Human coronavirus NL63 (HCoV-NL63) is a common respiratory virus that causes moderately severe infections. We have previously shown that the virus uses heparan sulfate proteoglycans (HSPGs) as the initial attachment factors, facilitating viral entry into the cell. In the present study, we show that the membrane protein (M) of HCoV-NL63 mediates this attachment. Using viruslike particles lacking the spike (S) protein, we demonstrate that binding to the cell is not S protein dependent. Furthermore, we mapped the M protein site responsible for the interaction with HSPG and confirmed its relevance using a viable virus. Importantly, in silico analysis of the region responsible for HSPG binding in different clinical isolates and the Amsterdam I strain did not exhibit any signs of cell culture adaptation. IMPORTANCE It is generally accepted that the coronaviral S protein is responsible for viral interaction with a cellular receptor. Here we show that the M protein is also an important player during early stages of HCoV-NL63 infection and that the concerted action of the two proteins (M and S) is a prerequisite for effective infection. We believe that this study broadens the understanding of HCoV-NL63 biology and may also alter the way in which we perceive the first steps of cell infection with the virus. The data presented here may also be important for future research into vaccine or drug development.

Virus like particles (VLPs) produced by the expression of viral structural proteins can serve as versatile nanovectors or potential vaccine candidates. In this study we describe for the first time the generation of HCoV-NL63 VLPs using baculovirus system. Major structural proteins of HCoV-NL63 have been expressed in tagged or native form, and their assembly to form VLPs was evaluated. Additionally, a novel procedure for chromatography purification of HCoV-NL63 VLPs was developed. Interestingly, we show that these nanoparticles may deliver cargo and selectively transduce cells expressing the ACE2 protein such as ciliated cells of the respiratory tract. Production of a specific delivery vector is a major challenge for research concerning targeting molecules. The obtained results show that HCoV-NL63 VLPs may be efficiently produced, purified, modified and serve as a delivery platform. This study constitutes an important basis for further development of a promising viral vector displaying narrow tissue tropism.

The aim of this study was to determine the effect of polyphenol-rich ethanol extract of bee pollen (EEP) on atherosclerosis induced by a high-fat diet in ApoE-knockout mice. EEP was given with feed in two doses of 0.1 and 1 g/kg body mass (BM). The studies have been conducted in a period of 16 weeks. The following factors were estimated: total cholesterol (TC), oxidized low density lipoproteins (ox-LDL), asymmetric dimethylarginine (ADMA), angiotensin-converting enzyme (ACE) and angiotensin II (ANG II) in the 5th, 10th, 12th, 14th, and 16th week of the experiment. In the last, i.e., 16th week of the studies the development of coronary artery disease (CAD) was also estimated histopathologically. Supplementing diet with EEP resulted in decreasing TC level. EEP reduced oxidative stress by lowering the levels of ox-LDL, ADMA, ANG II and ACE. EEP protected coronary arteries by significantly limiting the development of atherosclerosis (the dose of 0.1 g/kg BM) or completely preventing its occurrence (the dose of 1 g/kg BM). The obtained results demonstrate that EEP may be useful as a potential anti-atherogenic agent.

Ovarian cancer has the worst prognosis among all gynecological cancers. Therefore, it seems reasonable to seek new drugs that may improve the effectiveness of treatment or mitigate the adverse effects of chemotherapy. Caffeic acid phenethyl ester (CAPE) has many beneficial biological properties. The aim of the study was to assess the anticancer properties of CAPE against serum ovarian carcinoma cells. The morphology of the cells was evaluated in H-E staining and in transmission electron microscopy. The cytotoxic and proapoptotic activity of CAPE was investigated by using the XTT-NR-SRB assay, qRT-PCR analysis of BAX/BCL2 expression, and by cytometric evaluation. CAPE causes constriction in OV7 cells, numerous granulomas were observed in the cytoplasm, the cell nuclei were pyknotic. Autophagosomal vacuoles could suggest the occurrence of aponecrosis. CAPE significantly decreased the lysosomal activity and the total synthesis of cellular proteins. CAPE exhibited, dose and time dependent, cytotoxic activity against OV7 serum ovarian cancer cells. In OV7 cells CAPE induced apoptosis via dysregulation of BAX/BCL2 balance, while activated proapoptotic BAX gene expression level was 10 times higher than BCL2.

We have studied a preventive effect of polyphenol-rich bee pollen ethanol extract (EEP) against histological changes in the liver and cardiac blood vessels, abnormalities of lipid profile, and the levels of oxidized low density lipoproteins (ox-LDL), asymmetric dimethylarginine (ADMA), angiotensin-converting enzyme (ACE), and angiotensin II (ANG II) caused by a high-fat diet in C₅₇BL₆ mice. Supplementing the diet with EEP in the doses of 0.1 g/kg body mass (BM) and 1 g/kg BM resulted in a decrease of total cholesterol by 31% and 35%, respectively. It also decreased the level of low density lipoproteins by 67% and 90%, respectively. No differences in the levels of high density lipoprotein and triacylglycerols were observed. EEP reduced the level of ox-LDL by 33% and 47%, ADMA by 13% and 51%, ACE by 17% and 30%, as well as ANG II by 11% and 15% in a dose-dependent manner, which proves a protective effect of EEP in a high-fat diet. EEP reduces and/or prevents hepatic steatosis and degenerative changes caused by a high-fat diet in C₅₇BL₆ mice, which indicates its hepatoprotective effect. EEP used with standard feed does not disturb a normal concentration of the assayed parameters.