Interindividual Variability In Response Research Articles

Postprandial glucose variability in type 1 diabetes: The individual matters beyond the meal

AimTo explore intraindividual (between-meals) and interindividual (between-subjects) variability of postprandial glucose response (PGR) in type 1 diabetes (T1DM). MethodsData were taken from five cross-over trials in 61 subjects with T1DM on insulin pump wherein the effects of different dietary components or the intraindividual-variability of PGR to the same meal were evaluated by CGM. Predictors (type of meal or nutrient composition) of early (iAUC0-3h), late (iAUC3-6h), total (iAUC0-6h), and time-course of postprandial blood glucose changes (iAUC3-6hminus0-3h) were evaluated using two mixed-effect linear regression models considering the patient’s identification number as random-effect. ResultsHigh-glycemic-index (HGI) and low-glycemic-index meals were the best positive and negative predictors of glucose iAUC0-3h, respectively. A Low-Fat-HGI meal significantly predicted iAUC3-6hminus0-3h (Estimate 3268; p = 0.017). Among nutrients, dietary fiber was the only significant negative predictor of iAUC0-3h (Estimate −550; p < 0.001) and iAUC0-6h (Estimate −742; p = 0.01) and positive predictor of iAUC3-6hminus0-3h (Estimate 336; p = 0.043). For all models, the random-effect patient was statistically significant (p < 0.001 by ANOVA). ConclusionBeyond the meal characteristics (including glycemic index, fat and fiber content), individual traits significantly influence PGR. Specific interindividual factors should be further identified to properly predict glucose response to meals with different composition in individuals with T1DM.

ASSOCIATION BETWEEN SPORT RELATED POLYGENIC PROFILE AND MAGNITUDE OF PHYSICAL PERFORMANCES CHANGES FOLLOWING RESISTANCE TRAINING AMONG NOVICE FIELD HOCKEY ATHLETES

Background: Studies have shown that inter-individual variation in response to resistance training is attributed to genetic variation. Aim: To correlate total genotype scores (TGS) with the magnitude of physical performances (skeletal muscle mass, muscular strength, muscular power, performance decrement, and VO2max) change, following 8 weeks of resistance training. Methods: We included forty-five (N=45) participants (age = 16.53 ± .5 years old, body mass = 61.03 ± 6.67 kg, height = 1.67±.05 m) and randomly assigned into; high intensity resistance training (n=15), moderate intensity resistance training (n=15) and a control group (n=15). They were prescribed with the same upper and lower body exercise routines. Pre- and post-test physical performances were measured. Genotyping was conducted using in-house designed allele-specific polymerase chain reaction assays. TGS for nine SNPs: Angiotensin Converting Enzyme, ACE rs1799752; Alpha-acitin-3, ACTN3 rs1815739; Adrenergic Receptor B3, ADRB3 rs4994; Angiotensinogen, AGT rs699; Bradykinin Receptor B2, BDKRB2 rs1799722; Peroxisome Proliferator-Activated Receptor Alpha, PPARA rs4253778; Peroxisome Proliferator-Activated Receptor Gamma Co-Activator 1-Alpha, PPARGC1A rs8192678; Thyrotropin Releasing Hormone Receptor, TRHR rs7832552 and Vascular Endothelial Growth Factor, VEGF rs1870377,were calculated and assigned with strength-power and endurance quality. Pearson correlation analysis was employed to investigate the correlation between TGS, and magnitude of physical performances change following intervention. Result: There is a significant correlation between strength-power TGS with lower body muscular strength (r= .65, p&lt;.01) and power (r= -.69, p&lt;.01) following moderate intensity resistance training. Conclusion: In this study, it is demonstrated that participants with higher strength-power TGS, gained greater lower body strength improvement and lesser muscular power decrement even with moderate intensity as compared to high intensity resistance training. Therefore, personalising training based on athlete’s genetic profile may optimise performance.

Impact of single-nucleotide variants and nutritional status on population pharmacokinetics of Doxorubicin, and its effect on cardiotoxicity in children with leukemia.

Doxorubicin is an important antineoplastic agent with wide interindividual variability in response to treatment and in its cardiotoxic effects. To determine the effect of genotypic status of three single-nucleotide variants in ABCC1, NCF4, and CBR3 genes and nutritional status assessed by body mass index, on the population pharmacokinetics of Doxorubicin and its cardiotoxic effects in pediatric patients with leukemia. Seventy pediatric patients treated with Doxorubicin were studied, in which 189 biological samples were obtained to determine Doxorubicin concentrations (1 to 3 samples per patient) at different times, for 20 h. Low body mass index and age ≤ 7 years were associated with decreased clearance of Doxorubicin, and female gender was associated with increased clearance of Doxorubicin. Low BMI and low height were associated with a decrease and increase, respectively, in the intercompartmental clearance (Q) of Doxorubicin. TT homozygosity of the single-nucleotide variant rs3743527 of the ABCC1 gene was associated with an increase in clearance and decreased area under the curve, AA homozygosity of the single-nucleotide variant rs1883112 of the NCF4 gene was associated with a decrease in the volume of distribution in the peripheral compartment (V2), and GG homozygosity of CBR3 rs1056892 with increasing area under the curve. Some covariates studied are directly related to the increase or decrease of the pharmacokinetic parameters of Doxorubicin. Decreased clearance, V2, and increased area under the curve were associated with systolic dysfunction, and decreased Q and V2 were associated with diastolic dysfunction. These results may contribute to the effective and safe use of Doxorubicin in pediatric patients with leukemia.

Exposure-Response Analysis of Osimertinib in Patients with Advanced Non-Small-Cell Lung Cancer.

High interindividual variability (IIV) of the clinical response to epidermal growth factor receptor (EGFR) inhibitors such as osimertinib in non-small-cell lung cancer (NSCLC) might be related to the IIV in plasma exposure. The aim of this study was to evaluate the exposure–response relationship for toxicity and efficacy of osimertinib in unselected patients with advanced EGFR-mutant NSCLC. This retrospective analysis included 87 patients treated with osimertinib. Exposure–toxicity analysis was performed in the entire cohort and survival analysis only in second-line patients (n = 45). No significant relationship between occurrence of dose-limiting toxicity and plasma exposure was observed in the entire cohort (p = 0.23, n = 86). The median overall survival (OS) was approximately two-fold shorter in the 4th quartile (Q4) of osimertinib trough plasma concentration (>235 ng/mL) than in the Q1–Q3 group (12.2 months [CI95% = 8.0–not reached (NR)] vs. 22.7 months [CI95% = 17.1–34.1]), but the difference was not statistically significant (p = 0.15). To refine this result, the exposure–survival relationship was explored in a cohort of 41 NSCLC patients treated with erlotinib. The Q4 erlotinib exposure group (>1728 ng/mL) exhibited a six-fold shorter median OS than the Q1–Q3 group (4.8 months [CI95% = 3.3-NR] vs. 22.8 months (CI95% = 10.6–37.4), p = 0.00011). These results suggest that high exposure to EGFR inhibitors might be related to worse survival in NSCLC patients.

Ontogeny and individual heterogeneity of the corticosterone stress response in a wild altricial seabird, the snow petrel (Pagodroma nivea)

In the current context of global change, there is evidence of a large inter-individual variability in the way animals physiologically respond to anthropogenic changes. In that context, the Hypothalamus-Pituitary-Adrenal (HPA) axis and the corticosterone stress response are of primary importance because they are thought to govern the ability of individuals to adjust to stress. Several studies have reported that this stress response is variable among adults and they have successfully linked this variability with abiotic and biotic factors. However, the inter-individual variability of the glucocorticoid stress response has rarely been examined during the developmental phase in wild vertebrates, and its potential ecological determinants remain unclear. In this study, we examined the ontogeny of the corticosterone stress response in an altricial seabird species (i.e., how corticosterone levels increase in response to a standardized stress protocol), the Snow petrel. We reported a strong heterogeneity of the corticosterone stress response at all ages in snow petrel chicks (11-, 20-, and 37-days old chicks). Although the magnitude of this corticosterone stress response decreases with the age of the chick, we also found that this corticosterone stress response was repeatable throughout the post-hatching developmental period (repeatability: r &amp;gt; 0.50 for stress-induced corticosterone levels after a 30-min restraint). Importantly, this glucocorticoid stress response was negatively associated with the body condition of the chicks (i.e., mass corrected for body size), and previous exposure to sampling was associated with a dampened corticosterone stress response. However, we did not find any link between parental traits (parental condition or parental corticosterone stress response), nest quality, hatching date, and the chick’s corticosterone stress response. Our study suggests that the corticosterone stress response is a consistent individual trait that is affected to some extent by post-natal conditions, and which differs among individuals very early in life.

Epigenetics of functional hypothalamic amenorrhea.

Functional hypothalamic amenorrhea (FHA) is a temporary infertility characterized by the suppression of the hypothalamic–pituitary–gonadal (HPG) axis, induced by the inhibition of the hypothalamic pulsatile secretion of the gonadotropin-releasing hormone (GnRH), in the presence of stressors, including eating disorders, excessive exercise, and psychological distress. Although the stressful factors that may lead to FHA are well-established, little is known about the inter-individual variability in response to stress and the consequent inhibition of the HPG axis. Not all women, indeed, manifest FHA in presence of stressful conditions. Recent studies highlighted a genetic contribution to FHA. Rare or polymorphic variants in genes that control the development and/or function of GnRH neurons may contribute, indeed, to the adaptability of the reproductive axis to stress factors. Also epigenetic changes have been associated with different pathways involved in the HPG axis and therefore, take part in FHA and confer a personal predisposition to anovulation consequent to a stressful event, or represent biological markers of response to stress. This review summarizes recent advances in the identification of the contribution of (epi)genetics to FHA and to long-term complications of functional amenorrhea, and reports insights into the involvement of additional genetic loci in FHA development on the bases of the clinical and molecular overlap with other gynecological and/or psychological conditions. Finally, we describe the promising application of induced pluripotent stem cells (iPSCs) as a new approach to investigate the molecular pathways involved in FHA.

Role of Drug Transporters in Elucidating Inter-Individual Variability in Pediatric Chemotherapy-Related Toxicities and Response.

Pediatric cancer treatment has evolved significantly in recent decades. The implementation of risk stratification strategies and the selection of evidence-based chemotherapy combinations have improved survival outcomes. However, there is large interindividual variability in terms of chemotherapy-related toxicities and, sometimes, the response among this population. This variability is partly attributed to the functional variability of drug-metabolizing enzymes (DME) and drug transporters (DTS) involved in the process of absorption, distribution, metabolism and excretion (ADME). The DTS, being ubiquitous, affects drug disposition across membranes and has relevance in determining chemotherapy response in pediatric cancer patients. Among the factors affecting DTS function, ontogeny or maturation is important in the pediatric population. In this narrative review, we describe the role of drug uptake/efflux transporters in defining pediatric chemotherapy-treatment-related toxicities and responses. Developmental differences in DTS and the consequent implications are also briefly discussed for the most commonly used chemotherapeutic drugs in the pediatric population.

Polyunsaturated fatty acids and metabolic health: novel insights.

This review aims to discuss the potential roles of omega-3 (ω-3) and omega-6 (ω-6) polyunsaturated fatty acids (PUFAs) in the prevention and treatment of metabolic diseases, to provide the latest evidence from epidemiological and clinical studies, and to highlight novel insights into this field. Higher dietary or circulating ω-3 PUFA levels are related to a lower risk of metabolic syndrome. Novel findings in obesity indicate higher proportions of ω-6 and ω-3 PUFAs, a modulated oxylipin profile and an altered transcriptome in subcutaneous white adipose tissue, that seem resistant to the effects of ω-3 PUFAs compared with what occurs in normal weight individuals. ω-3 PUFAs may improve the blood lipid profile and glycemic outcomes in patients with type 2 diabetes mellitus and reduce liver fat in nonalcoholic fatty liver disease (NAFLD); the findings of several recent meta-analyses support these effects. Genetic background affects inter-individual variability in the insulin sensitivity response to ω-3 PUFA supplementation. ω-3 PUFAs have prebiotic effects, altering the gut microbiota. Although evidence for health benefits of ω-3 PUFAs is strong, recent findings suggest a more personalized approach to ω-3 PUFA intake for individuals at high risk for metabolic diseases.

Pharmacogenetic and drug interaction aspects on ketamine safety in its use as antidepressant ‐ implications for precision dosing in a global perspective

Ketamine and its enantiomer S-ketamine (esketamine) are known to produce rapid-onset antidepressant effects in major depression. Intranasal esketamine has recently come onto the market as an antidepressant. Besides experience from short-term use in anaesthesia and analgesia, the experience with ketamine as long-term medication is rather low. The use of ketamine and esketamine is limited due to potential neurotoxicity, psychotomimetic side effects, potential abuse and interindividual variability in treatment response including cessation of therapy. Therefore, taking a look at individual patient risks and potential underlying variability in pharmacokinetics may improve safety and dosing of these new antidepressant drugs in clinical practice. Differential drug metabolism due to polymorphic cytochrome P450 (CYP) enzymes and gene-drug interactions are known to influence the efficacy and safety of many drugs. Ketamine and esketamine are metabolized by polymorphic CYP enzymes including CYP2B6, CYP3A4, CYP2C9 and CYP2A6. In antidepressant drug therapy, usually multiple drugs are administered which are substrates of CYP enzymes, increasing the risk for drug-drug interactions. We reviewed the potential impact of polymorphic CYP variants and common drug-drug interactions in antidepressant drug therapy affecting ketamine pharmacokinetics, and the role for dose optimization. The use of ketamine or intranasal esketamine as antidepressants demands a better understanding of the factors that may impact its metabolism and efficacy in long-term use. In addition to other clinical and environmental confounders, prior information on the pharmacodynamic and pharmacokinetic determinants of response variability to ketamine and esketamine may inform on dose optimization and identification of individuals at risk of adverse drug reactions.

A Population-Based Human In Vitro Approach to Quantify Inter-Individual Variability in Responses to Chemical Mixtures.

Human cell-based population-wide in vitro models have been proposed as a strategy to derive chemical-specific estimates of inter-individual variability; however, the utility of this approach has not yet been tested for cumulative exposures in mixtures. This study aimed to test defined mixtures and their individual components and determine whether adverse effects of the mixtures were likely to be more variable in a population than those of the individual chemicals. The in vitro model comprised 146 human lymphoblastoid cell lines from four diverse subpopulations of European and African descent. Cells were exposed, in concentration–response, to 42 chemicals from diverse classes of environmental pollutants; in addition, eight defined mixtures were prepared from these chemicals using several exposure- or hazard-based scenarios. Points of departure for cytotoxicity were derived using Bayesian concentration–response modeling and population variability was quantified in the form of a toxicodynamic variability factor (TDVF). We found that 28 chemicals and all mixtures exhibited concentration–response cytotoxicity, enabling calculation of the TDVF. The median TDVF across test substances, for both individual chemicals or defined mixtures, ranged from a default assumption (101/2) of toxicodynamic variability in human population to >10. The data also provide a proof of principle for single-variant genome-wide association mapping for toxicity of the chemicals and mixtures, although replication would be necessary due to statistical power limitations with the current sample size. This study demonstrates the feasibility of using a set of human lymphoblastoid cell lines as an in vitro model to quantify the extent of inter-individual variability in hazardous properties of both individual chemicals and mixtures. The data show that population variability of the mixtures is unlikely to exceed that of the most variable component, and that similarity in genome-wide associations among components may be used to accrue additional evidence for grouping of constituents in a mixture for cumulative assessments.

Supplemental Material: A Population-Based Human In Vitro Approach to Quantify Inter-Individual Variability in Responses to Chemical Mixtures

Supplemental Material: A Population-Based Human In Vitro Approach to Quantify Inter-Individual Variability in Responses to Chemical Mixtures

SLCO1B1 and ABCB1 variants synergistically influencethe atorvastatin treatment response in South Indian coronary artery disease patients.

Introduction: Atorvastatin exhibits wide interindividual variability in treatment response, limiting the drug efficacy in coronary artery diseasepatients. Aim: To study the effect of genetic variants involved in atorvastatin transport/metabolism and correlate their lipid-lowering efficacy. Materials & methods: Genotyping was performed using 5'-hydrolysis probe method (n=412), and the studyevaluated the treatment response in 86 patients. Results: Significant reduction in total cholesterol and low-density lipoprotein cholesterol(LDL-C) were observed in SLCO1B1-rs4149056, rs4363657and ABCB1-rs1045642 genotypes. The combined genotypes of ABCB1 and SLCO1B1showed a strong synergistic effect in reducing the total cholesterol and LDL-C. Diabetes and smoking were observed to influence the LDL-C reduction. Conclusion: The genetic variants of SLCO1B1 and ABCB1 predict the lipid-lowering efficacy of atorvastatin, and this may be useful in genotype-guided statin therapy for coronary artery disease patients.

Genetic and Phenotypic Factors Affecting Glycemic Response to Metformin Therapy in Patients with Type 2 Diabetes Mellitus.

Metformin is an oral hypoglycemic agent widely used in clinical practice for treatment of patients with type 2 diabetes mellitus (T2DM). The wide interindividual variability of response to metformin therapy was shown, and recently the impact of several genetic variants was reported. To assess the independent and combined effect of the genetic polymorphism on glycemic response to metformin, we performed an association analysis of the variants in ATM, SLC22A1, SLC47A1, and SLC2A2 genes with metformin response in 299 patients with T2DM. Likewise, the distribution of allele and genotype frequencies of the studied gene variants was analyzed in an extended group of patients with T2DM (n = 464) and a population group (n = 129). According to our results, one variant, rs12208357 in the SLC22A1 gene, had a significant impact on response to metformin in T2DM patients. Carriers of TT genotype and T allele had a lower response to metformin compared to carriers of CC/CT genotypes and C allele (p-value = 0.0246, p-value = 0.0059, respectively). To identify the parameters that had the greatest importance for the prediction of the therapy response to metformin, we next built a set of machine learning models, based on the various combinations of genetic and phenotypic characteristics. The model based on a set of four parameters, including gender, rs12208357 genotype, familial T2DM background, and waist–hip ratio (WHR) showed the highest prediction accuracy for the response to metformin therapy in patients with T2DM (AUC = 0.62 in cross-validation). Further pharmacogenetic studies may aid in the discovery of the fundamental mechanisms of type 2 diabetes, the identification of new drug targets, and finally, it could advance the development of personalized treatment.

An Integrated Pharmacological Counselling Approach to Guide Decision-Making in the Treatment with CDK4/6 Inhibitors for Metastatic Breast Cancer

A wide inter-individual variability in the therapeutic response to cyclin-dependent kinases 4 and 6 inhibitors (CDKis) has been reported. We herein present a case series of five patients treated with either palbociclib or ribociclib referred to our clinical pharmacological counselling, including therapeutic drug monitoring (TDM), pharmacogenetics, and drug–drug interaction analysis to support clinicians in the management of CDKis treatment for metastatic breast cancer. Patients’ plasma samples for TDM analysis were collected at steady state and analyzed by an LC-MS/MS method for minimum plasma concentration (Cmin) evaluation. Under and overexposure to the drug were defined based on the mean Cmin values observed in population pharmacokinetic studies. Polymorphisms in selected genes encoding for proteins involved in drug absorption, distribution, metabolism, and elimination were analyzed (CYP3A4, CYP3A5, ABCB1, SLCO1B1, and ABCG2). Three of the five reported cases presented a CDKi plasma level above the population mean value and were referred for toxicity. One of them presented a low function ABCB1 haplotype (ABCB1-rs1128503, rs1045642, and rs2032582), possibly causative of both increased drug oral absorption and plasmatic concentration. Two patients showed underexposure to CDKis, and one of them was referred for early progression. In one patient, a CYP3A5*1/*3 genotype was found to be potentially responsible for more efficient drug metabolism and lower drug plasma concentration. This intensified pharmacological approach in clinical practice has been shown to be potentially effective in supporting prescribing oncologists with dose and drug selection and could be ultimately useful for increasing both the safety and efficacy profiles of CDKi treatment.

Model-based translation of DNA damage signaling dynamics across cell types

Interindividual variability in DNA damage response (DDR) dynamics may evoke differences in susceptibility to cancer. However, pathway dynamics are often studied in cell lines as alternative to primary cells, disregarding variability. To compare DDR dynamics in the cell line HepG2 with primary human hepatocytes (PHHs), we developed a HepG2-based computational model that describes the dynamics of DDR regulator p53 and targets MDM2, p21 and BTG2. We used this model to generate simulations of virtual PHHs and compared the results to those for PHH donor samples. Correlations between baseline p53 and p21 or BTG2 mRNA expression in the absence and presence of DNA damage for HepG2-derived virtual samples matched the moderately positive correlations observed for 50 PHH donor samples, but not the negative correlations between p53 and its inhibitor MDM2. Model parameter manipulation that affected p53 or MDM2 dynamics was not sufficient to accurately explain the negative correlation between these genes. Thus, extrapolation from HepG2 to PHH can be done for some DDR elements, yet our analysis also reveals a knowledge gap within p53 pathway regulation, which makes such extrapolation inaccurate for the regulator MDM2. This illustrates the relevance of studying pathway dynamics in addition to gene expression comparisons to allow reliable translation of cellular responses from cell lines to primary cells. Overall, with our approach we show that dynamical modeling can be used to improve our understanding of the sources of interindividual variability of pathway dynamics.

Influence of Glutathione-S-Transferase A1*B Allele on the Metabolism of the Aromatase Inhibitor, Exemestane, in Human Liver Cytosols and in Patients Treated With Exemestane.

Exemestane (EXE) is used to treat postmenopausal women diagnosed with estrogen receptor positive (ER+) breast cancer. A major mode of metabolism of EXE and its active metabolite, 17β-dihydroexemestane, is via glutathionylation by glutathione-S-transferase (GST) enzymes. The goal of the present study was to investigate the effects of genetic variation in EXE-metabolizing GST enzymes on overall EXE metabolism. Ex vivo assays examining human liver cytosols from 75 subjects revealed the GSTA1 *B*B genotype was associated with significant decreases in S-(androsta-1,4-diene-3,17-dion-6α-ylmethyl)-L-glutathione (P = 0.034) and S-(androsta-1,4-diene-17β-ol-3-on-6α-ylmethyl)-L-gutathione (P = 0.014) formation. In the plasma of 68 ER+ breast cancer patients treated with EXE, the GSTA1 *B*B genotype was associated with significant decreases in both EXE-cysteine (cys) (29%, P = 0.0056) and 17β-DHE-cys (34%, P = 0.032) as compared with patients with the GSTA1*A*A genotype, with significant decreases in EXE-cys (Ptrend = 0.0067) and 17β-DHE-cys (Ptrend = 0.028) observed in patients with increasing numbers of the GSTA1*B allele. A near-significant (Ptrend = 0.060) trend was also observed for urinary EXE-cys levels from the same patients. In contrast, plasma and urinary 17β-DHE-Gluc levels were significantly increased (36%, P = 0.00097 and 52%, P = 0.0089; respectively) in patients with the GSTA1 *B*B genotype. No significant correlations were observed between the GSTM1 null genotype and EXE metabolite levels. These data suggest that the GSTA1*B allele is associated with interindividual differences in EXE metabolism and may play a role in interindividual variability in overall response to EXE.SIGNIFICANCE STATEMENTThe present study is the first comprehensive pharmacogenomic investigation examining the role of genetic variability in GST enzymes on exemestane metabolism. The GSTA1 *B*B genotype was found to contribute to interindividual differences in the metabolism of EXE both ex vivo and in clinical samples from patients taking EXE for the treatment of ER+ breast cancer. Since GSTA1 is a major hepatic phase II metabolizing enzyme in EXE metabolism, the GSTA1*B allele may be an important biomarker for treatment outcomes and toxicities.

The emotional impact of disrupted environmental contexts: Enrichment loss and coping profiles influence stress response recovery in Long-Evans rats.

With increasing rates of anxiety and mood disorders across the world, there is an unprecedented need for preclinical animal models to generate translational results for humans experiencing disruptive emotional symptoms. Considering that life events resulting in a perception of loss are correlated with depressive symptoms, the enrichment‐loss rodent model offers promise as a translational model for stress‐initiated psychiatric disorders. Additionally, predisposed temperament characteristics such as coping styles have been found to influence an individual's stress response. Accordingly, male rats were profiled as either consistent or flexible copers and assigned to one of three environments: standard laboratory housing, enriched environment, or enriched environment exposure followed by downsizing to standard laboratory cages (i.e., enrichment‐loss group). Throughout the study, several behaviors were assessed to determine stress, social, and reward‐processing responses. To assess recovery of the stress response, fecal samples were collected following the swim stress in 3‐h increments to determine the recovery trajectory of corticosterone (CORT) and dehydroepiandrosterone (DHEA) metabolite levels. Upon death, neural markers of neuroplasticity including doublecortin, glial fibrillary acidic factor, and brain‐derived neurotrophic factor were assessed via immunohistochemistry. Results indicated the flexible coping animals in the continuous enriched group had higher DHEA/CORT ratios (consistent with adaptive responses in past research); furthermore, the enrichment‐loss animals exhibited a blunted CORT response throughout the assessments and enriched flexible copers had faster CORT recovery rates than consistent copers. Standard housed animals exhibited less exploratory behavior in the open field task and continuous enriched, flexible rats consumed more food rewards than the other groups. No differences in neuroplasticity neural markers were observed. In sum, the results of the present study support past research indicating the disruptive consequences of enrichment‐loss, providing evidence that the model represents a valuable approach for the investigation of neurobiological mechanisms contributing to interindividual variability in responses to changing experiential landscapes.

Characterization of ADME Gene Variation in Colombian Population by Exome Sequencing.

In genes related to drug pharmacokinetics, molecular variations determine interindividual variability in the therapeutic efficacy and adverse drug reactions. The assessment of single-nucleotide variants (SNVs) is used with growing frequency in pharmacogenetic practice, and recently, high-throughput genomic analyses obtained through next-generation sequencing (NGS) have been recognized as powerful tools to identify common, rare and novel variants. These genetic profiles remain underexplored in Latin-American populations, including Colombia. In this study, we investigated the variability of 35 genes included in the ADME core panel (absorption, distribution, metabolism, and excretion) by whole-exome sequencing (WES) of 509 unrelated Colombian individuals with no previous reports of adverse drug reactions. Rare variants were filtered according to the minor allele frequencies (MAF) <1% and potential deleterious consequences. The functional impact of novel and rare missense variants was assessed using an optimized framework for pharmacogenetic variants. Bioinformatic analyses included the identification of clinically validated variants described in PharmGKB and ClinVar databases. Ancestry from WES data was inferred using the R package EthSEQ v2.1.4. Allelic frequencies were compared to other populations reported in the public gnomAD database. Our analysis revealed that rare missense pharmacogenetic variants were 2.1 times more frequent than common variants with 121 variants predicted as potentially deleterious. Rare loss of function (LoF) variants were identified in 65.7% of evaluated genes. Regarding variants with clinical pharmacogenetic effect, our study revealed 89 sequence variations in 28 genes represented by missense (62%), synonymous (22.5%), splice site (11.2%), and indels (3.4%). In this group, ABCB1, ABCC2, CY2B6, CYP2D6, DPYD, NAT2, SLC22A1, and UGTB2B7, are the most polymorphic genes. NAT2, CYP2B6 and DPYD metabolizer phenotypes demonstrated the highest variability. Ancestry analysis indicated admixture in 73% of the population. Allelic frequencies exhibit significant differences with other Latin-American populations, highlighting the importance of pharmacogenomic studies in populations of different ethnicities. Altogether, our data revealed that rare variants are an important source of variability in pharmacogenes involved in the pharmacokinetics of drugs and likely account for the unexplained interindividual variability in drug response. These findings provide evidence of the utility of WES for pharmacogenomic testing and into clinical practice.

P-586 3D micro-Computed Tomography imaging and reconstruction of the mouse ovary before and after gonadotropins treatment

Abstract Study question How does gonadotropins treatment impact on the number of the different follicle types, their 3D localization, and their recruitment and selection dynamics inside the ovary? Summary answer Treatment with gonadotropins modifies the dynamics of follicles recruitment and selection within the 3D context of the ovary. What is known already Gonadotropins regulate mouse folliculogenesis during follicles recruitment (type 4-5, T4-5) and selection for growth or elimination (T6-7). To further our understanding of the impact of gonadotropins treatment on folliculogenetic dynamics inside the ovary, we used Computed Tomography (CT). 3D imaging of the ovary provides information on its inner spatial organization, and microCT is the only technique that combines high resolution with cubic voxels and allows the organ 3D in-silico reconstruction. We recently published the method for microCT analysis of the adult mouse ovary demonstrating that follicle recruitment occurs simultaneously all-over the cortex, and folliculogenesis is completed within the same region. Study design, size, duration 25-day-old CD1-mice were used since this age rightly precedes the first ovulation: follicles, from the primordial T1 to the pre-ovulatory T8, are all present, but corpora lutea (CL) are yet not formed. Ovaries from different individuals were analyzed by microCT: three not-treated controls (CTR); three injected with 3.5 I.U. PMSG and sacrificed 48hr later (PMSG); three treated first with PMSG, 48hr later injected with 3.5 I.U. hCG and then sacrificed after 15hr upon ovulation (PMSG+hCG). Participants/materials, setting, methods Ovaries were fixed in 4% Paraformaldehyde and treated with Lugol’s solution for 3hr at RT. Then, they were imaged with the EasyTom XL (RX Solutions) tomographic system, using a 1-1.2 µm/pixel resolution. Following microCT imaging, follicles classification (Fiji ImageJ, NIH), 3D mapping (XnConvert, XnSoft) and ovary in-silico reconstruction (Avizo-9, Thermo Fisher Scientific) were performed. ANOVA and Bonferroni post-hoc statistical analyses were done with RStudio &amp;gt; (p &amp;lt; 0.05). Main results and the role of chance Compared to CTR, 48hr after PMSG injection, the T3, T4 and T5 follicle classes remained numerically unchanged, suggesting that the FSH-dependent recruitment involving T4-5 follicles is balanced by an equivalent number of follicles growing from the preceding primordial pool. The most evident change in PMSG ovaries was a 5-fold decrease (p = 0.002) in the number of antral T7 follicles, at the stage of follicle selection. This observation was paralleled by the presence, in the medulla region, of many atretic-like follicles, characterized by a more intense microCT contrast associated with a collapsed antrum, de-structured granulosa-cell layers and fragmented oocytes. In PMSG+hCG ovaries, the number of T3-7 follicles was analogous to that described for PMSG, although the atretic-like follicles almost disappeared, suggesting their elimination sometime prior to ovulation. To understand whether follicle recruitment and selection have a territoriality within the 3D female gonad, ovaries were virtually divided into eight dorsal (D-I/II/III/IV) and ventral (V-I/II/III/IV) sectors. Compared to CTR, PMSG injection appeared to increase follicle selection in sectors V-I (p = 0.03), V-II (p = 0.01) and V-IV (p = 0.02), whereas PMSG+hCG displayed a higher follicle recruitment in sector V-IV (p = 0.0007). Overall, these data suggest a spatial differential effect of the gonadotropins treatment inside the 3D mouse ovary. Limitations, reasons for caution To strengthen the results and better account for the inter-individual variability in response to hormonal treatments, the number of ovaries/individuals should be increased. Also, important is extending the analysis to the time-interval after hCG injection, beyond 15 hr, to assess the effects of ovarian stimulation on subsequent cycles. Wider implications of the findings The method proposed allows to map all follicle stages and to reconstruct a 3D in-silico model of the mouse ovary. This approach could be extended to other Mammals, including human, in normal and pathological conditions, as well as in response to different hormonal stimuli (e.g., dose or type of gonadotropins). Trial registration number not applicable

Functional regulations between genetic alteration-driven genes and drug target genes acting as prognostic biomarkers in breast cancer

Differences in genetic molecular features including mutation, copy number alterations and DNA methylation, can explain interindividual variability in response to anti-cancer drugs in cancer patients. However, identifying genetic alteration-driven genes and characterizing their functional mechanisms in different cancer types are still major challenges for cancer studies. Here, we systematically identified functional regulations between genetic alteration-driven genes and drug target genes and their potential prognostic roles in breast cancer. We identified two mutation and copy number-driven gene pairs (PARP1-ACSL1 and PARP1-SRD5A3), three DNA methylation-driven gene pairs (PRLR-CDKN1C, PRLR-PODXL2 and PRLR-SRD5A3), six gene pairs between mutation-driven genes and drug target genes (SLC19A1-SLC47A2, SLC19A1-SRD5A3, AKR1C3-SLC19A1, ABCB1-SRD5A3, NR3C2-SRD5A3 and AKR1C3-SRD5A3), and four copy number-driven gene pairs (ADIPOR2-SRD5A3, CASP12-SRD5A3, SLC39A11-SRD5A3 and GALNT2-SRD5A3) that all served as prognostic biomarkers of breast cancer. In particular, RARP1 was found to be upregulated by simultaneous copy number amplification and gene mutation. Copy number deletion and downregulated expression of ACSL1 and upregulation of SRD5A3 both were observed in breast cancers. Moreover, copy number deletion of ACSL1 was associated with increased resistance to PARP inhibitors. PARP1-ACSL1 pair significantly correlated with poor overall survival in breast cancer owing to the suppression of the MAPK, mTOR and NF-kB signaling pathways, which induces apoptosis, autophagy and prevents inflammatory processes. Loss of SRD5A3 expression was also associated with increased sensitivity to PARP inhibitors. The PARP1-SRD5A3 pair significantly correlated with poor overall survival in breast cancer through regulating androgen receptors to induce cell proliferation. These results demonstrate that genetic alteration-driven gene pairs might serve as potential biomarkers for the prognosis of breast cancer and facilitate the identification of combination therapeutic targets for breast cancers.