High glucose enhances IL-1beta-induced cyclooxygenase-2 expression in rat vascular smooth muscle cells

The changes in vascular prostaglandin production are implicated in the derangement of vascular reactivity in diabetes. However, the mechanism of altered prostaglandin (PG) production in diabetes is largely unknown. In this study, we investigated the effect of high glucose on IL-1beta-induced PG production and the possible underlying mechanism in cultured vascular smooth muscle cell (VSMC). High glucose evoked an augmentation of IL-1beta-induced PG synthesis in a dose dependent manner and enhanced cyclooxygenase (COX) activity, which reached to maximum at 8-12 hours after stimulation. Western blot analysis supported the activity data. Protein kinase C (PKC) inhibitors, H-7 and chelerythrine, significantly inhibited the enhancement of IL-1beta-induced COX-2 expression by high glucose. The activation of PKC by PMA resulted in marked increase of PG production in low glucose group, whilst this was not the case in high glucose group. Furthermore, glucose-enhancing effect was significantly suppressed by zopolrestat, an aldose reductase inhibitor, and sodium pyruvate. These results suggest that the augmenting effect of high glucose on IL-1beta-induced PG production and COX-2 expression is, at least in part, due to increased glucose metabolism via sorbitol pathway following PKC activation.     

Metabolic Dysfunction in Familial, but Not Sporadic, Amyotrophic Lateral Sclerosis

Abstract: Autosomal dominant familial amyotrophic lateral sclerosis (FALS) is associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1). Previous studies have implicated the involvement of metabolic dysfunction in ALS pathogenesis. To further investigate the biochemical features of FALS and sporadic ALS (SALS), we examined SOD activity and mitochondrial oxidative phosphorylation enzyme activities in motor cortex (Brodmann area 4), parietal cortex (Brodmann area 40), and cerebellum from control subjects, FALS patients with and without known SOD mutations, SALS patients, and disease controls (Pick's disease, progressive supranuclear palsy, diffuse Lewy body disease). Cytosolic SOD activity, predominantly Cu/Zn SOD, was decreased ∼50% in all regions in FALS patients with SOD mutations but was not significantly altered in other patient groups. Marked increases in complex I and II–III activities were seen in FALS patients with SOD mutations but not in SALS patients. We also measured electron transport chain enzyme activities in a transgenic mouse model of FALS. Complex I activity was significantly increased in the forebrain of 60-day-old G93A transgenic mice overexpressing human mutant SOD1, relative to levels in transgenic wild-type animals, supporting the hypothesis that the motor neuron disorder associated with SOD1 mutations involves a defect in mitochondrial energy metabolism.     

Do Sustained Lung Inflations during Neonatal Resuscitation Affect Cerebral Blood Volume in Preterm Infants? A Randomized Controlled Pilot Study

Background

Sustained lung inflations (SLI) during neonatal resuscitation may promote alveolar recruitment in preterm infants. While most of the studies focus on respiratory outcome, the impact of SLI on the brain hasn’t been investigated yet.

Objective

Do SLI affect cerebral blood volume (CBV) in preterm infants?

Methods

Preterm infants of gestation 28 weeks 0 days to 33 weeks 6 days with requirement for respiratory support (RS) were included in this randomized controlled pilot trial. Within the first 15 minutes after birth near-infrared spectroscopy (NIRS) measurements using ‘NIRO-200-NX’ (Hamamatsu, Japan) were performed to evaluate changes in CBV and cerebral tissue oxygenation. Two groups were compared based on RS: In SLI group RS was given by applying 1–3 SLI (30 cmH₂O for 15 s) continued by respiratory standard care. Control group received respiratory standard care only.

Results

40 infants (20 in each group) with mean gestational age of 32 weeks one day (±2 days) and birth weight of 1707 (±470) g were included. In the control group ΔCBV was significantly decreasing, whereas in SLI group ΔCBV showed similar values during the whole period of 15 minutes. Comparing both groups within the first 15 minutes ΔCBV showed a tendency toward different overall courses (p = 0.051).

Conclusion

This is the first study demonstrating an impact of SLI on CBV. Further studies are warranted including reconfirmation of the present findings in infants with lower gestational age. Future investigations on SLI should not only focus on respiratory outcome but also on the consequences on the developing brain.

Trial Registration

German Clinical Trials Register DRKS00005161 https://drks-neu.uniklinik-freiburg.de/drks_web/setLocale_EN.do     

5S rRNA-assisted DnaK refolding

Although accumulating evidence has revealed that most proteins can fold without the assistance of molecular chaperones, little attention has been paid to other types of chaperoning macromolecules. A variety of proteins interact with diverse RNA molecules in vivo, suggesting a potential role of RNAs for folding of their interacting proteins. Here we show that the in vitro refolding of a representative molecular chaperone, DnaK, an Escherichia coli homolog of Hsp70, could be assisted by its interacting 5S rRNA. The folding enhancement occurred in RNA concentration and its size dependent manner whereas neither the RNA with the reverse sequence of 5S rRNA nor the RNase pretreated 5S rRNA stimulated the folding in vitro. Based on our results, we propose that 5S rRNA could exert the chaperoning activity on DnaK during the folding process. The results suggest an interesting possibility that the folding of RNA-interacting proteins could be assisted by their cognate RNA ligands.     

Tbx3, a transcriptional factor, involves in proliferation and osteogenic differentiation of human adipose stromal cells

Both, diabetes mellitus (DM) and hypercholesterolemia (HCH) are known as risk factors of ischemic heart disease, however, the effects of experimental DM, as well as of HCH alone, on ischemia/reperfusion-induced myocardial injury are not unequivocal. We have previously demonstrated an enhanced resistance to ischemia-induced arrhythmias in rat hearts in the acute phase of DM. Our objectives were thus to extend our knowledge on how DM in combination with HCH, a model that is relevant to diabetic patients with altered lipid metabolism, may affect the size of myocardial infarction and susceptibility to arrhythmias. A combination of streptozotocin (STZ; 80 mg/kg, i.p.) and the fat–cholesterol diet (1% cholesterol, 1% coconut oil; FCHD) was used as a double-disease model mimicking DM and HCH simultaneosly occurring in humans. Following 5 days after STZ injection and FCHD leading to increased blood glucose and cholesterol levels, anesthetized open-chest diabetic, diabetic–hypercholesterolemic (DM–HCH) and age-matched control rats were subjected to 6-min ischemia (occlusion of LAD coronary artery) followed by 10 reperfusion to test susceptibility to ventricular arrhythmias in the in vivo experiments and to 30-min ischemia and subsequent 2-h reperfusion for the evaluation of the infarct size (IS) in the Langendorff-perfused hearts. The incidence of the most life-threatening ventricular arrhythmia, ventricular fibrillation, was significantly increased in the DM–HCH rats as compared with non-diabetic control animals (100% vs. 50%; p<0.05). Likewise, arrhythmia severity score (AS) was significantly higher in the DM–HCH rats than in the controls (4.9±0.2 vs. 3.5±0.5; p<0.05), but was not increased in the diabetic animals (AS 3.7±0.9; p>0.05 vs. controls). Diabetic hearts exhibited a reduced IS (15.1±3.0% of the area at risk vs. 37.6±2.8% in the control hearts; p<0.05), however, a combination of DM and HCH increased the size of myocardial infarction to that observed in the controls. In conclusion, HCH abrogates enhanced resistance to ischemia-reperfusion injury in the diabetic rat heart.     

Differences of urease activity and expression of associated genes according to gastric topography

Background: We hypothesize that pH difference between acid‐secreting corpus and non‐secreting antrum might influence the activity of H. pylori’s urease and/or related genes. We therefore measured urease activity and the expression of amiE whose encoded protein that hydrolyzes short‐chain amides to produce ammonia. Materials and Methods: Fifty‐four patients were recruited into this study. Each gastroscopic biopsy specimen collected from the antrum and body of each patient was immediately used to measure urease activity using serial changes of urease activity (ammonia levels) during 60 minutes. Probe specific for amiE was labeled with a biotin nick‐translation kit and was used to detect expression of these genes (mRNA) in fresh‐frozen gastroscopic biopsy specimens using fluorescent in situ hybridization (FISH). Results: Urease activity at 60 minutes from the gastric antrum and body of all patients infected with H. pylori was 399.5 ± 490.5 and 837.9 ± 1038.9 μg/dL, respectively (p = .004). Urease activity in the antrum was correlated with H. pylori density. Urease activity or H. pylori density in the antrum was significantly correlated with chronic active inflammation; in contrast, this correlation was not found in the gastric body. The expression level of amiE was 1.5 times higher (p < .05) in the gastric body compared with the antrum. Conclusion: Topographically, the urease activity in body was much higher than in antrum. The expression level of amiE was higher in the gastric body compared with the antrum.     

Screening and characterization of a cellulase gene from the gut microflora of abalone using metagenomic library

A metagenomic fosmid library was constructed using genomic DNA isolated from abalone intestine. Screening of a library of 3,840 clones revealed a 36 kb insert of a cellulase positive clone (pAMHElO). A shotgun clone library was constructed using the positive clone (pAMHElO) and further screening of 3,840 shotgun clones with an approximately 5 kb insert size using a Congo red overlay revealed only one cellulase positive clone (pAMHL9). The pAMHL9 consisted of a 5,293-bp DNA sequence and three open reading frames (ORFs). Among the three ORFs, cellulase activity was only shown in the recombinant protein (CelAMll) coded by ORF3, which showed 100% identity with outer membrane protein A from Vibrio alginolyticus 12G01, but no significant sequence homology to known cellulases. The expressed protein (CelAMll) has a molecular weight of approximately 37 kDa and the highest CMC hydrolysis activity was observed at pH 7.0 and 37°C. The carboxymethyl cellulase activity was determined by zymogram active staining and different degraded product profiles for CelAMll were obtained when cellotetraose and cellopentaose were used as the substrates, while no substrate hydrolysis was observed on oligosaccharides such as cellobiose and cellotriose.     

Modulation of TNFSF expression in lymphoid tissue inducer cells by dendritic cells activated with Toll-like receptor ligands

Toll-like receptors (TLRs), which recognize structurally conserved components among pathogens, are mainly expressed by antigen-presenting cells such as dendritic cells (DCs), B cells, and macrophages. Recognition through TLRs triggers innate immune responses and influences antigen-specific adaptive immune responses. Although studies on the expression and functions of TLRs in antigen-presenting cells have been extensively reported, studies in lymphoid tissue inducer (LTi) cells have been limited. In this study, we observed that LTi cells expressed TLR2 and TLR4 mRNA as well as TLR2 protein and upregulated OX40L, CD30L, and TRANCE expression after stimulation with the TLR2 ligand zymosan or TLR4 ligand LPS. The expression of tumor necrosis factor superfamily (TNFSF) members was significantly upregulated when cells were cocultured with DCs, suggesting that upregulated TNFSF expression may contribute to antigen-specific adaptive immune responses.     

Enhancement of centelloside production from cultured plants of Centella asiatica by combination of thidiazuron and methyl jasmonate

In order to produce centellosides from whole plant cultures of Centella asiatica (L.) Urban, we evaluated the synergistic effects of thidiazuron (TDZ) and methyl jasmonate (MJ) on whole plant growth and centelloside production. After 4 weeks of treatment with 0.025 mg/L of TDZ coupled with 0.1 mM MJ, the production of madecassoside and asiaticoside from whole plant cultures was estimated to be 2.40- and 2.44-fold, respectively, above that of MJ elicitation alone. When whole plants were treated with a growth regulator and an elicitor, the growth of whole plants, as compared to the controls, did not differ. Additionally, total phytosyterol content in the leaves of whole plants co-treated with MJ and TDZ was 1.08-fold greater than those of MJ alone. These results demonstrate that combined treatments not only stimulate the accumulation of centellosides in the leaves but also inhibit the reduction of phytosterol levels caused by MJ elicitation.     

Radiation-sensitive Arabidopsis mutants are proficient for T-DNA transformation

Stable transformation of plants by Agrobacterium T-DNAs requires that the transgene insert into the host chromosome. Although most of the Agrobacterium Ti plasmid genes required for this process have been studied in depth, few plant-encoded factors have been identified, although such factors, presumably DNA repair proteins, are widely presumed to exist. It has previously been suggested that the UVH1 gene product is required for stable T-DNA integration in Arabidopsis. Here we present evidence suggesting that uvh1 mutants are essentially wild type for T-DNA integration following inoculation via the vacuum-infiltration procedure.