The sox gene Dichaete is expressed in local interneurons and functions in development of the Drosophila adult olfactory circuit

In insects, the primary sites of integration for olfactory sensory input are the glomeruli in the antennal lobes. Here, axons of olfactory receptor neurons synapse with dendrites of the projection neurons that relay olfactory input to higher brain centers, such as the mushroom bodies and lateral horn. Interactions between olfactory receptor neurons and projection neurons are modulated by excitatory and inhibitory input from a group of local interneurons. While significant insight has been gleaned into the differentiation of olfactory receptor and projection neurons, much less is known about the development and function of the local interneurons. We have found that Dichaete, a conserved Sox HMG box gene, is strongly expressed in a cluster of LAAL cells located adjacent to each antennal lobe in the adult brain. Within these clusters, Dichaete protein expression is detected in both cholinergic and GABAergic local interneurons. In contrast, Dichaete expression is not detected in mature or developing projection neurons, or developing olfactory receptor neurons. Analysis of novel viable Dichaete mutant alleles revealed misrouting of specific projection neuron dendrites and axons, and alterations in glomeruli organization. These results suggest noncell autonomous functions of Dichaete in projection neuron differentiation as well as a potential role for Dichaete‐expressing local interneurons in development of the adult olfactory circuitry. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2013     

Renal Ischemia/Reperfusion Injury in Soluble Epoxide Hydrolase-Deficient Mice

Aim

20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) are cytochrome P450 (CYP)-dependent eicosanoids that play opposite roles in the regulation of vascular tone, inflammation, and apoptosis. 20-HETE aggravates, whereas EETs ameliorate ischemia/reperfusion (I/R)-induced organ damage. EETs are rapidly metabolized to dihydroxyeicosatrienoic acids (DHETs) by the soluble epoxide hydrolase (sEH). We hypothesized that sEH gene (EPHX2) deletion would increase endogenous EET levels and thereby protect against I/R-induced acute kidney injury (AKI).

Methods

Kidney damage was evaluated in male wildtype (WT) and sEH-knockout (KO)-mice that underwent 22-min renal ischemia followed by two days of reperfusion. CYP-eicosanoids were analyzed by liquid chromatography tandem mass spectrometry.

Results

Contrary to our initial hypothesis, renal function declined more severely in sEH-KO mice as indicated by higher serum creatinine and urea levels. The sEH-KO-mice also featured stronger tubular lesion scores, tubular apoptosis, and inflammatory cell infiltration. Plasma and renal EET/DHET-ratios were higher in sEH-KO than WT mice, thus confirming the expected metabolic consequences of sEH deficiency. However, CYP-eicosanoid profiling also revealed that renal, but not plasma and hepatic, 20-HETE levels were significantly increased in sEH-KO compared to WT mice. In line with this finding, renal expression of Cyp4a12a, the murine 20-HETE-generating CYP-enzyme, was up-regulated both at the mRNA and protein level, and Cyp4a12a immunostaining was more intense in the renal arterioles of sEH-KO compared with WT mice.

Conclusion

These results indicate that the potential beneficial effects of reducing EET degradation were obliterated by a thus far unknown mechanism leading to kidney-specific up-regulation of 20-HETE formation in sEH-KO-mice.     

Cytokine gene polymorphisms and atopic disease in two European cohorts. (ECRHS-Basel and SAPALDIA)

Background

Avoidance of allergens is still recommended as the first and best way to prevent allergic illnesses and their comorbid diseases. Despite a variety of attempts there has been very limited success in the area of environmental control of allergic disease. Our objective was to identify a non-invasive, non-pharmacological method to reduce indoor allergen loads in atopic persons' homes and public environments. We employed a novel in vivo approach to examine the possibility of using aluminum sulfate to control environmental allergens.

Methods

Fifty skin test reactive patients were simultaneously skin tested with conventional test materials and the actions of the protein/glycoprotein modifier, aluminum sulfate. Common allergens, dog, cat, dust mite, Alternaria, and cockroach were used in the study.

Results

Skin test reactivity was significantly reduced by the modifier aluminum sulfate. Our studies demonstrate that the effects of histamine were not affected by the presence of aluminum sulfate. In fact, skin test reactivity was reduced independent of whether aluminum sulfate was present in the allergen test material or removed prior to testing, indicating that the allergens had in some way been inactivated.

Conclusion

Aluminum sulfate was found to reduce the in vivo allergic reaction cascade induced by skin testing with common allergens. The exact mechanism is not clear but appears to involve the alteration of IgE-binding epitopes on the allergen. Our results indicate that it may be possible to diminish the allergenicity of an environment by application of the active agent aluminum sulfate, thus producing environmental control without complete removal of the allergen.     

Systems analysis of primary Sjögren's syndrome pathogenesis in salivary glands identifies shared pathways in human and a mouse model

Bone tissue has an exceptional quality to regenerate to native tissue in response to injury. However, the fracture repair process requires mechanical stability or a viable biological microenvironment or both to ensure successful healing to native tissue. An improved understanding of the molecular and cellular events that occur during bone repair and remodeling has led to the development of biologic agents that can augment the biological microenvironment and enhance bone repair. Orthobiologics, including stem cells, osteoinductive growth factors, osteoconductive matrices, and anabolic agents, are available clinically for accelerating fracture repair and treatment of compromised bone repair situations like delayed unions and nonunions. Preclinical and clinical studies using biologic agents like recombinant bone morphogenetic proteins have demonstrated an efficacy similar or better than that of autologous bone graft in acute fracture healing. A lack of standardized outcome measures for comparison of biologic agents in clinical fracture repair trials, frequent off-label use, and a limited understanding of the biological activity of these agents at the bone repair site have limited their efficacy in clinical applications.     

A multicomponent assembly pathway contributes to the formation of acentrosomal microtubule arrays in interphase Drosophila cells

In animal cells, centrosomes nucleate microtubules that form polarized arrays to organize the cytoplasm. Drosophila presents an interesting paradox however, as centrosome-deficient mutant animals develop into viable adults. To understand this discrepancy, we analyzed behaviors of centrosomes and microtubules in Drosophila cells, in culture and in vivo, using a combination of live-cell imaging, electron microscopy, and RNAi. The canonical model of the cycle of centrosome function in animal cells states that centrosomes act as microtubule-organizing centers throughout the cell cycle. Unexpectedly, we found that many Drosophila cell-types display an altered cycle, in which functional centrosomes are only present during cell division. On mitotic exit, centrosomes disassemble producing interphase cells containing centrioles that lack microtubule-nucleating activity. Furthermore, steady-state interphase microtubule levels are not changed by codepleting both gamma-tubulins. However, gamma-tubulin RNAi delays microtubule regrowth after depolymerization, suggesting that it may function partially redundantly with another pathway. Therefore, we examined additional microtubule nucleating factors and found that Mini-spindles, CLIP-190, EB1, or dynein RNAi also delayed microtubule regrowth; surprisingly, this was not further prolonged when we codepleted gamma-tubulins. Taken together, these results modify our view of the cycle of centrosome function and reveal a multi-component acentrosomal microtubule assembly pathway to establish interphase microtubule arrays in Drosophila.     

Species distribution and <Emphasis Type="Italic">in vitro</Emphasis> antifungal susceptibility of oral yeast isolates from Tanzanian HIV-infected patients with primary and recurrent oropharyngeal candidiasis

Background  

In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis.     

Three dimensional typological studies using scanning electron microscopy for characterization of Termitomyces pellets obtained from submerged growth conditions

There are gaps in existing understanding of fungal pellet growth dynamics. We used scanning electron microscopy (SEM) for morphological characterization of the biomass organization of Termitomyces pellets for seven species: T. microcarpus (TMI1), T. albuminosus (TAL1, TAL2), T. striatus (TSTR), T. aurantiacus (TAUR), T. heimii (THE1, THE2), T. globulus (TGLO) and T. clypeatus (TCL1, TCL2, TCL3, TCL4, TCL5). We assessed the utility of SEM for morphological and structural characterization of Termitomyces spp. in three dimensional (3D) pellet form to identify ideal pellet morphology for industrial use. Typological classification of Termitomyces species was based on furrows, isotropy, total motifs and fractal dimensions. The pellets formed were entangled and exhibited highly compacted mycelial mass with microheterogeneity and microporosity. The mean density of furrows of Termitomyces species was between 10,000 and 11,300 cm/cm², percentage isotropy was 30?80 and total motifs varied from 300 to 2500. TGLO exhibited the highest furrow mean density, 11243 cm/cm², which indicated a compact, cerebroid structure with complex ridges and furrows, whereas TAL2 exhibited the lowest furrow density. TMI1a exhibited a high percentage isotropic value, 74.6, TSTR exhibited the lowest, 30.9. Total motif number also was used as a typological classification parameter. Fractal values were 2.64?2.78 for various submerged conditions of Termitomyces species. TAL1 exhibited the highest fractal dimension and TAL2 the lowest, which indicates the complexity of branching patterns. Three-dimensional SEM image analysis can provide insight into pellet micromorphology and is a powerful tool for exploring topographical details of pellets.     

Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload

We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.