Structure--activity relationships of chemical inducers of carotenoid biosynthesis

Fifteen amines having a profound effect on carotenogenesis in Marsh seedless grapefruit are reported. The compounds fall into three series: Et₂N(CH₂)_nMe (n = 4–8), Et₂N(CH₂)_nPh (n = 1–5), and Et₂NCH₂CH₂OC₆H₄R (R=H, p-Me, p-Et, p-iso-Pr, p-tert-Bu), There was up to an 11-fold increase in the total carotene content. Lycopene, not normally accumulated, became a major pigment. The inducing ability of the amines on carotenoid biosynthesis is correlated with the octanol-water partition coefficient. The mode of action appears to be similar to that of 2-(4-chlorophenylthio)triethylamine hydrochloride.     

Enzymes of purine catabolism in soybean plants

Remarkable formation and utilization of allantoin is observedin soybean (Glycine max variety A62-1). To study this, variousenzymes involved in purine catabolism (i.e., xanthine oxidase,uricase and allantoinase) were measured in different regionsof soybean plants during development. Uricase, which catalyzesthe direct formation of allantoin from uric acid, was studiedin detail. The activities of these three enzymes were highest in the rootnodules, indicating that the nodules are the major site of allantoinmetabolism. Radicles only showed appreciable activity about80 hr after the seeds were planted. Allantoinase activity wasdetected in all regions tested, showing that allantoin translocatedfrom the nodules can be metabolized in the roots, stem and leaves.In the nodules, xanthine oxidase was localized in the nuclearfraction, while uricase was mainly restricted to the mitochondrialfraction and allantoinase to the soluble fraction. Uricase was partially purified from the nodules and radicles,respectively. The pH optimum of enzyme from the nodules was9.5, whereas that of enzyme from the radicles was 7.0. The enzymefrom the nodules did not require a cofactor, while that fromthe radicles showed an absolute requirement for a cofactor,which was a low molecular substance easily separable from theapoprotein. Thus, the uricase in nodules differs in chemicalproperties from that in the host plant. The results are discussedin relation to change in the allantoin level in soybean tissues. (Received November 1, 1974; )     

Transmission of Thelohanellus hovorkai Achmerov, 1960 (Myxosporea: Myxozoa) to common carp Cyprinus carpio through the alternate oligochaete host

Thelohanellus hovorkai (Myxosporea: Myxozoa) was transmitted to common carp Cyprinus carpio by exposing fish to Aurantiactinomyxon spores collected from the oligochaete Branchiura sowerbyi. The morphological characteristics of the actinosporean stage are described in detail. B. sowerbyi were exposed to T. hovorkai spores isolated from the experimentally infected carp, and after 3 and 4 months the worms exhibited prevalences of the actinosporean stage at 19.47% (7/36) and 14.6% (6/41), respectively. Control, unexposed worms were negative for the actinosporean infection. This is the first report of an Aurantiactinomyxon transforming into a myxosporean belonging to the suborder Platysporina.     

Properties of common wheat ferredoxin, and a comparison with ferredoxins from related species of triticum and aegilops.

Wheat ferredoxin was purified from the leaves of common wheat (Triticum aestivum). The absorption spectrum showed maxima at 465, 425, 332, and 278 nm. The absorbance ratio, A425 nm/A278 nm was 0.49, and the millimolar extinction coefficient at 425 nm was 10.8 mM-1. cm-1. The amino acid composition was determined to be Lys5, His2, Arg1, Asp11, Thr5, Ser7, Glu18, Pro5, Gly6, Ala7, Cys5, Val7, Met1, Ile4, Leu7, Tyr4, Phe1, and Trp1. The total number of amino acid residues was 97. The molecular weight was calculated from the amino acid composition to be 10,829, including iron and sulfur atoms. This value was confirmed by other methods, which were based on the contents of non-heme iron and of terminal amino acid. The N-terminal amino acid was alanine, and the C-terminal amino acid sequence was -Glu-Leu-Thr-AlaCOOH. Comparative studies were performed between T. aestivum ferredoxin and ferredoxins isolated from closely related species; these were T. aegilopoides, T. durum, Ae. squarrosa, and Ae. ovata. No significant differences in the properties of these ferredoxins were detected. It was also shown that these ferredoxins are immunologically homologous. It is, therefore, likely that one molecular species of ferredoxin is distributed through two genera of Triticum and Aegilops.     

Effect of reproductive compensation and the desire to have male offspring on the incidence of a sex-linked lethal disease.

The effects of reproductive compensation on an X-linked recessive lethal are examined. Complete compensation without regard to the sex of the offspring increases the incidence of female carriers by a factor of 1.5, and of affected males by 1.33. However, if families reproduce until they have a healthy male offspring, the incidence of the X-linked lethal can be increased two or three orders of magnitude. Even only 1% of the population reproducing until a male is born can inflate the incidence of the disease by an order of magnitude, provided this pattern of family planning is culturally inherited. Similarly, reproducing until there is at least one child of each sex increases the incidence of an X-linked lethal. The impact of these types of sex-biased family planning on the fraction of new mutants among affect males is discussed.     

Antimicrobial activity and secondary structure of a novel peptide derived from ovalbumin

A novel antimicrobial peptide derived from ovalbumin has been discovered. First, the peptide fragment RKIKVYLPRMK (TK9.1) was identified based on computerized predictions of the secondary structure of peptides in a protein data bank. Using HeliQuest, the sequence was developed into RKIKRYLRRMI (TK9.1.3), which was synthesized using Fmoc‐solid phase peptide synthesis, and found to have strongly antimicrobial activity against Gram‐positive and Gram‐negative bacteria, and fungi but not cytotoxic to HeLa cells and hemolysis in mouse red blood cells. Although ovalbumin itself does not have an antibacterial activity, our results suggest that it may supply the organisms that consume it with antimicrobial peptides, in support of their immunodefence.     

Nitric oxide protection against adriamycin-induced tubulointerstitial injury

It is well known that oxidative stress is related to the pathogenesis of adriamycin (ADR) nephropathy. However, it is unclear how nitric oxide (NO) is associated with the pathophysiological process after ADR administration. The NO level in a kidney homogenate was assayed by electron paramagnetic resonance (EPR) spectrometry using a direct in vivo NO trapping technique after ADR administration. N-(3-(aminomethyl)benzyl)acetamidine (1400W) was used as a specific, inducible nitric oxide synthase (iNOS) inhibitor. The levels of NO after ADR administration gradually increased for 6 h and then decreased until 24 h after ADR administration. The fractional excretion of Na (FE_Na) in the urine was elevated in the ADR group on day 1. Pre-treatment of the animals with 1400W attenuated the increase in NO levels despite further elevation of FE_Na. These findings suggest that iNOS-derived NO does not produce a harmful effect but rather protects the ADR-treated kidney against sodium excretion.     

A complex interaction between Wnt signaling and TNF-α in nucleus pulposus cells

Introduction

Increased expression of the proinflammatory cytokine TNF-α in intervertebral discs (IVDs) leads to inflammation, which results in progressive IVD degeneration. We have previously reported that activation of Wnt-β-catenin (hereafter called Wnt) signaling suppresses the proliferation of nucleus pulposus cells and induces cell senescence, suggesting that Wnt signaling triggers the process of degeneration of the IVD. However, it is not known whether cross talk between TNF-α and Wnt signaling plays a role in the regulation of nucleus pulposus cells. The goal of the present study was to examine the effect of the interaction between Wnt signaling and the proinflammatory cytokine TNF-α in nucleus pulposus cells.

Methods

Cells isolated from rat nucleus pulposus regions of IVDs were cultured in monolayers, and the expression and promoter activity of Wnt signaling and TNF-α were evaluated. We also examined whether the inhibition of Wnt signaling using cotransfection with Dickkopf (DKK) isoforms and Sclerostin (SOST) could block the effects of pathological TNF-α expression in nucleus pulposus cells.

Results

TNF-α stimulated the expression and promoter activity of Wnt signaling in nucleus pulposus cells. In addition, the activation of Wnt signaling by 6-bromoindirubin-3′-oxime (BIO), which is a selective inhibitor of glycogen synthase kinase 3 (GSK-3) activity that activates Wnt signaling, increased TNF-α expression and promoter activity. Conversely, the suppression of TNF-α promoter activity using a β-catenin small interfering RNA was evident. Moreover, transfection with DKK-3, DKK-4, or SOST, which are inhibitors of Wnt signaling, blocked Wnt signaling-mediated TNF-α activation; these effects were not observed for DKK-1 or DKK-2.

Conclusions

Here, we have demonstrated that Wnt signaling regulates TNF-α and that Wnt signaling and TNF-α form a positive-feedback loop in nucleus pulposus cells. The results of the present study provide in vitro evidence that activation of Wnt signaling upregulates the TNF-α expression and might cause the degeneration of nucleus pulposus cells. We speculate that blocking this pathway might protect nucleus pulposus cells against degeneration.     

The influence of blood glucose on neutrophil function in individuals without diabetes

We assessed the association of neutrophil function with glycated hemoglobin (HbA1c) levels in a Japanese general population. Participants were 809 males and females who were over 20 years old living in the Iwaki region in Aomori Prefecture located in northern Japan. Lifestyle parameters (smoking, alcohol consumption, and exercise habits), HbA1c and neutrophil function such as reactive oxygen species (ROS) production capability and phagocytic activity (PA) were measured. ROS production capability was measured before and after phagocytic stimulus to obtain basal ROS production and stimulated ROS production. Level of HbA1c had a positive correlation with basal ROS production (p=0.053), a negative correlation with stimulated ROS production (p=0.072) and PA (p=0.059) only in post‐menopausal groups, and not in pre‐menopausal groups. However, there were no correlations between levels of HbA1c and neutrophil functions in male. In conclusion, in the present study, despite the presence of diabetes, chronic hyperglycemia was found to cause an increase in daily basal ROS production of neutrophils, and increased susceptibility to infection caused by reduced neutrophilic reaction in females in their menopause. Therefore, from the oxidative point of view, strict glycemic control is necessary to prevent post‐menopausal females from developing diabetic complications in spite of the presence of diabetes.