Gene therapy for cardiovascular disorders: is there a future?

The impact of oncolytic adenoviral therapy on the therapeutic efficacy of PD-1/PD-L1 blockade

Immunotherapy has revolutionized treatment of cancer during the last decades. Oncolytic virotherapy has also emerged as a strategy to fight against cancer cells both via lysis of malignant cells and activating immune responses. Accepted as a logical strategy, combination of monoclonal antibodies particularly against the programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) is introduced to improve clinical responses to immune checkpoint inhibitors (ICIs). Accordingly, Talimogene laherparepvec (T-VEC) has received approval for clinical use, while a number of oncolytic Adenoviruses (Ads) are being investigated in clinical trials of malignancies. Combination of oncolytic Ads with PD-1/PD-L1 inhibitors have shown potentials in promoting responses to ICIs, changing the tumor microenvironment, inducing long-term protection against tumor, and promoting survival among mice models of malignancies. Regarding the increasing importance of oncolytic Ads in combination therapy of cancers, in this review we decide to outline recent studies in this field.

SARS-CoV-2 spike protein induces abnormal inflammatory blood clots neutralized by fibrin immunotherapy

Blood clots are a central feature of coronavirus disease-2019 (COVID-19) and can culminate in pulmonary embolism, stroke, and sudden death. However, it is not known how abnormal blood clots form in COVID-19 or why they occur even in asymptomatic and convalescent patients. Here we report that the Spike protein from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to the blood coagulation factor fibrinogen and induces structurally abnormal blood clots with heightened proinflammatory activity. SARS-CoV-2 Spike virions enhanced fibrin-mediated microglia activation and induced fibrinogen-dependent lung pathology. COVID-19 patients had fibrin autoantibodies that persisted long after acute infection. Monoclonal antibody 5B8, targeting the cryptic inflammatory fibrin epitope, inhibited thromboinflammation. Our results reveal a procoagulant role for the SARS-CoV-2 Spike and propose fibrin-targeting interventions as a treatment for thromboinflammation in COVID-19.

One-Sentence Summary

SARS-CoV-2 spike induces structurally abnormal blood clots and thromboinflammation neutralized by a fibrin-targeting antibody.

Multiple extensive coronary artery stenting: does it compromise future surgical revascularization?

PURPOSE OF REVIEW

In the era of percutaneous coronary intervention, surgeons are confronted with performing coronary artery bypass graft surgery on patients with previous balloon dilatation or stenting. This review evaluates the impact of previous percutaneous coronary intervention on patient survival and choice of optimal myocardial revascularization technique.

RECENT FINDINGS

Aggressive atherosclerosis has been remarked in patients complicated with intrastent stenosis. Moreover, bypass grafting with venous grafts has shown an extremely high incidence of graft failure in the restenosis population due to limited nitric oxide (a natural vasodilator) production of venous grafts. The challenge is to achieve complete revascularization in an unfavourable setting (greater co-morbidities, complex coronary lesions) with a greater risk of graft occlusion.

SUMMARY

The internal thoracic artery is the optimal graft for myocardial revascularization in patients with and without previous in-stent restenosis. Coronary artery reconstruction by exclusive internal thoracic artery grafting gives superior patency rates and clinical outcomes. It is the most appropriate approach for myocardial revascularization in these patients.

24-Hour In-hospital Mortality Predictions in Coronary Artery Bypass Grafting Patients

BACKGROUND

The purpose of this study was to determine the factors that can help predict risk of mortality in the first 24 h of coronary artery bypass grafting (CABG), because mortality within a few hours of surgery is a disastrous event for surgeons and the patient's family.

METHODS

The study population consisted of 120 in-hospital mortality cases (1.07%) from 11,183 patients who underwent CABG from February 2002 to February 2006 by the same group of surgeons in a referral center. One group consisted of 40/120 (about 33.3%) patients who died during the first 24 h after surgery. The second group consisted of 80/120 patients (66.7%) who died between the 2(nd) and 30(th) day postoperatively. A set of data was gathered from the surgery database of the hospital and analyzed in a univariate model.

RESULTS

Among the studied variables, only the following factors proved to be significant: previous percutaneous transluminal coronary angioplasty (PTCA), previous cerebrovascular accident (CVA), cardiopulmonary bypass (CBP) time, and postoperative atrial fibrillation (AF) (p </=0.05).

CONCLUSIONS

This study revealed that influencing factors in 24-h in-hospital mortality are previous PTCA, previous CVA, CBP time, and postoperative AF. It is interesting that influencing factors in global 30-day hospital mortality such as body mass index, diabetes mellitus, preoperative arrhythmia, ejection fraction, history of previous CABG and resuscitation, or catastrophic states like poor runoff coronary vessels, triple vessel disease or associated procedures like valve surgery were not significant in the first 24-h mortality when comparing with in-hospital mortality in this study.

Patients With In-Stent Restenosis Have an Increased Risk of Mid-Term Venous Graft Failure

BACKGROUND

This study was designed to evaluate if patients in whom in-stent restenosis developed had an higher risk of early venous graft failure compared with normal patients.

METHODS

The study cohort comprised 120 patients (60 with previous in-stent restenosis and 60 controls) who received a total of 165 complementary venous grafts on the circumflex or right coronary artery system (84 in the restenosis group and 81 in the control group). All patients were prospectively followed-up and underwent reangiography at 5-years follow-up.

RESULTS

In the restenosis group, 28 venous grafts (33.%) were perfectly patent, 10 showed major irregularities, and 46 were occluded. In the control patients, 50 grafts (61.7%) were perfectly patent (p < 0.001 compared with the restenosis series), 12 showed major irregularities (p = .74), and 19 were occluded (p < 0.0001). In contrast, the 5-year outcome of internal thoracic artery grafts was not affected by history of in-stent restenosis.

CONCLUSIONS

Patients who developed in-stent restenosis have an higher risk of early venous graft failure compared with the control patients. Arterial grafts should probably be preferred in these patients.

Targeting vascular injury using Hantavirus-pseudotyped lentiviral vectors

Restenosis is a pathological condition involving intimal hyperplasia and negative arterial remodeling. Gene therapy vectors have shown modest therapeutic effects, but the level of infectivity has been relatively poor. In the present study we have designed a modified lentiviral vector (LV) pseudotyped with a strain of Hantavirus (HTNV) to improve the transduction efficiency into vascular smooth muscle and endothelial cells in vitro and in vivo. In vivo studies using adult New Zealand White rabbits demonstrated that local delivery of HTNV-pseudotyped LV (2 x 10(7) TU) into balloon-injured carotid arteries led to highly efficient transduction into endothelial and smooth muscle cells more effectively than VSV-G-pseudotyped LV (2 x 10(7) TU) or replication-defective adenoviral vectors (1-1.5 x 10(9) pfu) as determined by beta-gal immunohistochemistry. Overexpression of extracellular superoxide dismutase in balloon-injured carotid arteries 6 weeks after LV administration resulted in a significant reduction (P = 0.0024) of the intima/media ratio (0.18 +/- 0.09; n = 4) compared to vehicle-infused carotid arteries (0.69 +/- 0.08; n = 7). No beta-gal immunostaining was detected in other systemic organs, including the spleen, liver, heart, lung, kidneys, and brain. Moreover, no changes in plasma alanine aminotransferase or aspartate aminotransferase were detected following LV administration. In all, these data show that LV pseudotyped with Hantaviral glycoproteins can be a useful vector for targeting therapeutic genes to the vasculature in vivo.

Genomics and Cardiovascular Disease

PURPOSE

To describe genetic knowledge and discovery in the area of cardiovascular disease (CVD) and to discuss how these new advances will influence the clinical care of affected people.

ORGANIZING FRAMEWORK

A selective review of the literature is presented on the disease mechanism of both the Mendelian and multifactorial genetic cardiovascular conditions. A case study approach is used to illustrate how the genetic paradigm affects the healthcare experience of a family affected with familial hypertrophic cardiomyopathy.

FINDINGS

The current state of CVD treatment remains complex. An understanding of genomic concepts and a genome-based approach is necessary to determine: (a) the risk of CVD susceptibility beyond traditional risk factors; (b) early detection of illness; (c) response to treatment; and (d) molecular taxonomy of the disease.

CONCLUSIONS

The results of genetic research, education, and teaching will lead to a new understanding of genes and pathways, resulting in powerful new therapeutic approaches to CVD. The challenge is to translate genetic discoveries into clinical practice that ultimately leads to preventing CVD and reducing mortality.

Comparison between recombinant baculo- and adenoviral-vectors as transfer system in cardiovascular cells

The development of effective gene-therapeutic applications for cardiovascular disorders is in part limited by the lack of appropriate delivery systems. In an attempt to overcome this deficiency, we investigated the ability of baculoviral vectors to transduce human cardiovascular cells, for which data are missing in literature. Additionally, baculovirus ability to transduce target cells was compared to that of an adenoviral vector, a well characterized and widely used viral vector. Transduction experiments, performed using baculo/adenoviral vectors expressing the enhanced green fluorescence protein, revealed that, under the experimental condition considered, baculoviruses but not adenoviruses efficiently transduce human coronary smooth muscle cells (hCSMC); an opposite behavior was noticed for human coronary endothelial cells (hCEC). Thus, baculoviral vectors are potentially indicated as transfer system in the treatment of coronary restenosis, where growth inhibitory genes should reach hCSMC but not hCEC. When used to transduce human cardiomyocytes and fibroblasts, both vectors behaved similarly. Finally, studies on cellular DNA replication revealed a more prolonged and pronounced negative effect on cells transduced by adenoviral compared to baculoviral vectors. Our data indicate that baculoviruses represent an attractive alternative to adenoviruses as transfer vectors in cardiovascular cells and that baculovirus have the potential to be used as gene transfer system in cardiovascular diseases such as restenosis.