Imbalance between interleukin-6 and adrenomedullin mRNA levels in peripheral blood mononuclear cells of patients with lupus nephritis

Characterization of patients with systemic lupus erythematosus who meet the diagnostic criteria for TAFRO syndrome

Purpose

TAFRO syndrome is a novel disorder manifesting as fever, anasarca, thrombocytopenia, renal insufficiency and organomegaly, and its etiology has not been clarified. The aim of this study was to elucidate similarities and differences between systemic lupus erythematosus (SLE) and TAFRO syndrome.

Methods

We examined 46 consecutive patients diagnosed with SLE and determined whether they meet the proposed diagnostic criteria for TAFRO syndrome (2015 version).

Results

Of the 46 patients with SLE, four (8.7%) also met the TAFRO syndrome criteria (TAFRO-like group). All patients in the TAFRO-like group were males, and their mean age was significantly higher than that of the non-TAFRO group (67.5 ± 8.7 vs. 39.3 ± 18.1 years, p = 0.004). C-reactive protein and γ-glutamyl transpeptidase levels were significantly higher, and frequencies of anti-dsDNA and anti-Sm antibodies were significantly lower in the TAFRO-like than non-TAFRO group. Elder cases (onset age ≥ 50 years) met significantly more categories of the diagnostic criteria for TAFRO syndrome than did those with younger cases.

Conclusions

Several patients with SLE, especially elder cases, showed features similar to those of TAFRO syndrome. Although exclusion of SLE is needed in the diagnostic criteria for TAFRO syndrome, TAFRO syndrome-like SLE should be considered.

Beneficial effect of magnolol on lupus nephritis in MRL/lpr mice by attenuating the NLRP3 inflammasome and NF‑κB signaling pathway: A mechanistic analysis

Lupus nephritis (LN) is a common complication of systemic lupus erythematosus. The present study aimed to elucidate the protective effect of magnolol (MG) on the progression of LN, via inhibition of key signaling pathways. The results of the present study demonstrated that administration of MG caused inhibition of the activation of NACHT, LRR and PYD domains‑containing protein 3 and interleukin‑1β production. Histopathological analysis confirmed that the vehicle‑treated group exhibited characteristic glomerular disease, which was observed to be suppressed following the administration of MG; a marked decrease in glomerular and vascular lesions was observed compared with the vehicle control. This decrease was further demonstrated through analysis of kidney sections. The expression level of cell surface glycoprotein F4/80 was demonstrated to be markedly decreased in the MG‑treated mice compared with the vehicle control group. The MG‑treated mice exhibited a marked decrease in serum and renal tumor necrosis factor‑α expression levels.

Urinary mRNA in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a relapsing autoimmune disease with clinical manifestations that affect multiple organ systems. Lupus nephritis is recognized as one of the most severe organ involvements in SLE and affects half of the lupus patients. Notably, lupus nephritis is characterized by intrarenal lymphocyte activation and inflammation. Since most of the cytokines exert their effects in a paracrine fashion, measuring their expression at the site of pathology should be of biological relevance. Although kidney biopsy is widely used to determine the histology and severity of lupus nephritis, this invasive procedure has its own risk and is not practical for serial monitoring. In the past decade, extraction and quantification of messenger RNA (mRNA) from urinary sediment has emerged as a robust laboratory technique. Quantification of mRNA expression in urinary sediment has been tested as a noninvasive means to assess the disease activity of SLE patients. Available published evidence, however, is limited to small-scale studies. Based on the result of these studies, a number of cytokine and transcript factor genes have been found to have potential for the differentiation between active and inactive SLE, between proliferative and membranous types of lupus nephritis, assessment of the systemic lupus activity or histological activity of kidney biopsy specimen, monitoring of treatment response in active lupus nephritis, or detection of lupus disease flare in clinically quiescent patients. Being a simple and noninvasive method, urinary mRNA level deserves further studies to validate its role in risk stratification and monitoring of therapeutic response in patients with lupus nephritis.

Gene expression of C-type natriuretic peptide and of its specific receptor NPR-B in human leukocytes of healthy and heart failure subjects

C-type natriuretic peptide (CNP), a member of the family of natriuretic peptides, is synthesized and secreted from monocytes and macrophages that resulted to be a source of CNP at inflammatory sites. This suggests that special attention should be focused on the possible role of CNP in the immune system, in addition to its effects on the cardiovascular system. The aim of this study was to evaluate the possibility of measuring the mRNA expression of CNP and NPR-B, its specific receptor, in human whole blood samples of healthy (N; n=7) and heart failure (HF; n=7) subjects by Real-Time PCR (RT-PCR). Total RNA was extracted from leukocytes with QIAamp RNA Blood Kit and/or with PAXgene Blood RNA Kit. RT-PCR was performed and optimized for each primer. The experimental results were normalized with the three most stably expressed genes. CNP and NPR-B expression trend was similar in both fresh and frozen human whole blood. Significant higher levels of CNP and NPR-B mRNA expression were found in HF patients with respect to controls (CNP: N=1.23±0.33 vs. HF=6.54±2.09 p=0.027; NPR-B: N=0.85±0.23 vs. HF=5.31±1.98 p=0.04). A significant correlation between CNP and NPR-B (r=0.86, p<0.0001) was observed. Further studies are needed to clarify the pathophysiological properties of this peptide but the possibility to measure CNP and NPR-B mRNA expression in human leukocytes with a fast and easy procedure is a useful starting point for future investigation devoted to better understand the biomolecular processes associated to different diseases.

Monitoring of urinary messenger RNA levels for the prediction of flare in systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is characterized by disease flares and remission. We hypothesize that in clinically quiescent SLE patients, the mRNA level of target genes in the urinary sediment is an early indicator of disease flare.

METHODS

From a cohort of 134 adult SLE patients prospectively followed for 56 weeks, we identified 19 patients with a single disease flare. The mRNA level of eight pre-defined target genes in their urinary sediment before disease flare was compared to 19 matched controls with no disease flare during the same period.

RESULTS

Urinary mRNA level remained static in the control group during the study period. Before disease flare, there was a significant increase in the mRNA level of monocyte chemotactic protein (MCP)-1 and forkhead box P3 (FOXP3), and decrease in interleukin (IL)-17 and GATA-3, in the urinary sediment. The mRNA level of FOXP3 in urinary sediment increases 8 weeks prior to a flare, which precedes the corresponding change in serum complement and anti-DNA antibody titer, while that of MCP-1, IL-17, and GATA3 began to change 4 weeks prior to a flare. The same pattern of change in urinary mRNA level was observed in patients with mild-to-moderate or severe flare, and those with renal or non-renal flare. The SLE Disease Activity Index (SLEDAI) score at the time of flare significantly correlated with the change in urinary level of IL-17 (r=-0.462, p=0.046) and GATA-3 (r=-0.455, p=0.05), but not MCP-1 or FOXP3, prior to the flare.

CONCLUSION

Monitoring of MCP-1, IL-17, GATA-3 and FOXP3 mRNA level in urinary sediment may provide an early clue for detecting disease flare in SLE patients.

The role of cytokine in the lupus nephritis

Lupus nephritis (LN) is a major clinical manifestation of systemic lupus erythematosus (SLE). Although numerous abnormalities of immune system have been proposed, cytokine overexpression plays an essential role in the pathogenesis of LN. In the initial phase of the disease, the immune deposits and/or autoantibodies induce cytokine production in renal resident cells, leading to further inflammatory cytokine/chemokine expression and leukocyte infiltration and activation. Then, infiltrate leukocytes, such as macrophages (Mφ) and dendritic cells (DCs), secrete a variety of cytokines and activate naïve T cells, leading the cytokine profile towards T helper (Th)1, Th2, and/or Th17. Recent studies revealed these inflammatory processes in experimental animal models as well as human LN. The cytokine targeted intervention may have the therapeutic potentials for LN. This paper focuses on the expression of cytokine and its functional role in the pathogenesis of LN.

Angiogenic activity in sera of patients with systemic lupus erythematosus

Angiogenesis plays a critical role in the pathogenesis of several connective tissue diseases. There is, however, relatively little information available on the role of angiogenesis in systemic lupus erythematosus (SLE). The aim of this study was to investigate the angiogenic activity in sera of patients with SLE and to determine the association between angiogenic activity and clinical complications. Sera from 66 Tunisian females with SLE and from 32 healthy blood donors were studied for their angiogenic activity using the in-vitro tube formation test on Matrigel. Samples were divided into five groups according to their angiogenic activity, which was scored from 0 (no angiogenesis) to 4 (high angiogenic activity). Samples from each group were then tested randomly to assess serum concentration of vascular endothelial growth factor (VEGF). No correlation was found between angiogenic activity scores and serum VEGF levels. Considering angiogenesis assessment in-vitro, sera of patients with SLE showed a much higher angiogenic activity than healthy controls since a high angiogenic score (score 4) is present in 43.9% of patients and in 6.3% of controls ( P < 0.0002). This high angiogenic activity is not correlated with disease activity; however, SLE patients with anti-dsDNA antibodies and those with nephritis showed higher angiogenic activity compared with patients without these complications since score 4 is found in 50.9% and 67.9% versus 9.1% ( P = 0.017) and 26.3% ( P < 0.001), respectively. In conclusion, our study showed that high serum angiogenic activity in SLE was not correlated with the VEGF levels. We suggest the use of the ‘in-vitro’ tube formation test as a better tool to study the angiogenic potential of sera. We found that in patients with SLE, serum angiogenic activity is increased compared with healthy controls. This high angiogenic activity is associated with renal complications and with the presence of anti-dsDNA antibodies. These findings suggest an involvement of angiogenesis disturbance in the pathogenesis of SLE.

Vascular Endothelial Growth Factor (VEGF) in Autoimmune Diseases

Vascular endothelial growth factor (VEGF) is a potent stimulating factor for angiogenesis and vascular permeability. There are eight isoforms with different and sometimes overlapping functions. The mechanisms of action are under investigation with emerging insights into overlapping pathways and cross-talk between other receptors such as the neuropilins, which were not previously associated to angiogenesis. VEGF has important physiological actions on embryonic development, healing, and menstrual cycle. It also has a great role in pathological conditions that are associated to autoimmune diseases. There is considerable evidence in various autoimmune diseases such as in systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis of an interrelationship between the VEGF system and theses disorders. Serum levels of VEGF correlate with disease activity in a large number of autoimmune diseases and fall with the use of standard therapy. We raised the possible future therapeutic strategies in autoimmune diseases with the anti-VEGF or anti-VEGFR (receptor). So far, this therapy has been used in cancer and macular ocular degeneration in diabetes. This review outlines the evidence for VEGF participation in various autoimmune diseases and proposes lines for future research in this field.

The effect of immunosuppressive therapy on the messenger RNA expression of target genes in the urinary sediment of patients with active lupus nephritis

BACKGROUND

Previous studies have shown that messenger RNA (mRNA) expression of target genes is increased in the urinary sediment of patients with active lupus. We study the effect of immunosuppressive therapy on the urinary gene expression profile in patients with active lupus nephritis. Method. We recruited nine patients with active systemic lupus erythematosus (SLE) and renal disease, and required corticosteroid, with or without cytotoxic treatment. They were followed for 6 months, urine samples were collected at 0, 4, 12 and 24 weeks and gene expression profile was determined by polymerase chain reactions. The pattern of gene expression was compared to clinical parameters of therapeutic response.

RESULTS

Amongst the target genes studied, there was a progressive decline in the urinary expression of T-bet, interleukin (IL)-10, transforming growth factor-beta (TGF-beta), monocyte chemoattractant protein-1 (MCP-1), and interferon-gamma (IFN-gamma) after immunosuppressive treatment, although the change of IFN-gamma was not statistically significant. The time course of their urinary expression was parallel to the systemic activity as reflected by the systemic lupus erythematosus disease activity index (SLEDAI). Throughout the study period, the SLEDAI score correlated significantly with the expressions of IFN-gamma (r = 0.43, P = 0.009), T-bet (r = 0.40, P = 0.016), TGF-beta (r = 0.51, P = 0.002) and MCP-1 (r = 0.38, P = 0.022). The anti-double strand(anti-ds)DNA antibody titer correlated significantly with the expressions of IFN-gamma (r = 0.45, P = 0.009), T-bet (r = 0.37, P = 0.034), IL-10 (r = 0.59, P<0.001), TGF-beta (r = 0.44, P = 0.010) and MCP-1 (r = 0.49, P = 0.004). On the other hand, the expression level of IL-2, IL-4, IL-12, IL-18 and GATA-3 remained static throughout the study period.

CONCLUSIONS

The mRNA expression of T-bet, IL-10, TGF-beta, MCP-1, and probably IFN-gamma in the urinary sediment of patients with active lupus nephritis improves with successful immunosuppressive therapy, and the change in gene expression profile is in phase with the clinical disease activity. Measurement of urinary mRNA expression of target genes may be a potential non-invasive tool for the monitoring of lupus disease activity.

The role of vascular endothelial growth factor (VEGF) in renal pathophysiology

Vascular endothelial growth factor (VEGF) is an endothelial-specific growth factor that promotes endothelial cell proliferation, differentiation and survival, mediates endothelium-dependent vasodilatation, induces microvascular hyperpermeability and participates in interstitial matrix remodeling. In the kidney, VEGF expression is most prominent in glomerular podocytes and in tubular epithelial cells, while VEGF receptors are mainly found on preglomerular, glomerular, and peritubular endothelial cells. The role of VEGF in normal renal physiology is essentially unknown. The absence of prominent effects of VEGF blockade in normal experimental animals suggests a limited function during homeostasis, although a role in the formation and maintenance of glomerular capillary endothelial fenestrations has been suggested. VEGF and its receptors are up-regulated in experimental animals and humans with type 1 and type 2 diabetes. Inhibition of VEGF has beneficial effects on diabetes-induced functional and structural alterations, suggesting a deleterious role for VEGF in the pathophysiology of diabetic nephropathy. VEGF is required for glomerular and tubular hypertrophy and proliferation in response to nephron reduction, and loss of VEGF is associated with the development of glomerulosclerosis and tubulointerstitial fibrosis in the remnant kidney. No firm conclusions on the role of VEGF in minimal change or membranous glomerulonephritis can be drawn. VEGF may be an essential mediator of glomerular recovery in proliferative glomerulonephritis. Glomerular and tubulointerstitial repair in thrombotic microangiopathy and cyclosporin nephrotoxicity may also be VEGF-dependent. In conclusion, VEGF is required for growth and proliferation of glomerular and peritubular endothelial cells. While deleterious in some, it may contribute to recovery in other forms of renal diseases.

Cell and molecular biology of the multifunctional peptide, adrenomedullin

Adrenomedullin (AM) is a recently discovered regulatory peptide involved in many functions including vasodilatation, electrolyte balance, neurotransmission, growth, and hormone secretion regulation, among others. This 52-amino acid peptide is expressed by specific cell types in many organs throughout the body. A complex receptor system has been described for AM; it requires at least the presence of a seven-transmembrane-domain G-protein-coupled receptor, a single-transmembrane-domain receptor activity modifying protein, and a receptor component protein needed to establish the connection with the downstream signal transduction pathway, which usually involves cyclicAMP. In addition, a serum-binding protein regulates the biological actions of AM, frequently by increasing AM functional attributes. Changes in levels of circulating AM correlate with several critical diseases, including cardiovascular and renal disorders, sepsis, cancer, and diabetes. Whether AM is a causal agent, a protective reaction, or just a marker for these diseases is currently under investigation. New technologies seeking to elevate and/or reduce AM levels are being investigated as potential therapeutic avenues.

The role of transsignalling via the agonistic soluble IL-6 receptor in human diseases

The activation of cells that do not express the membrane bound interleukin-6 6 receptor (IL-6R) by IL-6 and the soluble IL-6 receptor (sIL-6R) is termed transsignalling. Transsignalling may be an pathogenetic factor in human diseases as diverse as multiple myeloma (MM), Castleman's disease, prostate carcinoma, Crohn's disease, systemic sclerosis, Still's disease, osteoporosis and cardiovascular diseases. IL-6 and sIL-6R may directly or indirectly enhance their own production on endothelial or bone marrow stromal cells. Positive feedback autocrine loops thus created in affected organs may either cause or maintain disease progression. In autoimmune or vasculitic disease, the ability of the IL-6/sIL-6R complex to inhibit apoptosis of autoreactive T-cells may be central to the development of tissue specific autoimmunity. The anti-apoptotic effect of the IL-6/sIL-6R complex may be involved in tumour genesis and resistance to chemotherapy. Only in rare cases, where counterregulation has failed, there is a notable systemic effect of IL-6/sIL-6R. Appropriate animal models are necessary to establish the pathogenetic role of the IL-6/sIL-6R complex. A specific treatment option for diseases influenced by the sIL-6R could be based on gp130-Fc, a soluble gp130 (sgp130) linked to the Fc-fragment of IgG1. gp130-Fc has shown efficacy in vivo in animal models of Crohn's disease.

Vascular endothelial growth factor plasma levels in patients with systemic lupus erythematosus and primary antiphospholipid syndrome

The objective of this study was to assess the possible role of vascular endothelial growth factor (VEGF) in the pathogenesis of systemic lupus erythematosus (SLE) and primary antiphospholipid syndrome (PAPS). We studied 28 patients with SLE, 10 patients with PAPS, and 24 healthy controls. VEGF plasma levels were measured by ELISA. Immunolocalization of VEGF was done in renal tissue from SLE patients and cadaveric controls. Our results showed that VEGF plasma levels were increased in SLE patients compared with PAPS and controls. The correlation between clinical manifestations and VEGF levels revealed that SLE patients with renal failure had significantly increased plasma VEGF levels (134.1 + 91.0 pg/ml) compared with SLE patients with normal renal function (42.9 + 19.0 pg/ml), PAPS patients (41.9 + 26.6 pg/ml), and controls (36.2 + 27.0 pg/ml; P < 0.01). Immunostaining showed a strong expression of VEGF in SLE renal tissue samples. Our preliminary results indicate that VEGF is increased in plasma from patients with lupus nephritis and a moderate degree of renal failure and is overexpressed in renal tissue from these patients.

Mediators of injury in lupus nephritis

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by the production of autoantibodies and the development of immune complex glomerulonephritis. Lupus nephritis (LN) remains a leading cause of morbidity and mortality in SLE. As a result, defining pathogenetic mediators in LN remains a major research effort. Progression to LN in SLE is dependent on the host breaking immune tolerance and forming autoantibodies that deposit in the kidney. A variety of predisposing factors in the host must then be present for this event to result in renal pathology. In this article, the authors review recent reports that advance our understanding of LN disease mediators, from autoantibody production and immune complex deposition to end stage fibrosis.