Second Generation Triple-Helical Peptide Inhibitors of Matrix Metalloproteinases.

The design of selective matrix metalloproteinase (MMP) inhibitors that also possess favorable solubility properties has proved to be especially challenging. A prior approach using collagen-model templates combined with transition state analogs produced a first generation of triple-helical peptide inhibitors (THPIs) that were effective in vitro against discrete members of the MMP family. These THPI constructs were also highly water-soluble.

Determining the Substrate Specificity of Matrix Metalloproteases using Fluorogenic Peptide Substrates.

A continuous assay method, such as the one that utilizes an increase in fluorescence upon hydrolysis, allows for rapid and convenient kinetic evaluation of proteases. To better understand MMP behaviors toward native substrates, a variety of fluorescence resonance energy transfer (FRET)/intramolecular fluorescence energy transfer (IFET) triple-helical substrates have been constructed to examine the collagenolytic activity of MMP family members. Results of these studies have been valuable for providing insights into (a) the relative triple-helical peptidase activities of the various collagenolytic MMPs, (b) the collagen preferences of these MMPs, and (c) the relative roles of MMP domains and specific residues in efficient collagenolysis.

Synthesis of dihydroimidazole tethered imidazolinethiones and their activity as novel antagonists of the nuclear retinoic acid receptor-related orphan receptors (RORs).

Targeting the transcriptional activity of nuclear hormone receptors has proven an effective strategy to treat certain human diseases, and they have become a major focus point to develop novel therapies for the treatment of cancer, inflammation, autoimmune diseases, metabolic disorders, and others. One family of nuclear receptors that has attracted most interest in recent years is the retinoic acid receptor-related orphan receptors (RORs), in particular RORγ. RORγ is a critical regulator of the immune system and RORγ antagonists have shown activity in animal models of inflammatory autoimmune diseases.

The neurotoxicity of amyloid β-protein oligomers is reversible in a primary neuron model.

Alzheimer's disease (AD) is characterized by the accumulation of extracellular amyloid β-protein (Aβ) and intracellular hyperphosphorylated tau proteins. Recent evidence suggests that soluble Aβ oligomers elicit neurotoxicity and synaptotoxicity, including tau abnormalities, and play an initiating role in the development of AD pathology. In this study, we focused on the unclarified issue of whether the neurotoxicity of Aβ oligomers is a reversible process.

Type 1 diabetes pathogenesis is modulated by spontaneous autoimmune responses to endogenous retrovirus antigens in NOD mice.

Secreted microvesicles (MVs) are potent inflammatory triggers that stimulate autoreactive B and T cells, causing Type 1 Diabetes in non-obese diabetic (NOD) mice. Proteomic analysis of purified MVs released from islet cells detected the presence of endogenous retrovirus (ERV) antigens, including Env and Gag sequences similar to the well-characterized murine leukemia retroviruses. This raises the possibility that ERV antigens may be expressed in the pancreatic islets via MV secretion.

Pneumonia and Pleural Empyema due to a Mixed spp. Infection as a Possible Early Esophageal Carcinoma Signature.

Lactobacilli are human commensals found in the gastrointestinal and genitourinary tract. Although generally conceived as non-pathogenic microorganisms, the existence of several reports implicating them in certain severe pathological entities renders this species as opportunistic pathogens. The case of a 58-year-old woman with mixed infection is described.

Deficiency of plasminogen receptor, Plg-R , causes defects in plasminogen binding and inflammatory macrophage recruitment in vivo.

Unlabelled: Essentials Plg-R is a novel integral membrane plasminogen receptor. The functions of Plg-R in vivo are not known. Plg-R is a key player in macrophage recruitment in the inflammatory response in vivo.

Matrix metalloproteinases as reagents for cell isolation.

Cell isolation methods for therapeutic purposes have seen little advancement over the years. The original methods of stem cell and islet isolation using bacterial collagenases were developed in the early 1980s and are still used today. Bacterial collagenases are subject to autodegradation, and isolates obtained with these enzymes may be contaminated with endotoxins, reducing cell viability and contributing to toxicity in downstream applications.

ANTISTAPHYBASE: database of antimicrobial peptides (AMPs) and essential oils (EOs) against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus.

Staphylococcus aureus and methicillin-resistant S. aureus are major pathogens. The antimicrobial peptides and essential oils (EOs) display narrow- or broad-spectrum activity against bacteria including these strains.

Identification of 5,6-dihydroimidazo[2,1-b]thiazoles as a new class of antimicrobial agents.

In an effort to develop novel antimicrobial agents against drug-resistant bacterial infections, 5,6-dihydroimidazo[2,1-b]thiazole compounds were synthesized and tested for their antimicrobial activity. Eight compounds comprised by two sub-scaffolds were identified as hits against methicillin-resistant Staphylococcus aureus (MRSA). These hits were modified at 6-position by replacing (S)-6 to (R)-6 configuration and the (R)-isomers increased their antimicrobial activities by two-fold.

Characterization of Potent SMAC Mimetics that Sensitize Cancer Cells to TNF Family-Induced Apoptosis.

Members of the Inhibitor of APoptosis (IAP) protein family suppress apoptosis within tumor cells, particularly in the context of immune cell-mediated killing by the tumor necrosis factor (TNF) superfamily cytokines. Most IAPs are opposed endogenously by the second mitochondrial activator of caspases (SMAC), which binds to selected baculovirus IAP repeat (BIR) domains of IAPs to displace interacting proteins. The development of SMAC mimetics as novel anticancer drugs has gained impetus, with several agents now in human clinical trials.

Transcription Factor EB Is Selectively Reduced in the Nuclear Fractions of Alzheimer's and Amyotrophic Lateral Sclerosis Brains.

Multiple studies suggest that autophagy is strongly dysregulated in Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS), as evidenced by accumulation of numerous autophagosomes, lysosomes with discontinuous membranes, and aggregated proteins in the patients' brains. Transcription factor EB (TFEB) was recently discovered to be a master regulator of lysosome biogenesis and autophagy. To examine whether aberrant autophagy in AD and ALS is due to alterations in TFEB expression, we systematically quantified the levels of TFEB in these brains by immunoblotting.

Preventing Data Ambiguity in Infectious Diseases with Four-Dimensional and Personalized Evaluations.

Background: Diagnostic errors can occur, in infectious diseases, when anti-microbial immune responses involve several temporal scales. When responses span from nanosecond to week and larger temporal scales, any pre-selected temporal scale is likely to miss some (faster or slower) responses. Hoping to prevent diagnostic errors, a pilot study was conducted to evaluate a four-dimensional (4D) method that captures the complexity and dynamics of infectious diseases.

Bilayer Membrane Modulation of Membrane Type 1 Matrix Metalloproteinase (MT1-MMP) Structure and Proteolytic Activity.

Cell surface proteolysis is an integral yet poorly understood physiological process. The present study has examined how the pericellular collagenase membrane-type 1 matrix metalloproteinase (MT1-MMP) and membrane-mimicking environments interplay in substrate binding and processing. NMR derived structural models indicate that MT1-MMP transiently associates with bicelles and cells through distinct residues in blades III and IV of its hemopexin-like domain, while binding of collagen-like triple-helices occurs within blades I and II of this domain.

Detecting the Hidden Properties of Immunological Data and Predicting the Mortality Risks of Infectious Syndromes.

Background: To extract more information, the properties of infectious disease data, including hidden relationships, could be considered. Here, blood leukocyte data were explored to elucidate whether hidden information, if uncovered, could forecast mortality.

Methods: Three sets of individuals (n = 132) were investigated, from whom blood leukocyte profiles and microbial tests were conducted (i) cross-sectional analyses performed at admission (before bacteriological tests were completed) from two groups of hospital patients, randomly selected at different time periods, who met septic criteria [confirmed infection and at least three systemic inflammatory response syndrome (SIRS) criteria] but lacked chronic conditions (study I, n = 36; and study II, n = 69); (ii) a similar group, tested over 3 days (n = 7); and (iii) non-infected, SIRS-negative individuals, tested once (n = 20).

Altered secondary structure of Dynorphin A associates with loss of opioid signalling and NMDA-mediated excitotoxicity in SCA23.

Spinocerebellar ataxia type 23 (SCA23) is caused by missense mutations in prodynorphin, encoding the precursor protein for the opioid neuropeptides α-neoendorphin, Dynorphin (Dyn) A and Dyn B, leading to neurotoxic elevated mutant Dyn A levels. Dyn A acts on opioid receptors to reduce pain in the spinal cord, but its cerebellar function remains largely unknown. Increased concentration of or prolonged exposure to Dyn A is neurotoxic and these deleterious effects are very likely caused by an N-methyl-d-aspartate-mediated non-opioid mechanism as Dyn A peptides were shown to bind NMDA receptors and potentiate their glutamate-evoked currents.

TFEB Overexpression in the P301S Model of Tauopathy Mitigates Increased PHF1 Levels and Lipofuscin Puncta and Rescues Memory Deficits.

Transcription factor EB (TFEB) was recently shown to be a master regulator of autophagy lysosome pathway. Here, we successfully generated and characterized transgenic mice overexpressing flag-TFEB. Enhanced autophagy in the flag-TFEB transgenic mice was confirmed by an increase in the cellular autophagy markers, as determined by both immunoblots and transmission electron microscopy.

Inhibition of methicillin-resistant Staphylococcus aureus (MRSA) by antimicrobial peptides (AMPs) and plant essential oils.

Context: Drug-resistant bacterial infections cause considerable patient mortality and morbidity. The annual frequency of deaths from methicillin-resistant Staphylococcus aureus (MRSA) has surpassed those caused by human immunodeficiency virus/acquired immune deficiency syndrome. The antimicrobial peptides (AMPs), plant essential oils (EOs) and their combinations have proven to be quite effective in killing a wide selection of bacterial pathogens including MRSA.

A key role for the N/OFQ-NOP receptor system in modulating nicotine taking in a model of nicotine and alcohol co-administration.

Alcohol and nicotine are often co-abused. Although the N/OFQ-NOP receptor system is considered a potential target for development of drug abuse pharmacotherapies, especially for alcoholism, little is known about the role of this system in nicotine dependence. Furthermore, the effect of prior history of nicotine dependence on subsequent nicotine and alcohol taking is understudied.

High-throughput sequencing reveals restricted TCR Vβ usage and public TCRβ clonotypes among pancreatic lymph node memory CD4(+) T cells and their involvement in autoimmune diabetes.

Islet-reactive memory CD4(+) T cells are an essential feature of type 1 diabetes (T1D) as they are involved in both spontaneous disease and in its recurrence after islet transplantation. Expansion and enrichment of memory T cells have also been shown in the peripheral blood of diabetic patients. Here, using high-throughput sequencing, we investigated the clonal diversity of the TCRβ repertoire of memory CD4(+) T cells in the pancreatic lymph nodes (PaLN) of non-obese diabetic (NOD) mice and examined their clonal overlap with islet-infiltrating memory CD4T cells.

Small-Molecule Inhibitors Targeting Topoisomerase I as Novel Antituberculosis Agents.

Bacterial topoisomerase functions are required for regulation of DNA supercoiling and overcoming the DNA topological barriers that are encountered during many vital cellular processes. DNA gyrase and topoisomerase IV of the type IIA bacterial topoisomerase family are important clinical targets for antibacterial therapy. Topoisomerase I, belonging to the type IA topoisomerase family, has recently been validated as a potential antitubercular target.

Synthesis and antitubercular activity of 1,2,4-trisubstitued piperazines.

Parallel solid phase synthesis offers a unique opportunity for the synthesis and screening of large numbers of compounds and significantly enhances the prospect of finding new leads. We report the synthesis and antitubercular activity of chiral 1,2,4-trisubstituted piperazines derived from resin bound acylated dipeptides against Mycobacterium tuberculosis strain H37Rv.

Nociceptin/Orphanin FQ Receptor Structure, Signaling, Ligands, Functions, and Interactions with Opioid Systems.

The NOP receptor (nociceptin/orphanin FQ opioid peptide receptor) is the most recently discovered member of the opioid receptor family and, together with its endogenous ligand, N/OFQ, make up the fourth members of the opioid receptor and opioid peptide family. Because of its more recent discovery, an understanding of the cellular and behavioral actions induced by NOP receptor activation are less well developed than for the other members of the opioid receptor family. All of these factors are important because NOP receptor activation has a clear modulatory role on mu opioid receptor-mediated actions and thereby affects opioid analgesia, tolerance development, and reward.

Fibulin-1 purification from human plasma using affinity chromatography on Factor H-Sepharose.

A method is reported to purify Fibulin-1 from human plasma resulting in a 36% recovery. The steps involve removal of the cryoglobulin and the vitamin K dependent proteins followed by polyethylene glycol and ammonium sulfate precipitations, DEAE-Sephadex column chromatography and finally Factor H-Sepharose affinity purification. The procedure is designed to be integrated into an overall scheme for the isolation of over 30 plasma proteins from a single batch of human plasma.

Imaging Matrix Metalloproteinase Activity Implicated in Breast Cancer Progression.

Proteolysis has been cited as an important contributor to cancer initiation and progression. One can take advantage of tumor-associated proteases to selectively deliver imaging agents. Protease-activated imaging systems have been developed using substrates designed for hydrolysis by members of the matrix metalloproteinase (MMP) family.