Circulating biomarkers associated with aortic diameter in male and female patients with thoracic aortic disease: a cross-sectional study

Epigenetic Biomarkers in Thoracic Aortic Aneurysm, Dissection, and Bicuspid Aortopathy: A Comprehensive Review

Thoracic aortic disease (TAD) encompasses a spectrum of life-threatening conditions, including thoracic aortic aneurysm (TAA), acute type A aortic dissection (ATAAD), and bicuspid aortic valve (BAV)-associated aortopathy. While genetic mutations are well-documented contributors, emerging evidence highlights epigenetic mechanisms as critical regulators of TAD pathogenesis. This comprehensive review explores the role of epigenetic modifications-DNA methylation, histone modifications, and microRNA (miRNA) regulation-in vascular remodeling, extracellular matrix degradation, and endothelial dysfunction. Aberrant DNA methylation patterns have been implicated in TAA and ATAAD, influencing genes responsible for vascular integrity and inflammation. Histone modifications modulate smooth muscle cell phenotype switching, impacting aneurysm progression. Additionally, dysregulated miRNA expression contributes to endothelial barrier disruption and extracellular matrix remodeling, presenting novel avenues for biomarker discovery. The reversibility of epigenetic modifications offers a promising therapeutic target, with pharmacological agents such as histone deacetylase inhibitors and miRNA-based therapies showing potential in preclinical models. This review underscores the translational potential of epigenetic biomarkers for early disease detection, risk stratification, and precision medicine approaches. Further research is needed to integrate these findings into clinical practice, paving the way for innovative diagnostic and therapeutic strategies in TAD management.

A multiphasic model for determination of mouse ascending thoracic aorta mass transport properties with and without aneurysm

Thoracic aortic aneurysms (TAAs) are associated with aortic wall remodeling that affects transmural transport or the movement of fluid and solute across the wall. In previous work, we used a Fbln4E57K/E57K (MU) mouse model to investigate transmural transport changes as a function of aneurysm severity. We compared wild-type (WT), MU with no aneurysm (MU-NA), MU with aneurysm (MU-A), and MU with an additional genetic mutation that led to increased aneurysm penetrance (MU-XA). We found that all aneurysmal aortas (MU-A and MU-XA) had lower fluid flux compared to WT. Non-aneurysmal aortas (MU-NA) had higher 4 kDa FITC-dextran solute flux than WT, but aneurysmal MU-A and MU-XA aortas had solute fluxes similar to WT. Our experimental results could not isolate competing factors, such as changes in aortic geometry and solid material properties among these mouse models, to determine how intrinsic transport properties change with aneurysm severity. The objective of this study is to use biphasic and multiphasic models to identify changes in transport material properties. Our biphasic model indicates that hydraulic permeability is significantly decreased in the severe aneurysm model (MU-XA) compared to non-aneurysmal aortas (MU-NA). Our multiphasic model shows that effective solute diffusivity is increased in MU-NA aortas compared to all others. Our findings reveal changes in intrinsic transport properties that depend on aneurysm severity and are important for understanding the movement of fluids and solutes that may play a role in the diagnosis, progression, or treatment of TAA.

Microfibrillar-associated protein 4 as a predictive biomarker of treatment response in patients with chronic inflammatory diseases initiating biologics: secondary analyses based on the prospective BELIEVE cohort study

BACKGROUND

Currently, there are no reliable biomarkers for predicting treatment response in chronic inflammatory diseases (CIDs).

OBJECTIVE

To determine whether serum microfibrillar-associated protein 4 (MFAP4) levels can predict the treatment response to biological therapy in patients with CIDs.

METHODS

The BELIEVE study was originally designed as a prospective, multi-center cohort study of 233 patients with either rheumatoid arthritis, psoriatic arthritis, psoriasis, axial spondyloarthritis, Crohn's disease, or ulcerative colitis, initiating treatment with a biologic agent (or switching to another). Clinical assessment and blood sample collection were performed at baseline and 14-16 weeks after treatment initiation. The primary analyses included participants with available blood samples at baseline; missing data were handled as non-responders. The patients were stratified into the upper tertile of serum MFAP4 (High MFAP4) versus a combined category of middle and lower tertiles (Other MFAP4). The primary outcome was the proportion of patients with clinical response to biologic therapy after 14-16 weeks.

RESULTS

211 patients were included in the primary analysis population. The mean age was 43.7 (SD: 14.8) years, and 120 (59%) were female. Positive treatment response was observed in 41 (59%) and 69 (49%) for High MFAP4 and Other MFAP4, respectively. When adjusting for pre-specified variables (CID, age, sex, smoking status, and BMI), the adjusted OR was 2.28 (95% CI: 1.07 to 4.85) for a positive treatment outcome in the High MFAP4 group.

CONCLUSION

A high MFAP4 status before initiating biological treatment is associated with a positive clinical response, when adjusting for confounding factors.

Unveiling cellular and molecular aspects of ascending thoracic aortic aneurysms and dissections

Ascending thoracic aortic aneurysm (ATAA) remains a significant medical concern, with its asymptomatic nature posing diagnostic and monitoring challenges, thereby increasing the risk of aortic wall dissection and rupture. Current management of aortic repair relies on an aortic diameter threshold. However, this approach underestimates the complexity of aortic wall disease due to important knowledge gaps in understanding its underlying pathologic mechanisms.Since traditional risk factors cannot explain the initiation and progression of ATAA leading to dissection, local vascular factors such as extracellular matrix (ECM) and vascular smooth muscle cells (VSMCs) might harbor targets for early diagnosis and intervention. Derived from diverse embryonic lineages, VSMCs exhibit varied responses to genetic abnormalities that regulate their contractility. The transition of VSMCs into different phenotypes is an adaptive response to stress stimuli such as hemodynamic changes resulting from cardiovascular disease, aging, lifestyle, and genetic predisposition. Upon longer exposure to stress stimuli, VSMC phenotypic switching can instigate pathologic remodeling that contributes to the pathogenesis of ATAA.This review aims to illuminate the current understanding of cellular and molecular characteristics associated with ATAA and dissection, emphasizing the need for a more nuanced comprehension of the impaired ECM-VSMC network.

Understanding genomic medicine for thoracic aortic disease through the lens of induced pluripotent stem cells

Thoracic aortic disease (TAD) is often silent until a life-threatening complication occurs. However, genetic information can inform both identification and treatment at an early stage. Indeed, a diagnosis is important for personalised surveillance and intervention plans, as well as cascade screening of family members. Currently, only 20% of heritable TAD patients have a causative mutation identified and, consequently, further advances in genetic coverage are required to define the remaining molecular landscape. The rapid expansion of next generation sequencing technologies is providing a huge resource of genetic data, but a critical issue remains in functionally validating these findings. Induced pluripotent stem cells (iPSCs) are patient-derived, reprogrammed cell lines which allow mechanistic insights, complex modelling of genetic disease and a platform to study aortic genetic variants. This review will address the need for iPSCs as a frontline diagnostic tool to evaluate variants identified by genomic discovery studies and explore their evolving role in biological insight through to drug discovery.