Ameliorating Effects of Coriander on Gastrocnemius Muscles Undergoing Precachexia in a Rat Model of Rheumatoid Arthritis: A Proteomics Analysis

Coriander is a commonly used vegetable, spice, and folk medicine, possessing both nutritional and medicinal properties. Up to two-thirds of patients with rheumatoid arthritis (RA) exhibit loss of body mass, predominately skeletal muscle mass, a process called rheumatoid cachexia, and this has major effects of the quality of life of patients. Owing to a lack of effective treatments, the initial stage of cachexia has been proposed as an important period for prevention and decreasing pathogenesis. In the current study, we found that cachexia-like molecular disorders and muscle weight loss were in progress in gastrocnemius muscle after only 5 days of RA induction in rats, although rheumatoid cachexia symptoms have been reported occurring approximately 45 days after RA induction. Oral administration of coriander slightly restored muscle loss. Moreover, iTRAQ-based quantitative proteomics revealed that coriander treatment could partially restore the molecular derangements induced by RA, including impaired carbon metabolism, deteriorated mitochondrial function (tricarboxylic acid cycle and oxidative phosphorylation), and myofiber-type alterations. Therefore, coriander could be a promising functional food and/or complementary therapy for patients with RA against cachexia.

POS0509 PREVALENCE OF RHEUMATOID CACHEXIA AND ITS ASSOCIATION WITH SERUM FETUIN-A LEVELS IN CAUCASIAN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:Rheumatoid cachexia is an under-recognized pathological condition, which is characterized by a loss of muscle strength and can be presented as a low fat-free mass and normal or high BMI in patients with rheumatoid arthritis determined by dual-energy X-ray absorptiometry (DEXA) [1]. Though fetuin-A is one of a major noncollagen proteins in bone tissue it is of interest to clarify its association with rheumatoid cachexia.Objectives:To define the prevalence of rheumatoid cachexia in Caucasian patients with rheumatoid arthritis determined by DEXA method and to study the association of serum fetuin-A levels with body composition and rheumatoid cachexia in this group.Methods:110 Caucasian patients with rheumatoid arthritis undergone DEXA with «Total Body» program. All patients fulfilled the 2010 ACR/EULAR classification criteria for rheumatoid arthritis. The diagnosis of rheumatoid cachexia was based on Engvall I.L. criteria: fat-free mass index less than 10th percentile with fat mass index above 25th percentile [1]. We used values for these indexes from the study performed in 2008 by Coin A. et al. on Italian population due to a lack of standard values [2]. Fetuin-A in serum was determined by enzyme-linked immunosorbent assay. 72 patients have been taking glucocorticoids for more than 3 months in dose equivalent or higher than 5 mg of prednisolone daily. Statistical analysis was performed using a software package “Statistica 12.0”. Parametric data is presented as M±St.dev, and nonparametric as Me [Q1-Q3].Results:Rheumatoid cachexia was diagnosed in 25 patients (22,7%) with mean age of 52,2±8,14 years. The prevalence of cachexia was the same in groups of patients who took glucocorticoids (n=16, 22,2%) and who didn’t (n=9, 23,7%; p = 0,465). Median cumulative dose of oral glucocorticoids in patients with rheumatoid cachexia was higher but fell just short of statistical significance (8,0 [2,9-13,5] g vs 5,4 [0,2-11,6] g; Z=-1,42; p = 0,156). Median serum fetuin-A levels were only slightly significantly lower in patients with rheumatoid cachexia (757,7 [700,5-932,0] µg/ml vs 769,3 [660,3-843,4] µg/ml; Z=-1,35; p=0,175). Positive statistically significant correlations were observed between serum fetuin-A levels and bone mass in right (r=0,222, p = 0,027) and left (r=0,263, p = 0,008) lower limbs, trunk (r=0,268, p = 0,007), gynoid region (r=0,293, p = 0,003), both lower limbs (r=0,246, p = 0,014) and whole-body (r=0,235, p = 0,019).Conclusion:Rheumatoid cachexia was diagnosed in 22,7% of patients with rheumatoid arthritis. No association was observed between glucocorticoids intake and rheumatoid cachexia, despite the expected influence of them on muscle mass. We may suggest that occurrence and pathogenesis of this condition is complex and should be studied more precisely. It is well-known that patients with such condition have a higher risk for metabolic syndrome, arterial hypertension and mortality. We observed positive correlations between serum fetuin-A levels and bone mass in lower limbs, trunk, gynoid region and whole-body. Considering that fetuin-A is also associated with bone mineral density [3], it may be regarded as a marker of bone remodeling.References:[1]Engvall I.L., Elkan A.C., Tengstrand B., Cederholm T., Brismar K., Hafstrom I. Cachexia in rheumatoid arthritis is associated with inflammatory activity, physical disability, and low bioavailable insulin-like growth factor. Scand J Rheumatol. 2008; 37 (5): 321–328.[2]Coin A., Sergi G., Minicuci N., Giannini S., Barbiero E., Manzato E., Pedrazzoni M., Minisola S., Rossini M., Del Puente A., Zamboni M., Inelmen E.M., Enzi G. Fat-free mass and fat mass reference values by dual-energy X-ray absorptiometry (DEXA) in a 20-80 year-old Italian population. Clinical Nutrition. 2008; 27 (1): 87-94.[3]Sari, A., & Uslu, T. The relationship between fetuin-a and bone mineral density in postmenopausal osteoporosis. Turkish Journal of Rheumatology. 2013; 28 (3): 195-201.Disclosure of Interests:None declared

Rheumatoid cachexia: the underappreciated role of myoblast, macrophage and fibroblast interplay in the skeletal muscle niche

Although rheumatoid arthritis affects 1% of the global population, the role of rheumatoid cachexia, which occurs in up to a third of patients, is relatively neglected as research focus, despite its significant contribution to decreased quality of life in patients. A better understanding of the cellular and molecular processes involved in rheumatoid cachexia, as well as its potential treatment, is dependent on elucidation of the intricate interactions of the cells involved, such as myoblasts, fibroblasts and macrophages. Persistent RA-associated inflammation results in a relative depletion of the capacity for regeneration and repair in the satellite cell niche. The repair that does proceed is suboptimal due to dysregulated communication from the other cellular role players in this multi-cellular environment. This includes the incomplete switch in macrophage phenotype resulting in a lingering pro-inflammatory state within the tissues, as well as fibroblast-associated dysregulation of the dynamic control of the extracellular matrix. Additional to this endogenous dysregulation, some treatment strategies for RA may exacerbate muscle wasting and no multi-cell investigation has been done in this context. This review summarizes the most recent literature characterising clinical RA cachexia and links these features to the roles of and complex communication between multiple cellular contributors in the muscle niche, highlighting the importance of a targeted approach to therapeutic intervention.

OP0332 MUSCLE DETERIORATION DUE TO RHEUMATOID ARTHRITIS: ASSESSMENT BY QUANTITATIVE MRI AND STRENGTH TESTING

Background:As well as joint damage, rheumatoid arthritis (RA) is also associated with altered body composition known as rheumatoid cachexia (RC). RC is characterised by reduced skeletal muscle and increased (white) fat mass and decreased strength. RC is associated with increased disease severity and disability (1). It is unknown at what stage muscle involvement begins in RA, and if the muscle damage is modifiable when patients achieve disease control.Quantitative MRI (qMRI) can measure the biomarkers associated with RC. MRI T2 is sensitive to fluid related to physiological changes at the molecular level, and is regarded as an indirect measure of muscle inflammation (2). MRI muscle fat fraction (FF) measurements are useful for identifying myosteatosis (3).Objectives:To obtain preliminary estimates of the extent to which muscle imaging phenotype differs between RA and healthy controls (HC); and to describe the RA phenotype at different levels of disease activity.Methods:39 RA patients (comprising three groups) and 13 age and gender directly matched HC had a MRI scan of their dominant thigh. The RA groups were:[1]13 ‘New RA’ - newly diagnosed, treatment naïve[2]13 ‘Active RA’ - diagnosed >1 year, persistent DAS28 >3.2 for >1 year[3]13 ‘Remission RA’ - diagnosed >1 year, persistent DAS28 <2.6 for >1 yearMR images of the mid-thigh were acquired using Dixon imaging to assess FF and a fat-suppressed multi-echo spin-echo to measure T2. Regions of interest were drawn around the quadriceps and hamstrings. All participants had knee extension and flexion torque measured on an isokinetic dynamometer, and isometric dynamometer to measure grip strength. One-Way ANOVA with Dunnett’s post-hoc analysis provided preliminary indication of potential differences between T2, FF, muscle volume and strength measurements between the disease stages.Results:39 RA patients were recruited: 13 new RA (mean age [years] 63 ± 15, DAS28 5.2 ± 3), 13 active RA (mean age [years] 65 ± 10, DAS28 4.8 ± 3), 13 remission RA (mean age [years] 67 ± 19, DAS28 1.7 ± 0.7) and also 13 HC. T2 and FF were higher in RA patients compared to HC (fig. 1). Within the hamstrings for T2, the mean differences between HC versus new, active and remission patients were 4.5ms (95% CI 2.5, 6.4; p<0.001), 3ms (95% CI 1.1, 4.9; p=0.001), and 5.0ms (95% CI 3.0, 6.4; p<0.001) respectively. Quadriceps results were similar. For muscle volume, the mean differences between HC versus new, active and remission patients were -517.3cm3(95% CI -751, -283; p<0.001), -370.5cm3(95% CI -605, -136; p=0.001), and -312.3cm3(95% CI -546. -77; p=0.006) respectively (fig. 2). Knee flexion/extension and handgrip strength were lower in all 3 groups of RA patients compared to HC. For knee flexion, the mean differences between HC versus new, active and remission patients were 18.4Nm (95% CI -35, -1; p=0.03), 10.1Nm (95% CI -27, 7; p=0.3), and 13.3Nm (95% CI -33, 0; p=0.1) respectively.Figure 1.Quantitative T2 and FF MRI of RA patients and healthy controlsConclusion:This pilot study suggests muscle health may be adversely affected in RA patients compared to matched HC. Our results suggest that muscle changes occur in the earliest stages of RA and persist throughout the disease duration, even in clinical remission. If confirmed, these data imply the need for adjunctive muscle intervention to current RA treatment strategies in order to improve patient outcomes.References:[1]Giles JT, et al. Arthritis Care & Research. 2008[2]Maillard SM, et al. Rheumatology (Oxford, England). 2004[3]Grimm A, et al. The Journal of Frailty & Aging. 2018.Figure 2.MRI muscle volume in RA patients and healthy controlsDisclosure of Interests:Matt Farrow: None declared, John Biglands: None declared, Steven Tanner: None declared, Elizabeth Hensor: None declared, Maya H Buch Grant/research support from: Pfizer, Roche, and UCB, Consultant of: Pfizer; AbbVie; Eli Lilly; Gilead Sciences, Inc.; Merck-Serono; Sandoz; and Sanofi, Paul Emery Grant/research support from: AbbVie, Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, Roche (all paid to employer), Consultant of: AbbVie (consultant, clinical trials, advisor), Bristol-Myers Squibb (consultant, clinical trials, advisor), Lilly (clinical trials, advisor), Merck Sharp & Dohme (consultant, clinical trials, advisor), Novartis (consultant, clinical trials, advisor), Pfizer (consultant, clinical trials, advisor), Roche (consultant, clinical trials, advisor), Samsung (clinical trials, advisor), Sandoz (clinical trials, advisor), UCB (consultant, clinical trials, advisor), Ai Lyn Tan: None declared

Levels of the Novel Endogenous Antagonist of Ghrelin Receptor, Liver-Enriched Antimicrobial Peptide-2, in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a debilitating, chronic, inflammatory, autoimmune disease associated with cachexia. The substitutive therapy of gut hormone ghrelin has been pointed at as a potential countermeasure for the management of metabolic and inflammatory complications in RA. The recent discovery of liver-expressed antimicrobial peptide 2 (LEAP2) as an endogenous inverse agonist/antagonist of the ghrelin receptor makes feasible the development of a more rational pharmacological approach. This work aimed to assess the serum LEAP2 levels, in a cohort of RA patients, in comparison with healthy individuals and determine its correlation with inflammatory parameters. LEAP2 levels were determined by a commercial ELISA kit, plasma C-reactive protein (CRP) levels were evaluated using immunoturbidimetry, and serum levels of inflammatory mediators, namely IL-6, IL-8, IL-1β, MIP1α, MCP1, and LCN2, were measured by XMap multiplex assay. LEAP2 serum levels were significantly increased in RA patients (n = 101) compared with control subjects (n = 26). Furthermore, the LEAP2 levels significantly correlated with CRP and inflammatory cytokines, but not with BMI. These data reveal LEAP2 as a new potential RA biomarker and indicated the pharmacological control of LEAP2 levels as a novel approach for the treatment of diseases with alterations on the ghrelin levels, such as rheumatoid cachexia.

Redox Status and Muscle Pathology in Rheumatoid Arthritis: Insights from Various Rat Hindlimb Muscles

Due to atrophy, muscle weakness is a common occurrence in rheumatoid arthritis (RA). The majority of human studies are conducted on the vastus lateralis muscle—a muscle with mixed fiber type—but little comparative data between multiple muscles in either rodent or human models are available. The current study therefore assessed both muscle ultrastructure and selected redox indicators across various muscles in a model of collagen-induced rheumatoid arthritis in female Sprague-Dawley rats. Only three muscles, the gastrocnemius, extensor digitorum longus (EDL), and soleus, had lower muscle mass (38%, 27%, and 25% loss of muscle mass, respectively; all at least P<0.01), while the vastus lateralis muscle mass was increased by 35% (P<0.01) in RA animals when compared to non-RA controls. However, all four muscles exhibited signs of deterioration indicative of rheumatoid cachexia. Cross-sectional area was similarly reduced in gastrocnemius, EDL, and soleus (60%, 58%, and 64%, respectively; all P<0.001), but vastus lateralis (22% smaller, P<0.05) was less affected, while collagen deposition was significantly increased in muscles. This pathology was associated with significant increases in tissue levels of reactive oxygen species (ROS) in all muscles except the vastus lateralis, while only the gastrocnemius had significantly increased levels of lipid peroxidation (TBARS) and antioxidant activity (FRAP). Current data illustrates the differential responses of different skeletal muscles of the hindlimb to a chronic inflammatory challenge both in terms of redox changes and resistance to cachexia.