Dragon (RGMb) is one of the three repulsive guidance molecule (RGM) family members RGMa, RGMb (Dragon) and RGMc (hemojuvelin). RGM family members are glycophosphatidylinositol (GPI)-anchored membrane proteins. The three RGM proteins have been identified as co-receptors that enhance BMP-Smad signaling. Previous studies showed that Dragon protein is expressed in the epithelial cells of kidney tubules including collecting ducts, distal convoluted tubules and thick ascending limbs, and that Dragon enhances BMP4 signaling in tubular epithelial cells. However, the biological roles of Dragon in the renal epithelial cells are yet to be defined. / We now showed that overexpression of Dragon inhibited E-Cadherin expression, but did not affect epithelial-to-mesenchymal transition (EMT) induced by TGF-β1 in mouse inner medullary collecting duct (IMCD3) cells. Dragon also increased cell death induced by hypoxia in association with increased cleaved PARP and cleaved Caspase-3 levels in IMCD3 cells. Dragon did not have any effect on the expression of inflammatory factors in IMCD3 cells. Previous studies suggest that the three RGM members can also function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-Cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. / Dragon expression in the kidney was upregulated by unilateral ureteral obstruction (UUO) in mice. Compared with wild-type mice, heterozygous Dragon knockout mice exhibited 45-66% reduction in Dragon mRNA expression, decreased epithelial cell apoptosis, increased tubular E-Cadherin expression, and had attenuated tubular injury after UUO. UUO-induced renal fibrosis and inflammation did not change between wild-type mice and heterozygous Dragon knockout mice. Similar results were obtained in the model of ischemia-reperfusion kidney injury. Compared with wild-type mice, heterozygous Dragon knockout mice showed decreased epithelial cell apoptosis. Ischemia-induced renal fibrosis and inflammation did not change between wild-type mice and heterozygous Dragon knockout mice. / Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial cell apoptosis both in vitro and in vivo. / Dragon (又稱排斥導向分子b) 是排斥導向分子家族中的一員。這個家族包括排斥導向分子a，排斥導向分子b (又稱Dragon) 和排斥導向分子c (又稱血幼素) 三名成員。它們都是一種磷脂酰肌醇(GPI) 錨定蛋白。研究發現，這三種排斥導向分子都可以作為輔助受體來加強骨形成蛋白信號通路。我們之前的研究發現，Dragon在集合管、遠曲小管和髓袢升支粗段的上皮細胞內都有表達，同時Dragon增強腎小管上皮細胞中骨形成蛋白(BMP)4的信號轉導。但是，Dragon在腎小管上皮細胞中的生物學功能尚不清楚。 / 我們的研究結果表明，Dragon過量表達后降低腎內髓集合管上皮細胞中上皮型鈣粘素 (E-Cadherin) 的表達，但是不影響轉化生長因子-β1誘導的上皮細胞向間充質細胞的轉化。在低氧的條件下，Dragon促進腎內髓集合管上皮細胞的死亡并同時增加活化的多聚二磷酸腺苷酸核糖聚合酶（PARP）和半胱天冬酶3 (Caspase-3) 的量。但是Dragon對腎內髓集合管上皮細胞分泌的免疫因子沒有影響。之前的研究表明，neogenin是這三個導向排斥分子的受體。同樣在我們的研究中發現，Dragon是通過neogenin受體而不是骨形成蛋白信號通路來影響腎內髓集合管上皮細胞的死亡和E-Cadherin的表達。 / 單側輸尿管結扎手術后，在受損傷的小鼠腎臟中Dragon的表達升高。與野生型的小鼠相比，雜合型Dragon敲除小鼠中Dragon信使核糖核酸的表達下降了45-66%，腎小管上皮細胞的凋亡減少，腎小管E-Cadherin的表達升高。單側輸尿管結扎手術后野生型和雜合型Dragon敲除小鼠腎臟皆存在纖維化和炎症，但是二者沒有差異。缺血再灌注的小鼠模型實驗中得到相似的結果。與野生型的小鼠相比，雜合子Dragon敲除小鼠中腎小管上皮細胞凋亡的數目減少。同樣缺血再灌注手術后野生型和雜合子Dragon敲除小鼠腎臟都也存在纖維化和炎症，但二者沒有差異。 / 體內和體外實驗结果均表明，在腎臟損傷過程中Dragon可能損害腎小管上皮的完整性并促進腎小管上皮細胞的凋亡。 / Liu, Wenjing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 192-212). / Abstracts also in Chinese. / Title from PDF title page (viewed on 03, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

Patients with chronic kidney disease (CKD) are a group with a markedly increased risk of adverse events following cardiac surgery. A particular problem for these patients is the development of post-operative acute kidney injury (AKI), which is associated with a significant increase in morbidity and mortality. Currently, there are no effective therapies proven to modify AKI in patients undergoing cardiac surgery. This thesis has three parts. The first describes an analysis of the Barts Health NHS Trust cardiac surgical dataset. Specifically, outcomes of patients with CKD and AKI were examined. The second describes a randomized control trial that examined the effect of remote ischaemic preconditioning (RIPC) upon AKI and myocardial injury in patients with CKD undergoing coronary artery bypass graft surgery (CABG). The final part describes the development of a panel of AKI biomarkers to allow the accurate prediction of AKI in patients with CKD undergoing CABG. The aims of this thesis were: 1. In our local cardiac surgical cohort, a. To assess the effects of CKD upon outcomes after CABG. b. To asses the prognostic importance of AKI after CABG. 2. To assess the potential for RIPC to reduce AKI and myocardial injury in patients with CKD undergoing CABG. 3. To investigate the diagnostic performance of serum and urine AKI biomarkers in a population of patients with CKD undergoing CABG. Analysis of the Barts Health NHS Trust cardiac surgical dataset confirmed that patients with CKD account for almost one-third of patients undergoing CABG. However, these patients account for a disproportionate two-thirds of all early mortality. CKD was also independently associated with late mortality after CABG. AKI was common in these patients. AKI was associated with late mortality even after accounting for pre-operative comorbidity and surgical complexity. In the randomized control trial, RIPC showed no effect upon the incidence of AKI or myocardial injury in the. 86 patients with CKD recruited. Secondary analysis of serum and urine biomarkers collected found change in serum cystatin C and NGAL as impressive predictors of AKI in patients with CKD. They allowed accurate early prediction of AKI more than 24 hours before diagnosis was possible using serum creatinine.

The increased risk of atherothrombosis in chronic kidney disease (CKD) has been under extensive examination for decades now. However, a treatment tailored for CKD patients is yet to be found. Current management plans can only tackle comorbidities and mostly fail. This thesis study examines the current literature related to CKD and thrombosis. The aim is to find a target suitable for therapeutic exploration. Normalizing the risk of thrombosis in CKD patients could curb a huge margin of their morbidity and mortality. In recent years, molecular biology studies attributed the extreme thrombogenicity in CKD to the retained uremic toxins. Indolic compounds are uremic toxins with a well described point of thrombotic activation. Of them, indoxyl sulfate is to be highlighted since it was shown to that it is one of the strongest pro-thrombotic uremic toxin. It is possible to therapeutically target this CKD specific cause of hyperthrombogenicity. Further research is very much needed in this area.

Urotensin II (UII) is a potent peptide hormone with a complex species and vessel-dependent vascular profile. UII and the homologous UII-related peptide (URP) bind to the g-protein coupled urotensin II receptor (UT) with high affinity. The peptide ligands and receptor have been detected in numerous human and rat tissues including heart, brain and kidney. The kidney is a major source of UII, which appears to act as both an endocrine and paracrine mediator of renal function. UII has been shown to influence renal blood flow, glomerular filtration rate and sodium handling in the renal tubules. More speculative actions of UII as a pro-fibrotic mediator include the activation of fibroblasts and promotion of collagen synthesis. Abnormally elevated UII, URP and UT expression has been highlighted in a number of cardio-renal disease states; particularly end stage renal disease, diabetes and diabetic nephropathy (DN). This work aims to investigate the role of the UII system in the development and progression of CKD using an experimental model of CKD in rodents. The first aim of the current work involved establishing the surgical 5/6th subtotal nephrectomy (SNx) model of chronic kidney disease (CKD) in the laboratory and forming a profile of UII expression in late stage experimental CKD to complement UII clinical data which are exclusively from patients in the later stages of disease. UII/URP and UT were substantially over-expressed in the kidneys of SNx rats in late stage CKD. This novel insight complements the clinical profile of CKD/DN where over expression of the UII system is routinely reported. In a second study the 5/6th SNx rat model was used to explore the effects of chronic UT receptor antagonism on the progression of CKD. Although there were no discernible differences in kidney mass or histological profile between the treatment groups at the end of the study, there was a small delay in the development of albuminuria and in the onset of systolic blood pressure elevation in the UT antagonist treated cohort. The study did not produce clear-cut evidence defining the potential therapeutic value of UT-antagonism in the treatment of CKD. Despite this the results are encouraging and suggest that the role of UT-inhibition in CKD is worth considering further.

The thunderstorm encroaches, the smoky raven like clouds float over my spirit. This writing takes place at a time of mourning, a deep and lonesome sadness for family relations who have passed over the last few years, many having died of kidney disease. Yet, I cannot escape this feeling that has filled the silent spaces and the deeper meanings that lie behind spoken words. These are the words of my relations, the words that fill these empty pages, the words of an enduring past and present. As I begin, I wonder, how will I shape these passages into an articulation that may bring an illumination of all that has happened over the last few months since the inception and then ethics approval of this work. So here I shall offer an understanding of the background that brought this study forward. I will recount the progression of thought that precipitated the methodology. Like water that flows and is fluid, this writing has become realized to be ever changing, boundless and repelling conventionality. It is not just a story about living with kidney disease, this is a passage that motions and travels through history making interconnections amidst the broader social, political and contextually traditional and creative ways of being. Through the methodology of the sweetgrass porcupine quill box, living stories came forth within the context of a First Nations community. Sharing circles involving ten participants conveyed the living stories of kidney disease that illumined the significance of Indigenous Knowledge, relationality, cultural safety and equitable access. / Graduate / 2020-04-19

The cortical collecting duct of the mammalian kidney plays a critical role in the regulation of body volume, sodium pH and osmolarity and is composed of two distinct cells types, principal cells and intercalated cells. Each cell type is detectable in the kidney by the localization of specific transport proteins such as Aqp2 and ENaC in principal cells and V-ATPase B1 and Cx30 in intercalated cells. mCCDcl1 cells have been widely used as a mouse principal cell line on the basis of their physiological characteristics. In this study, the mCCDcl1 parental cell line and three sub-lines cloned from isolated single cells (Ed1, Ed2, and Ed3) were grown on filters to assess their transepithelial resistance, transepithelial voltage, equivalent short circuit current and expression of the cell-specific markers Aqp2, ENaC, V-ATPaseB1 and Cx30. The parental mCCDcl1 cell line presented amiloride-sensitive electrogenic sodium transport indicative of principal cell function, however immunocytochemistry and RT-PCR showed that some cells expressed the intercalated cell-specific markers V-ATPase B1 and Cx30, including a subset of cells also positive for Aqp2 and ENaC. The three subclonal lines contained cells that were positive for both intercalated and principal cell-specific markers. The vertical transmission of both principal and intercalated cell characteristics via single cell cloning, reveals the plasticity of mCCDcl1 cells, and a direct lineage relationship between these two physiologically important cell types, and is consistent with mCCDcl1 cells being precursor cells. For observation of live mCCDcl1 in an environment closer to in vivo conditions, a model of collecting duct was designed and developed using 3D printing of porous polymers. mCCDcl1 were cultured successfully and demonstrated improved characteristics compared to classic culture such as improved lifespan, different morphology and increased protein expression, and retained their phenotypic plasticity.

Pericytes, progenitor cells embedded in the microvascular wall, are crucial for vascular homeostasis. Renin is the rate-limiting enzyme that regulates blood pressure and fluid/electrolyte balance. Previous work suggested the relationship between renin-expressing/ producing cells and pericytes, however human kidney pericytes have not been characterized in depth and the molecular switch controlling renin cell plasticity is not understood. Here, I describe a method of isolation of CD146+CD34-CD45-CD56- pericytes, putative progenitors for renin-producing cells, from the human foetal kidney and demonstrate their potential in vitro to express and produce renin. Co-staining of pericyte markers (CD146 and NG2) and renin showed coincidence in the juxtaglomerular region and along renal arterioles in the human foetal kidney. I have obtained primary cultures of renal pericytes from the developing human kidney that were purified via fluorescence-activated cell sorting. Primary cultures of renal pericytes exhibited tri-lineage mesodermal differentiation potential. Renin expression was triggered by cAMP induction (10μM forskolin and 100μM 3-isobutyl-1- methylxanthine [IBMX] and resulted in 64.3 fold increase of renin mRNA (p <0.01) and 41.5 fold increase in enzymatic activity of renin (p <0.05) over controls. Pericytes derived from non-renal tissues (placenta and foetal adrenal glands) also expressed renin in an inducible fashion. Renin positive cells following induction were confirmed to be CD146+/NG2+. Interestingly, alpha-smooth muscle actin expression was not always correlated with renin immunostaining. Wnt/β-catenin signalling plays a crucial role during kidney development and in disease, specifically; in pericyte modulation of the Wnt pathway has been shown to regulate cell differentiation. CHIR 99021, a specific inhibitor of glycogen synthase kinase 3, mimicking Wnt signalling, and C59, a potent Porcupine acyltransferase inhibitor that is required for Wnt biological activity, were tested in renin induction experiments. Preliminary data showed that renin expression was blocked by Wnt activation, whereas Wnt suppression increased renin mRNA levels above the level of stimulation achieved with cAMP inducers. These findings provide evidence that renin expression is an intrinsic feature of pericytes and can be regulated through the Wnt pathway.

ASSOCIATION OF AGE, GENDER AND RACE IN CHRONIC KIDNEY DISEASE PATIENTS WITH AND WITHOUT DIALYSIS 1Busayo Adeyemi Onatolu, 2Hemang Panchal, 3Edward Francis Leinaar, 1*Shimin Zheng, 2Timir K. Paul 1Department of Biostatistics and Epidemiology, College of Public Health, ETSU, Johnson City, TN 37614 2Department of Internal Medicine, Quillen College of Medicine, ETSU, Johnson City, TN, 37614 3Department of Health Services Management and Policy, CPH, ETSU, Johnson City, TN 37614 *Sponsoring faculty Introduction: Studies have shown that chronic kidney disease (CKD) is common among adults in the United States. The Centers for Disease Control and Prevention (CDC) states that 30 million people, or 15% of US adults, are estimated to have CKD. Forty-eight percent of those with severely reduced kidney function are not aware of having CKD, and therefore do not receive hemodialysis (HD). Methods: A nationwide inpatient sample database from 2012-2014 was used to identify all patients admitted to the hospital using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes (n= 534,845). Patients with dialysis dependent CKD (n=8,100) and CKD without dialysis (n=51,285) were compared to non-CKD patients (n=475,460). Hierarchical logistic regression was performed and p Results: Of the 534,845 patients, 88.9% were without CKD and 9.59% had CKD without HD and 1.51% had CKD with HD. Among patients with CKD, 13.64% were on HD and 86.34% were non-HD patients. The result shows that a higher proportion of patients with CKD without HD in the ≥ 80 years age group (≥ 80 = 37.84%, 65-79 = 36.94%, 50-64 = 20.80%, 35-49 = 4.12% and 18-34 = 0.30%) and a higher proportion of patients with CKD with HD in the 65-79 years age (≥ 80 = 16.30%, 65-79 = 41.79%, 50-64 = 33.09%, 35-64 = 8.09% and 18-34 = 1.29%). The OR of age group 18-34 compared to ≥ 80 is 5.690, 95% CI: 4.202,7.705, OR 35-49 is 4.552, 95% CI: 4.552, 95% CI: 4.103, 5.050, OR of 50-64 is 3.693, 95% CI: 3.444, 3.961 and OR 65-79 is 2.626, 95% CI: 2.457, 2.807. Males had higher rates of CKD than females, without HD (Male= 63.12%, female= 36.88%, p Conclusion: From this study, males had higher rates of CKD with and without HD than females, the age group ≥ 80 years had higher proportion of CKD without HD and those between 65-79 years had higher number of CKD with HD. Whites had higher rates of CKD with and without HD than other races.

The traditional roles of the tumor suppressor protein, p53, in transcriptional regulation are mostly defined in cancer or stressed cells and are centered on control of the cell cycle, DNA repair or senescence. In this thesis, data is presented demonstrating that the p53-regulated transcriptome is highly context-dependent as illustrated using the developing kidney as a model system. To this end, we utilized whole genome transcriptome and ChIP-Seq (chromatin immunoprecipitation-high throughput sequencing) analyses in p53+/+ and p53-/- mice to identify p53 regulated pathways in the embryonic kidney. This integrated approach allowed identification of novel genes that are direct p53 targets in the developing nephron. This approach was further refined using RNA-Seq analysis of lineage-tagged FACS-isolated nephron progenitors. We find that the p53-regulated transcriptome in the embryonic kidney is mostly involved in development, morphogenesis, and metabolic pathways. Interestingly, traditional targets of p53, such as DNA repair, cell cycle and apoptosis, accounted for < 5% of differentially expressed genes. The majority of 7,893 p53-binding genomic regions contain consensus p53 binding sites. Unlike a cancer cell line in which 7% of p53 binding sites lie within proximal promoters, 78% of p53 peaks in the developing kidney overlies the promoter. Moreover, 25% of the differentially expressed p53-bound genes belong to nephron progenitors and nascent nephrons, including key transcriptional regulators, components of Fgf, Wnt, Bmp, and Notch pathways, and ciliogenesis genes. RNA-Seq of nephron progenitors from wild-type and mutant p53 mice demonstrated repression of the nephron stem cell marker, Cited1, but not Six2. Moreover, cytoskeleton, cell adhesion, and energy metabolism genes were downregulated in mutant progenitors consistent with the loosely organized cap mesenchyme and disrupted mesenchyme-to-epithelium transition of p53-/- progenitors. In conclusion, our studies demonstrate that p53 genomic occupancy and regulated transcriptome are distinctly different in development and cancer. p53 is a key regulator of transcriptional programs that maintain nephron niche integrity, nephron progenitor cell renewal and differentiation. / acase@tulane.edu

Using grounded theory methodology this study examined the acquisition and exercise of nephrology nursing expertise, seeking to answer the following questions: what constitutes expertise and how it develops in nephrology nursing; and whether expert nephrology nurses practice differently from non-expert nephrology nurses and, if so, how. Sampling consisted of 6 non-expert and 11 expert nurses from a renal unit in New South Wales, and data were obtained from participant observation of the nurses and subsequent interviews. A substantive theory was generated utilising an orchestral metaphor to explain the skills-acquisitive/exercise process. Findings revealed a three stage skills-acquisitive process: non-expert, experienced non-expert and expert. Each stage was typified by four characteristics that altered during the acquisitive process: knowledge, experience, skills and focus. The findings also identified features of the skill-acquisitive/exercise process either not reported or left implicit in previous studies, including the centrality of recognition of expertise; blurring the boundaries to expert practice; and the role of motivation, enjoyment and commitment to the acquisition of / Doctor of Philosophy (PhD)