Ventral pigmentation variation in the meadow spittlebug Philaenus spumarius (L.) (Hemiptera,Cicadomorpha: Cercopidae)

The meadow spittlebug Philaenus spumarius (L.) (Hemiptera, Cicadomorpha: Cercopidae) exhibits heritable colour/pattern variation on the dorsal and ventral sides of the adults. Eleven principal dorsal morphs are grouped as melanics and non-melanics according to the pigmentation of the dorsal surface. An investigation of ventral pigmentation variation in Philaenus spumarius was carried out with laboratory breeding stock obtained from Llysdinam, Wales. Analyses of the 1552 individuals, 753 females and 799 males, indicated that the pigmentation on the ventral surface of the adult individuals which vary significantly is associated with dorsal morph. Ventral parts of the dorsal melanics are usually darker than in non-melanics in both females (Kruskal-Wallis one-way ANOVA: H = 372.70, d.f. = 7, P < 0.001) and males (H = 407.36, d.f. = 7, P < 0.001). The combined “C” group morphs (flavicollis + gibbus + leuco- cephalus) are always darker than all other morphs in both sexes.     

Assessment of the inhibitory effects and molecular docking of some sulfonamides on human serum paraoxonase 1

Paraoxonase‐1 (PON1) is an organophosphate hydrolyzer and antiatherogenic enzyme. Due to the PON1's crucial functions, inhibitors and activators of PON1 must be known for pharmacological applications. In this study, we investigated the in vitro effects of some sulfonamides compounds on human serum PON1 (hPON1). For this aim, we purified the hPON1 from human serum with high specific activity by using simple chromatographic methods, and after the purification processes, we investigated in vitro interactions between the enzyme and some sulfonamides (2‐amino‐5‐methyl‐1,3‐benzenedisulfonamide, 2‐chloro‐4‐sülfamoilaniline, 4‐amino‐3‐methylbenzenesulfanilamide, sulfisoxazole, sulfisomidine, and 5‐amino‐2‐methylbenzenesulfonamide). IC₅₀, K_i values, and inhibition types were calculated for each sulfonamide. 2‐amino‐5‐methyl‐1,3‐benzenedisulfonamide and 2‐chloro‐4‐sülfamoilaniline exhibited noncompetitive inhibition effect, whereas 4‐amino‐3‐methylbenzenesulfanilamide, sulfisoxazole, and sulfisomidine exhibited mixed type inhibition. On the other hand, 5‐amino‐2‐methylbenzenesulfonamide showed competitive inhibition and so molecular docking studies were performed for this compound in order to assess the probable binding mechanism into the active site of hPON1.     

Disruption of PTPRO causes childhood-onset nephrotic syndrome

Idiopathic nephrotic syndrome (INS) is a genetically heterogeneous group of disorders characterized by proteinuria, hypoalbuminemia, and edema. Because it typically results in end-stage kidney disease, the steroid-resistant subtype (SRNS) of INS is especially important when it occurs in children. The present study included 29 affected and 22 normal individuals from 17 SRNS families; genome-wide analysis was performed with Affymetrix 250K SNP arrays followed by homozygosity mapping. A large homozygous stretch on chromosomal region 12p12 was identified in one consanguineous family with two affected siblings. Direct sequencing of protein tyrosine phosphatase receptor type O (PTPRO; also known as glomerular epithelial protein-1 [GLEPP1]) showed homozygous c.2627+1G>T donor splice-site mutation. This mutation causes skipping of the evolutionarily conserved exon 16 (p.Glu854_Trp876del) at the RNA level. Immunohistochemistry with GLEPP1 antibody showed a similar staining pattern in the podocytes of the diseased and control kidney tissues. We used a highly polymorphic intragenic DNA marker-D12S1303-to search for homozygosity in 120 Turkish and 13 non-Turkish individuals in the PodoNet registry. This analysis yielded 17 candidate families, and a distinct homozygous c.2745+1G>A donor splice-site mutation in PTPRO was further identified via DNA sequencing in a second Turkish family. This mutation causes skipping of exon 19, and this introduces a premature stop codon at the very beginning of exon 20 (p.Asn888Lysfs*3) and causes degradation of mRNA via nonsense-mediated decay. Immunohistochemical analysis showed complete absence of immunoreactive PTPRO. Ultrastructural alterations, such as diffuse foot process fusion and extensive microvillus transformation of podocytes, were observed via electron microscopy in both families. The present study introduces mutations in PTPRO as another cause of autosomal-recessive nephrotic syndrome.     

N-linked glycosylation and its impact on the electrophoretic mobility and function of the human proton-coupled folate transporter (HsPCFT)

The human proton-coupled folate transporter (HsPCFT, SLC46A1) mediates intestinal absorption of folates and transport of folates into the liver, brain and other tissues. On Western blot, HsPCFT migrates as a broad band (~55 kDa), higher than predicted (~50 kDa) in cell lines. Western blot analysis required that membrane preparations not be incubated in the loading buffer above 50 degrees C to avoid aggregation of the protein. Treatment of membrane fractions from HsPCFT-transfected HeLa cells with peptidyl N-glycanase F, or cells with tunicamycin, resulted in conversion to a ~35 kDa species. Substitution of asparagine residues of two canonical glycosylation sites to glutamine, individually, yielded a ~47 kDa protein; substitution of both sites gave a smaller (~35 kDa) protein. Single mutants retained full transport activity; the double mutant retained a majority of activity. Transport function and molecular size were unchanged when the double mutant was hemagglutinin (HA) tagged at either the NH(2) or COOH terminus and probed with an anti-HA antibody excluding degradation of the deglycosylated protein. Wild-type or deglycosylated HsPCFT HA, tagged at amino or carboxyl termini, could only be visualized on the plasma membrane when HeLa cells were first permeabilized, consistent with the intracellular location of these domains.     

Serum cytokine levels in patients with acute brucellosis and their relation to the traditional inflammatory markers

The number of clinical studies on gamma interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) in human brucellosis is limited. The present study was focused on IFN-gamma, TNF-alpha and IL-4 levels in acute brucellosis cases, in the acute phase and at the end of the treatment. The relation of these cytokines to traditional inflammation markers was also investigated. The study included 27 cases of acute brucellosis and 20 healthy volunteers who had no complaints. It was found that mean IFN-gamma and TNF-alpha levels, CRP (C-reactive protein) levels and ESR (erythrocyte sedimentation rate) values were significantly higher in acute brucellosis cases as compared to post-treatment values and values measured in the control group. In addition, IFN-gamma and TNF-alpha levels measured in the acute phase correlated with the increase in CRP levels and ESR values. Our results confirmed that IFN-gamma and TNF-alpha are involved in the pathophysiology of brucellosis and are closely related to the inflammatory activation of the disease. In view of the present findings, it is suggested that IFN-gamma and TNFalpha may be used for monitoring brucellosis.     

What colour of flowers do Lepidoptera prefer for foraging?

Food plant preferences of some Lepidoptera species associated with particular colour of the flowers were investigated. Based on 1,329 field observations of 43 Lepidoptera and 66 plant species, Lepidoptera showed a high tendency (G-test, G _adj = 698.6, df = 6, P < 0.001) to use the yellow (29%) and pink (28%) coloured flowers for foraging. Compared to the other colours it was evident that plants with red flowers (2%) were not preferred. Moreover, the plants with red (H = 0.435) and yellow-white (H = 0.543) flowers were not visited by diverse Lepidoptera species. Although yellow and pink flowers were most frequently visited, the highest degrees of the Lepidoptera diversity values were associated with the plants having blue (H = 0.647) and purple (H = 0.634) flowers. Species of Nymphalidae were most numerous (14 spp.) in the study area and the members of this family were observed 430 times on 39 different plant species, but never on plants with red flowers. Pieris rapae was the most abundant species that occurred 136 times on a total of 21 different plant species of which eight had yellow flowers. But, this species has never been seen while feeding on red flowers.     

Insulin stimulates membrane conductance in a liver cell line: evidence for insertion of ion channels through a phosphoinositide 3-kinase-dependent mechanism

Activation of insulin receptors stimulates a rapid increase in the ion permeability of liver cells. To evaluate whether this response involves insertion of ion channels, plasma membrane turnover was measured in a model liver cell line using the fluorescent membrane marker FM1-43. Under basal conditions, the rate of constitutive membrane turnover was approximately 2%min(-1), and balanced exocytosis and endocytosis maintained the total cell membrane area constant. Exposure to insulin stimulated a transient increase in membrane turnover of up to 10-fold above constitutive rates. The response was concentration-dependent (0.001-10 microm). Insulin also caused a parallel increase in membrane conductance as measured by whole-cell patch clamp recording due to opening of Cl(-)- and K(+)-selective ion channels. The insulin-stimulated membrane turnover did not appear to involve the constitutive recycling compartments, suggesting that a distinct pool of vesicles may be involved. The effects of insulin on membrane turnover and membrane conductance were inhibited by blockers of phosphoinositide 3-kinase LY294002 and wortmannin or by disrupting microtubule assembly with nocodazole. Taken together, these findings indicate that insulin stimulates recruitment of new membranes through phosphoinositide 3-kinase-dependent mechanisms. Thus, regulated insertion of a separate population of ion channel-containing vesicles may represent one mechanism for mediating the changes in membrane conductance that are essential for the cellular response to insulin.     

Vesicular exocytosis contributes to volume-sensitive ATP release in biliary cells

Extracellular ATP is a potent autocrine/paracrine signal that regulates a broad range of liver functions through activation of purinergic receptors. In biliary epithelium, increases in cell volume stimulate ATP release through a phosphoinositide 3-kinase (PI3-kinase)-dependent mechanism. Because PI3-kinase also regulates vesicular exocytosis, the purpose of these studies was to determine whether volume-stimulated vesicular exocytosis contributes to cellular ATP release. In a human cholangiocarcinoma cell line, exocytosis was measured by using the plasma membrane marker FM1-43, whereas ATP release was assessed by using a luciferase-luciferin assay. Under basal conditions, cholangiocytes exhibited constitutive exocytosis at a rate of 1.6%/min, and low levels of extracellular ATP were detected at 48.2 arbitrary light units. Increases in cholangiocyte cell volume induced by hypotonic exposure resulted in a 10-fold increase in the rate of exocytosis and a robust 35-fold increase in ATP release. Both vesicular exocytosis and ATP release were proportional to cell volume, and both exhibited similar regulatory properties including: 1) dependence on intact PI3-kinase, 2) attenuation by inhibition of PKC, and 3) potentiation by activation of PKC before hypotonic exposure. These findings demonstrate that increases in cholangiocyte cell volume stimulate ATP release and vesicular exocytosis through similar regulatory paradigms. Functional interactions among cell volume, PKC, and PI3-kinase modulate exocytosis, thereby regulating ATP release and purinergic signaling in cholangiocytes. It is hypothesized that PKC is involved in the recruitment of a volume-sensitive vesicular pool to a readily releasable state.