Mammalian cells can initiate intracellular signalling pathways that activate pro-survival changes to maintain their integrity following their exposure to a range of extracellular stresses. One group of changes preserves cellular integrity through the regulation of cytoskeletal organization. Despite the recognised importance of maintaining microtubule (MT) networks, the specific mechanisms regulating cytoskeleton organisation in response to stress remain relatively poorly explored. Among the numerous proteins that regulate MT organisation, stathmin (STMN) is a key MT destabilising protein that regulates MT disassembly through its ability to bind tubulin dimers. The actions of STMN can be regulated by a number of growth factor-activated and cell cycle regulatory protein kinases. In preliminary work, our studies suggest the potential regulation of STMN by c-Jun N-terminal Kinase (JNK) in cells exposed to stress. Specifically, we observed changes in STMN phosphorylation which were coordinated with JNK activation. / This project has explored the contribution of stress-activated c-Jun N-terminal Kinase (JNK) to STMN phosphorylation observed during osmotic stress. More detailed in vitro biochemical analysis has revealed that JNK directly phosphorylates STMN. In addition, we have compared STMN phosphorylation by different MAPK family member. In particular, our results illustrated that JNK predominantly phosphorylate STMN on serine residue 38 (S38) whereas ERK most likely targeted STMN S25. By examining specifically the phosphorylation of the four regulatory serine residues in vitro, we proposed a model of hierarchical phosphorylation among STMN serine residues. Specifically, our results demonstrated that phosphorylation of S38 was a pre-requisite for S25 phosphorylation by JNK in vitro. Furthermore, our results also demonstrated the impacts of JNK binding domain (JBD) and tubulin on STMN phosphorylation in vitro. Overall, this project identified STMN as a novel JNK substrate. The results have broadened our understanding on the JNK-mediated STMN phosphorylation as the first step to provide deeper insights into the different functions of JNK in the mammalian stress response.

Thesis (doctoral)--University of Helsinki, 2007. / Includes bibliographical references. Also available on the World Wide Web.

The Hippo pathway is a cell signaling pathway involved in organ size regulation and tumorigenesis in mammals. This pathway regulates the activity of Yes-associated protein (YAP), a transcriptional coactivator which binds to the transcription factor TEAD to promote expression of genes controlling growth and proliferation of tissues, as well as inhibition of apoptosis. The Hippo pathway has recently been implicated as a pathogenic mechanism in neurodegenerative disorders. Specifically, mammalian sterile 20 (Ste20)-like kinase 1 (MST1), a protein kinase in the Hippo pathway, has been found to promote neuronal death under conditions of oxidative stress. Moreover, homozygous deletion of MST1 in a mouse model of Amyotrophic Lateral Sclerosis (ALS) significantly delayed onset of neurodegenerative symptoms. We examined the expression levels of key Hippo pathway components in cortex, lumbar spinal cord, and gastrocnemius muscle samples of male and female G39A SOD1 mice using western blots. Our results revealed a significant increase in phosphorylated MST1 (pMST1) in lumbar spinal cord of presymptomatic transgenic animals, and found this increase to be sex and gene copy number dependent. These results suggest that the Hippo pathway is dysregulated in the SOD1 mouse model and that MST1 may play a critical role in pathogenesis and disease progression in ALS.

Toll-like receptors (TLR) are a family of pattern recognition receptors crucial for pathogen pattern recognition. Upon activation, TLRs induce innate immune responses such as cytokine production. However irregular TLR activities can provide fatal, hence fine tuning of the TLR induced responses are necessary. The TLR mediated immune responses are controlled by the positive/negative regulation of TLR signalling pathways, relocation of TLR proteins and modulation of TLR transcription. Systematic analyses of the agonist-induced transcriptional changes of TLRs were shown for the first time in my thesis. In my experiments, I have shown that each agonist induced a unique pattern of TLR transcription. Following PAM stimulation, mRNA levels of the cognate TLR1/2 increased whereas mRNA levels of the cross-regulating TLR4, 7/8/9 reduced in both cell lines and splenic macrophages from different mice strains. Through investigation of the signalling pathways responsible for mediating such TLR transcriptional changes, I then discovered the balancing effect between NFÎoB and MAPK signalling pathways. PAM induced TLR transcriptional changes were controlled by the additive and/or antagonistic interference between MAPK signalling cascades, ERK, JNK, P38 and NFÎoB signalling pathways. This was the first time that signalling synergy between MAPK and NFÎoB pathways were shown. Furthermore, PAM induced transcription of TLR1 and TLR8 may be partially regulated by the indirect feedback mediated by protein production. Importantly, the maintenance of the basal TLR mRNA expression also required activation of both MAPK and NFÎoB signalling pathways. In addition, signalling control for TLR transcription induced by different agonists (PAM vs. LPS) or in different species (chicken vs. mice) was compared. LPS induced transcriptional changes of the cross-regulating TLR1/2 and 3 but not the cognate TLR4 in RAW cells. The LPS induced TLR transcriptional changes required activation of a combination of MAPK and NFÎoB signalling pathways which shared both similarities and differences to the PAM induced signalling activation. In chicken, PAM induced more potent signalling activation, regulating the TLR transcriptional changes at a lower concentration than in mice. Overall, this thesis demonstrates that the transcriptional regulation of TLRs is complex, mediated by the coordination between MAPK and NFÎoB signalling pathways. These studies have significant implications in providing detailed insight of TLR transcriptional regulation which plays an important role in the regulation of TLR mediated innate immune responses. Please watch the following videos that I made for: A short introduction about TLR regulation - https://youtu.be/LTDdEZ3S97o A short explanation about TLR signalling - https://youtu.be/51IY5XhdJR8.

Background: Around a third of the general population experience insomnia at some point in their lives. A lack of good quality sleep can negatively impact upon daytime functioning, relationships and behaviour. Although the issues and management of prisoner's mental health has been assessed thoroughly across the prison literature, the importance of poor sleep prevalence, associated causes and its management has failed to be systematically examined. My systematic integrative review of the sleep-prison literature collated and synthesized the evidence, informing the overall study objectives and design. Aim: The overarching aim of this mixed-methods thesis was to produce a treatment pathway to help manage insomnia in a prison population, acceptable to both staff and prisoners. Study 1: A national survey and telephone interviews examining current insomnia management practice in England and Wales prisons. Eight-four prisons took part (73%). The most common interventions were medication and sleep hygiene education. Analysis of telephone interviews revealed four main themes, insomnia as a normal occurrence in prison; the problem of medication in prison; the negative impact of the prison environment; and effective management of insomnia in prison. Study 2: A cross-sectional study looking at prevalence and associated factors of insomnia in male and female prisons was conducted. Two hundred and thirty seven prisoners completed a questionnaire battery. Around two-thirds had insomnia disorder and clinical, environmental and situational factors were much more likely in this group than those without insomnia. Study 3: Semi-structured interviews were conducted with staff and prisoners to explore perspectives of insomnia management. Three themes were found: value of good sleep, barriers and considerations for good sleep management and future direction of insomnia management in prison. Study 4: A modified Delphi consensus study was conducted with academic sleep researchers, prison staff and service users over three rounds of consultation. Consensus was achieved and a stepped-care treatment pathway was produced. Conclusion: When used in future practice, the treatment pathway should help practitioners to identify, assess and manage insomnia in a population that is twice as likely to experience insomnia as the general population.

The aim of this thesis was to investigate genes involved in the late steps of the Cytosolic Iron sulfur cluster Assembly (CIA) pathway in procyclic T. brucei, to determine their cellular localization and find their possible interaction partners and substrates.

This thesis is devoted to the evolution of the heme biosynthetic pathway in eukaryotic phototrophs with particular emphasis on algae possessing secondary and tertiary red and green derived plastids. Based on molecular biology and bioinformatics approaches it explores the diversity and similarities in heme biosynthesis among different algae. The core study of this thesis describes the heme biosynthesis in Bigelowiella natans and Guillardia theta, algae containing a remnant endosymbiont nucleus within their plastids, in dinoflagellates containing tertiary endosymbionts derived from diatoms called dinotoms, and in Lepidodinium chlorophorum, a dinoflagellate containing a secondary green plastid. The thesis further focusses on new insights in the heme biosynthetic pathway and general origin of the genes in chromerids the group of free-living algae closely related to apicomplexan parasites.

Cultivation of a model cyanobacterium Synechocystis PCC 6803 under low light conditions in the presence of glucose and TES buffer leads to a change of the medium color from colorless to yellow. The absorption spectrum of the excreted unknown compound indicated a possible relationship to plant chlorophyll degradation products. To confirm this speculation the compound was purified by a combination of solid phase extraction and HPLC. The mass and NMR characteristics excluded its close relationship to modified tetrapyrroles, nevertheless the precise structure could not be determined by these means due to a complicated nature of the compound and its high polarity.

Abstract The mammalian metanephric kidney develops through ureteric bud branching morphogenesis and tubule formation and involves secreted inductive signals and possibly their antagonists to regulate the process. Sprouty (spry) genes encode antagonists of FGFs and the EGF signalling pathways. To get an insight to potential developmental roles of the spry genes, the expression of spry1, 2 and 4 was analyzed in developing kidney. Spry1 is expressed in the ureteric bud, and spry2 and 4 in the ureteric bud, the kidney mesenchyme and the nephrons deriving from it suggesting developmental roles for the sprys in kidney development. Spry function was addressed in vivo in the kidney by targeting hspry2 expression to the ureteric bud with a Pax2 promoter. Hspry2 expression led to development of small, ectopic and cystic kidneys. Ureter branching was reduced and there was less glomeruli in a smaller kidney compared to the wild type controls. Spry2 may antagonize signalling of FGF2 and lead to changes in FGFR1 and FGFR3 expression. In organ culture ectopic FGFs restored ureteric branching of the hSpry2 transgenic kidneys suggesting that hSpry2 may antagonize FGF signalling in embryonic kidney. In addition to changes in FGFs, hspry2 expression also lead to downregulation of GDNF and BMP4. We conclude that the Sprouty-FGFs-FGFR signaling is important for kidney development. Wnt2b is a recently identified member of the Wnt family of secreted growth factors, but its function in organogenesis is unknown. In the kidney Wnt2b is localized to the perinephric mesenchymal cells at the initiation of organogenesis. Wnt2b signalling supported ureteric bud growth and branching in vitro. Ureteric bud that was co-cultured with Wnt2b expressive cells or incubated with a known Wnt pathway regulator lithium, and then recombined with isolated kidney mesenchyme led to recovery of the expression of some ureteric epithelial marker genes and reconstitution of early kidney development. Hence, Wnt2b signalling is critical for induction of ureteric branching in vitro. Type XVIII collagen is a matrix molecule and may be involved in Wnt signalling. Roles of type XVIII collagen in kidney and lung organogenesis was analysed. Type XVIII collagen expression correlated with the differences in epithelial branching in both of these organs and its expression in the epithelial tissue was mutually exclusive. In recombinants of ureteric bud and lung mesenchyme, type XVIII collagen expression pattern shifted from kidney to lung type and was accompanied by a shift in epithelial Sonic Hedgehog (Shh) expression and by ectopic lung Surfactant Protein C in the ureteric bud. Blocking of type XVIII collagen function prevented ureteric development with lung mesenchyme and associated with reduction in the expression of Wnt2. Taken together, the findings suggest critical roles for Sprouty2, Wnt2b and type XVIII collagen in controlling pattern formation and the mode of ureteric bud branching in the embryonic kidney.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13384号 / 論医博第2216号 / 新制||医||1048(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 高橋 淳, 教授 渡邊 直樹, 教授 中川 一路 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM