Trypsin inhibition by macrocyclic and open-chain variants of the squash inhibitor MCoTI-II

MCoTl-I and MCoTl-II from the seeds of Momordica cochinchinensis are inhibitors of trypsin-like proteases and the only known members of the large family of squash inhibitors that are cyclic and contain an additional loop connecting the amino- and the carboxy-terminus. To investigate the contribution of macrocycle formation to biological activity, we synthesized a set of open-chain variants of MCoTl-II that lack the cyclization loop and contain various natural and non-natural amino acid substitutions in the reactive-site loop. Upon replacement of P1 lysine residue \#10 within the open-chain variant of MCoTl-II by the non-natural isosteric nucleo amino acid AlaG{[}beta-(guanin-9-yl)-L-alanine], a conformationally restricted arginine mimetic, residual inhibitory activity was detected, albeit reduced by four orders of magnitude. While the cyclic inhibitors MCoTl-I and MCoTl-II were found to be very potent trypsin inhibitors, with picomolar inhibition constants, the open-chain variants displayed an approximately 10-fold lower affinity. These data suggest that the formation of a circular backbone in the MCoTI squash inhibitors results in enhanced affinity and therefore is a determinant of biological activity

Structural evolution drives diversification of the large LRR-RLK gene family

Cells are continuously exposed to chemical signals that they must discriminate between and respond to appropriately. In embryophytes, the leucine‐rich repeat receptor‐like kinases (LRR‐RLKs) are signal receptors critical in development and defense. LRR‐RLKs have diversified to hundreds of genes in many plant genomes. Although intensively studied, a well‐resolved LRR‐RLK gene tree has remained elusive. To resolve the LRR‐RLK gene tree, we developed an improved gene discovery method based on iterative hidden Markov model searching and phylogenetic inference. We used this method to infer complete gene trees for each of the LRR‐RLK subclades and reconstructed the deepest nodes of the full gene family. We discovered that the LRR‐RLK gene family is even larger than previously thought, and that protein domain gains and losses are prevalent. These structural modifications, some of which likely predate embryophyte diversification, led to misclassification of some LRR‐RLK variants as members of other gene families. Our work corrects this misclassification. Our results reveal ongoing structural evolution generating novel LRR‐RLK genes. These new genes are raw material for the diversification of signaling in development and defense. Our methods also enable phylogenetic reconstruction in any large gene family

Necrotizing meningoencephalitis in atypical dog breeds: a case series and literature review.

BackgroundCanine necrotizing meningoencephalitis (NME) is a fatal, noninfectious inflammatory disease of unknown etiology. NME has been reported only in a small number of dog breeds, which has led to the presumption that it is a breed-restricted disorder.Hypothesis/objectivesOur objective was to describe histopathologically confirmed NME in dog breeds in which the condition has not been reported previously and to provide preliminary evidence that NME affects a wider spectrum of dog breeds than previously reported.AnimalsFour dogs with NME.MethodsArchives from 3 institutions and from 1 author's (BS) collection were reviewed to identify histopathologically confirmed cases of NME in breeds in which the disease has not been reported previously. Age, sex, breed, survival from onset of clinical signs, and histopathologic findings were evaluated.ResultsNecrotizing meningoencephalitis was identified in 4 small dog breeds (Papillon, Shih Tzu, Coton de Tulear, and Brussels Griffon). Median age at clinical evaluation was 2.5 years. Histopathologic abnormalities included 2 or more of the following: lymphoplasmacytic or histiocytic meningoencephalitis or encephalitis, moderate-to-severe cerebrocortical necrosis, variable involvement of other anatomic locations within the brain (cerebellum, brainstem), and absence of detectable infectious agents.Conclusions and clinical importanceUntil now, NME has only been described in 5 small dog breeds. We document an additional 4 small breeds previously not shown to develop NME. Our cases further illustrate that NME is not a breed-restricted disorder and should be considered in the differential diagnosis for dogs with signalment and clinical signs consistent with inflammatory brain disease

A guide to chemokines and their receptors

The chemokines (or chemotactic cytokines) are a large family of small, secreted proteins that signal through cell surface G‐protein coupled heptahelical chemokine receptors. They are best known for their ability to stimulate the migration of cells, most notably white blood cells (leukocytes). Consequently, chemokines play a central role in the development and homeostasis of the immune system, and are involved in all protective or destructive immune and inflammatory responses. Classically viewed as inducers of directed chemotactic migration, it is now clear that chemokines can stimulate a variety of other types of directed and undirected migratory behaviour, such as haptotaxis, chemokinesis, and haptokinesis, in addition to inducing cell arrest or adhesion. However, chemokine receptors on leukocytes can do more than just direct migration, and these molecules can also be expressed on, and regulate the biology of, many non‐leukocytic cell types. Chemokines are profoundly affected by post‐translational modification, by interaction with the extracellular matrix (ECM), and by binding to heptahelical ‘atypical’ chemokine receptors that regulate chemokine localisation and abundance. This guide gives a broad overview of the chemokine and chemokine receptor families; summarises the complex physical interactions that occur in the chemokine network; and, using specific examples, discusses general principles of chemokine function, focussing particularly on their ability to direct leukocyte migration

The role of REVOLUTA and KANADI1 in plant development and environmental responses

In plants, the establishment of organ patterning and polarity is mediated by the action of several transcription factors. Among them, KANADIs and HD-ZIPIIIs act antagonistically by which they play crucial roles in organ polarity. Using a combination of chromatin immunoprecipitation (ChIP-Seq) approach and tiling arrays, we could identify a set of potential direct target genes of KAN1. Further analysis showed that a number of KAN1 targets appear to regulate organ patterning or response to auxin. In addition, KAN1 shares a set of common direct targets with REV, implying that the REV/KAN1 module acts in organ patterning through opposite regulation of shared targets. As sessile organisms, plants have to continuously adjust growth and development to changing environmental conditions. During the final stage of growth, plants induce leaf senescence to reallocate nutrients and energy-rich substances from mature leaves to reproductive seeds, leading to increased reproductive success. Therefore leaf senescence is tightly coupled to the developmental age of the plant. In this study, we show that class III HD-ZIP transcription factors have an additional role in controlling the onset of leaf senescence in Arabidopsis. We report that acting as a redox-sensitive transcription factor, REV directly and positively regulates the expression of WRKY53, a senescence-related transcription factor. REV is required for the induction of WRKY53 in response to oxidative stress, and reducing the activity of HD-ZIP III genes strongly delays the onset of leaf senescence. Besides WRKY53, we also identified nine direct REV targets which are differentially expressed during senescence. Thus, a crosstalk between early and late stages of leaf development appears to contribute to reproductive success

Effect of stress doses of hydrocortisone on S-100B vs. interleukin-8 and polymorphonuclear elastase levels in human septic shock

Stress doses of hydrocortisone a re known to have immunomodulatory effects in patients with hyperdynamic septic shock. The prognosis correlates with the presence and severity of septic encephalopathy. However, neurological evaluation is influenced by the use of analgesia sedation during artificial ventilation. The objective of this study was to demonstrate the effect of stress doses of hydrocortisone during the initial phase of human septic shock on the serum values of the neurospecific protein S-100B in comparison to the inflammation markers interleukin (IL)-8 in serum and polymorphonuclear (PMN) elastase in plasma. A total of 24 consecutive patients, who met the American College of Chest Physicians/Society of Critical Care Medicine criteria for septic shock, were enrolled in this prospective, randomized, double-blind, single-center trial. The severity of illness at recruitment was graded using the Acute Physiology and Chronic Health Evaluation 11 and the Simplified Acute Physiology Score 11 scoring systems. Multi-organ dysfunction syndrome was described by the Sepsis-related Organ Failure Assessment (SOFA) score. All patients were prospectively randomized to receive either stress doses of hydrocortisone or placebo. Hydrocortisone was started in 12 patients with a loading dose of 100 mg and followed by a continuous infusion of 0.18 mg/kg/h for 6 days. Median S-100B serum levels of the hydrocortisone group decreased from 0.32 ng/mL at study entry to 0.07 ng/mL 6 days later without significant differences compared to the placebo group. Initial IL-8 serum levels were significantly higher in the hydrocortisone group up to 12 h after study entry, and significantly decreased from 715 to 17 pg/mL at the end of the observation period. Median PMN elastase plasma levels were not affected by hydrocortisone infusion. Patients with initial S-100B serum levels >0.50 ng/mL revealed significantly higher SOFA scores up to 30 h, IL-8 serum levels up to 12 h, and PMN elastase plasma levels up to 36 h after study entry than those patients with <= 0.50 ng/mL. These effects were independent of the amount of fluid correction for hemodilution. Starting S-100B, IL-8 and PMN elastase values of the hydrocortisone group were within the ranges already known in patients with out-of-hospital cardiac arrest or severe traumatic brain injury. Stress doses of hydrocortisone resulted in a significant reduction in IL-8 serum, but not in S-100B serum and PMN elastase plasma concentrations in patients with hyperdynamic septic shock. For the first time, a similar extent of S-100B increase in serum of septic patients at the time of diagnosis was shown as reported for cardiac arrest or severe traumatic brain injury

Effect of stress doses of hydrocortisone on S-100B vs. interleukin-8 and polymorphonuclear elastase levels in human septic shock

Stress doses of hydrocortisone a re known to have immunomodulatory effects in patients with hyperdynamic septic shock. The prognosis correlates with the presence and severity of septic encephalopathy. However, neurological evaluation is influenced by the use of analgesia sedation during artificial ventilation. The objective of this study was to demonstrate the effect of stress doses of hydrocortisone during the initial phase of human septic shock on the serum values of the neurospecific protein S-100B in comparison to the inflammation markers interleukin (IL)-8 in serum and polymorphonuclear (PMN) elastase in plasma. A total of 24 consecutive patients, who met the American College of Chest Physicians/Society of Critical Care Medicine criteria for septic shock, were enrolled in this prospective, randomized, double-blind, single-center trial. The severity of illness at recruitment was graded using the Acute Physiology and Chronic Health Evaluation 11 and the Simplified Acute Physiology Score 11 scoring systems. Multi-organ dysfunction syndrome was described by the Sepsis-related Organ Failure Assessment (SOFA) score. All patients were prospectively randomized to receive either stress doses of hydrocortisone or placebo. Hydrocortisone was started in 12 patients with a loading dose of 100 mg and followed by a continuous infusion of 0.18 mg/kg/h for 6 days. Median S-100B serum levels of the hydrocortisone group decreased from 0.32 ng/mL at study entry to 0.07 ng/mL 6 days later without significant differences compared to the placebo group. Initial IL-8 serum levels were significantly higher in the hydrocortisone group up to 12 h after study entry, and significantly decreased from 715 to 17 pg/mL at the end of the observation period. Median PMN elastase plasma levels were not affected by hydrocortisone infusion. Patients with initial S-100B serum levels >0.50 ng/mL revealed significantly higher SOFA scores up to 30 h, IL-8 serum levels up to 12 h, and PMN elastase plasma levels up to 36 h after study entry than those patients with <= 0.50 ng/mL. These effects were independent of the amount of fluid correction for hemodilution. Starting S-100B, IL-8 and PMN elastase values of the hydrocortisone group were within the ranges already known in patients with out-of-hospital cardiac arrest or severe traumatic brain injury. Stress doses of hydrocortisone resulted in a significant reduction in IL-8 serum, but not in S-100B serum and PMN elastase plasma concentrations in patients with hyperdynamic septic shock. For the first time, a similar extent of S-100B increase in serum of septic patients at the time of diagnosis was shown as reported for cardiac arrest or severe traumatic brain injury

PERFLUOROOCTANE SULFONATE (PFOS) AND PERFLUOROOCTANOATE (PFOA) CONTAMINATION OF WATER ENVIRONMENT IN ASIAN COUNTRIES

Joint Research on Environmental Science and Technology for the Eart