Neu-Laxova Syndrome,an Inborn Error of Serine Metabolism,Is Caused by Mutations in PHGDH

Neu-Laxova syndrome (NLS) is a rare autosomal-recessive disorder characterized by severe fetal growth restriction, microcephaly, a distinct facial appearance, ichthyosis, skeletal anomalies, and perinatal lethality. The pathogenesis of NLS remains unclear despite extensive clinical and pathological phenotyping of the >70 affected individuals reported to date, emphasizing the need to identify the underlying genetic etiology, which remains unknown. In order to identify the cause of NLS, we conducted a positional-mapping study combining autozygosity mapping and whole-exome sequencing in three consanguineous families affected by NLS. Surprisingly, the NLS-associated locus identified in this study was solved at the gene level to reveal mutations in PHGDH, which is known to be mutated in individuals with microcephaly and developmental delay. PHGDH encodes the first enzyme in the phosphorylated pathway of de novo serine synthesis, and complete deficiency of its mouse ortholog recapitulates many of the key features of NLS. This study shows that NLS represents the extreme end of a known inborn error of serine metabolism and highlights the power of genomic sequencing in revealing the unsuspected allelic nature of apparently distinct clinical entities.     

MiR-155 inhibits cell migration of human cardiomyocyte progenitor cells (hCMPCs) via targeting of MMP-16

Undesired cell migration after targeted cell transplantation potentially limits beneficial effects for cardiac regeneration. MicroRNAs are known to be involved in several cellular processes, including cell migration. Here, we attempt to reduce human cardiomyocyte progenitor cell (hCMPC) migration via increasing microRNA‐155 (miR‐155) levels, and investigate the underlying mechanism. Human cardiomyocyte progenitor cells (hCMPCs) were transfected with pre‐miR‐155, anti‐miR‐155 or control‐miR (ctrl‐miR), followed by scratch‐ and transwell‐ assays. These functional assays displayed that miR‐155 over‐expression efficiently inhibited cell migration by 38 ± 3.6% and 59 ± 3.7% respectively. Conditioned medium from miR‐155 transfected cells was collected and zymography analysis showed a significant decrease in MMP‐2 and MMP‐9 activities. The predicted 3′‐UTR of MMP‐16, an activator of MMP‐2 and ‐9, was cloned into the pMIR‐REPORT vector and luciferase assays were performed. Introduction of miR‐155 significantly reduced luciferase activity which could be abolished by cotransfection with anti‐miR‐155 or target site mutagenesis. By using MMP‐16 siRNA to reduce MMP‐16 levels or by using an MMP‐16 blocking antibody, hCMPC migration could be blocked as well. By directly targeting MMP‐16, miR‐155 efficiently inhibits cell migration via a reduction in MMP‐2 and ‐9 activities. Our study shows that miR‐155 might be used to improve local retention of hCMPCs after intramyocardial delivery.     

Src Kinase-mediated Phosphorylation Stabilizes Inducible Nitric-oxide Synthase in Normal Cells and Cancer Cells

Src kinases are key regulators of cellular proliferation, survival, motility, and invasiveness. They play important roles in the regulation of inflammation and cancer. Overexpression or hyperactivity of c-Src has been implicated in the development of various types of cancer, including lung cancer. Src inhibition is currently being investigated as a potential therapy for non-small cell lung cancer in Phase I and II clinical trials. The mechanisms of Src implication in cancer and inflammation are linked to the ability of activated Src to phosphorylate multiple downstream targets that mediate its cellular effector functions. In this study, we reveal that inducible nitric-oxide synthase (iNOS), an enzyme also implicated in cancer and inflammation, is a downstream mediator of activated Src. We elucidate the molecular mechanisms of the association between Src and iNOS in models of inflammation induced by lipopolysaccharide and/or cytokines and in cancer cells and tissues. We identify human iNOS residue Tyr¹⁰⁵⁵ as a target for Src-mediated phosphorylation. These results are shown in normal cells and cancer cells as well as in vivo in mice. Importantly, such posttranslational modification serves to stabilize iNOS half-life. The data also demonstrate interactions and co-localization of iNOS and activated Src under inflammatory conditions and in cancer cells. This study demonstrates that phosphorylation of iNOS by Src plays an important role in the regulation of iNOS and nitric oxide production and hence could account for some Src-related roles in inflammation and cancer.     

Recombinant, Replication-Defective Adenovirus Gene Transfer Vectors Induce Cell Cycle Dysregulation and Inappropriate Expression of Cyclin Proteins

First-generation adenovirus (Ad) vectors that had been rendered replication defective by removal of the E1 region of the viral genome (ΔE1) or lacking the Ad E3 region in addition to E1 sequences (ΔE1ΔE3) induced G₂ cell cycle arrest and inhibited traverse across G₁/S in primary and immortalized human bronchial epithelial cells. Cell cycle arrest was independent of the cDNA contained in the expression cassette and was associated with the inappropriate expression and increase in cyclin A, cyclin B1, cyclin D, and cyclin-dependent kinase p34^cdc2 protein levels. In some instances, infection with ΔE1 or ΔE1ΔE3 Ad vectors produced aneuploid DNA histogram patterns and induced polyploidization as a result of successive rounds of cell division without mitosis. Cell cycle arrest was absent in cells infected with a second-generation ΔE1Ad vector in which all of the early region E4 except the sixth open reading frame was also deleted. Consequently, E4 viral gene products present in ΔE1 or ΔE1ΔE3 Ad vectors induce G₂ growth arrest, which may pose new and unintended consequences for human gene transfer and gene therapy.     

Topical treatment of erectile dysfunction: randomised double blind placebo controlled trial of cream containing aminophylline,isosorbide dinitrate,and co-dergocrine mesylate.

OBJECTIVE--To examine the effectiveness in treating impotence to topically applied cream containing three vasodilators--aminophylline, isosorbide dinitrate, and co-dergocrine mesylate--which act by different mechanisms. DESIGN--Randomised double blinded placebo controlled crossover trial over two weeks. SUBJECTS--36 men with erectile dysfunction randomly allocated to two equal groups. INTERVENTIONS--Active cream containing aminophylline 3%, isosorbide dinitrate 0.25%, and co-dergocrine mesylate 0.05% for one week and placebo for another. MAIN OUTCOME MEASURES--Patients'' reported experience of penile responses and side effects of treatment in questionnaires. Penile tumescence and arterial flow in the laboratory. RESULTS--21 patients reported full erection and satisfactory intercourse with the active cream. Three men reported full erection and satisfactory intercourse with either cream. The active cream was more effective in psychogenic than organic impotence (eight out of nine men with psychogenic impotence achieved a full erection upsilon four out of eight with neurogenic impotence and two out of seven with arterial insufficiency). No major side effects were reported. In the laboratory the active cream increased penile arterial flow (0.19 (SD 0.08) m/s upsilon 0.02 (0.15) m/s with placebo) and induced tumescence in 24 patients. CONCLUSIONS--Topical treatment with a cream containing three different vasodilators might be considered before intracavernous injection of vasoactive agents, particularly in psychogenic impotence.     

Pathogenicity of the rice root nematode,Hirschmanniella oryzae to rice plants in relation to nematode reproduction,plant growth,grain yield and biochemical changes

Influence of different inoculum levels of 0, 10, 100, 1000 and 10,000 individuals of Hirschmanniella oryzae on nematode reproduction and plant growth of rice cv. Giza171 and biochemical changes of infected plants was studied under screen-house conditions. Rate of nematode build up (P_f/P_i) was negatively correlated with the progressive increase in nematode inoculum levels. The percentage reduction in growth parameters, rice grain yield and the amount of total and reducing sugars were markedly affected showing a negative correlation with the tested inocula. The conspicuous reductions of plant growth, yield and total and reducing sugar contents were obtained by using 1000 and 10,000 nematodes per pot. The inoculum level of 1000 nematodes per pot was identified as critical population at which control programme must be started.     

Characterization of inhibitor(s) of β-glucuronidase enzyme activity in <Emphasis Type="Italic">GUS</Emphasis>-transgenic wheat

The uidA gene, encoding for β-glucuronidase (GUS), is the most frequently used reporter gene in plants. As a reporter enzyme, GUS can be assayed both qualitatively and quantitatively. In wheat, there are numerous reports of failure in detecting GUS enzyme activity in tissues of transgenic plants, while other reports have suggested presence of β-glucuronidase inhibitor(s) in wheat tissues. In the present study, we show that the β-glucuronidase enzyme activity is not only tissue-specific but also genotype-dependent. Our data demonstrate that the glucuronic acid could be the candidate inhibitor for β-glucuronidase enzyme activity in wheat leaves and roots. It should be noted that the assays to detect β-glucuronidase enzyme activity in wheat should be interpreted carefully. Based on the data of our present study, we recommend studying the chemical pathways, the unintended effects and the possible loss-of-function of any candidate transgene prior to transformation experiments.     

Impact of Compost on Metals Phytostabilization Potential of Two Halophytes Species

Phytostabilization of heavy metals in contaminated soils should be subject to two conditions, the first is the choice plant must be able to stabilize heavy metals in soil, the second is the plant material which produced from the phytostabilization process must be safe and useful to avoid overload on environmental system. A field experiment was conducted out to evaluate the phytostabilization potential of two halophytes species (Atriplex lentiformis and Atriplex undulata). Compost at rates of 0, 15 and 30 ton ha^?1 was used to examine its role in plant growth and heavy metals uptake. The high rate of compost (30 ton ha^?1) decreased zinc (Zn) concentrations in the leaves of A. lentiformis and A. undulata by 15.8 and 13.0%, while lead (Pb) in the leaves decreased by 37.6 and 35.2% respectively. Despite the extremely high total heavy metals concentrations in the studied soil, plants of Atriplex were able to grow and maintain shoots metals content below the toxic level and the produced plant materials had a high nutritive value compared to the conventional forage crops. Phosphorus (P) and chloride (Cl) in the roots of Atriplex plants play important function in heavy metals phytostabilization mechanism by the two halophytes plants.     

Leishmania major: activity of tamoxifen against experimental cutaneous leishmaniasis

Leishmaniasis is a family of diseases caused by protozoan parasites of the genus Leishmania. Various Leishmania species can cause human infection, producing a spectrum of clinical manifestations. The current treatments are unsatisfactory, and in absence of a vaccine, there is an urgent need for effective drugs to replace/supplement those currently in use. Recent studies have shown that the antineoplastic drug, tamoxifen, had direct leishmanicidal effect on several Leishmania species in vitro. Moreover, in vivo testing was carried out on some of the species and showed promising results. The authors have carried out the present work to complement previous published studies by investigating in vivo activity of tamoxifen in an experimental model of cutaneous leishmaniasis (CL) caused by Leishmania major. Groups of infected mice were given tamoxifen, orally, at a dose of 20 mg/kg/day for 15 days. Efficacy was assessed clinically, parasitologically, histopathologically by light and transmission electron microscope (TEM). Results showed that untreated infected mice suffered from autoamputation of the inoculated foot pad. However, those which received tamoxifen showed marked improvement of the cutaneous lesions and reduction of parasite burden. TEM of the cutaneous lesions from infected mice revealed the fine structure of normal Leishmania amastigotes, whereas those from infected mice treated with tamoxifen showed considerable changes. All male mice that received tamoxifen showed scrotal swelling with evident histopathological changes in the testes that could seriously compromise fertility of male mice. In conclusion, although tamoxifen causes significant side effects to the male reproductive system in the mouse model, it could provide an alternative to current agents. Results of this study demonstrated in vivo activity of tamoxifen against Leishmania major, thus, suggesting that tamoxifen is a suitable lead for the synthesis of more effective and less toxic antileishmanial derivatives.