Nyet Kui Wong

Respiratory Distress and Neonatal Lethality in Mice Lacking Golgi α1,2-Mannosidase IB Involved in N-Glycan Maturation

There are three mammalian Golgi α1,2-mannosidases, encoded by different genes, that form Man5GlcNAc2 from Man8-9GlcNAc2 for the biosynthesis of hybrid and complex N-glycans. Northern blot analysis and in situ hybridization indicate that the three paralogs display distinct developmental and tissue-specific expression. The physiological role of Golgi α1,2-mannosidase IB was investigated by targeted gene ablation. The null mice have normal gross appearance at birth, but they display respiratory distress and die within a few hours. Histology of fetal lungs the day before birth indicate some delay in development, whereas neonatal lungs show extensive pulmonary hemorrhage in the alveolar region. No significant histopathological changes occur in other tissues. No remarkable ultrastructural differences are detected between wild type and null lungs. The membranes of a subset of bronchiolar epithelial cells are stained with lectins from Phaseolus vulgaris (leukoagglutinin and erythroagglutinin) and Datura stramonium in wild type lungs, but this staining disappears in lungs from null mice. Mass spectrometry of N-glycans from different tissues shows no significant changes in global N-glycans of null mice. Therefore, only a few glycoproteins required for normal lung function depend on α1,2-mannosidase IB for maturation. There are no apparent differences in the expression of several lung epithelial cell and endothelial cell markers between null and wild type mice. The α1,2-mannosidase IB null phenotype differs from phenotypes caused by ablation of other enzymes in N-glycan biosynthesis and from other mouse gene disruptions that affect pulmonary development and function.

Immunomodulatory properties of Tamm-Horsfall glycoprotein (THP) and uromodulin

BACKGROUND Tamm-Horsfall glycoprotein (THP) and uromodulin are the most abundant glycoproteins in non-pregnant womens/mens and pregnant womens urine, respectively. However, the bioactivities of these glycoproteins are still unclear. OBJECTIVE To evaluate the immunomodulatory properties of THP and uromodulin on human peripheral blood mononuclear cells (PBMC) METHODS: THP and uromodulin isolated with diatomaceous earth filtration were subjected to several bioassays, such as MTS viability assay, immunophenotyping and cytokine analysis. RESULTS MTS viability assay and immunophenotyping analysis showed that uromodulin has greater inhibitory activities in suppressing PBMC viability and the percentage of CD4⁺ T helper cells and CD8⁺ cytotoxic T cells, compared to that of THP. In cytokine analysis, THP tended to induce pro-inflammatory cytokines such as IL-1β, TNF and Th1 cytokine IFN-γ; while uromodulin only induced IL-1β and suppressed both Th1 cytokine IFN-γ and Th2 cytokine IL-10. CONCLUSION These results demonstrate that uromodulin has greater immunosuppressive activities and lower inductive property in relation to activation of immune cells, which provides a more tolerant environment for the developing fetus.

COMPARISON STUDY OF THERAPEUTIC PROPERTIES OF PROTEINS AND SECONDARY METABOLITES FROM CARICA PAPAYA

Objective: The objectives of this study were to assess the prevalence of hypertension and the level of blood pressure (BP) control among a cohort of diabetic Lebanese patients on antihypertensive medications, as well as to identify factors associated with hypertension prevalence and uncontrolled BP. Methods: This cross-sectional retrospective study was conducted in a tertiary health care clinic that is specialized in the management and follow-up of diabetic outpatients. Results: Among the 700 type 2 diabetes mellitus patient files that were screened529 (75%) were found to have hypertension. Hypertension was more prevalent in women, patients aged ≥65-year-old, and those having a body mass index (BMI) of ≥30 (kg/m 2 ) (p-value<0.05). Among the hypertensive cohort, 465 T2DM were on antihypertensive medications and were included in the hypertension control analysis. Ninety-three patients (20%) attained BP control (SBP<140 and DBP<90 mmHg). Multivariate analyses revealed three factors that were significantly associated with uncontrolled BP control: Age being ≥65 y (adjusted OR = 1.96 (95% CI: 1.07–3.61, p-value<0.05), male gender (adjusted OR = 2.57, 95% CI: 1.41–4.66, p-value<0.05) and uncontrolled HDL (adjusted OR = 1.58, 95% CI: 1.33–2.01, p-value = 0.05). Conclusion : Hypertension is prevalent among the study patients. However, attainment of BP control was poor among these patients. Therefore, there is a need for studies that determine reasons behind this low BP control rate in order to design interventions aiming at improving the standard of care for these patients.

Sexual Dimorphic Responses in Lymphocytes of Healthy Individuals after Carica papaya Consumption

Sexual dimorphism in immune response is widely recognized, but few human studies have observed this distinction. Food with endo-immunomodulatory potential may reveal novel sex-biased in vivo interactions. Immunomodulatory effects of Carica papaya were compared between healthy male and female individuals. Volunteers were given fixed meals supplemented with papaya for 2 days. Changes in blood immune profiles and hormone levels were determined. In females, total natural killer (NK) cell percentages decreased (12.7 ± 4.4 vs 14.6 ± 5.8%, p = 0.018, n = 18) while B cells increased (15.2 ± 5.5 vs 14.5 ± 5.0, p = 0.037, n = 18) after papaya consumption. Increased 17β-estradiol (511.1 ± 579.7 vs 282.7 ± 165.0 pmol/l, p = 0.036, n = 9) observed in females may be crucial to this change. Differentiation markers (CD45RA, CD69, CD25) analyzed on lymphocytes showed naïve (CD45RA+) non-CD4+ lymphocytes were reduced in females (40.7 ± 8.1 vs 46.8 ± 5.4%, p = 0.012, n = 8) but not males. A general suppressive effect of papaya on CD69+ cells, and higher percentage of CD69+ populations in females and non-CD4 lymphocytes, may be relevant. CD107a+ NK cells were significantly increased in males (16.8 ± 7.0 vs 14.7 ± 4.8, p = 0.038, n = 9) but not females. Effect in females may be disrupted by the action of progesterone, which was significantly correlated with this population (R = 0.771, p = 0.025, n = 8) after papaya consumption. In males, total T helper cells were increased (33.4 ± 6.4 vs 32.4 ± 6.1%, p = 0.040, n = 15). Strong significant negative correlation between testosterone and CD25+CD4+ lymphocytes, may play a role in the lower total CD4+ T cells reported in males. Thus, dissimilar immune profiles were elicited in the sexes after papaya consumption and may have sex hormone influence.

Structural and immunosuppression study for bioactivities of Tamm-Horsfall glycoprotein and uromodulin

Abstract Introduction Tamm-Horsfall glycoprotein (THP) and uromodulin are the most abundant glycoproteins in the urine of non-pregnant women and pregnant women, respectively. Today, the structural profile and biological activities of these glycoproteins are controversial. Objectives To investigate the glycoforms and immunosuppressive activities of THP and Uromodulin Methods Uromodulin were isolated from diatomaceous earth filtration, N- and O-glycans were then analysed with mass spectrometer MALDI-TOF/TOF. MTS viability, cytokine and immunophenotyping assays were carried out to investigate the immunomodulatory activities of both THP and uromodulin Results & Discussion MALDI-TOF/TOF analysis showed that both THP and uromodulin expressed high mannose and complex-type N-glycan carrying sialic acid residues, Sda, LacNAc and LacdiNAc sequence as the capping antennae. Uromodulin tends to express multiple degree of sialylation, in which up to four sialic acid residues were expressed on its tetra-antennary Nglycans. Core 1 and core 2 type O-glycans were observed in THP and uromodulin, with THP expressing more O-glycans. MTS viability assay showed that 125μg/ml of uromodulin and 250μg/ml of THP significantly reduced the PHA-activated PBMC cell viability, to 85.64 ± 5.9 > % and 84.59 ±2.94%, respectively. Uromodulin was 2-fold more active in suppressing PBMC cell viability. Immunophenotyping analysis showed that CD4+ T helper cells, CD8+ cytotoxic T cells, CD56+ NK cells and CD14+ monocytes were suppressed by THP. It induced pro-inflammatory cytokines such as IL-1β, TNF and Th1 cytokine IFN-γ. On the other hand, uromodulin had slightly greater effect in suppressing CD4+ T helper cells and CD8+ cytotoxic T cells. It only induced IL-1β and suppressed both Th1 cytokine IFN-γ and Th2 cytokine IL-10. Hence, uromodulin is more immunosuppressive than THP because it suppressed CD4+ and CD8+ T cells, stimulated IL-1β only and withheld the TNF secretion. Conclusions Glycosylation changes as observed in THP are suggested to contribute to their differential immunosuppressive property. Developing

Culture Conditions for Optimal Growth of Actinomycetes from Marine Sponges

Actinomycetes are filamentous gram-positive bacteria that can be found abundantly in both terrestrial and marine environment. These bacteria are known as producers of many bioactive compounds through the production of secondary metabolites for their survival and adaptation in nature and have been widely used today as therapeutic agents. Marine actinomycetes have been the focus of research over the past decade for new drugs discovery due to its unique adaptation in the harsh sea environment. It is believed that marine actinomycetes could produce compounds that are rare and unique compared to the terrestrial actinomycetes. Despite its potential, marine actinomycetes are critically difficult to culture in laboratory because these actinomycetes live in extreme environment in the sea with high salt concentration, high pressure, low temperature, and constant pH changes of seawater in its natural environment. Hence, in this study, optimum condition to culture marine actinomycetes was achieved by culturing the marine actinomycetes from marine sponges on different culture condition such as different types of isolation media, pH, seasalt concentration, temperature, and incubation time. Starch casein agar (SCA) is shown to be the best isolation media compared to actinomycetes isolation agar (AIA) and Kuster agar (KUA). The growth of marine actinomycetes is optimum at pH 7, 40 % of seasalt concentration, 20–30 °C and 7–10 days of incubation time.

MS strategies for high throughput glycomics and glyco-proteomics

Ultra‐high sensitivity mass spectrometric strategies for defining the primary structures of highly complex mixtures of glycopolymers are revolutionizing structural glycobiology in the postgenomic era. MS strategies incorporating MALDI‐MS and ES‐MS/MS enable very complex mixtures from biological extracts and/or glycopolymer digests to be screened, thereby revealing the types of glycans present and, importantly, providing clues to structures that are likely to be functionally important.