Screening LRTOMT gene (DFNB63 locus) in patients with recessive nonsyndromic hearing loss in hormozgan province, Iran

Background: Congenital hearing loss is the most common sensory disorder is modern societies. Two modes of syndromic and nonsyndromic genetic hearing loss can be seen. Autosomal recessive nonsyndromic inheritance hearing loss (ARNSHL) is the most common form of inheritance hearing loss. So, far mapping it, 95 loci of the 41 regions of deafness genes have been identified. Despite numerous studies in this field, for DFNB63 (Leucine rich transmembrane and O-methyltransferase or LRTOMT gene), few studies have been conducted. Thus, the locus mutations can help us to better understand the genes involved in hearing loss. Methods: 90 cases of hearing loss in Hormozgan province, Iran, were studied. DNA extracted via phenol-chloroform method. Polymerase chian reaction (PCR) was performed. Then, the product was used to perform polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and polymerase chain reaction-heteroduplex analysis (PCR-HA) methods. Samples with different bands were sequenced to determine the nucleotide changes. Findings: In different exons, 8 samples (each in a specific exon) were sequenced to determine the type of changes that shift single-strand conformation polymorphism bands. No change was found in nucleotide sequencing of exons in any of the groups. Conclusion: The results showed no relationship between non-syndromic deafness and LRTOMT gene mutations. As this gene is discovered in recent years, there are few studies on it. So far, only 5 mutation of this gene have been identified in the world that can determine pale relationship of the gene and hearing loss. © 2014, Isfahan University of Medical Sciences(IUMS). All rights reserved

Mutation screening of 3’UTR and exons 1-2 of vsx1 gene by PCR-SSCP/HA and sequencing in patients with Vernal Keratoconjuctivis (VKC) in Shahrekord

Background and Objective: Vernal Keratoconjuctivis is an immune response in relation to environmental antigens, leading to inflammation of the conjunctiva. One of the presumable genetic factors in VKC is VSX1 gene. In this study, mutations in exon 1, exon 2 and 3'UTR of VSX1 gene in patients with VKC in Shahrekord were investigated by PCR-SSCP and PCR-HA. Materials and Methods: In this cross- sectional study, peripheral blood samples of 100 patients with VKC and 100 individuals with no confirmed eye disease as control group were investigated. Genomic DNA was extracted by phenol-chloroform method and then PCR was carried out. Then, SSCP and HA were performed and the samples with shifted bands were sequenced for the type of nucleotide change. Afterwards, to investigate the observed nucleotide change, RFLP method was used. Results: Our SSCP findings revealed six patients with shifted band in exons 1 and 2 and 13 patients in 3'UTR, which were sequenced for nucleotide change. Analysis of sequencing data showed a frameshift change (g. 25057561delG) in 3'UTR. There was no change in other sequences. Conclusion: The findings of this study showed that, VSX1 gene most probably has no effective role in VKC pathogenesis in the studied population. Therefore, the role of VSX1 genes in VKC pathogens needs further investigation

Genetic linkage analysis of DFNB93 locus in a group of families with autosomal recessive non-syndromic hearing loss in Chahar Mahal & Bakhtiari and Kohkiluyeh & Boyer Ahmad provinces of Iran

زمینه و هدف: ناشنوایی یک اختلال حسی، عصبی است و بیشترین اختلال موجود در هنگام تولد است. بیش از 60 موارد ناشنوایی ارثی است. انواع ژنتیکی آن به دو نوع سندرومی و غیر سندرومی تقسیم می شود که نا شنوایی غیر سندرومی مغلوب اتوزومی (ARNSHL) با بیشترین درصد (70) رخ می دهد. این مطالعه با هدف تعیین پیوستگی ژنتیکی به لوکوس DFNB93 در خانواده های مبتلا به ARNSHL انجام شد. روش بررسی: این مطالعه توصیفی آزمایشگاهی بر روی 40 شجره بزرگ مبتلا به ARNSHL دارای حداقل دو بیمار، والدین سالم و عمدتاً دارای ازدواج خویشاوندی و منفی از نظر جهش های ژن GJB2، از استان های چهارمحال و بختیاری و کهگیلویه و بویراحمد انجام گردید. سپس خانواده ها برای پیوستگی ژنتیکی به لوکوس DFNB93 با استفاده از نشانگرهای STR و روش PCR و سپس ژل پلی اکریل آمید بررسی شدند. یافته ها: از تعداد 40 خانواده، 1 خانواده (5/2) به لوکوس DFNB93 پیوستگی نشان داد. ارزش SLINK این خانواده 67/2 و LOD بیشینه دو نقطه ای 05/2 و LOD بیشینه چند نقطه ای 05/2 محاسبه شد. نتیجه گیری: بر اساس نتیجه پژوهش حاضر، این لوکوس احتمالاً نقش کمی در ایجاد ناشنوایی در جمعیت مورد مطالعه (دو استان) دارد ولی برای تعیین نقش دقیق تر این لوکوس در ایجاد ناشنوایی در جمعیت ایرانی، مطالعات بیشتری ضروری می باشد

Comparison between the cultures of human induced pluripotent stem cells (hiPSCs) on feeder- and serum-free system (Matrigel matrix), MEF and HDF feeder cell lines

Human induced pluripotent stem cells (hiPSCs) are a type of pluripotent stem cells artificially derived from an adult somatic cell (typically human fibroblast) by forced expression of specific genes. In recent years, different feeders like inactivated mouse embryonic fibroblasts (MEFs), human dermal fibroblasts (HDFs), and feeder free system have commonly been used for supporting the culture of stem cells in undifferentiated state. In the present work, the culture of hiPSCs and their characterizations on BD Matrigel (feeder- and serum-free system), MEF and HDF feeders using cell culture methods and molecular techniques were evaluated and compared. The isolated HDFs from foreskin samples were reprogrammed to hiPSCs using gene delivery system. Then, the pluripotency ability of hiPSCs cultured on each layer was determined by teratoma formation and immunohistochemical staining. After EBs generation the expression level of three germ layers genes were evaluated by Q-real-time PCR. Also, the cytogenetic stability of hiPSCs cultured on each condition was analyzed by karyotyping and comet assay. Then, the presence of pluripotency antigens were confirmed by Immunocytochemistry (ICC) test and alkaline phosphatase staining. This study were showed culturing of hiPSCs on BD Matrigel, MEF and HDF feeders had normal morphology and could maintain in undifferentiated state for prolonged expansion. The hiPSCs cultured in each system had normal karyotype without any chromosomal abnormalities and the DNA lesions were not observed by comet assay. Moreover, upregulation in three germ layers genes in cultured hiPSCs on each layer (same to ESCs) compare to normal HDFs were observed (p<0.05). The findings of the present work were showed in stem cells culturing especially hiPSCs both MEF and HDF feeders as well as feeder free system like Matrigel are proper despite benefits and disadvantages. Although, MEFs is suitable for supporting of stem cell culturing but it can animal pathogens transferring and inducing immune response. Furthermore, HDFs have homologous source with hiPSCs and can be used as feeder instead of MEF but in therapeutic approaches the cells contamination is a problem. So, this study were suggested feeder free culturing of hiPSCs on Matrigel in supplemented media (without using MEF conditioned medium) resolves these problems and could prepare easy applications of hiPSCs in therapeutic approaches of regenerative medicine such as stem-cell therapy and somatic cell nuclear in further researches