Implication of oxidative stress and its correlation with activity of matrix metalloproteinases in patients with Takayasu's arteritis disease

Biomarkers in Takayasu arteritis

Takayasu arteritis (TA) is a rare large vasculitis with unknown etiology, which affects the aorta and its primary branches, as well as the pulmonary and coronary arteries. Cellular and humoral immunity, chronic inflammation, and genetic factors are involved into TA pathogenesis. Several biomarkers, such as MMPs, TIMPs, cytokines, cell adhesion molecules, autoantibodies, complements, PTX3, sRAGE, NT-proBNP, 8-isoPGF_2α, NO₂^-, acute-phase and immunology-related proteins, thrombogenicity markers, ghrelin leptin and adipokines, endothelial damage and repair factors, genetic markers etc., related to the pathogenesis could be observed in patients with TA. These biomarkers have revealed great values in early diagnosis, evaluating disease activity, guiding clinical treatment options, and thus demonstrated significant clinical application values in TA. The combination of biomarkers assay and imaging examination may detect TA more accurately. The aim of this review is to systemically observe the clinical significance of these biomarkers in TA.

Outcome Measures and Biomarkers for Disease Assessment in Takayasu Arteritis

Takayasu arteritis (TAK) is a less common large vessel vasculitis where histopathology of involved arteries is difficult to access except during open surgical procedures. Assessment of disease activity in TAK, therefore, relies on surrogate measures. Clinical disease activity measures such as the National Institutes of Health (NIH) score, the Disease Extent Index in TAK (DEI.TAK) and the Indian TAK Clinical Activity Score (ITAS2010) inconsistently associate with acute phase reactants (APRs). Computerized tomographic angiography (CTA), magnetic resonance angiography (MRA), or color Doppler Ultrasound (CDUS) enables anatomical characterization of stenosis, dilatation, and vessel wall characteristics. Vascular wall uptake of 18-fluorodeoxyglucose or other ligands using positron emission tomography computerized tomography (PET-CT) helps assess metabolic activity, which reflects disease activity well in a subset of TAK with normal APRs. Angiographic scoring systems to quantitate the extent of vascular involvement in TAK have been developed recently. Erythrocyte sedimentation rate and C-reactive protein have a moderate performance in distinguishing active TAK. Numerous novel biomarkers are under evaluation in TAK. Limited literature suggests a better assessment of active disease by combining APRs, PET-CT, and circulating biomarkers. Validated damage indices and patient-reported outcome measures specific to TAK are lacking. Few biomarkers have been evaluated to reflect vascular damage in TAK and constitute important research agenda.

Enhanced Liver Fibrosis Score as a Biomarker for Vascular Damage Assessment in Patients with Takayasu Arteritis-A Pilot Study

Takayasu Arteritis (TA) is characterized by granulomatous panarteritis, vessel wall fibrosis, and irreversible vascular impairment. The aim of this study is to explore the usefulness of the Enhanced Liver Fibrosis score (ELF), procollagen-III aminoterminal propeptide (PIIINP), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), and hyaluronic acid (HA) in assessing vascular damage in TA patients. ELF, PIIINP, TIMP-1, and HA were measured in 24 TA patients, and the results were correlated with the clinical damage indexes (VDI and TADS), an imaging damage score (CARDS), and disease activity scores (NIH and ITAS2010). A mean ELF score 8.42 (±1.12) and values higher than 7.7 (cut-off for liver fibrosis) in 21/24 (87.5%) of patients were detected. The VDI and TADS correlated significantly to ELF (p < 0.01). Additionally, a strong association across ELF and CARDS (p < 0.0001), PIIINP and CARDS (p < 0.001), and HA and CARDS (p < 0.001) was observed. No correlations of the tested biomarkers with inflammatory parameters, NIH, and ITAS2010 scores were found. To our knowledge, this is the first study that suggests the association of the serum biomarkers PIIINP, HA, and ELF score with damage but not with disease activity in TA patients. The ELF score and PIIINP may be useful biomarkers reflecting an ongoing fibrotic process and quantifying vascular damage.

Single-Cell RNA Sequencing Revealed CD14+ Monocytes Increased in Patients With Takayasu's Arteritis Requiring Surgical Management

Objectives: Takayasu Arteritis (TA) is a highly specific vascular inflammation and poses threat to patients’ health. Although some patients have accepted medical treatment, their culprit lesions require surgical management (TARSM). This study aimed at dissecting the transcriptomes of peripheral blood mononuclear cells (PBMCs) in these patients and to explore potential clinical markers for TA development and progression.

Methods: Peripheral blood were collected from four TA patients requiring surgical management and four age-sex matched healthy donors. Single cell RNA sequencing (scRNA-seq) was adopted to explore the transcriptomic diversity and function of their PBMCs. ELISA, qPCR, and FACS were conducted to validate the results of the analysis.

Results: A total of 29918 qualified cells were included for downstream analysis. Nine major cell types were confirmed, including CD14⁺ monocytes, CD8⁺ T cells, NK cells, CD4⁺ T cells, B cells, CD16⁺ monocytes, megakaryocytes, dendritic cells and plasmacytoid dendritic cells. CD14⁺ monocytes (50.0 vs. 39.3%, p < 0.05) increased in TA patients, as validated by FACS results. TXNIP, AREG, THBS1, and CD163 increased in TA patients. ILs like IL-6, IL-6STP1, IL-6ST, IL-15, and IL-15RA increased in TA group.

Conclusion: Transcriptome heterogeneities of PBMCs in TA patients requiring surgical management were revealed in the present study. In the patients with TA, CD14⁺ monocytes and gene expressions involved in oxidative stress were increased, indicating a new treatment and research direction in this field.

Physical Exercise in Managing Takayasu Arteritis Patients Complicated With Cardiovascular Diseases

Takayasu arteritis (TA) is a kind of large-vessel vasculitis that mainly affects the aorta and its branches, and the patients are usually women at a relatively young age. The chronic inflammation of arteries in TA patients leads to stenosis, occlusion, dilatation, or aneurysm formation. Patients with TA thereby have a high risk of cardiovascular disease (CVD) complications, which are the most common cause of mortality. This review summarizes the main cardiovascular complications and the risk factors of cardiovascular complications in patients with TA. Here, we discuss the benefits and potential risks of physical exercise in patients with TA and give recommendations about exercise prescription for TA patients to decrease the risks of CVD and facilitate rehabilitation of cardiovascular complications, which might maximally improve the outcomes.

Pathogenesis of large vessel vasculitis: Implications for disease classification and future therapies

Despite being recognised over a century ago, the aetiology and pathogenesis of large vessel vasculitis (LVV) still remains elusive. Takayasu’s arteritis (TA) and giant cell arteritis (GCA) represent the two major categories of LVV, each with distinctive clinical features. Over the last 10 years an increased understanding of the immunopathogenesis of the inflammatory cascade within the aortic wall has revived the view that LVVs may represent subtypes of the same pathological process, with implications in the treatment of this disease. In this review, the histological, genetic and immunopathological features of TA and GCA will be discussed and the evidence for a common underlying disease mechanism examined. Novel markers of disease activity and therapies based on advances in our understanding of the immunopathogenesis of these conditions will also be discussed.

Oxidative stress, eryptosis and anemia: a pivotal mechanistic nexus in systemic diseases

The average lifespan of circulating erythrocytes usually exceeds hundred days. Prior to that, however, erythrocytes may be exposed to oxidative stress in the circulation which could cause injury and trigger their suicidal death or eryptosis. Oxidative stress activates Ca²⁺ -permeable nonselective cation channels in the cell membrane, thus, stimulating Ca²⁺ entry and subsequent cell membrane scrambling resulting in phosphatidylserine exposure and activation of Ca²⁺ -sensitive K⁺ channels leading to K⁺ exit, hyperpolarization, Cl^- exit, and ultimately cell shrinkage due to loss of KCl and osmotically driven water. While the mechanistic link between oxidative stress and anemia remains ill-defined, several diseases such as diabetes, hepatic failure, malignancy, chronic kidney disease and inflammation have been identified to display both increased oxidative stress as well as eryptosis. Recent compelling evidence suggests that oxidative stress is an important perpetrator in accelerating erythrocyte loss in different systemic conditions and an underlying mechanism for anemia associated with these pathological states. In the present review, we discuss the role of oxidative stress in reducing erythrocyte survival and provide novel insights into the possible use of antioxidants as putative antieryptotic and antianemic agents in a variety of systemic diseases.

The role of elastic fibers in pathogenesis of conjunctivochalasis

The PubMed, MEDLINE databases and China National Knowledge Infrastructure (CNKI) were searched for information regarding the etiology and pathogenesis of conjunctivochalasis (CCh) and the synthesis and degradation of elastic fibers. After analysis of the literature, we found elastic fibers was a complex protein molecule from the structure and composition; the degradation of elastic fibers was one of the histopathological features of the disease; the vast majority of the factors related to the pathogenesis of CCh ultimately pointed to abnormal elastic fibers. By reasonably speculating, we considered that abnormal elastic fibers cause the conjunctival relaxation. In conclusion, we hypothesize that elastic fibers play an important role in the pathogenesis of CCh. Studies on the mechanism of synthesis, degradation of elastic fibers are helpful to clarify the pathogenesis of the disease and to find effective treatment methods.

Prognostic Value of Brachial-Ankle Pulse Wave Velocity in Patients With Takayasu Arteritis With Drug-Eluting Stent Implantation

OBJECTIVE

This study investigates the long-term outcomes of drug-eluting stent (DES) implantation in patients with Takayasu arteritis (TAK).

METHODS

Data on 48 TAK patients and 40 age-, sex-, and severity-matched patients with coronary artery disease (CAD) receiving DES implantation and hospitalized in Fuwai Hospital from February 2004 to March 2014 were assessed. The clinical features, laboratory data, coronary angiographic findings, treatment, and followup outcomes were summarized retrospectively. Major adverse cardiac events (MACE), which include all-cause death, nonfatal myocardial infarction, and nonfatal target vessel revascularization, were recorded.

RESULTS

TAK patients exhibited increased mean ± SD brachial-ankle pulse wave velocity (baPWV) compared with patients with CAD (17.0 ± 3.8 versus 13.8 ± 3.0 meters/second; P = 0.002). However, CAD patients had higher levels of low-density lipoprotein cholesterol (2.5 ± 1.0 versus 2.3 ± 0.8 mmoles/liter; P = 0.04). Multiple linear regression analysis revealed that baPWV was independently associated with the extent of CAD, assessed by the SYNTAX (Synergy Between Percutaneous Coronary Intervention With TAXUS and Cardiac Surgery) score (β = 0.33, P = 0.03), in TAK patients. DES implantation was deployed in 73 coronary lesions in 48 TAK patients, and restenosis occurred in 48 lesions after an average of 25.6 months (range 9.0-68.0 months) following intervention. Logistic regression analysis identified that a baPWV of 17.00 meters/second or higher (odds ratio 5.50, 95% confidence interval [95% CI] 2.1-16.6, P = 0.008) may be considered as an independent predictor of DES restenosis. Moreover, the multivariate Cox proportional hazards model demonstrated that a baPWV of 17.00 meters/second or higher (hazard ratio 3.36, 95% CI 1.51-7.52, P = 0.003) was significant and may serve as an independent predictor of MACE in TAK patients who underwent DES implantation.

CONCLUSION

DES in-stent restenosis remains a challenge, affecting the long-term outcomes of patients with TAK. Measuring increased arterial stiffness through baPWV, with the addition of inflammation status monitoring during followup, would be of great clinical value to identify TAK patients with DES who have a high risk for in-stent restenosis and MACE.

F-18 FDG PET/CT in the evaluation of Takayasu arteritis: an experience from the tropics

OBJECTIVE

To evaluate the performance parameters of FDG PET/CT in patients with Takayasu arteritis at diagnosis and during immunosuppression.

METHODS

Retrospective analysis of 60 FDG PET/CT studies in 51 patients was performed (17 scans at diagnosis out of which 4 had follow-up scans also and 43 scans on immunosuppression). The degree of FDG uptake in the vessels was assessed visually using a 4-point scale and maximum standardized uptake value (SUVmax), SUVratio, extent of vasculitis and association with ESR were calculated.

RESULTS

PET/CT was positive for active vasculitis in all 17 patients at diagnosis. The mean SUVmax and mean SUV ratio of the active areas were 5.1 ± 3.0 and 3.2 ± 1.9, respectively. On immunosuppression, PET scan was positive for active vasculitis in 14/43 (32.5%) scans. The mean SUVmax and mean SUVratio of the active areas were 1.7 ± 2.1 and 0.95 ± 1.2, respectively. There was significant difference between the mean SUVmax and mean SUVratio at diagnosis and on immunosuppression, respectively (P < .01). The median number of vascular segments in each uptake grade group was also statistically different (P < .01) between scans at diagnosis and on immunosuppression. The median ESR level in PET positive scans was 29 mm/hour (2-53), whereas in PET negative scans was 35.5 mm/hour (6-50) and the difference was not statistically significant.

CONCLUSION

FDG PET/CT showed good sensitivity to detect active vasculitis at diagnosis and during immunosuppression. The change in SUVmax between the successive FDG PET/CT scans may give an objective assessment of response to immunosuppression.

Acknowledged signatures of matrix metalloproteinases in Takayasu's arteritis

Takayasu's arteritis (TA) was reported as an eye disease in the year 1905 and later was confirmed as a vasculitis. Since then, the etiology of the disease remains unknown; however, characteristic clinical features suggest multiple causative factors. Recent progress in vascular biology and other disciplines enlightens the pathophysiology of TA and demonstrated induction of various nonspecific inflammatory symptoms and destruction of the arterial wall, which leads to aneurysms and rupture of the affected arteries. Matrix metalloproteinases (MMPs) as an enzyme family have well-established roles in several vascular pathologies including intima formation, atherosclerosiss and aneurysms. MMPs have been proposed to be one of the molecules with a potential of having dual role in the course of TA, first as an active participant in pathophysiology and secondly as a diagnostic biomarker for TA disease. The desire to improve our understanding of the importance of MMPs and their endogenous inhibitors (TIMPs) in TA disease and for the development of therapeutic agents has inspired basic and clinical scientists for over a decade. In the present paper, we summarized the scientific rationale which highlights the signatures of matrix metalloproteinases and their endogenous inhibitors in pathophysiology as well as their being a potential candidate as biomarker for Takayasu's arteritis.

Analysis of oxidative stress enzymes and structural and functional proteins on human aortic tissue from different aortopathies

The role of oxidative stress in different aortopathies is evaluated. Thirty-two tissue samples from 18 men and 14 women were divided into: 4 control (C) subjects, 11 patients with systemic arterial hypertension (SAH), 4 with variants of Marfan's syndrome (MV), 9 with Marfan's syndrome (M), 2 with Turner's syndrome, and 2 with Takayasu's arteritis (TA). Aorta fragments were homogenized. Lipoperoxidation (LPO), copper-zinc and manganese superoxide dismutase (Mn and Cu-Zn-SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), endothelial nitric oxide synthase (eNOS), nitrates and nitrites (NO3(-)/NO2(-)), and type IV collagen, and laminin were evaluated. There was an increase in Mn- and Cu-Zn-SOD activity in SAH, MV, M, and Turner's syndrome. There was also an increase in CAT activity in M and Turner' syndrome. GPx and GST activity decreased and LPO increased in all groups. eNOS was decreased in SAH, MV, and M and NO3 (-)/NO2 (-) were increased in SAH and TA. Type IV collagen was decreased in Turner's syndrome and TA. Laminin γ-1 was decreased in MV and increased in M. In conclusion, similarities and differences in oxidative stress in the different aortopathies studied including pathologies with aneurysms were found with alterations in SOD, CAT, GPx, GST, and eNOS activity that modify subendothelial basement membrane proteins.

Takayasu arteritis: diagnosis, treatment and prognosis

Takayasu arteritis (TA) is a chronic nonspecific granulomatous vasculitis affecting aorta and its main branches, coronary and pulmonary arteries. TA often occurs in young women and has a characteristic heterogeneity depending on ethnicity and geographical location. Although the pathogenesis of TA remains unclear, the interaction of many factors, such as autoimmunity, inflammation, genetic and environmental factors and so on, is involved in the occurrence and development of TA. Angiography, which is recognized as the gold standard in evaluating vascular lesions in TA, combined with computer tomography angiography (CTA), magnetic resonance angiography (MRA), ultrasonography, (18)Fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) could not only provide important information for early diagnosis but also detect disease activity, and thus further guide the treatment in TA. In addition, beside the commonly used corticosteroids, immunosuppressive agents, percutaneous transluminal angioplasty (PTA) and surgical revascularization, anti-tumor necrosis factor (TNF) agent has been more widely used in refractory cases of TA. The objective of this review is to systemically describe the pathogenesis, clinical characteristics, diagnosis, treatment and prognosis of TA.

Development of outcome measures for large-vessel vasculitis for use in clinical trials: opportunities, challenges, and research agenda

Giant cell (GCA) and Takayasu's arteritis (TAK) are 2 forms of large-vessel vasculitis (LVV) that involve the aorta and its major branches. GCA has a predilection for the cranial branches, while TAK tends to affect the extracranial branches. Both disorders may also cause nonspecific constitutional symptoms. Although some clinical features are more common in one or the other disorder and the ages of initial presentation differ substantially, there is enough clinical and histopathologic overlap between these disorders that some investigators suggest GCA and TAK may be 2 processes within the spectrum of a single disease. There have been few randomized therapeutic trials completed in GCA, and none in TAK. The lack of therapeutic trials in LVV is only partially explained by the rarity of these diseases. It is likely that the lack of well validated outcome measures for LVV and uncertainties regarding trial design contribute to the paucity of trials for these diseases. An initiative to develop a core set of outcome measures for use in clinical trials of LVV was launched by the international OMERACT Vasculitis Working Group in 2009 and subsequently endorsed by the OMERACT community at the OMERACT 10 meeting. Aims of this initiative include: (1) to review the literature and existing data related to outcome assessments in LVV; (2) to obtain the opinion of experts and patients on disease content; and (3) to formulate a research agenda to facilitate a more data-based approach to outcomes development.

Dynamics of neuron-glia interplay upon exposure to unconjugated bilirubin

Microglia are the main players of the brain immune response. They act as active sensors that rapidly respond to injurious insults by shifting into different activated states. Elevated levels of unconjugated bilirubin (UCB) induce cell death, immunostimulation and oxidative stress in both neurons and astrocytes. We recently reported that microglial phagocytic phenotype precedes the release of pro-inflammatory cytokines upon UCB exposure. We investigated whether and how microglia microenvironment influences the response to UCB. Our findings revealed that conditioned media derived from UCB-treated astrocytes reduce microglial inflammatory reaction and cell death, suggesting an attempt to curtail microglial over activation. Conditioned medium from UCB-challenged neurons, although down-regulating tumor necrosis factor-α and interleukin-1β promoted the release of interleukin-6 and nitric oxide, the activation of matrix metalloproteinase-9, and cell death, as compared with UCB-direct effects on microglia. Moreover, soluble factors released by UCB-treated neurons intensified the phagocytic properties manifested by microglia under direct exposure to UCB. Results from neuron-microglia mixed cultures incubated with UCB evidenced that sensitized microglia were able to prevent neurite outgrowth impairment and cell death. In conclusion, our data indicate that stressed neurons signal microglial clearance functions, but also overstimulate its inflammatory potential ultimately leading to microglia demise.