Potential long-term effects of SARS-CoV-2 infection on the pulmonary vasculature: Multilayered cross-talks in the setting of coinfections and comorbidities.

The Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and its sublineages pose a new challenge to healthcare systems worldwide due to its ability to efficiently spread in immunized populations and its resistance to currently available therapies. COVID-19, although targeting primarily the respiratory system, is also now well established that later affects every organ in the body. Most importantly, despite the available therapy and vaccine-elicited protection, the long-term consequences of viral infection in breakthrough and asymptomatic individuals are areas of concern. In the past two years, investigators accumulated evidence on how the virus triggers our immune system and the molecular signals involved in the cross-talk between immune cells and structural cells in the pulmonary vasculature to drive pathological lung complications such as endothelial dysfunction and thrombosis. In the review, we emphasize recent updates on the pathophysiological inflammatory and immune responses associated with SARS-CoV-2 infection and their potential long-term consequences that may consequently lead to the development of pulmonary vascular diseases.

Picturing of the Lung Tumor Cellular Composition by Multispectral Flow Cytometry.

The lung tumor microenvironment plays a critical role in the tumorigenesis and metastasis of lung cancer, resulting from the crosstalk between cancer cells and microenvironmental cells. Therefore, comprehensive identification and characterization of cell populations in the complex lung structure is crucial for development of novel targeted anti-cancer therapies. Here, a hierarchical clustering approach with multispectral flow cytometry was established to delineate the cellular landscape of murine lungs under steady-state and cancer conditions. Fluorochromes were used multiple times to be able to measure 24 cell surface markers with only 13 detectors, yielding a broad picture for whole-lung phenotyping. Primary and metastatic murine lung tumor models were included to detect major cell populations in the lung, and to identify alterations to the distribution patterns in these models. In the primary tumor models, major altered populations included CD324+ epithelial cells, alveolar macrophages, dendritic cells, and blood and lymph endothelial cells. The number of fibroblasts, vascular smooth muscle cells, monocytes (Ly6C+ and Ly6C-) and neutrophils were elevated in metastatic models of lung cancer. Thus, the proposed clustering approach is a promising method to resolve cell populations from complex organs in detail even with basic flow cytometers.

Quercetin in the form of a nano-antioxidant (QTiO2) provides stabilization of quercetin and maximizes its antioxidant capacity in the mouse fibroblast model.

Living cells are constantly exposed to reactive oxygen species (ROS) causing them to rely on a constant supply of exogenous antioxidants. Quercetin (Q) is one of the potent exogenous antioxidants utilized in various antioxidant formulations. However, the potential application of Q is largely limited because of its poor water solubility. In this study, we employed titanium dioxide (TiO2) nanoparticles to maximize cellular penetration and antioxidant effect of Q on mouse fibroblast cells. To accomplish this, polyethylene glycol (PEG) modified TiO2-nanoparticle surfaces were utilized that exhibited better dispersion, with enhanced biocompatibility. Cell viability assays using Q and Q-conjugated TiO2-nanoparticles (QTiO2) were evaluated in terms of cell morphology as well as with an immunoblotting analysis to look for key biomarkers of apoptosis. In addition, cleavages of Cas 3 and PARP were obtained in cells treated with Q. Furthermore, antioxidant defence with QTiO2 was validated by means of the Nrf2 upregulation pathway. We also observed increased expressions of target enzymes; HO-1, NQO1 and SOD1 in QTiO2-treated cells. The antioxidant potency of the QTiO2 nano-antioxidant form was successfully tested in ROS and superoxide radicals induced cells. Our results demonstrated that the QTiO2 nano-antioxidant promoted a high quercetin bioavailability and stability, in cells with maximal antioxidant potency against ROS, with no signs of cytotoxicity.