Aortic Calcification in Takayasu Arteritis: Risk Factors and Relationship With Activity and Vascular Lesion. It Is Not Only an Aging Question

Association between premature vascular smooth muscle cells senescence and vascular inflammation in Takayasu's arteritis

OBJECTIVES

Arterial wall inflammation and remodelling are the characteristic features of Takayasu's arteritis (TAK). It has been proposed that vascular smooth muscle cells (VSMCs) are the main targeted cells of inflammatory damage and participate in arterial remodelling in TAK. Whether VSMCs are actively involved in arterial wall inflammation has not been elucidated. Studies have shown that cellular senescence in tissue is closely related to local inflammation persistence. We aimed to investigate whether VSMCs senescence contributes to vascular inflammation and the prosenescent factors in TAK.

METHODS

VSMCs senescence and senescence-associated secretory phenotype were detected by histological examination, bulk RNA-Seq and single-cell RNA-seq conducted on vascular surgery samples of TAK patients. The key prosenescent factors and the downstream signalling pathway were investigated in a series of in vitro and ex vivo experiments.

RESULTS

Histological findings, primary cell culture and transcriptomic analyses demonstrated that VSMCs of TAK patients had the features of premature senescence and contributed substantially to vascular inflammation by upregulating the expression of senescence-associated inflammatory cytokines. IL-6 was found to be the critical cytokine that drove VSMCs senescence and senescence-associated mitochondrial dysfunction in TAK. Mechanistically, IL-6-induced non-canonical mitochondrial localisation of phosphorylated STAT3 (Tyr705) prevented mitofusin 2 (MFN2) from proteasomal degradation, and subsequently promoted senescence-associated mitochondrial dysfunction and VSMCs senescence. Mitochondrial STAT3 or MFN2 inhibition ameliorated VSMCs senescence in ex vivo cultured arteries of TAK patients.

CONCLUSIONS

VSMCs present features of cellular senescence and are actively involved in vascular inflammation in TAK. Vascular IL-6-mitochondrial STAT3-MFN2 signalling is an important driver of VSMCs senescence.

Surgical Strategies and Long-Term Outcomes for Complex Coral Reef Aorta with Multisegmental Involvement: A Case Report

Coral reef aorta (CRA) is a rare condition characterized by the distribution of rock-hard calcifications in the visceral part of the aorta, leading to potentially life-threatening symptoms, such as hypertension, congestive heart failure, and limb and visceral ischemia. The patient was a 54-year-old female who presented with leg claudication and was diagnosed with CRA using computed tomography. CRA affected the descending thoracic and abdominal aortas, including the visceral portion, leading to reduced perfusion of both limbs and the left kidney. The surgical intervention involved bypass surgery from the descending thoracic aorta proximal to the CRA to the aortic bifurcation, including reimplantation of the left renal artery. Postoperative recovery was successful and the symptoms resolved. However, the patient experienced decreased right renal function due to CRA progression three years postoperatively. Given the uncertainty regarding the optimal surgical approach for CRA, long-term considerations are crucial for its management.

Aortic calcification correlates with pseudoaneurysm or penetrating aortic ulcer of different etiologies

Chronic risk factors for pseudoaneurysm (PSA) or penetrating aortic ulcer (PAU) have not been fully clarified. This study aims to evaluate the association of aortic calcification with PSA or PAU of different etiologies. Totally 77 pseudoaneurysms, 80 PAU, and 160 healthy controls (HCs) were retrospectively included, of which 30 were infected, 34 were immunological, and 93 were atherosclerotic etiologies. The aortic calcification status, position of aortic tears/ulcers, and risk factors for disease or acute aortic syndrome (AAS) were identified. Atherosclerotic patients aged more than 65 and infective patients aged more than 60 had significantly higher calcification scores. The immunological group had a lower level of calcification in the infrarenal aorta. For patients of infective or atherosclerotic etiology, 60% (18/30) and 60.22% (56/93) of the tears/ulcers occurred at the aortic parts with the highest level of calcification. Patients with longitudinal calcification exceeding 1/3 of the aortic arch had an increased risk of acquiring diseases (OR = 13.231). The presence of longitudinal calcification of the descending aorta or cross-sectional calcification of the infrarenal aorta increased the risks of acquiring diseases (OR = 8.484 and 8.804). After adjusting for age, longitudinal calcification of the descending aorta exceeding 1/3 length was found to be associated with AAS (OR = 4.662). Tears/ulcers of pseudoaneurysm and PAU were both generally found at the part of the aorta with most calcification. Distinct aorta calcification characteristics were observed for lesions of different etiologies. Longitudinal thoracic and cross-sectional infrarenal abdominal aortic calcification increased the risk of acquiring diseases, and descending aortic calcification was associated with symptomatic patients.

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.