Genome-wide microarray analysis of TGFβ signaling in the Drosophila brain

BACKGROUND: Members of TGFβ superfamily are found to play important roles in many cellular processes, such as proliferation, differentiation, development, apoptosis, and cancer. In Drosophila, there are seven ligands that function through combinations of three type I receptors and two type II receptors. These signals can be roughly grouped into two major TGFβ pathways, the dpp/BMP and activin pathways, which signal primarily through thick veins (tkv) and baboon (babo). Few downstream targets are known for either pathway, especially targets expressed in the Drosophila brain. RESULTS: tkv and babo both affect the growth of tissues, but have varying effects on patterning. We have identified targets for the tkv and babo pathways by employing microarray techniques using activated forms of the receptors expressed in the brain. In these experiments, we compare the similarities of target genes of these two pathways in the brain. About 500 of 13,500 examined genes changed expression at 95% confidence level (P < 0.05). Twenty-seven genes are co-regulated 1.5 fold by both the tkv and babo pathways. These regulated genes cluster into various functional groups such as DNA/RNA binding, signal transducers, enzymes, transcription regulators, and neuronal regulators. RNAi knockdown experiments of homologs of several of these genes show abnormal growth regulation, suggesting these genes may execute the growth properties of TGFβ. CONCLUSIONS: Our genomic-wide microarray analysis has revealed common targets for the tkv and babo pathways and provided new insights into downstream effectors of two distinct TGFβ like pathways. Many of these genes are novel and several genes are implicated in growth control. Among the genes regulated by both pathways is ultraspiracle, which further connects TGFβ with neuronal remodeling

Effect of switching from sevelamer hydrochloride to lanthanum carbonate on metabolic acidosis in dialysis patients

Treatments for hyperphosphatemia in dialysis patients include dietary therapy and oral administration of phosphate binders; however, it has recently been suggested that oral administration of sevelamer hydrochloride, a phosphate binder, may cause metabolic acidosis. Owing to the decreased supply of sevelamer hydrochloride after the Eastern Japan Great Earthquake Disaster on March 11, 2011, hyperphosphatemia patients switched to another phosphate binder, lanthanum carbonate. Here, we retrospectively evaluated the effect of this medication substitution on metabolic acidosis in patients on maintenance hemodialysis. 32 patients, who underwent maintenance hemodialysis at Nagasaki Kidney Center in Japan, were enrolled in our study and followed to evaluate the effect of switching medication on metabolic acidosis at 3 months after switching from sevelamer hydrochloride to lanthanum carbonate. The mean dose of sevelamer hydrochloride prior to the earthquake disaster was 3 g/day, and the mean dose of lanthanum carbonate thereafter was 0.9 g/day. Three months after the medication was changed, the concentration of bicarbonate ion did not increase significantly (p = 0.186), whereas pH and base excess increased significantly (p = 0.007 and p = 0.036, respectively). In this study, although the HCO3 - level was not significantly changed, the pH and base excess were significantly increased. Our findings indicate that lanthanum carbonate ameliorates metabolic acidosis

Association between serum calcium levels and prognosis, hematoma volume, and onset of cerebral hemorrhage in patients undergoing hemodialysis

Background: High serum calcium levels should be avoided in patients on hemodialysis (HD) because they can induce cardiovascular diseases and worsen the patient\u27s prognosis. In contrast, low serum calcium levels worsen the prognosis of patients with cerebral hemorrhage in the general population. So far, whether serum calcium levels in patients on HD are associated with cerebral hemorrhage remains unknown. This study aimed to reveal the association between serum calcium and cerebral hemorrhage in patients on HD, including in-hospital death, volume of hematoma, and onset of cerebral hemorrhage. Methods: This cross-sectional case-control study included 99 patients on HD with cerebral hemorrhage at a single center between July 1, 2007 and December 31, 2017. Controls included 339 patients on HD at a single HD center between July 1, 2011 and June 30, 2012. Data on serum calcium level, patient demographics, and comorbid conditions were collected, and associations between cerebral hemorrhage and subsequent death were evaluated by multivariate logistic regression analysis. Further, the association of these backgrounds and hematoma volume was evaluated by multiple regression analysis. Results: Of the 99 patients, 32 (32%) died from cerebral hemorrhage. The corrected serum calcium level (odds ratio [OR], 2.49; 95% confidence interval [CI], 1.43-4.35; P < 0.001) and antiplatelet drug use (OR, 3.95; 95% CI, 1.50-10.4; P = 0.005)had significant effects on the prognosis. Moreover, the corrected serum calcium (P = 0.003) and antiplatelet drug use (P = 0.01) were significantly correlated with hematoma volume. In the patients, the corrected serum calcium level (OR, 1.54; 95% CI, 1.07-2.22; P = 0.02) was associated with the onset of cerebral hemorrhage, as was pre-hemodialysis systolic blood pressure (per 10 mmHg) (OR, 1.40; 95% CI, 1.23-1.59; P < 0.001). Conclusions: Although the precise mechanisms remain unknown, a high serum calcium level is associated with cerebral hemorrhage in patients on HD. Thus, we should pay attentions to a patient\u27s calcium level

Evidence for an Essential Deglycosylation-Independent Activity of PNGase in Drosophila melanogaster

BACKGROUND: Peptide:N-glycanase (PNGase) is an enzyme which releases N-linked glycans from glycopeptides/glycoproteins. This enzyme plays a role in the ER-associated degradation (ERAD) pathway in yeast and mice, but the biological importance of this activity remains unknown. PRINCIPAL FINDINGS: In this study, we characterized the ortholog of cytoplasmic PNGases, PNGase-like (Pngl), in Drosophila melanogaster. Pngl was found to have a molecular weight of approximately 74K and was mainly localized in the cytosol. Pngl lacks a CXXC motif that is critical for enzymatic activity in other species and accordingly did not appear to possess PNGase activity, though it still retains carbohydrate-binding activity. We generated microdeletions in the Pngl locus in order to investigate the functional importance of this protein in vivo. Elimination of Pngl led to a serious developmental delay or arrest during the larval and pupal stages, and surviving mutant adult males and females were frequently sterile. Most importantly, these phenotypes were rescued by ubiquitous expression of Pngl, clearly indicating that those phenotypic consequences were indeed due to the lack of functional Pngl. Interestingly, a putative "catalytic-inactive" mutant could not rescue the growth-delay phenotype, indicating that a biochemical activity of this protein is important for its biological function. CONCLUSION: Pngl was shown to be inevitable for the proper developmental transition and the biochemical properties other than deglycosylation activity is important for its biological function

Co-Expression of NEU2 and GBA3 Causes a Drastic Reduction in Cytosolic Sialyl Free N-glycans in Human MKN45 Stomach Cancer Cells—Evidence for the Physical Interaction of NEU2 and GBA3

It is well known that the “free” form of glycans that are structurally related to asparagine (N)-linked glycans (“free N-glycans”) are found in a wide variety of organisms. The mechanisms responsible for the formation/degradation of high mannose-type free N-glycans have been extensively studied in mammalian cells. Recent evidence, however, also suggests that sialylated, complex-type free N-glycans are also present in the cytosol of various mammalian-derived cultured cells/tissues. We report herein on an investigation of the mechanism responsible for the degradation of such sialyl free N-glycans. The findings show that the amount of glycans is dramatically reduced upon the co-expression of cytosolic sialidase NEU2 with cytosolic β-glycosidase GBA3 in human stomach cancer-derived MKN45 cells. The physical interaction between NEU2 and GBA3 was confirmed by co-precipitation analyses as well as gel filtration assays. The NEU2 protein was found to be stabilized in the presence of GBA3 both in cellulo and in vitro. Our results thus indicate that cytosolic GBA3 is likely involved in the catabolism of cytosolic sialyl free N-glycans, possibly by stabilizing the activity of the NEU2 protein

Correction: Effect of statin on life prognosis in Japanese patients undergoing hemodialysis.

[This corrects the article DOI: 10.1371/journal.pone.0224111.]