Angiogenic growth factors in rheumatoid arthritis

Rheumatoid arthritis molecular targets and their importance to flavonoid-based therapy

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune, inflammatory, and systemic condition that primarily affects the synovial joints and adjacent tissues, including bone, muscle, and tendons. The World Health Organization recognizes RA as one of the most prevalent chronic inflammatory diseases. In the last decade, there was an expansion on the available RA therapeutic options which aimed to improve patient's quality of life. Despite the extensive research and the emergence of new therapeutic approaches and drugs, there are still significant unwanted side effects associated to these drugs and still a vast number of patients that do not respond positively to the existing therapeutic strategies. Over the years, several references to the use of flavonoids in the quest for new treatments for RA have emerged. This review aimed to summarize the existing literature about the flavonoids' effects on the major pathogenic/molecular targets of RA and their potential use as lead compounds for the development of new effective molecules for RA treatment. It is demonstrated that flavonoids can modulate various players in synovial inflammation, regulate immune cell function, decrease synoviocytes proliferation and balance the apoptotic process, decrease angiogenesis, and stop/prevent bone and cartilage degradation, which are all dominant features of RA. Although further investigation is necessary to determine the effectiveness of flavonoids in humans, the available data from in vitro and in vivo models suggest their potential as new disease-modifying anti-rheumatic drugs. This review highlights the use of flavonoids as a promising avenue for future research in the treatment of RA.

Identification of shared disease marker genes and underlying mechanisms between major depression and rheumatoid arthritis

Both depression and rheumatoid arthritis (RA) have a very high comorbidity rate. A bilateral association is estimated to increase the mutual risk and the common denominator is inflammation being observed in both diseases. Previous studies have mainly focused on assessing peripheral blood's inflammatory and pro-inflammatory cytokines levels. We aimed to extend insights into the molecular mechanisms of depression based on hub RA genes. To do so, we prioritized RA-related genes using in-silico tools. We then investigated whether RA-related genes undergo altered expression in patients with unipolar and bipolar depression without a concurrent RA diagnosis and any exponents of active inflammation. In addition, we selected a homogeneous group of patients treated with lithium (Li), which has immunomodulatory properties. The study was performed on patients with bipolar depression (BD, n = 45; Li, n = 20), unipolar depression (UD, n = 27), and healthy controls (HC, n = 22) of both sexes. To identify DEGs in peripheral blood mononuclear cells (PBMCs), we used the SurePrint G3 Microarray and GeneSpring software. We selected a list of 180 hub genes whose altered expression we analyzed using the expression microarray results. In the entire study group, we identified altered expression of 93 of the 180 genes, including 35 down-regulated (OPRM1 gene with highest FC > 3) and 58 up-regulated (TLR4 gene with highest FC > 3). In UD patients, we observed maximally up-regulated expression of the TEK gene (FC > 3), and in BD of the CXCL8 gene (FC > 5). On the other hand, in lithium-treated patients, the gene with the most reduced expression was the TRPV1 gene. The study proved that depression and RA are produced by a partially shared "inflammatory interactome" in which the opioid and angiogenesis pathways are important.

The role of the angiotensins in the pathogenesis of inflammatory joint disease

The significant humoral effect of the renin-angiotensin-aldosterone system on the regulation of the cardiovascular system and blood pressure has long been widely known. However, the identification and interpretation of new components of renin-angiotensin-aldosterone system in recent years can significantly expand the range of its potential effects on the body. The anti-inflammatory effect of drugs that block angiotensin II and its receptors, including in rheumatic diseases, can become practically significant for General therapists by their effect on reducing the concentration of inflammatory mediators and angiogenesis processes. The organoprotective and anti-inflammatory potentials of drugs that reduce the production of at demonstrated in vitro and in vivo experiments allow us to consider them as first-line angiotropic agents in patients with rheumatoid arthritis, especially in the presence of pathology of the cardiovascular system and kidneys.

KDR (VEGFR2) Genetic Variants and Serum Levels in Patients with Rheumatoid Arthritis

We investigated kinase insert domain-containing receptor (KDR) polymorphisms and protein levels in relation to susceptibility to and severity of Rheumatoid Arthritis (RA). 641 RA patients and 340 controls (HC) were examined for the rs1870377 KDR variant by the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method and for rs2305948 and rs2071559 KDR single nucleotide polymorphisms (SNPs) by TaqMan SNP genotyping assay. KDR serum levels were determined by enzyme-linked immunosorbent assay (ELISA). The rs1870377 KDR variant has shown association with RA under the codominant (p = 0.02, OR = 1.76, 95% CI = 1.09–2.85) and recessive models (p = 0.019, OR = 1.53, 95% CI = 1.07–2.20). KDR rs2305948 was associated with RA under the dominant model (p = 0.005, OR = 1.38, 95% CI = 1.10–1.73). Under the codominant model, the frequency of the rs2071559 TC and GG genotypes were lower in RA patients than in controls (p < 0.001, OR = 0.51, 95% CI = 0.37–0.69, and p = 0.002, OR = 0.57, 95% CI = 0.39–0.81). KDR rs2071559 T and rs2305948 A alleles were associated with RA (p = 0.001, OR = 0.60, 95% CI = 0.45–0.81 and p = 0.008, OR = 1.71, CI = 1.15–2.54). KDR rs2305948SNP was associated with Disease Activity Score (DAS)-28 score (p < 0.001), Visual Analog Scale (VAS) score (p < 0.001), number of swollen joints (p < 0.001), mean value of CRP (p < 0.001). A higher KDR serum level was found in RA patients than in HC (8018 pg/mL versus 7381 pg/mL, p = 0.002). Present results shed light on the role of KDR genetic variants in the severity of RA.

Correlation between circulating VEGF levels and disease activity in rheumatoid arthritis: a meta-analysis

OBJECTIVE

To systematically review evidence regarding the relationship between circulating vascular endothelial growth factor (VEGF) levels and rheumatoid arthritis (RA), the correlation between serum VEGF levels and RA activity, and the association between VEGF polymorphisms and RA susceptibility.

METHODS

We conducted a meta-analysis of the serum/plasma VEGF levels in patients with RA and controls, the correlation coefficients between the circulating VEGF levels and disease activity in patients with RA, and the association between VEGF -2578 A/C, -634 C/G, +936 T/C, and -1154 A/G polymorphisms and the risk for RA.

RESULTS

In total, 13 studies including 2508 patients with RA and 2489 controls were included. Meta-analysis revealed that VEGF level was significantly higher in the RA than in the control group (standard mean difference [SMD] = 1.480, 95% confidence interval [CI] = 0.71-2.241, p = 1.4 × 10^-4). Stratification by adjustment for age and gender revealed significantly higher VEGF levels for the adjustment and non-adjustment groups in the RA group (SMD = 1.360, 95% CI = 0.445-2.276, p = 0.004; SMD = 1.557, 95% CI = 0.252-2.861, p = 0.019, respectively). Meta-analysis of correlation coefficients showed a significantly positive correlation between circulating VEGF levels and disease activity in RA, and between circulating VEGF and C‑reactive protein levels. However, no association was found between RA and the VEGF -2578 A/C, -634 C/G, +936 T/C, and -1154 A/G polymorphisms.

CONCLUSION

Our meta-analysis revealed significantly higher circulating VEGF levels in patients with RA and a positive correlation between VEGF levels and disease activity in RA, but no association between the VEGF -2578 A/C, -634 C/G, +936 T/C, and -1154 A/G polymorphisms and the development of RA.

Angiotensins and rheumatoid arthritis

At present, the role of the renin-angiotensin system (RAS) in regulating the cardiovascular system and maintaining water and electrolyte homeostasis has been well studied. However, over the past decades, new components of the RAS have been identified, suggesting a wider range of its potential effects on the body. It is of fundamentally importance for rheumatologists to affect inflammation, including rheumatoid inflammation, through blockade of angiotensin (AT) II formation via the effects of AT 1–7 and angiotensin-converting enzyme inhibitors, as well as through suppression of angiogenesis, primarily by reducing the production of endothelial growth factor. The organ-protective and antiinflammatory potential of drugs that reduce the production of AT, which has been proven in in vitro and in vivo experiments, allows us to consider them as first-line angiotropic agents in patients with rheumatoid arthritis, especially in the presence of concomitant hypertension and/or nephropathy.

Association of Angiogenic and Inflammatory Markers with Power Doppler Ultrasound Vascularity Grade and DAS28-CRP in Early Rheumatoid Arthritis: A Comparative Analysis

Objective

Upregulation of various proinflammatory and angiogenic mediators orchestrates the typical pathological synovial alterations in rheumatoid arthritis (RA). DAS28-CRP is commonly used for assessment of RA disease activity and power Doppler ultrasonography (PDUS) is an important modality for assessing synovial vascularity. This study was intended to look for the association of various inflammatory and angiogenic mediators, with respect to different PDUS vascularity grades and disease activity status, in early RA patients.

Methods

50 early RA patients (<6 months disease duration) with either moderate or high disease activity and 30 healthy controls were included in this study. RA patients were subcategorized based on PDUS vascularity grading of wrist joints. Serum levels of proinflammatory cytokines [tumor necrosis factor-α (TNF- α); interleukin-6(IL-6)] and angiogenic markers [angiopoietin-1 and 2 (Ang-1 and Ang-2); vascular endothelial growth factor (VEGF) ] were measured and compared among different patient subgroups.

Results

Among 50 patients, 22 and 28 patients had moderate and high DAS28-CRP score, respectively. Patients with grade 3 PDUS score, even with moderate DAS value, showed a significant rise in Ang-1 (p<0.02), VEGF (p<0.008), Ang-2 (p <0.001), and TNF-α (p<0.005) level compared to grade 2 PDUS patients with high DAS values.

Conclusion

Higher serum level of angiogenic and inflammatory markers was noted among patients with moderate disease activity but with advanced PDUS vascularity (grade 3) in comparison to high disease activity group with less severe PDUS vascularity (grade 2). PDUS vascularity grading better reflects some markers of angiogenesis and inflammation, than composite disease activity index.

RETRACTED: GZMB gene silencing confers protection against synovial tissue hyperplasia and articular cartilage tissue injury in rheumatoid arthritis through the MAPK signaling pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. An Expression of Concern for this article was previously published while an investigation was conducted (see related editorial: https://doi.org/10.1016/j.biopha.2022.113812). This retraction notice supersedes the Expression of Concern published earlier. Concern was raised about the reliability of the Western blot data in Figure 7C, which appear to contain a similar phenotype to those found in other publications, as detailed here: https://pubpeer.com/publications/7DD2DDC979F8CE2B00555332B01F81; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. The journal requested the corresponding author comment on these concerns and provide the associated raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

Berberine ameliorates collagen-induced arthritis in rats associated with anti-inflammatory and anti-angiogenic effects

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by inflammation and joint destruction. In this study, we explored the effect of berberine on rats with bovine type II collagen-induced arthritis (CIA), an animal model for RA. Following treatment, berberine attenuates arthritic scores and suppresses collagen-specific immune responses in CIA rats. Compared with the un-treated CIA group, berberine reversed pathological changes, which showed a significant improvement in synovial hyperplasia and inflammatory infiltration. The expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-17 and vascular endothelial growth factor (VEGF) were obviously reduced in the sera of berberine-treated rats (all P<0.05). Moreover, berberine showed marked inhibition of the expression of VEGF and CD34 (all P<0.05). Interestingly, berberine significantly suppresses p-ERK, p-p38 and p-JNK activation (all P<0.05), which may partially explain the anti-RA activity of berberine. These results suggest that berberine ameliorates CIA in rats associated with anti-inflammatory and anti-angiogenic effects, which might be of great therapeutic value for RA.

The effects of infliximab or adalimumab on vascular endothelial growth factor and angiopoietin 1 angiogenic factor levels in inflammatory bowel disease: serial observations in 37 patients

BACKGROUND

Infliximab and adalimumab effectiveness might be related with changes in angiogenic factors. The aim of the study was to compare the concentrations of angiogenic proteins in patients with inflammatory bowel disease (IBD) and healthy controls and to analyze changes in the levels during infliximab and adalimumab treatment.

METHODS

A prospective case-control study was conducted in 37 patients with IBD starting treatment with infliximab (16 with Crohn's disease and 6 with ulcerative colitis) or adalimumab (15 with Crohn's disease) and 40 control subjects. Four samples were taken from IBD patients, one before each of the first 3 doses of infliximab/adalimumab and one at week 14. Serum levels of vascular endothelial growth factor (VEGF), placental growth factor, angiopoietin 1 (Ang1), angiopoietin 2, and Tie2 were measured using enzyme-linked immunosorbent assay.

RESULTS

Patients with IBD had higher VEGF levels than control subjects (511.5 ± 255.6 versus 395.5 ± 256.4; P = 0.05). Patients who achieved remission at the third dose of anti-TNF-alpha had lower VEGF levels at baseline (453.5 ± 250.7 versus 667.5 ± 153.9 pg/mL) and before the second (409.7 ± 217 versus 681.3 ± 350.6 pg/mL) and third (400.5 ± 222.8 versus 630.4 ± 243.1 pg/mL) doses compared with those with no remission (P < 0.05). Ang1 levels decreased before each treatment dose in patients who achieved remission (P < 0.05). High baseline VEGF levels predicted for a poor response to anti-TNF-alpha therapy (area under the receiver operating characteristics curve = 0.8), whereas high Ang1 levels were associated with disease remission (area under the receiver operating characteristics curve = 0.7). Concentrations of angiogenic proteins did not correlate with clinical activity scores.

CONCLUSIONS

Circulating VEGF and Ang1 levels decrease after anti-TNF-alpha therapy and may predict response to treatment. Whether these changes are a direct effect of anti-TNF-alpha therapy or a sign of disease improvement remains to be elucidated.

Body composition and serum levels of adiponectin, vascular endothelial growth factor, and interleukin-6 in patients with rheumatoid arthritis

Aim

To investigate differences in body composition and body mass index (BMI) in patients with rheumatoid arthritis (RA) and their correlations with serum production of adiponectin, interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF).

Methods

The study included 83 patients (age 53 ± 5 years) with RA treated with methotrexate. We determined their BMI, fat mass, and fat-free mass using bioimpedance analysis, and serum concentrations of adiponectin, VEGF, and IL-6 using immunoassay analysis.

Results

Normal BMI was found in 39 (47%), overweight and obesity in 26 (31%), and underweight in 18 (22%) patients. Concentration of adiponectin was lower in overweight/obese patients than in patients with normal BMI (2.1 [0.8-3.9] μg/mL vs 8.9 (7.2-11.3) μg/mL). In underweight patients, it was moderately increased (12.7 [9.3-14.8] μg/mL) and the correlation between the concentrations of adiponectin and IL-6 was positive (r = 0.4; P = 0.01). Concentrations of VEGF and IL-6 were increased in all groups with RA. The overweight/obese group showed a negative correlation between the concentrations of adiponectin and VEGF (r = - 0.34; P = 0.04), a positive correlation between VEGF concentration and fat mass (r = 0.39; P = 0.02), and a negative correlation between adiponectin concentration and fat mass (r = - 0.23; P = 0.02).

Conclusion

Inflammatory and angiogenesis activation was found in RA patients with all types of body composition, but only in those with obesity and overweight there was a direct antagonism between adiponectin and VEGF. Further research is needed to identify possible regimens of metabolic correction in different variations of body composition.