The GC-box is an important transcriptional regulatory element present in the promoters of many mammalian genes, and is found in most, if not all, oxidative phosphorylation (OXPHOS) promoters. In the present study we examine the effects of three Sp1 family members (Sp2, Sp3, and Sp4) on the adenine nucleotide translocase 2, cytochrome c1, F1-ATPase β-subunit, and the mitochondria transcription factor (mtTFA) promoters in Drosophila SL2 cell line. Sp3, like Sp1, strongly activates transcription all four promoters. SP4 stimulates, moderately, but Sp2 had no effect. In addition, Sp3 can, like Sp1, inhibit transcription from the proximal promoter of the ANT2 gene through binding to the Cbox GC element. By contrast, Sp4 and Sp2 do not repress promoter activity. Furthermore, since Sp4 and Sp2 bind to the Cbox repression element on the ANT2 promoter, but do not repress transcription, inhibition of transcription … arabic 21 English 97
Ahmed Zaid(1-2012)

Mutations in the TAL1 (T-cell acute leukemia 1) gene were recently described in patients with T-cell acute lymphoblastic leukaemia (T-ALL) and in those with lymphoblastic T-cell non-Hodgkin’s lymphoma (T-NHL). The purpose of this pilot study was to assess the prevalence of mutations in TAL1 gene in T-ALL and TNHL. DNA samples from 15 unrelated healthy controls, 20 T-ALL patients, and 10 T-NHL patients were analyzed using DNA-PCR and direct DNA sequencing to identify sequence genetic variations in TAL1 gene (exons 2 and 3). TAL1 exon 2 mutations were identified in 7.7% adult and 12.5% adolescent T-ALL patients analyzed. TAL1 exon 2 mutations were detected in 16.7% of the adult TNHL patients analyzed. Sequencing of TAL1 exon 3 showed no sequence variation for the T-ALL and T-NHL cancer patients analyzed. No sex difference where observed in the incidences of TAL1 exons 2 mutations between T-ALL and T-NHL patients with and without TAL1 mutations. TAL1 exon 2 missense and frame-shift mutations were present in 44.4% (4/9) and 55.6% (5/9) of T-ALL patients, respectively. However, the frame-shift and missense mutations in the T-NHL patients accounted for, where respectively, 60% (3/5) and 40% (4/5) of all TAL1 exon 2 mutations. Comparing the clinical features showed that there are no differences in PLT and WBC counts as well as the average age between T-ALL and T-NHL patients with and without TAL1 mutations. Overall, these findings indicate that TAL1 mutations are too rare to be of clinical relevance, and do not seem to be significantly associated with the increased T-ALL and T-NHL susceptibility, implying different pathways with respect to TAL1 genetic polymorphisms as a risk factor for T-ALL and T-NHL at least in this population of Libyans.
Amal E. Elarifi, Othman A. El-Ansari, Mohamed A. Al-Griw(12-2016)

Background & aim: There is significant evidence indicating that endocrine disrupted bisphenol A (BPA) seriously endangers human health. In males, BPA affects testis architecture and sperm quality, and ultimately reduces fertility. This study explored the therapeutic potential of Nigella sativa (NS) seed extract on testis and sperm abnormalities in BPA-exposed mice and characterized the underlying mechanism. Methods: Forty male Swiss albino mice (5.5 weeks old, N = 8 per group) were randomly divided into five groups: Group I, normal control, Group II, vehicle control (sterile corn oil); Group III, NS-exposed (oral 200 mg/kg); Group IV, BPA-exposed (oral 400 μg/kg body weight); Group V, BPA + NS-exposed mice. Animals were treated for 6 weeks and sacrificed for biochemical and histological examination. Results: The results indicated that BPA exposure results in significant testis and sperm abnormalities. Specifically, BPA promoted a marked reduction in the body and testis compared with the control group. Histopathological findings showed that BPA caused a widespread degeneration of spermatogenic cells of the seminiferous epithelium, decreased sperm counts and motility, and augmented sperm abnormalities, and whereas little alteration to sperm DNA was observed. In addition, BPA increased the levels of the lipid peroxidation marker, malondialdehyde (MDA), and reduced the levels of the antioxidant marker, reduced glutathione (GSH). Treatment with NS oil extract during BPA exposure significantly alleviated testis and sperm abnormalities, reduced MDA levels, and enhanced GSH levels. Conclusions: The results demonstrate that NS oil protects mice against BPA-induced sperm and testis abnormalities, likely by suppressing levels of the oxidative stress marker, MDA, and enhancing the levels of the antioxidant marker, GSH.
Mohamed A M Al Griw (5-2022)