Growth Differentiation Factor 11 and Myostatin: Mechanism and Therapeutic Role in Cardiovascular Diseases

During life, cardiac muscle is capable of remodeling in response to an increased hemodynamic demand through cardiac hypertrophy. However, in most cases, if the stress stimuli become chronic the initially compensatory hypertrophic response evolves towards a pathological condition and heart failure. In this scenario, a therapeutic approach capable of reducing pathological cardiac hypertrophy could be beneficial. Growth differentiation factor 11 (GDF11) is circulating factor able to reduce cardiac hypertrophy in mice. It is a member of TGF-β family, and it shares a high level of homology with myostatin (MSTN) a well-studied protein that regulates skeletal muscle mass and apparently minimal activity on cardiac mass. Our data showed different protein levels between cardiac and skeletal muscle tissues revealed a higher abundancy of type I TGF-β receptors (ALK4/5/7) in the heart samples. Moreover, ALK7 receptor knockout induced a significant reduction in SMAD3/4 signaling only after GDF11 treatment. These results showed a differential quantity and use of ALKs receptors, possibly explaining the higher GDF11 sensitivity of cardiomyocytes compared to skeletal myocytes. Using a model of pressure overload-induced cardiac hypertrophy it was possible to further confirm the anti-hypertrophic activity of GDF11. Interestingly, even if with lower potency, this effect was recapitulated also by MSTN, demonstrating that both peptides have overlapping effects on cardiac tissue. Furthermore, aiming to reduce controversies regarding GDF11 and MSTN serum quantifications, we contributed to develop a novel assay based on mass spectrometry that can discriminate and quantify reliably both proteins. Using this method, it was also possible to identify an age-dependent reduction of both GDF11 and MSTN ligand in mice. In conclusion, GDF11 and MSTN share a common cardiac anti-hypertrophic activity that was not previously expected. Modulation of GDF11/MSTN signaling pathway can be considered for development of novel therapeutic strategies and new biotherapeutics

Stem cells as source for retinal pigment epithelium transplantation

Inherited maculopathies, age related macular degeneration and some forms of retinitis pigmentosa are associated with impaired function or loss of the retinal pigment epithelium (RPE). Among potential treatments, transplantation approaches are particularly promising. The arrangement of RPE cells in a well-defined tissue layer makes the RPE amenable to cell or tissue sheet transplantation. Different cell sources have been suggested for RPE transplantation but the development of a clinical protocol faces several obstacles. The source should provide a sufficient number of cells to at least recover the macula area. Secondly, cells should be plastic enough to be able to integrate in the host tissue. Tissue sheets should be considered as well, but the substrate on which RPE cells are cultured needs to be carefully evaluated. Immunogenicity can also be an obstacle for effective transplantation as well as tumorigenicity of not fully differentiated cells. Finally, ethical concerns may represent drawbacks when embryo-derived cells are proposed for RPE transplantation. Here we discuss different cell sources that became available in recent years and their different properties. We also present data on a new source of human RPE. We provide a protocol for RPE differentiation of retinal stem cells derived from adult ciliary bodies of post-mortem donors. We show molecular characterization of the in vitro differentiated RPE tissue and demonstrate its functionality based on a phagocytosis assay. This new source may provide tissue for allogenic transplantation based on best matches through histocompatibility testing

Surgical Treatment of Angio‐Behçet

Patients with Behçet’s disease are at risk for multiple vessel‐related complications including thromboses, stenoses, occlusions, and aneurysms. Surgical treatment of Angio‐Behçet brings numerous challenges due to the peculiarities of the disease process and the high rate of complications. Recurrent vascular episodes are also quite common and Behçet patients require rigorous follow‐up. In this review, we focus on the manifestations of Behçet’s disease involving the venous system and the systemic arterial vasculitis focusing on the indications, workup, and techniques for surgical treatment. Several case studies from our own experience are presented together with supporting diagnostic imaging and the decision process whether to intervene is discussed. Although open surgery remains a valid option, new endovascular techniques are rapidly advancing and offer excellent results with important decrease in morbidity and mortality even in highly compromised patients

Wet-dry-wet drug screen leads to the synthesis of TS1, a novel compound reversing lung fibrosis through inhibition of myofibroblast differentiation

Therapies halting the progression of fibrosis are ineffective and limited. Activated myofibroblasts are emerging as important targets in the progression of fibrotic diseases. Previously, we performed a high-throughput screen on lung fibroblasts and subsequently demonstrated that the inhibition of myofibroblast activation is able to prevent lung fibrosis in bleomycin-treated mice. High-throughput screens are an ideal method of repurposing drugs, yet they contain an intrinsic limitation, which is the size of the library itself. Here, we exploited the data from our “wet” screen and used “dry” machine learning analysis to virtually screen millions of compounds, identifying novel anti-fibrotic hits which target myofibroblast differentiation, many of which were structurally related to dopamine. We synthesized and validated several compounds ex vivo (“wet”) and confirmed that both dopamine and its derivative TS1 are powerful inhibitors of myofibroblast activation. We further used RNAi-mediated knock-down and demonstrated that both molecules act through the dopamine receptor 3 and exert their anti-fibrotic effect by inhibiting the canonical transforming growth factor β pathway. Furthermore, molecular modelling confirmed the capability of TS1 to bind both human and mouse dopamine receptor 3. The anti-fibrotic effect on human cells was confirmed using primary fibroblasts from idiopathic pulmonary fibrosis patients. Finally, TS1 prevented and reversed disease progression in a murine model of lung fibrosis. Both our interdisciplinary approach and our novel compound TS1 are promising tools for understanding and combating lung fibrosis

EPHA2 Polymorphisms and Age-Related Cataract in India

Objective: We investigated whether previously reported single nucleotide polymorphisms (SNPs) of EPHA2 in European studies are associated with cataract in India. Methods: We carried out a population-based genetic association study. We enumerated randomly sampled villages in two areas of north and south India to identify people aged 40 and over. Participants attended a clinical examination including lens photography and provided a blood sample for genotyping. Lens images were graded by the Lens Opacification Classification System (LOCS III). Cataract was defined as a LOCS III grade of nuclear >= 4, cortical >= 3, posterior sub-capsular (PSC) >= 2, or dense opacities or aphakia/pseudophakia in either eye. We genotyped SNPs rs3754334, rs7543472 and rs11260867 on genomic DNA extracted from peripheral blood leukocytes using TaqMan assays in an ABI 7900 real-time PCR. We used logistic regression with robust standard errors to examine the association between cataract and the EPHA2 SNPs, adjusting for age, sex and location. Results: 7418 participants had data on at least one of the SNPs investigated. Genotype frequencies of controls were in Hardy-Weinberg Equilibrium (p > 0.05). There was no association of rs3754334 with cataract or type of cataract. Minor allele homozygous genotypes of rs7543472 and rs11260867 compared to the major homozygote genotype were associated with cortical cataract, Odds ratio (OR) = 1.8, 95% Confidence Interval (CI) (1.1, 3.1) p = 0.03 and 2.9 (1.2, 7.1) p = 0.01 respectively, and with PSC cataract, OR = 1.5 (1.1, 2.2) p = 0.02 and 1.8 (0.9, 3.6) p = 0.07 respectively. There was no consistent association of SNPs with nuclear cataract or a combined variable of any type of cataract including operated cataract. Conclusions: Our results in the Indian population agree with previous studies of the association of EPHA2 variants with cortical cataracts. We report new findings for the association with PSC which is particularly prevalent in Indians

Endovascular Abdominal Aortic Aneurysm Repair With Ovation Alto Stent Graft: Protocol for the ALTAIR (ALTo endogrAft Italian Registry) Study

Background: Since 2010, the Ovation Abdominal Stent Graft System has offered an innovative sealing option for abdominal aortic aneurysm (AAA) by including a sealing ring filled with polymer 13 mm from the renal arteries. In August 2020, the redesigned Ovation Alto, with a sealing ring 6 mm closer to the top of the fabric, received CE Mark approval. Objective: This registry study aims to evaluate intraoperative, perioperative, and postoperative results in patients treated by the Alto stent graft (Endologix Inc.) for elective AAA repair in a multicentric consecutive experience. Methods: All consecutive eligible patients submitted to endovascular aneurysm repair (EVAR) by Alto Endovascular AAA implantation will be included in this analysis. Patients will be submitted to EVAR procedures based on their own preferences, anatomical features, and operators experience. An estimated number of 300 patients submitted to EVAR with Alto stent graft should be enrolled. It is estimated that the inclusion period will be 24 months. The follow-up period is set to be 5 years. Full data sets and cross-sectional images of contrast-enhanced computed tomography scan performed before EVAR, at the first postoperative month, at 24 or 36 months, and at 5-year follow-up interval will be reported in the central database for a centralized core laboratory review of morphological changes. The primary endpoint of the study is to evaluate the technical and clinical success of EVAR with the Alto stent graft in short- (90-day), mid- (1-year), and long-term (5-year) follow-up periods. The following secondary endpoints will be also addressed: operative time; intraoperative radiation exposure; contrast medium usage; AAA sac shrinkage at 12-month and 5-year follow-up; any potential role of patients' baseline characteristics, valuated on preoperative computed tomography angiographic study, and of device configuration (number of component) in the primary endpoint. Results: The study is currently in the recruitment phase and the final patient is expected to be treated by the end of 2023 and then followed up for 5 years. A total of 300 patients will be recruited. Analyses will focus on primary and secondary endpoints. Updated results will be shared at 1- and 3-5-year follow-ups. Conclusions: The results from this registry study could validate the safety and effectiveness of the new design of the Ovation Alto Stent Graft. The technical modifications to the endograft could allow for accommodation of a more comprehensive range of anatomies on-label