Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 6 uppsatser.

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS). Neuropathological studies in both human MS and the experimental autoimmune encephalomyelitis (EAE) animal model have shown that endothelial cell (EC) inflammation, associated with focal breakdown of the blood-brain barrier (BBB) and neo-angiogenesis, is prevalent in demyelinating plaques. Neo-angiogenesis and BBB damage contribute to leakage of serum components, infiltration of immune cells into the CNS, neuroinflammation, axonal demyelination, neuronal dysfunction, and disease progression. In Chapter 1, I introduce MS and its pathological hallmarks related to immune and vascular dysfunctions, the clinical course of MS progression, genetic and environmental influences, current treatments, and animal models. Next, I elaborate upon the pathways and processes involved in the development of a functioning CNS vascular system and the BBB. Finally, I discuss what is currently known about the contribution and the underlying mechanisms of neo-angiogenesis in MS and other diseases. While an increase in vessel density has been documented for both MS and EAE lesions, the origin and pathways that drive formation of new, but leaky, blood vessels in EAE are poorly understood. In Chapter 3, I address these questions by performing single-cell RNA-sequencing (scRNA-seq) of 45309 ECs isolated from the spinal cord of control, acute and chronic MOG35-55 EAE mice. Based on expression patterns of blood vessel subtype-specific markers, I identified 23 distinct EC clusters with arterial, capillary, venule, and vein identities in either control or disease states. I performed differential gene expression and gene set enrichment analyses comparing control and disease EC clusters for each vascular subtype to identify which vessels exhibited gene expression profiles indicative of neo-angiogenesis in EAE. I found that molecular signatures of neo-angiogenesis are upregulated specifically in venous ECs during acute and, to a lesser extent, chronic EAE. Consistent with these data, EC proliferation is upregulated in veins in the EAE spinal cord. RNA fluorescent in situ hybridization and immunofluorescence staining confirmed increased expression of key angiogenic markers Egfl7, Ecm1, Serpine1 and Emcn, and the tip cell marker Mcam, with a corresponding increase in vein density, in demyelinating white matter lesions of EAE spinal cords relative to controls. I also assessed changes in expression of some of these markers in human MS tissue and discovered upregulated expression of EGFL7 in cortical white matter lesions of MS patients, concomitant with increased vascular density. In Chapter 4, I examine the signaling pathways that may trigger pathogenic angiogenesis in EAE. I discovered that, in contrast to developmental angiogenesis, VEGF-A and TGF-β signaling may act as the driver of neo-angiogenesis in EAE. To test this hypothesis, I used a humanized VEGF-A blocking antibody, bevacizumab, to block VEGF signaling and found that this treatment ameliorated the MOG35-55 EAE neurological score by reducing expression of several angiogenic markers Egfl7, Ecm1, Serpine1, and Emcn, as confirmed by both in situ hybridization and computational analysis of scRNA-seq data. Immune profiling of spleens and spinal cords by flow cytometry did not show changes in immune cell activation in bevacizumab-treated mice relative to IgG controls, indicating that the protective effects of VEGF blockade are not due to defects in the initiation of the immune response. Finally, in Chapter 5, I summarize the major findings of my dissertation and propose a model for the mechanisms by which neo-angiogenesis contributes to pathology in MS/EAE. I also present several future avenues of research that can be pursued to further our understanding of the molecular and cellular changes underlying pathogenic angiogenesis and its role in MS/EAE. While most current disease-modifying MS therapies aim to reduce inflammation and infiltration of immune cells into the CNS, these findings may lead to development of additional potential therapeutics that may reduce pathogenic neo-angiogenesis in order to alleviate long-term neurological deficits in MS. Additionally, since postcapillary venules and veins are the major sites of immune cell infiltration, BBB damage and neo-angiogenesis in EAE, the findings of this study suggest that development of treatment modalities that target venous ECs with anti-angiogenic compounds may be more effective in inhibiting the growth of pathogenic neovessels than therapies directed against the entire endothelium.

Thesis (PhD)--Stellenbosch University, 2001 / ENGLISH ABSTRACT: The eye is that biological instrument which conveys the light of the external world into the inner world of the mind, wherein we receive the miraculous gift of vision. So precious is this gift, that Science must search for ways to keep this portal clear for the flow of light. Indeed, Science is called upon to “make war upon the bloody tyrant, Time.” (Shakespeare W. Sonnet No. 16). For, in the course of ageing, the lens grows cloudy and cataractous. In this battle between Science and Time, we are fortunate to live in an era in which Science is uncovering the molecular basis for the various obstacles to vision. The question arises, whether or not, the ruinous hand of time can be stayed. Due to unrelenting, progressive lens opacification, most of the elderly are destined to be subjected to loss of vision and with passage of time, even blindness. Globally the cataract surgery rate is inadequate to keep pace with the ever growing demand on financial and human resources created by the cataract problem. An immense challenge therefore is directed to primary eye care: “Can cataract be prevented or can its onset at least be postponed?” This laudable ultimate aim can only be achieved once the etiology of cataractogenesis is well understood. This dissertation seeks to examine two previously unrecognized etiological aspects that, if correctly understood and managed, have the potential to achieve preventive ophthalmological goals that may indeed help to stay the ‘ruinous hand of time’. The first aspect deals with the role of lipids and was examined using a study group of dyslipidemic subjects. The first part of the study concluded that dyslipidemic patients develop cortical lens opacities more frequently and at an earlier age than the normal population, and that cortical lens opacities should be regarded as one of the most reliable clinical signs of dyslipidemia. Furthermore, an extremely strong correlation was found to exist between low HDL Cholesterol levels and the development of opacities. Below a HDL-Cholesterol level of 1,5mmol/l, subjects had more than seven-fold higher risk of falling in the lens opacity subgroup than those with HDLCholesterol levels above 1,5mmol/l. An equally strong correlation was demonstrated between high (>5) LDLHDL ratios and the development of lens opacities. Subjects with a LDL:HDL-C ratio below 5 possessed a 2.35 times greater risk of having lenticular opacities than the group with a LDL:HDL-C ratio greater than 5. The prevention or retardation of dyslipidemia associated lens opacities is therefore possible, provided patients with a genetic predisposition are detected early and their blood lipids managed adequately. The second aspect deals with the relationship between age related cataracts and the acetylation status of the individual. This study compellingly submits that the slow acetylator pheno- and genotype may be regarded as a genetic indicator of risk for age related cataract. The ability accurately to classify a patient genotypically and phenotypically, may henceforth be useful in health counseling since, if an individual is identified as being a slow acetylator, additional preventative and precautionary measures may be taken, i.e. the prevention of UVexposure to the eye and caution with the ingestion of xenobiotics like caffeine, commercial dyes, food preservatives, and drugs. Furthermore, such a finding should be taken into account in the long term therapeutic management of glaucoma, with special regard to carbonic anhydrase inhibitors which are sulphonamide-related drugs and totally dependent on the N-acetyltransferase pathway for metabolism. These drugs may accumulate in the slow acetylator over time and exert toxic effects intra-ocularly, conceivably including cataractogenesis. The search for genetic and metabolic mechanisms that may contribute to human cataractogenesis should be pursued with great enthusiasm. This endeavour may help Science to achieve its primary objective, ablate the effects of Time and really aid in preventing cataracts in man. / AFRIKAANSE OPSOMMING: Die wondergawe van visie word vir ons moontlik gemaak deur die oog wat as biologiese instrument die lig van die buitewereld inlaat na die binnewereld van die brein. So kosbaar is hierdie gawe dat die Wetenskap deurgaans moet poog om die poort oop te hou. Inteendeel, die Wetenskap word gemaan deur Shakespeare in sy Sonnet nommer 16 om “oorlog te maak teen die bloeddorstige tiran, Tyd”. Soos ‘n mens ouer word, word die lens dof en ‘n katarak mag vorm. Ten spyte van hierdie stryd tussen ‘Wetenskap’ en ‘Tyd’ leef ons in die gelukkige era waarin die Wetenskap meer en meer leer van die verskeie obstruksies tot visie. Die vraag ontstaan of die rinnewerende hand van ‘Tyd’ gestuit sal kan word. Vanwee ongenaakbare, progressiewe lensvertroebeling is die meeste bejaardes bestem om aan visie verlies, en met verloop van tyd selfs blindheid, te ly. Die wereldwye katarakchirurgie tempo is nie voldoende om by te hou by die immergroeiende finansiele en mannekrag eise wat deur die katarak probleem gestel word nie. Daar word dus ‘n reuse uitdaging aan primere oogsorg gestel naamlik: “Kan katarakte nie eerder voorkom of die aanvang daarvan ten minste uitgestel word nie?” Hierdie prysenswaardige doelwit kan nie bereik word alvorens die etiologie van kataraktogenese goed verstaan word nie. Hierdie tesis ondersoek twee voorheen onerkende etiologiese aspekte wat, indien hulle korrek verstaan en hanteer word, beslis die potensiaal het om die gemelde voorkomende doelwitte te bereik en sekerlik te kan bydrae om die rinnewerende hand van Tyd te stuit. Die eerste aspek spreek die rol van lipiede aan deur te kyk na 'n studiegroep van dislipidemiese persone. Die eerste deel van die studie kom tot die gevolgtrekking dat dislipidemiese pasiente kortikale lens opasiteite meer dikwels en op ‘n vroeer ouderdom ontwikkel as die normale populasie en dat sulke opasiteite beskou moet word as een van die mees betroubare kliniese tekens van dislipidemie. Daar is ook ‘n baie sterk korrelasie gevind tussen lae HDL cholesterol vlakke en die voorkoms van opasiteite. Persone in die studie met ‘n HDL cholesterol vlak laer as 1,5mmol/l het ‘n sewe keer hoer kans gehad om in die lensopasiteit subgroep te val as die met ‘n HDL cholesterol vlak laer as 1,5mmol/l. ‘n Sterk korrelasie tussen ‘n hoe (>5) LDLHDL verhouding en die voorkoms van lens opasiteite is ook gevind. Persone met ‘n LDLHDL verhouding >5 het ‘n 2.35 maal groter risiko gehad om lensopasiteite te he as die met ‘n LDL:HDL verhouding van <5. Die voorkoming of vertraging van dislipiedemie geassosieerde lens opasiteite is dus moontlik, solank persone met ‘n genetiese geneigdheid daartoe vroeg ontdek en hulle bloedlipiede voldoende beheer word. Die tweede deel van die tesis handel oor die verhouding tussen ouderdoms verwante katarakte en die asetilasie status van die individu. Met oortuiging kom hierdie studie tot die gevolgtrekking dat die stadige asetilator fenoen genotipe as 'n genetiese merker vir ouderdoms verwante katarakte beskou moet word. Die vermoe om ‘n individu beide genotipies en fenotipies akkuraat te klassifiseer mag voorts bruikbaar wees in gesondheidsraadgewing. Indien ‘n individu geTdentifiseer is as ‘n stadige asetileerder, kan addisionele voorsorg maatreels getref word soos bv. die voorkoming van blootstelling van die oog aan UV lig sowel as omsigtigheid met die inname van xenobiotika soos kaffei'ene, kleurstowwe, voedsel preserveermiddels en geneesmiddels. Hierdie bevinding moet ook in berekening gebring word in die langtermyn terapeutiese hantering van gloukoom. Die koolsuuranhidrase inhibitore, dikwels gebruik in die behandeling van gloukoom, is sulfonamied-agtige middels en dus totaal afhanklik van die N-asetieltransferase pad vir hulle metabolisme. Hierdie middels kan ophoop in die stadige asetileerder en gegewe genoeg tyd, bes moontlik toksiese intra-okulere effekte tot gevolg he. Die soeke na genetiese en metaboliese meganismes wat mag bydra tot menslike kataraktogenese behoort nagestreef te word met groot entoesiasme. Hierdie strewe mag dalk net vir die 'Wetenskap' bystaan om sy primere mikpunt te bereik, die effek van ‘Tyd’ te neutraliseer en te help om katarakte werklik te voorkom.

This thesis is broken into four chapters. The first two chapters summarize two separate lines of investigation into the role of a putative neurotoxin in the pathogenesis of Huntington's Disease (HD). The third chapter outlines an investigation of the putative role of beta-N-methylamino-L-alanine (BMAA) in the pathogenesis of amyotrophic lateral sclerosis (ALS), while the final chapter details a post-mortem investigation of the contents of biogenic amines and amino acids in the brain of a man who died of a familial form of parkinsonism. Chapter I is a description of a chromatographic technique developed to isolate quinolinic acid (QA), an endogenous compound implicated in the pathogenesis of HD, from deproteinized human sera. A cation exchange column was used to selectively isolate QA, which was eluted with 10 mM HCl. The eluted fractions were analyzed by UV spectrometry to isolate and quantify QA. Once the fractions corresponding the elution of authentic QA were isolated, concentrated and the excess HCl removed, the fractions were added to growing fetal rat striatal explant cultures as an assay of neurotoxicity. Since HD involves the selective degeneration of GABAergic neurons in the striatum, the activity of glutamic acid decarboxylase, the final enzyme in the synthesis of GABA, was used to determine the viability of the cultures. Unfortunately, the method was confounded by the contamination of all effluents by compounds originating from the cation exchange resin, which were discovered to be neurotoxic to the striatal cultures, and as a result the investigation had to be abandoned. Chapter II describes an investigation designed to further characterize the nature of neurotoxicity observed in the sera obtained from patients with HD (Perry et al. 1987). Compounds with the capacity to selectively stimulate neurons at the N-methyl-D-aspartate (NMDA) receptor have been implicated in a variety of neurodegenerative disorders, including HD. Selective antagonists at the NMDA receptor have been shown to protect neurons from the degenerative effects of such "excitotoxins". The investigation described used MK-801, a potent noncompetitive NMDA antagonist, in an attempt to protect fetal rat striatal cultures from the neurodegenerative effects of the sera obtained from HD patients. The results obtained were equivocal. No evidence was obtained to support a role of the NMDA receptor in the mediation of the neurotoxicity, and in addition the neurodegenerative effects of HD sera were not reproduced in the present investigation. A variety of possible explanations for the apparent discrepancy are suggested. Chapter III describes an experiment intended to produce an animal model of ALS based on the observations by Spencer et al. 1987 that chronic oral administration of BMAA in monkeys produced the histological and behavioural characteristics of this disease. In the present investigation synthetic D,L-BMAA was given by gavage to mice over an eleven week period. Since BMAA is known to act at the NMDA receptor, a subset of the mice were also given MK-801 in an effort to protect them from any deleterious effects based on the action of BMAA at this receptor. The animals were sacrificed at the end of the experiment, and biochemical analyses were performed on the striata and cortices of the animals. In addition, neuropathological studies were performed on the spinal cords, basal ganglia and related structures. The results indicated no biochemical or neuropathological abnormality as a result of BMAA administration. Chapter IV describes a post-mortem investigation of a man who was a member of a well described pedigree which carries an autosomal dominant form of parkinsonism. The object of the investigation was to determine post-mortem levels of dopamine, noradrenaline, serotonin and their metabolites, in addition to amino acids in various regions of brain. Although conflicting evidence was obtained during life, neuropathological findings and the present neurochemical analyses confirm the degeneration of the nigrostriatal dopaminergic tract, characteristic of parkinsonism, in this man. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

High-voltage activated calcium channels underlie many critical functions in excitable cells and their dysfunction has been implicated in a myriad of cardiovascular and neurological diseases. These channels are multimeric protein complexes composed of α1, β, and α2δ subunits; currently, all calcium channel blockers target either the pore-forming α1 or extracellular-facing α2δ auxiliary subunit. These pharmacological agents have been invaluable in delineating the individual function of each subunit within excitable cells that express multiple calcium channels. Yet, no current tool allows similar pharmacological dissection of individual cytosolic β subunits, preventing our understanding of how distinct β subunits affect the function of calcium channel complexes. Further, small-molecule calcium channel blockers are highly-valued therapeutics for certain conditions, yet their propensity for off-target effects precludes their use in other diseases. In certain applications, genetically-encoded calcium channel blockers may enable channel inhibition with greater tissue-precision and versatility than is achievable with small molecules. Previous work that found the family of RGK proteins powerfully inhibits high-voltage activated calcium channels in part via an association with the β subunit. However, the myriad functions of RGK proteins limit the utility of this approach. In this work, we circumvent this issue by isolating single-domain antibodies (nanobodies) that target the auxiliary CaVβ subunit. We then paired these nanobodies with the powerful enzymatic activity of the HECT domain E3 ubiquitin ligase Nedd4L, to selectively target the calcium channel for ubiquitination. We found this strategy effectively eliminated functional calcium channels from the surface of HEK293 cells, myocytes, and DRG neurons. This modular design permitted us to characterize a pan-β inhibitor (CaV-aβlator) in chapter 2 while refining the approach with a β1-selective channel inhibitor in chapter 3. In chapter 4 I demonstrate that it is possible to hijack the endogenous ubiquitin machinery of the cell by creating Divas: divalent nanobodies that are capable of recruiting endogenous Nedd4L to regulate the calcium channel. Finally, we demonstrate the potential for these genetically-encoded calcium inhibitors to be employed as therapeutic agents by targeting CaV-aβlator to sensory neurons in order to reduce the onset of neuropathic pain. Altogether, this work lays the foundation for nanobody-based genetically-encoded calcium channel inhibitors that have the potential to achieve superior precision in regards to molecular and tissue specificity.

The purpose of this study was to determine the prevalence of known etiological factors in mildly mentally handicapped students across minority and nonminority groups and to examine the similarities of these patterns. A comparison of early diagnoses was also made. The total population of all children labeled Educable Mentally Handicapped (EMH) and attending regular elementary schools within one of the largest districts in the southwest served as the sample for the present study. There were 128 children, 64 minorities and 64 nonminorities. The student records were reviewed for data regarding etiological factors, previous diagnoses and early medical factors. A pilot study which involved administering a questionnaire to a sample to twenty-eight social workers was conducted to ascertain the validity of obtained data. Eight specific hypotheses were addressed. A Chi-Square analysis yielded information about the patterns of category similarities (congenital, prenatal, perinatal, postnatal and familial), between two groups as well as the presence of professional diagnosis. A set of five factorial analysis of variance were performed to examine the impact of age, number of symptoms, presence of professional diagnosis and length of hospital stay on IQ scores of children in both groups. A discriminant function analysis was performed to determine the discriminatory power of four variables (IQ, length of hospital stay, number of symptoms and presence of professional diagnosis). The prevalence of perinatal and postnatal symptoms and diagnoses occurred with high frequency for both groups. Congenital factors occurred significantly more for the nonminority group. The findings indicated that there were no significant differences across minority and nonminority groups in terms of intellectual functioning due to the impact of the four previously mentioned variables. Consistent with the ANOVA results, the information obtained from the discriminant function analysis suggests similarity of the two groups in terms of the four variables. The results were discussed in relation to the utility of early etiological information and the importance of such research. The implications of such findings for placement of children in general in these classes or for the children from minority groups in particular, were emphasized.

published_or_final_version / Pharmacology and Pharmacy / Doctoral / Doctor of Philosophy

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.

Diisocyanates are very reactive low molecular weight chemicals that are widely used in the manufacture of polyurethane products. Diisocyanate exposure is one of the most commonly reported causes of occupational asthma. Although diisocyanates have been identified as causative agents of respiratory diseases, the specific mechanisms by which these diseases occur remain largely unknown. Tandem mass spectrometry was used to unambiguously identify the binding site of isocyanates within four model peptides (Leu-enkephalin (Leu-enk, YGGFL), Angiotensin I (DRVYIHPFHL), Substance P-amide (RPKPQQFFGLM-NH2), and Fibronectin-adhesion promoting peptide (FAPP, WQPPRARI)). In each case, isocyanates were observed to react to the N-terminus of the peptide. No evidence of side chain/isocyanate adduct formation exclusive of the N-terminus was observed. However, significant intra-molecular diisocyanate crosslinking between the N-terminal amine and a side chain amine group was observed for arginine, when located within two residues of the N-terminus. Addition of multiple isocyanates to the peptide occurs via polymerization at the N-terminus, rather than addition of multiple isocyanate molecules to varied residues within the peptide. Toluene diisocyanate (TDI)-specific monoclonal antibodies (mAbs) with potential use in immunoassays for exposure and biomarker assessments were produced. A total of 59 unique mAbs were produced (29 IgG1, 14 IgG2a, 4 IgG2b, 2 IgG3 and 10 IgM) against 2,4 and 2,6 TDI bound protein. The reactivities of these mAbs were characterized by a solid phase indirect enzyme-linked immunosorbent assay (ELISA), Dot ELISA and Western immunoblot against various monoisocyanate, diisocyanate and dithioisocyanate protein conjugates. A subset of the mAbs were specific for 2,4 or 2,6 TDI-conjugated proteins only while others reacted to multiple dNCO conjugates including methylene diphenyl diisocyanate- and hexamethelene diisocyanate- human serum albumin . Western blot analyses demonstrated that some TDI conjugates form inter- and intra-molecular links resulting in multimers and a change in the electrophoretic mobility of the conjugate. In general, 2,4/2,6 TDI reactive mAbs displayed (1) stronger recognition of monoisocyanate haptenated proteins when the isocyanate was in the ortho position relative to the tolyl group, and were able to discriminate between (2) isocyanate and isothiocyanate conjugates (i.e. between the urea and thiourea linkage); and (3) between aromatic and aliphatic diisocyanates. The mAbs produced were not carrier protein specific with estimated affinity constants toward toluene diisocyanate conjugated human serum albumin ranging from 2.21 x 107 to 1.07 x 1010 M-1 for IgG mAbs. Studies using TDI vapor exposed lung and epithelial cell lines suggest potential utility of these mAbs for both research and biomonitoring of isocyanate exposure.

目的： 转化生长因子－1（TGF-β1）通过与II型受体结合而引起I型受体活化，进一步激活其下游信号分子蛋白Smad2 和Smad3，它们与Smad4（Co-Smad）结合后形成Smad复合体并发生核转移，从而发挥广泛的生物学效应。同时，整个TGF-β信号通路又受到其抑制因子Smad7的负反馈调节。研究结果显示Smad3是肾脏炎症和纤维化中重要的致病分子，相反，Smad7在多种肾脏疾病中起保护作用。然而，由于转化生长因子II型受体（TβRII），Smad2 或Smad4基因敲除的小鼠无法存活，这些分子在TGF-β1介导的肾脏炎症和纤维化中的功能尚未见报道。因此，本研究旨在剖析TβRII、Smad2 和Smad4 在肾脏疾病发生发展中的作用及机制。 / 方法：本研究利用Cre/LoxP系统分别靶向敲除小鼠肾小管上皮细胞的TβRII、Smad2 或者Smad4，通过结扎小鼠单侧输尿管建立梗阻性肾病模型，观察这些分子对肾脏炎症和纤维化的影响，并用体外实验进行验证。具体实验结果请参见本论文第III,IV, V章。 / 结果：通过分析，本论文取得以下新的发现： / (1) TβRII在TGF-β1介导的肾脏炎症和纤维化的双向调节中起到了决定性的作用：研究结果显示条件性敲除TβRII明显抑制TGF-β/Smad3介导的肾脏纤维化，同时增强NF-κB引起的肾脏炎症反应。由此可见，TRII不仅仅是TGF-β/Smad信号通路的启动因子，更决定了TGF-β1对肾脏炎症和纤维化的双向性调节。(参见第III章) / (2)尽管Smad2和Smad3结构相似并共同介导了TGF-β1的生物学效应，本研究意外发现Smad2可反向调节Smad3引起的纤维化。体内和体外实验共同证实，敲除Smad2基因增强了Smad3的磷酸化，核转位及其转录子活性，并能促进Smad3与I型胶原转录子的结合，进而加重肾脏纤维化（参见第IV章）。 / (3)我们还发现Smad4不仅作为TGF-β/Smad信号通路的共有蛋白，它在TGF-β1介导肾脏炎症和纤维化中起到了重要的双向性调节作用：条件敲除Smad4显著降低了Smad7对NF-κB介导肾脏炎症的抑制作用，同时在转录水平（而非磷酸化水平）抑制Smad3的功能，从而减轻纤维化。（参见第V章） / 结论：TβRII和Smad4 在TGF-β1介导肾脏炎症和纤维化中起到了重要的双向性作用；Smad2通过抑制Smad3信号传导和功能，在肾脏纤维化中起保护作用。 / Objectives: TGF-β1 binds its receptor II (TβRII) and then activates receptor I to initiate the downstream Smad signaling, called Smad2 and Smad3 which bind a common Smad4 to form the Smad complex and then translocate to nucleus to exert its biological activities. This process is negatively regulated by an inhibitory Smad7. While the pathogenic role of Smad3 and the protective role of Smad7 in renal fibrosis and inflammation are clearly understood, the functional role of TβRII, Smad2 and Smad4 in kidney diseases remains largely unexplored due to the lethality of these knockout mice. Therefore, the aim of present study is to dissect the functional role of these TGF-β/Smad signaling molecules in renal inflammation and fibrosis. / Methods: Kidney conditional knockout (KO) mice for TβRII, Smad2 and Smad4 were generated by crossing the FloxFlox mice with the kidney specific promoter driven Cre (KspCre) mice, in which TβRII, Smad2 or Smad4 were specifically deleted from the kidney tubular epithelial cells (TEC) respectively. Then, a well-characterized progressive renal inflammation and fibrosis mouse model of Unilateral ureteral obstructive (UUO) nephropathy was induced in these conditional KO mice and the specific roles for TβRII, Smad2, and Smad4 in renal inflammation and fibrosis were investigated in vivo and in vitro as described in the Chapter III, IV and V of this thesis. / Results: There were several novel findings through this thesis: / 1. TGF-β1 signals through its TβRII to diversely regulate renal fibrosis and inflammation. We found that disrupted TRII suppressed Smad3-dependent renal fibrosis while enhancing NF-κB-driven renal inflammation. Thus, TβRII not only acts as a binding receptor for initiating the TGF-β signaling, but also determines the diverse role of TGF-β1 in inflammation and fibrosis, which was described in the Chapter III. / 2. As shown in the Chapter IV, an unexpected finding from this thesis was that although Smad2 and Smad3 were homologically similar and bound together in response to TGF-β1 stimulation, Smad2 counter-regulated Smad3-mediated renal fibrosis. This was evidenced by the findings that conditional deletion of Smad2 enhanced Smad3 signaling including phosphorylation, nuclear translocation, the Smad3 responsive promoter activity, and the binding of Smad3 to Col1A2 promoter. Thus, disrupted Smad2 from the kidney significantly enhanced Smad3-mediated renal fibrosis in the UUO kidney and in cultured TEC. / 3. Finally, we also showed that that Smad4 acted not only as a common Smad in TGF-β signaling, but exerted its regulatory role in determining the diverse role of TGF-β1 in renal inflammation and fibrosis. Disruption of Smad4 significantly enhanced renal inflammation by impairing inhibitory effect of Smad7 on NF-κB-driven renal inflammation. In contrast, disrupted Smad4 inhibited renal fibrosis by blocking Smad3 functional activity without influencing Smad3 signaling. Because deletion of Smad4 inhibited TGF-β1-induced Smad3 responsive promoter activity and the binding of Smad3 to the Col1A2 promoter without altering the phosphorylation and nuclear translocation of Smad3 (Chapter V). / Conclusions: TβRII and Smad4 may function as key regulators of TGF-β signaling and diversely regulate the renal inflammation and fibrosis. Smad2 plays a protective role in renal fibrosis by counter-regulating Smad3 signaling. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Meng, Xiaoming. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 202-231). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Declaration --- p.viii / Acknowledgement --- p.ix / Table of Contents --- p.xii / List of Abbreviations --- p.xxvii / List of Figures/Tables --- p.xxix / Chapter CHAPTER I --- INTRODUCTION --- p.1 / Chapter 1.1 --- TGF-β signaling pathway --- p.2 / Chapter 1.1.1 --- TGF-β superfamily --- p.2 / Chapter 1.1.2 --- TGF-β signaling transduction --- p.3 / Chapter 1.1.2.1 --- Smad-dependent TGF-β signaling --- p.4 / Chapter 1.1.2.2 --- Smad-independent TGF-β signaling --- p.10 / Chapter 1.2 --- Chronic Kideny disease (CKD) --- p.12 / Chapter 1.2.1 --- Epidemiology of CKD --- p.12 / Chapter 1.2.2 --- Pathophysiology of CKD --- p.12 / Chapter 1.3 --- TGF-β signaling in renal diseases --- p.13 / Chapter 1.3.1 --- Role of TGF-β1 in renal diseases --- p.13 / Chapter 1.3.2 --- Potential role of TβRII in renal diseases --- p.15 / Chapter 1.3.3 --- Potential role of Smad2 in renal diseases --- p.17 / Chapter 1.3.4 --- Potential role of Smad4 in renal diseases --- p.20 / Chapter 1.3.5 --- Role of Smad7 in renal diseases --- p.23 / Chapter 1.3.6 --- Role of Smad-independent TGF-β signaling in renal disease --- p.24 / Chapter CHAPTER II --- MATERIALS AND METHODS --- p.26 / Chapter 2.1 --- MATERIALS --- p.27 / Chapter 2.1.1 --- Reagents and Equipments --- p.27 / Chapter 2.1.1.1 --- General reagents and equipments for cell culture --- p.27 / Chapter 2.1.1.2 --- General reagents and equipments for real-time RT-PCR --- p.28 / Chapter 2.1.1.3 --- General reagents and equipments for Masson Trichrome Staining --- p.28 / Chapter 2.1.1.4 --- General reagents and equipments for Immunohistochemistry --- p.29 / Chapter 2.1.1.5 --- General reagents and equipments for Immunofluorescence --- p.29 / Chapter 2.1.1.6 --- General reagents and equipments for Western Blot --- p.29 / Chapter 2.1.1.7 --- General reagents and equipments for Promoter assay --- p.31 / Chapter 2.1.1.8 --- General reagents and equipments for ChIP assay --- p.32 / Chapter 2.1.2 --- Buffers --- p.32 / Chapter 2.1.2.1 --- Buffers for Immunohistochemistry --- p.32 / Chapter 2.1.2.2 --- Buffers for Western blot --- p.35 / Chapter 2.1.3 --- Sequences of Primers and siRNAs --- p.40 / Chapter 2.1.4 --- Antibodies --- p.42 / Chapter 2.2 --- METHODS --- p.44 / Chapter 2.2.1 --- Animal model of Unilateral Ureteral Obstruction (UUO) --- p.44 / Chapter 2.2.2 --- Cell culture --- p.44 / Chapter 2.2.2.1 --- NRK52E cell line --- p.44 / Chapter 2.2.2.2 --- Smad2 WT/KO mouse embryonic fibroblasts (MEFs) --- p.45 / Chapter 2.2.2.3 --- Primary culture of kidney fibroblasts --- p.45 / Chapter 2.2.2.4 --- Primary culture of peritoneal macrophages --- p.46 / Chapter 2.2.3 --- PAS staining --- p.47 / Chapter 2.2.3.1 --- Tissue Handling and Fixation --- p.47 / Chapter 2.2.3.2 --- Tissue embedding and sectioning --- p.47 / Chapter 2.2.3.3 --- Preparation of Paraffin Tissue Sections for PAS staining --- p.48 / Chapter 2.2.3.4 --- PAS staining --- p.48 / Chapter 2.2.4 --- Real-time RT-PCR --- p.48 / Chapter 2.2.4.1 --- Total RNA isolation --- p.48 / Chapter 2.2.4.2 --- Reverse Transcription --- p.49 / Chapter 2.2.4.3 --- Real-time PCR --- p.50 / Chapter 2.2.4.4 --- Analysis of Real-time PCR --- p.50 / Chapter 2.2.5 --- Masson Trichrome Staining --- p.51 / Chapter 2.2.6 --- Immunohistochemistry --- p.52 / Chapter 2.2.6.1 --- Preparation of Paraffin Tissue Sections for IHC --- p.52 / Chapter 2.2.6.2 --- Antigen-Antibody Reaction --- p.52 / Chapter 2.2.6.3 --- Signal Detection --- p.53 / Chapter 2.2.6.4 --- Semi-quantification of Immunohistochemistry --- p.53 / Chapter 2.2.7 --- Immunofluorescence --- p.54 / Chapter 2.2.8 --- Western blot analysis --- p.54 / Chapter 2.2.8.1 --- Protein preparation --- p.55 / Chapter 2.2.8.2 --- SDS-PAGE --- p.56 / Chapter 2.2.8.3 --- Transmembrane of protein --- p.56 / Chapter 2.2.8.4 --- Incubation of first and second antibody --- p.57 / Chapter 2.2.8.5 --- Signal capture and analysis --- p.57 / Chapter 2.2.8.6 --- Stripping --- p.57 / Chapter 2.2.9 --- Promoter assay --- p.58 / Chapter 2.2.10 --- ChIP assay --- p.61 / Chapter 2.2.11 --- Statistical analysis --- p.62 / Chapter CHAPTER III --- THE DIVERSE ROLE OF TGF-BETA RECEPTOR II IN RENAL INFLAMMATION AND FIBROSIS --- p.63 / Chapter 3.1 --- INTRODUCTION --- p.64 / Chapter 3.2 --- AIMS --- p.64 / Chapter 3.3 --- MATERIALS AND METHODS --- p.66 / Chapter 3.3.1 --- Generation and characterization of TβRII conditional Knockout mice --- p.66 / Chapter 3.3.2 --- Generation and characterization of TβRII disrupted tubular epithelial cell line (NRK52E) and kidney interstitial fibroblasts --- p.67 / Chapter 3.3.3 --- Animal model of Unilateral Ureteral Obstruction --- p.67 / Chapter 3.3.4 --- Cell culture --- p.67 / Chapter 3.3.5 --- Real-time RT-PCR --- p.68 / Chapter 3.3.6 --- Masson Trichrome Staining --- p.68 / Chapter 3.3.7 --- Immunohistochemistry --- p.68 / Chapter 3.3.8 --- PAS staining --- p.69 / Chapter 3.3.9 --- Immunofluorescence --- p.69 / Chapter 3.3.10 --- Western blot analysis --- p.70 / Chapter 3.3.11 --- Promoter assay --- p.70 / Chapter 3.3.12 --- Statistical analysis --- p.70 / Chapter 3.4 --- RESULTS --- p.71 / Chapter 3.4.1 --- Characterization of TβRII conditional Knockout mice and TβRII disrupted cells --- p.71 / Chapter 3.4.2 --- Disruption of TβRII suppresses renal interstitial damage in the UUO kidney --- p.72 / Chapter 3.4.3 --- Disruption of TβRII suppresses renal fibrosis in UUO kidney and TGF-β1-induced fibrotic response in vitro --- p.76 / Chapter 3.4.3.1 --- Conditional knockout of TβRII from the kidney decreases the collagen I level in UUO kidney --- p.76 / Chapter 3.4.3.2 --- Disruption of TβRII inhibits TGF-β1 induced collagen I level in vitro --- p.79 / Chapter 3.4.3.3 --- Conditional knockout of TβRII from the kidney decreases the α-SMA positive cells infiltration in vivo --- p.81 / Chapter 3.4.3.4 --- Disruption of TβRII inhibits TGF-β1-induced α-SMA expression in vitro --- p.83 / Chapter 3.4.3.5 --- Conditional knockout of TβRII from the kidney decreases the FN level in UUO nephropathy --- p.85 / Chapter 3.4.3.6 --- Disruption of TβRII decreases TGF-β1-induced FN expression in vitro --- p.87 / Chapter 3.4.4 --- Disruption of TβRII impairs the TGF-β/Smad signaling in vivo in the UUO kidney and in vitro in TGF-β1 treated tubular epithelial cells and kidney fibroblasts --- p.89 / Chapter 3.4.4.1 --- Conditional knockout of TβRII decreases the UUO induced TGF-β1 expression in vivo and the TGF-β1 auto-induction in vitro --- p.89 / Chapter 3.4.4.2 --- Disrupted TβRII decreases CTGF level in the UUO nephropathy in vivo and the TGF-β1 induced CTGF mRNA level in vitro --- p.91 / Chapter 3.4.4.3 --- Conditional knockout of TβRII impairs the Smad3 signaling in the injured kidney --- p.93 / Chapter 3.4.4.4 --- Disrupted TβRII inhibits TGF-β1-induced Smad3 phosphorylation, P-Smad3 nuclear translocation and Smad3 responsive promoter activity in vitro --- p.95 / Chapter 3.4.4.5 --- Conditional knockout of TβRII doesn’t alter the activation of ERK and P38 signaling in the UUO kidney --- p.97 / Chapter 3.4.4.6 --- Disrupted TβRII inhibits TGF-β1-induced ERK and P38 phosphorylation in vitro --- p.99 / Chapter 3.4.5 --- Disruption of TβRII enhances inflammatory cytokines expression in the UUO kidney and impairs the anti-inflammatory effect of TGF-β1 in response to IL-1β triggered inflammatory response in the TEC cells --- p.101 / Chapter 3.4.5.1 --- Conditional knockout of TβRII increases the TNF-α expression in the UUO nephropathy --- p.101 / Chapter 3.4.5.2 --- Conditional knockout of TβRII increases the IL-1β expression in the UUO nephropathy --- p.103 / Chapter 3.4.5.3 --- Conditional knockout of TβRII doesn’t enhance the MCP-1 expression and macrophages infiltration in the UUO nephropathy --- p.104 / Chapter 3.4.5.4 --- Disruption of TβRII in TECs decreases the anti-inflammatory effect of TGF-β1 in response to IL-1β --- p.106 / Chapter 3.4.6 --- Disruption of TβRII enhances NFκB activation in vivo and in vitro --- p.108 / Chapter 3.5 --- DISCUSSION --- p.110 / Chapter 3.6 --- CONCLUSION --- p.114 / Chapter CHAPTER IV --- Smad2 protects against TGF-β/Smad3 mediated renal fibrosis --- p.115 / Chapter 4.1 --- INTRODUCTION --- p.116 / Chapter 4.2 --- AIMS --- p.117 / Chapter 4.3 --- MATERIALS AND METHODS --- p.117 / Chapter 4.3.1 --- Generation and characterization of Smad2 conditional Knockout mice --- p.117 / Chapter 4.3.2 --- Generation and characterization of Smad2 KO MEFs and Smad2 knockdown/overexpression tubular epithelial cell line (NRK52E) --- p.118 / Chapter 4.3.3 --- Animal model of Unilateral Ureteral Obstruction --- p.118 / Chapter 4.3.4 --- Cell culture --- p.118 / Chapter 4.3.5 --- Real-time RT-PCR --- p.119 / Chapter 4.3.6 --- Western blot analysis --- p.119 / Chapter 4.3.7 --- Immunohistochemistry --- p.119 / Chapter 4.3.8 --- Masson Trichrome Staining --- p.119 / Chapter 4.3.9 --- Immunofluorescence --- p.120 / Chapter 4.3.10 --- Promoter assay --- p.120 / Chapter 4.3.11 --- ChIP assay --- p.120 / Chapter 4.3.12 --- Statistical analysis --- p.120 / Chapter 4.4 --- RESULTS --- p.121 / Chapter 4.4.1 --- Characterization of Smad2 disrupted mice and cells --- p.121 / Chapter 4.4.1.1 --- Characterization of Smad2 conditional Knockout mice --- p.121 / Chapter 4.4.1.2 --- Characterization of Smad2 knockout MEFs, Smad2 knockdown/overexpression TECs --- p.123 / Chapter 4.4.2 --- Disruption of Smad2 further enhances renal fibrosis in vivo and in vitro --- p.124 / Chapter 4.4.2.1 --- Conditional knockout of Smad2 increases total collagen deposition and Col.I level in the UUO kidney --- p.124 / Chapter 4.4.2.2 --- Disruption of Smad2 in MEFs and TECs increases Col.I production in a time- and dosage-dependent manner in response to TGF-β1 --- p.126 / Chapter 4.4.2.3 --- Conditional knockout of Smad2 increases Col.III level in the UUO kidney --- p.128 / Chapter 4.4.2.4 --- Disruption of Smad2 in MEFs and TECs increases Col.III production in a time- and dosage-dependent manner in response to TGF-β1 --- p.130 / Chapter 4.4.3 --- Disruption of Smad2 further enhances renal fibrosis by suppressing the collagen degradation system in vivo and in vitro --- p.132 / Chapter 4.4.3.1 --- Conditional knockout of Smad2 inhibits the MMP2 mRNA while enhances TIMP-1 production in UUO kidney --- p.132 / Chapter 4.4.3.2 --- Disruption of Smad2 in MEFs and TECs decreases the MMP2 level while enhances TIMP-1 production in response to TGF-β1 --- p.133 / Chapter 4.4.4 --- Disruption of Smad2 further increases renal fibrosis by increasing TGF-β1 auto-induction and CTGF level in vivo and in vitro --- p.135 / Chapter 4.4.4.1 --- Disruption of Smad2 increases TGF-β1 auto-induction in vivo and in vitro --- p.135 / Chapter 4.4.4.2 --- Disruption of Smad2 increases CTGF synthesis in vivo and in vitro --- p.137 / Chapter 4.4.5 --- Disruption of Smad2 further increases renal fibrosis by enhancing Smad3 signaling in vivo and in vitro --- p.139 / Chapter 4.4.5.1 --- Conditional knockout of Smad2 further enhances Smad3 phosphorylation and nuclear translocation --- p.139 / Chapter 4.4.5.2 --- Disruption of Smad2 in MEFs and TECs further enhances Smad3 phosphorylation, nuclear translocation, Smad3 responsive promoter activity and the binding to the Col1A2 promoter --- p.141 / Chapter 4.4.6 --- Overexpression of Smad2 suppresses Smad3 signaling therefore ameliorates the TGF-β1-induced fibrotic response in TECs --- p.144 / Chapter 4.4.6.1 --- Overexpression of Smad2 ameliorates the TGF-β1- induced fibrotic response in TECs --- p.144 / Chapter 4.4.6.2 --- Overexpression of Smad2 suppresses Smad3 phosphorylation --- p.146 / Chapter 4.5 --- DISCUSSION --- p.147 / Chapter 4.6 --- CONCLUSION --- p.150 / Chapter CHAPTER V --- THE DISTINCT ROLE OF SMAD4 IN RENAL INFLAMMATION AND FIBROSIS --- p.151 / Chapter 5.1 --- INTRODUCTION --- p.152 / Chapter 5.2 --- AIMS --- p.152 / Chapter 5.3 --- MATERIALS AND METHODS --- p.153 / Chapter 5.3.1 --- Generation and characterization of Smad4 conditional Knockout mice --- p.153 / Chapter 5.3.2 --- Generation and characterization of Smad4 disrupted kidney interstitial fibroblasts and peritoneal macrophages --- p.153 / Chapter 5.3.3 --- Animal model of Unilateral Ureteral Obstruction (UUO) --- p.154 / Chapter 5.3.4 --- Cell culture --- p.154 / Chapter 5.3.5 --- Real-time RT-PCR --- p.155 / Chapter 5.3.6 --- Western blot analysis --- p.155 / Chapter 5.3.7 --- Immunohistochemistry --- p.155 / Chapter 5.3.8 --- Masson Trichrome Staining --- p.155 / Chapter 5.3.9 --- Promoter assay --- p.156 / Chapter 5.3.10 --- ChIP assay --- p.156 / Chapter 5.3.11 --- Statistical analysis --- p.156 / Chapter 5.4 --- RESULTS --- p.157 / Chapter 5.4.1 --- Characterization of Smad4 conditional Knockout mice and Smad4 disrupted cells --- p.157 / Chapter 5.4.2 --- Disruption of Smad4 suppresses renal fibrosis in the UUO nephropathy in vivo and TGF-β1-induced fibrotic response in vitro --- p.160 / Chapter 5.4.2.1 --- Conditional knockout of Smad4 from the kidney decreases the total collagen deposition in the UUO nephropathy --- p.160 / Chapter 5.4.2.2 --- Conditional knockout of Smad4 from the kidney decreases the Col.I production in the UUO nephropathy --- p.161 / Chapter 5.4.2.3 --- Disruption of Smad4 inhibits TGF-β1-induced Col.I production in vitro --- p.163 / Chapter 5.4.3 --- Disruption of Smad4 impairs the Smad3 function in vivo and in vitro --- p.164 / Chapter 5.4.3.1 --- Conditional knockout of Smad4 doesn’t decrease Smad3 phosphorylation and P-Smad3 nuclear translocation in vivo and in vitro --- p.164 / Chapter 5.4.3.2 --- Disruption of Smad4 inhibits TGF-β1 induced Smad3 promoter activity and the Smad3 binding to Col1A2 promoter --- p.166 / Chapter 5.4.3.3 --- Disruption of Smad4 has minimal effect on the activation of ERK signaling in vivo and in vitro --- p.167 / Chapter 5.4.4 --- Disruption of Smad4 enhances renal inflammation and impairs the anti-inflammatory effect of TGF-β1 in response to IL-1β triggered inflammatory response in vitro --- p.169 / Chapter 5.4.4.1 --- Conditional knockout of Smad4 increases the inflammatory cells infiltration --- p.169 / Chapter 5.4.4.2 --- Conditional knockout of Smad4 increases the TNFα expression in the UUO nephropathy --- p.171 / Chapter 5.4.4.3 --- Conditional knockout of Smad4 increases the IL-1β expression in the UUO nephropathy --- p.172 / Chapter 5.4.4.4 --- Conditional knockout of Smad4 increases the MCP-1 expression in the UUO nephropathy --- p.173 / Chapter 5.4.4.5 --- Conditional knockout of Smad4 increases the ICAM-1 level in the UUO nephropathy --- p.174 / Chapter 5.4.4.6 --- Time and dosage dependent experiments in response to IL-1β in macrophages --- p.175 / Chapter 5.4.4.7 --- Disruption of Smad4 in macrophages decreases the anti-inflammatory effect of TGF-β1 in response to IL-1β --- p.176 / Chapter 5.4.5 --- Disruption of Smad4 impairs the inhibitory effect of Smad7 on NFκB activation in vivo and in vitro --- p.178 / Chapter 5.4.5.1 --- Conditional knockout of Smad4 largely inhibits Smad7 level in UUO kidney --- p.178 / Chapter 5.4.5.2 --- Conditional knockout of Smad4 suppresses IκBα and further increases NF-κB p65 activation in UUO kidney --- p.180 / Chapter 5.4.5.3 --- Disruption of Smad4 inhibits Smad7 synthesis in macrophages --- p.182 / Chapter 5.4.5.4 --- Conditional knockout of Smad4 impair the inhibition effect of TGF-β1 on the activation of NFκB p65 in macrophages --- p.184 / Chapter 5.5 --- DISCUSSION --- p.186 / Chapter 5.6 --- CONCLUSION --- p.189 / Chapter CHAPTER VI --- SUMMARY AND DISCUSSION OF THE MAJOR FINDINGS --- p.190 / Chapter 6.1 --- SUMMARY AND DISCUSSION --- p.192 / Chapter 6.1.1 --- The diverse role of TβRII in renal inflammation and fibrosis both in vivo and in vitro --- p.192 / Chapter 6.1.2 --- Smad2 protects renal fibrosis by counter-regulating Smad3 signaling --- p.192 / Chapter 6.1.3 --- Disruption of Smad4 increased renal inflammation while suppressed the renal fibrosis in vivo and in vitro --- p.194 / Chapter 6.1.4 --- Comparative analysis of functions and related mechanisms between TβRII and Smad4 in renal disease --- p.195 / Chapter 6.1.5 --- Inadequacies of current work and future plan --- p.197 / Chapter 6.1.6 --- Perspectives (1) : The balance within the TGF-b/Smad signaling may determine the fate of renal diseases --- p.197 / Chapter 6.1.7 --- Perspectives(2)：The balance within the TGF-β/Smad signaling may determine the fate of renal diseases --- p.198 / Chapter 6.2 --- CONCLUSION --- p.201 / REFERENCES --- p.202 / PUBLICATION LIST --- p.232 / HONORS AND AWARDS --- p.237