Adiponectin changes in relation to the macronutrient composition of a weight-loss diet

Adiponectin is an adipose-derived protein with beneficial metabolic effects. Low adiponectin is associated with obesity and related diseases. Significant weight loss increases adiponectin, reducing disease risk. This study compared the effects of two weight-loss diets with different macronutrient compositions on adiponectin. Eighty-one obese women in two cohorts were randomized to a low-fat (LF) or a low-carbohydrate (LC) diet. All subjects underwent equivalent weight-loss intervention, with weight and other measures assessed at baseline and after 6 (cohort I) or 4 (cohort II) months. Body fat was measured by dual energy X-ray absorptiometry. Adiponectin was measured by radioimmunoassay. Diet intake was assessed using 24-h recalls and 3-day diet records. Data were analyzed via t-tests and repeated-measures factorial ANOVA using time, diet, and replicate (cohort I vs. cohort II) as factors. Age, weight, body fat, BMI, adiponectin, and diet were similar at baseline. Following intervention, macronutrient composition of the diet was vastly different between the groups, reflecting the assigned diet. Both groups lost weight and body fat (P < 0.001), with effect in LC dieters greater than LF dieters (-9.1 kg vs. -4.97 kg weight, P < 0.05 and -5.45 kg vs. -2.62 kg fat, P < 0.001). Adiponectin increased in the LC (+1.92 mcg/ml, P < 0.01), but not the LF (+0.86 mcg/ml, P = 0.81), group. There was no correlation between weight loss and increase in adiponectin. These results confirm that diet-induced loss of weight and body fat is associated with increased adiponectin concentrations. This effect is evident with weight loss of 10% or more, and may be greater with LC diets.     

Early atherosclerosis in systemic sclerosis and its relation to disease or traditional risk factors

Introduction  

Several systemic autoimmune diseases are associated with an increased prevalence of atherosclerosis which could not be explained by traditional risk factors alone. In systemic sclerosis (SSc), microvascular abnormalities are well recognized. Previous studies have suggested an increased prevalence of macrovascular disease as well. We compared patients with SSc to healthy controls for signs of early atherosclerosis by measuring intima-media thickness (IMT) of the common carotid artery in relation to traditional risk factors and markers of endothelial activation.     

Adiponectin and osteocalcin: relation to insulin sensitivity

Obesity and osteoporosis have grave consequences for human health, quality of life, and even the efficiency of the labor force. Interestingly, these diseases share several features including a genetic predisposition and a common progenitor cell. Recent findings show that high adipocyte count in bone marrow is directly related to bone loss, as fat cells replace osteoblasts resulting in reduced bone mineral density and increased propensity towards osteoporosis. This close relationship has a positive aspect, whereby higher osteocalcin levels results in increased adiponectin production while the presence of adiponectin influences osteoblast proliferation and differentiation in a positive way. We focus on how osteoblasts and adipocytes affect each other and ultimately insulin resistance through the hormones they produce. This approach to whole animal physiology is the main stay of Alternative Medicine. It is assumed that the body is linked together intricately, and treating one is equal to treating the whole body. As we go further into bone and adipocytes physiology, it is evident that these organs affect each other. Therefore, elucidation on the actions of fat on bone and vice versa will unravel the complex mechanism of insulin resistance.     

Role of endothelin-1 in the skin fibrosis of systemic sclerosis

Endothelin-1 (ET-1) acts as a key regulator of vasoconstriction and fibrosis. Many previous studies have focused on the role of ET-1 in scleroderma (systemic sclerosis, SSc).We investigated the effects of ET-1 on the production of extracellular matrix in SSc and normal skin fibroblasts. Primary cultured dermal fibroblasts from SSc patients and healthy controls were treated with ET-1 (25 ng/mL) for 0 min, 15 min, 1 h, 24 h, 48 h and 72 h, respectively. Our results showed that, in SSc fibroblasts, ET-1 upregulated collagen type I, connective tissue growth factor (CTGF), type I plasminogen activator inhibitor (PAI-1) and pAkt in a time-dependent manner within 72 h; in normal fibroblasts, 25 ng/mL ET-1 stimulation correlated with high levels of CTGF, PAI-1 and pAkt. The secretion of fibronectin (FN), collagen type I, and PAI-1 is markedly increased in the supernatant of both SSc fibroblasts and normal fibroblasts. Furthermore, ET-1 phosphorylates Smad2 and Smad3 in normal fibroblasts, but not in SSc fibroblasts. In conclusion, our results demonstrated that ET-1 may induce fibrosis in dermal fibroblasts through Akt signals.     

Differential expression of tissue kallikrein in the skin of systemic sclerosis

Systemic sclerosis (SSc) is characterised by ischemic damage, impaired angiogenesis and skin fibrosis. Tissue kallikrein (t-kallikrein) is involved through kinins in inflammation, vasorelaxation and angiogenesis. T-kallikrein is synthetised by endothelial, smooth muscle, and inflammatory cells and, in skin, also by dark cells of the sweat glands, where it is involved in sweat formation. Our aim was to analyse, by immunohistochemistry and RT-PCR, the expression of t-kallikrein in the skin of patients with different SSc subsets, limited (lSSc) and diffuse (dSSc), and phases, early and advanced. Skin biopsies were taken from 18 SSc patients and 10 controls. Immunohistochemistry was performed on paraffin sections with an antibody against human urinary t-kallikrein. For RT-PCR, cDNA from skin biopsies was amplified using primers specific for human t-kallikrein. In the control skin, dark cells of the secretory units of sweat glands showed immunopositivity for t-kallikrein as well as blood vessels. In the lSSc skin, immunoreactivity was observed only in some glands, with weak staining in the advanced phase. In early lSSc skin, immunoreactivity was observed in microvessel walls and in the inflammatory infiltrate. In dSSc skin, dark cells of the glandular fundus units, and the few remaining vessels showed scarcity (early phase) or lack (advanced phase) of immunoreactivity for t-kallikrein. RT-PCR confirmed a decrease of t-kallikrein mRNA levels from early to advanced phase in SSc subsets, reaching its lowest level in advanced dSSc. In conclusion, immunohistochemical and biomolecular results indicate that t-kallikrein is decreased in the skin of SSc patients and decreases progressively from the early to advanced phase of lSSc and dSSc. The decreased expression of t-kallikrein may be involved in the impairment of the sweating process, vessel functionality and angiogenesis.     

Effect of menopause on the modified Rodnan skin score in systemic sclerosis

Introduction

We aimed to evaluate the effect of menopause on skin thickening, as measured by the modified Rodnan skin score (mRSS), in women with systemic sclerosis (SSc).

Methods

We identified women with either limited or diffuse SSc, aged ≥ 18 years, enrolled within the Canadian Scleroderma Research Group (CSRG) cohort, between 2004 and 2011. As part of the CSRG cohort, subjects undergo annual assessments with standardized questionnaires and physical examinations. We performed multivariate regression analyses using generalized estimating equation (GEE) to determine the effect of menopause on the mRSS, adjusting for relevant covariates including notably age, follow-up time, and disease duration.

Results

We identified 1070 women with SSc, contributing a total of 3546 observations over the study period. Of these women, at baseline, 65% had limited disease and 35% diffuse disease. In multivariate analyses, we observed a substantial effect of postmenopausal status on the mean mRSS in women with diffuse disease subtype [−2.62 units, 95% confidence interval (CI) -4.44, −0.80] and significant interaction between menopausal status and disease subtype (2.04 units, 95% CI 0.20, 3.88). The effect of postmenopausal status on the mean mRSS was smaller in women with limited SSc (−0.58, 95% CI −1.50, 0.34).

Conclusions

Our results suggest that menopause has a substantial effect on skin thickening in diffuse SSc, with postmenopausal status being associated with a lower mean mRSS compared to premenopausal status.     

Therapeutic targets in systemic sclerosis

The precise aetiology of systemic sclerosis (SSc) remains elusive, but significant advances over the past few years have improved our understanding of the underlying pathogenic processes and identified key pathways and mediators that are potential therapeutic targets. The situation is complicated by the clinical heterogeneity of SSc and the differential pathogenesis that underlies the two commonest subsets, namely diffuse and limited cutaneous disease. However, there are common mediators that could be targeted to provide clinical benefit in both types of disease. To date, clinical success with therapies directed against logical profibrotic mediators, such as connective tissue growth factor and transforming growth factor-beta, is yet to be reported, although studies are ongoing. More promising clinical results have been obtained with the dual endothelin receptor antagonist bosentan, which has been shown to manage two vascular complications of SSc effectively: pulmonary arterial hypertension and digital ulceration. It remains to be determined whether the identification of additional mediators merely furthers our knowledge of the natural history of SSc or presents targets that can be manipulated to manage SSc patients effectively.     

Cutaneous microcirculation in systemic sclerosis and response to intra-arterial reserpine.

The cutaneous microcirculation in the hand was measured in 23 patients with systemic sclerosis, 19 with Raynaud''s phenomenon and four without Raynaud''s phenomenon, and 20 controls. The patients with Raynaud''s phenomenon had a reduced basal blood flow and an exaggerated further reduction on local cold stimulation, though both were normal in patients without Raynaud''s phenomenon. Reflex-induced vascular changes by cold stimulation of the contralateral hand showed no differences between the three groups. The blood flows were similar in the affected skin of the anterior chest wall in four patients with systemic sclerosis and peripheral Raynaud''s phenomenon and matched controls. In the seven most severely affected patients 1 mg of intra-arterial reserpine produced a prompt improvement in the cutaneous microcirculation which usually lasted one to three weeks but occasionally much longer. By judicious use of repeated injection guided by measurements of the microcirculation it was possible to heal indolent ulcers of the fingers. The results indicate that vascular changes are common in systemic sclerosis but are not fundamental in the pathogenesis of the disease. More probably there is a general soft tissue abnormality that usually but not necessarily affects the vessels.     

Fetal-maternal HLA compatibility confers susceptibility to systemic sclerosis

 Systemic sclerosis (SSc) is a disease of unknown origin, which occurs predominantly in women after childbearing years. There are prominent clinical and histopathologic similarities between SSc and chronic graft-versus-host disease (GVHD). GVHD can occur after blood transfusions or after transplantation with HLA-compatible bone marrow. Here we examined the hypothesis that SSc may be caused by fetal cells crossing the placenta into the maternal circulation and providing donor lymphocytes which recognize disparate HLA antigens, resulting in a reaction similar to chronic GVHD. To test the hypothesis we analyzed the inheritance of HLA class I and class II haplotypes in the families of 37 SSc patients and 42 control individuals. Twenty-six (70.2%) SSc patients had HLA class II alleles compatible either for their offspring or mother, compared with only nine (21%) control individuals. The four patients with juvenile onset SSc we analyzed had alleles compatible with their mothers. These results suggest that in some patients, SSc may, indeed, be a form of chronic GVHD caused by fetal or maternal cells which have crossed the placenta during pregnancy and have remained unrecognized by the host due to class II HLA compatibility, and that subsequent activation of these cells by as yet unknown stimuli result in the development of the disease. Received: 20 February 1997 / Revised: 15 July 1997     

Serum neurotrophin profile in systemic sclerosis

Background

Neurotrophins (NTs) are able to activate lymphocytes and fibroblasts; they can modulate angiogenesis and sympathic vascular function. Thus, they can be implicated in the three pathogenic processes of systemic sclerosis (SSc). The aims of this study are to determine blood levels of Nerve Growth Factor (NGF), Brain-Derived Neurotrophic Factor (BDNF) and Neurotrophin-3 (NT-3) in SSc and to correlate them with clinical and biological data.

Methods

Serum samples were obtained from 55 SSc patients and 32 control subjects to measure NTs levels by ELISA and to determine their relationships with SSc profiles.

Findings

Serum NGF levels were higher in SSc patients (288.26±170.34 pg/mL) than in control subjects (170.34±50.8 pg/mL, p<0.001) and correlated with gammaglobulins levels and the presence of both anti-cardiolipin and anti-Scl-70 antibodies (p<0.05). In contrast, BDNF levels were lower in SSc patients than in controls (1121.9±158.1 vs 1372.9±190.9 pg/mL, p<0.0001), especially in pulmonary arterial hypertension and diffuse SSc as compared to limited forms (all p<0.05). NT-3 levels were similar in SSc and in the control group (2657.2±2296 vs 2959.3±2555 pg/mL, NS). BDNF levels correlated negatively with increased NGF levels in the SSc group (and not in controls).

Conclusion

Low BDNF serum levels were not previously documented in SSc, particularly in the diffuse SSc subset and in patients with pulmonary hypertension or anti-Scl-70 antibodies. The negative correlation between NGF and BDNF levels observed in SSc and not in healthy controls could be implicated in sympathic vascular dysfunction in SSc.     

Characterization of monocyte/macrophage subsets in the skin and peripheral blood derived from patients with systemic sclerosis

Introduction

Recent accumulating evidence indicates a crucial involvement of macrophage lineage in the pathogenesis of systemic sclerosis (SSc). To analyze the assembly of the monocyte/macrophage population, we evaluated the expression of CD163 and CD204 and various activated macrophage markers, in the inflammatory cells of the skin and in the peripheral blood mononuclear cells (PBMCs) derived from patients with SSc.

Methods

Skin biopsy specimens from 6 healthy controls and 10 SSc patients (7 limited cutaneous SSc and 3 diffuse cutaneous SSc) were analyzed by immunohistochemistry using monoclonal antibody against CD68 (pan-macrophage marker), CD163 and CD204. Surface and/or intracellular protein expression of CD14 (marker for monocyte lineage), CD163 and CD204 was analysed by flow cytometry in PBMCs from 16 healthy controls and 41 SSc patients (26 limited cutaneous SSc and 15 diffuse cutaneous SSc). Statistical analysis was carried out using Mann-Whitney U test for comparison of means.

Results

In the skin from SSc patients, the number of CD163⁺ cells or CD204⁺ cells between the collagen fibers was significantly larger than that in healthy controls. Flow cytometry showed that the population of CD14⁺ cells was significantly greater in PBMCs from SSc patients than that in healthy controls. Further analysis of CD14⁺ cells in SSc patients revealed higher expression of CD163 and the presence of two unique peaks in the CD204 histogram. Additionally, we found that the CD163⁺ cells belong to CD14^brightCD204⁺ population.

Conclusions

This is the first report indicating CD163⁺ or CD204⁺ activated macrophages may be one of the potential fibrogenic regulators in the SSc skin. Furthermore, this study suggests a portion of PBMCs in SSc patients abnormally differentiates into CD14^brightCD163⁺CD204⁺ subset. The subset specific to SSc may play an important role in the pathogenesis of this disease, as the source of CD163⁺ or CD204⁺ macrophages in the skin.     

Alpha-actinin-binding antibodies in relation to systemic lupus erythematosus and lupus nephritis

This study investigated the overall clinical impact of anti-α-actinin antibodies in patients with pre-selected autoimmune diseases and in a random group of anti-nuclear antibody (ANA)-positive individuals. The relation of anti-α-actinin antibodies with lupus nephritis and anti-double-stranded DNA (anti-dsDNA) antibodies represented a particular focus for the study. Using a cross-sectional design, the presence of antibodies to α-actinin was studied in selected groups, classified according to the relevant American College of Rheumatology classification criteria for systemic lupus erythematosus (SLE) (n = 99), rheumatoid arthritis (RA) (n = 68), Wegener's granulomatosis (WG) (n = 85), and fibromyalgia (FM) (n = 29), and in a random group of ANA-positive individuals (n = 142). Renal disease was defined as (increased) proteinuria with haematuria or presence of cellular casts. Sera from SLE, RA, and Sj?gren's syndrome (SS) patients had significantly higher levels of anti-α-actinin antibodies than the other patient groups. Using the geometric mean (± 2 standard deviations) in FM patients as the upper cutoff, 20% of SLE patients, 12% of RA patients, 4% of SS patients, and none of the WG patients were positive for anti-α-actinin antibodies. Within the SLE cohort, anti-α-actinin antibody levels were higher in patients with renal flares (p = 0.02) and correlated independently with anti-dsDNA antibody levels by enzyme-linked immunosorbent assay (p < 0.007) but not with other disease features. In the random ANA group, 14 individuals had anti-α-actinin antibodies. Of these, 36% had SLE, while 64% suffered from other, mostly autoimmune, disorders. Antibodies binding to α-actinin were detected in 20% of SLE patients but were not specific for SLE. They correlate with anti-dsDNA antibody levels, implying in vitro cross-reactivity of anti-dsDNA antibodies, which may explain the observed association with renal disease in SLE.     

Alpha-actinin-binding antibodies in relation to systemic lupus erythematosus and lupus nephritis

This study investigated the overall clinical impact of anti-α-actinin antibodies in patients with pre-selected autoimmune diseases and in a random group of anti-nuclear antibody (ANA)-positive individuals. The relation of anti-α-actinin antibodies with lupus nephritis and anti-double-stranded DNA (anti-dsDNA) antibodies represented a particular focus for the study. Using a cross-sectional design, the presence of antibodies to α-actinin was studied in selected groups, classified according to the relevant American College of Rheumatology classification criteria for systemic lupus erythematosus (SLE) (n = 99), rheumatoid arthritis (RA) (n = 68), Wegener's granulomatosis (WG) (n = 85), and fibromyalgia (FM) (n = 29), and in a random group of ANA-positive individuals (n = 142). Renal disease was defined as (increased) proteinuria with haematuria or presence of cellular casts. Sera from SLE, RA, and Sjøgren's syndrome (SS) patients had significantly higher levels of anti-α-actinin antibodies than the other patient groups. Using the geometric mean (± 2 standard deviations) in FM patients as the upper cutoff, 20% of SLE patients, 12% of RA patients, 4% of SS patients, and none of the WG patients were positive for anti-α-actinin antibodies. Within the SLE cohort, anti-α-actinin antibody levels were higher in patients with renal flares (p = 0.02) and correlated independently with anti-dsDNA antibody levels by enzyme-linked immunosorbent assay (p < 0.007) but not with other disease features. In the random ANA group, 14 individuals had anti-α-actinin antibodies. Of these, 36% had SLE, while 64% suffered from other, mostly autoimmune, disorders. Antibodies binding to α-actinin were detected in 20% of SLE patients but were not specific for SLE. They correlate with anti-dsDNA antibody levels, implying in vitro cross-reactivity of anti-dsDNA antibodies, which may explain the observed association with renal disease in SLE.     

Autoantibodies to angiotensin and endothelin receptors in systemic sclerosis induce cellular and systemic events associated with disease pathogenesis

Introduction

Vasculopathy, inflammatory fibrosis and functional autoantibodies (Abs) are major manifestations of systemic sclerosis (SSc). Abs directed against the angiotensin II type 1 receptor (AT₁R) and endothelin-1 type A receptor (ET_AR) are associated with characteristic disease features including vascular, inflammatory, and fibrotic complications indicating their role in SSc pathogenesis. Therefore, the impact of anti-AT₁R and anti-ET_AR Abs on initiation of inflammation and fibrosis was analyzed.

Methods

Anti-AT₁R and anti-ET_AR Ab-positive immunoglobulin G (IgG) from SSc patients (SSc-IgG) was used for experiments. Healthy donor IgG served as a normal control, and AT₁R and ET_AR activation was inhibited by antagonists. Protein expression was measured with ELISA, mRNA expression with real time-PCR, endothelial repair with a scratch assay, and collagen expression with immunocytochemistry. Transendothelial neutrophil migration was measured with a culture insert system, and neutrophil ROS activation with immunofluorescence. Neutrophils in bronchoalveolar lavage fluids (BALFs) were analyzed microscopically after passive transfer of SSc-IgG or NC-IgG into naïve C57BL/6J mice. KC plasma levels were quantified by a suspension array system. Histologic analyses were performed by using light microscopy.

Results

Anti-AT₁R and anti-ET_AR Ab-positive SSc-IgG induced activation of human microvascular endothelial cells (HMEC-1). Elevated protein and mRNA levels of the proinflammatory chemokine interleukin-8 (IL-8, CXCL8) and elevated mRNA levels of the vascular cell adhesion molecule-1 (VCAM-1) were induced in HMEC-1. Furthermore, activation of HMEC-1 with SSc-IgG increased neutrophil migration through an endothelial cell layer and activation of reactive oxygen species (ROS). SSc-IgG decreased HMEC-1 wound repair and induced type I collagen production in healthy donor skin fibroblasts. Effects of migration, wound repair, and collagen expression were dependent on the Ab-levels. Passive transfer of anti-AT₁R and anti-ET_AR Ab-positive SSc-IgG into naïve C57BL/6J mice increased neutrophil BALF counts. In parallel, increased levels of the murine functional IL-8 homologue, chemokine KC, were found in the plasma of SSc-IgG-treated mice as well as structural alterations of the lungs.

Conclusions

We conclude that angiotensin and endothelin-receptor activation via anti-AT₁R and anti-ET_AR Abs mediate pathogenic effects, indicating their contribution to pathogenesis of SSc. Therefore, anti-AT₁R and anti-ET_AR Abs could provide novel targets for therapeutic intervention in the treatment of SSc.