GM2 Ganglioside Regulates the Function of Ciliary Neurotrophic Factor Receptor in Murine Immortalized Motor Neuron-Like Cells (NSC-34)

We previously reported that ciliary neurotrophic factor (CNTF) increased the serum-free cell survival of immortalized motor neuron-like cells (NSC-34), and addition of the exogenous ganglioside GalNAc4(Neu5Ac3)Gal4GlcCer (GM2) facilitated cell survival together with CNTF. Moreover 1,4 N-acetylgalactosaminyltransferase (GM2 synthase) activity increased in NSC-34 cells cultured with CNTF. We now have examined whether CNTF-induced cell survival is associated with the collaboration between GM2 and the CNTF receptor (CNTF-R). Despite the presence of CNTF (50 ng/ml), anti-CNTF-R antibody caused cell death and prevented the up-regulation of GM2 synthase expression. The addition of GM2 (1 to 20 M) abrogated the anti-CNTF-R antibody effect which shortened cell survival and blocked GM2 synthase activation. Use of [¹²⁵I]CNTF showed the specificity of CNTF binding in NSC-34 cells in situ. GM2 produced a 5-fold increase in the CNTF binding affinity per cell but did not change the binding site number. The study by metabolic labeling with [1–¹⁴C]N-acetyl-D-galactosamine ([¹⁴C]GalNAc) showed that biosynthesized GM2 was involved in the immunoprecipitation of CNTF-R. These findings indicate that up-regulated GM2 synthesis induces functional conversion of CNTF-R to the activated state, in which it has affinity for CNTF. We conclude that GM2 is a bio-regulating molecule of CNTF-R in motor neurons.     

Synthesis and biological evaluation of some 6-arylamidomorphines as analogues of morphine-6-glucuronide

A series of 6-beta-arylamidomorphines was synthesized and biologically evaluated. Various aryl substituents were introduced into the arylamidomorphines to examine substituent structure-activity relationships. Competition binding assays showed that compounds 10a-h bound to the mu opioid receptor with high affinity (0.2-0.6 nM). Functional assays showed that compounds 10a-h acted as full mu opioid receptor agonists. The ED(50) of compound 10e.HCl as an analgesic was 12.6 mg/kg in the tail flick latency test in the rat.     

Biophysical studies of the c-MYC NHE III1 promoter: model quadruplex interactions with a cationic porphyrin

Regulation of the structural equilibrium of G-quadruplex-forming sequences located in the promoter regions of oncogenes by the binding of small molecules has shown potential as a new avenue for cancer chemotherapy. In this study, microcalorimetry (isothermal titration calorimetry and differential scanning calorimetry), electronic spectroscopy (ultraviolet-visible and circular dichroism), and molecular modeling were used to probe the complex interactions between a cationic porphryin mesotetra (N-methyl-4-pyridyl) porphine (TMPyP4) and the c-MYC PU 27-mer quadruplex. The stoichiometry at saturation is 4:1 mol of TMPyP4/c-MYC PU 27-mer G-quadruplex as determined by isothermal titration calorimetry, circular dichroism, and ultraviolet-visible spectroscopy. The four independent TMPyP4 binding sites fall into one of two modes. The two binding modes are different with respect to affinity, enthalpy change, and entropy change for formation of the 1:1 and 2:1, or 3:1 and 4:1 complexes. Binding of TMPyP4, at or near physiologic ionic strength ([K(+)] = 0.13 M), is described by a "two-independent-sites model." The two highest-affinity sites exhibit a K(1) of 1.6 x 10(7) M(-1) and the two lowest-affinity sites exhibit a K(2) of 4.2 x 10(5) M(-1). Dissection of the free-energy change into the enthalpy- and entropy-change contributions for the two modes is consistent with both "intercalative" and "exterior" binding mechanisms. An additional complexity is that there may be as many as six possible conformational quadruplex isomers based on the sequence. Differential scanning calorimetry experiments demonstrated two distinct melting events (T(m)1 = 74.7 degrees C and T(m)2 = 91.2 degrees C) resulting from a mixture of at least two conformers for the c-MYC PU 27-mer in solution.     

Evaluation of the <Emphasis Type="Italic">OPTC</Emphasis> gene in primary open angle glaucoma: functional significance of a silent change

Background  

We investigated the molecular basis of primary open-angle glaucoma (POAG) using Opticin (OPTC) as a candidate gene on the basis of its expression in the trabecular meshwork cells involved in the disease pathogenesis. Two hundred POAG patients and 100 controls were enrolled in this study. The coding sequence of OPTC was amplified by PCR from genomic DNA of POAG patients, followed by SSCP, DHPLC and DNA sequencing. Subsequent bioinformatic analysis, site-directed mutagenesis, quantitative RT-PCR and western blot experiments were performed to address the functional significance of a 'silent' change in the OPTC coding region while screening for mutations in POAG patients.     

Evolution of Transdisciplinarity and Ecosystem Health at the University of Newcastle,New South Wales,Australia

Antipodean pioneers of transdisciplinary (TD) thinking at the University of Newcastle, Glenn Albrecht and Nick Higginbotham have applied this perspective to contexts of human health globally and to the development of health social science as an emerging TD field. Nick Higginbotham has successfully championed the cause of TD thinking in international networks such as The International Clinical Epidemiology Network (INCLEN) and the International Forum for Social Sciences (IFSSEH). Glenn Albrecht has connected the Newcastle variety of TD thinking to its independently created doppelganger in the form of TD Ecosystem Health as pioneered by David Rapport in Canada. The convergence of TD thinking and Ecosystem Health at Newcastle has promoted a new curriculum in both undergraduate and postgraduate health and environmental sciences courses. Furthermore, TD research teams have been created and pursue investigations of both health and environmental problems. A successful national conference on transdisciplinary approaches to ecosystem health in Australia was held at Newcastle in April 2003. This article details the history of the evolution and synthesis of transdisciplinarity, ecosystem health, and ecohealth at the University of Newcastle, Australia, over a period from 1988 to the present.     

Intermediate CAG Repeat Expansion in the ATXN2 Gene Is a Unique Genetic Risk Factor for ALS?A Systematic Review and Meta-Analysis of Observational Studies

Amyotrophic lateral sclerosis (ALS) is a rare degenerative condition of the motor neurons. Over 10% of ALS cases are linked to monogenic mutations, with the remainder thought to be due to other risk factors, including environmental factors, genetic polymorphisms, and possibly gene-environmental interactions. We examined the association between ALS and an intermediate CAG repeat expansion in the ATXN2 gene using a meta-analytic approach. Observational studies were searched with relevant disease and gene terms from MEDLINE, EMBASE, and PsycINFO from January 2010 through to January 2014. All identified articles were screened using disease terms, gene terms, population information, and CAG repeat information according to PRISMA guidelines. The final list of 17 articles was further evaluated based on the study location, time period, and authors to exclude multiple usage of the same study populations: 13 relevant articles were retained for this study. The range 30–33 CAG repeats in the ATXN2 gene was most strongly associated with ALS. The meta-analysis revealed that the presence of an intermediate CAG repeat (30-33) in the ATXN2 gene was associated with an increased risk of ALS [odds ratio (OR) = 4.44, 95%CI: 2.91–6.76)] in Caucasian ALS patients. There was no significant difference in the association of this CAG intermediate repeat expansion in the ATXN2 gene between familial ALS cases (OR = 3.59, 1.58–8.17) and sporadic ALS cases (OR = 3.16, 1.88–5.32). These results indicate that the presence of intermediate CAG repeat expansion in the ATXN2 gene is a specific genetic risk factor for ALS, unlike monogenic mutations with an autosomal dominant transmission mode, which cause a more severe phenotype of ALS, with a higher prevalence in familial ALS.     

Cloning and sequencing of the medium-chain S-acyl fatty acid synthetase thioester hydrolase cDNA from rat mammary gland.

Catecholamines and Ca2+ mediate an increase in reactive-thiol status of phosphofructokinase, associated with an increase in activation of the enzyme. A correlation was observed between the number of reactive thiols and activation (r = 0.878; P less than 0.001) for 14 different treatments, with approx. 1 group per 85,000-Mr subunit becoming available over the range from the lowest to the highest state of activation.     

Transgenic Expression of Soluble Human CD5 Enhances Experimentally-Induced Autoimmune and Anti-Tumoral Immune Responses

CD5 is a lymphoid-specific transmembrane glycoprotein constitutively expressed on thymocytes and mature T and B1a lymphocytes. Current data support the view that CD5 is a negative regulator of antigen-specific receptor-mediated signaling in these cells, and that this would likely be achieved through interaction with CD5 ligand/s (CD5L) of still undefined nature expressed on immune or accessory cells. To determine the functional consequence of loss of CD5/CD5L interaction in vivo, a new transgenic mouse line was generated (shCD5EμTg), expressing a circulating soluble form of human CD5 (shCD5) as a decoy to impair membrane-bound CD5 function. These shCD5EμTg mice showed an enhanced response to autologous antigens, as deduced from the presentation of more severe forms of experimentally inducible autoimmune disease (collagen-induced arthritis, CIA; and experimental autoimmune encephalitis, EAE), as well as an increased anti-tumoral response in non-orthotopic cancer models (B16 melanoma). This enhancement of the immune response was in agreement with the finding of significantly reduced proportions of spleen and lymph node Treg cells (CD4+CD25+FoxP3+), and of peritoneal IL-10-producing and CD5+ B cells, as well as an increased proportion of spleen NKT cells in shCD5EμTg mice. Similar changes in lymphocyte subpopulations were observed in wild-type mice following repeated administration of exogenous recombinant shCD5 protein. These data reveal the relevant role played by CD5/CD5L interactions on the homeostasis of some functionally relevant lymphocyte subpopulations and the modulation of immune responses to autologous antigens.     

Histopathology, blood chemistry, and physiological status of normal and moribund striped bass (Morone saxatilis) involved in summer mortality ('die-off') in the Sacramento-San Joaquin Delta of California

Summer mortality ('die-off') is common in striped bass, Morone saxatilis (Walbaum), in the San Francisco Bay-Delta region. Tissue and blood samples of moribund and healthy striped bass collected during the summers of 1986–1988 were analysed. Sixteen moribund and 25 healthy reference fish from the Carquinez Strait area and eight fish caught in the Pacific Ocean were studied. Moribund fish plasma was invariably yellow-orange; most of the moribund fish had discoloured livers with haemorrhagic regions, and approximately one-third had haemorrhagic intestines. Piasma levels of aspartale aminotransferase, uric acid, alkaline phosphatase and cortisol were significantly higher than in reference fish from Carquinez Strait and the Pacific Ocean, whereas cholesterol, sodium, chloride, triiodothyronine and glucose levels were significantly lower. Hepatic heavy metal concentrations and bacterial content were similar in moribund and reference fish. Gill Na.⁺, K⁺ -ATPase activity was significantly lower in moribund fish. Liver, kidney, intestine, and thyroid follicles of moribund fish displayed various histopathological changes, and corticosteroidogenic (interrenal) tissue could not be identified positively in moribund fish. These findings are discussed in relation to recent work on the chemical burdens (industrial and agricultural hydrocarbons) found in livers from some of the fish examined in this study.