Identification of a Secreted Casein Kinase 1 in Leishmania donovani: Effect of Protein over Expression on Parasite Growth and Virulence

Casein kinase 1 (CK1) plays an important role in eukaryotic signaling pathways, and their substrates include key regulatory proteins involved in cell differentiation, proliferation and chromosome segregation. The Leishmania genome encodes six potential CK1 isoforms, of which five have orthologs in other trypanosomatidae. Leishmania donovani CK1 isoform 4 (Ldck1.4, orthologous to LmjF27.1780) is unique to Leishmania and contains a putative secretion signal peptide. The full-length gene and three shorter constructs were cloned and expressed in E. coli as His-tag proteins. Only the full-length 62.3 kDa protein showed protein kinase activity indicating that the N-terminal and C-terminal domains are essential for protein activity. LdCK1.4-FLAG was stably over expressed in L. donovani, and shown by immunofluorescence to be localized primarily in the cytosol. Western blotting using anti-FLAG and anti-CK1.4 antibodies showed that this CK1 isoform is expressed and secreted by promastigotes. Over expression of LdCK1.4 had a significant effect on promastigote growth in culture with these parasites growing to higher cell densities than the control parasites (wild-type or Ld:luciferase, P<0.001). Analysis by flow cytometry showed a higher percentage, ∼4–5-fold, of virulent metacyclic promastigotes on day 3 among the LdCK1.4 parasites. Finally, parasites over expressing LdCK1.4 gave significantly higher infections of mouse peritoneal macrophages compared to wild-type parasites, 28.6% versus 6.3%, respectively (p = 0.0005). These results suggest that LdCK1.4 plays an important role in parasite survival and virulence. Further studies are needed to validate CK1.4 as a therapeutic target in Leishmania.     

Cyanobacterial formation of intracellular Ca‐carbonates in undersaturated solutions

Cyanobacteria have long been thought to induce the formation of Ca‐carbonates as secondary by‐products of their metabolic activity, by shifting the chemical composition of their extracellular environment to conditions favoring mineral precipitation. Some cyanobacterial species forming Ca‐carbonates intracellularly were recently discovered. However, the environmental conditions under which this intracellular biomineralization process can occur and the impact of cyanobacterial species forming Ca‐carbonates intracellularly on extracellular carbonatogenesis are not known. Here, we show that these cyanobacteria can form Ca‐carbonates intracellularly while growing in extracellular solutions undersaturated with respect to all Ca‐carbonate phases, that is, conditions thermodynamically unfavorable to mineral precipitation. This shows that intracellular Ca‐carbonate biomineralization is an active process; that is, it costs energy provided by the cells. The cost of energy may be due to the active accumulation of Ca intracellularly. Moreover, unlike cyanobacterial strains that have been usually considered before by studies on Ca‐carbonate biomineralization, cyanobacteria forming intracellular carbonates may slow down or hamper extracellular carbonatogenesis, by decreasing the saturation index of their extracellular solution following the buffering of the concentration of extracellular calcium to low levels.     

Webbing life type and behavioral response of the date palm mite, <Emphasis Type="Italic">Oligonychus afrasiaticus</Emphasis>, to webbing residues on leaves and fruits of date palm

The present study examined the webbing life type and behavioral response of date palm mite (DPM) Oligonychus afrasiaticus (McGregor) toward its webbing residues, in presence or absence of immature individuals, on leaves and fruits of date palm. DPM exhibited a complicated web life type on both the leaves and fruits of date palm, which is characterized by the following features: complicated irregular web structure; webbing density on the leaves is medium and on the fruits extremely high; eggs are always laid on the threads of web without web cover; fecal pellets are deposited on the substrate surface (both leaf and fruit); quiescent stages are on the silken web threads; and the preferred site for feeding and walking is under the web. Behavioral observation of DPM females revealed that the midrib of leaves and the base of fruits of date palm were the preferred sites for feeding and web construction. The number and development stage of DPM affected the behavioral response of females on date palm leaves but not on the fruits. DPM spent most time feeding under the web on both the leaves and fruits of date palm.     

A human health risk assessment of soil and crops contaminated by heavy metals in industrial regions,central Iran

In this study, the concentrations of heavy metal (Cd, Pb, Fe, and Ni) in contaminated soils adjacent to two steel mill companies and in three crops (i.e., wheat, rice, and onion) grown in these regions were compared with a non-industrial site in Isfahan province, central Iran. The results were manifold. The heavy metal concentrations of both the soil and crops within the two industrial regions turned out to be more significant than the nonindustrial counterpart. In addition, the soils surrounding the companies were demonstrated to be contaminated by Cd, Pb, and Ni according to the limits provided by the international standards (i.e., USEPA and European Union standards). As for the crops from the investigated contaminated sites, the mean concentrations of Cd, Ni, and Pb exceeded the maximum permissible levels for human consumption stipulated by FAO/WHO standards. Furthermore, the values gained from the target hazard quotient were above one, meaning that the crops are contaminated. Given the results gained from a comparison made between estimated daily intake and tolerable daily intake, it can be concluded that the inhabitants of the two investigated contaminated sites are at a potentially serious health risk caused by exposure to the crops contaminated with the heavy metal.     

The relationship between antioxidant compounds contents and antioxidant enzymes under water-deficit stress in the three Iranian cultivars of basil (<Emphasis Type="Italic">Ocimum basilicum</Emphasis> L.)

The current investigation was conducted to elucidate the potential modulatory functions of both enzymatic and non-enzymatic scavenging elements of three Iranian basil (Ocimum basilicum L.) cultivars in response to different water-deficit stress treatments [i.e., control (W1: 100 % FC), mild (W2: 75 % FC), moderate (W3: 50 % FC), and severe (W4: 25 % FC)]. In general, the growth parameters, viz., plant height, number of lateral branches, number of flowers in the inflorescence per plant, and dry and fresh weights of leaves and inflorescence followed by yield were considerably affected by water-deficit stress levels (p ≤ 0.05), though some fluctuations were observed among three cultivars. Under severe water-deficit stress (W4), total chlorophyll content overall increased, while a pronounced reduction in the carotenoid content was observed by boosting of water-deficit stress intensities. Apart from some quantitative variations, ROS-scavenging enzymes, such as SOD, CAT, APX, GPX, and PPO, exhibited different behaviors versus different levels of water-deficit stress in the basil cultivars, concluding that their modulation could be a cultivar-dependent mechanism and stress-dependent mechanism. Among different metabolites detected in the essential oil of basil cultivars, both methyl chavicol and squalene were superior in the cultivars 2 and 3, while in cultivar 1, linalool and squalene were the predominant constituents, under water deprivation conditions. Taking all the features studied here into consideration, presumably, cultivar 1 is qualified enough to nominate as the most tolerant basil cultivar, could be accordingly utilized as a promising source/material for breeding programs of basil under drought stress, and possibly other abiotic stresses.     

The Management of Chronic Pulmonary Aspergillosis: The UK National Aspergillosis Centre Approach

Purpose of Review

Chronic pulmonary aspergillosis (CPA) is a serious long-term fungal disease of the lung with a worldwide prevalence. Treatment of CPA is not straightforward given the often-multiple associated co-morbidities, complex clinical picture, drug interactions, toxicities and intolerances.

Recent Findings

First line treatment is oral itraconazole or voriconazole. In the event of intolerance or toxicity, patients may be swapped from itraconazole to voriconazole or vice versa. In the event of resistance or further intolerance, third line treatment with posaconazole could be initiated. In those with pan-azole resistance, short-term courses of intravenous liposomal amphotericin B or micafungin are fourth line therapy, keeping in mind the nephrotoxic effects of amphotericin B.

Summary

The available evidence for current treatments in CPA is limited and based mostly on retrospective cohort studies. There is a real need to raise awareness of this devastating disease to enable early treatment as well as prospective drug trials and studies to identify potential patient factors that correlate with progression, severity and overall outcomes in order to target future therapies.

     

Psychiatric research: psychoproteomics, degradomics and systems biology

While proteomics has excelled in several disciplines in biology (cancer, injury and aging), neuroscience and psychiatryproteomic studies are still in their infancy. Several proteomic studies have been conducted in different areas of psychiatric disorders, including drug abuse (morphine, alcohol and methamphetamine) and other psychiatric disorders (depression, schizophrenia and psychosis). However, the exact cellular and molecular mechanisms underlying these conditions have not been fully investigated. Thus, one of the primary objectives of this review is to discuss psychoproteomic application in the area of psychiatric disorders, with special focus on substance- and drug-abuse research. In addition, we illustrate the potential role of degradomic utility in the area of psychiatric research and its application in establishing and identifying biomarkers relevant to neurotoxicity as a consequence of drug abuse. Finally, we will discuss the emerging role of systems biology and its current use in the field of neuroscience and its integral role in establishing a comprehensive understanding of specific brain disorders and brain function in general.