Nlrc4/Ipaf/CLAN/CARD12: More than a flagellin sensor

Nlrc4 is a member of the Nod-like receptors (NLRs), a family of cytosolic receptors involved in sensing bacterial molecules. NLRs are a group of proteins containing spans of leucine-rich repeats that senses bacterial factors within the eukaryotic cytosol. The recognition of bacterial factors provokes the formation of the inflammasome complex which includes specific NLRs. The inflammasome is responsible for caspase-1 activation which leads to the cleavage and maturation of inflammatory cytokines such as IL-1β and IL-18. Nlrc4 was considered to be a devoted flagellin sensor in eukaryotic cells. However, studies using a variety of pathogens such as Salmonella, Legionella, Shigella and Pseudomonas at high bacterial burdens revealed that Nlrc4 can mediate caspase-1 activation independent of bacterial flagellin. On the other hand, new reports showed that Nlrc4 can restrict bacterial infection independently of caspase-1. Therefore, Nlrc4 maybe involved in sensing more than one bacterial molecule and may participate in several immune complexes.     

Prevalence and distribution of MEFV mutations among Arabs from the Maghreb patients suffering from familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive inherited disease caused by mutations in MEFV. This disease is characterized by recurrent episodes of fever accompanied with topical signs of inflammation. Some patients can develop renal amyloidosis. We prospectively investigated MEFV mutations in a cohort of 209 unrelated Arab patients from Maghreb (85 Algerians, 87 Moroccans, and 37 Tunisians) with a clinical suspicion of FMF. FMF is the main cause of periodic fever syndrome in Maghreb. The most frequent MEFV mutations in this cohort were M694V and M694I. These mutations account for different proportions of the MEFV mutations in Algeria (5%, 80%), Morocco (49%, 37%), and Tunisia (50%, 25%) patients. M694I mutation is specific to the Arab population from Maghreb. Other rare mutations were observed: M680L, M680I, A744S, V726A, and E148Q. We estimated the frequency of MEFV mutation carriers among the Arab Maghrebian population at around 1%, which is significantly lower than in non-Ashkenazi Jews, Armenians or Turks.     

The AtNHX1 exchanger mediates potassium compartmentation in vacuoles of transgenic tomato

NHX‐type antiporters in the tonoplast have been reported to increase the salt tolerance of various plants species, and are thought to mediate the compartmentation of Na⁺ in vacuoles. However, all isoforms characterized so far catalyze both Na⁺/H⁺ and K⁺/H⁺ exchange. Here, we show that AtNHX1 has a critical involvement in the subcellular partitioning of K⁺, which in turn affects plant K⁺ nutrition and Na⁺ tolerance. Transgenic tomato plants overexpressing AtNHX1 had larger K⁺ vacuolar pools in all growth conditions tested, but no consistent enhancement of Na⁺ accumulation was observed under salt stress. Plants overexpressing AtNHX1 have a greater capacity to retain intracellular K⁺ and to withstand salt‐shock. Under K⁺‐limiting conditions, greater K⁺ compartmentation in the vacuole occurred at the expense of the cytosolic K⁺ pool, which was lower in transgenic plants. This caused the early activation of the high‐affinity K⁺ uptake system, enhanced K⁺ uptake by roots, and increased the K⁺ content in plant tissues and the xylem sap of transformed plants. Our results strongly suggest that NHX proteins are likely candidates for the H⁺‐linked K⁺ transport that is thought to facilitate active K⁺ uptake at the tonoplast, and the partitioning of K⁺ between vacuole and cytosol.     

Synthesis and Antimicrobial Activities of New S-Nucleosides of Chromeno[2,3-B]Pyridine Derivatives and C-Nucleosides of [1,2,4]Triazolo[1,5-A]Quinoline Derivatives

Direct preparation of 2-amino-5,6,7,8-tetrahydro-4-(4-methoxyphenyl)-7,7-dimethyl-5-oxo-4H-chromene-3-carbonitrile 2 and 1,2-diamino-1,4,5,6,7,8-hexahydro-4-(4-methoxyphenyl)-7,7-dimethyl-5-oxo-3-quinolinecarbonitrile 11, which were utilized as starting products for the synthesis of S-nucleoside analogues 10 and 15 and C-nucleoside analogues 12 and 13, is presented in the current study. The antibacterial and antifungal activities of these new compounds were evaluated. The structures of the new products were confirmed on the basis of elemental and spectral analysis results.     

Extraction of High Quality DNA from Seized Moroccan Cannabis Resin (Hashish)

The extraction and purification of nucleic acids is the first step in most molecular biology analysis techniques. The objective of this work is to obtain highly purified nucleic acids derived from Cannabis sativa resin seizure in order to conduct a DNA typing method for the individualization of cannabis resin samples. To obtain highly purified nucleic acids from cannabis resin (Hashish) free from contaminants that cause inhibition of PCR reaction, we have tested two protocols: the CTAB protocol of Wagner and a CTAB protocol described by Somma (2004) adapted for difficult matrix. We obtained high quality genomic DNA from 8 cannabis resin seizures using the adapted protocol. DNA extracted by the Wagner CTAB protocol failed to give polymerase chain reaction (PCR) amplification of tetrahydrocannabinolic acid (THCA) synthase coding gene. However, the extracted DNA by the second protocol permits amplification of THCA synthase coding gene using different sets of primers as assessed by PCR. We describe here for the first time the possibility of DNA extraction from (Hashish) resin derived from Cannabis sativa. This allows the use of DNA molecular tests under special forensic circumstances.     

Etude entomologique de cinq foyers de leishmaniose cutanée dans la province de Sidi Kacem au nord du Maroc

Résumé. La leishmaniose cutanée est un important problème de santé publique dans la province de Sidi Kacem au nord-ouest du Maroc. L'incidence de cette affetion, due aussi bien à Leishmania tropica qu'à L. infantum est en augmentation progressive depuis 1997. La présente étude a été menée dans le but d'étudier l'écologie et la dynamique des populations des vecteurs de cette maladie dans les principaux foyers de cette province. Un total de 4504 spécimens appartenant à deux genres et six espèces a été capturé à l'aide de pièges adhésifs et lumineux, dans cinq foyers. Les espèces dominantes sont Phlebotomus sergenti représentant 42,6% du total des phlébotomes capturés et P. longicuspis avec 27,2% des captures. Ces deux espèces sont présentes de mai à novembre et évoluent en deux générations avec deux pics de densité, le premier en juin et le second en septembre. En considérant la grande spécificité vecteur-parasite connue en épidémiologie des leishmanioses ainsi que l'abondance des espèces capturées pendant la saison favorable à la transmission, P. sergenti et P. longicuspis seraient respectivement les vecteurs les plus probables des leishmanioses à L. tropica et à L. infantum dans la région étudiée. Le risque de transmission de la maladie serait plus grand durant le deuxième pic de densité en fin été- début automne.     

Biodiversity of Wolbachia and of their effects in Trichogramma (Hymenoptera: Trichogrammatidae)

Hymenopteran egg parasitoids belonging to the Trichogramma genus are infected by endosymbionts of the Wolbachia genus distributed into 2 supergroups and 4 groups according to the sequence of the wsp gene. The symbionts are variously distributed according to host populations and species and induce, in most cases, thelytokous parthenogenetic reproduction and, sometimes strongly, increase fecundity. Nevertheless, after an interspecific artificial transfer, no effect on reproduction has so far been recorded. Wolbachia often have a negative effect, or no effect at all, on host fitness. Positive effects have, however, been recorded especially in completely infected species. Symbionts show a variable efficiency of vertical transmission and a variable sensitivity to high temperature in relation to host species.