Transient increase in proteinuria,poly-ubiquitylated proteins and ER stress markers in podocyte-specific autophagy-deficient mice following unilateral nephrectomy

Previous studies have revealed that podocytes normally can be associated with a very high degree of autophagic activity, and that a lack of autophagic activity in podocytes is associated with susceptibility to disease and to late-onset glomerulosclerosis. In the present study, we conducted unilateral nephrectomy as a surgical model for acute nephron reduction. First, using GFP-LC3 transgenic mice to monitor autophagy, we found that glomerular autophagy could be transiently suppressed by surgery, but that it was restored quickly. To further explore the significance of podocyte autophagy after unilateral nephrectomy, we investigated podocyte-specific Atg7-deficient mice. The knockout mice exhibited no pathological phenotype compared with wild-type mice before nephrectomy. However, 1 day after nephrectomy, significantly higher levels of proteinuria and ultrastructural changes that included foot process effacement and a significant reduction in podocyte number were detected in mice harboring Atg7-deficient podocytes. Moreover, biochemical and immunohistochemical analyses showed a robust increase in polyubiquitin levels and ER stress markers in the glomeruli of the mice with autophagy-deficient podocytes. These results show the importance of the autophagic process in podocytes for maintaining a normal degree of filtration function during the adaptation to compensatory kidney hypertrophy following unilateral nephrectomy.     

Proteome analysis of soybean leaves,hypocotyls and roots under salt stress

Background  

Salinity is one of the most widespread agricultural problems in arid and semi-arid regions that makes fields unproductive, and soil salinization is a serious problem in the entire world. To determine the effects of salt stress on soybean seedlings, a proteomic technique was used.     

Determination of Nucleic Acids in Yeast from the Viewpoint of Elution Behavior of Acid-Soluble Compounds

It was reported previously that Ogur and Rosen’s method for the determination of nucleic acids should be applied to fresh or durable yeast, after a freezing pretreatment with dry ice and ether. The fractionation of nucleic acids from the frozen yeast should precede with a complete elimination of alcohol-ether-soluble and acid-soluble compounds. It has been found that in Ogur and Rosen’s method, the elimination of the former compounds is complete, but the removal of acid-soluble compounds is unsatisfactory in the case of yeast.

In order to improve this defect, the best conditions for the elution of acid-soluble compounds have been investigated in detail, and it has been found that water is the most suitable solvent.     

Analysis of beat fluctuations and oxygen consumption in cardiomyocytes by scanning electrochemical microscopy

The contractile behavior of cardiomyocytes can be monitored by measuring their action potentials, and the analysis is essential for screening the safety of potential drugs. However, immobilizing cardiac cells on a specific electrode is considerably complicated. In this study, we demonstrate that scanning electrochemical microscopy (SECM) can be used to analyze rapid topographic changes in beating cardiomyocytes in a standard culture dish. Various cardiomyocyte contraction parameters and oxygen consumption based on cell respiration could be determined from SECM data. We also confirmed that cellular changes induced by adding the cardiotonic agent digoxin were conveniently monitored by this SECM system. These results show that SECM can be a potentially powerful tool for use in drug development for cardiovascular diseases.     

Analysis of cytoplasmic factors in developmental cleavage of mouse embryo

One-cell embryos from certain mouse strains were found incapable of developing beyond the 2-cell stage in vitro (2-cell block), but a microinjection of EDTA effectively overcame this block. When 2-cell arrested embryos were fused with embryos that had developed to the late 2-cell stage in vivo, the fusants developed beyond the 2-cell stage. Microinjection of cytoplasm of in vivo 2-cell embryos into 1-cell embryos also obviated the 2-cell block. Analyses of 35S-labeled embryos by 2-dimensional polyacrylamide gel electrophoresis indicated changes in synthetic protein patterns possibly related to this block.     

Nontypeable Haemophilus influenzae-Induced MyD88 Short Expression Is Regulated by Positive IKKβ and CREB Pathways and Negative ERK1/2 Pathway

Airway diseases such as asthma and chronic obstructive pulmonary disease (COPD) are characterized by excessive inflammation and are exacerbated by nontypeable Haemophilus influenzae (NTHi). Airway epithelial cells mount the initial innate immune responses to invading pathogens and thus modulate inflammation. While inflammation is necessary to eliminate a pathogen, excessive inflammation can cause damage to the host tissue. Therefore, the inflammatory response must be tightly regulated and deciphering the signaling pathways involved in this response will enhance our understanding of the regulation of the host inflammatory response. NTHi binds to TLR2 and signal propagation requires the adaptor molecule myeloid differentiation factor 88 (MyD88). An alternative spliced form of MyD88 is called MyD88 short (MyD88s) and has been identified in macrophages and embryonic cell lines as a negative regulator of inflammation. However, the role of MyD88s in NTHi-induced inflammation in airway epithelial cells remains unknown. Here we show that NTHi induces MyD88s expression and MyD88s is a negative regulator of inflammation in airway epithelial cells. We further demonstrate that MyD88s is positively regulated by IKKβ and CREB and negatively regulated by ERK1/2 signaling pathways. Taken together these data indicate that airway inflammation is controlled in a negative feedback manner involving MyD88s and suggest that airway epithelial cells are essential to maintain immune homeostasis.     

A New Form of Structural Peptidoglycan in Selenomonas ruminantium: Existence of Polyamine in Peptidoglycan

The chemical constituents of calluses of Thujopsis dolabrata (Hiba), Chamaecyparis obtusa (Hinoki), Chamaecyparis pisifera (Sawara), and Platycladus orientalis (Konotegashiwa), all of which belong to Cupressaceae, were examined by GC analysis. The main components of these calluses were diterpenoids of an abietane-type and sitosterol in common, while the chemical constituents of these parent plants were different from each other.     

Synthesis of alkyne-tagged and biotin-tagged Sortin1 as novel photoaffinity probes

Sortin1 is an inhibitor of vesicular biogenesis and transport, which is shared among eukaryotes and plants with an unknown mode of action. Toward exploration of its target proteins, we developed alkyne as well as biotin conjugated photoaffinity probes derived from Sortin1. Due to the presence of phenylketone moiety, Sortin1 was anticipated to serve as a photoreactive group in a similar manner to a commonly used photoreactive group, benzophenone. The core structure based on 5-oxo-1,4-dihydroindenopyridine was constructed in one step using three-component Hantzsch dihydropyridine synthesis. We demonstrated that Sortin1 displayed photocrosslinking reactivity against a model binding protein, which would be useful for capturing and detecting binding proteins.