Maria Rosaria De Pascale

Platelet Derivatives in Regenerative Medicine: An Update

Prior preclinical and clinical studies support the use of platelet-derived products for the treatment of soft and hard tissue lesions. These regenerative effects are controlled by autocrine and paracrine biomolecules including growth factors and cytokines contained in platelet alpha granules. Each growth factor is involved in a phase of the healing process, such as inflammation, collagen synthesis, tissue granulation, and angiogenesis collectively promoting tissue restitution. Platelet derivatives have been prepared as platelet-rich plasma, platelet gel, platelet-rich fibrin, and platelet eye drops. These products vary in their structure, growth factors, composition, and cytokine concentrations. Here, we review the current use of platelet-derived biological products focusing on the rationale for their use and the main requirements for their preparation. Variation in the apparent therapeutic efficacy may have resulted from a lack of reproducible, standardized protocols for preparation. Despite several individual studies showing favorable treatment effects, some randomized controlled trials as well as meta-analyses have found no constant clinical benefit from the application of platelet-derived products for prevention of tissue lesions. Recently, 3 published studies in dentistry showed an improvement in bone density. Seven published studies showed positive results in joint regeneration. Five published studies demonstrated an improvement in the wound healing, and an improvement of eye epithelial healing was observed in 2 reports. Currently, at least 14 ongoing clinical trials in phase 3 or 4 have been designed with large groups of treated patients (n > 100). Because the rationale of the therapy with platelet-derived compounds is still debated, a definitive insight can be acquired only when these large randomized trials will be completed.

Epigenetic control of autoimmune diseases: from bench to bedside.

Genome-wide association studies have revealed several genes predisposing to autoimmunity, however, concordance rates in monozygotic twins are significantly below 50% for several autoimmune diseases. The limited presence of a strong genetic association only in some patients supports that other non-genetic mechanisms are active in these pathologies. Epigenetic modifications such as DNA methylation, histone modification, and microRNA signaling regulate gene expression and are sensitive to external stimuli and they might be as bridging between genetic and environmental factors. Some evidence has highlighted the involvement of epigenetic alterations in the pathogenesis of various autoimmune diseases giving rise to great expectations among clinicians and researchers. The direct role of these alterations in the initiation/progression of autoimmune diseases is still unclear. The knowledge in depth of these pathogenic and epigenetic mechanisms will increase the possibility of the control and/or prevention of autoimmune diseases through the use of drugs that target epigenetic pathways. Moreover, we could use epigenetic-related biomarkers to follow this complicated framework (for example H3K4me3 and miRNA-155 are among those proposed biomarkers). This article reviews current understanding of the epigenetic involvement in the field of autoimmune diseases especially in systemic lupus erythematosus, rheumatoid arthritis, sclerosis multiple and type 1 diabetes.

Epigenetic-related therapeutic challenges in cardiovascular disease

Progress in human genetic and genomic research has led to the identification of genetic variants associated with specific cardiovascular diseases (CVDs), but the pathogenic mechanisms remain unclear. Recent studies have analyzed the involvement of epigenetic mechanisms such as DNA methylation and histone modifications in the development and progression of CVD. Preliminary work has investigated the correlations between DNA methylation, histone modifications, and RNA-based mechanisms with CVDs including atherosclerosis, heart failure (HF), myocardial infarction (MI), and cardiac hypertrophy. Remarkably, both in utero programming and postnatal hypercholesterolemia may affect the epigenetic signature in the human cardiovascular system, thereby providing novel early epigenetic-related pharmacological insights. Interestingly, some dietary compounds, including polyphenols, cocoa, and folic acid, can modulate DNA methylation status, whereas statins may promote epigenetic-based control in CVD prevention through histone modifications. We review recent findings on the epigenetic control of cardiovascular system and new challenges for therapeutic strategies in CVDs.

Novel epigenetic-based therapies useful in cardiovascular medicine.

Epigenetic modifications include DNA methylation, histone modifications, and microRNA. Gene alterations have been found to be associated with cardiovascular diseases, and epigenetic mechanisms are continuously being studied to find new useful strategies for the clinical management of afflicted patients. Numerous cardiovascular disorders are characterized by the abnormal methylation of CpG islands and so specific drugs that could inhibit DNA methyltransferase directly or by reducing its gene expression (e.g., hydralazine and procainamide) are currently under investigation. The anti-proliferative and anti-inflammatory properties of histone deacetylase inhibitors and their cardio-protective effects have been confirmed in preclinical studies. Furthermore, the regulation of the expression of microRNA targets through pharmacological tools is still under development. Indeed, large controlled trials are required to establish whether current possible candidate antisense microRNAs could offer better therapeutic benefits in clinical practice. Here, we updated therapeutic properties, side effects, and feasibility of emerging epigenetic-based strategies in cardiovascular diseases by highlighting specific problematic issues that still affect the development of large scale novel therapeutic protocols.

Epigenetic Reprogramming in Atherosclerosis

Recent data support the involvement of epigenetic alterations in the pathogenesis of atherosclerosis. The most widely investigated epigenetic mechanism is DNA methylation although also histone code changes occur during the diverse steps of atherosclerosis, such as endothelial cell proliferation, vascular smooth muscle cell (SMC) differentiation, and inflammatory pathway activation. In this review, we focus on the main genes that are epigenetically modified during the atherogenic process, particularly nitric oxide synthase (NOS), estrogen receptors (ERs), collagen type XV alpha 1 (COL15A1), vascular endothelial growth factor receptor (VEGFR), and ten-eleven translocation (TET), which are involved in endothelial dysfunction; gamma interferon (IFN-γ), forkhead box p3 (FOXP3), and tumor necrosis factor-α (TNF-α), associated with atherosclerotic inflammatory process; and p66shc, lectin-like oxLDL receptor (LOX1), and apolipoprotein E (APOE) genes, which are regulated by high cholesterol and homocysteine (Hcy) levels. Furthermore, we also discuss the role of non-coding RNAs (ncRNA) in atherosclerosis. NcRNAs are involved in epigenetic regulation of endothelial function, SMC proliferation, cholesterol synthesis, lipid metabolism, and inflammatory response.

Severe Type 2 Diabetes Induces Reversible Modifications of Endothelial Progenitor Cells Which are Ameliorate by Glycemic Control

Background Circulating endothelial progenitors cells (EPCs) play a critical role in neovascularization and endothelial repair. There is a growing evidence that hyperglycemia related to Diabetes Mellitus (DM) decreases EPC number and function so promoting vascular complications. Aim of the Study This study investigated whether an intensive glycemic control regimen in Type 2 DM can increase the number of EPCs and restores their function. Methods Sixty-two patients with Type 2 DM were studied. Patients were tested at baseline and after 3 months of an intensive regimen of glycemic control. The Type 2 DM group was compared to control group of subjects without diabetes. Patients with Type 2 DM (mean age 58.2±5.4 years, 25.6% women, disease duration of 15.4±6.3 years) had a baseline HgA1c of 8.7±0.5% and lower EPC levels (CD34+/KDR+) in comparison to healthy controls (p<0.01). Results The intensive glycemic control regimen (HgA1c decreased to 6.2±0.3%) was coupled with a significant increase of EPC levels (mean of 18%, p<0.04 vs. baseline) and number of EPCs CFUs (p<0.05 vs. baseline). Conclusion This study confirms that number and bioactivity of EPCs are reduced in patients with Type 2 DM and, most importantly, that the intensive glycemic control in Type 2 DM promotes EPC improvement both in their number and in bioactivity.

Screening tests for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus in blood donors: Evaluation of two chemiluminescent immunoassay systems

Abstract Automated chemiluminescent immunoassays (CLIAs) are useful for the detection of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus 1/2 antigen/antibodies (HIV 1/2 Ag/Ab) in blood donor screening. Eight hundred and forty serum samples were tested for hepatitis B surface antigen (HBsAg), HCV antibodies (anti-HCV), and HIV1/2 Ag/Ab in parallel using 2 different CLIAs (Abbott Architect i2000SR and Roche Cobas e411). The concordance between the 2 systems was high (Cohens kappa 0.97 for HBsAg, 0.77 for anti-HCV, 0.92 for HIV1/2 Ag/Ab) and the specificity and the positive predictive value were comparable. Among the 12 discrepant results, 11 were false-positive and 1 (reactive by Architect) was true-positive for anti-HCV. Positivity for HBV DNA, HCV RNA, and HIV RNA was recorded in 90.9%, 38.9%, and 100% of true-positive samples, respectively. This study represents the first stringent comparison between Architect i2000SR and Cobas e411 in blood donors. We observed a good correlation and high agreement among HBV, HCV, and HIV with the 2 automated systems.

Human Leukocyte Antigens and Alloimmunization in Heart Transplantation: An Open Debate

Considerable advances in heart transplantation outcome have been achieved through the improvement of donor-recipient selection, better organ preservation, lower rates of perioperative mortality and the use of innovative immunosuppressive protocols. Nevertheless, long-term survival is still influenced by late complications. We support the introduction of HLA matching as an additional criterion in the heart allocation. Indeed, allosensitization is an important factor affecting heart transplantation and the presence of anti-HLA antibodies causes an increased risk of antibody-mediated rejection and graft failure. On the other hand, the rate of heart-immunized patients awaiting transplantation is steadily increasing due to the limited availability of organs and an increased use of ventricular assist devices. Significant benefits may result from virtual crossmatch approach that prevents transplantation in the presence of unacceptable donor antigens. A combination of both virtual crossmatch and a tailored desensitization therapy could be a good compromise for a favorable outcome in highly sensitized patients. Here, we discuss the unresolved issue on the clinical immunology of heart transplantation.

Human Serum Eye Drops in Eye Alterations: An Insight and a Critical Analysis

Human serum contains a physiological plethora of bioactive elements naturally released by activated platelets which might have a significant effect on the regeneration of corneal layers by stimulating the cell growth. This mechanism supported the use of human serum eye drops in some ocular diseases associated with dystrophic changes and alterations of the tear film, such as persistent corneal epithelial defects and dry eye syndrome. We focused our effort on potential benefits and limitations of the use of human serum eye drops when conventional therapies failed. We reviewed the recent literature by reporting published studies from 2010 to 2014. Despite the limited evaluated study populations, most of the clinical studies have confirmed that serum eye drop therapy is effective in corneal healing by reducing ocular symptom, particularly during the short-term follow-up. In addition, three recent published studies have shown the efficacy of the serum eye drop therapy in comparison to traditional ones in intractable patients. Besides, reported ongoing clinical studies confirmed the open debate regarding the use of biologic tools for cornea regeneration. Results from these studies might open novel challenges and perspectives in the therapy of such refractory patients.

Syphilis detection: evaluation of serological screening and pilot reverse confirmatory assay algorithm in blood donors.

Serological assays are still considered the most useful tests in the diagnosis of syphilis. Since no single serological assay is able to provide a satisfactory result, in our laboratory we have evaluated the usefulness of a commercially-available immunoblot to diagnose syphilis infection among blood donors. From October 2012 to June 2013, 4572 blood donors were screened for syphilis with an automated chemiluminescent microparticle immunoassay (CMIA). To confirm the presence of treponemal antibodies, CMIA-reactive sera were tested by standard Treponema pallidum haemagglutination assay (TPHA). In addition, an alternative confirmatory test – the immunoblot INNO-LIA assay was introduced in our laboratory. Since two additional positives among CMIA-reactive-TPHA-negative samples were found, we concluded that the INNO-LIA immunoblot allowed a better detection of syphilis compared to TPHA. A confirmatory strategy based on the use of two treponemal assays could meet the screening requirements for blood donors as well as in our centre.