Marshalin, a microtubule minus-end binding protein, regulates cytoskeletal structure in the organ of Corti

Dramatic structural changes in microtubules (MT) and the assembly of complicated intercellular connections are seen during the development of the cellular matrix of the sense organ for hearing, the organ of Corti. This report examines the expression of marshalin, a minus-end binding protein, during this process of cochlear development. We discovered that marshalin is abundantly expressed in both sensory hair cells and supporting cells. In the adult, prominent marshalin expression is observed in the cuticular plates of hair cells and in the noncentrosomal MT organization centers (MTOC) of Deiters' and pillar cells. Based upon differences in marshalin expression patterns seen in the organ of Corti, we identified eight isoforms ranging from 863 to 1280 amino acids. mRNAs/proteins associated with marshalin's isoforms are detected at different times during development. These isoforms carry various protein-protein interacting domains, including coiled-coil (CC), calponin homology (CH), proline-rich (PR), and MT-binding domains, referred to as CKK. We, therefore, examined membranous organelles and structural changes in the cytoskeleton induced by expressing two of these marshalin isoforms in vitro. Long forms containing CC and PR domains induce thick, spindle-shaped bundles, whereas short isoforms lacking CC and PR induce more slender variants that develop into densely woven networks. Together, these data suggest that marshalin is closely associated with noncentrosomal MTOCs, and may be involved in MT bundle formation in supporting cells. As a scaffolding protein with multiple isoforms, marshalin is capable of modifying cytoskeletal networks, and consequently organelle positioning, through interactions with various protein partners present in different cells.

114. HYPERTENSIVE DISORDERS OF PREGNANCY ARE ASSOCIATED WITH IMMUNOREGULATORY GENE POLYMORPHISMS

Pregnancy is a controlled state of inflammation. Deregulation of cytokine networks can lead to adverse pregnancy outcomes including preeclampsia (PE). We aimed to identify single nucleotide polymorphisms in immunoregulatory genes that signify an increased risk of the gestational hypertensive disorders PE and gestational hypertension (GH). 1169 nulliparous pregnant women and their partners were recruited prospectively for the Adelaide SCOPE study. PE and GH were classified using strict guidelines. Uncomplicated pregnancies served as controls. Peripheral blood from couples and cord blood from neonates were collected. DNA was extracted and genotyped for Interleukin (IL)-6 rs1800795, IL-4 rs2243250, IL-10 rs1800896 and rs1800871, mannose binding lectin (MBL) rs1800450, transforming growth factor beta 1 (TGFβ-1) rs1800469 and cyclooxygenase (COX)-2 rs20417 & rs5275 and inducible nitric oxide synthase (NOS2A) rs1137933 using the Sequenom MassARRAY system. Genotypes for Caucasian PE (n = 75) and GH (n = 102) were compared with controls (n = 422) and analysed using Chi-Square. In neonates IL-6 G allele carriage was associated with PE (P = 0.011, OR=2.0, 95% CI = 1.2–3.7) and the CC genotype associated with GH (P = 0.002). Neonatal IL-10 RS180071 AA genotype associated with PE (P = 0.041) and IL-10 RS1800896 AA associated with GH (P = 0.022). Paternal NOS2A C allele was more frequent in PE (P = 0.03, OR = 2.1, 95% CI = 1.1–4.5), and maternal NOS2A CC more frequent in GH (P = 0.018). Increased neonatal carriage of MBL rs1800450 AA+GA genotypes associated with GH (P = 0.03, OR = 2.2, 95% CI = 1.1–4.5). No associations were observed between TGFβ-1 or COX2 genotypes and PE or GH. Associations between neonatal IL-6 G, which confers high placental IL-6 expression, and PE suggest a possible mechanism by which PE is a pro-inflammatory exacerbation of placental origin. Since placental IL-10 is important for maternal tolerance of the fetus, genotypes predisposing to low IL-10 expression in the neonate which associate with both PE and GH, suggest a role for decreased placental IL-10 in these disorders.

Fate of E. coli across mechanical dewatering processes

Five UK sludge treatment plants have been monitored for Escherichia coli (E.coli) variation after mechanical belt press and centrifuge dewatering processes. A complementary laboratory trial was also completed to examine the effects of varying centrifugal force on raw sludge E.coli content. An E.coli balance between the numbers contained in the flows entering and exiting four full scale centrifuge dewatering systems indicated a minimum 63 % increase in E.coli numbers between the input feed and sludge cake for a digested sludge input to the centrifuge. For two of the centrifuge sites this increase was statistically significant and corresponded to an increase in E.coli concentration ranging up to 1.4 Log after centrifugation. However, E.coli variation was found to be dependent on the type of sludge, as centrifuge dewatering of raw sludge at full scale resulted in a 40 % decrease in E.coli numbers. The complementary laboratory centrifuge work confirmed that E.coli numbers decreased in raw sludge after centrifugation. E.coli numbers were not observed to increase in digested sludge which had been dewatered using a belt press. A decrease of 44 % was observed.

Proteinuria after burn injury

Qualitative and quantitative aspects of the excretion of protein after burn injury have been investigated. The excretion of total protein and of albumin have been measured nephelometrically while the excretion of proteins of both serum and non-serum origin have been measured by immunoelectrophoresis using antiserum against serum proteins or against a pool of urine from burned patients. Comparison of the patterns of proteins observed in urine using these two different antisera showed the presence of at least three major proteins that did not originate from the plasma. The excretion of two of these three proteins followed closely the pattern of total protein excretion which reached a maximum at five to seven days after injury. The excretion of albumin was greatest in the first 48 hours after injury. Examination of the original burn patients' urine antigen by sodium dodecyl sulphate polyacrylamide gel electrophoresis showed that this urine pool contained greater amounts of lower molecular weight proteins than were observed in a pool of normal urines. The observations suggest that a biphasic renal pathophysiology is observed after burn injury. Initially, there develops a mild transient glomerular lesion which progresses to a different state which shows at least some of the features of a tubular proteinuria.