Angiotensin converting enzyme-2 (ACE2) is the receptor for the coronavirus SARS-CoV-2, which causes COVID-19. We propose the following hypothesis: Imbalance in the action of ACE1- and ACE2-derived peptides, thereby enhancing Angiotensin-II (ANG II) signaling, a primary driver of COVID-19 pathobiology. ACE1/ACE2 imbalance occurs due to the binding of SARS-CoV-2 to ACE2, reducing ACE2-mediated conversion of ANG II to ANG peptides that counteract pathophysiological effects of ACE1-generated ANGII. This hypothesis suggests several approaches to treat COVID-19 by restoring ACE1/ACE2 balance: 1) ANG II receptor blockers (ARBs); 2) ACE1 inhibitors (ACEIs); 3) Agonists of receptors activated by ACE2-derived peptides [e.g., ANG (1-7), which activates MAS1]; 4) Recombinant human ACE2 or ACE2 peptides as decoys for the virus. Reducing ACE1/ACE2 imbalance is predicted to blunt COVID-19-associated morbidity and mortality, especially in vulnerable patients. Importantly, approved ARBs and ACEIs can be rapidly repurposed to test their efficacy in treating COVID-19.
Background and Purpose: The promotion of hair regeneration and growth heavily depends on the activation of Wnt/β-catenin signaling in the hair follicle including dermal papilla (DP). KY19382, one of the newly synthesized analogs of indirubin-3’-monoxime (I3O) was identified as a Wnt/β-catenin signaling activator via inhibition of the interaction between CXXC-type zinc finger protein 5 (CXXC5) and Dishevelled (Dvl) interaction. Given the close relationship between the Wnt/β-catenin signaling and hair regeneration, we investigated the effect of KY19382 on hair re-growth and hair follicle neogenesis. Experimental Approach: In vitro hair induction effects of KY19382 was performed in human dermal papilla cells. The hair elongation effects of KY19382 was confirmed through the vibrissa culture system. In vivo hair regeneration abilities of KY19382 was identified in three models: hair regrowth, wound-induced hair follicle neogenesis (WIHN), and hair patch assays using C57BL/6 mice. The hair regeneration abilities were analyzed by immunoblotting, alkaline phosphatase (ALP) and immunohistochemical staining. Key results: KY19382 activated Wnt/β-catenin signaling and elevated the expression of ALP and proliferation marker PCNA in DP cells. KY19382 also increased hair length in ex vivo cultured mouse vibrissa follicles and induced hair regrowth in mice. Moreover, KY19382 significantly promoted the generation of de novo hair follicles as shown by WIHN and hair patch assays. Conclusion and Implications: These results indicate that KY19382 is a potential therapeutic drug that exhibits effective hair regeneration ability via activation of the Wnt/β-catenin signaling for alopecia treatments.
In this review, we identify opportunities for drug discovery in the treatment of COVID-19 and in so doing, provide a rational roadmap whereby pharmacology and pharmacologists can mitigate against the global pandemic. We assess the scope for targetting key host and viral targets in the mid-term, by first screening these targets against drugs already licensed; an agenda for drug re-purposing, which should allow rapid translation to clinical trials. A simultaneous, multi-pronged approach using conventional drug discovery methodologies aimed at discovering novel chemical and biological means targetting a short-list of host and viral entities should extend the arsenal of anti-SARS-CoV-2 agents. This longer-term strategy would provide a deeper pool of drug choices for future-proofing against acquired drug resistance. Second, there will be further viral threats, which will inevitably evade existing vaccines. This will require a coherent therapeutic strategy which pharmacology and pharmacologists are best placed to provide.
Vaccines have reduced the transmission and severity of COVID-19 but there remains a paucity of efficacious treatment for drug resistant strains and more susceptible individuals. Repurposing existing drugs is a timely, safe and scientifically robust method for treating pandemics such as COVID-19. Here, we review the pharmacology and scientific rationale for repurposing niclosamide, an anti-helminth already in human use as a treatment for COVID-19. In addition to potent antiviral activity, niclosamide has shown pleiotropic anti-inflammatory, antibacterial, bronchodilatory and anticancer effects in numerous pre-clinical and early clinical studies. The advantages and rationale for nebulised and intranasal formulations of niclosamide, which target the site of primary infection in COVID-19, are reviewed. Finally, we discuss the TACTIC-E clinical trial, an international COVID-19 therapeutic platform trial for the use of licensed and novel therapeutic agents, which is investigating niclosamide as a promising candidate against SARS-CoV-2.
Background and Purpose: Traumatic hemorrhage (TH) is the leading cause of potentially preventable deaths that occur during the prehospital phase of care. No effective pharmacological therapeutics are available for critical TH patients yet. Here, we identify terminal complement activation (TCA) as a therapeutic target in combat casualties and evaluate the efficacy of TCA inhibitor (nomacopan) on organ damage and survival in vivo. Experimental Approach: Complement activation products and cytokines were analyzed in plasma from 54 combat casualties, and the correlations between activated complement pathway(s) and the clinical outcomes in trauma patients were assessed. Nomacopan was administrated to rats subjected to lethal TH (blast injury and hemorrhagic shock). Effects of nomacopan on TH were determined using survival rate, organ damage, physiologic parameters, and laboratory profiles. Key Results: Early TCA was found to be associated with systemic inflammatory responses and clinical outcomes in this trauma cohort. Lethal TH in the untreated rats induced early TCA that correlated with severity of tissue damage and mortality. The addition of nomacopan to a damage control resuscitation (DCR) protocol significantly inhibited TCA, decreased local and systemic inflammatory responses, improved hemodynamics and metabolism, attenuated tissue and organ damage, and increased survival. Conclusion and Implications: Our findings reveal that early TCA represents a rational therapeutic target for trauma patients; and nomacopan as a prosurvival and organ-protective drug, could emerge as a promising adjunct to DCR that may significantly reduce the morbidity and mortality in severe TH patients while awaiting transport to critical care facilities.
Prostate cancer (PCa) is the second most common malignancy in men, and androgen deprivation therapy (ADT) is the first-line therapy. However, most cases will eventually develop into castration-resistant prostate cancer (CRPC) after ADT treatment. Enzalutamide (Enz) is a second-generation androgen receptor inhibitor approved by the Food and Drug Administration to treat patients with CRPC. Unfortunately, patients receiving Enz treatment will ultimately develop resistance via various complicated mechanisms. In this review, we introduce the emerging information on resistance mechanisms, including androgen receptor-related signalling pathways, glucocorticoid receptor-related pathways, and metabolic mechanisms. Notably, lineage plasticity and phenotype switching, gene polymorphisms, and the relationship between microRNAs and drug resistance are addressed. Furthermore, potential therapeutic strategies for Enz-resistant CRPC treatment are suggested, which can help in the discovery of more effective and specific regimens to overcome Enz resistance.
Background and Purpose: In recent decades, a focus on the most critical and fundamental concepts has proven highly advantageous to students and educators in many science disciplines. Pharmacology, unlike microbiology, biochemistry or physiology, lacks a consensus list of such core concepts. Experimental approach: We sought to develop a research-based, globally relevant list of core concepts that all students completing a foundational pharmacology course should master. This two-part project consisted of exploratory and refinement phases. The exploratory phase involved empirical data mining of the introductory sections of five key textbooks, in parallel with an online survey of over 200 pharmacology educators from 17 countries across six continents. The refinement phase involved three Delphi rounds involving 24 experts from 15 countries across six continents. Key Results: The exploratory phase resulted in a consolidated list of 74 candidate core concepts. In the refinement phase, the expert group produced a consensus list of 25 core concepts of pharmacology. Conclusion and Implications: This list will allow pharmacology educators everywhere to focus their efforts on the conceptual knowledge perceived to matter most by experts within the discipline. Next steps for this project include defining and unpacking each core concept and developing resources to help pharmacology educators globally teach and assess these concepts within their educational contexts.
The complement system is an ancient part of innate immunity sensing highly pathogenic coronaviruses by Mannan-binding lectin resulting in lectin pathway-activation and subsequent generation of the anaphylatoxins (AT) C3a and C5a as important effector molecules. Complement deposition in endothelial cells and high blood C5a serum levels have been reported in COVID-19 patients with severe illness, suggesting vigorous complement activation leading to systemic thrombotic microangiopathy (TMA). Strikingly, SARS-CoV-2-infected African Americans suffer from high mortality. Complement regulator gene variants prevalent in African Americans have been associated with a higher risk for severe TMA and multi-organ injury. These findings allow us to apply our knowledge from other complement-mediated diseases to COVID-19 infection to better understand severe disease pathogenesis. Here we will discuss the multiple aspects of complement activation, regulation, crosstalk with other parts of the immune system and the options to target complement in COVID-19 patients to halt disease progression and death.
COVID-19 is a complex disease and many difficulties are faced today especially in the proper choice of pharmacological treatments. The role of antiviral agents for COVID-19 is still being investigated. The evidence for immunomodulatory and anti-inflammatory drugs is quite conflicting, while the use of corticosteroids is supported by robust evidence. The use of heparins in hospitalized critically ill patients is preferred over other anticoagulants. Lastly, conflicting data were found regarding to the use of convalescent plasma and vitamin D. According to data shared by the WHO, many vaccines are under phase 3 clinical trials and some of them already received the marketing approval in EU countries and in the US. In conclusion, drugs repurposing has represented the main approach recently used in the treatment of patients with COVID-19. At this moment, the analysis of efficacy and safety data of drugs and vaccines used in real life context is strongly needed.
Background and Purpose: Pancreatic cancer is an exceptionally fatal disease. However, therapeutic drugs for pancreatic cancer have presented a serious shortage over the past few decades. Signal Transducer and Activator of Transcription-3 (STAT3) is persistently activated in many human cancers where it promotes tumor development and progression. Natural products serve as an inexhaustible source of anticancer drugs. Here, we identified the natural product Trienomycin A (TA), an ansamycin antibiotic, as a potential inhibitor of the STAT3 pathway with potent activity against pancreatic cancer. Experimental Approach: Utilizing the STAT3-luciferase (STAT3-luc) reporter system, we found that TA potently inhibits the transcriptional activity of STAT3. We subsequently investigated in vitro and in vivo inhibitory activity of TA against pancreatic cancer and its potential mechanism by using the molecular docking, SPR assay, MTS assay, colony formation assay, transwell migration/invasion assay, flow cytometric analysis, immunofluorescence staining, quantitative real-time PCR, western blotting, tumor xenograft model, H&E staining and immunohistochemistry. Key Results: TA directly bound to STAT3 and inhibited STAT3 (Tyr705) phosphorylation, leading to the inhibition of the STAT3 pathway. TA significantly inhibited the colony formation, proliferation, migration and invasion of pancreatic cancer cell lines. TA dramatically blocked pancreatic tumor growth. More importantly, TA did not show obvious toxicity at the effective dose in mice. Conclusions and Implications: TA exhibits antineoplastic activity by suppressing the STAT3 activation in pancreatic cancer. TA could be a novel therapeutic candidate for pancreatic cancer by blocking the STAT3 pathway.
Sepsis causes multi-organ dysfunction and is a major cause of death in intensive care units, but there are no treatments that reverse the pathophysiological effects of sepsis. Vitamin C has antioxidant, anti-inflammatory, anticoagulant and immune modulatory actions, so is a potential treatment for sepsis. Recent clinical trials of high-doses of intravenous vitamin C (6-16 g/day) had variable effects. Since much higher doses are without side-effects in cancer and burns patients, we studied the effects of a mega-dose of intravenous sodium ascorbate (150 g/40 kg) in a clinically relevant ovine model of sepsis. This treatment dramatically improved the clinical state and over 3-7-h improved cardiovascular, pulmonary, hepatic and renal function and reduced body temperature. In a critically ill COVID-19 patient, intravenous sodium ascorbate (60 g) restored arterial pressure, improved renal function and increased arterial blood oxygen levels. Clinical trials are testing the effectiveness of mega-dose vitamin C in septic patients.
COVID-19, the disease resulting from infection by a novel coronavirus: SARS-Cov2 that has rapidly spread since November 2019 leading to a global pandemic. SARS-Cov2 has infected over 2.8 million people and caused over 180,000 deaths worldwide. Although most cases are mild, a subset of patients develop a severe and atypical presentation of Acute Respiratory Distress Syndrome (ARDS) that is characterised by a cytokine release storm (CRS). Paradoxically, treatment with anti-inflammatory agents and immune regulators has been associated with worsening of ARDS. We hypothesize that the intrinsic circadian clock of the lung and the immune system may regulate individual components of CRS and thus chronotherapy may be used to effectively manage ARDS in COVID-19 patients.
Thrombosis contributes to one in four deaths worldwide and is the cause of a large proportion of mortality and morbidity. A reliable and rapid diagnosis of thrombosis will allow for immediate therapy, thereby providing significant benefits to patients. Molecular imaging is a fast-growing and captivating area of research, in both preclinical and clinical applications. Major advances have been achieved by improvements in three central areas of molecular imaging: 1) Better markers for diseases, with increased sensitivity and selectivity; 2) Optimised contrast agents with improved signal to noise ratio; 3) Progress in scanner technologies with higher sensitivity and resolution. Clinically available imaging modalities used for molecular imaging include, magnetic resonance imaging (MRI), X-ray computed tomography (CT), ultrasound, as well as nuclear imaging, such as positron emission tomography (PET) and single photon emission computed tomography (SPECT). In the preclinical imaging field, optical (fluorescence and bioluminescent) molecular imaging has provided new mechanistic insights in the pathology of thrombembolic diseases. Overall, the advances in molecular imaging, driven by the collaboration of various scientific disciplines, have substantially contributed to an improved understanding of thrombotic disease, and raises the exciting prospect of earlier diagnosis and individualised therapy for cardiovascular diseases. As such, these advances hold significant promise to be translated to clinical practice and ultimately to reduce mortality and morbidity in patients with thromboembolic diseases.
Background and Purpose Refractory status epilepticus is a clinical emergency associated with high mortality and morbidity. Increasing evidence suggests neuroinflammatory pathways contribute to the development of drug-refractoriness during status epilepticus. The ATP-gated P2X7 receptor (P2X7R) has been described as potential link between inflammation and increased hyperexcitability. The aim of the present study was to determine the contribution of the P2X7R to drug-refractory status epilepticus and its therapeutic potential. Experimental Approach Status epilepticus was induced via a unilateral microinjection of kainic acid into the amygdala in adult mice. Severity of status epilepticus was compared in animals overexpressing or knock-out in the P2X7R, after inflammatory priming by the pre-injection of bacterial lipopolysaccharide (LPS) and in mice treated with P2X7R-targeting and anti-inflammatory drugs. Key Results P2X7R overexpressing mice were unresponsive to several anticonvulsants (lorazepam, midazolam, phenytoin and carbamazepine) during status epilepticus. P2X7R expression was increased in microglia during drug-refractory status epilepticus, P2X7R overexpression led to a pro-inflammatory phenotype in microglia during status epilepticus and the anti-inflammatory drug minocycline restored normal responsiveness to anticonvulsants in P2X7R overexpressing mice. Pre-treatment of wildtype mice with LPS increased P2X7R levels in the brain and promoted the development of pharmaco-resistant status epilepticus, which was overcome by either a genetic deletion of the P2X7R or the administration of the P2X7R antagonists AFC-5128 or ITH15004. Conclusion and Implications Our results demonstrate that P2X7R-induced pro-inflammatory effects contribute to resistance to pharmacotherapy during status epilepticus and suggest therapies targeting the P2X7R as novel adjunctive treatments for drug-refractory status epilepticus.
Background and Purpose: Individualized assessment of the activity of cytochrome P450 2D6 (CYP2D6), a highly variable drug-metabolizing enzyme, is performed through phenotyping during which a probe drug is administered to measure the enzyme’s activity. In order to avoid any iatrogenic harm (allergic drug reaction, dosing error) related to the probe drug, the development of non-invasive tools for real-time phenotyping of CYP2D6 could significantly contribute to the expansion of precision medicine in clinical practice. This study focuses on the identification of endogenous markers of the CYP2D6 enzyme in human biofluids using a liquid chromatography (LC)-high-resolution mass spectrometry (HRMS)-based metabolomics approach. Experimental Approach: Data from a control session were compared to data from an inhibition session. Before the latter, healthy volunteers (extensive and ultrarapid metabolizers) received a daily dose of paroxetine 20 mg over seven days. CYP2D6 genotyping and phenotyping, using single oral dose of dextromethorphan 5 mg, were also performed in all participants. Key Results: In CYP2D6 extensive and ultrarapid metabolizers (n = 37), mean relative intensities of five features were significantly reduced during the inhibition session compared to the control session (fold changes ≤ 0.67, FDR-adjusted P < 0.0001). Furthermore, mean relative intensities of these candidates were significantly higher in the CYP2D6 extensive-ultrarapid metabolizer group (n = 37) compared to the poor metabolizer group (n = 6) (fold changes ≤ 0.67, P < 0.0001). Conclusion and Implications: The applied untargeted metabolomics strategy was able to identify five CYP2D6 endogenous metabolites, a promising discovery for non-invasive phenotyping and personalised medicine.
Intense effort is underway to evaluate potential therapeutic agents for the treatment of COVID-19. In order to respond quickly to the crisis, the repurposing of existing drugs is the primary pharmacological strategy. Despite the urgent clinical need for these therapies, it is imperative to consider potential safety issues. This is important due to the harm-benefit ratios that may be encountered when treating COVID-19, which can depend on the stage of the disease, when therapy is administered and underlying clinical factors in individual patients. Treatments are currently being trialled for a range of scenarios from prophylaxis (where benefit must greatly exceed risk) to severe life-threatening disease (where a degree of potential risk may be tolerated if it is exceeded by the potential benefit). In this perspective, we have reviewed some of the most widely-researched repurposed agents in order to identify potential safety considerations using existing information in the context of COVID-19.
Background and Purpose: Quercetin is a prominent neuroprotective compound from flavonoids. Previous studies found it may relieve psychiatric disorders, cognition deficits, and memory dysfunction through anti-oxidation and/or radical scavenging mechanisms. In addition, Quercetin also was found to modulate the physiological function of a few types of ion channels. However, the detailed ionic mechanisms of quercetin’s bioeffect remain unknown. Experimental Approach: We examined the effect neuronal activities changes in prefrontal cortex (PFC) and its ionic mechanisms upon quercetin application by using GCaMP calcium imaging and patch clamp in acute brain slices. Then we explored the potential ionic mechanism of quercetin on D-amphetamine induced manic-like using c-fos staining and the open field behavior test. Key Results: Quercetin reduced calcium influx triggered by PFC pyramidal neuronal activity. This effect was caused by increasing the rheobase of neuronal firing through decreasing membrane resistance upon quercetin treatment. Spadin, a TREK-1 potassium channel (a two-pore-domain background potassium channel) inhibitor, could block the effect of quercetin on the membrane resistance and neuronal firing. And also, Spadin can block the neural protective effects of quercetin. In addtion, intraperitoneal injection of quercetin could relieve the manic hyperlocomotion of the mice induced by D-amphetamine, which can be partially alleviated by Spadin. Conclusion and Implications: Our results demonstrated that TREK-1 channel is a novel target on quercetin treatment, which could contribute to both the neuroprotection and anti-manic-like effects.
Background and Purpose: Many psychotherapeutic drugs, including clozapine, display polypharmacology and act on GABAA receptors. Patients with schizophrenia show alterations in function, structure and molecular composition of the hippocampus, and a recent study demonstrated aberrant levels of hippocampal a5 subunit-containing GABAA receptors. The purpose of this study is to investigate tricyclic compounds in a5 subunit-containing receptor subtypes.Experimental Approach: Functional studies of effects by seven antipsychotic and antidepressant medications were performed in several GABAA receptor subtypes by two‐electrode voltage‐clamp electrophysiology using Xenopus laevis oocytes. Computational structural analysis was employed to design mutated constructs of the a5 subunit, probing a novel binding site. Radioligand displacement data complemented the functional and mutational findings. Key Results: We show that the antipsychotic drugs clozapine and chlorpromazine exert functional inhibition on multiple GABAA receptor subtypes, including a5-containing ones. Based on a chlorpromazine binding site observed in a GABA-gated bacterial homologue, we identified a novel site in a5 GABAA receptor subunits and demonstrate differential usage of this and the orthosteric sites by these ligands.Conclusion and Implications: Despite high molecular and functional similarities among the tested ligands, they reduce GABA currents by differential usage of allosteric and orthosteric sites. The C C C C C C site we describe here is a new potential target for optimizing antipsychotic medications with beneficial polypharmacology. Further studies in defined subtypes are needed to substantiate mechanistic links between the therapeutic effects of clozapine and its action on certain GABAA receptor subtypes.