Current Medicinal Chemistry - Volume 29, Issue 23, 2022

Background: The current coronavirus disease 2019 (COVID-19) pandemic, since first reported in Wuhan, has inspired worldwide efforts to develop effective COVID-19 vaccination strategies. mRNA vaccines encoding COVID-19 antigens have emerged prominantlyin this global race due to their high effectiveness and simple manufacturing process. Notably, two COVID-19 mRNA vaccines, mRNA-1273 and BNT162b2, have survived in clinical trials and been authorized for emergency use across variouscountries. Summary: Recent advances on mRNA vaccine development for COVID-19 are discussed in this perspective, including sequence design, chemical modification, manufacturing process, and in vivo delivery. Phase I to IV clinical trials of mRNA-1273 and BNT162b2 are then summarized, respectively. Conclusion: Using mRNA vaccines is a promising strategy to achieve mass vaccination in the COVID-19 pandemic. We hope that future studies of mRNA vaccine technology will overcome existing limitations and help people cope with COVID-19.

Carbon dots (CDs), an emerging nanoagent providing an alternative to conventional fluorescent agents, are sparking the scientist’s interest in biomedical applications owing to their unique advantages, including ease of synthesis, large scale production, low cost, prominent photoluminescence, good photostability, easy functionalization, sufficient biocompatibility, good nanocarrier, and excellent ability to generate reactive oxygen species or heat. Herein, this perspective provides a viewpoint about imaging-assisted biomedical applications using fluorescent CDs regarding in vitro and in vivo bioimaging, imaging-assisted sensing, and imaging-guided therapy. The opinions about their potential and challenges in applicable biomedical applications are discussed to develop, further ameliorated CDs for their intense exploitation in diverse imaging-assisted biomedical applications.

During the last decade, the understanding of the biological functions of cholesterol biosynthesis intermediates has changed significantly. Particularly, the enzyme sterol dehydrocholesterol reductase 24 (DHCR24) has taken center stage as a potential drug target. Inhibition of DHCR24 leads to accumulation of the endogenous, biologically active metabolite cholesta-5,24-dien-3β-ol (desmosterol). Desmosterol is an endogenous agonist of the liver X receptor (LXR). LXR is a master regulator of lipid metabolism and, as such, is involved in numerous pathophysiological processes such as inflammation, atherosclerosis, cancer, diabetes mellitus (DM), multiple sclerosis (MS), nonalcoholic steatohepatitis (NASH), and the progression of viral infections. Up to now, selective pharmacological targeting of LXR without activating the sterol-response element binding proteins (SREBP) and thereby boosting endogenous lipid biosynthesis has not been achieved. In turn, no selective LXR receptor agonists leveraging its beneficial activation have yet reached the clinic. Therefore, using potent and selective inhibitors of DHCR24 leading to an accumulation of endogenous desmosterol is a promising alternative strategy for the selective activation of LXR. Here we summarize the present landscape of novel lead structures for targeting DHCR24, covering steroidal enzyme inhibitors (e.g., 20,25-diazacholesterol, SH42) as well as nonsteroidal scaffolds (e.g., amiodarone, triparanol). Further, we explain the molecular mechanisms of DHCR24 inhibition/LXR activation, discuss possible therapeutic applications, and underpin why DHCR24 is an upcoming promising drug target.

Obesity leads to several metabolic disorders and, unfortunately, current pharmacological treatments for obesity are not very effective. In feeding mechanisms, the hypothalamus and some neuropeptides play an important role. Many data show that neuropeptide Y (NPY) is involved in these mechanisms. The aim of this review is to update the physiological actions mediated by the orexigenic peptide NPY, via its receptors, in the control of food intake and to review its involvement in food intake disorders. The relationships between NPY and other substances involved in food intake mechanisms, hypothalamic and extra-hypothalamic pathways involved in feeding and the potential pharmacological strategies to treat obesity will be discussed. Some research lines, focused on NPY, to be developed in the future are suggested. Neuropeptide systems are associated with redundancy and then therapies directed against a single target are generally ineffective. For this reason, other targets for the treatment of obesity are mentioned. It seems that combination therapies are the best option for successful anti-obesity treatments: new and more specific NPY receptor antagonists must be tested as anti-obesity drugs alone and in combination therapies.

The gut microbiome interacts with host physiology through various mechanisms, including the cardiovascular (CV) system. A healthy microbiome has the ability to process and digest complex carbohydrates into short-chain fatty acids (SCFA). These SCFA function as signaling molecules, immune-modulating molecules, and energy sources. However, when the microbiome is altered, it produces gut dysbiosis with overgrowth of certain bacteria that may lead to overproduction of trimethylamine-N-oxide (TMAO) from the metabolism of phosphatidylcholine, choline, and carnitine; dysbiosis also leads to increased intestinal permeability allowing the microbiome-derived lipopolysaccharide (LPS), a bacterial endotoxin, to enter the blood circulation, triggering inflammatory responses. An altered gastrointestinal (GI) tract environment and microbiome- derived metabolites are associated with CV events. Disrupted content and function of the microbiome leading to elevated TMAO and LPS levels, altered bile acid metabolism pathways, and SCFA production are associated with an increased risk of CV diseases (CVD), including atherosclerosis, myocardial infarction, thrombosis, arrhythmias, and stroke. Therapeutic interventions that may favorably influence a dysbiotic GI tract profile and promote a healthy microbiome may benefit the CV system and lead to a reduction of CVD incidence in certain situations. These issues are herein reviewed with a focus on the spectrum of microbiota-related CVD, the mechanisms involved, and the potential use of microbiome modification as a possible therapeutic intervention.

Cancer, a challenging medical problem, affects millions of people around the world. Cancer cell resistance is one of the main drawbacks in the complete prosperity of even more sophisticated therapies. Pore-forming peptides (PFPs), a group of natural defense system proteins are used by nearly all living organisms as anti-bacterial and anti-- fungal agents, and could also be regarded as novel tumoricidal peptides. PFPs approach entails using soluble peptides by assembling them mainly on the target cell membrane and forming potential death-causing pores. Physical damage induction by natural PFPs or their synthetic derivatives could conquer the resistance mechanisms of tumor cells. Given that peptide drugs involve a significant proportion of the pharmaceutical market primarily because of easy synthesis and safety, evaluating this nature provided a model system as a group of anticancer peptides seems a valuable approach. Here, the mode of action of PFPs and their anticancer mechanism are highlighted, followed by addressing the anticancer studies using PFPs from different sources along with various strategies applied to obtain selective action of PFPs against cancer cells. Challenges and future perspectives of these promising bioactive molecules in cancer treatment are also provided.

Background: The survival of premature newborns increased in the last decades due to advances in neonatal care. The physiology of this group is still under investigation, once the incomplete organogenesis entails functional particularities that are not yet clarified by current clinical knowledge. The immature kidneys are especially susceptible to acute injury with potential long-term impacts. Current diagnostic parameters of acute kidney injury are limited among the preterm population. The commonly used serum creatinine protein constitutes a poor biomarker to predict early lesions as it is susceptible to several factors, including muscle mass and gestational age. Objective: The present review explores the evidence on nephrogenesis, renal function, and acute kidney injury in neonatology, as well as studies on renal function biomarkers and their potential application for diagnosis, follow-up, and prognosis in preterm newborns. Results: Premature newborns reach full-term gestational age with reduced number and quality of nephrons. Consequently, the glomerular filtration rate and tubular function become impaired and are proportional to the gestational age. Despite having a high incidence among the pediatric population, acute kidney injury is still underdiagnosed and poorly managed due to the absence of proper, sensible, and non-invasive biomarkers. Although cystatin C, NGAL, and KIM-1, are promising urinary markers, current literature remains inconsistent. Conclusion: Further research is needed to properly identify and standardize sensible and specific urinary biomarkers to better assess kidney function in preterm newborns.

In recent years, cyclobutyl has become more influential in the field of drug design. Its unique four-membered ring structure is not only a useful intermediate for the synthesis of biomedical candidate materials but also an indispensable framework for drug design and application. According to the therapeutic field, cyclobutyl drugs are roughly divided into tumor and cancer drugs, nervous system drugs, analgesics, antiviral drugs, and gastrointestinal drugs. Among them, platinum-based anticancer drugs containing cyclobutyl fragments have achieved remarkable success in the treatment of cancer, bringing new hope for the development of more cyclobutyl drugs. This article provides details of the research progress of the structure types, structure-activity relationships, targets, and mechanisms of cyclobutyl drugs that have been on the market or are in the clinical stage and provides ideas for the discovery and synthesis of novel cyclobutyl-containing drugs.