Calcitriol downregulates TNF-α and IL-6 expression in cultured placental cells from preeclamptic women

Placenta is an important source and target of hormones that contribute to immunological tolerance and maintenance of pregnancy. In preeclampsia (PE), placental calcitriol synthesis is low; whereas pro-inflammatory cytokines levels are increased, threatening pregnancy outcome. Previously, we showed that calcitriol inhibits Th-1 cytokines under experimental inflammatory conditions in normal trophoblasts. However, a study of the regulation of inflammatory cytokines by calcitriol in trophoblasts from a natural inflammatory condition, such as PE, is still lacking. Therefore, the aim of the present study was to investigate calcitriol effects upon TNF-α, IFN-γ, IL-6 and IL-1β in cultured placental cells from preeclamptic women by using qPCR and ELISA. Placentas were collected after cesarean section from preeclamptic women and enriched trophoblastic preparations were cultured in the absence or presence of different calcitriol concentrations during 24 h. In these cell cultures, pro-inflammatory cytokines TNF-α and IL-6 secretion and mRNA expression were downregulated by calcitriol (P < 0.05). No significant effects of calcitriol upon IFN-γ and IL-1β were observed. In addition, basal expression of TNF-α, IL-6 and IL-1β decreased as the cells formed syncytia. Our study supports an important autocrine/paracrine role of placental calcitriol in controlling adverse immunological responses at the feto–maternal interface, particularly in gestational pathologies associated with exacerbated inflammatory responses such as preeclampsia.     

The tick fauna of Sulawesi, Indonesia (Acari: Ixodoidea: Argasidae and Ixodidae)

Twenty-six species of ticks are reported from the island of Sulawesi (Celebes), Indonesia. These include two species of soft ticks (Argasidae), Carios batuensis and C. vespertilionis, and the following 24 species of hard ticks (Ixodidae): Amblyomma babirussae, A. breviscutatum, A. cordiferum, A. fimbriatum, A. helvolum, A. testudinarium, A. trimaculatum, A. varanense, Dermacentor atrosignatus, D. steini, Haemaphysalis celebensis, H. hystricis, H. kadarsani, H. papuana, H. psalistos, H. renschi, H. toxopei, H. wellingtoni, Ixodes cordifer, I. granulatus, Rhipicephalus haemaphysaloides, R. (Boophilus) microplus, R. pilans and R. sanguineus. This represents an almost three-fold increase in the number of tick species recorded (9) from Sulawesi since the last available list in 1950. The tick records reported herein represent a culmination of data from specimens in the U.S. National Tick Collection, new records of ticks from endemic tarsiers and associated vertebrates, and literature reviews. Collectively, the tick fauna of Sulawesi shows most affinities with the fauna of southeast Asia but there are distinct faunal elements that show relationships with other Indonesian islands, the Philippines or Australasia, as well as a few tick species with widespread geographical distributions. Some ticks known from Sulawesi have known or potential medical-veterinary significance. These include R. (B.) microplus which is a significant pest of cattle and a vector of the agents of bovine anaplasmosis, I. granulatus which is a vector of Langat virus and Lyme disease spirochetes and has been shown to harbor pathogenic rickettsiae in other parts of its range, and R. sanguineus which is a globally widespread ectoparasite of canines and a vector of canine pathogens and parasites.     

Nuclear localization of the tight junction protein ZO-2 in epithelial cells

The tight junction constitutes the major barrier to solute and water flow through the paracellular space of epithelia and endothelia. It is formed by transmembrane proteins and submembranous molecules such as the MAGUKs ZOs. We have previously found that several MAGUKs, including those of the tight (ZO-1, ZO-2, and ZO-3) and septate junction (tamou and Dlg), contain one or two nuclear sorting signals located at their first PDZ and GK domains. Now we show that these proteins also contain a nuclear export signal and focus our study on the nuclear membrane shuttling of ZO-2. In sparse cultures this molecule concentrates at the nucleus in clusters, where it partially colocalizes with splicing factor SC35. Nuclear staining diminishes as the monolayer acquires confluence through a process sensitive to the nuclear export inhibitor leptomycin B. Nuclear localization can be induced by impairing cell-cell contacts, by mechanical injury. ZO-2 that shuttles from the cell periphery into the nucleus is not newly synthesized but originates from a preexistent pool. The movement of this protein is mediated by the actin cytoskeleton.     

Host Genetic Background Influences the Response to the Opportunistic Pseudomonas aeruginosa Infection Altering Cell-Mediated Immunity and Bacterial Replication

Pseudomonas aeruginosa is a common cause of healthcare-associated infections including pneumonia, bloodstream, urinary tract, and surgical site infections. The clinical outcome of P. aeruginosa infections may be extremely variable among individuals at risk and patients affected by cystic fibrosis. However, risk factors for P. aeruginosa infection remain largely unknown. To identify and track the host factors influencing P. aeruginosa lung infections, inbred immunocompetent mouse strains were screened in a pneumonia model system. A/J, BALB/cJ, BALB/cAnNCrl, BALB/cByJ, C3H/HeOuJ, C57BL/6J, C57BL/6NCrl, DBA/2J, and 129S2/SvPasCRL mice were infected with P. aeruginosa clinical strain and monitored for body weight and mortality up to seven days. The most deviant survival phenotypes were observed for A/J, 129S2/SvPasCRL and DBA/2J showing high susceptibility while BALB/cAnNCrl and C3H/HeOuJ showing more resistance to P. aeruginosa infection. Next, one of the most susceptible and resistant mouse strains were characterized for their deviant clinical and immunological phenotype by scoring bacterial count, cell-mediated immunity, cytokines and chemokines profile and lung pathology in an early time course. Susceptible A/J mice showed significantly higher bacterial burden, higher cytokines and chemokines levels but lower leukocyte recruitment, particularly neutrophils, when compared to C3H/HeOuJ resistant mice. Pathologic scores showed lower inflammatory severity, reduced intraluminal and interstitial inflammation extent, bronchial and parenchymal involvement and diminished alveolar damage in the lungs of A/J when compared to C3H/HeOuJ. Our findings indicate that during an early phase of infection a prompt inflammatory response in the airways set the conditions for a non-permissive environment to P. aeruginosa replication and lock the spread to other organs. Host gene(s) may have a role in the reduction of cell-mediated immunity playing a critical role in the control of P. aeruginosa infection. These results now provide a basis for mapping genomic regions underlying host susceptibility to P. aeruginosa infection.     

Rhenium(III) and rhenium(V) complexes stabilized by the potentially tetradentate ligand tris(2-diphenylphosphinoethyl)amine

The reaction of the rhenium(V) nitrido complex [Re(N)Cl₂(PPh₃)₂] with the tripodal ligand N(CH₂CH₂PPh₂)₃ (NP₃) in THF gave [Re(N)Cl₂(η²-P,P-NP₃)] (1) in which NP₃ acts as a tridentate ligand using the nitrogen and two phosphorus donors for coordination. Refluxing 1 in a polar solvent such as ethanol produced [(η⁴-NP₃)Re(N)Cl]Cl (2) in which NP₃ acts as a tetradentate ligand. Treatment of complex [Re(O)Cl₃(AsPh₃)₂] containing the [ReO]³⁺ core with NP₃ in THF yielded [ReCl₃{η³-N,P,P-(N{CH₂CH₂Ph₂}₂{CH₂CH₂P(O)Ph₂})}] (3). Complexes 1 and 3 have been characterized by single-crystal X-ray analyses.     

Changes in the distribution of ZO-1, occludin,and claudins in the rat uterine epithelium during the estrous cycle

During the estrous cycle, the endometrium epithelium experiences marked cellular structural changes. For fertilization to proceed, maintenance of an adequate uterine environment by ovarian hormones is essential. Epithelial cells lining the uterine lumen are associated with each other by tight junctions (TJs), which regulate the passage of ions and molecules through the paracellular pathway. The aim of the present study was to assess by confocal immunofluorescence the distribution pattern of the TJ proteins ZO-1, occludin, and claudins 1–7 in the rat uterus during the estrous cycle. Our results reveal that on proestrus, the day when mating takes place, ZO-1, occludin, and claudins 1 and 5 are located in the TJs, while claudins 3 and 7 display a basolateral distribution. In contrast, on metestrus day, when no sexual mating occurs and the uterine lumen is devoid of secretions, none of these proteins were detected in the TJ region, and only a diffuse cytosolic staining was observed for some of the proteins. On estrus and diestrus days, an intermediate situation was encountered, since ZO-1 localized in the TJs, whereas occludin was no longer detectable in the TJs. The distribution of claudins during these stages varied from the lowermost portion of the basolateral membrane to its apex. In conclusion, the results show that the protein composition of TJs present in the luminal epithelial cells of the uterus changes during the different days of the estrous cycle, and suggest that the expression of TJ proteins participates in providing an adequate environment for a successful fertilization.This work was supported by grants PAPIIT (IN210902, IX228504) and PAIP (6190-08) from the National Autonomous University of Mexico (UNAM), and by grants G34511-M and 37846-N from the Mexican National Council on Science and Technology (CONACYT).     

The integrative role of cryo electron microscopy in molecular and cellular structural biology

After gradually moving away from preparation methods prone to artefacts such as plastic embedding and negative staining for cell sections and single particles, the field of cryo electron microscopy (cryo‐EM) is now heading off at unprecedented speed towards high‐resolution analysis of biological objects of various sizes. This ‘revolution in resolution’ is happening largely thanks to new developments of new‐generation cameras used for recording the images in the cryo electron microscope which have much increased sensitivity being based on complementary metal oxide semiconductor devices. Combined with advanced image processing and 3D reconstruction, the cryo‐EM analysis of nucleoprotein complexes can provide unprecedented insights at molecular and atomic levels and address regulatory mechanisms in the cell. These advances reinforce the integrative role of cryo‐EM in synergy with other methods such as X‐ray crystallography, fluorescence imaging or focussed‐ion beam milling as exemplified here by some recent studies from our laboratory on ribosomes, viruses, chromatin and nuclear receptors. Such multi‐scale and multi‐resolution approaches allow integrating molecular and cellular levels when applied to purified or in situ macromolecular complexes, thus illustrating the trend of the field towards cellular structural biology.     

Effects of recombinant human gamma interferon on intracellular survival of Bordetella pertussis in human phagocytic cells

Abstract Several studies have demonstrated that Bordetella pertussis has the ability to enter and survive intracellularly within human polymorphonuclear leukocytes (PMNL) and human monocytes/macrophages. The effects of human recombinant gamma interferon (IFN-γ) on the survival of B. pertussis in PMNL and human monocytes, and on the oxidative burst activity of PMNL and human monocytes in response to B. pertussis were assessed in this study. IFN-γ partially increased intracellular killing of phagocytosed B. pertussis in human monocytes, as determined by an orange acridine-crystal violet assay. In contrast, IFN-γ did not enhance intracellular killing of B. pertussis in PMNL. No significant increase of superoxide production was noted in human monocytes in response to B. pertussis when stimulated with various concentrations of IFN-γ. The partial increase of B. pertussis killing by IFN-γ within monocytes, together with poor production of superoxide may explain how B. pertussis can survive within human phagocytic cells, and thus cause a more prolonged course of the disease.     

Anatomical studies of branchlet abscission related to crown modification in Quercus cerris L.

The basic anatomy of lateral twig insertion onto the main branch in both healthy and damaged Quercus cerris L. trees was studied. An abscission zone is always present: in healthy trees it is formed by a smaller number of cell layers than in damaged ones, where it is more evident with many layers of cells. Cells of the abscission zone are roundish, with many intercellular spaces between them; cell walls are thin, non-lignified and without secondary walls. No starch was found in cells of the abscission zone, where, instead, a few scattered calcium oxalate druses are seen.