Cyclophilin A/EMMPRIN Axis Is Involved in Pro-Fibrotic Processes Associated with Thoracic Aortic Aneurysm of Marfan Syndrome Patients

Intracellular and extracellular Cyclophilin a promote cardiac fibrosis through TGF-β signaling in response to angiotensin Ⅱ

Cardiac fibrosis is characterized by abnormal proliferation of cardiac fibroblasts (CFs) and ventricular remodeling, which finally leads to heart failure. Inflammation and oxidative stress play a central role in the development of cardiac fibrosis. CyPA (Cyclophilin A) is a main proinflammatory cytokine secreted under the conditions of oxidative stress. The mechanisms by which intracellular and extracellular CyPA interact with CFs are unclear. Male C57BL/6 J mice received angiotensin Ⅱ (Ang Ⅱ) or vehicle for 4 weeks. Inhibition of CyPA significantly reversed Ang Ⅱ-induced cardiac hypertrophy and fibrosis. Mechanically, TGF-β (Transforming growth factor-β) signaling was found to be an indispensable downstream factor of CyPA-mediated myofibroblast differentiation and proliferation. Furthermore, intracellular CyPA and extracellular CyPA activate TGF-β signaling through NOD-like receptor protein 3 (NLRP3) inflammasome and nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, respectively. Pharmacological inhibition of CyPA and its receptor CD147 implemented by Triptolide also attenuated the expression of TGF-β signaling and cardiac fibrosis in Ang Ⅱ-model. These studies elucidate a novel mechanism by which CyPA promotes TGF-β and its downstream signaling in CFs and identify CyPA (both intracellular and extracellular) as plausible therapeutic targets for preventing or treating cardiac fibrosis induced by chronic Ang Ⅱ stimulation.

High-Fat Diet Has a Protective Sex-Dependent Effect on Aortic Aneurysm Severity in a Marfan Syndrome Mouse Model

BACKGROUND

Marfan syndrome (MFS) is a genetic disorder caused by mutations in fibrillin-1 and is characterized by thoracic aortic aneurysms and other complications. Previous studies revealed sexual dimorphisms in formation of aortic aneurysm in patients with MFS. The current study aimed to investigate the combined role of a high-fat diet (HFD) and biological sex in aortic disease using the mgR/mgR MFS mouse model.

METHODS

Male and female mgR/mgR mice, as well as wild-type (WT) littermate mice, were fed a control diet (CD [10% fat]) or HFD (60% fat) from 4 to 12 weeks of age. Key aortic disease parameters analyzed included the diameter of the aortic wall; elastic fibre fragmentation; proteoglycan content; mRNA levels of Mmp12, Col1a1, Col3a1, and Fbn1; and fibrillin-1 deposition in the aortic wall.

RESULTS

HFD-fed female mgR/mgR mice had significantly reduced aortic diameters (35%), elastic fibre fragmentation (56%), pathologically enhanced proteoglycans (45%), and expression of Mmp12 (64%), Col1a1 (41%), and Col3a1 (43%) compared with male mgR/mgR mice on HFD. Fibrillin-1 deposition and Fbn1 mRNA levels were unaffected. The data reveal a protective effect of HFD in female mice. In contrast, CD did not exert any protective effects.

CONCLUSIONS

This study demonstrates a specific sexual dimorphism in MFS mice, with HFD exerting an explicit protective effect on severity of aortic disease in female mice. These preclinical data may be useful for developing nutritional recommendations for individuals with MFS in the longer term.

Multi-omics in thoracic aortic aneurysm: the complex road to the simplification

BACKGROUND

Thoracic aortic aneurysm (TAA) is a serious condition that affects the aorta, characterized by the dilation of its first segment. The causes of TAA (e.g., age, hypertension, genetic syndromes) are heterogeneous and contribute to the weakening of the aortic wall. This complexity makes treating this life-threatening aortopathy challenging, as there are currently no etiological therapy available, and pharmacological strategies, aimed at avoiding surgical aortic replacement, are merely palliative. Recent studies on novel therapies for TAA have focused on identifying biological targets and etiological mechanisms of the disease by using advanced -omics techniques, including epigenomics, transcriptomics, proteomics, and metabolomics approaches.

METHODS

This review presents the latest findings from -omics approaches and underscores the importance of integrating multi-omics data to gain more comprehensive understanding of TAA.

RESULTS

Literature suggests that the alterations in TAA mediators frequently involve members of pro-fibrotic process (i.e., TGF-β signaling pathways) or proteins associated with cell/extracellular structures (e.g., aggrecans). Further analyses often reported the importance in TAA of processes as inflammation (PCR, CD3, leukotriene compounds), oxidative stress (chromatin OXPHOS, fatty acids), mitochondrial respiration and glycolysis/gluconeogenesis (e.g., PPARs and HIF1a). Of note, more recent metabolomics studies added novel molecular markers to the list of TAA-specific detrimental mediators (proteoglycans).

CONCLUSION

It is increasingly clear that integrating data from different -omics branches, along with clinical data, is essential as well as complicated both to reveal hidden relevant information and to address complex diseases such as TAA. Importantly, recent progresses in metabolomics highlighted novel potential and unprecedented marks in TAA diagnosis and therapy.

Marfan Syndrome: Enhanced Diagnostic Tools and Follow-up Management Strategies

Marfan syndrome (MFS) is a rare inherited autosomic disorder, which encompasses a variety of systemic manifestations caused by mutations in the Fibrillin-1 encoding gene (FBN1). Cardinal clinical phenotypes of MFS are highly variable in terms of severity, and commonly involve cardiovascular, ocular, and musculoskeletal systems with a wide range of manifestations, such as ascending aorta aneurysms and dissection, mitral valve prolapse, ectopia lentis and long bone overgrowth, respectively. Of note, an accurate and prompt diagnosis is pivotal in order to provide the best treatment to the patients as early as possible. To date, the diagnosis of the syndrome has relied upon a systemic score calculation as well as DNA mutation identification. The aim of this review is to summarize the latest MFS evidence regarding the definition, differences and similarities with other connective tissue pathologies with severe systemic phenotypes (e.g., Autosomal dominant Weill-Marchesani syndrome, Loeys-Dietz syndrome, Ehlers-Danlos syndrome) and clinical assessment. In this regard, the management of MFS requires a multidisciplinary team in order to accurately control the evolution of the most severe and potentially life-threatening complications. Based on recent findings in the literature and our clinical experience, we propose a multidisciplinary approach involving specialists in different clinical fields (i.e., cardiologists, surgeons, ophthalmologists, orthopedics, pneumologists, neurologists, endocrinologists, geneticists, and psychologists) to comprehensively characterize, treat, and manage MFS patients with a personalized medicine approach.

CD147 and MMPs as key factors in physiological and pathological processes

Cluster of differentiation 147 (CD147) or extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that induces the synthesis of matrix metalloproteinases (MMPs). MMPs, as zinc-dependent proteases and versatile enzymes, play critical roles in the degradation of the extracellular matrix (ECM) components, cleaving of the receptors of cellular surfaces, signaling molecules, and other precursor proteins, which may lead to attenuation or activation of such targets. CD147 and MMPs play essential roles in physiological and pathological conditions and any disorder in the expression, synthesis, or function of CD147 and MMPs may be associated with various types of disease. In this review, we have focused on the roles of CD147 and MMPs in some major physiological and pathological processes.

CyPA interacts with SERPINH1 to promote extracellular matrix production and inhibit epithelial-mesenchymal transition of trophoblast via enhancing TGF-β/Smad3 pathway in preeclampsia

We previously reported that cyclophilin A (CyPA) production is upregulated in preeclampsia (PE). Moreover, CyPA is known to induce PE-like features in pregnant mice and impair trophoblast invasiveness. In this study, we further illustrated the role of CyPA in PE. RNA-seq analysis, RT-qPCR, immunohistochemical (IHC) staining, and western blotting of mouse placentae revealed that CyPA increased the levels of extracellular matrix (ECM) proteins, such as collagen I and fibronectin, and activated the TGF-β/Smad3 signaling pathway. Additionally, CyPA inhibited the expression of genes involved in epithelial-mesenchymal transition (EMT) (e.g., E-cadherin, N-cadherin, and vimentin) in mouse placentae. We then constructed stable overexpressing and knock-down CyPA cell models (using HTR8/SVneo cells) to clarify the molecular mechanism. We found that CyPA regulated the levels of ECM-related proteins and the EMT process through the TGF-β/Smad3 pathway. We also identified SERPINH1 as a putative CyPA-binding protein, using liquid chromatography-electrospray mass spectrometry (LC-MS)/MS. SERPINH1 was found to be upregulated in the placentae of PE. Silencing SERPINH1 expression reversed the upregulation of ECM proteins and inhibition of the EMT process induced by the overexpression of CyPA. These findings revealed the functions of CyPA in the impaired invasiveness of trophoblasts in PE and indicated that CyPA and SERPINH1 may represent promising targets for the treatment of PE.

Delicate regulation of IL-1β-mediated inflammation by cyclophilin A

The inflammatory response is tightly regulated, but its regulatory principles are still incompletely understood. Cyclophilin A (CypA) has long been considered as a pro-inflammatory factor. Here, we discover how CypA precisely regulates interleukin-1β (IL-1β)-mediated inflammatory responses. In lipopolysaccharide-treated mice, CypA deficiency initially inhibits and then promotes lung inflammation, which is closely related to IL-1β production. Mechanistically, CypA not only facilitates pro-IL-1β processing by increasing Smurf1-mediated K63-linked ubiquitination in an ATP-dependent manner but also accelerates pro-IL-1β degradation, depending on Smurf1-mediated K48-linked ubiquitination. Moreover, in IL-1β-treated mice, CypA exacerbates lung injury by enhancing cytokine production. It also upregulates the ILK/AKT pathway by inhibiting Cyld-mediated K63-linked ILK deubiquitination, which promotes the epithelial-mesenchymal transition (EMT) to facilitate lung repair. Collectively, CypA promotes inflammation activation by increasing IL-1β production and then promotes inflammation resolution by enhancing redundant pro-IL-1β degradation and IL-1β-induced EMT, indicating the complex and delicate regulation of inflammatory response.

Cyclophilin A inhibition as potential treatment of human aortic valve calcification

Aortic valve stenosis (AS) is a pathological condition that affects about 3% of the population, representing the most common valve disease. The main clinical feature of AS is represented by the impaired leaflet motility, due to calcification, which leads to the left ventricular outflow tract obstruction during systole. The formation and accumulation of calcium nodules are driven by valve interstitial cells (VICs). Unfortunately, to date, the in vitro and in vivo studies were not sufficient to fully recapitulate all the pathological pathways involved in AS development, as well as to define a specific and effective pharmacological treatment for AS patients. Cyclophilin A (CyPA), the most important immunophilin and endogenous ligand of cyclosporine A (CsA), is strongly involved in several detrimental cardiovascular processes, such as calcification. To date, there are no data on the CyPA role in VIC-mediated calcification process of AS. Here, we aimed to identify the role of CyPA in AS by studying VIC calcification, in vitro. In this study, we found that (i) CyPA is up-regulated in stenotic valves of AS patients, (ii) pro-calcifying medium promotes CyPA secretion by VICs, (iii) in vitro treatment of VICs with exogenous CyPA strongly stimulates calcium deposition, and (iv) exogenous CyPA inhibition mediated by CsA analogue MM284 abolished in vitro calcium potential. Thus, CyPA represents a biological target that may act as a novel candidate in the detrimental AS development and its inhibition may provide a novel pharmacological approach for AS treatment.

Promising Anti-atherosclerotic Effect of Berberine: Evidence from In Vitro, In Vivo, and Clinical Studies

Elevated levels of plasma cholesterol, impaired vascular wall, and presence of inflammatory macrophages are important atherogenic risk factors contributing to atherosclerotic plaque formation and progression. The interventions modulating these risk factors have been found to protect against atherosclerosis development and to decrease atherosclerosis-related cardiovascular disorders. Nutritional approaches involving supplements followed by improving dietary habits and lifestyle have become growingly attractive and acceptable methods used to control atherosclerosis risk factors, mainly high levels of plasma cholesterol. There are a large number of studies that show berberine, a plant bioactive compound, could ameliorate atherosclerosis-related risk factors. In the present literature review, we put together this studies and provide integrated evidence that exhibits berberine has the potential atheroprotective effect through reducing increased levels of plasma cholesterol, particularly low-density lipoprotein (LDL) cholesterol (LDL-C) via LDL receptor (LDLR)-dependent and LDL receptor-independent mechanisms, inhibiting migration and inflammatory activity of macrophages, improving the functionality of endothelial cells via anti-oxidant activities, and suppressing proliferation of vascular smooth muscle cells. In conclusion, berberine can exert inhibitory effects on the atherosclerotic plaque development mainly through LDL-lowering activity and suppressing atherogenic functions of mentioned cells. As the second achievement of this review, among the signaling pathways through which berberine regulates intracellular processes, AMP-activated protein kinase (AMPK) has a central and critical role, showing that enhancing activity of AMPK pathway can be considered as a promising therapeutic approach for atherosclerosis treatment.