Aggregation of Amyotrophic Lateral Sclerosis-Associated Cu/Zn Superoxide Dismutase

Amyotrophic lateral sclerosis (ALS) is a devastating, progressive, and fatal neurodegenerative disease. Despite the fact that ALS is the most common motor neuron disease in adulthood, there is no effective treatment for the disease. Although most ALS cases (90-95%) are sporadic (sALS), the remaining cases (5-10%) are dominantly inherited and referred to as familial ALS (fALS). Because sALS and fALS show indistinguishable disease symptoms, a common disease mechanism has been proposed. After the discovery of the link between fALS and mutants of cytosolic Cu/Zn superoxide dismutase (SOD1), over 140 mutations in SOD1 have been identified to account for ~20% of fALS. The location of these mutants are scattered throughout the primary and tertiary structures of the protein. It is widely accepted that fALS-linked mutations in SOD1 result in a gain of toxic function to cause the disease, rather than a loss of physiological function, although the nature of the toxic mechanism remains unclear. SOD1 is a -rich, homodimeric metalloenzyme that catalyzes the dismutation of superoxide radicals to O2 and H2O2. The protein is ubiquitously expressed and the mature form of SOD1 (holo SOD1) contains one catalytic Cu ion, one structural Zn ion, one intra-molecular disulfide bond (between C57 and C146) and two free Cys residues (C6 and C111) per 153 residue subunit. Analogous to many different human diseases in which protein aggregation is a hallmark, aggregation of Cu/Zn superoxide dismutase (SOD1) is implicated in the pathogenesis of ALS. This thesis reports the first observation of aggregation of the most abundant form of SOD1 in vivo, the native, metallated (holo) dimer, under physiologically relevant conditions (37 °C and pH 7.8). The medical relevance of aggregates is demonstrated by structural and tinctorial analyses as well as the novel observation of binding of an anti-SOD1 antibody that specifically recognizes pathological aggregates in ALS. Additionally, ALS-associated SOD1 mutations promote aggregation but are not required, supporting a common mechanism in familial and sporadic ALS. The aggregation is characterized by a lag phase, which is diminished by self- and cross-seeding where heterogeneous nucleation is the underlying mechanism. Moreover, multiple pathways of aggregation are elucidated including dimer dissociation and metal loss. It is shown that if holo SOD1 loses more Zn ions than Cu ions, the aggregation profiles have shorter duration and lower final intensity, whereas when holo SOD1 loses more Cu ions than Zn ions, the aggregation profiles have longer duration and higher intensity. Taken together, the data in this thesis establish a valuable system for understanding SOD1 aggregation and toxicity mechanisms which can be used for developing therapeutic strategies targeting protein aggregation

Transcription Factor Sp1 Is Involved in Expressional Regulation of Coxsackie and Adenovirus Receptor in Cancer Cells

Coxsackie and adenovirus receptor (CAR) was first known as a virus receptor. Recently, it is also known to have tumor suppressive activity such as inhibition of cell proliferation, migration, and invasion. It is important to understand how CAR expression can be regulated in cancers. Based on an existence of putative Sp1 binding site within CAR promoter, we investigated whether indeed Sp1 is involved in the regulation of CAR expression. We observed that deletion or mutation of Sp1 binding motif (−503/−498) prominently impaired the Sp1 binding affinity and activity of CAR promoter. Histone deacetylase inhibitor (TSA) treatment enhanced recruitment of Sp1 to the CAR promoter in ChIP assay. Meanwhile, Sp1 binding inhibitor suppressed the recruitment. Exogenous expression of wild-type Sp1 increased CAR expression in CAR-negative cells; meanwhile, dominant negative Sp1 decreased the CAR expression in CAR-positive cells. These results indicate that Sp1 is involved in regulation of CAR expression

Electrochemical performance of YST infiltrated and fe doped YST infiltrated YSZ anodes for IT-SOFC

Donor doped and donor-acceptor co-doped strontium titanate perovskite are investigated for intermediate temperature solid oxide fuel cells (IT-SOFCs) anodes. Y0.08Sr0.88TiO3-delta and Y0.08Sr0.92Ti1-xFexO3-delta (x = 0.2, 0.4) anodes were prepared by infiltration in 65% porous yttria stabilized zirconia (YSZ) scaffolds. The microstructure and electrical conductivity of Y0.08Sr0.88TiO3-delta and Y0.08Sr0.92Ti1-xFexO3-delta strongly depends on Fe content. The conductivity of Y0.08Sr0.88TiO3-delta andY(0.08)Sr(0.92)Ti(1-x)Fe(x)O(3-delta); decreases with increasing Fe content in humidified H-2. Y0.08Sr0.88TiO3-delta, Y0.08Sr0.92Ti0.8Fe0.2O3-delta, and Y0.08Sr0.92Ti0.6Fe0.4O3-delta, anodes with a Pd/CeO2 catalyst show peak power density of 298, 421, and 321 mW cm(-2), respectively, in wet H-2 at 1073 K.open0

Characteristics of children with trauma compared to those with disease in the emergency department: a Korean single regional emergency medical center study

Purpose Trauma is the leading cause of death and disability in children. We aimed to compare the clinical characteristics of children with trauma and disease. Methods We reviewed the medical records of children (< 19 years) who visited the emergency department of Pusan National University Hospital from 2016 through 2018. Data on the age, age group, sex, details of trauma or disease, severe trauma or disease (Korean Triage Acuity Scale 1-2), hospitalization rate (overall and intensive care unit [ICU]), hospital length of stay, in-hospital mortality, and the Injury Severity Score were compared between the children with trauma and those with disease. Results In a total of 10,205 children, 3,028 (29.7%) had trauma. The children with trauma were older than those with disease (median age, 78.5 months [interquartile range, 35.0-165.0] vs. 49.0 [16.0-120.0]; P < 0.001). Boys were more common in the former group than the latter (63.7% vs. 56.3%; P < 0.001). The most common injury mechanism was traffic accident (16.0%), followed by fall and foreign body. The overall hospitalization rate was higher in the children with disease (17.1% vs. 35.9%; P < 0.001). However, the children with trauma underwent more frequent ICU hospitalization, and showed higher in-hospital mortality rate and longer hospital length of stay than those with disease (all P < 0.001). The children with severe trauma showed higher median age, percentage of boys, in-hospital mortality, and ICU hospitalization rate, and longer hospital length of stay than those with severe disease (all P < 0.001). Conclusion Children with trauma tend to be older, and their condition may be more critical in severity than those with disease. This difference is more prominent in those with severe trauma or disease

Black rice (Oryza sativa L.) extract attenuates hepatic steatosis in C57BL/6 J mice fed a high-fat diet via fatty acid oxidation

<p>Abstract</p> <p>Background</p> <p>Two major risk factors for the onset of fatty liver disease are excessive alcohol intake and obesity, the latter being associated with non-alcoholic fatty liver disease (NAFLD). The aim of this study was to examine the effects of black rice extract (BRE) on hepatic steatosis and insulin resistance in high-fat diet-fed mice, providing a model of NAFLD.</p> <p>Methods</p> <p>Twenty-four mice were randomly divided into three groups (n = 8 in each group): normal fat diet (ND), high fat diet (HF), and high fat diet supplemented with 1% (w/w) BRE (HF +1% BRE). The experimental diets were fed for seven weeks.</p> <p>Results</p> <p>A HF induced hepatic steatosis with significant increases in the serum levels of free fatty acids (FFAs), triglyceride (TG), total cholesterol (TC), and insulin. By contrast, supplementary BRE (10 g/kg of diet) included in the HF alleviated hepatic steatosis and significantly decreased serum TG and TC levels (p < 0.01 for both). Dietary BRE also increased expression of fatty acid metabolism-related genes, including carnitine palmitoyltransferase (CPT1A), acyl-CoA oxidase (ACO), cytochrome P450 (CYP4A10), and peroxisome proliferator activated receptor (PPAR)-α (p < 0.05 for all).</p> <p>Conclusions</p> <p>Dietary BRE supplementation improved serum lipid profiles and significantly enhanced mRNA expression levels of fatty acid metabolism-related genes, primarily via β-oxidation and ω-oxidation in the liver. Taken together, these findings suggest that a BRE-supplemented diet could be useful in reducing the risks of hepatic steatosis and related disorders, including hyperlipidemia and hyperglycemia.</p

Crystal structure of Cmr5 from Pyrococcus furiosus and its functional implications

AbstractThe bacterial acquired immune system consists of clustered regularly interspaced short palindromic repeats (CRISPRs) and CRIPSR-associated (Cas) genes, which include Cas-module repeat-associated mysterious proteins (Cmr). The six Cmr proteins of Pyrococcus furiosus (pfCmr1–pfCmr6) form a Cmr effector complex that functions against exogenous nucleic acid. Among the Cmr proteins, the role of pfCmr5 and its involvement in the complex’s cleavage activity have been obscure. The elucidated pfCmr5 structure has two inserted α-helices compared with the other trimeric Cmr5 structure. However, pfCmr5 exists as a monomeric protein both in the crystalline state and in solution. In vitro assays indicate that pfCmr5 interacts with pfCmr4. These structural and biophysical data might help in understanding the complicated and ill-characterized Cmr effector complex.Structured summary of protein interactionspfCmr4 and pfCmr5 bind by molecular sieving (View interaction)pfCmr4 and pfCmr4 bind by molecular sieving (View interaction)pfCmr5 and pfCmr4 bind by ion exchange chromatography (View interaction

Deficiency of antidiuretic hormone: a rare cause of massive polyuria after kidney transplantation

A 15-year-old boy, who was diagnosed with Alport syndrome and end-stage renal disease, received a renal transplant from a living-related donor. On postoperative day 1, his daily urine output was 10,000 mL despite normal graft function. His laboratory findings including urine, serum osmolality, and antidiuretic hormone levels showed signs similar to central diabetes insipidus, so he was administered desmopressin acetate nasal spray. After administering the desmopressin, urine specific gravity and osmolality increased abruptly, and daily urine output declined to the normal range. The desmopressin acetate was tapered gradually and discontinued 3 months later. Graft function was good, and urine output was maintained within the normal range without desmopressin 20 months after the transplantation. We present a case of a massive polyuria due to transient deficiency of antidiuretic hormone with the necessity of desmopressin therapy immediately after kidney transplantation in a pediatric patient