Pluripotent stem cells (PSC) possess unlimited proliferation, self-renewal, and a differentiation capacity spanning all germ layers. Appropriate culture conditions are important for the maintenance of self-renewal, pluripotency, proliferation, differentiation, and epigenetic states. Oxygen concentrations vary across different human tissues depending on precise cell location and proximity to vascularisation. The bulk of PSC culture-based research is performed in a physiologically hyperoxic, air oxygen (21% O2) environment, with numerous reports now detailing the impact of a physiologic normoxia (physoxia), low oxygen culture in the maintenance of stemness, survival, morphology, proliferation, differentiation potential, and epigenetic profiles. Epigenetic mechanisms affect multiple cellular characteristics including gene expression during development and cell-fate determination in differentiated cells. We hypothesized that epigenetic marks are responsive to a reduced oxygen microenvironment in PSCs and their differentiation progeny. Here, we evaluated the role of physoxia in PSC culture, the regulation of DNA methylation (5mC (5-methylcytosine) and 5hmC (5-hydroxymethylcytosine)), and the expression of regulatory enzyme DNMTs and TETs. Physoxia enhanced the functional profile of PSC including proliferation, metabolic activity, and stemness attributes. PSCs cultured in physoxia revealed the significant downregulation of DNMT3B, DNMT3L, TET1, and TET3 vs. air oxygen, accompanied by significantly reduced 5mC and 5hmC levels. The downregulation of DNMT3B was associated with an increase in its promoter methylation. Coupled with the above, we also noted decreased HIF1A but increased HIF2A expression in physoxia-cultured PSCs versus air oxygen. In conclusion, PSCs display oxygen-sensitive methylation patterns that correlate with the transcriptional and translational regulation of the de novo methylase DNMT3B.
Red pigmented undecylprodigiosin produced by Streptomyces coelicolor (A3)2 is a
promising drug owing to its characteristics of antibacterial, antifungal,
immunosuppressive and anticancer activities. The culture of S. coelicolor in liquid
medium produces mainly the blue pigmented actinorhodin and only low quantities of
undecylprodigiosin. From an industrial point of view, it is necessary to find a strategy to
improve undecylprodigiosin production. The present study provides evidence that
cultivation of S. coelicolor on solid substrate resulted in a reversal in this pattern of
antibiotic production as the production of undecylprodigiosin was significantly increased
and actinorhodin was completely suppressed. Four di
Prodigiosin, is a natural red pigment produced by various bacteria that firstly
characterized from Serratia marcescens. It is an alkaloid secondary metabolite with
a unique tripyrrol structure.This pigment is a promising drug owing to its reported
characteristics of having antifungal, immunosuppressive and anti-cancer activity. In
this study prodigiosin was produced by Serratia marcescens., which was isolated
from soil identified and characterized by morphology, Gram’s staining, biochemical
and carbohydrate fermentation tested and confirmed by the API 20E test.
From these samples, six isolates of Serratia marcescens( 24) % were obtained out
of 25 soil samples. Ability of these isolates in prodigiosin production
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Chronic periodontitis (CP) is an inflammatory disease affecting tooth supporting structures in response to bacterial dental plaque causing irreversible tissue destruction. Cyclooxygenase-2 (COX-2) is an effective mediator in the pathogenesis of periodontitis. Polymorphisms in the COX-2 gene may contribute to its overexpression and increased disease susceptibility. To evaluate the association between -1195 A/G single nucleotide polymorphism (SNP) in the promotor area of the cyclooxygenase-2(COX-2) gene and severity of chronic periodontitis in a sample of Iraqi population. -1195A/ G COX-2 SNP was investigated in 70 chronic periodontitis (CP) cases and 30 healthy controls. CP cases composed of 2 subgroups (35 moderate CP cases and 35 severe CP
... Show MoreThe increasing use of antiseptic compounds creates selective pressure cause emergence of antiseptic resistance among Staphylococcus aureus .Resistance mechanism of antiseptic is driven mainly by multi drug resistant (MDR) efflux protein.Sixty five isolates of S.aureuswere collected from different clinical sources and subjected to 11 antibiotics most of them are recognized by efflux systems as extruded substrates. Range of efflux activity was estimated using cartwheel method. Simultaneous discrimination of antiseptic coding genes (qacA/B, smr and norA)as well as nuc and mecA genes among multidrug resistantS.aureus(MRSA) isolates was preformed using multiplex PCR assay
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The primitive streak and notochord and previously the anterior marginal crescent (AMC), anterior visceral endoderm (AVE) and the anterior hypoblast (AHB) are embryonic entities which identify main body axes and thus establish body plan in the early stages of embryonic development. All of the anterior pre-gastrulation differentiation structures are addressed terminology as anterior pre-gastrulation differentiation (APD). These structures are defined morphologically and are called in mouse (AVE), in rabbit (AMC) and in the pig (AHB). The anterior hypoblast cells of APD are higher and denser than at the opposite pole of the embryo. Moreover, the APD stretches variously between species and has different shapes in the mammalian embryos, for exam
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Abstract Background: The human epidermal growth factor receptor 2(HER2) proto-oncogene is overexpressed or amplified in approximately 15%-25% of invasive breast cancers. Approximately 35% of HER2-amplified breast cancers have coamplification of the topoisomerase II-alpha (TOP2A) gene encoding an enzyme that is a major target of anthracyclines. Hence, the determination of genetic alteration (amplification or deletion) of both genes is considered as an important predictive factor that determines the response of breast cancer patients to treatment. The aims of this study are to determinate TOP2A status gene amplification in a set of Iraqi patients with breast cancer that have had an equivocal (2+) and positive HER2/neu by immunohistochemistry
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Methylotrophs bacteria are ubiquitous, and they have the ability to consume single carbon (C1) which makes them biological conversion machines. It is the first study to find facultative methylotrophic bacteria in contaminated soils in Iraq. Conventional PCR was employed to amplify MxaF that encodes methanol dehydrogenase enzyme. DNA templates were extracted from bacteria isolated from five contaminated sites in Basra. The gene specific PCR detected Methylorubrum extorquens as the most dominant species in these environments. The ability of M. extorquens to degrade aliphatic hydrocarbons compound was tested at the laboratory. Within 7 days, gas chromatographic (GC) studies of remaining utilize
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Chemotherapy drugs have a major role in fighting cancer but, that doesn’t mean they are clear
from side effect on human health. One of these drugs is vincristine this study, the
chemopreventive potency of the crude extract ofIn Eruca Sativa Mill Which have a good
reputation as antioxidant and anticancer against chromosomal aberration and suppressed
mitotic index in bonemarrow cells of male albino mice treated with 50µ1 of vincristine
intrapritoneally(ip) have been detected.
Results Showed a Significant increasing in the percentage of the mitotic index nearly to the
control group and a significant decrease in chromosomal aberration after (35) days of
treatment with 250 mg/kg crude extract of Erucas