A phase Ib multiple ascending dose study evaluating safety,pharmacokinetics, and early clinical response of brodalumab,a human anti-IL-17R antibody,in methotrexate-resistant rheumatoid arthritis

Introduction

The aim of this study was to evaluate the safety, pharmacokinetics, and clinical response of brodalumab (AMG 827), a human, anti-IL-17 receptor A (IL-17RA) monoclonal antibody in subjects with moderate-to-severe rheumatoid arthritis (RA).

Methods

This phase Ib, randomized, placebo-controlled, double-blind multiple ascending dose study enrolled subjects with moderate to severe RA (≥6/66 swollen and ≥8/68 tender joints). Subjects were randomized 3:1 to receive brodalumab (50 mg, 140 mg, or 210 mg subcutaneously every two weeks for 6 doses per group; or 420 mg or 700 mg intravenously every 4 weeks for two doses per group) or placebo. Endpoints included incidence of adverse events (AEs) and pharmacokinetics. Exploratory endpoints included pharmacodynamics, and improvements in RA clinical metrics.

Results

Forty subjects were randomized to investigational product; one subject discontinued due to worsening of RA (placebo). The study was not designed to assess efficacy. AEs were reported by 70% (7/10) of placebo subjects and 77% (22/30) of brodalumab subjects. Three serious AEs were reported in two subjects; there were no opportunistic infections. Brodalumab treatment resulted in inhibition of IL-17 receptor signaling and receptor occupancy on circulating leukocytes. No treatment effects were observed with individual measures of RA disease activity. On day 85 (week 13) 37% (11/30) of brodalumab subjects and 22% (2/9) of placebo subjects achieved ACR20; 7% (2/30) brodalumab subjects and 11% (1/9) of placebo subjects achieved ACR50; and 0% (0/30) brodalumab subjects and 0% (0/9) of placebo subjects achieved ACR70.

Conclusions

Multiple dose administration of brodalumab was tolerated in subjects with active RA. There was no evidence of a clinical response to brodalumab in subjects with RA.

Trial registration

ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT00771030","term_id":"NCT00771030"}}NCT00771030     

CXCL8 in thyroid disease: From basic notions to potential applications in clinical practice

CXCL8 was the first chemokine shown to be secreted by thyrocytes. Experimental data suggest that CXCL8 plays a role in thyroid homeostasis but its role in thyroid diseases remains poorly investigated. Clinical studies measuring the serum levels of CXCL8 in patients with autoimmune-thyroid-diseases reported conflicting results. Solid evidences support a role of CXCL8 as a tumor-promoting agent in several human cancers. Studies in thyroid cancer are still in their initial stage, but promising. Several evidences indicate that thyroid cancer may share with other human malignancies some of the effects of CXCL8 and highlight the possibility of using CXCL8 as a marker of aggressiveness. Basic and clinical evidences in favor or against a role for CXCL8 in thyroid diseases are discussed.     

Hidden Behind Autophagy: The Unconventional Roles of ATG Proteins

Macroautophagy (hereafter referred to as autophagy) is an evolutionarily conserved intracellular catabolic transport route that generally allows the lysosomal degradation of cytoplasmic components, including bulk cytosol, protein aggregates, damaged or superfluous organelles and invading microbes. Target structures are sequestered by double‐membrane vesicles called autophagosomes, which are formed through the concerted action of the autophagy (ATG)‐related proteins. Until recently it was assumed that ATG proteins were exclusively involved in autophagy. A growing number of studies, however, have attributed functions to some of them that are distinct from their classical role in autophagosome biogenesis. Autophagy‐independent roles of the ATG proteins include the maintenance of cellular homeostasis and resistance to pathogens. For example, they assist and enhance the turnover of dead cells and microbes upon their phagocytic engulfment, and inhibit murine norovirus replication. Moreover, bone resorption by osteoclasts, innate immune regulation triggered by cytoplasmic DNA and the ER‐associated degradation regulation all have in common the requirement of a subset of ATG proteins. Microorganisms such as coronaviruses, Chlamydia trachomatis or Brucella abortus have even evolved ways to manipulate autophagy‐independent functions of ATG proteins in order to ensure the completion of their intracellular life cycle. Taken together these novel mechanisms add to the repertoire of functions and extend the number of cellular processes involving the ATG proteins.     

Chaperonin 60: a paradoxical,evolutionarily conserved protein family with multiple moonlighting functions

Chaperonin 60 is the prototypic molecular chaperone, an essential protein in eukaryotes and prokaryotes, whose sequence conservation provides an excellent basis for phylogenetic analysis. Escherichia coli chaperonin 60 (GroEL), the prototype of this family of proteins, has an established oligomeric‐structure‐based folding mechanism and a defined population of folding partners. However, there is a growing number of examples of chaperonin 60 proteins whose crystal structures and oligomeric composition are at variance with GroEL, suggesting that additional complexities in the protein‐folding function of this protein should be expected. In addition, many organisms have multiple chaperonin 60 proteins, some of which have lost their protein‐folding ability. It is emerging that this highly conserved protein has evolved a bewildering variety of additional biological functions – known as moonlighting functions – both within the cell and in the extracellular milieu. Indeed, in some organisms, it is these moonlighting functions that have been left after the loss of the protein‐folding activity. This highlights the major paradox in the biology of chaperonin 60. This article reviews the relationship between the folding and non‐folding (moonlighting) activities of the chaperonin 60 family and discusses current knowledge on their molecular evolution focusing on protein domains involved in the non‐folding chaperonin functions in an attempt to understand the emerging biology of this evolutionarily ancient protein family.     

An Optimized Whole-Body Cortisol Quantification Method for Assessing Stress Levels in Larval Zebrafish

Glucocorticoids serve important regulatory functions for many physiological processes and are critical mediators of the stress response. The stress response is a set of bodily processes aimed at counteracting a state of threatened homeostasis. Proper stress response is critical for the survival of an animal, however prolonged or abnormal stress response can be detrimental and is implicated in a number of human diseases such as depression and metabolic diseases. To dissect the underlying mechanism of this complex and important response, the zebrafish, Danio rerio offer important advantages such as ease of genetic manipulations and high-throughput behavioral analyses. However, there is a paucity of suitable methods to measure stress level in larval zebrafish. Therefore, an efficient low-cost method to monitor stress hormone levels will greatly facilitate stress research in zebrafish larvae. In this study, we optimized sample collection as well as cortisol extraction methods and developed a home-made ELISA protocol for measuring whole-body cortisol level in zebrafish larvae. Further, using our customized protocols, we characterized the response of larval zebrafish to a variety of stressors. This assay, developed for efficient cortisol quantification, will be useful for systematic and large-scale stress analyses in larval zebrafish.     

Structural and Physiological Analyses of the Alkanesulphonate-Binding Protein (SsuA) of the Citrus Pathogen Xanthomonas citri

Background

The uptake of sulphur-containing compounds plays a pivotal role in the physiology of bacteria that live in aerobic soils where organosulfur compounds such as sulphonates and sulphate esters represent more than 95% of the available sulphur. Until now, no information has been available on the uptake of sulphonates by bacterial plant pathogens, particularly those of the Xanthomonas genus, which encompasses several pathogenic species. In the present study, we characterised the alkanesulphonate uptake system (Ssu) of Xanthomonas axonopodis pv. citri 306 strain (X. citri), the etiological agent of citrus canker.

Methodology/Principal Findings

A single operon-like gene cluster (ssuEDACB) that encodes both the sulphur uptake system and enzymes involved in desulphurisation was detected in the genomes of X. citri and of the closely related species. We characterised X. citri SsuA protein, a periplasmic alkanesulphonate-binding protein that, together with SsuC and SsuB, defines the alkanesulphonate uptake system. The crystal structure of SsuA bound to MOPS, MES and HEPES, which is herein described for the first time, provides evidence for the importance of a conserved dipole in sulphate group coordination, identifies specific amino acids interacting with the sulphate group and shows the presence of a rather large binding pocket that explains the rather wide range of molecules recognised by the protein. Isolation of an isogenic ssuA-knockout derivative of the X. citri 306 strain showed that disruption of alkanesulphonate uptake affects both xanthan gum production and generation of canker lesions in sweet orange leaves.

Conclusions/Significance

The present study unravels unique structural and functional features of the X. citri SsuA protein and provides the first experimental evidence that an ABC uptake system affects the virulence of this phytopathogen.     

Comparative Outcomes of the Two Types of Sacral Extradural Spinal Meningeal Cysts Using Different Operation Methods: A Prospective Clinical Study

This prospective study compares different clinical characteristics and outcomes of patients with two types of sacral extradural spinal meningeal cysts (SESMC) undergoing different means of surgical excision. Using the relationship between the cysts and spinal nerve roots fibers (SNRF) as seen under microscope, SESMCs were divided into two types: cysts with SNRF known as Tarlov cysts and cysts without. The surgical methods were tailored to the different types of SESMCs. The improved Japanese Orthopedic Association (IJOA) scoring system was used to evaluate preoperative and postoperative neurological function of the patients. Preoperative IJOA scores were 18.5±1.73, and postoperative IJOA scores were 19.6±0.78. The difference between preoperative and postoperative IJOA scores was statistically significant (t = -4.52, p = 0.0001), with a significant improvement in neurological function after surgery. Among the improvements in neurological functions, the most significant was sensation (z=-2.74, p=0.006), followed by bowel/bladder function (z=-2.50, p=0.01). There was a statistically significant association between the types of SESMC and the number (F=12.57, p=0.001) and maximum diameter (F=8.08, p=0.006) of the cysts. SESMC with SNRF are often multiple and small, while cysts without SNRF tend to be solitary and large. We advocate early surgical intervention for symptomatic SESMCs in view of significant clinical improvement postoperatively.