are composed of a group of regulatory genes encoding transcription factors involved in the control of developmental processes. The homeodomain proteins could activate or repress the expression of downstream target genes. This study was conducted to in vivo identify the potential target gene(s) of TGIF2LX in colorectal adenocarcinoma. METHODS: A human colorectal adenocarcinoma cell line, SW48, was transfected with the recombinant pEGFPN1-TGIF2LX. The cells were injected subcutaneously into the flank of the three groups of 6-week-old female athymic C56BL/6 nude mice (n = 6 per group). The transcript profiles in the developed tumours were investigated using the cDNA amplified fragment length polymorphism (cDNA-AFLP) technique. RESULTS: The real-time RT-PCR and DNA sequencing data for the identified genes indicated that the N-terminal domain-interacting receptor 1 (Nir1) gene was suppressed whereas Nir2 and fragile histidine triad (FHIT) genes were upregulated followed by the overexpression of TGIF2LX gene. CONCLUSION: Downregulation of Nir1 and upregulation of Nir2 and FHIT genes due to the overexpression of TGIF2LX suggests that the gene plays an important role as a suppressor in colorectal adenocarcinoma.

The Role of MicroRNA Signature as Diagnostic Biomarkers in Different Clinical Stages of Colorectal Cancer.

OBJECTIVES: Colorectal cancer (CRC) is one of the most common cancers and a major cause of cancer-related death worldwide. The early diagnosis of colorectal tumors is one of the most important challenges in cancer management. MicroRNAs (miRNAs) have provided new insight into CRC development and have been suggested as reliable and stable biomarkers for diagnosis and prognosis. This study's objective was to analyze the differential expression of miRNAs at differentstages of CRC searching for possible correlation with clinicopathological features to examine their potential value as diagnostic biomarkers. MATERIALS AND METHODS: In this case-control study, plasma and matched tissue samples were collected from 74 CRC patients at stage II-IV as well as blood samples from 32 healthy controls. After exhaustive study of the current literature, eight miRNAs including miR-200c, 20a, 21, 31,135b, 133b,145 and let-7g were selected. The expression level of the miRNAs was assayed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Statistical analysis, including t test , Mann-Whitney U, Kruskall-Wallis tests and receiver operating characteristic (ROC) curve was applied, where needed. RESULTS: Significantly elevated levels of miR-21, miR-31, miR-20a, miR-135b, and decreased levels of miR- 200c, miR-145 and let-7 g were detected in both plasma and matched tissue samples compared to the healthy group (P<0.05). However, no significant differences were observed in the expression level of plasma and tissue miR-133b (P>0.05). ROC for tissue miRNAs showed an area under the ROC curve (AUC) of 0.98 and P<0.001 for miR-21, 0.91 and P<0.001 for miR-135b, 0.91 and P<0.001 for miR-31, and 0.92 and P<0.001 for miR-20a. CONCLUSIONS: Our results indicate that the expression levels of microRNAs are systematically altered in CRC tissue and plasma. In conclusion, detection of miR-21, miR-135b, miR-31 and miR-20a levels in the tissue might be helpful to illuminate the molecular mechanisms underlying CRC carcinogenesis and serve as tumor-associated biomarkers for diagnosis.

Association of Serotonin Transporter Gene Polymorphism with Recurrent Aphthous Stomatitis.

BACKGROUND: Recurrent Aphthous Stomatitis (RAS) is one of the most common diseases of the oral cavity all over the world (5-66%). RAS has a multifactorial etiology, while psychological factors such as stress and anger play a role in its manifestation. The serotonergic mechanisms particularly the serotonin-transporter gene (5-HTT) may affect the risk of psychological alterations and stress response. The aim of the present study was to evaluate the polymorphism of the promoter region of 5-HTT (5-HTTLPR) in the patients with RAS, compared to that in the control subjects. METHODS: In this case-control study, 100 patients with RAS and 100 healthy subjects were enrolled. PCR was performed on DNA of the samples, using a pair of primers capable of distinguishing S/L alleles and replicating 5-HTTLPR. RESULTS: No statistically significant difference existed between LL and LS genotype frequencies in the case and control groups. However, SS genotype frequency was significantly higher in the case group, as compared to the control group (p=0.001). CONCLUSION: The conclusion of the present study demonstrated that S allele could approximately double the risk of RAS.

Homeodomain Protein Transforming Growth Factor Beta-Induced Factor 2 Like, X-Linked Function in Colon Adenocarcinoma Cells

Background: TGIF2LX (transforming growth factor beta-induced factor 2 like, X-linked) is a homeodomain (HD) protein that has been implicated in the negative regulation of cell signaling pathways. The aim of this study was to investigate the possible functions of TGIF2LX in colon adenocarcinoma cells. Methods: The human SW48 cell line was transfected with cDNA for the wild-type TGIF2LX gene and gene/protein over-expression was confirmed by microscopic analysis, real time RT-PCR and Western blotting techniques. In vitro cell proliferation was evaluated by MTT and BrdU assays. After developing a colon tumor model in nude mice, immunohistochemical (IHC) staining of tumor tissue was carried out for Ki-67 (proliferation) and CD34 (angiogenesis) markers. To predict potential protein partners of TGIF2LX, in-silico analysis was also conducted. Results: Obtained results showed over-expression of TGIF2LX as a potential transcription factor could inhibit either proliferation or angiogenesis (P<0.05) in colon tumors. In-silico results predicted interaction of TGIF2LX with other proteins considered important for cellular development. Conclusions: Our findings provided evidence of molecular mechanisms by which TGIF2LX could act as a tumor suppressor in colon adenocarcinoma cells. Thus, this gene may potentially be a promising option for colon cancer gene-based therapeutic strategies.

The effect of antimicrobial photodynamic therapy on the expression of novel methicillin resistance markers determined using cDNA-AFLP approach in Staphylococcus aureus.

BACKGROUND: Widespread methicillin resistant Staphylococcus aureus (MRSA) and absence of effective antimicrobial agents has led to limited therapeutic options for treating MRSA infection. We aimed to evaluate the effect of antimicrobial photodynamic therapy (aPDT) on the expression of novel identified methicillin resistance markers (NIMRMs) in S. aureus using complementary DNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) approaches to address the therapeutic alternatives for MRSA infections. MATERIALS AND METHODS: We used cDNA-AFLP to compare MRSA and methicillin susceptible S. aureus (MSSA) for identification of target genes implicated in methicillin resistance. To determine the sub-lethal aPDT (sPDT), MRSA and MSSA clinical isolates photosensitized with toluidine blue O (TBO), and then were irradiated with diode laser. After sPDT, the colony forming units/mL was quantified. Antimicrobial susceptibility against methicillin was assessed for cell-surviving aPDT. Effects of sPDT on the expression of NIMRMs were evaluated by real-time quantitative reverse transcription PCR. RESULTS: According to our results, serine hydrolase family protein (Shfp) encoding gene and a gene encoding a conserved hypothetical protein (Chp) were implicated in methicillin resistance in MRSA. sPDT reduced the minimum inhibitory concentrations of methicillin by 3-fold in MRSA. sPDT could lead to about 10- and 6.2- fold suppression of expression of the Chp and Shfp encoding genes, respectively. CONCLUSION: sPDT would lead to reduction in resistance to methicillin of MRSA in surviving cells by suppressing the expression of the Shfp and Chp encoding genes associated with methicillin resistance. This may have potential implications of aPDT for the treatment of MRSA infections.

Possible involvement of CREB/BDNF signaling pathway in neuroprotective effects of topiramate against methylphenidate induced apoptosis, oxidative stress and inflammation in isolated hippocampus of rats: Molecular, biochemical and histological evidences.

Chronic abuse of methylphenidate (MPH) can cause serious neurotoxicity. The neuroprotective effects of topiramate (TPM) were approved, but its putative mechanism remains unclear. In current study the role of CREB/BDNF signaling pathway in TPM protection against methylphenidate-induced neurotoxicity in rat hippocampus was evaluated. 60 adult male rats were divided randomly into six groups. Groups received MPH (10mg/kg) only and concurrently with TPM (50mg/kg and 100mg/kg) and TPM (50 and 100mg/kg) only for 14 days. Open field test (OFT) was used to investigate motor activity. Some biomarkers of apoptotic, anti-apoptotic, oxidative, antioxidant and inflammatory factors were also measured in hippocampus. Expression of total (inactive) and phosphorylated (active) CREB and BDNF were also measured in gene and protein levels in dentate gyrus (DG) and CA1 areas of hippocampus. MPH caused significant decreases in motor activity in OFT while TPM (50 and 100mg/kg) inhibited MPH-induced decreases in motor activity. On the other hand, MPH caused remarkable increases in Bax protein level, lipid peroxidation, catalase activity, IL-1ß and TNF-α levels in hippocampal tissue. MPH also caused significant decreases of superoxide dismutase, activity and also decreased CREB, in both forms, BDNF and Bcl-2 protein levels. TPM, by the mentioned doses, attenuated these effects and increased superoxide dismutase, glutathione peroxidase and glutathione reductase activities and also increased CREB, in both forms, BDNF and Bcl-2 protein levels and inhibited MPH induced increase in Bax protein level, lipid peroxidation, catalase activity, IL-1ß and TNF-α levels. TPM also inhibited MPH induced decreases in cell number and changes in cell shapes in DG and CA1 areas. TPM can probably act as a neuroprotective agent against MPH induced neurotoxicity and this might have been mediated by CREB/BDNF signaling pathway.