Identification of an antibacterial polypeptide in mouse seminal vesicle secretions

In both men and women, pathogenic bacteria enter the reproductive tract and cause harmful symptoms. Intrauterine and oviductal inflammation after copulation may have severe effects, such as infertility, implantation failure, oviduct obstruction, and robust life-threatening bacterial infection. Human seminal plasma is considered to be protective against bacterial infection. Among its components, Semenogelin-I/-II proteins are digested to function as bactericidal factors; however, their sequences are not conserved in mammals. Therefore, alternative antibacterial (bactericidal and/or bacteriostatic) systems may exist across mammals. In this study, we examined the antibacterial activity in the seminal plasma of mice lacking a gene cluster encoding Semenogelin-I/-II counterparts. Even in the absence of the majority of seminal proteins, antibacterial activity remained in the seminal plasma. Moreover, a combination of gel chromatography and liquid chromatography coupled with tandem mass spectrometry revealed that the prostate and testis expressed 4 protein as a novel antibacterial (specifically, bacteriostatic) protein, the sequence of which is broadly conserved across mammals. Our results provide the first evidence of a bacteriostatic protein that is widely present in the mammalian seminal plasma.

POS0604 LONG TERM SAFETY AND TOLERABILITY WITH ETANERCEPT BIOSIMILAR (YLB113), RESULTS FROM A 2-YEAR OPEN LABEL EXTENSION STUDY (STUDY NO. YLB113-003)

Background:

Eligible subjects with moderate-to-severely active rheumatoid arthritis (RA) who completed a phase 3 double-blind comparative efficacy and safety study (Study No. YLB113-002; Yamanaka et al, 2019) of 50 mg etanercept biosimilar (YLB113) or etanercept reference product (RP) by subcutaneous administration with concomitant MTX treatment for 52 weeks, were enrolled in this open label extension (OLE) study (Study No. YLB113-003) to assess the long-term safety and tolerability of YLB113 through to 3 years.

Objectives:

This OLE study aimed to evaluate the long-term safety of YLB113 administration in subjects with RA who received RP or YLB113 in a phase 3 active comparator study. The main parameters assessed were safety and tolerability in terms of adverse events (AEs) and injection site reactions (ISRs), incidence of immunogenicity and efficacy as DAS28 improvement (disease activity score in 28 joints).

Methods:

Subjects received 50 mg of YLB113 subcutaneously once every 1 to 2 weeks. Safety was assessed by AEs after study drug administration, ISRs, physical examination findings, and immunogenicity. Efficacy (DAS28 score) was assessed at the time of transition to the OLE study (Week 0), and at weeks 12, 24, 48, 72, 96 and at the end of the study.

Results:

201 (Full analysis set [FAS]) subjects received the study drug and 184 subjects completed the study (91.5% completion rate). The average drug exposure in 94 subjects who continued to receive YLB113 and completed the study (94.0% completion rate) and 90 subjects who switched from RP to YLB113 and completed the study (89.1% completion rate) was 103 weeks providing the long-term drug exposure data of YLB113.

The CTCAE Grade of TEAEs and ADRs observed were Grade 2 or less in severity (with no Grade ≥3). The overall incidence of ISRs was 10.0% (20/201 subjects) 77 events. All the ISRs reported were Grade 1 except for one Grade 2.

An overview of the AEs experienced by the subjects is summarized in the Table 1.

Table 1.

Overview of Adverse events in OLE study

FASn (%)Number of eventsNumber of subjects201-Treatment emergent adverse events (TEAEs)188(93.5)975Adverse drug reactions (ADRs)82(40.8)221Serious adverse events (SAEs)21(10.4)27Serious adverse drug reactions (SADRs)7(3.5)7AEs leading to premature study discontinuation4(2.0)6ADRs leading to premature study discontinuation3(1.5)4SAEs leading to premature study discontinuation3(1.5)4SADRs leading to premature study discontinuation2(1.0)2

n - number of subjects with at least 1 AE in the category

The mean DAS28 (mean ± S.D.) of 2.22 ± 0.95 at the study transition was 2.10 ± 0.91 at Week 72 and 2.06 ± 0.89 at the end of the study. It was confirmed that DAS28 slightly decreased with time after the study transition and continued until the end of the study. The average DAS28 value remained low even with long-term administration of YLB113, suggesting that the effects of the study drug was sustained (Figure 1).

Figure 1.

DAS28 over time with YLB113 N: Number of subjects. * The administration period at the study completion differs for each subject, because the study transition time differs for each subject.

cts who tested positive for anti-drug antibodies (ADA) at least once in the OLE study were 1.0% (2/200 subjects). All ADA were transient and disappeared at study completion. Such transient ADA formation was reported in the phase 3 study as well. In the phase 3 study, ADA formation was more frequent in subjects who received RP at 24 weeks, but all subjects were negative in the OLE study after switching. Therefore, switching did not affect immunogenicity.

Conclusion:

The safety, efficacy and immunogenicity profile of YLB113 was maintained over the long-term through to 3 years. Switching from RP to YLB113 did not impact safety or immunogenicity.

References:

[1]Yamanaka H, Kamatani N, Tanaka Y, et al. A Comparative Study to Assess the Efficacy, Safety, and Immunogenicity of YLB113 and the Etanercept Reference Product for the Treatment of Patients with Rheumatoid Arthritis. Rheumatol Ther. 2020 Mar;7(1):149-163.

Disclosure of Interests:

Yamanaka Hisashi Speakers bureau: YL Biologics Ltd, Consultant of: YL Biologics Ltd, Yoshiya Tanaka Speakers bureau: Received speaking fees and/or honoraria from Daiichi-Sankyo, Eli Lilly, Novartis, YL Biologics, Bristol-Myers, Eisai, Chugai, Abbvie, Astellas, Pfizer, Sanofi, Asahi-kasei, GSK, Mitsubishi-Tanabe, Gilead, Janssen., Grant/research support from: Received research grants from Abbvie, Mitsubishi-Tanabe, Chugai, Asahi-Kasei, Eisai, Takeda, Daiichi-Sankyo., Toshihiko Hibino: None declared, Chirag Shah Shareholder of: Lupin LTD, Employee of: Lupin LTD, Dhananjay Bakhle Shareholder of: As part of Employee Stock Options Plan of Lupin LTD, Employee of: Lupin LTD, Dimitris Stefanidis Employee of: Sr. Director, Global Medical Affairs Lead, Immunology Biosimilars for Viatris GmbH

Determination of contrast medium dose for hepatic CT enhancement with improved body size dependency using a non-linear analysis based on pharmacokinetic principles

AIM

To propose a pharmacokinetic non-linear analysis method to determine contrast medium (CM) dose for computed tomography (CT) hepatic enhancement to improve body size dependency and validate the proposed CM dose determination method through a clinical study.

MATERIALS AND METHODS

Enhancement data of 105 patients who underwent hepatic dynamic CT with a fixed CM dose were analysed. From the analysis results, CM doses as a function of each of four body size indices (body weight [BW], lean body weight [LBW], blood volume [BV], and body surface area [BSA]) for achieving improved body size dependency were determined (proposed method), and the body size dependencies were simulated using the enhancement data from 105 patients. The proposed method was validated with a two-arm clinical study on BW. Body size dependency was evaluated using p-value of correlation coefficient between Body size indices and enhancements (p<0.05: significant dependency) and mean absolute error (MAE).

RESULTS

The simulation showed that significant body size dependencies not considered by the conventional method can be improved by the proposed method. MAEs of BW, LBW, and BV were also significantly reduced (p<0.05). The clinical study with BW demonstrated a similar improvement to that in the simulation result. MAE was also significantly reduced (p<0.001).

CONCLUSION

The proposed method demonstrated more improved BW, LBW, and BV dependence compared to the conventional method. Through the two-arm clinical study, the proposed method using BW only, without height information, is a suitable index for improving body size dependency.

P3718Identification of nine genes as novel susceptibility loci for early-onset ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage

Background

Given that substantial genetic components have been shown in ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH), a heritability may be higher in early-onset than late-onset individuals with these conditions. Although genome-wide association studies have identified various genes and loci significantly associated with ischemic stroke, ICH, or intracranial aneurysm mainly in European ancestry populations, genetic variants that contribute to susceptibility to these disorders in Japanese individuals remain to be identified definitively.

Purpose

The purpose of the study was to identify genetic variants that confer susceptibility to ischemic stroke, ICH, or SAH in Japanese. We have now performed exome-wide association studies (EWASs) in early-onset subjects with these conditions and corresponding controls.

Methods

A total of 6649 individuals aged ≤65 years were examined. For the EWAS of ischemic or hemorrhagic stroke, 6224 individuals (450 subjects with ischemic stroke, 5774 controls) or 6179 individuals (261 subjects with ICH, 176 subjects with SAH, 5742 controls), respectively, were examined. EWASs were performed with the use of Illumina Human Exome-12 v1.2 DNA Analysis BeadChip or Infinium Exome-24 v1.0 BeadChip. To compensate for multiple comparisons of allele frequencies with ischemic stroke, ICH, or SAH, we applied a false discovery rate (FDR) of <0.05 for statistical significance of association.

Results

The relation of allele frequencies of 31,245 single nucleotide polymorphisms (SNPs) that passed quality control to ischemic stroke was examined with Fisher's exact test, and 31 SNPs were significantly (FDR <0.05) associated with ischemic stroke. The relation of allele frequencies of 31,253 or 30,970 SNPs to ICH or SAH, respectively, was examined with Fisher's exact test, and six or two SNPs were significantly (FDR <0.05) associated with ICH or SAH, respectively. Multivariable logistic regression analysis with adjustment for age, sex, and the prevalence of hypertension and diabetes mellitus revealed that 12 SNPs were significantly [P <0.0004 (Bonferroni's correction, 0.05/124)] related to ischemic stroke. Similar analysis with adjustment for age, sex, and the prevalence of hypertension revealed that six or two SNPs were significantly [P <0.0016 (0.05/32)] related to ICH or SAH, respectively. After examination of linkage disequilibrium of identified SNPs and results of previous genome-wide association studies, we have newly identified HHIPL2, CTNNA3, LOC643770, UTP20, and TRIB3 as susceptibility loci for ischemic stroke, DNTTIP2 and FAM205A as susceptibility loci for ICH, and FAM160A1 and OR52E4 as such loci for SAH.

Conclusion

We have thus newly identified nine genes that confer susceptibility to early-onset ischemic stroke, ICH, or SAH. Determination of genotypes for the SNPs in these genes may prove informative for assessment of the genetic risk for ischemic stroke, ICH, or SAH in Japanese.

P4470Identification of four genes as novel susceptibility loci for early-onset type 2 diabetes mellitus, metabolic syndrome, or hyperuricemia in Japanese

Background

Given that early-onset type 2 diabetes mellitus (T2DM), metabolic syndrome, and hyperuricemia have been shown to have strong genetic components, statistical power of a genetic association study may be increased by focusing on early-onset subjects with these conditions. Although genome-wide association studies have identified various genes and loci significantly associated with T2DM, metabolic syndrome, and hyperuricemia, genetic variants that contribute to predisposition to these conditions in Japanese individuals remain to be identified definitively.

Purpose

The purpose of the study was to identify genetic variants that confer susceptibility to early-onset T2DM, metabolic syndrome, or hyperuricemia in Japanese. We have now performed exome-wide association studies (EWASs) for early-onset subjects with T2DM, metabolic syndrome, or hyperuricemia and corresponding controls.

Methods

A total of 8102 individuals aged ≤65 years was enrolled in the study. The EWAS for T2DM was performed with 7407 subjects (1696 cases, 5711 controls), that for metabolic syndrome with 4215 subjects (2296 cases, 1919 controls), and that for hyperuricemia with 7919 subjects (1365 cases, 6554 controls). Single nucleotide polymorphisms (SNPs) were genotyped with Illumina Human Exome-12 DNA Analysis BeadChip or Infinium Exome-24 BeadChip arrays. The relation of allele frequencies for 31,210, 31,521, or 31,142 SNPs that passed quality control to T2DM, metabolic syndrome, or hyperuricemia, respectively, was examined with Fisher's exact test. To compensate for multiple comparisons of genotypes with T2DM, metabolic syndrome, or hyperuricemia, we applied Bonferroni's correction for statistical significance of association.

Results

The EWAS of allele frequencies revealed that four, six, or nine SNPs were significantly associated with T2DM (P<1.60 × 10–6), metabolic syndrome (P<1.59 × 10–6), or hyperuricemia (P<1.61 × 10–6), respectively. Multivariable logistic regression analysis with adjustment for age and sex revealed that three, six, or nine SNPs were significantly related to T2DM (P<0.0031), metabolic syndrome (P<0.0021), or hyperuricemia (P<0.0014). After examination of the association of identified SNPs to T2DM-, metabolic syndrome-, or hyperuricemia-related traits, linkage disequilibrium of the SNPs, and results of previous genome-wide association studies, we have newly identified ZNF860 and OR4F6 as susceptibility loci for T2DM, OR52E4 and OR4F6 for metabolic syndrome, and HERPUD2 for hyperuricemia.

Conclusion

Given that OR4F6 was significantly associated with both T2DM and metabolic syndrome, we thus newly identified four genes (ZNF860, OR4F6, OR52E4, HERPUD2) that confer susceptibility to early-onset T2DM, metabolic syndrome, or hyperuricemia. Determination of genotypes for the SNPs in these genes may prove informative for assessment of the genetic risk for T2DM, metabolic syndrome, or hyperuricemia in Japanese.

Plasminogen Activator and Plasminogen Activator Inhibitor Associated with Granulomatous Inflammation: A Study with Murine Leprosy

Plasminogen activator that is associated with the development of hypersensitivity granulomas (gPA) was partially purified from a saline soluble fraction of murine lepromas elicited in “resistant” mice, C57BL/6N. The gPA was shown to consist of two subspecies (23,000 and 48,000 in molecular weight) with essentially identical enzymologic properties. The gPA was found to be a relatively heat stable weakly alkaline serine proteinase with trypsin-like characteristics in the specificity for synthetic substrates and proteinase inhibitors. It showed a high affinity for H- D-Ile-Pro-Arg-pNA (Km = 1.4 × 10-4 M) H-D-Val-Leu-Lys- pNA (Km = 5.2 × 10-4 M), and L-pyroGlu-Gly-Arg-pNA (Km = 9.3 × 10-4 M). The gPA did not demonstrate antigenic cross reaction with urokinase-type or tissue-type plasminogen activator.

Two distinct enzymatic regulators of the gPA were also demonstrated in the saline soluble fraction of the hypersensitivity granulomas. The gPA and its regulation are assumed to be correlated with macrophage activation in the hypersensitivity granulomas

Inhibitory effects of mycosporine-2-glycine isolated from a halotolerant cyanobacterium on protein glycation and collagenase activity

Mycosporine-2-glycine (M2G), isolated from the halotolerant cyanobacterium Aphanothece halophytica, was purified and characterized in order to determine its utility as a cosmetic and pharmaceutical ingredient. M2G efficiently inhibited protein crosslinking. The inhibitory activity of M2G was significantly greater than that of the well-known Maillard reaction inhibitor aminoguanidine. In addition, M2G and other known mycosporine-like amino acids inhibited bacterial collagenase activity. To the best of our knowledge, this is the first report describing that M2G specifically inhibits the formation of advanced glycation end-products (AGEs), which play a critical role in ageing process and age-related diseases. These observations indicate that M2G may have potential therapeutic applications by suppressing the formation of AGEs and inhibiting excess collagenase activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

Mycosporine-like amino acids (MAAs) are known as multifunctional natural compounds. The MAA mycosporine-2-glycine (M2G), isolated from the halotolerant cyanobacterium Aphanothece halophytica, has potential therapeutic applications for the prevention of skin ageing. Purified M2G was endotoxin-free. M2G had greater inhibitory activity of protein cross-linking compared with well-known inhibitor, aminoguanidine and hindered bacterial collagenase activity. The mechanisms for these inhibitory activities of M2G are discussed in this study.

Endothelin-1 Elicits TRP-Mediated Pain in an Acid-Induced Oral Ulcer Model

Oral ulcer is the most common oral disease and leads to pain during meals and speaking, reducing the quality of life of patients. Recent evidence using animal models suggests that oral ulcers induce cyclooxygenase-dependent spontaneous pain and cyclooxygenase-independent mechanical allodynia. Endothelin-1 is upregulated in oral mucosal inflammation, although it has not been shown to induce pain in oral ulcers. In the present study, we investigated the involvement of endothelin-1 signaling with oral ulcer-induced pain using our proprietary assay system in conscious rats. Endothelin-1 was significantly upregulated in oral ulcers experimentally induced by topical acetic acid treatment, while endothelin-1 production was suppressed by antibacterial pretreatment. Spontaneous nociceptive behavior in oral ulcer model rats was inhibited by swab applications of BQ-788 (ET_B receptor antagonist), ONO-8711 (prostanoid receptor EP₁ antagonist), and HC-030031 (TRPA1 antagonist). Prostaglandin E₂ production in the ulcers was suppressed by BQ-788. Mechanical allodynia in the model was inhibited not only by BQ-788 and HC-030031 but also by BQ-123 (ET_A receptor antagonist), SB-366791 (TRPV1 antagonist), and RN-1734 (TRPV4 antagonist). In naive rats, submucosal injection of endothelin-1 caused mechanical allodynia that was sensitive to HC-030031 and SB-366791 but not to RN-1734. These results suggest that endothelin-1 production following oral bacterial invasion via ulcerative regions elicits TRPA1-mediated spontaneous pain. This pain likely occurs through an indirect route that involves ET_B receptor-accelerated prostanoid production. Endothelin-1 elicits directly TRPA1- and TRPV1-mediated mechanical allodynia via both ET_A and ET_B receptors on nociceptive fibers. The TRPV4-mediated allodynia component seems to be independent of endothelin signaling. These findings highlight the potential of endothelin signaling blockers as effective analgesic approaches for oral ulcer patients.

IL17 factors are early regulators in the gut epithelium during inflammatory response to Vibrio in the sea urchin larva

IL17 cytokines are central mediators of mammalian immunity. In vertebrates, these factors derive from diverse cellular sources. Sea urchins share a molecular heritage with chordates that includes the IL17 system. Here, we characterize the role of epithelial expression of IL17 in the larval gut-associated immune response. The purple sea urchin genome encodes 10 IL17 subfamilies (35 genes) and 2 IL17 receptors. Most of these subfamilies are conserved throughout echinoderms. Two IL17 subfamilies are sequentially strongly upregulated and attenuated in the gut epithelium in response to bacterial disturbance. IL17R1 signal perturbation results in reduced expression of several response genes including an IL17 subtype, indicating a potential feedback. A third IL17 subfamily is activated in adult immune cells indicating that expression in immune cells and epithelia is divided among families. The larva provides a tractable model to investigate the regulation and consequences of gut epithelial IL17 expression across the organism.

DOI:http://dx.doi.org/10.7554/eLife.23481.001

To protect themselves from the constant invasion of harmful microbes, animals have evolved complex immune systems. The gut is one of the most active sites of the immune system and plays a key role in regulating immune responses. In mammals, cells lining the gut wall can sense the presence of harmful bacteria and communicate this information to tissues across the body by producing specialized proteins called Interleukin-17 (IL-17). IL-17 proteins are important for regulating inflammation and are thought to activate specific immune cells in an infected area.

Some aspects of immune systems are similar between different animal species, which can provide clues of how immunity evolved and how it is regulated. For example, sea urchins, which evolved 400-600 million years ago, begin life as simple larvae consisting of a few thousand cells. As oceans harbor a multitude of bacteria and viruses, sea urchin larvae need an efficient immune system to defend themselves. These larvae can respond to specific types of bacteria within a few hours after the microbes have entered their gut by modifying gene expression in distant cells. As these changes occur in cells that are removed from the bacteria, it is thought that the gut cells that initially sense the bacteria, somehow communicate this information.

Now, Buckley et al. exposed sea urchin larvae to a marine bacterium and measured the responses of the cells and their gene expression. The infection affected several types of cells, and in the first 24 hours, a subset of immune cells changed shape and started migrating to the gut wall. In addition, IL-17 gene expression changed significantly in gut cells in the early phases of the larval immune response. Buckley et al. identified three types of IL-17 proteins involved in sea urchin immunity: two that are important for the immune response in the gut during the larval stage, and a third that is only present in adults. These findings suggest that IL-17 signaling is an ancient and central element of gut-associated immune response, which even exists in animals that evolved long before humans.

These findings demonstrate that the sea urchin larva represents a unique and ideal experimental model to study immune responses in a living organism that is more closely related to mammals than some other models, like fruit flies or worms. By understanding the fundamental mechanisms that mediate gut health, this work may highlight new drug targets to treat conditions like Crohn’s disease and colon cancer.

DOI:http://dx.doi.org/10.7554/eLife.23481.002

Perturbation of gut bacteria induces a coordinated cellular immune response in the purple sea urchin larva

The purple sea urchin (Strongylocentrotus purpuratus) genome sequence contains a complex repertoire of genes encoding innate immune recognition proteins and homologs of important vertebrate immune regulatory factors. To characterize how this immune system is deployed within an experimentally tractable, intact animal, we investigate the immune capability of the larval stage. Sea urchin embryos and larvae are morphologically simple and transparent, providing an organism-wide model to view immune response at cellular resolution. Here we present evidence for immune function in five mesenchymal cell types based on morphology, behavior and gene expression. Two cell types are phagocytic; the others interact at sites of microbial detection or injury. We characterize immune-associated gene markers for three cell types, including a perforin-like molecule, a scavenger receptor, a complement-like thioester-containing protein and the echinoderm-specific immune response factor 185/333. We elicit larval immune responses by (1) bacterial injection into the blastocoel and (2) seawater exposure to the marine bacterium Vibrio diazotrophicus to perturb immune state in the gut. Exposure at the epithelium induces a strong response in which pigment cells (one type of immune cell) migrate from the ectoderm to interact with the gut epithelium. Bacteria that accumulate in the gut later invade the blastocoel, where they are cleared by phagocytic and granular immune cells. The complexity of this coordinated, dynamic inflammatory program within the simple larval morphology provides a system in which to characterize processes that direct both aspects of the echinoderm-specific immune response as well as those that are shared with other deuterostomes, including vertebrates.

Development of ciliary bands in larvae of the living isocrinid sea lily Metacrinus rotundus

Embryos and larvae of an isocrinid sea lily, Metacrinus rotundus, are described by scanning electron microscopy. Around hatching (35 h after fertilization), the outer surface of the gastrula becomes ubiquitously covered with short cilia. At 40 h, the hatched swimming embryo develops a cilia-free zone of ectoderm on the ventral side. By 3 days, the very early dipleurula larva develops a cilia-free zone ventrally, densely ciliated regions laterally, and a sparsely ciliated region dorsally. At this stage, the posterior and anterior ciliary bands first appear: the former runs along a low ridge separating the densely from the sparsely ciliated epidermal regions, while the latter is visible, at first discontinuously, along the boundary between the densely ciliated lateral regions and the cilia-free ventral zone. In the late dipleurula larva (5 days after fertilization), the anterior and posterior loops of ciliary bands are well defined. The transition from the dipleurula to the semidoliolaria larva occurs at 6 days as the posterior loop becomes rearranged to form incompletely circumferential ciliary bands. The larva becomes competent to settle at this stage. The arrangement of the ciliary bands on the semidoliolaria is maintained during the second week of development, while the larva retains its competence to settle. The larval ciliary patterns described here are compared with those of stalkless crinoids and eleutherozoan echinoderms. The closest morphological similarities are between M. rotundus and the basal eleutherozoan class Asteroidea.

Separation of ion components produced by plasma-assisted catalytic ionization

Positive and negative hydrogen ions are produced by plasma-assisted catalytic ionization using a porous nickel plate, where the irradiation current density and energy of positive ions produced by discharge to the porous plate are controlled. The ion energy distributions are analyzed from the properties of current densities of positive and negative ions extracted from the porous surface. Positive ions passing through fine pores of the porous plate and positive and negative ions produced on the porous surface are observed. It is clarified that the produced fluxes of positive and negative ions and the flux balance between them are controlled by the irradiation current density and energy, respectively.

Sp185/333: a novel family of genes and proteins involved in the purple sea urchin immune response

The Sp185/333 system of genes, messages and proteins are expressed in the coelomocytes of the purple sea urchin, Strongylocentrotus purpuratus, and is an extraordinary example of diversification of a putative innate immune response system in an invertebrate. Reviewed here, is the current understanding of this complex system as illustrated by sequence comparisons of the genes, messages and deduced proteins with descriptions of diversity, including preliminary results on genomic organization and descriptions of 185/333 in other echinoids. Sp185/333 gene expression in adults and embryos occurs in response to immune challenge and includes changes in the frequencies of Sp185/333-positive coelomocytes in the adults. The diversity of the Sp185/333 protein repertoire in coelomocytes is far greater than the sequence diversity encoded in the genes, which may be the result of rapid gene recombination, RNA editing and/or low-fidelity transcription, plus post-translational modifications. This review concludes with preliminary results and speculations on protein function.

Phylogenetic correspondence of the body axes in bilaterians is revealed by the right-sided expression of Pitx genes in echinoderm larvae

Chordates and echinoderms are two of the three major deuterostome phyla and show conspicuous left-right (LR) asymmetry. The establishment of LR asymmetry has been explored in vertebrates, but is largely unknown in echinoderms. Here, we report the expression pattern of genes that are orthologous to the chordate left-side specific gene Pitx, cloned from the sea urchin Hemicentrotus pulcherrimus (HpPitx) and the starfish Asterina pectinifera (ApPitx). HpPitx transcripts were first detected bilaterally in one cell of the ventrolateral primary mesenchyme-cell aggregate of early prism larvae. New expression was detected asymmetrically in the right counterpart of a bilateral pair of mesodermal coelomic pouches and in the right ectoderm. In starfish bipinnaria larvae, the ApPitx signal was detected in the right coelomic pouch and in the right half of the ectoderm along the ciliary bands. These results suggest that the function of Pitx in establishing LR asymmetry was introduced in the last common ancestor of echinoderms and chordates. However, the right-side specific expression in echinoderm larvae is inverted compared to chordate embryos. This indicates that the LR axis is inversely represented between echinoderms and chordates, which supports the scenario that dorsoventral axis inversion was introduced into the chordate lineage by turning upside down.

Genomic insights into the immune system of the sea urchin

Comparative analysis of the sea urchin genome has broad implications for the primitive state of deuterostome host defense and the genetic underpinnings of immunity in vertebrates. The sea urchin has an unprecedented complexity of innate immune recognition receptors relative to other animal species yet characterized. These receptor genes include a vast repertoire of 222 Toll-like receptors, a superfamily of more than 200 NACHT domain-leucine-rich repeat proteins (similar to nucleotide-binding and oligomerization domain (NOD) and NALP proteins of vertebrates), and a large family of scavenger receptor cysteine-rich proteins. More typical numbers of genes encode other immune recognition factors. Homologs of important immune and hematopoietic regulators, many of which have previously been identified only from chordates, as well as genes that are critical in adaptive immunity of jawed vertebrates, also are present. The findings serve to underscore the dynamic utilization of receptors and the complexity of immune recognition that may be basal for deuterostomes and predicts features of the ancestral bilaterian form.

The genome of the sea urchin Strongylocentrotus purpuratus

We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.

The immune gene repertoire encoded in the purple sea urchin genome

Echinoderms occupy a critical and largely unexplored phylogenetic vantage point from which to infer both the early evolution of bilaterian immunity and the underpinnings of the vertebrate adaptive immune system. Here we present an initial survey of the purple sea urchin genome for genes associated with immunity. An elaborate repertoire of potential immune receptors, regulators and effectors is present, including unprecedented expansions of innate pathogen recognition genes. These include a diverse array of 222 Toll-like receptor (TLR) genes and a coordinate expansion of directly associated signaling adaptors. Notably, a subset of sea urchin TLR genes encodes receptors with structural characteristics previously identified only in protostomes. A similarly expanded set of 203 NOD/NALP-like cytoplasmic recognition proteins is present. These genes have previously been identified only in vertebrates where they are represented in much lower numbers. Genes that mediate the alternative and lectin complement pathways are described, while gene homologues of the terminal pathway are not present. We have also identified several homologues of genes that function in jawed vertebrate adaptive immunity. The most striking of these is a gene cluster with similarity to the jawed vertebrate Recombination Activating Genes 1 and 2 (RAG1/2). Sea urchins are long-lived, complex organisms and these findings reveal an innate immune system of unprecedented complexity. Whether the presumably intense selective processes that molded these gene families also gave rise to novel immune mechanisms akin to adaptive systems remains to be seen. The genome sequence provides immediate opportunities to apply the advantages of the sea urchin model toward problems in developmental and evolutionary immunobiology.

RTK and TGF-beta signaling pathways genes in the sea urchin genome

The Receptor Tyrosine kinase (RTK) and TGF-beta signaling pathways play essential roles during development in many organisms and regulate a plethora of cellular responses. From the genome sequence of Strongylocentrotus purpuratus, we have made an inventory of the genes encoding receptor tyrosine kinases and their ligands, and of the genes encoding cytokines of the TGF-beta superfamily and their downstream components. The sea urchin genome contains at least 20 genes coding for canonical receptor tyrosine kinases. Seventeen of the nineteen vertebrate RTK families are represented in the sea urchin. Fourteen of these RTK among which ALK, CCK4/PTK7, DDR, EGFR, EPH, LMR, MET/RON, MUSK, RET, ROR, ROS, RYK, TIE and TRK are present as single copy genes while pairs of related genes are present for VEGFR, FGFR and INSR. Similarly, nearly all the subfamilies of TGF-beta ligands identified in vertebrates are present in the sea urchin genome including the BMP, ADMP, GDF, Activin, Myostatin, Nodal and Lefty, as well as the TGF-beta sensu stricto that had not been characterized in invertebrates so far. Expression analysis indicates that the early expression of nodal, BMP2/4 and lefty is restricted to the oral ectoderm reflecting their role in providing positional information along the oral-aboral axis of the embryo. The coincidence between the emergence of TGF-beta-related factors such as Nodal and Lefty and the emergence of the deuterostome lineage strongly suggests that the ancestral function of Nodal could have been related to the secondary opening of the mouth which characterizes this clade, a hypothesis supported by functional data in the extant species. The sea urchin genome contains 6 genes encoding TGF-beta receptors and 4 genes encoding prototypical Smad proteins. Furthermore, most of the transcriptional activators and repressors shown to interact with Smads in vertebrates have orthologues in echinoderms. Finally, the sea urchin genome contains an almost complete repertoire of genes encoding extracellular modulators of BMP signaling including Chordin, Noggin, Sclerotin, SFRP, Gremlin, DAN and Twisted gastrulation. Taken together, these findings indicate that the sea urchin complement of genes of the RTK and TGF-beta signaling pathways is qualitatively very similar to the repertoire present in vertebrates, and that these genes are part of the common genetool kit for intercellular signaling of deuterostomes.

Ion flow regulates left-right asymmetry in sea urchin development

The degree of conservation among phyla of early mechanisms that pattern the left-right (LR) axis is poorly understood. Larvae of sea urchins exhibit consistently oriented LR asymmetry. The main part of the adult rudiment is formed from the left coelomic sac of larvae, the left hydrocoel. Although this left preference is conserved among all echinoderm larvae, its mechanism is largely not understood. Using two marker genes, HpNot and HpFoxFQ-like, which are asymmetrically expressed during larval development of the sea urchin Hemicentrotus pulcherrimus, we examined in this study the possibility that the recently discovered ion flux mechanism controls asymmetry in sea urchins as it does in several vertebrate species. Several ion-transporter inhibitors were screened for the ability to alter the expression of the asymmetric marker genes. Blockers of the H(+)/K(+)-ATPase (omeprazole, lansoprazole and SCH28080), as well as a calcium ionophore (A23187), significantly altered the normal sidedness of asymmetric gene expression. Exposure to omeprazole disrupted the consistent asymmetry of adult rudiment formation in larvae. Immuno-detection revealed that H(+)/K(+)-ATPase-like antigens in sea urchin embryos were present through blastula stage and exhibited a striking asymmetry being present in a single blastomere in 32-cell embryos. These results suggest that, as in vertebrates, endogenous spatially-regulated early transport of H(+) and/or K(+), and also of Ca(2+), functions in the establishment of LR asymmetry in sea urchin development.

Molecular heterotopy in the expression of Brachyury orthologs in order Clypeasteroida (irregular sea urchins) and order Echinoida (regular sea urchins)

The expression patterns of Brachyury (Bra) orthologs in the development of four species of sand dollars (order: Clypeasteroida), including a direct-developing species, and of a sea urchin species (order: Echinoida) were investigated during the period from blastula to the pluteus stage, with special attention paid to the relationship between the expression pattern and the mode of gastrulation. The sand dollar species shared two expression domains of the Bra orthologs with the Echinoida species, in the vegetal ring (the first domain) and the oral ectoderm (the second domain). The following heterotopic changes in the expression of the Bra genes were found among the sand dollar species and between the sand dollars and the Echinoida species. (1) The vegetal ring expressing Bra in the sand dollars was much wider and was located at a higher position along the AV axis, compared with that in the Echinoida species. The characteristic Bra expression in the vegetal ring of the sand dollar embryos was thought to be involved in the mode of gastrulation, in which involution continues from the beginning of invagination until the end of gastrulation. (2) Two of the three indirect-developing sand dollar species that were examined exhibited a third domain, in which Bra was expressed on the oral side of the archenteron. (3) In the direct-developing sand dollar embryos, Bra was expressed with an oral-aboral asymmetry in the vegetal ring and with a left-right asymmetry in the oral ectoderm. In the Echinoida species, Bra was expressed in the vestibule at the six-armed pluteus stage.

Regrowth of the stalk of the sea lily, Metacrinus rotundus (Echinodermata: Crinoidea)

Sea lilies are critical to understanding the evolution of the echinoderm body plan, because they are the only extant group whose adults possess a stalk, a prevalent feature in the radiation of a number of primitive echinoderm lineages. Extensive crown regeneration ability has been reported in Metacrinus rotundus, but the regenerative potential of the stalk has never been determined in any species of sea lilies. In this study, we show that M. rotundus whose stalks have been completely excised are capable of stalk regeneration. The process is similar to the growth of the original stalk, but much slower, and the regenerated stalks are not morphologically identical to the original stalk. Since stalk regeneration, in contrast to well-studied regeneration events, probably requires little additional activation of morphogenetic programs, we refer to the stalk regeneration phenomenon as "stalk regrowth" to distinguish it as a special form of regeneration. Since specimens whose entire stalk below the basal plates had been removed were able to regrow, the basal plates, and probably the aboral nerve center within them, are essential for stalk regrowth. Sea lily stalk regrowth is described in detail, and the evolution of feather stars is discussed in light of the growth pattern of the sea lily stalk.

Extraction of total RNA from leaves of Eucalyptus and other woody and herbaceous plants using sodium isoascorbate

Rapid extraction of total RNA from Eucalyptus leaves is difficult due to the high content of polyphenolics and polysaccharides. A rapid and simple method was developed by using an extraction buffer containing sodium isoascorbate at a concentration of 500 mM. This method consisted of one or two chloroform extractions, one acid guanidium-phenol-chloroform extraction, and isopropanol precipitation alone. The yields of the RNA fractions were 246-1750 micrograms/g fresh weight when leaves of Eucalyptus, five other woody plants, and four herbaceous plants were used as samples. The contamination of the RNA fractions by proteins and polysaccharides was very limited as judged spectrophotometrically. When the RNA fractions were subjected to agarose gel electrophoresis, intact rRNA bands were detected. The RNA fractions could be used for RT-PCR. These results indicate that our new method achieves a simple and rapid preparation of high-quality RNA from leaves of Eucalyptus and other plant species.

Larval stages of a living sea lily (stalked crinoid echinoderm)

The embryos and larvae of stalked crinoids, which are considered the most basal group of extant echinoderms, have not previously been described. In contrast, much is known about the development of the more accessible stalkless crinoids (feather stars), which are phylogenetically derived from stalked forms. Here we describe the development of a sea lily from fertilization to larval settlement. There are two successive larval stages: the first is a non-feeding auricularia stage with partly longitudinal ciliary bands (similar to the auricularia and bipinnaria larvae of holothurian and asteroid echinoderms, respectively); the second is a doliolaria larva with circumferential ciliary bands (similar to the earliest larval stage of stalkless crinoids). We suggest that a dipleurula-type larva is primitive for echinoderms and is the starting point for the evolution of additional larval forms within the phylum. From a wider evolutionary viewpoint, the demonstration that the most basal kind of echinoderm larva is a dipleurula is consistent with Garstang's auricularia theory for the phylogenetic origin of the chordate neural tube.

M6a acts as a nerve growth factor-gated Ca(2+) channel in neuronal differentiation

To elucidate the function of M6a, which is a neuron-specific membrane glycoprotein of the brain and possesses putative phosphorylation sites for protein kinase C (PKC), we established rat M6a cDNA expression vector-transfected PC12 cells. These transfectants exhibited high susceptibilities to nerve growth factor (NGF) for neuronal differentiation. Interestingly, we found that Ca(2+) influx in these transfectants was significantly augmented by the treatment of NGF, but not epidermal growth factor (EGF), which stimulates PC12 cell growth. NGF-dependent augmentation of Ca(2+) influx was detected within 3h and severely inhibited by EGTA- and PKC-specific inhibitors. Anti-M6 antibody suppressed both NGF-triggered Ca(2+) influx and neuronal differentiation. These results support the idea that M6a implicates in neuronal differentiation as a novel Ca(2+) channel gated selectively by phosphorylation with PKC in the downstream of NGF signaling pathway.

The behavior and the morphology of sea lilies with shortened stalks: implications on the evolution of feather stars

Extant crinoids can be divided into two groups, stalked sea lilies and stalkless feather stars. Feather stars are considered to have evolved from stalked ancestors by losing most of the stalk, but other differences are present between the two groups. The unsegmented centrodorsal, long and curved cirri near the crown, small calyx, and the ability to swim are all feather star features not found in the sea lilies. To figure out which of the above features evolved directly correlating with loss of the stalk in feather stars, we cut off the stalk from the sea lily Metacrinus rotundus and kept them alive in an aquarium. The specimens with shortened stalks were able to stand and crawl with their arms without the support of their stalks, but swimming was not observed for any of the animals. Morphologically, neither fusion of the remaining segments nor the reduction of the size of the calyx were observed, but the cirri became long and curved near the crown. Therefore, the extant sea lilies possess a potential to adapt to incidents of stalk loss. Specimens autotomizing most of their stalks were observed, suggesting that the potential is actually employed in nature. This mechanism linking the reduction of the stalk and the changes in the morphology of cirri may have played an important role in the evolution of the feather stars, if the stalked ancestors of feather stars also possessed this potential. Experimental zoological approaches as this study may provide new insights to the questions of evolution.

Halotolerant cyanobacterium Aphanothece halophytica contains an Na(+)/H(+) antiporter, homologous to eukaryotic ones, with novel ion specificity affected by C-terminal tail

Recently, a cyanobacterium Synechocystis sp. PCC 6803 has been shown to contain an Na(+)/H(+) antiporter gene homologous to plants (SOS1 and AtNHX1 from Arabidopsis) and mammalians (NHEs from human) but not to Escherichia coli (nhaA and nhaB). Here, we examined whether a halotolerant cyanobacterium Aphanothece halophytica has homologous genes. It turned out that A. halophytica contains an Na(+)/H(+) antiporter homologous to plants, mammalians, and some bacteria (nhaP from Pseudomonas and synnhaP from Synechocystis) but with novel ion specificity. Its gene product, ApNhaP (Na(+)/H(+) antiporter from Aphanothece halophytica), exhibited the Na(+)/H(+) antiporter activity over a wide pH range between 5 and 9 and complemented the Na(+)-sensitive phenotype of the antiporter-deficient E. coli mutant. The ApNhaP had virtually no activity for the Li(+)/H(+) antiporter but showed high Ca(2+)/H(+) antiporter activity at alkaline pH. The ApNhaP complemented the Ca(2+)-sensitive phenotype of the E. coli mutant but not the Li(+)-sensitive phenotype. The replacement of a long C-terminal tail of ApNhaP with that of Synechocystis altered the ion specificity of the antiporter. These results suggest that the ion specificity of an Na(+)/H(+) antiporter is partly determined by the structural properties of the C-terminal tail, which was well exemplified in the case of A. halophytica.

Overexpression of DnaK from a halotolerant cyanobacterium Aphanothece halophytica enhances the high-temperatue tolerance of tobacco during germination and early growth

DnaK1 from a halotolerant cyanobacterium Aphanothece halophytica, was overexpressed in the cytosol of tobacco. When the control and transgenic tobacco seeds were incubated at 27 degrees C, more than 95% of the control and transgenic tobacco seeds germinated. However, at a high incubation temperature, 40 degrees C, only 27% of the control seeds germinated whereas 82% of the transgenic seeds germinated. High temperature treatment during the imbibition of seeds delayed germination more in the control plants than in the transformants although the maximum percentage of germination was similar in both plants. The quantum yields of electron transport and plant elongation were higher in the transformant during high temperature treatment in young seedlings, but similar in older leaves. DnaK1 was detected in small amounts in seeds and its levels increased during germination. These data indicate that the expression of DnaK1 from a halotolerant cyanobacterium A. halophytica improved the tolerance to high temperature during germination and early growth.

Molecular cloning and functional characterization of two kinds of betaine-aldehyde dehydrogenase in betaine-accumulating mangrove Avicennia marina (Forsk.) Vierh

Glycinebetaine is an important osmoprotectant in bacteria, plants, and animals, but only little information is available on the synthesis of glycinebetaine in tree plants. Among four mangrove species, glycinebetaine could be detected only in Avicennia marina. Pinitol was the main osmoprotectant in the other three species. The level of glycinebetaine in A. marina increased under high salinity. Betaine-aldehyde dehydrogenase (BADH) was detected in all four species, but choline monooxygenase could not be detected. A cDNA library was constructed from the leaves of A. marina. Two kinds of BADH cDNAs were isolated, one homologous to the spinach chloroplast BADH, and the other with unique residues SKL at the end of C-terminus. The BADH transcription levels of the former were higher than those of the latter. The levels of the former BADH increased at high salinity whereas those of the latter were independent of salinity. BADHs were expressed in Escherichia coli and purified. Two kinds of A. marina BADHs exhibited similar kinetic and stability properties, but were significantly different from those of spinach BADH. A. marina BADHs efficiently catalyzed the oxidation of betainealdehyde, but not the oxidation of omega-aminoaldehydes and were more stable at high temperature than the spinach BADH.

Na+/H+ antiporter from Synechocystis species PCC 6803, homologous to SOS1, contains an aspartic residue and long C-terminal tail important for the carrier activity

A putative Na(+)/H(+) antiporter gene whose deduced amino acid sequence was highly homologous to the NhaP antiporter from Pseudomonas aeruginosa and SOS1 antiporter from Arabidopsis was isolated from Synechocystis sp. PCC 6803. The Synechocystis NhaP antiporter (SynNhaP) was expressed in Escherichia coli mutant cells, which were deficient in Na(+)/H(+) antiporters. It was found that the SynNhaP complemented the salt-sensitive phenotype of the E. coli mutant. Membrane vesicles prepared from the E. coli mutant transformed with the SynNhaP exhibited the Na(+)/H(+) and Li(+)/H(+) antiporter activities, and their activities were insensitive to amiloride. Moreover, its activity was very high between pH 5 and 9. The replacement of aspartate-138 in SynNhaP with glutamate or tyrosine inactivated the SynNhaP antiporter activity. The deletion of a part of the long C-terminal hydrophilic tail significantly inhibited the antiporter activity. A topological model suggests that aspartate-138 in SynNhaP is conserved in NhaP, SOS1, and AtNHX1 and is involved in the exchange activity. Thus, it appeared that the SynNhaP would provide a model system for the study of structural and functional properties of eucaryotic Na(+)/H(+) antiporters.

Photo-induction of an NADPH dehydrogenase which functions as a mediator of electron transport to the intersystem chain in the cyanobacterium Synechocystis PCC6803

Illumination of the dark-incubated cells of Synechocystis PCC6803 caused recovery of both respiratory activity of oxygen uptake and PS I-cyclic electron flow, which was monitored by the dark reduction of P700(+) in the presence of DCMU after a 50 ms pulse light (MT) under background far-red light, but the effects were much smaller in those of the mutant M55, which has an ndh-B defective gene. Activity of an NADPH-NBT oxidoreductase with a higher molecular mass (around 380 kDa), which was only found in wild type but not in M55, became evident after the dark-incubated cells were exposed to the light. Immuno-blotting analysis indicated that the NADPH-NBT oxidoreductase contains the NdhB subunit of NDH. The expression of NdhB decreased in dark-incubated cells and increased upon transfer of the cells back to light. These results indicate that an NADPH-specific NDH participates in the light-regulated cyclic electron transport around Photosystem I as well as in respiratory electron transport to the intersystem chain in Synechocystis 6803.

Overproduction of spinach betaine aldehyde dehydrogenase in Escherichia coli. Structural and functional properties of wild-type, mutants and E. coli enzymes

Betaine aldehyde dehydrogenase (BADH) catalyzes the last step in the synthesis of the osmoprotectant glycine betaine from choline. Although betaine aldehyde has been thought to be a specific substrate for BADH, recent studies have shown that human and sugar beet BADHs also catalyze the oxidation of omega-aminoaldehydes. To characterize the kinetic and stability properties of spinach BADH, five kinds of expression vectors encoding full length, mature, E103Q, E103K, and chimera BADHs were constructed. These enzymes together with Escherichia coli BADH were expressed in E. coli and purified. The affinities for betaine aldehyde were similar in the spinach and E. coli BADHs, whereas those for omega-aminoaldehydes were higher in spinach BADH than in E. coli BADH. A chimera BADH in which part of the Rossmann type fold in the spinach BADH was replaced with that of E. coli BADH, showed properties which resembled spinach BADH more than E. coli BADH. The spinach E103K mutant was almost inactive, whereas the E103Q mutant showed a similar activity for the oxidation of betaine aldehyde to that of wild type BADH, but a lower affinity for omega-aminoaldehydes. All spinach BADHs were dimers whereas E. coli BADH was a tetramer. E. coli BADH was more stable at high temperature than spinach BADHs. The E103Q mutant was most labile to high temperature. These properties are discussed in relation to the structure of spinach BADH.

Effects of overexpression of Escherichia coli katE and bet genes on the tolerance for salt stress in a freshwater cyanobacterium Synechococcus sp. PCC 7942

To explore the potential role of catalase and glycine betaine in the protection of cyanobacteria from damage due to salt stress, we transformed a freshwater cyanobacterium Synechococcus sp. PCC 7942 with shuttle vectors that contained the Escherichia coli katE, bet, and katE plus bet (katE/bet) genes. The catalase activity in the cells overexpressing katE and katE/bet genes was about 1.4-1.8-fold higher than that in the control cells. The control and transformant cells had a similar growth rate in the medium with a low salinity. However, under a high-salinity condition, the cells transformed with katE grew faster than the control cells, and the cells expressing katE/bet genes grew faster than those expressing either the katE or bet gene alone. These results indicate that high-salinity caused oxidative stress and the coexpression of katE and bet genes in Synechococcus cells were superior to the expression of either katE or bet alone for the protection of the cells from the damage due to high-salinity.

A low-operating-temperature solid oxide fuel cell in hydrocarbon-Air mixtures

The performance of a single-chamber solid oxide fuel cell was studied using a ceria-based solid electrolyte at temperatures below 773 kelvin. Electromotive forces of approximately 900 millivolts were generated from the cell in a flowing mixture of ethane or propane and air, where the solid electrolyte functioned as a purely ionic conductor. The electrode-reaction resistance was negligibly small in the total internal resistances of the cell. The resulting peak power density reached 403 and 101 milliwatts per square centimeter at 773 and 623 kelvin, respectively.

Spectroscopic and electrochemical studies on structural change of plastocyanin and its tyrosine 83 mutants induced by interaction with lysine peptides

Interactions of wild-type and Tyr83 mutant (Y83F, Y83S, Y83L, and Y83H) plastocyanins (PCs) with lysine peptides as models for the PC interacting site of cytochrome f have been studied by absorption, resonance Raman, and electron paramagnetic resonance (EPR) spectroscopies and electrochemical measurements. The spectral and electrochemical properties of PCs corresponded well with each other; species having a longer wavelength maximum for the S(Cys) pi --> Cu 3d(x)()()2(-)(y)()()2 charge transfer (CT) band observed around 600 nm and a stronger intensity for the 460-nm absorption band exhibited stronger intensities for the positive Met --> Cu 3d(x)()()2(-)(y)()()2 and negative His pi(1) --> Cu 3d(x)()()2(-)(y)()()2 circular dichroism (CD) bands at about 420 and 470 nm, respectively, a lower average nu(Cu)(-)(S) frequency, a smaller |A( parallel)| EPR parameter, and a higher redox potential, properties all related to a weaker Cu-S(Cys) bond and a more tetrahedral planar geometry for the Cu site. Similarly, on oligolysine binding to wild-type and several Tyr83 mutant PCs, a longer absorption maximum for the 600-nm CT band, a stronger intensity for the 460-nm absorption band, stronger 420-nm positive and 470-nm negative CD bands, and a lower average nu(Cu)(-)(S) frequency were observed, suggesting that PC assumes a slight more tetrahedral geometry on binding of oligolysine. Since changes were observed for both wild-type and Tyr83 mutant PCs, the structural change due to binding of oligolysine to PC may not be transmitted through the path of Tyr83-Cys84-copper by a cation-pi interaction which is proposed for electron transfer.

Enhanced tolerance to salt stress in transgenic rice that overexpresses chloroplast glutamine synthetase

The potential role of photorespiration in the protection against salt stress was examined with transgenic rice plants. Oryza sativa L. cv. Kinuhikari was transformed with a chloroplastic glutamine synthetase (GS2) gene from rice. Each transgenic rice plant line showed a different accumulation level of GS2. A transgenic plant line, G39-2, which accumulated about 1.5-fold more GS2 than the control plant, had an increased photorespiration capacity. In another line, G241-12, GS2 was almost lost and photorespiration activity could not be detected. Fluorescence quenching analysis revealed that photorespiration could prevent the over-reduction of electron transport systems. When exposed to 150 mM NaCl for 2 weeks, the control rice plants completely lost photosystem II activity, but G39-2 plants retained more than 90% activity after the 2-week treatment, whereas G241-12 plants lost these activities within one week. In the presence of isonicotinic acid hydrazide, an inhibitor of photorespiration, G39-2 showed the same salt tolerance as the control plants. The intracellular contents of NH4+ and Na+ in the stressed plants correlated well with the levels of GS2. Thus, the enhancement of photorespiration conferred resistance to salt in rice plants. Preliminary results suggest chilling tolerance in the transformant.

Control of murine hair follicle regression (catagen) by TGF-beta1 in vivo

The regression phase of the hair cycle (catagen) is an apoptosis-driven process accompanied by terminal differentiation, proteolysis, and matrix remodeling. As an inhibitor of keratinocyte proliferation and inductor of keratinocyte apoptosis, transforming growth factor beta1 (TGF-beta1) has been proposed to play an important role in catagen regulation. This is suggested, for example, by maximal expression of TGF-beta1 and its receptors during late anagen and the onset of catagen of the hair cycle. We examined the potential involvement of TGF-beta1 in catagen control. We compared the first spontaneous entry of hair follicles into catagen between TGF-beta1 null mice and age-matched wild-type littermates, and assessed the effects of TGF-beta1 injection on murine anagen hair follicles in vivo. At day 18 p.p., hair follicles in TGF-beta1 -/- mice were still in early catagen, whereas hair follicles of +/+ littermates had already entered the subsequent resting phase (telogen). TGF-beta1-/- mice displayed more Ki-67-positive cells and fewer apoptotic cells than comparable catagen follicles from +/+ mice. In contrast, injection of TGF-beta1 into the back skin of mice induced premature catagen development. In addition, the number of proliferating follicle keratinocytes was reduced and the number of TUNEL + cells was increased in the TGF-beta1-treated mice compared to controls. Double visualization of TGF-beta type II receptor (TGFRII) and TUNEL reactivity revealed colocalization of apoptotic nuclei and TGFRII in catagen follicles. These data strongly support that TGF-beta1 ranks among the elusive endogenous regulators of catagen induction in vivo, possibly via the inhibition of keratinocyte proliferation and induction of apoptosis. Thus, TGF-betaRII agonists and antagonists may provide useful therapeutic tools for human hair growth disorders based on premature or retarded catagen development (effluvium, alopecia, hirsutism).