Development of an automated, high-throughput assay to detect angiotensin AT2-receptor agonistic compounds by nitric oxide measurements in vitro.

Angiotensin AT2-receptor (AT2R) agonists have shown a wide range of protective effects in many preclinical disease models. However, the availability of AT2R-agonists is very limited due to the lack of high-throughput assays for AT2R-agonist identification. Therefore, we aimed to design and validate an assay for high-throughput screening of AT2R-agonist candidates. The assay is based on nitric oxide (NO) release measurements in primary human aortic endothelial cells (HAEC), in AT2R-transfected CHO cells (AT2R-CHO) or in non-transfected CHO cells (Flp-CHO) using the fluorescent probe DAF-FM diacetate. It is run in 96-well plates and fluorescence signals are semi-automatically quantified. The assay was tested for sensitivity (recognition of true positive results), selectivity (recognition of true negative results), and reliability (by calculating the repeatability coefficient (RC)). The high-throughput, semi-automated method was proven suitable, as the NO-releasing agents C21, CGP42112A, angiotensin-(1-7) and acetylcholine significantly increased NO release from HAEC. The assay is sensitive and selective, since the established AT2R-agonists C21, CGP42112A and angiotensin II significantly increased NO release from AT2R-CHO cells, while the non-AT2R-agonists angiotensin-(1-7) and acetylcholine had no effect. Assay reliability was shown by high-throughput screening of a library comprised of 40 potential AT2R-agonists, of which 39 met our requirements for reliability (RC ≤ 20% different from RC for C21). Our newly developed high-throughput method for detection of AT2R-agonistic activity was proven to be sensitive, selective, and reliable. This method is suitable for the screening of potential AT2R-agonists in future drug development programs.

Neurofilament light chain as a biomarker of axonal damage in sensory neurons and paclitaxel-induced peripheral neuropathy in patients with ovarian cancer.

ABSTRACT: Paclitaxel-induced peripheral neuropathy (PIPN) is a barrier to effective cancer treatment and impacts quality of life among patients with cancer. We used a translational approach to assess the utility of neurofilament light chain (NFL) as a biomarker of PIPN in a human cell model and in patients with ovarian cancer. We measured NFL in medium from human induced pluripotent stem cell-derived sensory neurons (iPSC-SNs) exposed to paclitaxel. Serum NFL (sNFL) levels were quantified in 190 patients with ovarian cancer receiving paclitaxel/carboplatin chemotherapy at baseline and after each of the following 2 or 6 cycles. Adverse outcomes related to PIPN were retrospectively obtained, and Cox regression model was performed with different sNFL cut-offs after first cycle. The apparent elimination half-life of sNFL was estimated in patients who discontinued paclitaxel. Paclitaxel neurotoxicity in iPSC-SNs was accompanied by NFL release in a concentration-dependent manner ( P < 0.001, analysis of variance). Serum NFL levels increased substantially in patients during paclitaxel/carboplatin chemotherapy with considerable interindividual variability. Patients with sNFL >150 pg/mL after first cycle had increased risk to discontinue paclitaxel early (unadjusted HR: 2.47 [95% CI 1.16-5.22], adjusted HR: 2.25 [95% CI: 0.88-5.79]). Similar trends were shown for risk of severe PIPN and paclitaxel dose reduction because of PIPN. The median elimination half-life of sNFL was 43 days (IQR 27-82 days). Neurofilament light chain constitutes an objective biomarker of neurotoxicity in iPSC-SNs and in ovarian cancer patients with high sNFL predicting PIPN-related adverse outcomes. If prospectively validated, NFL can be used to study PIPN and may guide clinical decision making and personalize treatment with paclitaxel.

Bridging the Translational Gap in Chemotherapy-Induced Peripheral Neuropathy with iPSC-Based Modeling.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and potentially serious adverse effect of a wide range of chemotherapeutics. The lack of understanding of the molecular mechanisms underlying CIPN limits the efficacy of chemotherapy and development of therapeutics for treatment and prevention of CIPN. Human induced pluripotent stem cells (iPSCs) have become an important tool to generate the cell types associated with CIPN symptoms in cancer patients. We reviewed the literature for iPSC-derived models that assessed neurotoxicity among chemotherapeutics associated with CIPN. Furthermore, we discuss the gaps in our current knowledge and provide guidance for selecting clinically relevant concentrations of chemotherapy for in vitro studies. Studies in iPSC-derived neurons revealed differential sensitivity towards mechanistically diverse chemotherapeutics associated with CIPN. Additionally, the sensitivity to chemotherapy was determined by donor background and whether the neurons had a central or peripheral nervous system identity. We propose to utilize clinically relevant concentrations that reflect the free, unbound fraction of chemotherapeutics in plasma in future studies. In conclusion, iPSC-derived sensory neurons are a valuable model to assess CIPN; however, studies in Schwann cells and motor neurons are warranted. The inclusion of multiple iPSC donors and concentrations of chemotherapy known to be achievable in patients can potentially improve translational success.

Tutorial: Statistical analysis and reporting of clinical pharmacokinetic studies.

Pharmacokinetics is the cornerstone of understanding drug absorption, distribution, metabolism, and elimination. It is also the key to describing variability in drug response caused by drug-drug interactions (DDIs), pharmacogenetics, impaired kidney and liver function, etc. This tutorial aims to provide a guideline and step-by-step tutorial on essential considerations when designing clinical pharmacokinetic studies and reporting results. This includes a comprehensive guide on how to conduct the statistical analysis and a complete code for the statistical software R. As an example, we created a mock dataset simulating a clinical pharmacokinetic DDI study with 12 subjects who were administered 2 mg oral midazolam with and without an inducer of cytochrome P450 3A. We provide a step-by-step guide to the statistical analysis of this clinical pharmacokinetic study, including sample size/power calculation, descriptive statistics, noncompartmental analyses, and hypothesis testing. The different analyses and parameters are described in detail, and we provide a complete R code ready to use in supplementary files. Finally, we discuss important considerations when designing and reporting clinical pharmacokinetic studies. The scope of this tutorial is not limited to DDI studies, and with minor adjustments, it applies to all types of clinical pharmacokinetic studies. This work was done by early career researchers for early career researchers. We hope this tutorial may help early career researchers when getting started on their own pharmacokinetic studies. We encourage you to use this as an inspiration and starting point and continuously evolve your statistical skills.

Clinical and Molecular Perspectives on Inflammation-Mediated Regulation of Drug Metabolism and Transport.

Inflammation is a possible cause of variability in drug response and toxicity due to altered regulation in drug-metabolizing enzymes and transporters (DMETs) in humans. Here, we evaluate the clinical and in vitro evidence on inflammation-mediated modulation of DMETs, and the impact on drug metabolism in humans. Furthermore, we identify and discuss the gaps in our current knowledge. A systematic literature search on PubMed, Embase, and grey literature was performed in the period of February to September 2020. A total of 203 papers was included. In vitro studies in primary human hepatocytes revealed strong evidence that CYP3A4 is strongly downregulated by inflammatory cytokines IL-6 and IL-1ß. CYP1A2, CYP2C9, CYP2C19, and CYP2D6 were downregulated to a lesser extent. In clinical studies, acute and chronic inflammatory diseases were observed to cause downregulation of CYP enzymes in a similar pattern. However, there is no clear correlation between in vitro studies and clinical studies, mainly because most in vitro studies use supraphysiological cytokine doses. Moreover, clinical studies demonstrate considerable variability in terms of methodology and inconsistencies in evaluation of the inflammatory state. In conclusion, we find inflammation and pro-inflammatory cytokines to be important factors in regulation of drug-metabolizing enzymes and transporters. The observed downregulation is clinically relevant, and we emphasize caution when treating patients in an inflammatory state with narrow therapeutic index drugs. Further research is needed to identify the full extent of inflammation-mediated changes in DMETs and to further support personalized medicine.

P-Glycoprotein Inhibition Exacerbates Paclitaxel Neurotoxicity in Neurons and Patients With Cancer.

Paclitaxel-induced peripheral neuropathy (PIPN) is a common and dose-limiting adverse event. The role of P-glycoprotein (P-gp) in the neuronal efflux of paclitaxel was assessed using a translational approach. SH-SY5Y cells were differentiated to neurons and paclitaxel toxicity in the absence and presence of a P-gp inhibitor was determined. Paclitaxel caused marked dose-dependent toxicity in SH-SY5Y-derived neurons. Paclitaxel neurotoxicity was exacerbated with concomitant P-gp inhibition by valspodar and verapamil, consistent with increased intracellular accumulation of paclitaxel. Patients with cancer treated with paclitaxel and P-gp inhibitors had a 2.4-fold (95% confidence interval (CI) 1.3-4.3) increased risk of peripheral neuropathy-induced dose modification while a 4.7-fold (95% CI 1.9-11.9) increased risk for patients treated with strong P-gp inhibitors was observed, and a 7.0-fold (95% CI 2.3-21.5) increased risk in patients treated with atorvastatin. Atorvastatin also increased neurotoxicity by paclitaxel in SH-SY5Y-derived neurons. Clinicians should be aware that comedication with P-gp inhibitors may lead to increased risk of PIPN.

An investigation of multidisciplinary complex health care interventions--steps towards an integrative treatment model in the rehabilitation of people with multiple sclerosis.

BACKGROUND: The Danish Multiple Sclerosis Society initiated a large-scale bridge building and integrative treatment project to take place from 2004-2010 at a specialized Multiple Sclerosis (MS) hospital. In this project, a team of five conventional health care practitioners and five alternative practitioners was set up to work together in developing and offering individualized treatments to 200 people with MS. The purpose of this paper is to present results from the six year treatment collaboration process regarding the development of an integrative treatment model. DISCUSSION: The collaborative work towards an integrative treatment model for people with MS, involved six steps: 1) Working with an initial model 2) Unfolding the different treatment philosophies 3) Discussing the elements of the Intervention-Mechanism-Context-Outcome-scheme (the IMCO-scheme) 4) Phrasing the common assumptions for an integrative MS program theory 5) Developing the integrative MS program theory 6) Building the integrative MS treatment model. The model includes important elements of the different treatment philosophies represented in the team and thereby describes a common understanding of the complexity of the courses of treatment. SUMMARY: An integrative team of practitioners has developed an integrative model for combined treatments of People with Multiple Sclerosis. The model unites different treatment philosophies and focuses on process-oriented factors and the strengthening of the patients' resources and competences on a physical, an emotional and a cognitive level.