Avian influenza is one of the largest known threats to domestic poultry. Influenza outbreaks on poultry farms typically lead to the complete slaughter of the entire domestic bird population, causing severe economic losses worldwide. Moreover, there are highly pathogenic avian influenza (HPAI) strains that are able to infect the swine or human population in addition to their primary avian host and, as such, have the potential of being a global zoonotic and pandemic threat. Migratory birds, especially waterfowl, are a natural reservoir of the avian influenza virus; they carry and exchange different virus strains along their migration routes, leading to antigenic drift and antigenic shift, which results in the emergence of novel HPAI viruses. This requires monitoring over time and in different locations to allow for the upkeep of relevant knowledge on avian influenza virus evolution and the prevention of novel epizootic and epidemic outbreaks. In this review, we assess the role of migratory birds in the spread and introduction of influenza strains on a global level, based on recent data. Our analysis sheds light on the details of viral dissemination linked to avian migration, the viral exchange between migratory waterfowl and domestic poultry, virus ecology in general, and viral evolution as a process tightly linked to bird migration. We also provide insight into methods used to detect and quantify avian influenza in the wild. This review may be beneficial for the influenza research community and may pave the way to novel strategies of avian influenza and HPAI zoonosis outbreak monitoring and prevention.

Tissue autofluorescence of fixed tissue sections is a major concern of fluorescence microscopy. The adrenal cortex emits intense intrinsic fluorescence that interferes with signals from fluorescent labels, resulting in poor-quality images and complicating data analysis. We used confocal scanning laser microscopy imaging and lambda scanning to characterize the mouse adrenal cortex autofluorescence. We evaluated the efficacy of tissue treatment methods in reducing the intensity of the observed autofluorescence, such as trypan blue, copper sulfate, ammonia/ethanol, Sudan Black B, TrueVIEW^TM Autofluorescence Quenching Kit, MaxBlock^TM Autofluorescence Reducing Reagent Kit, and TrueBlack^TM Lipofuscin Autofluorescence Quencher. Quantitative analysis demonstrated autofluorescence reduction by 12–95%, depending on the tissue treatment method and excitation wavelength. TrueBlack^TM Lipofuscin Autofluorescence Quencher and MaxBlock^TM Autofluorescence Reducing Reagent Kit were the most effective treatments, reducing the autofluorescence intensity by 89–93% and 90–95%, respectively. The treatment with TrueBlack^TM Lipofuscin Autofluorescence Quencher preserved the specific fluorescence signals and tissue integrity, allowing reliable detection of fluorescent labels in the adrenal cortex tissue. This study demonstrates a feasible, easy-to-perform, and cost-effective method to quench tissue autofluorescence and improve the signal-to-noise ratio in adrenal tissue sections for fluorescence microscopy.

The adrenal glands are important endocrine organs that play a major role in the stress response. Some adrenal glands abnormalities are treated with hormone replacement therapy, which does not address physiological requirements. Modern technologies make it possible to develop gene therapy drugs that can completely cure diseases caused by mutations in specific genes. Congenital adrenal hyperplasia (CAH) is an example of such a potentially treatable monogenic disease. CAH is an autosomal recessive inherited disease with an overall incidence of 1:9500–1:20,000 newborns. To date, there are several promising drugs for CAH gene therapy. At the same time, it remains unclear how new approaches can be tested, as there are no models for this disease. The present review focuses on modern models for inherited adrenal gland insufficiency and their detailed characterization. In addition, the advantages and disadvantages of various pathological models are discussed, and ways of further development are suggested.

Our current understanding of the molecular and cellular mechanisms in tissues and organs during normal and pathological conditions opens up substantial prospects for the development of novel approaches to treatment of various diseases. For instance, lifelong replacement therapy is no longer mandatory for the management of some monogenic hereditary diseases. Genome editing techniques that have emerged in the last decade are being actively investigated as tools for correcting mutations in affected organs. Furthermore, new protocols for obtaining various types of human and animal cells and cellular systems are evolving, increasingly reflecting the real structures in vivo. These methods, together with the accompanying gene and cell therapy, are being actively developed and several approaches are already undergoing clinical trials. Adrenal insufficiency caused by a variety of factors can potentially be the target of such therapeutic strategies. The adrenal gland is a highly organized organ, with multiple structural components interacting with each other via a complex network of endocrine and paracrine signals. This review summarizes the findings of studies in the field of structural organization and functioning of the adrenal gland at the molecular level, as well as the modern approaches to the treatment of adrenal pathologies.

Differentiation approaches to obtain mesenchymal stem cells (MSCs) have gradually developed over the last few decades. The problem is that different protocols give different MSC types, making further research difficult. Here, we tried three different approaches to differentiate embryonic stem cells (ESCs) from early mesoderm to MSCs using serum-containing or xeno-free differentiation medium and observed differences in the cells’ morphology, doubling rate, ability to form colonies, surface marker analysis, and multilineage differentiation potential of the obtained cell lines. We concluded that the xeno-free medium best fits the criteria of MSCs’ morphology, growth kinetics, and surface marker characterization. In contrast, the serum-containing medium gives better potential for further MSC differentiation into osteogenic, chondrogenic, and adipogenic lineages.

Nowadays stem cells of adult type are attractive in case of active development of cell and genome technologies. They are the target of new therapeutic approaches, which are based on correction of mutations or replenishment of organs, that were damaged by autoimmune reactions, aging or other pathological processes. Also stem cells, including patient-specific (induced Pluripotent Stem Cells, iPSCs), and obtained by differentiation from them tissue cultures and organoids are the closest models to in vivo researches on humans, which gives an opportunity to get more relevant data while testing different therapeutic approaches and pharmacological drugs. The main molecular pathways, that are essential for homeostasis of a cortex of a adrenal gland — compound, structurally and functionally heterogeneous organ, is described the presented review. The adrenal cortex is renewing during the organism’s ontogenesis at the expense of the pool of stem and progenitors cells, which are in tight junctions with differentiated steroidogenic cells and which are under constant control of endocrine and paracrine signals. The understanding of signaling pathways and interactions of different cell types will give an opportunity to develop the most suitable protocols for obtaining cells of adrenal gland cortex in a different stages of differentiation to use them in scientific and medical purposes.