PPAR Ligands Induce Antiviral Effects Targeting Perturbed Lipid Metabolism during SARS-CoV-2, HCV, and HCMV Infection

The manipulation of host metabolisms by viral infections has been demonstrated by several studies, with a marked influence on the synthesis and utilization of glucose, nucleotides, fatty acids, and amino acids. The ability of virus to perturb the metabolic status of the infected organism is directly linked to the outcome of the viral infection. A great deal of research in recent years has been focusing on these metabolic aspects, pointing at modifications induced by virus, and suggesting novel strategies to counteract the perturbed host metabolism. In this review, our attention is turned on PPARs, nuclear receptors controlling multiple metabolic actions, and on the effects played by PPAR ligands during viral infections. The role of PPAR agonists and antagonists during SARS-CoV-2, HCV, and HCMV infections will be analyzed.

Natural Products Targeting Liver X Receptors or Farnesoid X Receptor

Nuclear receptors (NRs) are a superfamily of transcription factors induced by ligands and also function as integrators of hormonal and nutritional signals. Among NRs, the liver X receptors (LXRs) and farnesoid X receptor (FXR) have been of significance as targets for the treatment of metabolic syndrome-related diseases. In recent years, natural products targeting LXRs and FXR have received remarkable interests as a valuable source of novel ligands encompassing diverse chemical structures and bioactive properties. This review aims to survey natural products, originating from terrestrial plants and microorganisms, marine organisms, and marine-derived microorganisms, which could influence LXRs and FXR. In the recent two decades (2000–2020), 261 natural products were discovered from natural resources such as LXRs/FXR modulators, 109 agonists and 38 antagonists targeting LXRs, and 72 agonists and 55 antagonists targeting FXR. The docking evaluation of desired natural products targeted LXRs/FXR is finally discussed. This comprehensive overview will provide a reference for future study of novel LXRs and FXR agonists and antagonists to target human diseases, and attract an increasing number of professional scholars majoring in pharmacy and biology with more in-depth discussion.

New Insights Into Gut-Bacteria-Derived Indole and Its Derivatives in Intestinal and Liver Diseases

The interaction between host and microorganism widely affects the immune and metabolic status. Indole and its derivatives are metabolites produced by the metabolism of tryptophan catalyzed by intestinal microorganisms. By activating nuclear receptors, regulating intestinal hormones, and affecting the biological effects of bacteria as signaling molecules, indole and its derivatives maintain intestinal homeostasis and impact liver metabolism and the immune response, which shows good therapeutic prospects. We reviewed recent studies on indole and its derivatives, including related metabolism, the influence of diets and intestinal commensal bacteria, and the targets and mechanisms in pathological conditions, especially progress in therapeutic strategies. New research insights into indoles will facilitate a better understanding of their druggability and application in intestinal and liver diseases.

Thyroid Hormone Nuclear Receptor TRα1 and Canonical WNT Pathway Cross-Regulation in Normal Intestine and Cancer

A pivotal role of thyroid hormones and their nuclear receptors in intestinal development and homeostasis have been described, whereas their involvement in intestinal carcinogenesis is still controversial. In this perspective article we briefly summarize the recent advances in this field and present new data regarding their functional interaction with one of the most important signaling pathway, such as WNT, regulating intestinal development and carcinogenesis. These complex interactions unveil new concepts and will surely be of importance for translational research.

Molecule which changed the view on skin treatment

Objective — to study the modern classification, mechanisms of action and clinical effects of vitamin A derivatives, to analyze retinoid for local treatment of various dermatoses with a universal mechanism of action at the epidermis and dermis levels. Materials and methods. A review of the literature and an analysis of the results of international clinical trials of drugs based on the natural retinoid of the first generation — tretinoin (retinoic acid) is presented. The works of dozens of authors since 1980s to the present day are analyzed. Most sources provide detailed information on the results of topical retinoids in acne therapy, which are the base of clinical guidelines. Long-term (6 months or more) studies of retinoic acid-based preparations carried out in recent decades have discovered the unique clinical effects of tretinoin in the treatment of skin photoaging, actinic keratosis, etc. They are achieved due to the effect of tretinoid on the nuclear receptors of keratinocytes and fibroblasts. Results and discussion. The molecular mechanisms of action of retinoic acid, realizing the cellular and tissue effects of the most studied retinoid, are systematized and grouped in a single review. It has been proven that a unique feature of tretinin is its ability to activate directly all subtypes of RARs- and, indirectly, RARs-nuclear receptors of skin cells. A new modern drug for external use is presented — AltrenoТМ lotion containing micronized 0.05 % tretinoin in combination with sodium hyaluronate, soluble collagen and glycerin. This combination exhibits the expected clinical efficacy in acne therapy and prevents side effects such as dryness, redness and exfoliation. AltrenoТМ is approved for use in children of 9 years of age and older. Conclusions. Tretinoin (retinoic acid) is a modern powerful retinoid with a universal mechanism of action, recommended for the treatment of acne.