Natural products and their putative effect on NORAD

Während der Großteil des menschlichen Genoms transkribiert wird, wird letztendlich nur ein kleiner Teil dieser RNA-Transkripte in Proteine übersetzt. Die Vielzahl an nicht-kodierender RNAs erlangt zunehmend an Beachtung, wobei die Gruppe der langen nicht-kodieren RNAs (long non-coding RNA, lncRNAs) aufgrund ihrer Funktionen bei der Embryonalentwicklung und verschiedenen Krankheiten besonders hervorsticht. Noncoding RNA activated by DNA damage (NORAD) ist eine häufig vorkommende und konservierte lncRNA, die erst kürzlich als Regulator von genomischer Stabilität, Mitochondrienfunktion und des Alterns in Säugetierzellen und -geweben beschrieben wurde. Darüber hinaus ist bekannt, dass die Expression von NORAD durch zelluläre Stressoren wie DNA-Schäden und Hypoxie stimuliert wird, wobei die genaue Beteiligung der RNA und die funktionellen Konsequenzen ihrer Induktion in diesen und anderen Aspekten der zellulären Stressantwort noch nicht bekannt sind. Naturstoffe werden für eine Vielzahl menschlicher Krankheiten untersucht und haben sich in mehreren menschlichen Krankheitsmodellen als Modulatoren von lncRNAs erwiesen. Aus diesem Grund wurden für diese Arbeit sieben Naturstoffe ausgewählt, die vor allem für ihre antikarzinogenen, antioxidativen und lebensverlängernden Effekte bekannt sind, um einen möglichen Effekt auf NORAD zu untersuchen. Während in Bezug auf Lebendzellanteil und intrazellulärer ROS-Produktion keine Unterschiede zwischen NORAD +/+ und NORAD -/- Zellen nach Behandlung mit den ausgewählten Stoffen festzustellen waren, ergab die qRT-PCR-Analyse eine Induktion von NORAD durch Curcumin (10 µM), Rapamycin (5 µM und 1 µM) und Resveratrol (100 µM). Diese Induktion tritt möglicherweise als Folge von intrazellulärem Stress auf, der durch Behandlung mit den Testsubstanzen verursacht wird. Eine mögliche Korrelation zwischen einem Anstieg in oxidativem Stress und einem Anstieg von NORAD, sowie ein potentieller Zusammenhang zwischen NORAD-Induktion und p53, konnte in den Untersuchungen aufgezeigt werden. Die Ergebnisse dieser Arbeit unterstreichen daher die Rolle von NORAD in der zellulären Stressantwort und liefern Ansatzpunkte für weitere Untersuchungen hinsichtlich der Mechanismen und Konsequenzen der NORAD-Modulation durch Naturstoffe.While the majority of the human genome is transcribed, only a small fraction of these RNA transcripts is ultimately translated into proteins. The plethora of non-coding RNAs have increasingly attracted attention, with the group of long non-coding RNAs (lncRNAs) emerging as particularly interesting, because of their functions in embryonic development, differentiation and disease. Noncoding RNA activated by DNA damage (NORAD) is an abundant and conserved lncRNA that has recently been uncovered as a regulator of genomic stability, mitochondrial function and aging in mammalian cells and tissues. Furthermore, NORAD expression can be increased by cellular stressors, including DNA damage and hypoxia, although the exact involvement of the lncRNA and the functional consequences of its induction in these and other stress response pathways, are not yet understood. Natural products have been investigated for a myriad of human diseases and have emerged as modulators of lncRNAs in several human disease models. Therefore, seven natural products, all known to exhibit anti-cancer, antioxidant, anti-aging and longevity effects among others, were selected to explore a potential effect on NORAD in this thesis. While NORAD +/+ and NORAD -/- cells did not differ in viability or intracellular ROS production upon treatment with the selected compounds, qRT-PCR analysis revealed an induction of NORAD by curcumin at 10 µM, rapamycin at 5 µM and 1 µM and resveratrol at 100 µM. This induction may likely be a result of cellular stress caused by the compounds, as we suggest a possible correlation between an increase in oxidative stress and an increase in NORAD, as well as a potential connection of NORAD induction to p53. These findings therefore emphasize the role of NORAD in cellular stress response and may provide further lines of investigation into the mechanisms and outcomes of NORAD modulation by the hereby tested compounds, as well as the involvement of the lncRNA in other stress response pathways and whether these could be modulated by natural products

Time to Kill and Time to Heal: The Multifaceted Role of Lactoferrin and Lactoferricin in Host Defense

Lactoferrin is an iron-binding glycoprotein present in most human exocrine fluids, particularly breast milk. Lactoferrin is also released from neutrophil granules, and its concentration increases rapidly at the site of inflammation. Immune cells of both the innate and the adaptive immune system express receptors for lactoferrin to modulate their functions in response to it. On the basis of these interactions, lactoferrin plays many roles in host defense, ranging from augmenting or calming inflammatory pathways to direct killing of pathogens. Complex biological activities of lactoferrin are determined by its ability to sequester iron and by its highly basic N-terminus, via which lactoferrin binds to a plethora of negatively charged surfaces of microorganisms and viruses, as well as to mammalian cells, both normal and cancerous. Proteolytic cleavage of lactoferrin in the digestive tract generates smaller peptides, such as N-terminally derived lactoferricin. Lactoferricin shares some of the properties of lactoferrin, but also exhibits unique characteristics and functions. In this review, we discuss the structure, functions, and potential therapeutic uses of lactoferrin, lactoferricin, and other lactoferrin-derived bioactive peptides in treating various infections and inflammatory conditions. Furthermore, we summarize clinical trials examining the effect of lactoferrin supplementation in disease treatment, with a special focus on its potential use in treating COVID-19

Vaccine Based on Recombinant Fusion Protein Combining Hepatitis B Virus PreS with SARS-CoV-2 Wild-Type- and Omicron-Derived Receptor Binding Domain Strongly Induces Omicron-Neutralizing Antibodies in a Murine Model

COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a recurrent endemic disease affecting the whole world. Since November 2021, Omicron and its subvariants have dominated in the spread of the disease. In order to prevent severe courses of disease, vaccines are needed to boost and maintain antibody levels capable of neutralizing Omicron. Recently, we produced and characterized a SARS-CoV-2 vaccine based on a recombinant fusion protein consisting of hepatitis B virus (HBV)-derived PreS and two SARS-CoV-2 wild-type RBDs.To develop a PreS-RBD vaccine which induces high levels of Omicron-specific neutralizing antibodies.We designed, produced, characterized and compared strain-specific (wild-type: W-PreS-W; Omicron: O-PreS-O), bivalent (mix of W-PreS-W and O-PreS-O) and chimeric (i.e., W-PreS-O) SARS-CoV-2 protein subunit vaccines. Immunogens were characterized in vitro using protein chemical methods, mass spectrometry, and circular dichroism in combination with thermal denaturation and immunological methods. In addition, BALB/c mice were immunized with aluminum-hydroxide-adsorbed proteins and aluminum hydroxide alone (i.e., placebo) to study the specific antibody and cytokine responses, safety and Omicron neutralization.Defined and pure immunogens could be produced in significant quantities as secreted and folded proteins in mammalian cells. The antibodies induced after vaccination with different doses of strain-specific, bivalent and chimeric PreS-RBD fusion proteins reacted with wild-type and Omicron RBD in a dose-dependent manner and resulted in a mixed Th1/Th2 immune response. Interestingly, the RBD-specific IgG levels induced with the different vaccines were comparable, but the W-PreS-O-induced virus neutralization titers against Omicron (median VNT50: 5000) were seven- and twofold higher than the W-PreS-W- and O-PreS-O-specific ones, respectively, and they were six-fold higher than those of the bivalent vaccine.Among the tested immunogens, the chimeric PreS-RBD subunit vaccine, W-PreS-O, induced the highest neutralizing antibody titers against Omicron. Thus, W-PreS-O seems to be a highly promising COVID-19 vaccine candidate for further preclinical and clinical evaluation